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OpenCloudOS-Kernel/fs/cifs/dir.c

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/*
* fs/cifs/dir.c
*
* vfs operations that deal with dentries
*
* 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/slab.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"
void
renew_parental_timestamps(struct dentry *direntry)
{
/* BB check if there is a way to get the kernel to do this or if we really need this */
do {
direntry->d_time = jiffies;
direntry = direntry->d_parent;
} while (!IS_ROOT(direntry));
}
/* Note: caller must free return buffer */
char *
build_path_from_dentry(struct dentry *direntry)
{
struct dentry *temp;
int namelen = 0;
char *full_path;
char dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
if(direntry == NULL)
return NULL; /* not much we can do if dentry is freed and
we need to reopen the file after it was closed implicitly
when the server crashed */
cifs_bp_rename_retry:
for (temp = direntry; !IS_ROOT(temp);) {
namelen += (1 + temp->d_name.len);
temp = temp->d_parent;
if(temp == NULL) {
cERROR(1,("corrupt dentry"));
return NULL;
}
}
full_path = kmalloc(namelen+1, GFP_KERNEL);
if(full_path == NULL)
return full_path;
full_path[namelen] = 0; /* trailing null */
for (temp = direntry; !IS_ROOT(temp);) {
namelen -= 1 + temp->d_name.len;
if (namelen < 0) {
break;
} else {
full_path[namelen] = dirsep;
strncpy(full_path + namelen + 1, temp->d_name.name,
temp->d_name.len);
cFYI(0, (" name: %s ", full_path + namelen));
}
temp = temp->d_parent;
if(temp == NULL) {
cERROR(1,("corrupt dentry"));
kfree(full_path);
return NULL;
}
}
if (namelen != 0) {
cERROR(1,
("We did not end path lookup where we expected namelen is %d",
namelen));
/* presumably this is only possible if we were racing with a rename
of one of the parent directories (we can not lock the dentries
above us to prevent this, but retrying should be harmless) */
kfree(full_path);
namelen = 0;
goto cifs_bp_rename_retry;
}
return full_path;
}
/* char * build_wildcard_path_from_dentry(struct dentry *direntry)
{
if(full_path == NULL)
return full_path;
full_path[namelen] = '\\';
full_path[namelen+1] = '*';
full_path[namelen+2] = 0;
BB remove above eight lines BB */
/* Inode operations in similar order to how they appear in the Linux file fs.h */
int
cifs_create(struct inode *inode, struct dentry *direntry, int mode,
struct nameidata *nd)
{
int rc = -ENOENT;
int xid;
int oplock = 0;
int desiredAccess = GENERIC_READ | GENERIC_WRITE;
__u16 fileHandle;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
FILE_ALL_INFO * buf = NULL;
struct inode *newinode = NULL;
struct cifsFileInfo * pCifsFile = NULL;
struct cifsInodeInfo * pCifsInode;
int disposition = FILE_OVERWRITE_IF;
int write_only = FALSE;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
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 == NULL) {
FreeXid(xid);
return -ENOMEM;
}
if(nd) {
if ((nd->intent.open.flags & O_ACCMODE) == O_RDONLY)
desiredAccess = GENERIC_READ;
else if ((nd->intent.open.flags & O_ACCMODE) == O_WRONLY) {
desiredAccess = GENERIC_WRITE;
write_only = TRUE;
} else if ((nd->intent.open.flags & O_ACCMODE) == O_RDWR) {
/* GENERIC_ALL is too much permission to request */
/* can cause unnecessary access denied on create */
/* desiredAccess = GENERIC_ALL; */
desiredAccess = GENERIC_READ | GENERIC_WRITE;
}
if((nd->intent.open.flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
disposition = FILE_CREATE;
else if((nd->intent.open.flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
disposition = FILE_OVERWRITE_IF;
else if((nd->intent.open.flags & O_CREAT) == O_CREAT)
disposition = FILE_OPEN_IF;
else {
cFYI(1,("Create flag not set in create function"));
}
}
/* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
if (oplockEnabled)
oplock = REQ_OPLOCK;
buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
if(buf == NULL) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
desiredAccess, CREATE_NOT_DIR,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if(rc == -EIO) {
/* old server, retry the open legacy style */
rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
desiredAccess, CREATE_NOT_DIR,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
}
if (rc) {
cFYI(1, ("cifs_create returned 0x%x ", rc));
} else {
/* If Open reported that we actually created a file
then we now have to set the mode if possible */
if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
(oplock & CIFS_CREATE_ACTION))
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
(__u64)current->euid,
(__u64)current->egid,
0 /* dev */,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
} else {
CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
(__u64)-1,
(__u64)-1,
0 /* dev */,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
}
else {
/* BB implement mode setting via Windows security descriptors */
/* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
/* could set r/o dos attribute if mode & 0222 == 0 */
}
/* BB server might mask mode so we have to query for Unix case*/
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,
buf, inode->i_sb,xid);
if(newinode)
newinode->i_mode = mode;
}
if (rc != 0) {
cFYI(1,
("Create worked but get_inode_info failed 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);
}
if((nd->flags & LOOKUP_OPEN) == FALSE) {
/* mknod case - do not leave file open */
CIFSSMBClose(xid, pTcon, fileHandle);
} else if(newinode) {
pCifsFile =
kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
if(pCifsFile == NULL)
goto cifs_create_out;
memset((char *)pCifsFile, 0,
sizeof (struct cifsFileInfo));
pCifsFile->netfid = fileHandle;
pCifsFile->pid = current->tgid;
pCifsFile->pInode = newinode;
pCifsFile->invalidHandle = FALSE;
pCifsFile->closePend = FALSE;
init_MUTEX(&pCifsFile->fh_sem);
/* set the following in open now
pCifsFile->pfile = file; */
write_lock(&GlobalSMBSeslock);
list_add(&pCifsFile->tlist,&pTcon->openFileList);
pCifsInode = CIFS_I(newinode);
if(pCifsInode) {
/* if readable file instance put first in list*/
if (write_only == TRUE) {
list_add_tail(&pCifsFile->flist,
&pCifsInode->openFileList);
} else {
list_add(&pCifsFile->flist,
&pCifsInode->openFileList);
}
if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
pCifsInode->clientCanCacheAll = TRUE;
pCifsInode->clientCanCacheRead = TRUE;
cFYI(1,("Exclusive Oplock for inode %p",
newinode));
} else if((oplock & 0xF) == OPLOCK_READ)
pCifsInode->clientCanCacheRead = TRUE;
}
write_unlock(&GlobalSMBSeslock);
}
}
cifs_create_out:
kfree(buf);
kfree(full_path);
FreeXid(xid);
return rc;
}
int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number)
{
int rc = -EPERM;
int xid;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
struct inode * newinode = NULL;
if (!old_valid_dev(device_number))
return -EINVAL;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
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 == NULL)
rc = -ENOMEM;
else if (pTcon->ses->capabilities & CAP_UNIX) {
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
mode,(__u64)current->euid,(__u64)current->egid,
device_number, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
} else {
rc = CIFSSMBUnixSetPerms(xid, pTcon,
full_path, mode, (__u64)-1, (__u64)-1,
device_number, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
}
if(!rc) {
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb,xid);
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
if(rc == 0)
d_instantiate(direntry, newinode);
}
} else {
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
int oplock = 0;
u16 fileHandle;
FILE_ALL_INFO * buf;
cFYI(1,("sfu compat create special file"));
buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
if(buf == NULL) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
rc = CIFSSMBOpen(xid, pTcon, full_path,
FILE_CREATE, /* fail if exists */
GENERIC_WRITE /* BB would
WRITE_OWNER | WRITE_DAC be better? */,
/* Create a file and set the
file attribute to SYSTEM */
CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
&fileHandle, &oplock, buf,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if(!rc) {
/* BB Do not bother to decode buf since no
local inode yet to put timestamps in */
CIFSSMBClose(xid, pTcon, fileHandle);
d_drop(direntry);
}
kfree(buf);
/* add code here to set EAs */
}
}
kfree(full_path);
FreeXid(xid);
return rc;
}
struct dentry *
cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
{
int xid;
int rc = 0; /* to get around spurious gcc warning, set to zero here */
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
struct inode *newInode = NULL;
char *full_path = NULL;
xid = GetXid();
cFYI(1,
(" parent inode = 0x%p name is: %s and dentry = 0x%p",
parent_dir_inode, direntry->d_name.name, direntry));
/* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
/* check whether path exists */
cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
pTcon = cifs_sb->tcon;
/* can not grab the rename sem here since it would
deadlock in the cases (beginning of sys_rename itself)
in which we already have the sb rename sem */
full_path = build_path_from_dentry(direntry);
if(full_path == NULL) {
FreeXid(xid);
return ERR_PTR(-ENOMEM);
}
if (direntry->d_inode != NULL) {
cFYI(1, (" non-NULL inode in lookup"));
} else {
cFYI(1, (" NULL inode in lookup"));
}
cFYI(1,
(" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
if (pTcon->ses->capabilities & CAP_UNIX)
rc = cifs_get_inode_info_unix(&newInode, full_path,
parent_dir_inode->i_sb,xid);
else
rc = cifs_get_inode_info(&newInode, full_path, NULL,
parent_dir_inode->i_sb,xid);
if ((rc == 0) && (newInode != NULL)) {
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_add(direntry, newInode);
/* since paths are not looked up by component - the parent directories are presumed to be good here */
renew_parental_timestamps(direntry);
} else if (rc == -ENOENT) {
rc = 0;
d_add(direntry, NULL);
} else {
cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
rc,full_path));
/* BB special case check for Access Denied - watch security
exposure of returning dir info implicitly via different rc
if file exists or not but no access BB */
}
kfree(full_path);
FreeXid(xid);
return ERR_PTR(rc);
}
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
int isValid = 1;
/* lock_kernel(); *//* surely we do not want to lock the kernel for a whole network round trip which could take seconds */
if (direntry->d_inode) {
if (cifs_revalidate(direntry)) {
/* unlock_kernel(); */
return 0;
}
} else {
cFYI(1,
("In cifs_d_revalidate with no inode but name = %s and dentry 0x%p",
direntry->d_name.name, direntry));
}
/* unlock_kernel(); */
return isValid;
}
/* static int cifs_d_delete(struct dentry *direntry)
{
int rc = 0;
cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
return rc;
} */
struct dentry_operations cifs_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
/* d_delete: cifs_d_delete, *//* not needed except for debugging */
/* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
};
static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
{
struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
unsigned long hash;
int i;
hash = init_name_hash();
for (i = 0; i < q->len; i++)
hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
hash);
q->hash = end_name_hash(hash);
return 0;
}
static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
struct qstr *b)
{
struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
if ((a->len == b->len) &&
(nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
/*
* To preserve case, don't let an existing negative dentry's
* case take precedence. If a is not a negative dentry, this
* should have no side effects
*/
memcpy((unsigned char *)a->name, b->name, a->len);
return 0;
}
return 1;
}
struct dentry_operations cifs_ci_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
.d_hash = cifs_ci_hash,
.d_compare = cifs_ci_compare,
};
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