link.c
/*
* 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
#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 = -ENOMEM;
int xid;
char *full_path = NULL;
char *target_path = NULL;
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifsTconInfo *tcon = cifs_sb->tcon;
xid = GetXid();
/*
* For now, we just handle symlinks with unix extensions enabled.
* Eventually we should handle NTFS reparse points, and MacOS
* symlink support. For instance…
*
* rc = CIFSSMBQueryReparseLinkInfo(…)
*
* For now, just return -EACCES when the server doesn’t support posix
* extensions. Note that we still allow querying symlinks when posix
* extensions are manually disabled. We could disable these as well
* but there doesn’t seem to be any harm in allowing the client to
* read them.
*/
if (!(tcon->ses->capabilities & CAP_UNIX)) {
rc = -EACCES;
goto out;
}
full_path = build_path_from_dentry(direntry);
if (!full_path)
goto out;
cFYI(1, (»Full path: %s inode = 0x%p», full_path, inode));
rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, &target_path,
cifs_sb->local_nls);
kfree(full_path);
out:
if (rc != 0) {
kfree(target_path);
target_path = ERR_PTR(rc);
}
FreeXid(xid);
nd_set_link(nd, target_path);
return NULL;
}
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) {
rc = -ENOMEM;
FreeXid(xid);
return rc;
}
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;
}
void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
{
char *p = nd_get_link(nd);
if (!IS_ERR(p))
kfree(p);
}