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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., 2002,2009
* 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 <linux/mount.h>
#include <linux/file.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 dfsplen;
char *full_path;
char dirsep;
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
unsigned seq;
dirsep = CIFS_DIR_SEP(cifs_sb);
if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
else
dfsplen = 0;
cifs_bp_rename_retry:
namelen = dfsplen;
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
for (temp = direntry; !IS_ROOT(temp);) {
namelen += (1 + temp->d_name.len);
temp = temp->d_parent;
if (temp == NULL) {
cERROR(1, "corrupt dentry");
rcu_read_unlock();
return NULL;
}
}
rcu_read_unlock();
full_path = kmalloc(namelen+1, GFP_KERNEL);
if (full_path == NULL)
return full_path;
full_path[namelen] = 0; /* trailing null */
rcu_read_lock();
for (temp = direntry; !IS_ROOT(temp);) {
spin_lock(&temp->d_lock);
namelen -= 1 + temp->d_name.len;
if (namelen < 0) {
spin_unlock(&temp->d_lock);
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);
}
spin_unlock(&temp->d_lock);
temp = temp->d_parent;
if (temp == NULL) {
cERROR(1, "corrupt dentry");
rcu_read_unlock();
kfree(full_path);
return NULL;
}
}
rcu_read_unlock();
if (namelen != dfsplen || read_seqretry(&rename_lock, seq)) {
cFYI(1, "did not end path lookup where expected. namelen=%d "
"dfsplen=%d", namelen, dfsplen);
/* 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, 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] = '/';
}
}
}
return full_path;
}
/*
* Don't allow the separator character in a path component.
* The VFS will not allow "/", but "\" is allowed by posix.
*/
static int
check_name(struct dentry *direntry)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
int i;
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)) {
for (i = 0; i < direntry->d_name.len; i++) {
if (direntry->d_name.name[i] == '\\') {
cFYI(1, "Invalid file name");
return -EINVAL;
}
}
}
return 0;
}
/* Inode operations in similar order to how they appear in Linux file fs.h */
static int
cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
struct tcon_link *tlink, unsigned oflags, umode_t mode,
__u32 *oplock, __u16 *fileHandle, int *created)
{
int rc = -ENOENT;
int create_options = CREATE_NOT_DIR;
int desiredAccess;
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifs_tcon *tcon = tlink_tcon(tlink);
char *full_path = NULL;
FILE_ALL_INFO *buf = NULL;
struct inode *newinode = NULL;
int disposition;
*oplock = 0;
if (tcon->ses->server->oplocks)
*oplock = REQ_OPLOCK;
full_path = build_path_from_dentry(direntry);
if (full_path == NULL) {
rc = -ENOMEM;
goto out;
}
if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
(CIFS_UNIX_POSIX_PATH_OPS_CAP &
le64_to_cpu(tcon->fsUnixInfo.Capability))) {
rc = cifs_posix_open(full_path, &newinode,
inode->i_sb, mode, oflags, oplock, fileHandle, xid);
switch (rc) {
case 0:
if (newinode == NULL) {
/* query inode info */
goto cifs_create_get_file_info;
}
if (!S_ISREG(newinode->i_mode)) {
/*
* The server may allow us to open things like
* FIFOs, but the client isn't set up to deal
* with that. If it's not a regular file, just
* close it and proceed as if it were a normal
* lookup.
*/
CIFSSMBClose(xid, tcon, *fileHandle);
goto cifs_create_get_file_info;
}
/* success, no need to query */
goto cifs_create_set_dentry;
case -ENOENT:
goto cifs_create_get_file_info;
case -EIO:
case -EINVAL:
/*
* EIO could indicate that (posix open) operation is not
* supported, despite what server claimed in capability
* negotiation.
*
* POSIX open in samba versions 3.3.1 and earlier could
* incorrectly fail with invalid parameter.
*/
tcon->broken_posix_open = true;
break;
case -EREMOTE:
case -EOPNOTSUPP:
/*
* EREMOTE indicates DFS junction, which is not handled
* in posix open. If either that or op not supported
* returned, follow the normal lookup.
*/
break;
default:
goto out;
}
/*
* fallthrough to retry, using older open call, this is case
* where server does not support this SMB level, and falsely
* claims capability (also get here for DFS case which should be
* rare for path not covered on files)
*/
}
desiredAccess = 0;
if (OPEN_FMODE(oflags) & FMODE_READ)
desiredAccess |= GENERIC_READ; /* is this too little? */
if (OPEN_FMODE(oflags) & FMODE_WRITE)
desiredAccess |= GENERIC_WRITE;
disposition = FILE_OVERWRITE_IF;
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 */
buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
if (buf == NULL) {
rc = -ENOMEM;
goto out;
}
/*
* if we're not using unix extensions, see if we need to set
* ATTR_READONLY on the create call
*/
if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
create_options |= CREATE_OPTION_READONLY;
if (backup_cred(cifs_sb))
create_options |= CREATE_OPEN_BACKUP_INTENT;
if (tcon->ses->capabilities & CAP_NT_SMBS)
rc = CIFSSMBOpen(xid, tcon, 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, tcon, 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);
goto out;
}
/* If Open reported that we actually created a file
then we now have to set the mode if possible */
if ((tcon->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,
};
*created |= FILE_CREATED;
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;
}
CIFSSMBUnixSetFileInfo(xid, tcon, &args, *fileHandle,
current->tgid);
} else {
/* BB implement mode setting via Windows security
descriptors e.g. */
/* CIFSSMBWinSetPerms(xid,tcon,path,mode,-1,-1,nls);*/
/* Could set r/o dos attribute if mode & 0222 == 0 */
}
cifs_create_get_file_info:
/* server might mask mode so we have to query for it */
if (tcon->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();
}
}
}
cifs_create_set_dentry:
if (rc != 0) {
cFYI(1, "Create worked, get_inode_info failed rc = %d", rc);
CIFSSMBClose(xid, tcon, *fileHandle);
goto out;
}
d_drop(direntry);
d_add(direntry, newinode);
out:
kfree(buf);
kfree(full_path);
return rc;
}
int
cifs_atomic_open(struct inode *inode, struct dentry *direntry,
struct file *file, unsigned oflags, umode_t mode,
int *opened)
{
int rc;
unsigned int xid;
struct tcon_link *tlink;
struct cifs_tcon *tcon;
struct cifs_fid fid;
__u32 oplock;
struct cifsFileInfo *file_info;
/*
* Posix open is only called (at lookup time) for file create now. For
* opens (rather than creates), because we do not know if it is a file
* or directory yet, and current Samba no longer allows us to do posix
* open on dirs, we could end up wasting an open call on what turns out
* to be a dir. For file opens, we wait to call posix open till
* cifs_open. It could be added to atomic_open in the future but the
* performance tradeoff of the extra network request when EISDIR or
* EACCES is returned would have to be weighed against the 50% reduction
* in network traffic in the other paths.
*/
if (!(oflags & O_CREAT)) {
struct dentry *res = cifs_lookup(inode, direntry, 0);
if (IS_ERR(res))
return PTR_ERR(res);
return finish_no_open(file, res);
}
rc = check_name(direntry);
if (rc)
return rc;
xid = get_xid();
cFYI(1, "parent inode = 0x%p name is: %s and dentry = 0x%p",
inode, direntry->d_name.name, direntry);
tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
if (IS_ERR(tlink))
goto out_free_xid;
tcon = tlink_tcon(tlink);
rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
&oplock, &fid.netfid, opened);
if (rc)
goto out;
rc = finish_open(file, direntry, generic_file_open, opened);
if (rc) {
CIFSSMBClose(xid, tcon, fid.netfid);
goto out;
}
file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
if (file_info == NULL) {
CIFSSMBClose(xid, tcon, fid.netfid);
rc = -ENOMEM;
}
out:
cifs_put_tlink(tlink);
out_free_xid:
free_xid(xid);
return rc;
}
int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
bool excl)
{
int rc;
unsigned int xid = get_xid();
/*
* BB below access is probably too much for mknod to request
* but we have to do query and setpathinfo so requesting
* less could fail (unless we want to request getatr and setatr
* permissions (only). At least for POSIX we do not have to
* request so much.
*/
unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
struct tcon_link *tlink;
__u16 fileHandle;
__u32 oplock;
int created = FILE_CREATED;
cFYI(1, "cifs_create parent inode = 0x%p name is: %s and dentry = 0x%p",
inode, direntry->d_name.name, direntry);
tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
rc = PTR_ERR(tlink);
if (IS_ERR(tlink))
goto out_free_xid;
rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
&oplock, &fileHandle, &created);
if (!rc)
CIFSSMBClose(xid, tlink_tcon(tlink), fileHandle);
cifs_put_tlink(tlink);
out_free_xid:
free_xid(xid);
return rc;
}
int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
dev_t device_number)
{
int rc = -EPERM;
unsigned int xid;
int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct cifs_io_parms io_parms;
char *full_path = NULL;
struct inode *newinode = NULL;
int oplock = 0;
u16 fileHandle;
FILE_ALL_INFO *buf = NULL;
unsigned int bytes_written;
struct win_dev *pdev;
if (!old_valid_dev(device_number))
return -EINVAL;
cifs_sb = CIFS_SB(inode->i_sb);
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
pTcon = tlink_tcon(tlink);
xid = get_xid();
full_path = build_path_from_dentry(direntry);
if (full_path == NULL) {
rc = -ENOMEM;
goto mknod_out;
}
if (pTcon->unix_ext) {
struct cifs_unix_set_info_args args = {
.mode = mode & ~current_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 = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc)
goto mknod_out;
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb, xid);
if (rc == 0)
d_instantiate(direntry, newinode);
goto mknod_out;
}
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
goto mknod_out;
cFYI(1, "sfu compat create special file");
buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
if (buf == NULL) {
kfree(full_path);
rc = -ENOMEM;
free_xid(xid);
return rc;
}
if (backup_cred(cifs_sb))
create_options |= CREATE_OPEN_BACKUP_INTENT;
rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE,
GENERIC_WRITE, create_options,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc)
goto mknod_out;
/* BB Do not bother to decode buf since no local inode yet to put
* timestamps in, but we can reuse it safely */
pdev = (struct win_dev *)buf;
io_parms.netfid = fileHandle;
io_parms.pid = current->tgid;
io_parms.tcon = pTcon;
io_parms.offset = 0;
io_parms.length = sizeof(struct win_dev);
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, &io_parms,
&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, &io_parms,
&bytes_written, (char *)pdev,
NULL, 0);
} /* else if (S_ISFIFO) */
CIFSSMBClose(xid, pTcon, fileHandle);
d_drop(direntry);
/* FIXME: add code here to set EAs */
mknod_out:
kfree(full_path);
kfree(buf);
free_xid(xid);
cifs_put_tlink(tlink);
return rc;
}
struct dentry *
cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
unsigned int flags)
{
unsigned int xid;
int rc = 0; /* to get around spurious gcc warning, set to zero here */
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct inode *newInode = NULL;
char *full_path = NULL;
xid = get_xid();
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);
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
free_xid(xid);
return (struct dentry *)tlink;
}
pTcon = tlink_tcon(tlink);
rc = check_name(direntry);
if (rc)
goto lookup_out;
/* 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) {
rc = -ENOMEM;
goto lookup_out;
}
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)) {
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;
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 */
}
lookup_out:
kfree(full_path);
cifs_put_tlink(tlink);
free_xid(xid);
return ERR_PTR(rc);
}
static int
cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
{
if (flags & LOOKUP_RCU)
return -ECHILD;
if (direntry->d_inode) {
if (cifs_revalidate_dentry(direntry))
return 0;
else {
/*
* If the inode wasn't known to be a dfs entry when
* the dentry was instantiated, such as when created
* via ->readdir(), it needs to be set now since the
* attributes will have been updated by
* cifs_revalidate_dentry().
*/
if (IS_AUTOMOUNT(direntry->d_inode) &&
!(direntry->d_flags & DCACHE_NEED_AUTOMOUNT)) {
spin_lock(&direntry->d_lock);
direntry->d_flags |= DCACHE_NEED_AUTOMOUNT;
spin_unlock(&direntry->d_lock);
}
return 1;
}
}
/*
* This may be nfsd (or something), anyway, we can't see the
* intent of this. So, since this can be for creation, drop it.
*/
if (!flags)
return 0;
/*
* Drop the negative dentry, in order to make sure to use the
* case sensitive name which is specified by user if this is
* for creation.
*/
if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
return 0;
if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
return 0;
return 1;
}
/* 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;
} */
const struct dentry_operations cifs_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
.d_automount = cifs_dfs_d_automount,
/* d_delete: cifs_d_delete, */ /* not needed except for debugging */
};
static int cifs_ci_hash(const struct dentry *dentry, const struct inode *inode,
struct qstr *q)
{
struct nls_table *codepage = CIFS_SB(dentry->d_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(const struct dentry *parent,
const struct inode *pinode,
const struct dentry *dentry, const struct inode *inode,
unsigned int len, const char *str, const struct qstr *name)
{
struct nls_table *codepage = CIFS_SB(pinode->i_sb)->local_nls;
if ((name->len == len) &&
(nls_strnicmp(codepage, name->name, str, len) == 0))
return 0;
return 1;
}
const struct dentry_operations cifs_ci_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
.d_hash = cifs_ci_hash,
.d_compare = cifs_ci_compare,
.d_automount = cifs_dfs_d_automount,
};
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