linux/fs/cifs/dir.c
Christoph Hellwig 6b2f3d1f76 vfs: Implement proper O_SYNC semantics
While Linux provided an O_SYNC flag basically since day 1, it took until
Linux 2.4.0-test12pre2 to actually get it implemented for filesystems,
since that day we had generic_osync_around with only minor changes and the
great "For now, when the user asks for O_SYNC, we'll actually give
O_DSYNC" comment.  This patch intends to actually give us real O_SYNC
semantics in addition to the O_DSYNC semantics.  After Jan's O_SYNC
patches which are required before this patch it's actually surprisingly
simple, we just need to figure out when to set the datasync flag to
vfs_fsync_range and when not.

This patch renames the existing O_SYNC flag to O_DSYNC while keeping it's
numerical value to keep binary compatibility, and adds a new real O_SYNC
flag.  To guarantee backwards compatiblity it is defined as expanding to
both the O_DSYNC and the new additional binary flag (__O_SYNC) to make
sure we are backwards-compatible when compiled against the new headers.

This also means that all places that don't care about the differences can
just check O_DSYNC and get the right behaviour for O_SYNC, too - only
places that actuall care need to check __O_SYNC in addition.  Drivers and
network filesystems have been updated in a fail safe way to always do the
full sync magic if O_DSYNC is set.  The few places setting O_SYNC for
lower layers are kept that way for now to stay failsafe.

We enforce that O_DSYNC is set when __O_SYNC is set early in the open path
to make sure we always get these sane options.

Note that parisc really screwed up their headers as they already define a
O_DSYNC that has always been a no-op.  We try to repair it by using it for
the new O_DSYNC and redefinining O_SYNC to send both the traditional
O_SYNC numerical value _and_ the O_DSYNC one.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger@sun.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10 15:02:50 +01:00

808 lines
23 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 "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;
}
struct cifsFileInfo *
cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle,
struct file *file, struct vfsmount *mnt, unsigned int oflags)
{
int oplock = 0;
struct cifsFileInfo *pCifsFile;
struct cifsInodeInfo *pCifsInode;
struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
if (pCifsFile == NULL)
return pCifsFile;
if (oplockEnabled)
oplock = REQ_OPLOCK;
pCifsFile->netfid = fileHandle;
pCifsFile->pid = current->tgid;
pCifsFile->pInode = igrab(newinode);
pCifsFile->mnt = mnt;
pCifsFile->pfile = file;
pCifsFile->invalidHandle = false;
pCifsFile->closePend = false;
mutex_init(&pCifsFile->fh_mutex);
mutex_init(&pCifsFile->lock_mutex);
INIT_LIST_HEAD(&pCifsFile->llist);
atomic_set(&pCifsFile->count, 1);
slow_work_init(&pCifsFile->oplock_break, &cifs_oplock_break_ops);
write_lock(&GlobalSMBSeslock);
list_add(&pCifsFile->tlist, &cifs_sb->tcon->openFileList);
pCifsInode = CIFS_I(newinode);
if (pCifsInode) {
/* if readable file instance put first in list*/
if (oflags & FMODE_READ)
list_add(&pCifsFile->flist, &pCifsInode->openFileList);
else
list_add_tail(&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);
return pCifsFile;
}
int cifs_posix_open(char *full_path, struct inode **pinode,
struct vfsmount *mnt, int mode, int oflags,
__u32 *poplock, __u16 *pnetfid, int xid)
{
int rc;
FILE_UNIX_BASIC_INFO *presp_data;
__u32 posix_flags = 0;
struct cifs_sb_info *cifs_sb = CIFS_SB(mnt->mnt_sb);
struct cifs_fattr fattr;
cFYI(1, ("posix open %s", full_path));
presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
if (presp_data == NULL)
return -ENOMEM;
/* So far cifs posix extensions can only map the following flags.
There are other valid fmode oflags such as FMODE_LSEEK, FMODE_PREAD, but
so far we do not seem to need them, and we can treat them as local only */
if ((oflags & (FMODE_READ | FMODE_WRITE)) ==
(FMODE_READ | FMODE_WRITE))
posix_flags = SMB_O_RDWR;
else if (oflags & FMODE_READ)
posix_flags = SMB_O_RDONLY;
else if (oflags & FMODE_WRITE)
posix_flags = SMB_O_WRONLY;
if (oflags & O_CREAT)
posix_flags |= SMB_O_CREAT;
if (oflags & O_EXCL)
posix_flags |= SMB_O_EXCL;
if (oflags & O_TRUNC)
posix_flags |= SMB_O_TRUNC;
/* be safe and imply O_SYNC for O_DSYNC */
if (oflags & O_DSYNC)
posix_flags |= SMB_O_SYNC;
if (oflags & O_DIRECTORY)
posix_flags |= SMB_O_DIRECTORY;
if (oflags & O_NOFOLLOW)
posix_flags |= SMB_O_NOFOLLOW;
if (oflags & O_DIRECT)
posix_flags |= SMB_O_DIRECT;
mode &= ~current_umask();
rc = CIFSPOSIXCreate(xid, cifs_sb->tcon, posix_flags, mode,
pnetfid, presp_data, poplock, full_path,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc)
goto posix_open_ret;
if (presp_data->Type == cpu_to_le32(-1))
goto posix_open_ret; /* open ok, caller does qpathinfo */
if (!pinode)
goto posix_open_ret; /* caller does not need info */
cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
/* get new inode and set it up */
if (*pinode == NULL) {
*pinode = cifs_iget(mnt->mnt_sb, &fattr);
if (!*pinode) {
rc = -ENOMEM;
goto posix_open_ret;
}
} else {
cifs_fattr_to_inode(*pinode, &fattr);
}
cifs_new_fileinfo(*pinode, *pnetfid, NULL, mnt, oflags);
posix_open_ret:
kfree(presp_data);
return rc;
}
static void setup_cifs_dentry(struct cifsTconInfo *tcon,
struct dentry *direntry,
struct inode *newinode)
{
if (tcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_instantiate(direntry, newinode);
}
/* 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;
__u32 oplock = 0;
int oflags;
bool posix_create = false;
/*
* 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.
*/
int desiredAccess = GENERIC_READ | GENERIC_WRITE;
__u16 fileHandle;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *tcon;
char *full_path = NULL;
FILE_ALL_INFO *buf = NULL;
struct inode *newinode = NULL;
int disposition = FILE_OVERWRITE_IF;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
tcon = cifs_sb->tcon;
full_path = build_path_from_dentry(direntry);
if (full_path == NULL) {
rc = -ENOMEM;
FreeXid(xid);
return rc;
}
if (oplockEnabled)
oplock = REQ_OPLOCK;
if (nd && (nd->flags & LOOKUP_OPEN))
oflags = nd->intent.open.flags;
else
oflags = FMODE_READ;
if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) &&
(CIFS_UNIX_POSIX_PATH_OPS_CAP &
le64_to_cpu(tcon->fsUnixInfo.Capability))) {
rc = cifs_posix_open(full_path, &newinode, nd->path.mnt,
mode, oflags, &oplock, &fileHandle, xid);
/* EIO could indicate that (posix open) operation is not
supported, despite what server claimed in capability
negotation. EREMOTE indicates DFS junction, which is not
handled in posix open */
if (rc == 0) {
posix_create = true;
if (newinode == NULL) /* query inode info */
goto cifs_create_get_file_info;
else /* success, no need to query */
goto cifs_create_set_dentry;
} else if ((rc != -EIO) && (rc != -EREMOTE) &&
(rc != -EOPNOTSUPP) && (rc != -EINVAL))
goto cifs_create_out;
/* else 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) */
}
if (nd && (nd->flags & LOOKUP_OPEN)) {
/* if the file is going to stay open, then we
need to set the desired access properly */
desiredAccess = 0;
if (oflags & FMODE_READ)
desiredAccess |= GENERIC_READ; /* is this too little? */
if (oflags & FMODE_WRITE)
desiredAccess |= GENERIC_WRITE;
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) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
/*
* 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 (cifs_sb->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 cifs_create_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 = (__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;
}
CIFSSMBUnixSetPathInfo(xid, tcon, 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,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)
setup_cifs_dentry(tcon, direntry, newinode);
else
cFYI(1, ("Create worked, get_inode_info failed rc = %d", rc));
/* nfsd case - nfs srv does not set nd */
if ((nd == NULL) || (!(nd->flags & LOOKUP_OPEN))) {
/* mknod case - do not leave file open */
CIFSSMBClose(xid, tcon, fileHandle);
} else if (!(posix_create) && (newinode)) {
cifs_new_fileinfo(newinode, fileHandle, NULL,
nd->path.mnt, oflags);
}
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_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) {
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);
rc = -ENOMEM;
FreeXid(xid);
return rc;
}
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 */
__u32 oplock = 0;
__u16 fileHandle = 0;
bool posix_open = false;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
struct inode *newInode = NULL;
char *full_path = NULL;
struct file *filp;
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);
}
}
/*
* O_EXCL: optimize away the lookup, but don't hash the dentry. Let
* the VFS handle the create.
*/
if (nd && (nd->flags & LOOKUP_EXCL)) {
d_instantiate(direntry, NULL);
return NULL;
}
/* 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));
/* 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 here (lookup) 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 (pTcon->unix_ext) {
if (nd && !(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY)) &&
(nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
(nd->intent.open.flags & O_CREAT)) {
rc = cifs_posix_open(full_path, &newInode, nd->path.mnt,
nd->intent.open.create_mode,
nd->intent.open.flags, &oplock,
&fileHandle, xid);
/*
* The check below works around a bug in POSIX
* open in samba versions 3.3.1 and earlier where
* open could incorrectly fail with invalid parameter.
* If either that or op not supported returned, follow
* the normal lookup.
*/
if ((rc == 0) || (rc == -ENOENT))
posix_open = true;
else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP))
pTcon->broken_posix_open = true;
}
if (!posix_open)
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);
if (posix_open)
filp = lookup_instantiate_filp(nd, direntry, NULL);
/* 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;
} */
const 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;
}
const struct dentry_operations cifs_ci_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
.d_hash = cifs_ci_hash,
.d_compare = cifs_ci_compare,
};