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Commit 1ce12bad authored by Ian Kent's avatar Ian Kent Committed by Linus Torvalds
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[PATCH] autofs4: simplify expire tree traversal 



Simplify the expire tree traversal code by using a function from namespace.c
to calculate the next entry in the top down tree traversals carried out during
the expire operation.

Signed-off-by: default avatarIan Kent <raven@themaw.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 1f5f2c30

fs/autofs4/expire.c

+40 −62
Original line number Diff line number Diff line
@@ -72,6 +72,27 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) 
	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 +101,7 @@ static int autofs4_tree_busy(struct vfsmount *mnt, 
			     unsigned long timeout,

			     int do_now)

{

	struct dentry *this_parent = top;

	struct list_head *next;

	struct dentry *p;



	DPRINTK("top %p %.*s",

		top, (int)top->d_name.len, top->d_name.name);
@@ -99,49 +119,28 @@ static int autofs4_tree_busy(struct vfsmount *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);

			p, (int) p->d_name.len, p->d_name.name);



		if (!simple_empty_nolock(dentry)) {

			this_parent = dentry;

			goto repeat;

		}



		dentry = dget(dentry);

		p = dget(p);

		spin_unlock(&dcache_lock);



		if (d_mountpoint(dentry)) {

		if (d_mountpoint(p)) {

			/* First busy => tree busy */

			if (autofs4_mount_busy(mnt, dentry)) {

				dput(dentry);

			if (autofs4_mount_busy(mnt, p)) {

				dput(p);

				return 1;

			}

		}



		dput(dentry);

		dput(p);

		spin_lock(&dcache_lock);

		next = next->next;

	}



	if (this_parent != top) {

		next = this_parent->d_u.d_child.next;

		this_parent = this_parent->d_parent;

		goto resume;

	}

	spin_unlock(&dcache_lock);



	return 0;

}
@@ -150,59 +149,38 @@ 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);



		if (!list_empty(&dentry->d_subdirs)) {

			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)) {

		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;

}