2001-10-28 22:12:50

by Andreas Dilger

[permalink] [raw]
Subject: [PATCH] minor UFS cleanup

Linus,
a minor cleanup of the UFS code, originally inspired by the Stanford checker.
They found that "dir" was being checked for non-NULLness after it was being
dereferenced.

I also added a local variable for rlen, because SWAB16 cannot be removed
at compile time for either little- or big-endian systems.

The second hunk is again from the Stanford checker, avoiding NULL dereference.

Cheers, Andreas
=============================================================================
diff -ru linux.orig/fs/ufs/dir.c linux/fs/ufs/dir.c
--- linux.orig/fs/ufs/dir.c Thu Oct 25 03:05:12 2001
+++ linux/fs/ufs/dir.c Thu Oct 25 02:55:49 2001
@@ -290,34 +290,32 @@
struct ufs_dir_entry * de, struct buffer_head * bh,
unsigned long offset)
{
- struct super_block * sb;
- const char * error_msg;
- unsigned flags, swab;
-
- sb = dir->i_sb;
- flags = sb->u.ufs_sb.s_flags;
- swab = sb->u.ufs_sb.s_swab;
- error_msg = NULL;
-
- if (SWAB16(de->d_reclen) < UFS_DIR_REC_LEN(1))
+ struct super_block *sb = dir->i_sb;
+ const char *error_msg = NULL;
+ unsigned flags = sb->u.ufs_sb.s_flags;
+ unsigned swab = sb->u.ufs_sb.s_swab;
+ int rlen = SWAB16(de->d_reclen);
+
+ if (rlen < UFS_DIR_REC_LEN(1))
error_msg = "reclen is smaller than minimal";
- else if (SWAB16(de->d_reclen) % 4 != 0)
+ else if (rlen % 4 != 0)
error_msg = "reclen % 4 != 0";
- else if (SWAB16(de->d_reclen) < UFS_DIR_REC_LEN(ufs_get_de_namlen(de)))
+ else if (rlen < UFS_DIR_REC_LEN(ufs_get_de_namlen(de)))
error_msg = "reclen is too small for namlen";
- else if (dir && ((char *) de - bh->b_data) + SWAB16(de->d_reclen) >
- dir->i_sb->s_blocksize)
+ else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
error_msg = "directory entry across blocks";
- else if (dir && SWAB32(de->d_ino) > (sb->u.ufs_sb.s_uspi->s_ipg * sb->u.ufs_sb.s_uspi->s_ncg))
+ else if (SWAB32(de->d_ino) > (sb->u.ufs_sb.s_uspi->s_ipg *
+ sb->u.ufs_sb.s_uspi->s_ncg))
error_msg = "inode out of bounds";

if (error_msg != NULL)
- ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - "
+ ufs_error (sb, function,
+ "bad entry in directory #%lu, size %Lu: %s - "
"offset=%lu, inode=%lu, reclen=%d, namlen=%d",
dir->i_ino, dir->i_size, error_msg, offset,
(unsigned long) SWAB32(de->d_ino),
- SWAB16(de->d_reclen), ufs_get_de_namlen(de));
-
+ rlen, ufs_get_de_namlen(de));
+
return (error_msg == NULL ? 1 : 0);
}

diff -ru linux.orig/fs/ufs/super.c linux/fs/ufs/super.c
--- linux.orig/fs/ufs/super.c Tue May 29 13:13:21 2001
+++ linux/fs/ufs/super.c Tue May 29 20:14:02 2001
@@ -265,6 +265,10 @@
*value++ = 0;
if (!strcmp (this_char, "ufstype")) {
ufs_clear_opt (*mount_options, UFSTYPE);
+ if (!value) {
+ printk ("UFS-fs: ufstype option needs value\n");
+ return 0;
+ }
if (!strcmp (value, "old"))
ufs_set_opt (*mount_options, UFSTYPE_OLD);
else if (!strcmp (value, "sun"))
@@ -288,6 +292,10 @@
}
else if (!strcmp (this_char, "onerror")) {
ufs_clear_opt (*mount_options, ONERROR);
+ if (!value) {
+ printk ("UFS-fs: onerror option needs value\n");
+ return 0;
+ }
if (!strcmp (value, "panic"))
ufs_set_opt (*mount_options, ONERROR_PANIC);
else if (!strcmp (value, "lock"))
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/