4 files changed, 40 insertions, 14 deletions

diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index f5a52c871726..c7b2b8890188 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -84,6 +84,7 @@ struct autofs_wait_queue {
 	char *name;
 	/* This is for status reporting upon return */
 	int status;
+	atomic_t notified;
 	atomic_t wait_ctr;
 };
 
@@ -101,6 +102,7 @@ struct autofs_sb_info {
 	int needs_reghost;
 	struct super_block *sb;
 	struct semaphore wq_sem;
+	spinlock_t fs_lock;
 	struct autofs_wait_queue *queues; /* Wait queue pointer */
 };
 
@@ -126,9 +128,18 @@ static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
 static inline int autofs4_ispending(struct dentry *dentry)
 {
 	struct autofs_info *inf = autofs4_dentry_ino(dentry);
+	int pending = 0;
 
-	return (dentry->d_flags & DCACHE_AUTOFS_PENDING) ||
-		(inf != NULL && inf->flags & AUTOFS_INF_EXPIRING);
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+		return 1;
+
+	if (inf) {
+		spin_lock(&inf->sbi->fs_lock);
+		pending = inf->flags & AUTOFS_INF_EXPIRING;
+		spin_unlock(&inf->sbi->fs_lock);
+	}
+
+	return pending;
 }
 
 static inline void autofs4_copy_atime(struct file *src, struct file *dst)
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 31540a6404d9..500425e24fba 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -99,6 +99,10 @@ static int autofs4_check_tree(struct vfsmount *mnt,
 	if (!autofs4_can_expire(top, timeout, do_now))
 		return 0;
 
+	/* Is someone visiting anywhere in the tree ? */
+	if (may_umount_tree(mnt))
+		return 0;
+
 	spin_lock(&dcache_lock);
 repeat:
 	next = this_parent->d_subdirs.next;
@@ -270,10 +274,18 @@ static struct dentry *autofs4_expire(struct super_block *sb,
 
 		/* Case 2: tree mount, expire iff entire tree is not busy */
 		if (!exp_leaves) {
+			/* Lock the tree as we must expire as a whole */
+			spin_lock(&sbi->fs_lock);
 			if (autofs4_check_tree(mnt, dentry, timeout, do_now)) {
-			expired = dentry;
-			break;
+				struct autofs_info *inf = autofs4_dentry_ino(dentry);
+
+				/* Set this flag early to catch sys_chdir and the like */
+				inf->flags |= AUTOFS_INF_EXPIRING;
+				spin_unlock(&sbi->fs_lock);
+				expired = dentry;
+				break;
 			}
+			spin_unlock(&sbi->fs_lock);
 		/* Case 3: direct mount, expire individual leaves */
 		} else {
 			expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index a52560746628..4bb14cc68040 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -206,6 +206,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
 	sbi->version = 0;
 	sbi->sub_version = 0;
 	init_MUTEX(&sbi->wq_sem);
+	spin_lock_init(&sbi->fs_lock);
 	sbi->queues = NULL;
 	s->s_blocksize = 1024;
 	s->s_blocksize_bits = 10;
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 1ab24a662e09..5a40d36e5a51 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -210,17 +210,8 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 		wq->len = len;
 		wq->status = -EINTR; /* Status return if interrupted */
 		atomic_set(&wq->wait_ctr, 2);
+		atomic_set(&wq->notified, 1);
 		up(&sbi->wq_sem);
-
-		DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d",
-			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
-		/* autofs4_notify_daemon() may block */
-		if (notify != NFY_NONE) {
-			autofs4_notify_daemon(sbi,wq, 
-					notify == NFY_MOUNT ?
-						  autofs_ptype_missing :
-						  autofs_ptype_expire_multi);
-		}
 	} else {
 		atomic_inc(&wq->wait_ctr);
 		up(&sbi->wq_sem);
@@ -229,6 +220,17 @@ 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)) {
+		int type = (notify == NFY_MOUNT ?
+			autofs_ptype_missing : autofs_ptype_expire_multi);
+
+		DPRINTK(("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify));
+
+		/* autofs4_notify_daemon() may block */
+		autofs4_notify_daemon(sbi, wq, type);
+	}
+
 	/* wq->name is NULL if and only if the lock is already released */
 
 	if ( sbi->catatonic ) {