FAT_VALID_MEDIA(): remove pointless test (73f20e58) · Commits · 戴 / test

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>

fs/fat/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1215,7 +1215,7 @@ int fat_fill_super(struct super_block sb, void data, int silent,
		*/

		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);

include/linux/msdos_fs.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -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))

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