diff options
author | David Howells <dhowells@redhat.com> | 2011-01-14 19:10:03 +0000 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-01-15 20:07:48 -0500 |
commit | ea5b778a8b98c85a87d66bf844904f9c3802b869 (patch) | |
tree | baa56cbe1a907d76341f2cad53e16569cc1d3288 /fs/nfs | |
parent | ab90911ff90cdab59b31c045c3f0ae480d14f29d (diff) |
Unexport do_add_mount() and add in follow_automount(), not ->d_automount()
Unexport do_add_mount() and make ->d_automount() return the vfsmount to be
added rather than calling do_add_mount() itself. follow_automount() will then
do the addition.
This slightly complicates things as ->d_automount() normally wants to add the
new vfsmount to an expiration list and start an expiration timer. The problem
with that is that the vfsmount will be deleted if it has a refcount of 1 and
the timer will not repeat if the expiration list is empty.
To this end, we require the vfsmount to be returned from d_automount() with a
refcount of (at least) 2. One of these refs will be dropped unconditionally.
In addition, follow_automount() must get a 3rd ref around the call to
do_add_mount() lest it eat a ref and return an error, leaving the mount we
have open to being expired as we would otherwise have only 1 ref on it.
d_automount() should also add the the vfsmount to the expiration list (by
calling mnt_set_expiry()) and start the expiration timer before returning, if
this mechanism is to be used. The vfsmount will be unlinked from the
expiration list by follow_automount() if do_add_mount() fails.
This patch also fixes the call to do_add_mount() for AFS to propagate the mount
flags from the parent vfsmount.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/nfs')
-rw-r--r-- | fs/nfs/namespace.c | 24 |
1 files changed, 4 insertions, 20 deletions
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index f3fbb1bf3f1..f32b8603dca 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -149,26 +149,10 @@ struct vfsmount *nfs_d_automount(struct path *path) if (IS_ERR(mnt)) goto out; - mntget(mnt); - err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE, - &nfs_automount_list); - switch (err) { - case 0: - dprintk("%s: done, success\n", __func__); - schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); - break; - case -EBUSY: - /* someone else made a mount here whilst we were busy */ - mntput(mnt); - dprintk("%s: done, collision\n", __func__); - mnt = NULL; - break; - default: - mntput(mnt); - dprintk("%s: done, error %d\n", __func__, err); - mnt = ERR_PTR(err); - break; - } + dprintk("%s: done, success\n", __func__); + mntget(mnt); /* prevent immediate expiration */ + mnt_set_expiry(mnt, &nfs_automount_list); + schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout); out: nfs_free_fattr(fattr); |