Commit e1f19857 authored by Richard Weinberger's avatar Richard Weinberger Committed by Chuck Lever
Browse files

fs: namei: Allow follow_down() to uncover auto mounts 



This function is only used by NFSD to cross mount points.
If a mount point is of type auto mount, follow_down() will
not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags
to have ->d_automount() called when NFSD walks down the
mount tree.

Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
Reviewed-by: default avatarIan Kent <raven@themaw.net>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Acked-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 50f5fdae

fs/namei.c

+3 −3
Original line number Diff line number Diff line
@@ -1458,11 +1458,11 @@ EXPORT_SYMBOL(follow_down_one); 
 * point, the filesystem owning that dentry may be queried as to whether the

 * caller is permitted to proceed or not.

 */

int follow_down(struct path *path)

int follow_down(struct path *path, unsigned int flags)

{

	struct vfsmount *mnt = path->mnt;

	bool jumped;

	int ret = traverse_mounts(path, &jumped, NULL, 0);

	int ret = traverse_mounts(path, &jumped, NULL, flags);



	if (path->mnt != mnt)

		mntput(mnt);
@@ -2864,7 +2864,7 @@ int path_pts(struct path *path) 


	path->dentry = child;

	dput(parent);

	follow_down(path);

	follow_down(path, 0);

	return 0;

}

#endif

fs/nfsd/vfs.c

+5 −1
Original line number Diff line number Diff line
@@ -126,9 +126,13 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 
	struct dentry *dentry = *dpp;

	struct path path = {.mnt = mntget(exp->ex_path.mnt),

			    .dentry = dget(dentry)};

	unsigned int follow_flags = 0;

	int err = 0;



	err = follow_down(&path);

	if (exp->ex_flags & NFSEXP_CROSSMOUNT)

		follow_flags = LOOKUP_AUTOMOUNT;



	err = follow_down(&path, follow_flags);

	if (err < 0)

		goto out;

	if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&

include/linux/namei.h

+1 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns, 
					    struct dentry *base, int len);



extern int follow_down_one(struct path *);

extern int follow_down(struct path *);

extern int follow_down(struct path *path, unsigned int flags);

extern int follow_up(struct path *);



extern struct dentry *lock_rename(struct dentry *, struct dentry *);