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- // 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 "ctree.h"
- #include "disk-io.h"
- #include "volumes.h"
- #include "raid56.h"
- #include "async-thread.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[];
- };
- enum btrfs_rbio_ops {
- BTRFS_RBIO_WRITE,
- BTRFS_RBIO_READ_REBUILD,
- BTRFS_RBIO_PARITY_SCRUB,
- BTRFS_RBIO_REBUILD_MISSING,
- };
- struct btrfs_raid_bio {
- struct btrfs_fs_info *fs_info;
- struct btrfs_bio *bbio;
- /* while we're doing rmw on a stripe
- * we put it into a hash table so we can
- * lock the stripe and merge more rbios
- * into it.
- */
- struct list_head hash_list;
- /*
- * LRU list for the stripe cache
- */
- struct list_head stripe_cache;
- /*
- * for scheduling work in the helper threads
- */
- struct btrfs_work work;
- /*
- * bio list and bio_list_lock are used
- * to add more bios into the stripe
- * in hopes of avoiding the full rmw
- */
- struct bio_list bio_list;
- spinlock_t bio_list_lock;
- /* also protected by the bio_list_lock, the
- * plug list is used by the plugging code
- * to collect partial bios while plugged. The
- * stripe locking code also uses it to hand off
- * the stripe lock to the next pending IO
- */
- struct list_head plug_list;
- /*
- * flags that tell us if it is safe to
- * merge with this bio
- */
- unsigned long flags;
- /* size of each individual stripe on disk */
- int stripe_len;
- /* number of data stripes (no p/q) */
- int nr_data;
- int real_stripes;
- int stripe_npages;
- /*
- * set if we're doing a parity rebuild
- * for a read from higher up, which is handled
- * differently from a parity rebuild as part of
- * rmw
- */
- enum btrfs_rbio_ops operation;
- /* first bad stripe */
- int faila;
- /* second bad stripe (for raid6 use) */
- int failb;
- int scrubp;
- /*
- * number of pages needed to represent the full
- * stripe
- */
- int nr_pages;
- /*
- * size of all the bios in the bio_list. This
- * helps us decide if the rbio maps to a full
- * stripe or not
- */
- int bio_list_bytes;
- int generic_bio_cnt;
- refcount_t refs;
- atomic_t stripes_pending;
- atomic_t error;
- /*
- * these are two arrays of pointers. We allocate the
- * rbio big enough to hold them both and setup their
- * locations when the rbio is allocated
- */
- /* pointers to pages that we allocated for
- * reading/writing stripes directly from the disk (including P/Q)
- */
- struct page **stripe_pages;
- /*
- * pointers to the pages in the bio_list. Stored
- * here for faster lookup
- */
- struct page **bio_pages;
- /*
- * bitmap to record which horizontal stripe has data
- */
- unsigned long *dbitmap;
- /* allocated with real_stripes-many pointers for finish_*() calls */
- void **finish_pointers;
- /* allocated with stripe_npages-many bits for finish_*() calls */
- unsigned long *finish_pbitmap;
- };
- static int __raid56_parity_recover(struct btrfs_raid_bio *rbio);
- static noinline void finish_rmw(struct btrfs_raid_bio *rbio);
- static void rmw_work(struct btrfs_work *work);
- static void read_rebuild_work(struct btrfs_work *work);
- static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio);
- static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed);
- static void __free_raid_bio(struct btrfs_raid_bio *rbio);
- static void index_rbio_pages(struct btrfs_raid_bio *rbio);
- static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
- static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
- int need_check);
- static void scrub_parity_work(struct btrfs_work *work);
- static void start_async_work(struct btrfs_raid_bio *rbio, btrfs_func_t work_func)
- {
- btrfs_init_work(&rbio->work, work_func, NULL, NULL);
- btrfs_queue_work(rbio->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);
- if (x)
- kvfree(x);
- return 0;
- }
- /*
- * caching an rbio means to copy anything from the
- * bio_pages 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;
- char *s;
- char *d;
- int ret;
- ret = alloc_rbio_pages(rbio);
- if (ret)
- return;
- for (i = 0; i < rbio->nr_pages; i++) {
- if (!rbio->bio_pages[i])
- continue;
- s = kmap(rbio->bio_pages[i]);
- d = kmap(rbio->stripe_pages[i]);
- copy_page(d, s);
- kunmap(rbio->bio_pages[i]);
- kunmap(rbio->stripe_pages[i]);
- SetPageUptodate(rbio->stripe_pages[i]);
- }
- 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->bbio->raid_map[0];
- /*
- * 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);
- }
- /*
- * stealing an rbio means taking all the uptodate pages from the stripe
- * array in the source rbio and putting them into the destination rbio
- */
- static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
- {
- int i;
- struct page *s;
- struct page *d;
- if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
- return;
- for (i = 0; i < dest->nr_pages; i++) {
- s = src->stripe_pages[i];
- if (!s || !PageUptodate(s)) {
- continue;
- }
- d = dest->stripe_pages[i];
- if (d)
- __free_page(d);
- dest->stripe_pages[i] = s;
- src->stripe_pages[i] = NULL;
- }
- }
- /*
- * 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;
- dest->generic_bio_cnt += victim->generic_bio_cnt;
- 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->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;
- unsigned long flags;
- if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
- return;
- table = rbio->fs_info->stripe_hash_table;
- spin_lock_irqsave(&table->cache_lock, flags);
- __remove_rbio_from_cache(rbio);
- spin_unlock_irqrestore(&table->cache_lock, flags);
- }
- /*
- * remove everything in the cache
- */
- static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
- {
- struct btrfs_stripe_hash_table *table;
- unsigned long flags;
- struct btrfs_raid_bio *rbio;
- table = info->stripe_hash_table;
- spin_lock_irqsave(&table->cache_lock, flags);
- 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_irqrestore(&table->cache_lock, flags);
- }
- /*
- * 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;
- unsigned long flags;
- if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
- return;
- table = rbio->fs_info->stripe_hash_table;
- spin_lock_irqsave(&table->cache_lock, flags);
- 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_irqrestore(&table->cache_lock, flags);
- }
- /*
- * 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 flags;
- unsigned long size = rbio->bio_list_bytes;
- int ret = 1;
- spin_lock_irqsave(&rbio->bio_list_lock, flags);
- if (size != rbio->nr_data * rbio->stripe_len)
- ret = 0;
- BUG_ON(size > rbio->nr_data * rbio->stripe_len);
- spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
- 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->bbio->raid_map[0] !=
- cur->bbio->raid_map[0])
- 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)
- return 0;
- if (last->operation == BTRFS_RBIO_READ_REBUILD) {
- int fa = last->faila;
- int fb = last->failb;
- int cur_fa = cur->faila;
- int cur_fb = cur->failb;
- if (last->faila >= last->failb) {
- fa = last->failb;
- fb = last->faila;
- }
- if (cur->faila >= cur->failb) {
- cur_fa = cur->failb;
- cur_fb = cur->faila;
- }
- if (fa != cur_fa || fb != cur_fb)
- return 0;
- }
- return 1;
- }
- static int rbio_stripe_page_index(struct btrfs_raid_bio *rbio, int stripe,
- int index)
- {
- return stripe * rbio->stripe_npages + index;
- }
- /*
- * these are just the pages from the rbio array, not from anything
- * the FS sent down to us
- */
- static struct page *rbio_stripe_page(struct btrfs_raid_bio *rbio, int stripe,
- int index)
- {
- return rbio->stripe_pages[rbio_stripe_page_index(rbio, stripe, index)];
- }
- /*
- * helper to index into the pstripe
- */
- static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index)
- {
- return rbio_stripe_page(rbio, rbio->nr_data, index);
- }
- /*
- * helper to index into the qstripe, returns null
- * if there is no qstripe
- */
- static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index)
- {
- if (rbio->nr_data + 1 == rbio->real_stripes)
- return NULL;
- return rbio_stripe_page(rbio, rbio->nr_data + 1, index);
- }
- /*
- * 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;
- unsigned long flags;
- struct btrfs_raid_bio *freeit = NULL;
- struct btrfs_raid_bio *cache_drop = NULL;
- int ret = 0;
- h = rbio->fs_info->stripe_hash_table->table + rbio_bucket(rbio);
- spin_lock_irqsave(&h->lock, flags);
- list_for_each_entry(cur, &h->hash_list, hash_list) {
- if (cur->bbio->raid_map[0] != rbio->bbio->raid_map[0])
- 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_irqrestore(&h->lock, flags);
- if (cache_drop)
- remove_rbio_from_cache(cache_drop);
- if (freeit)
- __free_raid_bio(freeit);
- return ret;
- }
- /*
- * 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;
- unsigned long flags;
- int keep_cache = 0;
- bucket = rbio_bucket(rbio);
- h = rbio->fs_info->stripe_hash_table->table + bucket;
- if (list_empty(&rbio->plug_list))
- cache_rbio(rbio);
- spin_lock_irqsave(&h->lock, flags);
- 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_irqrestore(&h->lock, flags);
- if (next->operation == BTRFS_RBIO_READ_REBUILD)
- start_async_work(next, read_rebuild_work);
- else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) {
- steal_rbio(rbio, next);
- start_async_work(next, read_rebuild_work);
- } else if (next->operation == BTRFS_RBIO_WRITE) {
- steal_rbio(rbio, next);
- start_async_work(next, rmw_work);
- } else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
- steal_rbio(rbio, next);
- start_async_work(next, scrub_parity_work);
- }
- goto done_nolock;
- }
- }
- done:
- spin_unlock(&rbio->bio_list_lock);
- spin_unlock_irqrestore(&h->lock, flags);
- done_nolock:
- if (!keep_cache)
- remove_rbio_from_cache(rbio);
- }
- 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_bbio(rbio->bbio);
- kfree(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;
- if (rbio->generic_bio_cnt)
- btrfs_bio_counter_sub(rbio->fs_info, rbio->generic_bio_cnt);
- /*
- * 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);
- }
- /*
- * end io function used by finish_rmw. When we finally
- * get here, we've written a full stripe
- */
- static void raid_write_end_io(struct bio *bio)
- {
- struct btrfs_raid_bio *rbio = bio->bi_private;
- blk_status_t err = bio->bi_status;
- int max_errors;
- if (err)
- fail_bio_stripe(rbio, bio);
- bio_put(bio);
- if (!atomic_dec_and_test(&rbio->stripes_pending))
- return;
- err = BLK_STS_OK;
- /* OK, we have read all the stripes we need to. */
- max_errors = (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) ?
- 0 : rbio->bbio->max_errors;
- if (atomic_read(&rbio->error) > max_errors)
- err = BLK_STS_IOERR;
- rbio_orig_end_io(rbio, err);
- }
- /*
- * the read/modify/write code wants to use the original bio for
- * any pages it included, and then use the rbio for everything
- * else. This function decides if a given index (stripe number)
- * and page number in that stripe fall inside the original bio
- * or the rbio.
- *
- * if you set bio_list_only, you'll get a NULL back for any ranges
- * that are outside the bio_list
- *
- * This doesn't take any refs on anything, you get a bare page pointer
- * and the caller must bump refs as required.
- *
- * You must call index_rbio_pages once before you can trust
- * the answers from this function.
- */
- static struct page *page_in_rbio(struct btrfs_raid_bio *rbio,
- int index, int pagenr, int bio_list_only)
- {
- int chunk_page;
- struct page *p = NULL;
- chunk_page = index * (rbio->stripe_len >> PAGE_SHIFT) + pagenr;
- spin_lock_irq(&rbio->bio_list_lock);
- p = rbio->bio_pages[chunk_page];
- spin_unlock_irq(&rbio->bio_list_lock);
- if (p || bio_list_only)
- return p;
- return rbio->stripe_pages[chunk_page];
- }
- /*
- * number of pages we need for the entire stripe across all the
- * drives
- */
- static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes)
- {
- return DIV_ROUND_UP(stripe_len, PAGE_SIZE) * nr_stripes;
- }
- /*
- * 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_bio *bbio,
- u64 stripe_len)
- {
- struct btrfs_raid_bio *rbio;
- int nr_data = 0;
- int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
- int num_pages = rbio_nr_pages(stripe_len, real_stripes);
- int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE);
- void *p;
- rbio = kzalloc(sizeof(*rbio) +
- sizeof(*rbio->stripe_pages) * num_pages +
- sizeof(*rbio->bio_pages) * num_pages +
- sizeof(*rbio->finish_pointers) * real_stripes +
- sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_npages) +
- sizeof(*rbio->finish_pbitmap) *
- BITS_TO_LONGS(stripe_npages),
- GFP_NOFS);
- if (!rbio)
- return ERR_PTR(-ENOMEM);
- bio_list_init(&rbio->bio_list);
- 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);
- rbio->bbio = bbio;
- rbio->fs_info = fs_info;
- rbio->stripe_len = stripe_len;
- rbio->nr_pages = num_pages;
- rbio->real_stripes = real_stripes;
- rbio->stripe_npages = stripe_npages;
- rbio->faila = -1;
- rbio->failb = -1;
- refcount_set(&rbio->refs, 1);
- atomic_set(&rbio->error, 0);
- atomic_set(&rbio->stripes_pending, 0);
- /*
- * the stripe_pages, bio_pages, etc arrays point to the extra
- * memory we allocated past the end of the rbio
- */
- p = rbio + 1;
- #define CONSUME_ALLOC(ptr, count) do { \
- ptr = p; \
- p = (unsigned char *)p + sizeof(*(ptr)) * (count); \
- } while (0)
- CONSUME_ALLOC(rbio->stripe_pages, num_pages);
- CONSUME_ALLOC(rbio->bio_pages, num_pages);
- CONSUME_ALLOC(rbio->finish_pointers, real_stripes);
- CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_npages));
- CONSUME_ALLOC(rbio->finish_pbitmap, BITS_TO_LONGS(stripe_npages));
- #undef CONSUME_ALLOC
- if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
- nr_data = real_stripes - 1;
- else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
- nr_data = real_stripes - 2;
- else
- BUG();
- rbio->nr_data = nr_data;
- return rbio;
- }
- /* allocate pages for all the stripes in the bio, including parity */
- static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
- {
- int i;
- struct page *page;
- for (i = 0; i < rbio->nr_pages; i++) {
- if (rbio->stripe_pages[i])
- continue;
- page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (!page)
- return -ENOMEM;
- rbio->stripe_pages[i] = page;
- }
- return 0;
- }
- /* only allocate pages for p/q stripes */
- static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
- {
- int i;
- struct page *page;
- i = rbio_stripe_page_index(rbio, rbio->nr_data, 0);
- for (; i < rbio->nr_pages; i++) {
- if (rbio->stripe_pages[i])
- continue;
- page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (!page)
- return -ENOMEM;
- rbio->stripe_pages[i] = page;
- }
- return 0;
- }
- /*
- * add a single page from a specific stripe into our list of bios for IO
- * this will try to merge into existing bios if possible, and returns
- * zero if all went well.
- */
- static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
- struct bio_list *bio_list,
- struct page *page,
- int stripe_nr,
- unsigned long page_index,
- unsigned long bio_max_len)
- {
- struct bio *last = bio_list->tail;
- int ret;
- struct bio *bio;
- struct btrfs_bio_stripe *stripe;
- u64 disk_start;
- stripe = &rbio->bbio->stripes[stripe_nr];
- disk_start = stripe->physical + (page_index << PAGE_SHIFT);
- /* if the device is missing, just fail this stripe */
- if (!stripe->dev->bdev)
- return fail_rbio_index(rbio, stripe_nr);
- /* see if we can add this page onto our existing bio */
- if (last) {
- u64 last_end = (u64)last->bi_iter.bi_sector << 9;
- 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_disk == stripe->dev->bdev->bd_disk &&
- last->bi_partno == stripe->dev->bdev->bd_partno) {
- ret = bio_add_page(last, page, PAGE_SIZE, 0);
- if (ret == PAGE_SIZE)
- return 0;
- }
- }
- /* put a new bio on the list */
- bio = btrfs_io_bio_alloc(bio_max_len >> PAGE_SHIFT ?: 1);
- btrfs_io_bio(bio)->device = stripe->dev;
- bio->bi_iter.bi_size = 0;
- bio_set_dev(bio, stripe->dev->bdev);
- bio->bi_iter.bi_sector = disk_start >> 9;
- bio_add_page(bio, page, PAGE_SIZE, 0);
- bio_list_add(bio_list, bio);
- return 0;
- }
- /*
- * while we're doing the read/modify/write cycle, we could
- * have errors in reading pages off the disk. This checks
- * for errors and if we're not able to read the page it'll
- * trigger parity reconstruction. The rmw will be finished
- * after we've reconstructed the failed stripes
- */
- static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio)
- {
- if (rbio->faila >= 0 || rbio->failb >= 0) {
- BUG_ON(rbio->faila == rbio->real_stripes - 1);
- __raid56_parity_recover(rbio);
- } else {
- finish_rmw(rbio);
- }
- }
- /*
- * 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;
- u64 start;
- unsigned long stripe_offset;
- unsigned long page_index;
- spin_lock_irq(&rbio->bio_list_lock);
- bio_list_for_each(bio, &rbio->bio_list) {
- struct bio_vec bvec;
- struct bvec_iter iter;
- int i = 0;
- start = (u64)bio->bi_iter.bi_sector << 9;
- stripe_offset = start - rbio->bbio->raid_map[0];
- page_index = stripe_offset >> PAGE_SHIFT;
- if (bio_flagged(bio, BIO_CLONED))
- bio->bi_iter = btrfs_io_bio(bio)->iter;
- bio_for_each_segment(bvec, bio, iter) {
- rbio->bio_pages[page_index + i] = bvec.bv_page;
- i++;
- }
- }
- spin_unlock_irq(&rbio->bio_list_lock);
- }
- /*
- * this is called from one of two situations. We either
- * have a full stripe from the higher layers, or we've read all
- * the missing bits off disk.
- *
- * This will calculate the parity and then send down any
- * changed blocks.
- */
- static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
- {
- struct btrfs_bio *bbio = rbio->bbio;
- void **pointers = rbio->finish_pointers;
- int nr_data = rbio->nr_data;
- int stripe;
- int pagenr;
- bool has_qstripe;
- struct bio_list bio_list;
- struct bio *bio;
- 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();
- /* at this point we either have a full stripe,
- * or we've read the full stripe from the drive.
- * recalculate 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.
- */
- spin_lock_irq(&rbio->bio_list_lock);
- set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
- spin_unlock_irq(&rbio->bio_list_lock);
- atomic_set(&rbio->error, 0);
- /*
- * now that we've set rmw_locked, run through the
- * bio list one last time and map the page pointers
- *
- * 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.
- */
- index_rbio_pages(rbio);
- if (!rbio_is_full(rbio))
- cache_rbio_pages(rbio);
- else
- clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- struct page *p;
- /* first collect one page from each data stripe */
- for (stripe = 0; stripe < nr_data; stripe++) {
- p = page_in_rbio(rbio, stripe, pagenr, 0);
- pointers[stripe] = kmap(p);
- }
- /* then add the parity stripe */
- p = rbio_pstripe_page(rbio, pagenr);
- SetPageUptodate(p);
- pointers[stripe++] = kmap(p);
- if (has_qstripe) {
- /*
- * raid6, add the qstripe and call the
- * library function to fill in our p/q
- */
- p = rbio_qstripe_page(rbio, pagenr);
- SetPageUptodate(p);
- pointers[stripe++] = kmap(p);
- raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
- pointers);
- } else {
- /* raid5 */
- copy_page(pointers[nr_data], pointers[0]);
- run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
- }
- for (stripe = 0; stripe < rbio->real_stripes; stripe++)
- kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
- }
- /*
- * 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 (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- struct page *page;
- if (stripe < rbio->nr_data) {
- page = page_in_rbio(rbio, stripe, pagenr, 1);
- if (!page)
- continue;
- } else {
- page = rbio_stripe_page(rbio, stripe, pagenr);
- }
- ret = rbio_add_io_page(rbio, &bio_list,
- page, stripe, pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- }
- if (likely(!bbio->num_tgtdevs))
- goto write_data;
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- if (!bbio->tgtdev_map[stripe])
- continue;
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- struct page *page;
- if (stripe < rbio->nr_data) {
- page = page_in_rbio(rbio, stripe, pagenr, 1);
- if (!page)
- continue;
- } else {
- page = rbio_stripe_page(rbio, stripe, pagenr);
- }
- ret = rbio_add_io_page(rbio, &bio_list, page,
- rbio->bbio->tgtdev_map[stripe],
- pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- }
- write_data:
- atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list));
- BUG_ON(atomic_read(&rbio->stripes_pending) == 0);
- while ((bio = bio_list_pop(&bio_list))) {
- bio->bi_private = rbio;
- bio->bi_end_io = raid_write_end_io;
- bio->bi_opf = REQ_OP_WRITE;
- submit_bio(bio);
- }
- return;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- while ((bio = bio_list_pop(&bio_list)))
- bio_put(bio);
- }
- /*
- * helper to find the stripe number for a given bio. Used to figure out which
- * stripe has failed. This expects the bio to correspond to a physical disk,
- * so it looks up based on physical sector numbers.
- */
- static int find_bio_stripe(struct btrfs_raid_bio *rbio,
- struct bio *bio)
- {
- u64 physical = bio->bi_iter.bi_sector;
- int i;
- struct btrfs_bio_stripe *stripe;
- physical <<= 9;
- for (i = 0; i < rbio->bbio->num_stripes; i++) {
- stripe = &rbio->bbio->stripes[i];
- if (in_range(physical, stripe->physical, rbio->stripe_len) &&
- stripe->dev->bdev &&
- bio->bi_disk == stripe->dev->bdev->bd_disk &&
- bio->bi_partno == stripe->dev->bdev->bd_partno) {
- return i;
- }
- }
- return -1;
- }
- /*
- * helper to find the stripe number for a given
- * bio (before mapping). Used to figure out which stripe has
- * failed. This looks up based on logical block numbers.
- */
- static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
- struct bio *bio)
- {
- u64 logical = (u64)bio->bi_iter.bi_sector << 9;
- int i;
- for (i = 0; i < rbio->nr_data; i++) {
- u64 stripe_start = rbio->bbio->raid_map[i];
- if (in_range(logical, stripe_start, rbio->stripe_len))
- return i;
- }
- return -1;
- }
- /*
- * returns -EIO if we had too many failures
- */
- static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed)
- {
- unsigned long flags;
- int ret = 0;
- spin_lock_irqsave(&rbio->bio_list_lock, flags);
- /* we already know this stripe is bad, move on */
- if (rbio->faila == failed || rbio->failb == failed)
- goto out;
- if (rbio->faila == -1) {
- /* first failure on this rbio */
- rbio->faila = failed;
- atomic_inc(&rbio->error);
- } else if (rbio->failb == -1) {
- /* second failure on this rbio */
- rbio->failb = failed;
- atomic_inc(&rbio->error);
- } else {
- ret = -EIO;
- }
- out:
- spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
- return ret;
- }
- /*
- * helper to fail a stripe based on a physical disk
- * bio.
- */
- static int fail_bio_stripe(struct btrfs_raid_bio *rbio,
- struct bio *bio)
- {
- int failed = find_bio_stripe(rbio, bio);
- if (failed < 0)
- return -EIO;
- return fail_rbio_index(rbio, failed);
- }
- /*
- * 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 bio *bio)
- {
- 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)
- SetPageUptodate(bvec->bv_page);
- }
- /*
- * end io for the read phase of the rmw cycle. All the bios here are physical
- * stripe bios we've read from the disk so we can recalculate the parity of the
- * stripe.
- *
- * This will usually kick off finish_rmw once all the bios are read in, but it
- * may trigger parity reconstruction if we had any errors along the way
- */
- static void raid_rmw_end_io(struct bio *bio)
- {
- struct btrfs_raid_bio *rbio = bio->bi_private;
- if (bio->bi_status)
- fail_bio_stripe(rbio, bio);
- else
- set_bio_pages_uptodate(bio);
- bio_put(bio);
- if (!atomic_dec_and_test(&rbio->stripes_pending))
- return;
- if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
- goto cleanup;
- /*
- * this will normally call finish_rmw to start our write
- * but if there are any failed stripes we'll reconstruct
- * from parity first
- */
- validate_rbio_for_rmw(rbio);
- return;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- }
- /*
- * the stripe must be locked by the caller. It will
- * unlock after all the writes are done
- */
- static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio)
- {
- int bios_to_read = 0;
- struct bio_list bio_list;
- int ret;
- int pagenr;
- int stripe;
- struct bio *bio;
- bio_list_init(&bio_list);
- ret = alloc_rbio_pages(rbio);
- if (ret)
- goto cleanup;
- index_rbio_pages(rbio);
- atomic_set(&rbio->error, 0);
- /*
- * build a list of bios to read all the missing parts of this
- * stripe
- */
- for (stripe = 0; stripe < rbio->nr_data; stripe++) {
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- struct page *page;
- /*
- * we want to find all the pages missing from
- * the rbio and read them from the disk. If
- * page_in_rbio finds a page in the bio list
- * we don't need to read it off the stripe.
- */
- page = page_in_rbio(rbio, stripe, pagenr, 1);
- if (page)
- continue;
- page = rbio_stripe_page(rbio, stripe, pagenr);
- /*
- * the bio cache may have handed us an uptodate
- * page. If so, be happy and use it
- */
- if (PageUptodate(page))
- continue;
- ret = rbio_add_io_page(rbio, &bio_list, page,
- stripe, pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- }
- bios_to_read = bio_list_size(&bio_list);
- if (!bios_to_read) {
- /*
- * this can happen if others have merged with
- * us, it means there is nothing left to read.
- * But if there are missing devices it may not be
- * safe to do the full stripe write yet.
- */
- goto finish;
- }
- /*
- * the bbio may be freed once we submit the last bio. Make sure
- * not to touch it after that
- */
- atomic_set(&rbio->stripes_pending, bios_to_read);
- while ((bio = bio_list_pop(&bio_list))) {
- bio->bi_private = rbio;
- bio->bi_end_io = raid_rmw_end_io;
- bio->bi_opf = REQ_OP_READ;
- btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
- submit_bio(bio);
- }
- /* the actual write will happen once the reads are done */
- return 0;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- while ((bio = bio_list_pop(&bio_list)))
- bio_put(bio);
- return -EIO;
- finish:
- validate_rbio_for_rmw(rbio);
- return 0;
- }
- /*
- * if the upper layers pass in a full stripe, we thank them by only allocating
- * enough pages to hold the parity, and sending it all down quickly.
- */
- static int full_stripe_write(struct btrfs_raid_bio *rbio)
- {
- int ret;
- ret = alloc_rbio_parity_pages(rbio);
- if (ret) {
- __free_raid_bio(rbio);
- return ret;
- }
- ret = lock_stripe_add(rbio);
- if (ret == 0)
- finish_rmw(rbio);
- return 0;
- }
- /*
- * partial stripe writes get handed over to async helpers.
- * We're really hoping to merge a few more writes into this
- * rbio before calculating new parity
- */
- static int partial_stripe_write(struct btrfs_raid_bio *rbio)
- {
- int ret;
- ret = lock_stripe_add(rbio);
- if (ret == 0)
- start_async_work(rbio, rmw_work);
- return 0;
- }
- /*
- * sometimes while we were reading from the drive to
- * recalculate parity, enough new bios come into create
- * a full stripe. So we do a check here to see if we can
- * go directly to finish_rmw
- */
- static int __raid56_parity_write(struct btrfs_raid_bio *rbio)
- {
- /* head off into rmw land if we don't have a full stripe */
- if (!rbio_is_full(rbio))
- return partial_stripe_write(rbio);
- return full_stripe_write(rbio);
- }
- /*
- * 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 btrfs_work work;
- };
- /*
- * rbios on the plug list are sorted for easier merging.
- */
- static int plug_cmp(void *priv, struct list_head *a, struct list_head *b)
- {
- struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
- plug_list);
- 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 run_plug(struct btrfs_plug_cb *plug)
- {
- struct btrfs_raid_bio *cur;
- struct btrfs_raid_bio *last = NULL;
- /*
- * sort our plug list then try to merge
- * everything we can in hopes of creating full
- * stripes.
- */
- 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)) {
- int ret;
- /* we have a full stripe, send it down */
- ret = full_stripe_write(cur);
- BUG_ON(ret);
- continue;
- }
- if (last) {
- if (rbio_can_merge(last, cur)) {
- merge_rbio(last, cur);
- __free_raid_bio(cur);
- continue;
- }
- __raid56_parity_write(last);
- }
- last = cur;
- }
- if (last) {
- __raid56_parity_write(last);
- }
- kfree(plug);
- }
- /*
- * if the unplug comes from schedule, we have to push the
- * work off to a helper thread
- */
- static void unplug_work(struct btrfs_work *work)
- {
- struct btrfs_plug_cb *plug;
- plug = container_of(work, struct btrfs_plug_cb, work);
- run_plug(plug);
- }
- static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
- {
- struct btrfs_plug_cb *plug;
- plug = container_of(cb, struct btrfs_plug_cb, cb);
- if (from_schedule) {
- btrfs_init_work(&plug->work, unplug_work, NULL, NULL);
- btrfs_queue_work(plug->info->rmw_workers,
- &plug->work);
- return;
- }
- run_plug(plug);
- }
- /*
- * our main entry point for writes from the rest of the FS.
- */
- int raid56_parity_write(struct btrfs_fs_info *fs_info, struct bio *bio,
- struct btrfs_bio *bbio, u64 stripe_len)
- {
- struct btrfs_raid_bio *rbio;
- struct btrfs_plug_cb *plug = NULL;
- struct blk_plug_cb *cb;
- int ret;
- rbio = alloc_rbio(fs_info, bbio, stripe_len);
- if (IS_ERR(rbio)) {
- btrfs_put_bbio(bbio);
- return PTR_ERR(rbio);
- }
- bio_list_add(&rbio->bio_list, bio);
- rbio->bio_list_bytes = bio->bi_iter.bi_size;
- rbio->operation = BTRFS_RBIO_WRITE;
- btrfs_bio_counter_inc_noblocked(fs_info);
- rbio->generic_bio_cnt = 1;
- /*
- * don't plug on full rbios, just get them out the door
- * as quickly as we can
- */
- if (rbio_is_full(rbio)) {
- ret = full_stripe_write(rbio);
- if (ret)
- btrfs_bio_counter_dec(fs_info);
- return ret;
- }
- cb = blk_check_plugged(btrfs_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);
- ret = 0;
- } else {
- ret = __raid56_parity_write(rbio);
- if (ret)
- btrfs_bio_counter_dec(fs_info);
- }
- return ret;
- }
- /*
- * all parity reconstruction happens here. We've read in everything
- * we can find from the drives and this does the heavy lifting of
- * sorting the good from the bad.
- */
- static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
- {
- int pagenr, stripe;
- void **pointers;
- int faila = -1, failb = -1;
- struct page *page;
- blk_status_t err;
- int i;
- pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
- if (!pointers) {
- err = BLK_STS_RESOURCE;
- goto cleanup_io;
- }
- faila = rbio->faila;
- failb = rbio->failb;
- if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
- spin_lock_irq(&rbio->bio_list_lock);
- set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
- spin_unlock_irq(&rbio->bio_list_lock);
- }
- index_rbio_pages(rbio);
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- /*
- * 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(pagenr, rbio->dbitmap))
- continue;
- /* setup our array of pointers with pages
- * from each stripe
- */
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- /*
- * if we're rebuilding a read, we have to use
- * pages from the bio list
- */
- if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
- (stripe == faila || stripe == failb)) {
- page = page_in_rbio(rbio, stripe, pagenr, 0);
- } else {
- page = rbio_stripe_page(rbio, stripe, pagenr);
- }
- pointers[stripe] = kmap(page);
- }
- /* all raid6 handling here */
- if (rbio->bbio->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.
- * TODO, we should redo the xor here.
- */
- err = BLK_STS_IOERR;
- goto cleanup;
- }
- /*
- * a single failure in raid6 is rebuilt
- * in the pstripe code below
- */
- goto pstripe;
- }
- /* make sure our ps and qs are in order */
- if (faila > failb)
- swap(faila, failb);
- /* 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 (rbio->bbio->raid_map[failb] == RAID6_Q_STRIPE) {
- if (rbio->bbio->raid_map[faila] ==
- RAID5_P_STRIPE) {
- err = BLK_STS_IOERR;
- goto cleanup;
- }
- /*
- * otherwise we have one bad data stripe and
- * a good P stripe. raid5!
- */
- goto pstripe;
- }
- if (rbio->bbio->raid_map[failb] == RAID5_P_STRIPE) {
- raid6_datap_recov(rbio->real_stripes,
- PAGE_SIZE, faila, pointers);
- } else {
- raid6_2data_recov(rbio->real_stripes,
- PAGE_SIZE, faila, failb,
- pointers);
- }
- } else {
- void *p;
- /* rebuild from P stripe here (raid5 or raid6) */
- BUG_ON(failb != -1);
- pstripe:
- /* Copy parity block into failed block to start with */
- copy_page(pointers[faila], pointers[rbio->nr_data]);
- /* rearrange the pointer array */
- p = pointers[faila];
- for (stripe = faila; stripe < rbio->nr_data - 1; stripe++)
- pointers[stripe] = pointers[stripe + 1];
- pointers[rbio->nr_data - 1] = p;
- /* xor in the rest */
- run_xor(pointers, rbio->nr_data - 1, PAGE_SIZE);
- }
- /* if we're doing this rebuild as part of an rmw, go through
- * and set all of our private rbio pages in the
- * failed stripes as uptodate. This way finish_rmw will
- * know they can be trusted. If this was a read reconstruction,
- * other endio functions will fiddle the uptodate bits
- */
- if (rbio->operation == BTRFS_RBIO_WRITE) {
- for (i = 0; i < rbio->stripe_npages; i++) {
- if (faila != -1) {
- page = rbio_stripe_page(rbio, faila, i);
- SetPageUptodate(page);
- }
- if (failb != -1) {
- page = rbio_stripe_page(rbio, failb, i);
- SetPageUptodate(page);
- }
- }
- }
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- /*
- * if we're rebuilding a read, we have to use
- * pages from the bio list
- */
- if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
- (stripe == faila || stripe == failb)) {
- page = page_in_rbio(rbio, stripe, pagenr, 0);
- } else {
- page = rbio_stripe_page(rbio, stripe, pagenr);
- }
- kunmap(page);
- }
- }
- err = BLK_STS_OK;
- cleanup:
- kfree(pointers);
- cleanup_io:
- /*
- * Similar to READ_REBUILD, REBUILD_MISSING at this point also has a
- * valid rbio which is consistent with ondisk content, thus such a
- * valid rbio can be cached to avoid further disk reads.
- */
- if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
- /*
- * - In case of two failures, where rbio->failb != -1:
- *
- * Do not cache this rbio since the above read reconstruction
- * (raid6_datap_recov() or raid6_2data_recov()) may have
- * changed some content of stripes which are not identical to
- * on-disk content any more, otherwise, a later write/recover
- * may steal stripe_pages from this rbio and end up with
- * corruptions or rebuild failures.
- *
- * - In case of single failure, where rbio->failb == -1:
- *
- * Cache this rbio iff the above read reconstruction is
- * executed without problems.
- */
- if (err == BLK_STS_OK && rbio->failb < 0)
- cache_rbio_pages(rbio);
- else
- clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
- rbio_orig_end_io(rbio, err);
- } else if (err == BLK_STS_OK) {
- rbio->faila = -1;
- rbio->failb = -1;
- if (rbio->operation == BTRFS_RBIO_WRITE)
- finish_rmw(rbio);
- else if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB)
- finish_parity_scrub(rbio, 0);
- else
- BUG();
- } else {
- rbio_orig_end_io(rbio, err);
- }
- }
- /*
- * This is called only for stripes we've read from disk to
- * reconstruct the parity.
- */
- static void raid_recover_end_io(struct bio *bio)
- {
- struct btrfs_raid_bio *rbio = bio->bi_private;
- /*
- * we only read stripe pages off the disk, set them
- * up to date if there were no errors
- */
- if (bio->bi_status)
- fail_bio_stripe(rbio, bio);
- else
- set_bio_pages_uptodate(bio);
- bio_put(bio);
- if (!atomic_dec_and_test(&rbio->stripes_pending))
- return;
- if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- else
- __raid_recover_end_io(rbio);
- }
- /*
- * reads everything we need off the disk to reconstruct
- * the parity. endio handlers trigger final reconstruction
- * when the IO is done.
- *
- * This is used both for reads from the higher layers and for
- * parity construction required to finish a rmw cycle.
- */
- static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
- {
- int bios_to_read = 0;
- struct bio_list bio_list;
- int ret;
- int pagenr;
- int stripe;
- struct bio *bio;
- bio_list_init(&bio_list);
- ret = alloc_rbio_pages(rbio);
- if (ret)
- goto cleanup;
- atomic_set(&rbio->error, 0);
- /*
- * read everything that hasn't failed. Thanks to the
- * stripe cache, it is possible that some or all of these
- * pages are going to be uptodate.
- */
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- if (rbio->faila == stripe || rbio->failb == stripe) {
- atomic_inc(&rbio->error);
- continue;
- }
- for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
- struct page *p;
- /*
- * the rmw code may have already read this
- * page in
- */
- p = rbio_stripe_page(rbio, stripe, pagenr);
- if (PageUptodate(p))
- continue;
- ret = rbio_add_io_page(rbio, &bio_list,
- rbio_stripe_page(rbio, stripe, pagenr),
- stripe, pagenr, rbio->stripe_len);
- if (ret < 0)
- goto cleanup;
- }
- }
- bios_to_read = bio_list_size(&bio_list);
- if (!bios_to_read) {
- /*
- * we might have no bios to read just because the pages
- * were up to date, or we might have no bios to read because
- * the devices were gone.
- */
- if (atomic_read(&rbio->error) <= rbio->bbio->max_errors) {
- __raid_recover_end_io(rbio);
- return 0;
- } else {
- goto cleanup;
- }
- }
- /*
- * the bbio may be freed once we submit the last bio. Make sure
- * not to touch it after that
- */
- atomic_set(&rbio->stripes_pending, bios_to_read);
- while ((bio = bio_list_pop(&bio_list))) {
- bio->bi_private = rbio;
- bio->bi_end_io = raid_recover_end_io;
- bio->bi_opf = REQ_OP_READ;
- btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
- submit_bio(bio);
- }
- return 0;
- cleanup:
- if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING)
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- while ((bio = bio_list_pop(&bio_list)))
- bio_put(bio);
- return -EIO;
- }
- /*
- * 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.
- */
- int raid56_parity_recover(struct btrfs_fs_info *fs_info, struct bio *bio,
- struct btrfs_bio *bbio, u64 stripe_len,
- int mirror_num, int generic_io)
- {
- struct btrfs_raid_bio *rbio;
- int ret;
- if (generic_io) {
- ASSERT(bbio->mirror_num == mirror_num);
- btrfs_io_bio(bio)->mirror_num = mirror_num;
- }
- rbio = alloc_rbio(fs_info, bbio, stripe_len);
- if (IS_ERR(rbio)) {
- if (generic_io)
- btrfs_put_bbio(bbio);
- return PTR_ERR(rbio);
- }
- rbio->operation = BTRFS_RBIO_READ_REBUILD;
- bio_list_add(&rbio->bio_list, bio);
- rbio->bio_list_bytes = bio->bi_iter.bi_size;
- rbio->faila = find_logical_bio_stripe(rbio, bio);
- if (rbio->faila == -1) {
- btrfs_warn(fs_info,
- "%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)",
- __func__, (u64)bio->bi_iter.bi_sector << 9,
- (u64)bio->bi_iter.bi_size, bbio->map_type);
- if (generic_io)
- btrfs_put_bbio(bbio);
- kfree(rbio);
- return -EIO;
- }
- if (generic_io) {
- btrfs_bio_counter_inc_noblocked(fs_info);
- rbio->generic_bio_cnt = 1;
- } else {
- btrfs_get_bbio(bbio);
- }
- /*
- * 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) {
- /*
- * 'mirror == 3' is to fail the p stripe and
- * reconstruct from the q stripe. 'mirror > 3' is to
- * fail a data stripe and reconstruct from p+q stripe.
- */
- rbio->failb = rbio->real_stripes - (mirror_num - 1);
- ASSERT(rbio->failb > 0);
- if (rbio->failb <= rbio->faila)
- rbio->failb--;
- }
- ret = lock_stripe_add(rbio);
- /*
- * __raid56_parity_recover will end the bio with
- * any errors it hits. We don't want to return
- * its error value up the stack because our caller
- * will end up calling bio_endio with any nonzero
- * return
- */
- if (ret == 0)
- __raid56_parity_recover(rbio);
- /*
- * our rbio has been added to the list of
- * rbios that will be handled after the
- * currently lock owner is done
- */
- return 0;
- }
- static void rmw_work(struct btrfs_work *work)
- {
- struct btrfs_raid_bio *rbio;
- rbio = container_of(work, struct btrfs_raid_bio, work);
- raid56_rmw_stripe(rbio);
- }
- static void read_rebuild_work(struct btrfs_work *work)
- {
- struct btrfs_raid_bio *rbio;
- rbio = container_of(work, struct btrfs_raid_bio, work);
- __raid56_parity_recover(rbio);
- }
- /*
- * The following code is used to scrub/replace the parity stripe
- *
- * Caller must have already increased bio_counter for getting @bbio.
- *
- * 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 btrfs_fs_info *fs_info, struct bio *bio,
- struct btrfs_bio *bbio, u64 stripe_len,
- struct btrfs_device *scrub_dev,
- unsigned long *dbitmap, int stripe_nsectors)
- {
- struct btrfs_raid_bio *rbio;
- int i;
- rbio = alloc_rbio(fs_info, bbio, stripe_len);
- 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 bbio 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 (bbio->stripes[i].dev == scrub_dev) {
- rbio->scrubp = i;
- break;
- }
- }
- ASSERT(i < rbio->real_stripes);
- /* Now we just support the sectorsize equals to page size */
- ASSERT(fs_info->sectorsize == PAGE_SIZE);
- ASSERT(rbio->stripe_npages == stripe_nsectors);
- bitmap_copy(rbio->dbitmap, dbitmap, stripe_nsectors);
- /*
- * We have already increased bio_counter when getting bbio, record it
- * so we can free it at rbio_orig_end_io().
- */
- rbio->generic_bio_cnt = 1;
- return rbio;
- }
- /* Used for both parity scrub and missing. */
- void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
- u64 logical)
- {
- int stripe_offset;
- int index;
- ASSERT(logical >= rbio->bbio->raid_map[0]);
- ASSERT(logical + PAGE_SIZE <= rbio->bbio->raid_map[0] +
- rbio->stripe_len * rbio->nr_data);
- stripe_offset = (int)(logical - rbio->bbio->raid_map[0]);
- index = stripe_offset >> PAGE_SHIFT;
- rbio->bio_pages[index] = page;
- }
- /*
- * 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)
- {
- int i;
- int bit;
- int index;
- struct page *page;
- for_each_set_bit(bit, rbio->dbitmap, rbio->stripe_npages) {
- for (i = 0; i < rbio->real_stripes; i++) {
- index = i * rbio->stripe_npages + bit;
- if (rbio->stripe_pages[index])
- continue;
- page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (!page)
- return -ENOMEM;
- rbio->stripe_pages[index] = page;
- }
- }
- return 0;
- }
- static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
- int need_check)
- {
- struct btrfs_bio *bbio = rbio->bbio;
- void **pointers = rbio->finish_pointers;
- unsigned long *pbitmap = rbio->finish_pbitmap;
- int nr_data = rbio->nr_data;
- int stripe;
- int pagenr;
- bool has_qstripe;
- struct page *p_page = NULL;
- struct page *q_page = NULL;
- struct bio_list bio_list;
- struct bio *bio;
- 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();
- if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) {
- is_replace = 1;
- bitmap_copy(pbitmap, rbio->dbitmap, rbio->stripe_npages);
- }
- /*
- * 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_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (!p_page)
- goto cleanup;
- SetPageUptodate(p_page);
- if (has_qstripe) {
- /* RAID6, allocate and map temp space for the Q stripe */
- q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
- if (!q_page) {
- __free_page(p_page);
- goto cleanup;
- }
- SetPageUptodate(q_page);
- pointers[rbio->real_stripes - 1] = kmap(q_page);
- }
- atomic_set(&rbio->error, 0);
- /* Map the parity stripe just once */
- pointers[nr_data] = kmap(p_page);
- for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
- struct page *p;
- void *parity;
- /* first collect one page from each data stripe */
- for (stripe = 0; stripe < nr_data; stripe++) {
- p = page_in_rbio(rbio, stripe, pagenr, 0);
- pointers[stripe] = kmap(p);
- }
- if (has_qstripe) {
- /* RAID6, call the library function to fill in our P/Q */
- raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
- pointers);
- } else {
- /* raid5 */
- copy_page(pointers[nr_data], pointers[0]);
- run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
- }
- /* Check scrubbing parity and repair it */
- p = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
- parity = kmap(p);
- if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))
- copy_page(parity, pointers[rbio->scrubp]);
- else
- /* Parity is right, needn't writeback */
- bitmap_clear(rbio->dbitmap, pagenr, 1);
- kunmap(p);
- for (stripe = 0; stripe < nr_data; stripe++)
- kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
- }
- kunmap(p_page);
- __free_page(p_page);
- if (q_page) {
- kunmap(q_page);
- __free_page(q_page);
- }
- 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(pagenr, rbio->dbitmap, rbio->stripe_npages) {
- struct page *page;
- page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
- ret = rbio_add_io_page(rbio, &bio_list,
- page, rbio->scrubp, pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- if (!is_replace)
- goto submit_write;
- for_each_set_bit(pagenr, pbitmap, rbio->stripe_npages) {
- struct page *page;
- page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
- ret = rbio_add_io_page(rbio, &bio_list, page,
- bbio->tgtdev_map[rbio->scrubp],
- pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- submit_write:
- nr_data = bio_list_size(&bio_list);
- if (!nr_data) {
- /* Every parity is right */
- rbio_orig_end_io(rbio, BLK_STS_OK);
- return;
- }
- atomic_set(&rbio->stripes_pending, nr_data);
- while ((bio = bio_list_pop(&bio_list))) {
- bio->bi_private = rbio;
- bio->bi_end_io = raid_write_end_io;
- bio->bi_opf = REQ_OP_WRITE;
- submit_bio(bio);
- }
- return;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- while ((bio = bio_list_pop(&bio_list)))
- bio_put(bio);
- }
- static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
- {
- if (stripe >= 0 && stripe < rbio->nr_data)
- return 1;
- return 0;
- }
- /*
- * While we're doing the parity check and repair, we could have errors
- * in reading pages off the disk. This checks for errors and if we're
- * not able to read the page it'll trigger parity reconstruction. The
- * parity scrub will be finished after we've reconstructed the failed
- * stripes
- */
- static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio)
- {
- if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
- goto cleanup;
- if (rbio->faila >= 0 || rbio->failb >= 0) {
- int dfail = 0, failp = -1;
- if (is_data_stripe(rbio, rbio->faila))
- dfail++;
- else if (is_parity_stripe(rbio->faila))
- failp = rbio->faila;
- if (is_data_stripe(rbio, rbio->failb))
- dfail++;
- else if (is_parity_stripe(rbio->failb))
- failp = rbio->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->bbio->max_errors - 1)
- goto cleanup;
- /*
- * If all data is good, only parity is correctly, just
- * repair the parity.
- */
- if (dfail == 0) {
- finish_parity_scrub(rbio, 0);
- return;
- }
- /*
- * 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)
- goto cleanup;
- __raid_recover_end_io(rbio);
- } else {
- finish_parity_scrub(rbio, 1);
- }
- return;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- }
- /*
- * end io for the read phase of the rmw cycle. All the bios here are physical
- * stripe bios we've read from the disk so we can recalculate the parity of the
- * stripe.
- *
- * This will usually kick off finish_rmw once all the bios are read in, but it
- * may trigger parity reconstruction if we had any errors along the way
- */
- static void raid56_parity_scrub_end_io(struct bio *bio)
- {
- struct btrfs_raid_bio *rbio = bio->bi_private;
- if (bio->bi_status)
- fail_bio_stripe(rbio, bio);
- else
- set_bio_pages_uptodate(bio);
- bio_put(bio);
- if (!atomic_dec_and_test(&rbio->stripes_pending))
- return;
- /*
- * this will normally call finish_rmw to start our write
- * but if there are any failed stripes we'll reconstruct
- * from parity first
- */
- validate_rbio_for_parity_scrub(rbio);
- }
- static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio)
- {
- int bios_to_read = 0;
- struct bio_list bio_list;
- int ret;
- int pagenr;
- int stripe;
- struct bio *bio;
- bio_list_init(&bio_list);
- ret = alloc_rbio_essential_pages(rbio);
- if (ret)
- goto cleanup;
- atomic_set(&rbio->error, 0);
- /*
- * build a list of bios to read all the missing parts of this
- * stripe
- */
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
- struct page *page;
- /*
- * we want to find all the pages missing from
- * the rbio and read them from the disk. If
- * page_in_rbio finds a page in the bio list
- * we don't need to read it off the stripe.
- */
- page = page_in_rbio(rbio, stripe, pagenr, 1);
- if (page)
- continue;
- page = rbio_stripe_page(rbio, stripe, pagenr);
- /*
- * the bio cache may have handed us an uptodate
- * page. If so, be happy and use it
- */
- if (PageUptodate(page))
- continue;
- ret = rbio_add_io_page(rbio, &bio_list, page,
- stripe, pagenr, rbio->stripe_len);
- if (ret)
- goto cleanup;
- }
- }
- bios_to_read = bio_list_size(&bio_list);
- if (!bios_to_read) {
- /*
- * this can happen if others have merged with
- * us, it means there is nothing left to read.
- * But if there are missing devices it may not be
- * safe to do the full stripe write yet.
- */
- goto finish;
- }
- /*
- * the bbio may be freed once we submit the last bio. Make sure
- * not to touch it after that
- */
- atomic_set(&rbio->stripes_pending, bios_to_read);
- while ((bio = bio_list_pop(&bio_list))) {
- bio->bi_private = rbio;
- bio->bi_end_io = raid56_parity_scrub_end_io;
- bio->bi_opf = REQ_OP_READ;
- btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
- submit_bio(bio);
- }
- /* the actual write will happen once the reads are done */
- return;
- cleanup:
- rbio_orig_end_io(rbio, BLK_STS_IOERR);
- while ((bio = bio_list_pop(&bio_list)))
- bio_put(bio);
- return;
- finish:
- validate_rbio_for_parity_scrub(rbio);
- }
- static void scrub_parity_work(struct btrfs_work *work)
- {
- struct btrfs_raid_bio *rbio;
- rbio = container_of(work, struct btrfs_raid_bio, work);
- raid56_parity_scrub_stripe(rbio);
- }
- void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
- {
- if (!lock_stripe_add(rbio))
- start_async_work(rbio, scrub_parity_work);
- }
- /* The following code is used for dev replace of a missing RAID 5/6 device. */
- struct btrfs_raid_bio *
- raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
- struct btrfs_bio *bbio, u64 length)
- {
- struct btrfs_raid_bio *rbio;
- rbio = alloc_rbio(fs_info, bbio, length);
- if (IS_ERR(rbio))
- return NULL;
- rbio->operation = BTRFS_RBIO_REBUILD_MISSING;
- 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->faila = find_logical_bio_stripe(rbio, bio);
- if (rbio->faila == -1) {
- BUG();
- kfree(rbio);
- return NULL;
- }
- /*
- * When we get bbio, we have already increased bio_counter, record it
- * so we can free it at rbio_orig_end_io()
- */
- rbio->generic_bio_cnt = 1;
- return rbio;
- }
- void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio)
- {
- if (!lock_stripe_add(rbio))
- start_async_work(rbio, read_rebuild_work);
- }
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