minixfs: fix block limit check
Vladimir Serbinenko [Mon, 30 Jul 2012 21:42:00 +0000 (14:42 -0700)]
On minix2 and minix3 usually max_size is 7fffffff and the check in
question prohibits creation of last block spanning right before 7fffffff,
due to downward rounding during the division.  Fix it by using
multiplication instead.

[akpm@linux-foundation.org: fix up code layout, use local `sb']
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/minix/itree_v2.c

index 13487ad..78e2d93 100644 (file)
@@ -32,7 +32,8 @@ static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
        if (block < 0) {
                printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n",
                        block, bdevname(sb->s_bdev, b));
-       } else if (block >= (minix_sb(inode->i_sb)->s_max_size/sb->s_blocksize)) {
+       } else if ((u64)block * (u64)sb->s_blocksize >=
+                       minix_sb(sb)->s_max_size) {
                if (printk_ratelimit())
                        printk("MINIX-fs: block_to_path: "
                               "block %ld too big on dev %s\n",