linux-stable/fs/cifs/smb2inode.c
Steve French 3d4ef9a153 smb3: fix redundant opens on root
In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share
over and over again in various places during mount and path revalidation
and also in statfs.  This patch cuts redundant traffic (opens and closes)
by simply keeping the directory handle for the root around (and reopening
it as needed on reconnect), so query calls don't require three round
trips to copmlete - just one, and eases load on network, client and
server (on mount alone, cuts network traffic by more than a third).

Also add a new cifs mount parm "nohandlecache" to allow users whose
servers might have resource constraints (eg in case they have a server
with so many users connecting to it that this extra handle per mount
could possibly be a resource concern).

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2018-05-27 17:56:35 -05:00

296 lines
8.2 KiB
C

/*
* fs/cifs/smb2inode.c
*
* Copyright (C) International Business Machines Corp., 2002, 2011
* Etersoft, 2012
* Author(s): Pavel Shilovsky (pshilovsky@samba.org),
* 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/pagemap.h>
#include <asm/div64.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"
#include "fscache.h"
#include "smb2glob.h"
#include "smb2pdu.h"
#include "smb2proto.h"
static int
smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
__u32 desired_access, __u32 create_disposition,
__u32 create_options, void *data, int command)
{
int rc, tmprc = 0;
__le16 *utf16_path = NULL;
__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
struct cifs_open_parms oparms;
struct cifs_fid fid;
bool use_cached_root_handle = false;
if ((strcmp(full_path, "") == 0) && (create_options == 0) &&
(desired_access == FILE_READ_ATTRIBUTES) &&
(create_disposition == FILE_OPEN) &&
(tcon->nohandlecache == false)) {
rc = open_shroot(xid, tcon, &fid);
if (rc == 0)
use_cached_root_handle = true;
}
if (use_cached_root_handle == false) {
utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
if (!utf16_path)
return -ENOMEM;
oparms.tcon = tcon;
oparms.desired_access = desired_access;
oparms.disposition = create_disposition;
oparms.create_options = create_options;
oparms.fid = &fid;
oparms.reconnect = false;
rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
if (rc) {
kfree(utf16_path);
return rc;
}
}
switch (command) {
case SMB2_OP_DELETE:
break;
case SMB2_OP_QUERY_INFO:
tmprc = SMB2_query_info(xid, tcon, fid.persistent_fid,
fid.volatile_fid,
(struct smb2_file_all_info *)data);
break;
case SMB2_OP_MKDIR:
/*
* Directories are created through parameters in the
* SMB2_open() call.
*/
break;
case SMB2_OP_RMDIR:
tmprc = SMB2_rmdir(xid, tcon, fid.persistent_fid,
fid.volatile_fid);
break;
case SMB2_OP_RENAME:
tmprc = SMB2_rename(xid, tcon, fid.persistent_fid,
fid.volatile_fid, (__le16 *)data);
break;
case SMB2_OP_HARDLINK:
tmprc = SMB2_set_hardlink(xid, tcon, fid.persistent_fid,
fid.volatile_fid, (__le16 *)data);
break;
case SMB2_OP_SET_EOF:
tmprc = SMB2_set_eof(xid, tcon, fid.persistent_fid,
fid.volatile_fid, current->tgid,
(__le64 *)data, false);
break;
case SMB2_OP_SET_INFO:
tmprc = SMB2_set_info(xid, tcon, fid.persistent_fid,
fid.volatile_fid,
(FILE_BASIC_INFO *)data);
break;
default:
cifs_dbg(VFS, "Invalid command\n");
break;
}
if (use_cached_root_handle == false)
rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
if (tmprc)
rc = tmprc;
kfree(utf16_path);
return rc;
}
void
move_smb2_info_to_cifs(FILE_ALL_INFO *dst, struct smb2_file_all_info *src)
{
memcpy(dst, src, (size_t)(&src->CurrentByteOffset) - (size_t)src);
dst->CurrentByteOffset = src->CurrentByteOffset;
dst->Mode = src->Mode;
dst->AlignmentRequirement = src->AlignmentRequirement;
dst->IndexNumber1 = 0; /* we don't use it */
}
int
smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
FILE_ALL_INFO *data, bool *adjust_tz, bool *symlink)
{
int rc;
struct smb2_file_all_info *smb2_data;
*adjust_tz = false;
*symlink = false;
smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
GFP_KERNEL);
if (smb2_data == NULL)
return -ENOMEM;
rc = smb2_open_op_close(xid, tcon, cifs_sb, full_path,
FILE_READ_ATTRIBUTES, FILE_OPEN, 0,
smb2_data, SMB2_OP_QUERY_INFO);
if (rc == -EOPNOTSUPP) {
*symlink = true;
/* Failed on a symbolic link - query a reparse point info */
rc = smb2_open_op_close(xid, tcon, cifs_sb, full_path,
FILE_READ_ATTRIBUTES, FILE_OPEN,
OPEN_REPARSE_POINT, smb2_data,
SMB2_OP_QUERY_INFO);
}
if (rc)
goto out;
move_smb2_info_to_cifs(data, smb2_data);
out:
kfree(smb2_data);
return rc;
}
int
smb2_mkdir(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_open_op_close(xid, tcon, cifs_sb, name,
FILE_WRITE_ATTRIBUTES, FILE_CREATE,
CREATE_NOT_FILE, NULL, SMB2_OP_MKDIR);
}
void
smb2_mkdir_setinfo(struct inode *inode, const char *name,
struct cifs_sb_info *cifs_sb, struct cifs_tcon *tcon,
const unsigned int xid)
{
FILE_BASIC_INFO data;
struct cifsInodeInfo *cifs_i;
u32 dosattrs;
int tmprc;
memset(&data, 0, sizeof(data));
cifs_i = CIFS_I(inode);
dosattrs = cifs_i->cifsAttrs | ATTR_READONLY;
data.Attributes = cpu_to_le32(dosattrs);
tmprc = smb2_open_op_close(xid, tcon, cifs_sb, name,
FILE_WRITE_ATTRIBUTES, FILE_CREATE,
CREATE_NOT_FILE, &data, SMB2_OP_SET_INFO);
if (tmprc == 0)
cifs_i->cifsAttrs = dosattrs;
}
int
smb2_rmdir(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_open_op_close(xid, tcon, cifs_sb, name, DELETE, FILE_OPEN,
CREATE_NOT_FILE,
NULL, SMB2_OP_RMDIR);
}
int
smb2_unlink(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_open_op_close(xid, tcon, cifs_sb, name, DELETE, FILE_OPEN,
CREATE_DELETE_ON_CLOSE | OPEN_REPARSE_POINT,
NULL, SMB2_OP_DELETE);
}
static int
smb2_set_path_attr(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb, __u32 access, int command)
{
__le16 *smb2_to_name = NULL;
int rc;
smb2_to_name = cifs_convert_path_to_utf16(to_name, cifs_sb);
if (smb2_to_name == NULL) {
rc = -ENOMEM;
goto smb2_rename_path;
}
rc = smb2_open_op_close(xid, tcon, cifs_sb, from_name, access,
FILE_OPEN, 0, smb2_to_name, command);
smb2_rename_path:
kfree(smb2_to_name);
return rc;
}
int
smb2_rename_path(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb)
{
return smb2_set_path_attr(xid, tcon, from_name, to_name, cifs_sb,
DELETE, SMB2_OP_RENAME);
}
int
smb2_create_hardlink(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb)
{
return smb2_set_path_attr(xid, tcon, from_name, to_name, cifs_sb,
FILE_READ_ATTRIBUTES, SMB2_OP_HARDLINK);
}
int
smb2_set_path_size(const unsigned int xid, struct cifs_tcon *tcon,
const char *full_path, __u64 size,
struct cifs_sb_info *cifs_sb, bool set_alloc)
{
__le64 eof = cpu_to_le64(size);
return smb2_open_op_close(xid, tcon, cifs_sb, full_path,
FILE_WRITE_DATA, FILE_OPEN, 0, &eof,
SMB2_OP_SET_EOF);
}
int
smb2_set_file_info(struct inode *inode, const char *full_path,
FILE_BASIC_INFO *buf, const unsigned int xid)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct tcon_link *tlink;
int rc;
if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&
(buf->LastWriteTime == 0) && (buf->ChangeTime) &&
(buf->Attributes == 0))
return 0; /* would be a no op, no sense sending this */
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
rc = smb2_open_op_close(xid, tlink_tcon(tlink), cifs_sb, full_path,
FILE_WRITE_ATTRIBUTES, FILE_OPEN, 0, buf,
SMB2_OP_SET_INFO);
cifs_put_tlink(tlink);
return rc;
}