From: Josef Bacik josef@toxicpanda.com
[ Upstream commit 1784b7d502a94b561eae58249adde5f72c26eb3c ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/file-item.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 91ae1caa1bdb..a68d9cab12ea 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -366,6 +366,7 @@ 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; @@ -375,6 +376,7 @@ 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 (!fs_info->csum_root || (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) return BLK_STS_OK; @@ -397,7 +399,7 @@ 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); @@ -453,21 +455,27 @@ 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; @@ -488,7 +496,7 @@ 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,