[XFS] fix unaligned access in readdir
This patch should fix the issue seen on Alpha with unaligned accesses in
the new readdir code. By aligning each dirent to sizeof(u64) we'll avoid
unaligned accesses. To make doubly sure we're not hitting problems also
rearrange struct hack_dirent to avoid holes.
SGI-PV: 975411
SGI-Modid: xfs-linux-melb:xfs-kern:30302a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 4847eb8..21a1c2b 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -261,9 +261,9 @@
#else
struct hack_dirent {
- int namlen;
- loff_t offset;
u64 ino;
+ loff_t offset;
+ int namlen;
unsigned int d_type;
char name[];
};
@@ -285,8 +285,10 @@
{
struct hack_callback *buf = __buf;
struct hack_dirent *de = (struct hack_dirent *)(buf->dirent + buf->used);
+ unsigned int reclen;
- if (buf->used + sizeof(struct hack_dirent) + namlen > buf->len)
+ reclen = ALIGN(sizeof(struct hack_dirent) + namlen, sizeof(u64));
+ if (buf->used + reclen > buf->len)
return -EINVAL;
de->namlen = namlen;
@@ -294,7 +296,7 @@
de->ino = ino;
de->d_type = d_type;
memcpy(de->name, name, namlen);
- buf->used += sizeof(struct hack_dirent) + namlen;
+ buf->used += reclen;
return 0;
}
@@ -334,7 +336,8 @@
offset = filp->f_pos;
while (!eof) {
- int reclen;
+ unsigned int reclen;
+
start_offset = offset;
buf.used = 0;
@@ -355,7 +358,8 @@
goto done;
}
- reclen = sizeof(struct hack_dirent) + de->namlen;
+ reclen = ALIGN(sizeof(struct hack_dirent) + de->namlen,
+ sizeof(u64));
size -= reclen;
de = (struct hack_dirent *)((char *)de + reclen);
curr_offset = de->offset /* & 0x7fffffff */;