| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| * Written by Alex Tomas <alex@clusterfs.com> |
| */ |
| |
| |
| /* |
| * mballoc.c contains the multiblocks allocation routines |
| */ |
| |
| #include "ext4_jbd2.h" |
| #include "mballoc.h" |
| #include <linux/log2.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/nospec.h> |
| #include <linux/backing-dev.h> |
| #include <linux/freezer.h> |
| #include <trace/events/ext4.h> |
| #include <kunit/static_stub.h> |
| |
| /* |
| * MUSTDO: |
| * - test ext4_ext_search_left() and ext4_ext_search_right() |
| * - search for metadata in few groups |
| * |
| * TODO v4: |
| * - normalization should take into account whether file is still open |
| * - discard preallocations if no free space left (policy?) |
| * - don't normalize tails |
| * - quota |
| * - reservation for superuser |
| * |
| * TODO v3: |
| * - bitmap read-ahead (proposed by Oleg Drokin aka green) |
| * - track min/max extents in each group for better group selection |
| * - mb_mark_used() may allocate chunk right after splitting buddy |
| * - tree of groups sorted by number of free blocks |
| * - error handling |
| */ |
| |
| /* |
| * The allocation request involve request for multiple number of blocks |
| * near to the goal(block) value specified. |
| * |
| * During initialization phase of the allocator we decide to use the |
| * group preallocation or inode preallocation depending on the size of |
| * the file. The size of the file could be the resulting file size we |
| * would have after allocation, or the current file size, which ever |
| * is larger. If the size is less than sbi->s_mb_stream_request we |
| * select to use the group preallocation. The default value of |
| * s_mb_stream_request is 16 blocks. This can also be tuned via |
| * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in |
| * terms of number of blocks. |
| * |
| * The main motivation for having small file use group preallocation is to |
| * ensure that we have small files closer together on the disk. |
| * |
| * First stage the allocator looks at the inode prealloc list, |
| * ext4_inode_info->i_prealloc_list, which contains list of prealloc |
| * spaces for this particular inode. The inode prealloc space is |
| * represented as: |
| * |
| * pa_lstart -> the logical start block for this prealloc space |
| * pa_pstart -> the physical start block for this prealloc space |
| * pa_len -> length for this prealloc space (in clusters) |
| * pa_free -> free space available in this prealloc space (in clusters) |
| * |
| * The inode preallocation space is used looking at the _logical_ start |
| * block. If only the logical file block falls within the range of prealloc |
| * space we will consume the particular prealloc space. This makes sure that |
| * we have contiguous physical blocks representing the file blocks |
| * |
| * The important thing to be noted in case of inode prealloc space is that |
| * we don't modify the values associated to inode prealloc space except |
| * pa_free. |
| * |
| * If we are not able to find blocks in the inode prealloc space and if we |
| * have the group allocation flag set then we look at the locality group |
| * prealloc space. These are per CPU prealloc list represented as |
| * |
| * ext4_sb_info.s_locality_groups[smp_processor_id()] |
| * |
| * The reason for having a per cpu locality group is to reduce the contention |
| * between CPUs. It is possible to get scheduled at this point. |
| * |
| * The locality group prealloc space is used looking at whether we have |
| * enough free space (pa_free) within the prealloc space. |
| * |
| * If we can't allocate blocks via inode prealloc or/and locality group |
| * prealloc then we look at the buddy cache. The buddy cache is represented |
| * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets |
| * mapped to the buddy and bitmap information regarding different |
| * groups. The buddy information is attached to buddy cache inode so that |
| * we can access them through the page cache. The information regarding |
| * each group is loaded via ext4_mb_load_buddy. The information involve |
| * block bitmap and buddy information. The information are stored in the |
| * inode as: |
| * |
| * { page } |
| * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... |
| * |
| * |
| * one block each for bitmap and buddy information. So for each group we |
| * take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE / |
| * blocksize) blocks. So it can have information regarding groups_per_page |
| * which is blocks_per_page/2 |
| * |
| * The buddy cache inode is not stored on disk. The inode is thrown |
| * away when the filesystem is unmounted. |
| * |
| * We look for count number of blocks in the buddy cache. If we were able |
| * to locate that many free blocks we return with additional information |
| * regarding rest of the contiguous physical block available |
| * |
| * Before allocating blocks via buddy cache we normalize the request |
| * blocks. This ensure we ask for more blocks that we needed. The extra |
| * blocks that we get after allocation is added to the respective prealloc |
| * list. In case of inode preallocation we follow a list of heuristics |
| * based on file size. This can be found in ext4_mb_normalize_request. If |
| * we are doing a group prealloc we try to normalize the request to |
| * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is |
| * dependent on the cluster size; for non-bigalloc file systems, it is |
| * 512 blocks. This can be tuned via |
| * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in |
| * terms of number of blocks. If we have mounted the file system with -O |
| * stripe=<value> option the group prealloc request is normalized to the |
| * smallest multiple of the stripe value (sbi->s_stripe) which is |
| * greater than the default mb_group_prealloc. |
| * |
| * If "mb_optimize_scan" mount option is set, we maintain in memory group info |
| * structures in two data structures: |
| * |
| * 1) Array of largest free order lists (sbi->s_mb_largest_free_orders) |
| * |
| * Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks) |
| * |
| * This is an array of lists where the index in the array represents the |
| * largest free order in the buddy bitmap of the participating group infos of |
| * that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total |
| * number of buddy bitmap orders possible) number of lists. Group-infos are |
| * placed in appropriate lists. |
| * |
| * 2) Average fragment size lists (sbi->s_mb_avg_fragment_size) |
| * |
| * Locking: sbi->s_mb_avg_fragment_size_locks(array of rw locks) |
| * |
| * This is an array of lists where in the i-th list there are groups with |
| * average fragment size >= 2^i and < 2^(i+1). The average fragment size |
| * is computed as ext4_group_info->bb_free / ext4_group_info->bb_fragments. |
| * Note that we don't bother with a special list for completely empty groups |
| * so we only have MB_NUM_ORDERS(sb) lists. |
| * |
| * When "mb_optimize_scan" mount option is set, mballoc consults the above data |
| * structures to decide the order in which groups are to be traversed for |
| * fulfilling an allocation request. |
| * |
| * At CR_POWER2_ALIGNED , we look for groups which have the largest_free_order |
| * >= the order of the request. We directly look at the largest free order list |
| * in the data structure (1) above where largest_free_order = order of the |
| * request. If that list is empty, we look at remaining list in the increasing |
| * order of largest_free_order. This allows us to perform CR_POWER2_ALIGNED |
| * lookup in O(1) time. |
| * |
| * At CR_GOAL_LEN_FAST, we only consider groups where |
| * average fragment size > request size. So, we lookup a group which has average |
| * fragment size just above or equal to request size using our average fragment |
| * size group lists (data structure 2) in O(1) time. |
| * |
| * At CR_BEST_AVAIL_LEN, we aim to optimize allocations which can't be satisfied |
| * in CR_GOAL_LEN_FAST. The fact that we couldn't find a group in |
| * CR_GOAL_LEN_FAST suggests that there is no BG that has avg |
| * fragment size > goal length. So before falling to the slower |
| * CR_GOAL_LEN_SLOW, in CR_BEST_AVAIL_LEN we proactively trim goal length and |
| * then use the same fragment lists as CR_GOAL_LEN_FAST to find a BG with a big |
| * enough average fragment size. This increases the chances of finding a |
| * suitable block group in O(1) time and results in faster allocation at the |
| * cost of reduced size of allocation. |
| * |
| * If "mb_optimize_scan" mount option is not set, mballoc traverses groups in |
| * linear order which requires O(N) search time for each CR_POWER2_ALIGNED and |
| * CR_GOAL_LEN_FAST phase. |
| * |
| * The regular allocator (using the buddy cache) supports a few tunables. |
| * |
| * /sys/fs/ext4/<partition>/mb_min_to_scan |
| * /sys/fs/ext4/<partition>/mb_max_to_scan |
| * /sys/fs/ext4/<partition>/mb_order2_req |
| * /sys/fs/ext4/<partition>/mb_linear_limit |
| * |
| * The regular allocator uses buddy scan only if the request len is power of |
| * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The |
| * value of s_mb_order2_reqs can be tuned via |
| * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to |
| * stripe size (sbi->s_stripe), we try to search for contiguous block in |
| * stripe size. This should result in better allocation on RAID setups. If |
| * not, we search in the specific group using bitmap for best extents. The |
| * tunable min_to_scan and max_to_scan control the behaviour here. |
| * min_to_scan indicate how long the mballoc __must__ look for a best |
| * extent and max_to_scan indicates how long the mballoc __can__ look for a |
| * best extent in the found extents. Searching for the blocks starts with |
| * the group specified as the goal value in allocation context via |
| * ac_g_ex. Each group is first checked based on the criteria whether it |
| * can be used for allocation. ext4_mb_good_group explains how the groups are |
| * checked. |
| * |
| * When "mb_optimize_scan" is turned on, as mentioned above, the groups may not |
| * get traversed linearly. That may result in subsequent allocations being not |
| * close to each other. And so, the underlying device may get filled up in a |
| * non-linear fashion. While that may not matter on non-rotational devices, for |
| * rotational devices that may result in higher seek times. "mb_linear_limit" |
| * tells mballoc how many groups mballoc should search linearly before |
| * performing consulting above data structures for more efficient lookups. For |
| * non rotational devices, this value defaults to 0 and for rotational devices |
| * this is set to MB_DEFAULT_LINEAR_LIMIT. |
| * |
| * Both the prealloc space are getting populated as above. So for the first |
| * request we will hit the buddy cache which will result in this prealloc |
| * space getting filled. The prealloc space is then later used for the |
| * subsequent request. |
| */ |
| |
| /* |
| * mballoc operates on the following data: |
| * - on-disk bitmap |
| * - in-core buddy (actually includes buddy and bitmap) |
| * - preallocation descriptors (PAs) |
| * |
| * there are two types of preallocations: |
| * - inode |
| * assiged to specific inode and can be used for this inode only. |
| * it describes part of inode's space preallocated to specific |
| * physical blocks. any block from that preallocated can be used |
| * independent. the descriptor just tracks number of blocks left |
| * unused. so, before taking some block from descriptor, one must |
| * make sure corresponded logical block isn't allocated yet. this |
| * also means that freeing any block within descriptor's range |
| * must discard all preallocated blocks. |
| * - locality group |
| * assigned to specific locality group which does not translate to |
| * permanent set of inodes: inode can join and leave group. space |
| * from this type of preallocation can be used for any inode. thus |
| * it's consumed from the beginning to the end. |
| * |
| * relation between them can be expressed as: |
| * in-core buddy = on-disk bitmap + preallocation descriptors |
| * |
| * this mean blocks mballoc considers used are: |
| * - allocated blocks (persistent) |
| * - preallocated blocks (non-persistent) |
| * |
| * consistency in mballoc world means that at any time a block is either |
| * free or used in ALL structures. notice: "any time" should not be read |
| * literally -- time is discrete and delimited by locks. |
| * |
| * to keep it simple, we don't use block numbers, instead we count number of |
| * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. |
| * |
| * all operations can be expressed as: |
| * - init buddy: buddy = on-disk + PAs |
| * - new PA: buddy += N; PA = N |
| * - use inode PA: on-disk += N; PA -= N |
| * - discard inode PA buddy -= on-disk - PA; PA = 0 |
| * - use locality group PA on-disk += N; PA -= N |
| * - discard locality group PA buddy -= PA; PA = 0 |
| * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap |
| * is used in real operation because we can't know actual used |
| * bits from PA, only from on-disk bitmap |
| * |
| * if we follow this strict logic, then all operations above should be atomic. |
| * given some of them can block, we'd have to use something like semaphores |
| * killing performance on high-end SMP hardware. let's try to relax it using |
| * the following knowledge: |
| * 1) if buddy is referenced, it's already initialized |
| * 2) while block is used in buddy and the buddy is referenced, |
| * nobody can re-allocate that block |
| * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has |
| * bit set and PA claims same block, it's OK. IOW, one can set bit in |
| * on-disk bitmap if buddy has same bit set or/and PA covers corresponded |
| * block |
| * |
| * so, now we're building a concurrency table: |
| * - init buddy vs. |
| * - new PA |
| * blocks for PA are allocated in the buddy, buddy must be referenced |
| * until PA is linked to allocation group to avoid concurrent buddy init |
| * - use inode PA |
| * we need to make sure that either on-disk bitmap or PA has uptodate data |
| * given (3) we care that PA-=N operation doesn't interfere with init |
| * - discard inode PA |
| * the simplest way would be to have buddy initialized by the discard |
| * - use locality group PA |
| * again PA-=N must be serialized with init |
| * - discard locality group PA |
| * the simplest way would be to have buddy initialized by the discard |
| * - new PA vs. |
| * - use inode PA |
| * i_data_sem serializes them |
| * - discard inode PA |
| * discard process must wait until PA isn't used by another process |
| * - use locality group PA |
| * some mutex should serialize them |
| * - discard locality group PA |
| * discard process must wait until PA isn't used by another process |
| * - use inode PA |
| * - use inode PA |
| * i_data_sem or another mutex should serializes them |
| * - discard inode PA |
| * discard process must wait until PA isn't used by another process |
| * - use locality group PA |
| * nothing wrong here -- they're different PAs covering different blocks |
| * - discard locality group PA |
| * discard process must wait until PA isn't used by another process |
| * |
| * now we're ready to make few consequences: |
| * - PA is referenced and while it is no discard is possible |
| * - PA is referenced until block isn't marked in on-disk bitmap |
| * - PA changes only after on-disk bitmap |
| * - discard must not compete with init. either init is done before |
| * any discard or they're serialized somehow |
| * - buddy init as sum of on-disk bitmap and PAs is done atomically |
| * |
| * a special case when we've used PA to emptiness. no need to modify buddy |
| * in this case, but we should care about concurrent init |
| * |
| */ |
| |
| /* |
| * Logic in few words: |
| * |
| * - allocation: |
| * load group |
| * find blocks |
| * mark bits in on-disk bitmap |
| * release group |
| * |
| * - use preallocation: |
| * find proper PA (per-inode or group) |
| * load group |
| * mark bits in on-disk bitmap |
| * release group |
| * release PA |
| * |
| * - free: |
| * load group |
| * mark bits in on-disk bitmap |
| * release group |
| * |
| * - discard preallocations in group: |
| * mark PAs deleted |
| * move them onto local list |
| * load on-disk bitmap |
| * load group |
| * remove PA from object (inode or locality group) |
| * mark free blocks in-core |
| * |
| * - discard inode's preallocations: |
| */ |
| |
| /* |
| * Locking rules |
| * |
| * Locks: |
| * - bitlock on a group (group) |
| * - object (inode/locality) (object) |
| * - per-pa lock (pa) |
| * - cr_power2_aligned lists lock (cr_power2_aligned) |
| * - cr_goal_len_fast lists lock (cr_goal_len_fast) |
| * |
| * Paths: |
| * - new pa |
| * object |
| * group |
| * |
| * - find and use pa: |
| * pa |
| * |
| * - release consumed pa: |
| * pa |
| * group |
| * object |
| * |
| * - generate in-core bitmap: |
| * group |
| * pa |
| * |
| * - discard all for given object (inode, locality group): |
| * object |
| * pa |
| * group |
| * |
| * - discard all for given group: |
| * group |
| * pa |
| * group |
| * object |
| * |
| * - allocation path (ext4_mb_regular_allocator) |
| * group |
| * cr_power2_aligned/cr_goal_len_fast |
| */ |
| static struct kmem_cache *ext4_pspace_cachep; |
| static struct kmem_cache *ext4_ac_cachep; |
| static struct kmem_cache *ext4_free_data_cachep; |
| |
| /* We create slab caches for groupinfo data structures based on the |
| * superblock block size. There will be one per mounted filesystem for |
| * each unique s_blocksize_bits */ |
| #define NR_GRPINFO_CACHES 8 |
| static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES]; |
| |
| static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = { |
| "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k", |
| "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k", |
| "ext4_groupinfo_64k", "ext4_groupinfo_128k" |
| }; |
| |
| static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
| ext4_group_t group); |
| static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac); |
| |
| static bool ext4_mb_good_group(struct ext4_allocation_context *ac, |
| ext4_group_t group, enum criteria cr); |
| |
| static int ext4_try_to_trim_range(struct super_block *sb, |
| struct ext4_buddy *e4b, ext4_grpblk_t start, |
| ext4_grpblk_t max, ext4_grpblk_t minblocks); |
| |
| /* |
| * The algorithm using this percpu seq counter goes below: |
| * 1. We sample the percpu discard_pa_seq counter before trying for block |
| * allocation in ext4_mb_new_blocks(). |
| * 2. We increment this percpu discard_pa_seq counter when we either allocate |
| * or free these blocks i.e. while marking those blocks as used/free in |
| * mb_mark_used()/mb_free_blocks(). |
| * 3. We also increment this percpu seq counter when we successfully identify |
| * that the bb_prealloc_list is not empty and hence proceed for discarding |
| * of those PAs inside ext4_mb_discard_group_preallocations(). |
| * |
| * Now to make sure that the regular fast path of block allocation is not |
| * affected, as a small optimization we only sample the percpu seq counter |
| * on that cpu. Only when the block allocation fails and when freed blocks |
| * found were 0, that is when we sample percpu seq counter for all cpus using |
| * below function ext4_get_discard_pa_seq_sum(). This happens after making |
| * sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty. |
| */ |
| static DEFINE_PER_CPU(u64, discard_pa_seq); |
| static inline u64 ext4_get_discard_pa_seq_sum(void) |
| { |
| int __cpu; |
| u64 __seq = 0; |
| |
| for_each_possible_cpu(__cpu) |
| __seq += per_cpu(discard_pa_seq, __cpu); |
| return __seq; |
| } |
| |
| static inline void *mb_correct_addr_and_bit(int *bit, void *addr) |
| { |
| #if BITS_PER_LONG == 64 |
| *bit += ((unsigned long) addr & 7UL) << 3; |
| addr = (void *) ((unsigned long) addr & ~7UL); |
| #elif BITS_PER_LONG == 32 |
| *bit += ((unsigned long) addr & 3UL) << 3; |
| addr = (void *) ((unsigned long) addr & ~3UL); |
| #else |
| #error "how many bits you are?!" |
| #endif |
| return addr; |
| } |
| |
| static inline int mb_test_bit(int bit, void *addr) |
| { |
| /* |
| * ext4_test_bit on architecture like powerpc |
| * needs unsigned long aligned address |
| */ |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| return ext4_test_bit(bit, addr); |
| } |
| |
| static inline void mb_set_bit(int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_set_bit(bit, addr); |
| } |
| |
| static inline void mb_clear_bit(int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| ext4_clear_bit(bit, addr); |
| } |
| |
| static inline int mb_test_and_clear_bit(int bit, void *addr) |
| { |
| addr = mb_correct_addr_and_bit(&bit, addr); |
| return ext4_test_and_clear_bit(bit, addr); |
| } |
| |
| static inline int mb_find_next_zero_bit(void *addr, int max, int start) |
| { |
| int fix = 0, ret, tmpmax; |
| addr = mb_correct_addr_and_bit(&fix, addr); |
| tmpmax = max + fix; |
| start += fix; |
| |
| ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix; |
| if (ret > max) |
| return max; |
| return ret; |
| } |
| |
| static inline int mb_find_next_bit(void *addr, int max, int start) |
| { |
| int fix = 0, ret, tmpmax; |
| addr = mb_correct_addr_and_bit(&fix, addr); |
| tmpmax = max + fix; |
| start += fix; |
| |
| ret = ext4_find_next_bit(addr, tmpmax, start) - fix; |
| if (ret > max) |
| return max; |
| return ret; |
| } |
| |
| static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) |
| { |
| char *bb; |
| |
| BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); |
| BUG_ON(max == NULL); |
| |
| if (order > e4b->bd_blkbits + 1) { |
| *max = 0; |
| return NULL; |
| } |
| |
| /* at order 0 we see each particular block */ |
| if (order == 0) { |
| *max = 1 << (e4b->bd_blkbits + 3); |
| return e4b->bd_bitmap; |
| } |
| |
| bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; |
| *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; |
| |
| return bb; |
| } |
| |
| #ifdef DOUBLE_CHECK |
| static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| int i; |
| struct super_block *sb = e4b->bd_sb; |
| |
| if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| return; |
| assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); |
| for (i = 0; i < count; i++) { |
| if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { |
| ext4_fsblk_t blocknr; |
| |
| blocknr = ext4_group_first_block_no(sb, e4b->bd_group); |
| blocknr += EXT4_C2B(EXT4_SB(sb), first + i); |
| ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| ext4_grp_locked_error(sb, e4b->bd_group, |
| inode ? inode->i_ino : 0, |
| blocknr, |
| "freeing block already freed " |
| "(bit %u)", |
| first + i); |
| } |
| mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); |
| } |
| } |
| |
| static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) |
| { |
| int i; |
| |
| if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| return; |
| assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
| for (i = 0; i < count; i++) { |
| BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); |
| mb_set_bit(first + i, e4b->bd_info->bb_bitmap); |
| } |
| } |
| |
| static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| { |
| if (unlikely(e4b->bd_info->bb_bitmap == NULL)) |
| return; |
| if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { |
| unsigned char *b1, *b2; |
| int i; |
| b1 = (unsigned char *) e4b->bd_info->bb_bitmap; |
| b2 = (unsigned char *) bitmap; |
| for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { |
| if (b1[i] != b2[i]) { |
| ext4_msg(e4b->bd_sb, KERN_ERR, |
| "corruption in group %u " |
| "at byte %u(%u): %x in copy != %x " |
| "on disk/prealloc", |
| e4b->bd_group, i, i * 8, b1[i], b2[i]); |
| BUG(); |
| } |
| } |
| } |
| } |
| |
| static void mb_group_bb_bitmap_alloc(struct super_block *sb, |
| struct ext4_group_info *grp, ext4_group_t group) |
| { |
| struct buffer_head *bh; |
| |
| grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS); |
| if (!grp->bb_bitmap) |
| return; |
| |
| bh = ext4_read_block_bitmap(sb, group); |
| if (IS_ERR_OR_NULL(bh)) { |
| kfree(grp->bb_bitmap); |
| grp->bb_bitmap = NULL; |
| return; |
| } |
| |
| memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize); |
| put_bh(bh); |
| } |
| |
| static void mb_group_bb_bitmap_free(struct ext4_group_info *grp) |
| { |
| kfree(grp->bb_bitmap); |
| } |
| |
| #else |
| static inline void mb_free_blocks_double(struct inode *inode, |
| struct ext4_buddy *e4b, int first, int count) |
| { |
| return; |
| } |
| static inline void mb_mark_used_double(struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| return; |
| } |
| static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) |
| { |
| return; |
| } |
| |
| static inline void mb_group_bb_bitmap_alloc(struct super_block *sb, |
| struct ext4_group_info *grp, ext4_group_t group) |
| { |
| return; |
| } |
| |
| static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp) |
| { |
| return; |
| } |
| #endif |
| |
| #ifdef AGGRESSIVE_CHECK |
| |
| #define MB_CHECK_ASSERT(assert) \ |
| do { \ |
| if (!(assert)) { \ |
| printk(KERN_EMERG \ |
| "Assertion failure in %s() at %s:%d: \"%s\"\n", \ |
| function, file, line, # assert); \ |
| BUG(); \ |
| } \ |
| } while (0) |
| |
| static void __mb_check_buddy(struct ext4_buddy *e4b, char *file, |
| const char *function, int line) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| int order = e4b->bd_blkbits + 1; |
| int max; |
| int max2; |
| int i; |
| int j; |
| int k; |
| int count; |
| struct ext4_group_info *grp; |
| int fragments = 0; |
| int fstart; |
| struct list_head *cur; |
| void *buddy; |
| void *buddy2; |
| |
| if (e4b->bd_info->bb_check_counter++ % 10) |
| return; |
| |
| while (order > 1) { |
| buddy = mb_find_buddy(e4b, order, &max); |
| MB_CHECK_ASSERT(buddy); |
| buddy2 = mb_find_buddy(e4b, order - 1, &max2); |
| MB_CHECK_ASSERT(buddy2); |
| MB_CHECK_ASSERT(buddy != buddy2); |
| MB_CHECK_ASSERT(max * 2 == max2); |
| |
| count = 0; |
| for (i = 0; i < max; i++) { |
| |
| if (mb_test_bit(i, buddy)) { |
| /* only single bit in buddy2 may be 0 */ |
| if (!mb_test_bit(i << 1, buddy2)) { |
| MB_CHECK_ASSERT( |
| mb_test_bit((i<<1)+1, buddy2)); |
| } |
| continue; |
| } |
| |
| /* both bits in buddy2 must be 1 */ |
| MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); |
| MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); |
| |
| for (j = 0; j < (1 << order); j++) { |
| k = (i * (1 << order)) + j; |
| MB_CHECK_ASSERT( |
| !mb_test_bit(k, e4b->bd_bitmap)); |
| } |
| count++; |
| } |
| MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); |
| order--; |
| } |
| |
| fstart = -1; |
| buddy = mb_find_buddy(e4b, 0, &max); |
| for (i = 0; i < max; i++) { |
| if (!mb_test_bit(i, buddy)) { |
| MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); |
| if (fstart == -1) { |
| fragments++; |
| fstart = i; |
| } |
| continue; |
| } |
| fstart = -1; |
| /* check used bits only */ |
| for (j = 0; j < e4b->bd_blkbits + 1; j++) { |
| buddy2 = mb_find_buddy(e4b, j, &max2); |
| k = i >> j; |
| MB_CHECK_ASSERT(k < max2); |
| MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); |
| } |
| } |
| MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); |
| MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); |
| |
| grp = ext4_get_group_info(sb, e4b->bd_group); |
| if (!grp) |
| return; |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| ext4_group_t groupnr; |
| struct ext4_prealloc_space *pa; |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); |
| MB_CHECK_ASSERT(groupnr == e4b->bd_group); |
| for (i = 0; i < pa->pa_len; i++) |
| MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); |
| } |
| } |
| #undef MB_CHECK_ASSERT |
| #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ |
| __FILE__, __func__, __LINE__) |
| #else |
| #define mb_check_buddy(e4b) |
| #endif |
| |
| /* |
| * Divide blocks started from @first with length @len into |
| * smaller chunks with power of 2 blocks. |
| * Clear the bits in bitmap which the blocks of the chunk(s) covered, |
| * then increase bb_counters[] for corresponded chunk size. |
| */ |
| static void ext4_mb_mark_free_simple(struct super_block *sb, |
| void *buddy, ext4_grpblk_t first, ext4_grpblk_t len, |
| struct ext4_group_info *grp) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_grpblk_t min; |
| ext4_grpblk_t max; |
| ext4_grpblk_t chunk; |
| unsigned int border; |
| |
| BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb)); |
| |
| border = 2 << sb->s_blocksize_bits; |
| |
| while (len > 0) { |
| /* find how many blocks can be covered since this position */ |
| max = ffs(first | border) - 1; |
| |
| /* find how many blocks of power 2 we need to mark */ |
| min = fls(len) - 1; |
| |
| if (max < min) |
| min = max; |
| chunk = 1 << min; |
| |
| /* mark multiblock chunks only */ |
| grp->bb_counters[min]++; |
| if (min > 0) |
| mb_clear_bit(first >> min, |
| buddy + sbi->s_mb_offsets[min]); |
| |
| len -= chunk; |
| first += chunk; |
| } |
| } |
| |
| static int mb_avg_fragment_size_order(struct super_block *sb, ext4_grpblk_t len) |
| { |
| int order; |
| |
| /* |
| * We don't bother with a special lists groups with only 1 block free |
| * extents and for completely empty groups. |
| */ |
| order = fls(len) - 2; |
| if (order < 0) |
| return 0; |
| if (order == MB_NUM_ORDERS(sb)) |
| order--; |
| if (WARN_ON_ONCE(order > MB_NUM_ORDERS(sb))) |
| order = MB_NUM_ORDERS(sb) - 1; |
| return order; |
| } |
| |
| /* Move group to appropriate avg_fragment_size list */ |
| static void |
| mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int new_order; |
| |
| if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0) |
| return; |
| |
| new_order = mb_avg_fragment_size_order(sb, |
| grp->bb_free / grp->bb_fragments); |
| if (new_order == grp->bb_avg_fragment_size_order) |
| return; |
| |
| if (grp->bb_avg_fragment_size_order != -1) { |
| write_lock(&sbi->s_mb_avg_fragment_size_locks[ |
| grp->bb_avg_fragment_size_order]); |
| list_del(&grp->bb_avg_fragment_size_node); |
| write_unlock(&sbi->s_mb_avg_fragment_size_locks[ |
| grp->bb_avg_fragment_size_order]); |
| } |
| grp->bb_avg_fragment_size_order = new_order; |
| write_lock(&sbi->s_mb_avg_fragment_size_locks[ |
| grp->bb_avg_fragment_size_order]); |
| list_add_tail(&grp->bb_avg_fragment_size_node, |
| &sbi->s_mb_avg_fragment_size[grp->bb_avg_fragment_size_order]); |
| write_unlock(&sbi->s_mb_avg_fragment_size_locks[ |
| grp->bb_avg_fragment_size_order]); |
| } |
| |
| /* |
| * Choose next group by traversing largest_free_order lists. Updates *new_cr if |
| * cr level needs an update. |
| */ |
| static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context *ac, |
| enum criteria *new_cr, ext4_group_t *group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_group_info *iter; |
| int i; |
| |
| if (ac->ac_status == AC_STATUS_FOUND) |
| return; |
| |
| if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED)) |
| atomic_inc(&sbi->s_bal_p2_aligned_bad_suggestions); |
| |
| for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) { |
| if (list_empty(&sbi->s_mb_largest_free_orders[i])) |
| continue; |
| read_lock(&sbi->s_mb_largest_free_orders_locks[i]); |
| if (list_empty(&sbi->s_mb_largest_free_orders[i])) { |
| read_unlock(&sbi->s_mb_largest_free_orders_locks[i]); |
| continue; |
| } |
| list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i], |
| bb_largest_free_order_node) { |
| if (sbi->s_mb_stats) |
| atomic64_inc(&sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]); |
| if (likely(ext4_mb_good_group(ac, iter->bb_group, CR_POWER2_ALIGNED))) { |
| *group = iter->bb_group; |
| ac->ac_flags |= EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED; |
| read_unlock(&sbi->s_mb_largest_free_orders_locks[i]); |
| return; |
| } |
| } |
| read_unlock(&sbi->s_mb_largest_free_orders_locks[i]); |
| } |
| |
| /* Increment cr and search again if no group is found */ |
| *new_cr = CR_GOAL_LEN_FAST; |
| } |
| |
| /* |
| * Find a suitable group of given order from the average fragments list. |
| */ |
| static struct ext4_group_info * |
| ext4_mb_find_good_group_avg_frag_lists(struct ext4_allocation_context *ac, int order) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct list_head *frag_list = &sbi->s_mb_avg_fragment_size[order]; |
| rwlock_t *frag_list_lock = &sbi->s_mb_avg_fragment_size_locks[order]; |
| struct ext4_group_info *grp = NULL, *iter; |
| enum criteria cr = ac->ac_criteria; |
| |
| if (list_empty(frag_list)) |
| return NULL; |
| read_lock(frag_list_lock); |
| if (list_empty(frag_list)) { |
| read_unlock(frag_list_lock); |
| return NULL; |
| } |
| list_for_each_entry(iter, frag_list, bb_avg_fragment_size_node) { |
| if (sbi->s_mb_stats) |
| atomic64_inc(&sbi->s_bal_cX_groups_considered[cr]); |
| if (likely(ext4_mb_good_group(ac, iter->bb_group, cr))) { |
| grp = iter; |
| break; |
| } |
| } |
| read_unlock(frag_list_lock); |
| return grp; |
| } |
| |
| /* |
| * Choose next group by traversing average fragment size list of suitable |
| * order. Updates *new_cr if cr level needs an update. |
| */ |
| static void ext4_mb_choose_next_group_goal_fast(struct ext4_allocation_context *ac, |
| enum criteria *new_cr, ext4_group_t *group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_group_info *grp = NULL; |
| int i; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED)) { |
| if (sbi->s_mb_stats) |
| atomic_inc(&sbi->s_bal_goal_fast_bad_suggestions); |
| } |
| |
| for (i = mb_avg_fragment_size_order(ac->ac_sb, ac->ac_g_ex.fe_len); |
| i < MB_NUM_ORDERS(ac->ac_sb); i++) { |
| grp = ext4_mb_find_good_group_avg_frag_lists(ac, i); |
| if (grp) { |
| *group = grp->bb_group; |
| ac->ac_flags |= EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED; |
| return; |
| } |
| } |
| |
| /* |
| * CR_BEST_AVAIL_LEN works based on the concept that we have |
| * a larger normalized goal len request which can be trimmed to |
| * a smaller goal len such that it can still satisfy original |
| * request len. However, allocation request for non-regular |
| * files never gets normalized. |
| * See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA). |
| */ |
| if (ac->ac_flags & EXT4_MB_HINT_DATA) |
| *new_cr = CR_BEST_AVAIL_LEN; |
| else |
| *new_cr = CR_GOAL_LEN_SLOW; |
| } |
| |
| /* |
| * We couldn't find a group in CR_GOAL_LEN_FAST so try to find the highest free fragment |
| * order we have and proactively trim the goal request length to that order to |
| * find a suitable group faster. |
| * |
| * This optimizes allocation speed at the cost of slightly reduced |
| * preallocations. However, we make sure that we don't trim the request too |
| * much and fall to CR_GOAL_LEN_SLOW in that case. |
| */ |
| static void ext4_mb_choose_next_group_best_avail(struct ext4_allocation_context *ac, |
| enum criteria *new_cr, ext4_group_t *group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_group_info *grp = NULL; |
| int i, order, min_order; |
| unsigned long num_stripe_clusters = 0; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED)) { |
| if (sbi->s_mb_stats) |
| atomic_inc(&sbi->s_bal_best_avail_bad_suggestions); |
| } |
| |
| /* |
| * mb_avg_fragment_size_order() returns order in a way that makes |
| * retrieving back the length using (1 << order) inaccurate. Hence, use |
| * fls() instead since we need to know the actual length while modifying |
| * goal length. |
| */ |
| order = fls(ac->ac_g_ex.fe_len) - 1; |
| if (WARN_ON_ONCE(order - 1 > MB_NUM_ORDERS(ac->ac_sb))) |
| order = MB_NUM_ORDERS(ac->ac_sb); |
| min_order = order - sbi->s_mb_best_avail_max_trim_order; |
| if (min_order < 0) |
| min_order = 0; |
| |
| if (sbi->s_stripe > 0) { |
| /* |
| * We are assuming that stripe size is always a multiple of |
| * cluster ratio otherwise __ext4_fill_super exists early. |
| */ |
| num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe); |
| if (1 << min_order < num_stripe_clusters) |
| /* |
| * We consider 1 order less because later we round |
| * up the goal len to num_stripe_clusters |
| */ |
| min_order = fls(num_stripe_clusters) - 1; |
| } |
| |
| if (1 << min_order < ac->ac_o_ex.fe_len) |
| min_order = fls(ac->ac_o_ex.fe_len); |
| |
| for (i = order; i >= min_order; i--) { |
| int frag_order; |
| /* |
| * Scale down goal len to make sure we find something |
| * in the free fragments list. Basically, reduce |
| * preallocations. |
| */ |
| ac->ac_g_ex.fe_len = 1 << i; |
| |
| if (num_stripe_clusters > 0) { |
| /* |
| * Try to round up the adjusted goal length to |
| * stripe size (in cluster units) multiple for |
| * efficiency. |
| */ |
| ac->ac_g_ex.fe_len = roundup(ac->ac_g_ex.fe_len, |
| num_stripe_clusters); |
| } |
| |
| frag_order = mb_avg_fragment_size_order(ac->ac_sb, |
| ac->ac_g_ex.fe_len); |
| |
| grp = ext4_mb_find_good_group_avg_frag_lists(ac, frag_order); |
| if (grp) { |
| *group = grp->bb_group; |
| ac->ac_flags |= EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED; |
| return; |
| } |
| } |
| |
| /* Reset goal length to original goal length before falling into CR_GOAL_LEN_SLOW */ |
| ac->ac_g_ex.fe_len = ac->ac_orig_goal_len; |
| *new_cr = CR_GOAL_LEN_SLOW; |
| } |
| |
| static inline int should_optimize_scan(struct ext4_allocation_context *ac) |
| { |
| if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN))) |
| return 0; |
| if (ac->ac_criteria >= CR_GOAL_LEN_SLOW) |
| return 0; |
| if (!ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * Return next linear group for allocation. |
| */ |
| static ext4_group_t |
| next_linear_group(ext4_group_t group, ext4_group_t ngroups) |
| { |
| /* |
| * Artificially restricted ngroups for non-extent |
| * files makes group > ngroups possible on first loop. |
| */ |
| return group + 1 >= ngroups ? 0 : group + 1; |
| } |
| |
| /* |
| * ext4_mb_choose_next_group: choose next group for allocation. |
| * |
| * @ac Allocation Context |
| * @new_cr This is an output parameter. If the there is no good group |
| * available at current CR level, this field is updated to indicate |
| * the new cr level that should be used. |
| * @group This is an input / output parameter. As an input it indicates the |
| * next group that the allocator intends to use for allocation. As |
| * output, this field indicates the next group that should be used as |
| * determined by the optimization functions. |
| * @ngroups Total number of groups |
| */ |
| static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac, |
| enum criteria *new_cr, ext4_group_t *group, ext4_group_t ngroups) |
| { |
| *new_cr = ac->ac_criteria; |
| |
| if (!should_optimize_scan(ac)) { |
| *group = next_linear_group(*group, ngroups); |
| return; |
| } |
| |
| /* |
| * Optimized scanning can return non adjacent groups which can cause |
| * seek overhead for rotational disks. So try few linear groups before |
| * trying optimized scan. |
| */ |
| if (ac->ac_groups_linear_remaining) { |
| *group = next_linear_group(*group, ngroups); |
| ac->ac_groups_linear_remaining--; |
| return; |
| } |
| |
| if (*new_cr == CR_POWER2_ALIGNED) { |
| ext4_mb_choose_next_group_p2_aligned(ac, new_cr, group); |
| } else if (*new_cr == CR_GOAL_LEN_FAST) { |
| ext4_mb_choose_next_group_goal_fast(ac, new_cr, group); |
| } else if (*new_cr == CR_BEST_AVAIL_LEN) { |
| ext4_mb_choose_next_group_best_avail(ac, new_cr, group); |
| } else { |
| /* |
| * TODO: For CR_GOAL_LEN_SLOW, we can arrange groups in an |
| * rb tree sorted by bb_free. But until that happens, we should |
| * never come here. |
| */ |
| WARN_ON(1); |
| } |
| } |
| |
| /* |
| * Cache the order of the largest free extent we have available in this block |
| * group. |
| */ |
| static void |
| mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int i; |
| |
| for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--) |
| if (grp->bb_counters[i] > 0) |
| break; |
| /* No need to move between order lists? */ |
| if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || |
| i == grp->bb_largest_free_order) { |
| grp->bb_largest_free_order = i; |
| return; |
| } |
| |
| if (grp->bb_largest_free_order >= 0) { |
| write_lock(&sbi->s_mb_largest_free_orders_locks[ |
| grp->bb_largest_free_order]); |
| list_del_init(&grp->bb_largest_free_order_node); |
| write_unlock(&sbi->s_mb_largest_free_orders_locks[ |
| grp->bb_largest_free_order]); |
| } |
| grp->bb_largest_free_order = i; |
| if (grp->bb_largest_free_order >= 0 && grp->bb_free) { |
| write_lock(&sbi->s_mb_largest_free_orders_locks[ |
| grp->bb_largest_free_order]); |
| list_add_tail(&grp->bb_largest_free_order_node, |
| &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]); |
| write_unlock(&sbi->s_mb_largest_free_orders_locks[ |
| grp->bb_largest_free_order]); |
| } |
| } |
| |
| static noinline_for_stack |
| void ext4_mb_generate_buddy(struct super_block *sb, |
| void *buddy, void *bitmap, ext4_group_t group, |
| struct ext4_group_info *grp) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); |
| ext4_grpblk_t i = 0; |
| ext4_grpblk_t first; |
| ext4_grpblk_t len; |
| unsigned free = 0; |
| unsigned fragments = 0; |
| unsigned long long period = get_cycles(); |
| |
| /* initialize buddy from bitmap which is aggregation |
| * of on-disk bitmap and preallocations */ |
| i = mb_find_next_zero_bit(bitmap, max, 0); |
| grp->bb_first_free = i; |
| while (i < max) { |
| fragments++; |
| first = i; |
| i = mb_find_next_bit(bitmap, max, i); |
| len = i - first; |
| free += len; |
| if (len > 1) |
| ext4_mb_mark_free_simple(sb, buddy, first, len, grp); |
| else |
| grp->bb_counters[0]++; |
| if (i < max) |
| i = mb_find_next_zero_bit(bitmap, max, i); |
| } |
| grp->bb_fragments = fragments; |
| |
| if (free != grp->bb_free) { |
| ext4_grp_locked_error(sb, group, 0, 0, |
| "block bitmap and bg descriptor " |
| "inconsistent: %u vs %u free clusters", |
| free, grp->bb_free); |
| /* |
| * If we intend to continue, we consider group descriptor |
| * corrupt and update bb_free using bitmap value |
| */ |
| grp->bb_free = free; |
| ext4_mark_group_bitmap_corrupted(sb, group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| } |
| mb_set_largest_free_order(sb, grp); |
| mb_update_avg_fragment_size(sb, grp); |
| |
| clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); |
| |
| period = get_cycles() - period; |
| atomic_inc(&sbi->s_mb_buddies_generated); |
| atomic64_add(period, &sbi->s_mb_generation_time); |
| } |
| |
| static void mb_regenerate_buddy(struct ext4_buddy *e4b) |
| { |
| int count; |
| int order = 1; |
| void *buddy; |
| |
| while ((buddy = mb_find_buddy(e4b, order++, &count))) |
| mb_set_bits(buddy, 0, count); |
| |
| e4b->bd_info->bb_fragments = 0; |
| memset(e4b->bd_info->bb_counters, 0, |
| sizeof(*e4b->bd_info->bb_counters) * |
| (e4b->bd_sb->s_blocksize_bits + 2)); |
| |
| ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy, |
| e4b->bd_bitmap, e4b->bd_group, e4b->bd_info); |
| } |
| |
| /* The buddy information is attached the buddy cache inode |
| * for convenience. The information regarding each group |
| * is loaded via ext4_mb_load_buddy. The information involve |
| * block bitmap and buddy information. The information are |
| * stored in the inode as |
| * |
| * { page } |
| * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... |
| * |
| * |
| * one block each for bitmap and buddy information. |
| * So for each group we take up 2 blocks. A page can |
| * contain blocks_per_page (PAGE_SIZE / blocksize) blocks. |
| * So it can have information regarding groups_per_page which |
| * is blocks_per_page/2 |
| * |
| * Locking note: This routine takes the block group lock of all groups |
| * for this page; do not hold this lock when calling this routine! |
| */ |
| |
| static int ext4_mb_init_cache(struct folio *folio, char *incore, gfp_t gfp) |
| { |
| ext4_group_t ngroups; |
| unsigned int blocksize; |
| int blocks_per_page; |
| int groups_per_page; |
| int err = 0; |
| int i; |
| ext4_group_t first_group, group; |
| int first_block; |
| struct super_block *sb; |
| struct buffer_head *bhs; |
| struct buffer_head **bh = NULL; |
| struct inode *inode; |
| char *data; |
| char *bitmap; |
| struct ext4_group_info *grinfo; |
| |
| inode = folio->mapping->host; |
| sb = inode->i_sb; |
| ngroups = ext4_get_groups_count(sb); |
| blocksize = i_blocksize(inode); |
| blocks_per_page = PAGE_SIZE / blocksize; |
| |
| mb_debug(sb, "init folio %lu\n", folio->index); |
| |
| groups_per_page = blocks_per_page >> 1; |
| if (groups_per_page == 0) |
| groups_per_page = 1; |
| |
| /* allocate buffer_heads to read bitmaps */ |
| if (groups_per_page > 1) { |
| i = sizeof(struct buffer_head *) * groups_per_page; |
| bh = kzalloc(i, gfp); |
| if (bh == NULL) |
| return -ENOMEM; |
| } else |
| bh = &bhs; |
| |
| first_group = folio->index * blocks_per_page / 2; |
| |
| /* read all groups the folio covers into the cache */ |
| for (i = 0, group = first_group; i < groups_per_page; i++, group++) { |
| if (group >= ngroups) |
| break; |
| |
| grinfo = ext4_get_group_info(sb, group); |
| if (!grinfo) |
| continue; |
| /* |
| * If page is uptodate then we came here after online resize |
| * which added some new uninitialized group info structs, so |
| * we must skip all initialized uptodate buddies on the folio, |
| * which may be currently in use by an allocating task. |
| */ |
| if (folio_test_uptodate(folio) && |
| !EXT4_MB_GRP_NEED_INIT(grinfo)) { |
| bh[i] = NULL; |
| continue; |
| } |
| bh[i] = ext4_read_block_bitmap_nowait(sb, group, false); |
| if (IS_ERR(bh[i])) { |
| err = PTR_ERR(bh[i]); |
| bh[i] = NULL; |
| goto out; |
| } |
| mb_debug(sb, "read bitmap for group %u\n", group); |
| } |
| |
| /* wait for I/O completion */ |
| for (i = 0, group = first_group; i < groups_per_page; i++, group++) { |
| int err2; |
| |
| if (!bh[i]) |
| continue; |
| err2 = ext4_wait_block_bitmap(sb, group, bh[i]); |
| if (!err) |
| err = err2; |
| } |
| |
| first_block = folio->index * blocks_per_page; |
| for (i = 0; i < blocks_per_page; i++) { |
| group = (first_block + i) >> 1; |
| if (group >= ngroups) |
| break; |
| |
| if (!bh[group - first_group]) |
| /* skip initialized uptodate buddy */ |
| continue; |
| |
| if (!buffer_verified(bh[group - first_group])) |
| /* Skip faulty bitmaps */ |
| continue; |
| err = 0; |
| |
| /* |
| * data carry information regarding this |
| * particular group in the format specified |
| * above |
| * |
| */ |
| data = folio_address(folio) + (i * blocksize); |
| bitmap = bh[group - first_group]->b_data; |
| |
| /* |
| * We place the buddy block and bitmap block |
| * close together |
| */ |
| grinfo = ext4_get_group_info(sb, group); |
| if (!grinfo) { |
| err = -EFSCORRUPTED; |
| goto out; |
| } |
| if ((first_block + i) & 1) { |
| /* this is block of buddy */ |
| BUG_ON(incore == NULL); |
| mb_debug(sb, "put buddy for group %u in folio %lu/%x\n", |
| group, folio->index, i * blocksize); |
| trace_ext4_mb_buddy_bitmap_load(sb, group); |
| grinfo->bb_fragments = 0; |
| memset(grinfo->bb_counters, 0, |
| sizeof(*grinfo->bb_counters) * |
| (MB_NUM_ORDERS(sb))); |
| /* |
| * incore got set to the group block bitmap below |
| */ |
| ext4_lock_group(sb, group); |
| /* init the buddy */ |
| memset(data, 0xff, blocksize); |
| ext4_mb_generate_buddy(sb, data, incore, group, grinfo); |
| ext4_unlock_group(sb, group); |
| incore = NULL; |
| } else { |
| /* this is block of bitmap */ |
| BUG_ON(incore != NULL); |
| mb_debug(sb, "put bitmap for group %u in folio %lu/%x\n", |
| group, folio->index, i * blocksize); |
| trace_ext4_mb_bitmap_load(sb, group); |
| |
| /* see comments in ext4_mb_put_pa() */ |
| ext4_lock_group(sb, group); |
| memcpy(data, bitmap, blocksize); |
| |
| /* mark all preallocated blks used in in-core bitmap */ |
| ext4_mb_generate_from_pa(sb, data, group); |
| WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root)); |
| ext4_unlock_group(sb, group); |
| |
| /* set incore so that the buddy information can be |
| * generated using this |
| */ |
| incore = data; |
| } |
| } |
| folio_mark_uptodate(folio); |
| |
| out: |
| if (bh) { |
| for (i = 0; i < groups_per_page; i++) |
| brelse(bh[i]); |
| if (bh != &bhs) |
| kfree(bh); |
| } |
| return err; |
| } |
| |
| /* |
| * Lock the buddy and bitmap pages. This make sure other parallel init_group |
| * on the same buddy page doesn't happen whild holding the buddy page lock. |
| * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap |
| * are on the same page e4b->bd_buddy_folio is NULL and return value is 0. |
| */ |
| static int ext4_mb_get_buddy_page_lock(struct super_block *sb, |
| ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp) |
| { |
| struct inode *inode = EXT4_SB(sb)->s_buddy_cache; |
| int block, pnum, poff; |
| int blocks_per_page; |
| struct folio *folio; |
| |
| e4b->bd_buddy_folio = NULL; |
| e4b->bd_bitmap_folio = NULL; |
| |
| blocks_per_page = PAGE_SIZE / sb->s_blocksize; |
| /* |
| * the buddy cache inode stores the block bitmap |
| * and buddy information in consecutive blocks. |
| * So for each group we need two blocks. |
| */ |
| block = group * 2; |
| pnum = block / blocks_per_page; |
| poff = block % blocks_per_page; |
| folio = __filemap_get_folio(inode->i_mapping, pnum, |
| FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); |
| if (IS_ERR(folio)) |
| return PTR_ERR(folio); |
| BUG_ON(folio->mapping != inode->i_mapping); |
| e4b->bd_bitmap_folio = folio; |
| e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize); |
| |
| if (blocks_per_page >= 2) { |
| /* buddy and bitmap are on the same page */ |
| return 0; |
| } |
| |
| /* blocks_per_page == 1, hence we need another page for the buddy */ |
| folio = __filemap_get_folio(inode->i_mapping, block + 1, |
| FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); |
| if (IS_ERR(folio)) |
| return PTR_ERR(folio); |
| BUG_ON(folio->mapping != inode->i_mapping); |
| e4b->bd_buddy_folio = folio; |
| return 0; |
| } |
| |
| static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b) |
| { |
| if (e4b->bd_bitmap_folio) { |
| folio_unlock(e4b->bd_bitmap_folio); |
| folio_put(e4b->bd_bitmap_folio); |
| } |
| if (e4b->bd_buddy_folio) { |
| folio_unlock(e4b->bd_buddy_folio); |
| folio_put(e4b->bd_buddy_folio); |
| } |
| } |
| |
| /* |
| * Locking note: This routine calls ext4_mb_init_cache(), which takes the |
| * block group lock of all groups for this page; do not hold the BG lock when |
| * calling this routine! |
| */ |
| static noinline_for_stack |
| int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp) |
| { |
| |
| struct ext4_group_info *this_grp; |
| struct ext4_buddy e4b; |
| struct folio *folio; |
| int ret = 0; |
| |
| might_sleep(); |
| mb_debug(sb, "init group %u\n", group); |
| this_grp = ext4_get_group_info(sb, group); |
| if (!this_grp) |
| return -EFSCORRUPTED; |
| |
| /* |
| * This ensures that we don't reinit the buddy cache |
| * page which map to the group from which we are already |
| * allocating. If we are looking at the buddy cache we would |
| * have taken a reference using ext4_mb_load_buddy and that |
| * would have pinned buddy page to page cache. |
| * The call to ext4_mb_get_buddy_page_lock will mark the |
| * page accessed. |
| */ |
| ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b, gfp); |
| if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) { |
| /* |
| * somebody initialized the group |
| * return without doing anything |
| */ |
| goto err; |
| } |
| |
| folio = e4b.bd_bitmap_folio; |
| ret = ext4_mb_init_cache(folio, NULL, gfp); |
| if (ret) |
| goto err; |
| if (!folio_test_uptodate(folio)) { |
| ret = -EIO; |
| goto err; |
| } |
| |
| if (e4b.bd_buddy_folio == NULL) { |
| /* |
| * If both the bitmap and buddy are in |
| * the same page we don't need to force |
| * init the buddy |
| */ |
| ret = 0; |
| goto err; |
| } |
| /* init buddy cache */ |
| folio = e4b.bd_buddy_folio; |
| ret = ext4_mb_init_cache(folio, e4b.bd_bitmap, gfp); |
| if (ret) |
| goto err; |
| if (!folio_test_uptodate(folio)) { |
| ret = -EIO; |
| goto err; |
| } |
| err: |
| ext4_mb_put_buddy_page_lock(&e4b); |
| return ret; |
| } |
| |
| /* |
| * Locking note: This routine calls ext4_mb_init_cache(), which takes the |
| * block group lock of all groups for this page; do not hold the BG lock when |
| * calling this routine! |
| */ |
| static noinline_for_stack int |
| ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group, |
| struct ext4_buddy *e4b, gfp_t gfp) |
| { |
| int blocks_per_page; |
| int block; |
| int pnum; |
| int poff; |
| struct folio *folio; |
| int ret; |
| struct ext4_group_info *grp; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct inode *inode = sbi->s_buddy_cache; |
| |
| might_sleep(); |
| mb_debug(sb, "load group %u\n", group); |
| |
| blocks_per_page = PAGE_SIZE / sb->s_blocksize; |
| grp = ext4_get_group_info(sb, group); |
| if (!grp) |
| return -EFSCORRUPTED; |
| |
| e4b->bd_blkbits = sb->s_blocksize_bits; |
| e4b->bd_info = grp; |
| e4b->bd_sb = sb; |
| e4b->bd_group = group; |
| e4b->bd_buddy_folio = NULL; |
| e4b->bd_bitmap_folio = NULL; |
| |
| if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
| /* |
| * we need full data about the group |
| * to make a good selection |
| */ |
| ret = ext4_mb_init_group(sb, group, gfp); |
| if (ret) |
| return ret; |
| } |
| |
| /* |
| * the buddy cache inode stores the block bitmap |
| * and buddy information in consecutive blocks. |
| * So for each group we need two blocks. |
| */ |
| block = group * 2; |
| pnum = block / blocks_per_page; |
| poff = block % blocks_per_page; |
| |
| /* Avoid locking the folio in the fast path ... */ |
| folio = __filemap_get_folio(inode->i_mapping, pnum, FGP_ACCESSED, 0); |
| if (IS_ERR(folio) || !folio_test_uptodate(folio)) { |
| if (!IS_ERR(folio)) |
| /* |
| * drop the folio reference and try |
| * to get the folio with lock. If we |
| * are not uptodate that implies |
| * somebody just created the folio but |
| * is yet to initialize it. So |
| * wait for it to initialize. |
| */ |
| folio_put(folio); |
| folio = __filemap_get_folio(inode->i_mapping, pnum, |
| FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); |
| if (!IS_ERR(folio)) { |
| if (WARN_RATELIMIT(folio->mapping != inode->i_mapping, |
| "ext4: bitmap's mapping != inode->i_mapping\n")) { |
| /* should never happen */ |
| folio_unlock(folio); |
| ret = -EINVAL; |
| goto err; |
| } |
| if (!folio_test_uptodate(folio)) { |
| ret = ext4_mb_init_cache(folio, NULL, gfp); |
| if (ret) { |
| folio_unlock(folio); |
| goto err; |
| } |
| mb_cmp_bitmaps(e4b, folio_address(folio) + |
| (poff * sb->s_blocksize)); |
| } |
| folio_unlock(folio); |
| } |
| } |
| if (IS_ERR(folio)) { |
| ret = PTR_ERR(folio); |
| goto err; |
| } |
| if (!folio_test_uptodate(folio)) { |
| ret = -EIO; |
| goto err; |
| } |
| |
| /* Folios marked accessed already */ |
| e4b->bd_bitmap_folio = folio; |
| e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize); |
| |
| block++; |
| pnum = block / blocks_per_page; |
| poff = block % blocks_per_page; |
| |
| folio = __filemap_get_folio(inode->i_mapping, pnum, FGP_ACCESSED, 0); |
| if (IS_ERR(folio) || !folio_test_uptodate(folio)) { |
| if (!IS_ERR(folio)) |
| folio_put(folio); |
| folio = __filemap_get_folio(inode->i_mapping, pnum, |
| FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); |
| if (!IS_ERR(folio)) { |
| if (WARN_RATELIMIT(folio->mapping != inode->i_mapping, |
| "ext4: buddy bitmap's mapping != inode->i_mapping\n")) { |
| /* should never happen */ |
| folio_unlock(folio); |
| ret = -EINVAL; |
| goto err; |
| } |
| if (!folio_test_uptodate(folio)) { |
| ret = ext4_mb_init_cache(folio, e4b->bd_bitmap, |
| gfp); |
| if (ret) { |
| folio_unlock(folio); |
| goto err; |
| } |
| } |
| folio_unlock(folio); |
| } |
| } |
| if (IS_ERR(folio)) { |
| ret = PTR_ERR(folio); |
| goto err; |
| } |
| if (!folio_test_uptodate(folio)) { |
| ret = -EIO; |
| goto err; |
| } |
| |
| /* Folios marked accessed already */ |
| e4b->bd_buddy_folio = folio; |
| e4b->bd_buddy = folio_address(folio) + (poff * sb->s_blocksize); |
| |
| return 0; |
| |
| err: |
| if (!IS_ERR_OR_NULL(folio)) |
| folio_put(folio); |
| if (e4b->bd_bitmap_folio) |
| folio_put(e4b->bd_bitmap_folio); |
| |
| e4b->bd_buddy = NULL; |
| e4b->bd_bitmap = NULL; |
| return ret; |
| } |
| |
| static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, |
| struct ext4_buddy *e4b) |
| { |
| return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS); |
| } |
| |
| static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) |
| { |
| if (e4b->bd_bitmap_folio) |
| folio_put(e4b->bd_bitmap_folio); |
| if (e4b->bd_buddy_folio) |
| folio_put(e4b->bd_buddy_folio); |
| } |
| |
| |
| static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) |
| { |
| int order = 1, max; |
| void *bb; |
| |
| BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); |
| BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); |
| |
| while (order <= e4b->bd_blkbits + 1) { |
| bb = mb_find_buddy(e4b, order, &max); |
| if (!mb_test_bit(block >> order, bb)) { |
| /* this block is part of buddy of order 'order' */ |
| return order; |
| } |
| order++; |
| } |
| return 0; |
| } |
| |
| static void mb_clear_bits(void *bm, int cur, int len) |
| { |
| __u32 *addr; |
| |
| len = cur + len; |
| while (cur < len) { |
| if ((cur & 31) == 0 && (len - cur) >= 32) { |
| /* fast path: clear whole word at once */ |
| addr = bm + (cur >> 3); |
| *addr = 0; |
| cur += 32; |
| continue; |
| } |
| mb_clear_bit(cur, bm); |
| cur++; |
| } |
| } |
| |
| /* clear bits in given range |
| * will return first found zero bit if any, -1 otherwise |
| */ |
| static int mb_test_and_clear_bits(void *bm, int cur, int len) |
| { |
| __u32 *addr; |
| int zero_bit = -1; |
| |
| len = cur + len; |
| while (cur < len) { |
| if ((cur & 31) == 0 && (len - cur) >= 32) { |
| /* fast path: clear whole word at once */ |
| addr = bm + (cur >> 3); |
| if (*addr != (__u32)(-1) && zero_bit == -1) |
| zero_bit = cur + mb_find_next_zero_bit(addr, 32, 0); |
| *addr = 0; |
| cur += 32; |
| continue; |
| } |
| if (!mb_test_and_clear_bit(cur, bm) && zero_bit == -1) |
| zero_bit = cur; |
| cur++; |
| } |
| |
| return zero_bit; |
| } |
| |
| void mb_set_bits(void *bm, int cur, int len) |
| { |
| __u32 *addr; |
| |
| len = cur + len; |
| while (cur < len) { |
| if ((cur & 31) == 0 && (len - cur) >= 32) { |
| /* fast path: set whole word at once */ |
| addr = bm + (cur >> 3); |
| *addr = 0xffffffff; |
| cur += 32; |
| continue; |
| } |
| mb_set_bit(cur, bm); |
| cur++; |
| } |
| } |
| |
| static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side) |
| { |
| if (mb_test_bit(*bit + side, bitmap)) { |
| mb_clear_bit(*bit, bitmap); |
| (*bit) -= side; |
| return 1; |
| } |
| else { |
| (*bit) += side; |
| mb_set_bit(*bit, bitmap); |
| return -1; |
| } |
| } |
| |
| static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last) |
| { |
| int max; |
| int order = 1; |
| void *buddy = mb_find_buddy(e4b, order, &max); |
| |
| while (buddy) { |
| void *buddy2; |
| |
| /* Bits in range [first; last] are known to be set since |
| * corresponding blocks were allocated. Bits in range |
| * (first; last) will stay set because they form buddies on |
| * upper layer. We just deal with borders if they don't |
| * align with upper layer and then go up. |
| * Releasing entire group is all about clearing |
| * single bit of highest order buddy. |
| */ |
| |
| /* Example: |
| * --------------------------------- |
| * | 1 | 1 | 1 | 1 | |
| * --------------------------------- |
| * | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | |
| * --------------------------------- |
| * 0 1 2 3 4 5 6 7 |
| * \_____________________/ |
| * |
| * Neither [1] nor [6] is aligned to above layer. |
| * Left neighbour [0] is free, so mark it busy, |
| * decrease bb_counters and extend range to |
| * [0; 6] |
| * Right neighbour [7] is busy. It can't be coaleasced with [6], so |
| * mark [6] free, increase bb_counters and shrink range to |
| * [0; 5]. |
| * Then shift range to [0; 2], go up and do the same. |
| */ |
| |
| |
| if (first & 1) |
| e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy, -1); |
| if (!(last & 1)) |
| e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&last, buddy, 1); |
| if (first > last) |
| break; |
| order++; |
| |
| buddy2 = mb_find_buddy(e4b, order, &max); |
| if (!buddy2) { |
| mb_clear_bits(buddy, first, last - first + 1); |
| e4b->bd_info->bb_counters[order - 1] += last - first + 1; |
| break; |
| } |
| first >>= 1; |
| last >>= 1; |
| buddy = buddy2; |
| } |
| } |
| |
| static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, |
| int first, int count) |
| { |
| int left_is_free = 0; |
| int right_is_free = 0; |
| int block; |
| int last = first + count - 1; |
| struct super_block *sb = e4b->bd_sb; |
| |
| if (WARN_ON(count == 0)) |
| return; |
| BUG_ON(last >= (sb->s_blocksize << 3)); |
| assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); |
| /* Don't bother if the block group is corrupt. */ |
| if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) |
| return; |
| |
| mb_check_buddy(e4b); |
| mb_free_blocks_double(inode, e4b, first, count); |
| |
| /* access memory sequentially: check left neighbour, |
| * clear range and then check right neighbour |
| */ |
| if (first != 0) |
| left_is_free = !mb_test_bit(first - 1, e4b->bd_bitmap); |
| block = mb_test_and_clear_bits(e4b->bd_bitmap, first, count); |
| if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0]) |
| right_is_free = !mb_test_bit(last + 1, e4b->bd_bitmap); |
| |
| if (unlikely(block != -1)) { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_fsblk_t blocknr; |
| |
| /* |
| * Fastcommit replay can free already freed blocks which |
| * corrupts allocation info. Regenerate it. |
| */ |
| if (sbi->s_mount_state & EXT4_FC_REPLAY) { |
| mb_regenerate_buddy(e4b); |
| goto check; |
| } |
| |
| blocknr = ext4_group_first_block_no(sb, e4b->bd_group); |
| blocknr += EXT4_C2B(sbi, block); |
| ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| ext4_grp_locked_error(sb, e4b->bd_group, |
| inode ? inode->i_ino : 0, blocknr, |
| "freeing already freed block (bit %u); block bitmap corrupt.", |
| block); |
| return; |
| } |
| |
| this_cpu_inc(discard_pa_seq); |
| e4b->bd_info->bb_free += count; |
| if (first < e4b->bd_info->bb_first_free) |
| e4b->bd_info->bb_first_free = first; |
| |
| /* let's maintain fragments counter */ |
| if (left_is_free && right_is_free) |
| e4b->bd_info->bb_fragments--; |
| else if (!left_is_free && !right_is_free) |
| e4b->bd_info->bb_fragments++; |
| |
| /* buddy[0] == bd_bitmap is a special case, so handle |
| * it right away and let mb_buddy_mark_free stay free of |
| * zero order checks. |
| * Check if neighbours are to be coaleasced, |
| * adjust bitmap bb_counters and borders appropriately. |
| */ |
| if (first & 1) { |
| first += !left_is_free; |
| e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1; |
| } |
| if (!(last & 1)) { |
| last -= !right_is_free; |
| e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1; |
| } |
| |
| if (first <= last) |
| mb_buddy_mark_free(e4b, first >> 1, last >> 1); |
| |
| mb_set_largest_free_order(sb, e4b->bd_info); |
| mb_update_avg_fragment_size(sb, e4b->bd_info); |
| check: |
| mb_check_buddy(e4b); |
| } |
| |
| static int mb_find_extent(struct ext4_buddy *e4b, int block, |
| int needed, struct ext4_free_extent *ex) |
| { |
| int max, order, next; |
| void *buddy; |
| |
| assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
| BUG_ON(ex == NULL); |
| |
| buddy = mb_find_buddy(e4b, 0, &max); |
| BUG_ON(buddy == NULL); |
| BUG_ON(block >= max); |
| if (mb_test_bit(block, buddy)) { |
| ex->fe_len = 0; |
| ex->fe_start = 0; |
| ex->fe_group = 0; |
| return 0; |
| } |
| |
| /* find actual order */ |
| order = mb_find_order_for_block(e4b, block); |
| |
| ex->fe_len = (1 << order) - (block & ((1 << order) - 1)); |
| ex->fe_start = block; |
| ex->fe_group = e4b->bd_group; |
| |
| block = block >> order; |
| |
| while (needed > ex->fe_len && |
| mb_find_buddy(e4b, order, &max)) { |
| |
| if (block + 1 >= max) |
| break; |
| |
| next = (block + 1) * (1 << order); |
| if (mb_test_bit(next, e4b->bd_bitmap)) |
| break; |
| |
| order = mb_find_order_for_block(e4b, next); |
| |
| block = next >> order; |
| ex->fe_len += 1 << order; |
| } |
| |
| if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) { |
| /* Should never happen! (but apparently sometimes does?!?) */ |
| WARN_ON(1); |
| ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0, |
| "corruption or bug in mb_find_extent " |
| "block=%d, order=%d needed=%d ex=%u/%d/%d@%u", |
| block, order, needed, ex->fe_group, ex->fe_start, |
| ex->fe_len, ex->fe_logical); |
| ex->fe_len = 0; |
| ex->fe_start = 0; |
| ex->fe_group = 0; |
| } |
| return ex->fe_len; |
| } |
| |
| static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) |
| { |
| int ord; |
| int mlen = 0; |
| int max = 0; |
| int start = ex->fe_start; |
| int len = ex->fe_len; |
| unsigned ret = 0; |
| int len0 = len; |
| void *buddy; |
| int ord_start, ord_end; |
| |
| BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); |
| BUG_ON(e4b->bd_group != ex->fe_group); |
| assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); |
| mb_check_buddy(e4b); |
| mb_mark_used_double(e4b, start, len); |
| |
| this_cpu_inc(discard_pa_seq); |
| e4b->bd_info->bb_free -= len; |
| if (e4b->bd_info->bb_first_free == start) |
| e4b->bd_info->bb_first_free += len; |
| |
| /* let's maintain fragments counter */ |
| if (start != 0) |
| mlen = !mb_test_bit(start - 1, e4b->bd_bitmap); |
| if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) |
| max = !mb_test_bit(start + len, e4b->bd_bitmap); |
| if (mlen && max) |
| e4b->bd_info->bb_fragments++; |
| else if (!mlen && !max) |
| e4b->bd_info->bb_fragments--; |
| |
| /* let's maintain buddy itself */ |
| while (len) { |
| ord = mb_find_order_for_block(e4b, start); |
| |
| if (((start >> ord) << ord) == start && len >= (1 << ord)) { |
| /* the whole chunk may be allocated at once! */ |
| mlen = 1 << ord; |
| buddy = mb_find_buddy(e4b, ord, &max); |
| BUG_ON((start >> ord) >= max); |
| mb_set_bit(start >> ord, buddy); |
| e4b->bd_info->bb_counters[ord]--; |
| start += mlen; |
| len -= mlen; |
| BUG_ON(len < 0); |
| continue; |
| } |
| |
| /* store for history */ |
| if (ret == 0) |
| ret = len | (ord << 16); |
| |
| BUG_ON(ord <= 0); |
| buddy = mb_find_buddy(e4b, ord, &max); |
| mb_set_bit(start >> ord, buddy); |
| e4b->bd_info->bb_counters[ord]--; |
| |
| ord_start = (start >> ord) << ord; |
| ord_end = ord_start + (1 << ord); |
| /* first chunk */ |
| if (start > ord_start) |
| ext4_mb_mark_free_simple(e4b->bd_sb, e4b->bd_buddy, |
| ord_start, start - ord_start, |
| e4b->bd_info); |
| |
| /* last chunk */ |
| if (start + len < ord_end) { |
| ext4_mb_mark_free_simple(e4b->bd_sb, e4b->bd_buddy, |
| start + len, |
| ord_end - (start + len), |
| e4b->bd_info); |
| break; |
| } |
| len = start + len - ord_end; |
| start = ord_end; |
| } |
| mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); |
| |
| mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info); |
| mb_set_bits(e4b->bd_bitmap, ex->fe_start, len0); |
| mb_check_buddy(e4b); |
| |
| return ret; |
| } |
| |
| /* |
| * Must be called under group lock! |
| */ |
| static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| int ret; |
| |
| BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); |
| BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| |
| ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); |
| ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; |
| ret = mb_mark_used(e4b, &ac->ac_b_ex); |
| |
| /* preallocation can change ac_b_ex, thus we store actually |
| * allocated blocks for history */ |
| ac->ac_f_ex = ac->ac_b_ex; |
| |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_tail = ret & 0xffff; |
| ac->ac_buddy = ret >> 16; |
| |
| /* |
| * take the page reference. We want the page to be pinned |
| * so that we don't get a ext4_mb_init_cache_call for this |
| * group until we update the bitmap. That would mean we |
| * double allocate blocks. The reference is dropped |
| * in ext4_mb_release_context |
| */ |
| ac->ac_bitmap_folio = e4b->bd_bitmap_folio; |
| folio_get(ac->ac_bitmap_folio); |
| ac->ac_buddy_folio = e4b->bd_buddy_folio; |
| folio_get(ac->ac_buddy_folio); |
| /* store last allocated for subsequent stream allocation */ |
| if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { |
| spin_lock(&sbi->s_md_lock); |
| sbi->s_mb_last_group = ac->ac_f_ex.fe_group; |
| sbi->s_mb_last_start = ac->ac_f_ex.fe_start; |
| spin_unlock(&sbi->s_md_lock); |
| } |
| /* |
| * As we've just preallocated more space than |
| * user requested originally, we store allocated |
| * space in a special descriptor. |
| */ |
| if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) |
| ext4_mb_new_preallocation(ac); |
| |
| } |
| |
| static void ext4_mb_check_limits(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b, |
| int finish_group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_free_extent *bex = &ac->ac_b_ex; |
| struct ext4_free_extent *gex = &ac->ac_g_ex; |
| |
| if (ac->ac_status == AC_STATUS_FOUND) |
| return; |
| /* |
| * We don't want to scan for a whole year |
| */ |
| if (ac->ac_found > sbi->s_mb_max_to_scan && |
| !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| ac->ac_status = AC_STATUS_BREAK; |
| return; |
| } |
| |
| /* |
| * Haven't found good chunk so far, let's continue |
| */ |
| if (bex->fe_len < gex->fe_len) |
| return; |
| |
| if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan) |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| |
| /* |
| * The routine checks whether found extent is good enough. If it is, |
| * then the extent gets marked used and flag is set to the context |
| * to stop scanning. Otherwise, the extent is compared with the |
| * previous found extent and if new one is better, then it's stored |
| * in the context. Later, the best found extent will be used, if |
| * mballoc can't find good enough extent. |
| * |
| * The algorithm used is roughly as follows: |
| * |
| * * If free extent found is exactly as big as goal, then |
| * stop the scan and use it immediately |
| * |
| * * If free extent found is smaller than goal, then keep retrying |
| * upto a max of sbi->s_mb_max_to_scan times (default 200). After |
| * that stop scanning and use whatever we have. |
| * |
| * * If free extent found is bigger than goal, then keep retrying |
| * upto a max of sbi->s_mb_min_to_scan times (default 10) before |
| * stopping the scan and using the extent. |
| * |
| * |
| * FIXME: real allocation policy is to be designed yet! |
| */ |
| static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, |
| struct ext4_free_extent *ex, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_free_extent *bex = &ac->ac_b_ex; |
| struct ext4_free_extent *gex = &ac->ac_g_ex; |
| |
| BUG_ON(ex->fe_len <= 0); |
| BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); |
| BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); |
| BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); |
| |
| ac->ac_found++; |
| ac->ac_cX_found[ac->ac_criteria]++; |
| |
| /* |
| * The special case - take what you catch first |
| */ |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| *bex = *ex; |
| ext4_mb_use_best_found(ac, e4b); |
| return; |
| } |
| |
| /* |
| * Let's check whether the chuck is good enough |
| */ |
| if (ex->fe_len == gex->fe_len) { |
| *bex = *ex; |
| ext4_mb_use_best_found(ac, e4b); |
| return; |
| } |
| |
| /* |
| * If this is first found extent, just store it in the context |
| */ |
| if (bex->fe_len == 0) { |
| *bex = *ex; |
| return; |
| } |
| |
| /* |
| * If new found extent is better, store it in the context |
| */ |
| if (bex->fe_len < gex->fe_len) { |
| /* if the request isn't satisfied, any found extent |
| * larger than previous best one is better */ |
| if (ex->fe_len > bex->fe_len) |
| *bex = *ex; |
| } else if (ex->fe_len > gex->fe_len) { |
| /* if the request is satisfied, then we try to find |
| * an extent that still satisfy the request, but is |
| * smaller than previous one */ |
| if (ex->fe_len < bex->fe_len) |
| *bex = *ex; |
| } |
| |
| ext4_mb_check_limits(ac, e4b, 0); |
| } |
| |
| static noinline_for_stack |
| void ext4_mb_try_best_found(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct ext4_free_extent ex = ac->ac_b_ex; |
| ext4_group_t group = ex.fe_group; |
| int max; |
| int err; |
| |
| BUG_ON(ex.fe_len <= 0); |
| err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| if (err) |
| return; |
| |
| ext4_lock_group(ac->ac_sb, group); |
| if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) |
| goto out; |
| |
| max = mb_find_extent(e4b, ex.fe_start, ex.fe_len, &ex); |
| |
| if (max > 0) { |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| |
| out: |
| ext4_unlock_group(ac->ac_sb, group); |
| ext4_mb_unload_buddy(e4b); |
| } |
| |
| static noinline_for_stack |
| int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| ext4_group_t group = ac->ac_g_ex.fe_group; |
| int max; |
| int err; |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
| struct ext4_free_extent ex; |
| |
| if (!grp) |
| return -EFSCORRUPTED; |
| if (!(ac->ac_flags & (EXT4_MB_HINT_TRY_GOAL | EXT4_MB_HINT_GOAL_ONLY))) |
| return 0; |
| if (grp->bb_free == 0) |
| return 0; |
| |
| err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); |
| if (err) |
| return err; |
| |
| ext4_lock_group(ac->ac_sb, group); |
| if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) |
| goto out; |
| |
| max = mb_find_extent(e4b, ac->ac_g_ex.fe_start, |
| ac->ac_g_ex.fe_len, &ex); |
| ex.fe_logical = 0xDEADFA11; /* debug value */ |
| |
| if (max >= ac->ac_g_ex.fe_len && |
| ac->ac_g_ex.fe_len == EXT4_NUM_B2C(sbi, sbi->s_stripe)) { |
| ext4_fsblk_t start; |
| |
| start = ext4_grp_offs_to_block(ac->ac_sb, &ex); |
| /* use do_div to get remainder (would be 64-bit modulo) */ |
| if (do_div(start, sbi->s_stripe) == 0) { |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| } else if (max >= ac->ac_g_ex.fe_len) { |
| BUG_ON(ex.fe_len <= 0); |
| BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { |
| /* Sometimes, caller may want to merge even small |
| * number of blocks to an existing extent */ |
| BUG_ON(ex.fe_len <= 0); |
| BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); |
| BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); |
| ac->ac_found++; |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| } |
| out: |
| ext4_unlock_group(ac->ac_sb, group); |
| ext4_mb_unload_buddy(e4b); |
| |
| return 0; |
| } |
| |
| /* |
| * The routine scans buddy structures (not bitmap!) from given order |
| * to max order and tries to find big enough chunk to satisfy the req |
| */ |
| static noinline_for_stack |
| void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_group_info *grp = e4b->bd_info; |
| void *buddy; |
| int i; |
| int k; |
| int max; |
| |
| BUG_ON(ac->ac_2order <= 0); |
| for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) { |
| if (grp->bb_counters[i] == 0) |
| continue; |
| |
| buddy = mb_find_buddy(e4b, i, &max); |
| if (WARN_RATELIMIT(buddy == NULL, |
| "ext4: mb_simple_scan_group: mb_find_buddy failed, (%d)\n", i)) |
| continue; |
| |
| k = mb_find_next_zero_bit(buddy, max, 0); |
| if (k >= max) { |
| ext4_mark_group_bitmap_corrupted(ac->ac_sb, |
| e4b->bd_group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0, |
| "%d free clusters of order %d. But found 0", |
| grp->bb_counters[i], i); |
| break; |
| } |
| ac->ac_found++; |
| ac->ac_cX_found[ac->ac_criteria]++; |
| |
| ac->ac_b_ex.fe_len = 1 << i; |
| ac->ac_b_ex.fe_start = k << i; |
| ac->ac_b_ex.fe_group = e4b->bd_group; |
| |
| ext4_mb_use_best_found(ac, e4b); |
| |
| BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len); |
| |
| if (EXT4_SB(sb)->s_mb_stats) |
| atomic_inc(&EXT4_SB(sb)->s_bal_2orders); |
| |
| break; |
| } |
| } |
| |
| /* |
| * The routine scans the group and measures all found extents. |
| * In order to optimize scanning, caller must pass number of |
| * free blocks in the group, so the routine can know upper limit. |
| */ |
| static noinline_for_stack |
| void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| void *bitmap = e4b->bd_bitmap; |
| struct ext4_free_extent ex; |
| int i, j, freelen; |
| int free; |
| |
| free = e4b->bd_info->bb_free; |
| if (WARN_ON(free <= 0)) |
| return; |
| |
| i = e4b->bd_info->bb_first_free; |
| |
| while (free && ac->ac_status == AC_STATUS_CONTINUE) { |
| i = mb_find_next_zero_bit(bitmap, |
| EXT4_CLUSTERS_PER_GROUP(sb), i); |
| if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) { |
| /* |
| * IF we have corrupt bitmap, we won't find any |
| * free blocks even though group info says we |
| * have free blocks |
| */ |
| ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, |
| "%d free clusters as per " |
| "group info. But bitmap says 0", |
| free); |
| break; |
| } |
| |
| if (!ext4_mb_cr_expensive(ac->ac_criteria)) { |
| /* |
| * In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are |
| * sure that this group will have a large enough |
| * continuous free extent, so skip over the smaller free |
| * extents |
| */ |
| j = mb_find_next_bit(bitmap, |
| EXT4_CLUSTERS_PER_GROUP(sb), i); |
| freelen = j - i; |
| |
| if (freelen < ac->ac_g_ex.fe_len) { |
| i = j; |
| free -= freelen; |
| continue; |
| } |
| } |
| |
| mb_find_extent(e4b, i, ac->ac_g_ex.fe_len, &ex); |
| if (WARN_ON(ex.fe_len <= 0)) |
| break; |
| if (free < ex.fe_len) { |
| ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group, |
| EXT4_GROUP_INFO_BBITMAP_CORRUPT); |
| ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, |
| "%d free clusters as per " |
| "group info. But got %d blocks", |
| free, ex.fe_len); |
| /* |
| * The number of free blocks differs. This mostly |
| * indicate that the bitmap is corrupt. So exit |
| * without claiming the space. |
| */ |
| break; |
| } |
| ex.fe_logical = 0xDEADC0DE; /* debug value */ |
| ext4_mb_measure_extent(ac, &ex, e4b); |
| |
| i += ex.fe_len; |
| free -= ex.fe_len; |
| } |
| |
| ext4_mb_check_limits(ac, e4b, 1); |
| } |
| |
| /* |
| * This is a special case for storages like raid5 |
| * we try to find stripe-aligned chunks for stripe-size-multiple requests |
| */ |
| static noinline_for_stack |
| void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, |
| struct ext4_buddy *e4b) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| void *bitmap = e4b->bd_bitmap; |
| struct ext4_free_extent ex; |
| ext4_fsblk_t first_group_block; |
| ext4_fsblk_t a; |
| ext4_grpblk_t i, stripe; |
| int max; |
| |
| BUG_ON(sbi->s_stripe == 0); |
| |
| /* find first stripe-aligned block in group */ |
| first_group_block = ext4_group_first_block_no(sb, e4b->bd_group); |
| |
| a = first_group_block + sbi->s_stripe - 1; |
| do_div(a, sbi->s_stripe); |
| i = (a * sbi->s_stripe) - first_group_block; |
| |
| stripe = EXT4_NUM_B2C(sbi, sbi->s_stripe); |
| i = EXT4_B2C(sbi, i); |
| while (i < EXT4_CLUSTERS_PER_GROUP(sb)) { |
| if (!mb_test_bit(i, bitmap)) { |
| max = mb_find_extent(e4b, i, stripe, &ex); |
| if (max >= stripe) { |
| ac->ac_found++; |
| ac->ac_cX_found[ac->ac_criteria]++; |
| ex.fe_logical = 0xDEADF00D; /* debug value */ |
| ac->ac_b_ex = ex; |
| ext4_mb_use_best_found(ac, e4b); |
| break; |
| } |
| } |
| i += stripe; |
| } |
| } |
| |
| /* |
| * This is also called BEFORE we load the buddy bitmap. |
| * Returns either 1 or 0 indicating that the group is either suitable |
| * for the allocation or not. |
| */ |
| static bool ext4_mb_good_group(struct ext4_allocation_context *ac, |
| ext4_group_t group, enum criteria cr) |
| { |
| ext4_grpblk_t free, fragments; |
| int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); |
| struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
| |
| BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS); |
| |
| if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) |
| return false; |
| |
| free = grp->bb_free; |
| if (free == 0) |
| return false; |
| |
| fragments = grp->bb_fragments; |
| if (fragments == 0) |
| return false; |
| |
| switch (cr) { |
| case CR_POWER2_ALIGNED: |
| BUG_ON(ac->ac_2order == 0); |
| |
| /* Avoid using the first bg of a flexgroup for data files */ |
| if ((ac->ac_flags & EXT4_MB_HINT_DATA) && |
| (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && |
| ((group % flex_size) == 0)) |
| return false; |
| |
| if (free < ac->ac_g_ex.fe_len) |
| return false; |
| |
| if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb)) |
| return true; |
| |
| if (grp->bb_largest_free_order < ac->ac_2order) |
| return false; |
| |
| return true; |
| case CR_GOAL_LEN_FAST: |
| case CR_BEST_AVAIL_LEN: |
| if ((free / fragments) >= ac->ac_g_ex.fe_len) |
| return true; |
| break; |
| case CR_GOAL_LEN_SLOW: |
| if (free >= ac->ac_g_ex.fe_len) |
| return true; |
| break; |
| case CR_ANY_FREE: |
| return true; |
| default: |
| BUG(); |
| } |
| |
| return false; |
| } |
| |
| /* |
| * This could return negative error code if something goes wrong |
| * during ext4_mb_init_group(). This should not be called with |
| * ext4_lock_group() held. |
| * |
| * Note: because we are conditionally operating with the group lock in |
| * the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this |
| * function using __acquire and __release. This means we need to be |
| * super careful before messing with the error path handling via "goto |
| * out"! |
| */ |
| static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, |
| ext4_group_t group, enum criteria cr) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK; |
| ext4_grpblk_t free; |
| int ret = 0; |
| |
| if (!grp) |
| return -EFSCORRUPTED; |
| if (sbi->s_mb_stats) |
| atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]); |
| if (should_lock) { |
| ext4_lock_group(sb, group); |
| __release(ext4_group_lock_ptr(sb, group)); |
| } |
| free = grp->bb_free; |
| if (free == 0) |
| goto out; |
| /* |
| * In all criterias except CR_ANY_FREE we try to avoid groups that |
| * can't possibly satisfy the full goal request due to insufficient |
| * free blocks. |
| */ |
| if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len) |
| goto out; |
| if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) |
| goto out; |
| if (should_lock) { |
| __acquire(ext4_group_lock_ptr(sb, group)); |
| ext4_unlock_group(sb, group); |
| } |
| |
| /* We only do this if the grp has never been initialized */ |
| if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
| struct ext4_group_desc *gdp = |
| ext4_get_group_desc(sb, group, NULL); |
| int ret; |
| |
| /* |
| * CR_POWER2_ALIGNED/CR_GOAL_LEN_FAST is a very optimistic |
| * search to find large good chunks almost for free. If buddy |
| * data is not ready, then this optimization makes no sense. But |
| * we never skip the first block group in a flex_bg, since this |
| * gets used for metadata block allocation, and we want to make |
| * sure we locate metadata blocks in the first block group in |
| * the flex_bg if possible. |
| */ |
| if (!ext4_mb_cr_expensive(cr) && |
| (!sbi->s_log_groups_per_flex || |
| ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) && |
| !(ext4_has_group_desc_csum(sb) && |
| (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))) |
| return 0; |
| ret = ext4_mb_init_group(sb, group, GFP_NOFS); |
| if (ret) |
| return ret; |
| } |
| |
| if (should_lock) { |
| ext4_lock_group(sb, group); |
| __release(ext4_group_lock_ptr(sb, group)); |
| } |
| ret = ext4_mb_good_group(ac, group, cr); |
| out: |
| if (should_lock) { |
| __acquire(ext4_group_lock_ptr(sb, group)); |
| ext4_unlock_group(sb, group); |
| } |
| return ret; |
| } |
| |
| /* |
| * Start prefetching @nr block bitmaps starting at @group. |
| * Return the next group which needs to be prefetched. |
| */ |
| ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group, |
| unsigned int nr, int *cnt) |
| { |
| ext4_group_t ngroups = ext4_get_groups_count(sb); |
| struct buffer_head *bh; |
| struct blk_plug plug; |
| |
| blk_start_plug(&plug); |
| while (nr-- > 0) { |
| struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, |
| NULL); |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| |
| /* |
| * Prefetch block groups with free blocks; but don't |
| * bother if it is marked uninitialized on disk, since |
| * it won't require I/O to read. Also only try to |
| * prefetch once, so we avoid getblk() call, which can |
| * be expensive. |
| */ |
| if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) && |
| EXT4_MB_GRP_NEED_INIT(grp) && |
| ext4_free_group_clusters(sb, gdp) > 0 ) { |
| bh = ext4_read_block_bitmap_nowait(sb, group, true); |
| if (bh && !IS_ERR(bh)) { |
| if (!buffer_uptodate(bh) && cnt) |
| (*cnt)++; |
| brelse(bh); |
| } |
| } |
| if (++group >= ngroups) |
| group = 0; |
| } |
| blk_finish_plug(&plug); |
| return group; |
| } |
| |
| /* |
| * Prefetching reads the block bitmap into the buffer cache; but we |
| * need to make sure that the buddy bitmap in the page cache has been |
| * initialized. Note that ext4_mb_init_group() will block if the I/O |
| * is not yet completed, or indeed if it was not initiated by |
| * ext4_mb_prefetch did not start the I/O. |
| * |
| * TODO: We should actually kick off the buddy bitmap setup in a work |
| * queue when the buffer I/O is completed, so that we don't block |
| * waiting for the block allocation bitmap read to finish when |
| * ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator(). |
| */ |
| void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group, |
| unsigned int nr) |
| { |
| struct ext4_group_desc *gdp; |
| struct ext4_group_info *grp; |
| |
| while (nr-- > 0) { |
| if (!group) |
| group = ext4_get_groups_count(sb); |
| group--; |
| gdp = ext4_get_group_desc(sb, group, NULL); |
| grp = ext4_get_group_info(sb, group); |
| |
| if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) && |
| ext4_free_group_clusters(sb, gdp) > 0) { |
| if (ext4_mb_init_group(sb, group, GFP_NOFS)) |
| break; |
| } |
| } |
| } |
| |
| static noinline_for_stack int |
| ext4_mb_regular_allocator(struct ext4_allocation_context *ac) |
| { |
| ext4_group_t prefetch_grp = 0, ngroups, group, i; |
| enum criteria new_cr, cr = CR_GOAL_LEN_FAST; |
| int err = 0, first_err = 0; |
| unsigned int nr = 0, prefetch_ios = 0; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| struct ext4_buddy e4b; |
| int lost; |
| |
| sb = ac->ac_sb; |
| sbi = EXT4_SB(sb); |
| ngroups = ext4_get_groups_count(sb); |
| /* non-extent files are limited to low blocks/groups */ |
| if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))) |
| ngroups = sbi->s_blockfile_groups; |
| |
| BUG_ON(ac->ac_status == AC_STATUS_FOUND); |
| |
| /* first, try the goal */ |
| err = ext4_mb_find_by_goal(ac, &e4b); |
| if (err || ac->ac_status == AC_STATUS_FOUND) |
| goto out; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| goto out; |
| |
| /* |
| * ac->ac_2order is set only if the fe_len is a power of 2 |
| * if ac->ac_2order is set we also set criteria to CR_POWER2_ALIGNED |
| * so that we try exact allocation using buddy. |
| */ |
| i = fls(ac->ac_g_ex.fe_len); |
| ac->ac_2order = 0; |
| /* |
| * We search using buddy data only if the order of the request |
| * is greater than equal to the sbi_s_mb_order2_reqs |
| * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req |
| * We also support searching for power-of-two requests only for |
| * requests upto maximum buddy size we have constructed. |
| */ |
| if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) { |
| if (is_power_of_2(ac->ac_g_ex.fe_len)) |
| ac->ac_2order = array_index_nospec(i - 1, |
| MB_NUM_ORDERS(sb)); |
| } |
| |
| /* if stream allocation is enabled, use global goal */ |
| if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { |
| /* TBD: may be hot point */ |
| spin_lock(&sbi->s_md_lock); |
| ac->ac_g_ex.fe_group = sbi->s_mb_last_group; |
| ac->ac_g_ex.fe_start = sbi->s_mb_last_start; |
| spin_unlock(&sbi->s_md_lock); |
| } |
| |
| /* |
| * Let's just scan groups to find more-less suitable blocks We |
| * start with CR_GOAL_LEN_FAST, unless it is power of 2 |
| * aligned, in which case let's do that faster approach first. |
| */ |
| if (ac->ac_2order) |
| cr = CR_POWER2_ALIGNED; |
| repeat: |
| for (; cr < EXT4_MB_NUM_CRS && ac->ac_status == AC_STATUS_CONTINUE; cr++) { |
| ac->ac_criteria = cr; |
| /* |
| * searching for the right group start |
| * from the goal value specified |
| */ |
| group = ac->ac_g_ex.fe_group; |
| ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups; |
| prefetch_grp = group; |
| nr = 0; |
| |
| for (i = 0, new_cr = cr; i < ngroups; i++, |
| ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups)) { |
| int ret = 0; |
| |
| cond_resched(); |
| if (new_cr != cr) { |
| cr = new_cr; |
| goto repeat; |
| } |
| |
| /* |
| * Batch reads of the block allocation bitmaps |
| * to get multiple READs in flight; limit |
| * prefetching at inexpensive CR, otherwise mballoc |
| * can spend a lot of time loading imperfect groups |
| */ |
| if ((prefetch_grp == group) && |
| (ext4_mb_cr_expensive(cr) || |
| prefetch_ios < sbi->s_mb_prefetch_limit)) { |
| nr = sbi->s_mb_prefetch; |
| if (ext4_has_feature_flex_bg(sb)) { |
| nr = 1 << sbi->s_log_groups_per_flex; |
| nr -= group & (nr - 1); |
| nr = min(nr, sbi->s_mb_prefetch); |
| } |
| prefetch_grp = ext4_mb_prefetch(sb, group, |
| nr, &prefetch_ios); |
| } |
| |
| /* This now checks without needing the buddy page */ |
| ret = ext4_mb_good_group_nolock(ac, group, cr); |
| if (ret <= 0) { |
| if (!first_err) |
| first_err = ret; |
| continue; |
| } |
| |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) |
| goto out; |
| |
| ext4_lock_group(sb, group); |
| |
| /* |
| * We need to check again after locking the |
| * block group |
| */ |
| ret = ext4_mb_good_group(ac, group, cr); |
| if (ret == 0) { |
| ext4_unlock_group(sb, group); |
| ext4_mb_unload_buddy(&e4b); |
| continue; |
| } |
| |
| ac->ac_groups_scanned++; |
| if (cr == CR_POWER2_ALIGNED) |
| ext4_mb_simple_scan_group(ac, &e4b); |
| else { |
| bool is_stripe_aligned = |
| (sbi->s_stripe >= |
| sbi->s_cluster_ratio) && |
| !(ac->ac_g_ex.fe_len % |
| EXT4_NUM_B2C(sbi, sbi->s_stripe)); |
| |
| if ((cr == CR_GOAL_LEN_FAST || |
| cr == CR_BEST_AVAIL_LEN) && |
| is_stripe_aligned) |
| ext4_mb_scan_aligned(ac, &e4b); |
| |
| if (ac->ac_status == AC_STATUS_CONTINUE) |
| ext4_mb_complex_scan_group(ac, &e4b); |
| } |
| |
| ext4_unlock_group(sb, group); |
| ext4_mb_unload_buddy(&e4b); |
| |
| if (ac->ac_status != AC_STATUS_CONTINUE) |
| break; |
| } |
| /* Processed all groups and haven't found blocks */ |
| if (sbi->s_mb_stats && i == ngroups) |
| atomic64_inc(&sbi->s_bal_cX_failed[cr]); |
| |
| if (i == ngroups && ac->ac_criteria == CR_BEST_AVAIL_LEN) |
| /* Reset goal length to original goal length before |
| * falling into CR_GOAL_LEN_SLOW */ |
| ac->ac_g_ex.fe_len = ac->ac_orig_goal_len; |
| } |
| |
| if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && |
| !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { |
| /* |
| * We've been searching too long. Let's try to allocate |
| * the best chunk we've found so far |
| */ |
| ext4_mb_try_best_found(ac, &e4b); |
| if (ac->ac_status != AC_STATUS_FOUND) { |
| /* |
| * Someone more lucky has already allocated it. |
| * The only thing we can do is just take first |
| * found block(s) |
| */ |
| lost = atomic_inc_return(&sbi->s_mb_lost_chunks); |
| mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n", |
| ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start, |
| ac->ac_b_ex.fe_len, lost); |
| |
| ac->ac_b_ex.fe_group = 0; |
| ac->ac_b_ex.fe_start = 0; |
| ac->ac_b_ex.fe_len = 0; |
| ac->ac_status = AC_STATUS_CONTINUE; |
| ac->ac_flags |= EXT4_MB_HINT_FIRST; |
| cr = CR_ANY_FREE; |
| goto repeat; |
| } |
| } |
| |
| if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND) |
| atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]); |
| out: |
| if (!err && ac->ac_status != AC_STATUS_FOUND && first_err) |
| err = first_err; |
| |
| mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n", |
| ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status, |
| ac->ac_flags, cr, err); |
| |
| if (nr) |
| ext4_mb_prefetch_fini(sb, prefetch_grp, nr); |
| |
| return err; |
| } |
| |
| static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| ext4_group_t group; |
| |
| if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) |
| return NULL; |
| group = *pos + 1; |
| return (void *) ((unsigned long) group); |
| } |
| |
| static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| ext4_group_t group; |
| |
| ++*pos; |
| if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) |
| return NULL; |
| group = *pos + 1; |
| return (void *) ((unsigned long) group); |
| } |
| |
| static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| ext4_group_t group = (ext4_group_t) ((unsigned long) v); |
| int i, err; |
| char nbuf[16]; |
| struct ext4_buddy e4b; |
| struct ext4_group_info *grinfo; |
| unsigned char blocksize_bits = min_t(unsigned char, |
| sb->s_blocksize_bits, |
| EXT4_MAX_BLOCK_LOG_SIZE); |
| struct sg { |
| struct ext4_group_info info; |
| ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2]; |
| } sg; |
| |
| group--; |
| if (group == 0) |
| seq_puts(seq, "#group: free frags first [" |
| " 2^0 2^1 2^2 2^3 2^4 2^5 2^6 " |
| " 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n"); |
| |
| i = (blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + |
| sizeof(struct ext4_group_info); |
| |
| grinfo = ext4_get_group_info(sb, group); |
| if (!grinfo) |
| return 0; |
| /* Load the group info in memory only if not already loaded. */ |
| if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) { |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) { |
| seq_printf(seq, "#%-5u: %s\n", group, ext4_decode_error(NULL, err, nbuf)); |
| return 0; |
| } |
| ext4_mb_unload_buddy(&e4b); |
| } |
| |
| /* |
| * We care only about free space counters in the group info and |
| * these are safe to access even after the buddy has been unloaded |
| */ |
| memcpy(&sg, grinfo, i); |
| seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free, |
| sg.info.bb_fragments, sg.info.bb_first_free); |
| for (i = 0; i <= 13; i++) |
| seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ? |
| sg.info.bb_counters[i] : 0); |
| seq_puts(seq, " ]"); |
| if (EXT4_MB_GRP_BBITMAP_CORRUPT(&sg.info)) |
| seq_puts(seq, " Block bitmap corrupted!"); |
| seq_putc(seq, '\n'); |
| return 0; |
| } |
| |
| static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| const struct seq_operations ext4_mb_seq_groups_ops = { |
| .start = ext4_mb_seq_groups_start, |
| .next = ext4_mb_seq_groups_next, |
| .stop = ext4_mb_seq_groups_stop, |
| .show = ext4_mb_seq_groups_show, |
| }; |
| |
| int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset) |
| { |
| struct super_block *sb = seq->private; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| seq_puts(seq, "mballoc:\n"); |
| if (!sbi->s_mb_stats) { |
| seq_puts(seq, "\tmb stats collection turned off.\n"); |
| seq_puts( |
| seq, |
| "\tTo enable, please write \"1\" to sysfs file mb_stats.\n"); |
| return 0; |
| } |
| seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs)); |
| seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success)); |
| |
| seq_printf(seq, "\tgroups_scanned: %u\n", |
| atomic_read(&sbi->s_bal_groups_scanned)); |
| |
| /* CR_POWER2_ALIGNED stats */ |
| seq_puts(seq, "\tcr_p2_aligned_stats:\n"); |
| seq_printf(seq, "\t\thits: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_hits[CR_POWER2_ALIGNED])); |
| seq_printf( |
| seq, "\t\tgroups_considered: %llu\n", |
| atomic64_read( |
| &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED])); |
| seq_printf(seq, "\t\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_cX_ex_scanned[CR_POWER2_ALIGNED])); |
| seq_printf(seq, "\t\tuseless_loops: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_failed[CR_POWER2_ALIGNED])); |
| seq_printf(seq, "\t\tbad_suggestions: %u\n", |
| atomic_read(&sbi->s_bal_p2_aligned_bad_suggestions)); |
| |
| /* CR_GOAL_LEN_FAST stats */ |
| seq_puts(seq, "\tcr_goal_fast_stats:\n"); |
| seq_printf(seq, "\t\thits: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_FAST])); |
| seq_printf(seq, "\t\tgroups_considered: %llu\n", |
| atomic64_read( |
| &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_FAST])); |
| seq_printf(seq, "\t\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_FAST])); |
| seq_printf(seq, "\t\tuseless_loops: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_FAST])); |
| seq_printf(seq, "\t\tbad_suggestions: %u\n", |
| atomic_read(&sbi->s_bal_goal_fast_bad_suggestions)); |
| |
| /* CR_BEST_AVAIL_LEN stats */ |
| seq_puts(seq, "\tcr_best_avail_stats:\n"); |
| seq_printf(seq, "\t\thits: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_hits[CR_BEST_AVAIL_LEN])); |
| seq_printf( |
| seq, "\t\tgroups_considered: %llu\n", |
| atomic64_read( |
| &sbi->s_bal_cX_groups_considered[CR_BEST_AVAIL_LEN])); |
| seq_printf(seq, "\t\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_cX_ex_scanned[CR_BEST_AVAIL_LEN])); |
| seq_printf(seq, "\t\tuseless_loops: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_failed[CR_BEST_AVAIL_LEN])); |
| seq_printf(seq, "\t\tbad_suggestions: %u\n", |
| atomic_read(&sbi->s_bal_best_avail_bad_suggestions)); |
| |
| /* CR_GOAL_LEN_SLOW stats */ |
| seq_puts(seq, "\tcr_goal_slow_stats:\n"); |
| seq_printf(seq, "\t\thits: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_hits[CR_GOAL_LEN_SLOW])); |
| seq_printf(seq, "\t\tgroups_considered: %llu\n", |
| atomic64_read( |
| &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_SLOW])); |
| seq_printf(seq, "\t\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_SLOW])); |
| seq_printf(seq, "\t\tuseless_loops: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_failed[CR_GOAL_LEN_SLOW])); |
| |
| /* CR_ANY_FREE stats */ |
| seq_puts(seq, "\tcr_any_free_stats:\n"); |
| seq_printf(seq, "\t\thits: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_hits[CR_ANY_FREE])); |
| seq_printf( |
| seq, "\t\tgroups_considered: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_groups_considered[CR_ANY_FREE])); |
| seq_printf(seq, "\t\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_cX_ex_scanned[CR_ANY_FREE])); |
| seq_printf(seq, "\t\tuseless_loops: %llu\n", |
| atomic64_read(&sbi->s_bal_cX_failed[CR_ANY_FREE])); |
| |
| /* Aggregates */ |
| seq_printf(seq, "\textents_scanned: %u\n", |
| atomic_read(&sbi->s_bal_ex_scanned)); |
| seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals)); |
| seq_printf(seq, "\t\tlen_goal_hits: %u\n", |
| atomic_read(&sbi->s_bal_len_goals)); |
| seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders)); |
| seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks)); |
| seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks)); |
| seq_printf(seq, "\tbuddies_generated: %u/%u\n", |
| atomic_read(&sbi->s_mb_buddies_generated), |
| ext4_get_groups_count(sb)); |
| seq_printf(seq, "\tbuddies_time_used: %llu\n", |
| atomic64_read(&sbi->s_mb_generation_time)); |
| seq_printf(seq, "\tpreallocated: %u\n", |
| atomic_read(&sbi->s_mb_preallocated)); |
| seq_printf(seq, "\tdiscarded: %u\n", atomic_read(&sbi->s_mb_discarded)); |
| return 0; |
| } |
| |
| static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| unsigned long position; |
| |
| if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb)) |
| return NULL; |
| position = *pos + 1; |
| return (void *) ((unsigned long) position); |
| } |
| |
| static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| unsigned long position; |
| |
| ++*pos; |
| if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb)) |
| return NULL; |
| position = *pos + 1; |
| return (void *) ((unsigned long) position); |
| } |
| |
| static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v) |
| { |
| struct super_block *sb = pde_data(file_inode(seq->file)); |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned long position = ((unsigned long) v); |
| struct ext4_group_info *grp; |
| unsigned int count; |
| |
| position--; |
| if (position >= MB_NUM_ORDERS(sb)) { |
| position -= MB_NUM_ORDERS(sb); |
| if (position == 0) |
| seq_puts(seq, "avg_fragment_size_lists:\n"); |
| |
| count = 0; |
| read_lock(&sbi->s_mb_avg_fragment_size_locks[position]); |
| list_for_each_entry(grp, &sbi->s_mb_avg_fragment_size[position], |
| bb_avg_fragment_size_node) |
| count++; |
| read_unlock(&sbi->s_mb_avg_fragment_size_locks[position]); |
| seq_printf(seq, "\tlist_order_%u_groups: %u\n", |
| (unsigned int)position, count); |
| return 0; |
| } |
| |
| if (position == 0) { |
| seq_printf(seq, "optimize_scan: %d\n", |
| test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0); |
| seq_puts(seq, "max_free_order_lists:\n"); |
| } |
| count = 0; |
| read_lock(&sbi->s_mb_largest_free_orders_locks[position]); |
| list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position], |
| bb_largest_free_order_node) |
| count++; |
| read_unlock(&sbi->s_mb_largest_free_orders_locks[position]); |
| seq_printf(seq, "\tlist_order_%u_groups: %u\n", |
| (unsigned int)position, count); |
| |
| return 0; |
| } |
| |
| static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v) |
| { |
| } |
| |
| const struct seq_operations ext4_mb_seq_structs_summary_ops = { |
| .start = ext4_mb_seq_structs_summary_start, |
| .next = ext4_mb_seq_structs_summary_next, |
| .stop = ext4_mb_seq_structs_summary_stop, |
| .show = ext4_mb_seq_structs_summary_show, |
| }; |
| |
| static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) |
| { |
| int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; |
| struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index]; |
| |
| BUG_ON(!cachep); |
| return cachep; |
| } |
| |
| /* |
| * Allocate the top-level s_group_info array for the specified number |
| * of groups |
| */ |
| int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned size; |
| struct ext4_group_info ***old_groupinfo, ***new_groupinfo; |
| |
| size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| EXT4_DESC_PER_BLOCK_BITS(sb); |
| if (size <= sbi->s_group_info_size) |
| return 0; |
| |
| size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size); |
| new_groupinfo = kvzalloc(size, GFP_KERNEL); |
| if (!new_groupinfo) { |
| ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group"); |
| return -ENOMEM; |
| } |
| rcu_read_lock(); |
| old_groupinfo = rcu_dereference(sbi->s_group_info); |
| if (old_groupinfo) |
| memcpy(new_groupinfo, old_groupinfo, |
| sbi->s_group_info_size * sizeof(*sbi->s_group_info)); |
| rcu_read_unlock(); |
| rcu_assign_pointer(sbi->s_group_info, new_groupinfo); |
| sbi->s_group_info_size = size / sizeof(*sbi->s_group_info); |
| if (old_groupinfo) |
| ext4_kvfree_array_rcu(old_groupinfo); |
| ext4_debug("allocated s_groupinfo array for %d meta_bg's\n", |
| sbi->s_group_info_size); |
| return 0; |
| } |
| |
| /* Create and initialize ext4_group_info data for the given group. */ |
| int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, |
| struct ext4_group_desc *desc) |
| { |
| int i; |
| int metalen = 0; |
| int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb); |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_group_info **meta_group_info; |
| struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
| |
| /* |
| * First check if this group is the first of a reserved block. |
| * If it's true, we have to allocate a new table of pointers |
| * to ext4_group_info structures |
| */ |
| if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { |
| metalen = sizeof(*meta_group_info) << |
| EXT4_DESC_PER_BLOCK_BITS(sb); |
| meta_group_info = kmalloc(metalen, GFP_NOFS); |
| if (meta_group_info == NULL) { |
| ext4_msg(sb, KERN_ERR, "can't allocate mem " |
| "for a buddy group"); |
| return -ENOMEM; |
| } |
| rcu_read_lock(); |
| rcu_dereference(sbi->s_group_info)[idx] = meta_group_info; |
| rcu_read_unlock(); |
| } |
| |
| meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx); |
| i = group & (EXT4_DESC_PER_BLOCK(sb) - 1); |
| |
| meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS); |
| if (meta_group_info[i] == NULL) { |
| ext4_msg(sb, KERN_ERR, "can't allocate buddy mem"); |
| goto exit_group_info; |
| } |
| set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, |
| &(meta_group_info[i]->bb_state)); |
| |
| /* |
| * initialize bb_free to be able to skip |
| * empty groups without initialization |
| */ |
| if (ext4_has_group_desc_csum(sb) && |
| (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { |
| meta_group_info[i]->bb_free = |
| ext4_free_clusters_after_init(sb, group, desc); |
| } else { |
| meta_group_info[i]->bb_free = |
| ext4_free_group_clusters(sb, desc); |
| } |
| |
| INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); |
| init_rwsem(&meta_group_info[i]->alloc_sem); |
| meta_group_info[i]->bb_free_root = RB_ROOT; |
| INIT_LIST_HEAD(&meta_group_info[i]->bb_largest_free_order_node); |
| INIT_LIST_HEAD(&meta_group_info[i]->bb_avg_fragment_size_node); |
| meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ |
| meta_group_info[i]->bb_avg_fragment_size_order = -1; /* uninit */ |
| meta_group_info[i]->bb_group = group; |
| |
| mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group); |
| return 0; |
| |
| exit_group_info: |
| /* If a meta_group_info table has been allocated, release it now */ |
| if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { |
| struct ext4_group_info ***group_info; |
| |
| rcu_read_lock(); |
| group_info = rcu_dereference(sbi->s_group_info); |
| kfree(group_info[idx]); |
| group_info[idx] = NULL; |
| rcu_read_unlock(); |
| } |
| return -ENOMEM; |
| } /* ext4_mb_add_groupinfo */ |
| |
| static int ext4_mb_init_backend(struct super_block *sb) |
| { |
| ext4_group_t ngroups = ext4_get_groups_count(sb); |
| ext4_group_t i; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| int err; |
| struct ext4_group_desc *desc; |
| struct ext4_group_info ***group_info; |
| struct kmem_cache *cachep; |
| |
| err = ext4_mb_alloc_groupinfo(sb, ngroups); |
| if (err) |
| return err; |
| |
| sbi->s_buddy_cache = new_inode(sb); |
| if (sbi->s_buddy_cache == NULL) { |
| ext4_msg(sb, KERN_ERR, "can't get new inode"); |
| goto err_freesgi; |
| } |
| /* To avoid potentially colliding with an valid on-disk inode number, |
| * use EXT4_BAD_INO for the buddy cache inode number. This inode is |
| * not in the inode hash, so it should never be found by iget(), but |
| * this will avoid confusion if it ever shows up during debugging. */ |
| sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; |
| EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; |
| for (i = 0; i < ngroups; i++) { |
| cond_resched(); |
| desc = ext4_get_group_desc(sb, i, NULL); |
| if (desc == NULL) { |
| ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); |
| goto err_freebuddy; |
| } |
| if (ext4_mb_add_groupinfo(sb, i, desc) != 0) |
| goto err_freebuddy; |
| } |
| |
| if (ext4_has_feature_flex_bg(sb)) { |
| /* a single flex group is supposed to be read by a single IO. |
| * 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is |
| * unsigned integer, so the maximum shift is 32. |
| */ |
| if (sbi->s_es->s_log_groups_per_flex >= 32) { |
| ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group"); |
| goto err_freebuddy; |
| } |
| sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex, |
| BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9)); |
| sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */ |
| } else { |
| sbi->s_mb_prefetch = 32; |
| } |
| if (sbi->s_mb_prefetch > ext4_get_groups_count(sb)) |
| sbi->s_mb_prefetch = ext4_get_groups_count(sb); |
| /* |
| * now many real IOs to prefetch within a single allocation at |
| * CR_POWER2_ALIGNED. Given CR_POWER2_ALIGNED is an CPU-related |
| * optimization we shouldn't try to load too many groups, at some point |
| * we should start to use what we've got in memory. |
| * with an average random access time 5ms, it'd take a second to get |
| * 200 groups (* N with flex_bg), so let's make this limit 4 |
| */ |
| sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4; |
| if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb)) |
| sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb); |
| |
| return 0; |
| |
| err_freebuddy: |
| cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
| while (i-- > 0) { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, i); |
| |
| if (grp) |
| kmem_cache_free(cachep, grp); |
| } |
| i = sbi->s_group_info_size; |
| rcu_read_lock(); |
| group_info = rcu_dereference(sbi->s_group_info); |
| while (i-- > 0) |
| kfree(group_info[i]); |
| rcu_read_unlock(); |
| iput(sbi->s_buddy_cache); |
| err_freesgi: |
| rcu_read_lock(); |
| kvfree(rcu_dereference(sbi->s_group_info)); |
| rcu_read_unlock(); |
| return -ENOMEM; |
| } |
| |
| static void ext4_groupinfo_destroy_slabs(void) |
| { |
| int i; |
| |
| for (i = 0; i < NR_GRPINFO_CACHES; i++) { |
| kmem_cache_destroy(ext4_groupinfo_caches[i]); |
| ext4_groupinfo_caches[i] = NULL; |
| } |
| } |
| |
| static int ext4_groupinfo_create_slab(size_t size) |
| { |
| static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex); |
| int slab_size; |
| int blocksize_bits = order_base_2(size); |
| int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; |
| struct kmem_cache *cachep; |
| |
| if (cache_index >= NR_GRPINFO_CACHES) |
| return -EINVAL; |
| |
| if (unlikely(cache_index < 0)) |
| cache_index = 0; |
| |
| mutex_lock(&ext4_grpinfo_slab_create_mutex); |
| if (ext4_groupinfo_caches[cache_index]) { |
| mutex_unlock(&ext4_grpinfo_slab_create_mutex); |
| return 0; /* Already created */ |
| } |
| |
| slab_size = offsetof(struct ext4_group_info, |
| bb_counters[blocksize_bits + 2]); |
| |
| cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index], |
| slab_size, 0, SLAB_RECLAIM_ACCOUNT, |
| NULL); |
| |
| ext4_groupinfo_caches[cache_index] = cachep; |
| |
| mutex_unlock(&ext4_grpinfo_slab_create_mutex); |
| if (!cachep) { |
| printk(KERN_EMERG |
| "EXT4-fs: no memory for groupinfo slab cache\n"); |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| static void ext4_discard_work(struct work_struct *work) |
| { |
| struct ext4_sb_info *sbi = container_of(work, |
| struct ext4_sb_info, s_discard_work); |
| struct super_block *sb = sbi->s_sb; |
| struct ext4_free_data *fd, *nfd; |
| struct ext4_buddy e4b; |
| LIST_HEAD(discard_list); |
| ext4_group_t grp, load_grp; |
| int err = 0; |
| |
| spin_lock(&sbi->s_md_lock); |
| list_splice_init(&sbi->s_discard_list, &discard_list); |
| spin_unlock(&sbi->s_md_lock); |
| |
| load_grp = UINT_MAX; |
| list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) { |
| /* |
| * If filesystem is umounting or no memory or suffering |
| * from no space, give up the discard |
| */ |
| if ((sb->s_flags & SB_ACTIVE) && !err && |
| !atomic_read(&sbi->s_retry_alloc_pending)) { |
| grp = fd->efd_group; |
| if (grp != load_grp) { |
| if (load_grp != UINT_MAX) |
| ext4_mb_unload_buddy(&e4b); |
| |
| err = ext4_mb_load_buddy(sb, grp, &e4b); |
| if (err) { |
| kmem_cache_free(ext4_free_data_cachep, fd); |
| load_grp = UINT_MAX; |
| continue; |
| } else { |
| load_grp = grp; |
| } |
| } |
| |
| ext4_lock_group(sb, grp); |
| ext4_try_to_trim_range(sb, &e4b, fd->efd_start_cluster, |
| fd->efd_start_cluster + fd->efd_count - 1, 1); |
| ext4_unlock_group(sb, grp); |
| } |
| kmem_cache_free(ext4_free_data_cachep, fd); |
| } |
| |
| if (load_grp != UINT_MAX) |
| ext4_mb_unload_buddy(&e4b); |
| } |
| |
| int ext4_mb_init(struct super_block *sb) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned i, j; |
| unsigned offset, offset_incr; |
| unsigned max; |
| int ret; |
| |
| i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets); |
| |
| sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); |
| if (sbi->s_mb_offsets == NULL) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs); |
| sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); |
| if (sbi->s_mb_maxs == NULL) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = ext4_groupinfo_create_slab(sb->s_blocksize); |
| if (ret < 0) |
| goto out; |
| |
| /* order 0 is regular bitmap */ |
| sbi->s_mb_maxs[0] = sb->s_blocksize << 3; |
| sbi->s_mb_offsets[0] = 0; |
| |
| i = 1; |
| offset = 0; |
| offset_incr = 1 << (sb->s_blocksize_bits - 1); |
| max = sb->s_blocksize << 2; |
| do { |
| sbi->s_mb_offsets[i] = offset; |
| sbi->s_mb_maxs[i] = max; |
| offset += offset_incr; |
| offset_incr = offset_incr >> 1; |
| max = max >> 1; |
| i++; |
| } while (i < MB_NUM_ORDERS(sb)); |
| |
| sbi->s_mb_avg_fragment_size = |
| kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head), |
| GFP_KERNEL); |
| if (!sbi->s_mb_avg_fragment_size) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| sbi->s_mb_avg_fragment_size_locks = |
| kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t), |
| GFP_KERNEL); |
| if (!sbi->s_mb_avg_fragment_size_locks) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| for (i = 0; i < MB_NUM_ORDERS(sb); i++) { |
| INIT_LIST_HEAD(&sbi->s_mb_avg_fragment_size[i]); |
| rwlock_init(&sbi->s_mb_avg_fragment_size_locks[i]); |
| } |
| sbi->s_mb_largest_free_orders = |
| kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head), |
| GFP_KERNEL); |
| if (!sbi->s_mb_largest_free_orders) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| sbi->s_mb_largest_free_orders_locks = |
| kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t), |
| GFP_KERNEL); |
| if (!sbi->s_mb_largest_free_orders_locks) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| for (i = 0; i < MB_NUM_ORDERS(sb); i++) { |
| INIT_LIST_HEAD(&sbi->s_mb_largest_free_orders[i]); |
| rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]); |
| } |
| |
| spin_lock_init(&sbi->s_md_lock); |
| sbi->s_mb_free_pending = 0; |
| INIT_LIST_HEAD(&sbi->s_freed_data_list[0]); |
| INIT_LIST_HEAD(&sbi->s_freed_data_list[1]); |
| INIT_LIST_HEAD(&sbi->s_discard_list); |
| INIT_WORK(&sbi->s_discard_work, ext4_discard_work); |
| atomic_set(&sbi->s_retry_alloc_pending, 0); |
| |
| sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; |
| sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; |
| sbi->s_mb_stats = MB_DEFAULT_STATS; |
| sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; |
| sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; |
| sbi->s_mb_best_avail_max_trim_order = MB_DEFAULT_BEST_AVAIL_TRIM_ORDER; |
| |
| /* |
| * The default group preallocation is 512, which for 4k block |
| * sizes translates to 2 megabytes. However for bigalloc file |
| * systems, this is probably too big (i.e, if the cluster size |
| * is 1 megabyte, then group preallocation size becomes half a |
| * gigabyte!). As a default, we will keep a two megabyte |
| * group pralloc size for cluster sizes up to 64k, and after |
| * that, we will force a minimum group preallocation size of |
| * 32 clusters. This translates to 8 megs when the cluster |
| * size is 256k, and 32 megs when the cluster size is 1 meg, |
| * which seems reasonable as a default. |
| */ |
| sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >> |
| sbi->s_cluster_bits, 32); |
| /* |
| * If there is a s_stripe > 1, then we set the s_mb_group_prealloc |
| * to the lowest multiple of s_stripe which is bigger than |
| * the s_mb_group_prealloc as determined above. We want |
| * the preallocation size to be an exact multiple of the |
| * RAID stripe size so that preallocations don't fragment |
| * the stripes. |
| */ |
| if (sbi->s_stripe > 1) { |
| sbi->s_mb_group_prealloc = roundup( |
| sbi->s_mb_group_prealloc, EXT4_NUM_B2C(sbi, sbi->s_stripe)); |
| } |
| |
| sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); |
| if (sbi->s_locality_groups == NULL) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| for_each_possible_cpu(i) { |
| struct ext4_locality_group *lg; |
| lg = per_cpu_ptr(sbi->s_locality_groups, i); |
| mutex_init(&lg->lg_mutex); |
| for (j = 0; j < PREALLOC_TB_SIZE; j++) |
| INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); |
| spin_lock_init(&lg->lg_prealloc_lock); |
| } |
| |
| if (bdev_nonrot(sb->s_bdev)) |
| sbi->s_mb_max_linear_groups = 0; |
| else |
| sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT; |
| /* init file for buddy data */ |
| ret = ext4_mb_init_backend(sb); |
| if (ret != 0) |
| goto out_free_locality_groups; |
| |
| return 0; |
| |
| out_free_locality_groups: |
| free_percpu(sbi->s_locality_groups); |
| sbi->s_locality_groups = NULL; |
| out: |
| kfree(sbi->s_mb_avg_fragment_size); |
| kfree(sbi->s_mb_avg_fragment_size_locks); |
| kfree(sbi->s_mb_largest_free_orders); |
| kfree(sbi->s_mb_largest_free_orders_locks); |
| kfree(sbi->s_mb_offsets); |
| sbi->s_mb_offsets = NULL; |
| kfree(sbi->s_mb_maxs); |
| sbi->s_mb_maxs = NULL; |
| return ret; |
| } |
| |
| /* need to called with the ext4 group lock held */ |
| static int ext4_mb_cleanup_pa(struct ext4_group_info *grp) |
| { |
| struct ext4_prealloc_space *pa; |
| struct list_head *cur, *tmp; |
| int count = 0; |
| |
| list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| list_del(&pa->pa_group_list); |
| count++; |
| kmem_cache_free(ext4_pspace_cachep, pa); |
| } |
| return count; |
| } |
| |
| void ext4_mb_release(struct super_block *sb) |
| { |
| ext4_group_t ngroups = ext4_get_groups_count(sb); |
| ext4_group_t i; |
| int num_meta_group_infos; |
| struct ext4_group_info *grinfo, ***group_info; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); |
| int count; |
| |
| if (test_opt(sb, DISCARD)) { |
| /* |
| * wait the discard work to drain all of ext4_free_data |
| */ |
| flush_work(&sbi->s_discard_work); |
| WARN_ON_ONCE(!list_empty(&sbi->s_discard_list)); |
| } |
| |
| if (sbi->s_group_info) { |
| for (i = 0; i < ngroups; i++) { |
| cond_resched(); |
| grinfo = ext4_get_group_info(sb, i); |
| if (!grinfo) |
| continue; |
| mb_group_bb_bitmap_free(grinfo); |
| ext4_lock_group(sb, i); |
| count = ext4_mb_cleanup_pa(grinfo); |
| if (count) |
| mb_debug(sb, "mballoc: %d PAs left\n", |
| count); |
| ext4_unlock_group(sb, i); |
| kmem_cache_free(cachep, grinfo); |
| } |
| num_meta_group_infos = (ngroups + |
| EXT4_DESC_PER_BLOCK(sb) - 1) >> |
| EXT4_DESC_PER_BLOCK_BITS(sb); |
| rcu_read_lock(); |
| group_info = rcu_dereference(sbi->s_group_info); |
| for (i = 0; i < num_meta_group_infos; i++) |
| kfree(group_info[i]); |
| kvfree(group_info); |
| rcu_read_unlock(); |
| } |
| kfree(sbi->s_mb_avg_fragment_size); |
| kfree(sbi->s_mb_avg_fragment_size_locks); |
| kfree(sbi->s_mb_largest_free_orders); |
| kfree(sbi->s_mb_largest_free_orders_locks); |
| kfree(sbi->s_mb_offsets); |
| kfree(sbi->s_mb_maxs); |
| iput(sbi->s_buddy_cache); |
| if (sbi->s_mb_stats) { |
| ext4_msg(sb, KERN_INFO, |
| "mballoc: %u blocks %u reqs (%u success)", |
| atomic_read(&sbi->s_bal_allocated), |
| atomic_read(&sbi->s_bal_reqs), |
| atomic_read(&sbi->s_bal_success)); |
| ext4_msg(sb, KERN_INFO, |
| "mballoc: %u extents scanned, %u groups scanned, %u goal hits, " |
| "%u 2^N hits, %u breaks, %u lost", |
| atomic_read(&sbi->s_bal_ex_scanned), |
| atomic_read(&sbi->s_bal_groups_scanned), |
| atomic_read(&sbi->s_bal_goals), |
| atomic_read(&sbi->s_bal_2orders), |
| atomic_read(&sbi->s_bal_breaks), |
| atomic_read(&sbi->s_mb_lost_chunks)); |
| ext4_msg(sb, KERN_INFO, |
| "mballoc: %u generated and it took %llu", |
| atomic_read(&sbi->s_mb_buddies_generated), |
| atomic64_read(&sbi->s_mb_generation_time)); |
| ext4_msg(sb, KERN_INFO, |
| "mballoc: %u preallocated, %u discarded", |
| atomic_read(&sbi->s_mb_preallocated), |
| atomic_read(&sbi->s_mb_discarded)); |
| } |
| |
| free_percpu(sbi->s_locality_groups); |
| } |
| |
| static inline int ext4_issue_discard(struct super_block *sb, |
| ext4_group_t block_group, ext4_grpblk_t cluster, int count) |
| { |
| ext4_fsblk_t discard_block; |
| |
| discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) + |
| ext4_group_first_block_no(sb, block_group)); |
| count = EXT4_C2B(EXT4_SB(sb), count); |
| trace_ext4_discard_blocks(sb, |
| (unsigned long long) discard_block, count); |
| |
| return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0); |
| } |
| |
| static void ext4_free_data_in_buddy(struct super_block *sb, |
| struct ext4_free_data *entry) |
| { |
| struct ext4_buddy e4b; |
| struct ext4_group_info *db; |
| int err, count = 0; |
| |
| mb_debug(sb, "gonna free %u blocks in group %u (0x%p):", |
| entry->efd_count, entry->efd_group, entry); |
| |
| err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b); |
| /* we expect to find existing buddy because it's pinned */ |
| BUG_ON(err != 0); |
| |
| spin_lock(&EXT4_SB(sb)->s_md_lock); |
| EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count; |
| spin_unlock(&EXT4_SB(sb)->s_md_lock); |
| |
| db = e4b.bd_info; |
| /* there are blocks to put in buddy to make them really free */ |
| count += entry->efd_count; |
| ext4_lock_group(sb, entry->efd_group); |
| /* Take it out of per group rb tree */ |
| rb_erase(&entry->efd_node, &(db->bb_free_root)); |
| mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count); |
| |
| /* |
| * Clear the trimmed flag for the group so that the next |
| * ext4_trim_fs can trim it. |
| */ |
| EXT4_MB_GRP_CLEAR_TRIMMED(db); |
| |
| if (!db->bb_free_root.rb_node) { |
| /* No more items in the per group rb tree |
| * balance refcounts from ext4_mb_free_metadata() |
| */ |
| folio_put(e4b.bd_buddy_folio); |
| folio_put(e4b.bd_bitmap_folio); |
| } |
| ext4_unlock_group(sb, entry->efd_group); |
| ext4_mb_unload_buddy(&e4b); |
| |
| mb_debug(sb, "freed %d blocks in 1 structures\n", count); |
| } |
| |
| /* |
| * This function is called by the jbd2 layer once the commit has finished, |
| * so we know we can free the blocks that were released with that commit. |
| */ |
| void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_free_data *entry, *tmp; |
| LIST_HEAD(freed_data_list); |
| struct list_head *s_freed_head = &sbi->s_freed_data_list[commit_tid & 1]; |
| bool wake; |
| |
| list_replace_init(s_freed_head, &freed_data_list); |
| |
| list_for_each_entry(entry, &freed_data_list, efd_list) |
| ext4_free_data_in_buddy(sb, entry); |
| |
| if (test_opt(sb, DISCARD)) { |
| spin_lock(&sbi->s_md_lock); |
| wake = list_empty(&sbi->s_discard_list); |
| list_splice_tail(&freed_data_list, &sbi->s_discard_list); |
| spin_unlock(&sbi->s_md_lock); |
| if (wake) |
| queue_work(system_unbound_wq, &sbi->s_discard_work); |
| } else { |
| list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list) |
| kmem_cache_free(ext4_free_data_cachep, entry); |
| } |
| } |
| |
| int __init ext4_init_mballoc(void) |
| { |
| ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space, |
| SLAB_RECLAIM_ACCOUNT); |
| if (ext4_pspace_cachep == NULL) |
| goto out; |
| |
| ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context, |
| SLAB_RECLAIM_ACCOUNT); |
| if (ext4_ac_cachep == NULL) |
| goto out_pa_free; |
| |
| ext4_free_data_cachep = KMEM_CACHE(ext4_free_data, |
| SLAB_RECLAIM_ACCOUNT); |
| if (ext4_free_data_cachep == NULL) |
| goto out_ac_free; |
| |
| return 0; |
| |
| out_ac_free: |
| kmem_cache_destroy(ext4_ac_cachep); |
| out_pa_free: |
| kmem_cache_destroy(ext4_pspace_cachep); |
| out: |
| return -ENOMEM; |
| } |
| |
| void ext4_exit_mballoc(void) |
| { |
| /* |
| * Wait for completion of call_rcu()'s on ext4_pspace_cachep |
| * before destroying the slab cache. |
| */ |
| rcu_barrier(); |
| kmem_cache_destroy(ext4_pspace_cachep); |
| kmem_cache_destroy(ext4_ac_cachep); |
| kmem_cache_destroy(ext4_free_data_cachep); |
| ext4_groupinfo_destroy_slabs(); |
| } |
| |
| #define EXT4_MB_BITMAP_MARKED_CHECK 0x0001 |
| #define EXT4_MB_SYNC_UPDATE 0x0002 |
| static int |
| ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state, |
| ext4_group_t group, ext4_grpblk_t blkoff, |
| ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_group_desc *gdp; |
| struct buffer_head *gdp_bh; |
| int err; |
| unsigned int i, already, changed = len; |
| |
| KUNIT_STATIC_STUB_REDIRECT(ext4_mb_mark_context, |
| handle, sb, state, group, blkoff, len, |
| flags, ret_changed); |
| |
| if (ret_changed) |
| *ret_changed = 0; |
| bitmap_bh = ext4_read_block_bitmap(sb, group); |
| if (IS_ERR(bitmap_bh)) |
| return PTR_ERR(bitmap_bh); |
| |
| if (handle) { |
| BUFFER_TRACE(bitmap_bh, "getting write access"); |
| err = ext4_journal_get_write_access(handle, sb, bitmap_bh, |
| EXT4_JTR_NONE); |
| if (err) |
| goto out_err; |
| } |
| |
| err = -EIO; |
| gdp = ext4_get_group_desc(sb, group, &gdp_bh); |
| if (!gdp) |
| goto out_err; |
| |
| if (handle) { |
| BUFFER_TRACE(gdp_bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, sb, gdp_bh, |
| EXT4_JTR_NONE); |
| if (err) |
| goto out_err; |
| } |
| |
| ext4_lock_group(sb, group); |
| if (ext4_has_group_desc_csum(sb) && |
| (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { |
| gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
| ext4_free_group_clusters_set(sb, gdp, |
| ext4_free_clusters_after_init(sb, group, gdp)); |
| } |
| |
| if (flags & EXT4_MB_BITMAP_MARKED_CHECK) { |
| already = 0; |
| for (i = 0; i < len; i++) |
| if (mb_test_bit(blkoff + i, bitmap_bh->b_data) == |
| state) |
| already++; |
| changed = len - already; |
| } |
| |
| if (state) { |
| mb_set_bits(bitmap_bh->b_data, blkoff, len); |
| ext4_free_group_clusters_set(sb, gdp, |
| ext4_free_group_clusters(sb, gdp) - changed); |
| } else { |
| mb_clear_bits(bitmap_bh->b_data, blkoff, len); |
| ext4_free_group_clusters_set(sb, gdp, |
| ext4_free_group_clusters(sb, gdp) + changed); |
| } |
| |
| ext4_block_bitmap_csum_set(sb, gdp, bitmap_bh); |
| ext4_group_desc_csum_set(sb, group, gdp); |
| ext4_unlock_group(sb, group); |
| if (ret_changed) |
| *ret_changed = changed; |
| |
| if (sbi->s_log_groups_per_flex) { |
| ext4_group_t flex_group = ext4_flex_group(sbi, group); |
| struct flex_groups *fg = sbi_array_rcu_deref(sbi, |
| s_flex_groups, flex_group); |
| |
| if (state) |
| atomic64_sub(changed, &fg->free_clusters); |
| else |
| atomic64_add(changed, &fg->free_clusters); |
| } |
| |
| err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
| if (err) |
| goto out_err; |
| err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh); |
| if (err) |
| goto out_err; |
| |
| if (flags & EXT4_MB_SYNC_UPDATE) { |
| sync_dirty_buffer(bitmap_bh); |
| sync_dirty_buffer(gdp_bh); |
| } |
| |
| out_err: |
| brelse(bitmap_bh); |
| return err; |
| } |
| |
| /* |
| * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps |
| * Returns 0 if success or error code |
| */ |
| static noinline_for_stack int |
| ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, |
| handle_t *handle, unsigned int reserv_clstrs) |
| { |
| struct ext4_group_desc *gdp; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| ext4_fsblk_t block; |
| int err, len; |
| int flags = 0; |
| ext4_grpblk_t changed; |
| |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(ac->ac_b_ex.fe_len <= 0); |
| |
| sb = ac->ac_sb; |
| sbi = EXT4_SB(sb); |
| |
| gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, NULL); |
| if (!gdp) |
| return -EIO; |
| ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group, |
| ext4_free_group_clusters(sb, gdp)); |
| |
| block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
| if (!ext4_inode_block_valid(ac->ac_inode, block, len)) { |
| ext4_error(sb, "Allocating blocks %llu-%llu which overlap " |
| "fs metadata", block, block+len); |
| /* File system mounted not to panic on error |
| * Fix the bitmap and return EFSCORRUPTED |
| * We leak some of the blocks here. |
| */ |
| err = ext4_mb_mark_context(handle, sb, true, |
| ac->ac_b_ex.fe_group, |
| ac->ac_b_ex.fe_start, |
| ac->ac_b_ex.fe_len, |
| 0, NULL); |
| if (!err) |
| err = -EFSCORRUPTED; |
| return err; |
| } |
| |
| #ifdef AGGRESSIVE_CHECK |
| flags |= EXT4_MB_BITMAP_MARKED_CHECK; |
| #endif |
| err = ext4_mb_mark_context(handle, sb, true, ac->ac_b_ex.fe_group, |
| ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len, |
| flags, &changed); |
| |
| if (err && changed == 0) |
| return err; |
| |
| #ifdef AGGRESSIVE_CHECK |
| BUG_ON(changed != ac->ac_b_ex.fe_len); |
| #endif |
| percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); |
| /* |
| * Now reduce the dirty block count also. Should not go negative |
| */ |
| if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) |
| /* release all the reserved blocks if non delalloc */ |
| percpu_counter_sub(&sbi->s_dirtyclusters_counter, |
| reserv_clstrs); |
| |
| return err; |
| } |
| |
| /* |
| * Idempotent helper for Ext4 fast commit replay path to set the state of |
| * blocks in bitmaps and update counters. |
| */ |
| void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, |
| int len, bool state) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_group_t group; |
| ext4_grpblk_t blkoff; |
| int err = 0; |
| unsigned int clen, thisgrp_len; |
| |
| while (len > 0) { |
| ext4_get_group_no_and_offset(sb, block, &group, &blkoff); |
| |
| /* |
| * Check to see if we are freeing blocks across a group |
| * boundary. |
| * In case of flex_bg, this can happen that (block, len) may |
| * span across more than one group. In that case we need to |
| * get the corresponding group metadata to work with. |
| * For this we have goto again loop. |
| */ |
| thisgrp_len = min_t(unsigned int, (unsigned int)len, |
| EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff)); |
| clen = EXT4_NUM_B2C(sbi, thisgrp_len); |
| |
| if (!ext4_sb_block_valid(sb, NULL, block, thisgrp_len)) { |
| ext4_error(sb, "Marking blocks in system zone - " |
| "Block = %llu, len = %u", |
| block, thisgrp_len); |
| break; |
| } |
| |
| err = ext4_mb_mark_context(NULL, sb, state, |
| group, blkoff, clen, |
| EXT4_MB_BITMAP_MARKED_CHECK | |
| EXT4_MB_SYNC_UPDATE, |
| NULL); |
| if (err) |
| break; |
| |
| block += thisgrp_len; |
| len -= thisgrp_len; |
| BUG_ON(len < 0); |
| } |
| } |
| |
| /* |
| * here we normalize request for locality group |
| * Group request are normalized to s_mb_group_prealloc, which goes to |
| * s_strip if we set the same via mount option. |
| * s_mb_group_prealloc can be configured via |
| * /sys/fs/ext4/<partition>/mb_group_prealloc |
| * |
| * XXX: should we try to preallocate more than the group has now? |
| */ |
| static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_locality_group *lg = ac->ac_lg; |
| |
| BUG_ON(lg == NULL); |
| ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; |
| mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len); |
| } |
| |
| /* |
| * This function returns the next element to look at during inode |
| * PA rbtree walk. We assume that we have held the inode PA rbtree lock |
| * (ei->i_prealloc_lock) |
| * |
| * new_start The start of the range we want to compare |
| * cur_start The existing start that we are comparing against |
| * node The node of the rb_tree |
| */ |
| static inline struct rb_node* |
| ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_node *node) |
| { |
| if (new_start < cur_start) |
| return node->rb_left; |
| else |
| return node->rb_right; |
| } |
| |
| static inline void |
| ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac, |
| ext4_lblk_t start, loff_t end) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| struct ext4_prealloc_space *tmp_pa; |
| ext4_lblk_t tmp_pa_start; |
| loff_t tmp_pa_end; |
| struct rb_node *iter; |
| |
| read_lock(&ei->i_prealloc_lock); |
| for (iter = ei->i_prealloc_node.rb_node; iter; |
| iter = ext4_mb_pa_rb_next_iter(start, tmp_pa_start, iter)) { |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| tmp_pa_start = tmp_pa->pa_lstart; |
| tmp_pa_end = pa_logical_end(sbi, tmp_pa); |
| |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0) |
| BUG_ON(!(start >= tmp_pa_end || end <= tmp_pa_start)); |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| read_unlock(&ei->i_prealloc_lock); |
| } |
| |
| /* |
| * Given an allocation context "ac" and a range "start", "end", check |
| * and adjust boundaries if the range overlaps with any of the existing |
| * preallocatoins stored in the corresponding inode of the allocation context. |
| * |
| * Parameters: |
| * ac allocation context |
| * start start of the new range |
| * end end of the new range |
| */ |
| static inline void |
| ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac, |
| ext4_lblk_t *start, loff_t *end) |
| { |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL; |
| struct rb_node *iter; |
| ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1; |
| loff_t new_end, tmp_pa_end, left_pa_end = -1; |
| |
| new_start = *start; |
| new_end = *end; |
| |
| /* |
| * Adjust the normalized range so that it doesn't overlap with any |
| * existing preallocated blocks(PAs). Make sure to hold the rbtree lock |
| * so it doesn't change underneath us. |
| */ |
| read_lock(&ei->i_prealloc_lock); |
| |
| /* Step 1: find any one immediate neighboring PA of the normalized range */ |
| for (iter = ei->i_prealloc_node.rb_node; iter; |
| iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical, |
| tmp_pa_start, iter)) { |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| tmp_pa_start = tmp_pa->pa_lstart; |
| tmp_pa_end = pa_logical_end(sbi, tmp_pa); |
| |
| /* PA must not overlap original request */ |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0) |
| BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end || |
| ac->ac_o_ex.fe_logical < tmp_pa_start)); |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| |
| /* |
| * Step 2: check if the found PA is left or right neighbor and |
| * get the other neighbor |
| */ |
| if (tmp_pa) { |
| if (tmp_pa->pa_lstart < ac->ac_o_ex.fe_logical) { |
| struct rb_node *tmp; |
| |
| left_pa = tmp_pa; |
| tmp = rb_next(&left_pa->pa_node.inode_node); |
| if (tmp) { |
| right_pa = rb_entry(tmp, |
| struct ext4_prealloc_space, |
| pa_node.inode_node); |
| } |
| } else { |
| struct rb_node *tmp; |
| |
| right_pa = tmp_pa; |
| tmp = rb_prev(&right_pa->pa_node.inode_node); |
| if (tmp) { |
| left_pa = rb_entry(tmp, |
| struct ext4_prealloc_space, |
| pa_node.inode_node); |
| } |
| } |
| } |
| |
| /* Step 3: get the non deleted neighbors */ |
| if (left_pa) { |
| for (iter = &left_pa->pa_node.inode_node;; |
| iter = rb_prev(iter)) { |
| if (!iter) { |
| left_pa = NULL; |
| break; |
| } |
| |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| left_pa = tmp_pa; |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0) { |
| spin_unlock(&tmp_pa->pa_lock); |
| break; |
| } |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| } |
| |
| if (right_pa) { |
| for (iter = &right_pa->pa_node.inode_node;; |
| iter = rb_next(iter)) { |
| if (!iter) { |
| right_pa = NULL; |
| break; |
| } |
| |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| right_pa = tmp_pa; |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0) { |
| spin_unlock(&tmp_pa->pa_lock); |
| break; |
| } |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| } |
| |
| if (left_pa) { |
| left_pa_end = pa_logical_end(sbi, left_pa); |
| BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical); |
| } |
| |
| if (right_pa) { |
| right_pa_start = right_pa->pa_lstart; |
| BUG_ON(right_pa_start <= ac->ac_o_ex.fe_logical); |
| } |
| |
| /* Step 4: trim our normalized range to not overlap with the neighbors */ |
| if (left_pa) { |
| if (left_pa_end > new_start) |
| new_start = left_pa_end; |
| } |
| |
| if (right_pa) { |
| if (right_pa_start < new_end) |
| new_end = right_pa_start; |
| } |
| read_unlock(&ei->i_prealloc_lock); |
| |
| /* XXX: extra loop to check we really don't overlap preallocations */ |
| ext4_mb_pa_assert_overlap(ac, new_start, new_end); |
| |
| *start = new_start; |
| *end = new_end; |
| } |
| |
| /* |
| * Normalization means making request better in terms of |
| * size and alignment |
| */ |
| static noinline_for_stack void |
| ext4_mb_normalize_request(struct ext4_allocation_context *ac, |
| struct ext4_allocation_request *ar) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_super_block *es = sbi->s_es; |
| int bsbits, max; |
| loff_t size, start_off, end; |
| loff_t orig_size __maybe_unused; |
| ext4_lblk_t start; |
| |
| /* do normalize only data requests, metadata requests |
| do not need preallocation */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return; |
| |
| /* sometime caller may want exact blocks */ |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| return; |
| |
| /* caller may indicate that preallocation isn't |
| * required (it's a tail, for example) */ |
| if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) |
| return; |
| |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { |
| ext4_mb_normalize_group_request(ac); |
| return ; |
| } |
| |
| bsbits = ac->ac_sb->s_blocksize_bits; |
| |
| /* first, let's learn actual file size |
| * given current request is allocated */ |
| size = extent_logical_end(sbi, &ac->ac_o_ex); |
| size = size << bsbits; |
| if (size < i_size_read(ac->ac_inode)) |
| size = i_size_read(ac->ac_inode); |
| orig_size = size; |
| |
| /* max size of free chunks */ |
| max = 2 << bsbits; |
| |
| #define NRL_CHECK_SIZE(req, size, max, chunk_size) \ |
| (req <= (size) || max <= (chunk_size)) |
| |
| /* first, try to predict filesize */ |
| /* XXX: should this table be tunable? */ |
| start_off = 0; |
| if (size <= 16 * 1024) { |
| size = 16 * 1024; |
| } else if (size <= 32 * 1024) { |
| size = 32 * 1024; |
| } else if (size <= 64 * 1024) { |
| size = 64 * 1024; |
| } else if (size <= 128 * 1024) { |
| size = 128 * 1024; |
| } else if (size <= 256 * 1024) { |
| size = 256 * 1024; |
| } else if (size <= 512 * 1024) { |
| size = 512 * 1024; |
| } else if (size <= 1024 * 1024) { |
| size = 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (21 - bsbits)) << 21; |
| size = 2 * 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (22 - bsbits)) << 22; |
| size = 4 * 1024 * 1024; |
| } else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len), |
| (8<<20)>>bsbits, max, 8 * 1024)) { |
| start_off = ((loff_t)ac->ac_o_ex.fe_logical >> |
| (23 - bsbits)) << 23; |
| size = 8 * 1024 * 1024; |
| } else { |
| start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits; |
| size = (loff_t) EXT4_C2B(sbi, |
| ac->ac_o_ex.fe_len) << bsbits; |
| } |
| size = size >> bsbits; |
| start = start_off >> bsbits; |
| |
| /* |
| * For tiny groups (smaller than 8MB) the chosen allocation |
| * alignment may be larger than group size. Make sure the |
| * alignment does not move allocation to a different group which |
| * makes mballoc fail assertions later. |
| */ |
| start = max(start, rounddown(ac->ac_o_ex.fe_logical, |
| (ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb))); |
| |
| /* avoid unnecessary preallocation that may trigger assertions */ |
| if (start + size > EXT_MAX_BLOCKS) |
| size = EXT_MAX_BLOCKS - start; |
| |
| /* don't cover already allocated blocks in selected range */ |
| if (ar->pleft && start <= ar->lleft) { |
| size -= ar->lleft + 1 - start; |
| start = ar->lleft + 1; |
| } |
| if (ar->pright && start + size - 1 >= ar->lright) |
| size -= start + size - ar->lright; |
| |
| /* |
| * Trim allocation request for filesystems with artificially small |
| * groups. |
| */ |
| if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) |
| size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb); |
| |
| end = start + size; |
| |
| ext4_mb_pa_adjust_overlap(ac, &start, &end); |
| |
| size = end - start; |
| |
| /* |
| * In this function "start" and "size" are normalized for better |
| * alignment and length such that we could preallocate more blocks. |
| * This normalization is done such that original request of |
| * ac->ac_o_ex.fe_logical & fe_len should always lie within "start" and |
| * "size" boundaries. |
| * (Note fe_len can be relaxed since FS block allocation API does not |
| * provide gurantee on number of contiguous blocks allocation since that |
| * depends upon free space left, etc). |
| * In case of inode pa, later we use the allocated blocks |
| * [pa_pstart + fe_logical - pa_lstart, fe_len/size] from the preallocated |
| * range of goal/best blocks [start, size] to put it at the |
| * ac_o_ex.fe_logical extent of this inode. |
| * (See ext4_mb_use_inode_pa() for more details) |
| */ |
| if (start + size <= ac->ac_o_ex.fe_logical || |
| start > ac->ac_o_ex.fe_logical) { |
| ext4_msg(ac->ac_sb, KERN_ERR, |
| "start %lu, size %lu, fe_logical %lu", |
| (unsigned long) start, (unsigned long) size, |
| (unsigned long) ac->ac_o_ex.fe_logical); |
| BUG(); |
| } |
| BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)); |
| |
| /* now prepare goal request */ |
| |
| /* XXX: is it better to align blocks WRT to logical |
| * placement or satisfy big request as is */ |
| ac->ac_g_ex.fe_logical = start; |
| ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size); |
| ac->ac_orig_goal_len = ac->ac_g_ex.fe_len; |
| |
| /* define goal start in order to merge */ |
| if (ar->pright && (ar->lright == (start + size)) && |
| ar->pright >= size && |
| ar->pright - size >= le32_to_cpu(es->s_first_data_block)) { |
| /* merge to the right */ |
| ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, |
| &ac->ac_g_ex.fe_group, |
| &ac->ac_g_ex.fe_start); |
| ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| } |
| if (ar->pleft && (ar->lleft + 1 == start) && |
| ar->pleft + 1 < ext4_blocks_count(es)) { |
| /* merge to the left */ |
| ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, |
| &ac->ac_g_ex.fe_group, |
| &ac->ac_g_ex.fe_start); |
| ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; |
| } |
| |
| mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size, |
| orig_size, start); |
| } |
| |
| static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| |
| if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) { |
| atomic_inc(&sbi->s_bal_reqs); |
| atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); |
| if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) |
| atomic_inc(&sbi->s_bal_success); |
| |
| atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); |
| for (int i=0; i<EXT4_MB_NUM_CRS; i++) { |
| atomic_add(ac->ac_cX_found[i], &sbi->s_bal_cX_ex_scanned[i]); |
| } |
| |
| atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned); |
| if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && |
| ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) |
| atomic_inc(&sbi->s_bal_goals); |
| /* did we allocate as much as normalizer originally wanted? */ |
| if (ac->ac_f_ex.fe_len == ac->ac_orig_goal_len) |
| atomic_inc(&sbi->s_bal_len_goals); |
| |
| if (ac->ac_found > sbi->s_mb_max_to_scan) |
| atomic_inc(&sbi->s_bal_breaks); |
| } |
| |
| if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) |
| trace_ext4_mballoc_alloc(ac); |
| else |
| trace_ext4_mballoc_prealloc(ac); |
| } |
| |
| /* |
| * Called on failure; free up any blocks from the inode PA for this |
| * context. We don't need this for MB_GROUP_PA because we only change |
| * pa_free in ext4_mb_release_context(), but on failure, we've already |
| * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed. |
| */ |
| static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) |
| { |
| struct ext4_prealloc_space *pa = ac->ac_pa; |
| struct ext4_buddy e4b; |
| int err; |
| |
| if (pa == NULL) { |
| if (ac->ac_f_ex.fe_len == 0) |
| return; |
| err = ext4_mb_load_buddy(ac->ac_sb, ac->ac_f_ex.fe_group, &e4b); |
| if (WARN_RATELIMIT(err, |
| "ext4: mb_load_buddy failed (%d)", err)) |
| /* |
| * This should never happen since we pin the |
| * pages in the ext4_allocation_context so |
| * ext4_mb_load_buddy() should never fail. |
| */ |
| return; |
| ext4_lock_group(ac->ac_sb, ac->ac_f_ex.fe_group); |
| mb_free_blocks(ac->ac_inode, &e4b, ac->ac_f_ex.fe_start, |
| ac->ac_f_ex.fe_len); |
| ext4_unlock_group(ac->ac_sb, ac->ac_f_ex.fe_group); |
| ext4_mb_unload_buddy(&e4b); |
| return; |
| } |
| if (pa->pa_type == MB_INODE_PA) { |
| spin_lock(&pa->pa_lock); |
| pa->pa_free += ac->ac_b_ex.fe_len; |
| spin_unlock(&pa->pa_lock); |
| } |
| } |
| |
| /* |
| * use blocks preallocated to inode |
| */ |
| static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, |
| struct ext4_prealloc_space *pa) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| ext4_fsblk_t start; |
| ext4_fsblk_t end; |
| int len; |
| |
| /* found preallocated blocks, use them */ |
| start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); |
| end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len), |
| start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len)); |
| len = EXT4_NUM_B2C(sbi, end - start); |
| ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, |
| &ac->ac_b_ex.fe_start); |
| ac->ac_b_ex.fe_len = len; |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_pa = pa; |
| |
| BUG_ON(start < pa->pa_pstart); |
| BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len)); |
| BUG_ON(pa->pa_free < len); |
| BUG_ON(ac->ac_b_ex.fe_len <= 0); |
| pa->pa_free -= len; |
| |
| mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa); |
| } |
| |
| /* |
| * use blocks preallocated to locality group |
| */ |
| static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, |
| struct ext4_prealloc_space *pa) |
| { |
| unsigned int len = ac->ac_o_ex.fe_len; |
| |
| ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, |
| &ac->ac_b_ex.fe_group, |
| &ac->ac_b_ex.fe_start); |
| ac->ac_b_ex.fe_len = len; |
| ac->ac_status = AC_STATUS_FOUND; |
| ac->ac_pa = pa; |
| |
| /* we don't correct pa_pstart or pa_len here to avoid |
| * possible race when the group is being loaded concurrently |
| * instead we correct pa later, after blocks are marked |
| * in on-disk bitmap -- see ext4_mb_release_context() |
| * Other CPUs are prevented from allocating from this pa by lg_mutex |
| */ |
| mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n", |
| pa->pa_lstart, len, pa); |
| } |
| |
| /* |
| * Return the prealloc space that have minimal distance |
| * from the goal block. @cpa is the prealloc |
| * space that is having currently known minimal distance |
| * from the goal block. |
| */ |
| static struct ext4_prealloc_space * |
| ext4_mb_check_group_pa(ext4_fsblk_t goal_block, |
| struct ext4_prealloc_space *pa, |
| struct ext4_prealloc_space *cpa) |
| { |
| ext4_fsblk_t cur_distance, new_distance; |
| |
| if (cpa == NULL) { |
| atomic_inc(&pa->pa_count); |
| return pa; |
| } |
| cur_distance = abs(goal_block - cpa->pa_pstart); |
| new_distance = abs(goal_block - pa->pa_pstart); |
| |
| if (cur_distance <= new_distance) |
| return cpa; |
| |
| /* drop the previous reference */ |
| atomic_dec(&cpa->pa_count); |
| atomic_inc(&pa->pa_count); |
| return pa; |
| } |
| |
| /* |
| * check if found pa meets EXT4_MB_HINT_GOAL_ONLY |
| */ |
| static bool |
| ext4_mb_pa_goal_check(struct ext4_allocation_context *ac, |
| struct ext4_prealloc_space *pa) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| ext4_fsblk_t start; |
| |
| if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))) |
| return true; |
| |
| /* |
| * If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted |
| * in ext4_mb_normalize_request and will keep same with ac_o_ex |
| * from ext4_mb_initialize_context. Choose ac_g_ex here to keep |
| * consistent with ext4_mb_find_by_goal. |
| */ |
| start = pa->pa_pstart + |
| (ac->ac_g_ex.fe_logical - pa->pa_lstart); |
| if (ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex) != start) |
| return false; |
| |
| if (ac->ac_g_ex.fe_len > pa->pa_len - |
| EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart)) |
| return false; |
| |
| return true; |
| } |
| |
| /* |
| * search goal blocks in preallocated space |
| */ |
| static noinline_for_stack bool |
| ext4_mb_use_preallocated(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| int order, i; |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| struct ext4_locality_group *lg; |
| struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL; |
| struct rb_node *iter; |
| ext4_fsblk_t goal_block; |
| |
| /* only data can be preallocated */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return false; |
| |
| /* |
| * first, try per-file preallocation by searching the inode pa rbtree. |
| * |
| * Here, we can't do a direct traversal of the tree because |
| * ext4_mb_discard_group_preallocation() can paralelly mark the pa |
| * deleted and that can cause direct traversal to skip some entries. |
| */ |
| read_lock(&ei->i_prealloc_lock); |
| |
| if (RB_EMPTY_ROOT(&ei->i_prealloc_node)) { |
| goto try_group_pa; |
| } |
| |
| /* |
| * Step 1: Find a pa with logical start immediately adjacent to the |
| * original logical start. This could be on the left or right. |
| * |
| * (tmp_pa->pa_lstart never changes so we can skip locking for it). |
| */ |
| for (iter = ei->i_prealloc_node.rb_node; iter; |
| iter = ext4_mb_pa_rb_next_iter(ac->ac_o_ex.fe_logical, |
| tmp_pa->pa_lstart, iter)) { |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| } |
| |
| /* |
| * Step 2: The adjacent pa might be to the right of logical start, find |
| * the left adjacent pa. After this step we'd have a valid tmp_pa whose |
| * logical start is towards the left of original request's logical start |
| */ |
| if (tmp_pa->pa_lstart > ac->ac_o_ex.fe_logical) { |
| struct rb_node *tmp; |
| tmp = rb_prev(&tmp_pa->pa_node.inode_node); |
| |
| if (tmp) { |
| tmp_pa = rb_entry(tmp, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| } else { |
| /* |
| * If there is no adjacent pa to the left then finding |
| * an overlapping pa is not possible hence stop searching |
| * inode pa tree |
| */ |
| goto try_group_pa; |
| } |
| } |
| |
| BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical)); |
| |
| /* |
| * Step 3: If the left adjacent pa is deleted, keep moving left to find |
| * the first non deleted adjacent pa. After this step we should have a |
| * valid tmp_pa which is guaranteed to be non deleted. |
| */ |
| for (iter = &tmp_pa->pa_node.inode_node;; iter = rb_prev(iter)) { |
| if (!iter) { |
| /* |
| * no non deleted left adjacent pa, so stop searching |
| * inode pa tree |
| */ |
| goto try_group_pa; |
| } |
| tmp_pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0) { |
| /* |
| * We will keep holding the pa_lock from |
| * this point on because we don't want group discard |
| * to delete this pa underneath us. Since group |
| * discard is anyways an ENOSPC operation it |
| * should be okay for it to wait a few more cycles. |
| */ |
| break; |
| } else { |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| } |
| |
| BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical)); |
| BUG_ON(tmp_pa->pa_deleted == 1); |
| |
| /* |
| * Step 4: We now have the non deleted left adjacent pa. Only this |
| * pa can possibly satisfy the request hence check if it overlaps |
| * original logical start and stop searching if it doesn't. |
| */ |
| if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, tmp_pa)) { |
| spin_unlock(&tmp_pa->pa_lock); |
| goto try_group_pa; |
| } |
| |
| /* non-extent files can't have physical blocks past 2^32 */ |
| if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) && |
| (tmp_pa->pa_pstart + EXT4_C2B(sbi, tmp_pa->pa_len) > |
| EXT4_MAX_BLOCK_FILE_PHYS)) { |
| /* |
| * Since PAs don't overlap, we won't find any other PA to |
| * satisfy this. |
| */ |
| spin_unlock(&tmp_pa->pa_lock); |
| goto try_group_pa; |
| } |
| |
| if (tmp_pa->pa_free && likely(ext4_mb_pa_goal_check(ac, tmp_pa))) { |
| atomic_inc(&tmp_pa->pa_count); |
| ext4_mb_use_inode_pa(ac, tmp_pa); |
| spin_unlock(&tmp_pa->pa_lock); |
| read_unlock(&ei->i_prealloc_lock); |
| return true; |
| } else { |
| /* |
| * We found a valid overlapping pa but couldn't use it because |
| * it had no free blocks. This should ideally never happen |
| * because: |
| * |
| * 1. When a new inode pa is added to rbtree it must have |
| * pa_free > 0 since otherwise we won't actually need |
| * preallocation. |
| * |
| * 2. An inode pa that is in the rbtree can only have it's |
| * pa_free become zero when another thread calls: |
| * ext4_mb_new_blocks |
| * ext4_mb_use_preallocated |
| * ext4_mb_use_inode_pa |
| * |
| * 3. Further, after the above calls make pa_free == 0, we will |
| * immediately remove it from the rbtree in: |
| * ext4_mb_new_blocks |
| * ext4_mb_release_context |
| * ext4_mb_put_pa |
| * |
| * 4. Since the pa_free becoming 0 and pa_free getting removed |
| * from tree both happen in ext4_mb_new_blocks, which is always |
| * called with i_data_sem held for data allocations, we can be |
| * sure that another process will never see a pa in rbtree with |
| * pa_free == 0. |
| */ |
| WARN_ON_ONCE(tmp_pa->pa_free == 0); |
| } |
| spin_unlock(&tmp_pa->pa_lock); |
| try_group_pa: |
| read_unlock(&ei->i_prealloc_lock); |
| |
| /* can we use group allocation? */ |
| if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) |
| return false; |
| |
| /* inode may have no locality group for some reason */ |
| lg = ac->ac_lg; |
| if (lg == NULL) |
| return false; |
| order = fls(ac->ac_o_ex.fe_len) - 1; |
| if (order > PREALLOC_TB_SIZE - 1) |
| /* The max size of hash table is PREALLOC_TB_SIZE */ |
| order = PREALLOC_TB_SIZE - 1; |
| |
| goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex); |
| /* |
| * search for the prealloc space that is having |
| * minimal distance from the goal block. |
| */ |
| for (i = order; i < PREALLOC_TB_SIZE; i++) { |
| rcu_read_lock(); |
| list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[i], |
| pa_node.lg_list) { |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted == 0 && |
| tmp_pa->pa_free >= ac->ac_o_ex.fe_len) { |
| |
| cpa = ext4_mb_check_group_pa(goal_block, |
| tmp_pa, cpa); |
| } |
| spin_unlock(&tmp_pa->pa_lock); |
| } |
| rcu_read_unlock(); |
| } |
| if (cpa) { |
| ext4_mb_use_group_pa(ac, cpa); |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| * the function goes through all preallocation in this group and marks them |
| * used in in-core bitmap. buddy must be generated from this bitmap |
| * Need to be called with ext4 group lock held |
| */ |
| static noinline_for_stack |
| void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, |
| ext4_group_t group) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| struct ext4_prealloc_space *pa; |
| struct list_head *cur; |
| ext4_group_t groupnr; |
| ext4_grpblk_t start; |
| int preallocated = 0; |
| int len; |
| |
| if (!grp) |
| return; |
| |
| /* all form of preallocation discards first load group, |
| * so the only competing code is preallocation use. |
| * we don't need any locking here |
| * notice we do NOT ignore preallocations with pa_deleted |
| * otherwise we could leave used blocks available for |
| * allocation in buddy when concurrent ext4_mb_put_pa() |
| * is dropping preallocation |
| */ |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); |
| spin_lock(&pa->pa_lock); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| &groupnr, &start); |
| len = pa->pa_len; |
| spin_unlock(&pa->pa_lock); |
| if (unlikely(len == 0)) |
| continue; |
| BUG_ON(groupnr != group); |
| mb_set_bits(bitmap, start, len); |
| preallocated += len; |
| } |
| mb_debug(sb, "preallocated %d for group %u\n", preallocated, group); |
| } |
| |
| static void ext4_mb_mark_pa_deleted(struct super_block *sb, |
| struct ext4_prealloc_space *pa) |
| { |
| struct ext4_inode_info *ei; |
| |
| if (pa->pa_deleted) { |
| ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n", |
| pa->pa_type, pa->pa_pstart, pa->pa_lstart, |
| pa->pa_len); |
| return; |
| } |
| |
| pa->pa_deleted = 1; |
| |
| if (pa->pa_type == MB_INODE_PA) { |
| ei = EXT4_I(pa->pa_inode); |
| atomic_dec(&ei->i_prealloc_active); |
| } |
| } |
| |
| static inline void ext4_mb_pa_free(struct ext4_prealloc_space *pa) |
| { |
| BUG_ON(!pa); |
| BUG_ON(atomic_read(&pa->pa_count)); |
| BUG_ON(pa->pa_deleted == 0); |
| kmem_cache_free(ext4_pspace_cachep, pa); |
| } |
| |
| static void ext4_mb_pa_callback(struct rcu_head *head) |
| { |
| struct ext4_prealloc_space *pa; |
| |
| pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); |
| ext4_mb_pa_free(pa); |
| } |
| |
| /* |
| * drops a reference to preallocated space descriptor |
| * if this was the last reference and the space is consumed |
| */ |
| static void ext4_mb_put_pa(struct ext4_allocation_context *ac, |
| struct super_block *sb, struct ext4_prealloc_space *pa) |
| { |
| ext4_group_t grp; |
| ext4_fsblk_t grp_blk; |
| struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); |
| |
| /* in this short window concurrent discard can set pa_deleted */ |
| spin_lock(&pa->pa_lock); |
| if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) { |
| spin_unlock(&pa->pa_lock); |
| return; |
| } |
| |
| if (pa->pa_deleted == 1) { |
| spin_unlock(&pa->pa_lock); |
| return; |
| } |
| |
| ext4_mb_mark_pa_deleted(sb, pa); |
| spin_unlock(&pa->pa_lock); |
| |
| grp_blk = pa->pa_pstart; |
| /* |
| * If doing group-based preallocation, pa_pstart may be in the |
| * next group when pa is used up |
| */ |
| if (pa->pa_type == MB_GROUP_PA) |
| grp_blk--; |
| |
| grp = ext4_get_group_number(sb, grp_blk); |
| |
| /* |
| * possible race: |
| * |
| * P1 (buddy init) P2 (regular allocation) |
| * find block B in PA |
| * copy on-disk bitmap to buddy |
| * mark B in on-disk bitmap |
| * drop PA from group |
| * mark all PAs in buddy |
| * |
| * thus, P1 initializes buddy with B available. to prevent this |
| * we make "copy" and "mark all PAs" atomic and serialize "drop PA" |
| * against that pair |
| */ |
| ext4_lock_group(sb, grp); |
| list_del(&pa->pa_group_list); |
| ext4_unlock_group(sb, grp); |
| |
| if (pa->pa_type == MB_INODE_PA) { |
| write_lock(pa->pa_node_lock.inode_lock); |
| rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); |
| write_unlock(pa->pa_node_lock.inode_lock); |
| ext4_mb_pa_free(pa); |
| } else { |
| spin_lock(pa->pa_node_lock.lg_lock); |
| list_del_rcu(&pa->pa_node.lg_list); |
| spin_unlock(pa->pa_node_lock.lg_lock); |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } |
| } |
| |
| static void ext4_mb_pa_rb_insert(struct rb_root *root, struct rb_node *new) |
| { |
| struct rb_node **iter = &root->rb_node, *parent = NULL; |
| struct ext4_prealloc_space *iter_pa, *new_pa; |
| ext4_lblk_t iter_start, new_start; |
| |
| while (*iter) { |
| iter_pa = rb_entry(*iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| new_pa = rb_entry(new, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| iter_start = iter_pa->pa_lstart; |
| new_start = new_pa->pa_lstart; |
| |
| parent = *iter; |
| if (new_start < iter_start) |
| iter = &((*iter)->rb_left); |
| else |
| iter = &((*iter)->rb_right); |
| } |
| |
| rb_link_node(new, parent, iter); |
| rb_insert_color(new, root); |
| } |
| |
| /* |
| * creates new preallocated space for given inode |
| */ |
| static noinline_for_stack void |
| ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_prealloc_space *pa; |
| struct ext4_group_info *grp; |
| struct ext4_inode_info *ei; |
| |
| /* preallocate only when found space is larger then requested */ |
| BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| BUG_ON(ac->ac_pa == NULL); |
| |
| pa = ac->ac_pa; |
| |
| if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) { |
| struct ext4_free_extent ex = { |
| .fe_logical = ac->ac_g_ex.fe_logical, |
| .fe_len = ac->ac_orig_goal_len, |
| }; |
| loff_t orig_goal_end = extent_logical_end(sbi, &ex); |
| loff_t o_ex_end = extent_logical_end(sbi, &ac->ac_o_ex); |
| |
| /* |
| * We can't allocate as much as normalizer wants, so we try |
| * to get proper lstart to cover the original request, except |
| * when the goal doesn't cover the original request as below: |
| * |
| * orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048 |
| * best_ex:0/200(200) -> adjusted: 1848/2048(200) |
| */ |
| BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); |
| BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); |
| |
| /* |
| * Use the below logic for adjusting best extent as it keeps |
| * fragmentation in check while ensuring logical range of best |
| * extent doesn't overflow out of goal extent: |
| * |
| * 1. Check if best ex can be kept at end of goal (before |
| * cr_best_avail trimmed it) and still cover original start |
| * 2. Else, check if best ex can be kept at start of goal and |
| * still cover original end |
| * 3. Else, keep the best ex at start of original request. |
| */ |
| ex.fe_len = ac->ac_b_ex.fe_len; |
| |
| ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len); |
| if (ac->ac_o_ex.fe_logical >= ex.fe_logical) |
| goto adjust_bex; |
| |
| ex.fe_logical = ac->ac_g_ex.fe_logical; |
| if (o_ex_end <= extent_logical_end(sbi, &ex)) |
| goto adjust_bex; |
| |
| ex.fe_logical = ac->ac_o_ex.fe_logical; |
| adjust_bex: |
| ac->ac_b_ex.fe_logical = ex.fe_logical; |
| |
| BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); |
| BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end); |
| } |
| |
| pa->pa_lstart = ac->ac_b_ex.fe_logical; |
| pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| pa->pa_len = ac->ac_b_ex.fe_len; |
| pa->pa_free = pa->pa_len; |
| spin_lock_init(&pa->pa_lock); |
| INIT_LIST_HEAD(&pa->pa_group_list); |
| pa->pa_deleted = 0; |
| pa->pa_type = MB_INODE_PA; |
| |
| mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, |
| pa->pa_len, pa->pa_lstart); |
| trace_ext4_mb_new_inode_pa(ac, pa); |
| |
| atomic_add(pa->pa_free, &sbi->s_mb_preallocated); |
| ext4_mb_use_inode_pa(ac, pa); |
| |
| ei = EXT4_I(ac->ac_inode); |
| grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| if (!grp) |
| return; |
| |
| pa->pa_node_lock.inode_lock = &ei->i_prealloc_lock; |
| pa->pa_inode = ac->ac_inode; |
| |
| list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| |
| write_lock(pa->pa_node_lock.inode_lock); |
| ext4_mb_pa_rb_insert(&ei->i_prealloc_node, &pa->pa_node.inode_node); |
| write_unlock(pa->pa_node_lock.inode_lock); |
| atomic_inc(&ei->i_prealloc_active); |
| } |
| |
| /* |
| * creates new preallocated space for locality group inodes belongs to |
| */ |
| static noinline_for_stack void |
| ext4_mb_new_group_pa(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_locality_group *lg; |
| struct ext4_prealloc_space *pa; |
| struct ext4_group_info *grp; |
| |
| /* preallocate only when found space is larger then requested */ |
| BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); |
| BUG_ON(ac->ac_status != AC_STATUS_FOUND); |
| BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); |
| BUG_ON(ac->ac_pa == NULL); |
| |
| pa = ac->ac_pa; |
| |
| pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| pa->pa_lstart = pa->pa_pstart; |
| pa->pa_len = ac->ac_b_ex.fe_len; |
| pa->pa_free = pa->pa_len; |
| spin_lock_init(&pa->pa_lock); |
| INIT_LIST_HEAD(&pa->pa_node.lg_list); |
| INIT_LIST_HEAD(&pa->pa_group_list); |
| pa->pa_deleted = 0; |
| pa->pa_type = MB_GROUP_PA; |
| |
| mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart, |
| pa->pa_len, pa->pa_lstart); |
| trace_ext4_mb_new_group_pa(ac, pa); |
| |
| ext4_mb_use_group_pa(ac, pa); |
| atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); |
| |
| grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); |
| if (!grp) |
| return; |
| lg = ac->ac_lg; |
| BUG_ON(lg == NULL); |
| |
| pa->pa_node_lock.lg_lock = &lg->lg_prealloc_lock; |
| pa->pa_inode = NULL; |
| |
| list_add(&pa->pa_group_list, &grp->bb_prealloc_list); |
| |
| /* |
| * We will later add the new pa to the right bucket |
| * after updating the pa_free in ext4_mb_release_context |
| */ |
| } |
| |
| static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac) |
| { |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| ext4_mb_new_group_pa(ac); |
| else |
| ext4_mb_new_inode_pa(ac); |
| } |
| |
| /* |
| * finds all unused blocks in on-disk bitmap, frees them in |
| * in-core bitmap and buddy. |
| * @pa must be unlinked from inode and group lists, so that |
| * nobody else can find/use it. |
| * the caller MUST hold group/inode locks. |
| * TODO: optimize the case when there are no in-core structures yet |
| */ |
| static noinline_for_stack void |
| ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, |
| struct ext4_prealloc_space *pa) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| unsigned int end; |
| unsigned int next; |
| ext4_group_t group; |
| ext4_grpblk_t bit; |
| unsigned long long grp_blk_start; |
| int free = 0; |
| |
| BUG_ON(pa->pa_deleted == 0); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit); |
| BUG_ON(group != e4b->bd_group && pa->pa_len != 0); |
| end = bit + pa->pa_len; |
| |
| while (bit < end) { |
| bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); |
| if (bit >= end) |
| break; |
| next = mb_find_next_bit(bitmap_bh->b_data, end, bit); |
| mb_debug(sb, "free preallocated %u/%u in group %u\n", |
| (unsigned) ext4_group_first_block_no(sb, group) + bit, |
| (unsigned) next - bit, (unsigned) group); |
| free += next - bit; |
| |
| trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit); |
| trace_ext4_mb_release_inode_pa(pa, (grp_blk_start + |
| EXT4_C2B(sbi, bit)), |
| next - bit); |
| mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); |
| bit = next + 1; |
| } |
| if (free != pa->pa_free) { |
| ext4_msg(e4b->bd_sb, KERN_CRIT, |
| "pa %p: logic %lu, phys. %lu, len %d", |
| pa, (unsigned long) pa->pa_lstart, |
| (unsigned long) pa->pa_pstart, |
| pa->pa_len); |
| ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u", |
| free, pa->pa_free); |
| /* |
| * pa is already deleted so we use the value obtained |
| * from the bitmap and continue. |
| */ |
| } |
| atomic_add(free, &sbi->s_mb_discarded); |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_release_group_pa(struct ext4_buddy *e4b, |
| struct ext4_prealloc_space *pa) |
| { |
| struct super_block *sb = e4b->bd_sb; |
| ext4_group_t group; |
| ext4_grpblk_t bit; |
| |
| trace_ext4_mb_release_group_pa(sb, pa); |
| BUG_ON(pa->pa_deleted == 0); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); |
| if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) { |
| ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu", |
| e4b->bd_group, group, pa->pa_pstart); |
| return; |
| } |
| mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); |
| atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); |
| trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len); |
| } |
| |
| /* |
| * releases all preallocations in given group |
| * |
| * first, we need to decide discard policy: |
| * - when do we discard |
| * 1) ENOSPC |
| * - how many do we discard |
| * 1) how many requested |
| */ |
| static noinline_for_stack int |
| ext4_mb_discard_group_preallocations(struct super_block *sb, |
| ext4_group_t group, int *busy) |
| { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, group); |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_prealloc_space *pa, *tmp; |
| LIST_HEAD(list); |
| struct ext4_buddy e4b; |
| struct ext4_inode_info *ei; |
| int err; |
| int free = 0; |
| |
| if (!grp) |
| return 0; |
| mb_debug(sb, "discard preallocation for group %u\n", group); |
| if (list_empty(&grp->bb_prealloc_list)) |
| goto out_dbg; |
| |
| bitmap_bh = ext4_read_block_bitmap(sb, group); |
| if (IS_ERR(bitmap_bh)) { |
| err = PTR_ERR(bitmap_bh); |
| ext4_error_err(sb, -err, |
| "Error %d reading block bitmap for %u", |
| err, group); |
| goto out_dbg; |
| } |
| |
| err = ext4_mb_load_buddy(sb, group, &e4b); |
| if (err) { |
| ext4_warning(sb, "Error %d loading buddy information for %u", |
| err, group); |
| put_bh(bitmap_bh); |
| goto out_dbg; |
| } |
| |
| ext4_lock_group(sb, group); |
| list_for_each_entry_safe(pa, tmp, |
| &grp->bb_prealloc_list, pa_group_list) { |
| spin_lock(&pa->pa_lock); |
| if (atomic_read(&pa->pa_count)) { |
| spin_unlock(&pa->pa_lock); |
| *busy = 1; |
| continue; |
| } |
| if (pa->pa_deleted) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| |
| /* seems this one can be freed ... */ |
| ext4_mb_mark_pa_deleted(sb, pa); |
| |
| if (!free) |
| this_cpu_inc(discard_pa_seq); |
| |
| /* we can trust pa_free ... */ |
| free += pa->pa_free; |
| |
| spin_unlock(&pa->pa_lock); |
| |
| list_del(&pa->pa_group_list); |
| list_add(&pa->u.pa_tmp_list, &list); |
| } |
| |
| /* now free all selected PAs */ |
| list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| |
| /* remove from object (inode or locality group) */ |
| if (pa->pa_type == MB_GROUP_PA) { |
| spin_lock(pa->pa_node_lock.lg_lock); |
| list_del_rcu(&pa->pa_node.lg_list); |
| spin_unlock(pa->pa_node_lock.lg_lock); |
| } else { |
| write_lock(pa->pa_node_lock.inode_lock); |
| ei = EXT4_I(pa->pa_inode); |
| rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); |
| write_unlock(pa->pa_node_lock.inode_lock); |
| } |
| |
| list_del(&pa->u.pa_tmp_list); |
| |
| if (pa->pa_type == MB_GROUP_PA) { |
| ext4_mb_release_group_pa(&e4b, pa); |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } else { |
| ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
| ext4_mb_pa_free(pa); |
| } |
| } |
| |
| ext4_unlock_group(sb, group); |
| ext4_mb_unload_buddy(&e4b); |
| put_bh(bitmap_bh); |
| out_dbg: |
| mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n", |
| free, group, grp->bb_free); |
| return free; |
| } |
| |
| /* |
| * releases all non-used preallocated blocks for given inode |
| * |
| * It's important to discard preallocations under i_data_sem |
| * We don't want another block to be served from the prealloc |
| * space when we are discarding the inode prealloc space. |
| * |
| * FIXME!! Make sure it is valid at all the call sites |
| */ |
| void ext4_discard_preallocations(struct inode *inode) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct super_block *sb = inode->i_sb; |
| struct buffer_head *bitmap_bh = NULL; |
| struct ext4_prealloc_space *pa, *tmp; |
| ext4_group_t group = 0; |
| LIST_HEAD(list); |
| struct ext4_buddy e4b; |
| struct rb_node *iter; |
| int err; |
| |
| if (!S_ISREG(inode->i_mode)) |
| return; |
| |
| if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) |
| return; |
| |
| mb_debug(sb, "discard preallocation for inode %lu\n", |
| inode->i_ino); |
| trace_ext4_discard_preallocations(inode, |
| atomic_read(&ei->i_prealloc_active)); |
| |
| repeat: |
| /* first, collect all pa's in the inode */ |
| write_lock(&ei->i_prealloc_lock); |
| for (iter = rb_first(&ei->i_prealloc_node); iter; |
| iter = rb_next(iter)) { |
| pa = rb_entry(iter, struct ext4_prealloc_space, |
| pa_node.inode_node); |
| BUG_ON(pa->pa_node_lock.inode_lock != &ei->i_prealloc_lock); |
| |
| spin_lock(&pa->pa_lock); |
| if (atomic_read(&pa->pa_count)) { |
| /* this shouldn't happen often - nobody should |
| * use preallocation while we're discarding it */ |
| spin_unlock(&pa->pa_lock); |
| write_unlock(&ei->i_prealloc_lock); |
| ext4_msg(sb, KERN_ERR, |
| "uh-oh! used pa while discarding"); |
| WARN_ON(1); |
| schedule_timeout_uninterruptible(HZ); |
| goto repeat; |
| |
| } |
| if (pa->pa_deleted == 0) { |
| ext4_mb_mark_pa_deleted(sb, pa); |
| spin_unlock(&pa->pa_lock); |
| rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node); |
| list_add(&pa->u.pa_tmp_list, &list); |
| continue; |
| } |
| |
| /* someone is deleting pa right now */ |
| spin_unlock(&pa->pa_lock); |
| write_unlock(&ei->i_prealloc_lock); |
| |
| /* we have to wait here because pa_deleted |
| * doesn't mean pa is already unlinked from |
| * the list. as we might be called from |
| * ->clear_inode() the inode will get freed |
| * and concurrent thread which is unlinking |
| * pa from inode's list may access already |
| * freed memory, bad-bad-bad */ |
| |
| /* XXX: if this happens too often, we can |
| * add a flag to force wait only in case |
| * of ->clear_inode(), but not in case of |
| * regular truncate */ |
| schedule_timeout_uninterruptible(HZ); |
| goto repeat; |
| } |
| write_unlock(&ei->i_prealloc_lock); |
| |
| list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { |
| BUG_ON(pa->pa_type != MB_INODE_PA); |
| group = ext4_get_group_number(sb, pa->pa_pstart); |
| |
| err = ext4_mb_load_buddy_gfp(sb, group, &e4b, |
| GFP_NOFS|__GFP_NOFAIL); |
| if (err) { |
| ext4_error_err(sb, -err, "Error %d loading buddy information for %u", |
| err, group); |
| continue; |
| } |
| |
| bitmap_bh = ext4_read_block_bitmap(sb, group); |
| if (IS_ERR(bitmap_bh)) { |
| err = PTR_ERR(bitmap_bh); |
| ext4_error_err(sb, -err, "Error %d reading block bitmap for %u", |
| err, group); |
| ext4_mb_unload_buddy(&e4b); |
| continue; |
| } |
| |
| ext4_lock_group(sb, group); |
| list_del(&pa->pa_group_list); |
| ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); |
| ext4_unlock_group(sb, group); |
| |
| ext4_mb_unload_buddy(&e4b); |
| put_bh(bitmap_bh); |
| |
| list_del(&pa->u.pa_tmp_list); |
| ext4_mb_pa_free(pa); |
| } |
| } |
| |
| static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac) |
| { |
| struct ext4_prealloc_space *pa; |
| |
| BUG_ON(ext4_pspace_cachep == NULL); |
| pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS); |
| if (!pa) |
| return -ENOMEM; |
| atomic_set(&pa->pa_count, 1); |
| ac->ac_pa = pa; |
| return 0; |
| } |
| |
| static void ext4_mb_pa_put_free(struct ext4_allocation_context *ac) |
| { |
| struct ext4_prealloc_space *pa = ac->ac_pa; |
| |
| BUG_ON(!pa); |
| ac->ac_pa = NULL; |
| WARN_ON(!atomic_dec_and_test(&pa->pa_count)); |
| /* |
| * current function is only called due to an error or due to |
| * len of found blocks < len of requested blocks hence the PA has not |
| * been added to grp->bb_prealloc_list. So we don't need to lock it |
| */ |
| pa->pa_deleted = 1; |
| ext4_mb_pa_free(pa); |
| } |
| |
| #ifdef CONFIG_EXT4_DEBUG |
| static inline void ext4_mb_show_pa(struct super_block *sb) |
| { |
| ext4_group_t i, ngroups; |
| |
| if (ext4_forced_shutdown(sb)) |
| return; |
| |
| ngroups = ext4_get_groups_count(sb); |
| mb_debug(sb, "groups: "); |
| for (i = 0; i < ngroups; i++) { |
| struct ext4_group_info *grp = ext4_get_group_info(sb, i); |
| struct ext4_prealloc_space *pa; |
| ext4_grpblk_t start; |
| struct list_head *cur; |
| |
| if (!grp) |
| continue; |
| ext4_lock_group(sb, i); |
| list_for_each(cur, &grp->bb_prealloc_list) { |
| pa = list_entry(cur, struct ext4_prealloc_space, |
| pa_group_list); |
| spin_lock(&pa->pa_lock); |
| ext4_get_group_no_and_offset(sb, pa->pa_pstart, |
| NULL, &start); |
| spin_unlock(&pa->pa_lock); |
| mb_debug(sb, "PA:%u:%d:%d\n", i, start, |
| pa->pa_len); |
| } |
| ext4_unlock_group(sb, i); |
| mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free, |
| grp->bb_fragments); |
| } |
| } |
| |
| static void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| { |
| struct super_block *sb = ac->ac_sb; |
| |
| if (ext4_forced_shutdown(sb)) |
| return; |
| |
| mb_debug(sb, "Can't allocate:" |
| " Allocation context details:"); |
| mb_debug(sb, "status %u flags 0x%x", |
| ac->ac_status, ac->ac_flags); |
| mb_debug(sb, "orig %lu/%lu/%lu@%lu, " |
| "goal %lu/%lu/%lu@%lu, " |
| "best %lu/%lu/%lu@%lu cr %d", |
| (unsigned long)ac->ac_o_ex.fe_group, |
| (unsigned long)ac->ac_o_ex.fe_start, |
| (unsigned long)ac->ac_o_ex.fe_len, |
| (unsigned long)ac->ac_o_ex.fe_logical, |
| (unsigned long)ac->ac_g_ex.fe_group, |
| (unsigned long)ac->ac_g_ex.fe_start, |
| (unsigned long)ac->ac_g_ex.fe_len, |
| (unsigned long)ac->ac_g_ex.fe_logical, |
| (unsigned long)ac->ac_b_ex.fe_group, |
| (unsigned long)ac->ac_b_ex.fe_start, |
| (unsigned long)ac->ac_b_ex.fe_len, |
| (unsigned long)ac->ac_b_ex.fe_logical, |
| (int)ac->ac_criteria); |
| mb_debug(sb, "%u found", ac->ac_found); |
| mb_debug(sb, "used pa: %s, ", str_yes_no(ac->ac_pa)); |
| if (ac->ac_pa) |
| mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ? |
| "group pa" : "inode pa"); |
| ext4_mb_show_pa(sb); |
| } |
| #else |
| static inline void ext4_mb_show_pa(struct super_block *sb) |
| { |
| } |
| static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) |
| { |
| ext4_mb_show_pa(ac->ac_sb); |
| } |
| #endif |
| |
| /* |
| * We use locality group preallocation for small size file. The size of the |
| * file is determined by the current size or the resulting size after |
| * allocation which ever is larger |
| * |
| * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req |
| */ |
| static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| int bsbits = ac->ac_sb->s_blocksize_bits; |
| loff_t size, isize; |
| bool inode_pa_eligible, group_pa_eligible; |
| |
| if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) |
| return; |
| |
| if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) |
| return; |
| |
| group_pa_eligible = sbi->s_mb_group_prealloc > 0; |
| inode_pa_eligible = true; |
| size = extent_logical_end(sbi, &ac->ac_o_ex); |
| isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) |
| >> bsbits; |
| |
| /* No point in using inode preallocation for closed files */ |
| if ((size == isize) && !ext4_fs_is_busy(sbi) && |
| !inode_is_open_for_write(ac->ac_inode)) |
| inode_pa_eligible = false; |
| |
| size = max(size, isize); |
| /* Don't use group allocation for large files */ |
| if (size > sbi->s_mb_stream_request) |
| group_pa_eligible = false; |
| |
| if (!group_pa_eligible) { |
| if (inode_pa_eligible) |
| ac->ac_flags |= EXT4_MB_STREAM_ALLOC; |
| else |
| ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; |
| return; |
| } |
| |
| BUG_ON(ac->ac_lg != NULL); |
| /* |
| * locality group prealloc space are per cpu. The reason for having |
| * per cpu locality group is to reduce the contention between block |
| * request from multiple CPUs. |
| */ |
| ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups); |
| |
| /* we're going to use group allocation */ |
| ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; |
| |
| /* serialize all allocations in the group */ |
| mutex_lock(&ac->ac_lg->lg_mutex); |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_initialize_context(struct ext4_allocation_context *ac, |
| struct ext4_allocation_request *ar) |
| { |
| struct super_block *sb = ar->inode->i_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_super_block *es = sbi->s_es; |
| ext4_group_t group; |
| unsigned int len; |
| ext4_fsblk_t goal; |
| ext4_grpblk_t block; |
| |
| /* we can't allocate > group size */ |
| len = ar->len; |
| |
| /* just a dirty hack to filter too big requests */ |
| if (len >= EXT4_CLUSTERS_PER_GROUP(sb)) |
| len = EXT4_CLUSTERS_PER_GROUP(sb); |
| |
| /* start searching from the goal */ |
| goal = ar->goal; |
| if (goal < le32_to_cpu(es->s_first_data_block) || |
| goal >= ext4_blocks_count(es)) |
| goal = le32_to_cpu(es->s_first_data_block); |
| ext4_get_group_no_and_offset(sb, goal, &group, &block); |
| |
| /* set up allocation goals */ |
| ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical); |
| ac->ac_status = AC_STATUS_CONTINUE; |
| ac->ac_sb = sb; |
| ac->ac_inode = ar->inode; |
| ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical; |
| ac->ac_o_ex.fe_group = group; |
| ac->ac_o_ex.fe_start = block; |
| ac->ac_o_ex.fe_len = len; |
| ac->ac_g_ex = ac->ac_o_ex; |
| ac->ac_orig_goal_len = ac->ac_g_ex.fe_len; |
| ac->ac_flags = ar->flags; |
| |
| /* we have to define context: we'll work with a file or |
| * locality group. this is a policy, actually */ |
| ext4_mb_group_or_file(ac); |
| |
| mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, " |
| "left: %u/%u, right %u/%u to %swritable\n", |
| (unsigned) ar->len, (unsigned) ar->logical, |
| (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, |
| (unsigned) ar->lleft, (unsigned) ar->pleft, |
| (unsigned) ar->lright, (unsigned) ar->pright, |
| inode_is_open_for_write(ar->inode) ? "" : "non-"); |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_discard_lg_preallocations(struct super_block *sb, |
| struct ext4_locality_group *lg, |
| int order, int total_entries) |
| { |
| ext4_group_t group = 0; |
| struct ext4_buddy e4b; |
| LIST_HEAD(discard_list); |
| struct ext4_prealloc_space *pa, *tmp; |
| |
| mb_debug(sb, "discard locality group preallocation\n"); |
| |
| spin_lock(&lg->lg_prealloc_lock); |
| list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order], |
| pa_node.lg_list, |
| lockdep_is_held(&lg->lg_prealloc_lock)) { |
| spin_lock(&pa->pa_lock); |
| if (atomic_read(&pa->pa_count)) { |
| /* |
| * This is the pa that we just used |
| * for block allocation. So don't |
| * free that |
| */ |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| if (pa->pa_deleted) { |
| spin_unlock(&pa->pa_lock); |
| continue; |
| } |
| /* only lg prealloc space */ |
| BUG_ON(pa->pa_type != MB_GROUP_PA); |
| |
| /* seems this one can be freed ... */ |
| ext4_mb_mark_pa_deleted(sb, pa); |
| spin_unlock(&pa->pa_lock); |
| |
| list_del_rcu(&pa->pa_node.lg_list); |
| list_add(&pa->u.pa_tmp_list, &discard_list); |
| |
| total_entries--; |
| if (total_entries <= 5) { |
| /* |
| * we want to keep only 5 entries |
| * allowing it to grow to 8. This |
| * mak sure we don't call discard |
| * soon for this list. |
| */ |
| break; |
| } |
| } |
| spin_unlock(&lg->lg_prealloc_lock); |
| |
| list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { |
| int err; |
| |
| group = ext4_get_group_number(sb, pa->pa_pstart); |
| err = ext4_mb_load_buddy_gfp(sb, group, &e4b, |
| GFP_NOFS|__GFP_NOFAIL); |
| if (err) { |
| ext4_error_err(sb, -err, "Error %d loading buddy information for %u", |
| err, group); |
| continue; |
| } |
| ext4_lock_group(sb, group); |
| list_del(&pa->pa_group_list); |
| ext4_mb_release_group_pa(&e4b, pa); |
| ext4_unlock_group(sb, group); |
| |
| ext4_mb_unload_buddy(&e4b); |
| list_del(&pa->u.pa_tmp_list); |
| call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); |
| } |
| } |
| |
| /* |
| * We have incremented pa_count. So it cannot be freed at this |
| * point. Also we hold lg_mutex. So no parallel allocation is |
| * possible from this lg. That means pa_free cannot be updated. |
| * |
| * A parallel ext4_mb_discard_group_preallocations is possible. |
| * which can cause the lg_prealloc_list to be updated. |
| */ |
| |
| static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) |
| { |
| int order, added = 0, lg_prealloc_count = 1; |
| struct super_block *sb = ac->ac_sb; |
| struct ext4_locality_group *lg = ac->ac_lg; |
| struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa; |
| |
| order = fls(pa->pa_free) - 1; |
| if (order > PREALLOC_TB_SIZE - 1) |
| /* The max size of hash table is PREALLOC_TB_SIZE */ |
| order = PREALLOC_TB_SIZE - 1; |
| /* Add the prealloc space to lg */ |
| spin_lock(&lg->lg_prealloc_lock); |
| list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], |
| pa_node.lg_list, |
| lockdep_is_held(&lg->lg_prealloc_lock)) { |
| spin_lock(&tmp_pa->pa_lock); |
| if (tmp_pa->pa_deleted) { |
| spin_unlock(&tmp_pa->pa_lock); |
| continue; |
| } |
| if (!added && pa->pa_free < tmp_pa->pa_free) { |
| /* Add to the tail of the previous entry */ |
| list_add_tail_rcu(&pa->pa_node.lg_list, |
| &tmp_pa->pa_node.lg_list); |
| added = 1; |
| /* |
| * we want to count the total |
| * number of entries in the list |
| */ |
| } |
| spin_unlock(&tmp_pa->pa_lock); |
| lg_prealloc_count++; |
| } |
| if (!added) |
| list_add_tail_rcu(&pa->pa_node.lg_list, |
| &lg->lg_prealloc_list[order]); |
| spin_unlock(&lg->lg_prealloc_lock); |
| |
| /* Now trim the list to be not more than 8 elements */ |
| if (lg_prealloc_count > 8) |
| ext4_mb_discard_lg_preallocations(sb, lg, |
| order, lg_prealloc_count); |
| } |
| |
| /* |
| * release all resource we used in allocation |
| */ |
| static void ext4_mb_release_context(struct ext4_allocation_context *ac) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); |
| struct ext4_prealloc_space *pa = ac->ac_pa; |
| if (pa) { |
| if (pa->pa_type == MB_GROUP_PA) { |
| /* see comment in ext4_mb_use_group_pa() */ |
| spin_lock(&pa->pa_lock); |
| pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
| pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); |
| pa->pa_free -= ac->ac_b_ex.fe_len; |
| pa->pa_len -= ac->ac_b_ex.fe_len; |
| spin_unlock(&pa->pa_lock); |
| |
| /* |
| * We want to add the pa to the right bucket. |
| * Remove it from the list and while adding |
| * make sure the list to which we are adding |
| * doesn't grow big. |
| */ |
| if (likely(pa->pa_free)) { |
| spin_lock(pa->pa_node_lock.lg_lock); |
| list_del_rcu(&pa->pa_node.lg_list); |
| spin_unlock(pa->pa_node_lock.lg_lock); |
| ext4_mb_add_n_trim(ac); |
| } |
| } |
| |
| ext4_mb_put_pa(ac, ac->ac_sb, pa); |
| } |
| if (ac->ac_bitmap_folio) |
| folio_put(ac->ac_bitmap_folio); |
| if (ac->ac_buddy_folio) |
| folio_put(ac->ac_buddy_folio); |
| if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) |
| mutex_unlock(&ac->ac_lg->lg_mutex); |
| ext4_mb_collect_stats(ac); |
| } |
| |
| static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) |
| { |
| ext4_group_t i, ngroups = ext4_get_groups_count(sb); |
| int ret; |
| int freed = 0, busy = 0; |
| int retry = 0; |
| |
| trace_ext4_mb_discard_preallocations(sb, needed); |
| |
| if (needed == 0) |
| needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; |
| repeat: |
| for (i = 0; i < ngroups && needed > 0; i++) { |
| ret = ext4_mb_discard_group_preallocations(sb, i, &busy); |
| freed += ret; |
| needed -= ret; |
| cond_resched(); |
| } |
| |
| if (needed > 0 && busy && ++retry < 3) { |
| busy = 0; |
| goto repeat; |
| } |
| |
| return freed; |
| } |
| |
| static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb, |
| struct ext4_allocation_context *ac, u64 *seq) |
| { |
| int freed; |
| u64 seq_retry = 0; |
| bool ret = false; |
| |
| freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); |
| if (freed) { |
| ret = true; |
| goto out_dbg; |
| } |
| seq_retry = ext4_get_discard_pa_seq_sum(); |
| if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) { |
| ac->ac_flags |= EXT4_MB_STRICT_CHECK; |
| *seq = seq_retry; |
| ret = true; |
| } |
| |
| out_dbg: |
| mb_debug(sb, "freed %d, retry ? %s\n", freed, str_yes_no(ret)); |
| return ret; |
| } |
| |
| /* |
| * Simple allocator for Ext4 fast commit replay path. It searches for blocks |
| * linearly starting at the goal block and also excludes the blocks which |
| * are going to be in use after fast commit replay. |
| */ |
| static ext4_fsblk_t |
| ext4_mb_new_blocks_simple(struct ext4_allocation_request *ar, int *errp) |
| { |
| struct buffer_head *bitmap_bh; |
| struct super_block *sb = ar->inode->i_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_group_t group, nr; |
| ext4_grpblk_t blkoff; |
| ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); |
| ext4_grpblk_t i = 0; |
| ext4_fsblk_t goal, block; |
| struct ext4_super_block *es = sbi->s_es; |
| |
| goal = ar->goal; |
| if (goal < le32_to_cpu(es->s_first_data_block) || |
| goal >= ext4_blocks_count(es)) |
| goal = le32_to_cpu(es->s_first_data_block); |
| |
| ar->len = 0; |
| ext4_get_group_no_and_offset(sb, goal, &group, &blkoff); |
| for (nr = ext4_get_groups_count(sb); nr > 0; nr--) { |
| bitmap_bh = ext4_read_block_bitmap(sb, group); |
| if (IS_ERR(bitmap_bh)) { |
| *errp = PTR_ERR(bitmap_bh); |
| pr_warn("Failed to read block bitmap\n"); |
| return 0; |
| } |
| |
| while (1) { |
| i = mb_find_next_zero_bit(bitmap_bh->b_data, max, |
| blkoff); |
| if (i >= max) |
| break; |
| if (ext4_fc_replay_check_excluded(sb, |
| ext4_group_first_block_no(sb, group) + |
| EXT4_C2B(sbi, i))) { |
| blkoff = i + 1; |
| } else |
| break; |
| } |
| brelse(bitmap_bh); |
| if (i < max) |
| break; |
| |
| if (++group >= ext4_get_groups_count(sb)) |
| group = 0; |
| |
| blkoff = 0; |
| } |
| |
| if (i >= max) { |
| *errp = -ENOSPC; |
| return 0; |
| } |
| |
| block = ext4_group_first_block_no(sb, group) + EXT4_C2B(sbi, i); |
| ext4_mb_mark_bb(sb, block, 1, true); |
| ar->len = 1; |
| |
| *errp = 0; |
| return block; |
| } |
| |
| /* |
| * Main entry point into mballoc to allocate blocks |
| * it tries to use preallocation first, then falls back |
| * to usual allocation |
| */ |
| ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, |
| struct ext4_allocation_request *ar, int *errp) |
| { |
| struct ext4_allocation_context *ac = NULL; |
| struct ext4_sb_info *sbi; |
| struct super_block *sb; |
| ext4_fsblk_t block = 0; |
| unsigned int inquota = 0; |
| unsigned int reserv_clstrs = 0; |
| int retries = 0; |
| u64 seq; |
| |
| might_sleep(); |
| sb = ar->inode->i_sb; |
| sbi = EXT4_SB(sb); |
| |
| trace_ext4_request_blocks(ar); |
| if (sbi->s_mount_state & EXT4_FC_REPLAY) |
| return ext4_mb_new_blocks_simple(ar, errp); |
| |
| /* Allow to use superuser reservation for quota file */ |
| if (ext4_is_quota_file(ar->inode)) |
| ar->flags |= EXT4_MB_USE_ROOT_BLOCKS; |
| |
| if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) { |
| /* Without delayed allocation we need to verify |
| * there is enough free blocks to do block allocation |
| * and verify allocation doesn't exceed the quota limits. |
| */ |
| while (ar->len && |
| ext4_claim_free_clusters(sbi, ar->len, ar->flags)) { |
| |
| /* let others to free the space */ |
| cond_resched(); |
| ar->len = ar->len >> 1; |
| } |
| if (!ar->len) { |
| ext4_mb_show_pa(sb); |
| *errp = -ENOSPC; |
| return 0; |
| } |
| reserv_clstrs = ar->len; |
| if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) { |
| dquot_alloc_block_nofail(ar->inode, |
| EXT4_C2B(sbi, ar->len)); |
| } else { |
| while (ar->len && |
| dquot_alloc_block(ar->inode, |
| EXT4_C2B(sbi, ar->len))) { |
| |
| ar->flags |= EXT4_MB_HINT_NOPREALLOC; |
| ar->len--; |
| } |
| } |
| inquota = ar->len; |
| if (ar->len == 0) { |
| *errp = -EDQUOT; |
| goto out; |
| } |
| } |
| |
| ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS); |
| if (!ac) { |
| ar->len = 0; |
| *errp = -ENOMEM; |
| goto out; |
| } |
| |
| ext4_mb_initialize_context(ac, ar); |
| |
| ac->ac_op = EXT4_MB_HISTORY_PREALLOC; |
| seq = this_cpu_read(discard_pa_seq); |
| if (!ext4_mb_use_preallocated(ac)) { |
| ac->ac_op = EXT4_MB_HISTORY_ALLOC; |
| ext4_mb_normalize_request(ac, ar); |
| |
| *errp = ext4_mb_pa_alloc(ac); |
| if (*errp) |
| goto errout; |
| repeat: |
| /* allocate space in core */ |
| *errp = ext4_mb_regular_allocator(ac); |
| /* |
| * pa allocated above is added to grp->bb_prealloc_list only |
| * when we were able to allocate some block i.e. when |
| * ac->ac_status == AC_STATUS_FOUND. |
| * And error from above mean ac->ac_status != AC_STATUS_FOUND |
| * So we have to free this pa here itself. |
| */ |
| if (*errp) { |
| ext4_mb_pa_put_free(ac); |
| ext4_discard_allocated_blocks(ac); |
| goto errout; |
| } |
| if (ac->ac_status == AC_STATUS_FOUND && |
| ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len) |
| ext4_mb_pa_put_free(ac); |
| } |
| if (likely(ac->ac_status == AC_STATUS_FOUND)) { |
| *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); |
| if (*errp) { |
| ext4_discard_allocated_blocks(ac); |
| goto errout; |
| } else { |
| block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); |
| ar->len = ac->ac_b_ex.fe_len; |
| } |
| } else { |
| if (++retries < 3 && |
| ext4_mb_discard_preallocations_should_retry(sb, ac, &seq)) |
| goto repeat; |
| /* |
| * If block allocation fails then the pa allocated above |
| * needs to be freed here itself. |
| */ |
| ext4_mb_pa_put_free(ac); |
| *errp = -ENOSPC; |
| } |
| |
| if (*errp) { |
| errout: |
| ac->ac_b_ex.fe_len = 0; |
| ar->len = 0; |
| ext4_mb_show_ac(ac); |
| } |
| ext4_mb_release_context(ac); |
| kmem_cache_free(ext4_ac_cachep, ac); |
| out: |
| if (inquota && ar->len < inquota) |
| dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); |
| if (!ar->len) { |
| if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) |
| /* release all the reserved blocks if non delalloc */ |
| percpu_counter_sub(&sbi->s_dirtyclusters_counter, |
| reserv_clstrs); |
| } |
| |
| trace_ext4_allocate_blocks(ar, (unsigned long long)block); |
| |
| return block; |
| } |
| |
| /* |
| * We can merge two free data extents only if the physical blocks |
| * are contiguous, AND the extents were freed by the same transaction, |
| * AND the blocks are associated with the same group. |
| */ |
| static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi, |
| struct ext4_free_data *entry, |
| struct ext4_free_data *new_entry, |
| struct rb_root *entry_rb_root) |
| { |
| if ((entry->efd_tid != new_entry->efd_tid) || |
| (entry->efd_group != new_entry->efd_group)) |
| return; |
| if (entry->efd_start_cluster + entry->efd_count == |
| new_entry->efd_start_cluster) { |
| new_entry->efd_start_cluster = entry->efd_start_cluster; |
| new_entry->efd_count += entry->efd_count; |
| } else if (new_entry->efd_start_cluster + new_entry->efd_count == |
| entry->efd_start_cluster) { |
| new_entry->efd_count += entry->efd_count; |
| } else |
| return; |
| spin_lock(&sbi->s_md_lock); |
| list_del(&entry->efd_list); |
| spin_unlock(&sbi->s_md_lock); |
| rb_erase(&entry->efd_node, entry_rb_root); |
| kmem_cache_free(ext4_free_data_cachep, entry); |
| } |
| |
| static noinline_for_stack void |
| ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, |
| struct ext4_free_data *new_entry) |
| { |
| ext4_group_t group = e4b->bd_group; |
| ext4_grpblk_t cluster; |
| ext4_grpblk_t clusters = new_entry->efd_count; |
| struct ext4_free_data *entry; |
| struct ext4_group_info *db = e4b->bd_info; |
| struct super_block *sb = e4b->bd_sb; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct rb_node **n = &db->bb_free_root.rb_node, *node; |
| struct rb_node *parent = NULL, *new_node; |
| |
| BUG_ON(!ext4_handle_valid(handle)); |
| BUG_ON(e4b->bd_bitmap_folio == NULL); |
| BUG_ON(e4b->bd_buddy_folio == NULL); |
| |
| new_node = &new_entry->efd_node; |
| cluster = new_entry->efd_start_cluster; |
| |
| if (!*n) { |
| /* first free block exent. We need to |
| protect buddy cache from being freed, |
| * otherwise we'll refresh it from |
| * on-disk bitmap and lose not-yet-available |
| * blocks */ |
| folio_get(e4b->bd_buddy_folio); |
| folio_get(e4b->bd_bitmap_folio); |
| } |
| while (*n) { |
| parent = *n; |
| entry = rb_entry(parent, struct ext4_free_data, efd_node); |
| if (cluster < entry->efd_start_cluster) |
| n = &(*n)->rb_left; |
| else if (cluster >= (entry->efd_start_cluster + entry->efd_count)) |
| n = &(*n)->rb_right; |
| else { |
| ext4_grp_locked_error(sb, group, 0, |
| ext4_group_first_block_no(sb, group) + |
| EXT4_C2B(sbi, cluster), |
| "Block already on to-be-freed list"); |
| kmem_cache_free(ext4_free_data_cachep, new_entry); |
| return; |
| } |
| } |
| |
| rb_link_node(new_node, parent, n); |
| rb_insert_color(new_node, &db->bb_free_root); |
| |
| /* Now try to see the extent can be merged to left and right */ |
| node = rb_prev(new_node); |
| if (node) { |
| entry = rb_entry(node, struct ext4_free_data, efd_node); |
| ext4_try_merge_freed_extent(sbi, entry, new_entry, |
| &(db->bb_free_root)); |
| } |
| |
| node = rb_next(new_node); |
| if (node) { |
| entry = rb_entry(node, struct ext4_free_data, efd_node); |
| ext4_try_merge_freed_extent(sbi, entry, new_entry, |
| &(db->bb_free_root)); |
| } |
| |
| spin_lock(&sbi->s_md_lock); |
| list_add_tail(&new_entry->efd_list, &sbi->s_freed_data_list[new_entry->efd_tid & 1]); |
| sbi->s_mb_free_pending += clusters; |
| spin_unlock(&sbi->s_md_lock); |
| } |
| |
| static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block, |
| unsigned long count) |
| { |
| struct super_block *sb = inode->i_sb; |
| ext4_group_t group; |
| ext4_grpblk_t blkoff; |
| |
| ext4_get_group_no_and_offset(sb, block, &group, &blkoff); |
| ext4_mb_mark_context(NULL, sb, false, group, blkoff, count, |
| EXT4_MB_BITMAP_MARKED_CHECK | |
| EXT4_MB_SYNC_UPDATE, |
| NULL); |
| } |
| |
| /** |
| * ext4_mb_clear_bb() -- helper function for freeing blocks. |
| * Used by ext4_free_blocks() |
| * @handle: handle for this transaction |
| * @inode: inode |
| * @block: starting physical block to be freed |
| * @count: number of blocks to be freed |
| * @flags: flags used by ext4_free_blocks |
| */ |
| static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode, |
| ext4_fsblk_t block, unsigned long count, |
| int flags) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct ext4_group_info *grp; |
| unsigned int overflow; |
| ext4_grpblk_t bit; |
| ext4_group_t block_group; |
| struct ext4_sb_info *sbi; |
| struct ext4_buddy e4b; |
| unsigned int count_clusters; |
| int err = 0; |
| int mark_flags = 0; |
| ext4_grpblk_t changed; |
| |
| sbi = EXT4_SB(sb); |
| |
| if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && |
| !ext4_inode_block_valid(inode, block, count)) { |
| ext4_error(sb, "Freeing blocks in system zone - " |
| "Block = %llu, count = %lu", block, count); |
| /* err = 0. ext4_std_error should be a no op */ |
| goto error_out; |
| } |
| flags |= EXT4_FREE_BLOCKS_VALIDATED; |
| |
| do_more: |
| overflow = 0; |
| ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
| |
| grp = ext4_get_group_info(sb, block_group); |
| if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) |
| return; |
| |
| /* |
| * Check to see if we are freeing blocks across a group |
| * boundary. |
| */ |
| if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) { |
| overflow = EXT4_C2B(sbi, bit) + count - |
| EXT4_BLOCKS_PER_GROUP(sb); |
| count -= overflow; |
| /* The range changed so it's no longer validated */ |
| flags &= ~EXT4_FREE_BLOCKS_VALIDATED; |
| } |
| count_clusters = EXT4_NUM_B2C(sbi, count); |
| trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters); |
| |
| /* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */ |
| err = ext4_mb_load_buddy_gfp(sb, block_group, &e4b, |
| GFP_NOFS|__GFP_NOFAIL); |
| if (err) |
| goto error_out; |
| |
| if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && |
| !ext4_inode_block_valid(inode, block, count)) { |
| ext4_error(sb, "Freeing blocks in system zone - " |
| "Block = %llu, count = %lu", block, count); |
| /* err = 0. ext4_std_error should be a no op */ |
| goto error_clean; |
| } |
| |
| #ifdef AGGRESSIVE_CHECK |
| mark_flags |= EXT4_MB_BITMAP_MARKED_CHECK; |
| #endif |
| err = ext4_mb_mark_context(handle, sb, false, block_group, bit, |
| count_clusters, mark_flags, &changed); |
| |
| |
| if (err && changed == 0) |
| goto error_clean; |
| |
| #ifdef AGGRESSIVE_CHECK |
| BUG_ON(changed != count_clusters); |
| #endif |
| |
| /* |
| * We need to make sure we don't reuse the freed block until after the |
| * transaction is committed. We make an exception if the inode is to be |
| * written in writeback mode since writeback mode has weak data |
| * consistency guarantees. |
| */ |
| if (ext4_handle_valid(handle) && |
| ((flags & EXT4_FREE_BLOCKS_METADATA) || |
| !ext4_should_writeback_data(inode))) { |
| struct ext4_free_data *new_entry; |
| /* |
| * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed |
| * to fail. |
| */ |
| new_entry = kmem_cache_alloc(ext4_free_data_cachep, |
| GFP_NOFS|__GFP_NOFAIL); |
| new_entry->efd_start_cluster = bit; |
| new_entry->efd_group = block_group; |
| new_entry->efd_count = count_clusters; |
| new_entry->efd_tid = handle->h_transaction->t_tid; |
| |
| ext4_lock_group(sb, block_group); |
| ext4_mb_free_metadata(handle, &e4b, new_entry); |
| } else { |
| if (test_opt(sb, DISCARD)) { |
| err = ext4_issue_discard(sb, block_group, bit, |
| count_clusters); |
| /* |
| * Ignore EOPNOTSUPP error. This is consistent with |
| * what happens when using journal. |
| */ |
| if (err == -EOPNOTSUPP) |
| err = 0; |
| if (err) |
| ext4_msg(sb, KERN_WARNING, "discard request in" |
| " group:%u block:%d count:%lu failed" |
| " with %d", block_group, bit, count, |
| err); |
| } |
| |
| EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info); |
| |
| ext4_lock_group(sb, block_group); |
| mb_free_blocks(inode, &e4b, bit, count_clusters); |
| } |
| |
| ext4_unlock_group(sb, block_group); |
| |
| /* |
| * on a bigalloc file system, defer the s_freeclusters_counter |
| * update to the caller (ext4_remove_space and friends) so they |
| * can determine if a cluster freed here should be rereserved |
| */ |
| if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) { |
| if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) |
| dquot_free_block(inode, EXT4_C2B(sbi, count_clusters)); |
| percpu_counter_add(&sbi->s_freeclusters_counter, |
| count_clusters); |
| } |
| |
| if (overflow && !err) { |
| block += count; |
| count = overflow; |
| ext4_mb_unload_buddy(&e4b); |
| /* The range changed so it's no longer validated */ |
| flags &= ~EXT4_FREE_BLOCKS_VALIDATED; |
| goto do_more; |
| } |
| |
| error_clean: |
| ext4_mb_unload_buddy(&e4b); |
| error_out: |
| ext4_std_error(sb, err); |
| } |
| |
| /** |
| * ext4_free_blocks() -- Free given blocks and update quota |
| * @handle: handle for this transaction |
| * @inode: inode |
| * @bh: optional buffer of the block to be freed |
| * @block: starting physical block to be freed |
| * @count: number of blocks to be freed |
| * @flags: flags used by ext4_free_blocks |
| */ |
| void ext4_free_blocks(handle_t *handle, struct inode *inode, |
| struct buffer_head *bh, ext4_fsblk_t block, |
| unsigned long count, int flags) |
| { |
| struct super_block *sb = inode->i_sb; |
| unsigned int overflow; |
| struct ext4_sb_info *sbi; |
| |
| sbi = EXT4_SB(sb); |
| |
| if (bh) { |
| if (block) |
| BUG_ON(block != bh->b_blocknr); |
| else |
| block = bh->b_blocknr; |
| } |
| |
| if (sbi->s_mount_state & EXT4_FC_REPLAY) { |
| ext4_free_blocks_simple(inode, block, EXT4_NUM_B2C(sbi, count)); |
| return; |
| } |
| |
| might_sleep(); |
| |
| if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && |
| !ext4_inode_block_valid(inode, block, count)) { |
| ext4_error(sb, "Freeing blocks not in datazone - " |
| "block = %llu, count = %lu", block, count); |
| return; |
| } |
| flags |= EXT4_FREE_BLOCKS_VALIDATED; |
| |
| ext4_debug("freeing block %llu\n", block); |
| trace_ext4_free_blocks(inode, block, count, flags); |
| |
| if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { |
| BUG_ON(count > 1); |
| |
| ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, |
| inode, bh, block); |
| } |
| |
| /* |
| * If the extent to be freed does not begin on a cluster |
| * boundary, we need to deal with partial clusters at the |
| * beginning and end of the extent. Normally we will free |
| * blocks at the beginning or the end unless we are explicitly |
| * requested to avoid doing so. |
| */ |
| overflow = EXT4_PBLK_COFF(sbi, block); |
| if (overflow) { |
| if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) { |
| overflow = sbi->s_cluster_ratio - overflow; |
| block += overflow; |
| if (count > overflow) |
| count -= overflow; |
| else |
| return; |
| } else { |
| block -= overflow; |
| count += overflow; |
| } |
| /* The range changed so it's no longer validated */ |
| flags &= ~EXT4_FREE_BLOCKS_VALIDATED; |
| } |
| overflow = EXT4_LBLK_COFF(sbi, count); |
| if (overflow) { |
| if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) { |
| if (count > overflow) |
| count -= overflow; |
| else |
| return; |
| } else |
| count += sbi->s_cluster_ratio - overflow; |
| /* The range changed so it's no longer validated */ |
| flags &= ~EXT4_FREE_BLOCKS_VALIDATED; |
| } |
| |
| if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) { |
| int i; |
| int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA; |
| |
| for (i = 0; i < count; i++) { |
| cond_resched(); |
| if (is_metadata) |
| bh = sb_find_get_block(inode->i_sb, block + i); |
| ext4_forget(handle, is_metadata, inode, bh, block + i); |
| } |
| } |
| |
| ext4_mb_clear_bb(handle, inode, block, count, flags); |
| } |
| |
| /** |
| * ext4_group_add_blocks() -- Add given blocks to an existing group |
| * @handle: handle to this transaction |
| * @sb: super block |
| * @block: start physical block to add to the block group |
| * @count: number of blocks to free |
| * |
| * This marks the blocks as free in the bitmap and buddy. |
| */ |
| int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, |
| ext4_fsblk_t block, unsigned long count) |
| { |
| ext4_group_t block_group; |
| ext4_grpblk_t bit; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_buddy e4b; |
| int err = 0; |
| ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block); |
| ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1); |
| unsigned long cluster_count = last_cluster - first_cluster + 1; |
| ext4_grpblk_t changed; |
| |
| ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); |
| |
| if (cluster_count == 0) |
| return 0; |
| |
| ext4_get_group_no_and_offset(sb, block, &block_group, &bit); |
| /* |
| * Check to see if we are freeing blocks across a group |
| * boundary. |
| */ |
| if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) { |
| ext4_warning(sb, "too many blocks added to group %u", |
| block_group); |
| err = -EINVAL; |
| goto error_out; |
| } |
| |
| err = ext4_mb_load_buddy(sb, block_group, &e4b); |
| if (err) |
| goto error_out; |
| |
| if (!ext4_sb_block_valid(sb, NULL, block, count)) { |
| ext4_error(sb, "Adding blocks in system zones - " |
| "Block = %llu, count = %lu", |
| block, count); |
| err = -EINVAL; |
| goto error_clean; |
| } |
| |
| err = ext4_mb_mark_context(handle, sb, false, block_group, bit, |
| cluster_count, EXT4_MB_BITMAP_MARKED_CHECK, |
| &changed); |
| if (err && changed == 0) |
| goto error_clean; |
| |
| if (changed != cluster_count) |
| ext4_error(sb, "bit already cleared in group %u", block_group); |
| |
| ext4_lock_group(sb, block_group); |
| mb_free_blocks(NULL, &e4b, bit, cluster_count); |
| ext4_unlock_group(sb, block_group); |
| percpu_counter_add(&sbi->s_freeclusters_counter, |
| changed); |
| |
| error_clean: |
| ext4_mb_unload_buddy(&e4b); |
| error_out: |
| ext4_std_error(sb, err); |
| return err; |
| } |
| |
| /** |
| * ext4_trim_extent -- function to TRIM one single free extent in the group |
| * @sb: super block for the file system |
| * @start: starting block of the free extent in the alloc. group |
| * @count: number of blocks to TRIM |
| * @e4b: ext4 buddy for the group |
| * |
| * Trim "count" blocks starting at "start" in the "group". To assure that no |
| * one will allocate those blocks, mark it as used in buddy bitmap. This must |
| * be called with under the group lock. |
| */ |
| static int ext4_trim_extent(struct super_block *sb, |
| int start, int count, struct ext4_buddy *e4b) |
| __releases(bitlock) |
| __acquires(bitlock) |
| { |
| struct ext4_free_extent ex; |
| ext4_group_t group = e4b->bd_group; |
| int ret = 0; |
| |
| trace_ext4_trim_extent(sb, group, start, count); |
| |
| assert_spin_locked(ext4_group_lock_ptr(sb, group)); |
| |
| ex.fe_start = start; |
| ex.fe_group = group; |
| ex.fe_len = count; |
| |
| /* |
| * Mark blocks used, so no one can reuse them while |
| * being trimmed. |
| */ |
| mb_mark_used(e4b, &ex); |
| ext4_unlock_group(sb, group); |
| ret = ext4_issue_discard(sb, group, start, count); |
| ext4_lock_group(sb, group); |
| mb_free_blocks(NULL, e4b, start, ex.fe_len); |
| return ret; |
| } |
| |
| static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb, |
| ext4_group_t grp) |
| { |
| unsigned long nr_clusters_in_group; |
| |
| if (grp < (ext4_get_groups_count(sb) - 1)) |
| nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb); |
| else |
| nr_clusters_in_group = (ext4_blocks_count(EXT4_SB(sb)->s_es) - |
| ext4_group_first_block_no(sb, grp)) |
| >> EXT4_CLUSTER_BITS(sb); |
| |
| return nr_clusters_in_group - 1; |
| } |
| |
| static bool ext4_trim_interrupted(void) |
| { |
| return fatal_signal_pending(current) || freezing(current); |
| } |
| |
| static int ext4_try_to_trim_range(struct super_block *sb, |
| struct ext4_buddy *e4b, ext4_grpblk_t start, |
| ext4_grpblk_t max, ext4_grpblk_t minblocks) |
| __acquires(ext4_group_lock_ptr(sb, e4b->bd_group)) |
| __releases(ext4_group_lock_ptr(sb, e4b->bd_group)) |
| { |
| ext4_grpblk_t next, count, free_count, last, origin_start; |
| bool set_trimmed = false; |
| void *bitmap; |
| |
| if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) |
| return 0; |
| |
| last = ext4_last_grp_cluster(sb, e4b->bd_group); |
| bitmap = e4b->bd_bitmap; |
| if (start == 0 && max >= last) |
| set_trimmed = true; |
| origin_start = start; |
| start = max(e4b->bd_info->bb_first_free, start); |
| count = 0; |
| free_count = 0; |
| |
| while (start <= max) { |
| start = mb_find_next_zero_bit(bitmap, max + 1, start); |
| if (start > max) |
| break; |
| |
| next = mb_find_next_bit(bitmap, last + 1, start); |
| if (origin_start == 0 && next >= last) |
| set_trimmed = true; |
| |
| if ((next - start) >= minblocks) { |
| int ret = ext4_trim_extent(sb, start, next - start, e4b); |
| |
| if (ret && ret != -EOPNOTSUPP) |
| return count; |
| count += next - start; |
| } |
| free_count += next - start; |
| start = next + 1; |
| |
| if (ext4_trim_interrupted()) |
| return count; |
| |
| if (need_resched()) { |
| ext4_unlock_group(sb, e4b->bd_group); |
| cond_resched(); |
| ext4_lock_group(sb, e4b->bd_group); |
| } |
| |
| if ((e4b->bd_info->bb_free - free_count) < minblocks) |
| break; |
| } |
| |
| if (set_trimmed) |
| EXT4_MB_GRP_SET_TRIMMED(e4b->bd_info); |
| |
| return count; |
| } |
| |
| /** |
| * ext4_trim_all_free -- function to trim all free space in alloc. group |
| * @sb: super block for file system |
| * @group: group to be trimmed |
| * @start: first group block to examine |
| * @max: last group block to examine |
| * @minblocks: minimum extent block count |
| * |
| * ext4_trim_all_free walks through group's block bitmap searching for free |
| * extents. When the free extent is found, mark it as used in group buddy |
| * bitmap. Then issue a TRIM command on this extent and free the extent in |
| * the group buddy bitmap. |
| */ |
| static ext4_grpblk_t |
| ext4_trim_all_free(struct super_block *sb, ext4_group_t group, |
| ext4_grpblk_t start, ext4_grpblk_t max, |
| ext4_grpblk_t minblocks) |
| { |
| struct ext4_buddy e4b; |
| int ret; |
| |
| trace_ext4_trim_all_free(sb, group, start, max); |
| |
| ret = ext4_mb_load_buddy(sb, group, &e4b); |
| if (ret) { |
| ext4_warning(sb, "Error %d loading buddy information for %u", |
| ret, group); |
| return ret; |
| } |
| |
| ext4_lock_group(sb, group); |
| |
| if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) || |
| minblocks < EXT4_SB(sb)->s_last_trim_minblks) |
| ret = ext4_try_to_trim_range(sb, &e4b, start, max, minblocks); |
| else |
| ret = 0; |
| |
| ext4_unlock_group(sb, group); |
| ext4_mb_unload_buddy(&e4b); |
| |
| ext4_debug("trimmed %d blocks in the group %d\n", |
| ret, group); |
| |
| return ret; |
| } |
| |
| /** |
| * ext4_trim_fs() -- trim ioctl handle function |
| * @sb: superblock for filesystem |
| * @range: fstrim_range structure |
| * |
| * start: First Byte to trim |
| * len: number of Bytes to trim from start |
| * minlen: minimum extent length in Bytes |
| * ext4_trim_fs goes through all allocation groups containing Bytes from |
| * start to start+len. For each such a group ext4_trim_all_free function |
| * is invoked to trim all free space. |
| */ |
| int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) |
| { |
| unsigned int discard_granularity = bdev_discard_granularity(sb->s_bdev); |
| struct ext4_group_info *grp; |
| ext4_group_t group, first_group, last_group; |
| ext4_grpblk_t cnt = 0, first_cluster, last_cluster; |
| uint64_t start, end, minlen, trimmed = 0; |
| ext4_fsblk_t first_data_blk = |
| le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); |
| ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es); |
| int ret = 0; |
| |
| start = range->start >> sb->s_blocksize_bits; |
| end = start + (range->len >> sb->s_blocksize_bits) - 1; |
| minlen = EXT4_NUM_B2C(EXT4_SB(sb), |
| range->minlen >> sb->s_blocksize_bits); |
| |
| if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) || |
| start >= max_blks || |
| range->len < sb->s_blocksize) |
| return -EINVAL; |
| /* No point to try to trim less than discard granularity */ |
| if (range->minlen < discard_granularity) { |
| minlen = EXT4_NUM_B2C(EXT4_SB(sb), |
| discard_granularity >> sb->s_blocksize_bits); |
| if (minlen > EXT4_CLUSTERS_PER_GROUP(sb)) |
| goto out; |
| } |
| if (end >= max_blks - 1) |
| end = max_blks - 1; |
| if (end <= first_data_blk) |
| goto out; |
| if (start < first_data_blk) |
| start = first_data_blk; |
| |
| /* Determine first and last group to examine based on start and end */ |
| ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start, |
| &first_group, &first_cluster); |
| ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end, |
| &last_group, &last_cluster); |
| |
| /* end now represents the last cluster to discard in this group */ |
| end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; |
| |
| for (group = first_group; group <= last_group; group++) { |
| if (ext4_trim_interrupted()) |
| break; |
| grp = ext4_get_group_info(sb, group); |
| if (!grp) |
| continue; |
| /* We only do this if the grp has never been initialized */ |
| if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { |
| ret = ext4_mb_init_group(sb, group, GFP_NOFS); |
| if (ret) |
| break; |
| } |
| |
| /* |
| * For all the groups except the last one, last cluster will |
| * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to |
| * change it for the last group, note that last_cluster is |
| * already computed earlier by ext4_get_group_no_and_offset() |
| */ |
| if (group == last_group) |
| end = last_cluster; |
| if (grp->bb_free >= minlen) { |
| cnt = ext4_trim_all_free(sb, group, first_cluster, |
| end, minlen); |
| if (cnt < 0) { |
| ret = cnt; |
| break; |
| } |
| trimmed += cnt; |
| } |
| |
| /* |
| * For every group except the first one, we are sure |
| * that the first cluster to discard will be cluster #0. |
| */ |
| first_cluster = 0; |
| } |
| |
| if (!ret) |
| EXT4_SB(sb)->s_last_trim_minblks = minlen; |
| |
| out: |
| range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits; |
| return ret; |
| } |
| |
| /* Iterate all the free extents in the group. */ |
| int |
| ext4_mballoc_query_range( |
| struct super_block *sb, |
| ext4_group_t group, |
| ext4_grpblk_t first, |
| ext4_grpblk_t end, |
| ext4_mballoc_query_range_fn meta_formatter, |
| ext4_mballoc_query_range_fn formatter, |
| void *priv) |
| { |
| void *bitmap; |
| ext4_grpblk_t start, next; |
| struct ext4_buddy e4b; |
| int error; |
| |
| error = ext4_mb_load_buddy(sb, group, &e4b); |
| if (error) |
| return error; |
| bitmap = e4b.bd_bitmap; |
| |
| ext4_lock_group(sb, group); |
| |
| start = max(e4b.bd_info->bb_first_free, first); |
| if (end >= EXT4_CLUSTERS_PER_GROUP(sb)) |
| end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; |
| if (meta_formatter && start != first) { |
| if (start > end) |
| start = end; |
| ext4_unlock_group(sb, group); |
| error = meta_formatter(sb, group, first, start - first, |
| priv); |
| if (error) |
| goto out_unload; |
| ext4_lock_group(sb, group); |
| } |
| while (start <= end) { |
| start = mb_find_next_zero_bit(bitmap, end + 1, start); |
| if (start > end) |
| break; |
| next = mb_find_next_bit(bitmap, end + 1, start); |
| |
| ext4_unlock_group(sb, group); |
| error = formatter(sb, group, start, next - start, priv); |
| if (error) |
| goto out_unload; |
| ext4_lock_group(sb, group); |
| |
| start = next + 1; |
| } |
| |
| ext4_unlock_group(sb, group); |
| out_unload: |
| ext4_mb_unload_buddy(&e4b); |
| |
| return error; |
| } |
| |
| #ifdef CONFIG_EXT4_KUNIT_TESTS |
| #include "mballoc-test.c" |
| #endif |
