zfs-builds-mm/zfs-0.8.4/module/zfs/zpl_export.c

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2020-07-19 16:21:53 +02:00
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2011 Gunnar Beutner
* Copyright (c) 2012 Cyril Plisko. All rights reserved.
*/
#include <sys/zfs_vnops.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_ctldir.h>
#include <sys/zpl.h>
static int
#ifdef HAVE_ENCODE_FH_WITH_INODE
zpl_encode_fh(struct inode *ip, __u32 *fh, int *max_len, struct inode *parent)
{
#else
zpl_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len, int connectable)
{
/* CSTYLED */
struct inode *ip = dentry->d_inode;
#endif /* HAVE_ENCODE_FH_WITH_INODE */
fstrans_cookie_t cookie;
fid_t *fid = (fid_t *)fh;
int len_bytes, rc;
len_bytes = *max_len * sizeof (__u32);
if (len_bytes < offsetof(fid_t, fid_data))
return (255);
fid->fid_len = len_bytes - offsetof(fid_t, fid_data);
cookie = spl_fstrans_mark();
if (zfsctl_is_node(ip))
rc = zfsctl_fid(ip, fid);
else
rc = zfs_fid(ip, fid);
spl_fstrans_unmark(cookie);
len_bytes = offsetof(fid_t, fid_data) + fid->fid_len;
*max_len = roundup(len_bytes, sizeof (__u32)) / sizeof (__u32);
return (rc == 0 ? FILEID_INO32_GEN : 255);
}
static struct dentry *
zpl_dentry_obtain_alias(struct inode *ip)
{
struct dentry *result;
#ifdef HAVE_D_OBTAIN_ALIAS
result = d_obtain_alias(ip);
#else
result = d_alloc_anon(ip);
if (result == NULL) {
iput(ip);
result = ERR_PTR(-ENOMEM);
}
#endif /* HAVE_D_OBTAIN_ALIAS */
return (result);
}
static struct dentry *
zpl_fh_to_dentry(struct super_block *sb, struct fid *fh,
int fh_len, int fh_type)
{
fid_t *fid = (fid_t *)fh;
fstrans_cookie_t cookie;
struct inode *ip;
int len_bytes, rc;
len_bytes = fh_len * sizeof (__u32);
if (fh_type != FILEID_INO32_GEN ||
len_bytes < offsetof(fid_t, fid_data) ||
len_bytes < offsetof(fid_t, fid_data) + fid->fid_len)
return (ERR_PTR(-EINVAL));
cookie = spl_fstrans_mark();
rc = zfs_vget(sb, &ip, fid);
spl_fstrans_unmark(cookie);
if (rc) {
/*
* If we see ENOENT it might mean that an NFSv4 * client
* is using a cached inode value in a file handle and
* that the sought after file has had its inode changed
* by a third party. So change the error to ESTALE
* which will trigger a full lookup by the client and
* will find the new filename/inode pair if it still
* exists.
*/
if (rc == ENOENT)
rc = ESTALE;
return (ERR_PTR(-rc));
}
ASSERT((ip != NULL) && !IS_ERR(ip));
return (zpl_dentry_obtain_alias(ip));
}
static struct dentry *
zpl_get_parent(struct dentry *child)
{
cred_t *cr = CRED();
fstrans_cookie_t cookie;
struct inode *ip;
int error;
crhold(cr);
cookie = spl_fstrans_mark();
error = -zfs_lookup(child->d_inode, "..", &ip, 0, cr, NULL, NULL);
spl_fstrans_unmark(cookie);
crfree(cr);
ASSERT3S(error, <=, 0);
if (error)
return (ERR_PTR(error));
return (zpl_dentry_obtain_alias(ip));
}
#ifdef HAVE_COMMIT_METADATA
static int
zpl_commit_metadata(struct inode *inode)
{
cred_t *cr = CRED();
fstrans_cookie_t cookie;
int error;
if (zfsctl_is_node(inode))
return (0);
crhold(cr);
cookie = spl_fstrans_mark();
error = -zfs_fsync(inode, 0, cr);
spl_fstrans_unmark(cookie);
crfree(cr);
ASSERT3S(error, <=, 0);
return (error);
}
#endif /* HAVE_COMMIT_METADATA */
const struct export_operations zpl_export_operations = {
.encode_fh = zpl_encode_fh,
.fh_to_dentry = zpl_fh_to_dentry,
.get_parent = zpl_get_parent,
#ifdef HAVE_COMMIT_METADATA
.commit_metadata = zpl_commit_metadata,
#endif /* HAVE_COMMIT_METADATA */
};