Commit 7e38326f authored by Chris Mason's avatar Chris Mason

Btrfs: Handle checksumming errors while reading data blocks

Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent f188591e
......@@ -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;
......
......@@ -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) {
......
......@@ -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,
......
......@@ -385,6 +385,86 @@ int btrfs_readpage_io_hook(struct page *page, u64 start, u64 end)
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 @@ int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
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,
};
......
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