From 7e38326f5b125288a2baea1d815c500502ab9fc0 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 9 Apr 2008 16:28:12 -0400 Subject: Btrfs: Handle checksumming errors while reading data blocks Signed-off-by: Chris Mason diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 9b9db9c..fe6ef8e 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -29,6 +29,7 @@ struct btrfs_inode { struct btrfs_key location; struct extent_map_tree extent_tree; struct extent_io_tree io_tree; + struct extent_io_tree io_failure_tree; struct inode vfs_inode; u64 ordered_trans; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2f15937..866460c 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1534,6 +1534,15 @@ static int end_bio_extent_readpage(struct bio *bio, if (ret) uptodate = 0; } + if (!uptodate && tree->ops && + tree->ops->readpage_io_failed_hook) { + ret = tree->ops->readpage_io_failed_hook(bio, page, + start, end, state); + if (ret == 0) { + state = NULL; + continue; + } + } spin_lock_irqsave(&tree->lock, flags); if (!state || state->end != end) { diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 8d6b8a1..b47859c 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -32,6 +32,9 @@ struct extent_io_ops { int (*merge_bio_hook)(struct page *page, unsigned long offset, size_t size, struct bio *bio); int (*readpage_io_hook)(struct page *page, u64 start, u64 end); + int (*readpage_io_failed_hook)(struct bio *bio, struct page *page, + u64 start, u64 end, + struct extent_state *state); int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end, struct extent_state *state); void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 8c2d5d0..48f1d1b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -385,6 +385,86 @@ out: return ret; } +struct io_failure_record { + struct page *page; + u64 start; + u64 len; + u64 logical; + int last_mirror; +}; + +int btrfs_readpage_io_failed_hook(struct bio *failed_bio, + struct page *page, u64 start, u64 end, + struct extent_state *state) +{ + struct io_failure_record *failrec = NULL; + u64 private; + struct extent_map *em; + struct inode *inode = page->mapping->host; + struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; + struct bio *bio; + int num_copies; + int ret; + u64 logical; + + ret = get_state_private(failure_tree, start, &private); + if (ret) { + size_t pg_offset = start - page_offset(page); + failrec = kmalloc(sizeof(*failrec), GFP_NOFS); + if (!failrec) + return -ENOMEM; + failrec->start = start; + failrec->len = end - start + 1; + failrec->last_mirror = 0; + + em = btrfs_get_extent(inode, NULL, pg_offset, start, + failrec->len, 0); + + if (!em || IS_ERR(em)) { + kfree(failrec); + return -EIO; + } + logical = start - em->start; + logical = em->block_start + logical; + failrec->logical = logical; + free_extent_map(em); + set_extent_bits(failure_tree, start, end, EXTENT_LOCKED | + EXTENT_DIRTY, GFP_NOFS); + set_state_private(failure_tree, start, (u64)failrec); + } else { + failrec = (struct io_failure_record *)private; + } + num_copies = btrfs_num_copies( + &BTRFS_I(inode)->root->fs_info->mapping_tree, + failrec->logical, failrec->len); + failrec->last_mirror++; + if (!state) { + spin_lock_irq(&BTRFS_I(inode)->io_tree.lock); + state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree, + failrec->start, + EXTENT_LOCKED); + if (state && state->start != failrec->start) + state = NULL; + spin_unlock_irq(&BTRFS_I(inode)->io_tree.lock); + } + if (!state || failrec->last_mirror > num_copies) { + set_state_private(failure_tree, failrec->start, 0); + clear_extent_bits(failure_tree, failrec->start, + failrec->start + failrec->len - 1, + EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS); + kfree(failrec); + return -EIO; + } + bio = bio_alloc(GFP_NOFS, 1); + bio->bi_private = state; + bio->bi_end_io = failed_bio->bi_end_io; + bio->bi_sector = failrec->logical >> 9; + bio->bi_bdev = failed_bio->bi_bdev; + bio_add_page(bio, page, failrec->len, start - page_offset(page)); + btrfs_submit_bio_hook(inode, READ, bio, failrec->last_mirror); + return 0; +} + int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, struct extent_state *state) { @@ -419,6 +499,29 @@ int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end, } kunmap_atomic(kaddr, KM_IRQ0); local_irq_restore(flags); + + /* if the io failure tree for this inode is non-empty, + * check to see if we've recovered from a failed IO + */ + private = 0; + if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private, + (u64)-1, 1, EXTENT_DIRTY)) { + u64 private_failure; + struct io_failure_record *failure; + ret = get_state_private(&BTRFS_I(inode)->io_failure_tree, + start, &private_failure); + if (ret == 0) { + failure = (struct io_failure_record *)private_failure; + set_state_private(&BTRFS_I(inode)->io_failure_tree, + failure->start, 0); + clear_extent_bits(&BTRFS_I(inode)->io_failure_tree, + failure->start, + failure->start + failure->len - 1, + EXTENT_DIRTY | EXTENT_LOCKED, + GFP_NOFS); + kfree(failure); + } + } return 0; zeroit: @@ -429,7 +532,7 @@ zeroit: flush_dcache_page(page); kunmap_atomic(kaddr, KM_IRQ0); local_irq_restore(flags); - return 0; + return -EIO; } void btrfs_read_locked_inode(struct inode *inode) @@ -1271,6 +1374,8 @@ static int btrfs_init_locked_inode(struct inode *inode, void *p) extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS); extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode->i_mapping, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree, + inode->i_mapping, GFP_NOFS); return 0; } @@ -1578,6 +1683,8 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS); extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode->i_mapping, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree, + inode->i_mapping, GFP_NOFS); BTRFS_I(inode)->delalloc_bytes = 0; BTRFS_I(inode)->root = root; @@ -1803,6 +1910,8 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry, extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS); extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode->i_mapping, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree, + inode->i_mapping, GFP_NOFS); BTRFS_I(inode)->delalloc_bytes = 0; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; } @@ -2972,6 +3081,8 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry, extent_map_tree_init(&BTRFS_I(inode)->extent_tree, GFP_NOFS); extent_io_tree_init(&BTRFS_I(inode)->io_tree, inode->i_mapping, GFP_NOFS); + extent_io_tree_init(&BTRFS_I(inode)->io_failure_tree, + inode->i_mapping, GFP_NOFS); BTRFS_I(inode)->delalloc_bytes = 0; BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops; } @@ -3070,6 +3181,7 @@ static struct extent_io_ops btrfs_extent_io_ops = { .merge_bio_hook = btrfs_merge_bio_hook, .readpage_io_hook = btrfs_readpage_io_hook, .readpage_end_io_hook = btrfs_readpage_end_io_hook, + .readpage_io_failed_hook = btrfs_readpage_io_failed_hook, .set_bit_hook = btrfs_set_bit_hook, .clear_bit_hook = btrfs_clear_bit_hook, }; -- cgit v0.10.2