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NFS: Use d_automount() rather than abusing follow_link() 

Make NFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
David Howells 2011-01-14 18:45:42 +00:00 committed by Al Viro
parent d18610b0ce
commit 36d43a4376
5 changed files with 46 additions and 48 deletions
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4
fs/nfs/dir.c
View File

@ -970,7 +970,7 @@ int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
{
struct nfs_server *server = NFS_SERVER(inode);
if (test_bit(NFS_INO_MOUNTPOINT, &NFS_I(inode)->flags))
if (IS_AUTOMOUNT(inode))
return 0;
if (nd != NULL) {
/* VFS wants an on-the-wire revalidation */
@ -1173,6 +1173,7 @@ const struct dentry_operations nfs_dentry_operations = {
.d_revalidate = nfs_lookup_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
};
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
@ -1246,6 +1247,7 @@ const struct dentry_operations nfs4_dentry_operations = {
.d_revalidate = nfs_open_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
.d_automount = nfs_d_automount,
};
/*

4
fs/nfs/inode.c
View File

@ -300,7 +300,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
else
inode->i_op = &nfs_mountpoint_inode_operations;
inode->i_fop = NULL;
set_bit(NFS_INO_MOUNTPOINT, &nfsi->flags);
inode->i_flags |= S_AUTOMOUNT;
}
} else if (S_ISLNK(inode->i_mode))
inode->i_op = &nfs_symlink_inode_operations;
@ -1208,7 +1208,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
/* Update the fsid? */
if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
!test_bit(NFS_INO_MOUNTPOINT, &nfsi->flags))
!IS_AUTOMOUNT(inode))
server->fsid = fattr->fsid;
/*

1
fs/nfs/internal.h
View File

@ -252,6 +252,7 @@ extern char *nfs_path(const char *base,
const struct dentry *droot,
const struct dentry *dentry,
char *buffer, ssize_t buflen);
extern struct vfsmount *nfs_d_automount(struct path *path);
/* getroot.c */
extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);

84
fs/nfs/namespace.c
View File

@ -97,9 +97,8 @@ Elong:
}
/*
* nfs_follow_mountpoint - handle crossing a mountpoint on the server
* @dentry - dentry of mountpoint
* @nd - nameidata info
* nfs_d_automount - Handle crossing a mountpoint on the server
* @path - The mountpoint
*
* When we encounter a mountpoint on the server, we want to set up
* a mountpoint on the client too, to prevent inode numbers from
@ -109,84 +108,81 @@ Elong:
* 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 *nfs_d_automount(struct path *path)
{
struct vfsmount *mnt;
struct nfs_server *server = NFS_SERVER(dentry->d_inode);
struct nfs_server *server = NFS_SERVER(path->dentry->d_inode);
struct dentry *parent;
struct nfs_fh *fh = NULL;
struct nfs_fattr *fattr = NULL;
int err;
dprintk("--> nfs_follow_mountpoint()\n");
dprintk("--> nfs_d_automount()\n");
err = -ESTALE;
if (IS_ROOT(dentry))
goto out_err;
mnt = ERR_PTR(-ESTALE);
if (IS_ROOT(path->dentry))
goto out_nofree;
err = -ENOMEM;
mnt = ERR_PTR(-ENOMEM);
fh = nfs_alloc_fhandle();
fattr = nfs_alloc_fattr();
if (fh == NULL || fattr == NULL)
goto out_err;
goto out;
dprintk("%s: enter\n", __func__);
dput(nd->path.dentry);
nd->path.dentry = dget(dentry);
/* Look it up again */
parent = dget_parent(nd->path.dentry);
/* Look it up again to get its attributes */
parent = dget_parent(path->dentry);
err = server->nfs_client->rpc_ops->lookup(parent->d_inode,
&nd->path.dentry->d_name,
&path->dentry->d_name,
fh, fattr);
dput(parent);
if (err != 0)
goto out_err;
if (err != 0) {
mnt = ERR_PTR(err);
goto out;
}
if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
mnt = nfs_do_refmount(nd->path.mnt, nd->path.dentry);
mnt = nfs_do_refmount(path->mnt, path->dentry);
else
mnt = nfs_do_submount(nd->path.mnt, nd->path.dentry, fh,
fattr);
err = PTR_ERR(mnt);
mnt = nfs_do_submount(path->mnt, path->dentry, fh, fattr);
if (IS_ERR(mnt))
goto out_err;
goto out;
mntget(mnt);
err = do_add_mount(mnt, &nd->path, nd->path.mnt->mnt_flags|MNT_SHRINKABLE,
err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE,
&nfs_automount_list);
if (err < 0) {
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);
if (err == -EBUSY)
goto out_follow;
goto out_err;
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;
}
path_put(&nd->path);
nd->path.mnt = mnt;
nd->path.dentry = dget(mnt->mnt_root);
schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
out:
nfs_free_fattr(fattr);
nfs_free_fhandle(fh);
dprintk("%s: done, returned %d\n", __func__, err);
dprintk("<-- nfs_follow_mountpoint() = %d\n", err);
return ERR_PTR(err);
out_err:
path_put(&nd->path);
goto out;
out_follow:
err = follow_down(&nd->path, false);
goto out;
out_nofree:
dprintk("<-- nfs_follow_mountpoint() = %p\n", mnt);
return mnt;
}
const struct inode_operations nfs_mountpoint_inode_operations = {
.follow_link = nfs_follow_mountpoint,
.getattr = nfs_getattr,
};
const struct inode_operations nfs_referral_inode_operations = {
.follow_link = nfs_follow_mountpoint,
};
static void nfs_expire_automounts(struct work_struct *work)

1
include/linux/nfs_fs.h
View File

@ -215,7 +215,6 @@ struct nfs_inode {
#define NFS_INO_ADVISE_RDPLUS (0) /* advise readdirplus */
#define NFS_INO_STALE (1) /* possible stale inode */
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
#define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */
#define NFS_INO_FLUSHING (4) /* inode is flushing out data */
#define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
#define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */