[XFS] avoid memory allocations in xfs_fs_vcmn_err

xfs_fs_vcmn_err can be called under a spinlock, but does a sleeping memory
allocation to create buffer for it's internal sprintf.  Fortunately it's
the only caller of icmn_err, so we can merge the two and have one single
static buffer and spinlock protecting it.  While we're at it make sure
we proper __attribute__ format annotations so that the compiler can detect
mismatched format strings.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
index 11543f10b0c6..0c93051c4651 100644
--- a/fs/xfs/xfs_error.h
+++ b/fs/xfs/xfs_error.h
@@ -159,11 +159,15 @@ extern int xfs_errortag_clearall(xfs_mount_t *mp, int loud);
 #define         XFS_PTAG_FSBLOCK_ZERO           0x00000080
 
 struct xfs_mount;
-/* PRINTFLIKE4 */
+
+extern void xfs_fs_vcmn_err(int level, struct xfs_mount *mp,
+                char *fmt, va_list ap)
+        __attribute__ ((format (printf, 3, 0)));
 extern void xfs_cmn_err(int panic_tag, int level, struct xfs_mount *mp,
-                        char *fmt, ...);
-/* PRINTFLIKE3 */
-extern void xfs_fs_cmn_err(int level, struct xfs_mount *mp, char *fmt, ...);
+                        char *fmt, ...)
+        __attribute__ ((format (printf, 4, 5)));
+extern void xfs_fs_cmn_err(int level, struct xfs_mount *mp, char *fmt, ...)
+        __attribute__ ((format (printf, 3, 4)));
 
 extern void xfs_hex_dump(void *p, int length);