[PATCH] autofs4: atomic var underflow

Fix accidental underflow of the atomic counter.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 5 insertions, 3 deletions

diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index ff6239d57b4b..617fd7b37447 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -85,7 +85,7 @@ struct autofs_wait_queue {
         pid_t tgid;
         /* This is for status reporting upon return */
         int status;
-        atomic_t notified;
+        atomic_t notify;
         atomic_t wait_ctr;
 };
 
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 894d74671bd0..142ab6aa2aa1 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -263,7 +263,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                 wq->tgid = current->tgid;
                 wq->status = -EINTR; /* Status return if interrupted */
                 atomic_set(&wq->wait_ctr, 2);
-                atomic_set(&wq->notified, 1);
+                atomic_set(&wq->notify, 1);
                 mutex_unlock(&sbi->wq_mutex);
         } else {
                 atomic_inc(&wq->wait_ctr);
@@ -273,9 +273,11 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
                         (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
         }
 
-        if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) {
+        if (notify != NFY_NONE && atomic_read(&wq->notify)) {
                 int type;
 
+                atomic_dec(&wq->notify);
+
                 if (sbi->version < 5) {
                         if (notify == NFY_MOUNT)
                                 type = autofs_ptype_missing;