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| author | Omar Sandoval <osandov@fb.com> | 2020-03-03 01:02:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-12 15:00:20 +0300 |
| commit | 0c8eccc28e69d13f11f54efd4a294862ad17bb74 (patch) | |
| tree | 0e3098649d75db558e1aa8158836d7cc5a556273 /fs | |
| parent | 557693d1d3a7ac4c675da1c45ab4d72d612f842c (diff) | |
| download | linux-0c8eccc28e69d13f11f54efd4a294862ad17bb74.tar.xz | |
btrfs: fix RAID direct I/O reads with alternate csums
commit e7a04894c766daa4248cb736efee93550f2d5872 upstream.
btrfs_lookup_and_bind_dio_csum() does pointer arithmetic which assumes
32-bit checksums. If using a larger checksum, this leads to spurious
failures when a direct I/O read crosses a stripe. This is easy
to reproduce:
# mkfs.btrfs -f --checksum blake2 -d raid0 /dev/vdc /dev/vdd
...
# mount /dev/vdc /mnt
# cd /mnt
# dd if=/dev/urandom of=foo bs=1M count=1 status=none
# dd if=foo of=/dev/null bs=1M iflag=direct status=none
dd: error reading 'foo': Input/output error
# dmesg | tail -1
[ 135.821568] BTRFS warning (device vdc): csum failed root 5 ino 257 off 421888 ...
Fix it by using the actual checksum size.
Fixes: 1e25a2e3ca0d ("btrfs: don't assume ordered sums to be 4 bytes")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/inode.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 50feb01f27f3..c056d12cbb3c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8426,6 +8426,7 @@ static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode, { struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio); + u16 csum_size; blk_status_t ret; /* @@ -8445,7 +8446,8 @@ static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode, file_offset -= dip->logical_offset; file_offset >>= inode->i_sb->s_blocksize_bits; - io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset); + csum_size = btrfs_super_csum_size(btrfs_sb(inode->i_sb)->super_copy); + io_bio->csum = orig_io_bio->csum + csum_size * file_offset; return 0; } |