[PATCH 6/6] xfs: pad xfs_attr_leaf_name_remote to avoid tripping on m68k
From: Dave Chinner <david@fromorbit.com>
Date: 2016-03-06 21:50:14
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: "Darrick J. Wong" <redacted> Pad the xfs_attr_leaf_name_remote so that we don't trip the structure size checker on m68k. [dchinner: add comment, XFS_ATTR_LEAF_NAME_BYTES constant and make sure xfs_attr_leaf_entsize_remote() does the right thing. ] Signed-off-by: Darrick J. Wong <redacted> Reviewed-by: Dave Chinner <redacted> Signed-off-by: Dave Chinner <david@fromorbit.com> --- fs/xfs/libxfs/xfs_da_format.h | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
index 8d4d8bc..b6d58f6 100644
--- a/fs/xfs/libxfs/xfs_da_format.h
+++ b/fs/xfs/libxfs/xfs_da_format.h@@ -686,11 +686,19 @@ typedef struct xfs_attr_leaf_name_local { __u8 nameval[1]; /* name/value bytes */ } xfs_attr_leaf_name_local_t; +/* + * some platforms (like m68k) don't like non-word sized structures and pad them + * out inappropriately. To work around this, we set the name array to the size + * that pads out to a 4 byte word size. We need to take this away from the size + * of the structure when calculating the length of the entry in + * xfs_attr_leaf_entsize_remote(), hence we define a constant for this value. + */ +#define XFS_ATTR_LEAF_NAME_BYTES 3 typedef struct xfs_attr_leaf_name_remote { __be32 valueblk; /* block number of value bytes */ __be32 valuelen; /* number of bytes in value */ __u8 namelen; /* length of name bytes */ - __u8 name[1]; /* name bytes */ + __u8 name[XFS_ATTR_LEAF_NAME_BYTES]; /* name bytes */ } xfs_attr_leaf_name_remote_t; typedef struct xfs_attr_leafblock {
@@ -847,8 +855,10 @@ xfs_attr3_leaf_name_local(xfs_attr_leafblock_t *leafp, int idx) */ static inline int xfs_attr_leaf_entsize_remote(int nlen) { - return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - 1 + (nlen) + \ - XFS_ATTR_LEAF_NAME_ALIGN - 1) & ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); + return ((uint)sizeof(xfs_attr_leaf_name_remote_t) - + XFS_ATTR_LEAF_NAME_BYTES + nlen + + XFS_ATTR_LEAF_NAME_ALIGN - 1) & + ~(XFS_ATTR_LEAF_NAME_ALIGN - 1); } static inline int xfs_attr_leaf_entsize_local(int nlen, int vlen)
--
2.7.0
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