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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-01-04 16:13:21 +1100 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2016-01-04 16:13:21 +1100 |
| commit | 96f859d52bcb1c6ea6f3388d39862bf7143e2f30 (patch) | |
| tree | 0f70d2c8cd62cd3a2d947a4ee002aa4cac9414fe | |
| parent | 6d3eb1eca0e35cc1c0c80eacb7e7fe23c0dbfb07 (diff) | |
| download | linux-96f859d52bcb1c6ea6f3388d39862bf7143e2f30.tar.gz linux-96f859d52bcb1c6ea6f3388d39862bf7143e2f30.tar.bz2 linux-96f859d52bcb1c6ea6f3388d39862bf7143e2f30.zip | |
libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct
Because struct xfs_agfl is 36 bytes long and has a 64-bit integer
inside it, gcc will quietly round the structure size up to the nearest
64 bits -- in this case, 40 bytes. This results in the XFS_AGFL_SIZE
macro returning incorrect results for v5 filesystems on 64-bit
machines (118 items instead of 119). As a result, a 32-bit xfs_repair
will see garbage in AGFL item 119 and complain.
Therefore, tell gcc not to pad the structure so that the AGFL size
calculation is correct.
cc: <stable@vger.kernel.org> # 3.10 - 4.4
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/xfs/libxfs/xfs_format.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index 8774498ce0ff..e2536bb1c760 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -786,7 +786,7 @@ typedef struct xfs_agfl { __be64 agfl_lsn; __be32 agfl_crc; __be32 agfl_bno[]; /* actually XFS_AGFL_SIZE(mp) */ -} xfs_agfl_t; +} __attribute__((packed)) xfs_agfl_t; #define XFS_AGFL_CRC_OFF offsetof(struct xfs_agfl, agfl_crc) |