xfs: Add __packed to xfs_dir2_sf_entry_t definition

Source kernel commit: ca78eee7b4ac13b63f5e872f7c3a5ca66b2df8da

xfs_check_ondisk_structs() verifies that the sizes of the data types
used by xfs are correct via the XFS_CHECK_STRUCT_SIZE() macro.

Since the structures padding can vary depending on the ABI (e.g. on
ARM OABI structures are padded to multiple of 32 bits), it may happen
that xfs_dir2_sf_entry_t size check breaks the compilation with the
assertion below:

In file included from linux/include/linux/string.h:6,
from linux/include/linux/uuid.h:12,
from linux/fs/xfs/xfs_linux.h:10,
from linux/fs/xfs/xfs.h:22,
from linux/fs/xfs/xfs_super.c:7:
In function ‘xfs_check_ondisk_structs’,
inlined from ‘init_xfs_fs’ at linux/fs/xfs/xfs_super.c:2025:2:
linux/include/linux/compiler.h:350:38:
error: call to ‘__compiletime_assert_107’ declared with attribute
error: XFS: sizeof(xfs_dir2_sf_entry_t) is wrong, expected 3
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)

Restore the correct behavior adding __packed to the structure definition.

Cc: Darrick J. Wong <darrick.wong@oracle.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_da_format.h b/libxfs/xfs_da_format.h
index 05615d1f411320803124c542957d002fc8cdd60c..734837a9b51a739cb531d60d3f89520463fab097 100644 (file)
--- a/libxfs/xfs_da_format.h
+++ b/libxfs/xfs_da_format.h
@@ -217,7 +217,7 @@ typedef struct xfs_dir2_sf_entry {
         * A 64-bit or 32-bit inode number follows here, at a variable offset
         * after the name.
         */
-} xfs_dir2_sf_entry_t;
+} __packed xfs_dir2_sf_entry_t;
 
 static inline int xfs_dir2_sf_hdr_size(int i8count)
 {