Commit f60aef7e authored by Al Viro's avatar Al Viro
Browse files

drop out of RCU in return_reval 



... thus killing the need to handle drop-from-RCU in d_revalidate()

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent f5e1c1c1

fs/namei.c

+6 −19
Original line number Original line Diff line number Diff line
@@ -571,25 +571,9 @@ void release_open_intent(struct nameidata *nd) 
	}

	}

}

}





/*

static inline int d_revalidate(struct dentry *dentry, struct nameidata *nd)

 * Call d_revalidate and handle filesystems that request rcu-walk

 * to be dropped. This may be called and return in rcu-walk mode,

 * regardless of success or error. If -ECHILD is returned, the caller

 * must return -ECHILD back up the path walk stack so path walk may

 * be restarted in ref-walk mode.

 */

static int d_revalidate(struct dentry *dentry, struct nameidata *nd)

{

{

	int status;

	return dentry->d_op->d_revalidate(dentry, nd);



	status = dentry->d_op->d_revalidate(dentry, nd);

	if (status == -ECHILD) {

		if (nameidata_dentry_drop_rcu(nd, dentry))

			return status;

		status = dentry->d_op->d_revalidate(dentry, nd);

	}



	return status;

}

}





static struct dentry *

static struct dentry *
@@ -617,7 +601,7 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd) 
static inline struct dentry *

static inline struct dentry *

do_revalidate_rcu(struct dentry *dentry, struct nameidata *nd)

do_revalidate_rcu(struct dentry *dentry, struct nameidata *nd)

{

{

	int status = dentry->d_op->d_revalidate(dentry, nd);

	int status = d_revalidate(dentry, nd);

	if (likely(status > 0))

	if (likely(status > 0))

		return dentry;

		return dentry;

	if (status == -ECHILD) {

	if (status == -ECHILD) {
@@ -1517,12 +1501,15 @@ static int link_path_walk(const char *name, struct nameidata *nd) 
		 * We may need to check the cached dentry for staleness.

		 * We may need to check the cached dentry for staleness.

		 */

		 */

		if (need_reval_dot(nd->path.dentry)) {

		if (need_reval_dot(nd->path.dentry)) {

			if (nameidata_drop_rcu_last_maybe(nd))

				return -ECHILD;

			/* Note: we do not d_invalidate() */

			/* Note: we do not d_invalidate() */

			err = d_revalidate(nd->path.dentry, nd);

			err = d_revalidate(nd->path.dentry, nd);

			if (!err)

			if (!err)

				err = -ESTALE;

				err = -ESTALE;

			if (err < 0)

			if (err < 0)

				break;

				break;

			return 0;

		}

		}

return_base:

return_base:

		if (nameidata_drop_rcu_last_maybe(nd))

		if (nameidata_drop_rcu_last_maybe(nd))