[PATCH] UFS sanity checks

The real rule is not "block size is at most 32Kb", it's "block size is
at most 8 times the fragment size".

diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 6d4af87b3ec93c2d7627c0154efda4f20e5b58e7..9ed79dece381774c788f2057d25cd5bbd738bde0 100644 (file)
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -651,16 +651,34 @@ magic_found:
        uspi->s_fmask = fs32_to_cpu(sb, usb1->fs_fmask);
        uspi->s_fshift = fs32_to_cpu(sb, usb1->fs_fshift);
 
-       /* block size must be a power-of-two between 4k and 32k */
-       if ((uspi->s_bsize & (uspi->s_bsize-1)) ||
-           (uspi->s_bsize < 4096 || uspi->s_bsize > 32768)) {
-               printk("ufs_read_super: fs_bsize %u != {4096, 8192, 16384, 32768}\n", uspi->s_bsize);
+       if (uspi->s_fsize & (uspi->s_fsize - 1)) {
+               printk("ufs_read_super: fragment size %u is not a power of 2\n",
+                       uspi->s_fsize);
+                       goto failed;
+       }
+       if (uspi->s_fsize < 512) {
+               printk("ufs_read_super: fragment size %u is too small\n"
+                       uspi->s_fsize);
+               goto failed;
+       }
+       if (uspi->s_fsize > 4096) {
+               printk("ufs_read_super: fragment size %u is too large\n"
+                       uspi->s_fsize);
+               goto failed;
+       }
+       if (uspi->s_bsize & (uspi->s_bsize - 1)) {
+               printk("ufs_read_super: block size %u is not a power of 2\n",
+                       uspi->s_bsize);
+               goto failed;
+       }
+       if (uspi->s_bsize < 4096) {
+               printk("ufs_read_super: block size %u is too small\n"
+                       uspi->s_fsize);
                goto failed;
        }
-       /* fragment size must be a power-of-two between 512 and 4096 bytes */
-       if ((uspi->s_fsize & (uspi->s_fsize-1)) ||
-           (uspi->s_fsize < 512 || uspi->s_fsize > 4096)) {
-               printk("ufs_read_super: fs_fsize %u != {512, 1024, 2048. 4096}\n", uspi->s_fsize);
+       if (uspi->s_bsize / uspi->s_fsize > 8) {
+               printk("ufs_read_super: too many fragments per block (%u)\n"
+                       uspi->s_bsize / uspi->s_fsize);
                goto failed;
        }
        if (uspi->s_fsize != block_size || uspi->s_sbsize != super_block_size) {