From ea441d1104cf1efb471fa81bc91e9fd1e6ae29fd Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 16 Nov 2011 21:43:59 -0500 Subject: new helper: mount_subtree() takes vfsmount and relative path, does lookup within that vfsmount (possibly triggering automounts) and returns the result as root of subtree suitable for return by ->mount() (i.e. a reference to dentry and an active reference to its superblock grabbed, superblock locked exclusive). btrfs and nfs switched to it instead of open-coding the sucker. Signed-off-by: Al Viro --- fs/nfs/super.c | 30 ++++++------------------------ 1 file changed, 6 insertions(+), 24 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 46d69f38fd5..134777406ee 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2787,35 +2787,17 @@ static void nfs_referral_loop_unprotect(void) static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt, const char *export_path) { - struct mnt_namespace *ns_private; - struct super_block *s; struct dentry *dentry; - struct path path; - int ret; + int ret = nfs_referral_loop_protect(); - ns_private = create_mnt_ns(root_mnt); - if (IS_ERR(ns_private)) - return ERR_CAST(ns_private); - - ret = nfs_referral_loop_protect(); - if (ret == 0) { - ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt, - export_path, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, - &path); - nfs_referral_loop_unprotect(); - } - - put_mnt_ns(ns_private); - - if (ret != 0) + if (ret) { + mntput(root_mnt); return ERR_PTR(ret); + } - s = path.mnt->mnt_sb; - atomic_inc(&s->s_active); - dentry = dget(path.dentry); + dentry = mount_subtree(root_mnt, export_path); + nfs_referral_loop_unprotect(); - path_put(&path); - down_write(&s->s_umount); return dentry; } -- cgit v1.2.3-70-g09d2