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-rw-r--r--fs/btrfs/scrub.c4558
1 files changed, 4558 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
new file mode 100644
index 000000000..1672d4846
--- /dev/null
+++ b/fs/btrfs/scrub.c
@@ -0,0 +1,4558 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2011, 2012 STRATO. All rights reserved.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/ratelimit.h>
+#include <linux/sched/mm.h>
+#include <crypto/hash.h>
+#include "ctree.h"
+#include "discard.h"
+#include "volumes.h"
+#include "disk-io.h"
+#include "ordered-data.h"
+#include "transaction.h"
+#include "backref.h"
+#include "extent_io.h"
+#include "dev-replace.h"
+#include "check-integrity.h"
+#include "rcu-string.h"
+#include "raid56.h"
+#include "block-group.h"
+#include "zoned.h"
+
+/*
+ * This is only the first step towards a full-features scrub. It reads all
+ * extent and super block and verifies the checksums. In case a bad checksum
+ * is found or the extent cannot be read, good data will be written back if
+ * any can be found.
+ *
+ * Future enhancements:
+ * - In case an unrepairable extent is encountered, track which files are
+ * affected and report them
+ * - track and record media errors, throw out bad devices
+ * - add a mode to also read unallocated space
+ */
+
+struct scrub_block;
+struct scrub_ctx;
+
+/*
+ * The following three values only influence the performance.
+ *
+ * The last one configures the number of parallel and outstanding I/O
+ * operations. The first one configures an upper limit for the number
+ * of (dynamically allocated) pages that are added to a bio.
+ */
+#define SCRUB_SECTORS_PER_BIO 32 /* 128KiB per bio for 4KiB pages */
+#define SCRUB_BIOS_PER_SCTX 64 /* 8MiB per device in flight for 4KiB pages */
+
+/*
+ * The following value times PAGE_SIZE needs to be large enough to match the
+ * largest node/leaf/sector size that shall be supported.
+ */
+#define SCRUB_MAX_SECTORS_PER_BLOCK (BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K)
+
+#define SCRUB_MAX_PAGES (DIV_ROUND_UP(BTRFS_MAX_METADATA_BLOCKSIZE, PAGE_SIZE))
+
+struct scrub_recover {
+ refcount_t refs;
+ struct btrfs_io_context *bioc;
+ u64 map_length;
+};
+
+struct scrub_sector {
+ struct scrub_block *sblock;
+ struct list_head list;
+ u64 flags; /* extent flags */
+ u64 generation;
+ /* Offset in bytes to @sblock. */
+ u32 offset;
+ atomic_t refs;
+ unsigned int have_csum:1;
+ unsigned int io_error:1;
+ u8 csum[BTRFS_CSUM_SIZE];
+
+ struct scrub_recover *recover;
+};
+
+struct scrub_bio {
+ int index;
+ struct scrub_ctx *sctx;
+ struct btrfs_device *dev;
+ struct bio *bio;
+ blk_status_t status;
+ u64 logical;
+ u64 physical;
+ struct scrub_sector *sectors[SCRUB_SECTORS_PER_BIO];
+ int sector_count;
+ int next_free;
+ struct work_struct work;
+};
+
+struct scrub_block {
+ /*
+ * Each page will have its page::private used to record the logical
+ * bytenr.
+ */
+ struct page *pages[SCRUB_MAX_PAGES];
+ struct scrub_sector *sectors[SCRUB_MAX_SECTORS_PER_BLOCK];
+ struct btrfs_device *dev;
+ /* Logical bytenr of the sblock */
+ u64 logical;
+ u64 physical;
+ u64 physical_for_dev_replace;
+ /* Length of sblock in bytes */
+ u32 len;
+ int sector_count;
+ int mirror_num;
+
+ atomic_t outstanding_sectors;
+ refcount_t refs; /* free mem on transition to zero */
+ struct scrub_ctx *sctx;
+ struct scrub_parity *sparity;
+ struct {
+ unsigned int header_error:1;
+ unsigned int checksum_error:1;
+ unsigned int no_io_error_seen:1;
+ unsigned int generation_error:1; /* also sets header_error */
+
+ /* The following is for the data used to check parity */
+ /* It is for the data with checksum */
+ unsigned int data_corrected:1;
+ };
+ struct work_struct work;
+};
+
+/* Used for the chunks with parity stripe such RAID5/6 */
+struct scrub_parity {
+ struct scrub_ctx *sctx;
+
+ struct btrfs_device *scrub_dev;
+
+ u64 logic_start;
+
+ u64 logic_end;
+
+ int nsectors;
+
+ u32 stripe_len;
+
+ refcount_t refs;
+
+ struct list_head sectors_list;
+
+ /* Work of parity check and repair */
+ struct work_struct work;
+
+ /* Mark the parity blocks which have data */
+ unsigned long dbitmap;
+
+ /*
+ * Mark the parity blocks which have data, but errors happen when
+ * read data or check data
+ */
+ unsigned long ebitmap;
+};
+
+struct scrub_ctx {
+ struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
+ struct btrfs_fs_info *fs_info;
+ int first_free;
+ int curr;
+ atomic_t bios_in_flight;
+ atomic_t workers_pending;
+ spinlock_t list_lock;
+ wait_queue_head_t list_wait;
+ struct list_head csum_list;
+ atomic_t cancel_req;
+ int readonly;
+ int sectors_per_bio;
+
+ /* State of IO submission throttling affecting the associated device */
+ ktime_t throttle_deadline;
+ u64 throttle_sent;
+
+ int is_dev_replace;
+ u64 write_pointer;
+
+ struct scrub_bio *wr_curr_bio;
+ struct mutex wr_lock;
+ struct btrfs_device *wr_tgtdev;
+ bool flush_all_writes;
+
+ /*
+ * statistics
+ */
+ struct btrfs_scrub_progress stat;
+ spinlock_t stat_lock;
+
+ /*
+ * Use a ref counter to avoid use-after-free issues. Scrub workers
+ * decrement bios_in_flight and workers_pending and then do a wakeup
+ * on the list_wait wait queue. We must ensure the main scrub task
+ * doesn't free the scrub context before or while the workers are
+ * doing the wakeup() call.
+ */
+ refcount_t refs;
+};
+
+struct scrub_warning {
+ struct btrfs_path *path;
+ u64 extent_item_size;
+ const char *errstr;
+ u64 physical;
+ u64 logical;
+ struct btrfs_device *dev;
+};
+
+struct full_stripe_lock {
+ struct rb_node node;
+ u64 logical;
+ u64 refs;
+ struct mutex mutex;
+};
+
+#ifndef CONFIG_64BIT
+/* This structure is for archtectures whose (void *) is smaller than u64 */
+struct scrub_page_private {
+ u64 logical;
+};
+#endif
+
+static int attach_scrub_page_private(struct page *page, u64 logical)
+{
+#ifdef CONFIG_64BIT
+ attach_page_private(page, (void *)logical);
+ return 0;
+#else
+ struct scrub_page_private *spp;
+
+ spp = kmalloc(sizeof(*spp), GFP_KERNEL);
+ if (!spp)
+ return -ENOMEM;
+ spp->logical = logical;
+ attach_page_private(page, (void *)spp);
+ return 0;
+#endif
+}
+
+static void detach_scrub_page_private(struct page *page)
+{
+#ifdef CONFIG_64BIT
+ detach_page_private(page);
+ return;
+#else
+ struct scrub_page_private *spp;
+
+ spp = detach_page_private(page);
+ kfree(spp);
+ return;
+#endif
+}
+
+static struct scrub_block *alloc_scrub_block(struct scrub_ctx *sctx,
+ struct btrfs_device *dev,
+ u64 logical, u64 physical,
+ u64 physical_for_dev_replace,
+ int mirror_num)
+{
+ struct scrub_block *sblock;
+
+ sblock = kzalloc(sizeof(*sblock), GFP_KERNEL);
+ if (!sblock)
+ return NULL;
+ refcount_set(&sblock->refs, 1);
+ sblock->sctx = sctx;
+ sblock->logical = logical;
+ sblock->physical = physical;
+ sblock->physical_for_dev_replace = physical_for_dev_replace;
+ sblock->dev = dev;
+ sblock->mirror_num = mirror_num;
+ sblock->no_io_error_seen = 1;
+ /*
+ * Scrub_block::pages will be allocated at alloc_scrub_sector() when
+ * the corresponding page is not allocated.
+ */
+ return sblock;
+}
+
+/*
+ * Allocate a new scrub sector and attach it to @sblock.
+ *
+ * Will also allocate new pages for @sblock if needed.
+ */
+static struct scrub_sector *alloc_scrub_sector(struct scrub_block *sblock,
+ u64 logical, gfp_t gfp)
+{
+ const pgoff_t page_index = (logical - sblock->logical) >> PAGE_SHIFT;
+ struct scrub_sector *ssector;
+
+ /* We must never have scrub_block exceed U32_MAX in size. */
+ ASSERT(logical - sblock->logical < U32_MAX);
+
+ ssector = kzalloc(sizeof(*ssector), gfp);
+ if (!ssector)
+ return NULL;
+
+ /* Allocate a new page if the slot is not allocated */
+ if (!sblock->pages[page_index]) {
+ int ret;
+
+ sblock->pages[page_index] = alloc_page(gfp);
+ if (!sblock->pages[page_index]) {
+ kfree(ssector);
+ return NULL;
+ }
+ ret = attach_scrub_page_private(sblock->pages[page_index],
+ sblock->logical + (page_index << PAGE_SHIFT));
+ if (ret < 0) {
+ kfree(ssector);
+ __free_page(sblock->pages[page_index]);
+ sblock->pages[page_index] = NULL;
+ return NULL;
+ }
+ }
+
+ atomic_set(&ssector->refs, 1);
+ ssector->sblock = sblock;
+ /* The sector to be added should not be used */
+ ASSERT(sblock->sectors[sblock->sector_count] == NULL);
+ ssector->offset = logical - sblock->logical;
+
+ /* The sector count must be smaller than the limit */
+ ASSERT(sblock->sector_count < SCRUB_MAX_SECTORS_PER_BLOCK);
+
+ sblock->sectors[sblock->sector_count] = ssector;
+ sblock->sector_count++;
+ sblock->len += sblock->sctx->fs_info->sectorsize;
+
+ return ssector;
+}
+
+static struct page *scrub_sector_get_page(struct scrub_sector *ssector)
+{
+ struct scrub_block *sblock = ssector->sblock;
+ pgoff_t index;
+ /*
+ * When calling this function, ssector must be alreaday attached to the
+ * parent sblock.
+ */
+ ASSERT(sblock);
+
+ /* The range should be inside the sblock range */
+ ASSERT(ssector->offset < sblock->len);
+
+ index = ssector->offset >> PAGE_SHIFT;
+ ASSERT(index < SCRUB_MAX_PAGES);
+ ASSERT(sblock->pages[index]);
+ ASSERT(PagePrivate(sblock->pages[index]));
+ return sblock->pages[index];
+}
+
+static unsigned int scrub_sector_get_page_offset(struct scrub_sector *ssector)
+{
+ struct scrub_block *sblock = ssector->sblock;
+
+ /*
+ * When calling this function, ssector must be already attached to the
+ * parent sblock.
+ */
+ ASSERT(sblock);
+
+ /* The range should be inside the sblock range */
+ ASSERT(ssector->offset < sblock->len);
+
+ return offset_in_page(ssector->offset);
+}
+
+static char *scrub_sector_get_kaddr(struct scrub_sector *ssector)
+{
+ return page_address(scrub_sector_get_page(ssector)) +
+ scrub_sector_get_page_offset(ssector);
+}
+
+static int bio_add_scrub_sector(struct bio *bio, struct scrub_sector *ssector,
+ unsigned int len)
+{
+ return bio_add_page(bio, scrub_sector_get_page(ssector), len,
+ scrub_sector_get_page_offset(ssector));
+}
+
+static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
+ struct scrub_block *sblocks_for_recheck[]);
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int retry_failed_mirror);
+static void scrub_recheck_block_checksum(struct scrub_block *sblock);
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good);
+static int scrub_repair_sector_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int sector_num, int force_write);
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
+static int scrub_write_sector_to_dev_replace(struct scrub_block *sblock,
+ int sector_num);
+static int scrub_checksum_data(struct scrub_block *sblock);
+static int scrub_checksum_tree_block(struct scrub_block *sblock);
+static int scrub_checksum_super(struct scrub_block *sblock);
+static void scrub_block_put(struct scrub_block *sblock);
+static void scrub_sector_get(struct scrub_sector *sector);
+static void scrub_sector_put(struct scrub_sector *sector);
+static void scrub_parity_get(struct scrub_parity *sparity);
+static void scrub_parity_put(struct scrub_parity *sparity);
+static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum,
+ u64 physical_for_dev_replace);
+static void scrub_bio_end_io(struct bio *bio);
+static void scrub_bio_end_io_worker(struct work_struct *work);
+static void scrub_block_complete(struct scrub_block *sblock);
+static void scrub_find_good_copy(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u32 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num);
+static int scrub_add_sector_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_sector *sector);
+static void scrub_wr_submit(struct scrub_ctx *sctx);
+static void scrub_wr_bio_end_io(struct bio *bio);
+static void scrub_wr_bio_end_io_worker(struct work_struct *work);
+static void scrub_put_ctx(struct scrub_ctx *sctx);
+
+static inline int scrub_is_page_on_raid56(struct scrub_sector *sector)
+{
+ return sector->recover &&
+ (sector->recover->bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
+}
+
+static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
+{
+ refcount_inc(&sctx->refs);
+ atomic_inc(&sctx->bios_in_flight);
+}
+
+static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
+{
+ atomic_dec(&sctx->bios_in_flight);
+ wake_up(&sctx->list_wait);
+ scrub_put_ctx(sctx);
+}
+
+static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
+{
+ while (atomic_read(&fs_info->scrub_pause_req)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrub_pause_req) == 0);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+}
+
+static void scrub_pause_on(struct btrfs_fs_info *fs_info)
+{
+ atomic_inc(&fs_info->scrubs_paused);
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+static void scrub_pause_off(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ __scrub_blocked_if_needed(fs_info);
+ atomic_dec(&fs_info->scrubs_paused);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
+{
+ scrub_pause_on(fs_info);
+ scrub_pause_off(fs_info);
+}
+
+/*
+ * Insert new full stripe lock into full stripe locks tree
+ *
+ * Return pointer to existing or newly inserted full_stripe_lock structure if
+ * everything works well.
+ * Return ERR_PTR(-ENOMEM) if we failed to allocate memory
+ *
+ * NOTE: caller must hold full_stripe_locks_root->lock before calling this
+ * function
+ */
+static struct full_stripe_lock *insert_full_stripe_lock(
+ struct btrfs_full_stripe_locks_tree *locks_root,
+ u64 fstripe_logical)
+{
+ struct rb_node **p;
+ struct rb_node *parent = NULL;
+ struct full_stripe_lock *entry;
+ struct full_stripe_lock *ret;
+
+ lockdep_assert_held(&locks_root->lock);
+
+ p = &locks_root->root.rb_node;
+ while (*p) {
+ parent = *p;
+ entry = rb_entry(parent, struct full_stripe_lock, node);
+ if (fstripe_logical < entry->logical) {
+ p = &(*p)->rb_left;
+ } else if (fstripe_logical > entry->logical) {
+ p = &(*p)->rb_right;
+ } else {
+ entry->refs++;
+ return entry;
+ }
+ }
+
+ /*
+ * Insert new lock.
+ */
+ ret = kmalloc(sizeof(*ret), GFP_KERNEL);
+ if (!ret)
+ return ERR_PTR(-ENOMEM);
+ ret->logical = fstripe_logical;
+ ret->refs = 1;
+ mutex_init(&ret->mutex);
+
+ rb_link_node(&ret->node, parent, p);
+ rb_insert_color(&ret->node, &locks_root->root);
+ return ret;
+}
+
+/*
+ * Search for a full stripe lock of a block group
+ *
+ * Return pointer to existing full stripe lock if found
+ * Return NULL if not found
+ */
+static struct full_stripe_lock *search_full_stripe_lock(
+ struct btrfs_full_stripe_locks_tree *locks_root,
+ u64 fstripe_logical)
+{
+ struct rb_node *node;
+ struct full_stripe_lock *entry;
+
+ lockdep_assert_held(&locks_root->lock);
+
+ node = locks_root->root.rb_node;
+ while (node) {
+ entry = rb_entry(node, struct full_stripe_lock, node);
+ if (fstripe_logical < entry->logical)
+ node = node->rb_left;
+ else if (fstripe_logical > entry->logical)
+ node = node->rb_right;
+ else
+ return entry;
+ }
+ return NULL;
+}
+
+/*
+ * Helper to get full stripe logical from a normal bytenr.
+ *
+ * Caller must ensure @cache is a RAID56 block group.
+ */
+static u64 get_full_stripe_logical(struct btrfs_block_group *cache, u64 bytenr)
+{
+ u64 ret;
+
+ /*
+ * Due to chunk item size limit, full stripe length should not be
+ * larger than U32_MAX. Just a sanity check here.
+ */
+ WARN_ON_ONCE(cache->full_stripe_len >= U32_MAX);
+
+ /*
+ * round_down() can only handle power of 2, while RAID56 full
+ * stripe length can be 64KiB * n, so we need to manually round down.
+ */
+ ret = div64_u64(bytenr - cache->start, cache->full_stripe_len) *
+ cache->full_stripe_len + cache->start;
+ return ret;
+}
+
+/*
+ * Lock a full stripe to avoid concurrency of recovery and read
+ *
+ * It's only used for profiles with parities (RAID5/6), for other profiles it
+ * does nothing.
+ *
+ * Return 0 if we locked full stripe covering @bytenr, with a mutex held.
+ * So caller must call unlock_full_stripe() at the same context.
+ *
+ * Return <0 if encounters error.
+ */
+static int lock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
+ bool *locked_ret)
+{
+ struct btrfs_block_group *bg_cache;
+ struct btrfs_full_stripe_locks_tree *locks_root;
+ struct full_stripe_lock *existing;
+ u64 fstripe_start;
+ int ret = 0;
+
+ *locked_ret = false;
+ bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
+ if (!bg_cache) {
+ ASSERT(0);
+ return -ENOENT;
+ }
+
+ /* Profiles not based on parity don't need full stripe lock */
+ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
+ goto out;
+ locks_root = &bg_cache->full_stripe_locks_root;
+
+ fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
+
+ /* Now insert the full stripe lock */
+ mutex_lock(&locks_root->lock);
+ existing = insert_full_stripe_lock(locks_root, fstripe_start);
+ mutex_unlock(&locks_root->lock);
+ if (IS_ERR(existing)) {
+ ret = PTR_ERR(existing);
+ goto out;
+ }
+ mutex_lock(&existing->mutex);
+ *locked_ret = true;
+out:
+ btrfs_put_block_group(bg_cache);
+ return ret;
+}
+
+/*
+ * Unlock a full stripe.
+ *
+ * NOTE: Caller must ensure it's the same context calling corresponding
+ * lock_full_stripe().
+ *
+ * Return 0 if we unlock full stripe without problem.
+ * Return <0 for error
+ */
+static int unlock_full_stripe(struct btrfs_fs_info *fs_info, u64 bytenr,
+ bool locked)
+{
+ struct btrfs_block_group *bg_cache;
+ struct btrfs_full_stripe_locks_tree *locks_root;
+ struct full_stripe_lock *fstripe_lock;
+ u64 fstripe_start;
+ bool freeit = false;
+ int ret = 0;
+
+ /* If we didn't acquire full stripe lock, no need to continue */
+ if (!locked)
+ return 0;
+
+ bg_cache = btrfs_lookup_block_group(fs_info, bytenr);
+ if (!bg_cache) {
+ ASSERT(0);
+ return -ENOENT;
+ }
+ if (!(bg_cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK))
+ goto out;
+
+ locks_root = &bg_cache->full_stripe_locks_root;
+ fstripe_start = get_full_stripe_logical(bg_cache, bytenr);
+
+ mutex_lock(&locks_root->lock);
+ fstripe_lock = search_full_stripe_lock(locks_root, fstripe_start);
+ /* Unpaired unlock_full_stripe() detected */
+ if (!fstripe_lock) {
+ WARN_ON(1);
+ ret = -ENOENT;
+ mutex_unlock(&locks_root->lock);
+ goto out;
+ }
+
+ if (fstripe_lock->refs == 0) {
+ WARN_ON(1);
+ btrfs_warn(fs_info, "full stripe lock at %llu refcount underflow",
+ fstripe_lock->logical);
+ } else {
+ fstripe_lock->refs--;
+ }
+
+ if (fstripe_lock->refs == 0) {
+ rb_erase(&fstripe_lock->node, &locks_root->root);
+ freeit = true;
+ }
+ mutex_unlock(&locks_root->lock);
+
+ mutex_unlock(&fstripe_lock->mutex);
+ if (freeit)
+ kfree(fstripe_lock);
+out:
+ btrfs_put_block_group(bg_cache);
+ return ret;
+}
+
+static void scrub_free_csums(struct scrub_ctx *sctx)
+{
+ while (!list_empty(&sctx->csum_list)) {
+ struct btrfs_ordered_sum *sum;
+ sum = list_first_entry(&sctx->csum_list,
+ struct btrfs_ordered_sum, list);
+ list_del(&sum->list);
+ kfree(sum);
+ }
+}
+
+static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
+{
+ int i;
+
+ if (!sctx)
+ return;
+
+ /* this can happen when scrub is cancelled */
+ if (sctx->curr != -1) {
+ struct scrub_bio *sbio = sctx->bios[sctx->curr];
+
+ for (i = 0; i < sbio->sector_count; i++)
+ scrub_block_put(sbio->sectors[i]->sblock);
+ bio_put(sbio->bio);
+ }
+
+ for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
+ struct scrub_bio *sbio = sctx->bios[i];
+
+ if (!sbio)
+ break;
+ kfree(sbio);
+ }
+
+ kfree(sctx->wr_curr_bio);
+ scrub_free_csums(sctx);
+ kfree(sctx);
+}
+
+static void scrub_put_ctx(struct scrub_ctx *sctx)
+{
+ if (refcount_dec_and_test(&sctx->refs))
+ scrub_free_ctx(sctx);
+}
+
+static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
+ struct btrfs_fs_info *fs_info, int is_dev_replace)
+{
+ struct scrub_ctx *sctx;
+ int i;
+
+ sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
+ if (!sctx)
+ goto nomem;
+ refcount_set(&sctx->refs, 1);
+ sctx->is_dev_replace = is_dev_replace;
+ sctx->sectors_per_bio = SCRUB_SECTORS_PER_BIO;
+ sctx->curr = -1;
+ sctx->fs_info = fs_info;
+ INIT_LIST_HEAD(&sctx->csum_list);
+ for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
+ struct scrub_bio *sbio;
+
+ sbio = kzalloc(sizeof(*sbio), GFP_KERNEL);
+ if (!sbio)
+ goto nomem;
+ sctx->bios[i] = sbio;
+
+ sbio->index = i;
+ sbio->sctx = sctx;
+ sbio->sector_count = 0;
+ INIT_WORK(&sbio->work, scrub_bio_end_io_worker);
+
+ if (i != SCRUB_BIOS_PER_SCTX - 1)
+ sctx->bios[i]->next_free = i + 1;
+ else
+ sctx->bios[i]->next_free = -1;
+ }
+ sctx->first_free = 0;
+ atomic_set(&sctx->bios_in_flight, 0);
+ atomic_set(&sctx->workers_pending, 0);
+ atomic_set(&sctx->cancel_req, 0);
+
+ spin_lock_init(&sctx->list_lock);
+ spin_lock_init(&sctx->stat_lock);
+ init_waitqueue_head(&sctx->list_wait);
+ sctx->throttle_deadline = 0;
+
+ WARN_ON(sctx->wr_curr_bio != NULL);
+ mutex_init(&sctx->wr_lock);
+ sctx->wr_curr_bio = NULL;
+ if (is_dev_replace) {
+ WARN_ON(!fs_info->dev_replace.tgtdev);
+ sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
+ sctx->flush_all_writes = false;
+ }
+
+ return sctx;
+
+nomem:
+ scrub_free_ctx(sctx);
+ return ERR_PTR(-ENOMEM);
+}
+
+static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
+ void *warn_ctx)
+{
+ u32 nlink;
+ int ret;
+ int i;
+ unsigned nofs_flag;
+ struct extent_buffer *eb;
+ struct btrfs_inode_item *inode_item;
+ struct scrub_warning *swarn = warn_ctx;
+ struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
+ struct inode_fs_paths *ipath = NULL;
+ struct btrfs_root *local_root;
+ struct btrfs_key key;
+
+ local_root = btrfs_get_fs_root(fs_info, root, true);
+ if (IS_ERR(local_root)) {
+ ret = PTR_ERR(local_root);
+ goto err;
+ }
+
+ /*
+ * this makes the path point to (inum INODE_ITEM ioff)
+ */
+ key.objectid = inum;
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
+ if (ret) {
+ btrfs_put_root(local_root);
+ btrfs_release_path(swarn->path);
+ goto err;
+ }
+
+ eb = swarn->path->nodes[0];
+ inode_item = btrfs_item_ptr(eb, swarn->path->slots[0],
+ struct btrfs_inode_item);
+ nlink = btrfs_inode_nlink(eb, inode_item);
+ btrfs_release_path(swarn->path);
+
+ /*
+ * init_path might indirectly call vmalloc, or use GFP_KERNEL. Scrub
+ * uses GFP_NOFS in this context, so we keep it consistent but it does
+ * not seem to be strictly necessary.
+ */
+ nofs_flag = memalloc_nofs_save();
+ ipath = init_ipath(4096, local_root, swarn->path);
+ memalloc_nofs_restore(nofs_flag);
+ if (IS_ERR(ipath)) {
+ btrfs_put_root(local_root);
+ ret = PTR_ERR(ipath);
+ ipath = NULL;
+ goto err;
+ }
+ ret = paths_from_inode(inum, ipath);
+
+ if (ret < 0)
+ goto err;
+
+ /*
+ * we deliberately ignore the bit ipath might have been too small to
+ * hold all of the paths here
+ */
+ for (i = 0; i < ipath->fspath->elem_cnt; ++i)
+ btrfs_warn_in_rcu(fs_info,
+"%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu, length %u, links %u (path: %s)",
+ swarn->errstr, swarn->logical,
+ rcu_str_deref(swarn->dev->name),
+ swarn->physical,
+ root, inum, offset,
+ fs_info->sectorsize, nlink,
+ (char *)(unsigned long)ipath->fspath->val[i]);
+
+ btrfs_put_root(local_root);
+ free_ipath(ipath);
+ return 0;
+
+err:
+ btrfs_warn_in_rcu(fs_info,
+ "%s at logical %llu on dev %s, physical %llu, root %llu, inode %llu, offset %llu: path resolving failed with ret=%d",
+ swarn->errstr, swarn->logical,
+ rcu_str_deref(swarn->dev->name),
+ swarn->physical,
+ root, inum, offset, ret);
+
+ free_ipath(ipath);
+ return 0;
+}
+
+static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
+{
+ struct btrfs_device *dev;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_path *path;
+ struct btrfs_key found_key;
+ struct extent_buffer *eb;
+ struct btrfs_extent_item *ei;
+ struct scrub_warning swarn;
+ unsigned long ptr = 0;
+ u64 extent_item_pos;
+ u64 flags = 0;
+ u64 ref_root;
+ u32 item_size;
+ u8 ref_level = 0;
+ int ret;
+
+ WARN_ON(sblock->sector_count < 1);
+ dev = sblock->dev;
+ fs_info = sblock->sctx->fs_info;
+
+ /* Super block error, no need to search extent tree. */
+ if (sblock->sectors[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
+ btrfs_warn_in_rcu(fs_info, "%s on device %s, physical %llu",
+ errstr, rcu_str_deref(dev->name),
+ sblock->physical);
+ return;
+ }
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+
+ swarn.physical = sblock->physical;
+ swarn.logical = sblock->logical;
+ swarn.errstr = errstr;
+ swarn.dev = NULL;
+
+ ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
+ &flags);
+ if (ret < 0)
+ goto out;
+
+ extent_item_pos = swarn.logical - found_key.objectid;
+ swarn.extent_item_size = found_key.offset;
+
+ eb = path->nodes[0];
+ ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
+ item_size = btrfs_item_size(eb, path->slots[0]);
+
+ if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ do {
+ ret = tree_backref_for_extent(&ptr, eb, &found_key, ei,
+ item_size, &ref_root,
+ &ref_level);
+ btrfs_warn_in_rcu(fs_info,
+"%s at logical %llu on dev %s, physical %llu: metadata %s (level %d) in tree %llu",
+ errstr, swarn.logical,
+ rcu_str_deref(dev->name),
+ swarn.physical,
+ ref_level ? "node" : "leaf",
+ ret < 0 ? -1 : ref_level,
+ ret < 0 ? -1 : ref_root);
+ } while (ret != 1);
+ btrfs_release_path(path);
+ } else {
+ btrfs_release_path(path);
+ swarn.path = path;
+ swarn.dev = dev;
+ iterate_extent_inodes(fs_info, found_key.objectid,
+ extent_item_pos, 1,
+ scrub_print_warning_inode, &swarn, false);
+ }
+
+out:
+ btrfs_free_path(path);
+}
+
+static inline void scrub_get_recover(struct scrub_recover *recover)
+{
+ refcount_inc(&recover->refs);
+}
+
+static inline void scrub_put_recover(struct btrfs_fs_info *fs_info,
+ struct scrub_recover *recover)
+{
+ if (refcount_dec_and_test(&recover->refs)) {
+ btrfs_bio_counter_dec(fs_info);
+ btrfs_put_bioc(recover->bioc);
+ kfree(recover);
+ }
+}
+
+/*
+ * scrub_handle_errored_block gets called when either verification of the
+ * sectors failed or the bio failed to read, e.g. with EIO. In the latter
+ * case, this function handles all sectors in the bio, even though only one
+ * may be bad.
+ * The goal of this function is to repair the errored block by using the
+ * contents of one of the mirrors.
+ */
+static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
+{
+ struct scrub_ctx *sctx = sblock_to_check->sctx;
+ struct btrfs_device *dev = sblock_to_check->dev;
+ struct btrfs_fs_info *fs_info;
+ u64 logical;
+ unsigned int failed_mirror_index;
+ unsigned int is_metadata;
+ unsigned int have_csum;
+ /* One scrub_block for each mirror */
+ struct scrub_block *sblocks_for_recheck[BTRFS_MAX_MIRRORS] = { 0 };
+ struct scrub_block *sblock_bad;
+ int ret;
+ int mirror_index;
+ int sector_num;
+ int success;
+ bool full_stripe_locked;
+ unsigned int nofs_flag;
+ static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ BUG_ON(sblock_to_check->sector_count < 1);
+ fs_info = sctx->fs_info;
+ if (sblock_to_check->sectors[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
+ /*
+ * If we find an error in a super block, we just report it.
+ * They will get written with the next transaction commit
+ * anyway
+ */
+ scrub_print_warning("super block error", sblock_to_check);
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ return 0;
+ }
+ logical = sblock_to_check->logical;
+ ASSERT(sblock_to_check->mirror_num);
+ failed_mirror_index = sblock_to_check->mirror_num - 1;
+ is_metadata = !(sblock_to_check->sectors[0]->flags &
+ BTRFS_EXTENT_FLAG_DATA);
+ have_csum = sblock_to_check->sectors[0]->have_csum;
+
+ if (!sctx->is_dev_replace && btrfs_repair_one_zone(fs_info, logical))
+ return 0;
+
+ /*
+ * We must use GFP_NOFS because the scrub task might be waiting for a
+ * worker task executing this function and in turn a transaction commit
+ * might be waiting the scrub task to pause (which needs to wait for all
+ * the worker tasks to complete before pausing).
+ * We do allocations in the workers through insert_full_stripe_lock()
+ * and scrub_add_sector_to_wr_bio(), which happens down the call chain of
+ * this function.
+ */
+ nofs_flag = memalloc_nofs_save();
+ /*
+ * For RAID5/6, race can happen for a different device scrub thread.
+ * For data corruption, Parity and Data threads will both try
+ * to recovery the data.
+ * Race can lead to doubly added csum error, or even unrecoverable
+ * error.
+ */
+ ret = lock_full_stripe(fs_info, logical, &full_stripe_locked);
+ if (ret < 0) {
+ memalloc_nofs_restore(nofs_flag);
+ spin_lock(&sctx->stat_lock);
+ if (ret == -ENOMEM)
+ sctx->stat.malloc_errors++;
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return ret;
+ }
+
+ /*
+ * read all mirrors one after the other. This includes to
+ * re-read the extent or metadata block that failed (that was
+ * the cause that this fixup code is called) another time,
+ * sector by sector this time in order to know which sectors
+ * caused I/O errors and which ones are good (for all mirrors).
+ * It is the goal to handle the situation when more than one
+ * mirror contains I/O errors, but the errors do not
+ * overlap, i.e. the data can be repaired by selecting the
+ * sectors from those mirrors without I/O error on the
+ * particular sectors. One example (with blocks >= 2 * sectorsize)
+ * would be that mirror #1 has an I/O error on the first sector,
+ * the second sector is good, and mirror #2 has an I/O error on
+ * the second sector, but the first sector is good.
+ * Then the first sector of the first mirror can be repaired by
+ * taking the first sector of the second mirror, and the
+ * second sector of the second mirror can be repaired by
+ * copying the contents of the 2nd sector of the 1st mirror.
+ * One more note: if the sectors of one mirror contain I/O
+ * errors, the checksum cannot be verified. In order to get
+ * the best data for repairing, the first attempt is to find
+ * a mirror without I/O errors and with a validated checksum.
+ * Only if this is not possible, the sectors are picked from
+ * mirrors with I/O errors without considering the checksum.
+ * If the latter is the case, at the end, the checksum of the
+ * repaired area is verified in order to correctly maintain
+ * the statistics.
+ */
+ for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; mirror_index++) {
+ /*
+ * Note: the two members refs and outstanding_sectors are not
+ * used in the blocks that are used for the recheck procedure.
+ *
+ * But alloc_scrub_block() will initialize sblock::ref anyway,
+ * so we can use scrub_block_put() to clean them up.
+ *
+ * And here we don't setup the physical/dev for the sblock yet,
+ * they will be correctly initialized in scrub_setup_recheck_block().
+ */
+ sblocks_for_recheck[mirror_index] = alloc_scrub_block(sctx, NULL,
+ logical, 0, 0, mirror_index);
+ if (!sblocks_for_recheck[mirror_index]) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ goto out;
+ }
+ }
+
+ /* Setup the context, map the logical blocks and alloc the sectors */
+ ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
+ if (ret) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ goto out;
+ }
+ BUG_ON(failed_mirror_index >= BTRFS_MAX_MIRRORS);
+ sblock_bad = sblocks_for_recheck[failed_mirror_index];
+
+ /* build and submit the bios for the failed mirror, check checksums */
+ scrub_recheck_block(fs_info, sblock_bad, 1);
+
+ if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
+ sblock_bad->no_io_error_seen) {
+ /*
+ * The error disappeared after reading sector by sector, or
+ * the area was part of a huge bio and other parts of the
+ * bio caused I/O errors, or the block layer merged several
+ * read requests into one and the error is caused by a
+ * different bio (usually one of the two latter cases is
+ * the cause)
+ */
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.unverified_errors++;
+ sblock_to_check->data_corrected = 1;
+ spin_unlock(&sctx->stat_lock);
+
+ if (sctx->is_dev_replace)
+ scrub_write_block_to_dev_replace(sblock_bad);
+ goto out;
+ }
+
+ if (!sblock_bad->no_io_error_seen) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&rs))
+ scrub_print_warning("i/o error", sblock_to_check);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+ } else if (sblock_bad->checksum_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.csum_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&rs))
+ scrub_print_warning("checksum error", sblock_to_check);
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ } else if (sblock_bad->header_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.verify_errors++;
+ spin_unlock(&sctx->stat_lock);
+ if (__ratelimit(&rs))
+ scrub_print_warning("checksum/header error",
+ sblock_to_check);
+ if (sblock_bad->generation_error)
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_GENERATION_ERRS);
+ else
+ btrfs_dev_stat_inc_and_print(dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ }
+
+ if (sctx->readonly) {
+ ASSERT(!sctx->is_dev_replace);
+ goto out;
+ }
+
+ /*
+ * now build and submit the bios for the other mirrors, check
+ * checksums.
+ * First try to pick the mirror which is completely without I/O
+ * errors and also does not have a checksum error.
+ * If one is found, and if a checksum is present, the full block
+ * that is known to contain an error is rewritten. Afterwards
+ * the block is known to be corrected.
+ * If a mirror is found which is completely correct, and no
+ * checksum is present, only those sectors are rewritten that had
+ * an I/O error in the block to be repaired, since it cannot be
+ * determined, which copy of the other sectors is better (and it
+ * could happen otherwise that a correct sector would be
+ * overwritten by a bad one).
+ */
+ for (mirror_index = 0; ;mirror_index++) {
+ struct scrub_block *sblock_other;
+
+ if (mirror_index == failed_mirror_index)
+ continue;
+
+ /* raid56's mirror can be more than BTRFS_MAX_MIRRORS */
+ if (!scrub_is_page_on_raid56(sblock_bad->sectors[0])) {
+ if (mirror_index >= BTRFS_MAX_MIRRORS)
+ break;
+ if (!sblocks_for_recheck[mirror_index]->sector_count)
+ break;
+
+ sblock_other = sblocks_for_recheck[mirror_index];
+ } else {
+ struct scrub_recover *r = sblock_bad->sectors[0]->recover;
+ int max_allowed = r->bioc->num_stripes - r->bioc->num_tgtdevs;
+
+ if (mirror_index >= max_allowed)
+ break;
+ if (!sblocks_for_recheck[1]->sector_count)
+ break;
+
+ ASSERT(failed_mirror_index == 0);
+ sblock_other = sblocks_for_recheck[1];
+ sblock_other->mirror_num = 1 + mirror_index;
+ }
+
+ /* build and submit the bios, check checksums */
+ scrub_recheck_block(fs_info, sblock_other, 0);
+
+ if (!sblock_other->header_error &&
+ !sblock_other->checksum_error &&
+ sblock_other->no_io_error_seen) {
+ if (sctx->is_dev_replace) {
+ scrub_write_block_to_dev_replace(sblock_other);
+ goto corrected_error;
+ } else {
+ ret = scrub_repair_block_from_good_copy(
+ sblock_bad, sblock_other);
+ if (!ret)
+ goto corrected_error;
+ }
+ }
+ }
+
+ if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
+ goto did_not_correct_error;
+
+ /*
+ * In case of I/O errors in the area that is supposed to be
+ * repaired, continue by picking good copies of those sectors.
+ * Select the good sectors from mirrors to rewrite bad sectors from
+ * the area to fix. Afterwards verify the checksum of the block
+ * that is supposed to be repaired. This verification step is
+ * only done for the purpose of statistic counting and for the
+ * final scrub report, whether errors remain.
+ * A perfect algorithm could make use of the checksum and try
+ * all possible combinations of sectors from the different mirrors
+ * until the checksum verification succeeds. For example, when
+ * the 2nd sector of mirror #1 faces I/O errors, and the 2nd sector
+ * of mirror #2 is readable but the final checksum test fails,
+ * then the 2nd sector of mirror #3 could be tried, whether now
+ * the final checksum succeeds. But this would be a rare
+ * exception and is therefore not implemented. At least it is
+ * avoided that the good copy is overwritten.
+ * A more useful improvement would be to pick the sectors
+ * without I/O error based on sector sizes (512 bytes on legacy
+ * disks) instead of on sectorsize. Then maybe 512 byte of one
+ * mirror could be repaired by taking 512 byte of a different
+ * mirror, even if other 512 byte sectors in the same sectorsize
+ * area are unreadable.
+ */
+ success = 1;
+ for (sector_num = 0; sector_num < sblock_bad->sector_count;
+ sector_num++) {
+ struct scrub_sector *sector_bad = sblock_bad->sectors[sector_num];
+ struct scrub_block *sblock_other = NULL;
+
+ /* Skip no-io-error sectors in scrub */
+ if (!sector_bad->io_error && !sctx->is_dev_replace)
+ continue;
+
+ if (scrub_is_page_on_raid56(sblock_bad->sectors[0])) {
+ /*
+ * In case of dev replace, if raid56 rebuild process
+ * didn't work out correct data, then copy the content
+ * in sblock_bad to make sure target device is identical
+ * to source device, instead of writing garbage data in
+ * sblock_for_recheck array to target device.
+ */
+ sblock_other = NULL;
+ } else if (sector_bad->io_error) {
+ /* Try to find no-io-error sector in mirrors */
+ for (mirror_index = 0;
+ mirror_index < BTRFS_MAX_MIRRORS &&
+ sblocks_for_recheck[mirror_index]->sector_count > 0;
+ mirror_index++) {
+ if (!sblocks_for_recheck[mirror_index]->
+ sectors[sector_num]->io_error) {
+ sblock_other = sblocks_for_recheck[mirror_index];
+ break;
+ }
+ }
+ if (!sblock_other)
+ success = 0;
+ }
+
+ if (sctx->is_dev_replace) {
+ /*
+ * Did not find a mirror to fetch the sector from.
+ * scrub_write_sector_to_dev_replace() handles this
+ * case (sector->io_error), by filling the block with
+ * zeros before submitting the write request
+ */
+ if (!sblock_other)
+ sblock_other = sblock_bad;
+
+ if (scrub_write_sector_to_dev_replace(sblock_other,
+ sector_num) != 0) {
+ atomic64_inc(
+ &fs_info->dev_replace.num_write_errors);
+ success = 0;
+ }
+ } else if (sblock_other) {
+ ret = scrub_repair_sector_from_good_copy(sblock_bad,
+ sblock_other,
+ sector_num, 0);
+ if (0 == ret)
+ sector_bad->io_error = 0;
+ else
+ success = 0;
+ }
+ }
+
+ if (success && !sctx->is_dev_replace) {
+ if (is_metadata || have_csum) {
+ /*
+ * need to verify the checksum now that all
+ * sectors on disk are repaired (the write
+ * request for data to be repaired is on its way).
+ * Just be lazy and use scrub_recheck_block()
+ * which re-reads the data before the checksum
+ * is verified, but most likely the data comes out
+ * of the page cache.
+ */
+ scrub_recheck_block(fs_info, sblock_bad, 1);
+ if (!sblock_bad->header_error &&
+ !sblock_bad->checksum_error &&
+ sblock_bad->no_io_error_seen)
+ goto corrected_error;
+ else
+ goto did_not_correct_error;
+ } else {
+corrected_error:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.corrected_errors++;
+ sblock_to_check->data_corrected = 1;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "fixed up error at logical %llu on dev %s",
+ logical, rcu_str_deref(dev->name));
+ }
+ } else {
+did_not_correct_error:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "unable to fixup (regular) error at logical %llu on dev %s",
+ logical, rcu_str_deref(dev->name));
+ }
+
+out:
+ for (mirror_index = 0; mirror_index < BTRFS_MAX_MIRRORS; mirror_index++) {
+ struct scrub_block *sblock = sblocks_for_recheck[mirror_index];
+ struct scrub_recover *recover;
+ int sector_index;
+
+ /* Not allocated, continue checking the next mirror */
+ if (!sblock)
+ continue;
+
+ for (sector_index = 0; sector_index < sblock->sector_count;
+ sector_index++) {
+ /*
+ * Here we just cleanup the recover, each sector will be
+ * properly cleaned up by later scrub_block_put()
+ */
+ recover = sblock->sectors[sector_index]->recover;
+ if (recover) {
+ scrub_put_recover(fs_info, recover);
+ sblock->sectors[sector_index]->recover = NULL;
+ }
+ }
+ scrub_block_put(sblock);
+ }
+
+ ret = unlock_full_stripe(fs_info, logical, full_stripe_locked);
+ memalloc_nofs_restore(nofs_flag);
+ if (ret < 0)
+ return ret;
+ return 0;
+}
+
+static inline int scrub_nr_raid_mirrors(struct btrfs_io_context *bioc)
+{
+ if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID5)
+ return 2;
+ else if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID6)
+ return 3;
+ else
+ return (int)bioc->num_stripes;
+}
+
+static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
+ u64 *raid_map,
+ int nstripes, int mirror,
+ int *stripe_index,
+ u64 *stripe_offset)
+{
+ int i;
+
+ if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ /* RAID5/6 */
+ for (i = 0; i < nstripes; i++) {
+ if (raid_map[i] == RAID6_Q_STRIPE ||
+ raid_map[i] == RAID5_P_STRIPE)
+ continue;
+
+ if (logical >= raid_map[i] &&
+ logical < raid_map[i] + BTRFS_STRIPE_LEN)
+ break;
+ }
+
+ *stripe_index = i;
+ *stripe_offset = logical - raid_map[i];
+ } else {
+ /* The other RAID type */
+ *stripe_index = mirror;
+ *stripe_offset = 0;
+ }
+}
+
+static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
+ struct scrub_block *sblocks_for_recheck[])
+{
+ struct scrub_ctx *sctx = original_sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 logical = original_sblock->logical;
+ u64 length = original_sblock->sector_count << fs_info->sectorsize_bits;
+ u64 generation = original_sblock->sectors[0]->generation;
+ u64 flags = original_sblock->sectors[0]->flags;
+ u64 have_csum = original_sblock->sectors[0]->have_csum;
+ struct scrub_recover *recover;
+ struct btrfs_io_context *bioc;
+ u64 sublen;
+ u64 mapped_length;
+ u64 stripe_offset;
+ int stripe_index;
+ int sector_index = 0;
+ int mirror_index;
+ int nmirrors;
+ int ret;
+
+ while (length > 0) {
+ sublen = min_t(u64, length, fs_info->sectorsize);
+ mapped_length = sublen;
+ bioc = NULL;
+
+ /*
+ * With a length of sectorsize, each returned stripe represents
+ * one mirror
+ */
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
+ logical, &mapped_length, &bioc);
+ if (ret || !bioc || mapped_length < sublen) {
+ btrfs_put_bioc(bioc);
+ btrfs_bio_counter_dec(fs_info);
+ return -EIO;
+ }
+
+ recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
+ if (!recover) {
+ btrfs_put_bioc(bioc);
+ btrfs_bio_counter_dec(fs_info);
+ return -ENOMEM;
+ }
+
+ refcount_set(&recover->refs, 1);
+ recover->bioc = bioc;
+ recover->map_length = mapped_length;
+
+ ASSERT(sector_index < SCRUB_MAX_SECTORS_PER_BLOCK);
+
+ nmirrors = min(scrub_nr_raid_mirrors(bioc), BTRFS_MAX_MIRRORS);
+
+ for (mirror_index = 0; mirror_index < nmirrors;
+ mirror_index++) {
+ struct scrub_block *sblock;
+ struct scrub_sector *sector;
+
+ sblock = sblocks_for_recheck[mirror_index];
+ sblock->sctx = sctx;
+
+ sector = alloc_scrub_sector(sblock, logical, GFP_NOFS);
+ if (!sector) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_put_recover(fs_info, recover);
+ return -ENOMEM;
+ }
+ sector->flags = flags;
+ sector->generation = generation;
+ sector->have_csum = have_csum;
+ if (have_csum)
+ memcpy(sector->csum,
+ original_sblock->sectors[0]->csum,
+ sctx->fs_info->csum_size);
+
+ scrub_stripe_index_and_offset(logical,
+ bioc->map_type,
+ bioc->raid_map,
+ bioc->num_stripes -
+ bioc->num_tgtdevs,
+ mirror_index,
+ &stripe_index,
+ &stripe_offset);
+ /*
+ * We're at the first sector, also populate @sblock
+ * physical and dev.
+ */
+ if (sector_index == 0) {
+ sblock->physical =
+ bioc->stripes[stripe_index].physical +
+ stripe_offset;
+ sblock->dev = bioc->stripes[stripe_index].dev;
+ sblock->physical_for_dev_replace =
+ original_sblock->physical_for_dev_replace;
+ }
+
+ BUG_ON(sector_index >= original_sblock->sector_count);
+ scrub_get_recover(recover);
+ sector->recover = recover;
+ }
+ scrub_put_recover(fs_info, recover);
+ length -= sublen;
+ logical += sublen;
+ sector_index++;
+ }
+
+ return 0;
+}
+
+static void scrub_bio_wait_endio(struct bio *bio)
+{
+ complete(bio->bi_private);
+}
+
+static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
+ struct bio *bio,
+ struct scrub_sector *sector)
+{
+ DECLARE_COMPLETION_ONSTACK(done);
+
+ bio->bi_iter.bi_sector = (sector->offset + sector->sblock->logical) >>
+ SECTOR_SHIFT;
+ bio->bi_private = &done;
+ bio->bi_end_io = scrub_bio_wait_endio;
+ raid56_parity_recover(bio, sector->recover->bioc, sector->sblock->mirror_num);
+
+ wait_for_completion_io(&done);
+ return blk_status_to_errno(bio->bi_status);
+}
+
+static void scrub_recheck_block_on_raid56(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock)
+{
+ struct scrub_sector *first_sector = sblock->sectors[0];
+ struct bio *bio;
+ int i;
+
+ /* All sectors in sblock belong to the same stripe on the same device. */
+ ASSERT(sblock->dev);
+ if (!sblock->dev->bdev)
+ goto out;
+
+ bio = bio_alloc(sblock->dev->bdev, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
+
+ for (i = 0; i < sblock->sector_count; i++) {
+ struct scrub_sector *sector = sblock->sectors[i];
+
+ bio_add_scrub_sector(bio, sector, fs_info->sectorsize);
+ }
+
+ if (scrub_submit_raid56_bio_wait(fs_info, bio, first_sector)) {
+ bio_put(bio);
+ goto out;
+ }
+
+ bio_put(bio);
+
+ scrub_recheck_block_checksum(sblock);
+
+ return;
+out:
+ for (i = 0; i < sblock->sector_count; i++)
+ sblock->sectors[i]->io_error = 1;
+
+ sblock->no_io_error_seen = 0;
+}
+
+/*
+ * This function will check the on disk data for checksum errors, header errors
+ * and read I/O errors. If any I/O errors happen, the exact sectors which are
+ * errored are marked as being bad. The goal is to enable scrub to take those
+ * sectors that are not errored from all the mirrors so that the sectors that
+ * are errored in the just handled mirror can be repaired.
+ */
+static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int retry_failed_mirror)
+{
+ int i;
+
+ sblock->no_io_error_seen = 1;
+
+ /* short cut for raid56 */
+ if (!retry_failed_mirror && scrub_is_page_on_raid56(sblock->sectors[0]))
+ return scrub_recheck_block_on_raid56(fs_info, sblock);
+
+ for (i = 0; i < sblock->sector_count; i++) {
+ struct scrub_sector *sector = sblock->sectors[i];
+ struct bio bio;
+ struct bio_vec bvec;
+
+ if (sblock->dev->bdev == NULL) {
+ sector->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ continue;
+ }
+
+ bio_init(&bio, sblock->dev->bdev, &bvec, 1, REQ_OP_READ);
+ bio_add_scrub_sector(&bio, sector, fs_info->sectorsize);
+ bio.bi_iter.bi_sector = (sblock->physical + sector->offset) >>
+ SECTOR_SHIFT;
+
+ btrfsic_check_bio(&bio);
+ if (submit_bio_wait(&bio)) {
+ sector->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ }
+
+ bio_uninit(&bio);
+ }
+
+ if (sblock->no_io_error_seen)
+ scrub_recheck_block_checksum(sblock);
+}
+
+static inline int scrub_check_fsid(u8 fsid[], struct scrub_sector *sector)
+{
+ struct btrfs_fs_devices *fs_devices = sector->sblock->dev->fs_devices;
+ int ret;
+
+ ret = memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
+ return !ret;
+}
+
+static void scrub_recheck_block_checksum(struct scrub_block *sblock)
+{
+ sblock->header_error = 0;
+ sblock->checksum_error = 0;
+ sblock->generation_error = 0;
+
+ if (sblock->sectors[0]->flags & BTRFS_EXTENT_FLAG_DATA)
+ scrub_checksum_data(sblock);
+ else
+ scrub_checksum_tree_block(sblock);
+}
+
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good)
+{
+ int i;
+ int ret = 0;
+
+ for (i = 0; i < sblock_bad->sector_count; i++) {
+ int ret_sub;
+
+ ret_sub = scrub_repair_sector_from_good_copy(sblock_bad,
+ sblock_good, i, 1);
+ if (ret_sub)
+ ret = ret_sub;
+ }
+
+ return ret;
+}
+
+static int scrub_repair_sector_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int sector_num, int force_write)
+{
+ struct scrub_sector *sector_bad = sblock_bad->sectors[sector_num];
+ struct scrub_sector *sector_good = sblock_good->sectors[sector_num];
+ struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
+ const u32 sectorsize = fs_info->sectorsize;
+
+ if (force_write || sblock_bad->header_error ||
+ sblock_bad->checksum_error || sector_bad->io_error) {
+ struct bio bio;
+ struct bio_vec bvec;
+ int ret;
+
+ if (!sblock_bad->dev->bdev) {
+ btrfs_warn_rl(fs_info,
+ "scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
+ return -EIO;
+ }
+
+ bio_init(&bio, sblock_bad->dev->bdev, &bvec, 1, REQ_OP_WRITE);
+ bio.bi_iter.bi_sector = (sblock_bad->physical +
+ sector_bad->offset) >> SECTOR_SHIFT;
+ ret = bio_add_scrub_sector(&bio, sector_good, sectorsize);
+
+ btrfsic_check_bio(&bio);
+ ret = submit_bio_wait(&bio);
+ bio_uninit(&bio);
+
+ if (ret) {
+ btrfs_dev_stat_inc_and_print(sblock_bad->dev,
+ BTRFS_DEV_STAT_WRITE_ERRS);
+ atomic64_inc(&fs_info->dev_replace.num_write_errors);
+ return -EIO;
+ }
+ }
+
+ return 0;
+}
+
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
+{
+ struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
+ int i;
+
+ /*
+ * This block is used for the check of the parity on the source device,
+ * so the data needn't be written into the destination device.
+ */
+ if (sblock->sparity)
+ return;
+
+ for (i = 0; i < sblock->sector_count; i++) {
+ int ret;
+
+ ret = scrub_write_sector_to_dev_replace(sblock, i);
+ if (ret)
+ atomic64_inc(&fs_info->dev_replace.num_write_errors);
+ }
+}
+
+static int scrub_write_sector_to_dev_replace(struct scrub_block *sblock, int sector_num)
+{
+ const u32 sectorsize = sblock->sctx->fs_info->sectorsize;
+ struct scrub_sector *sector = sblock->sectors[sector_num];
+
+ if (sector->io_error)
+ memset(scrub_sector_get_kaddr(sector), 0, sectorsize);
+
+ return scrub_add_sector_to_wr_bio(sblock->sctx, sector);
+}
+
+static int fill_writer_pointer_gap(struct scrub_ctx *sctx, u64 physical)
+{
+ int ret = 0;
+ u64 length;
+
+ if (!btrfs_is_zoned(sctx->fs_info))
+ return 0;
+
+ if (!btrfs_dev_is_sequential(sctx->wr_tgtdev, physical))
+ return 0;
+
+ if (sctx->write_pointer < physical) {
+ length = physical - sctx->write_pointer;
+
+ ret = btrfs_zoned_issue_zeroout(sctx->wr_tgtdev,
+ sctx->write_pointer, length);
+ if (!ret)
+ sctx->write_pointer = physical;
+ }
+ return ret;
+}
+
+static void scrub_block_get(struct scrub_block *sblock)
+{
+ refcount_inc(&sblock->refs);
+}
+
+static int scrub_add_sector_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_sector *sector)
+{
+ struct scrub_block *sblock = sector->sblock;
+ struct scrub_bio *sbio;
+ int ret;
+ const u32 sectorsize = sctx->fs_info->sectorsize;
+
+ mutex_lock(&sctx->wr_lock);
+again:
+ if (!sctx->wr_curr_bio) {
+ sctx->wr_curr_bio = kzalloc(sizeof(*sctx->wr_curr_bio),
+ GFP_KERNEL);
+ if (!sctx->wr_curr_bio) {
+ mutex_unlock(&sctx->wr_lock);
+ return -ENOMEM;
+ }
+ sctx->wr_curr_bio->sctx = sctx;
+ sctx->wr_curr_bio->sector_count = 0;
+ }
+ sbio = sctx->wr_curr_bio;
+ if (sbio->sector_count == 0) {
+ ret = fill_writer_pointer_gap(sctx, sector->offset +
+ sblock->physical_for_dev_replace);
+ if (ret) {
+ mutex_unlock(&sctx->wr_lock);
+ return ret;
+ }
+
+ sbio->physical = sblock->physical_for_dev_replace + sector->offset;
+ sbio->logical = sblock->logical + sector->offset;
+ sbio->dev = sctx->wr_tgtdev;
+ if (!sbio->bio) {
+ sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
+ REQ_OP_WRITE, GFP_NOFS);
+ }
+ sbio->bio->bi_private = sbio;
+ sbio->bio->bi_end_io = scrub_wr_bio_end_io;
+ sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
+ sbio->status = 0;
+ } else if (sbio->physical + sbio->sector_count * sectorsize !=
+ sblock->physical_for_dev_replace + sector->offset ||
+ sbio->logical + sbio->sector_count * sectorsize !=
+ sblock->logical + sector->offset) {
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ ret = bio_add_scrub_sector(sbio->bio, sector, sectorsize);
+ if (ret != sectorsize) {
+ if (sbio->sector_count < 1) {
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ mutex_unlock(&sctx->wr_lock);
+ return -EIO;
+ }
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ sbio->sectors[sbio->sector_count] = sector;
+ scrub_sector_get(sector);
+ /*
+ * Since ssector no longer holds a page, but uses sblock::pages, we
+ * have to ensure the sblock had not been freed before our write bio
+ * finished.
+ */
+ scrub_block_get(sector->sblock);
+
+ sbio->sector_count++;
+ if (sbio->sector_count == sctx->sectors_per_bio)
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ return 0;
+}
+
+static void scrub_wr_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_bio *sbio;
+
+ if (!sctx->wr_curr_bio)
+ return;
+
+ sbio = sctx->wr_curr_bio;
+ sctx->wr_curr_bio = NULL;
+ scrub_pending_bio_inc(sctx);
+ /* process all writes in a single worker thread. Then the block layer
+ * orders the requests before sending them to the driver which
+ * doubled the write performance on spinning disks when measured
+ * with Linux 3.5 */
+ btrfsic_check_bio(sbio->bio);
+ submit_bio(sbio->bio);
+
+ if (btrfs_is_zoned(sctx->fs_info))
+ sctx->write_pointer = sbio->physical + sbio->sector_count *
+ sctx->fs_info->sectorsize;
+}
+
+static void scrub_wr_bio_end_io(struct bio *bio)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
+
+ sbio->status = bio->bi_status;
+ sbio->bio = bio;
+
+ INIT_WORK(&sbio->work, scrub_wr_bio_end_io_worker);
+ queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
+}
+
+static void scrub_wr_bio_end_io_worker(struct work_struct *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ ASSERT(sbio->sector_count <= SCRUB_SECTORS_PER_BIO);
+ if (sbio->status) {
+ struct btrfs_dev_replace *dev_replace =
+ &sbio->sctx->fs_info->dev_replace;
+
+ for (i = 0; i < sbio->sector_count; i++) {
+ struct scrub_sector *sector = sbio->sectors[i];
+
+ sector->io_error = 1;
+ atomic64_inc(&dev_replace->num_write_errors);
+ }
+ }
+
+ /*
+ * In scrub_add_sector_to_wr_bio() we grab extra ref for sblock, now in
+ * endio we should put the sblock.
+ */
+ for (i = 0; i < sbio->sector_count; i++) {
+ scrub_block_put(sbio->sectors[i]->sblock);
+ scrub_sector_put(sbio->sectors[i]);
+ }
+
+ bio_put(sbio->bio);
+ kfree(sbio);
+ scrub_pending_bio_dec(sctx);
+}
+
+static int scrub_checksum(struct scrub_block *sblock)
+{
+ u64 flags;
+ int ret;
+
+ /*
+ * No need to initialize these stats currently,
+ * because this function only use return value
+ * instead of these stats value.
+ *
+ * Todo:
+ * always use stats
+ */
+ sblock->header_error = 0;
+ sblock->generation_error = 0;
+ sblock->checksum_error = 0;
+
+ WARN_ON(sblock->sector_count < 1);
+ flags = sblock->sectors[0]->flags;
+ ret = 0;
+ if (flags & BTRFS_EXTENT_FLAG_DATA)
+ ret = scrub_checksum_data(sblock);
+ else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+ ret = scrub_checksum_tree_block(sblock);
+ else if (flags & BTRFS_EXTENT_FLAG_SUPER)
+ ret = scrub_checksum_super(sblock);
+ else
+ WARN_ON(1);
+ if (ret)
+ scrub_handle_errored_block(sblock);
+
+ return ret;
+}
+
+static int scrub_checksum_data(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+ u8 csum[BTRFS_CSUM_SIZE];
+ struct scrub_sector *sector;
+ char *kaddr;
+
+ BUG_ON(sblock->sector_count < 1);
+ sector = sblock->sectors[0];
+ if (!sector->have_csum)
+ return 0;
+
+ kaddr = scrub_sector_get_kaddr(sector);
+
+ shash->tfm = fs_info->csum_shash;
+ crypto_shash_init(shash);
+
+ crypto_shash_digest(shash, kaddr, fs_info->sectorsize, csum);
+
+ if (memcmp(csum, sector->csum, fs_info->csum_size))
+ sblock->checksum_error = 1;
+ return sblock->checksum_error;
+}
+
+static int scrub_checksum_tree_block(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_header *h;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u8 on_disk_csum[BTRFS_CSUM_SIZE];
+ /*
+ * This is done in sectorsize steps even for metadata as there's a
+ * constraint for nodesize to be aligned to sectorsize. This will need
+ * to change so we don't misuse data and metadata units like that.
+ */
+ const u32 sectorsize = sctx->fs_info->sectorsize;
+ const int num_sectors = fs_info->nodesize >> fs_info->sectorsize_bits;
+ int i;
+ struct scrub_sector *sector;
+ char *kaddr;
+
+ BUG_ON(sblock->sector_count < 1);
+
+ /* Each member in sectors is just one sector */
+ ASSERT(sblock->sector_count == num_sectors);
+
+ sector = sblock->sectors[0];
+ kaddr = scrub_sector_get_kaddr(sector);
+ h = (struct btrfs_header *)kaddr;
+ memcpy(on_disk_csum, h->csum, sctx->fs_info->csum_size);
+
+ /*
+ * we don't use the getter functions here, as we
+ * a) don't have an extent buffer and
+ * b) the page is already kmapped
+ */
+ if (sblock->logical != btrfs_stack_header_bytenr(h)) {
+ sblock->header_error = 1;
+ btrfs_warn_rl(fs_info,
+ "tree block %llu mirror %u has bad bytenr, has %llu want %llu",
+ sblock->logical, sblock->mirror_num,
+ btrfs_stack_header_bytenr(h),
+ sblock->logical);
+ goto out;
+ }
+
+ if (!scrub_check_fsid(h->fsid, sector)) {
+ sblock->header_error = 1;
+ btrfs_warn_rl(fs_info,
+ "tree block %llu mirror %u has bad fsid, has %pU want %pU",
+ sblock->logical, sblock->mirror_num,
+ h->fsid, sblock->dev->fs_devices->fsid);
+ goto out;
+ }
+
+ if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid, BTRFS_UUID_SIZE)) {
+ sblock->header_error = 1;
+ btrfs_warn_rl(fs_info,
+ "tree block %llu mirror %u has bad chunk tree uuid, has %pU want %pU",
+ sblock->logical, sblock->mirror_num,
+ h->chunk_tree_uuid, fs_info->chunk_tree_uuid);
+ goto out;
+ }
+
+ shash->tfm = fs_info->csum_shash;
+ crypto_shash_init(shash);
+ crypto_shash_update(shash, kaddr + BTRFS_CSUM_SIZE,
+ sectorsize - BTRFS_CSUM_SIZE);
+
+ for (i = 1; i < num_sectors; i++) {
+ kaddr = scrub_sector_get_kaddr(sblock->sectors[i]);
+ crypto_shash_update(shash, kaddr, sectorsize);
+ }
+
+ crypto_shash_final(shash, calculated_csum);
+ if (memcmp(calculated_csum, on_disk_csum, sctx->fs_info->csum_size)) {
+ sblock->checksum_error = 1;
+ btrfs_warn_rl(fs_info,
+ "tree block %llu mirror %u has bad csum, has " CSUM_FMT " want " CSUM_FMT,
+ sblock->logical, sblock->mirror_num,
+ CSUM_FMT_VALUE(fs_info->csum_size, on_disk_csum),
+ CSUM_FMT_VALUE(fs_info->csum_size, calculated_csum));
+ goto out;
+ }
+
+ if (sector->generation != btrfs_stack_header_generation(h)) {
+ sblock->header_error = 1;
+ sblock->generation_error = 1;
+ btrfs_warn_rl(fs_info,
+ "tree block %llu mirror %u has bad generation, has %llu want %llu",
+ sblock->logical, sblock->mirror_num,
+ btrfs_stack_header_generation(h),
+ sector->generation);
+ }
+
+out:
+ return sblock->header_error || sblock->checksum_error;
+}
+
+static int scrub_checksum_super(struct scrub_block *sblock)
+{
+ struct btrfs_super_block *s;
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ struct scrub_sector *sector;
+ char *kaddr;
+ int fail_gen = 0;
+ int fail_cor = 0;
+
+ BUG_ON(sblock->sector_count < 1);
+ sector = sblock->sectors[0];
+ kaddr = scrub_sector_get_kaddr(sector);
+ s = (struct btrfs_super_block *)kaddr;
+
+ if (sblock->logical != btrfs_super_bytenr(s))
+ ++fail_cor;
+
+ if (sector->generation != btrfs_super_generation(s))
+ ++fail_gen;
+
+ if (!scrub_check_fsid(s->fsid, sector))
+ ++fail_cor;
+
+ shash->tfm = fs_info->csum_shash;
+ crypto_shash_init(shash);
+ crypto_shash_digest(shash, kaddr + BTRFS_CSUM_SIZE,
+ BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, calculated_csum);
+
+ if (memcmp(calculated_csum, s->csum, sctx->fs_info->csum_size))
+ ++fail_cor;
+
+ return fail_cor + fail_gen;
+}
+
+static void scrub_block_put(struct scrub_block *sblock)
+{
+ if (refcount_dec_and_test(&sblock->refs)) {
+ int i;
+
+ if (sblock->sparity)
+ scrub_parity_put(sblock->sparity);
+
+ for (i = 0; i < sblock->sector_count; i++)
+ scrub_sector_put(sblock->sectors[i]);
+ for (i = 0; i < DIV_ROUND_UP(sblock->len, PAGE_SIZE); i++) {
+ if (sblock->pages[i]) {
+ detach_scrub_page_private(sblock->pages[i]);
+ __free_page(sblock->pages[i]);
+ }
+ }
+ kfree(sblock);
+ }
+}
+
+static void scrub_sector_get(struct scrub_sector *sector)
+{
+ atomic_inc(&sector->refs);
+}
+
+static void scrub_sector_put(struct scrub_sector *sector)
+{
+ if (atomic_dec_and_test(&sector->refs))
+ kfree(sector);
+}
+
+/*
+ * Throttling of IO submission, bandwidth-limit based, the timeslice is 1
+ * second. Limit can be set via /sys/fs/UUID/devinfo/devid/scrub_speed_max.
+ */
+static void scrub_throttle(struct scrub_ctx *sctx)
+{
+ const int time_slice = 1000;
+ struct scrub_bio *sbio;
+ struct btrfs_device *device;
+ s64 delta;
+ ktime_t now;
+ u32 div;
+ u64 bwlimit;
+
+ sbio = sctx->bios[sctx->curr];
+ device = sbio->dev;
+ bwlimit = READ_ONCE(device->scrub_speed_max);
+ if (bwlimit == 0)
+ return;
+
+ /*
+ * Slice is divided into intervals when the IO is submitted, adjust by
+ * bwlimit and maximum of 64 intervals.
+ */
+ div = max_t(u32, 1, (u32)(bwlimit / (16 * 1024 * 1024)));
+ div = min_t(u32, 64, div);
+
+ /* Start new epoch, set deadline */
+ now = ktime_get();
+ if (sctx->throttle_deadline == 0) {
+ sctx->throttle_deadline = ktime_add_ms(now, time_slice / div);
+ sctx->throttle_sent = 0;
+ }
+
+ /* Still in the time to send? */
+ if (ktime_before(now, sctx->throttle_deadline)) {
+ /* If current bio is within the limit, send it */
+ sctx->throttle_sent += sbio->bio->bi_iter.bi_size;
+ if (sctx->throttle_sent <= div_u64(bwlimit, div))
+ return;
+
+ /* We're over the limit, sleep until the rest of the slice */
+ delta = ktime_ms_delta(sctx->throttle_deadline, now);
+ } else {
+ /* New request after deadline, start new epoch */
+ delta = 0;
+ }
+
+ if (delta) {
+ long timeout;
+
+ timeout = div_u64(delta * HZ, 1000);
+ schedule_timeout_interruptible(timeout);
+ }
+
+ /* Next call will start the deadline period */
+ sctx->throttle_deadline = 0;
+}
+
+static void scrub_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_bio *sbio;
+
+ if (sctx->curr == -1)
+ return;
+
+ scrub_throttle(sctx);
+
+ sbio = sctx->bios[sctx->curr];
+ sctx->curr = -1;
+ scrub_pending_bio_inc(sctx);
+ btrfsic_check_bio(sbio->bio);
+ submit_bio(sbio->bio);
+}
+
+static int scrub_add_sector_to_rd_bio(struct scrub_ctx *sctx,
+ struct scrub_sector *sector)
+{
+ struct scrub_block *sblock = sector->sblock;
+ struct scrub_bio *sbio;
+ const u32 sectorsize = sctx->fs_info->sectorsize;
+ int ret;
+
+again:
+ /*
+ * grab a fresh bio or wait for one to become available
+ */
+ while (sctx->curr == -1) {
+ spin_lock(&sctx->list_lock);
+ sctx->curr = sctx->first_free;
+ if (sctx->curr != -1) {
+ sctx->first_free = sctx->bios[sctx->curr]->next_free;
+ sctx->bios[sctx->curr]->next_free = -1;
+ sctx->bios[sctx->curr]->sector_count = 0;
+ spin_unlock(&sctx->list_lock);
+ } else {
+ spin_unlock(&sctx->list_lock);
+ wait_event(sctx->list_wait, sctx->first_free != -1);
+ }
+ }
+ sbio = sctx->bios[sctx->curr];
+ if (sbio->sector_count == 0) {
+ sbio->physical = sblock->physical + sector->offset;
+ sbio->logical = sblock->logical + sector->offset;
+ sbio->dev = sblock->dev;
+ if (!sbio->bio) {
+ sbio->bio = bio_alloc(sbio->dev->bdev, sctx->sectors_per_bio,
+ REQ_OP_READ, GFP_NOFS);
+ }
+ sbio->bio->bi_private = sbio;
+ sbio->bio->bi_end_io = scrub_bio_end_io;
+ sbio->bio->bi_iter.bi_sector = sbio->physical >> 9;
+ sbio->status = 0;
+ } else if (sbio->physical + sbio->sector_count * sectorsize !=
+ sblock->physical + sector->offset ||
+ sbio->logical + sbio->sector_count * sectorsize !=
+ sblock->logical + sector->offset ||
+ sbio->dev != sblock->dev) {
+ scrub_submit(sctx);
+ goto again;
+ }
+
+ sbio->sectors[sbio->sector_count] = sector;
+ ret = bio_add_scrub_sector(sbio->bio, sector, sectorsize);
+ if (ret != sectorsize) {
+ if (sbio->sector_count < 1) {
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ return -EIO;
+ }
+ scrub_submit(sctx);
+ goto again;
+ }
+
+ scrub_block_get(sblock); /* one for the page added to the bio */
+ atomic_inc(&sblock->outstanding_sectors);
+ sbio->sector_count++;
+ if (sbio->sector_count == sctx->sectors_per_bio)
+ scrub_submit(sctx);
+
+ return 0;
+}
+
+static void scrub_missing_raid56_end_io(struct bio *bio)
+{
+ struct scrub_block *sblock = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
+
+ btrfs_bio_counter_dec(fs_info);
+ if (bio->bi_status)
+ sblock->no_io_error_seen = 0;
+
+ bio_put(bio);
+
+ queue_work(fs_info->scrub_workers, &sblock->work);
+}
+
+static void scrub_missing_raid56_worker(struct work_struct *work)
+{
+ struct scrub_block *sblock = container_of(work, struct scrub_block, work);
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 logical;
+ struct btrfs_device *dev;
+
+ logical = sblock->logical;
+ dev = sblock->dev;
+
+ if (sblock->no_io_error_seen)
+ scrub_recheck_block_checksum(sblock);
+
+ if (!sblock->no_io_error_seen) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "IO error rebuilding logical %llu for dev %s",
+ logical, rcu_str_deref(dev->name));
+ } else if (sblock->header_error || sblock->checksum_error) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_err_rl_in_rcu(fs_info,
+ "failed to rebuild valid logical %llu for dev %s",
+ logical, rcu_str_deref(dev->name));
+ } else {
+ scrub_write_block_to_dev_replace(sblock);
+ }
+
+ if (sctx->is_dev_replace && sctx->flush_all_writes) {
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ }
+
+ scrub_block_put(sblock);
+ scrub_pending_bio_dec(sctx);
+}
+
+static void scrub_missing_raid56_pages(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ u64 length = sblock->sector_count << fs_info->sectorsize_bits;
+ u64 logical = sblock->logical;
+ struct btrfs_io_context *bioc = NULL;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ int ret;
+ int i;
+
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
+ &length, &bioc);
+ if (ret || !bioc || !bioc->raid_map)
+ goto bioc_out;
+
+ if (WARN_ON(!sctx->is_dev_replace ||
+ !(bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK))) {
+ /*
+ * We shouldn't be scrubbing a missing device. Even for dev
+ * replace, we should only get here for RAID 5/6. We either
+ * managed to mount something with no mirrors remaining or
+ * there's a bug in scrub_find_good_copy()/btrfs_map_block().
+ */
+ goto bioc_out;
+ }
+
+ bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
+ bio->bi_iter.bi_sector = logical >> 9;
+ bio->bi_private = sblock;
+ bio->bi_end_io = scrub_missing_raid56_end_io;
+
+ rbio = raid56_alloc_missing_rbio(bio, bioc);
+ if (!rbio)
+ goto rbio_out;
+
+ for (i = 0; i < sblock->sector_count; i++) {
+ struct scrub_sector *sector = sblock->sectors[i];
+
+ raid56_add_scrub_pages(rbio, scrub_sector_get_page(sector),
+ scrub_sector_get_page_offset(sector),
+ sector->offset + sector->sblock->logical);
+ }
+
+ INIT_WORK(&sblock->work, scrub_missing_raid56_worker);
+ scrub_block_get(sblock);
+ scrub_pending_bio_inc(sctx);
+ raid56_submit_missing_rbio(rbio);
+ btrfs_put_bioc(bioc);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bioc_out:
+ btrfs_bio_counter_dec(fs_info);
+ btrfs_put_bioc(bioc);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+}
+
+static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum,
+ u64 physical_for_dev_replace)
+{
+ struct scrub_block *sblock;
+ const u32 sectorsize = sctx->fs_info->sectorsize;
+ int index;
+
+ sblock = alloc_scrub_block(sctx, dev, logical, physical,
+ physical_for_dev_replace, mirror_num);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_sector *sector;
+ /*
+ * Here we will allocate one page for one sector to scrub.
+ * This is fine if PAGE_SIZE == sectorsize, but will cost
+ * more memory for PAGE_SIZE > sectorsize case.
+ */
+ u32 l = min(sectorsize, len);
+
+ sector = alloc_scrub_sector(sblock, logical, GFP_KERNEL);
+ if (!sector) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ sector->flags = flags;
+ sector->generation = gen;
+ if (csum) {
+ sector->have_csum = 1;
+ memcpy(sector->csum, csum, sctx->fs_info->csum_size);
+ } else {
+ sector->have_csum = 0;
+ }
+ len -= l;
+ logical += l;
+ physical += l;
+ physical_for_dev_replace += l;
+ }
+
+ WARN_ON(sblock->sector_count == 0);
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
+ /*
+ * This case should only be hit for RAID 5/6 device replace. See
+ * the comment in scrub_missing_raid56_pages() for details.
+ */
+ scrub_missing_raid56_pages(sblock);
+ } else {
+ for (index = 0; index < sblock->sector_count; index++) {
+ struct scrub_sector *sector = sblock->sectors[index];
+ int ret;
+
+ ret = scrub_add_sector_to_rd_bio(sctx, sector);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ if (flags & BTRFS_EXTENT_FLAG_SUPER)
+ scrub_submit(sctx);
+ }
+
+ /* last one frees, either here or in bio completion for last page */
+ scrub_block_put(sblock);
+ return 0;
+}
+
+static void scrub_bio_end_io(struct bio *bio)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
+
+ sbio->status = bio->bi_status;
+ sbio->bio = bio;
+
+ queue_work(fs_info->scrub_workers, &sbio->work);
+}
+
+static void scrub_bio_end_io_worker(struct work_struct *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ ASSERT(sbio->sector_count <= SCRUB_SECTORS_PER_BIO);
+ if (sbio->status) {
+ for (i = 0; i < sbio->sector_count; i++) {
+ struct scrub_sector *sector = sbio->sectors[i];
+
+ sector->io_error = 1;
+ sector->sblock->no_io_error_seen = 0;
+ }
+ }
+
+ /* Now complete the scrub_block items that have all pages completed */
+ for (i = 0; i < sbio->sector_count; i++) {
+ struct scrub_sector *sector = sbio->sectors[i];
+ struct scrub_block *sblock = sector->sblock;
+
+ if (atomic_dec_and_test(&sblock->outstanding_sectors))
+ scrub_block_complete(sblock);
+ scrub_block_put(sblock);
+ }
+
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ spin_lock(&sctx->list_lock);
+ sbio->next_free = sctx->first_free;
+ sctx->first_free = sbio->index;
+ spin_unlock(&sctx->list_lock);
+
+ if (sctx->is_dev_replace && sctx->flush_all_writes) {
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ }
+
+ scrub_pending_bio_dec(sctx);
+}
+
+static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
+ unsigned long *bitmap,
+ u64 start, u32 len)
+{
+ u64 offset;
+ u32 nsectors;
+ u32 sectorsize_bits = sparity->sctx->fs_info->sectorsize_bits;
+
+ if (len >= sparity->stripe_len) {
+ bitmap_set(bitmap, 0, sparity->nsectors);
+ return;
+ }
+
+ start -= sparity->logic_start;
+ start = div64_u64_rem(start, sparity->stripe_len, &offset);
+ offset = offset >> sectorsize_bits;
+ nsectors = len >> sectorsize_bits;
+
+ if (offset + nsectors <= sparity->nsectors) {
+ bitmap_set(bitmap, offset, nsectors);
+ return;
+ }
+
+ bitmap_set(bitmap, offset, sparity->nsectors - offset);
+ bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset));
+}
+
+static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity,
+ u64 start, u32 len)
+{
+ __scrub_mark_bitmap(sparity, &sparity->ebitmap, start, len);
+}
+
+static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
+ u64 start, u32 len)
+{
+ __scrub_mark_bitmap(sparity, &sparity->dbitmap, start, len);
+}
+
+static void scrub_block_complete(struct scrub_block *sblock)
+{
+ int corrupted = 0;
+
+ if (!sblock->no_io_error_seen) {
+ corrupted = 1;
+ scrub_handle_errored_block(sblock);
+ } else {
+ /*
+ * if has checksum error, write via repair mechanism in
+ * dev replace case, otherwise write here in dev replace
+ * case.
+ */
+ corrupted = scrub_checksum(sblock);
+ if (!corrupted && sblock->sctx->is_dev_replace)
+ scrub_write_block_to_dev_replace(sblock);
+ }
+
+ if (sblock->sparity && corrupted && !sblock->data_corrected) {
+ u64 start = sblock->logical;
+ u64 end = sblock->logical +
+ sblock->sectors[sblock->sector_count - 1]->offset +
+ sblock->sctx->fs_info->sectorsize;
+
+ ASSERT(end - start <= U32_MAX);
+ scrub_parity_mark_sectors_error(sblock->sparity,
+ start, end - start);
+ }
+}
+
+static void drop_csum_range(struct scrub_ctx *sctx, struct btrfs_ordered_sum *sum)
+{
+ sctx->stat.csum_discards += sum->len >> sctx->fs_info->sectorsize_bits;
+ list_del(&sum->list);
+ kfree(sum);
+}
+
+/*
+ * Find the desired csum for range [logical, logical + sectorsize), and store
+ * the csum into @csum.
+ *
+ * The search source is sctx->csum_list, which is a pre-populated list
+ * storing bytenr ordered csum ranges. We're responsible to cleanup any range
+ * that is before @logical.
+ *
+ * Return 0 if there is no csum for the range.
+ * Return 1 if there is csum for the range and copied to @csum.
+ */
+static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum)
+{
+ bool found = false;
+
+ while (!list_empty(&sctx->csum_list)) {
+ struct btrfs_ordered_sum *sum = NULL;
+ unsigned long index;
+ unsigned long num_sectors;
+
+ sum = list_first_entry(&sctx->csum_list,
+ struct btrfs_ordered_sum, list);
+ /* The current csum range is beyond our range, no csum found */
+ if (sum->bytenr > logical)
+ break;
+
+ /*
+ * The current sum is before our bytenr, since scrub is always
+ * done in bytenr order, the csum will never be used anymore,
+ * clean it up so that later calls won't bother with the range,
+ * and continue search the next range.
+ */
+ if (sum->bytenr + sum->len <= logical) {
+ drop_csum_range(sctx, sum);
+ continue;
+ }
+
+ /* Now the csum range covers our bytenr, copy the csum */
+ found = true;
+ index = (logical - sum->bytenr) >> sctx->fs_info->sectorsize_bits;
+ num_sectors = sum->len >> sctx->fs_info->sectorsize_bits;
+
+ memcpy(csum, sum->sums + index * sctx->fs_info->csum_size,
+ sctx->fs_info->csum_size);
+
+ /* Cleanup the range if we're at the end of the csum range */
+ if (index == num_sectors - 1)
+ drop_csum_range(sctx, sum);
+ break;
+ }
+ if (!found)
+ return 0;
+ return 1;
+}
+
+/* scrub extent tries to collect up to 64 kB for each bio */
+static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
+ u64 logical, u32 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num)
+{
+ struct btrfs_device *src_dev = dev;
+ u64 src_physical = physical;
+ int src_mirror = mirror_num;
+ int ret;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u32 blocksize;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ blocksize = map->stripe_len;
+ else
+ blocksize = sctx->fs_info->sectorsize;
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.data_extents_scrubbed++;
+ sctx->stat.data_bytes_scrubbed += len;
+ spin_unlock(&sctx->stat_lock);
+ } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
+ blocksize = map->stripe_len;
+ else
+ blocksize = sctx->fs_info->nodesize;
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.tree_extents_scrubbed++;
+ sctx->stat.tree_bytes_scrubbed += len;
+ spin_unlock(&sctx->stat_lock);
+ } else {
+ blocksize = sctx->fs_info->sectorsize;
+ WARN_ON(1);
+ }
+
+ /*
+ * For dev-replace case, we can have @dev being a missing device.
+ * Regular scrub will avoid its execution on missing device at all,
+ * as that would trigger tons of read error.
+ *
+ * Reading from missing device will cause read error counts to
+ * increase unnecessarily.
+ * So here we change the read source to a good mirror.
+ */
+ if (sctx->is_dev_replace && !dev->bdev)
+ scrub_find_good_copy(sctx->fs_info, logical, len, &src_physical,
+ &src_dev, &src_mirror);
+ while (len) {
+ u32 l = min(len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, csum);
+ if (have_csum == 0)
+ ++sctx->stat.no_csum;
+ }
+ ret = scrub_sectors(sctx, logical, l, src_physical, src_dev,
+ flags, gen, src_mirror,
+ have_csum ? csum : NULL, physical);
+ if (ret)
+ return ret;
+ len -= l;
+ logical += l;
+ physical += l;
+ src_physical += l;
+ }
+ return 0;
+}
+
+static int scrub_sectors_for_parity(struct scrub_parity *sparity,
+ u64 logical, u32 len,
+ u64 physical, struct btrfs_device *dev,
+ u64 flags, u64 gen, int mirror_num, u8 *csum)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct scrub_block *sblock;
+ const u32 sectorsize = sctx->fs_info->sectorsize;
+ int index;
+
+ ASSERT(IS_ALIGNED(len, sectorsize));
+
+ sblock = alloc_scrub_block(sctx, dev, logical, physical, physical, mirror_num);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ sblock->sparity = sparity;
+ scrub_parity_get(sparity);
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_sector *sector;
+
+ sector = alloc_scrub_sector(sblock, logical, GFP_KERNEL);
+ if (!sector) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ sblock->sectors[index] = sector;
+ /* For scrub parity */
+ scrub_sector_get(sector);
+ list_add_tail(&sector->list, &sparity->sectors_list);
+ sector->flags = flags;
+ sector->generation = gen;
+ if (csum) {
+ sector->have_csum = 1;
+ memcpy(sector->csum, csum, sctx->fs_info->csum_size);
+ } else {
+ sector->have_csum = 0;
+ }
+
+ /* Iterate over the stripe range in sectorsize steps */
+ len -= sectorsize;
+ logical += sectorsize;
+ physical += sectorsize;
+ }
+
+ WARN_ON(sblock->sector_count == 0);
+ for (index = 0; index < sblock->sector_count; index++) {
+ struct scrub_sector *sector = sblock->sectors[index];
+ int ret;
+
+ ret = scrub_add_sector_to_rd_bio(sctx, sector);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ /* Last one frees, either here or in bio completion for last sector */
+ scrub_block_put(sblock);
+ return 0;
+}
+
+static int scrub_extent_for_parity(struct scrub_parity *sparity,
+ u64 logical, u32 len,
+ u64 physical, struct btrfs_device *dev,
+ u64 flags, u64 gen, int mirror_num)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ int ret;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u32 blocksize;
+
+ if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) {
+ scrub_parity_mark_sectors_error(sparity, logical, len);
+ return 0;
+ }
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ blocksize = sparity->stripe_len;
+ } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ blocksize = sparity->stripe_len;
+ } else {
+ blocksize = sctx->fs_info->sectorsize;
+ WARN_ON(1);
+ }
+
+ while (len) {
+ u32 l = min(len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, csum);
+ if (have_csum == 0)
+ goto skip;
+ }
+ ret = scrub_sectors_for_parity(sparity, logical, l, physical, dev,
+ flags, gen, mirror_num,
+ have_csum ? csum : NULL);
+ if (ret)
+ return ret;
+skip:
+ len -= l;
+ logical += l;
+ physical += l;
+ }
+ return 0;
+}
+
+/*
+ * Given a physical address, this will calculate it's
+ * logical offset. if this is a parity stripe, it will return
+ * the most left data stripe's logical offset.
+ *
+ * return 0 if it is a data stripe, 1 means parity stripe.
+ */
+static int get_raid56_logic_offset(u64 physical, int num,
+ struct map_lookup *map, u64 *offset,
+ u64 *stripe_start)
+{
+ int i;
+ int j = 0;
+ u64 stripe_nr;
+ u64 last_offset;
+ u32 stripe_index;
+ u32 rot;
+ const int data_stripes = nr_data_stripes(map);
+
+ last_offset = (physical - map->stripes[num].physical) * data_stripes;
+ if (stripe_start)
+ *stripe_start = last_offset;
+
+ *offset = last_offset;
+ for (i = 0; i < data_stripes; i++) {
+ *offset = last_offset + i * map->stripe_len;
+
+ stripe_nr = div64_u64(*offset, map->stripe_len);
+ stripe_nr = div_u64(stripe_nr, data_stripes);
+
+ /* Work out the disk rotation on this stripe-set */
+ stripe_nr = div_u64_rem(stripe_nr, map->num_stripes, &rot);
+ /* calculate which stripe this data locates */
+ rot += i;
+ stripe_index = rot % map->num_stripes;
+ if (stripe_index == num)
+ return 0;
+ if (stripe_index < num)
+ j++;
+ }
+ *offset = last_offset + j * map->stripe_len;
+ return 1;
+}
+
+static void scrub_free_parity(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct scrub_sector *curr, *next;
+ int nbits;
+
+ nbits = bitmap_weight(&sparity->ebitmap, sparity->nsectors);
+ if (nbits) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.read_errors += nbits;
+ sctx->stat.uncorrectable_errors += nbits;
+ spin_unlock(&sctx->stat_lock);
+ }
+
+ list_for_each_entry_safe(curr, next, &sparity->sectors_list, list) {
+ list_del_init(&curr->list);
+ scrub_sector_put(curr);
+ }
+
+ kfree(sparity);
+}
+
+static void scrub_parity_bio_endio_worker(struct work_struct *work)
+{
+ struct scrub_parity *sparity = container_of(work, struct scrub_parity,
+ work);
+ struct scrub_ctx *sctx = sparity->sctx;
+
+ btrfs_bio_counter_dec(sctx->fs_info);
+ scrub_free_parity(sparity);
+ scrub_pending_bio_dec(sctx);
+}
+
+static void scrub_parity_bio_endio(struct bio *bio)
+{
+ struct scrub_parity *sparity = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
+
+ if (bio->bi_status)
+ bitmap_or(&sparity->ebitmap, &sparity->ebitmap,
+ &sparity->dbitmap, sparity->nsectors);
+
+ bio_put(bio);
+
+ INIT_WORK(&sparity->work, scrub_parity_bio_endio_worker);
+ queue_work(fs_info->scrub_parity_workers, &sparity->work);
+}
+
+static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ struct btrfs_io_context *bioc = NULL;
+ u64 length;
+ int ret;
+
+ if (!bitmap_andnot(&sparity->dbitmap, &sparity->dbitmap,
+ &sparity->ebitmap, sparity->nsectors))
+ goto out;
+
+ length = sparity->logic_end - sparity->logic_start;
+
+ btrfs_bio_counter_inc_blocked(fs_info);
+ ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
+ &length, &bioc);
+ if (ret || !bioc || !bioc->raid_map)
+ goto bioc_out;
+
+ bio = bio_alloc(NULL, BIO_MAX_VECS, REQ_OP_READ, GFP_NOFS);
+ bio->bi_iter.bi_sector = sparity->logic_start >> 9;
+ bio->bi_private = sparity;
+ bio->bi_end_io = scrub_parity_bio_endio;
+
+ rbio = raid56_parity_alloc_scrub_rbio(bio, bioc,
+ sparity->scrub_dev,
+ &sparity->dbitmap,
+ sparity->nsectors);
+ btrfs_put_bioc(bioc);
+ if (!rbio)
+ goto rbio_out;
+
+ scrub_pending_bio_inc(sctx);
+ raid56_parity_submit_scrub_rbio(rbio);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bioc_out:
+ btrfs_bio_counter_dec(fs_info);
+ bitmap_or(&sparity->ebitmap, &sparity->ebitmap, &sparity->dbitmap,
+ sparity->nsectors);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+out:
+ scrub_free_parity(sparity);
+}
+
+static void scrub_parity_get(struct scrub_parity *sparity)
+{
+ refcount_inc(&sparity->refs);
+}
+
+static void scrub_parity_put(struct scrub_parity *sparity)
+{
+ if (!refcount_dec_and_test(&sparity->refs))
+ return;
+
+ scrub_parity_check_and_repair(sparity);
+}
+
+/*
+ * Return 0 if the extent item range covers any byte of the range.
+ * Return <0 if the extent item is before @search_start.
+ * Return >0 if the extent item is after @start_start + @search_len.
+ */
+static int compare_extent_item_range(struct btrfs_path *path,
+ u64 search_start, u64 search_len)
+{
+ struct btrfs_fs_info *fs_info = path->nodes[0]->fs_info;
+ u64 len;
+ struct btrfs_key key;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ ASSERT(key.type == BTRFS_EXTENT_ITEM_KEY ||
+ key.type == BTRFS_METADATA_ITEM_KEY);
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ len = fs_info->nodesize;
+ else
+ len = key.offset;
+
+ if (key.objectid + len <= search_start)
+ return -1;
+ if (key.objectid >= search_start + search_len)
+ return 1;
+ return 0;
+}
+
+/*
+ * Locate one extent item which covers any byte in range
+ * [@search_start, @search_start + @search_length)
+ *
+ * If the path is not initialized, we will initialize the search by doing
+ * a btrfs_search_slot().
+ * If the path is already initialized, we will use the path as the initial
+ * slot, to avoid duplicated btrfs_search_slot() calls.
+ *
+ * NOTE: If an extent item starts before @search_start, we will still
+ * return the extent item. This is for data extent crossing stripe boundary.
+ *
+ * Return 0 if we found such extent item, and @path will point to the extent item.
+ * Return >0 if no such extent item can be found, and @path will be released.
+ * Return <0 if hit fatal error, and @path will be released.
+ */
+static int find_first_extent_item(struct btrfs_root *extent_root,
+ struct btrfs_path *path,
+ u64 search_start, u64 search_len)
+{
+ struct btrfs_fs_info *fs_info = extent_root->fs_info;
+ struct btrfs_key key;
+ int ret;
+
+ /* Continue using the existing path */
+ if (path->nodes[0])
+ goto search_forward;
+
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = search_start;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+
+ ASSERT(ret > 0);
+ /*
+ * Here we intentionally pass 0 as @min_objectid, as there could be
+ * an extent item starting before @search_start.
+ */
+ ret = btrfs_previous_extent_item(extent_root, path, 0);
+ if (ret < 0)
+ return ret;
+ /*
+ * No matter whether we have found an extent item, the next loop will
+ * properly do every check on the key.
+ */
+search_forward:
+ while (true) {
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ if (key.objectid >= search_start + search_len)
+ break;
+ if (key.type != BTRFS_METADATA_ITEM_KEY &&
+ key.type != BTRFS_EXTENT_ITEM_KEY)
+ goto next;
+
+ ret = compare_extent_item_range(path, search_start, search_len);
+ if (ret == 0)
+ return ret;
+ if (ret > 0)
+ break;
+next:
+ path->slots[0]++;
+ if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(extent_root, path);
+ if (ret) {
+ /* Either no more item or fatal error */
+ btrfs_release_path(path);
+ return ret;
+ }
+ }
+ }
+ btrfs_release_path(path);
+ return 1;
+}
+
+static void get_extent_info(struct btrfs_path *path, u64 *extent_start_ret,
+ u64 *size_ret, u64 *flags_ret, u64 *generation_ret)
+{
+ struct btrfs_key key;
+ struct btrfs_extent_item *ei;
+
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ ASSERT(key.type == BTRFS_METADATA_ITEM_KEY ||
+ key.type == BTRFS_EXTENT_ITEM_KEY);
+ *extent_start_ret = key.objectid;
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ *size_ret = path->nodes[0]->fs_info->nodesize;
+ else
+ *size_ret = key.offset;
+ ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item);
+ *flags_ret = btrfs_extent_flags(path->nodes[0], ei);
+ *generation_ret = btrfs_extent_generation(path->nodes[0], ei);
+}
+
+static bool does_range_cross_boundary(u64 extent_start, u64 extent_len,
+ u64 boundary_start, u64 boudary_len)
+{
+ return (extent_start < boundary_start &&
+ extent_start + extent_len > boundary_start) ||
+ (extent_start < boundary_start + boudary_len &&
+ extent_start + extent_len > boundary_start + boudary_len);
+}
+
+static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,
+ struct scrub_parity *sparity,
+ struct map_lookup *map,
+ struct btrfs_device *sdev,
+ struct btrfs_path *path,
+ u64 logical)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *extent_root = btrfs_extent_root(fs_info, logical);
+ struct btrfs_root *csum_root = btrfs_csum_root(fs_info, logical);
+ u64 cur_logical = logical;
+ int ret;
+
+ ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
+
+ /* Path must not be populated */
+ ASSERT(!path->nodes[0]);
+
+ while (cur_logical < logical + map->stripe_len) {
+ struct btrfs_io_context *bioc = NULL;
+ struct btrfs_device *extent_dev;
+ u64 extent_start;
+ u64 extent_size;
+ u64 mapped_length;
+ u64 extent_flags;
+ u64 extent_gen;
+ u64 extent_physical;
+ u64 extent_mirror_num;
+
+ ret = find_first_extent_item(extent_root, path, cur_logical,
+ logical + map->stripe_len - cur_logical);
+ /* No more extent item in this data stripe */
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ if (ret < 0)
+ break;
+ get_extent_info(path, &extent_start, &extent_size, &extent_flags,
+ &extent_gen);
+
+ /* Metadata should not cross stripe boundaries */
+ if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
+ does_range_cross_boundary(extent_start, extent_size,
+ logical, map->stripe_len)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
+ extent_start, logical);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ cur_logical += extent_size;
+ continue;
+ }
+
+ /* Skip hole range which doesn't have any extent */
+ cur_logical = max(extent_start, cur_logical);
+
+ /* Truncate the range inside this data stripe */
+ extent_size = min(extent_start + extent_size,
+ logical + map->stripe_len) - cur_logical;
+ extent_start = cur_logical;
+ ASSERT(extent_size <= U32_MAX);
+
+ scrub_parity_mark_sectors_data(sparity, extent_start, extent_size);
+
+ mapped_length = extent_size;
+ ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_start,
+ &mapped_length, &bioc, 0);
+ if (!ret && (!bioc || mapped_length < extent_size))
+ ret = -EIO;
+ if (ret) {
+ btrfs_put_bioc(bioc);
+ scrub_parity_mark_sectors_error(sparity, extent_start,
+ extent_size);
+ break;
+ }
+ extent_physical = bioc->stripes[0].physical;
+ extent_mirror_num = bioc->mirror_num;
+ extent_dev = bioc->stripes[0].dev;
+ btrfs_put_bioc(bioc);
+
+ ret = btrfs_lookup_csums_range(csum_root, extent_start,
+ extent_start + extent_size - 1,
+ &sctx->csum_list, 1, false);
+ if (ret) {
+ scrub_parity_mark_sectors_error(sparity, extent_start,
+ extent_size);
+ break;
+ }
+
+ ret = scrub_extent_for_parity(sparity, extent_start,
+ extent_size, extent_physical,
+ extent_dev, extent_flags,
+ extent_gen, extent_mirror_num);
+ scrub_free_csums(sctx);
+
+ if (ret) {
+ scrub_parity_mark_sectors_error(sparity, extent_start,
+ extent_size);
+ break;
+ }
+
+ cond_resched();
+ cur_logical += extent_size;
+ }
+ btrfs_release_path(path);
+ return ret;
+}
+
+static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *sdev,
+ u64 logic_start,
+ u64 logic_end)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_path *path;
+ u64 cur_logical;
+ int ret;
+ struct scrub_parity *sparity;
+ int nsectors;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ ASSERT(map->stripe_len <= U32_MAX);
+ nsectors = map->stripe_len >> fs_info->sectorsize_bits;
+ ASSERT(nsectors <= BITS_PER_LONG);
+ sparity = kzalloc(sizeof(struct scrub_parity), GFP_NOFS);
+ if (!sparity) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_free_path(path);
+ return -ENOMEM;
+ }
+
+ ASSERT(map->stripe_len <= U32_MAX);
+ sparity->stripe_len = map->stripe_len;
+ sparity->nsectors = nsectors;
+ sparity->sctx = sctx;
+ sparity->scrub_dev = sdev;
+ sparity->logic_start = logic_start;
+ sparity->logic_end = logic_end;
+ refcount_set(&sparity->refs, 1);
+ INIT_LIST_HEAD(&sparity->sectors_list);
+
+ ret = 0;
+ for (cur_logical = logic_start; cur_logical < logic_end;
+ cur_logical += map->stripe_len) {
+ ret = scrub_raid56_data_stripe_for_parity(sctx, sparity, map,
+ sdev, path, cur_logical);
+ if (ret < 0)
+ break;
+ }
+
+ scrub_parity_put(sparity);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ btrfs_free_path(path);
+ return ret < 0 ? ret : 0;
+}
+
+static void sync_replace_for_zoned(struct scrub_ctx *sctx)
+{
+ if (!btrfs_is_zoned(sctx->fs_info))
+ return;
+
+ sctx->flush_all_writes = true;
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+}
+
+static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
+ u64 physical, u64 physical_end)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ int ret = 0;
+
+ if (!btrfs_is_zoned(fs_info))
+ return 0;
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+
+ mutex_lock(&sctx->wr_lock);
+ if (sctx->write_pointer < physical_end) {
+ ret = btrfs_sync_zone_write_pointer(sctx->wr_tgtdev, logical,
+ physical,
+ sctx->write_pointer);
+ if (ret)
+ btrfs_err(fs_info,
+ "zoned: failed to recover write pointer");
+ }
+ mutex_unlock(&sctx->wr_lock);
+ btrfs_dev_clear_zone_empty(sctx->wr_tgtdev, physical);
+
+ return ret;
+}
+
+/*
+ * Scrub one range which can only has simple mirror based profile.
+ * (Including all range in SINGLE/DUP/RAID1/RAID1C*, and each stripe in
+ * RAID0/RAID10).
+ *
+ * Since we may need to handle a subset of block group, we need @logical_start
+ * and @logical_length parameter.
+ */
+static int scrub_simple_mirror(struct scrub_ctx *sctx,
+ struct btrfs_root *extent_root,
+ struct btrfs_root *csum_root,
+ struct btrfs_block_group *bg,
+ struct map_lookup *map,
+ u64 logical_start, u64 logical_length,
+ struct btrfs_device *device,
+ u64 physical, int mirror_num)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ const u64 logical_end = logical_start + logical_length;
+ /* An artificial limit, inherit from old scrub behavior */
+ const u32 max_length = SZ_64K;
+ struct btrfs_path path = { 0 };
+ u64 cur_logical = logical_start;
+ int ret;
+
+ /* The range must be inside the bg */
+ ASSERT(logical_start >= bg->start && logical_end <= bg->start + bg->length);
+
+ path.search_commit_root = 1;
+ path.skip_locking = 1;
+ /* Go through each extent items inside the logical range */
+ while (cur_logical < logical_end) {
+ u64 extent_start;
+ u64 extent_len;
+ u64 extent_flags;
+ u64 extent_gen;
+ u64 scrub_len;
+
+ /* Canceled? */
+ if (atomic_read(&fs_info->scrub_cancel_req) ||
+ atomic_read(&sctx->cancel_req)) {
+ ret = -ECANCELED;
+ break;
+ }
+ /* Paused? */
+ if (atomic_read(&fs_info->scrub_pause_req)) {
+ /* Push queued extents */
+ sctx->flush_all_writes = true;
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ sctx->flush_all_writes = false;
+ scrub_blocked_if_needed(fs_info);
+ }
+ /* Block group removed? */
+ spin_lock(&bg->lock);
+ if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags)) {
+ spin_unlock(&bg->lock);
+ ret = 0;
+ break;
+ }
+ spin_unlock(&bg->lock);
+
+ ret = find_first_extent_item(extent_root, &path, cur_logical,
+ logical_end - cur_logical);
+ if (ret > 0) {
+ /* No more extent, just update the accounting */
+ sctx->stat.last_physical = physical + logical_length;
+ ret = 0;
+ break;
+ }
+ if (ret < 0)
+ break;
+ get_extent_info(&path, &extent_start, &extent_len,
+ &extent_flags, &extent_gen);
+ /* Skip hole range which doesn't have any extent */
+ cur_logical = max(extent_start, cur_logical);
+
+ /*
+ * Scrub len has three limits:
+ * - Extent size limit
+ * - Scrub range limit
+ * This is especially imporatant for RAID0/RAID10 to reuse
+ * this function
+ * - Max scrub size limit
+ */
+ scrub_len = min(min(extent_start + extent_len,
+ logical_end), cur_logical + max_length) -
+ cur_logical;
+
+ if (extent_flags & BTRFS_EXTENT_FLAG_DATA) {
+ ret = btrfs_lookup_csums_range(csum_root, cur_logical,
+ cur_logical + scrub_len - 1,
+ &sctx->csum_list, 1, false);
+ if (ret)
+ break;
+ }
+ if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
+ does_range_cross_boundary(extent_start, extent_len,
+ logical_start, logical_length)) {
+ btrfs_err(fs_info,
+"scrub: tree block %llu spanning boundaries, ignored. boundary=[%llu, %llu)",
+ extent_start, logical_start, logical_end);
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.uncorrectable_errors++;
+ spin_unlock(&sctx->stat_lock);
+ cur_logical += scrub_len;
+ continue;
+ }
+ ret = scrub_extent(sctx, map, cur_logical, scrub_len,
+ cur_logical - logical_start + physical,
+ device, extent_flags, extent_gen,
+ mirror_num);
+ scrub_free_csums(sctx);
+ if (ret)
+ break;
+ if (sctx->is_dev_replace)
+ sync_replace_for_zoned(sctx);
+ cur_logical += scrub_len;
+ /* Don't hold CPU for too long time */
+ cond_resched();
+ }
+ btrfs_release_path(&path);
+ return ret;
+}
+
+/* Calculate the full stripe length for simple stripe based profiles */
+static u64 simple_stripe_full_stripe_len(const struct map_lookup *map)
+{
+ ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID10));
+
+ return map->num_stripes / map->sub_stripes * map->stripe_len;
+}
+
+/* Get the logical bytenr for the stripe */
+static u64 simple_stripe_get_logical(struct map_lookup *map,
+ struct btrfs_block_group *bg,
+ int stripe_index)
+{
+ ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID10));
+ ASSERT(stripe_index < map->num_stripes);
+
+ /*
+ * (stripe_index / sub_stripes) gives how many data stripes we need to
+ * skip.
+ */
+ return (stripe_index / map->sub_stripes) * map->stripe_len + bg->start;
+}
+
+/* Get the mirror number for the stripe */
+static int simple_stripe_mirror_num(struct map_lookup *map, int stripe_index)
+{
+ ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
+ BTRFS_BLOCK_GROUP_RAID10));
+ ASSERT(stripe_index < map->num_stripes);
+
+ /* For RAID0, it's fixed to 1, for RAID10 it's 0,1,0,1... */
+ return stripe_index % map->sub_stripes + 1;
+}
+
+static int scrub_simple_stripe(struct scrub_ctx *sctx,
+ struct btrfs_root *extent_root,
+ struct btrfs_root *csum_root,
+ struct btrfs_block_group *bg,
+ struct map_lookup *map,
+ struct btrfs_device *device,
+ int stripe_index)
+{
+ const u64 logical_increment = simple_stripe_full_stripe_len(map);
+ const u64 orig_logical = simple_stripe_get_logical(map, bg, stripe_index);
+ const u64 orig_physical = map->stripes[stripe_index].physical;
+ const int mirror_num = simple_stripe_mirror_num(map, stripe_index);
+ u64 cur_logical = orig_logical;
+ u64 cur_physical = orig_physical;
+ int ret = 0;
+
+ while (cur_logical < bg->start + bg->length) {
+ /*
+ * Inside each stripe, RAID0 is just SINGLE, and RAID10 is
+ * just RAID1, so we can reuse scrub_simple_mirror() to scrub
+ * this stripe.
+ */
+ ret = scrub_simple_mirror(sctx, extent_root, csum_root, bg, map,
+ cur_logical, map->stripe_len, device,
+ cur_physical, mirror_num);
+ if (ret)
+ return ret;
+ /* Skip to next stripe which belongs to the target device */
+ cur_logical += logical_increment;
+ /* For physical offset, we just go to next stripe */
+ cur_physical += map->stripe_len;
+ }
+ return ret;
+}
+
+static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
+ struct btrfs_block_group *bg,
+ struct extent_map *em,
+ struct btrfs_device *scrub_dev,
+ int stripe_index)
+{
+ struct btrfs_path *path;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *root;
+ struct btrfs_root *csum_root;
+ struct blk_plug plug;
+ struct map_lookup *map = em->map_lookup;
+ const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
+ const u64 chunk_logical = bg->start;
+ int ret;
+ u64 physical = map->stripes[stripe_index].physical;
+ const u64 dev_stripe_len = btrfs_calc_stripe_length(em);
+ const u64 physical_end = physical + dev_stripe_len;
+ u64 logical;
+ u64 logic_end;
+ /* The logical increment after finishing one stripe */
+ u64 increment;
+ /* Offset inside the chunk */
+ u64 offset;
+ u64 stripe_logical;
+ u64 stripe_end;
+ int stop_loop = 0;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ /*
+ * work on commit root. The related disk blocks are static as
+ * long as COW is applied. This means, it is save to rewrite
+ * them to repair disk errors without any race conditions
+ */
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+ path->reada = READA_FORWARD;
+
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ scrub_blocked_if_needed(fs_info);
+
+ root = btrfs_extent_root(fs_info, bg->start);
+ csum_root = btrfs_csum_root(fs_info, bg->start);
+
+ /*
+ * collect all data csums for the stripe to avoid seeking during
+ * the scrub. This might currently (crc32) end up to be about 1MB
+ */
+ blk_start_plug(&plug);
+
+ if (sctx->is_dev_replace &&
+ btrfs_dev_is_sequential(sctx->wr_tgtdev, physical)) {
+ mutex_lock(&sctx->wr_lock);
+ sctx->write_pointer = physical;
+ mutex_unlock(&sctx->wr_lock);
+ sctx->flush_all_writes = true;
+ }
+
+ /*
+ * There used to be a big double loop to handle all profiles using the
+ * same routine, which grows larger and more gross over time.
+ *
+ * So here we handle each profile differently, so simpler profiles
+ * have simpler scrubbing function.
+ */
+ if (!(profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_RAID56_MASK))) {
+ /*
+ * Above check rules out all complex profile, the remaining
+ * profiles are SINGLE|DUP|RAID1|RAID1C*, which is simple
+ * mirrored duplication without stripe.
+ *
+ * Only @physical and @mirror_num needs to calculated using
+ * @stripe_index.
+ */
+ ret = scrub_simple_mirror(sctx, root, csum_root, bg, map,
+ bg->start, bg->length, scrub_dev,
+ map->stripes[stripe_index].physical,
+ stripe_index + 1);
+ offset = 0;
+ goto out;
+ }
+ if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
+ ret = scrub_simple_stripe(sctx, root, csum_root, bg, map,
+ scrub_dev, stripe_index);
+ offset = map->stripe_len * (stripe_index / map->sub_stripes);
+ goto out;
+ }
+
+ /* Only RAID56 goes through the old code */
+ ASSERT(map->type & BTRFS_BLOCK_GROUP_RAID56_MASK);
+ ret = 0;
+
+ /* Calculate the logical end of the stripe */
+ get_raid56_logic_offset(physical_end, stripe_index,
+ map, &logic_end, NULL);
+ logic_end += chunk_logical;
+
+ /* Initialize @offset in case we need to go to out: label */
+ get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
+ increment = map->stripe_len * nr_data_stripes(map);
+
+ /*
+ * Due to the rotation, for RAID56 it's better to iterate each stripe
+ * using their physical offset.
+ */
+ while (physical < physical_end) {
+ ret = get_raid56_logic_offset(physical, stripe_index, map,
+ &logical, &stripe_logical);
+ logical += chunk_logical;
+ if (ret) {
+ /* it is parity strip */
+ stripe_logical += chunk_logical;
+ stripe_end = stripe_logical + increment;
+ ret = scrub_raid56_parity(sctx, map, scrub_dev,
+ stripe_logical,
+ stripe_end);
+ if (ret)
+ goto out;
+ goto next;
+ }
+
+ /*
+ * Now we're at a data stripe, scrub each extents in the range.
+ *
+ * At this stage, if we ignore the repair part, inside each data
+ * stripe it is no different than SINGLE profile.
+ * We can reuse scrub_simple_mirror() here, as the repair part
+ * is still based on @mirror_num.
+ */
+ ret = scrub_simple_mirror(sctx, root, csum_root, bg, map,
+ logical, map->stripe_len,
+ scrub_dev, physical, 1);
+ if (ret < 0)
+ goto out;
+next:
+ logical += increment;
+ physical += map->stripe_len;
+ spin_lock(&sctx->stat_lock);
+ if (stop_loop)
+ sctx->stat.last_physical =
+ map->stripes[stripe_index].physical + dev_stripe_len;
+ else
+ sctx->stat.last_physical = physical;
+ spin_unlock(&sctx->stat_lock);
+ if (stop_loop)
+ break;
+ }
+out:
+ /* push queued extents */
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ blk_finish_plug(&plug);
+ btrfs_free_path(path);
+
+ if (sctx->is_dev_replace && ret >= 0) {
+ int ret2;
+
+ ret2 = sync_write_pointer_for_zoned(sctx,
+ chunk_logical + offset,
+ map->stripes[stripe_index].physical,
+ physical_end);
+ if (ret2)
+ ret = ret2;
+ }
+
+ return ret < 0 ? ret : 0;
+}
+
+static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
+ struct btrfs_block_group *bg,
+ struct btrfs_device *scrub_dev,
+ u64 dev_offset,
+ u64 dev_extent_len)
+{
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct extent_map_tree *map_tree = &fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct extent_map *em;
+ int i;
+ int ret = 0;
+
+ read_lock(&map_tree->lock);
+ em = lookup_extent_mapping(map_tree, bg->start, bg->length);
+ read_unlock(&map_tree->lock);
+
+ if (!em) {
+ /*
+ * Might have been an unused block group deleted by the cleaner
+ * kthread or relocation.
+ */
+ spin_lock(&bg->lock);
+ if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &bg->runtime_flags))
+ ret = -EINVAL;
+ spin_unlock(&bg->lock);
+
+ return ret;
+ }
+ if (em->start != bg->start)
+ goto out;
+ if (em->len < dev_extent_len)
+ goto out;
+
+ map = em->map_lookup;
+ for (i = 0; i < map->num_stripes; ++i) {
+ if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
+ map->stripes[i].physical == dev_offset) {
+ ret = scrub_stripe(sctx, bg, em, scrub_dev, i);
+ if (ret)
+ goto out;
+ }
+ }
+out:
+ free_extent_map(em);
+
+ return ret;
+}
+
+static int finish_extent_writes_for_zoned(struct btrfs_root *root,
+ struct btrfs_block_group *cache)
+{
+ struct btrfs_fs_info *fs_info = cache->fs_info;
+ struct btrfs_trans_handle *trans;
+
+ if (!btrfs_is_zoned(fs_info))
+ return 0;
+
+ btrfs_wait_block_group_reservations(cache);
+ btrfs_wait_nocow_writers(cache);
+ btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start, cache->length);
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+ return btrfs_commit_transaction(trans);
+}
+
+static noinline_for_stack
+int scrub_enumerate_chunks(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev, u64 start, u64 end)
+{
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+ struct btrfs_root *root = fs_info->dev_root;
+ u64 chunk_offset;
+ int ret = 0;
+ int ro_set;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_block_group *cache;
+ struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = READA_FORWARD;
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+
+ key.objectid = scrub_dev->devid;
+ key.offset = 0ull;
+ key.type = BTRFS_DEV_EXTENT_KEY;
+
+ while (1) {
+ u64 dev_extent_len;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ if (path->slots[0] >=
+ btrfs_header_nritems(path->nodes[0])) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ break;
+ if (ret > 0) {
+ ret = 0;
+ break;
+ }
+ } else {
+ ret = 0;
+ }
+ }
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+
+ if (found_key.objectid != scrub_dev->devid)
+ break;
+
+ if (found_key.type != BTRFS_DEV_EXTENT_KEY)
+ break;
+
+ if (found_key.offset >= end)
+ break;
+
+ if (found_key.offset < key.offset)
+ break;
+
+ dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
+ dev_extent_len = btrfs_dev_extent_length(l, dev_extent);
+
+ if (found_key.offset + dev_extent_len <= start)
+ goto skip;
+
+ chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
+
+ /*
+ * get a reference on the corresponding block group to prevent
+ * the chunk from going away while we scrub it
+ */
+ cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+
+ /* some chunks are removed but not committed to disk yet,
+ * continue scrubbing */
+ if (!cache)
+ goto skip;
+
+ ASSERT(cache->start <= chunk_offset);
+ /*
+ * We are using the commit root to search for device extents, so
+ * that means we could have found a device extent item from a
+ * block group that was deleted in the current transaction. The
+ * logical start offset of the deleted block group, stored at
+ * @chunk_offset, might be part of the logical address range of
+ * a new block group (which uses different physical extents).
+ * In this case btrfs_lookup_block_group() has returned the new
+ * block group, and its start address is less than @chunk_offset.
+ *
+ * We skip such new block groups, because it's pointless to
+ * process them, as we won't find their extents because we search
+ * for them using the commit root of the extent tree. For a device
+ * replace it's also fine to skip it, we won't miss copying them
+ * to the target device because we have the write duplication
+ * setup through the regular write path (by btrfs_map_block()),
+ * and we have committed a transaction when we started the device
+ * replace, right after setting up the device replace state.
+ */
+ if (cache->start < chunk_offset) {
+ btrfs_put_block_group(cache);
+ goto skip;
+ }
+
+ if (sctx->is_dev_replace && btrfs_is_zoned(fs_info)) {
+ if (!test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags)) {
+ btrfs_put_block_group(cache);
+ goto skip;
+ }
+ }
+
+ /*
+ * Make sure that while we are scrubbing the corresponding block
+ * group doesn't get its logical address and its device extents
+ * reused for another block group, which can possibly be of a
+ * different type and different profile. We do this to prevent
+ * false error detections and crashes due to bogus attempts to
+ * repair extents.
+ */
+ spin_lock(&cache->lock);
+ if (test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags)) {
+ spin_unlock(&cache->lock);
+ btrfs_put_block_group(cache);
+ goto skip;
+ }
+ btrfs_freeze_block_group(cache);
+ spin_unlock(&cache->lock);
+
+ /*
+ * we need call btrfs_inc_block_group_ro() with scrubs_paused,
+ * to avoid deadlock caused by:
+ * btrfs_inc_block_group_ro()
+ * -> btrfs_wait_for_commit()
+ * -> btrfs_commit_transaction()
+ * -> btrfs_scrub_pause()
+ */
+ scrub_pause_on(fs_info);
+
+ /*
+ * Don't do chunk preallocation for scrub.
+ *
+ * This is especially important for SYSTEM bgs, or we can hit
+ * -EFBIG from btrfs_finish_chunk_alloc() like:
+ * 1. The only SYSTEM bg is marked RO.
+ * Since SYSTEM bg is small, that's pretty common.
+ * 2. New SYSTEM bg will be allocated
+ * Due to regular version will allocate new chunk.
+ * 3. New SYSTEM bg is empty and will get cleaned up
+ * Before cleanup really happens, it's marked RO again.
+ * 4. Empty SYSTEM bg get scrubbed
+ * We go back to 2.
+ *
+ * This can easily boost the amount of SYSTEM chunks if cleaner
+ * thread can't be triggered fast enough, and use up all space
+ * of btrfs_super_block::sys_chunk_array
+ *
+ * While for dev replace, we need to try our best to mark block
+ * group RO, to prevent race between:
+ * - Write duplication
+ * Contains latest data
+ * - Scrub copy
+ * Contains data from commit tree
+ *
+ * If target block group is not marked RO, nocow writes can
+ * be overwritten by scrub copy, causing data corruption.
+ * So for dev-replace, it's not allowed to continue if a block
+ * group is not RO.
+ */
+ ret = btrfs_inc_block_group_ro(cache, sctx->is_dev_replace);
+ if (!ret && sctx->is_dev_replace) {
+ ret = finish_extent_writes_for_zoned(root, cache);
+ if (ret) {
+ btrfs_dec_block_group_ro(cache);
+ scrub_pause_off(fs_info);
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+
+ if (ret == 0) {
+ ro_set = 1;
+ } else if (ret == -ENOSPC && !sctx->is_dev_replace &&
+ !(cache->flags & BTRFS_BLOCK_GROUP_RAID56_MASK)) {
+ /*
+ * btrfs_inc_block_group_ro return -ENOSPC when it
+ * failed in creating new chunk for metadata.
+ * It is not a problem for scrub, because
+ * metadata are always cowed, and our scrub paused
+ * commit_transactions.
+ *
+ * For RAID56 chunks, we have to mark them read-only
+ * for scrub, as later we would use our own cache
+ * out of RAID56 realm.
+ * Thus we want the RAID56 bg to be marked RO to
+ * prevent RMW from screwing up out cache.
+ */
+ ro_set = 0;
+ } else if (ret == -ETXTBSY) {
+ btrfs_warn(fs_info,
+ "skipping scrub of block group %llu due to active swapfile",
+ cache->start);
+ scrub_pause_off(fs_info);
+ ret = 0;
+ goto skip_unfreeze;
+ } else {
+ btrfs_warn(fs_info,
+ "failed setting block group ro: %d", ret);
+ btrfs_unfreeze_block_group(cache);
+ btrfs_put_block_group(cache);
+ scrub_pause_off(fs_info);
+ break;
+ }
+
+ /*
+ * Now the target block is marked RO, wait for nocow writes to
+ * finish before dev-replace.
+ * COW is fine, as COW never overwrites extents in commit tree.
+ */
+ if (sctx->is_dev_replace) {
+ btrfs_wait_nocow_writers(cache);
+ btrfs_wait_ordered_roots(fs_info, U64_MAX, cache->start,
+ cache->length);
+ }
+
+ scrub_pause_off(fs_info);
+ down_write(&dev_replace->rwsem);
+ dev_replace->cursor_right = found_key.offset + dev_extent_len;
+ dev_replace->cursor_left = found_key.offset;
+ dev_replace->item_needs_writeback = 1;
+ up_write(&dev_replace->rwsem);
+
+ ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset,
+ dev_extent_len);
+
+ /*
+ * flush, submit all pending read and write bios, afterwards
+ * wait for them.
+ * Note that in the dev replace case, a read request causes
+ * write requests that are submitted in the read completion
+ * worker. Therefore in the current situation, it is required
+ * that all write requests are flushed, so that all read and
+ * write requests are really completed when bios_in_flight
+ * changes to 0.
+ */
+ sctx->flush_all_writes = true;
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_lock);
+
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+
+ scrub_pause_on(fs_info);
+
+ /*
+ * must be called before we decrease @scrub_paused.
+ * make sure we don't block transaction commit while
+ * we are waiting pending workers finished.
+ */
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->workers_pending) == 0);
+ sctx->flush_all_writes = false;
+
+ scrub_pause_off(fs_info);
+
+ if (sctx->is_dev_replace &&
+ !btrfs_finish_block_group_to_copy(dev_replace->srcdev,
+ cache, found_key.offset))
+ ro_set = 0;
+
+ down_write(&dev_replace->rwsem);
+ dev_replace->cursor_left = dev_replace->cursor_right;
+ dev_replace->item_needs_writeback = 1;
+ up_write(&dev_replace->rwsem);
+
+ if (ro_set)
+ btrfs_dec_block_group_ro(cache);
+
+ /*
+ * We might have prevented the cleaner kthread from deleting
+ * this block group if it was already unused because we raced
+ * and set it to RO mode first. So add it back to the unused
+ * list, otherwise it might not ever be deleted unless a manual
+ * balance is triggered or it becomes used and unused again.
+ */
+ spin_lock(&cache->lock);
+ if (!test_bit(BLOCK_GROUP_FLAG_REMOVED, &cache->runtime_flags) &&
+ !cache->ro && cache->reserved == 0 && cache->used == 0) {
+ spin_unlock(&cache->lock);
+ if (btrfs_test_opt(fs_info, DISCARD_ASYNC))
+ btrfs_discard_queue_work(&fs_info->discard_ctl,
+ cache);
+ else
+ btrfs_mark_bg_unused(cache);
+ } else {
+ spin_unlock(&cache->lock);
+ }
+skip_unfreeze:
+ btrfs_unfreeze_block_group(cache);
+ btrfs_put_block_group(cache);
+ if (ret)
+ break;
+ if (sctx->is_dev_replace &&
+ atomic64_read(&dev_replace->num_write_errors) > 0) {
+ ret = -EIO;
+ break;
+ }
+ if (sctx->stat.malloc_errors > 0) {
+ ret = -ENOMEM;
+ break;
+ }
+skip:
+ key.offset = found_key.offset + dev_extent_len;
+ btrfs_release_path(path);
+ }
+
+ btrfs_free_path(path);
+
+ return ret;
+}
+
+static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev)
+{
+ int i;
+ u64 bytenr;
+ u64 gen;
+ int ret;
+ struct btrfs_fs_info *fs_info = sctx->fs_info;
+
+ if (BTRFS_FS_ERROR(fs_info))
+ return -EROFS;
+
+ /* Seed devices of a new filesystem has their own generation. */
+ if (scrub_dev->fs_devices != fs_info->fs_devices)
+ gen = scrub_dev->generation;
+ else
+ gen = fs_info->last_trans_committed;
+
+ for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
+ bytenr = btrfs_sb_offset(i);
+ if (bytenr + BTRFS_SUPER_INFO_SIZE >
+ scrub_dev->commit_total_bytes)
+ break;
+ if (!btrfs_check_super_location(scrub_dev, bytenr))
+ continue;
+
+ ret = scrub_sectors(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
+ scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
+ NULL, bytenr);
+ if (ret)
+ return ret;
+ }
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+
+ return 0;
+}
+
+static void scrub_workers_put(struct btrfs_fs_info *fs_info)
+{
+ if (refcount_dec_and_mutex_lock(&fs_info->scrub_workers_refcnt,
+ &fs_info->scrub_lock)) {
+ struct workqueue_struct *scrub_workers = fs_info->scrub_workers;
+ struct workqueue_struct *scrub_wr_comp =
+ fs_info->scrub_wr_completion_workers;
+ struct workqueue_struct *scrub_parity =
+ fs_info->scrub_parity_workers;
+
+ fs_info->scrub_workers = NULL;
+ fs_info->scrub_wr_completion_workers = NULL;
+ fs_info->scrub_parity_workers = NULL;
+ mutex_unlock(&fs_info->scrub_lock);
+
+ if (scrub_workers)
+ destroy_workqueue(scrub_workers);
+ if (scrub_wr_comp)
+ destroy_workqueue(scrub_wr_comp);
+ if (scrub_parity)
+ destroy_workqueue(scrub_parity);
+ }
+}
+
+/*
+ * get a reference count on fs_info->scrub_workers. start worker if necessary
+ */
+static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
+ int is_dev_replace)
+{
+ struct workqueue_struct *scrub_workers = NULL;
+ struct workqueue_struct *scrub_wr_comp = NULL;
+ struct workqueue_struct *scrub_parity = NULL;
+ unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
+ int max_active = fs_info->thread_pool_size;
+ int ret = -ENOMEM;
+
+ if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
+ return 0;
+
+ scrub_workers = alloc_workqueue("btrfs-scrub", flags,
+ is_dev_replace ? 1 : max_active);
+ if (!scrub_workers)
+ goto fail_scrub_workers;
+
+ scrub_wr_comp = alloc_workqueue("btrfs-scrubwrc", flags, max_active);
+ if (!scrub_wr_comp)
+ goto fail_scrub_wr_completion_workers;
+
+ scrub_parity = alloc_workqueue("btrfs-scrubparity", flags, max_active);
+ if (!scrub_parity)
+ goto fail_scrub_parity_workers;
+
+ mutex_lock(&fs_info->scrub_lock);
+ if (refcount_read(&fs_info->scrub_workers_refcnt) == 0) {
+ ASSERT(fs_info->scrub_workers == NULL &&
+ fs_info->scrub_wr_completion_workers == NULL &&
+ fs_info->scrub_parity_workers == NULL);
+ fs_info->scrub_workers = scrub_workers;
+ fs_info->scrub_wr_completion_workers = scrub_wr_comp;
+ fs_info->scrub_parity_workers = scrub_parity;
+ refcount_set(&fs_info->scrub_workers_refcnt, 1);
+ mutex_unlock(&fs_info->scrub_lock);
+ return 0;
+ }
+ /* Other thread raced in and created the workers for us */
+ refcount_inc(&fs_info->scrub_workers_refcnt);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ ret = 0;
+ destroy_workqueue(scrub_parity);
+fail_scrub_parity_workers:
+ destroy_workqueue(scrub_wr_comp);
+fail_scrub_wr_completion_workers:
+ destroy_workqueue(scrub_workers);
+fail_scrub_workers:
+ return ret;
+}
+
+int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
+ u64 end, struct btrfs_scrub_progress *progress,
+ int readonly, int is_dev_replace)
+{
+ struct btrfs_dev_lookup_args args = { .devid = devid };
+ struct scrub_ctx *sctx;
+ int ret;
+ struct btrfs_device *dev;
+ unsigned int nofs_flag;
+ bool need_commit = false;
+
+ if (btrfs_fs_closing(fs_info))
+ return -EAGAIN;
+
+ /* At mount time we have ensured nodesize is in the range of [4K, 64K]. */
+ ASSERT(fs_info->nodesize <= BTRFS_STRIPE_LEN);
+
+ /*
+ * SCRUB_MAX_SECTORS_PER_BLOCK is calculated using the largest possible
+ * value (max nodesize / min sectorsize), thus nodesize should always
+ * be fine.
+ */
+ ASSERT(fs_info->nodesize <=
+ SCRUB_MAX_SECTORS_PER_BLOCK << fs_info->sectorsize_bits);
+
+ /* Allocate outside of device_list_mutex */
+ sctx = scrub_setup_ctx(fs_info, is_dev_replace);
+ if (IS_ERR(sctx))
+ return PTR_ERR(sctx);
+
+ ret = scrub_workers_get(fs_info, is_dev_replace);
+ if (ret)
+ goto out_free_ctx;
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info->fs_devices, &args);
+ if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
+ !is_dev_replace)) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (!is_dev_replace && !readonly &&
+ !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state)) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ btrfs_err_in_rcu(fs_info,
+ "scrub on devid %llu: filesystem on %s is not writable",
+ devid, rcu_str_deref(dev->name));
+ ret = -EROFS;
+ goto out;
+ }
+
+ mutex_lock(&fs_info->scrub_lock);
+ if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &dev->dev_state) ||
+ test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &dev->dev_state)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ ret = -EIO;
+ goto out;
+ }
+
+ down_read(&fs_info->dev_replace.rwsem);
+ if (dev->scrub_ctx ||
+ (!is_dev_replace &&
+ btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
+ up_read(&fs_info->dev_replace.rwsem);
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ ret = -EINPROGRESS;
+ goto out;
+ }
+ up_read(&fs_info->dev_replace.rwsem);
+
+ sctx->readonly = readonly;
+ dev->scrub_ctx = sctx;
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ /*
+ * checking @scrub_pause_req here, we can avoid
+ * race between committing transaction and scrubbing.
+ */
+ __scrub_blocked_if_needed(fs_info);
+ atomic_inc(&fs_info->scrubs_running);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ /*
+ * In order to avoid deadlock with reclaim when there is a transaction
+ * trying to pause scrub, make sure we use GFP_NOFS for all the
+ * allocations done at btrfs_scrub_sectors() and scrub_sectors_for_parity()
+ * invoked by our callees. The pausing request is done when the
+ * transaction commit starts, and it blocks the transaction until scrub
+ * is paused (done at specific points at scrub_stripe() or right above
+ * before incrementing fs_info->scrubs_running).
+ */
+ nofs_flag = memalloc_nofs_save();
+ if (!is_dev_replace) {
+ u64 old_super_errors;
+
+ spin_lock(&sctx->stat_lock);
+ old_super_errors = sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+
+ btrfs_info(fs_info, "scrub: started on devid %llu", devid);
+ /*
+ * by holding device list mutex, we can
+ * kick off writing super in log tree sync.
+ */
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ ret = scrub_supers(sctx, dev);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ spin_lock(&sctx->stat_lock);
+ /*
+ * Super block errors found, but we can not commit transaction
+ * at current context, since btrfs_commit_transaction() needs
+ * to pause the current running scrub (hold by ourselves).
+ */
+ if (sctx->stat.super_errors > old_super_errors && !sctx->readonly)
+ need_commit = true;
+ spin_unlock(&sctx->stat_lock);
+ }
+
+ if (!ret)
+ ret = scrub_enumerate_chunks(sctx, dev, start, end);
+ memalloc_nofs_restore(nofs_flag);
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+ atomic_dec(&fs_info->scrubs_running);
+ wake_up(&fs_info->scrub_pause_wait);
+
+ wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0);
+
+ if (progress)
+ memcpy(progress, &sctx->stat, sizeof(*progress));
+
+ if (!is_dev_replace)
+ btrfs_info(fs_info, "scrub: %s on devid %llu with status: %d",
+ ret ? "not finished" : "finished", devid, ret);
+
+ mutex_lock(&fs_info->scrub_lock);
+ dev->scrub_ctx = NULL;
+ mutex_unlock(&fs_info->scrub_lock);
+
+ scrub_workers_put(fs_info);
+ scrub_put_ctx(sctx);
+
+ /*
+ * We found some super block errors before, now try to force a
+ * transaction commit, as scrub has finished.
+ */
+ if (need_commit) {
+ struct btrfs_trans_handle *trans;
+
+ trans = btrfs_start_transaction(fs_info->tree_root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ btrfs_err(fs_info,
+ "scrub: failed to start transaction to fix super block errors: %d", ret);
+ return ret;
+ }
+ ret = btrfs_commit_transaction(trans);
+ if (ret < 0)
+ btrfs_err(fs_info,
+ "scrub: failed to commit transaction to fix super block errors: %d", ret);
+ }
+ return ret;
+out:
+ scrub_workers_put(fs_info);
+out_free_ctx:
+ scrub_free_ctx(sctx);
+
+ return ret;
+}
+
+void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ atomic_inc(&fs_info->scrub_pause_req);
+ while (atomic_read(&fs_info->scrubs_paused) !=
+ atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrubs_paused) ==
+ atomic_read(&fs_info->scrubs_running));
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ mutex_unlock(&fs_info->scrub_lock);
+}
+
+void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
+{
+ atomic_dec(&fs_info->scrub_pause_req);
+ wake_up(&fs_info->scrub_pause_wait);
+}
+
+int btrfs_scrub_cancel(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->scrub_lock);
+ if (!atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ return -ENOTCONN;
+ }
+
+ atomic_inc(&fs_info->scrub_cancel_req);
+ while (atomic_read(&fs_info->scrubs_running)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ atomic_read(&fs_info->scrubs_running) == 0);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ atomic_dec(&fs_info->scrub_cancel_req);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ return 0;
+}
+
+int btrfs_scrub_cancel_dev(struct btrfs_device *dev)
+{
+ struct btrfs_fs_info *fs_info = dev->fs_info;
+ struct scrub_ctx *sctx;
+
+ mutex_lock(&fs_info->scrub_lock);
+ sctx = dev->scrub_ctx;
+ if (!sctx) {
+ mutex_unlock(&fs_info->scrub_lock);
+ return -ENOTCONN;
+ }
+ atomic_inc(&sctx->cancel_req);
+ while (dev->scrub_ctx) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ dev->scrub_ctx == NULL);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ mutex_unlock(&fs_info->scrub_lock);
+
+ return 0;
+}
+
+int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
+ struct btrfs_scrub_progress *progress)
+{
+ struct btrfs_dev_lookup_args args = { .devid = devid };
+ struct btrfs_device *dev;
+ struct scrub_ctx *sctx = NULL;
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info->fs_devices, &args);
+ if (dev)
+ sctx = dev->scrub_ctx;
+ if (sctx)
+ memcpy(progress, &sctx->stat, sizeof(*progress));
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+ return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
+}
+
+static void scrub_find_good_copy(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u32 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num)
+{
+ u64 mapped_length;
+ struct btrfs_io_context *bioc = NULL;
+ int ret;
+
+ mapped_length = extent_len;
+ ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
+ &mapped_length, &bioc, 0);
+ if (ret || !bioc || mapped_length < extent_len ||
+ !bioc->stripes[0].dev->bdev) {
+ btrfs_put_bioc(bioc);
+ return;
+ }
+
+ *extent_physical = bioc->stripes[0].physical;
+ *extent_mirror_num = bioc->mirror_num;
+ *extent_dev = bioc->stripes[0].dev;
+ btrfs_put_bioc(bioc);
+}