Fix remount races with symlink handling in affs
A couple of fields in affs_sb_info is used in follow_link() and
symlink() for handling AFFS "absolute" symlinks. Need locking
against affs_remount() updates.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/affs/symlink.c b/fs/affs/symlink.c
index 4178253..ee00f08 100644
--- a/fs/affs/symlink.c
+++ b/fs/affs/symlink.c
@@ -20,7 +20,6 @@
int i, j;
char c;
char lc;
- char *pf;
pr_debug("AFFS: follow_link(ino=%lu)\n",inode->i_ino);
@@ -32,11 +31,15 @@
j = 0;
lf = (struct slink_front *)bh->b_data;
lc = 0;
- pf = AFFS_SB(inode->i_sb)->s_prefix ? AFFS_SB(inode->i_sb)->s_prefix : "/";
if (strchr(lf->symname,':')) { /* Handle assign or volume name */
+ struct affs_sb_info *sbi = AFFS_SB(inode->i_sb);
+ char *pf;
+ spin_lock(&sbi->symlink_lock);
+ pf = sbi->s_prefix ? sbi->s_prefix : "/";
while (i < 1023 && (c = pf[i]))
link[i++] = c;
+ spin_unlock(&sbi->symlink_lock);
while (i < 1023 && lf->symname[j] != ':')
link[i++] = lf->symname[j++];
if (i < 1023)