[patch 16/33] FAT_VALID_MEDIA(): remove pointless test

Greg KH
2008-08-04T20:26:37Z

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2.6.25-stable review patch. If anyone has any objections, please let us
know.

------------------

From: Andrew Morton <akpm@linux-foundation.org>

commit 73f20e58b1d586e9f6d3ddc3aad872829aca7743 upstream

The on-disk media specification field in FAT is only 8-bits, so testing for
<=0xff is pointless, and can generate a "comparison is always true due to
limited range of data type" warning.

While we're there, convert FAT_VALID_MEDIA() into a C function - the present
implementation is buggy: it generates either one or two references to its
argument.

Cc: Frank Seidel <fseidel@suse.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/fat/inode.c | 2 +-
include/linux/msdos_fs.h | 6 +++++-
2 files changed, 6 insertions(+), 2 deletions(-)

--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -1208,7 +1208,7 @@ int fat_fill_super(struct super_block *s
*/

media = b->media;
- if (!FAT_VALID_MEDIA(media)) {
+ if (!fat_valid_media(media)) {
if (!silent)
printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
media);
--- a/include/linux/msdos_fs.h
+++ b/include/linux/msdos_fs.h
@@ -58,7 +58,11 @@
#define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */

/* media of boot sector */
-#define FAT_VALID_MEDIA(x) ((0xF8 <= (x) && (x) <= 0xFF) || (x) == 0xF0)
+static inline int fat_valid_media(u8 media)
+{
+ return 0xf8 <= media || media == 0xf0;
+}
+
#define FAT_FIRST_ENT(s, x) ((MSDOS_SB(s)->fat_bits == 32 ? 0x0FFFFF00 : \
MSDOS_SB(s)->fat_bits == 16 ? 0xFF00 : 0xF00) | (x))

--