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-rw-r--r--fs/btrfs/scrub.c4228
1 files changed, 4228 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
new file mode 100644
index 000000000..ab5811545
--- /dev/null
+++ b/fs/btrfs/scrub.c
@@ -0,0 +1,4228 @@
+/*
+ * Copyright (C) 2011, 2012 STRATO. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/ratelimit.h>
+#include "ctree.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"
+
+/*
+ * 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 two values configure an upper limit for the number
+ * of (dynamically allocated) pages that are added to a bio.
+ */
+#define SCRUB_PAGES_PER_RD_BIO 32 /* 128k per bio */
+#define SCRUB_PAGES_PER_WR_BIO 32 /* 128k per bio */
+#define SCRUB_BIOS_PER_SCTX 64 /* 8MB per device in flight */
+
+/*
+ * the following value times PAGE_SIZE needs to be large enough to match the
+ * largest node/leaf/sector size that shall be supported.
+ * Values larger than BTRFS_STRIPE_LEN are not supported.
+ */
+#define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */
+
+struct scrub_recover {
+ atomic_t refs;
+ struct btrfs_bio *bbio;
+ u64 map_length;
+};
+
+struct scrub_page {
+ struct scrub_block *sblock;
+ struct page *page;
+ struct btrfs_device *dev;
+ struct list_head list;
+ u64 flags; /* extent flags */
+ u64 generation;
+ u64 logical;
+ u64 physical;
+ u64 physical_for_dev_replace;
+ atomic_t refs;
+ struct {
+ unsigned int mirror_num:8;
+ 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;
+ int err;
+ u64 logical;
+ u64 physical;
+#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
+ struct scrub_page *pagev[SCRUB_PAGES_PER_WR_BIO];
+#else
+ struct scrub_page *pagev[SCRUB_PAGES_PER_RD_BIO];
+#endif
+ int page_count;
+ int next_free;
+ struct btrfs_work work;
+};
+
+struct scrub_block {
+ struct scrub_page *pagev[SCRUB_MAX_PAGES_PER_BLOCK];
+ int page_count;
+ atomic_t outstanding_pages;
+ atomic_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;
+ };
+};
+
+/* 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;
+
+ int stripe_len;
+
+ atomic_t refs;
+
+ struct list_head spages;
+
+ /* Work of parity check and repair */
+ struct btrfs_work 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;
+
+ unsigned long bitmap[0];
+};
+
+struct scrub_wr_ctx {
+ struct scrub_bio *wr_curr_bio;
+ struct btrfs_device *tgtdev;
+ int pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
+ atomic_t flush_all_writes;
+ struct mutex wr_lock;
+};
+
+struct scrub_ctx {
+ struct scrub_bio *bios[SCRUB_BIOS_PER_SCTX];
+ struct btrfs_root *dev_root;
+ int first_free;
+ int curr;
+ atomic_t bios_in_flight;
+ atomic_t workers_pending;
+ spinlock_t list_lock;
+ wait_queue_head_t list_wait;
+ u16 csum_size;
+ struct list_head csum_list;
+ atomic_t cancel_req;
+ int readonly;
+ int pages_per_rd_bio;
+ u32 sectorsize;
+ u32 nodesize;
+
+ int is_dev_replace;
+ struct scrub_wr_ctx wr_ctx;
+
+ /*
+ * 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.
+ */
+ atomic_t refs;
+};
+
+struct scrub_fixup_nodatasum {
+ struct scrub_ctx *sctx;
+ struct btrfs_device *dev;
+ u64 logical;
+ struct btrfs_root *root;
+ struct btrfs_work work;
+ int mirror_num;
+};
+
+struct scrub_nocow_inode {
+ u64 inum;
+ u64 offset;
+ u64 root;
+ struct list_head list;
+};
+
+struct scrub_copy_nocow_ctx {
+ struct scrub_ctx *sctx;
+ u64 logical;
+ u64 len;
+ int mirror_num;
+ u64 physical_for_dev_replace;
+ struct list_head inodes;
+ struct btrfs_work work;
+};
+
+struct scrub_warning {
+ struct btrfs_path *path;
+ u64 extent_item_size;
+ const char *errstr;
+ sector_t sector;
+ u64 logical;
+ struct btrfs_device *dev;
+};
+
+static void scrub_pending_bio_inc(struct scrub_ctx *sctx);
+static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
+static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
+static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
+static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
+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 is_metadata,
+ int have_csum, u8 *csum, u64 generation,
+ u16 csum_size, int retry_failed_mirror);
+static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int is_metadata, int have_csum,
+ const u8 *csum, u64 generation,
+ u16 csum_size);
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good);
+static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int page_num, int force_write);
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock);
+static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
+ int page_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_get(struct scrub_block *sblock);
+static void scrub_block_put(struct scrub_block *sblock);
+static void scrub_page_get(struct scrub_page *spage);
+static void scrub_page_put(struct scrub_page *spage);
+static void scrub_parity_get(struct scrub_parity *sparity);
+static void scrub_parity_put(struct scrub_parity *sparity);
+static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage);
+static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum, int force,
+ u64 physical_for_dev_replace);
+static void scrub_bio_end_io(struct bio *bio, int err);
+static void scrub_bio_end_io_worker(struct btrfs_work *work);
+static void scrub_block_complete(struct scrub_block *sblock);
+static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u64 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num);
+static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
+ struct scrub_wr_ctx *wr_ctx,
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_device *dev,
+ int is_dev_replace);
+static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx);
+static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage);
+static void scrub_wr_submit(struct scrub_ctx *sctx);
+static void scrub_wr_bio_end_io(struct bio *bio, int err);
+static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
+static int write_page_nocow(struct scrub_ctx *sctx,
+ u64 physical_for_dev_replace, struct page *page);
+static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
+ struct scrub_copy_nocow_ctx *ctx);
+static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ int mirror_num, u64 physical_for_dev_replace);
+static void copy_nocow_pages_worker(struct btrfs_work *work);
+static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
+static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
+static void scrub_put_ctx(struct scrub_ctx *sctx);
+
+
+static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
+{
+ atomic_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_blocked_if_needed(struct btrfs_fs_info *fs_info)
+{
+ atomic_inc(&fs_info->scrubs_paused);
+ wake_up(&fs_info->scrub_pause_wait);
+
+ 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);
+}
+
+/*
+ * used for workers that require transaction commits (i.e., for the
+ * NOCOW case)
+ */
+static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
+{
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+
+ atomic_inc(&sctx->refs);
+ /*
+ * increment scrubs_running to prevent cancel requests from
+ * completing as long as a worker is running. we must also
+ * increment scrubs_paused to prevent deadlocking on pause
+ * requests used for transactions commits (as the worker uses a
+ * transaction context). it is safe to regard the worker
+ * as paused for all matters practical. effectively, we only
+ * avoid cancellation requests from completing.
+ */
+ mutex_lock(&fs_info->scrub_lock);
+ atomic_inc(&fs_info->scrubs_running);
+ atomic_inc(&fs_info->scrubs_paused);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ /*
+ * check if @scrubs_running=@scrubs_paused condition
+ * inside wait_event() is not an atomic operation.
+ * which means we may inc/dec @scrub_running/paused
+ * at any time. Let's wake up @scrub_pause_wait as
+ * much as we can to let commit transaction blocked less.
+ */
+ wake_up(&fs_info->scrub_pause_wait);
+
+ atomic_inc(&sctx->workers_pending);
+}
+
+/* used for workers that require transaction commits */
+static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
+{
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+
+ /*
+ * see scrub_pending_trans_workers_inc() why we're pretending
+ * to be paused in the scrub counters
+ */
+ mutex_lock(&fs_info->scrub_lock);
+ atomic_dec(&fs_info->scrubs_running);
+ atomic_dec(&fs_info->scrubs_paused);
+ mutex_unlock(&fs_info->scrub_lock);
+ atomic_dec(&sctx->workers_pending);
+ wake_up(&fs_info->scrub_pause_wait);
+ wake_up(&sctx->list_wait);
+ scrub_put_ctx(sctx);
+}
+
+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;
+
+ scrub_free_wr_ctx(&sctx->wr_ctx);
+
+ /* this can happen when scrub is cancelled */
+ if (sctx->curr != -1) {
+ struct scrub_bio *sbio = sctx->bios[sctx->curr];
+
+ for (i = 0; i < sbio->page_count; i++) {
+ WARN_ON(!sbio->pagev[i]->page);
+ scrub_block_put(sbio->pagev[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);
+ }
+
+ scrub_free_csums(sctx);
+ kfree(sctx);
+}
+
+static void scrub_put_ctx(struct scrub_ctx *sctx)
+{
+ if (atomic_dec_and_test(&sctx->refs))
+ scrub_free_ctx(sctx);
+}
+
+static noinline_for_stack
+struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
+{
+ struct scrub_ctx *sctx;
+ int i;
+ struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
+ int pages_per_rd_bio;
+ int ret;
+
+ /*
+ * the setting of pages_per_rd_bio is correct for scrub but might
+ * be wrong for the dev_replace code where we might read from
+ * different devices in the initial huge bios. However, that
+ * code is able to correctly handle the case when adding a page
+ * to a bio fails.
+ */
+ if (dev->bdev)
+ pages_per_rd_bio = min_t(int, SCRUB_PAGES_PER_RD_BIO,
+ bio_get_nr_vecs(dev->bdev));
+ else
+ pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
+ sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
+ if (!sctx)
+ goto nomem;
+ atomic_set(&sctx->refs, 1);
+ sctx->is_dev_replace = is_dev_replace;
+ sctx->pages_per_rd_bio = pages_per_rd_bio;
+ sctx->curr = -1;
+ sctx->dev_root = dev->dev_root;
+ for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
+ struct scrub_bio *sbio;
+
+ sbio = kzalloc(sizeof(*sbio), GFP_NOFS);
+ if (!sbio)
+ goto nomem;
+ sctx->bios[i] = sbio;
+
+ sbio->index = i;
+ sbio->sctx = sctx;
+ sbio->page_count = 0;
+ btrfs_init_work(&sbio->work, btrfs_scrub_helper,
+ scrub_bio_end_io_worker, NULL, NULL);
+
+ 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;
+ sctx->nodesize = dev->dev_root->nodesize;
+ sctx->sectorsize = dev->dev_root->sectorsize;
+ atomic_set(&sctx->bios_in_flight, 0);
+ atomic_set(&sctx->workers_pending, 0);
+ atomic_set(&sctx->cancel_req, 0);
+ sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy);
+ INIT_LIST_HEAD(&sctx->csum_list);
+
+ spin_lock_init(&sctx->list_lock);
+ spin_lock_init(&sctx->stat_lock);
+ init_waitqueue_head(&sctx->list_wait);
+
+ ret = scrub_setup_wr_ctx(sctx, &sctx->wr_ctx, fs_info,
+ fs_info->dev_replace.tgtdev, is_dev_replace);
+ if (ret) {
+ scrub_free_ctx(sctx);
+ return ERR_PTR(ret);
+ }
+ 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)
+{
+ u64 isize;
+ u32 nlink;
+ int ret;
+ int i;
+ struct extent_buffer *eb;
+ struct btrfs_inode_item *inode_item;
+ struct scrub_warning *swarn = warn_ctx;
+ struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
+ struct inode_fs_paths *ipath = NULL;
+ struct btrfs_root *local_root;
+ struct btrfs_key root_key;
+ struct btrfs_key key;
+
+ root_key.objectid = root;
+ root_key.type = BTRFS_ROOT_ITEM_KEY;
+ root_key.offset = (u64)-1;
+ local_root = btrfs_read_fs_root_no_name(fs_info, &root_key);
+ 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_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);
+ isize = btrfs_inode_size(eb, inode_item);
+ nlink = btrfs_inode_nlink(eb, inode_item);
+ btrfs_release_path(swarn->path);
+
+ ipath = init_ipath(4096, local_root, swarn->path);
+ if (IS_ERR(ipath)) {
+ 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)
+ printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
+ "%s, sector %llu, root %llu, inode %llu, offset %llu, "
+ "length %llu, links %u (path: %s)\n", swarn->errstr,
+ swarn->logical, rcu_str_deref(swarn->dev->name),
+ (unsigned long long)swarn->sector, root, inum, offset,
+ min(isize - offset, (u64)PAGE_SIZE), nlink,
+ (char *)(unsigned long)ipath->fspath->val[i]);
+
+ free_ipath(ipath);
+ return 0;
+
+err:
+ printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
+ "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
+ "resolving failed with ret=%d\n", swarn->errstr,
+ swarn->logical, rcu_str_deref(swarn->dev->name),
+ (unsigned long long)swarn->sector, 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;
+ int ret;
+
+ WARN_ON(sblock->page_count < 1);
+ dev = sblock->pagev[0]->dev;
+ fs_info = sblock->sctx->dev_root->fs_info;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return;
+
+ swarn.sector = (sblock->pagev[0]->physical) >> 9;
+ swarn.logical = sblock->pagev[0]->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_nr(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);
+ printk_in_rcu(KERN_WARNING
+ "BTRFS: %s at logical %llu on dev %s, "
+ "sector %llu: metadata %s (level %d) in tree "
+ "%llu\n", errstr, swarn.logical,
+ rcu_str_deref(dev->name),
+ (unsigned long long)swarn.sector,
+ 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);
+ }
+
+out:
+ btrfs_free_path(path);
+}
+
+static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
+{
+ struct page *page = NULL;
+ unsigned long index;
+ struct scrub_fixup_nodatasum *fixup = fixup_ctx;
+ int ret;
+ int corrected = 0;
+ struct btrfs_key key;
+ struct inode *inode = NULL;
+ struct btrfs_fs_info *fs_info;
+ u64 end = offset + PAGE_SIZE - 1;
+ struct btrfs_root *local_root;
+ int srcu_index;
+
+ key.objectid = root;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ fs_info = fixup->root->fs_info;
+ srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
+
+ local_root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(local_root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
+ return PTR_ERR(local_root);
+ }
+
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.objectid = inum;
+ key.offset = 0;
+ inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
+ srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ index = offset >> PAGE_CACHE_SHIFT;
+
+ page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+ if (!page) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (PageUptodate(page)) {
+ if (PageDirty(page)) {
+ /*
+ * we need to write the data to the defect sector. the
+ * data that was in that sector is not in memory,
+ * because the page was modified. we must not write the
+ * modified page to that sector.
+ *
+ * TODO: what could be done here: wait for the delalloc
+ * runner to write out that page (might involve
+ * COW) and see whether the sector is still
+ * referenced afterwards.
+ *
+ * For the meantime, we'll treat this error
+ * incorrectable, although there is a chance that a
+ * later scrub will find the bad sector again and that
+ * there's no dirty page in memory, then.
+ */
+ ret = -EIO;
+ goto out;
+ }
+ ret = repair_io_failure(inode, offset, PAGE_SIZE,
+ fixup->logical, page,
+ offset - page_offset(page),
+ fixup->mirror_num);
+ unlock_page(page);
+ corrected = !ret;
+ } else {
+ /*
+ * we need to get good data first. the general readpage path
+ * will call repair_io_failure for us, we just have to make
+ * sure we read the bad mirror.
+ */
+ ret = set_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
+ EXTENT_DAMAGED, GFP_NOFS);
+ if (ret) {
+ /* set_extent_bits should give proper error */
+ WARN_ON(ret > 0);
+ if (ret > 0)
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = extent_read_full_page(&BTRFS_I(inode)->io_tree, page,
+ btrfs_get_extent,
+ fixup->mirror_num);
+ wait_on_page_locked(page);
+
+ corrected = !test_range_bit(&BTRFS_I(inode)->io_tree, offset,
+ end, EXTENT_DAMAGED, 0, NULL);
+ if (!corrected)
+ clear_extent_bits(&BTRFS_I(inode)->io_tree, offset, end,
+ EXTENT_DAMAGED, GFP_NOFS);
+ }
+
+out:
+ if (page)
+ put_page(page);
+
+ iput(inode);
+
+ if (ret < 0)
+ return ret;
+
+ if (ret == 0 && corrected) {
+ /*
+ * we only need to call readpage for one of the inodes belonging
+ * to this extent. so make iterate_extent_inodes stop
+ */
+ return 1;
+ }
+
+ return -EIO;
+}
+
+static void scrub_fixup_nodatasum(struct btrfs_work *work)
+{
+ int ret;
+ struct scrub_fixup_nodatasum *fixup;
+ struct scrub_ctx *sctx;
+ struct btrfs_trans_handle *trans = NULL;
+ struct btrfs_path *path;
+ int uncorrectable = 0;
+
+ fixup = container_of(work, struct scrub_fixup_nodatasum, work);
+ sctx = fixup->sctx;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.malloc_errors;
+ spin_unlock(&sctx->stat_lock);
+ uncorrectable = 1;
+ goto out;
+ }
+
+ trans = btrfs_join_transaction(fixup->root);
+ if (IS_ERR(trans)) {
+ uncorrectable = 1;
+ goto out;
+ }
+
+ /*
+ * the idea is to trigger a regular read through the standard path. we
+ * read a page from the (failed) logical address by specifying the
+ * corresponding copynum of the failed sector. thus, that readpage is
+ * expected to fail.
+ * that is the point where on-the-fly error correction will kick in
+ * (once it's finished) and rewrite the failed sector if a good copy
+ * can be found.
+ */
+ ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
+ path, scrub_fixup_readpage,
+ fixup);
+ if (ret < 0) {
+ uncorrectable = 1;
+ goto out;
+ }
+ WARN_ON(ret != 1);
+
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.corrected_errors;
+ spin_unlock(&sctx->stat_lock);
+
+out:
+ if (trans && !IS_ERR(trans))
+ btrfs_end_transaction(trans, fixup->root);
+ if (uncorrectable) {
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.uncorrectable_errors;
+ spin_unlock(&sctx->stat_lock);
+ btrfs_dev_replace_stats_inc(
+ &sctx->dev_root->fs_info->dev_replace.
+ num_uncorrectable_read_errors);
+ printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
+ "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
+ fixup->logical, rcu_str_deref(fixup->dev->name));
+ }
+
+ btrfs_free_path(path);
+ kfree(fixup);
+
+ scrub_pending_trans_workers_dec(sctx);
+}
+
+static inline void scrub_get_recover(struct scrub_recover *recover)
+{
+ atomic_inc(&recover->refs);
+}
+
+static inline void scrub_put_recover(struct scrub_recover *recover)
+{
+ if (atomic_dec_and_test(&recover->refs)) {
+ btrfs_put_bbio(recover->bbio);
+ kfree(recover);
+ }
+}
+
+/*
+ * scrub_handle_errored_block gets called when either verification of the
+ * pages failed or the bio failed to read, e.g. with EIO. In the latter
+ * case, this function handles all pages 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;
+ struct btrfs_fs_info *fs_info;
+ u64 length;
+ u64 logical;
+ u64 generation;
+ unsigned int failed_mirror_index;
+ unsigned int is_metadata;
+ unsigned int have_csum;
+ u8 *csum;
+ struct scrub_block *sblocks_for_recheck; /* holds one for each mirror */
+ struct scrub_block *sblock_bad;
+ int ret;
+ int mirror_index;
+ int page_num;
+ int success;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ BUG_ON(sblock_to_check->page_count < 1);
+ fs_info = sctx->dev_root->fs_info;
+ if (sblock_to_check->pagev[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
+ */
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+ return 0;
+ }
+ length = sblock_to_check->page_count * PAGE_SIZE;
+ logical = sblock_to_check->pagev[0]->logical;
+ generation = sblock_to_check->pagev[0]->generation;
+ BUG_ON(sblock_to_check->pagev[0]->mirror_num < 1);
+ failed_mirror_index = sblock_to_check->pagev[0]->mirror_num - 1;
+ is_metadata = !(sblock_to_check->pagev[0]->flags &
+ BTRFS_EXTENT_FLAG_DATA);
+ have_csum = sblock_to_check->pagev[0]->have_csum;
+ csum = sblock_to_check->pagev[0]->csum;
+ dev = sblock_to_check->pagev[0]->dev;
+
+ if (sctx->is_dev_replace && !is_metadata && !have_csum) {
+ sblocks_for_recheck = NULL;
+ goto nodatasum_case;
+ }
+
+ /*
+ * 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,
+ * page by page this time in order to know which pages
+ * 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
+ * pages from those mirrors without I/O error on the
+ * particular pages. One example (with blocks >= 2 * PAGE_SIZE)
+ * would be that mirror #1 has an I/O error on the first page,
+ * the second page is good, and mirror #2 has an I/O error on
+ * the second page, but the first page is good.
+ * Then the first page of the first mirror can be repaired by
+ * taking the first page of the second mirror, and the
+ * second page of the second mirror can be repaired by
+ * copying the contents of the 2nd page of the 1st mirror.
+ * One more note: if the pages 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 pages 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.
+ */
+
+ sblocks_for_recheck = kcalloc(BTRFS_MAX_MIRRORS,
+ sizeof(*sblocks_for_recheck), GFP_NOFS);
+ if (!sblocks_for_recheck) {
+ 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 pages */
+ 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, is_metadata, have_csum,
+ csum, generation, sctx->csum_size, 1);
+
+ if (!sblock_bad->header_error && !sblock_bad->checksum_error &&
+ sblock_bad->no_io_error_seen) {
+ /*
+ * the error disappeared after reading page by page, 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;
+ }
+
+ if (!is_metadata && !have_csum) {
+ struct scrub_fixup_nodatasum *fixup_nodatasum;
+
+ WARN_ON(sctx->is_dev_replace);
+
+nodatasum_case:
+
+ /*
+ * !is_metadata and !have_csum, this means that the data
+ * might not be COW'ed, that it might be modified
+ * concurrently. The general strategy to work on the
+ * commit root does not help in the case when COW is not
+ * used.
+ */
+ fixup_nodatasum = kzalloc(sizeof(*fixup_nodatasum), GFP_NOFS);
+ if (!fixup_nodatasum)
+ goto did_not_correct_error;
+ fixup_nodatasum->sctx = sctx;
+ fixup_nodatasum->dev = dev;
+ fixup_nodatasum->logical = logical;
+ fixup_nodatasum->root = fs_info->extent_root;
+ fixup_nodatasum->mirror_num = failed_mirror_index + 1;
+ scrub_pending_trans_workers_inc(sctx);
+ btrfs_init_work(&fixup_nodatasum->work, btrfs_scrub_helper,
+ scrub_fixup_nodatasum, NULL, NULL);
+ btrfs_queue_work(fs_info->scrub_workers,
+ &fixup_nodatasum->work);
+ 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 pages are rewritten that had
+ * an I/O error in the block to be repaired, since it cannot be
+ * determined, which copy of the other pages is better (and it
+ * could happen otherwise that a correct page would be
+ * overwritten by a bad one).
+ */
+ for (mirror_index = 0;
+ mirror_index < BTRFS_MAX_MIRRORS &&
+ sblocks_for_recheck[mirror_index].page_count > 0;
+ mirror_index++) {
+ struct scrub_block *sblock_other;
+
+ if (mirror_index == failed_mirror_index)
+ continue;
+ sblock_other = sblocks_for_recheck + mirror_index;
+
+ /* build and submit the bios, check checksums */
+ scrub_recheck_block(fs_info, sblock_other, is_metadata,
+ have_csum, csum, generation,
+ sctx->csum_size, 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 pages.
+ * Select the good pages from mirrors to rewrite bad pages 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 pages from the different mirrors
+ * until the checksum verification succeeds. For example, when
+ * the 2nd page of mirror #1 faces I/O errors, and the 2nd page
+ * of mirror #2 is readable but the final checksum test fails,
+ * then the 2nd page of mirror #3 could be tried, whether now
+ * the final checksum succeedes. 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 PAGE_SIZE. 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 PAGE_SIZE
+ * area are unreadable.
+ */
+ success = 1;
+ for (page_num = 0; page_num < sblock_bad->page_count;
+ page_num++) {
+ struct scrub_page *page_bad = sblock_bad->pagev[page_num];
+ struct scrub_block *sblock_other = NULL;
+
+ /* skip no-io-error page in scrub */
+ if (!page_bad->io_error && !sctx->is_dev_replace)
+ continue;
+
+ /* try to find no-io-error page in mirrors */
+ if (page_bad->io_error) {
+ for (mirror_index = 0;
+ mirror_index < BTRFS_MAX_MIRRORS &&
+ sblocks_for_recheck[mirror_index].page_count > 0;
+ mirror_index++) {
+ if (!sblocks_for_recheck[mirror_index].
+ pagev[page_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 page
+ * from. scrub_write_page_to_dev_replace()
+ * handles this case (page->io_error), by
+ * filling the block with zeros before
+ * submitting the write request
+ */
+ if (!sblock_other)
+ sblock_other = sblock_bad;
+
+ if (scrub_write_page_to_dev_replace(sblock_other,
+ page_num) != 0) {
+ btrfs_dev_replace_stats_inc(
+ &sctx->dev_root->
+ fs_info->dev_replace.
+ num_write_errors);
+ success = 0;
+ }
+ } else if (sblock_other) {
+ ret = scrub_repair_page_from_good_copy(sblock_bad,
+ sblock_other,
+ page_num, 0);
+ if (0 == ret)
+ page_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,
+ is_metadata, have_csum, csum,
+ generation, sctx->csum_size, 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);
+ printk_ratelimited_in_rcu(KERN_ERR
+ "BTRFS: fixed up error at logical %llu on dev %s\n",
+ 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);
+ printk_ratelimited_in_rcu(KERN_ERR
+ "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
+ logical, rcu_str_deref(dev->name));
+ }
+
+out:
+ if (sblocks_for_recheck) {
+ 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 page_index;
+
+ for (page_index = 0; page_index < sblock->page_count;
+ page_index++) {
+ sblock->pagev[page_index]->sblock = NULL;
+ recover = sblock->pagev[page_index]->recover;
+ if (recover) {
+ scrub_put_recover(recover);
+ sblock->pagev[page_index]->recover =
+ NULL;
+ }
+ scrub_page_put(sblock->pagev[page_index]);
+ }
+ }
+ kfree(sblocks_for_recheck);
+ }
+
+ return 0;
+}
+
+static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
+{
+ if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
+ return 2;
+ else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
+ return 3;
+ else
+ return (int)bbio->num_stripes;
+}
+
+static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
+ u64 *raid_map,
+ u64 mapped_length,
+ 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] + mapped_length)
+ 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->dev_root->fs_info;
+ u64 length = original_sblock->page_count * PAGE_SIZE;
+ u64 logical = original_sblock->pagev[0]->logical;
+ struct scrub_recover *recover;
+ struct btrfs_bio *bbio;
+ u64 sublen;
+ u64 mapped_length;
+ u64 stripe_offset;
+ int stripe_index;
+ int page_index = 0;
+ int mirror_index;
+ int nmirrors;
+ int ret;
+
+ /*
+ * note: the two members refs and outstanding_pages
+ * are not used (and not set) in the blocks that are used for
+ * the recheck procedure
+ */
+
+ while (length > 0) {
+ sublen = min_t(u64, length, PAGE_SIZE);
+ mapped_length = sublen;
+ bbio = NULL;
+
+ /*
+ * with a length of PAGE_SIZE, each returned stripe
+ * represents one mirror
+ */
+ ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical,
+ &mapped_length, &bbio, 0, 1);
+ if (ret || !bbio || mapped_length < sublen) {
+ btrfs_put_bbio(bbio);
+ return -EIO;
+ }
+
+ recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
+ if (!recover) {
+ btrfs_put_bbio(bbio);
+ return -ENOMEM;
+ }
+
+ atomic_set(&recover->refs, 1);
+ recover->bbio = bbio;
+ recover->map_length = mapped_length;
+
+ BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
+
+ nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
+
+ for (mirror_index = 0; mirror_index < nmirrors;
+ mirror_index++) {
+ struct scrub_block *sblock;
+ struct scrub_page *page;
+
+ sblock = sblocks_for_recheck + mirror_index;
+ sblock->sctx = sctx;
+ page = kzalloc(sizeof(*page), GFP_NOFS);
+ if (!page) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_put_recover(recover);
+ return -ENOMEM;
+ }
+ scrub_page_get(page);
+ sblock->pagev[page_index] = page;
+ page->logical = logical;
+
+ scrub_stripe_index_and_offset(logical,
+ bbio->map_type,
+ bbio->raid_map,
+ mapped_length,
+ bbio->num_stripes -
+ bbio->num_tgtdevs,
+ mirror_index,
+ &stripe_index,
+ &stripe_offset);
+ page->physical = bbio->stripes[stripe_index].physical +
+ stripe_offset;
+ page->dev = bbio->stripes[stripe_index].dev;
+
+ BUG_ON(page_index >= original_sblock->page_count);
+ page->physical_for_dev_replace =
+ original_sblock->pagev[page_index]->
+ physical_for_dev_replace;
+ /* for missing devices, dev->bdev is NULL */
+ page->mirror_num = mirror_index + 1;
+ sblock->page_count++;
+ page->page = alloc_page(GFP_NOFS);
+ if (!page->page)
+ goto leave_nomem;
+
+ scrub_get_recover(recover);
+ page->recover = recover;
+ }
+ scrub_put_recover(recover);
+ length -= sublen;
+ logical += sublen;
+ page_index++;
+ }
+
+ return 0;
+}
+
+struct scrub_bio_ret {
+ struct completion event;
+ int error;
+};
+
+static void scrub_bio_wait_endio(struct bio *bio, int error)
+{
+ struct scrub_bio_ret *ret = bio->bi_private;
+
+ ret->error = error;
+ complete(&ret->event);
+}
+
+static inline int scrub_is_page_on_raid56(struct scrub_page *page)
+{
+ return page->recover &&
+ (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
+}
+
+static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
+ struct bio *bio,
+ struct scrub_page *page)
+{
+ struct scrub_bio_ret done;
+ int ret;
+
+ init_completion(&done.event);
+ done.error = 0;
+ bio->bi_iter.bi_sector = page->logical >> 9;
+ bio->bi_private = &done;
+ bio->bi_end_io = scrub_bio_wait_endio;
+
+ ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
+ page->recover->map_length,
+ page->mirror_num, 0);
+ if (ret)
+ return ret;
+
+ wait_for_completion(&done.event);
+ if (done.error)
+ return -EIO;
+
+ return 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 pages
+ * which are errored are marked as being bad. The goal is to enable scrub
+ * to take those pages that are not errored from all the mirrors so that
+ * the pages 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 is_metadata,
+ int have_csum, u8 *csum, u64 generation,
+ u16 csum_size, int retry_failed_mirror)
+{
+ int page_num;
+
+ sblock->no_io_error_seen = 1;
+ sblock->header_error = 0;
+ sblock->checksum_error = 0;
+
+ for (page_num = 0; page_num < sblock->page_count; page_num++) {
+ struct bio *bio;
+ struct scrub_page *page = sblock->pagev[page_num];
+
+ if (page->dev->bdev == NULL) {
+ page->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ continue;
+ }
+
+ WARN_ON(!page->page);
+ bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
+ if (!bio) {
+ page->io_error = 1;
+ sblock->no_io_error_seen = 0;
+ continue;
+ }
+ bio->bi_bdev = page->dev->bdev;
+
+ bio_add_page(bio, page->page, PAGE_SIZE, 0);
+ if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
+ if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
+ sblock->no_io_error_seen = 0;
+ } else {
+ bio->bi_iter.bi_sector = page->physical >> 9;
+
+ if (btrfsic_submit_bio_wait(READ, bio))
+ sblock->no_io_error_seen = 0;
+ }
+
+ bio_put(bio);
+ }
+
+ if (sblock->no_io_error_seen)
+ scrub_recheck_block_checksum(fs_info, sblock, is_metadata,
+ have_csum, csum, generation,
+ csum_size);
+
+ return;
+}
+
+static inline int scrub_check_fsid(u8 fsid[],
+ struct scrub_page *spage)
+{
+ struct btrfs_fs_devices *fs_devices = spage->dev->fs_devices;
+ int ret;
+
+ ret = memcmp(fsid, fs_devices->fsid, BTRFS_UUID_SIZE);
+ return !ret;
+}
+
+static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
+ struct scrub_block *sblock,
+ int is_metadata, int have_csum,
+ const u8 *csum, u64 generation,
+ u16 csum_size)
+{
+ int page_num;
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u32 crc = ~(u32)0;
+ void *mapped_buffer;
+
+ WARN_ON(!sblock->pagev[0]->page);
+ if (is_metadata) {
+ struct btrfs_header *h;
+
+ mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
+ h = (struct btrfs_header *)mapped_buffer;
+
+ if (sblock->pagev[0]->logical != btrfs_stack_header_bytenr(h) ||
+ !scrub_check_fsid(h->fsid, sblock->pagev[0]) ||
+ memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
+ BTRFS_UUID_SIZE)) {
+ sblock->header_error = 1;
+ } else if (generation != btrfs_stack_header_generation(h)) {
+ sblock->header_error = 1;
+ sblock->generation_error = 1;
+ }
+ csum = h->csum;
+ } else {
+ if (!have_csum)
+ return;
+
+ mapped_buffer = kmap_atomic(sblock->pagev[0]->page);
+ }
+
+ for (page_num = 0;;) {
+ if (page_num == 0 && is_metadata)
+ crc = btrfs_csum_data(
+ ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE,
+ crc, PAGE_SIZE - BTRFS_CSUM_SIZE);
+ else
+ crc = btrfs_csum_data(mapped_buffer, crc, PAGE_SIZE);
+
+ kunmap_atomic(mapped_buffer);
+ page_num++;
+ if (page_num >= sblock->page_count)
+ break;
+ WARN_ON(!sblock->pagev[page_num]->page);
+
+ mapped_buffer = kmap_atomic(sblock->pagev[page_num]->page);
+ }
+
+ btrfs_csum_final(crc, calculated_csum);
+ if (memcmp(calculated_csum, csum, csum_size))
+ sblock->checksum_error = 1;
+}
+
+static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good)
+{
+ int page_num;
+ int ret = 0;
+
+ for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
+ int ret_sub;
+
+ ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
+ sblock_good,
+ page_num, 1);
+ if (ret_sub)
+ ret = ret_sub;
+ }
+
+ return ret;
+}
+
+static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
+ struct scrub_block *sblock_good,
+ int page_num, int force_write)
+{
+ struct scrub_page *page_bad = sblock_bad->pagev[page_num];
+ struct scrub_page *page_good = sblock_good->pagev[page_num];
+
+ BUG_ON(page_bad->page == NULL);
+ BUG_ON(page_good->page == NULL);
+ if (force_write || sblock_bad->header_error ||
+ sblock_bad->checksum_error || page_bad->io_error) {
+ struct bio *bio;
+ int ret;
+
+ if (!page_bad->dev->bdev) {
+ printk_ratelimited(KERN_WARNING "BTRFS: "
+ "scrub_repair_page_from_good_copy(bdev == NULL) "
+ "is unexpected!\n");
+ return -EIO;
+ }
+
+ bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
+ if (!bio)
+ return -EIO;
+ bio->bi_bdev = page_bad->dev->bdev;
+ bio->bi_iter.bi_sector = page_bad->physical >> 9;
+
+ ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
+ if (PAGE_SIZE != ret) {
+ bio_put(bio);
+ return -EIO;
+ }
+
+ if (btrfsic_submit_bio_wait(WRITE, bio)) {
+ btrfs_dev_stat_inc_and_print(page_bad->dev,
+ BTRFS_DEV_STAT_WRITE_ERRS);
+ btrfs_dev_replace_stats_inc(
+ &sblock_bad->sctx->dev_root->fs_info->
+ dev_replace.num_write_errors);
+ bio_put(bio);
+ return -EIO;
+ }
+ bio_put(bio);
+ }
+
+ return 0;
+}
+
+static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
+{
+ int page_num;
+
+ /*
+ * 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 (page_num = 0; page_num < sblock->page_count; page_num++) {
+ int ret;
+
+ ret = scrub_write_page_to_dev_replace(sblock, page_num);
+ if (ret)
+ btrfs_dev_replace_stats_inc(
+ &sblock->sctx->dev_root->fs_info->dev_replace.
+ num_write_errors);
+ }
+}
+
+static int scrub_write_page_to_dev_replace(struct scrub_block *sblock,
+ int page_num)
+{
+ struct scrub_page *spage = sblock->pagev[page_num];
+
+ BUG_ON(spage->page == NULL);
+ if (spage->io_error) {
+ void *mapped_buffer = kmap_atomic(spage->page);
+
+ memset(mapped_buffer, 0, PAGE_CACHE_SIZE);
+ flush_dcache_page(spage->page);
+ kunmap_atomic(mapped_buffer);
+ }
+ return scrub_add_page_to_wr_bio(sblock->sctx, spage);
+}
+
+static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage)
+{
+ struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
+ struct scrub_bio *sbio;
+ int ret;
+
+ mutex_lock(&wr_ctx->wr_lock);
+again:
+ if (!wr_ctx->wr_curr_bio) {
+ wr_ctx->wr_curr_bio = kzalloc(sizeof(*wr_ctx->wr_curr_bio),
+ GFP_NOFS);
+ if (!wr_ctx->wr_curr_bio) {
+ mutex_unlock(&wr_ctx->wr_lock);
+ return -ENOMEM;
+ }
+ wr_ctx->wr_curr_bio->sctx = sctx;
+ wr_ctx->wr_curr_bio->page_count = 0;
+ }
+ sbio = wr_ctx->wr_curr_bio;
+ if (sbio->page_count == 0) {
+ struct bio *bio;
+
+ sbio->physical = spage->physical_for_dev_replace;
+ sbio->logical = spage->logical;
+ sbio->dev = wr_ctx->tgtdev;
+ bio = sbio->bio;
+ if (!bio) {
+ bio = btrfs_io_bio_alloc(GFP_NOFS, wr_ctx->pages_per_wr_bio);
+ if (!bio) {
+ mutex_unlock(&wr_ctx->wr_lock);
+ return -ENOMEM;
+ }
+ sbio->bio = bio;
+ }
+
+ bio->bi_private = sbio;
+ bio->bi_end_io = scrub_wr_bio_end_io;
+ bio->bi_bdev = sbio->dev->bdev;
+ bio->bi_iter.bi_sector = sbio->physical >> 9;
+ sbio->err = 0;
+ } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
+ spage->physical_for_dev_replace ||
+ sbio->logical + sbio->page_count * PAGE_SIZE !=
+ spage->logical) {
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
+ if (ret != PAGE_SIZE) {
+ if (sbio->page_count < 1) {
+ bio_put(sbio->bio);
+ sbio->bio = NULL;
+ mutex_unlock(&wr_ctx->wr_lock);
+ return -EIO;
+ }
+ scrub_wr_submit(sctx);
+ goto again;
+ }
+
+ sbio->pagev[sbio->page_count] = spage;
+ scrub_page_get(spage);
+ sbio->page_count++;
+ if (sbio->page_count == wr_ctx->pages_per_wr_bio)
+ scrub_wr_submit(sctx);
+ mutex_unlock(&wr_ctx->wr_lock);
+
+ return 0;
+}
+
+static void scrub_wr_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_wr_ctx *wr_ctx = &sctx->wr_ctx;
+ struct scrub_bio *sbio;
+
+ if (!wr_ctx->wr_curr_bio)
+ return;
+
+ sbio = wr_ctx->wr_curr_bio;
+ wr_ctx->wr_curr_bio = NULL;
+ WARN_ON(!sbio->bio->bi_bdev);
+ 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_submit_bio(WRITE, sbio->bio);
+}
+
+static void scrub_wr_bio_end_io(struct bio *bio, int err)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
+
+ sbio->err = err;
+ sbio->bio = bio;
+
+ btrfs_init_work(&sbio->work, btrfs_scrubwrc_helper,
+ scrub_wr_bio_end_io_worker, NULL, NULL);
+ btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
+}
+
+static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
+ if (sbio->err) {
+ struct btrfs_dev_replace *dev_replace =
+ &sbio->sctx->dev_root->fs_info->dev_replace;
+
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+
+ spage->io_error = 1;
+ btrfs_dev_replace_stats_inc(&dev_replace->
+ num_write_errors);
+ }
+ }
+
+ for (i = 0; i < sbio->page_count; i++)
+ scrub_page_put(sbio->pagev[i]);
+
+ bio_put(sbio->bio);
+ kfree(sbio);
+ scrub_pending_bio_dec(sctx);
+}
+
+static int scrub_checksum(struct scrub_block *sblock)
+{
+ u64 flags;
+ int ret;
+
+ WARN_ON(sblock->page_count < 1);
+ flags = sblock->pagev[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)
+ (void)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;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u8 *on_disk_csum;
+ struct page *page;
+ void *buffer;
+ u32 crc = ~(u32)0;
+ int fail = 0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ if (!sblock->pagev[0]->have_csum)
+ return 0;
+
+ on_disk_csum = sblock->pagev[0]->csum;
+ page = sblock->pagev[0]->page;
+ buffer = kmap_atomic(page);
+
+ len = sctx->sectorsize;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ crc = btrfs_csum_data(buffer, crc, l);
+ kunmap_atomic(buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ buffer = kmap_atomic(page);
+ }
+
+ btrfs_csum_final(crc, csum);
+ if (memcmp(csum, on_disk_csum, sctx->csum_size))
+ fail = 1;
+
+ return fail;
+}
+
+static int scrub_checksum_tree_block(struct scrub_block *sblock)
+{
+ struct scrub_ctx *sctx = sblock->sctx;
+ struct btrfs_header *h;
+ struct btrfs_root *root = sctx->dev_root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u8 on_disk_csum[BTRFS_CSUM_SIZE];
+ struct page *page;
+ void *mapped_buffer;
+ u64 mapped_size;
+ void *p;
+ u32 crc = ~(u32)0;
+ int fail = 0;
+ int crc_fail = 0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ page = sblock->pagev[0]->page;
+ mapped_buffer = kmap_atomic(page);
+ h = (struct btrfs_header *)mapped_buffer;
+ memcpy(on_disk_csum, h->csum, sctx->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->pagev[0]->logical != btrfs_stack_header_bytenr(h))
+ ++fail;
+
+ if (sblock->pagev[0]->generation != btrfs_stack_header_generation(h))
+ ++fail;
+
+ if (!scrub_check_fsid(h->fsid, sblock->pagev[0]))
+ ++fail;
+
+ if (memcmp(h->chunk_tree_uuid, fs_info->chunk_tree_uuid,
+ BTRFS_UUID_SIZE))
+ ++fail;
+
+ len = sctx->nodesize - BTRFS_CSUM_SIZE;
+ mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
+ p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, mapped_size);
+
+ crc = btrfs_csum_data(p, crc, l);
+ kunmap_atomic(mapped_buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ mapped_buffer = kmap_atomic(page);
+ mapped_size = PAGE_SIZE;
+ p = mapped_buffer;
+ }
+
+ btrfs_csum_final(crc, calculated_csum);
+ if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
+ ++crc_fail;
+
+ return fail || crc_fail;
+}
+
+static int scrub_checksum_super(struct scrub_block *sblock)
+{
+ struct btrfs_super_block *s;
+ struct scrub_ctx *sctx = sblock->sctx;
+ u8 calculated_csum[BTRFS_CSUM_SIZE];
+ u8 on_disk_csum[BTRFS_CSUM_SIZE];
+ struct page *page;
+ void *mapped_buffer;
+ u64 mapped_size;
+ void *p;
+ u32 crc = ~(u32)0;
+ int fail_gen = 0;
+ int fail_cor = 0;
+ u64 len;
+ int index;
+
+ BUG_ON(sblock->page_count < 1);
+ page = sblock->pagev[0]->page;
+ mapped_buffer = kmap_atomic(page);
+ s = (struct btrfs_super_block *)mapped_buffer;
+ memcpy(on_disk_csum, s->csum, sctx->csum_size);
+
+ if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
+ ++fail_cor;
+
+ if (sblock->pagev[0]->generation != btrfs_super_generation(s))
+ ++fail_gen;
+
+ if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
+ ++fail_cor;
+
+ len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
+ mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
+ p = ((u8 *)mapped_buffer) + BTRFS_CSUM_SIZE;
+ index = 0;
+ for (;;) {
+ u64 l = min_t(u64, len, mapped_size);
+
+ crc = btrfs_csum_data(p, crc, l);
+ kunmap_atomic(mapped_buffer);
+ len -= l;
+ if (len == 0)
+ break;
+ index++;
+ BUG_ON(index >= sblock->page_count);
+ BUG_ON(!sblock->pagev[index]->page);
+ page = sblock->pagev[index]->page;
+ mapped_buffer = kmap_atomic(page);
+ mapped_size = PAGE_SIZE;
+ p = mapped_buffer;
+ }
+
+ btrfs_csum_final(crc, calculated_csum);
+ if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
+ ++fail_cor;
+
+ if (fail_cor + fail_gen) {
+ /*
+ * if we find an error in a super block, we just report it.
+ * They will get written with the next transaction commit
+ * anyway
+ */
+ spin_lock(&sctx->stat_lock);
+ ++sctx->stat.super_errors;
+ spin_unlock(&sctx->stat_lock);
+ if (fail_cor)
+ btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+ BTRFS_DEV_STAT_CORRUPTION_ERRS);
+ else
+ btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+ BTRFS_DEV_STAT_GENERATION_ERRS);
+ }
+
+ return fail_cor + fail_gen;
+}
+
+static void scrub_block_get(struct scrub_block *sblock)
+{
+ atomic_inc(&sblock->refs);
+}
+
+static void scrub_block_put(struct scrub_block *sblock)
+{
+ if (atomic_dec_and_test(&sblock->refs)) {
+ int i;
+
+ if (sblock->sparity)
+ scrub_parity_put(sblock->sparity);
+
+ for (i = 0; i < sblock->page_count; i++)
+ scrub_page_put(sblock->pagev[i]);
+ kfree(sblock);
+ }
+}
+
+static void scrub_page_get(struct scrub_page *spage)
+{
+ atomic_inc(&spage->refs);
+}
+
+static void scrub_page_put(struct scrub_page *spage)
+{
+ if (atomic_dec_and_test(&spage->refs)) {
+ if (spage->page)
+ __free_page(spage->page);
+ kfree(spage);
+ }
+}
+
+static void scrub_submit(struct scrub_ctx *sctx)
+{
+ struct scrub_bio *sbio;
+
+ if (sctx->curr == -1)
+ return;
+
+ sbio = sctx->bios[sctx->curr];
+ sctx->curr = -1;
+ scrub_pending_bio_inc(sctx);
+
+ if (!sbio->bio->bi_bdev) {
+ /*
+ * this case should not happen. If btrfs_map_block() is
+ * wrong, it could happen for dev-replace operations on
+ * missing devices when no mirrors are available, but in
+ * this case it should already fail the mount.
+ * This case is handled correctly (but _very_ slowly).
+ */
+ printk_ratelimited(KERN_WARNING
+ "BTRFS: scrub_submit(bio bdev == NULL) is unexpected!\n");
+ bio_endio(sbio->bio, -EIO);
+ } else {
+ btrfsic_submit_bio(READ, sbio->bio);
+ }
+}
+
+static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx,
+ struct scrub_page *spage)
+{
+ struct scrub_block *sblock = spage->sblock;
+ struct scrub_bio *sbio;
+ 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]->page_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->page_count == 0) {
+ struct bio *bio;
+
+ sbio->physical = spage->physical;
+ sbio->logical = spage->logical;
+ sbio->dev = spage->dev;
+ bio = sbio->bio;
+ if (!bio) {
+ bio = btrfs_io_bio_alloc(GFP_NOFS, sctx->pages_per_rd_bio);
+ if (!bio)
+ return -ENOMEM;
+ sbio->bio = bio;
+ }
+
+ bio->bi_private = sbio;
+ bio->bi_end_io = scrub_bio_end_io;
+ bio->bi_bdev = sbio->dev->bdev;
+ bio->bi_iter.bi_sector = sbio->physical >> 9;
+ sbio->err = 0;
+ } else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
+ spage->physical ||
+ sbio->logical + sbio->page_count * PAGE_SIZE !=
+ spage->logical ||
+ sbio->dev != spage->dev) {
+ scrub_submit(sctx);
+ goto again;
+ }
+
+ sbio->pagev[sbio->page_count] = spage;
+ ret = bio_add_page(sbio->bio, spage->page, PAGE_SIZE, 0);
+ if (ret != PAGE_SIZE) {
+ if (sbio->page_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_pages);
+ sbio->page_count++;
+ if (sbio->page_count == sctx->pages_per_rd_bio)
+ scrub_submit(sctx);
+
+ return 0;
+}
+
+static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u8 *csum, int force,
+ u64 physical_for_dev_replace)
+{
+ struct scrub_block *sblock;
+ int index;
+
+ sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ /* one ref inside this function, plus one for each page added to
+ * a bio later on */
+ atomic_set(&sblock->refs, 1);
+ sblock->sctx = sctx;
+ sblock->no_io_error_seen = 1;
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_page *spage;
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ spage = kzalloc(sizeof(*spage), GFP_NOFS);
+ if (!spage) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+ scrub_page_get(spage);
+ sblock->pagev[index] = spage;
+ spage->sblock = sblock;
+ spage->dev = dev;
+ spage->flags = flags;
+ spage->generation = gen;
+ spage->logical = logical;
+ spage->physical = physical;
+ spage->physical_for_dev_replace = physical_for_dev_replace;
+ spage->mirror_num = mirror_num;
+ if (csum) {
+ spage->have_csum = 1;
+ memcpy(spage->csum, csum, sctx->csum_size);
+ } else {
+ spage->have_csum = 0;
+ }
+ sblock->page_count++;
+ spage->page = alloc_page(GFP_NOFS);
+ if (!spage->page)
+ goto leave_nomem;
+ len -= l;
+ logical += l;
+ physical += l;
+ physical_for_dev_replace += l;
+ }
+
+ WARN_ON(sblock->page_count == 0);
+ for (index = 0; index < sblock->page_count; index++) {
+ struct scrub_page *spage = sblock->pagev[index];
+ int ret;
+
+ ret = scrub_add_page_to_rd_bio(sctx, spage);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ if (force)
+ 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, int err)
+{
+ struct scrub_bio *sbio = bio->bi_private;
+ struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
+
+ sbio->err = err;
+ sbio->bio = bio;
+
+ btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
+}
+
+static void scrub_bio_end_io_worker(struct btrfs_work *work)
+{
+ struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
+ struct scrub_ctx *sctx = sbio->sctx;
+ int i;
+
+ BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
+ if (sbio->err) {
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+
+ spage->io_error = 1;
+ spage->sblock->no_io_error_seen = 0;
+ }
+ }
+
+ /* now complete the scrub_block items that have all pages completed */
+ for (i = 0; i < sbio->page_count; i++) {
+ struct scrub_page *spage = sbio->pagev[i];
+ struct scrub_block *sblock = spage->sblock;
+
+ if (atomic_dec_and_test(&sblock->outstanding_pages))
+ 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 &&
+ atomic_read(&sctx->wr_ctx.flush_all_writes)) {
+ mutex_lock(&sctx->wr_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+ }
+
+ scrub_pending_bio_dec(sctx);
+}
+
+static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
+ unsigned long *bitmap,
+ u64 start, u64 len)
+{
+ u32 offset;
+ int nsectors;
+ int sectorsize = sparity->sctx->dev_root->sectorsize;
+
+ if (len >= sparity->stripe_len) {
+ bitmap_set(bitmap, 0, sparity->nsectors);
+ return;
+ }
+
+ start -= sparity->logic_start;
+ start = div_u64_rem(start, sparity->stripe_len, &offset);
+ offset /= sectorsize;
+ nsectors = (int)len / sectorsize;
+
+ 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, u64 len)
+{
+ __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len);
+}
+
+static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity,
+ u64 start, u64 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->pagev[0]->logical;
+ u64 end = sblock->pagev[sblock->page_count - 1]->logical +
+ PAGE_SIZE;
+
+ scrub_parity_mark_sectors_error(sblock->sparity,
+ start, end - start);
+ }
+}
+
+static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u8 *csum)
+{
+ struct btrfs_ordered_sum *sum = NULL;
+ unsigned long index;
+ unsigned long num_sectors;
+
+ while (!list_empty(&sctx->csum_list)) {
+ sum = list_first_entry(&sctx->csum_list,
+ struct btrfs_ordered_sum, list);
+ if (sum->bytenr > logical)
+ return 0;
+ if (sum->bytenr + sum->len > logical)
+ break;
+
+ ++sctx->stat.csum_discards;
+ list_del(&sum->list);
+ kfree(sum);
+ sum = NULL;
+ }
+ if (!sum)
+ return 0;
+
+ index = ((u32)(logical - sum->bytenr)) / sctx->sectorsize;
+ num_sectors = sum->len / sctx->sectorsize;
+ memcpy(csum, sum->sums + index, sctx->csum_size);
+ if (index == num_sectors - 1) {
+ list_del(&sum->list);
+ kfree(sum);
+ }
+ return 1;
+}
+
+/* scrub extent tries to collect up to 64 kB for each bio */
+static int scrub_extent(struct scrub_ctx *sctx, u64 logical, u64 len,
+ u64 physical, struct btrfs_device *dev, u64 flags,
+ u64 gen, int mirror_num, u64 physical_for_dev_replace)
+{
+ int ret;
+ u8 csum[BTRFS_CSUM_SIZE];
+ u32 blocksize;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ blocksize = sctx->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) {
+ blocksize = sctx->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->sectorsize;
+ WARN_ON(1);
+ }
+
+ while (len) {
+ u64 l = min_t(u64, len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, l, csum);
+ if (have_csum == 0)
+ ++sctx->stat.no_csum;
+ if (sctx->is_dev_replace && !have_csum) {
+ ret = copy_nocow_pages(sctx, logical, l,
+ mirror_num,
+ physical_for_dev_replace);
+ goto behind_scrub_pages;
+ }
+ }
+ ret = scrub_pages(sctx, logical, l, physical, dev, flags, gen,
+ mirror_num, have_csum ? csum : NULL, 0,
+ physical_for_dev_replace);
+behind_scrub_pages:
+ if (ret)
+ return ret;
+ len -= l;
+ logical += l;
+ physical += l;
+ physical_for_dev_replace += l;
+ }
+ return 0;
+}
+
+static int scrub_pages_for_parity(struct scrub_parity *sparity,
+ u64 logical, u64 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;
+ int index;
+
+ sblock = kzalloc(sizeof(*sblock), GFP_NOFS);
+ if (!sblock) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ /* one ref inside this function, plus one for each page added to
+ * a bio later on */
+ atomic_set(&sblock->refs, 1);
+ sblock->sctx = sctx;
+ sblock->no_io_error_seen = 1;
+ sblock->sparity = sparity;
+ scrub_parity_get(sparity);
+
+ for (index = 0; len > 0; index++) {
+ struct scrub_page *spage;
+ u64 l = min_t(u64, len, PAGE_SIZE);
+
+ spage = kzalloc(sizeof(*spage), GFP_NOFS);
+ if (!spage) {
+leave_nomem:
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ scrub_block_put(sblock);
+ return -ENOMEM;
+ }
+ BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+ /* For scrub block */
+ scrub_page_get(spage);
+ sblock->pagev[index] = spage;
+ /* For scrub parity */
+ scrub_page_get(spage);
+ list_add_tail(&spage->list, &sparity->spages);
+ spage->sblock = sblock;
+ spage->dev = dev;
+ spage->flags = flags;
+ spage->generation = gen;
+ spage->logical = logical;
+ spage->physical = physical;
+ spage->mirror_num = mirror_num;
+ if (csum) {
+ spage->have_csum = 1;
+ memcpy(spage->csum, csum, sctx->csum_size);
+ } else {
+ spage->have_csum = 0;
+ }
+ sblock->page_count++;
+ spage->page = alloc_page(GFP_NOFS);
+ if (!spage->page)
+ goto leave_nomem;
+ len -= l;
+ logical += l;
+ physical += l;
+ }
+
+ WARN_ON(sblock->page_count == 0);
+ for (index = 0; index < sblock->page_count; index++) {
+ struct scrub_page *spage = sblock->pagev[index];
+ int ret;
+
+ ret = scrub_add_page_to_rd_bio(sctx, spage);
+ if (ret) {
+ scrub_block_put(sblock);
+ return ret;
+ }
+ }
+
+ /* last one frees, either here or in bio completion for last page */
+ scrub_block_put(sblock);
+ return 0;
+}
+
+static int scrub_extent_for_parity(struct scrub_parity *sparity,
+ u64 logical, u64 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 (flags & BTRFS_EXTENT_FLAG_DATA) {
+ blocksize = sctx->sectorsize;
+ } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+ blocksize = sctx->nodesize;
+ } else {
+ blocksize = sctx->sectorsize;
+ WARN_ON(1);
+ }
+
+ while (len) {
+ u64 l = min_t(u64, len, blocksize);
+ int have_csum = 0;
+
+ if (flags & BTRFS_EXTENT_FLAG_DATA) {
+ /* push csums to sbio */
+ have_csum = scrub_find_csum(sctx, logical, l, csum);
+ if (have_csum == 0)
+ goto skip;
+ }
+ ret = scrub_pages_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;
+
+ last_offset = (physical - map->stripes[num].physical) *
+ nr_data_stripes(map);
+ if (stripe_start)
+ *stripe_start = last_offset;
+
+ *offset = last_offset;
+ for (i = 0; i < nr_data_stripes(map); i++) {
+ *offset = last_offset + i * map->stripe_len;
+
+ stripe_nr = div_u64(*offset, map->stripe_len);
+ stripe_nr = div_u64(stripe_nr, nr_data_stripes(map));
+
+ /* 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_page *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->spages, list) {
+ list_del_init(&curr->list);
+ scrub_page_put(curr);
+ }
+
+ kfree(sparity);
+}
+
+static void scrub_parity_bio_endio(struct bio *bio, int error)
+{
+ struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
+ struct scrub_ctx *sctx = sparity->sctx;
+
+ if (error)
+ bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
+ sparity->nsectors);
+
+ scrub_free_parity(sparity);
+ scrub_pending_bio_dec(sctx);
+ bio_put(bio);
+}
+
+static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
+{
+ struct scrub_ctx *sctx = sparity->sctx;
+ struct bio *bio;
+ struct btrfs_raid_bio *rbio;
+ struct scrub_page *spage;
+ struct btrfs_bio *bbio = 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 + 1;
+ ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
+ sparity->logic_start,
+ &length, &bbio, 0, 1);
+ if (ret || !bbio || !bbio->raid_map)
+ goto bbio_out;
+
+ bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
+ if (!bio)
+ goto bbio_out;
+
+ 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(sctx->dev_root, bio, bbio,
+ length, sparity->scrub_dev,
+ sparity->dbitmap,
+ sparity->nsectors);
+ if (!rbio)
+ goto rbio_out;
+
+ list_for_each_entry(spage, &sparity->spages, list)
+ raid56_parity_add_scrub_pages(rbio, spage->page,
+ spage->logical);
+
+ scrub_pending_bio_inc(sctx);
+ raid56_parity_submit_scrub_rbio(rbio);
+ return;
+
+rbio_out:
+ bio_put(bio);
+bbio_out:
+ btrfs_put_bbio(bbio);
+ 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 inline int scrub_calc_parity_bitmap_len(int nsectors)
+{
+ return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8);
+}
+
+static void scrub_parity_get(struct scrub_parity *sparity)
+{
+ atomic_inc(&sparity->refs);
+}
+
+static void scrub_parity_put(struct scrub_parity *sparity)
+{
+ if (!atomic_dec_and_test(&sparity->refs))
+ return;
+
+ scrub_parity_check_and_repair(sparity);
+}
+
+static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *sdev,
+ struct btrfs_path *path,
+ u64 logic_start,
+ u64 logic_end)
+{
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_root *csum_root = fs_info->csum_root;
+ struct btrfs_extent_item *extent;
+ u64 flags;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ u64 generation;
+ u64 extent_logical;
+ u64 extent_physical;
+ u64 extent_len;
+ struct btrfs_device *extent_dev;
+ struct scrub_parity *sparity;
+ int nsectors;
+ int bitmap_len;
+ int extent_mirror_num;
+ int stop_loop = 0;
+
+ nsectors = map->stripe_len / root->sectorsize;
+ bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
+ sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
+ GFP_NOFS);
+ if (!sparity) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ 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;
+ atomic_set(&sparity->refs, 1);
+ INIT_LIST_HEAD(&sparity->spages);
+ sparity->dbitmap = sparity->bitmap;
+ sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
+
+ ret = 0;
+ while (logic_start < logic_end) {
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = logic_start;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = btrfs_previous_extent_item(root, path, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+ stop_loop = 0;
+ while (1) {
+ u64 bytes;
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+
+ stop_loop = 1;
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ bytes = root->nodesize;
+ else
+ bytes = key.offset;
+
+ if (key.objectid + bytes <= logic_start)
+ goto next;
+
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+
+ if (key.objectid > logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ while (key.objectid >= logic_start + map->stripe_len)
+ logic_start += map->stripe_len;
+
+ extent = btrfs_item_ptr(l, slot,
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(l, extent);
+ generation = btrfs_extent_generation(l, extent);
+
+ if (key.objectid < logic_start &&
+ (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning stripes, ignored. logical=%llu",
+ key.objectid, logic_start);
+ goto next;
+ }
+again:
+ extent_logical = key.objectid;
+ extent_len = bytes;
+
+ if (extent_logical < logic_start) {
+ extent_len -= logic_start - extent_logical;
+ extent_logical = logic_start;
+ }
+
+ if (extent_logical + extent_len >
+ logic_start + map->stripe_len)
+ extent_len = logic_start + map->stripe_len -
+ extent_logical;
+
+ scrub_parity_mark_sectors_data(sparity, extent_logical,
+ extent_len);
+
+ scrub_remap_extent(fs_info, extent_logical,
+ extent_len, &extent_physical,
+ &extent_dev,
+ &extent_mirror_num);
+
+ ret = btrfs_lookup_csums_range(csum_root,
+ extent_logical,
+ extent_logical + extent_len - 1,
+ &sctx->csum_list, 1);
+ if (ret)
+ goto out;
+
+ ret = scrub_extent_for_parity(sparity, extent_logical,
+ extent_len,
+ extent_physical,
+ extent_dev, flags,
+ generation,
+ extent_mirror_num);
+ if (ret)
+ goto out;
+
+ scrub_free_csums(sctx);
+ if (extent_logical + extent_len <
+ key.objectid + bytes) {
+ logic_start += map->stripe_len;
+
+ if (logic_start >= logic_end) {
+ stop_loop = 1;
+ break;
+ }
+
+ if (logic_start < key.objectid + bytes) {
+ cond_resched();
+ goto again;
+ }
+ }
+next:
+ path->slots[0]++;
+ }
+
+ btrfs_release_path(path);
+
+ if (stop_loop)
+ break;
+
+ logic_start += map->stripe_len;
+ }
+out:
+ if (ret < 0)
+ scrub_parity_mark_sectors_error(sparity, logic_start,
+ logic_end - logic_start + 1);
+ scrub_parity_put(sparity);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+
+ btrfs_release_path(path);
+ return ret < 0 ? ret : 0;
+}
+
+static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
+ struct map_lookup *map,
+ struct btrfs_device *scrub_dev,
+ int num, u64 base, u64 length,
+ int is_dev_replace)
+{
+ struct btrfs_path *path, *ppath;
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+ struct btrfs_root *root = fs_info->extent_root;
+ struct btrfs_root *csum_root = fs_info->csum_root;
+ struct btrfs_extent_item *extent;
+ struct blk_plug plug;
+ u64 flags;
+ int ret;
+ int slot;
+ u64 nstripes;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ u64 physical;
+ u64 logical;
+ u64 logic_end;
+ u64 physical_end;
+ u64 generation;
+ int mirror_num;
+ struct reada_control *reada1;
+ struct reada_control *reada2;
+ struct btrfs_key key_start;
+ struct btrfs_key key_end;
+ u64 increment = map->stripe_len;
+ u64 offset;
+ u64 extent_logical;
+ u64 extent_physical;
+ u64 extent_len;
+ u64 stripe_logical;
+ u64 stripe_end;
+ struct btrfs_device *extent_dev;
+ int extent_mirror_num;
+ int stop_loop = 0;
+
+ physical = map->stripes[num].physical;
+ offset = 0;
+ nstripes = div_u64(length, map->stripe_len);
+ if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
+ offset = map->stripe_len * num;
+ increment = map->stripe_len * map->num_stripes;
+ mirror_num = 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
+ int factor = map->num_stripes / map->sub_stripes;
+ offset = map->stripe_len * (num / map->sub_stripes);
+ increment = map->stripe_len * factor;
+ mirror_num = num % map->sub_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
+ increment = map->stripe_len;
+ mirror_num = num % map->num_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
+ increment = map->stripe_len;
+ mirror_num = num % map->num_stripes + 1;
+ } else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ get_raid56_logic_offset(physical, num, map, &offset, NULL);
+ increment = map->stripe_len * nr_data_stripes(map);
+ mirror_num = 1;
+ } else {
+ increment = map->stripe_len;
+ mirror_num = 1;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ppath = btrfs_alloc_path();
+ if (!ppath) {
+ btrfs_free_path(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;
+
+ ppath->search_commit_root = 1;
+ ppath->skip_locking = 1;
+ /*
+ * trigger the readahead for extent tree csum tree and wait for
+ * completion. During readahead, the scrub is officially paused
+ * to not hold off transaction commits
+ */
+ logical = base + offset;
+ physical_end = physical + nstripes * map->stripe_len;
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ get_raid56_logic_offset(physical_end, num,
+ map, &logic_end, NULL);
+ logic_end += base;
+ } else {
+ logic_end = logical + increment * nstripes;
+ }
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ scrub_blocked_if_needed(fs_info);
+
+ /* FIXME it might be better to start readahead at commit root */
+ key_start.objectid = logical;
+ key_start.type = BTRFS_EXTENT_ITEM_KEY;
+ key_start.offset = (u64)0;
+ key_end.objectid = logic_end;
+ key_end.type = BTRFS_METADATA_ITEM_KEY;
+ key_end.offset = (u64)-1;
+ reada1 = btrfs_reada_add(root, &key_start, &key_end);
+
+ key_start.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key_start.type = BTRFS_EXTENT_CSUM_KEY;
+ key_start.offset = logical;
+ key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key_end.type = BTRFS_EXTENT_CSUM_KEY;
+ key_end.offset = logic_end;
+ reada2 = btrfs_reada_add(csum_root, &key_start, &key_end);
+
+ if (!IS_ERR(reada1))
+ btrfs_reada_wait(reada1);
+ if (!IS_ERR(reada2))
+ btrfs_reada_wait(reada2);
+
+
+ /*
+ * 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);
+
+ /*
+ * now find all extents for each stripe and scrub them
+ */
+ ret = 0;
+ while (physical < physical_end) {
+ /* for raid56, we skip parity stripe */
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ ret = get_raid56_logic_offset(physical, num,
+ map, &logical, &stripe_logical);
+ logical += base;
+ if (ret) {
+ stripe_logical += base;
+ stripe_end = stripe_logical + increment - 1;
+ ret = scrub_raid56_parity(sctx, map, scrub_dev,
+ ppath, stripe_logical,
+ stripe_end);
+ if (ret)
+ goto out;
+ goto skip;
+ }
+ }
+ /*
+ * canceled?
+ */
+ if (atomic_read(&fs_info->scrub_cancel_req) ||
+ atomic_read(&sctx->cancel_req)) {
+ ret = -ECANCELED;
+ goto out;
+ }
+ /*
+ * check to see if we have to pause
+ */
+ if (atomic_read(&fs_info->scrub_pause_req)) {
+ /* push queued extents */
+ atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
+ scrub_blocked_if_needed(fs_info);
+ }
+
+ if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
+ key.type = BTRFS_METADATA_ITEM_KEY;
+ else
+ key.type = BTRFS_EXTENT_ITEM_KEY;
+ key.objectid = logical;
+ key.offset = (u64)-1;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ ret = btrfs_previous_extent_item(root, path, 0);
+ if (ret < 0)
+ goto out;
+ if (ret > 0) {
+ /* there's no smaller item, so stick with the
+ * larger one */
+ btrfs_release_path(path);
+ ret = btrfs_search_slot(NULL, root, &key,
+ path, 0, 0);
+ if (ret < 0)
+ goto out;
+ }
+ }
+
+ stop_loop = 0;
+ while (1) {
+ u64 bytes;
+
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto out;
+
+ stop_loop = 1;
+ break;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+
+ if (key.type == BTRFS_METADATA_ITEM_KEY)
+ bytes = root->nodesize;
+ else
+ bytes = key.offset;
+
+ if (key.objectid + bytes <= logical)
+ goto next;
+
+ if (key.type != BTRFS_EXTENT_ITEM_KEY &&
+ key.type != BTRFS_METADATA_ITEM_KEY)
+ goto next;
+
+ if (key.objectid >= logical + map->stripe_len) {
+ /* out of this device extent */
+ if (key.objectid >= logic_end)
+ stop_loop = 1;
+ break;
+ }
+
+ extent = btrfs_item_ptr(l, slot,
+ struct btrfs_extent_item);
+ flags = btrfs_extent_flags(l, extent);
+ generation = btrfs_extent_generation(l, extent);
+
+ if (key.objectid < logical &&
+ (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) {
+ btrfs_err(fs_info,
+ "scrub: tree block %llu spanning "
+ "stripes, ignored. logical=%llu",
+ key.objectid, logical);
+ goto next;
+ }
+
+again:
+ extent_logical = key.objectid;
+ extent_len = bytes;
+
+ /*
+ * trim extent to this stripe
+ */
+ if (extent_logical < logical) {
+ extent_len -= logical - extent_logical;
+ extent_logical = logical;
+ }
+ if (extent_logical + extent_len >
+ logical + map->stripe_len) {
+ extent_len = logical + map->stripe_len -
+ extent_logical;
+ }
+
+ extent_physical = extent_logical - logical + physical;
+ extent_dev = scrub_dev;
+ extent_mirror_num = mirror_num;
+ if (is_dev_replace)
+ scrub_remap_extent(fs_info, extent_logical,
+ extent_len, &extent_physical,
+ &extent_dev,
+ &extent_mirror_num);
+
+ ret = btrfs_lookup_csums_range(csum_root, logical,
+ logical + map->stripe_len - 1,
+ &sctx->csum_list, 1);
+ if (ret)
+ goto out;
+
+ ret = scrub_extent(sctx, extent_logical, extent_len,
+ extent_physical, extent_dev, flags,
+ generation, extent_mirror_num,
+ extent_logical - logical + physical);
+ if (ret)
+ goto out;
+
+ scrub_free_csums(sctx);
+ if (extent_logical + extent_len <
+ key.objectid + bytes) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ /*
+ * loop until we find next data stripe
+ * or we have finished all stripes.
+ */
+loop:
+ physical += map->stripe_len;
+ ret = get_raid56_logic_offset(physical,
+ num, map, &logical,
+ &stripe_logical);
+ logical += base;
+
+ if (ret && physical < physical_end) {
+ stripe_logical += base;
+ stripe_end = stripe_logical +
+ increment - 1;
+ ret = scrub_raid56_parity(sctx,
+ map, scrub_dev, ppath,
+ stripe_logical,
+ stripe_end);
+ if (ret)
+ goto out;
+ goto loop;
+ }
+ } else {
+ physical += map->stripe_len;
+ logical += increment;
+ }
+ if (logical < key.objectid + bytes) {
+ cond_resched();
+ goto again;
+ }
+
+ if (physical >= physical_end) {
+ stop_loop = 1;
+ break;
+ }
+ }
+next:
+ path->slots[0]++;
+ }
+ btrfs_release_path(path);
+skip:
+ logical += increment;
+ physical += map->stripe_len;
+ spin_lock(&sctx->stat_lock);
+ if (stop_loop)
+ sctx->stat.last_physical = map->stripes[num].physical +
+ length;
+ 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_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+
+ blk_finish_plug(&plug);
+ btrfs_free_path(path);
+ btrfs_free_path(ppath);
+ return ret < 0 ? ret : 0;
+}
+
+static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev,
+ u64 chunk_tree, u64 chunk_objectid,
+ u64 chunk_offset, u64 length,
+ u64 dev_offset, int is_dev_replace)
+{
+ struct btrfs_mapping_tree *map_tree =
+ &sctx->dev_root->fs_info->mapping_tree;
+ struct map_lookup *map;
+ struct extent_map *em;
+ int i;
+ int ret = 0;
+
+ read_lock(&map_tree->map_tree.lock);
+ em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
+ read_unlock(&map_tree->map_tree.lock);
+
+ if (!em)
+ return -EINVAL;
+
+ map = (struct map_lookup *)em->bdev;
+ if (em->start != chunk_offset)
+ goto out;
+
+ if (em->len < length)
+ goto out;
+
+ 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, map, scrub_dev, i,
+ chunk_offset, length,
+ is_dev_replace);
+ if (ret)
+ goto out;
+ }
+ }
+out:
+ free_extent_map(em);
+
+ return ret;
+}
+
+static noinline_for_stack
+int scrub_enumerate_chunks(struct scrub_ctx *sctx,
+ struct btrfs_device *scrub_dev, u64 start, u64 end,
+ int is_dev_replace)
+{
+ struct btrfs_dev_extent *dev_extent = NULL;
+ struct btrfs_path *path;
+ struct btrfs_root *root = sctx->dev_root;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ u64 length;
+ u64 chunk_tree;
+ u64 chunk_objectid;
+ u64 chunk_offset;
+ int ret;
+ int slot;
+ struct extent_buffer *l;
+ struct btrfs_key key;
+ struct btrfs_key found_key;
+ struct btrfs_block_group_cache *cache;
+ struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->reada = 2;
+ 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) {
+ 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)
+ break;
+ }
+ }
+
+ 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);
+ length = btrfs_dev_extent_length(l, dev_extent);
+
+ if (found_key.offset + length <= start)
+ goto skip;
+
+ chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
+ chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
+ 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;
+
+ dev_replace->cursor_right = found_key.offset + length;
+ dev_replace->cursor_left = found_key.offset;
+ dev_replace->item_needs_writeback = 1;
+ ret = scrub_chunk(sctx, scrub_dev, chunk_tree, chunk_objectid,
+ chunk_offset, length, found_key.offset,
+ is_dev_replace);
+
+ /*
+ * 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.
+ */
+ atomic_set(&sctx->wr_ctx.flush_all_writes, 1);
+ scrub_submit(sctx);
+ mutex_lock(&sctx->wr_ctx.wr_lock);
+ scrub_wr_submit(sctx);
+ mutex_unlock(&sctx->wr_ctx.wr_lock);
+
+ wait_event(sctx->list_wait,
+ atomic_read(&sctx->bios_in_flight) == 0);
+ atomic_inc(&fs_info->scrubs_paused);
+ wake_up(&fs_info->scrub_pause_wait);
+
+ /*
+ * 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);
+ atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
+
+ 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);
+
+ btrfs_put_block_group(cache);
+ if (ret)
+ break;
+ if (is_dev_replace &&
+ atomic64_read(&dev_replace->num_write_errors) > 0) {
+ ret = -EIO;
+ break;
+ }
+ if (sctx->stat.malloc_errors > 0) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ dev_replace->cursor_left = dev_replace->cursor_right;
+ dev_replace->item_needs_writeback = 1;
+skip:
+ key.offset = found_key.offset + length;
+ btrfs_release_path(path);
+ }
+
+ btrfs_free_path(path);
+
+ /*
+ * ret can still be 1 from search_slot or next_leaf,
+ * that's not an error
+ */
+ return ret < 0 ? ret : 0;
+}
+
+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_root *root = sctx->dev_root;
+
+ if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
+ return -EIO;
+
+ /* Seed devices of a new filesystem has their own generation. */
+ if (scrub_dev->fs_devices != root->fs_info->fs_devices)
+ gen = scrub_dev->generation;
+ else
+ gen = root->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;
+
+ ret = scrub_pages(sctx, bytenr, BTRFS_SUPER_INFO_SIZE, bytenr,
+ scrub_dev, BTRFS_EXTENT_FLAG_SUPER, gen, i,
+ NULL, 1, bytenr);
+ if (ret)
+ return ret;
+ }
+ wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0);
+
+ return 0;
+}
+
+/*
+ * 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)
+{
+ int ret = 0;
+ unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
+ int max_active = fs_info->thread_pool_size;
+
+ if (fs_info->scrub_workers_refcnt == 0) {
+ if (is_dev_replace)
+ fs_info->scrub_workers =
+ btrfs_alloc_workqueue("btrfs-scrub", flags,
+ 1, 4);
+ else
+ fs_info->scrub_workers =
+ btrfs_alloc_workqueue("btrfs-scrub", flags,
+ max_active, 4);
+ if (!fs_info->scrub_workers) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ fs_info->scrub_wr_completion_workers =
+ btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
+ max_active, 2);
+ if (!fs_info->scrub_wr_completion_workers) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ fs_info->scrub_nocow_workers =
+ btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
+ if (!fs_info->scrub_nocow_workers) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ ++fs_info->scrub_workers_refcnt;
+out:
+ return ret;
+}
+
+static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
+{
+ if (--fs_info->scrub_workers_refcnt == 0) {
+ btrfs_destroy_workqueue(fs_info->scrub_workers);
+ btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
+ btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
+ }
+ WARN_ON(fs_info->scrub_workers_refcnt < 0);
+}
+
+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 scrub_ctx *sctx;
+ int ret;
+ struct btrfs_device *dev;
+ struct rcu_string *name;
+
+ if (btrfs_fs_closing(fs_info))
+ return -EINVAL;
+
+ if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
+ /*
+ * in this case scrub is unable to calculate the checksum
+ * the way scrub is implemented. Do not handle this
+ * situation at all because it won't ever happen.
+ */
+ btrfs_err(fs_info,
+ "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
+ fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
+ return -EINVAL;
+ }
+
+ if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
+ /* not supported for data w/o checksums */
+ btrfs_err(fs_info,
+ "scrub: size assumption sectorsize != PAGE_SIZE "
+ "(%d != %lu) fails",
+ fs_info->chunk_root->sectorsize, PAGE_SIZE);
+ return -EINVAL;
+ }
+
+ if (fs_info->chunk_root->nodesize >
+ PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
+ fs_info->chunk_root->sectorsize >
+ PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
+ /*
+ * would exhaust the array bounds of pagev member in
+ * struct scrub_block
+ */
+ btrfs_err(fs_info, "scrub: size assumption nodesize and sectorsize "
+ "<= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
+ fs_info->chunk_root->nodesize,
+ SCRUB_MAX_PAGES_PER_BLOCK,
+ fs_info->chunk_root->sectorsize,
+ SCRUB_MAX_PAGES_PER_BLOCK);
+ return -EINVAL;
+ }
+
+
+ mutex_lock(&fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+ if (!dev || (dev->missing && !is_dev_replace)) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -ENODEV;
+ }
+
+ if (!is_dev_replace && !readonly && !dev->writeable) {
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ rcu_read_lock();
+ name = rcu_dereference(dev->name);
+ btrfs_err(fs_info, "scrub: device %s is not writable",
+ name->str);
+ rcu_read_unlock();
+ return -EROFS;
+ }
+
+ mutex_lock(&fs_info->scrub_lock);
+ if (!dev->in_fs_metadata || dev->is_tgtdev_for_dev_replace) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -EIO;
+ }
+
+ btrfs_dev_replace_lock(&fs_info->dev_replace);
+ if (dev->scrub_device ||
+ (!is_dev_replace &&
+ btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {
+ btrfs_dev_replace_unlock(&fs_info->dev_replace);
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return -EINPROGRESS;
+ }
+ btrfs_dev_replace_unlock(&fs_info->dev_replace);
+
+ ret = scrub_workers_get(fs_info, is_dev_replace);
+ if (ret) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ return ret;
+ }
+
+ sctx = scrub_setup_ctx(dev, is_dev_replace);
+ if (IS_ERR(sctx)) {
+ mutex_unlock(&fs_info->scrub_lock);
+ mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+ scrub_workers_put(fs_info);
+ return PTR_ERR(sctx);
+ }
+ sctx->readonly = readonly;
+ dev->scrub_device = 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);
+
+ if (!is_dev_replace) {
+ /*
+ * 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);
+ }
+
+ if (!ret)
+ ret = scrub_enumerate_chunks(sctx, dev, start, end,
+ is_dev_replace);
+
+ 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));
+
+ mutex_lock(&fs_info->scrub_lock);
+ dev->scrub_device = NULL;
+ scrub_workers_put(fs_info);
+ mutex_unlock(&fs_info->scrub_lock);
+
+ scrub_put_ctx(sctx);
+
+ return ret;
+}
+
+void btrfs_scrub_pause(struct btrfs_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->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_root *root)
+{
+ struct btrfs_fs_info *fs_info = root->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_fs_info *fs_info,
+ struct btrfs_device *dev)
+{
+ struct scrub_ctx *sctx;
+
+ mutex_lock(&fs_info->scrub_lock);
+ sctx = dev->scrub_device;
+ if (!sctx) {
+ mutex_unlock(&fs_info->scrub_lock);
+ return -ENOTCONN;
+ }
+ atomic_inc(&sctx->cancel_req);
+ while (dev->scrub_device) {
+ mutex_unlock(&fs_info->scrub_lock);
+ wait_event(fs_info->scrub_pause_wait,
+ dev->scrub_device == NULL);
+ mutex_lock(&fs_info->scrub_lock);
+ }
+ mutex_unlock(&fs_info->scrub_lock);
+
+ return 0;
+}
+
+int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
+ struct btrfs_scrub_progress *progress)
+{
+ struct btrfs_device *dev;
+ struct scrub_ctx *sctx = NULL;
+
+ mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+ dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
+ if (dev)
+ sctx = dev->scrub_device;
+ if (sctx)
+ memcpy(progress, &sctx->stat, sizeof(*progress));
+ mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+
+ return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
+}
+
+static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
+ u64 extent_logical, u64 extent_len,
+ u64 *extent_physical,
+ struct btrfs_device **extent_dev,
+ int *extent_mirror_num)
+{
+ u64 mapped_length;
+ struct btrfs_bio *bbio = NULL;
+ int ret;
+
+ mapped_length = extent_len;
+ ret = btrfs_map_block(fs_info, READ, extent_logical,
+ &mapped_length, &bbio, 0);
+ if (ret || !bbio || mapped_length < extent_len ||
+ !bbio->stripes[0].dev->bdev) {
+ btrfs_put_bbio(bbio);
+ return;
+ }
+
+ *extent_physical = bbio->stripes[0].physical;
+ *extent_mirror_num = bbio->mirror_num;
+ *extent_dev = bbio->stripes[0].dev;
+ btrfs_put_bbio(bbio);
+}
+
+static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,
+ struct scrub_wr_ctx *wr_ctx,
+ struct btrfs_fs_info *fs_info,
+ struct btrfs_device *dev,
+ int is_dev_replace)
+{
+ WARN_ON(wr_ctx->wr_curr_bio != NULL);
+
+ mutex_init(&wr_ctx->wr_lock);
+ wr_ctx->wr_curr_bio = NULL;
+ if (!is_dev_replace)
+ return 0;
+
+ WARN_ON(!dev->bdev);
+ wr_ctx->pages_per_wr_bio = min_t(int, SCRUB_PAGES_PER_WR_BIO,
+ bio_get_nr_vecs(dev->bdev));
+ wr_ctx->tgtdev = dev;
+ atomic_set(&wr_ctx->flush_all_writes, 0);
+ return 0;
+}
+
+static void scrub_free_wr_ctx(struct scrub_wr_ctx *wr_ctx)
+{
+ mutex_lock(&wr_ctx->wr_lock);
+ kfree(wr_ctx->wr_curr_bio);
+ wr_ctx->wr_curr_bio = NULL;
+ mutex_unlock(&wr_ctx->wr_lock);
+}
+
+static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
+ int mirror_num, u64 physical_for_dev_replace)
+{
+ struct scrub_copy_nocow_ctx *nocow_ctx;
+ struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+
+ nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
+ if (!nocow_ctx) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+
+ scrub_pending_trans_workers_inc(sctx);
+
+ nocow_ctx->sctx = sctx;
+ nocow_ctx->logical = logical;
+ nocow_ctx->len = len;
+ nocow_ctx->mirror_num = mirror_num;
+ nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
+ btrfs_init_work(&nocow_ctx->work, btrfs_scrubnc_helper,
+ copy_nocow_pages_worker, NULL, NULL);
+ INIT_LIST_HEAD(&nocow_ctx->inodes);
+ btrfs_queue_work(fs_info->scrub_nocow_workers,
+ &nocow_ctx->work);
+
+ return 0;
+}
+
+static int record_inode_for_nocow(u64 inum, u64 offset, u64 root, void *ctx)
+{
+ struct scrub_copy_nocow_ctx *nocow_ctx = ctx;
+ struct scrub_nocow_inode *nocow_inode;
+
+ nocow_inode = kzalloc(sizeof(*nocow_inode), GFP_NOFS);
+ if (!nocow_inode)
+ return -ENOMEM;
+ nocow_inode->inum = inum;
+ nocow_inode->offset = offset;
+ nocow_inode->root = root;
+ list_add_tail(&nocow_inode->list, &nocow_ctx->inodes);
+ return 0;
+}
+
+#define COPY_COMPLETE 1
+
+static void copy_nocow_pages_worker(struct btrfs_work *work)
+{
+ struct scrub_copy_nocow_ctx *nocow_ctx =
+ container_of(work, struct scrub_copy_nocow_ctx, work);
+ struct scrub_ctx *sctx = nocow_ctx->sctx;
+ u64 logical = nocow_ctx->logical;
+ u64 len = nocow_ctx->len;
+ int mirror_num = nocow_ctx->mirror_num;
+ u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
+ int ret;
+ struct btrfs_trans_handle *trans = NULL;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_path *path;
+ struct btrfs_root *root;
+ int not_written = 0;
+
+ fs_info = sctx->dev_root->fs_info;
+ root = fs_info->extent_root;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ not_written = 1;
+ goto out;
+ }
+
+ trans = btrfs_join_transaction(root);
+ if (IS_ERR(trans)) {
+ not_written = 1;
+ goto out;
+ }
+
+ ret = iterate_inodes_from_logical(logical, fs_info, path,
+ record_inode_for_nocow, nocow_ctx);
+ if (ret != 0 && ret != -ENOENT) {
+ btrfs_warn(fs_info, "iterate_inodes_from_logical() failed: log %llu, "
+ "phys %llu, len %llu, mir %u, ret %d",
+ logical, physical_for_dev_replace, len, mirror_num,
+ ret);
+ not_written = 1;
+ goto out;
+ }
+
+ btrfs_end_transaction(trans, root);
+ trans = NULL;
+ while (!list_empty(&nocow_ctx->inodes)) {
+ struct scrub_nocow_inode *entry;
+ entry = list_first_entry(&nocow_ctx->inodes,
+ struct scrub_nocow_inode,
+ list);
+ list_del_init(&entry->list);
+ ret = copy_nocow_pages_for_inode(entry->inum, entry->offset,
+ entry->root, nocow_ctx);
+ kfree(entry);
+ if (ret == COPY_COMPLETE) {
+ ret = 0;
+ break;
+ } else if (ret) {
+ break;
+ }
+ }
+out:
+ while (!list_empty(&nocow_ctx->inodes)) {
+ struct scrub_nocow_inode *entry;
+ entry = list_first_entry(&nocow_ctx->inodes,
+ struct scrub_nocow_inode,
+ list);
+ list_del_init(&entry->list);
+ kfree(entry);
+ }
+ if (trans && !IS_ERR(trans))
+ btrfs_end_transaction(trans, root);
+ if (not_written)
+ btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
+ num_uncorrectable_read_errors);
+
+ btrfs_free_path(path);
+ kfree(nocow_ctx);
+
+ scrub_pending_trans_workers_dec(sctx);
+}
+
+static int check_extent_to_block(struct inode *inode, u64 start, u64 len,
+ u64 logical)
+{
+ struct extent_state *cached_state = NULL;
+ struct btrfs_ordered_extent *ordered;
+ struct extent_io_tree *io_tree;
+ struct extent_map *em;
+ u64 lockstart = start, lockend = start + len - 1;
+ int ret = 0;
+
+ io_tree = &BTRFS_I(inode)->io_tree;
+
+ lock_extent_bits(io_tree, lockstart, lockend, 0, &cached_state);
+ ordered = btrfs_lookup_ordered_range(inode, lockstart, len);
+ if (ordered) {
+ btrfs_put_ordered_extent(ordered);
+ ret = 1;
+ goto out_unlock;
+ }
+
+ em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto out_unlock;
+ }
+
+ /*
+ * This extent does not actually cover the logical extent anymore,
+ * move on to the next inode.
+ */
+ if (em->block_start > logical ||
+ em->block_start + em->block_len < logical + len) {
+ free_extent_map(em);
+ ret = 1;
+ goto out_unlock;
+ }
+ free_extent_map(em);
+
+out_unlock:
+ unlock_extent_cached(io_tree, lockstart, lockend, &cached_state,
+ GFP_NOFS);
+ return ret;
+}
+
+static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
+ struct scrub_copy_nocow_ctx *nocow_ctx)
+{
+ struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
+ struct btrfs_key key;
+ struct inode *inode;
+ struct page *page;
+ struct btrfs_root *local_root;
+ struct extent_io_tree *io_tree;
+ u64 physical_for_dev_replace;
+ u64 nocow_ctx_logical;
+ u64 len = nocow_ctx->len;
+ unsigned long index;
+ int srcu_index;
+ int ret = 0;
+ int err = 0;
+
+ key.objectid = root;
+ key.type = BTRFS_ROOT_ITEM_KEY;
+ key.offset = (u64)-1;
+
+ srcu_index = srcu_read_lock(&fs_info->subvol_srcu);
+
+ local_root = btrfs_read_fs_root_no_name(fs_info, &key);
+ if (IS_ERR(local_root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
+ return PTR_ERR(local_root);
+ }
+
+ key.type = BTRFS_INODE_ITEM_KEY;
+ key.objectid = inum;
+ key.offset = 0;
+ inode = btrfs_iget(fs_info->sb, &key, local_root, NULL);
+ srcu_read_unlock(&fs_info->subvol_srcu, srcu_index);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ /* Avoid truncate/dio/punch hole.. */
+ mutex_lock(&inode->i_mutex);
+ inode_dio_wait(inode);
+
+ physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
+ io_tree = &BTRFS_I(inode)->io_tree;
+ nocow_ctx_logical = nocow_ctx->logical;
+
+ ret = check_extent_to_block(inode, offset, len, nocow_ctx_logical);
+ if (ret) {
+ ret = ret > 0 ? 0 : ret;
+ goto out;
+ }
+
+ while (len >= PAGE_CACHE_SIZE) {
+ index = offset >> PAGE_CACHE_SHIFT;
+again:
+ page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+ if (!page) {
+ btrfs_err(fs_info, "find_or_create_page() failed");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (PageUptodate(page)) {
+ if (PageDirty(page))
+ goto next_page;
+ } else {
+ ClearPageError(page);
+ err = extent_read_full_page(io_tree, page,
+ btrfs_get_extent,
+ nocow_ctx->mirror_num);
+ if (err) {
+ ret = err;
+ goto next_page;
+ }
+
+ lock_page(page);
+ /*
+ * If the page has been remove from the page cache,
+ * the data on it is meaningless, because it may be
+ * old one, the new data may be written into the new
+ * page in the page cache.
+ */
+ if (page->mapping != inode->i_mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ goto again;
+ }
+ if (!PageUptodate(page)) {
+ ret = -EIO;
+ goto next_page;
+ }
+ }
+
+ ret = check_extent_to_block(inode, offset, len,
+ nocow_ctx_logical);
+ if (ret) {
+ ret = ret > 0 ? 0 : ret;
+ goto next_page;
+ }
+
+ err = write_page_nocow(nocow_ctx->sctx,
+ physical_for_dev_replace, page);
+ if (err)
+ ret = err;
+next_page:
+ unlock_page(page);
+ page_cache_release(page);
+
+ if (ret)
+ break;
+
+ offset += PAGE_CACHE_SIZE;
+ physical_for_dev_replace += PAGE_CACHE_SIZE;
+ nocow_ctx_logical += PAGE_CACHE_SIZE;
+ len -= PAGE_CACHE_SIZE;
+ }
+ ret = COPY_COMPLETE;
+out:
+ mutex_unlock(&inode->i_mutex);
+ iput(inode);
+ return ret;
+}
+
+static int write_page_nocow(struct scrub_ctx *sctx,
+ u64 physical_for_dev_replace, struct page *page)
+{
+ struct bio *bio;
+ struct btrfs_device *dev;
+ int ret;
+
+ dev = sctx->wr_ctx.tgtdev;
+ if (!dev)
+ return -EIO;
+ if (!dev->bdev) {
+ printk_ratelimited(KERN_WARNING
+ "BTRFS: scrub write_page_nocow(bdev == NULL) is unexpected!\n");
+ return -EIO;
+ }
+ bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
+ if (!bio) {
+ spin_lock(&sctx->stat_lock);
+ sctx->stat.malloc_errors++;
+ spin_unlock(&sctx->stat_lock);
+ return -ENOMEM;
+ }
+ bio->bi_iter.bi_size = 0;
+ bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
+ bio->bi_bdev = dev->bdev;
+ ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
+ if (ret != PAGE_CACHE_SIZE) {
+leave_with_eio:
+ bio_put(bio);
+ btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
+ return -EIO;
+ }
+
+ if (btrfsic_submit_bio_wait(WRITE_SYNC, bio))
+ goto leave_with_eio;
+
+ bio_put(bio);
+ return 0;
+}