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DEFINITIONS
This source file includes following definitions.
- cifs_hardlink
- cifs_follow_link
- cifs_symlink
- cifs_readlink
- cifs_put_link
/*
* fs/cifs/link.c
*
* Copyright (C) International Business Machines Corp., 2002,2008
* 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) */
fromName = build_path_from_dentry(old_file);
toName = build_path_from_dentry(direntry);
if ((fromName == NULL) || (toName == NULL)) {
rc = -ENOMEM;
goto cifs_hl_exit;
}
/* if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)*/
if (pTcon->unix_ext)
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 == -EINVAL))
rc = -EOPNOTSUPP;
}
d_drop(direntry); /* force new lookup from server of target */
/* if source file is cached (oplocked) revalidate will not go to server
until the file is closed or oplock broken so update nlinks locally */
if (old_file->d_inode) {
cifsInode = CIFS_I(old_file->d_inode);
if (rc == 0) {
old_file->d_inode->i_nlink++;
/* BB should we make this contingent on superblock flag NOATIME? */
/* old_file->d_inode->i_ctime = CURRENT_TIME;*/
/* parent dir timestamps will update from srv
within a second, would it really be worth it
to set the parent dir cifs inode time to zero
to force revalidate (faster) for it too? */
}
/* if not oplocked will force revalidate to get info
on source file from srv */
cifsInode->time = 0;
/* Will update parent dir timestamps from srv within a second.
Would it really be worth it to set the parent dir (cifs
inode) time field to zero to force revalidate on parent
directory faster ie
CIFS_I(inode)->time = 0; */
}
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();
full_path = build_path_from_dentry(direntry);
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;
}
/* We could change this to:
if (pTcon->unix_ext)
but there does not seem any point in refusing to
get symlink info if we can, even if unix extensions
turned off for this mount */
if (pTcon->ses->capabilities & CAP_UNIX)
rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
target_path,
PATH_MAX-1,
cifs_sb->local_nls);
else {
/* BB add read reparse point symlink code here */
/* 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;
full_path = build_path_from_dentry(direntry);
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 (pTcon->unix_ext)
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->unix_ext)
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, NULL);
if (rc != 0) {
cFYI(1, ("Create symlink ok, getinodeinfo fail 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 = 0;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
char *tmpbuffer;
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? */
/* mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
full_path = build_path_from_dentry(direntry);
/* mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/
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 */
/* We could disable this based on pTcon->unix_ext flag instead ... but why? */
if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
tmpbuffer,
len - 1,
cifs_sb->local_nls);
else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
cERROR(1, ("SFU style symlinks not implemented yet"));
/* add open and read as in fs/cifs/inode.c */
} 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 it is a DFS junction earlier we would have gotten
PATH_NOT_COVERED returned from server so we do
not need to request the DFS info here */
}
}
/* 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);
}