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huanghua authoredi=yong.fan i=rahul.deshmukh i=nikita.danilov - use req_capsule interface for client. - add some interoperability support on server side.
huanghua authoredi=yong.fan i=rahul.deshmukh i=nikita.danilov - use req_capsule interface for client. - add some interoperability support on server side.
symlink.c 6.70 KiB
/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
* Copyright (c) 2002 Cluster File Systems, Inc.
*
* This file is part of Lustre, http://www.lustre.org.
*
* Lustre is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* Lustre is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Lustre; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/smp_lock.h>
#include <linux/version.h>
#define DEBUG_SUBSYSTEM S_LLITE
#include <lustre_lite.h>
#include "llite_internal.h"
static int ll_readlink_internal(struct inode *inode,
struct ptlrpc_request **request, char **symname)
{
struct ll_inode_info *lli = ll_i2info(inode);
struct ll_sb_info *sbi = ll_i2sbi(inode);
int rc, symlen = i_size_read(inode) + 1;
struct mdt_body *body;
struct obd_capa *oc;
ENTRY;
*request = NULL;
if (lli->lli_symlink_name) {
*symname = lli->lli_symlink_name;
CDEBUG(D_INODE, "using cached symlink %s\n", *symname);
RETURN(0);
}
oc = ll_mdscapa_get(inode);
rc = md_getattr(sbi->ll_md_exp, ll_inode2fid(inode), oc,
OBD_MD_LINKNAME, symlen, request);
capa_put(oc);
if (rc) {
if (rc != -ENOENT)
CERROR("inode %lu: rc = %d\n", inode->i_ino, rc);
GOTO (failed, rc);
}
body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
LASSERT(body != NULL);
if ((body->valid & OBD_MD_LINKNAME) == 0) {
CERROR("OBD_MD_LINKNAME not set on reply\n");
GOTO(failed, rc = -EPROTO);
}
LASSERT(symlen != 0);
if (body->eadatasize != symlen) {
CERROR("inode %lu: symlink length %d not expected %d\n",
inode->i_ino, body->eadatasize - 1, symlen - 1); GOTO(failed, rc = -EPROTO);
}
*symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
if (*symname == NULL ||
strnlen(*symname, symlen) != symlen - 1) {
/* not full/NULL terminated */
CERROR("inode %lu: symlink not NULL terminated string"
"of length %d\n", inode->i_ino, symlen - 1);
GOTO(failed, rc = -EPROTO);
}
OBD_ALLOC(lli->lli_symlink_name, symlen);
/* do not return an error if we cannot cache the symlink locally */
if (lli->lli_symlink_name) {
memcpy(lli->lli_symlink_name, *symname, symlen);
ptlrpc_req_finished (*request);
*request = NULL;
*symname = lli->lli_symlink_name;
}
RETURN(0);
failed:
ptlrpc_req_finished (*request);
RETURN (rc);
}
static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
{
struct inode *inode = dentry->d_inode;
struct ll_inode_info *lli = ll_i2info(inode);
struct ptlrpc_request *request;
char *symname;
int rc;
ENTRY;
CDEBUG(D_VFSTRACE, "VFS Op\n");
/* on symlinks lli_open_sem protects lli_symlink_name allocation/data */
down(&lli->lli_size_sem);
rc = ll_readlink_internal(inode, &request, &symname);
if (rc)
GOTO(out, rc);
rc = vfs_readlink(dentry, buffer, buflen, symname);
ptlrpc_req_finished(request);
out:
up(&lli->lli_size_sem);
RETURN(rc);
}
#ifdef HAVE_COOKIE_FOLLOW_LINK
# define LL_FOLLOW_LINK_RETURN_TYPE void *
#else
# define LL_FOLLOW_LINK_RETURN_TYPE int
#endif
static LL_FOLLOW_LINK_RETURN_TYPE ll_follow_link(struct dentry *dentry,
struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
struct ll_inode_info *lli = ll_i2info(inode);
#ifdef HAVE_VFS_INTENT_PATCHES
struct lookup_intent *it = ll_nd2it(nd);
#endif
struct ptlrpc_request *request;
int rc;
char *symname;
ENTRY;
#ifdef HAVE_VFS_INTENT_PATCHES
if (it != NULL) {
int op = it->it_op;
int mode = it->it_create_mode;
ll_intent_release(it);
it->it_op = op;
it->it_create_mode = mode;
}
#endif
CDEBUG(D_VFSTRACE, "VFS Op\n");
down(&lli->lli_size_sem);
rc = ll_readlink_internal(inode, &request, &symname);
up(&lli->lli_size_sem);
if (rc) {
path_release(nd); /* Kernel assumes that ->follow_link()
releases nameidata on error */
GOTO(out, rc);
}
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8))
rc = vfs_follow_link(nd, symname);
#else
#ifdef HAVE_COOKIE_FOLLOW_LINK
nd_set_link(nd, symname);
/* @symname may contain a pointer to the request message buffer,
we delay request releasing until ll_put_link then. */
RETURN(request);
#else
if (request != NULL) {
/* falling back to recursive follow link if the request
* needs to be cleaned up still. */
rc = vfs_follow_link(nd, symname);
GOTO(out, rc);
}
nd_set_link(nd, symname);
RETURN(0);
#endif
#endif
out:
ptlrpc_req_finished(request);
#ifdef HAVE_COOKIE_FOLLOW_LINK
RETURN(ERR_PTR(rc));
#else
RETURN(rc);
#endif
}
#ifdef HAVE_COOKIE_FOLLOW_LINK
static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
{
ptlrpc_req_finished(cookie);
}
#endif
struct inode_operations ll_fast_symlink_inode_operations = {
.readlink = ll_readlink,
.setattr = ll_setattr,
#ifdef HAVE_VFS_INTENT_PATCHES
.setattr_raw = ll_setattr_raw,
#endif
.follow_link = ll_follow_link,
#ifdef HAVE_COOKIE_FOLLOW_LINK
.put_link = ll_put_link,
#endif
.getattr = ll_getattr,
.permission = ll_inode_permission,
.setxattr = ll_setxattr,
.getxattr = ll_getxattr, .listxattr = ll_listxattr,
.removexattr = ll_removexattr,
};