2.6.0-test1: autofs4 doesn't expire
In 2.6.0-test1, the autofs4 automounter doesn't expire mounts anymore, both NFS and CDROM mounts. It did work in my previous kernel, 2.5.72. When I try to unmount manually, I get "device is busy", although "fuser -m" doesn't report anything. I've also searched /proc/*/fd/, but there are no open files below the mount points.
Is anybody else seeing this? Any ideas what could be the cause?
Signature · 3 lines
Dick Streefland //// De Bilt [email protected] (@ @) The Netherlands ------------------------------oOO--(_)--OOo------------------
[email protected] (Dick Streefland) wrote:
| In 2.6.0-test1, the autofs4 automounter doesn't expire mounts anymore, | both NFS and CDROM mounts. It did work in my previous kernel, 2.5.72. | When I try to unmount manually, I get "device is busy", although | "fuser -m" doesn't report anything. I've also searched /proc/*/fd/, | but there are no open files below the mount points. | | Is anybody else seeing this? Any ideas what could be the cause?
Update: 2.5.75 is OK, so the problem was introduced in 2.6.0-test1. I have not yet verified it, but I suspect that the addition of the mntget() call is the cause:
==> fs/namespace.c <==
+/*
+ * Now, lookup_mnt increments the ref count before returning
+ * the vfsmount struct.
+ */
struct vfsmount *lookup_mnt(struct vfsmount *mnt, struct dentry *dentry) {
struct list_head * head = mount_hashtable + hash(mnt, dentry); struct list_head * tmp = head;
- struct vfsmount *p;
+ struct vfsmount *p, *found = NULL;
+ spin_lock(&vfsmount_lock);
for (;;) {
tmp = tmp->next;
p = NULL;
if (tmp == head)
break;
p = list_entry(tmp, struct vfsmount, mnt_hash);
- if (p->mnt_parent == mnt && p->mnt_mountpoint == dentry)
+ if (p->mnt_parent == mnt && p->mnt_mountpoint == dentry) {
+ found = mntget(p);
break;
+ }
}
- return p;
+ spin_unlock(&vfsmount_lock);
+ return found;
}
Signature · 3 lines
Dick Streefland //// De Bilt [email protected] (@ @) The Netherlands ------------------------------oOO--(_)--OOo------------------
Quoted 9 lines · Dick Streefland
[email protected] (Dick Streefland) wrote:
| In 2.6.0-test1, the autofs4 automounter doesn't expire mounts anymore, | both NFS and CDROM mounts. It did work in my previous kernel, 2.5.72. | When I try to unmount manually, I get "device is busy", although | "fuser -m" doesn't report anything. I've also searched /proc/*/fd/, | but there are no open files below the mount points. | | Is anybody else seeing this? Any ideas what could be the cause?
Quoted 3 lines
Update: 2.5.75 is OK, so the problem was introduced in 2.6.0-test1. I have not yet verified it, but I suspect that the addition of the
mntget()call is the cause:
Hm, that does look like it would upset autofs4. I'll take a look.
J