autofs4 - fix get_next_positive_subdir()

[karo-tx-linux.git] / fs / autofs4 / expire.c

diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 1feb68ecef9509dd88a4323f3193845af6a84e15..8c0e56d92938c49ad61fef0bfb3888f47429ebc9 100644 (file)
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -94,25 +94,21 @@ static struct dentry *get_next_positive_subdir(struct dentry *prev,
 {
        struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
        struct list_head *next;
-       struct dentry *p, *q;
+       struct dentry *q;
 
        spin_lock(&sbi->lookup_lock);
+       spin_lock(&root->d_lock);
 
-       if (prev == NULL) {
-               spin_lock(&root->d_lock);
+       if (prev)
+               next = prev->d_u.d_child.next;
+       else {
                prev = dget_dlock(root);
                next = prev->d_subdirs.next;
-               p = prev;
-               goto start;
        }
 
-       p = prev;
-       spin_lock(&p->d_lock);
-again:
-       next = p->d_u.d_child.next;
-start:
+cont:
        if (next == &root->d_subdirs) {
-               spin_unlock(&p->d_lock);
+               spin_unlock(&root->d_lock);
                spin_unlock(&sbi->lookup_lock);
                dput(prev);
                return NULL;
@@ -121,16 +117,15 @@ start:
        q = list_entry(next, struct dentry, d_u.d_child);
 
        spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
-       /* Negative dentry - try next */
-       if (!simple_positive(q)) {
-               spin_unlock(&p->d_lock);
-               lock_set_subclass(&q->d_lock.dep_map, 0, _RET_IP_);
-               p = q;
-               goto again;
+       /* Already gone or negative dentry (under construction) - try next */
+       if (q->d_count == 0 || !simple_positive(q)) {
+               spin_unlock(&q->d_lock);
+               next = q->d_u.d_child.next;
+               goto cont;
        }
        dget_dlock(q);
        spin_unlock(&q->d_lock);
-       spin_unlock(&p->d_lock);
+       spin_unlock(&root->d_lock);
        spin_unlock(&sbi->lookup_lock);
 
        dput(prev);