| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Qu Wenruo | 6350 | 54.75% | 55 | 28.65% |
| David Woodhouse | 2006 | 17.30% | 1 | 0.52% |
| Miao Xie | 1331 | 11.48% | 6 | 3.12% |
| Chris Mason | 889 | 7.67% | 23 | 11.98% |
| Christoph Hellwig | 274 | 2.36% | 25 | 13.02% |
| Liu Bo | 158 | 1.36% | 12 | 6.25% |
| David Sterba | 97 | 0.84% | 12 | 6.25% |
| Omar Sandoval | 93 | 0.80% | 1 | 0.52% |
| Ira Weiny | 75 | 0.65% | 3 | 1.56% |
| Zhao Lei | 47 | 0.41% | 4 | 2.08% |
| Li Dongyang | 36 | 0.31% | 1 | 0.52% |
| Stefan Behrens | 31 | 0.27% | 4 | 2.08% |
| Kees Cook | 27 | 0.23% | 1 | 0.52% |
| Josef Bacik | 25 | 0.22% | 5 | 2.60% |
| Arne Jansen | 23 | 0.20% | 1 | 0.52% |
| Johannes Thumshirn | 22 | 0.19% | 3 | 1.56% |
| Zheng Yan | 16 | 0.14% | 6 | 3.12% |
| Sweet Tea Dorminy | 13 | 0.11% | 1 | 0.52% |
| Nikolay Borisov | 9 | 0.08% | 3 | 1.56% |
| Filipe David Borba Manana | 8 | 0.07% | 1 | 0.52% |
| Elena Reshetova | 7 | 0.06% | 1 | 0.52% |
| Jeff Mahoney | 7 | 0.06% | 2 | 1.04% |
| Kent Overstreet | 6 | 0.05% | 1 | 0.52% |
| Jan Schmidt | 6 | 0.05% | 1 | 0.52% |
| Josef Whiter | 5 | 0.04% | 2 | 1.04% |
| Ming Lei | 5 | 0.04% | 1 | 0.52% |
| Bart Van Assche | 4 | 0.03% | 1 | 0.52% |
| Colin Ian King | 4 | 0.03% | 1 | 0.52% |
| Andrea Righi | 3 | 0.03% | 1 | 0.52% |
| Linus Torvalds (pre-git) | 2 | 0.02% | 1 | 0.52% |
| Ilya Dryomov | 2 | 0.02% | 1 | 0.52% |
| Nicholas D Steeves | 2 | 0.02% | 1 | 0.52% |
| Anand Jain | 2 | 0.02% | 2 | 1.04% |
| Shilong Wang | 2 | 0.02% | 1 | 0.52% |
| Sage Weil | 2 | 0.02% | 1 | 0.52% |
| Eric Sandeen | 2 | 0.02% | 1 | 0.52% |
| Geert Uytterhoeven | 2 | 0.02% | 1 | 0.52% |
| Sami Tolvanen | 2 | 0.02% | 1 | 0.52% |
| Zach Brown | 1 | 0.01% | 1 | 0.52% |
| Tanmay Bhushan | 1 | 0.01% | 1 | 0.52% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.52% |
| Total | 11598 | 192 |
// 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 "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 static void dump_bioc(const struct btrfs_fs_info *fs_info, const struct btrfs_io_context *bioc) { if (unlikely(!bioc)) { btrfs_crit(fs_info, "bioc=NULL"); return; } btrfs_crit(fs_info, "bioc logical=%llu full_stripe=%llu size=%llu map_type=0x%llx mirror=%u replace_nr_stripes=%u replace_stripe_src=%d num_stripes=%u", bioc->logical, bioc->full_stripe_logical, bioc->size, bioc->map_type, bioc->mirror_num, bioc->replace_nr_stripes, bioc->replace_stripe_src, bioc->num_stripes); for (int i = 0; i < bioc->num_stripes; i++) { btrfs_crit(fs_info, " nr=%d devid=%llu physical=%llu", i, bioc->stripes[i].dev->devid, bioc->stripes[i].physical); } } static void btrfs_dump_rbio(const struct btrfs_fs_info *fs_info, const struct btrfs_raid_bio *rbio) { if (!IS_ENABLED(CONFIG_BTRFS_ASSERT)) return; dump_bioc(fs_info, rbio->bioc); btrfs_crit(fs_info, "rbio flags=0x%lx nr_sectors=%u nr_data=%u real_stripes=%u stripe_nsectors=%u scrubp=%u dbitmap=0x%lx", rbio->flags, rbio->nr_sectors, rbio->nr_data, rbio->real_stripes, rbio->stripe_nsectors, rbio->scrubp, rbio->dbitmap); } #define ASSERT_RBIO(expr, rbio) \ ({ \ if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \ const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \ (rbio)->bioc->fs_info : NULL; \ \ btrfs_dump_rbio(__fs_info, (rbio)); \ } \ ASSERT((expr)); \ }) #define ASSERT_RBIO_STRIPE(expr, rbio, stripe_nr) \ ({ \ if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \ const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \ (rbio)->bioc->fs_info : NULL; \ \ btrfs_dump_rbio(__fs_info, (rbio)); \ btrfs_crit(__fs_info, "stripe_nr=%d", (stripe_nr)); \ } \ ASSERT((expr)); \ }) #define ASSERT_RBIO_SECTOR(expr, rbio, sector_nr) \ ({ \ if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \ const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \ (rbio)->bioc->fs_info : NULL; \ \ btrfs_dump_rbio(__fs_info, (rbio)); \ btrfs_crit(__fs_info, "sector_nr=%d", (sector_nr)); \ } \ ASSERT((expr)); \ }) #define ASSERT_RBIO_LOGICAL(expr, rbio, logical) \ ({ \ if (IS_ENABLED(CONFIG_BTRFS_ASSERT) && unlikely(!(expr))) { \ const struct btrfs_fs_info *__fs_info = (rbio)->bioc ? \ (rbio)->bioc->fs_info : NULL; \ \ btrfs_dump_rbio(__fs_info, (rbio)); \ btrfs_crit(__fs_info, "logical=%llu", (logical)); \ } \ ASSERT((expr)); \ }) /* 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); 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_init(&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); } /* * 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_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_RBIO_STRIPE(stripe_nr < rbio->real_stripes, rbio, stripe_nr); ASSERT_RBIO_SECTOR(sector_nr < rbio->stripe_nsectors, rbio, sector_nr); 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_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_RBIO_STRIPE(stripe_nr >= 0 && stripe_nr < rbio->real_stripes, rbio, stripe_nr); ASSERT_RBIO_SECTOR(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors, rbio, sector_nr); 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); /* * Real stripes must be between 2 (2 disks RAID5, aka RAID1) and 256 * (limited by u8). */ ASSERT(real_stripes >= 2); ASSERT(real_stripes <= U8_MAX); 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); ASSERT(rbio->nr_data > 0); 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, false); 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, false); 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_RBIO_STRIPE(stripe_nr >= 0 && stripe_nr < rbio->bioc->num_stripes, rbio, stripe_nr); ASSERT_RBIO_SECTOR(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors, rbio, sector_nr); 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); } static void assert_rbio(struct btrfs_raid_bio *rbio) { if (!IS_ENABLED(CONFIG_BTRFS_DEBUG) || !IS_ENABLED(CONFIG_BTRFS_ASSERT)) return; /* * At least two stripes (2 disks RAID5), and since real_stripes is U8, * we won't go beyond 256 disks anyway. */ ASSERT_RBIO(rbio->real_stripes >= 2, rbio); ASSERT_RBIO(rbio->nr_data > 0, rbio); /* * This is another check to make sure nr data stripes is smaller * than total stripes. */ ASSERT_RBIO(rbio->nr_data < rbio->real_stripes, rbio); } /* 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; assert_rbio(rbio); 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_read_enabled()) { struct raid56_bio_trace_info trace_info = { 0 }; bio_get_trace_info(rbio, bio, &trace_info); trace_raid56_read(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, false); 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; }; /* * 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_RBIO_LOGICAL(orig_logical >= full_stripe_start && orig_logical + orig_len <= full_stripe_start + rbio->nr_data * BTRFS_STRIPE_LEN, rbio, orig_logical); 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) { 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) { 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) { 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, NULL, start, start + len - 1, rbio->csum_buf, rbio->csum_bitmap); 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_enabled()) { struct raid56_bio_trace_info trace_info = { 0 }; bio_get_trace_info(rbio, bio, &trace_info); trace_raid56_write(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_RBIO_STRIPE(i < rbio->real_stripes, rbio, i); 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) { 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); 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) { assert_rbio(rbio); /* 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; } /* * 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(rbio->bioc->replace_stripe_src >= 0, rbio); 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) { 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); 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; } }
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