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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2016-01-04 16:13:21 +1100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-02-25 10:49:19 +0100 |
| commit | 811848048f1e4d74efaf299b0eba05ef50bc3e4f (patch) | |
| tree | ceeda0a3ac289b20fc75666fca3d08c320d6266c | |
| parent | 9aa1d60820b8fb0ce71d2ee7e406836c86ab55e9 (diff) | |
| download | lwn-811848048f1e4d74efaf299b0eba05ef50bc3e4f.tar.gz lwn-811848048f1e4d74efaf299b0eba05ef50bc3e4f.zip | |
libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct
commit 96f859d52bcb1c6ea6f3388d39862bf7143e2f30 upstream.
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.
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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | fs/xfs/xfs_ag.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h index 1cb740afd674..78ec58fc282e 100644 --- a/fs/xfs/xfs_ag.h +++ b/fs/xfs/xfs_ag.h @@ -224,7 +224,7 @@ 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; /* * tags for inode radix tree |