diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 7a7521c87c88..8a42adb4e5ed 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -44,6 +44,17 @@ #define BTRFS_INODE_IN_DELALLOC_LIST 9 #define BTRFS_INODE_READDIO_NEED_LOCK 10 #define BTRFS_INODE_HAS_PROPS 11 +/* + * The following 3 bits are meant only for the btree inode. + * When any of them is set, it means an error happened while writing an + * extent buffer belonging to: + * 1) a non-log btree + * 2) a log btree and first log sub-transaction + * 3) a log btree and second log sub-transaction + */ +#define BTRFS_INODE_BTREE_ERR 12 +#define BTRFS_INODE_BTREE_LOG1_ERR 13 +#define BTRFS_INODE_BTREE_LOG2_ERR 14 /* in memory btrfs inode */ struct btrfs_inode { diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4780e6623c7b..09b3c8a0c790 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -607,7 +607,7 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, goto err; eb->read_mirror = mirror; - if (test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) { + if (test_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags)) { ret = -EIO; goto err; } @@ -680,7 +680,7 @@ static int btree_io_failed_hook(struct page *page, int failed_mirror) struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; eb = (struct extent_buffer *)page->private; - set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); eb->read_mirror = failed_mirror; atomic_dec(&eb->io_pages); if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 44d04979f071..8ebe6bf66e78 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7235,17 +7235,19 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, btrfs_set_buffer_uptodate(buf); if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + buf->log_index = root->log_transid % 2; /* * we allow two log transactions at a time, use different * EXENT bit to differentiate dirty pages. */ - if (root->log_transid % 2 == 0) + if (buf->log_index == 0) set_extent_dirty(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); else set_extent_new(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } else { + buf->log_index = -1; set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 4267a054b9c1..215603b911f1 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3601,6 +3601,68 @@ static void end_extent_buffer_writeback(struct extent_buffer *eb) wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); } +static void set_btree_ioerr(struct page *page) +{ + struct extent_buffer *eb = (struct extent_buffer *)page->private; + struct btrfs_inode *btree_ino = BTRFS_I(eb->fs_info->btree_inode); + + SetPageError(page); + if (test_and_set_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) + return; + + /* + * If writeback for a btree extent that doesn't belong to a log tree + * failed, increment the counter transaction->eb_write_errors. + * We do this because while the transaction is running and before it's + * committing (when we call filemap_fdata[write|wait]_range against + * the btree inode), we might have + * btree_inode->i_mapping->a_ops->writepages() called by the VM - if it + * returns an error or an error happens during writeback, when we're + * committing the transaction we wouldn't know about it, since the pages + * can be no longer dirty nor marked anymore for writeback (if a + * subsequent modification to the extent buffer didn't happen before the + * transaction commit), which makes filemap_fdata[write|wait]_range not + * able to find the pages tagged with SetPageError at transaction + * commit time. So if this happens we must abort the transaction, + * otherwise we commit a super block with btree roots that point to + * btree nodes/leafs whose content on disk is invalid - either garbage + * or the content of some node/leaf from a past generation that got + * cowed or deleted and is no longer valid. + * + * Note: setting AS_EIO/AS_ENOSPC in the btree inode's i_mapping would + * not be enough - we need to distinguish between log tree extents vs + * non-log tree extents, and the next filemap_fdatawait_range() call + * will catch and clear such errors in the mapping - and that call might + * be from a log sync and not from a transaction commit. Also, checking + * for the eb flag EXTENT_BUFFER_WRITE_ERR at transaction commit time is + * not done and would not be reliable - the eb might have been released + * from memory and reading it back again means that flag would not be + * set (since it's a runtime flag, not persisted on disk). + * + * Using the flags below in the btree inode also makes us achieve the + * goal of AS_EIO/AS_ENOSPC when writepages() returns success, started + * writeback for all dirty pages and before filemap_fdatawait_range() + * is called, the writeback for all dirty pages had already finished + * with errors - because we were not using AS_EIO/AS_ENOSPC, + * filemap_fdatawait_range() would return success, as it could not know + * that writeback errors happened (the pages were no longer tagged for + * writeback). + */ + switch (eb->log_index) { + case -1: + set_bit(BTRFS_INODE_BTREE_ERR, &btree_ino->runtime_flags); + break; + case 0: + set_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags); + break; + case 1: + set_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags); + break; + default: + BUG(); /* unexpected, logic error */ + } +} + static void end_bio_extent_buffer_writepage(struct bio *bio, int err) { struct bio_vec *bvec; @@ -3614,10 +3676,9 @@ static void end_bio_extent_buffer_writepage(struct bio *bio, int err) BUG_ON(!eb); done = atomic_dec_and_test(&eb->io_pages); - if (err || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) { - set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + if (err || test_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags)) { ClearPageUptodate(page); - SetPageError(page); + set_btree_ioerr(page); } end_page_writeback(page); @@ -3644,7 +3705,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META; int ret = 0; - clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags); num_pages = num_extent_pages(eb->start, eb->len); atomic_set(&eb->io_pages, num_pages); if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) @@ -3661,8 +3722,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, 0, epd->bio_flags, bio_flags); epd->bio_flags = bio_flags; if (ret) { - set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); - SetPageError(p); + set_btree_ioerr(p); end_page_writeback(p); if (atomic_sub_and_test(num_pages - i, &eb->io_pages)) end_extent_buffer_writeback(eb); @@ -5055,7 +5115,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, goto unlock_exit; } - clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + clear_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); eb->read_mirror = 0; atomic_set(&eb->io_pages, num_reads); for (i = start_i; i < num_pages; i++) { diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 5e91fb9d1764..06f030c0084c 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -41,9 +41,10 @@ #define EXTENT_BUFFER_TREE_REF 5 #define EXTENT_BUFFER_STALE 6 #define EXTENT_BUFFER_WRITEBACK 7 -#define EXTENT_BUFFER_IOERR 8 +#define EXTENT_BUFFER_READ_ERR 8 /* read IO error */ #define EXTENT_BUFFER_DUMMY 9 #define EXTENT_BUFFER_IN_TREE 10 +#define EXTENT_BUFFER_WRITE_ERR 11 /* write IO error */ /* these are flags for extent_clear_unlock_delalloc */ #define PAGE_UNLOCK (1 << 0) @@ -141,7 +142,9 @@ struct extent_buffer { atomic_t blocking_readers; atomic_t spinning_readers; atomic_t spinning_writers; - int lock_nested; + short lock_nested; + /* >= 0 if eb belongs to a log tree, -1 otherwise */ + short log_index; /* protects write locks */ rwlock_t lock; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 16d0c1b62b3e..a47b1000a6e5 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -851,6 +851,8 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, struct extent_state *cached_state = NULL; u64 start = 0; u64 end; + struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode); + bool errors = false; while (!find_first_extent_bit(dirty_pages, start, &start, &end, EXTENT_NEED_WAIT, &cached_state)) { @@ -864,6 +866,26 @@ int btrfs_wait_marked_extents(struct btrfs_root *root, } if (err) werr = err; + + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + if ((mark & EXTENT_DIRTY) && + test_and_clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, + &btree_ino->runtime_flags)) + errors = true; + + if ((mark & EXTENT_NEW) && + test_and_clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, + &btree_ino->runtime_flags)) + errors = true; + } else { + if (test_and_clear_bit(BTRFS_INODE_BTREE_ERR, + &btree_ino->runtime_flags)) + errors = true; + } + + if (errors && !werr) + werr = -EIO; + return werr; } @@ -1629,6 +1651,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, { struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_transaction *prev_trans = NULL; + struct btrfs_inode *btree_ino = BTRFS_I(root->fs_info->btree_inode); int ret; /* Stop the commit early if ->aborted is set */ @@ -1871,6 +1894,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans, btrfs_update_commit_device_size(root->fs_info); btrfs_update_commit_device_bytes_used(root, cur_trans); + clear_bit(BTRFS_INODE_BTREE_LOG1_ERR, &btree_ino->runtime_flags); + clear_bit(BTRFS_INODE_BTREE_LOG2_ERR, &btree_ino->runtime_flags); + spin_lock(&root->fs_info->trans_lock); cur_trans->state = TRANS_STATE_UNBLOCKED; root->fs_info->running_transaction = NULL;