kernel-ark/fs/cifs/transport.c
Steve French 31ca3bc3c5 [PATCH] cifs: Do not init smb requests or block when sending requests
if cifsd thread is no longer running to demultixplex responses.

Do not send FindClose request when FindFirst failed without reaching end
of search. 

Signed-off-by: Steve French (sfrench@us.ibm.com)
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-28 22:41:11 -07:00

636 lines
17 KiB
C

/*
* fs/cifs/transport.c
*
* Copyright (C) International Business Machines Corp., 2002,2005
* 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/list.h>
#include <linux/wait.h>
#include <linux/net.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
extern mempool_t *cifs_mid_poolp;
extern kmem_cache_t *cifs_oplock_cachep;
static struct mid_q_entry *
AllocMidQEntry(struct smb_hdr *smb_buffer, struct cifsSesInfo *ses)
{
struct mid_q_entry *temp;
if (ses == NULL) {
cERROR(1, ("Null session passed in to AllocMidQEntry"));
return NULL;
}
if (ses->server == NULL) {
cERROR(1, ("Null TCP session in AllocMidQEntry"));
return NULL;
}
temp = (struct mid_q_entry *) mempool_alloc(cifs_mid_poolp,SLAB_KERNEL | SLAB_NOFS);
if (temp == NULL)
return temp;
else {
memset(temp, 0, sizeof (struct mid_q_entry));
temp->mid = smb_buffer->Mid; /* always LE */
temp->pid = current->pid;
temp->command = smb_buffer->Command;
cFYI(1, ("For smb_command %d", temp->command));
do_gettimeofday(&temp->when_sent);
temp->ses = ses;
temp->tsk = current;
}
spin_lock(&GlobalMid_Lock);
list_add_tail(&temp->qhead, &ses->server->pending_mid_q);
atomic_inc(&midCount);
temp->midState = MID_REQUEST_ALLOCATED;
spin_unlock(&GlobalMid_Lock);
return temp;
}
static void
DeleteMidQEntry(struct mid_q_entry *midEntry)
{
spin_lock(&GlobalMid_Lock);
midEntry->midState = MID_FREE;
list_del(&midEntry->qhead);
atomic_dec(&midCount);
spin_unlock(&GlobalMid_Lock);
if(midEntry->largeBuf)
cifs_buf_release(midEntry->resp_buf);
else
cifs_small_buf_release(midEntry->resp_buf);
mempool_free(midEntry, cifs_mid_poolp);
}
struct oplock_q_entry *
AllocOplockQEntry(struct inode * pinode, __u16 fid, struct cifsTconInfo * tcon)
{
struct oplock_q_entry *temp;
if ((pinode== NULL) || (tcon == NULL)) {
cERROR(1, ("Null parms passed to AllocOplockQEntry"));
return NULL;
}
temp = (struct oplock_q_entry *) kmem_cache_alloc(cifs_oplock_cachep,
SLAB_KERNEL);
if (temp == NULL)
return temp;
else {
temp->pinode = pinode;
temp->tcon = tcon;
temp->netfid = fid;
spin_lock(&GlobalMid_Lock);
list_add_tail(&temp->qhead, &GlobalOplock_Q);
spin_unlock(&GlobalMid_Lock);
}
return temp;
}
void DeleteOplockQEntry(struct oplock_q_entry * oplockEntry)
{
spin_lock(&GlobalMid_Lock);
/* should we check if list empty first? */
list_del(&oplockEntry->qhead);
spin_unlock(&GlobalMid_Lock);
kmem_cache_free(cifs_oplock_cachep, oplockEntry);
}
int
smb_send(struct socket *ssocket, struct smb_hdr *smb_buffer,
unsigned int smb_buf_length, struct sockaddr *sin)
{
int rc = 0;
int i = 0;
struct msghdr smb_msg;
struct kvec iov;
unsigned len = smb_buf_length + 4;
if(ssocket == NULL)
return -ENOTSOCK; /* BB eventually add reconnect code here */
iov.iov_base = smb_buffer;
iov.iov_len = len;
smb_msg.msg_name = sin;
smb_msg.msg_namelen = sizeof (struct sockaddr);
smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0;
smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; /* BB add more flags?*/
/* smb header is converted in header_assemble. bcc and rest of SMB word
area, and byte area if necessary, is converted to littleendian in
cifssmb.c and RFC1001 len is converted to bigendian in smb_send
Flags2 is converted in SendReceive */
smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
cFYI(1, ("Sending smb of length %d ", smb_buf_length));
dump_smb(smb_buffer, len);
while (len > 0) {
rc = kernel_sendmsg(ssocket, &smb_msg, &iov, 1, len);
if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
i++;
if(i > 60) {
cERROR(1,
("sends on sock %p stuck for 30 seconds",
ssocket));
rc = -EAGAIN;
break;
}
msleep(500);
continue;
}
if (rc < 0)
break;
iov.iov_base += rc;
iov.iov_len -= rc;
len -= rc;
}
if (rc < 0) {
cERROR(1,("Error %d sending data on socket to server.", rc));
} else {
rc = 0;
}
return rc;
}
#ifdef CIFS_EXPERIMENTAL
/* BB finish off this function, adding support for writing set of pages as iovec */
/* and also adding support for operations that need to parse the response smb */
int
smb_sendv(struct socket *ssocket, struct smb_hdr *smb_buffer,
unsigned int smb_buf_length, struct kvec * write_vector
/* page list */, struct sockaddr *sin)
{
int rc = 0;
int i = 0;
struct msghdr smb_msg;
number_of_pages += 1; /* account for SMB header */
struct kvec * piov = kmalloc(number_of_pages * sizeof(struct kvec));
unsigned len = smb_buf_length + 4;
if(ssocket == NULL)
return -ENOTSOCK; /* BB eventually add reconnect code here */
iov.iov_base = smb_buffer;
iov.iov_len = len;
smb_msg.msg_name = sin;
smb_msg.msg_namelen = sizeof (struct sockaddr);
smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0;
smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; /* BB add more flags?*/
/* smb header is converted in header_assemble. bcc and rest of SMB word
area, and byte area if necessary, is converted to littleendian in
cifssmb.c and RFC1001 len is converted to bigendian in smb_send
Flags2 is converted in SendReceive */
smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
cFYI(1, ("Sending smb of length %d ", smb_buf_length));
dump_smb(smb_buffer, len);
while (len > 0) {
rc = kernel_sendmsg(ssocket, &smb_msg, &iov, number_of_pages,
len);
if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
i++;
if(i > 60) {
cERROR(1,
("sends on sock %p stuck for 30 seconds",
ssocket));
rc = -EAGAIN;
break;
}
msleep(500);
continue;
}
if (rc < 0)
break;
iov.iov_base += rc;
iov.iov_len -= rc;
len -= rc;
}
if (rc < 0) {
cERROR(1,("Error %d sending data on socket to server.", rc));
} else {
rc = 0;
}
return rc;
}
int
CIFSSendRcv(const unsigned int xid, struct cifsSesInfo *ses,
struct smb_hdr *in_buf, struct kvec * write_vector /* page list */, int *pbytes_returned, const int long_op)
{
int rc = 0;
unsigned long timeout = 15 * HZ;
struct mid_q_entry *midQ = NULL;
if (ses == NULL) {
cERROR(1,("Null smb session"));
return -EIO;
}
if(ses->server == NULL) {
cERROR(1,("Null tcp session"));
return -EIO;
}
if(pbytes_returned == NULL)
return -EIO;
else
*pbytes_returned = 0;
if(ses->server->tcpStatus == CIFS_EXITING)
return -ENOENT;
/* Ensure that we do not send more than 50 overlapping requests
to the same server. We may make this configurable later or
use ses->maxReq */
if(long_op == -1) {
/* oplock breaks must not be held up */
atomic_inc(&ses->server->inFlight);
} else {
spin_lock(&GlobalMid_Lock);
while(1) {
if(atomic_read(&ses->server->inFlight) >= cifs_max_pending){
spin_unlock(&GlobalMid_Lock);
wait_event(ses->server->request_q,
atomic_read(&ses->server->inFlight)
< cifs_max_pending);
spin_lock(&GlobalMid_Lock);
} else {
if(ses->server->tcpStatus == CifsExiting) {
spin_unlock(&GlobalMid_Lock);
return -ENOENT;
}
/* can not count locking commands against total since
they are allowed to block on server */
if(long_op < 3) {
/* update # of requests on the wire to server */
atomic_inc(&ses->server->inFlight);
}
spin_unlock(&GlobalMid_Lock);
break;
}
}
}
/* make sure that we sign in the same order that we send on this socket
and avoid races inside tcp sendmsg code that could cause corruption
of smb data */
down(&ses->server->tcpSem);
if (ses->server->tcpStatus == CifsExiting) {
rc = -ENOENT;
goto cifs_out_label;
} else if (ses->server->tcpStatus == CifsNeedReconnect) {
cFYI(1,("tcp session dead - return to caller to retry"));
rc = -EAGAIN;
goto cifs_out_label;
} else if (ses->status != CifsGood) {
/* check if SMB session is bad because we are setting it up */
if((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
(in_buf->Command != SMB_COM_NEGOTIATE)) {
rc = -EAGAIN;
goto cifs_out_label;
} /* else ok - we are setting up session */
}
midQ = AllocMidQEntry(in_buf, ses);
if (midQ == NULL) {
up(&ses->server->tcpSem);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return -ENOMEM;
}
if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
up(&ses->server->tcpSem);
cERROR(1,
("Illegal length, greater than maximum frame, %d ",
in_buf->smb_buf_length));
DeleteMidQEntry(midQ);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return -EIO;
}
/* BB can we sign efficiently in this path? */
rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
midQ->midState = MID_REQUEST_SUBMITTED;
/* rc = smb_sendv(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
piovec,
(struct sockaddr *) &(ses->server->addr.sockAddr));*/
if(rc < 0) {
DeleteMidQEntry(midQ);
up(&ses->server->tcpSem);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
} else
up(&ses->server->tcpSem);
cifs_out_label:
if(midQ)
DeleteMidQEntry(midQ);
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
}
#endif /* CIFS_EXPERIMENTAL */
int
SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
struct smb_hdr *in_buf, struct smb_hdr *out_buf,
int *pbytes_returned, const int long_op)
{
int rc = 0;
unsigned int receive_len;
unsigned long timeout;
struct mid_q_entry *midQ;
if (ses == NULL) {
cERROR(1,("Null smb session"));
return -EIO;
}
if(ses->server == NULL) {
cERROR(1,("Null tcp session"));
return -EIO;
}
if(ses->server->tcpStatus == CifsExiting)
return -ENOENT;
/* Ensure that we do not send more than 50 overlapping requests
to the same server. We may make this configurable later or
use ses->maxReq */
if(long_op == -1) {
/* oplock breaks must not be held up */
atomic_inc(&ses->server->inFlight);
} else {
spin_lock(&GlobalMid_Lock);
while(1) {
if(atomic_read(&ses->server->inFlight) >=
cifs_max_pending){
spin_unlock(&GlobalMid_Lock);
wait_event(ses->server->request_q,
atomic_read(&ses->server->inFlight)
< cifs_max_pending);
spin_lock(&GlobalMid_Lock);
} else {
if(ses->server->tcpStatus == CifsExiting) {
spin_unlock(&GlobalMid_Lock);
return -ENOENT;
}
/* can not count locking commands against total since
they are allowed to block on server */
if(long_op < 3) {
/* update # of requests on the wire to server */
atomic_inc(&ses->server->inFlight);
}
spin_unlock(&GlobalMid_Lock);
break;
}
}
}
/* make sure that we sign in the same order that we send on this socket
and avoid races inside tcp sendmsg code that could cause corruption
of smb data */
down(&ses->server->tcpSem);
if (ses->server->tcpStatus == CifsExiting) {
rc = -ENOENT;
goto out_unlock;
} else if (ses->server->tcpStatus == CifsNeedReconnect) {
cFYI(1,("tcp session dead - return to caller to retry"));
rc = -EAGAIN;
goto out_unlock;
} else if (ses->status != CifsGood) {
/* check if SMB session is bad because we are setting it up */
if((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
(in_buf->Command != SMB_COM_NEGOTIATE)) {
rc = -EAGAIN;
goto out_unlock;
} /* else ok - we are setting up session */
}
midQ = AllocMidQEntry(in_buf, ses);
if (midQ == NULL) {
up(&ses->server->tcpSem);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return -ENOMEM;
}
if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
up(&ses->server->tcpSem);
cERROR(1,
("Illegal length, greater than maximum frame, %d ",
in_buf->smb_buf_length));
DeleteMidQEntry(midQ);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return -EIO;
}
rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
midQ->midState = MID_REQUEST_SUBMITTED;
rc = smb_send(ses->server->ssocket, in_buf, in_buf->smb_buf_length,
(struct sockaddr *) &(ses->server->addr.sockAddr));
if(rc < 0) {
DeleteMidQEntry(midQ);
up(&ses->server->tcpSem);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
} else
up(&ses->server->tcpSem);
if (long_op == -1)
goto cifs_no_response_exit;
else if (long_op == 2) /* writes past end of file can take loong time */
timeout = 300 * HZ;
else if (long_op == 1)
timeout = 45 * HZ; /* should be greater than
servers oplock break timeout (about 43 seconds) */
else if (long_op > 2) {
timeout = MAX_SCHEDULE_TIMEOUT;
} else
timeout = 15 * HZ;
/* wait for 15 seconds or until woken up due to response arriving or
due to last connection to this server being unmounted */
if (signal_pending(current)) {
/* if signal pending do not hold up user for full smb timeout
but we still give response a change to complete */
timeout = 2 * HZ;
}
/* No user interrupts in wait - wreaks havoc with performance */
if(timeout != MAX_SCHEDULE_TIMEOUT) {
timeout += jiffies;
wait_event(ses->server->response_q,
(!(midQ->midState & MID_REQUEST_SUBMITTED)) ||
time_after(jiffies, timeout) ||
((ses->server->tcpStatus != CifsGood) &&
(ses->server->tcpStatus != CifsNew)));
} else {
wait_event(ses->server->response_q,
(!(midQ->midState & MID_REQUEST_SUBMITTED)) ||
((ses->server->tcpStatus != CifsGood) &&
(ses->server->tcpStatus != CifsNew)));
}
spin_lock(&GlobalMid_Lock);
if (midQ->resp_buf) {
spin_unlock(&GlobalMid_Lock);
receive_len = be32_to_cpu(*(__be32 *)midQ->resp_buf);
} else {
cERROR(1,("No response buffer"));
if(midQ->midState == MID_REQUEST_SUBMITTED) {
if(ses->server->tcpStatus == CifsExiting)
rc = -EHOSTDOWN;
else {
ses->server->tcpStatus = CifsNeedReconnect;
midQ->midState = MID_RETRY_NEEDED;
}
}
if (rc != -EHOSTDOWN) {
if(midQ->midState == MID_RETRY_NEEDED) {
rc = -EAGAIN;
cFYI(1,("marking request for retry"));
} else {
rc = -EIO;
}
}
spin_unlock(&GlobalMid_Lock);
DeleteMidQEntry(midQ);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
}
if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
cERROR(1, ("Frame too large received. Length: %d Xid: %d",
receive_len, xid));
rc = -EIO;
} else { /* rcvd frame is ok */
if (midQ->resp_buf && out_buf
&& (midQ->midState == MID_RESPONSE_RECEIVED)) {
out_buf->smb_buf_length = receive_len;
memcpy((char *)out_buf + 4,
(char *)midQ->resp_buf + 4,
receive_len);
dump_smb(out_buf, 92);
/* convert the length into a more usable form */
if((receive_len > 24) &&
(ses->server->secMode & (SECMODE_SIGN_REQUIRED |
SECMODE_SIGN_ENABLED))) {
rc = cifs_verify_signature(out_buf,
ses->server->mac_signing_key,
midQ->sequence_number+1);
if(rc) {
cERROR(1,("Unexpected SMB signature"));
/* BB FIXME add code to kill session */
}
}
*pbytes_returned = out_buf->smb_buf_length;
/* BB special case reconnect tid and uid here? */
rc = map_smb_to_linux_error(out_buf);
/* convert ByteCount if necessary */
if (receive_len >=
sizeof (struct smb_hdr) -
4 /* do not count RFC1001 header */ +
(2 * out_buf->WordCount) + 2 /* bcc */ )
BCC(out_buf) = le16_to_cpu(BCC(out_buf));
} else {
rc = -EIO;
cFYI(1,("Bad MID state? "));
}
}
cifs_no_response_exit:
DeleteMidQEntry(midQ);
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
out_unlock:
up(&ses->server->tcpSem);
/* If not lock req, update # of requests on wire to server */
if(long_op < 3) {
atomic_dec(&ses->server->inFlight);
wake_up(&ses->server->request_q);
}
return rc;
}