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linux-next/fs/cifs/smb2file.c
Steve French 592fafe644 Add resilienthandles mount parm
Since many servers (Windows clients, and non-clustered servers) do not
support persistent handles but do support resilient handles, allow
the user to specify a mount option "resilienthandles" in order
to get more reliable connections and less chance of data loss
(at least when SMB2.1 or later).  Default resilient handle
timeout (120 seconds to recent Windows server) is used.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
2015-11-03 10:10:36 -06:00

285 lines
7.5 KiB
C

/*
* fs/cifs/smb2file.c
*
* Copyright (C) International Business Machines Corp., 2002, 2011
* Author(s): Steve French (sfrench@us.ibm.com),
* Pavel Shilovsky ((pshilovsky@samba.org) 2012
*
* 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 "smb2proto.h"
int
smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
__u32 *oplock, FILE_ALL_INFO *buf)
{
int rc;
__le16 *smb2_path;
struct smb2_file_all_info *smb2_data = NULL;
__u8 smb2_oplock[17];
struct cifs_fid *fid = oparms->fid;
struct network_resiliency_req nr_ioctl_req;
smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
if (smb2_path == NULL) {
rc = -ENOMEM;
goto out;
}
smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
GFP_KERNEL);
if (smb2_data == NULL) {
rc = -ENOMEM;
goto out;
}
oparms->desired_access |= FILE_READ_ATTRIBUTES;
*smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);
if (rc)
goto out;
if (oparms->tcon->use_resilient) {
nr_ioctl_req.Timeout = 0; /* use server default (120 seconds) */
nr_ioctl_req.Reserved = 0;
rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, true,
(char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
NULL, NULL /* no return info */);
if (rc == -EOPNOTSUPP) {
cifs_dbg(VFS,
"resiliency not supported by server, disabling\n");
oparms->tcon->use_resilient = false;
} else if (rc)
cifs_dbg(FYI, "error %d setting resiliency\n", rc);
rc = 0;
}
if (buf) {
/* open response does not have IndexNumber field - get it */
rc = SMB2_get_srv_num(xid, oparms->tcon, fid->persistent_fid,
fid->volatile_fid,
&smb2_data->IndexNumber);
if (rc) {
/* let get_inode_info disable server inode numbers */
smb2_data->IndexNumber = 0;
rc = 0;
}
move_smb2_info_to_cifs(buf, smb2_data);
}
*oplock = *smb2_oplock;
out:
kfree(smb2_data);
kfree(smb2_path);
return rc;
}
int
smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
const unsigned int xid)
{
int rc = 0, stored_rc;
unsigned int max_num, num = 0, max_buf;
struct smb2_lock_element *buf, *cur;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
struct cifsLockInfo *li, *tmp;
__u64 length = 1 + flock->fl_end - flock->fl_start;
struct list_head tmp_llist;
INIT_LIST_HEAD(&tmp_llist);
/*
* Accessing maxBuf is racy with cifs_reconnect - need to store value
* and check it for zero before using.
*/
max_buf = tcon->ses->server->maxBuf;
if (!max_buf)
return -EINVAL;
max_num = max_buf / sizeof(struct smb2_lock_element);
buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
if (!buf)
return -ENOMEM;
cur = buf;
down_write(&cinode->lock_sem);
list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
if (flock->fl_start > li->offset ||
(flock->fl_start + length) <
(li->offset + li->length))
continue;
if (current->tgid != li->pid)
continue;
if (cinode->can_cache_brlcks) {
/*
* We can cache brlock requests - simply remove a lock
* from the file's list.
*/
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
continue;
}
cur->Length = cpu_to_le64(li->length);
cur->Offset = cpu_to_le64(li->offset);
cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
/*
* We need to save a lock here to let us add it again to the
* file's list if the unlock range request fails on the server.
*/
list_move(&li->llist, &tmp_llist);
if (++num == max_num) {
stored_rc = smb2_lockv(xid, tcon,
cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
current->tgid, num, buf);
if (stored_rc) {
/*
* We failed on the unlock range request - add
* all locks from the tmp list to the head of
* the file's list.
*/
cifs_move_llist(&tmp_llist,
&cfile->llist->locks);
rc = stored_rc;
} else
/*
* The unlock range request succeed - free the
* tmp list.
*/
cifs_free_llist(&tmp_llist);
cur = buf;
num = 0;
} else
cur++;
}
if (num) {
stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
cfile->fid.volatile_fid, current->tgid,
num, buf);
if (stored_rc) {
cifs_move_llist(&tmp_llist, &cfile->llist->locks);
rc = stored_rc;
} else
cifs_free_llist(&tmp_llist);
}
up_write(&cinode->lock_sem);
kfree(buf);
return rc;
}
static int
smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
struct smb2_lock_element *buf, unsigned int max_num)
{
int rc = 0, stored_rc;
struct cifsFileInfo *cfile = fdlocks->cfile;
struct cifsLockInfo *li;
unsigned int num = 0;
struct smb2_lock_element *cur = buf;
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
list_for_each_entry(li, &fdlocks->locks, llist) {
cur->Length = cpu_to_le64(li->length);
cur->Offset = cpu_to_le64(li->offset);
cur->Flags = cpu_to_le32(li->type |
SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
if (++num == max_num) {
stored_rc = smb2_lockv(xid, tcon,
cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
current->tgid, num, buf);
if (stored_rc)
rc = stored_rc;
cur = buf;
num = 0;
} else
cur++;
}
if (num) {
stored_rc = smb2_lockv(xid, tcon,
cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
current->tgid, num, buf);
if (stored_rc)
rc = stored_rc;
}
return rc;
}
int
smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
{
int rc = 0, stored_rc;
unsigned int xid;
unsigned int max_num, max_buf;
struct smb2_lock_element *buf;
struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
struct cifs_fid_locks *fdlocks;
xid = get_xid();
/*
* Accessing maxBuf is racy with cifs_reconnect - need to store value
* and check it for zero before using.
*/
max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
if (!max_buf) {
free_xid(xid);
return -EINVAL;
}
max_num = max_buf / sizeof(struct smb2_lock_element);
buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
if (!buf) {
free_xid(xid);
return -ENOMEM;
}
list_for_each_entry(fdlocks, &cinode->llist, llist) {
stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
if (stored_rc)
rc = stored_rc;
}
kfree(buf);
free_xid(xid);
return rc;
}