[PATCH] namei fixes (16/19)

Conditional mntput() moved into __do_follow_link().  There it collapses with
unconditional mntget() on the same sucker, closing another too-early-mntput()
race.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 6a884682b0a7..444086d441e1 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -506,7 +506,8 @@ static inline int __do_follow_link(struct path *path, struct nameidata *nd)
         touch_atime(nd->mnt, dentry);
         nd_set_link(nd, NULL);
 
-        mntget(path->mnt);
+        if (path->mnt == nd->mnt)
+                mntget(path->mnt);
         error = dentry->d_inode->i_op->follow_link(dentry, nd);
         if (!error) {
                 char *s = nd_get_link(nd);
@@ -543,8 +544,6 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd)
         current->link_count++;
         current->total_link_count++;
         nd->depth++;
-        if (path->mnt != nd->mnt)
-                mntput(path->mnt);
         err = __do_follow_link(path, nd);
         current->link_count--;
         nd->depth--;
@@ -1550,8 +1549,6 @@ do_link:
         error = security_inode_follow_link(path.dentry, nd);
         if (error)
                 goto exit_dput;
-        if (nd->mnt != path.mnt)
-                mntput(path.mnt);
         error = __do_follow_link(&path, nd);
         if (error)
                 return error;