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authorJosef Bacik <josef@toxicpanda.com>2022-02-18 10:03:23 -0500
committerDavid Sterba <dsterba@suse.com>2022-03-14 13:13:51 +0100
commit1784b7d502a94b561eae58249adde5f72c26eb3c (patch)
treed9883e341cf061dbaad174891b50fcccb31b3cbf /fs/btrfs
parent03ddb19d2ea745228879b9334f3b550c88acb10a (diff)
btrfs: handle csum lookup errors properly on reads
Currently any error we get while trying to lookup csums during reads shows up as a missing csum, and then on the read completion side we print an error saying there was a csum mismatch and we increase the device corruption count. However we could have gotten an EIO from the lookup. We could also be inside of a memory constrained container and gotten a ENOMEM while trying to do the read. In either case we don't want to make this look like a file system corruption problem, we want to make it look like the actual error it is. Capture any negative value, convert it to the appropriate blk_status_t, free the csum array if we have one and bail. Note: a possible improvement would be to make the relocation code look up the owning inode and see if it's marked as NODATASUM and set EXTENT_NODATASUM there, that way if there's corruption and there isn't a checksum when we want it we can fail here rather than later. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/file-item.c36
1 files changed, 22 insertions, 14 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1c6c621d1b0f..c828f971a346 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -368,6 +368,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_bio *bbio = NULL;
struct btrfs_path *path;
const u32 sectorsize = fs_info->sectorsize;
const u32 csum_size = fs_info->csum_size;
@@ -377,6 +378,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
u8 *csum;
const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
int count = 0;
+ blk_status_t ret = BLK_STS_OK;
if ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) ||
test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
@@ -400,7 +402,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
return BLK_STS_RESOURCE;
if (!dst) {
- struct btrfs_bio *bbio = btrfs_bio(bio);
+ bbio = btrfs_bio(bio);
if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
@@ -456,21 +458,27 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
count = search_csum_tree(fs_info, path, cur_disk_bytenr,
search_len, csum_dst);
- if (count <= 0) {
- /*
- * Either we hit a critical error or we didn't find
- * the csum.
- * Either way, we put zero into the csums dst, and skip
- * to the next sector.
- */
+ if (count < 0) {
+ ret = errno_to_blk_status(count);
+ if (bbio)
+ btrfs_bio_free_csum(bbio);
+ break;
+ }
+
+ /*
+ * We didn't find a csum for this range. We need to make sure
+ * we complain loudly about this, because we are not NODATASUM.
+ *
+ * However for the DATA_RELOC inode we could potentially be
+ * relocating data extents for a NODATASUM inode, so the inode
+ * itself won't be marked with NODATASUM, but the extent we're
+ * copying is in fact NODATASUM. If we don't find a csum we
+ * assume this is the case.
+ */
+ if (count == 0) {
memset(csum_dst, 0, csum_size);
count = 1;
- /*
- * For data reloc inode, we need to mark the range
- * NODATASUM so that balance won't report false csum
- * error.
- */
if (BTRFS_I(inode)->root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
u64 file_offset;
@@ -491,7 +499,7 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
}
btrfs_free_path(path);
- return BLK_STS_OK;
+ return ret;
}
int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,