linux/fs/cifs/link.c

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/*
* fs/cifs/link.c
*
* Copyright (C) International Business Machines Corp., 2002,2003
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/namei.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
int
cifs_hardlink(struct dentry *old_file, struct inode *inode,
struct dentry *direntry)
{
int rc = -EACCES;
int xid;
char *fromName = NULL;
char *toName = NULL;
struct cifs_sb_info *cifs_sb_target;
struct cifsTconInfo *pTcon;
struct cifsInodeInfo *cifsInode;
xid = GetXid();
cifs_sb_target = CIFS_SB(inode->i_sb);
pTcon = cifs_sb_target->tcon;
/* No need to check for cross device links since server will do that
BB note DFS case in future though (when we may have to check) */
down(&inode->i_sb->s_vfs_rename_sem);
fromName = build_path_from_dentry(old_file);
toName = build_path_from_dentry(direntry);
up(&inode->i_sb->s_vfs_rename_sem);
if((fromName == NULL) || (toName == NULL)) {
rc = -ENOMEM;
goto cifs_hl_exit;
}
if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
cifs_sb_target->local_nls,
cifs_sb_target->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
else {
rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
cifs_sb_target->local_nls,
cifs_sb_target->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if(rc == -EIO)
rc = -EOPNOTSUPP;
}
/* if (!rc) */
{
/* renew_parental_timestamps(old_file);
inode->i_nlink++;
mark_inode_dirty(inode);
d_instantiate(direntry, inode); */
/* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
}
d_drop(direntry); /* force new lookup from server */
cifsInode = CIFS_I(old_file->d_inode);
cifsInode->time = 0; /* will force revalidate to go get info when needed */
cifs_hl_exit:
kfree(fromName);
kfree(toName);
FreeXid(xid);
return rc;
}
void *
cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
{
struct inode *inode = direntry->d_inode;
int rc = -EACCES;
int xid;
char *full_path = NULL;
char * target_path = ERR_PTR(-ENOMEM);
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
xid = GetXid();
down(&direntry->d_sb->s_vfs_rename_sem);
full_path = build_path_from_dentry(direntry);
up(&direntry->d_sb->s_vfs_rename_sem);
if (!full_path)
goto out_no_free;
cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
target_path = kmalloc(PATH_MAX, GFP_KERNEL);
if (!target_path) {
target_path = ERR_PTR(-ENOMEM);
goto out;
}
/* BB add read reparse point symlink code and Unix extensions symlink code here BB */
if (pTcon->ses->capabilities & CAP_UNIX)
rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
target_path,
PATH_MAX-1,
cifs_sb->local_nls);
else {
/* rc = CIFSSMBQueryReparseLinkInfo */
/* BB Add code to Query ReparsePoint info */
/* BB Add MAC style xsymlink check here if enabled */
}
if (rc == 0) {
/* BB Add special case check for Samba DFS symlinks */
target_path[PATH_MAX-1] = 0;
} else {
kfree(target_path);
target_path = ERR_PTR(rc);
}
out:
kfree(full_path);
out_no_free:
FreeXid(xid);
nd_set_link(nd, target_path);
return NULL; /* No cookie */
}
int
cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
{
int rc = -EOPNOTSUPP;
int xid;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
struct inode *newinode = NULL;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
down(&inode->i_sb->s_vfs_rename_sem);
full_path = build_path_from_dentry(direntry);
up(&inode->i_sb->s_vfs_rename_sem);
if(full_path == NULL) {
FreeXid(xid);
return -ENOMEM;
}
cFYI(1, ("Full path: %s ", full_path));
cFYI(1, ("symname is %s", symname));
/* BB what if DFS and this volume is on different share? BB */
if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
cifs_sb->local_nls);
/* else
rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */
if (rc == 0) {
if (pTcon->ses->capabilities & CAP_UNIX)
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb,xid);
else
rc = cifs_get_inode_info(&newinode, full_path, NULL,
inode->i_sb,xid);
if (rc != 0) {
cFYI(1,
("Create symlink worked but get_inode_info failed with rc = %d ",
rc));
} else {
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_instantiate(direntry, newinode);
}
}
kfree(full_path);
FreeXid(xid);
return rc;
}
int
cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
{
struct inode *inode = direntry->d_inode;
int rc = -EACCES;
int xid;
int oplock = FALSE;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
char *tmp_path = NULL;
char * tmpbuffer;
unsigned char * referrals = NULL;
int num_referrals = 0;
int len;
__u16 fid;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
/* BB would it be safe against deadlock to grab this sem
even though rename itself grabs the sem and calls lookup? */
/* down(&inode->i_sb->s_vfs_rename_sem);*/
full_path = build_path_from_dentry(direntry);
/* up(&inode->i_sb->s_vfs_rename_sem);*/
if(full_path == NULL) {
FreeXid(xid);
return -ENOMEM;
}
cFYI(1,
("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
full_path, inode, pBuffer, buflen));
if(buflen > PATH_MAX)
len = PATH_MAX;
else
len = buflen;
tmpbuffer = kmalloc(len,GFP_KERNEL);
if(tmpbuffer == NULL) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
/* BB add read reparse point symlink code and Unix extensions symlink code here BB */
if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
tmpbuffer,
len - 1,
cifs_sb->local_nls);
else {
rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
OPEN_REPARSE_POINT,&fid, &oplock, NULL,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if(!rc) {
rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
tmpbuffer,
len - 1,
fid,
cifs_sb->local_nls);
if(CIFSSMBClose(xid, pTcon, fid)) {
cFYI(1,("Error closing junction point (open for ioctl)"));
}
if(rc == -EIO) {
/* Query if DFS Junction */
tmp_path =
kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
GFP_KERNEL);
if (tmp_path) {
strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
strncat(tmp_path, full_path, MAX_PATHCONF);
rc = get_dfs_path(xid, pTcon->ses, tmp_path,
cifs_sb->local_nls,
&num_referrals, &referrals,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
if((num_referrals == 0) && (rc == 0))
rc = -EACCES;
else {
cFYI(1,("num referral: %d",num_referrals));
if(referrals) {
cFYI(1,("referral string: %s ",referrals));
strncpy(tmpbuffer, referrals, len-1);
}
}
kfree(referrals);
kfree(tmp_path);
}
/* BB add code like else decode referrals then memcpy to
tmpbuffer and free referrals string array BB */
}
}
}
/* BB Anything else to do to handle recursive links? */
/* BB Should we be using page ops here? */
/* BB null terminate returned string in pBuffer? BB */
if (rc == 0) {
rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
cFYI(1,
("vfs_readlink called from cifs_readlink returned %d",
rc));
}
kfree(tmpbuffer);
kfree(full_path);
FreeXid(xid);
return rc;
}
void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
{
char *p = nd_get_link(nd);
if (!IS_ERR(p))
kfree(p);
}