| // SPDX-License-Identifier: GPL-2.0 |
| |
| #include <linux/sizes.h> |
| #include <linux/list_sort.h> |
| #include "misc.h" |
| #include "ctree.h" |
| #include "block-group.h" |
| #include "space-info.h" |
| #include "disk-io.h" |
| #include "free-space-cache.h" |
| #include "free-space-tree.h" |
| #include "volumes.h" |
| #include "transaction.h" |
| #include "ref-verify.h" |
| #include "sysfs.h" |
| #include "tree-log.h" |
| #include "delalloc-space.h" |
| #include "discard.h" |
| #include "raid56.h" |
| #include "zoned.h" |
| #include "fs.h" |
| #include "accessors.h" |
| #include "extent-tree.h" |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| int btrfs_should_fragment_free_space(struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| |
| return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) && |
| block_group->flags & BTRFS_BLOCK_GROUP_METADATA) || |
| (btrfs_test_opt(fs_info, FRAGMENT_DATA) && |
| block_group->flags & BTRFS_BLOCK_GROUP_DATA); |
| } |
| #endif |
| |
| /* |
| * Return target flags in extended format or 0 if restripe for this chunk_type |
| * is not in progress |
| * |
| * Should be called with balance_lock held |
| */ |
| static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| struct btrfs_balance_control *bctl = fs_info->balance_ctl; |
| u64 target = 0; |
| |
| if (!bctl) |
| return 0; |
| |
| if (flags & BTRFS_BLOCK_GROUP_DATA && |
| bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target; |
| } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM && |
| bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target; |
| } else if (flags & BTRFS_BLOCK_GROUP_METADATA && |
| bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target; |
| } |
| |
| return target; |
| } |
| |
| /* |
| * @flags: available profiles in extended format (see ctree.h) |
| * |
| * Return reduced profile in chunk format. If profile changing is in progress |
| * (either running or paused) picks the target profile (if it's already |
| * available), otherwise falls back to plain reducing. |
| */ |
| static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| u64 num_devices = fs_info->fs_devices->rw_devices; |
| u64 target; |
| u64 raid_type; |
| u64 allowed = 0; |
| |
| /* |
| * See if restripe for this chunk_type is in progress, if so try to |
| * reduce to the target profile |
| */ |
| spin_lock(&fs_info->balance_lock); |
| target = get_restripe_target(fs_info, flags); |
| if (target) { |
| spin_unlock(&fs_info->balance_lock); |
| return extended_to_chunk(target); |
| } |
| spin_unlock(&fs_info->balance_lock); |
| |
| /* First, mask out the RAID levels which aren't possible */ |
| for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) { |
| if (num_devices >= btrfs_raid_array[raid_type].devs_min) |
| allowed |= btrfs_raid_array[raid_type].bg_flag; |
| } |
| allowed &= flags; |
| |
| /* Select the highest-redundancy RAID level. */ |
| if (allowed & BTRFS_BLOCK_GROUP_RAID1C4) |
| allowed = BTRFS_BLOCK_GROUP_RAID1C4; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID6) |
| allowed = BTRFS_BLOCK_GROUP_RAID6; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID1C3) |
| allowed = BTRFS_BLOCK_GROUP_RAID1C3; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID5) |
| allowed = BTRFS_BLOCK_GROUP_RAID5; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID10) |
| allowed = BTRFS_BLOCK_GROUP_RAID10; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID1) |
| allowed = BTRFS_BLOCK_GROUP_RAID1; |
| else if (allowed & BTRFS_BLOCK_GROUP_DUP) |
| allowed = BTRFS_BLOCK_GROUP_DUP; |
| else if (allowed & BTRFS_BLOCK_GROUP_RAID0) |
| allowed = BTRFS_BLOCK_GROUP_RAID0; |
| |
| flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK; |
| |
| return extended_to_chunk(flags | allowed); |
| } |
| |
| u64 btrfs_get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags) |
| { |
| unsigned seq; |
| u64 flags; |
| |
| do { |
| flags = orig_flags; |
| seq = read_seqbegin(&fs_info->profiles_lock); |
| |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| flags |= fs_info->avail_data_alloc_bits; |
| else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| flags |= fs_info->avail_system_alloc_bits; |
| else if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| flags |= fs_info->avail_metadata_alloc_bits; |
| } while (read_seqretry(&fs_info->profiles_lock, seq)); |
| |
| return btrfs_reduce_alloc_profile(fs_info, flags); |
| } |
| |
| void btrfs_get_block_group(struct btrfs_block_group *cache) |
| { |
| refcount_inc(&cache->refs); |
| } |
| |
| void btrfs_put_block_group(struct btrfs_block_group *cache) |
| { |
| if (refcount_dec_and_test(&cache->refs)) { |
| WARN_ON(cache->pinned > 0); |
| /* |
| * If there was a failure to cleanup a log tree, very likely due |
| * to an IO failure on a writeback attempt of one or more of its |
| * extent buffers, we could not do proper (and cheap) unaccounting |
| * of their reserved space, so don't warn on reserved > 0 in that |
| * case. |
| */ |
| if (!(cache->flags & BTRFS_BLOCK_GROUP_METADATA) || |
| !BTRFS_FS_LOG_CLEANUP_ERROR(cache->fs_info)) |
| WARN_ON(cache->reserved > 0); |
| |
| /* |
| * A block_group shouldn't be on the discard_list anymore. |
| * Remove the block_group from the discard_list to prevent us |
| * from causing a panic due to NULL pointer dereference. |
| */ |
| if (WARN_ON(!list_empty(&cache->discard_list))) |
| btrfs_discard_cancel_work(&cache->fs_info->discard_ctl, |
| cache); |
| |
| kfree(cache->free_space_ctl); |
| btrfs_free_chunk_map(cache->physical_map); |
| kfree(cache); |
| } |
| } |
| |
| /* |
| * This adds the block group to the fs_info rb tree for the block group cache |
| */ |
| static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, |
| struct btrfs_block_group *block_group) |
| { |
| struct rb_node **p; |
| struct rb_node *parent = NULL; |
| struct btrfs_block_group *cache; |
| bool leftmost = true; |
| |
| ASSERT(block_group->length != 0); |
| |
| write_lock(&info->block_group_cache_lock); |
| p = &info->block_group_cache_tree.rb_root.rb_node; |
| |
| while (*p) { |
| parent = *p; |
| cache = rb_entry(parent, struct btrfs_block_group, cache_node); |
| if (block_group->start < cache->start) { |
| p = &(*p)->rb_left; |
| } else if (block_group->start > cache->start) { |
| p = &(*p)->rb_right; |
| leftmost = false; |
| } else { |
| write_unlock(&info->block_group_cache_lock); |
| return -EEXIST; |
| } |
| } |
| |
| rb_link_node(&block_group->cache_node, parent, p); |
| rb_insert_color_cached(&block_group->cache_node, |
| &info->block_group_cache_tree, leftmost); |
| |
| write_unlock(&info->block_group_cache_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * This will return the block group at or after bytenr if contains is 0, else |
| * it will return the block group that contains the bytenr |
| */ |
| static struct btrfs_block_group *block_group_cache_tree_search( |
| struct btrfs_fs_info *info, u64 bytenr, int contains) |
| { |
| struct btrfs_block_group *cache, *ret = NULL; |
| struct rb_node *n; |
| u64 end, start; |
| |
| read_lock(&info->block_group_cache_lock); |
| n = info->block_group_cache_tree.rb_root.rb_node; |
| |
| while (n) { |
| cache = rb_entry(n, struct btrfs_block_group, cache_node); |
| end = cache->start + cache->length - 1; |
| start = cache->start; |
| |
| if (bytenr < start) { |
| if (!contains && (!ret || start < ret->start)) |
| ret = cache; |
| n = n->rb_left; |
| } else if (bytenr > start) { |
| if (contains && bytenr <= end) { |
| ret = cache; |
| break; |
| } |
| n = n->rb_right; |
| } else { |
| ret = cache; |
| break; |
| } |
| } |
| if (ret) |
| btrfs_get_block_group(ret); |
| read_unlock(&info->block_group_cache_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * Return the block group that starts at or after bytenr |
| */ |
| struct btrfs_block_group *btrfs_lookup_first_block_group( |
| struct btrfs_fs_info *info, u64 bytenr) |
| { |
| return block_group_cache_tree_search(info, bytenr, 0); |
| } |
| |
| /* |
| * Return the block group that contains the given bytenr |
| */ |
| struct btrfs_block_group *btrfs_lookup_block_group( |
| struct btrfs_fs_info *info, u64 bytenr) |
| { |
| return block_group_cache_tree_search(info, bytenr, 1); |
| } |
| |
| struct btrfs_block_group *btrfs_next_block_group( |
| struct btrfs_block_group *cache) |
| { |
| struct btrfs_fs_info *fs_info = cache->fs_info; |
| struct rb_node *node; |
| |
| read_lock(&fs_info->block_group_cache_lock); |
| |
| /* If our block group was removed, we need a full search. */ |
| if (RB_EMPTY_NODE(&cache->cache_node)) { |
| const u64 next_bytenr = cache->start + cache->length; |
| |
| read_unlock(&fs_info->block_group_cache_lock); |
| btrfs_put_block_group(cache); |
| return btrfs_lookup_first_block_group(fs_info, next_bytenr); |
| } |
| node = rb_next(&cache->cache_node); |
| btrfs_put_block_group(cache); |
| if (node) { |
| cache = rb_entry(node, struct btrfs_block_group, cache_node); |
| btrfs_get_block_group(cache); |
| } else |
| cache = NULL; |
| read_unlock(&fs_info->block_group_cache_lock); |
| return cache; |
| } |
| |
| /* |
| * Check if we can do a NOCOW write for a given extent. |
| * |
| * @fs_info: The filesystem information object. |
| * @bytenr: Logical start address of the extent. |
| * |
| * Check if we can do a NOCOW write for the given extent, and increments the |
| * number of NOCOW writers in the block group that contains the extent, as long |
| * as the block group exists and it's currently not in read-only mode. |
| * |
| * Returns: A non-NULL block group pointer if we can do a NOCOW write, the caller |
| * is responsible for calling btrfs_dec_nocow_writers() later. |
| * |
| * Or NULL if we can not do a NOCOW write |
| */ |
| struct btrfs_block_group *btrfs_inc_nocow_writers(struct btrfs_fs_info *fs_info, |
| u64 bytenr) |
| { |
| struct btrfs_block_group *bg; |
| bool can_nocow = true; |
| |
| bg = btrfs_lookup_block_group(fs_info, bytenr); |
| if (!bg) |
| return NULL; |
| |
| spin_lock(&bg->lock); |
| if (bg->ro) |
| can_nocow = false; |
| else |
| atomic_inc(&bg->nocow_writers); |
| spin_unlock(&bg->lock); |
| |
| if (!can_nocow) { |
| btrfs_put_block_group(bg); |
| return NULL; |
| } |
| |
| /* No put on block group, done by btrfs_dec_nocow_writers(). */ |
| return bg; |
| } |
| |
| /* |
| * Decrement the number of NOCOW writers in a block group. |
| * |
| * This is meant to be called after a previous call to btrfs_inc_nocow_writers(), |
| * and on the block group returned by that call. Typically this is called after |
| * creating an ordered extent for a NOCOW write, to prevent races with scrub and |
| * relocation. |
| * |
| * After this call, the caller should not use the block group anymore. It it wants |
| * to use it, then it should get a reference on it before calling this function. |
| */ |
| void btrfs_dec_nocow_writers(struct btrfs_block_group *bg) |
| { |
| if (atomic_dec_and_test(&bg->nocow_writers)) |
| wake_up_var(&bg->nocow_writers); |
| |
| /* For the lookup done by a previous call to btrfs_inc_nocow_writers(). */ |
| btrfs_put_block_group(bg); |
| } |
| |
| void btrfs_wait_nocow_writers(struct btrfs_block_group *bg) |
| { |
| wait_var_event(&bg->nocow_writers, !atomic_read(&bg->nocow_writers)); |
| } |
| |
| void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info, |
| const u64 start) |
| { |
| struct btrfs_block_group *bg; |
| |
| bg = btrfs_lookup_block_group(fs_info, start); |
| ASSERT(bg); |
| if (atomic_dec_and_test(&bg->reservations)) |
| wake_up_var(&bg->reservations); |
| btrfs_put_block_group(bg); |
| } |
| |
| void btrfs_wait_block_group_reservations(struct btrfs_block_group *bg) |
| { |
| struct btrfs_space_info *space_info = bg->space_info; |
| |
| ASSERT(bg->ro); |
| |
| if (!(bg->flags & BTRFS_BLOCK_GROUP_DATA)) |
| return; |
| |
| /* |
| * Our block group is read only but before we set it to read only, |
| * some task might have had allocated an extent from it already, but it |
| * has not yet created a respective ordered extent (and added it to a |
| * root's list of ordered extents). |
| * Therefore wait for any task currently allocating extents, since the |
| * block group's reservations counter is incremented while a read lock |
| * on the groups' semaphore is held and decremented after releasing |
| * the read access on that semaphore and creating the ordered extent. |
| */ |
| down_write(&space_info->groups_sem); |
| up_write(&space_info->groups_sem); |
| |
| wait_var_event(&bg->reservations, !atomic_read(&bg->reservations)); |
| } |
| |
| struct btrfs_caching_control *btrfs_get_caching_control( |
| struct btrfs_block_group *cache) |
| { |
| struct btrfs_caching_control *ctl; |
| |
| spin_lock(&cache->lock); |
| if (!cache->caching_ctl) { |
| spin_unlock(&cache->lock); |
| return NULL; |
| } |
| |
| ctl = cache->caching_ctl; |
| refcount_inc(&ctl->count); |
| spin_unlock(&cache->lock); |
| return ctl; |
| } |
| |
| static void btrfs_put_caching_control(struct btrfs_caching_control *ctl) |
| { |
| if (refcount_dec_and_test(&ctl->count)) |
| kfree(ctl); |
| } |
| |
| /* |
| * When we wait for progress in the block group caching, its because our |
| * allocation attempt failed at least once. So, we must sleep and let some |
| * progress happen before we try again. |
| * |
| * This function will sleep at least once waiting for new free space to show |
| * up, and then it will check the block group free space numbers for our min |
| * num_bytes. Another option is to have it go ahead and look in the rbtree for |
| * a free extent of a given size, but this is a good start. |
| * |
| * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using |
| * any of the information in this block group. |
| */ |
| void btrfs_wait_block_group_cache_progress(struct btrfs_block_group *cache, |
| u64 num_bytes) |
| { |
| struct btrfs_caching_control *caching_ctl; |
| int progress; |
| |
| caching_ctl = btrfs_get_caching_control(cache); |
| if (!caching_ctl) |
| return; |
| |
| /* |
| * We've already failed to allocate from this block group, so even if |
| * there's enough space in the block group it isn't contiguous enough to |
| * allow for an allocation, so wait for at least the next wakeup tick, |
| * or for the thing to be done. |
| */ |
| progress = atomic_read(&caching_ctl->progress); |
| |
| wait_event(caching_ctl->wait, btrfs_block_group_done(cache) || |
| (progress != atomic_read(&caching_ctl->progress) && |
| (cache->free_space_ctl->free_space >= num_bytes))); |
| |
| btrfs_put_caching_control(caching_ctl); |
| } |
| |
| static int btrfs_caching_ctl_wait_done(struct btrfs_block_group *cache, |
| struct btrfs_caching_control *caching_ctl) |
| { |
| wait_event(caching_ctl->wait, btrfs_block_group_done(cache)); |
| return cache->cached == BTRFS_CACHE_ERROR ? -EIO : 0; |
| } |
| |
| static int btrfs_wait_block_group_cache_done(struct btrfs_block_group *cache) |
| { |
| struct btrfs_caching_control *caching_ctl; |
| int ret; |
| |
| caching_ctl = btrfs_get_caching_control(cache); |
| if (!caching_ctl) |
| return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0; |
| ret = btrfs_caching_ctl_wait_done(cache, caching_ctl); |
| btrfs_put_caching_control(caching_ctl); |
| return ret; |
| } |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| static void fragment_free_space(struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| u64 start = block_group->start; |
| u64 len = block_group->length; |
| u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ? |
| fs_info->nodesize : fs_info->sectorsize; |
| u64 step = chunk << 1; |
| |
| while (len > chunk) { |
| btrfs_remove_free_space(block_group, start, chunk); |
| start += step; |
| if (len < step) |
| len = 0; |
| else |
| len -= step; |
| } |
| } |
| #endif |
| |
| /* |
| * Add a free space range to the in memory free space cache of a block group. |
| * This checks if the range contains super block locations and any such |
| * locations are not added to the free space cache. |
| * |
| * @block_group: The target block group. |
| * @start: Start offset of the range. |
| * @end: End offset of the range (exclusive). |
| * @total_added_ret: Optional pointer to return the total amount of space |
| * added to the block group's free space cache. |
| * |
| * Returns 0 on success or < 0 on error. |
| */ |
| int btrfs_add_new_free_space(struct btrfs_block_group *block_group, u64 start, |
| u64 end, u64 *total_added_ret) |
| { |
| struct btrfs_fs_info *info = block_group->fs_info; |
| u64 extent_start, extent_end, size; |
| int ret; |
| |
| if (total_added_ret) |
| *total_added_ret = 0; |
| |
| while (start < end) { |
| if (!find_first_extent_bit(&info->excluded_extents, start, |
| &extent_start, &extent_end, |
| EXTENT_DIRTY | EXTENT_UPTODATE, |
| NULL)) |
| break; |
| |
| if (extent_start <= start) { |
| start = extent_end + 1; |
| } else if (extent_start > start && extent_start < end) { |
| size = extent_start - start; |
| ret = btrfs_add_free_space_async_trimmed(block_group, |
| start, size); |
| if (ret) |
| return ret; |
| if (total_added_ret) |
| *total_added_ret += size; |
| start = extent_end + 1; |
| } else { |
| break; |
| } |
| } |
| |
| if (start < end) { |
| size = end - start; |
| ret = btrfs_add_free_space_async_trimmed(block_group, start, |
| size); |
| if (ret) |
| return ret; |
| if (total_added_ret) |
| *total_added_ret += size; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Get an arbitrary extent item index / max_index through the block group |
| * |
| * @block_group the block group to sample from |
| * @index: the integral step through the block group to grab from |
| * @max_index: the granularity of the sampling |
| * @key: return value parameter for the item we find |
| * |
| * Pre-conditions on indices: |
| * 0 <= index <= max_index |
| * 0 < max_index |
| * |
| * Returns: 0 on success, 1 if the search didn't yield a useful item, negative |
| * error code on error. |
| */ |
| static int sample_block_group_extent_item(struct btrfs_caching_control *caching_ctl, |
| struct btrfs_block_group *block_group, |
| int index, int max_index, |
| struct btrfs_key *found_key) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| struct btrfs_root *extent_root; |
| u64 search_offset; |
| u64 search_end = block_group->start + block_group->length; |
| struct btrfs_path *path; |
| struct btrfs_key search_key; |
| int ret = 0; |
| |
| ASSERT(index >= 0); |
| ASSERT(index <= max_index); |
| ASSERT(max_index > 0); |
| lockdep_assert_held(&caching_ctl->mutex); |
| lockdep_assert_held_read(&fs_info->commit_root_sem); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| extent_root = btrfs_extent_root(fs_info, max_t(u64, block_group->start, |
| BTRFS_SUPER_INFO_OFFSET)); |
| |
| path->skip_locking = 1; |
| path->search_commit_root = 1; |
| path->reada = READA_FORWARD; |
| |
| search_offset = index * div_u64(block_group->length, max_index); |
| search_key.objectid = block_group->start + search_offset; |
| search_key.type = BTRFS_EXTENT_ITEM_KEY; |
| search_key.offset = 0; |
| |
| btrfs_for_each_slot(extent_root, &search_key, found_key, path, ret) { |
| /* Success; sampled an extent item in the block group */ |
| if (found_key->type == BTRFS_EXTENT_ITEM_KEY && |
| found_key->objectid >= block_group->start && |
| found_key->objectid + found_key->offset <= search_end) |
| break; |
| |
| /* We can't possibly find a valid extent item anymore */ |
| if (found_key->objectid >= search_end) { |
| ret = 1; |
| break; |
| } |
| } |
| |
| lockdep_assert_held(&caching_ctl->mutex); |
| lockdep_assert_held_read(&fs_info->commit_root_sem); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * Best effort attempt to compute a block group's size class while caching it. |
| * |
| * @block_group: the block group we are caching |
| * |
| * We cannot infer the size class while adding free space extents, because that |
| * logic doesn't care about contiguous file extents (it doesn't differentiate |
| * between a 100M extent and 100 contiguous 1M extents). So we need to read the |
| * file extent items. Reading all of them is quite wasteful, because usually |
| * only a handful are enough to give a good answer. Therefore, we just grab 5 of |
| * them at even steps through the block group and pick the smallest size class |
| * we see. Since size class is best effort, and not guaranteed in general, |
| * inaccuracy is acceptable. |
| * |
| * To be more explicit about why this algorithm makes sense: |
| * |
| * If we are caching in a block group from disk, then there are three major cases |
| * to consider: |
| * 1. the block group is well behaved and all extents in it are the same size |
| * class. |
| * 2. the block group is mostly one size class with rare exceptions for last |
| * ditch allocations |
| * 3. the block group was populated before size classes and can have a totally |
| * arbitrary mix of size classes. |
| * |
| * In case 1, looking at any extent in the block group will yield the correct |
| * result. For the mixed cases, taking the minimum size class seems like a good |
| * approximation, since gaps from frees will be usable to the size class. For |
| * 2., a small handful of file extents is likely to yield the right answer. For |
| * 3, we can either read every file extent, or admit that this is best effort |
| * anyway and try to stay fast. |
| * |
| * Returns: 0 on success, negative error code on error. |
| */ |
| static int load_block_group_size_class(struct btrfs_caching_control *caching_ctl, |
| struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| struct btrfs_key key; |
| int i; |
| u64 min_size = block_group->length; |
| enum btrfs_block_group_size_class size_class = BTRFS_BG_SZ_NONE; |
| int ret; |
| |
| if (!btrfs_block_group_should_use_size_class(block_group)) |
| return 0; |
| |
| lockdep_assert_held(&caching_ctl->mutex); |
| lockdep_assert_held_read(&fs_info->commit_root_sem); |
| for (i = 0; i < 5; ++i) { |
| ret = sample_block_group_extent_item(caching_ctl, block_group, i, 5, &key); |
| if (ret < 0) |
| goto out; |
| if (ret > 0) |
| continue; |
| min_size = min_t(u64, min_size, key.offset); |
| size_class = btrfs_calc_block_group_size_class(min_size); |
| } |
| if (size_class != BTRFS_BG_SZ_NONE) { |
| spin_lock(&block_group->lock); |
| block_group->size_class = size_class; |
| spin_unlock(&block_group->lock); |
| } |
| out: |
| return ret; |
| } |
| |
| static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl) |
| { |
| struct btrfs_block_group *block_group = caching_ctl->block_group; |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| struct btrfs_root *extent_root; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| u64 total_found = 0; |
| u64 last = 0; |
| u32 nritems; |
| int ret; |
| bool wakeup = true; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| last = max_t(u64, block_group->start, BTRFS_SUPER_INFO_OFFSET); |
| extent_root = btrfs_extent_root(fs_info, last); |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| /* |
| * If we're fragmenting we don't want to make anybody think we can |
| * allocate from this block group until we've had a chance to fragment |
| * the free space. |
| */ |
| if (btrfs_should_fragment_free_space(block_group)) |
| wakeup = false; |
| #endif |
| /* |
| * We don't want to deadlock with somebody trying to allocate a new |
| * extent for the extent root while also trying to search the extent |
| * root to add free space. So we skip locking and search the commit |
| * root, since its read-only |
| */ |
| path->skip_locking = 1; |
| path->search_commit_root = 1; |
| path->reada = READA_FORWARD; |
| |
| key.objectid = last; |
| key.offset = 0; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| next: |
| ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| |
| while (1) { |
| if (btrfs_fs_closing(fs_info) > 1) { |
| last = (u64)-1; |
| break; |
| } |
| |
| if (path->slots[0] < nritems) { |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| } else { |
| ret = btrfs_find_next_key(extent_root, path, &key, 0, 0); |
| if (ret) |
| break; |
| |
| if (need_resched() || |
| rwsem_is_contended(&fs_info->commit_root_sem)) { |
| btrfs_release_path(path); |
| up_read(&fs_info->commit_root_sem); |
| mutex_unlock(&caching_ctl->mutex); |
| cond_resched(); |
| mutex_lock(&caching_ctl->mutex); |
| down_read(&fs_info->commit_root_sem); |
| goto next; |
| } |
| |
| ret = btrfs_next_leaf(extent_root, path); |
| if (ret < 0) |
| goto out; |
| if (ret) |
| break; |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| continue; |
| } |
| |
| if (key.objectid < last) { |
| key.objectid = last; |
| key.offset = 0; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| btrfs_release_path(path); |
| goto next; |
| } |
| |
| if (key.objectid < block_group->start) { |
| path->slots[0]++; |
| continue; |
| } |
| |
| if (key.objectid >= block_group->start + block_group->length) |
| break; |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY || |
| key.type == BTRFS_METADATA_ITEM_KEY) { |
| u64 space_added; |
| |
| ret = btrfs_add_new_free_space(block_group, last, |
| key.objectid, &space_added); |
| if (ret) |
| goto out; |
| total_found += space_added; |
| if (key.type == BTRFS_METADATA_ITEM_KEY) |
| last = key.objectid + |
| fs_info->nodesize; |
| else |
| last = key.objectid + key.offset; |
| |
| if (total_found > CACHING_CTL_WAKE_UP) { |
| total_found = 0; |
| if (wakeup) { |
| atomic_inc(&caching_ctl->progress); |
| wake_up(&caching_ctl->wait); |
| } |
| } |
| } |
| path->slots[0]++; |
| } |
| |
| ret = btrfs_add_new_free_space(block_group, last, |
| block_group->start + block_group->length, |
| NULL); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| static inline void btrfs_free_excluded_extents(const struct btrfs_block_group *bg) |
| { |
| clear_extent_bits(&bg->fs_info->excluded_extents, bg->start, |
| bg->start + bg->length - 1, EXTENT_UPTODATE); |
| } |
| |
| static noinline void caching_thread(struct btrfs_work *work) |
| { |
| struct btrfs_block_group *block_group; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_caching_control *caching_ctl; |
| int ret; |
| |
| caching_ctl = container_of(work, struct btrfs_caching_control, work); |
| block_group = caching_ctl->block_group; |
| fs_info = block_group->fs_info; |
| |
| mutex_lock(&caching_ctl->mutex); |
| down_read(&fs_info->commit_root_sem); |
| |
| load_block_group_size_class(caching_ctl, block_group); |
| if (btrfs_test_opt(fs_info, SPACE_CACHE)) { |
| ret = load_free_space_cache(block_group); |
| if (ret == 1) { |
| ret = 0; |
| goto done; |
| } |
| |
| /* |
| * We failed to load the space cache, set ourselves to |
| * CACHE_STARTED and carry on. |
| */ |
| spin_lock(&block_group->lock); |
| block_group->cached = BTRFS_CACHE_STARTED; |
| spin_unlock(&block_group->lock); |
| wake_up(&caching_ctl->wait); |
| } |
| |
| /* |
| * If we are in the transaction that populated the free space tree we |
| * can't actually cache from the free space tree as our commit root and |
| * real root are the same, so we could change the contents of the blocks |
| * while caching. Instead do the slow caching in this case, and after |
| * the transaction has committed we will be safe. |
| */ |
| if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && |
| !(test_bit(BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED, &fs_info->flags))) |
| ret = load_free_space_tree(caching_ctl); |
| else |
| ret = load_extent_tree_free(caching_ctl); |
| done: |
| spin_lock(&block_group->lock); |
| block_group->caching_ctl = NULL; |
| block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED; |
| spin_unlock(&block_group->lock); |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| if (btrfs_should_fragment_free_space(block_group)) { |
| u64 bytes_used; |
| |
| spin_lock(&block_group->space_info->lock); |
| spin_lock(&block_group->lock); |
| bytes_used = block_group->length - block_group->used; |
| block_group->space_info->bytes_used += bytes_used >> 1; |
| spin_unlock(&block_group->lock); |
| spin_unlock(&block_group->space_info->lock); |
| fragment_free_space(block_group); |
| } |
| #endif |
| |
| up_read(&fs_info->commit_root_sem); |
| btrfs_free_excluded_extents(block_group); |
| mutex_unlock(&caching_ctl->mutex); |
| |
| wake_up(&caching_ctl->wait); |
| |
| btrfs_put_caching_control(caching_ctl); |
| btrfs_put_block_group(block_group); |
| } |
| |
| int btrfs_cache_block_group(struct btrfs_block_group *cache, bool wait) |
| { |
| struct btrfs_fs_info *fs_info = cache->fs_info; |
| struct btrfs_caching_control *caching_ctl = NULL; |
| int ret = 0; |
| |
| /* Allocator for zoned filesystems does not use the cache at all */ |
| if (btrfs_is_zoned(fs_info)) |
| return 0; |
| |
| caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS); |
| if (!caching_ctl) |
| return -ENOMEM; |
| |
| INIT_LIST_HEAD(&caching_ctl->list); |
| mutex_init(&caching_ctl->mutex); |
| init_waitqueue_head(&caching_ctl->wait); |
| caching_ctl->block_group = cache; |
| refcount_set(&caching_ctl->count, 2); |
| atomic_set(&caching_ctl->progress, 0); |
| btrfs_init_work(&caching_ctl->work, caching_thread, NULL); |
| |
| spin_lock(&cache->lock); |
| if (cache->cached != BTRFS_CACHE_NO) { |
| kfree(caching_ctl); |
| |
| caching_ctl = cache->caching_ctl; |
| if (caching_ctl) |
| refcount_inc(&caching_ctl->count); |
| spin_unlock(&cache->lock); |
| goto out; |
| } |
| WARN_ON(cache->caching_ctl); |
| cache->caching_ctl = caching_ctl; |
| cache->cached = BTRFS_CACHE_STARTED; |
| spin_unlock(&cache->lock); |
| |
| write_lock(&fs_info->block_group_cache_lock); |
| refcount_inc(&caching_ctl->count); |
| list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); |
| write_unlock(&fs_info->block_group_cache_lock); |
| |
| btrfs_get_block_group(cache); |
| |
| btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work); |
| out: |
| if (wait && caching_ctl) |
| ret = btrfs_caching_ctl_wait_done(cache, caching_ctl); |
| if (caching_ctl) |
| btrfs_put_caching_control(caching_ctl); |
| |
| return ret; |
| } |
| |
| static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| u64 extra_flags = chunk_to_extended(flags) & |
| BTRFS_EXTENDED_PROFILE_MASK; |
| |
| write_seqlock(&fs_info->profiles_lock); |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| fs_info->avail_data_alloc_bits &= ~extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| fs_info->avail_metadata_alloc_bits &= ~extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| fs_info->avail_system_alloc_bits &= ~extra_flags; |
| write_sequnlock(&fs_info->profiles_lock); |
| } |
| |
| /* |
| * Clear incompat bits for the following feature(s): |
| * |
| * - RAID56 - in case there's neither RAID5 nor RAID6 profile block group |
| * in the whole filesystem |
| * |
| * - RAID1C34 - same as above for RAID1C3 and RAID1C4 block groups |
| */ |
| static void clear_incompat_bg_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| bool found_raid56 = false; |
| bool found_raid1c34 = false; |
| |
| if ((flags & BTRFS_BLOCK_GROUP_RAID56_MASK) || |
| (flags & BTRFS_BLOCK_GROUP_RAID1C3) || |
| (flags & BTRFS_BLOCK_GROUP_RAID1C4)) { |
| struct list_head *head = &fs_info->space_info; |
| struct btrfs_space_info *sinfo; |
| |
| list_for_each_entry_rcu(sinfo, head, list) { |
| down_read(&sinfo->groups_sem); |
| if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID5])) |
| found_raid56 = true; |
| if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID6])) |
| found_raid56 = true; |
| if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID1C3])) |
| found_raid1c34 = true; |
| if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID1C4])) |
| found_raid1c34 = true; |
| up_read(&sinfo->groups_sem); |
| } |
| if (!found_raid56) |
| btrfs_clear_fs_incompat(fs_info, RAID56); |
| if (!found_raid1c34) |
| btrfs_clear_fs_incompat(fs_info, RAID1C34); |
| } |
| } |
| |
| static int remove_block_group_item(struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, |
| struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_root *root; |
| struct btrfs_key key; |
| int ret; |
| |
| root = btrfs_block_group_root(fs_info); |
| key.objectid = block_group->start; |
| key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| key.offset = block_group->length; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) |
| ret = -ENOENT; |
| if (ret < 0) |
| return ret; |
| |
| ret = btrfs_del_item(trans, root, path); |
| return ret; |
| } |
| |
| int btrfs_remove_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_chunk_map *map) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_path *path; |
| struct btrfs_block_group *block_group; |
| struct btrfs_free_cluster *cluster; |
| struct inode *inode; |
| struct kobject *kobj = NULL; |
| int ret; |
| int index; |
| int factor; |
| struct btrfs_caching_control *caching_ctl = NULL; |
| bool remove_map; |
| bool remove_rsv = false; |
| |
| block_group = btrfs_lookup_block_group(fs_info, map->start); |
| if (!block_group) |
| return -ENOENT; |
| |
| BUG_ON(!block_group->ro); |
| |
| trace_btrfs_remove_block_group(block_group); |
| /* |
| * Free the reserved super bytes from this block group before |
| * remove it. |
| */ |
| btrfs_free_excluded_extents(block_group); |
| btrfs_free_ref_tree_range(fs_info, block_group->start, |
| block_group->length); |
| |
| index = btrfs_bg_flags_to_raid_index(block_group->flags); |
| factor = btrfs_bg_type_to_factor(block_group->flags); |
| |
| /* make sure this block group isn't part of an allocation cluster */ |
| cluster = &fs_info->data_alloc_cluster; |
| spin_lock(&cluster->refill_lock); |
| btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&cluster->refill_lock); |
| |
| /* |
| * make sure this block group isn't part of a metadata |
| * allocation cluster |
| */ |
| cluster = &fs_info->meta_alloc_cluster; |
| spin_lock(&cluster->refill_lock); |
| btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&cluster->refill_lock); |
| |
| btrfs_clear_treelog_bg(block_group); |
| btrfs_clear_data_reloc_bg(block_group); |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| /* |
| * get the inode first so any iput calls done for the io_list |
| * aren't the final iput (no unlinks allowed now) |
| */ |
| inode = lookup_free_space_inode(block_group, path); |
| |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| /* |
| * Make sure our free space cache IO is done before removing the |
| * free space inode |
| */ |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| if (!list_empty(&block_group->io_list)) { |
| list_del_init(&block_group->io_list); |
| |
| WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode); |
| |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| btrfs_wait_cache_io(trans, block_group, path); |
| btrfs_put_block_group(block_group); |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| } |
| |
| if (!list_empty(&block_group->dirty_list)) { |
| list_del_init(&block_group->dirty_list); |
| remove_rsv = true; |
| btrfs_put_block_group(block_group); |
| } |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| |
| ret = btrfs_remove_free_space_inode(trans, inode, block_group); |
| if (ret) |
| goto out; |
| |
| write_lock(&fs_info->block_group_cache_lock); |
| rb_erase_cached(&block_group->cache_node, |
| &fs_info->block_group_cache_tree); |
| RB_CLEAR_NODE(&block_group->cache_node); |
| |
| /* Once for the block groups rbtree */ |
| btrfs_put_block_group(block_group); |
| |
| write_unlock(&fs_info->block_group_cache_lock); |
| |
| down_write(&block_group->space_info->groups_sem); |
| /* |
| * we must use list_del_init so people can check to see if they |
| * are still on the list after taking the semaphore |
| */ |
| list_del_init(&block_group->list); |
| if (list_empty(&block_group->space_info->block_groups[index])) { |
| kobj = block_group->space_info->block_group_kobjs[index]; |
| block_group->space_info->block_group_kobjs[index] = NULL; |
| clear_avail_alloc_bits(fs_info, block_group->flags); |
| } |
| up_write(&block_group->space_info->groups_sem); |
| clear_incompat_bg_bits(fs_info, block_group->flags); |
| if (kobj) { |
| kobject_del(kobj); |
| kobject_put(kobj); |
| } |
| |
| if (block_group->cached == BTRFS_CACHE_STARTED) |
| btrfs_wait_block_group_cache_done(block_group); |
| |
| write_lock(&fs_info->block_group_cache_lock); |
| caching_ctl = btrfs_get_caching_control(block_group); |
| if (!caching_ctl) { |
| struct btrfs_caching_control *ctl; |
| |
| list_for_each_entry(ctl, &fs_info->caching_block_groups, list) { |
| if (ctl->block_group == block_group) { |
| caching_ctl = ctl; |
| refcount_inc(&caching_ctl->count); |
| break; |
| } |
| } |
| } |
| if (caching_ctl) |
| list_del_init(&caching_ctl->list); |
| write_unlock(&fs_info->block_group_cache_lock); |
| |
| if (caching_ctl) { |
| /* Once for the caching bgs list and once for us. */ |
| btrfs_put_caching_control(caching_ctl); |
| btrfs_put_caching_control(caching_ctl); |
| } |
| |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| WARN_ON(!list_empty(&block_group->dirty_list)); |
| WARN_ON(!list_empty(&block_group->io_list)); |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| |
| btrfs_remove_free_space_cache(block_group); |
| |
| spin_lock(&block_group->space_info->lock); |
| list_del_init(&block_group->ro_list); |
| |
| if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { |
| WARN_ON(block_group->space_info->total_bytes |
| < block_group->length); |
| WARN_ON(block_group->space_info->bytes_readonly |
| < block_group->length - block_group->zone_unusable); |
| WARN_ON(block_group->space_info->bytes_zone_unusable |
| < block_group->zone_unusable); |
| WARN_ON(block_group->space_info->disk_total |
| < block_group->length * factor); |
| } |
| block_group->space_info->total_bytes -= block_group->length; |
| block_group->space_info->bytes_readonly -= |
| (block_group->length - block_group->zone_unusable); |
| block_group->space_info->bytes_zone_unusable -= |
| block_group->zone_unusable; |
| block_group->space_info->disk_total -= block_group->length * factor; |
| |
| spin_unlock(&block_group->space_info->lock); |
| |
| /* |
| * Remove the free space for the block group from the free space tree |
| * and the block group's item from the extent tree before marking the |
| * block group as removed. This is to prevent races with tasks that |
| * freeze and unfreeze a block group, this task and another task |
| * allocating a new block group - the unfreeze task ends up removing |
| * the block group's extent map before the task calling this function |
| * deletes the block group item from the extent tree, allowing for |
| * another task to attempt to create another block group with the same |
| * item key (and failing with -EEXIST and a transaction abort). |
| */ |
| ret = remove_block_group_free_space(trans, block_group); |
| if (ret) |
| goto out; |
| |
| ret = remove_block_group_item(trans, path, block_group); |
| if (ret < 0) |
| goto out; |
| |
| spin_lock(&block_group->lock); |
| set_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags); |
| |
| /* |
| * At this point trimming or scrub can't start on this block group, |
| * because we removed the block group from the rbtree |
| * fs_info->block_group_cache_tree so no one can't find it anymore and |
| * even if someone already got this block group before we removed it |
| * from the rbtree, they have already incremented block_group->frozen - |
| * if they didn't, for the trimming case they won't find any free space |
| * entries because we already removed them all when we called |
| * btrfs_remove_free_space_cache(). |
| * |
| * And we must not remove the chunk map from the fs_info->mapping_tree |
| * to prevent the same logical address range and physical device space |
| * ranges from being reused for a new block group. This is needed to |
| * avoid races with trimming and scrub. |
| * |
| * An fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is |
| * completely transactionless, so while it is trimming a range the |
| * currently running transaction might finish and a new one start, |
| * allowing for new block groups to be created that can reuse the same |
| * physical device locations unless we take this special care. |
| * |
| * There may also be an implicit trim operation if the file system |
| * is mounted with -odiscard. The same protections must remain |
| * in place until the extents have been discarded completely when |
| * the transaction commit has completed. |
| */ |
| remove_map = (atomic_read(&block_group->frozen) == 0); |
| spin_unlock(&block_group->lock); |
| |
| if (remove_map) |
| btrfs_remove_chunk_map(fs_info, map); |
| |
| out: |
| /* Once for the lookup reference */ |
| btrfs_put_block_group(block_group); |
| if (remove_rsv) |
| btrfs_dec_delayed_refs_rsv_bg_updates(fs_info); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| struct btrfs_trans_handle *btrfs_start_trans_remove_block_group( |
| struct btrfs_fs_info *fs_info, const u64 chunk_offset) |
| { |
| struct btrfs_root *root = btrfs_block_group_root(fs_info); |
| struct btrfs_chunk_map *map; |
| unsigned int num_items; |
| |
| map = btrfs_find_chunk_map(fs_info, chunk_offset, 1); |
| ASSERT(map != NULL); |
| ASSERT(map->start == chunk_offset); |
| |
| /* |
| * We need to reserve 3 + N units from the metadata space info in order |
| * to remove a block group (done at btrfs_remove_chunk() and at |
| * btrfs_remove_block_group()), which are used for: |
| * |
| * 1 unit for adding the free space inode's orphan (located in the tree |
| * of tree roots). |
| * 1 unit for deleting the block group item (located in the extent |
| * tree). |
| * 1 unit for deleting the free space item (located in tree of tree |
| * roots). |
| * N units for deleting N device extent items corresponding to each |
| * stripe (located in the device tree). |
| * |
| * In order to remove a block group we also need to reserve units in the |
| * system space info in order to update the chunk tree (update one or |
| * more device items and remove one chunk item), but this is done at |
| * btrfs_remove_chunk() through a call to check_system_chunk(). |
| */ |
| num_items = 3 + map->num_stripes; |
| btrfs_free_chunk_map(map); |
| |
| return btrfs_start_transaction_fallback_global_rsv(root, num_items); |
| } |
| |
| /* |
| * Mark block group @cache read-only, so later write won't happen to block |
| * group @cache. |
| * |
| * If @force is not set, this function will only mark the block group readonly |
| * if we have enough free space (1M) in other metadata/system block groups. |
| * If @force is not set, this function will mark the block group readonly |
| * without checking free space. |
| * |
| * NOTE: This function doesn't care if other block groups can contain all the |
| * data in this block group. That check should be done by relocation routine, |
| * not this function. |
| */ |
| static int inc_block_group_ro(struct btrfs_block_group *cache, int force) |
| { |
| struct btrfs_space_info *sinfo = cache->space_info; |
| u64 num_bytes; |
| int ret = -ENOSPC; |
| |
| spin_lock(&sinfo->lock); |
| spin_lock(&cache->lock); |
| |
| if (cache->swap_extents) { |
| ret = -ETXTBSY; |
| goto out; |
| } |
| |
| if (cache->ro) { |
| cache->ro++; |
| ret = 0; |
| goto out; |
| } |
| |
| num_bytes = cache->length - cache->reserved - cache->pinned - |
| cache->bytes_super - cache->zone_unusable - cache->used; |
| |
| /* |
| * Data never overcommits, even in mixed mode, so do just the straight |
| * check of left over space in how much we have allocated. |
| */ |
| if (force) { |
| ret = 0; |
| } else if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) { |
| u64 sinfo_used = btrfs_space_info_used(sinfo, true); |
| |
| /* |
| * Here we make sure if we mark this bg RO, we still have enough |
| * free space as buffer. |
| */ |
| if (sinfo_used + num_bytes <= sinfo->total_bytes) |
| ret = 0; |
| } else { |
| /* |
| * We overcommit metadata, so we need to do the |
| * btrfs_can_overcommit check here, and we need to pass in |
| * BTRFS_RESERVE_NO_FLUSH to give ourselves the most amount of |
| * leeway to allow us to mark this block group as read only. |
| */ |
| if (btrfs_can_overcommit(cache->fs_info, sinfo, num_bytes, |
| BTRFS_RESERVE_NO_FLUSH)) |
| ret = 0; |
| } |
| |
| if (!ret) { |
| sinfo->bytes_readonly += num_bytes; |
| if (btrfs_is_zoned(cache->fs_info)) { |
| /* Migrate zone_unusable bytes to readonly */ |
| sinfo->bytes_readonly += cache->zone_unusable; |
| sinfo->bytes_zone_unusable -= cache->zone_unusable; |
| cache->zone_unusable = 0; |
| } |
| cache->ro++; |
| list_add_tail(&cache->ro_list, &sinfo->ro_bgs); |
| } |
| out: |
| spin_unlock(&cache->lock); |
| spin_unlock(&sinfo->lock); |
| if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) { |
| btrfs_info(cache->fs_info, |
| "unable to make block group %llu ro", cache->start); |
| btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0); |
| } |
| return ret; |
| } |
| |
| static bool clean_pinned_extents(struct btrfs_trans_handle *trans, |
| struct btrfs_block_group *bg) |
| { |
| struct btrfs_fs_info *fs_info = bg->fs_info; |
| struct btrfs_transaction *prev_trans = NULL; |
| const u64 start = bg->start; |
| const u64 end = start + bg->length - 1; |
| int ret; |
| |
| spin_lock(&fs_info->trans_lock); |
| if (trans->transaction->list.prev != &fs_info->trans_list) { |
| prev_trans = list_last_entry(&trans->transaction->list, |
| struct btrfs_transaction, list); |
| refcount_inc(&prev_trans->use_count); |
| } |
| spin_unlock(&fs_info->trans_lock); |
| |
| /* |
| * Hold the unused_bg_unpin_mutex lock to avoid racing with |
| * btrfs_finish_extent_commit(). If we are at transaction N, another |
| * task might be running finish_extent_commit() for the previous |
| * transaction N - 1, and have seen a range belonging to the block |
| * group in pinned_extents before we were able to clear the whole block |
| * group range from pinned_extents. This means that task can lookup for |
| * the block group after we unpinned it from pinned_extents and removed |
| * it, leading to an error at unpin_extent_range(). |
| */ |
| mutex_lock(&fs_info->unused_bg_unpin_mutex); |
| if (prev_trans) { |
| ret = clear_extent_bits(&prev_trans->pinned_extents, start, end, |
| EXTENT_DIRTY); |
| if (ret) |
| goto out; |
| } |
| |
| ret = clear_extent_bits(&trans->transaction->pinned_extents, start, end, |
| EXTENT_DIRTY); |
| out: |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| if (prev_trans) |
| btrfs_put_transaction(prev_trans); |
| |
| return ret == 0; |
| } |
| |
| /* |
| * Process the unused_bgs list and remove any that don't have any allocated |
| * space inside of them. |
| */ |
| void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) |
| { |
| LIST_HEAD(retry_list); |
| struct btrfs_block_group *block_group; |
| struct btrfs_space_info *space_info; |
| struct btrfs_trans_handle *trans; |
| const bool async_trim_enabled = btrfs_test_opt(fs_info, DISCARD_ASYNC); |
| int ret = 0; |
| |
| if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags)) |
| return; |
| |
| if (btrfs_fs_closing(fs_info)) |
| return; |
| |
| /* |
| * Long running balances can keep us blocked here for eternity, so |
| * simply skip deletion if we're unable to get the mutex. |
| */ |
| if (!mutex_trylock(&fs_info->reclaim_bgs_lock)) |
| return; |
| |
| spin_lock(&fs_info->unused_bgs_lock); |
| while (!list_empty(&fs_info->unused_bgs)) { |
| u64 used; |
| int trimming; |
| |
| block_group = list_first_entry(&fs_info->unused_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| list_del_init(&block_group->bg_list); |
| |
| space_info = block_group->space_info; |
| |
| if (ret || btrfs_mixed_space_info(space_info)) { |
| btrfs_put_block_group(block_group); |
| continue; |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| |
| btrfs_discard_cancel_work(&fs_info->discard_ctl, block_group); |
| |
| /* Don't want to race with allocators so take the groups_sem */ |
| down_write(&space_info->groups_sem); |
| |
| /* |
| * Async discard moves the final block group discard to be prior |
| * to the unused_bgs code path. Therefore, if it's not fully |
| * trimmed, punt it back to the async discard lists. |
| */ |
| if (btrfs_test_opt(fs_info, DISCARD_ASYNC) && |
| !btrfs_is_free_space_trimmed(block_group)) { |
| trace_btrfs_skip_unused_block_group(block_group); |
| up_write(&space_info->groups_sem); |
| /* Requeue if we failed because of async discard */ |
| btrfs_discard_queue_work(&fs_info->discard_ctl, |
| block_group); |
| goto next; |
| } |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&block_group->lock); |
| if (btrfs_is_block_group_used(block_group) || block_group->ro || |
| list_is_singular(&block_group->list)) { |
| /* |
| * We want to bail if we made new allocations or have |
| * outstanding allocations in this block group. We do |
| * the ro check in case balance is currently acting on |
| * this block group. |
| * |
| * Also bail out if this is the only block group for its |
| * type, because otherwise we would lose profile |
| * information from fs_info->avail_*_alloc_bits and the |
| * next block group of this type would be created with a |
| * "single" profile (even if we're in a raid fs) because |
| * fs_info->avail_*_alloc_bits would be 0. |
| */ |
| trace_btrfs_skip_unused_block_group(block_group); |
| spin_unlock(&block_group->lock); |
| spin_unlock(&space_info->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| |
| /* |
| * The block group may be unused but there may be space reserved |
| * accounting with the existence of that block group, that is, |
| * space_info->bytes_may_use was incremented by a task but no |
| * space was yet allocated from the block group by the task. |
| * That space may or may not be allocated, as we are generally |
| * pessimistic about space reservation for metadata as well as |
| * for data when using compression (as we reserve space based on |
| * the worst case, when data can't be compressed, and before |
| * actually attempting compression, before starting writeback). |
| * |
| * So check if the total space of the space_info minus the size |
| * of this block group is less than the used space of the |
| * space_info - if that's the case, then it means we have tasks |
| * that might be relying on the block group in order to allocate |
| * extents, and add back the block group to the unused list when |
| * we finish, so that we retry later in case no tasks ended up |
| * needing to allocate extents from the block group. |
| */ |
| used = btrfs_space_info_used(space_info, true); |
| if (space_info->total_bytes - block_group->length < used && |
| block_group->zone_unusable < block_group->length) { |
| /* |
| * Add a reference for the list, compensate for the ref |
| * drop under the "next" label for the |
| * fs_info->unused_bgs list. |
| */ |
| btrfs_get_block_group(block_group); |
| list_add_tail(&block_group->bg_list, &retry_list); |
| |
| trace_btrfs_skip_unused_block_group(block_group); |
| spin_unlock(&block_group->lock); |
| spin_unlock(&space_info->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| |
| spin_unlock(&block_group->lock); |
| spin_unlock(&space_info->lock); |
| |
| /* We don't want to force the issue, only flip if it's ok. */ |
| ret = inc_block_group_ro(block_group, 0); |
| up_write(&space_info->groups_sem); |
| if (ret < 0) { |
| ret = 0; |
| goto next; |
| } |
| |
| ret = btrfs_zone_finish(block_group); |
| if (ret < 0) { |
| btrfs_dec_block_group_ro(block_group); |
| if (ret == -EAGAIN) |
| ret = 0; |
| goto next; |
| } |
| |
| /* |
| * Want to do this before we do anything else so we can recover |
| * properly if we fail to join the transaction. |
| */ |
| trans = btrfs_start_trans_remove_block_group(fs_info, |
| block_group->start); |
| if (IS_ERR(trans)) { |
| btrfs_dec_block_group_ro(block_group); |
| ret = PTR_ERR(trans); |
| goto next; |
| } |
| |
| /* |
| * We could have pending pinned extents for this block group, |
| * just delete them, we don't care about them anymore. |
| */ |
| if (!clean_pinned_extents(trans, block_group)) { |
| btrfs_dec_block_group_ro(block_group); |
| goto end_trans; |
| } |
| |
| /* |
| * At this point, the block_group is read only and should fail |
| * new allocations. However, btrfs_finish_extent_commit() can |
| * cause this block_group to be placed back on the discard |
| * lists because now the block_group isn't fully discarded. |
| * Bail here and try again later after discarding everything. |
| */ |
| spin_lock(&fs_info->discard_ctl.lock); |
| if (!list_empty(&block_group->discard_list)) { |
| spin_unlock(&fs_info->discard_ctl.lock); |
| btrfs_dec_block_group_ro(block_group); |
| btrfs_discard_queue_work(&fs_info->discard_ctl, |
| block_group); |
| goto end_trans; |
| } |
| spin_unlock(&fs_info->discard_ctl.lock); |
| |
| /* Reset pinned so btrfs_put_block_group doesn't complain */ |
| spin_lock(&space_info->lock); |
| spin_lock(&block_group->lock); |
| |
| btrfs_space_info_update_bytes_pinned(fs_info, space_info, |
| -block_group->pinned); |
| space_info->bytes_readonly += block_group->pinned; |
| block_group->pinned = 0; |
| |
| spin_unlock(&block_group->lock); |
| spin_unlock(&space_info->lock); |
| |
| /* |
| * The normal path here is an unused block group is passed here, |
| * then trimming is handled in the transaction commit path. |
| * Async discard interposes before this to do the trimming |
| * before coming down the unused block group path as trimming |
| * will no longer be done later in the transaction commit path. |
| */ |
| if (!async_trim_enabled && btrfs_test_opt(fs_info, DISCARD_ASYNC)) |
| goto flip_async; |
| |
| /* |
| * DISCARD can flip during remount. On zoned filesystems, we |
| * need to reset sequential-required zones. |
| */ |
| trimming = btrfs_test_opt(fs_info, DISCARD_SYNC) || |
| btrfs_is_zoned(fs_info); |
| |
| /* Implicit trim during transaction commit. */ |
| if (trimming) |
| btrfs_freeze_block_group(block_group); |
| |
| /* |
| * Btrfs_remove_chunk will abort the transaction if things go |
| * horribly wrong. |
| */ |
| ret = btrfs_remove_chunk(trans, block_group->start); |
| |
| if (ret) { |
| if (trimming) |
| btrfs_unfreeze_block_group(block_group); |
| goto end_trans; |
| } |
| |
| /* |
| * If we're not mounted with -odiscard, we can just forget |
| * about this block group. Otherwise we'll need to wait |
| * until transaction commit to do the actual discard. |
| */ |
| if (trimming) { |
| spin_lock(&fs_info->unused_bgs_lock); |
| /* |
| * A concurrent scrub might have added us to the list |
| * fs_info->unused_bgs, so use a list_move operation |
| * to add the block group to the deleted_bgs list. |
| */ |
| list_move(&block_group->bg_list, |
| &trans->transaction->deleted_bgs); |
| spin_unlock(&fs_info->unused_bgs_lock); |
| btrfs_get_block_group(block_group); |
| } |
| end_trans: |
| btrfs_end_transaction(trans); |
| next: |
| btrfs_put_block_group(block_group); |
| spin_lock(&fs_info->unused_bgs_lock); |
| } |
| list_splice_tail(&retry_list, &fs_info->unused_bgs); |
| spin_unlock(&fs_info->unused_bgs_lock); |
| mutex_unlock(&fs_info->reclaim_bgs_lock); |
| return; |
| |
| flip_async: |
| btrfs_end_transaction(trans); |
| spin_lock(&fs_info->unused_bgs_lock); |
| list_splice_tail(&retry_list, &fs_info->unused_bgs); |
| spin_unlock(&fs_info->unused_bgs_lock); |
| mutex_unlock(&fs_info->reclaim_bgs_lock); |
| btrfs_put_block_group(block_group); |
| btrfs_discard_punt_unused_bgs_list(fs_info); |
| } |
| |
| void btrfs_mark_bg_unused(struct btrfs_block_group *bg) |
| { |
| struct btrfs_fs_info *fs_info = bg->fs_info; |
| |
| spin_lock(&fs_info->unused_bgs_lock); |
| if (list_empty(&bg->bg_list)) { |
| btrfs_get_block_group(bg); |
| trace_btrfs_add_unused_block_group(bg); |
| list_add_tail(&bg->bg_list, &fs_info->unused_bgs); |
| } else if (!test_bit(BLOCK_GROUP_FLAG_NEW, &bg->runtime_flags)) { |
| /* Pull out the block group from the reclaim_bgs list. */ |
| trace_btrfs_add_unused_block_group(bg); |
| list_move_tail(&bg->bg_list, &fs_info->unused_bgs); |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| } |
| |
| /* |
| * We want block groups with a low number of used bytes to be in the beginning |
| * of the list, so they will get reclaimed first. |
| */ |
| static int reclaim_bgs_cmp(void *unused, const struct list_head *a, |
| const struct list_head *b) |
| { |
| const struct btrfs_block_group *bg1, *bg2; |
| |
| bg1 = list_entry(a, struct btrfs_block_group, bg_list); |
| bg2 = list_entry(b, struct btrfs_block_group, bg_list); |
| |
| return bg1->used > bg2->used; |
| } |
| |
| static inline bool btrfs_should_reclaim(struct btrfs_fs_info *fs_info) |
| { |
| if (btrfs_is_zoned(fs_info)) |
| return btrfs_zoned_should_reclaim(fs_info); |
| return true; |
| } |
| |
| static bool should_reclaim_block_group(struct btrfs_block_group *bg, u64 bytes_freed) |
| { |
| const struct btrfs_space_info *space_info = bg->space_info; |
| const int reclaim_thresh = READ_ONCE(space_info->bg_reclaim_threshold); |
| const u64 new_val = bg->used; |
| const u64 old_val = new_val + bytes_freed; |
| u64 thresh; |
| |
| if (reclaim_thresh == 0) |
| return false; |
| |
| thresh = mult_perc(bg->length, reclaim_thresh); |
| |
| /* |
| * If we were below the threshold before don't reclaim, we are likely a |
| * brand new block group and we don't want to relocate new block groups. |
| */ |
| if (old_val < thresh) |
| return false; |
| if (new_val >= thresh) |
| return false; |
| return true; |
| } |
| |
| void btrfs_reclaim_bgs_work(struct work_struct *work) |
| { |
| struct btrfs_fs_info *fs_info = |
| container_of(work, struct btrfs_fs_info, reclaim_bgs_work); |
| struct btrfs_block_group *bg; |
| struct btrfs_space_info *space_info; |
| LIST_HEAD(retry_list); |
| |
| if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags)) |
| return; |
| |
| if (btrfs_fs_closing(fs_info)) |
| return; |
| |
| if (!btrfs_should_reclaim(fs_info)) |
| return; |
| |
| sb_start_write(fs_info->sb); |
| |
| if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { |
| sb_end_write(fs_info->sb); |
| return; |
| } |
| |
| /* |
| * Long running balances can keep us blocked here for eternity, so |
| * simply skip reclaim if we're unable to get the mutex. |
| */ |
| if (!mutex_trylock(&fs_info->reclaim_bgs_lock)) { |
| btrfs_exclop_finish(fs_info); |
| sb_end_write(fs_info->sb); |
| return; |
| } |
| |
| spin_lock(&fs_info->unused_bgs_lock); |
| /* |
| * Sort happens under lock because we can't simply splice it and sort. |
| * The block groups might still be in use and reachable via bg_list, |
| * and their presence in the reclaim_bgs list must be preserved. |
| */ |
| list_sort(NULL, &fs_info->reclaim_bgs, reclaim_bgs_cmp); |
| while (!list_empty(&fs_info->reclaim_bgs)) { |
| u64 zone_unusable; |
| int ret = 0; |
| |
| bg = list_first_entry(&fs_info->reclaim_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| list_del_init(&bg->bg_list); |
| |
| space_info = bg->space_info; |
| spin_unlock(&fs_info->unused_bgs_lock); |
| |
| /* Don't race with allocators so take the groups_sem */ |
| down_write(&space_info->groups_sem); |
| |
| spin_lock(&bg->lock); |
| if (bg->reserved || bg->pinned || bg->ro) { |
| /* |
| * We want to bail if we made new allocations or have |
| * outstanding allocations in this block group. We do |
| * the ro check in case balance is currently acting on |
| * this block group. |
| */ |
| spin_unlock(&bg->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| if (bg->used == 0) { |
| /* |
| * It is possible that we trigger relocation on a block |
| * group as its extents are deleted and it first goes |
| * below the threshold, then shortly after goes empty. |
| * |
| * In this case, relocating it does delete it, but has |
| * some overhead in relocation specific metadata, looking |
| * for the non-existent extents and running some extra |
| * transactions, which we can avoid by using one of the |
| * other mechanisms for dealing with empty block groups. |
| */ |
| if (!btrfs_test_opt(fs_info, DISCARD_ASYNC)) |
| btrfs_mark_bg_unused(bg); |
| spin_unlock(&bg->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| |
| } |
| /* |
| * The block group might no longer meet the reclaim condition by |
| * the time we get around to reclaiming it, so to avoid |
| * reclaiming overly full block_groups, skip reclaiming them. |
| * |
| * Since the decision making process also depends on the amount |
| * being freed, pass in a fake giant value to skip that extra |
| * check, which is more meaningful when adding to the list in |
| * the first place. |
| */ |
| if (!should_reclaim_block_group(bg, bg->length)) { |
| spin_unlock(&bg->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| spin_unlock(&bg->lock); |
| |
| /* |
| * Get out fast, in case we're read-only or unmounting the |
| * filesystem. It is OK to drop block groups from the list even |
| * for the read-only case. As we did sb_start_write(), |
| * "mount -o remount,ro" won't happen and read-only filesystem |
| * means it is forced read-only due to a fatal error. So, it |
| * never gets back to read-write to let us reclaim again. |
| */ |
| if (btrfs_need_cleaner_sleep(fs_info)) { |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| |
| /* |
| * Cache the zone_unusable value before turning the block group |
| * to read only. As soon as the blog group is read only it's |
| * zone_unusable value gets moved to the block group's read-only |
| * bytes and isn't available for calculations anymore. |
| */ |
| zone_unusable = bg->zone_unusable; |
| ret = inc_block_group_ro(bg, 0); |
| up_write(&space_info->groups_sem); |
| if (ret < 0) |
| goto next; |
| |
| btrfs_info(fs_info, |
| "reclaiming chunk %llu with %llu%% used %llu%% unusable", |
| bg->start, |
| div64_u64(bg->used * 100, bg->length), |
| div64_u64(zone_unusable * 100, bg->length)); |
| trace_btrfs_reclaim_block_group(bg); |
| ret = btrfs_relocate_chunk(fs_info, bg->start); |
| if (ret) { |
| btrfs_dec_block_group_ro(bg); |
| btrfs_err(fs_info, "error relocating chunk %llu", |
| bg->start); |
| } |
| |
| next: |
| if (ret) { |
| /* Refcount held by the reclaim_bgs list after splice. */ |
| spin_lock(&fs_info->unused_bgs_lock); |
| /* |
| * This block group might be added to the unused list |
| * during the above process. Move it back to the |
| * reclaim list otherwise. |
| */ |
| if (list_empty(&bg->bg_list)) { |
| btrfs_get_block_group(bg); |
| list_add_tail(&bg->bg_list, &retry_list); |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| } |
| btrfs_put_block_group(bg); |
| |
| mutex_unlock(&fs_info->reclaim_bgs_lock); |
| /* |
| * Reclaiming all the block groups in the list can take really |
| * long. Prioritize cleaning up unused block groups. |
| */ |
| btrfs_delete_unused_bgs(fs_info); |
| /* |
| * If we are interrupted by a balance, we can just bail out. The |
| * cleaner thread restart again if necessary. |
| */ |
| if (!mutex_trylock(&fs_info->reclaim_bgs_lock)) |
| goto end; |
| spin_lock(&fs_info->unused_bgs_lock); |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| mutex_unlock(&fs_info->reclaim_bgs_lock); |
| end: |
| spin_lock(&fs_info->unused_bgs_lock); |
| list_splice_tail(&retry_list, &fs_info->reclaim_bgs); |
| spin_unlock(&fs_info->unused_bgs_lock); |
| btrfs_exclop_finish(fs_info); |
| sb_end_write(fs_info->sb); |
| } |
| |
| void btrfs_reclaim_bgs(struct btrfs_fs_info *fs_info) |
| { |
| spin_lock(&fs_info->unused_bgs_lock); |
| if (!list_empty(&fs_info->reclaim_bgs)) |
| queue_work(system_unbound_wq, &fs_info->reclaim_bgs_work); |
| spin_unlock(&fs_info->unused_bgs_lock); |
| } |
| |
| void btrfs_mark_bg_to_reclaim(struct btrfs_block_group *bg) |
| { |
| struct btrfs_fs_info *fs_info = bg->fs_info; |
| |
| spin_lock(&fs_info->unused_bgs_lock); |
| if (list_empty(&bg->bg_list)) { |
| btrfs_get_block_group(bg); |
| trace_btrfs_add_reclaim_block_group(bg); |
| list_add_tail(&bg->bg_list, &fs_info->reclaim_bgs); |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| } |
| |
| static int read_bg_from_eb(struct btrfs_fs_info *fs_info, struct btrfs_key *key, |
| struct btrfs_path *path) |
| { |
| struct btrfs_chunk_map *map; |
| struct btrfs_block_group_item bg; |
| struct extent_buffer *leaf; |
| int slot; |
| u64 flags; |
| int ret = 0; |
| |
| slot = path->slots[0]; |
| leaf = path->nodes[0]; |
| |
| map = btrfs_find_chunk_map(fs_info, key->objectid, key->offset); |
| if (!map) { |
| btrfs_err(fs_info, |
| "logical %llu len %llu found bg but no related chunk", |
| key->objectid, key->offset); |
| return -ENOENT; |
| } |
| |
| if (map->start != key->objectid || map->chunk_len != key->offset) { |
| btrfs_err(fs_info, |
| "block group %llu len %llu mismatch with chunk %llu len %llu", |
| key->objectid, key->offset, map->start, map->chunk_len); |
| ret = -EUCLEAN; |
| goto out_free_map; |
| } |
| |
| read_extent_buffer(leaf, &bg, btrfs_item_ptr_offset(leaf, slot), |
| sizeof(bg)); |
| flags = btrfs_stack_block_group_flags(&bg) & |
| BTRFS_BLOCK_GROUP_TYPE_MASK; |
| |
| if (flags != (map->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { |
| btrfs_err(fs_info, |
| "block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx", |
| key->objectid, key->offset, flags, |
| (BTRFS_BLOCK_GROUP_TYPE_MASK & map->type)); |
| ret = -EUCLEAN; |
| } |
| |
| out_free_map: |
| btrfs_free_chunk_map(map); |
| return ret; |
| } |
| |
| static int find_first_block_group(struct btrfs_fs_info *fs_info, |
| struct btrfs_path *path, |
| struct btrfs_key *key) |
| { |
| struct btrfs_root *root = btrfs_block_group_root(fs_info); |
| int ret; |
| struct btrfs_key found_key; |
| |
| btrfs_for_each_slot(root, key, &found_key, path, ret) { |
| if (found_key.objectid >= key->objectid && |
| found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| return read_bg_from_eb(fs_info, &found_key, path); |
| } |
| } |
| return ret; |
| } |
| |
| static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| u64 extra_flags = chunk_to_extended(flags) & |
| BTRFS_EXTENDED_PROFILE_MASK; |
| |
| write_seqlock(&fs_info->profiles_lock); |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| fs_info->avail_data_alloc_bits |= extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| fs_info->avail_metadata_alloc_bits |= extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| fs_info->avail_system_alloc_bits |= extra_flags; |
| write_sequnlock(&fs_info->profiles_lock); |
| } |
| |
| /* |
| * Map a physical disk address to a list of logical addresses. |
| * |
| * @fs_info: the filesystem |
| * @chunk_start: logical address of block group |
| * @physical: physical address to map to logical addresses |
| * @logical: return array of logical addresses which map to @physical |
| * @naddrs: length of @logical |
| * @stripe_len: size of IO stripe for the given block group |
| * |
| * Maps a particular @physical disk address to a list of @logical addresses. |
| * Used primarily to exclude those portions of a block group that contain super |
| * block copies. |
| */ |
| int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start, |
| u64 physical, u64 **logical, int *naddrs, int *stripe_len) |
| { |
| struct btrfs_chunk_map *map; |
| u64 *buf; |
| u64 bytenr; |
| u64 data_stripe_length; |
| u64 io_stripe_size; |
| int i, nr = 0; |
| int ret = 0; |
| |
| map = btrfs_get_chunk_map(fs_info, chunk_start, 1); |
| if (IS_ERR(map)) |
| return -EIO; |
| |
| data_stripe_length = map->stripe_size; |
| io_stripe_size = BTRFS_STRIPE_LEN; |
| chunk_start = map->start; |
| |
| /* For RAID5/6 adjust to a full IO stripe length */ |
| if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) |
| io_stripe_size = btrfs_stripe_nr_to_offset(nr_data_stripes(map)); |
| |
| buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS); |
| if (!buf) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| for (i = 0; i < map->num_stripes; i++) { |
| bool already_inserted = false; |
| u32 stripe_nr; |
| u32 offset; |
| int j; |
| |
| if (!in_range(physical, map->stripes[i].physical, |
| data_stripe_length)) |
| continue; |
| |
| stripe_nr = (physical - map->stripes[i].physical) >> |
| BTRFS_STRIPE_LEN_SHIFT; |
| offset = (physical - map->stripes[i].physical) & |
| BTRFS_STRIPE_LEN_MASK; |
| |
| if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| stripe_nr = div_u64(stripe_nr * map->num_stripes + i, |
| map->sub_stripes); |
| /* |
| * The remaining case would be for RAID56, multiply by |
| * nr_data_stripes(). Alternatively, just use rmap_len below |
| * instead of map->stripe_len |
| */ |
| bytenr = chunk_start + stripe_nr * io_stripe_size + offset; |
| |
| /* Ensure we don't add duplicate addresses */ |
| for (j = 0; j < nr; j++) { |
| if (buf[j] == bytenr) { |
| already_inserted = true; |
| break; |
| } |
| } |
| |
| if (!already_inserted) |
| buf[nr++] = bytenr; |
| } |
| |
| *logical = buf; |
| *naddrs = nr; |
| *stripe_len = io_stripe_size; |
| out: |
| btrfs_free_chunk_map(map); |
| return ret; |
| } |
| |
| static int exclude_super_stripes(struct btrfs_block_group *cache) |
| { |
| struct btrfs_fs_info *fs_info = cache->fs_info; |
| const bool zoned = btrfs_is_zoned(fs_info); |
| u64 bytenr; |
| u64 *logical; |
| int stripe_len; |
| int i, nr, ret; |
| |
| if (cache->start < BTRFS_SUPER_INFO_OFFSET) { |
| stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->start; |
| cache->bytes_super += stripe_len; |
| ret = set_extent_bit(&fs_info->excluded_extents, cache->start, |
| cache->start + stripe_len - 1, |
| EXTENT_UPTODATE, NULL); |
| if (ret) |
| return ret; |
| } |
| |
| for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { |
| bytenr = btrfs_sb_offset(i); |
| ret = btrfs_rmap_block(fs_info, cache->start, |
| bytenr, &logical, &nr, &stripe_len); |
| if (ret) |
| return ret; |
| |
| /* Shouldn't have super stripes in sequential zones */ |
| if (zoned && nr) { |
| kfree(logical); |
| btrfs_err(fs_info, |
| "zoned: block group %llu must not contain super block", |
| cache->start); |
| return -EUCLEAN; |
| } |
| |
| while (nr--) { |
| u64 len = min_t(u64, stripe_len, |
| cache->start + cache->length - logical[nr]); |
| |
| cache->bytes_super += len; |
| ret = set_extent_bit(&fs_info->excluded_extents, logical[nr], |
| logical[nr] + len - 1, |
| EXTENT_UPTODATE, NULL); |
| if (ret) { |
| kfree(logical); |
| return ret; |
| } |
| } |
| |
| kfree(logical); |
| } |
| return 0; |
| } |
| |
| static struct btrfs_block_group *btrfs_create_block_group_cache( |
| struct btrfs_fs_info *fs_info, u64 start) |
| { |
| struct btrfs_block_group *cache; |
| |
| cache = kzalloc(sizeof(*cache), GFP_NOFS); |
| if (!cache) |
| return NULL; |
| |
| cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl), |
| GFP_NOFS); |
| if (!cache->free_space_ctl) { |
| kfree(cache); |
| return NULL; |
| } |
| |
| cache->start = start; |
| |
| cache->fs_info = fs_info; |
| cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start); |
| |
| cache->discard_index = BTRFS_DISCARD_INDEX_UNUSED; |
| |
| refcount_set(&cache->refs, 1); |
| spin_lock_init(&cache->lock); |
| init_rwsem(&cache->data_rwsem); |
| INIT_LIST_HEAD(&cache->list); |
| INIT_LIST_HEAD(&cache->cluster_list); |
| INIT_LIST_HEAD(&cache->bg_list); |
| INIT_LIST_HEAD(&cache->ro_list); |
| INIT_LIST_HEAD(&cache->discard_list); |
| INIT_LIST_HEAD(&cache->dirty_list); |
| INIT_LIST_HEAD(&cache->io_list); |
| INIT_LIST_HEAD(&cache->active_bg_list); |
| btrfs_init_free_space_ctl(cache, cache->free_space_ctl); |
| atomic_set(&cache->frozen, 0); |
| mutex_init(&cache->free_space_lock); |
| |
| return cache; |
| } |
| |
| /* |
| * Iterate all chunks and verify that each of them has the corresponding block |
| * group |
| */ |
| static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info) |
| { |
| u64 start = 0; |
| int ret = 0; |
| |
| while (1) { |
| struct btrfs_chunk_map *map; |
| struct btrfs_block_group *bg; |
| |
| /* |
| * btrfs_find_chunk_map() will return the first chunk map |
| * intersecting the range, so setting @length to 1 is enough to |
| * get the first chunk. |
| */ |
| map = btrfs_find_chunk_map(fs_info, start, 1); |
| if (!map) |
| break; |
| |
| bg = btrfs_lookup_block_group(fs_info, map->start); |
| if (!bg) { |
| btrfs_err(fs_info, |
| "chunk start=%llu len=%llu doesn't have corresponding block group", |
| map->start, map->chunk_len); |
| ret = -EUCLEAN; |
| btrfs_free_chunk_map(map); |
| break; |
| } |
| if (bg->start != map->start || bg->length != map->chunk_len || |
| (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) != |
| (map->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { |
| btrfs_err(fs_info, |
| "chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx", |
| map->start, map->chunk_len, |
| map->type & BTRFS_BLOCK_GROUP_TYPE_MASK, |
| bg->start, bg->length, |
| bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK); |
| ret = -EUCLEAN; |
| btrfs_free_chunk_map(map); |
| btrfs_put_block_group(bg); |
| break; |
| } |
| start = map->start + map->chunk_len; |
| btrfs_free_chunk_map(map); |
| btrfs_put_block_group(bg); |
| } |
| return ret; |
| } |
| |
| static int read_one_block_group(struct btrfs_fs_info *info, |
| struct btrfs_block_group_item *bgi, |
| const struct btrfs_key *key, |
| int need_clear) |
| { |
| struct btrfs_block_group *cache; |
| const bool mixed = btrfs_fs_incompat(info, MIXED_GROUPS); |
| int ret; |
| |
| ASSERT(key->type == BTRFS_BLOCK_GROUP_ITEM_KEY); |
| |
| cache = btrfs_create_block_group_cache(info, key->objectid); |
| if (!cache) |
| return -ENOMEM; |
| |
| cache->length = key->offset; |
| cache->used = btrfs_stack_block_group_used(bgi); |
| cache->commit_used = cache->used; |
| cache->flags = btrfs_stack_block_group_flags(bgi); |
| cache->global_root_id = btrfs_stack_block_group_chunk_objectid(bgi); |
| |
| set_free_space_tree_thresholds(cache); |
| |
| if (need_clear) { |
| /* |
| * When we mount with old space cache, we need to |
| * set BTRFS_DC_CLEAR and set dirty flag. |
| * |
| * a) Setting 'BTRFS_DC_CLEAR' makes sure that we |
| * truncate the old free space cache inode and |
| * setup a new one. |
| * b) Setting 'dirty flag' makes sure that we flush |
| * the new space cache info onto disk. |
| */ |
| if (btrfs_test_opt(info, SPACE_CACHE)) |
| cache->disk_cache_state = BTRFS_DC_CLEAR; |
| } |
| if (!mixed && ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) && |
| (cache->flags & BTRFS_BLOCK_GROUP_DATA))) { |
| btrfs_err(info, |
| "bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups", |
| cache->start); |
| ret = -EINVAL; |
| goto error; |
| } |
| |
| ret = btrfs_load_block_group_zone_info(cache, false); |
| if (ret) { |
| btrfs_err(info, "zoned: failed to load zone info of bg %llu", |
| cache->start); |
| goto error; |
| } |
| |
| /* |
| * We need to exclude the super stripes now so that the space info has |
| * super bytes accounted for, otherwise we'll think we have more space |
| * than we actually do. |
| */ |
| ret = exclude_super_stripes(cache); |
| if (ret) { |
| /* We may have excluded something, so call this just in case. */ |
| btrfs_free_excluded_extents(cache); |
| goto error; |
| } |
| |
| /* |
| * For zoned filesystem, space after the allocation offset is the only |
| * free space for a block group. So, we don't need any caching work. |
| * btrfs_calc_zone_unusable() will set the amount of free space and |
| * zone_unusable space. |
| * |
| * For regular filesystem, check for two cases, either we are full, and |
| * therefore don't need to bother with the caching work since we won't |
| * find any space, or we are empty, and we can just add all the space |
| * in and be done with it. This saves us _a_lot_ of time, particularly |
| * in the full case. |
| */ |
| if (btrfs_is_zoned(info)) { |
| btrfs_calc_zone_unusable(cache); |
| /* Should not have any excluded extents. Just in case, though. */ |
| btrfs_free_excluded_extents(cache); |
| } else if (cache->length == cache->used) { |
| cache->cached = BTRFS_CACHE_FINISHED; |
| btrfs_free_excluded_extents(cache); |
| } else if (cache->used == 0) { |
| cache->cached = BTRFS_CACHE_FINISHED; |
| ret = btrfs_add_new_free_space(cache, cache->start, |
| cache->start + cache->length, NULL); |
| btrfs_free_excluded_extents(cache); |
| if (ret) |
| goto error; |
| } |
| |
| ret = btrfs_add_block_group_cache(info, cache); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| goto error; |
| } |
| trace_btrfs_add_block_group(info, cache, 0); |
| btrfs_add_bg_to_space_info(info, cache); |
| |
| set_avail_alloc_bits(info, cache->flags); |
| if (btrfs_chunk_writeable(info, cache->start)) { |
| if (cache->used == 0) { |
| ASSERT(list_empty(&cache->bg_list)); |
| if (btrfs_test_opt(info, DISCARD_ASYNC)) |
| btrfs_discard_queue_work(&info->discard_ctl, cache); |
| else |
| btrfs_mark_bg_unused(cache); |
| } |
| } else { |
| inc_block_group_ro(cache, 1); |
| } |
| |
| return 0; |
| error: |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| |
| static int fill_dummy_bgs(struct btrfs_fs_info *fs_info) |
| { |
| struct rb_node *node; |
| int ret = 0; |
| |
| for (node = rb_first_cached(&fs_info->mapping_tree); node; node = rb_next(node)) { |
| struct btrfs_chunk_map *map; |
| struct btrfs_block_group *bg; |
| |
| map = rb_entry(node, struct btrfs_chunk_map, rb_node); |
| bg = btrfs_create_block_group_cache(fs_info, map->start); |
| if (!bg) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| /* Fill dummy cache as FULL */ |
| bg->length = map->chunk_len; |
| bg->flags = map->type; |
| bg->cached = BTRFS_CACHE_FINISHED; |
| bg->used = map->chunk_len; |
| bg->flags = map->type; |
| ret = btrfs_add_block_group_cache(fs_info, bg); |
| /* |
| * We may have some valid block group cache added already, in |
| * that case we skip to the next one. |
| */ |
| if (ret == -EEXIST) { |
| ret = 0; |
| btrfs_put_block_group(bg); |
| continue; |
| } |
| |
| if (ret) { |
| btrfs_remove_free_space_cache(bg); |
| btrfs_put_block_group(bg); |
| break; |
| } |
| |
| btrfs_add_bg_to_space_info(fs_info, bg); |
| |
| set_avail_alloc_bits(fs_info, bg->flags); |
| } |
| if (!ret) |
| btrfs_init_global_block_rsv(fs_info); |
| return ret; |
| } |
| |
| int btrfs_read_block_groups(struct btrfs_fs_info *info) |
| { |
| struct btrfs_root *root = btrfs_block_group_root(info); |
| struct btrfs_path *path; |
| int ret; |
| struct btrfs_block_group *cache; |
| struct btrfs_space_info *space_info; |
| struct btrfs_key key; |
| int need_clear = 0; |
| u64 cache_gen; |
| |
| /* |
| * Either no extent root (with ibadroots rescue option) or we have |
| * unsupported RO options. The fs can never be mounted read-write, so no |
| * need to waste time searching block group items. |
| * |
| * This also allows new extent tree related changes to be RO compat, |
| * no need for a full incompat flag. |
| */ |
| if (!root || (btrfs_super_compat_ro_flags(info->super_copy) & |
| ~BTRFS_FEATURE_COMPAT_RO_SUPP)) |
| return fill_dummy_bgs(info); |
| |
| key.objectid = 0; |
| key.offset = 0; |
| key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| cache_gen = btrfs_super_cache_generation(info->super_copy); |
| if (btrfs_test_opt(info, SPACE_CACHE) && |
| btrfs_super_generation(info->super_copy) != cache_gen) |
| need_clear = 1; |
| if (btrfs_test_opt(info, CLEAR_CACHE)) |
| need_clear = 1; |
| |
| while (1) { |
| struct btrfs_block_group_item bgi; |
| struct extent_buffer *leaf; |
| int slot; |
| |
| ret = find_first_block_group(info, path, &key); |
| if (ret > 0) |
| break; |
| if (ret != 0) |
| goto error; |
| |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| |
| read_extent_buffer(leaf, &bgi, btrfs_item_ptr_offset(leaf, slot), |
| sizeof(bgi)); |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| btrfs_release_path(path); |
| ret = read_one_block_group(info, &bgi, &key, need_clear); |
| if (ret < 0) |
| goto error; |
| key.objectid += key.offset; |
| key.offset = 0; |
| } |
| btrfs_release_path(path); |
| |
| list_for_each_entry(space_info, &info->space_info, list) { |
| int i; |
| |
| for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { |
| if (list_empty(&space_info->block_groups[i])) |
| continue; |
| cache = list_first_entry(&space_info->block_groups[i], |
| struct btrfs_block_group, |
| list); |
| btrfs_sysfs_add_block_group_type(cache); |
| } |
| |
| if (!(btrfs_get_alloc_profile(info, space_info->flags) & |
| (BTRFS_BLOCK_GROUP_RAID10 | |
| BTRFS_BLOCK_GROUP_RAID1_MASK | |
| BTRFS_BLOCK_GROUP_RAID56_MASK | |
| BTRFS_BLOCK_GROUP_DUP))) |
| continue; |
| /* |
| * Avoid allocating from un-mirrored block group if there are |
| * mirrored block groups. |
| */ |
| list_for_each_entry(cache, |
| &space_info->block_groups[BTRFS_RAID_RAID0], |
| list) |
| inc_block_group_ro(cache, 1); |
| list_for_each_entry(cache, |
| &space_info->block_groups[BTRFS_RAID_SINGLE], |
| list) |
| inc_block_group_ro(cache, 1); |
| } |
| |
| btrfs_init_global_block_rsv(info); |
| ret = check_chunk_block_group_mappings(info); |
| error: |
| btrfs_free_path(path); |
| /* |
| * We've hit some error while reading the extent tree, and have |
| * rescue=ibadroots mount option. |
| * Try to fill the tree using dummy block groups so that the user can |
| * continue to mount and grab their data. |
| */ |
| if (ret && btrfs_test_opt(info, IGNOREBADROOTS)) |
| ret = fill_dummy_bgs(info); |
| return ret; |
| } |
| |
| /* |
| * This function, insert_block_group_item(), belongs to the phase 2 of chunk |
| * allocation. |
| * |
| * See the comment at btrfs_chunk_alloc() for details about the chunk allocation |
| * phases. |
| */ |
| static int insert_block_group_item(struct btrfs_trans_handle *trans, |
| struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group_item bgi; |
| struct btrfs_root *root = btrfs_block_group_root(fs_info); |
| struct btrfs_key key; |
| u64 old_commit_used; |
| int ret; |
| |
| spin_lock(&block_group->lock); |
| btrfs_set_stack_block_group_used(&bgi, block_group->used); |
| btrfs_set_stack_block_group_chunk_objectid(&bgi, |
| block_group->global_root_id); |
| btrfs_set_stack_block_group_flags(&bgi, block_group->flags); |
| old_commit_used = block_group->commit_used; |
| block_group->commit_used = block_group->used; |
| key.objectid = block_group->start; |
| key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| key.offset = block_group->length; |
| spin_unlock(&block_group->lock); |
| |
| ret = btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi)); |
| if (ret < 0) { |
| spin_lock(&block_group->lock); |
| block_group->commit_used = old_commit_used; |
| spin_unlock(&block_group->lock); |
| } |
| |
| return ret; |
| } |
| |
| static int insert_dev_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_device *device, u64 chunk_offset, |
| u64 start, u64 num_bytes) |
| { |
| struct btrfs_fs_info *fs_info = device->fs_info; |
| struct btrfs_root *root = fs_info->dev_root; |
| struct btrfs_path *path; |
| struct btrfs_dev_extent *extent; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| int ret; |
| |
| WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state)); |
| WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| key.objectid = device->devid; |
| key.type = BTRFS_DEV_EXTENT_KEY; |
| key.offset = start; |
| ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*extent)); |
| if (ret) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_extent); |
| btrfs_set_dev_extent_chunk_tree(leaf, extent, BTRFS_CHUNK_TREE_OBJECTID); |
| btrfs_set_dev_extent_chunk_objectid(leaf, extent, |
| BTRFS_FIRST_CHUNK_TREE_OBJECTID); |
| btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset); |
| |
| btrfs_set_dev_extent_length(leaf, extent, num_bytes); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * This function belongs to phase 2. |
| * |
| * See the comment at btrfs_chunk_alloc() for details about the chunk allocation |
| * phases. |
| */ |
| static int insert_dev_extents(struct btrfs_trans_handle *trans, |
| u64 chunk_offset, u64 chunk_size) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_device *device; |
| struct btrfs_chunk_map *map; |
| u64 dev_offset; |
| int i; |
| int ret = 0; |
| |
| map = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size); |
| if (IS_ERR(map)) |
| return PTR_ERR(map); |
| |
| /* |
| * Take the device list mutex to prevent races with the final phase of |
| * a device replace operation that replaces the device object associated |
| * with the map's stripes, because the device object's id can change |
| * at any time during that final phase of the device replace operation |
| * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the |
| * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID, |
| * resulting in persisting a device extent item with such ID. |
| */ |
| mutex_lock(&fs_info->fs_devices->device_list_mutex); |
| for (i = 0; i < map->num_stripes; i++) { |
| device = map->stripes[i].dev; |
| dev_offset = map->stripes[i].physical; |
| |
| ret = insert_dev_extent(trans, device, chunk_offset, dev_offset, |
| map->stripe_size); |
| if (ret) |
| break; |
| } |
| mutex_unlock(&fs_info->fs_devices->device_list_mutex); |
| |
| btrfs_free_chunk_map(map); |
| return ret; |
| } |
| |
| /* |
| * This function, btrfs_create_pending_block_groups(), belongs to the phase 2 of |
| * chunk allocation. |
| * |
| * See the comment at btrfs_chunk_alloc() for details about the chunk allocation |
| * phases. |
| */ |
| void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *block_group; |
| int ret = 0; |
| |
| while (!list_empty(&trans->new_bgs)) { |
| int index; |
| |
| block_group = list_first_entry(&trans->new_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| if (ret) |
| goto next; |
| |
| index = btrfs_bg_flags_to_raid_index(block_group->flags); |
| |
| ret = insert_block_group_item(trans, block_group); |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| if (!test_bit(BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED, |
| &block_group->runtime_flags)) { |
| mutex_lock(&fs_info->chunk_mutex); |
| ret = btrfs_chunk_alloc_add_chunk_item(trans, block_group); |
| mutex_unlock(&fs_info->chunk_mutex); |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| } |
| ret = insert_dev_extents(trans, block_group->start, |
| block_group->length); |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| add_block_group_free_space(trans, block_group); |
| |
| /* |
| * If we restriped during balance, we may have added a new raid |
| * type, so now add the sysfs entries when it is safe to do so. |
| * We don't have to worry about locking here as it's handled in |
| * btrfs_sysfs_add_block_group_type. |
| */ |
| if (block_group->space_info->block_group_kobjs[index] == NULL) |
| btrfs_sysfs_add_block_group_type(block_group); |
| |
| /* Already aborted the transaction if it failed. */ |
| next: |
| btrfs_dec_delayed_refs_rsv_bg_inserts(fs_info); |
| list_del_init(&block_group->bg_list); |
| clear_bit(BLOCK_GROUP_FLAG_NEW, &block_group->runtime_flags); |
| |
| /* |
| * If the block group is still unused, add it to the list of |
| * unused block groups. The block group may have been created in |
| * order to satisfy a space reservation, in which case the |
| * extent allocation only happens later. But often we don't |
| * actually need to allocate space that we previously reserved, |
| * so the block group may become unused for a long time. For |
| * example for metadata we generally reserve space for a worst |
| * possible scenario, but then don't end up allocating all that |
| * space or none at all (due to no need to COW, extent buffers |
| * were already COWed in the current transaction and still |
| * unwritten, tree heights lower than the maximum possible |
| * height, etc). For data we generally reserve the axact amount |
| * of space we are going to allocate later, the exception is |
| * when using compression, as we must reserve space based on the |
| * uncompressed data size, because the compression is only done |
| * when writeback triggered and we don't know how much space we |
| * are actually going to need, so we reserve the uncompressed |
| * size because the data may be uncompressible in the worst case. |
| */ |
| if (ret == 0) { |
| bool used; |
| |
| spin_lock(&block_group->lock); |
| used = btrfs_is_block_group_used(block_group); |
| spin_unlock(&block_group->lock); |
| |
| if (!used) |
| btrfs_mark_bg_unused(block_group); |
| } |
| } |
| btrfs_trans_release_chunk_metadata(trans); |
| } |
| |
| /* |
| * For extent tree v2 we use the block_group_item->chunk_offset to point at our |
| * global root id. For v1 it's always set to BTRFS_FIRST_CHUNK_TREE_OBJECTID. |
| */ |
| static u64 calculate_global_root_id(struct btrfs_fs_info *fs_info, u64 offset) |
| { |
| u64 div = SZ_1G; |
| u64 index; |
| |
| if (!btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) |
| return BTRFS_FIRST_CHUNK_TREE_OBJECTID; |
| |
| /* If we have a smaller fs index based on 128MiB. */ |
| if (btrfs_super_total_bytes(fs_info->super_copy) <= (SZ_1G * 10ULL)) |
| div = SZ_128M; |
| |
| offset = div64_u64(offset, div); |
| div64_u64_rem(offset, fs_info->nr_global_roots, &index); |
| return index; |
| } |
| |
| struct btrfs_block_group *btrfs_make_block_group(struct btrfs_trans_handle *trans, |
| u64 type, |
| u64 chunk_offset, u64 size) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *cache; |
| int ret; |
| |
| btrfs_set_log_full_commit(trans); |
| |
| cache = btrfs_create_block_group_cache(fs_info, chunk_offset); |
| if (!cache) |
| return ERR_PTR(-ENOMEM); |
| |
| /* |
| * Mark it as new before adding it to the rbtree of block groups or any |
| * list, so that no other task finds it and calls btrfs_mark_bg_unused() |
| * before the new flag is set. |
| */ |
| set_bit(BLOCK_GROUP_FLAG_NEW, &cache->runtime_flags); |
| |
| cache->length = size; |
| set_free_space_tree_thresholds(cache); |
| cache->flags = type; |
| cache->cached = BTRFS_CACHE_FINISHED; |
| cache->global_root_id = calculate_global_root_id(fs_info, cache->start); |
| |
| if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) |
| set_bit(BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE, &cache->runtime_flags); |
| |
| ret = btrfs_load_block_group_zone_info(cache, true); |
| if (ret) { |
| btrfs_put_block_group(cache); |
| return ERR_PTR(ret); |
| } |
| |
| ret = exclude_super_stripes(cache); |
| if (ret) { |
| /* We may have excluded something, so call this just in case */ |
| btrfs_free_excluded_extents(cache); |
| btrfs_put_block_group(cache); |
| return ERR_PTR(ret); |
| } |
| |
| ret = btrfs_add_new_free_space(cache, chunk_offset, chunk_offset + size, NULL); |
| btrfs_free_excluded_extents(cache); |
| if (ret) { |
| btrfs_put_block_group(cache); |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * Ensure the corresponding space_info object is created and |
| * assigned to our block group. We want our bg to be added to the rbtree |
| * with its ->space_info set. |
| */ |
| cache->space_info = btrfs_find_space_info(fs_info, cache->flags); |
| ASSERT(cache->space_info); |
| |
| ret = btrfs_add_block_group_cache(fs_info, cache); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| btrfs_put_block_group(cache); |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * Now that our block group has its ->space_info set and is inserted in |
| * the rbtree, update the space info's counters. |
| */ |
| trace_btrfs_add_block_group(fs_info, cache, 1); |
| btrfs_add_bg_to_space_info(fs_info, cache); |
| btrfs_update_global_block_rsv(fs_info); |
| |
| #ifdef CONFIG_BTRFS_DEBUG |
| if (btrfs_should_fragment_free_space(cache)) { |
| cache->space_info->bytes_used += size >> 1; |
| fragment_free_space(cache); |
| } |
| #endif |
| |
| list_add_tail(&cache->bg_list, &trans->new_bgs); |
| btrfs_inc_delayed_refs_rsv_bg_inserts(fs_info); |
| |
| set_avail_alloc_bits(fs_info, type); |
| return cache; |
| } |
| |
| /* |
| * Mark one block group RO, can be called several times for the same block |
| * group. |
| * |
| * @cache: the destination block group |
| * @do_chunk_alloc: whether need to do chunk pre-allocation, this is to |
| * ensure we still have some free space after marking this |
| * block group RO. |
| */ |
| int btrfs_inc_block_group_ro(struct btrfs_block_group *cache, |
| bool do_chunk_alloc) |
| { |
| struct btrfs_fs_info *fs_info = cache->fs_info; |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *root = btrfs_block_group_root(fs_info); |
| u64 alloc_flags; |
| int ret; |
| bool dirty_bg_running; |
| |
| /* |
| * This can only happen when we are doing read-only scrub on read-only |
| * mount. |
| * In that case we should not start a new transaction on read-only fs. |
| * Thus here we skip all chunk allocations. |
| */ |
| if (sb_rdonly(fs_info->sb)) { |
| mutex_lock(&fs_info->ro_block_group_mutex); |
| ret = inc_block_group_ro(cache, 0); |
| mutex_unlock(&fs_info->ro_block_group_mutex); |
| return ret; |
| } |
| |
| do { |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| dirty_bg_running = false; |
| |
| /* |
| * We're not allowed to set block groups readonly after the dirty |
| * block group cache has started writing. If it already started, |
| * back off and let this transaction commit. |
| */ |
| mutex_lock(&fs_info->ro_block_group_mutex); |
| if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) { |
| u64 transid = trans->transid; |
| |
| mutex_unlock(&fs_info->ro_block_group_mutex); |
| btrfs_end_transaction(trans); |
| |
| ret = btrfs_wait_for_commit(fs_info, transid); |
| if (ret) |
| return ret; |
| dirty_bg_running = true; |
| } |
| } while (dirty_bg_running); |
| |
| if (do_chunk_alloc) { |
| /* |
| * If we are changing raid levels, try to allocate a |
| * corresponding block group with the new raid level. |
| */ |
| alloc_flags = btrfs_get_alloc_profile(fs_info, cache->flags); |
| if (alloc_flags != cache->flags) { |
| ret = btrfs_chunk_alloc(trans, alloc_flags, |
| CHUNK_ALLOC_FORCE); |
| /* |
| * ENOSPC is allowed here, we may have enough space |
| * already allocated at the new raid level to carry on |
| */ |
| if (ret == -ENOSPC) |
| ret = 0; |
| if (ret < 0) |
| goto out; |
| } |
| } |
| |
| ret = inc_block_group_ro(cache, 0); |
| if (!ret) |
| goto out; |
| if (ret == -ETXTBSY) |
| goto unlock_out; |
| |
| /* |
| * Skip chunk allocation if the bg is SYSTEM, this is to avoid system |
| * chunk allocation storm to exhaust the system chunk array. Otherwise |
| * we still want to try our best to mark the block group read-only. |
| */ |
| if (!do_chunk_alloc && ret == -ENOSPC && |
| (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM)) |
| goto unlock_out; |
| |
| alloc_flags = btrfs_get_alloc_profile(fs_info, cache->space_info->flags); |
| ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE); |
| if (ret < 0) |
| goto out; |
| /* |
| * We have allocated a new chunk. We also need to activate that chunk to |
| * grant metadata tickets for zoned filesystem. |
| */ |
| ret = btrfs_zoned_activate_one_bg(fs_info, cache->space_info, true); |
| if (ret < 0) |
| goto out; |
| |
| ret = inc_block_group_ro(cache, 0); |
| if (ret == -ETXTBSY) |
| goto unlock_out; |
| out: |
| if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { |
| alloc_flags = btrfs_get_alloc_profile(fs_info, cache->flags); |
| mutex_lock(&fs_info->chunk_mutex); |
| check_system_chunk(trans, alloc_flags); |
| mutex_unlock(&fs_info->chunk_mutex); |
| } |
| unlock_out: |
| mutex_unlock(&fs_info->ro_block_group_mutex); |
| |
| btrfs_end_transaction(trans); |
| return ret; |
| } |
| |
| void btrfs_dec_block_group_ro(struct btrfs_block_group *cache) |
| { |
| struct btrfs_space_info *sinfo = cache->space_info; |
| u64 num_bytes; |
| |
| BUG_ON(!cache->ro); |
| |
| spin_lock(&sinfo->lock); |
| spin_lock(&cache->lock); |
| if (!--cache->ro) { |
| if (btrfs_is_zoned(cache->fs_info)) { |
| /* Migrate zone_unusable bytes back */ |
| cache->zone_unusable = |
| (cache->alloc_offset - cache->used) + |
| (cache->length - cache->zone_capacity); |
| sinfo->bytes_zone_unusable += cache->zone_unusable; |
| sinfo->bytes_readonly -= cache->zone_unusable; |
| } |
| num_bytes = cache->length - cache->reserved - |
| cache->pinned - cache->bytes_super - |
| cache->zone_unusable - cache->used; |
| sinfo->bytes_readonly -= num_bytes; |
| list_del_init(&cache->ro_list); |
| } |
| spin_unlock(&cache->lock); |
| spin_unlock(&sinfo->lock); |
| } |
| |
| static int update_block_group_item(struct btrfs_trans_handle *trans, |
| struct btrfs_path *path, |
| struct btrfs_block_group *cache) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| int ret; |
| struct btrfs_root *root = btrfs_block_group_root(fs_info); |
| unsigned long bi; |
| struct extent_buffer *leaf; |
| struct btrfs_block_group_item bgi; |
| struct btrfs_key key; |
| u64 old_commit_used; |
| u64 used; |
| |
| /* |
| * Block group items update can be triggered out of commit transaction |
| * critical section, thus we need a consistent view of used bytes. |
| * We cannot use cache->used directly outside of the spin lock, as it |
| * may be changed. |
| */ |
| spin_lock(&cache->lock); |
| old_commit_used = cache->commit_used; |
| used = cache->used; |
| /* No change in used bytes, can safely skip it. */ |
| if (cache->commit_used == used) { |
| spin_unlock(&cache->lock); |
| return 0; |
| } |
| cache->commit_used = used; |
| spin_unlock(&cache->lock); |
| |
| key.objectid = cache->start; |
| key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| key.offset = cache->length; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| if (ret) { |
| if (ret > 0) |
| ret = -ENOENT; |
| goto fail; |
| } |
| |
| leaf = path->nodes[0]; |
| bi = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| btrfs_set_stack_block_group_used(&bgi, used); |
| btrfs_set_stack_block_group_chunk_objectid(&bgi, |
| cache->global_root_id); |
| btrfs_set_stack_block_group_flags(&bgi, cache->flags); |
| write_extent_buffer(leaf, &bgi, bi, sizeof(bgi)); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| fail: |
| btrfs_release_path(path); |
| /* |
| * We didn't update the block group item, need to revert commit_used |
| * unless the block group item didn't exist yet - this is to prevent a |
| * race with a concurrent insertion of the block group item, with |
| * insert_block_group_item(), that happened just after we attempted to |
| * update. In that case we would reset commit_used to 0 just after the |
| * insertion set it to a value greater than 0 - if the block group later |
| * becomes with 0 used bytes, we would incorrectly skip its update. |
| */ |
| if (ret < 0 && ret != -ENOENT) { |
| spin_lock(&cache->lock); |
| cache->commit_used = old_commit_used; |
| spin_unlock(&cache->lock); |
| } |
| return ret; |
| |
| } |
| |
| static int cache_save_setup(struct btrfs_block_group *block_group, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| struct inode *inode = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| u64 alloc_hint = 0; |
| int dcs = BTRFS_DC_ERROR; |
| u64 cache_size = 0; |
| int retries = 0; |
| int ret = 0; |
| |
| if (!btrfs_test_opt(fs_info, SPACE_CACHE)) |
| return 0; |
| |
| /* |
| * If this block group is smaller than 100 megs don't bother caching the |
| * block group. |
| */ |
| if (block_group->length < (100 * SZ_1M)) { |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_WRITTEN; |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| |
| if (TRANS_ABORTED(trans)) |
| return 0; |
| again: |
| inode = lookup_free_space_inode(block_group, path); |
| if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { |
| ret = PTR_ERR(inode); |
| btrfs_release_path(path); |
| goto out; |
| } |
| |
| if (IS_ERR(inode)) { |
| BUG_ON(retries); |
| retries++; |
| |
| if (block_group->ro) |
| goto out_free; |
| |
| ret = create_free_space_inode(trans, block_group, path); |
| if (ret) |
| goto out_free; |
| goto again; |
| } |
| |
| /* |
| * We want to set the generation to 0, that way if anything goes wrong |
| * from here on out we know not to trust this cache when we load up next |
| * time. |
| */ |
| BTRFS_I(inode)->generation = 0; |
| ret = btrfs_update_inode(trans, BTRFS_I(inode)); |
| if (ret) { |
| /* |
| * So theoretically we could recover from this, simply set the |
| * super cache generation to 0 so we know to invalidate the |
| * cache, but then we'd have to keep track of the block groups |
| * that fail this way so we know we _have_ to reset this cache |
| * before the next commit or risk reading stale cache. So to |
| * limit our exposure to horrible edge cases lets just abort the |
| * transaction, this only happens in really bad situations |
| * anyway. |
| */ |
| btrfs_abort_transaction(trans, ret); |
| goto out_put; |
| } |
| WARN_ON(ret); |
| |
| /* We've already setup this transaction, go ahead and exit */ |
| if (block_group->cache_generation == trans->transid && |
| i_size_read(inode)) { |
| dcs = BTRFS_DC_SETUP; |
| goto out_put; |
| } |
| |
| if (i_size_read(inode) > 0) { |
| ret = btrfs_check_trunc_cache_free_space(fs_info, |
| &fs_info->global_block_rsv); |
| if (ret) |
| goto out_put; |
| |
| ret = btrfs_truncate_free_space_cache(trans, NULL, inode); |
| if (ret) |
| goto out_put; |
| } |
| |
| spin_lock(&block_group->lock); |
| if (block_group->cached != BTRFS_CACHE_FINISHED || |
| !btrfs_test_opt(fs_info, SPACE_CACHE)) { |
| /* |
| * don't bother trying to write stuff out _if_ |
| * a) we're not cached, |
| * b) we're with nospace_cache mount option, |
| * c) we're with v2 space_cache (FREE_SPACE_TREE). |
| */ |
| dcs = BTRFS_DC_WRITTEN; |
| spin_unlock(&block_group->lock); |
| goto out_put; |
| } |
| spin_unlock(&block_group->lock); |
| |
| /* |
| * We hit an ENOSPC when setting up the cache in this transaction, just |
| * skip doing the setup, we've already cleared the cache so we're safe. |
| */ |
| if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) { |
| ret = -ENOSPC; |
| goto out_put; |
| } |
| |
| /* |
| * Try to preallocate enough space based on how big the block group is. |
| * Keep in mind this has to include any pinned space which could end up |
| * taking up quite a bit since it's not folded into the other space |
| * cache. |
| */ |
| cache_size = div_u64(block_group->length, SZ_256M); |
| if (!cache_size) |
| cache_size = 1; |
| |
| cache_size *= 16; |
| cache_size *= fs_info->sectorsize; |
| |
| ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, 0, |
| cache_size, false); |
| if (ret) |
| goto out_put; |
| |
| ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, cache_size, |
| cache_size, cache_size, |
| &alloc_hint); |
| /* |
| * Our cache requires contiguous chunks so that we don't modify a bunch |
| * of metadata or split extents when writing the cache out, which means |
| * we can enospc if we are heavily fragmented in addition to just normal |
| * out of space conditions. So if we hit this just skip setting up any |
| * other block groups for this transaction, maybe we'll unpin enough |
| * space the next time around. |
| */ |
| if (!ret) |
| dcs = BTRFS_DC_SETUP; |
| else if (ret == -ENOSPC) |
| set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags); |
| |
| out_put: |
| iput(inode); |
| out_free: |
| btrfs_release_path(path); |
| out: |
| spin_lock(&block_group->lock); |
| if (!ret && dcs == BTRFS_DC_SETUP) |
| block_group->cache_generation = trans->transid; |
| block_group->disk_cache_state = dcs; |
| spin_unlock(&block_group->lock); |
| |
| extent_changeset_free(data_reserved); |
| return ret; |
| } |
| |
| int btrfs_setup_space_cache(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *cache, *tmp; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| struct btrfs_path *path; |
| |
| if (list_empty(&cur_trans->dirty_bgs) || |
| !btrfs_test_opt(fs_info, SPACE_CACHE)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* Could add new block groups, use _safe just in case */ |
| list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs, |
| dirty_list) { |
| if (cache->disk_cache_state == BTRFS_DC_CLEAR) |
| cache_save_setup(cache, trans, path); |
| } |
| |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| /* |
| * Transaction commit does final block group cache writeback during a critical |
| * section where nothing is allowed to change the FS. This is required in |
| * order for the cache to actually match the block group, but can introduce a |
| * lot of latency into the commit. |
| * |
| * So, btrfs_start_dirty_block_groups is here to kick off block group cache IO. |
| * There's a chance we'll have to redo some of it if the block group changes |
| * again during the commit, but it greatly reduces the commit latency by |
| * getting rid of the easy block groups while we're still allowing others to |
| * join the commit. |
| */ |
| int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *cache; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| int ret = 0; |
| int should_put; |
| struct btrfs_path *path = NULL; |
| LIST_HEAD(dirty); |
| struct list_head *io = &cur_trans->io_bgs; |
| int loops = 0; |
| |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| if (list_empty(&cur_trans->dirty_bgs)) { |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| return 0; |
| } |
| list_splice_init(&cur_trans->dirty_bgs, &dirty); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| |
| again: |
| /* Make sure all the block groups on our dirty list actually exist */ |
| btrfs_create_pending_block_groups(trans); |
| |
| if (!path) { |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| /* |
| * cache_write_mutex is here only to save us from balance or automatic |
| * removal of empty block groups deleting this block group while we are |
| * writing out the cache |
| */ |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| while (!list_empty(&dirty)) { |
| bool drop_reserve = true; |
| |
| cache = list_first_entry(&dirty, struct btrfs_block_group, |
| dirty_list); |
| /* |
| * This can happen if something re-dirties a block group that |
| * is already under IO. Just wait for it to finish and then do |
| * it all again |
| */ |
| if (!list_empty(&cache->io_list)) { |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(trans, cache, path); |
| btrfs_put_block_group(cache); |
| } |
| |
| |
| /* |
| * btrfs_wait_cache_io uses the cache->dirty_list to decide if |
| * it should update the cache_state. Don't delete until after |
| * we wait. |
| * |
| * Since we're not running in the commit critical section |
| * we need the dirty_bgs_lock to protect from update_block_group |
| */ |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| list_del_init(&cache->dirty_list); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| |
| should_put = 1; |
| |
| cache_save_setup(cache, trans, path); |
| |
| if (cache->disk_cache_state == BTRFS_DC_SETUP) { |
| cache->io_ctl.inode = NULL; |
| ret = btrfs_write_out_cache(trans, cache, path); |
| if (ret == 0 && cache->io_ctl.inode) { |
| should_put = 0; |
| |
| /* |
| * The cache_write_mutex is protecting the |
| * io_list, also refer to the definition of |
| * btrfs_transaction::io_bgs for more details |
| */ |
| list_add_tail(&cache->io_list, io); |
| } else { |
| /* |
| * If we failed to write the cache, the |
| * generation will be bad and life goes on |
| */ |
| ret = 0; |
| } |
| } |
| if (!ret) { |
| ret = update_block_group_item(trans, path, cache); |
| /* |
| * Our block group might still be attached to the list |
| * of new block groups in the transaction handle of some |
| * other task (struct btrfs_trans_handle->new_bgs). This |
| * means its block group item isn't yet in the extent |
| * tree. If this happens ignore the error, as we will |
| * try again later in the critical section of the |
| * transaction commit. |
| */ |
| if (ret == -ENOENT) { |
| ret = 0; |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| if (list_empty(&cache->dirty_list)) { |
| list_add_tail(&cache->dirty_list, |
| &cur_trans->dirty_bgs); |
| btrfs_get_block_group(cache); |
| drop_reserve = false; |
| } |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| } else if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| } |
| } |
| |
| /* If it's not on the io list, we need to put the block group */ |
| if (should_put) |
| btrfs_put_block_group(cache); |
| if (drop_reserve) |
| btrfs_dec_delayed_refs_rsv_bg_updates(fs_info); |
| /* |
| * Avoid blocking other tasks for too long. It might even save |
| * us from writing caches for block groups that are going to be |
| * removed. |
| */ |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| if (ret) |
| goto out; |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| } |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| |
| /* |
| * Go through delayed refs for all the stuff we've just kicked off |
| * and then loop back (just once) |
| */ |
| if (!ret) |
| ret = btrfs_run_delayed_refs(trans, 0); |
| if (!ret && loops == 0) { |
| loops++; |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| list_splice_init(&cur_trans->dirty_bgs, &dirty); |
| /* |
| * dirty_bgs_lock protects us from concurrent block group |
| * deletes too (not just cache_write_mutex). |
| */ |
| if (!list_empty(&dirty)) { |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| goto again; |
| } |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| } |
| out: |
| if (ret < 0) { |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| list_splice_init(&dirty, &cur_trans->dirty_bgs); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| btrfs_cleanup_dirty_bgs(cur_trans, fs_info); |
| } |
| |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_block_group *cache; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| int ret = 0; |
| int should_put; |
| struct btrfs_path *path; |
| struct list_head *io = &cur_trans->io_bgs; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* |
| * Even though we are in the critical section of the transaction commit, |
| * we can still have concurrent tasks adding elements to this |
| * transaction's list of dirty block groups. These tasks correspond to |
| * endio free space workers started when writeback finishes for a |
| * space cache, which run inode.c:btrfs_finish_ordered_io(), and can |
| * allocate new block groups as a result of COWing nodes of the root |
| * tree when updating the free space inode. The writeback for the space |
| * caches is triggered by an earlier call to |
| * btrfs_start_dirty_block_groups() and iterations of the following |
| * loop. |
| * Also we want to do the cache_save_setup first and then run the |
| * delayed refs to make sure we have the best chance at doing this all |
| * in one shot. |
| */ |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| while (!list_empty(&cur_trans->dirty_bgs)) { |
| cache = list_first_entry(&cur_trans->dirty_bgs, |
| struct btrfs_block_group, |
| dirty_list); |
| |
| /* |
| * This can happen if cache_save_setup re-dirties a block group |
| * that is already under IO. Just wait for it to finish and |
| * then do it all again |
| */ |
| if (!list_empty(&cache->io_list)) { |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(trans, cache, path); |
| btrfs_put_block_group(cache); |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| } |
| |
| /* |
| * Don't remove from the dirty list until after we've waited on |
| * any pending IO |
| */ |
| list_del_init(&cache->dirty_list); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| should_put = 1; |
| |
| cache_save_setup(cache, trans, path); |
| |
| if (!ret) |
| ret = btrfs_run_delayed_refs(trans, U64_MAX); |
| |
| if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) { |
| cache->io_ctl.inode = NULL; |
| ret = btrfs_write_out_cache(trans, cache, path); |
| if (ret == 0 && cache->io_ctl.inode) { |
| should_put = 0; |
| list_add_tail(&cache->io_list, io); |
| } else { |
| /* |
| * If we failed to write the cache, the |
| * generation will be bad and life goes on |
| */ |
| ret = 0; |
| } |
| } |
| if (!ret) { |
| ret = update_block_group_item(trans, path, cache); |
| /* |
| * One of the free space endio workers might have |
| * created a new block group while updating a free space |
| * cache's inode (at inode.c:btrfs_finish_ordered_io()) |
| * and hasn't released its transaction handle yet, in |
| * which case the new block group is still attached to |
| * its transaction handle and its creation has not |
| * finished yet (no block group item in the extent tree |
| * yet, etc). If this is the case, wait for all free |
| * space endio workers to finish and retry. This is a |
| * very rare case so no need for a more efficient and |
| * complex approach. |
| */ |
| if (ret == -ENOENT) { |
| wait_event(cur_trans->writer_wait, |
| atomic_read(&cur_trans->num_writers) == 1); |
| ret = update_block_group_item(trans, path, cache); |
| } |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| } |
| |
| /* If its not on the io list, we need to put the block group */ |
| if (should_put) |
| btrfs_put_block_group(cache); |
| btrfs_dec_delayed_refs_rsv_bg_updates(fs_info); |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| } |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| |
| /* |
| * Refer to the definition of io_bgs member for details why it's safe |
| * to use it without any locking |
| */ |
| while (!list_empty(io)) { |
| cache = list_first_entry(io, struct btrfs_block_group, |
| io_list); |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(trans, cache, path); |
| btrfs_put_block_group(cache); |
| } |
| |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_update_block_group(struct btrfs_trans_handle *trans, |
| u64 bytenr, u64 num_bytes, bool alloc) |
| { |
| struct btrfs_fs_info *info = trans->fs_info; |
| struct btrfs_space_info *space_info; |
| struct btrfs_block_group *cache; |
| u64 old_val; |
| bool reclaim = false; |
| bool bg_already_dirty = true; |
| int factor; |
| |
| /* Block accounting for super block */ |
| spin_lock(&info->delalloc_root_lock); |
| old_val = btrfs_super_bytes_used(info->super_copy); |
| if (alloc) |
| old_val += num_bytes; |
| else |
| old_val -= num_bytes; |
| btrfs_set_super_bytes_used(info->super_copy, old_val); |
| spin_unlock(&info->delalloc_root_lock); |
| |
| cache = btrfs_lookup_block_group(info, bytenr); |
| if (!cache) |
| return -ENOENT; |
| |
| /* An extent can not span multiple block groups. */ |
| ASSERT(bytenr + num_bytes <= cache->start + cache->length); |
| |
| space_info = cache->space_info; |
| factor = btrfs_bg_type_to_factor(cache->flags); |
| |
| /* |
| * If this block group has free space cache written out, we need to make |
| * sure to load it if we are removing space. This is because we need |
| * the unpinning stage to actually add the space back to the block group, |
| * otherwise we will leak space. |
| */ |
| if (!alloc && !btrfs_block_group_done(cache)) |
| btrfs_cache_block_group(cache, true); |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&cache->lock); |
| |
| if (btrfs_test_opt(info, SPACE_CACHE) && |
| cache->disk_cache_state < BTRFS_DC_CLEAR) |
| cache->disk_cache_state = BTRFS_DC_CLEAR; |
| |
| old_val = cache->used; |
| if (alloc) { |
| old_val += num_bytes; |
| cache->used = old_val; |
| cache->reserved -= num_bytes; |
| space_info->bytes_reserved -= num_bytes; |
| space_info->bytes_used += num_bytes; |
| space_info->disk_used += num_bytes * factor; |
| spin_unlock(&cache->lock); |
| spin_unlock(&space_info->lock); |
| } else { |
| old_val -= num_bytes; |
| cache->used = old_val; |
| cache->pinned += num_bytes; |
| btrfs_space_info_update_bytes_pinned(info, space_info, num_bytes); |
| space_info->bytes_used -= num_bytes; |
| space_info->disk_used -= num_bytes * factor; |
| |
| reclaim = should_reclaim_block_group(cache, num_bytes); |
| |
| spin_unlock(&cache->lock); |
| spin_unlock(&space_info->lock); |
| |
| set_extent_bit(&trans->transaction->pinned_extents, bytenr, |
| bytenr + num_bytes - 1, EXTENT_DIRTY, NULL); |
| } |
| |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| if (list_empty(&cache->dirty_list)) { |
| list_add_tail(&cache->dirty_list, &trans->transaction->dirty_bgs); |
| bg_already_dirty = false; |
| btrfs_get_block_group(cache); |
| } |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| |
| /* |
| * No longer have used bytes in this block group, queue it for deletion. |
| * We do this after adding the block group to the dirty list to avoid |
| * races between cleaner kthread and space cache writeout. |
| */ |
| if (!alloc && old_val == 0) { |
| if (!btrfs_test_opt(info, DISCARD_ASYNC)) |
| btrfs_mark_bg_unused(cache); |
| } else if (!alloc && reclaim) { |
| btrfs_mark_bg_to_reclaim(cache); |
| } |
| |
| btrfs_put_block_group(cache); |
| |
| /* Modified block groups are accounted for in the delayed_refs_rsv. */ |
| if (!bg_already_dirty) |
| btrfs_inc_delayed_refs_rsv_bg_updates(info); |
| |
| return 0; |
| } |
| |
| /* |
| * Update the block_group and space info counters. |
| * |
| * @cache: The cache we are manipulating |
| * @ram_bytes: The number of bytes of file content, and will be same to |
| * @num_bytes except for the compress path. |
| * @num_bytes: The number of bytes in question |
| * @delalloc: The blocks are allocated for the delalloc write |
| * |
| * This is called by the allocator when it reserves space. If this is a |
| * reservation and the block group has become read only we cannot make the |
| * reservation and return -EAGAIN, otherwise this function always succeeds. |
| */ |
| int btrfs_add_reserved_bytes(struct btrfs_block_group *cache, |
| u64 ram_bytes, u64 num_bytes, int delalloc, |
| bool force_wrong_size_class) |
| { |
| struct btrfs_space_info *space_info = cache->space_info; |
| enum btrfs_block_group_size_class size_class; |
| int ret = 0; |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&cache->lock); |
| if (cache->ro) { |
| ret = -EAGAIN; |
| goto out; |
| } |
| |
| if (btrfs_block_group_should_use_size_class(cache)) { |
| size_class = btrfs_calc_block_group_size_class(num_bytes); |
| ret = btrfs_use_block_group_size_class(cache, size_class, force_wrong_size_class); |
| if (ret) |
| goto out; |
| } |
| cache->reserved += num_bytes; |
| space_info->bytes_reserved += num_bytes; |
| trace_btrfs_space_reservation(cache->fs_info, "space_info", |
| space_info->flags, num_bytes, 1); |
| btrfs_space_info_update_bytes_may_use(cache->fs_info, |
| space_info, -ram_bytes); |
| if (delalloc) |
| cache->delalloc_bytes += num_bytes; |
| |
| /* |
| * Compression can use less space than we reserved, so wake tickets if |
| * that happens. |
| */ |
| if (num_bytes < ram_bytes) |
| btrfs_try_granting_tickets(cache->fs_info, space_info); |
| out: |
| spin_unlock(&cache->lock); |
| spin_unlock(&space_info->lock); |
| return ret; |
| } |
| |
| /* |
| * Update the block_group and space info counters. |
| * |
| * @cache: The cache we are manipulating |
| * @num_bytes: The number of bytes in question |
| * @delalloc: The blocks are allocated for the delalloc write |
| * |
| * This is called by somebody who is freeing space that was never actually used |
| * on disk. For example if you reserve some space for a new leaf in transaction |
| * A and before transaction A commits you free that leaf, you call this with |
| * reserve set to 0 in order to clear the reservation. |
| */ |
| void btrfs_free_reserved_bytes(struct btrfs_block_group *cache, |
| u64 num_bytes, int delalloc) |
| { |
| struct btrfs_space_info *space_info = cache->space_info; |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&cache->lock); |
| if (cache->ro) |
| space_info->bytes_readonly += num_bytes; |
| cache->reserved -= num_bytes; |
| space_info->bytes_reserved -= num_bytes; |
| space_info->max_extent_size = 0; |
| |
| if (delalloc) |
| cache->delalloc_bytes -= num_bytes; |
| spin_unlock(&cache->lock); |
| |
| btrfs_try_granting_tickets(cache->fs_info, space_info); |
| spin_unlock(&space_info->lock); |
| } |
| |
| static void force_metadata_allocation(struct btrfs_fs_info *info) |
| { |
| struct list_head *head = &info->space_info; |
| struct btrfs_space_info *found; |
| |
| list_for_each_entry(found, head, list) { |
| if (found->flags & BTRFS_BLOCK_GROUP_METADATA) |
| found->force_alloc = CHUNK_ALLOC_FORCE; |
| } |
| } |
| |
| static int should_alloc_chunk(struct btrfs_fs_info *fs_info, |
| struct btrfs_space_info *sinfo, int force) |
| { |
| u64 bytes_used = btrfs_space_info_used(sinfo, false); |
| u64 thresh; |
| |
| if (force == CHUNK_ALLOC_FORCE) |
| return 1; |
| |
| /* |
| * in limited mode, we want to have some free space up to |
| * about 1% of the FS size. |
| */ |
| if (force == CHUNK_ALLOC_LIMITED) { |
| thresh = btrfs_super_total_bytes(fs_info->super_copy); |
| thresh = max_t(u64, SZ_64M, mult_perc(thresh, 1)); |
| |
| if (sinfo->total_bytes - bytes_used < thresh) |
| return 1; |
| } |
| |
| if (bytes_used + SZ_2M < mult_perc(sinfo->total_bytes, 80)) |
| return 0; |
| return 1; |
| } |
| |
| int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type) |
| { |
| u64 alloc_flags = btrfs_get_alloc_profile(trans->fs_info, type); |
| |
| return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE); |
| } |
| |
| static struct btrfs_block_group *do_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags) |
| { |
| struct btrfs_block_group *bg; |
| int ret; |
| |
| /* |
| * Check if we have enough space in the system space info because we |
| * will need to update device items in the chunk btree and insert a new |
| * chunk item in the chunk btree as well. This will allocate a new |
| * system block group if needed. |
| */ |
| check_system_chunk(trans, flags); |
| |
| bg = btrfs_create_chunk(trans, flags); |
| if (IS_ERR(bg)) { |
| ret = PTR_ERR(bg); |
| goto out; |
| } |
| |
| ret = btrfs_chunk_alloc_add_chunk_item(trans, bg); |
| /* |
| * Normally we are not expected to fail with -ENOSPC here, since we have |
| * previously reserved space in the system space_info and allocated one |
| * new system chunk if necessary. However there are three exceptions: |
| * |
| * 1) We may have enough free space in the system space_info but all the |
| * existing system block groups have a profile which can not be used |
| * for extent allocation. |
| * |
| * This happens when mounting in degraded mode. For example we have a |
| * RAID1 filesystem with 2 devices, lose one device and mount the fs |
| * using the other device in degraded mode. If we then allocate a chunk, |
| * we may have enough free space in the existing system space_info, but |
| * none of the block groups can be used for extent allocation since they |
| * have a RAID1 profile, and because we are in degraded mode with a |
| * single device, we are forced to allocate a new system chunk with a |
| * SINGLE profile. Making check_system_chunk() iterate over all system |
| * block groups and check if they have a usable profile and enough space |
| * can be slow on very large filesystems, so we tolerate the -ENOSPC and |
| * try again after forcing allocation of a new system chunk. Like this |
| * we avoid paying the cost of that search in normal circumstances, when |
| * we were not mounted in degraded mode; |
| * |
| * 2) We had enough free space info the system space_info, and one suitable |
| * block group to allocate from when we called check_system_chunk() |
| * above. However right after we called it, the only system block group |
| * with enough free space got turned into RO mode by a running scrub, |
| * and in this case we have to allocate a new one and retry. We only |
| * need do this allocate and retry once, since we have a transaction |
| * handle and scrub uses the commit root to search for block groups; |
| * |
| * 3) We had one system block group with enough free space when we called |
| * check_system_chunk(), but after that, right before we tried to |
| * allocate the last extent buffer we needed, a discard operation came |
| * in and it temporarily removed the last free space entry from the |
| * block group (discard removes a free space entry, discards it, and |
| * then adds back the entry to the block group cache). |
| */ |
| if (ret == -ENOSPC) { |
| const u64 sys_flags = btrfs_system_alloc_profile(trans->fs_info); |
| struct btrfs_block_group *sys_bg; |
| |
| sys_bg = btrfs_create_chunk(trans, sys_flags); |
| if (IS_ERR(sys_bg)) { |
| ret = PTR_ERR(sys_bg); |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| ret = btrfs_chunk_alloc_add_chunk_item(trans, sys_bg); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| ret = btrfs_chunk_alloc_add_chunk_item(trans, bg); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } else if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| out: |
| btrfs_trans_release_chunk_metadata(trans); |
| |
| if (ret) |
| return ERR_PTR(ret); |
| |
| btrfs_get_block_group(bg); |
| return bg; |
| } |
| |
| /* |
| * Chunk allocation is done in 2 phases: |
| * |
| * 1) Phase 1 - through btrfs_chunk_alloc() we allocate device extents for |
| * the chunk, the chunk mapping, create its block group and add the items |
| * that belong in the chunk btree to it - more specifically, we need to |
| * update device items in the chunk btree and add a new chunk item to it. |
| * |
| * 2) Phase 2 - through btrfs_create_pending_block_groups(), we add the block |
| * group item to the extent btree and the device extent items to the devices |
| * btree. |
| * |
| * This is done to prevent deadlocks. For example when COWing a node from the |
| * extent btree we are holding a write lock on the node's parent and if we |
| * trigger chunk allocation and attempted to insert the new block group item |
| * in the extent btree right way, we could deadlock because the path for the |
| * insertion can include that parent node. At first glance it seems impossible |
| * to trigger chunk allocation after starting a transaction since tasks should |
| * reserve enough transaction units (metadata space), however while that is true |
| * most of the time, chunk allocation may still be triggered for several reasons: |
| * |
| * 1) When reserving metadata, we check if there is enough free space in the |
| * metadata space_info and therefore don't trigger allocation of a new chunk. |
| * However later when the task actually tries to COW an extent buffer from |
| * the extent btree or from the device btree for example, it is forced to |
| * allocate a new block group (chunk) because the only one that had enough |
| * free space was just turned to RO mode by a running scrub for example (or |
| * device replace, block group reclaim thread, etc), so we can not use it |
| * for allocating an extent and end up being forced to allocate a new one; |
| * |
| * 2) Because we only check that the metadata space_info has enough free bytes, |
| * we end up not allocating a new metadata chunk in that case. However if |
| * the filesystem was mounted in degraded mode, none of the existing block |
| * groups might be suitable for extent allocation due to their incompatible |
| * profile (for e.g. mounting a 2 devices filesystem, where all block groups |
| * use a RAID1 profile, in degraded mode using a single device). In this case |
| * when the task attempts to COW some extent buffer of the extent btree for |
| * example, it will trigger allocation of a new metadata block group with a |
| * suitable profile (SINGLE profile in the example of the degraded mount of |
| * the RAID1 filesystem); |
| * |
| * 3) The task has reserved enough transaction units / metadata space, but when |
| * it attempts to COW an extent buffer from the extent or device btree for |
| * example, it does not find any free extent in any metadata block group, |
| * therefore forced to try to allocate a new metadata block group. |
| * This is because some other task allocated all available extents in the |
| * meanwhile - this typically happens with tasks that don't reserve space |
| * properly, either intentionally or as a bug. One example where this is |
| * done intentionally is fsync, as it does not reserve any transaction units |
| * and ends up allocating a variable number of metadata extents for log |
| * tree extent buffers; |
| * |
| * 4) The task has reserved enough transaction units / metadata space, but right |
| * before it tries to allocate the last extent buffer it needs, a discard |
| * operation comes in and, temporarily, removes the last free space entry from |
| * the only metadata block group that had free space (discard starts by |
| * removing a free space entry from a block group, then does the discard |
| * operation and, once it's done, it adds back the free space entry to the |
| * block group). |
| * |
| * We also need this 2 phases setup when adding a device to a filesystem with |
| * a seed device - we must create new metadata and system chunks without adding |
| * any of the block group items to the chunk, extent and device btrees. If we |
| * did not do it this way, we would get ENOSPC when attempting to update those |
| * btrees, since all the chunks from the seed device are read-only. |
| * |
| * Phase 1 does the updates and insertions to the chunk btree because if we had |
| * it done in phase 2 and have a thundering herd of tasks allocating chunks in |
| * parallel, we risk having too many system chunks allocated by many tasks if |
| * many tasks reach phase 1 without the previous ones completing phase 2. In the |
| * extreme case this leads to exhaustion of the system chunk array in the |
| * superblock. This is easier to trigger if using a btree node/leaf size of 64K |
| * and with RAID filesystems (so we have more device items in the chunk btree). |
| * This has happened before and commit eafa4fd0ad0607 ("btrfs: fix exhaustion of |
| * the system chunk array due to concurrent allocations") provides more details. |
| * |
| * Allocation of system chunks does not happen through this function. A task that |
| * needs to update the chunk btree (the only btree that uses system chunks), must |
| * preallocate chunk space by calling either check_system_chunk() or |
| * btrfs_reserve_chunk_metadata() - the former is used when allocating a data or |
| * metadata chunk or when removing a chunk, while the later is used before doing |
| * a modification to the chunk btree - use cases for the later are adding, |
| * removing and resizing a device as well as relocation of a system chunk. |
| * See the comment below for more details. |
| * |
| * The reservation of system space, done through check_system_chunk(), as well |
| * as all the updates and insertions into the chunk btree must be done while |
| * holding fs_info->chunk_mutex. This is important to guarantee that while COWing |
| * an extent buffer from the chunks btree we never trigger allocation of a new |
| * system chunk, which would result in a deadlock (trying to lock twice an |
| * extent buffer of the chunk btree, first time before triggering the chunk |
| * allocation and the second time during chunk allocation while attempting to |
| * update the chunks btree). The system chunk array is also updated while holding |
| * that mutex. The same logic applies to removing chunks - we must reserve system |
| * space, update the chunk btree and the system chunk array in the superblock |
| * while holding fs_info->chunk_mutex. |
| * |
| * This function, btrfs_chunk_alloc(), belongs to phase 1. |
| * |
| * If @force is CHUNK_ALLOC_FORCE: |
| * - return 1 if it successfully allocates a chunk, |
| * - return errors including -ENOSPC otherwise. |
| * If @force is NOT CHUNK_ALLOC_FORCE: |
| * - return 0 if it doesn't need to allocate a new chunk, |
| * - return 1 if it successfully allocates a chunk, |
| * - return errors including -ENOSPC otherwise. |
| */ |
| int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags, |
| enum btrfs_chunk_alloc_enum force) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_space_info *space_info; |
| struct btrfs_block_group *ret_bg; |
| bool wait_for_alloc = false; |
| bool should_alloc = false; |
| bool from_extent_allocation = false; |
| int ret = 0; |
| |
| if (force == CHUNK_ALLOC_FORCE_FOR_EXTENT) { |
| from_extent_allocation = true; |
| force = CHUNK_ALLOC_FORCE; |
| } |
| |
| /* Don't re-enter if we're already allocating a chunk */ |
| if (trans->allocating_chunk) |
| return -ENOSPC; |
| /* |
| * Allocation of system chunks can not happen through this path, as we |
| * could end up in a deadlock if we are allocating a data or metadata |
| * chunk and there is another task modifying the chunk btree. |
| * |
| * This is because while we are holding the chunk mutex, we will attempt |
| * to add the new chunk item to the chunk btree or update an existing |
| * device item in the chunk btree, while the other task that is modifying |
| * the chunk btree is attempting to COW an extent buffer while holding a |
| * lock on it and on its parent - if the COW operation triggers a system |
| * chunk allocation, then we can deadlock because we are holding the |
| * chunk mutex and we may need to access that extent buffer or its parent |
| * in order to add the chunk item or update a device item. |
| * |
| * Tasks that want to modify the chunk tree should reserve system space |
| * before updating the chunk btree, by calling either |
| * btrfs_reserve_chunk_metadata() or check_system_chunk(). |
| * It's possible that after a task reserves the space, it still ends up |
| * here - this happens in the cases described above at do_chunk_alloc(). |
| * The task will have to either retry or fail. |
| */ |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| return -ENOSPC; |
| |
| space_info = btrfs_find_space_info(fs_info, flags); |
| ASSERT(space_info); |
| |
| do { |
| spin_lock(&space_info->lock); |
| if (force < space_info->force_alloc) |
| force = space_info->force_alloc; |
| should_alloc = should_alloc_chunk(fs_info, space_info, force); |
| if (space_info->full) { |
| /* No more free physical space */ |
| if (should_alloc) |
| ret = -ENOSPC; |
| else |
| ret = 0; |
| spin_unlock(&space_info->lock); |
| return ret; |
| } else if (!should_alloc) { |
| spin_unlock(&space_info->lock); |
| return 0; |
| } else if (space_info->chunk_alloc) { |
| /* |
| * Someone is already allocating, so we need to block |
| * until this someone is finished and then loop to |
| * recheck if we should continue with our allocation |
| * attempt. |
| */ |
| wait_for_alloc = true; |
| force = CHUNK_ALLOC_NO_FORCE; |
| spin_unlock(&space_info->lock); |
| mutex_lock(&fs_info->chunk_mutex); |
| mutex_unlock(&fs_info->chunk_mutex); |
| } else { |
| /* Proceed with allocation */ |
| space_info->chunk_alloc = 1; |
| wait_for_alloc = false; |
| spin_unlock(&space_info->lock); |
| } |
| |
| cond_resched(); |
| } while (wait_for_alloc); |
| |
| mutex_lock(&fs_info->chunk_mutex); |
| trans->allocating_chunk = true; |
| |
| /* |
| * If we have mixed data/metadata chunks we want to make sure we keep |
| * allocating mixed chunks instead of individual chunks. |
| */ |
| if (btrfs_mixed_space_info(space_info)) |
| flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA); |
| |
| /* |
| * if we're doing a data chunk, go ahead and make sure that |
| * we keep a reasonable number of metadata chunks allocated in the |
| * FS as well. |
| */ |
| if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) { |
| fs_info->data_chunk_allocations++; |
| if (!(fs_info->data_chunk_allocations % |
| fs_info->metadata_ratio)) |
| force_metadata_allocation(fs_info); |
| } |
| |
| ret_bg = do_chunk_alloc(trans, flags); |
| trans->allocating_chunk = false; |
| |
| if (IS_ERR(ret_bg)) { |
| ret = PTR_ERR(ret_bg); |
| } else if (from_extent_allocation && (flags & BTRFS_BLOCK_GROUP_DATA)) { |
| /* |
| * New block group is likely to be used soon. Try to activate |
| * it now. Failure is OK for now. |
| */ |
| btrfs_zone_activate(ret_bg); |
| } |
| |
| if (!ret) |
| btrfs_put_block_group(ret_bg); |
| |
| spin_lock(&space_info->lock); |
| if (ret < 0) { |
| if (ret == -ENOSPC) |
| space_info->full = 1; |
| else |
| goto out; |
| } else { |
| ret = 1; |
| space_info->max_extent_size = 0; |
| } |
| |
| space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; |
| out: |
| space_info->chunk_alloc = 0; |
| spin_unlock(&space_info->lock); |
| mutex_unlock(&fs_info->chunk_mutex); |
| |
| return ret; |
| } |
| |
| static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type) |
| { |
| u64 num_dev; |
| |
| num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max; |
| if (!num_dev) |
| num_dev = fs_info->fs_devices->rw_devices; |
| |
| return num_dev; |
| } |
| |
| static void reserve_chunk_space(struct btrfs_trans_handle *trans, |
| u64 bytes, |
| u64 type) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_space_info *info; |
| u64 left; |
| int ret = 0; |
| |
| /* |
| * Needed because we can end up allocating a system chunk and for an |
| * atomic and race free space reservation in the chunk block reserve. |
| */ |
| lockdep_assert_held(&fs_info->chunk_mutex); |
| |
| info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); |
| spin_lock(&info->lock); |
| left = info->total_bytes - btrfs_space_info_used(info, true); |
| spin_unlock(&info->lock); |
| |
| if (left < bytes && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { |
| btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu", |
| left, bytes, type); |
| btrfs_dump_space_info(fs_info, info, 0, 0); |
| } |
| |
| if (left < bytes) { |
| u64 flags = btrfs_system_alloc_profile(fs_info); |
| struct btrfs_block_group *bg; |
| |
| /* |
| * Ignore failure to create system chunk. We might end up not |
| * needing it, as we might not need to COW all nodes/leafs from |
| * the paths we visit in the chunk tree (they were already COWed |
| * or created in the current transaction for example). |
| */ |
| bg = btrfs_create_chunk(trans, flags); |
| if (IS_ERR(bg)) { |
| ret = PTR_ERR(bg); |
| } else { |
| /* |
| * We have a new chunk. We also need to activate it for |
| * zoned filesystem. |
| */ |
| ret = btrfs_zoned_activate_one_bg(fs_info, info, true); |
| if (ret < 0) |
| return; |
| |
| /* |
| * If we fail to add the chunk item here, we end up |
| * trying again at phase 2 of chunk allocation, at |
| * btrfs_create_pending_block_groups(). So ignore |
| * any error here. An ENOSPC here could happen, due to |
| * the cases described at do_chunk_alloc() - the system |
| * block group we just created was just turned into RO |
| * mode by a scrub for example, or a running discard |
| * temporarily removed its free space entries, etc. |
| */ |
| btrfs_chunk_alloc_add_chunk_item(trans, bg); |
| } |
| } |
| |
| if (!ret) { |
| ret = btrfs_block_rsv_add(fs_info, |
| &fs_info->chunk_block_rsv, |
| bytes, BTRFS_RESERVE_NO_FLUSH); |
| if (!ret) |
| trans->chunk_bytes_reserved += bytes; |
| } |
| } |
| |
| /* |
| * Reserve space in the system space for allocating or removing a chunk. |
| * The caller must be holding fs_info->chunk_mutex. |
| */ |
| void check_system_chunk(struct btrfs_trans_handle *trans, u64 type) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| const u64 num_devs = get_profile_num_devs(fs_info, type); |
| u64 bytes; |
| |
| /* num_devs device items to update and 1 chunk item to add or remove. */ |
| bytes = btrfs_calc_metadata_size(fs_info, num_devs) + |
| btrfs_calc_insert_metadata_size(fs_info, 1); |
| |
| reserve_chunk_space(trans, bytes, type); |
| } |
| |
| /* |
| * Reserve space in the system space, if needed, for doing a modification to the |
| * chunk btree. |
| * |
| * @trans: A transaction handle. |
| * @is_item_insertion: Indicate if the modification is for inserting a new item |
| * in the chunk btree or if it's for the deletion or update |
| * of an existing item. |
| * |
| * This is used in a context where we need to update the chunk btree outside |
| * block group allocation and removal, to avoid a deadlock with a concurrent |
| * task that is allocating a metadata or data block group and therefore needs to |
| * update the chunk btree while holding the chunk mutex. After the update to the |
| * chunk btree is done, btrfs_trans_release_chunk_metadata() should be called. |
| * |
| */ |
| void btrfs_reserve_chunk_metadata(struct btrfs_trans_handle *trans, |
| bool is_item_insertion) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| u64 bytes; |
| |
| if (is_item_insertion) |
| bytes = btrfs_calc_insert_metadata_size(fs_info, 1); |
| else |
| bytes = btrfs_calc_metadata_size(fs_info, 1); |
| |
| mutex_lock(&fs_info->chunk_mutex); |
| reserve_chunk_space(trans, bytes, BTRFS_BLOCK_GROUP_SYSTEM); |
| mutex_unlock(&fs_info->chunk_mutex); |
| } |
| |
| void btrfs_put_block_group_cache(struct btrfs_fs_info *info) |
| { |
| struct btrfs_block_group *block_group; |
| |
| block_group = btrfs_lookup_first_block_group(info, 0); |
| while (block_group) { |
| btrfs_wait_block_group_cache_done(block_group); |
| spin_lock(&block_group->lock); |
| if (test_and_clear_bit(BLOCK_GROUP_FLAG_IREF, |
| &block_group->runtime_flags)) { |
| struct inode *inode = block_group->inode; |
| |
| block_group->inode = NULL; |
| spin_unlock(&block_group->lock); |
| |
| ASSERT(block_group->io_ctl.inode == NULL); |
| iput(inode); |
| } else { |
| spin_unlock(&block_group->lock); |
| } |
| block_group = btrfs_next_block_group(block_group); |
| } |
| } |
| |
| /* |
| * Must be called only after stopping all workers, since we could have block |
| * group caching kthreads running, and therefore they could race with us if we |
| * freed the block groups before stopping them. |
| */ |
| int btrfs_free_block_groups(struct btrfs_fs_info *info) |
| { |
| struct btrfs_block_group *block_group; |
| struct btrfs_space_info *space_info; |
| struct btrfs_caching_control *caching_ctl; |
| struct rb_node *n; |
| |
| if (btrfs_is_zoned(info)) { |
| if (info->active_meta_bg) { |
| btrfs_put_block_group(info->active_meta_bg); |
| info->active_meta_bg = NULL; |
| } |
| if (info->active_system_bg) { |
| btrfs_put_block_group(info->active_system_bg); |
| info->active_system_bg = NULL; |
| } |
| } |
| |
| write_lock(&info->block_group_cache_lock); |
| while (!list_empty(&info->caching_block_groups)) { |
| caching_ctl = list_entry(info->caching_block_groups.next, |
| struct btrfs_caching_control, list); |
| list_del(&caching_ctl->list); |
| btrfs_put_caching_control(caching_ctl); |
| } |
| write_unlock(&info->block_group_cache_lock); |
| |
| spin_lock(&info->unused_bgs_lock); |
| while (!list_empty(&info->unused_bgs)) { |
| block_group = list_first_entry(&info->unused_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| list_del_init(&block_group->bg_list); |
| btrfs_put_block_group(block_group); |
| } |
| |
| while (!list_empty(&info->reclaim_bgs)) { |
| block_group = list_first_entry(&info->reclaim_bgs, |
| struct btrfs_block_group, |
| bg_list); |
| list_del_init(&block_group->bg_list); |
| btrfs_put_block_group(block_group); |
| } |
| spin_unlock(&info->unused_bgs_lock); |
| |
| spin_lock(&info->zone_active_bgs_lock); |
| while (!list_empty(&info->zone_active_bgs)) { |
| block_group = list_first_entry(&info->zone_active_bgs, |
| struct btrfs_block_group, |
| active_bg_list); |
| list_del_init(&block_group->active_bg_list); |
| btrfs_put_block_group(block_group); |
| } |
| spin_unlock(&info->zone_active_bgs_lock); |
| |
| write_lock(&info->block_group_cache_lock); |
| while ((n = rb_last(&info->block_group_cache_tree.rb_root)) != NULL) { |
| block_group = rb_entry(n, struct btrfs_block_group, |
| cache_node); |
| rb_erase_cached(&block_group->cache_node, |
| &info->block_group_cache_tree); |
| RB_CLEAR_NODE(&block_group->cache_node); |
| write_unlock(&info->block_group_cache_lock); |
| |
| down_write(&block_group->space_info->groups_sem); |
| list_del(&block_group->list); |
| up_write(&block_group->space_info->groups_sem); |
| |
| /* |
| * We haven't cached this block group, which means we could |
| * possibly have excluded extents on this block group. |
| */ |
| if (block_group->cached == BTRFS_CACHE_NO || |
| block_group->cached == BTRFS_CACHE_ERROR) |
| btrfs_free_excluded_extents(block_group); |
| |
| btrfs_remove_free_space_cache(block_group); |
| ASSERT(block_group->cached != BTRFS_CACHE_STARTED); |
| ASSERT(list_empty(&block_group->dirty_list)); |
| ASSERT(list_empty(&block_group->io_list)); |
| ASSERT(list_empty(&block_group->bg_list)); |
| ASSERT(refcount_read(&block_group->refs) == 1); |
| ASSERT(block_group->swap_extents == 0); |
| btrfs_put_block_group(block_group); |
| |
| write_lock(&info->block_group_cache_lock); |
| } |
| write_unlock(&info->block_group_cache_lock); |
| |
| btrfs_release_global_block_rsv(info); |
| |
| while (!list_empty(&info->space_info)) { |
| space_info = list_entry(info->space_info.next, |
| struct btrfs_space_info, |
| list); |
| |
| /* |
| * Do not hide this behind enospc_debug, this is actually |
| * important and indicates a real bug if this happens. |
| */ |
| if (WARN_ON(space_info->bytes_pinned > 0 || |
| space_info->bytes_may_use > 0)) |
| btrfs_dump_space_info(info, space_info, 0, 0); |
| |
| /* |
| * If there was a failure to cleanup a log tree, very likely due |
| * to an IO failure on a writeback attempt of one or more of its |
| * extent buffers, we could not do proper (and cheap) unaccounting |
| * of their reserved space, so don't warn on bytes_reserved > 0 in |
| * that case. |
| */ |
| if (!(space_info->flags & BTRFS_BLOCK_GROUP_METADATA) || |
| !BTRFS_FS_LOG_CLEANUP_ERROR(info)) { |
| if (WARN_ON(space_info->bytes_reserved > 0)) |
| btrfs_dump_space_info(info, space_info, 0, 0); |
| } |
| |
| WARN_ON(space_info->reclaim_size > 0); |
| list_del(&space_info->list); |
| btrfs_sysfs_remove_space_info(space_info); |
| } |
| return 0; |
| } |
| |
| void btrfs_freeze_block_group(struct btrfs_block_group *cache) |
| { |
| atomic_inc(&cache->frozen); |
| } |
| |
| void btrfs_unfreeze_block_group(struct btrfs_block_group *block_group) |
| { |
| struct btrfs_fs_info *fs_info = block_group->fs_info; |
| bool cleanup; |
| |
| spin_lock(&block_group->lock); |
| cleanup = (atomic_dec_and_test(&block_group->frozen) && |
| test_bit(BLOCK_GROUP_FLAG_REMOVED, &block_group->runtime_flags)); |
| spin_unlock(&block_group->lock); |
| |
| if (cleanup) { |
| struct btrfs_chunk_map *map; |
| |
| map = btrfs_find_chunk_map(fs_info, block_group->start, 1); |
| /* Logic error, can't happen. */ |
| ASSERT(map); |
| |
| btrfs_remove_chunk_map(fs_info, map); |
| |
| /* Once for our lookup reference. */ |
| btrfs_free_chunk_map(map); |
| |
| /* |
| * We may have left one free space entry and other possible |
| * tasks trimming this block group have left 1 entry each one. |
| * Free them if any. |
| */ |
| btrfs_remove_free_space_cache(block_group); |
| } |
| } |
| |
| bool btrfs_inc_block_group_swap_extents(struct btrfs_block_group *bg) |
| { |
| bool ret = true; |
| |
| spin_lock(&bg->lock); |
| if (bg->ro) |
| ret = false; |
| else |
| bg->swap_extents++; |
| spin_unlock(&bg->lock); |
| |
| return ret; |
| } |
| |
| void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount) |
| { |
| spin_lock(&bg->lock); |
| ASSERT(!bg->ro); |
| ASSERT(bg->swap_extents >= amount); |
| bg->swap_extents -= amount; |
| spin_unlock(&bg->lock); |
| } |
| |
| enum btrfs_block_group_size_class btrfs_calc_block_group_size_class(u64 size) |
| { |
| if (size <= SZ_128K) |
| return BTRFS_BG_SZ_SMALL; |
| if (size <= SZ_8M) |
| return BTRFS_BG_SZ_MEDIUM; |
| return BTRFS_BG_SZ_LARGE; |
| } |
| |
| /* |
| * Handle a block group allocating an extent in a size class |
| * |
| * @bg: The block group we allocated in. |
| * @size_class: The size class of the allocation. |
| * @force_wrong_size_class: Whether we are desperate enough to allow |
| * mismatched size classes. |
| * |
| * Returns: 0 if the size class was valid for this block_group, -EAGAIN in the |
| * case of a race that leads to the wrong size class without |
| * force_wrong_size_class set. |
| * |
| * find_free_extent will skip block groups with a mismatched size class until |
| * it really needs to avoid ENOSPC. In that case it will set |
| * force_wrong_size_class. However, if a block group is newly allocated and |
| * doesn't yet have a size class, then it is possible for two allocations of |
| * different sizes to race and both try to use it. The loser is caught here and |
| * has to retry. |
| */ |
| int btrfs_use_block_group_size_class(struct btrfs_block_group *bg, |
| enum btrfs_block_group_size_class size_class, |
| bool force_wrong_size_class) |
| { |
| ASSERT(size_class != BTRFS_BG_SZ_NONE); |
| |
| /* The new allocation is in the right size class, do nothing */ |
| if (bg->size_class == size_class) |
| return 0; |
| /* |
| * The new allocation is in a mismatched size class. |
| * This means one of two things: |
| * |
| * 1. Two tasks in find_free_extent for different size_classes raced |
| * and hit the same empty block_group. Make the loser try again. |
| * 2. A call to find_free_extent got desperate enough to set |
| * 'force_wrong_slab'. Don't change the size_class, but allow the |
| * allocation. |
| */ |
| if (bg->size_class != BTRFS_BG_SZ_NONE) { |
| if (force_wrong_size_class) |
| return 0; |
| return -EAGAIN; |
| } |
| /* |
| * The happy new block group case: the new allocation is the first |
| * one in the block_group so we set size_class. |
| */ |
| bg->size_class = size_class; |
| |
| return 0; |
| } |
| |
| bool btrfs_block_group_should_use_size_class(struct btrfs_block_group *bg) |
| { |
| if (btrfs_is_zoned(bg->fs_info)) |
| return false; |
| if (!btrfs_is_block_group_data_only(bg)) |
| return false; |
| return true; |
| } |