don't drop newmnt on error in do_add_mount()

That gets rid of the kludge in finish_automount() - we need
to keep refcount on the vfsmount as-is until we evict it from
expiry list.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-01-17 01:41:58 -05:00
parent 19a167af7c
commit 15f9a3f3e1

View File

@ -1880,6 +1880,7 @@ static int do_new_mount(struct path *path, char *type, int flags,
int mnt_flags, char *name, void *data)
{
struct vfsmount *mnt;
int err;
if (!type)
return -EINVAL;
@ -1892,7 +1893,10 @@ static int do_new_mount(struct path *path, char *type, int flags,
if (IS_ERR(mnt))
return PTR_ERR(mnt);
return do_add_mount(mnt, path, mnt_flags);
err = do_add_mount(mnt, path, mnt_flags);
if (err)
mntput(mnt);
return err;
}
int finish_automount(struct vfsmount *m, struct path *path)
@ -1911,26 +1915,17 @@ int finish_automount(struct vfsmount *m, struct path *path)
return -ELOOP;
}
/* We need to add the mountpoint to the parent. The filesystem may
* have placed it on an expiry list, and so we need to make sure it
* won't be expired under us if do_add_mount() fails (do_add_mount()
* will eat a reference unconditionally).
*/
mntget(m);
err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
if (err) {
mnt_clear_expiry(m);
mntput(m);
mntput(m);
} else {
mntput(m);
}
return err;
}
/*
* add a mount into a namespace's mount tree
* - this unconditionally eats one of the caller's references to newmnt.
*/
int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
{
@ -1967,7 +1962,6 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
unlock:
up_write(&namespace_sem);
mntput(newmnt);
return err;
}