120 lines
3.1 KiB
C
120 lines
3.1 KiB
C
/*
|
|
* linux/fs/nfs/namespace.c
|
|
*
|
|
* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
|
|
*
|
|
* NFS namespace
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
|
|
#include <linux/dcache.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/namei.h>
|
|
#include <linux/nfs_fs.h>
|
|
#include <linux/string.h>
|
|
#include <linux/sunrpc/clnt.h>
|
|
#include <linux/vfs.h>
|
|
|
|
#define NFSDBG_FACILITY NFSDBG_VFS
|
|
|
|
LIST_HEAD(nfs_automount_list);
|
|
static void nfs_expire_automounts(void *list);
|
|
static DECLARE_WORK(nfs_automount_task, nfs_expire_automounts, &nfs_automount_list);
|
|
int nfs_mountpoint_expiry_timeout = 500 * HZ;
|
|
|
|
/*
|
|
* nfs_follow_mountpoint - handle crossing a mountpoint on the server
|
|
* @dentry - dentry of mountpoint
|
|
* @nd - nameidata info
|
|
*
|
|
* When we encounter a mountpoint on the server, we want to set up
|
|
* a mountpoint on the client too, to prevent inode numbers from
|
|
* colliding, and to allow "df" to work properly.
|
|
* On NFSv4, we also want to allow for the fact that different
|
|
* filesystems may be migrated to different servers in a failover
|
|
* situation, and that different filesystems may want to use
|
|
* different security flavours.
|
|
*/
|
|
static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
|
|
{
|
|
struct vfsmount *mnt;
|
|
struct nfs_server *server = NFS_SERVER(dentry->d_inode);
|
|
struct dentry *parent;
|
|
struct nfs_fh fh;
|
|
struct nfs_fattr fattr;
|
|
int err;
|
|
|
|
BUG_ON(IS_ROOT(dentry));
|
|
dprintk("%s: enter\n", __FUNCTION__);
|
|
dput(nd->dentry);
|
|
nd->dentry = dget(dentry);
|
|
if (d_mountpoint(nd->dentry))
|
|
goto out_follow;
|
|
/* Look it up again */
|
|
parent = dget_parent(nd->dentry);
|
|
err = server->rpc_ops->lookup(parent->d_inode, &nd->dentry->d_name, &fh, &fattr);
|
|
dput(parent);
|
|
if (err != 0)
|
|
goto out_err;
|
|
|
|
if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL)
|
|
mnt = nfs_do_refmount(nd->mnt, nd->dentry);
|
|
else
|
|
mnt = nfs_do_submount(nd->mnt, nd->dentry, &fh, &fattr);
|
|
err = PTR_ERR(mnt);
|
|
if (IS_ERR(mnt))
|
|
goto out_err;
|
|
|
|
mntget(mnt);
|
|
err = do_add_mount(mnt, nd, nd->mnt->mnt_flags|MNT_SHRINKABLE, &nfs_automount_list);
|
|
if (err < 0) {
|
|
mntput(mnt);
|
|
if (err == -EBUSY)
|
|
goto out_follow;
|
|
goto out_err;
|
|
}
|
|
mntput(nd->mnt);
|
|
dput(nd->dentry);
|
|
nd->mnt = mnt;
|
|
nd->dentry = dget(mnt->mnt_root);
|
|
schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
|
|
out:
|
|
dprintk("%s: done, returned %d\n", __FUNCTION__, err);
|
|
return ERR_PTR(err);
|
|
out_err:
|
|
path_release(nd);
|
|
goto out;
|
|
out_follow:
|
|
while(d_mountpoint(nd->dentry) && follow_down(&nd->mnt, &nd->dentry))
|
|
;
|
|
err = 0;
|
|
goto out;
|
|
}
|
|
|
|
struct inode_operations nfs_mountpoint_inode_operations = {
|
|
.follow_link = nfs_follow_mountpoint,
|
|
.getattr = nfs_getattr,
|
|
};
|
|
|
|
struct inode_operations nfs_referral_inode_operations = {
|
|
.follow_link = nfs_follow_mountpoint,
|
|
};
|
|
|
|
static void nfs_expire_automounts(void *data)
|
|
{
|
|
struct list_head *list = (struct list_head *)data;
|
|
|
|
mark_mounts_for_expiry(list);
|
|
if (!list_empty(list))
|
|
schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
|
|
}
|
|
|
|
void nfs_release_automount_timer(void)
|
|
{
|
|
if (list_empty(&nfs_automount_list)) {
|
|
cancel_delayed_work(&nfs_automount_task);
|
|
flush_scheduled_work();
|
|
}
|
|
}
|