proc: Update proc_flush_task_mnt to use d_invalidate

Now that d_invalidate always succeeds and flushes mount points use
it in stead of a combination of shrink_dcache_parent and d_drop
in proc_flush_task_mnt.  This removes the danger of a mount point
under /proc/<pid>/... becoming unreachable after the d_drop.

Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index aa62b37f130347031dae38c603b812ff91dcd878..40d97e576d32352e9d92e95ae3685613f4a91d29 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2700,8 +2700,7 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
        /* no ->d_hash() rejects on procfs */
        dentry = d_hash_and_lookup(mnt->mnt_root, &name);
        if (dentry) {
-               shrink_dcache_parent(dentry);
-               d_drop(dentry);
+               d_invalidate(dentry);
                dput(dentry);
        }
 
@@ -2721,8 +2720,7 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
        name.len = snprintf(buf, sizeof(buf), "%d", pid);
        dentry = d_hash_and_lookup(dir, &name);
        if (dentry) {
-               shrink_dcache_parent(dentry);
-               d_drop(dentry);
+               d_invalidate(dentry);
                dput(dentry);
        }