autofs: change autofs4_wait() to take struct path

In order to use the functions path_is_mountpoint() and path_has_submounts()
autofs needs to pass a struct path in several places.

Now change autofs4_wait() to take a struct path instead of a struct
dentry.

Link: http://lkml.kernel.org/r/20161011053413.27645.84666.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/autofs4/autofs_i.h

@@ -217,7 +217,8 @@ static inline int autofs_prepare_pipe(struct file *pipe)
 
 /* Queue management functions */
 
-int autofs4_wait(struct autofs_sb_info *, struct dentry *, enum autofs_notify);
+int autofs4_wait(struct autofs_sb_info *,
+		 const struct path *, enum autofs_notify);
 int autofs4_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
 void autofs4_catatonic_mode(struct autofs_sb_info *);
 

fs/autofs4/expire.c

@@ -526,7 +526,7 @@ retry:
 
 		pr_debug("waiting for expire %p name=%pd\n", dentry, dentry);
 
-		status = autofs4_wait(sbi, dentry, NFY_NONE);
+		status = autofs4_wait(sbi, path, NFY_NONE);
 		wait_for_completion(&ino->expire_complete);
 
 		pr_debug("expire done status=%d\n", status);
@@ -593,11 +593,12 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 
 	if (dentry) {
 		struct autofs_info *ino = autofs4_dentry_ino(dentry);
+		struct path path = { .mnt = mnt, .dentry = dentry };
 
 		/* This is synchronous because it makes the daemon a
 		 * little easier
 		 */
-		ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
+		ret = autofs4_wait(sbi, &path, NFY_EXPIRE);
 
 		spin_lock(&sbi->fs_lock);
 		/* avoid rapid-fire expire attempts if expiry fails */

fs/autofs4/root.c

@@ -269,17 +269,17 @@ next:
 	return NULL;
 }
 
-static int autofs4_mount_wait(struct dentry *dentry, bool rcu_walk)
+static int autofs4_mount_wait(const struct path *path, bool rcu_walk)
 {
-	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	struct autofs_sb_info *sbi = autofs4_sbi(path->dentry->d_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(path->dentry);
 	int status = 0;
 
 	if (ino->flags & AUTOFS_INF_PENDING) {
 		if (rcu_walk)
 			return -ECHILD;
-		pr_debug("waiting for mount name=%pd\n", dentry);
-		status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+		pr_debug("waiting for mount name=%pd\n", path->dentry);
+		status = autofs4_wait(sbi, path, NFY_MOUNT);
 		pr_debug("mount wait done status=%d\n", status);
 	}
 	ino->last_used = jiffies;
@@ -364,7 +364,7 @@ static struct vfsmount *autofs4_d_automount(struct path *path)
 	spin_lock(&sbi->fs_lock);
 	if (ino->flags & AUTOFS_INF_PENDING) {
 		spin_unlock(&sbi->fs_lock);
-		status = autofs4_mount_wait(dentry, 0);
+		status = autofs4_mount_wait(path, 0);
 		if (status)
 			return ERR_PTR(status);
 		goto done;
@@ -405,7 +405,7 @@ static struct vfsmount *autofs4_d_automount(struct path *path)
 		}
 		ino->flags |= AUTOFS_INF_PENDING;
 		spin_unlock(&sbi->fs_lock);
-		status = autofs4_mount_wait(dentry, 0);
+		status = autofs4_mount_wait(path, 0);
 		spin_lock(&sbi->fs_lock);
 		ino->flags &= ~AUTOFS_INF_PENDING;
 		if (status) {
@@ -447,7 +447,7 @@ static int autofs4_d_manage(const struct path *path, bool rcu_walk)
 	 * This dentry may be under construction so wait on mount
 	 * completion.
 	 */
-	status = autofs4_mount_wait(dentry, rcu_walk);
+	status = autofs4_mount_wait(path, rcu_walk);
 	if (status)
 		return status;
 

fs/autofs4/waitq.c

@@ -345,8 +345,9 @@ static int validate_request(struct autofs_wait_queue **wait,
 }
 
 int autofs4_wait(struct autofs_sb_info *sbi,
-		 struct dentry *dentry, enum autofs_notify notify)
+		 const struct path *path, enum autofs_notify notify)
 {
+	struct dentry *dentry = path->dentry;
 	struct autofs_wait_queue *wq;
 	struct qstr qstr;
 	char *name;