X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fautofs4%2Fexpire.c;h=053d92a745b91c9624cc585f54b718bb8dc22c63;hb=1aff3c8b0511b5bb54acf7859e0c6ec9ae7287a9;hp=bcc17f533699728658ea6833a4ec0e160f5ce65d;hpb=1f5f2c3059ae8cc23cb3303daf324b06ba79517a;p=linux-2.6-omap-h63xx.git

diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index bcc17f53369..053d92a745b 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -72,6 +72,27 @@ done:
 	return status;
 }
 
+/*
+ * Calculate next entry in top down tree traversal.
+ * From next_mnt in namespace.c - elegant.
+ */
+static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
+{
+	struct list_head *next = p->d_subdirs.next;
+
+	if (next == &p->d_subdirs) {
+		while (1) {
+			if (p == root)
+				return NULL;
+			next = p->d_u.d_child.next;
+			if (next != &p->d_parent->d_subdirs)
+				break;
+			p = p->d_parent;
+		}
+	}
+	return list_entry(next, struct dentry, d_u.d_child);
+}
+
 /* Check a directory tree of mount points for busyness
  * The tree is not busy iff no mountpoints are busy
  */
@@ -80,8 +101,8 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
 			     unsigned long timeout,
 			     int do_now)
 {
-	struct dentry *this_parent = top;
-	struct list_head *next;
+	struct autofs_info *ino;
+	struct dentry *p;
 
 	DPRINTK("top %p %.*s",
 		top, (int)top->d_name.len, top->d_name.name);
@@ -90,58 +111,52 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
 	if (!simple_positive(top))
 		return 1;
 
-	/* Timeout of a tree mount is determined by its top dentry */
-	if (!autofs4_can_expire(top, timeout, do_now))
-		return 1;
-
-	/* Is someone visiting anywhere in the tree ? */
-	if (may_umount_tree(mnt))
-		return 1;
-
 	spin_lock(&dcache_lock);
-repeat:
-	next = this_parent->d_subdirs.next;
-resume:
-	while (next != &this_parent->d_subdirs) {
-		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
-
+	for (p = top; p; p = next_dentry(p, top)) {
 		/* Negative dentry - give up */
-		if (!simple_positive(dentry)) {
-			next = next->next;
+		if (!simple_positive(p))
 			continue;
-		}
 
 		DPRINTK("dentry %p %.*s",
-			dentry, (int)dentry->d_name.len, dentry->d_name.name);
-
-		if (!simple_empty_nolock(dentry)) {
-			this_parent = dentry;
-			goto repeat;
-		}
+			p, (int) p->d_name.len, p->d_name.name);
 
-		dentry = dget(dentry);
+		p = dget(p);
 		spin_unlock(&dcache_lock);
 
-		if (d_mountpoint(dentry)) {
-			/* First busy => tree busy */
-			if (autofs4_mount_busy(mnt, dentry)) {
-				dput(dentry);
+		/*
+		 * Is someone visiting anywhere in the subtree ?
+		 * If there's no mount we need to check the usage
+		 * count for the autofs dentry.
+		 */
+		ino = autofs4_dentry_ino(p);
+		if (d_mountpoint(p)) {
+			if (autofs4_mount_busy(mnt, p)) {
+				dput(p);
 				return 1;
 			}
-		}
+		} else {
+			unsigned int ino_count = atomic_read(&ino->count);
 
-		dput(dentry);
-		spin_lock(&dcache_lock);
-		next = next->next;
-	}
+			/* allow for dget above and top is already dgot */
+			if (p == top)
+				ino_count += 2;
+			else
+				ino_count++;
 
-	if (this_parent != top) {
-		next = this_parent->d_u.d_child.next;
-		this_parent = this_parent->d_parent;
-		goto resume;
+			if (atomic_read(&p->d_count) > ino_count) {
+				dput(p);
+				return 1;
+			}
+		}
+		dput(p);
+		spin_lock(&dcache_lock);
 	}
 	spin_unlock(&dcache_lock);
 
+	/* Timeout of a tree mount is ultimately determined by its top dentry */
+	if (!autofs4_can_expire(top, timeout, do_now))
+		return 1;
+
 	return 0;
 }
 
@@ -150,59 +165,38 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
 					   unsigned long timeout,
 					   int do_now)
 {
-	struct dentry *this_parent = parent;
-	struct list_head *next;
+	struct dentry *p;
 
 	DPRINTK("parent %p %.*s",
 		parent, (int)parent->d_name.len, parent->d_name.name);
 
 	spin_lock(&dcache_lock);
-repeat:
-	next = this_parent->d_subdirs.next;
-resume:
-	while (next != &this_parent->d_subdirs) {
-		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
-
+	for (p = parent; p; p = next_dentry(p, parent)) {
 		/* Negative dentry - give up */
-		if (!simple_positive(dentry)) {
-			next = next->next;
+		if (!simple_positive(p))
 			continue;
-		}
 
 		DPRINTK("dentry %p %.*s",
-			dentry, (int)dentry->d_name.len, dentry->d_name.name);
+			p, (int) p->d_name.len, p->d_name.name);
 
-		if (!list_empty(&dentry->d_subdirs)) {
-			this_parent = dentry;
-			goto repeat;
-		}
-
-		dentry = dget(dentry);
+		p = dget(p);
 		spin_unlock(&dcache_lock);
 
-		if (d_mountpoint(dentry)) {
+		if (d_mountpoint(p)) {
 			/* Can we expire this guy */
-			if (!autofs4_can_expire(dentry, timeout, do_now))
+			if (!autofs4_can_expire(p, timeout, do_now))
 				goto cont;
 
 			/* Can we umount this guy */
-			if (!autofs4_mount_busy(mnt, dentry))
-				return dentry;
+			if (!autofs4_mount_busy(mnt, p))
+				return p;
 
 		}
 cont:
-		dput(dentry);
+		dput(p);
 		spin_lock(&dcache_lock);
-		next = next->next;
-	}
-
-	if (this_parent != parent) {
-		next = this_parent->d_u.d_child.next;
-		this_parent = this_parent->d_parent;
-		goto resume;
 	}
 	spin_unlock(&dcache_lock);
-
 	return NULL;
 }