Commit 5b83d2c5 authored by Ram Pai's avatar Ram Pai Committed by Linus Torvalds
Browse files

[PATCH] sanitize the interface of graft_tree().



Old semantics: graft_tree() grabs a reference on the vfsmount before
returning success.

New one: graft_tree() leaves that to caller.

All the callers of graft_tree() immediately dropped that reference
anyway.  Changing the interface takes care of this unnecessary overhead.

Idea proposed by Al Viro.
Signed-off-by: default avatarRam Pai <linuxram@us.ibm.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b58fed8b
......@@ -650,7 +650,6 @@ static int graft_tree(struct vfsmount *mnt, struct nameidata *nd)
attach_mnt(mnt, nd);
list_add_tail(&head, &mnt->mnt_list);
list_splice(&head, current->namespace->list.prev);
mntget(mnt);
err = 0;
touch_namespace(current->namespace);
}
......@@ -702,8 +701,7 @@ static int do_loopback(struct nameidata *nd, char *old_name, int recurse)
spin_lock(&vfsmount_lock);
umount_tree(mnt);
spin_unlock(&vfsmount_lock);
} else
mntput(mnt);
}
out:
up_write(&current->namespace->sem);
......@@ -857,15 +855,17 @@ int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
goto unlock;
newmnt->mnt_flags = mnt_flags;
newmnt->mnt_namespace = current->namespace;
err = graft_tree(newmnt, nd);
if ((err = graft_tree(newmnt, nd)))
goto unlock;
if (err == 0 && fslist) {
if (fslist) {
/* add to the specified expiration list */
spin_lock(&vfsmount_lock);
list_add_tail(&newmnt->mnt_expire, fslist);
spin_unlock(&vfsmount_lock);
}
up_write(&current->namespace->sem);
return 0;
unlock:
up_write(&current->namespace->sem);
......
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