kernel-fxtec-pro1x/fs/cifs/dir.c
Al Viro a8ab0b7097 cifs_atomic_open(): fix double-put on late allocation failure
commit d9a9f4849fe0c9d560851ab22a85a666cddfdd24 upstream.

several iterations of ->atomic_open() calling conventions ago, we
used to need fput() if ->atomic_open() failed at some point after
successful finish_open().  Now (since 2016) it's not needed -
struct file carries enough state to make fput() work regardless
of the point in struct file lifecycle and discarding it on
failure exits in open() got unified.  Unfortunately, I'd missed
the fact that we had an instance of ->atomic_open() (cifs one)
that used to need that fput(), as well as the stale comment in
finish_open() demanding such late failure handling.  Trivially
fixed...

Fixes: fe9ec8291f "do_last(): take fput() on error after opening to out:"
Cc: stable@kernel.org # v4.7+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 07:14:21 +01:00

981 lines
25 KiB
C

/*
* 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"
#include "cifs_unicode.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 {
cifs_set_time(direntry, jiffies);
direntry = direntry->d_parent;
} while (!IS_ROOT(direntry));
}
char *
cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb,
struct cifs_tcon *tcon, int add_treename)
{
int pplen = vol->prepath ? strlen(vol->prepath) + 1 : 0;
int dfsplen;
char *full_path = NULL;
/* if no prefix path, simply set path to the root of share to "" */
if (pplen == 0) {
full_path = kzalloc(1, GFP_KERNEL);
return full_path;
}
if (add_treename)
dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
else
dfsplen = 0;
full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL);
if (full_path == NULL)
return full_path;
if (dfsplen)
strncpy(full_path, tcon->treeName, dfsplen);
full_path[dfsplen] = CIFS_DIR_SEP(cifs_sb);
strncpy(full_path + dfsplen + 1, vol->prepath, pplen);
convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
full_path[dfsplen + pplen] = 0; /* add trailing null */
return full_path;
}
/* Note: caller must free return buffer */
char *
build_path_from_dentry(struct dentry *direntry)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
return build_path_from_dentry_optional_prefix(direntry,
prefix);
}
char *
build_path_from_dentry_optional_prefix(struct dentry *direntry, bool prefix)
{
struct dentry *temp;
int namelen;
int dfsplen;
int pplen = 0;
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 (prefix)
dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
else
dfsplen = 0;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
cifs_bp_rename_retry:
namelen = dfsplen + pplen;
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) {
cifs_dbg(VFS, "corrupt dentry\n");
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);
cifs_dbg(FYI, "name: %s\n", full_path + namelen);
}
spin_unlock(&temp->d_lock);
temp = temp->d_parent;
if (temp == NULL) {
cifs_dbg(VFS, "corrupt dentry\n");
rcu_read_unlock();
kfree(full_path);
return NULL;
}
}
rcu_read_unlock();
if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
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 (pplen) {
int i;
cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
full_path[dfsplen] = dirsep;
for (i = 0; i < pplen-1; i++)
if (full_path[dfsplen+1+i] == '/')
full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
}
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 path components longer than the server max.
* 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_tcon *tcon)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
int i;
if (unlikely(tcon->fsAttrInfo.MaxPathNameComponentLength &&
direntry->d_name.len >
le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength)))
return -ENAMETOOLONG;
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] == '\\') {
cifs_dbg(FYI, "Invalid file name\n");
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, struct cifs_fid *fid)
{
int rc = -ENOENT;
int create_options = CREATE_NOT_DIR;
int desired_access;
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;
struct TCP_Server_Info *server = tcon->ses->server;
struct cifs_open_parms oparms;
*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, &fid->netfid, xid);
switch (rc) {
case 0:
if (newinode == NULL) {
/* query inode info */
goto cifs_create_get_file_info;
}
if (S_ISDIR(newinode->i_mode)) {
CIFSSMBClose(xid, tcon, fid->netfid);
iput(newinode);
rc = -EISDIR;
goto out;
}
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, fid->netfid);
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)
*/
}
desired_access = 0;
if (OPEN_FMODE(oflags) & FMODE_READ)
desired_access |= GENERIC_READ; /* is this too little? */
if (OPEN_FMODE(oflags) & FMODE_WRITE)
desired_access |= 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
cifs_dbg(FYI, "Create flag not set in create function\n");
/*
* BB add processing to set equivalent of mode - e.g. via CreateX with
* ACLs
*/
if (!server->ops->open) {
rc = -ENOSYS;
goto out;
}
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;
oparms.tcon = tcon;
oparms.cifs_sb = cifs_sb;
oparms.desired_access = desired_access;
oparms.create_options = create_options;
oparms.disposition = disposition;
oparms.path = full_path;
oparms.fid = fid;
oparms.reconnect = false;
oparms.mode = mode;
rc = server->ops->open(xid, &oparms, oplock, buf);
if (rc) {
cifs_dbg(FYI, "cifs_create returned 0x%x\n", 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,
};
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
args.uid = current_fsuid();
if (inode->i_mode & S_ISGID)
args.gid = inode->i_gid;
else
args.gid = current_fsgid();
} else {
args.uid = INVALID_UID; /* no change */
args.gid = INVALID_GID; /* no change */
}
CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
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, fid);
if (newinode) {
if (server->ops->set_lease_key)
server->ops->set_lease_key(newinode, fid);
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) {
cifs_dbg(FYI, "Create worked, get_inode_info failed rc = %d\n",
rc);
goto out_err;
}
if (S_ISDIR(newinode->i_mode)) {
rc = -EISDIR;
goto out_err;
}
d_drop(direntry);
d_add(direntry, newinode);
out:
kfree(buf);
kfree(full_path);
return rc;
out_err:
if (server->ops->close)
server->ops->close(xid, tcon, fid);
if (newinode)
iput(newinode);
goto out;
}
int
cifs_atomic_open(struct inode *inode, struct dentry *direntry,
struct file *file, unsigned oflags, umode_t mode)
{
int rc;
unsigned int xid;
struct tcon_link *tlink;
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
struct cifs_fid fid;
struct cifs_pending_open open;
__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;
/*
* Check for hashed negative dentry. We have already revalidated
* the dentry and it is fine. No need to perform another lookup.
*/
if (!d_in_lookup(direntry))
return -ENOENT;
res = cifs_lookup(inode, direntry, 0);
if (IS_ERR(res))
return PTR_ERR(res);
return finish_no_open(file, res);
}
xid = get_xid();
cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
inode, direntry, direntry);
tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
goto out_free_xid;
}
tcon = tlink_tcon(tlink);
rc = check_name(direntry, tcon);
if (rc)
goto out;
server = tcon->ses->server;
if (server->ops->new_lease_key)
server->ops->new_lease_key(&fid);
cifs_add_pending_open(&fid, tlink, &open);
rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
&oplock, &fid);
if (rc) {
cifs_del_pending_open(&open);
goto out;
}
if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
file->f_mode |= FMODE_CREATED;
rc = finish_open(file, direntry, generic_file_open);
if (rc) {
if (server->ops->close)
server->ops->close(xid, tcon, &fid);
cifs_del_pending_open(&open);
goto out;
}
if (file->f_flags & O_DIRECT &&
CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
if (CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
file->f_op = &cifs_file_direct_nobrl_ops;
else
file->f_op = &cifs_file_direct_ops;
}
file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
if (file_info == NULL) {
if (server->ops->close)
server->ops->close(xid, tcon, &fid);
cifs_del_pending_open(&open);
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;
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
struct cifs_fid fid;
__u32 oplock;
cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
inode, direntry, direntry);
tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
rc = PTR_ERR(tlink);
if (IS_ERR(tlink))
goto out_free_xid;
tcon = tlink_tcon(tlink);
server = tcon->ses->server;
if (server->ops->new_lease_key)
server->ops->new_lease_key(&fid);
rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
&oplock, &fid);
if (!rc && server->ops->close)
server->ops->close(xid, tcon, &fid);
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 *tcon;
struct cifs_io_parms io_parms;
char *full_path = NULL;
struct inode *newinode = NULL;
__u32 oplock = 0;
struct cifs_fid fid;
struct cifs_open_parms oparms;
FILE_ALL_INFO *buf = NULL;
unsigned int bytes_written;
struct win_dev *pdev;
struct kvec iov[2];
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);
tcon = tlink_tcon(tlink);
xid = get_xid();
full_path = build_path_from_dentry(direntry);
if (full_path == NULL) {
rc = -ENOMEM;
goto mknod_out;
}
if (tcon->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 = current_fsuid();
args.gid = current_fsgid();
} else {
args.uid = INVALID_UID; /* no change */
args.gid = INVALID_GID; /* no change */
}
rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
cifs_sb->local_nls,
cifs_remap(cifs_sb));
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 (!S_ISCHR(mode) && !S_ISBLK(mode))
goto mknod_out;
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
goto mknod_out;
cifs_dbg(FYI, "sfu compat create special file\n");
buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
if (buf == NULL) {
rc = -ENOMEM;
goto mknod_out;
}
if (backup_cred(cifs_sb))
create_options |= CREATE_OPEN_BACKUP_INTENT;
oparms.tcon = tcon;
oparms.cifs_sb = cifs_sb;
oparms.desired_access = GENERIC_WRITE;
oparms.create_options = create_options;
oparms.disposition = FILE_CREATE;
oparms.path = full_path;
oparms.fid = &fid;
oparms.reconnect = false;
if (tcon->ses->server->oplocks)
oplock = REQ_OPLOCK;
else
oplock = 0;
rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
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.pid = current->tgid;
io_parms.tcon = tcon;
io_parms.offset = 0;
io_parms.length = sizeof(struct win_dev);
iov[1].iov_base = buf;
iov[1].iov_len = 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 = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
&bytes_written, iov, 1);
} 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 = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
&bytes_written, iov, 1);
}
tcon->ses->server->ops->close(xid, tcon, &fid);
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();
cifs_dbg(FYI, "parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
parent_dir_inode, direntry, 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 ERR_CAST(tlink);
}
pTcon = tlink_tcon(tlink);
rc = check_name(direntry, pTcon);
if (unlikely(rc)) {
cifs_put_tlink(tlink);
free_xid(xid);
return ERR_PTR(rc);
}
/* 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) {
cifs_put_tlink(tlink);
free_xid(xid);
return ERR_PTR(-ENOMEM);
}
if (d_really_is_positive(direntry)) {
cifs_dbg(FYI, "non-NULL inode in lookup\n");
} else {
cifs_dbg(FYI, "NULL inode in lookup\n");
}
cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
full_path, d_inode(direntry));
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) {
/* 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) {
cifs_set_time(direntry, jiffies);
newInode = NULL;
} else {
if (rc != -EACCES) {
cifs_dbg(FYI, "Unexpected lookup error %d\n", rc);
/* We special case check for Access Denied - since that
is a common return code */
}
newInode = ERR_PTR(rc);
}
kfree(full_path);
cifs_put_tlink(tlink);
free_xid(xid);
return d_splice_alias(newInode, direntry);
}
static int
cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
{
struct inode *inode;
if (flags & LOOKUP_RCU)
return -ECHILD;
if (d_really_is_positive(direntry)) {
inode = d_inode(direntry);
if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
CIFS_I(inode)->time = 0; /* force reval */
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(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, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
return 0;
return 1;
}
/* static int cifs_d_delete(struct dentry *direntry)
{
int rc = 0;
cifs_dbg(FYI, "In cifs d_delete, name = %pd\n", direntry);
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, struct qstr *q)
{
struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
unsigned long hash;
wchar_t c;
int i, charlen;
hash = init_name_hash(dentry);
for (i = 0; i < q->len; i += charlen) {
charlen = codepage->char2uni(&q->name[i], q->len - i, &c);
/* error out if we can't convert the character */
if (unlikely(charlen < 0))
return charlen;
hash = partial_name_hash(cifs_toupper(c), hash);
}
q->hash = end_name_hash(hash);
return 0;
}
static int cifs_ci_compare(const struct dentry *dentry,
unsigned int len, const char *str, const struct qstr *name)
{
struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
wchar_t c1, c2;
int i, l1, l2;
/*
* We make the assumption here that uppercase characters in the local
* codepage are always the same length as their lowercase counterparts.
*
* If that's ever not the case, then this will fail to match it.
*/
if (name->len != len)
return 1;
for (i = 0; i < len; i += l1) {
/* Convert characters in both strings to UTF-16. */
l1 = codepage->char2uni(&str[i], len - i, &c1);
l2 = codepage->char2uni(&name->name[i], name->len - i, &c2);
/*
* If we can't convert either character, just declare it to
* be 1 byte long and compare the original byte.
*/
if (unlikely(l1 < 0 && l2 < 0)) {
if (str[i] != name->name[i])
return 1;
l1 = 1;
continue;
}
/*
* Here, we again ass|u|me that upper/lowercase versions of
* a character are the same length in the local NLS.
*/
if (l1 != l2)
return 1;
/* Now compare uppercase versions of these characters */
if (cifs_toupper(c1) != cifs_toupper(c2))
return 1;
}
return 0;
}
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,
};