| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2012 Fusion-io All rights reserved. |
| * Copyright (C) 2012 Intel Corp. All rights reserved. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/bio.h> |
| #include <linux/slab.h> |
| #include <linux/blkdev.h> |
| #include <linux/raid/pq.h> |
| #include <linux/hash.h> |
| #include <linux/list_sort.h> |
| #include <linux/raid/xor.h> |
| #include <linux/mm.h> |
| #include "messages.h" |
| #include "misc.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "volumes.h" |
| #include "raid56.h" |
| #include "async-thread.h" |
| #include "file-item.h" |
| #include "btrfs_inode.h" |
| |
| /* set when additional merges to this rbio are not allowed */ |
| #define RBIO_RMW_LOCKED_BIT 1 |
| |
| /* |
| * set when this rbio is sitting in the hash, but it is just a cache |
| * of past RMW |
| */ |
| #define RBIO_CACHE_BIT 2 |
| |
| /* |
| * set when it is safe to trust the stripe_pages for caching |
| */ |
| #define RBIO_CACHE_READY_BIT 3 |
| |
| #define RBIO_CACHE_SIZE 1024 |
| |
| #define BTRFS_STRIPE_HASH_TABLE_BITS 11 |
| |
| /* Used by the raid56 code to lock stripes for read/modify/write */ |
| struct btrfs_stripe_hash { |
| struct list_head hash_list; |
| spinlock_t lock; |
| }; |
| |
| /* Used by the raid56 code to lock stripes for read/modify/write */ |
| struct btrfs_stripe_hash_table { |
| struct list_head stripe_cache; |
| spinlock_t cache_lock; |
| int cache_size; |
| struct btrfs_stripe_hash table[]; |
| }; |
| |
| /* |
| * A bvec like structure to present a sector inside a page. |
| * |
| * Unlike bvec we don't need bvlen, as it's fixed to sectorsize. |
| */ |
| struct sector_ptr { |
| struct page *page; |
| unsigned int pgoff:24; |
| unsigned int uptodate:8; |
| }; |
| |
| static void rmw_rbio_work(struct work_struct *work); |
| static void rmw_rbio_work_locked(struct work_struct *work); |
| static void index_rbio_pages(struct btrfs_raid_bio *rbio); |
| static int alloc_rbio_pages(struct btrfs_raid_bio *rbio); |
| |
| static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check); |
| static void scrub_rbio_work_locked(struct work_struct *work); |
| |
| static void free_raid_bio_pointers(struct btrfs_raid_bio *rbio) |
| { |
| bitmap_free(rbio->error_bitmap); |
| kfree(rbio->stripe_pages); |
| kfree(rbio->bio_sectors); |
| kfree(rbio->stripe_sectors); |
| kfree(rbio->finish_pointers); |
| } |
| |
| static void free_raid_bio(struct btrfs_raid_bio *rbio) |
| { |
| int i; |
| |
| if (!refcount_dec_and_test(&rbio->refs)) |
| return; |
| |
| WARN_ON(!list_empty(&rbio->stripe_cache)); |
| WARN_ON(!list_empty(&rbio->hash_list)); |
| WARN_ON(!bio_list_empty(&rbio->bio_list)); |
| |
| for (i = 0; i < rbio->nr_pages; i++) { |
| if (rbio->stripe_pages[i]) { |
| __free_page(rbio->stripe_pages[i]); |
| rbio->stripe_pages[i] = NULL; |
| } |
| } |
| |
| btrfs_put_bioc(rbio->bioc); |
| free_raid_bio_pointers(rbio); |
| kfree(rbio); |
| } |
| |
| static void start_async_work(struct btrfs_raid_bio *rbio, work_func_t work_func) |
| { |
| INIT_WORK(&rbio->work, work_func); |
| queue_work(rbio->bioc->fs_info->rmw_workers, &rbio->work); |
| } |
| |
| /* |
| * the stripe hash table is used for locking, and to collect |
| * bios in hopes of making a full stripe |
| */ |
| int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info) |
| { |
| struct btrfs_stripe_hash_table *table; |
| struct btrfs_stripe_hash_table *x; |
| struct btrfs_stripe_hash *cur; |
| struct btrfs_stripe_hash *h; |
| int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS; |
| int i; |
| |
| if (info->stripe_hash_table) |
| return 0; |
| |
| /* |
| * The table is large, starting with order 4 and can go as high as |
| * order 7 in case lock debugging is turned on. |
| * |
| * Try harder to allocate and fallback to vmalloc to lower the chance |
| * of a failing mount. |
| */ |
| table = kvzalloc(struct_size(table, table, num_entries), GFP_KERNEL); |
| if (!table) |
| return -ENOMEM; |
| |
| spin_lock_init(&table->cache_lock); |
| INIT_LIST_HEAD(&table->stripe_cache); |
| |
| h = table->table; |
| |
| for (i = 0; i < num_entries; i++) { |
| cur = h + i; |
| INIT_LIST_HEAD(&cur->hash_list); |
| spin_lock_init(&cur->lock); |
| } |
| |
| x = cmpxchg(&info->stripe_hash_table, NULL, table); |
| kvfree(x); |
| return 0; |
| } |
| |
| /* |
| * caching an rbio means to copy anything from the |
| * bio_sectors array into the stripe_pages array. We |
| * use the page uptodate bit in the stripe cache array |
| * to indicate if it has valid data |
| * |
| * once the caching is done, we set the cache ready |
| * bit. |
| */ |
| static void cache_rbio_pages(struct btrfs_raid_bio *rbio) |
| { |
| int i; |
| int ret; |
| |
| ret = alloc_rbio_pages(rbio); |
| if (ret) |
| return; |
| |
| for (i = 0; i < rbio->nr_sectors; i++) { |
| /* Some range not covered by bio (partial write), skip it */ |
| if (!rbio->bio_sectors[i].page) { |
| /* |
| * Even if the sector is not covered by bio, if it is |
| * a data sector it should still be uptodate as it is |
| * read from disk. |
| */ |
| if (i < rbio->nr_data * rbio->stripe_nsectors) |
| ASSERT(rbio->stripe_sectors[i].uptodate); |
| continue; |
| } |
| |
| ASSERT(rbio->stripe_sectors[i].page); |
| memcpy_page(rbio->stripe_sectors[i].page, |
| rbio->stripe_sectors[i].pgoff, |
| rbio->bio_sectors[i].page, |
| rbio->bio_sectors[i].pgoff, |
| rbio->bioc->fs_info->sectorsize); |
| rbio->stripe_sectors[i].uptodate = 1; |
| } |
| set_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
| } |
| |
| /* |
| * we hash on the first logical address of the stripe |
| */ |
| static int rbio_bucket(struct btrfs_raid_bio *rbio) |
| { |
| u64 num = rbio->bioc->full_stripe_logical; |
| |
| /* |
| * we shift down quite a bit. We're using byte |
| * addressing, and most of the lower bits are zeros. |
| * This tends to upset hash_64, and it consistently |
| * returns just one or two different values. |
| * |
| * shifting off the lower bits fixes things. |
| */ |
| return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS); |
| } |
| |
| static bool full_page_sectors_uptodate(struct btrfs_raid_bio *rbio, |
| unsigned int page_nr) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| const u32 sectors_per_page = PAGE_SIZE / sectorsize; |
| int i; |
| |
| ASSERT(page_nr < rbio->nr_pages); |
| |
| for (i = sectors_per_page * page_nr; |
| i < sectors_per_page * page_nr + sectors_per_page; |
| i++) { |
| if (!rbio->stripe_sectors[i].uptodate) |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * Update the stripe_sectors[] array to use correct page and pgoff |
| * |
| * Should be called every time any page pointer in stripes_pages[] got modified. |
| */ |
| static void index_stripe_sectors(struct btrfs_raid_bio *rbio) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| u32 offset; |
| int i; |
| |
| for (i = 0, offset = 0; i < rbio->nr_sectors; i++, offset += sectorsize) { |
| int page_index = offset >> PAGE_SHIFT; |
| |
| ASSERT(page_index < rbio->nr_pages); |
| rbio->stripe_sectors[i].page = rbio->stripe_pages[page_index]; |
| rbio->stripe_sectors[i].pgoff = offset_in_page(offset); |
| } |
| } |
| |
| static void steal_rbio_page(struct btrfs_raid_bio *src, |
| struct btrfs_raid_bio *dest, int page_nr) |
| { |
| const u32 sectorsize = src->bioc->fs_info->sectorsize; |
| const u32 sectors_per_page = PAGE_SIZE / sectorsize; |
| int i; |
| |
| if (dest->stripe_pages[page_nr]) |
| __free_page(dest->stripe_pages[page_nr]); |
| dest->stripe_pages[page_nr] = src->stripe_pages[page_nr]; |
| src->stripe_pages[page_nr] = NULL; |
| |
| /* Also update the sector->uptodate bits. */ |
| for (i = sectors_per_page * page_nr; |
| i < sectors_per_page * page_nr + sectors_per_page; i++) |
| dest->stripe_sectors[i].uptodate = true; |
| } |
| |
| static bool is_data_stripe_page(struct btrfs_raid_bio *rbio, int page_nr) |
| { |
| const int sector_nr = (page_nr << PAGE_SHIFT) >> |
| rbio->bioc->fs_info->sectorsize_bits; |
| |
| /* |
| * We have ensured PAGE_SIZE is aligned with sectorsize, thus |
| * we won't have a page which is half data half parity. |
| * |
| * Thus if the first sector of the page belongs to data stripes, then |
| * the full page belongs to data stripes. |
| */ |
| return (sector_nr < rbio->nr_data * rbio->stripe_nsectors); |
| } |
| |
| /* |
| * Stealing an rbio means taking all the uptodate pages from the stripe array |
| * in the source rbio and putting them into the destination rbio. |
| * |
| * This will also update the involved stripe_sectors[] which are referring to |
| * the old pages. |
| */ |
| static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest) |
| { |
| int i; |
| |
| if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags)) |
| return; |
| |
| for (i = 0; i < dest->nr_pages; i++) { |
| struct page *p = src->stripe_pages[i]; |
| |
| /* |
| * We don't need to steal P/Q pages as they will always be |
| * regenerated for RMW or full write anyway. |
| */ |
| if (!is_data_stripe_page(src, i)) |
| continue; |
| |
| /* |
| * If @src already has RBIO_CACHE_READY_BIT, it should have |
| * all data stripe pages present and uptodate. |
| */ |
| ASSERT(p); |
| ASSERT(full_page_sectors_uptodate(src, i)); |
| steal_rbio_page(src, dest, i); |
| } |
| index_stripe_sectors(dest); |
| index_stripe_sectors(src); |
| } |
| |
| /* |
| * merging means we take the bio_list from the victim and |
| * splice it into the destination. The victim should |
| * be discarded afterwards. |
| * |
| * must be called with dest->rbio_list_lock held |
| */ |
| static void merge_rbio(struct btrfs_raid_bio *dest, |
| struct btrfs_raid_bio *victim) |
| { |
| bio_list_merge(&dest->bio_list, &victim->bio_list); |
| dest->bio_list_bytes += victim->bio_list_bytes; |
| /* Also inherit the bitmaps from @victim. */ |
| bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap, |
| dest->stripe_nsectors); |
| bio_list_init(&victim->bio_list); |
| } |
| |
| /* |
| * used to prune items that are in the cache. The caller |
| * must hold the hash table lock. |
| */ |
| static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio) |
| { |
| int bucket = rbio_bucket(rbio); |
| struct btrfs_stripe_hash_table *table; |
| struct btrfs_stripe_hash *h; |
| int freeit = 0; |
| |
| /* |
| * check the bit again under the hash table lock. |
| */ |
| if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) |
| return; |
| |
| table = rbio->bioc->fs_info->stripe_hash_table; |
| h = table->table + bucket; |
| |
| /* hold the lock for the bucket because we may be |
| * removing it from the hash table |
| */ |
| spin_lock(&h->lock); |
| |
| /* |
| * hold the lock for the bio list because we need |
| * to make sure the bio list is empty |
| */ |
| spin_lock(&rbio->bio_list_lock); |
| |
| if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) { |
| list_del_init(&rbio->stripe_cache); |
| table->cache_size -= 1; |
| freeit = 1; |
| |
| /* if the bio list isn't empty, this rbio is |
| * still involved in an IO. We take it out |
| * of the cache list, and drop the ref that |
| * was held for the list. |
| * |
| * If the bio_list was empty, we also remove |
| * the rbio from the hash_table, and drop |
| * the corresponding ref |
| */ |
| if (bio_list_empty(&rbio->bio_list)) { |
| if (!list_empty(&rbio->hash_list)) { |
| list_del_init(&rbio->hash_list); |
| refcount_dec(&rbio->refs); |
| BUG_ON(!list_empty(&rbio->plug_list)); |
| } |
| } |
| } |
| |
| spin_unlock(&rbio->bio_list_lock); |
| spin_unlock(&h->lock); |
| |
| if (freeit) |
| free_raid_bio(rbio); |
| } |
| |
| /* |
| * prune a given rbio from the cache |
| */ |
| static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio) |
| { |
| struct btrfs_stripe_hash_table *table; |
| |
| if (!test_bit(RBIO_CACHE_BIT, &rbio->flags)) |
| return; |
| |
| table = rbio->bioc->fs_info->stripe_hash_table; |
| |
| spin_lock(&table->cache_lock); |
| __remove_rbio_from_cache(rbio); |
| spin_unlock(&table->cache_lock); |
| } |
| |
| /* |
| * remove everything in the cache |
| */ |
| static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info) |
| { |
| struct btrfs_stripe_hash_table *table; |
| struct btrfs_raid_bio *rbio; |
| |
| table = info->stripe_hash_table; |
| |
| spin_lock(&table->cache_lock); |
| while (!list_empty(&table->stripe_cache)) { |
| rbio = list_entry(table->stripe_cache.next, |
| struct btrfs_raid_bio, |
| stripe_cache); |
| __remove_rbio_from_cache(rbio); |
| } |
| spin_unlock(&table->cache_lock); |
| } |
| |
| /* |
| * remove all cached entries and free the hash table |
| * used by unmount |
| */ |
| void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info) |
| { |
| if (!info->stripe_hash_table) |
| return; |
| btrfs_clear_rbio_cache(info); |
| kvfree(info->stripe_hash_table); |
| info->stripe_hash_table = NULL; |
| } |
| |
| /* |
| * insert an rbio into the stripe cache. It |
| * must have already been prepared by calling |
| * cache_rbio_pages |
| * |
| * If this rbio was already cached, it gets |
| * moved to the front of the lru. |
| * |
| * If the size of the rbio cache is too big, we |
| * prune an item. |
| */ |
| static void cache_rbio(struct btrfs_raid_bio *rbio) |
| { |
| struct btrfs_stripe_hash_table *table; |
| |
| if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags)) |
| return; |
| |
| table = rbio->bioc->fs_info->stripe_hash_table; |
| |
| spin_lock(&table->cache_lock); |
| spin_lock(&rbio->bio_list_lock); |
| |
| /* bump our ref if we were not in the list before */ |
| if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags)) |
| refcount_inc(&rbio->refs); |
| |
| if (!list_empty(&rbio->stripe_cache)){ |
| list_move(&rbio->stripe_cache, &table->stripe_cache); |
| } else { |
| list_add(&rbio->stripe_cache, &table->stripe_cache); |
| table->cache_size += 1; |
| } |
| |
| spin_unlock(&rbio->bio_list_lock); |
| |
| if (table->cache_size > RBIO_CACHE_SIZE) { |
| struct btrfs_raid_bio *found; |
| |
| found = list_entry(table->stripe_cache.prev, |
| struct btrfs_raid_bio, |
| stripe_cache); |
| |
| if (found != rbio) |
| __remove_rbio_from_cache(found); |
| } |
| |
| spin_unlock(&table->cache_lock); |
| } |
| |
| /* |
| * helper function to run the xor_blocks api. It is only |
| * able to do MAX_XOR_BLOCKS at a time, so we need to |
| * loop through. |
| */ |
| static void run_xor(void **pages, int src_cnt, ssize_t len) |
| { |
| int src_off = 0; |
| int xor_src_cnt = 0; |
| void *dest = pages[src_cnt]; |
| |
| while(src_cnt > 0) { |
| xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS); |
| xor_blocks(xor_src_cnt, len, dest, pages + src_off); |
| |
| src_cnt -= xor_src_cnt; |
| src_off += xor_src_cnt; |
| } |
| } |
| |
| /* |
| * Returns true if the bio list inside this rbio covers an entire stripe (no |
| * rmw required). |
| */ |
| static int rbio_is_full(struct btrfs_raid_bio *rbio) |
| { |
| unsigned long size = rbio->bio_list_bytes; |
| int ret = 1; |
| |
| spin_lock(&rbio->bio_list_lock); |
| if (size != rbio->nr_data * BTRFS_STRIPE_LEN) |
| ret = 0; |
| BUG_ON(size > rbio->nr_data * BTRFS_STRIPE_LEN); |
| spin_unlock(&rbio->bio_list_lock); |
| |
| return ret; |
| } |
| |
| /* |
| * returns 1 if it is safe to merge two rbios together. |
| * The merging is safe if the two rbios correspond to |
| * the same stripe and if they are both going in the same |
| * direction (read vs write), and if neither one is |
| * locked for final IO |
| * |
| * The caller is responsible for locking such that |
| * rmw_locked is safe to test |
| */ |
| static int rbio_can_merge(struct btrfs_raid_bio *last, |
| struct btrfs_raid_bio *cur) |
| { |
| if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) || |
| test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) |
| return 0; |
| |
| /* |
| * we can't merge with cached rbios, since the |
| * idea is that when we merge the destination |
| * rbio is going to run our IO for us. We can |
| * steal from cached rbios though, other functions |
| * handle that. |
| */ |
| if (test_bit(RBIO_CACHE_BIT, &last->flags) || |
| test_bit(RBIO_CACHE_BIT, &cur->flags)) |
| return 0; |
| |
| if (last->bioc->full_stripe_logical != cur->bioc->full_stripe_logical) |
| return 0; |
| |
| /* we can't merge with different operations */ |
| if (last->operation != cur->operation) |
| return 0; |
| /* |
| * We've need read the full stripe from the drive. |
| * check and repair the parity and write the new results. |
| * |
| * We're not allowed to add any new bios to the |
| * bio list here, anyone else that wants to |
| * change this stripe needs to do their own rmw. |
| */ |
| if (last->operation == BTRFS_RBIO_PARITY_SCRUB) |
| return 0; |
| |
| if (last->operation == BTRFS_RBIO_REBUILD_MISSING || |
| last->operation == BTRFS_RBIO_READ_REBUILD) |
| return 0; |
| |
| return 1; |
| } |
| |
| static unsigned int rbio_stripe_sector_index(const struct btrfs_raid_bio *rbio, |
| unsigned int stripe_nr, |
| unsigned int sector_nr) |
| { |
| ASSERT(stripe_nr < rbio->real_stripes); |
| ASSERT(sector_nr < rbio->stripe_nsectors); |
| |
| return stripe_nr * rbio->stripe_nsectors + sector_nr; |
| } |
| |
| /* Return a sector from rbio->stripe_sectors, not from the bio list */ |
| static struct sector_ptr *rbio_stripe_sector(const struct btrfs_raid_bio *rbio, |
| unsigned int stripe_nr, |
| unsigned int sector_nr) |
| { |
| return &rbio->stripe_sectors[rbio_stripe_sector_index(rbio, stripe_nr, |
| sector_nr)]; |
| } |
| |
| /* Grab a sector inside P stripe */ |
| static struct sector_ptr *rbio_pstripe_sector(const struct btrfs_raid_bio *rbio, |
| unsigned int sector_nr) |
| { |
| return rbio_stripe_sector(rbio, rbio->nr_data, sector_nr); |
| } |
| |
| /* Grab a sector inside Q stripe, return NULL if not RAID6 */ |
| static struct sector_ptr *rbio_qstripe_sector(const struct btrfs_raid_bio *rbio, |
| unsigned int sector_nr) |
| { |
| if (rbio->nr_data + 1 == rbio->real_stripes) |
| return NULL; |
| return rbio_stripe_sector(rbio, rbio->nr_data + 1, sector_nr); |
| } |
| |
| /* |
| * The first stripe in the table for a logical address |
| * has the lock. rbios are added in one of three ways: |
| * |
| * 1) Nobody has the stripe locked yet. The rbio is given |
| * the lock and 0 is returned. The caller must start the IO |
| * themselves. |
| * |
| * 2) Someone has the stripe locked, but we're able to merge |
| * with the lock owner. The rbio is freed and the IO will |
| * start automatically along with the existing rbio. 1 is returned. |
| * |
| * 3) Someone has the stripe locked, but we're not able to merge. |
| * The rbio is added to the lock owner's plug list, or merged into |
| * an rbio already on the plug list. When the lock owner unlocks, |
| * the next rbio on the list is run and the IO is started automatically. |
| * 1 is returned |
| * |
| * If we return 0, the caller still owns the rbio and must continue with |
| * IO submission. If we return 1, the caller must assume the rbio has |
| * already been freed. |
| */ |
| static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio) |
| { |
| struct btrfs_stripe_hash *h; |
| struct btrfs_raid_bio *cur; |
| struct btrfs_raid_bio *pending; |
| struct btrfs_raid_bio *freeit = NULL; |
| struct btrfs_raid_bio *cache_drop = NULL; |
| int ret = 0; |
| |
| h = rbio->bioc->fs_info->stripe_hash_table->table + rbio_bucket(rbio); |
| |
| spin_lock(&h->lock); |
| list_for_each_entry(cur, &h->hash_list, hash_list) { |
| if (cur->bioc->full_stripe_logical != rbio->bioc->full_stripe_logical) |
| continue; |
| |
| spin_lock(&cur->bio_list_lock); |
| |
| /* Can we steal this cached rbio's pages? */ |
| if (bio_list_empty(&cur->bio_list) && |
| list_empty(&cur->plug_list) && |
| test_bit(RBIO_CACHE_BIT, &cur->flags) && |
| !test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) { |
| list_del_init(&cur->hash_list); |
| refcount_dec(&cur->refs); |
| |
| steal_rbio(cur, rbio); |
| cache_drop = cur; |
| spin_unlock(&cur->bio_list_lock); |
| |
| goto lockit; |
| } |
| |
| /* Can we merge into the lock owner? */ |
| if (rbio_can_merge(cur, rbio)) { |
| merge_rbio(cur, rbio); |
| spin_unlock(&cur->bio_list_lock); |
| freeit = rbio; |
| ret = 1; |
| goto out; |
| } |
| |
| |
| /* |
| * We couldn't merge with the running rbio, see if we can merge |
| * with the pending ones. We don't have to check for rmw_locked |
| * because there is no way they are inside finish_rmw right now |
| */ |
| list_for_each_entry(pending, &cur->plug_list, plug_list) { |
| if (rbio_can_merge(pending, rbio)) { |
| merge_rbio(pending, rbio); |
| spin_unlock(&cur->bio_list_lock); |
| freeit = rbio; |
| ret = 1; |
| goto out; |
| } |
| } |
| |
| /* |
| * No merging, put us on the tail of the plug list, our rbio |
| * will be started with the currently running rbio unlocks |
| */ |
| list_add_tail(&rbio->plug_list, &cur->plug_list); |
| spin_unlock(&cur->bio_list_lock); |
| ret = 1; |
| goto out; |
| } |
| lockit: |
| refcount_inc(&rbio->refs); |
| list_add(&rbio->hash_list, &h->hash_list); |
| out: |
| spin_unlock(&h->lock); |
| if (cache_drop) |
| remove_rbio_from_cache(cache_drop); |
| if (freeit) |
| free_raid_bio(freeit); |
| return ret; |
| } |
| |
| static void recover_rbio_work_locked(struct work_struct *work); |
| |
| /* |
| * called as rmw or parity rebuild is completed. If the plug list has more |
| * rbios waiting for this stripe, the next one on the list will be started |
| */ |
| static noinline void unlock_stripe(struct btrfs_raid_bio *rbio) |
| { |
| int bucket; |
| struct btrfs_stripe_hash *h; |
| int keep_cache = 0; |
| |
| bucket = rbio_bucket(rbio); |
| h = rbio->bioc->fs_info->stripe_hash_table->table + bucket; |
| |
| if (list_empty(&rbio->plug_list)) |
| cache_rbio(rbio); |
| |
| spin_lock(&h->lock); |
| spin_lock(&rbio->bio_list_lock); |
| |
| if (!list_empty(&rbio->hash_list)) { |
| /* |
| * if we're still cached and there is no other IO |
| * to perform, just leave this rbio here for others |
| * to steal from later |
| */ |
| if (list_empty(&rbio->plug_list) && |
| test_bit(RBIO_CACHE_BIT, &rbio->flags)) { |
| keep_cache = 1; |
| clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
| BUG_ON(!bio_list_empty(&rbio->bio_list)); |
| goto done; |
| } |
| |
| list_del_init(&rbio->hash_list); |
| refcount_dec(&rbio->refs); |
| |
| /* |
| * we use the plug list to hold all the rbios |
| * waiting for the chance to lock this stripe. |
| * hand the lock over to one of them. |
| */ |
| if (!list_empty(&rbio->plug_list)) { |
| struct btrfs_raid_bio *next; |
| struct list_head *head = rbio->plug_list.next; |
| |
| next = list_entry(head, struct btrfs_raid_bio, |
| plug_list); |
| |
| list_del_init(&rbio->plug_list); |
| |
| list_add(&next->hash_list, &h->hash_list); |
| refcount_inc(&next->refs); |
| spin_unlock(&rbio->bio_list_lock); |
| spin_unlock(&h->lock); |
| |
| if (next->operation == BTRFS_RBIO_READ_REBUILD) |
| start_async_work(next, recover_rbio_work_locked); |
| else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) { |
| steal_rbio(rbio, next); |
| start_async_work(next, recover_rbio_work_locked); |
| } else if (next->operation == BTRFS_RBIO_WRITE) { |
| steal_rbio(rbio, next); |
| start_async_work(next, rmw_rbio_work_locked); |
| } else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) { |
| steal_rbio(rbio, next); |
| start_async_work(next, scrub_rbio_work_locked); |
| } |
| |
| goto done_nolock; |
| } |
| } |
| done: |
| spin_unlock(&rbio->bio_list_lock); |
| spin_unlock(&h->lock); |
| |
| done_nolock: |
| if (!keep_cache) |
| remove_rbio_from_cache(rbio); |
| } |
| |
| static void rbio_endio_bio_list(struct bio *cur, blk_status_t err) |
| { |
| struct bio *next; |
| |
| while (cur) { |
| next = cur->bi_next; |
| cur->bi_next = NULL; |
| cur->bi_status = err; |
| bio_endio(cur); |
| cur = next; |
| } |
| } |
| |
| /* |
| * this frees the rbio and runs through all the bios in the |
| * bio_list and calls end_io on them |
| */ |
| static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err) |
| { |
| struct bio *cur = bio_list_get(&rbio->bio_list); |
| struct bio *extra; |
| |
| kfree(rbio->csum_buf); |
| bitmap_free(rbio->csum_bitmap); |
| rbio->csum_buf = NULL; |
| rbio->csum_bitmap = NULL; |
| |
| /* |
| * Clear the data bitmap, as the rbio may be cached for later usage. |
| * do this before before unlock_stripe() so there will be no new bio |
| * for this bio. |
| */ |
| bitmap_clear(&rbio->dbitmap, 0, rbio->stripe_nsectors); |
| |
| /* |
| * At this moment, rbio->bio_list is empty, however since rbio does not |
| * always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the |
| * hash list, rbio may be merged with others so that rbio->bio_list |
| * becomes non-empty. |
| * Once unlock_stripe() is done, rbio->bio_list will not be updated any |
| * more and we can call bio_endio() on all queued bios. |
| */ |
| unlock_stripe(rbio); |
| extra = bio_list_get(&rbio->bio_list); |
| free_raid_bio(rbio); |
| |
| rbio_endio_bio_list(cur, err); |
| if (extra) |
| rbio_endio_bio_list(extra, err); |
| } |
| |
| /* |
| * Get a sector pointer specified by its @stripe_nr and @sector_nr. |
| * |
| * @rbio: The raid bio |
| * @stripe_nr: Stripe number, valid range [0, real_stripe) |
| * @sector_nr: Sector number inside the stripe, |
| * valid range [0, stripe_nsectors) |
| * @bio_list_only: Whether to use sectors inside the bio list only. |
| * |
| * The read/modify/write code wants to reuse the original bio page as much |
| * as possible, and only use stripe_sectors as fallback. |
| */ |
| static struct sector_ptr *sector_in_rbio(struct btrfs_raid_bio *rbio, |
| int stripe_nr, int sector_nr, |
| bool bio_list_only) |
| { |
| struct sector_ptr *sector; |
| int index; |
| |
| ASSERT(stripe_nr >= 0 && stripe_nr < rbio->real_stripes); |
| ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors); |
| |
| index = stripe_nr * rbio->stripe_nsectors + sector_nr; |
| ASSERT(index >= 0 && index < rbio->nr_sectors); |
| |
| spin_lock(&rbio->bio_list_lock); |
| sector = &rbio->bio_sectors[index]; |
| if (sector->page || bio_list_only) { |
| /* Don't return sector without a valid page pointer */ |
| if (!sector->page) |
| sector = NULL; |
| spin_unlock(&rbio->bio_list_lock); |
| return sector; |
| } |
| spin_unlock(&rbio->bio_list_lock); |
| |
| return &rbio->stripe_sectors[index]; |
| } |
| |
| /* |
| * allocation and initial setup for the btrfs_raid_bio. Not |
| * this does not allocate any pages for rbio->pages. |
| */ |
| static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info, |
| struct btrfs_io_context *bioc) |
| { |
| const unsigned int real_stripes = bioc->num_stripes - bioc->replace_nr_stripes; |
| const unsigned int stripe_npages = BTRFS_STRIPE_LEN >> PAGE_SHIFT; |
| const unsigned int num_pages = stripe_npages * real_stripes; |
| const unsigned int stripe_nsectors = |
| BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits; |
| const unsigned int num_sectors = stripe_nsectors * real_stripes; |
| struct btrfs_raid_bio *rbio; |
| |
| /* PAGE_SIZE must also be aligned to sectorsize for subpage support */ |
| ASSERT(IS_ALIGNED(PAGE_SIZE, fs_info->sectorsize)); |
| /* |
| * Our current stripe len should be fixed to 64k thus stripe_nsectors |
| * (at most 16) should be no larger than BITS_PER_LONG. |
| */ |
| ASSERT(stripe_nsectors <= BITS_PER_LONG); |
| |
| rbio = kzalloc(sizeof(*rbio), GFP_NOFS); |
| if (!rbio) |
| return ERR_PTR(-ENOMEM); |
| rbio->stripe_pages = kcalloc(num_pages, sizeof(struct page *), |
| GFP_NOFS); |
| rbio->bio_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr), |
| GFP_NOFS); |
| rbio->stripe_sectors = kcalloc(num_sectors, sizeof(struct sector_ptr), |
| GFP_NOFS); |
| rbio->finish_pointers = kcalloc(real_stripes, sizeof(void *), GFP_NOFS); |
| rbio->error_bitmap = bitmap_zalloc(num_sectors, GFP_NOFS); |
| |
| if (!rbio->stripe_pages || !rbio->bio_sectors || !rbio->stripe_sectors || |
| !rbio->finish_pointers || !rbio->error_bitmap) { |
| free_raid_bio_pointers(rbio); |
| kfree(rbio); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| bio_list_init(&rbio->bio_list); |
| init_waitqueue_head(&rbio->io_wait); |
| INIT_LIST_HEAD(&rbio->plug_list); |
| spin_lock_init(&rbio->bio_list_lock); |
| INIT_LIST_HEAD(&rbio->stripe_cache); |
| INIT_LIST_HEAD(&rbio->hash_list); |
| btrfs_get_bioc(bioc); |
| rbio->bioc = bioc; |
| rbio->nr_pages = num_pages; |
| rbio->nr_sectors = num_sectors; |
| rbio->real_stripes = real_stripes; |
| rbio->stripe_npages = stripe_npages; |
| rbio->stripe_nsectors = stripe_nsectors; |
| refcount_set(&rbio->refs, 1); |
| atomic_set(&rbio->stripes_pending, 0); |
| |
| ASSERT(btrfs_nr_parity_stripes(bioc->map_type)); |
| rbio->nr_data = real_stripes - btrfs_nr_parity_stripes(bioc->map_type); |
| |
| return rbio; |
| } |
| |
| /* allocate pages for all the stripes in the bio, including parity */ |
| static int alloc_rbio_pages(struct btrfs_raid_bio *rbio) |
| { |
| int ret; |
| |
| ret = btrfs_alloc_page_array(rbio->nr_pages, rbio->stripe_pages); |
| if (ret < 0) |
| return ret; |
| /* Mapping all sectors */ |
| index_stripe_sectors(rbio); |
| return 0; |
| } |
| |
| /* only allocate pages for p/q stripes */ |
| static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio) |
| { |
| const int data_pages = rbio->nr_data * rbio->stripe_npages; |
| int ret; |
| |
| ret = btrfs_alloc_page_array(rbio->nr_pages - data_pages, |
| rbio->stripe_pages + data_pages); |
| if (ret < 0) |
| return ret; |
| |
| index_stripe_sectors(rbio); |
| return 0; |
| } |
| |
| /* |
| * Return the total number of errors found in the vertical stripe of @sector_nr. |
| * |
| * @faila and @failb will also be updated to the first and second stripe |
| * number of the errors. |
| */ |
| static int get_rbio_veritical_errors(struct btrfs_raid_bio *rbio, int sector_nr, |
| int *faila, int *failb) |
| { |
| int stripe_nr; |
| int found_errors = 0; |
| |
| if (faila || failb) { |
| /* |
| * Both @faila and @failb should be valid pointers if any of |
| * them is specified. |
| */ |
| ASSERT(faila && failb); |
| *faila = -1; |
| *failb = -1; |
| } |
| |
| for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) { |
| int total_sector_nr = stripe_nr * rbio->stripe_nsectors + sector_nr; |
| |
| if (test_bit(total_sector_nr, rbio->error_bitmap)) { |
| found_errors++; |
| if (faila) { |
| /* Update faila and failb. */ |
| if (*faila < 0) |
| *faila = stripe_nr; |
| else if (*failb < 0) |
| *failb = stripe_nr; |
| } |
| } |
| } |
| return found_errors; |
| } |
| |
| /* |
| * Add a single sector @sector into our list of bios for IO. |
| * |
| * Return 0 if everything went well. |
| * Return <0 for error. |
| */ |
| static int rbio_add_io_sector(struct btrfs_raid_bio *rbio, |
| struct bio_list *bio_list, |
| struct sector_ptr *sector, |
| unsigned int stripe_nr, |
| unsigned int sector_nr, |
| enum req_op op) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| struct bio *last = bio_list->tail; |
| int ret; |
| struct bio *bio; |
| struct btrfs_io_stripe *stripe; |
| u64 disk_start; |
| |
| /* |
| * Note: here stripe_nr has taken device replace into consideration, |
| * thus it can be larger than rbio->real_stripe. |
| * So here we check against bioc->num_stripes, not rbio->real_stripes. |
| */ |
| ASSERT(stripe_nr >= 0 && stripe_nr < rbio->bioc->num_stripes); |
| ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors); |
| ASSERT(sector->page); |
| |
| stripe = &rbio->bioc->stripes[stripe_nr]; |
| disk_start = stripe->physical + sector_nr * sectorsize; |
| |
| /* if the device is missing, just fail this stripe */ |
| if (!stripe->dev->bdev) { |
| int found_errors; |
| |
| set_bit(stripe_nr * rbio->stripe_nsectors + sector_nr, |
| rbio->error_bitmap); |
| |
| /* Check if we have reached tolerance early. */ |
| found_errors = get_rbio_veritical_errors(rbio, sector_nr, |
| NULL, NULL); |
| if (found_errors > rbio->bioc->max_errors) |
| return -EIO; |
| return 0; |
| } |
| |
| /* see if we can add this page onto our existing bio */ |
| if (last) { |
| u64 last_end = last->bi_iter.bi_sector << SECTOR_SHIFT; |
| last_end += last->bi_iter.bi_size; |
| |
| /* |
| * we can't merge these if they are from different |
| * devices or if they are not contiguous |
| */ |
| if (last_end == disk_start && !last->bi_status && |
| last->bi_bdev == stripe->dev->bdev) { |
| ret = bio_add_page(last, sector->page, sectorsize, |
| sector->pgoff); |
| if (ret == sectorsize) |
| return 0; |
| } |
| } |
| |
| /* put a new bio on the list */ |
| bio = bio_alloc(stripe->dev->bdev, |
| max(BTRFS_STRIPE_LEN >> PAGE_SHIFT, 1), |
| op, GFP_NOFS); |
| bio->bi_iter.bi_sector = disk_start >> SECTOR_SHIFT; |
| bio->bi_private = rbio; |
| |
| __bio_add_page(bio, sector->page, sectorsize, sector->pgoff); |
| bio_list_add(bio_list, bio); |
| return 0; |
| } |
| |
| static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| struct bio_vec bvec; |
| struct bvec_iter iter; |
| u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) - |
| rbio->bioc->full_stripe_logical; |
| |
| bio_for_each_segment(bvec, bio, iter) { |
| u32 bvec_offset; |
| |
| for (bvec_offset = 0; bvec_offset < bvec.bv_len; |
| bvec_offset += sectorsize, offset += sectorsize) { |
| int index = offset / sectorsize; |
| struct sector_ptr *sector = &rbio->bio_sectors[index]; |
| |
| sector->page = bvec.bv_page; |
| sector->pgoff = bvec.bv_offset + bvec_offset; |
| ASSERT(sector->pgoff < PAGE_SIZE); |
| } |
| } |
| } |
| |
| /* |
| * helper function to walk our bio list and populate the bio_pages array with |
| * the result. This seems expensive, but it is faster than constantly |
| * searching through the bio list as we setup the IO in finish_rmw or stripe |
| * reconstruction. |
| * |
| * This must be called before you trust the answers from page_in_rbio |
| */ |
| static void index_rbio_pages(struct btrfs_raid_bio *rbio) |
| { |
| struct bio *bio; |
| |
| spin_lock(&rbio->bio_list_lock); |
| bio_list_for_each(bio, &rbio->bio_list) |
| index_one_bio(rbio, bio); |
| |
| spin_unlock(&rbio->bio_list_lock); |
| } |
| |
| static void bio_get_trace_info(struct btrfs_raid_bio *rbio, struct bio *bio, |
| struct raid56_bio_trace_info *trace_info) |
| { |
| const struct btrfs_io_context *bioc = rbio->bioc; |
| int i; |
| |
| ASSERT(bioc); |
| |
| /* We rely on bio->bi_bdev to find the stripe number. */ |
| if (!bio->bi_bdev) |
| goto not_found; |
| |
| for (i = 0; i < bioc->num_stripes; i++) { |
| if (bio->bi_bdev != bioc->stripes[i].dev->bdev) |
| continue; |
| trace_info->stripe_nr = i; |
| trace_info->devid = bioc->stripes[i].dev->devid; |
| trace_info->offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) - |
| bioc->stripes[i].physical; |
| return; |
| } |
| |
| not_found: |
| trace_info->devid = -1; |
| trace_info->offset = -1; |
| trace_info->stripe_nr = -1; |
| } |
| |
| static inline void bio_list_put(struct bio_list *bio_list) |
| { |
| struct bio *bio; |
| |
| while ((bio = bio_list_pop(bio_list))) |
| bio_put(bio); |
| } |
| |
| /* Generate PQ for one vertical stripe. */ |
| static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr) |
| { |
| void **pointers = rbio->finish_pointers; |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| struct sector_ptr *sector; |
| int stripe; |
| const bool has_qstripe = rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6; |
| |
| /* First collect one sector from each data stripe */ |
| for (stripe = 0; stripe < rbio->nr_data; stripe++) { |
| sector = sector_in_rbio(rbio, stripe, sectornr, 0); |
| pointers[stripe] = kmap_local_page(sector->page) + |
| sector->pgoff; |
| } |
| |
| /* Then add the parity stripe */ |
| sector = rbio_pstripe_sector(rbio, sectornr); |
| sector->uptodate = 1; |
| pointers[stripe++] = kmap_local_page(sector->page) + sector->pgoff; |
| |
| if (has_qstripe) { |
| /* |
| * RAID6, add the qstripe and call the library function |
| * to fill in our p/q |
| */ |
| sector = rbio_qstripe_sector(rbio, sectornr); |
| sector->uptodate = 1; |
| pointers[stripe++] = kmap_local_page(sector->page) + |
| sector->pgoff; |
| |
| raid6_call.gen_syndrome(rbio->real_stripes, sectorsize, |
| pointers); |
| } else { |
| /* raid5 */ |
| memcpy(pointers[rbio->nr_data], pointers[0], sectorsize); |
| run_xor(pointers + 1, rbio->nr_data - 1, sectorsize); |
| } |
| for (stripe = stripe - 1; stripe >= 0; stripe--) |
| kunmap_local(pointers[stripe]); |
| } |
| |
| static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio, |
| struct bio_list *bio_list) |
| { |
| /* The total sector number inside the full stripe. */ |
| int total_sector_nr; |
| int sectornr; |
| int stripe; |
| int ret; |
| |
| ASSERT(bio_list_size(bio_list) == 0); |
| |
| /* We should have at least one data sector. */ |
| ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors)); |
| |
| /* |
| * Reset errors, as we may have errors inherited from from degraded |
| * write. |
| */ |
| bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors); |
| |
| /* |
| * Start assembly. Make bios for everything from the higher layers (the |
| * bio_list in our rbio) and our P/Q. Ignore everything else. |
| */ |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| struct sector_ptr *sector; |
| |
| stripe = total_sector_nr / rbio->stripe_nsectors; |
| sectornr = total_sector_nr % rbio->stripe_nsectors; |
| |
| /* This vertical stripe has no data, skip it. */ |
| if (!test_bit(sectornr, &rbio->dbitmap)) |
| continue; |
| |
| if (stripe < rbio->nr_data) { |
| sector = sector_in_rbio(rbio, stripe, sectornr, 1); |
| if (!sector) |
| continue; |
| } else { |
| sector = rbio_stripe_sector(rbio, stripe, sectornr); |
| } |
| |
| ret = rbio_add_io_sector(rbio, bio_list, sector, stripe, |
| sectornr, REQ_OP_WRITE); |
| if (ret) |
| goto error; |
| } |
| |
| if (likely(!rbio->bioc->replace_nr_stripes)) |
| return 0; |
| |
| /* |
| * Make a copy for the replace target device. |
| * |
| * Thus the source stripe number (in replace_stripe_src) should be valid. |
| */ |
| ASSERT(rbio->bioc->replace_stripe_src >= 0); |
| |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| struct sector_ptr *sector; |
| |
| stripe = total_sector_nr / rbio->stripe_nsectors; |
| sectornr = total_sector_nr % rbio->stripe_nsectors; |
| |
| /* |
| * For RAID56, there is only one device that can be replaced, |
| * and replace_stripe_src[0] indicates the stripe number we |
| * need to copy from. |
| */ |
| if (stripe != rbio->bioc->replace_stripe_src) { |
| /* |
| * We can skip the whole stripe completely, note |
| * total_sector_nr will be increased by one anyway. |
| */ |
| ASSERT(sectornr == 0); |
| total_sector_nr += rbio->stripe_nsectors - 1; |
| continue; |
| } |
| |
| /* This vertical stripe has no data, skip it. */ |
| if (!test_bit(sectornr, &rbio->dbitmap)) |
| continue; |
| |
| if (stripe < rbio->nr_data) { |
| sector = sector_in_rbio(rbio, stripe, sectornr, 1); |
| if (!sector) |
| continue; |
| } else { |
| sector = rbio_stripe_sector(rbio, stripe, sectornr); |
| } |
| |
| ret = rbio_add_io_sector(rbio, bio_list, sector, |
| rbio->real_stripes, |
| sectornr, REQ_OP_WRITE); |
| if (ret) |
| goto error; |
| } |
| |
| return 0; |
| error: |
| bio_list_put(bio_list); |
| return -EIO; |
| } |
| |
| static void set_rbio_range_error(struct btrfs_raid_bio *rbio, struct bio *bio) |
| { |
| struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) - |
| rbio->bioc->full_stripe_logical; |
| int total_nr_sector = offset >> fs_info->sectorsize_bits; |
| |
| ASSERT(total_nr_sector < rbio->nr_data * rbio->stripe_nsectors); |
| |
| bitmap_set(rbio->error_bitmap, total_nr_sector, |
| bio->bi_iter.bi_size >> fs_info->sectorsize_bits); |
| |
| /* |
| * Special handling for raid56_alloc_missing_rbio() used by |
| * scrub/replace. Unlike call path in raid56_parity_recover(), they |
| * pass an empty bio here. Thus we have to find out the missing device |
| * and mark the stripe error instead. |
| */ |
| if (bio->bi_iter.bi_size == 0) { |
| bool found_missing = false; |
| int stripe_nr; |
| |
| for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) { |
| if (!rbio->bioc->stripes[stripe_nr].dev->bdev) { |
| found_missing = true; |
| bitmap_set(rbio->error_bitmap, |
| stripe_nr * rbio->stripe_nsectors, |
| rbio->stripe_nsectors); |
| } |
| } |
| ASSERT(found_missing); |
| } |
| } |
| |
| /* |
| * For subpage case, we can no longer set page Up-to-date directly for |
| * stripe_pages[], thus we need to locate the sector. |
| */ |
| static struct sector_ptr *find_stripe_sector(struct btrfs_raid_bio *rbio, |
| struct page *page, |
| unsigned int pgoff) |
| { |
| int i; |
| |
| for (i = 0; i < rbio->nr_sectors; i++) { |
| struct sector_ptr *sector = &rbio->stripe_sectors[i]; |
| |
| if (sector->page == page && sector->pgoff == pgoff) |
| return sector; |
| } |
| return NULL; |
| } |
| |
| /* |
| * this sets each page in the bio uptodate. It should only be used on private |
| * rbio pages, nothing that comes in from the higher layers |
| */ |
| static void set_bio_pages_uptodate(struct btrfs_raid_bio *rbio, struct bio *bio) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| struct bio_vec *bvec; |
| struct bvec_iter_all iter_all; |
| |
| ASSERT(!bio_flagged(bio, BIO_CLONED)); |
| |
| bio_for_each_segment_all(bvec, bio, iter_all) { |
| struct sector_ptr *sector; |
| int pgoff; |
| |
| for (pgoff = bvec->bv_offset; pgoff - bvec->bv_offset < bvec->bv_len; |
| pgoff += sectorsize) { |
| sector = find_stripe_sector(rbio, bvec->bv_page, pgoff); |
| ASSERT(sector); |
| if (sector) |
| sector->uptodate = 1; |
| } |
| } |
| } |
| |
| static int get_bio_sector_nr(struct btrfs_raid_bio *rbio, struct bio *bio) |
| { |
| struct bio_vec *bv = bio_first_bvec_all(bio); |
| int i; |
| |
| for (i = 0; i < rbio->nr_sectors; i++) { |
| struct sector_ptr *sector; |
| |
| sector = &rbio->stripe_sectors[i]; |
| if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset) |
| break; |
| sector = &rbio->bio_sectors[i]; |
| if (sector->page == bv->bv_page && sector->pgoff == bv->bv_offset) |
| break; |
| } |
| ASSERT(i < rbio->nr_sectors); |
| return i; |
| } |
| |
| static void rbio_update_error_bitmap(struct btrfs_raid_bio *rbio, struct bio *bio) |
| { |
| int total_sector_nr = get_bio_sector_nr(rbio, bio); |
| u32 bio_size = 0; |
| struct bio_vec *bvec; |
| int i; |
| |
| bio_for_each_bvec_all(bvec, bio, i) |
| bio_size += bvec->bv_len; |
| |
| /* |
| * Since we can have multiple bios touching the error_bitmap, we cannot |
| * call bitmap_set() without protection. |
| * |
| * Instead use set_bit() for each bit, as set_bit() itself is atomic. |
| */ |
| for (i = total_sector_nr; i < total_sector_nr + |
| (bio_size >> rbio->bioc->fs_info->sectorsize_bits); i++) |
| set_bit(i, rbio->error_bitmap); |
| } |
| |
| /* Verify the data sectors at read time. */ |
| static void verify_bio_data_sectors(struct btrfs_raid_bio *rbio, |
| struct bio *bio) |
| { |
| struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| int total_sector_nr = get_bio_sector_nr(rbio, bio); |
| struct bio_vec *bvec; |
| struct bvec_iter_all iter_all; |
| |
| /* No data csum for the whole stripe, no need to verify. */ |
| if (!rbio->csum_bitmap || !rbio->csum_buf) |
| return; |
| |
| /* P/Q stripes, they have no data csum to verify against. */ |
| if (total_sector_nr >= rbio->nr_data * rbio->stripe_nsectors) |
| return; |
| |
| bio_for_each_segment_all(bvec, bio, iter_all) { |
| int bv_offset; |
| |
| for (bv_offset = bvec->bv_offset; |
| bv_offset < bvec->bv_offset + bvec->bv_len; |
| bv_offset += fs_info->sectorsize, total_sector_nr++) { |
| u8 csum_buf[BTRFS_CSUM_SIZE]; |
| u8 *expected_csum = rbio->csum_buf + |
| total_sector_nr * fs_info->csum_size; |
| int ret; |
| |
| /* No csum for this sector, skip to the next sector. */ |
| if (!test_bit(total_sector_nr, rbio->csum_bitmap)) |
| continue; |
| |
| ret = btrfs_check_sector_csum(fs_info, bvec->bv_page, |
| bv_offset, csum_buf, expected_csum); |
| if (ret < 0) |
| set_bit(total_sector_nr, rbio->error_bitmap); |
| } |
| } |
| } |
| |
| static void raid_wait_read_end_io(struct bio *bio) |
| { |
| struct btrfs_raid_bio *rbio = bio->bi_private; |
| |
| if (bio->bi_status) { |
| rbio_update_error_bitmap(rbio, bio); |
| } else { |
| set_bio_pages_uptodate(rbio, bio); |
| verify_bio_data_sectors(rbio, bio); |
| } |
| |
| bio_put(bio); |
| if (atomic_dec_and_test(&rbio->stripes_pending)) |
| wake_up(&rbio->io_wait); |
| } |
| |
| static void submit_read_wait_bio_list(struct btrfs_raid_bio *rbio, |
| struct bio_list *bio_list) |
| { |
| struct bio *bio; |
| |
| atomic_set(&rbio->stripes_pending, bio_list_size(bio_list)); |
| while ((bio = bio_list_pop(bio_list))) { |
| bio->bi_end_io = raid_wait_read_end_io; |
| |
| if (trace_raid56_scrub_read_recover_enabled()) { |
| struct raid56_bio_trace_info trace_info = { 0 }; |
| |
| bio_get_trace_info(rbio, bio, &trace_info); |
| trace_raid56_scrub_read_recover(rbio, bio, &trace_info); |
| } |
| submit_bio(bio); |
| } |
| |
| wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0); |
| } |
| |
| static int alloc_rbio_data_pages(struct btrfs_raid_bio *rbio) |
| { |
| const int data_pages = rbio->nr_data * rbio->stripe_npages; |
| int ret; |
| |
| ret = btrfs_alloc_page_array(data_pages, rbio->stripe_pages); |
| if (ret < 0) |
| return ret; |
| |
| index_stripe_sectors(rbio); |
| return 0; |
| } |
| |
| /* |
| * We use plugging call backs to collect full stripes. |
| * Any time we get a partial stripe write while plugged |
| * we collect it into a list. When the unplug comes down, |
| * we sort the list by logical block number and merge |
| * everything we can into the same rbios |
| */ |
| struct btrfs_plug_cb { |
| struct blk_plug_cb cb; |
| struct btrfs_fs_info *info; |
| struct list_head rbio_list; |
| struct work_struct work; |
| }; |
| |
| /* |
| * rbios on the plug list are sorted for easier merging. |
| */ |
| static int plug_cmp(void *priv, const struct list_head *a, |
| const struct list_head *b) |
| { |
| const struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio, |
| plug_list); |
| const struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio, |
| plug_list); |
| u64 a_sector = ra->bio_list.head->bi_iter.bi_sector; |
| u64 b_sector = rb->bio_list.head->bi_iter.bi_sector; |
| |
| if (a_sector < b_sector) |
| return -1; |
| if (a_sector > b_sector) |
| return 1; |
| return 0; |
| } |
| |
| static void raid_unplug(struct blk_plug_cb *cb, bool from_schedule) |
| { |
| struct btrfs_plug_cb *plug = container_of(cb, struct btrfs_plug_cb, cb); |
| struct btrfs_raid_bio *cur; |
| struct btrfs_raid_bio *last = NULL; |
| |
| list_sort(NULL, &plug->rbio_list, plug_cmp); |
| |
| while (!list_empty(&plug->rbio_list)) { |
| cur = list_entry(plug->rbio_list.next, |
| struct btrfs_raid_bio, plug_list); |
| list_del_init(&cur->plug_list); |
| |
| if (rbio_is_full(cur)) { |
| /* We have a full stripe, queue it down. */ |
| start_async_work(cur, rmw_rbio_work); |
| continue; |
| } |
| if (last) { |
| if (rbio_can_merge(last, cur)) { |
| merge_rbio(last, cur); |
| free_raid_bio(cur); |
| continue; |
| } |
| start_async_work(last, rmw_rbio_work); |
| } |
| last = cur; |
| } |
| if (last) |
| start_async_work(last, rmw_rbio_work); |
| kfree(plug); |
| } |
| |
| /* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */ |
| static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio) |
| { |
| const struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT; |
| const u64 full_stripe_start = rbio->bioc->full_stripe_logical; |
| const u32 orig_len = orig_bio->bi_iter.bi_size; |
| const u32 sectorsize = fs_info->sectorsize; |
| u64 cur_logical; |
| |
| ASSERT(orig_logical >= full_stripe_start && |
| orig_logical + orig_len <= full_stripe_start + |
| rbio->nr_data * BTRFS_STRIPE_LEN); |
| |
| bio_list_add(&rbio->bio_list, orig_bio); |
| rbio->bio_list_bytes += orig_bio->bi_iter.bi_size; |
| |
| /* Update the dbitmap. */ |
| for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len; |
| cur_logical += sectorsize) { |
| int bit = ((u32)(cur_logical - full_stripe_start) >> |
| fs_info->sectorsize_bits) % rbio->stripe_nsectors; |
| |
| set_bit(bit, &rbio->dbitmap); |
| } |
| } |
| |
| /* |
| * our main entry point for writes from the rest of the FS. |
| */ |
| void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) |
| { |
| struct btrfs_fs_info *fs_info = bioc->fs_info; |
| struct btrfs_raid_bio *rbio; |
| struct btrfs_plug_cb *plug = NULL; |
| struct blk_plug_cb *cb; |
| |
| rbio = alloc_rbio(fs_info, bioc); |
| if (IS_ERR(rbio)) { |
| bio->bi_status = errno_to_blk_status(PTR_ERR(rbio)); |
| bio_endio(bio); |
| return; |
| } |
| rbio->operation = BTRFS_RBIO_WRITE; |
| rbio_add_bio(rbio, bio); |
| |
| /* |
| * Don't plug on full rbios, just get them out the door |
| * as quickly as we can |
| */ |
| if (!rbio_is_full(rbio)) { |
| cb = blk_check_plugged(raid_unplug, fs_info, sizeof(*plug)); |
| if (cb) { |
| plug = container_of(cb, struct btrfs_plug_cb, cb); |
| if (!plug->info) { |
| plug->info = fs_info; |
| INIT_LIST_HEAD(&plug->rbio_list); |
| } |
| list_add_tail(&rbio->plug_list, &plug->rbio_list); |
| return; |
| } |
| } |
| |
| /* |
| * Either we don't have any existing plug, or we're doing a full stripe, |
| * queue the rmw work now. |
| */ |
| start_async_work(rbio, rmw_rbio_work); |
| } |
| |
| static int verify_one_sector(struct btrfs_raid_bio *rbio, |
| int stripe_nr, int sector_nr) |
| { |
| struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| struct sector_ptr *sector; |
| u8 csum_buf[BTRFS_CSUM_SIZE]; |
| u8 *csum_expected; |
| int ret; |
| |
| if (!rbio->csum_bitmap || !rbio->csum_buf) |
| return 0; |
| |
| /* No way to verify P/Q as they are not covered by data csum. */ |
| if (stripe_nr >= rbio->nr_data) |
| return 0; |
| /* |
| * If we're rebuilding a read, we have to use pages from the |
| * bio list if possible. |
| */ |
| if ((rbio->operation == BTRFS_RBIO_READ_REBUILD || |
| rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) { |
| sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0); |
| } else { |
| sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr); |
| } |
| |
| ASSERT(sector->page); |
| |
| csum_expected = rbio->csum_buf + |
| (stripe_nr * rbio->stripe_nsectors + sector_nr) * |
| fs_info->csum_size; |
| ret = btrfs_check_sector_csum(fs_info, sector->page, sector->pgoff, |
| csum_buf, csum_expected); |
| return ret; |
| } |
| |
| /* |
| * Recover a vertical stripe specified by @sector_nr. |
| * @*pointers are the pre-allocated pointers by the caller, so we don't |
| * need to allocate/free the pointers again and again. |
| */ |
| static int recover_vertical(struct btrfs_raid_bio *rbio, int sector_nr, |
| void **pointers, void **unmap_array) |
| { |
| struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| struct sector_ptr *sector; |
| const u32 sectorsize = fs_info->sectorsize; |
| int found_errors; |
| int faila; |
| int failb; |
| int stripe_nr; |
| int ret = 0; |
| |
| /* |
| * Now we just use bitmap to mark the horizontal stripes in |
| * which we have data when doing parity scrub. |
| */ |
| if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB && |
| !test_bit(sector_nr, &rbio->dbitmap)) |
| return 0; |
| |
| found_errors = get_rbio_veritical_errors(rbio, sector_nr, &faila, |
| &failb); |
| /* |
| * No errors in the vertical stripe, skip it. Can happen for recovery |
| * which only part of a stripe failed csum check. |
| */ |
| if (!found_errors) |
| return 0; |
| |
| if (found_errors > rbio->bioc->max_errors) |
| return -EIO; |
| |
| /* |
| * Setup our array of pointers with sectors from each stripe |
| * |
| * NOTE: store a duplicate array of pointers to preserve the |
| * pointer order. |
| */ |
| for (stripe_nr = 0; stripe_nr < rbio->real_stripes; stripe_nr++) { |
| /* |
| * If we're rebuilding a read, we have to use pages from the |
| * bio list if possible. |
| */ |
| if ((rbio->operation == BTRFS_RBIO_READ_REBUILD || |
| rbio->operation == BTRFS_RBIO_REBUILD_MISSING)) { |
| sector = sector_in_rbio(rbio, stripe_nr, sector_nr, 0); |
| } else { |
| sector = rbio_stripe_sector(rbio, stripe_nr, sector_nr); |
| } |
| ASSERT(sector->page); |
| pointers[stripe_nr] = kmap_local_page(sector->page) + |
| sector->pgoff; |
| unmap_array[stripe_nr] = pointers[stripe_nr]; |
| } |
| |
| /* All raid6 handling here */ |
| if (rbio->bioc->map_type & BTRFS_BLOCK_GROUP_RAID6) { |
| /* Single failure, rebuild from parity raid5 style */ |
| if (failb < 0) { |
| if (faila == rbio->nr_data) |
| /* |
| * Just the P stripe has failed, without |
| * a bad data or Q stripe. |
| * We have nothing to do, just skip the |
| * recovery for this stripe. |
| */ |
| goto cleanup; |
| /* |
| * a single failure in raid6 is rebuilt |
| * in the pstripe code below |
| */ |
| goto pstripe; |
| } |
| |
| /* |
| * If the q stripe is failed, do a pstripe reconstruction from |
| * the xors. |
| * If both the q stripe and the P stripe are failed, we're |
| * here due to a crc mismatch and we can't give them the |
| * data they want. |
| */ |
| if (failb == rbio->real_stripes - 1) { |
| if (faila == rbio->real_stripes - 2) |
| /* |
| * Only P and Q are corrupted. |
| * We only care about data stripes recovery, |
| * can skip this vertical stripe. |
| */ |
| goto cleanup; |
| /* |
| * Otherwise we have one bad data stripe and |
| * a good P stripe. raid5! |
| */ |
| goto pstripe; |
| } |
| |
| if (failb == rbio->real_stripes - 2) { |
| raid6_datap_recov(rbio->real_stripes, sectorsize, |
| faila, pointers); |
| } else { |
| raid6_2data_recov(rbio->real_stripes, sectorsize, |
| faila, failb, pointers); |
| } |
| } else { |
| void *p; |
| |
| /* Rebuild from P stripe here (raid5 or raid6). */ |
| ASSERT(failb == -1); |
| pstripe: |
| /* Copy parity block into failed block to start with */ |
| memcpy(pointers[faila], pointers[rbio->nr_data], sectorsize); |
| |
| /* Rearrange the pointer array */ |
| p = pointers[faila]; |
| for (stripe_nr = faila; stripe_nr < rbio->nr_data - 1; |
| stripe_nr++) |
| pointers[stripe_nr] = pointers[stripe_nr + 1]; |
| pointers[rbio->nr_data - 1] = p; |
| |
| /* Xor in the rest */ |
| run_xor(pointers, rbio->nr_data - 1, sectorsize); |
| |
| } |
| |
| /* |
| * No matter if this is a RMW or recovery, we should have all |
| * failed sectors repaired in the vertical stripe, thus they are now |
| * uptodate. |
| * Especially if we determine to cache the rbio, we need to |
| * have at least all data sectors uptodate. |
| * |
| * If possible, also check if the repaired sector matches its data |
| * checksum. |
| */ |
| if (faila >= 0) { |
| ret = verify_one_sector(rbio, faila, sector_nr); |
| if (ret < 0) |
| goto cleanup; |
| |
| sector = rbio_stripe_sector(rbio, faila, sector_nr); |
| sector->uptodate = 1; |
| } |
| if (failb >= 0) { |
| ret = verify_one_sector(rbio, failb, sector_nr); |
| if (ret < 0) |
| goto cleanup; |
| |
| sector = rbio_stripe_sector(rbio, failb, sector_nr); |
| sector->uptodate = 1; |
| } |
| |
| cleanup: |
| for (stripe_nr = rbio->real_stripes - 1; stripe_nr >= 0; stripe_nr--) |
| kunmap_local(unmap_array[stripe_nr]); |
| return ret; |
| } |
| |
| static int recover_sectors(struct btrfs_raid_bio *rbio) |
| { |
| void **pointers = NULL; |
| void **unmap_array = NULL; |
| int sectornr; |
| int ret = 0; |
| |
| /* |
| * @pointers array stores the pointer for each sector. |
| * |
| * @unmap_array stores copy of pointers that does not get reordered |
| * during reconstruction so that kunmap_local works. |
| */ |
| pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS); |
| unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS); |
| if (!pointers || !unmap_array) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| if (rbio->operation == BTRFS_RBIO_READ_REBUILD || |
| rbio->operation == BTRFS_RBIO_REBUILD_MISSING) { |
| spin_lock(&rbio->bio_list_lock); |
| set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
| spin_unlock(&rbio->bio_list_lock); |
| } |
| |
| index_rbio_pages(rbio); |
| |
| for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) { |
| ret = recover_vertical(rbio, sectornr, pointers, unmap_array); |
| if (ret < 0) |
| break; |
| } |
| |
| out: |
| kfree(pointers); |
| kfree(unmap_array); |
| return ret; |
| } |
| |
| static void recover_rbio(struct btrfs_raid_bio *rbio) |
| { |
| struct bio_list bio_list = BIO_EMPTY_LIST; |
| int total_sector_nr; |
| int ret = 0; |
| |
| /* |
| * Either we're doing recover for a read failure or degraded write, |
| * caller should have set error bitmap correctly. |
| */ |
| ASSERT(bitmap_weight(rbio->error_bitmap, rbio->nr_sectors)); |
| |
| /* For recovery, we need to read all sectors including P/Q. */ |
| ret = alloc_rbio_pages(rbio); |
| if (ret < 0) |
| goto out; |
| |
| index_rbio_pages(rbio); |
| |
| /* |
| * Read everything that hasn't failed. However this time we will |
| * not trust any cached sector. |
| * As we may read out some stale data but higher layer is not reading |
| * that stale part. |
| * |
| * So here we always re-read everything in recovery path. |
| */ |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| int stripe = total_sector_nr / rbio->stripe_nsectors; |
| int sectornr = total_sector_nr % rbio->stripe_nsectors; |
| struct sector_ptr *sector; |
| |
| /* |
| * Skip the range which has error. It can be a range which is |
| * marked error (for csum mismatch), or it can be a missing |
| * device. |
| */ |
| if (!rbio->bioc->stripes[stripe].dev->bdev || |
| test_bit(total_sector_nr, rbio->error_bitmap)) { |
| /* |
| * Also set the error bit for missing device, which |
| * may not yet have its error bit set. |
| */ |
| set_bit(total_sector_nr, rbio->error_bitmap); |
| continue; |
| } |
| |
| sector = rbio_stripe_sector(rbio, stripe, sectornr); |
| ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe, |
| sectornr, REQ_OP_READ); |
| if (ret < 0) { |
| bio_list_put(&bio_list); |
| goto out; |
| } |
| } |
| |
| submit_read_wait_bio_list(rbio, &bio_list); |
| ret = recover_sectors(rbio); |
| out: |
| rbio_orig_end_io(rbio, errno_to_blk_status(ret)); |
| } |
| |
| static void recover_rbio_work(struct work_struct *work) |
| { |
| struct btrfs_raid_bio *rbio; |
| |
| rbio = container_of(work, struct btrfs_raid_bio, work); |
| if (!lock_stripe_add(rbio)) |
| recover_rbio(rbio); |
| } |
| |
| static void recover_rbio_work_locked(struct work_struct *work) |
| { |
| recover_rbio(container_of(work, struct btrfs_raid_bio, work)); |
| } |
| |
| static void set_rbio_raid6_extra_error(struct btrfs_raid_bio *rbio, int mirror_num) |
| { |
| bool found = false; |
| int sector_nr; |
| |
| /* |
| * This is for RAID6 extra recovery tries, thus mirror number should |
| * be large than 2. |
| * Mirror 1 means read from data stripes. Mirror 2 means rebuild using |
| * RAID5 methods. |
| */ |
| ASSERT(mirror_num > 2); |
| for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) { |
| int found_errors; |
| int faila; |
| int failb; |
| |
| found_errors = get_rbio_veritical_errors(rbio, sector_nr, |
| &faila, &failb); |
| /* This vertical stripe doesn't have errors. */ |
| if (!found_errors) |
| continue; |
| |
| /* |
| * If we found errors, there should be only one error marked |
| * by previous set_rbio_range_error(). |
| */ |
| ASSERT(found_errors == 1); |
| found = true; |
| |
| /* Now select another stripe to mark as error. */ |
| failb = rbio->real_stripes - (mirror_num - 1); |
| if (failb <= faila) |
| failb--; |
| |
| /* Set the extra bit in error bitmap. */ |
| if (failb >= 0) |
| set_bit(failb * rbio->stripe_nsectors + sector_nr, |
| rbio->error_bitmap); |
| } |
| |
| /* We should found at least one vertical stripe with error.*/ |
| ASSERT(found); |
| } |
| |
| /* |
| * the main entry point for reads from the higher layers. This |
| * is really only called when the normal read path had a failure, |
| * so we assume the bio they send down corresponds to a failed part |
| * of the drive. |
| */ |
| void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, |
| int mirror_num) |
| { |
| struct btrfs_fs_info *fs_info = bioc->fs_info; |
| struct btrfs_raid_bio *rbio; |
| |
| rbio = alloc_rbio(fs_info, bioc); |
| if (IS_ERR(rbio)) { |
| bio->bi_status = errno_to_blk_status(PTR_ERR(rbio)); |
| bio_endio(bio); |
| return; |
| } |
| |
| rbio->operation = BTRFS_RBIO_READ_REBUILD; |
| rbio_add_bio(rbio, bio); |
| |
| set_rbio_range_error(rbio, bio); |
| |
| /* |
| * Loop retry: |
| * for 'mirror == 2', reconstruct from all other stripes. |
| * for 'mirror_num > 2', select a stripe to fail on every retry. |
| */ |
| if (mirror_num > 2) |
| set_rbio_raid6_extra_error(rbio, mirror_num); |
| |
| start_async_work(rbio, recover_rbio_work); |
| } |
| |
| static void fill_data_csums(struct btrfs_raid_bio *rbio) |
| { |
| struct btrfs_fs_info *fs_info = rbio->bioc->fs_info; |
| struct btrfs_root *csum_root = btrfs_csum_root(fs_info, |
| rbio->bioc->full_stripe_logical); |
| const u64 start = rbio->bioc->full_stripe_logical; |
| const u32 len = (rbio->nr_data * rbio->stripe_nsectors) << |
| fs_info->sectorsize_bits; |
| int ret; |
| |
| /* The rbio should not have its csum buffer initialized. */ |
| ASSERT(!rbio->csum_buf && !rbio->csum_bitmap); |
| |
| /* |
| * Skip the csum search if: |
| * |
| * - The rbio doesn't belong to data block groups |
| * Then we are doing IO for tree blocks, no need to search csums. |
| * |
| * - The rbio belongs to mixed block groups |
| * This is to avoid deadlock, as we're already holding the full |
| * stripe lock, if we trigger a metadata read, and it needs to do |
| * raid56 recovery, we will deadlock. |
| */ |
| if (!(rbio->bioc->map_type & BTRFS_BLOCK_GROUP_DATA) || |
| rbio->bioc->map_type & BTRFS_BLOCK_GROUP_METADATA) |
| return; |
| |
| rbio->csum_buf = kzalloc(rbio->nr_data * rbio->stripe_nsectors * |
| fs_info->csum_size, GFP_NOFS); |
| rbio->csum_bitmap = bitmap_zalloc(rbio->nr_data * rbio->stripe_nsectors, |
| GFP_NOFS); |
| if (!rbio->csum_buf || !rbio->csum_bitmap) { |
| ret = -ENOMEM; |
| goto error; |
| } |
| |
| ret = btrfs_lookup_csums_bitmap(csum_root, start, start + len - 1, |
| rbio->csum_buf, rbio->csum_bitmap, false); |
| if (ret < 0) |
| goto error; |
| if (bitmap_empty(rbio->csum_bitmap, len >> fs_info->sectorsize_bits)) |
| goto no_csum; |
| return; |
| |
| error: |
| /* |
| * We failed to allocate memory or grab the csum, but it's not fatal, |
| * we can still continue. But better to warn users that RMW is no |
| * longer safe for this particular sub-stripe write. |
| */ |
| btrfs_warn_rl(fs_info, |
| "sub-stripe write for full stripe %llu is not safe, failed to get csum: %d", |
| rbio->bioc->full_stripe_logical, ret); |
| no_csum: |
| kfree(rbio->csum_buf); |
| bitmap_free(rbio->csum_bitmap); |
| rbio->csum_buf = NULL; |
| rbio->csum_bitmap = NULL; |
| } |
| |
| static int rmw_read_wait_recover(struct btrfs_raid_bio *rbio) |
| { |
| struct bio_list bio_list = BIO_EMPTY_LIST; |
| int total_sector_nr; |
| int ret = 0; |
| |
| /* |
| * Fill the data csums we need for data verification. We need to fill |
| * the csum_bitmap/csum_buf first, as our endio function will try to |
| * verify the data sectors. |
| */ |
| fill_data_csums(rbio); |
| |
| /* |
| * Build a list of bios to read all sectors (including data and P/Q). |
| * |
| * This behavior is to compensate the later csum verification and recovery. |
| */ |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| struct sector_ptr *sector; |
| int stripe = total_sector_nr / rbio->stripe_nsectors; |
| int sectornr = total_sector_nr % rbio->stripe_nsectors; |
| |
| sector = rbio_stripe_sector(rbio, stripe, sectornr); |
| ret = rbio_add_io_sector(rbio, &bio_list, sector, |
| stripe, sectornr, REQ_OP_READ); |
| if (ret) { |
| bio_list_put(&bio_list); |
| return ret; |
| } |
| } |
| |
| /* |
| * We may or may not have any corrupted sectors (including missing dev |
| * and csum mismatch), just let recover_sectors() to handle them all. |
| */ |
| submit_read_wait_bio_list(rbio, &bio_list); |
| return recover_sectors(rbio); |
| } |
| |
| static void raid_wait_write_end_io(struct bio *bio) |
| { |
| struct btrfs_raid_bio *rbio = bio->bi_private; |
| blk_status_t err = bio->bi_status; |
| |
| if (err) |
| rbio_update_error_bitmap(rbio, bio); |
| bio_put(bio); |
| if (atomic_dec_and_test(&rbio->stripes_pending)) |
| wake_up(&rbio->io_wait); |
| } |
| |
| static void submit_write_bios(struct btrfs_raid_bio *rbio, |
| struct bio_list *bio_list) |
| { |
| struct bio *bio; |
| |
| atomic_set(&rbio->stripes_pending, bio_list_size(bio_list)); |
| while ((bio = bio_list_pop(bio_list))) { |
| bio->bi_end_io = raid_wait_write_end_io; |
| |
| if (trace_raid56_write_stripe_enabled()) { |
| struct raid56_bio_trace_info trace_info = { 0 }; |
| |
| bio_get_trace_info(rbio, bio, &trace_info); |
| trace_raid56_write_stripe(rbio, bio, &trace_info); |
| } |
| submit_bio(bio); |
| } |
| } |
| |
| /* |
| * To determine if we need to read any sector from the disk. |
| * Should only be utilized in RMW path, to skip cached rbio. |
| */ |
| static bool need_read_stripe_sectors(struct btrfs_raid_bio *rbio) |
| { |
| int i; |
| |
| for (i = 0; i < rbio->nr_data * rbio->stripe_nsectors; i++) { |
| struct sector_ptr *sector = &rbio->stripe_sectors[i]; |
| |
| /* |
| * We have a sector which doesn't have page nor uptodate, |
| * thus this rbio can not be cached one, as cached one must |
| * have all its data sectors present and uptodate. |
| */ |
| if (!sector->page || !sector->uptodate) |
| return true; |
| } |
| return false; |
| } |
| |
| static void rmw_rbio(struct btrfs_raid_bio *rbio) |
| { |
| struct bio_list bio_list; |
| int sectornr; |
| int ret = 0; |
| |
| /* |
| * Allocate the pages for parity first, as P/Q pages will always be |
| * needed for both full-stripe and sub-stripe writes. |
| */ |
| ret = alloc_rbio_parity_pages(rbio); |
| if (ret < 0) |
| goto out; |
| |
| /* |
| * Either full stripe write, or we have every data sector already |
| * cached, can go to write path immediately. |
| */ |
| if (!rbio_is_full(rbio) && need_read_stripe_sectors(rbio)) { |
| /* |
| * Now we're doing sub-stripe write, also need all data stripes |
| * to do the full RMW. |
| */ |
| ret = alloc_rbio_data_pages(rbio); |
| if (ret < 0) |
| goto out; |
| |
| index_rbio_pages(rbio); |
| |
| ret = rmw_read_wait_recover(rbio); |
| if (ret < 0) |
| goto out; |
| } |
| |
| /* |
| * At this stage we're not allowed to add any new bios to the |
| * bio list any more, anyone else that wants to change this stripe |
| * needs to do their own rmw. |
| */ |
| spin_lock(&rbio->bio_list_lock); |
| set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags); |
| spin_unlock(&rbio->bio_list_lock); |
| |
| bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors); |
| |
| index_rbio_pages(rbio); |
| |
| /* |
| * We don't cache full rbios because we're assuming |
| * the higher layers are unlikely to use this area of |
| * the disk again soon. If they do use it again, |
| * hopefully they will send another full bio. |
| */ |
| if (!rbio_is_full(rbio)) |
| cache_rbio_pages(rbio); |
| else |
| clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
| |
| for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) |
| generate_pq_vertical(rbio, sectornr); |
| |
| bio_list_init(&bio_list); |
| ret = rmw_assemble_write_bios(rbio, &bio_list); |
| if (ret < 0) |
| goto out; |
| |
| /* We should have at least one bio assembled. */ |
| ASSERT(bio_list_size(&bio_list)); |
| submit_write_bios(rbio, &bio_list); |
| wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0); |
| |
| /* We may have more errors than our tolerance during the read. */ |
| for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++) { |
| int found_errors; |
| |
| found_errors = get_rbio_veritical_errors(rbio, sectornr, NULL, NULL); |
| if (found_errors > rbio->bioc->max_errors) { |
| ret = -EIO; |
| break; |
| } |
| } |
| out: |
| rbio_orig_end_io(rbio, errno_to_blk_status(ret)); |
| } |
| |
| static void rmw_rbio_work(struct work_struct *work) |
| { |
| struct btrfs_raid_bio *rbio; |
| |
| rbio = container_of(work, struct btrfs_raid_bio, work); |
| if (lock_stripe_add(rbio) == 0) |
| rmw_rbio(rbio); |
| } |
| |
| static void rmw_rbio_work_locked(struct work_struct *work) |
| { |
| rmw_rbio(container_of(work, struct btrfs_raid_bio, work)); |
| } |
| |
| /* |
| * The following code is used to scrub/replace the parity stripe |
| * |
| * Caller must have already increased bio_counter for getting @bioc. |
| * |
| * Note: We need make sure all the pages that add into the scrub/replace |
| * raid bio are correct and not be changed during the scrub/replace. That |
| * is those pages just hold metadata or file data with checksum. |
| */ |
| |
| struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio, |
| struct btrfs_io_context *bioc, |
| struct btrfs_device *scrub_dev, |
| unsigned long *dbitmap, int stripe_nsectors) |
| { |
| struct btrfs_fs_info *fs_info = bioc->fs_info; |
| struct btrfs_raid_bio *rbio; |
| int i; |
| |
| rbio = alloc_rbio(fs_info, bioc); |
| if (IS_ERR(rbio)) |
| return NULL; |
| bio_list_add(&rbio->bio_list, bio); |
| /* |
| * This is a special bio which is used to hold the completion handler |
| * and make the scrub rbio is similar to the other types |
| */ |
| ASSERT(!bio->bi_iter.bi_size); |
| rbio->operation = BTRFS_RBIO_PARITY_SCRUB; |
| |
| /* |
| * After mapping bioc with BTRFS_MAP_WRITE, parities have been sorted |
| * to the end position, so this search can start from the first parity |
| * stripe. |
| */ |
| for (i = rbio->nr_data; i < rbio->real_stripes; i++) { |
| if (bioc->stripes[i].dev == scrub_dev) { |
| rbio->scrubp = i; |
| break; |
| } |
| } |
| ASSERT(i < rbio->real_stripes); |
| |
| bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors); |
| return rbio; |
| } |
| |
| /* |
| * We just scrub the parity that we have correct data on the same horizontal, |
| * so we needn't allocate all pages for all the stripes. |
| */ |
| static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio) |
| { |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| int total_sector_nr; |
| |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| struct page *page; |
| int sectornr = total_sector_nr % rbio->stripe_nsectors; |
| int index = (total_sector_nr * sectorsize) >> PAGE_SHIFT; |
| |
| if (!test_bit(sectornr, &rbio->dbitmap)) |
| continue; |
| if (rbio->stripe_pages[index]) |
| continue; |
| page = alloc_page(GFP_NOFS); |
| if (!page) |
| return -ENOMEM; |
| rbio->stripe_pages[index] = page; |
| } |
| index_stripe_sectors(rbio); |
| return 0; |
| } |
| |
| static int finish_parity_scrub(struct btrfs_raid_bio *rbio, int need_check) |
| { |
| struct btrfs_io_context *bioc = rbio->bioc; |
| const u32 sectorsize = bioc->fs_info->sectorsize; |
| void **pointers = rbio->finish_pointers; |
| unsigned long *pbitmap = &rbio->finish_pbitmap; |
| int nr_data = rbio->nr_data; |
| int stripe; |
| int sectornr; |
| bool has_qstripe; |
| struct sector_ptr p_sector = { 0 }; |
| struct sector_ptr q_sector = { 0 }; |
| struct bio_list bio_list; |
| int is_replace = 0; |
| int ret; |
| |
| bio_list_init(&bio_list); |
| |
| if (rbio->real_stripes - rbio->nr_data == 1) |
| has_qstripe = false; |
| else if (rbio->real_stripes - rbio->nr_data == 2) |
| has_qstripe = true; |
| else |
| BUG(); |
| |
| /* |
| * Replace is running and our P/Q stripe is being replaced, then we |
| * need to duplicate the final write to replace target. |
| */ |
| if (bioc->replace_nr_stripes && bioc->replace_stripe_src == rbio->scrubp) { |
| is_replace = 1; |
| bitmap_copy(pbitmap, &rbio->dbitmap, rbio->stripe_nsectors); |
| } |
| |
| /* |
| * Because the higher layers(scrubber) are unlikely to |
| * use this area of the disk again soon, so don't cache |
| * it. |
| */ |
| clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); |
| |
| if (!need_check) |
| goto writeback; |
| |
| p_sector.page = alloc_page(GFP_NOFS); |
| if (!p_sector.page) |
| return -ENOMEM; |
| p_sector.pgoff = 0; |
| p_sector.uptodate = 1; |
| |
| if (has_qstripe) { |
| /* RAID6, allocate and map temp space for the Q stripe */ |
| q_sector.page = alloc_page(GFP_NOFS); |
| if (!q_sector.page) { |
| __free_page(p_sector.page); |
| p_sector.page = NULL; |
| return -ENOMEM; |
| } |
| q_sector.pgoff = 0; |
| q_sector.uptodate = 1; |
| pointers[rbio->real_stripes - 1] = kmap_local_page(q_sector.page); |
| } |
| |
| bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors); |
| |
| /* Map the parity stripe just once */ |
| pointers[nr_data] = kmap_local_page(p_sector.page); |
| |
| for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) { |
| struct sector_ptr *sector; |
| void *parity; |
| |
| /* first collect one page from each data stripe */ |
| for (stripe = 0; stripe < nr_data; stripe++) { |
| sector = sector_in_rbio(rbio, stripe, sectornr, 0); |
| pointers[stripe] = kmap_local_page(sector->page) + |
| sector->pgoff; |
| } |
| |
| if (has_qstripe) { |
| /* RAID6, call the library function to fill in our P/Q */ |
| raid6_call.gen_syndrome(rbio->real_stripes, sectorsize, |
| pointers); |
| } else { |
| /* raid5 */ |
| memcpy(pointers[nr_data], pointers[0], sectorsize); |
| run_xor(pointers + 1, nr_data - 1, sectorsize); |
| } |
| |
| /* Check scrubbing parity and repair it */ |
| sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr); |
| parity = kmap_local_page(sector->page) + sector->pgoff; |
| if (memcmp(parity, pointers[rbio->scrubp], sectorsize) != 0) |
| memcpy(parity, pointers[rbio->scrubp], sectorsize); |
| else |
| /* Parity is right, needn't writeback */ |
| bitmap_clear(&rbio->dbitmap, sectornr, 1); |
| kunmap_local(parity); |
| |
| for (stripe = nr_data - 1; stripe >= 0; stripe--) |
| kunmap_local(pointers[stripe]); |
| } |
| |
| kunmap_local(pointers[nr_data]); |
| __free_page(p_sector.page); |
| p_sector.page = NULL; |
| if (q_sector.page) { |
| kunmap_local(pointers[rbio->real_stripes - 1]); |
| __free_page(q_sector.page); |
| q_sector.page = NULL; |
| } |
| |
| writeback: |
| /* |
| * time to start writing. Make bios for everything from the |
| * higher layers (the bio_list in our rbio) and our p/q. Ignore |
| * everything else. |
| */ |
| for_each_set_bit(sectornr, &rbio->dbitmap, rbio->stripe_nsectors) { |
| struct sector_ptr *sector; |
| |
| sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr); |
| ret = rbio_add_io_sector(rbio, &bio_list, sector, rbio->scrubp, |
| sectornr, REQ_OP_WRITE); |
| if (ret) |
| goto cleanup; |
| } |
| |
| if (!is_replace) |
| goto submit_write; |
| |
| /* |
| * Replace is running and our parity stripe needs to be duplicated to |
| * the target device. Check we have a valid source stripe number. |
| */ |
| ASSERT(rbio->bioc->replace_stripe_src >= 0); |
| for_each_set_bit(sectornr, pbitmap, rbio->stripe_nsectors) { |
| struct sector_ptr *sector; |
| |
| sector = rbio_stripe_sector(rbio, rbio->scrubp, sectornr); |
| ret = rbio_add_io_sector(rbio, &bio_list, sector, |
| rbio->real_stripes, |
| sectornr, REQ_OP_WRITE); |
| if (ret) |
| goto cleanup; |
| } |
| |
| submit_write: |
| submit_write_bios(rbio, &bio_list); |
| return 0; |
| |
| cleanup: |
| bio_list_put(&bio_list); |
| return ret; |
| } |
| |
| static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe) |
| { |
| if (stripe >= 0 && stripe < rbio->nr_data) |
| return 1; |
| return 0; |
| } |
| |
| static int recover_scrub_rbio(struct btrfs_raid_bio *rbio) |
| { |
| void **pointers = NULL; |
| void **unmap_array = NULL; |
| int sector_nr; |
| int ret = 0; |
| |
| /* |
| * @pointers array stores the pointer for each sector. |
| * |
| * @unmap_array stores copy of pointers that does not get reordered |
| * during reconstruction so that kunmap_local works. |
| */ |
| pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS); |
| unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS); |
| if (!pointers || !unmap_array) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) { |
| int dfail = 0, failp = -1; |
| int faila; |
| int failb; |
| int found_errors; |
| |
| found_errors = get_rbio_veritical_errors(rbio, sector_nr, |
| &faila, &failb); |
| if (found_errors > rbio->bioc->max_errors) { |
| ret = -EIO; |
| goto out; |
| } |
| if (found_errors == 0) |
| continue; |
| |
| /* We should have at least one error here. */ |
| ASSERT(faila >= 0 || failb >= 0); |
| |
| if (is_data_stripe(rbio, faila)) |
| dfail++; |
| else if (is_parity_stripe(faila)) |
| failp = faila; |
| |
| if (is_data_stripe(rbio, failb)) |
| dfail++; |
| else if (is_parity_stripe(failb)) |
| failp = failb; |
| /* |
| * Because we can not use a scrubbing parity to repair the |
| * data, so the capability of the repair is declined. (In the |
| * case of RAID5, we can not repair anything.) |
| */ |
| if (dfail > rbio->bioc->max_errors - 1) { |
| ret = -EIO; |
| goto out; |
| } |
| /* |
| * If all data is good, only parity is correctly, just repair |
| * the parity, no need to recover data stripes. |
| */ |
| if (dfail == 0) |
| continue; |
| |
| /* |
| * Here means we got one corrupted data stripe and one |
| * corrupted parity on RAID6, if the corrupted parity is |
| * scrubbing parity, luckily, use the other one to repair the |
| * data, or we can not repair the data stripe. |
| */ |
| if (failp != rbio->scrubp) { |
| ret = -EIO; |
| goto out; |
| } |
| |
| ret = recover_vertical(rbio, sector_nr, pointers, unmap_array); |
| if (ret < 0) |
| goto out; |
| } |
| out: |
| kfree(pointers); |
| kfree(unmap_array); |
| return ret; |
| } |
| |
| static int scrub_assemble_read_bios(struct btrfs_raid_bio *rbio) |
| { |
| struct bio_list bio_list = BIO_EMPTY_LIST; |
| int total_sector_nr; |
| int ret = 0; |
| |
| /* Build a list of bios to read all the missing parts. */ |
| for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors; |
| total_sector_nr++) { |
| int sectornr = total_sector_nr % rbio->stripe_nsectors; |
| int stripe = total_sector_nr / rbio->stripe_nsectors; |
| struct sector_ptr *sector; |
| |
| /* No data in the vertical stripe, no need to read. */ |
| if (!test_bit(sectornr, &rbio->dbitmap)) |
| continue; |
| |
| /* |
| * We want to find all the sectors missing from the rbio and |
| * read them from the disk. If sector_in_rbio() finds a sector |
| * in the bio list we don't need to read it off the stripe. |
| */ |
| sector = sector_in_rbio(rbio, stripe, sectornr, 1); |
| if (sector) |
| continue; |
| |
| sector = rbio_stripe_sector(rbio, stripe, sectornr); |
| /* |
| * The bio cache may have handed us an uptodate sector. If so, |
| * use it. |
| */ |
| if (sector->uptodate) |
| continue; |
| |
| ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe, |
| sectornr, REQ_OP_READ); |
| if (ret) { |
| bio_list_put(&bio_list); |
| return ret; |
| } |
| } |
| |
| submit_read_wait_bio_list(rbio, &bio_list); |
| return 0; |
| } |
| |
| static void scrub_rbio(struct btrfs_raid_bio *rbio) |
| { |
| bool need_check = false; |
| int sector_nr; |
| int ret; |
| |
| ret = alloc_rbio_essential_pages(rbio); |
| if (ret) |
| goto out; |
| |
| bitmap_clear(rbio->error_bitmap, 0, rbio->nr_sectors); |
| |
| ret = scrub_assemble_read_bios(rbio); |
| if (ret < 0) |
| goto out; |
| |
| /* We may have some failures, recover the failed sectors first. */ |
| ret = recover_scrub_rbio(rbio); |
| if (ret < 0) |
| goto out; |
| |
| /* |
| * We have every sector properly prepared. Can finish the scrub |
| * and writeback the good content. |
| */ |
| ret = finish_parity_scrub(rbio, need_check); |
| wait_event(rbio->io_wait, atomic_read(&rbio->stripes_pending) == 0); |
| for (sector_nr = 0; sector_nr < rbio->stripe_nsectors; sector_nr++) { |
| int found_errors; |
| |
| found_errors = get_rbio_veritical_errors(rbio, sector_nr, NULL, NULL); |
| if (found_errors > rbio->bioc->max_errors) { |
| ret = -EIO; |
| break; |
| } |
| } |
| out: |
| rbio_orig_end_io(rbio, errno_to_blk_status(ret)); |
| } |
| |
| static void scrub_rbio_work_locked(struct work_struct *work) |
| { |
| scrub_rbio(container_of(work, struct btrfs_raid_bio, work)); |
| } |
| |
| void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio) |
| { |
| if (!lock_stripe_add(rbio)) |
| start_async_work(rbio, scrub_rbio_work_locked); |
| } |
| |
| /* |
| * This is for scrub call sites where we already have correct data contents. |
| * This allows us to avoid reading data stripes again. |
| * |
| * Unfortunately here we have to do page copy, other than reusing the pages. |
| * This is due to the fact rbio has its own page management for its cache. |
| */ |
| void raid56_parity_cache_data_pages(struct btrfs_raid_bio *rbio, |
| struct page **data_pages, u64 data_logical) |
| { |
| const u64 offset_in_full_stripe = data_logical - |
| rbio->bioc->full_stripe_logical; |
| const int page_index = offset_in_full_stripe >> PAGE_SHIFT; |
| const u32 sectorsize = rbio->bioc->fs_info->sectorsize; |
| const u32 sectors_per_page = PAGE_SIZE / sectorsize; |
| int ret; |
| |
| /* |
| * If we hit ENOMEM temporarily, but later at |
| * raid56_parity_submit_scrub_rbio() time it succeeded, we just do |
| * the extra read, not a big deal. |
| * |
| * If we hit ENOMEM later at raid56_parity_submit_scrub_rbio() time, |
| * the bio would got proper error number set. |
| */ |
| ret = alloc_rbio_data_pages(rbio); |
| if (ret < 0) |
| return; |
| |
| /* data_logical must be at stripe boundary and inside the full stripe. */ |
| ASSERT(IS_ALIGNED(offset_in_full_stripe, BTRFS_STRIPE_LEN)); |
| ASSERT(offset_in_full_stripe < (rbio->nr_data << BTRFS_STRIPE_LEN_SHIFT)); |
| |
| for (int page_nr = 0; page_nr < (BTRFS_STRIPE_LEN >> PAGE_SHIFT); page_nr++) { |
| struct page *dst = rbio->stripe_pages[page_nr + page_index]; |
| struct page *src = data_pages[page_nr]; |
| |
| memcpy_page(dst, 0, src, 0, PAGE_SIZE); |
| for (int sector_nr = sectors_per_page * page_index; |
| sector_nr < sectors_per_page * (page_index + 1); |
| sector_nr++) |
| rbio->stripe_sectors[sector_nr].uptodate = true; |
| } |
| } |