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DEFINITIONS
This source file includes following definitions.
- renew_parental_timestamps
- build_path_from_dentry
- cifs_create
- cifs_mknod
- cifs_lookup
- cifs_d_revalidate
- cifs_ci_hash
- cifs_ci_compare
/*
* fs/cifs/dir.c
*
* vfs operations that deal with dentries
*
* 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/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"
static 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;
int pplen;
int dfsplen;
char *full_path;
char dirsep;
struct cifs_sb_info *cifs_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_sb = CIFS_SB(direntry->d_sb);
dirsep = CIFS_DIR_SEP(cifs_sb);
pplen = cifs_sb->prepathlen;
if (cifs_sb->tcon && (cifs_sb->tcon->Flags & SMB_SHARE_IS_IN_DFS))
dfsplen = strnlen(cifs_sb->tcon->treeName, MAX_TREE_SIZE + 1);
else
dfsplen = 0;
cifs_bp_rename_retry:
namelen = pplen + dfsplen;
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 != pplen + dfsplen) {
cERROR(1,
("did not end path lookup where expected namelen is %d",
namelen));
/* presumably this is only possible if 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);
goto cifs_bp_rename_retry;
}
/* DIR_SEP already set for byte 0 / vs \ but not for
subsequent slashes in prepath which currently must
be entered the right way - not sure if there is an alternative
since the '\' is a valid posix character so we can not switch
those safely to '/' if any are found in the middle of the prepath */
/* BB test paths to Windows with '/' in the midst of prepath */
if (dfsplen) {
strncpy(full_path, cifs_sb->tcon->treeName, dfsplen);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
int i;
for (i = 0; i < dfsplen; i++) {
if (full_path[i] == '\\')
full_path[i] = '/';
}
}
}
strncpy(full_path + dfsplen, CIFS_SB(direntry->d_sb)->prepath, pplen);
return full_path;
}
/* Inode operations in similar order to how they appear in Linux file fs.h */
int
cifs_create(struct inode *inode, struct dentry *direntry, int mode,
struct nameidata *nd)
{
int rc = -ENOENT;
int xid;
int create_options = CREATE_NOT_DIR;
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;
bool write_only = false;
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;
}
if (nd && (nd->flags & LOOKUP_OPEN)) {
int oflags = nd->intent.open.flags;
desiredAccess = 0;
if (oflags & FMODE_READ)
desiredAccess |= GENERIC_READ;
if (oflags & FMODE_WRITE) {
desiredAccess |= GENERIC_WRITE;
if (!(oflags & FMODE_READ))
write_only = true;
}
if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
disposition = FILE_CREATE;
else if ((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
disposition = FILE_OVERWRITE_IF;
else if ((oflags & 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;
}
mode &= ~current->fs->umask;
/*
* if we're not using unix extensions, see if we need to set
* ATTR_READONLY on the create call
*/
if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
create_options |= CREATE_OPTION_READONLY;
if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
desiredAccess, create_options,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
else
rc = -EIO; /* no NT SMB support fall into legacy open below */
if (rc == -EIO) {
/* old server, retry the open legacy style */
rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
desiredAccess, create_options,
&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 ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
struct cifs_unix_set_info_args args = {
.mode = mode,
.ctime = NO_CHANGE_64,
.atime = NO_CHANGE_64,
.mtime = NO_CHANGE_64,
.device = 0,
};
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
args.uid = (__u64) current->fsuid;
if (inode->i_mode & S_ISGID)
args.gid = (__u64) inode->i_gid;
else
args.gid = (__u64) current->fsgid;
} else {
args.uid = NO_CHANGE_64;
args.gid = NO_CHANGE_64;
}
CIFSSMBUnixSetInfo(xid, pTcon, full_path, &args,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
} else {
/* BB implement mode setting via Windows security
descriptors e.g. */
/* CIFSSMBWinSetPerms(xid,pTcon,path,mode,-1,-1,nls);*/
/* Could set r/o dos attribute if mode & 0222 == 0 */
}
/* server might mask mode so we have to query for it */
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,
buf, inode->i_sb, xid,
&fileHandle);
if (newinode) {
if (cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_DYNPERM)
newinode->i_mode = mode;
if ((oplock & CIFS_CREATE_ACTION) &&
(cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_SET_UID)) {
newinode->i_uid = current->fsuid;
if (inode->i_mode & S_ISGID)
newinode->i_gid =
inode->i_gid;
else
newinode->i_gid =
current->fsgid;
}
}
}
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 == NULL /* nfsd case - nfs srv does not set nd */) ||
(!(nd->flags & LOOKUP_OPEN))) {
/* mknod case - do not leave file open */
CIFSSMBClose(xid, pTcon, fileHandle);
} else if (newinode) {
pCifsFile =
kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
if (pCifsFile == NULL)
goto cifs_create_out;
pCifsFile->netfid = fileHandle;
pCifsFile->pid = current->tgid;
pCifsFile->pInode = newinode;
pCifsFile->invalidHandle = false;
pCifsFile->closePend = false;
init_MUTEX(&pCifsFile->fh_sem);
mutex_init(&pCifsFile->lock_mutex);
INIT_LIST_HEAD(&pCifsFile->llist);
atomic_set(&pCifsFile->wrtPending, 0);
/* 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) {
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 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;
full_path = build_path_from_dentry(direntry);
if (full_path == NULL)
rc = -ENOMEM;
else if (pTcon->unix_ext) {
struct cifs_unix_set_info_args args = {
.mode = mode & ~current->fs->umask,
.ctime = NO_CHANGE_64,
.atime = NO_CHANGE_64,
.mtime = NO_CHANGE_64,
.device = device_number,
};
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
args.uid = (__u64) current->fsuid;
args.gid = (__u64) current->fsgid;
} else {
args.uid = NO_CHANGE_64;
args.gid = NO_CHANGE_64;
}
rc = CIFSSMBUnixSetInfo(xid, pTcon, full_path,
&args, 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);
/* BB FIXME - add handling for backlevel servers
which need legacy open and check for all
calls to SMBOpen for fallback to SMBLeagcyOpen */
if (!rc) {
/* BB Do not bother to decode buf since no
local inode yet to put timestamps in,
but we can reuse it safely */
unsigned int bytes_written;
struct win_dev *pdev;
pdev = (struct win_dev *)buf;
if (S_ISCHR(mode)) {
memcpy(pdev->type, "IntxCHR", 8);
pdev->major =
cpu_to_le64(MAJOR(device_number));
pdev->minor =
cpu_to_le64(MINOR(device_number));
rc = CIFSSMBWrite(xid, pTcon,
fileHandle,
sizeof(struct win_dev),
0, &bytes_written, (char *)pdev,
NULL, 0);
} else if (S_ISBLK(mode)) {
memcpy(pdev->type, "IntxBLK", 8);
pdev->major =
cpu_to_le64(MAJOR(device_number));
pdev->minor =
cpu_to_le64(MINOR(device_number));
rc = CIFSSMBWrite(xid, pTcon,
fileHandle,
sizeof(struct win_dev),
0, &bytes_written, (char *)pdev,
NULL, 0);
} /* else if(S_ISFIFO */
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));
/* check whether path exists */
cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
pTcon = cifs_sb->tcon;
/*
* Don't allow the separator character in a path component.
* The VFS will not allow "/", but "\" is allowed by posix.
*/
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
int i;
for (i = 0; i < direntry->d_name.len; i++)
if (direntry->d_name.name[i] == '\\') {
cFYI(1, ("Invalid file name"));
FreeXid(xid);
return ERR_PTR(-EINVAL);
}
}
/* 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->unix_ext)
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, NULL);
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;
direntry->d_time = jiffies;
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_add(direntry, NULL);
/* if it was once a directory (but how can we tell?) we could do
shrink_dcache_parent(direntry); */
} else if (rc != -EACCES) {
cERROR(1, ("Unexpected lookup error %d", rc));
/* We special case check for Access Denied - since that
is a common return code */
}
kfree(full_path);
FreeXid(xid);
return ERR_PTR(rc);
}
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
int isValid = 1;
if (direntry->d_inode) {
if (cifs_revalidate(direntry))
return 0;
} else {
cFYI(1, ("neg dentry 0x%p name = %s",
direntry, direntry->d_name.name));
if (time_after(jiffies, direntry->d_time + HZ) ||
!lookupCacheEnabled) {
d_drop(direntry);
isValid = 0;
}
}
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 */
};
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((void *)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,
};