linux-stable/fs/smbfs/request.c
Paul Mundt 20c2df83d2 mm: Remove slab destructors from kmem_cache_create().
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-20 10:11:58 +09:00

818 lines
20 KiB
C

/*
* request.c
*
* Copyright (C) 2001 by Urban Widmark
*
* Please add a note about your changes to smbfs in the ChangeLog file.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/sched.h>
#include <linux/smb_fs.h>
#include <linux/smbno.h>
#include <linux/smb_mount.h>
#include "smb_debug.h"
#include "request.h"
#include "proto.h"
/* #define SMB_SLAB_DEBUG (SLAB_RED_ZONE | SLAB_POISON) */
#define SMB_SLAB_DEBUG 0
/* cache for request structures */
static struct kmem_cache *req_cachep;
static int smb_request_send_req(struct smb_request *req);
/*
/proc/slabinfo:
name, active, num, objsize, active_slabs, num_slaps, #pages
*/
int smb_init_request_cache(void)
{
req_cachep = kmem_cache_create("smb_request",
sizeof(struct smb_request), 0,
SMB_SLAB_DEBUG | SLAB_HWCACHE_ALIGN,
NULL);
if (req_cachep == NULL)
return -ENOMEM;
return 0;
}
void smb_destroy_request_cache(void)
{
kmem_cache_destroy(req_cachep);
}
/*
* Allocate and initialise a request structure
*/
static struct smb_request *smb_do_alloc_request(struct smb_sb_info *server,
int bufsize)
{
struct smb_request *req;
unsigned char *buf = NULL;
req = kmem_cache_zalloc(req_cachep, GFP_KERNEL);
VERBOSE("allocating request: %p\n", req);
if (!req)
goto out;
if (bufsize > 0) {
buf = kmalloc(bufsize, GFP_NOFS);
if (!buf) {
kmem_cache_free(req_cachep, req);
return NULL;
}
}
req->rq_buffer = buf;
req->rq_bufsize = bufsize;
req->rq_server = server;
init_waitqueue_head(&req->rq_wait);
INIT_LIST_HEAD(&req->rq_queue);
atomic_set(&req->rq_count, 1);
out:
return req;
}
struct smb_request *smb_alloc_request(struct smb_sb_info *server, int bufsize)
{
struct smb_request *req = NULL;
for (;;) {
atomic_inc(&server->nr_requests);
if (atomic_read(&server->nr_requests) <= MAX_REQUEST_HARD) {
req = smb_do_alloc_request(server, bufsize);
if (req != NULL)
break;
}
#if 0
/*
* Try to free up at least one request in order to stay
* below the hard limit
*/
if (nfs_try_to_free_pages(server))
continue;
if (signalled() && (server->flags & NFS_MOUNT_INTR))
return ERR_PTR(-ERESTARTSYS);
current->policy = SCHED_YIELD;
schedule();
#else
/* FIXME: we want something like nfs does above, but that
requires changes to all callers and can wait. */
break;
#endif
}
return req;
}
static void smb_free_request(struct smb_request *req)
{
atomic_dec(&req->rq_server->nr_requests);
if (req->rq_buffer && !(req->rq_flags & SMB_REQ_STATIC))
kfree(req->rq_buffer);
kfree(req->rq_trans2buffer);
kmem_cache_free(req_cachep, req);
}
/*
* What prevents a rget to race with a rput? The count must never drop to zero
* while it is in use. Only rput if it is ok that it is free'd.
*/
static void smb_rget(struct smb_request *req)
{
atomic_inc(&req->rq_count);
}
void smb_rput(struct smb_request *req)
{
if (atomic_dec_and_test(&req->rq_count)) {
list_del_init(&req->rq_queue);
smb_free_request(req);
}
}
/* setup to receive the data part of the SMB */
static int smb_setup_bcc(struct smb_request *req)
{
int result = 0;
req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;
if (req->rq_rlen > req->rq_bufsize) {
PARANOIA("Packet too large %d > %d\n",
req->rq_rlen, req->rq_bufsize);
return -ENOBUFS;
}
req->rq_iov[0].iov_base = req->rq_buffer;
req->rq_iov[0].iov_len = req->rq_rlen;
req->rq_iovlen = 1;
return result;
}
/*
* Prepare a "normal" request structure.
*/
static int smb_setup_request(struct smb_request *req)
{
int len = smb_len(req->rq_header) + 4;
req->rq_slen = len;
/* if we expect a data part in the reply we set the iov's to read it */
if (req->rq_resp_bcc)
req->rq_setup_read = smb_setup_bcc;
/* This tries to support re-using the same request */
req->rq_bytes_sent = 0;
req->rq_rcls = 0;
req->rq_err = 0;
req->rq_errno = 0;
req->rq_fragment = 0;
kfree(req->rq_trans2buffer);
req->rq_trans2buffer = NULL;
return 0;
}
/*
* Prepare a transaction2 request structure
*/
static int smb_setup_trans2request(struct smb_request *req)
{
struct smb_sb_info *server = req->rq_server;
int mparam, mdata;
static unsigned char padding[4];
/* I know the following is very ugly, but I want to build the
smb packet as efficiently as possible. */
const int smb_parameters = 15;
const int header = SMB_HEADER_LEN + 2 * smb_parameters + 2;
const int oparam = ALIGN(header + 3, sizeof(u32));
const int odata = ALIGN(oparam + req->rq_lparm, sizeof(u32));
const int bcc = (req->rq_data ? odata + req->rq_ldata :
oparam + req->rq_lparm) - header;
if ((bcc + oparam) > server->opt.max_xmit)
return -ENOMEM;
smb_setup_header(req, SMBtrans2, smb_parameters, bcc);
/*
* max parameters + max data + max setup == bufsize to make NT4 happy
* and not abort the transfer or split into multiple responses. It also
* makes smbfs happy as handling packets larger than the buffer size
* is extra work.
*
* OS/2 is probably going to hate me for this ...
*/
mparam = SMB_TRANS2_MAX_PARAM;
mdata = req->rq_bufsize - mparam;
mdata = server->opt.max_xmit - mparam - 100;
if (mdata < 1024) {
mdata = 1024;
mparam = 20;
}
#if 0
/* NT/win2k has ~4k max_xmit, so with this we request more than it wants
to return as one SMB. Useful for testing the fragmented trans2
handling. */
mdata = 8192;
#endif
WSET(req->rq_header, smb_tpscnt, req->rq_lparm);
WSET(req->rq_header, smb_tdscnt, req->rq_ldata);
WSET(req->rq_header, smb_mprcnt, mparam);
WSET(req->rq_header, smb_mdrcnt, mdata);
WSET(req->rq_header, smb_msrcnt, 0); /* max setup always 0 ? */
WSET(req->rq_header, smb_flags, 0);
DSET(req->rq_header, smb_timeout, 0);
WSET(req->rq_header, smb_pscnt, req->rq_lparm);
WSET(req->rq_header, smb_psoff, oparam - 4);
WSET(req->rq_header, smb_dscnt, req->rq_ldata);
WSET(req->rq_header, smb_dsoff, req->rq_data ? odata - 4 : 0);
*(req->rq_header + smb_suwcnt) = 0x01; /* setup count */
*(req->rq_header + smb_suwcnt + 1) = 0x00; /* reserved */
WSET(req->rq_header, smb_setup0, req->rq_trans2_command);
req->rq_iovlen = 2;
req->rq_iov[0].iov_base = (void *) req->rq_header;
req->rq_iov[0].iov_len = oparam;
req->rq_iov[1].iov_base = (req->rq_parm==NULL) ? padding : req->rq_parm;
req->rq_iov[1].iov_len = req->rq_lparm;
req->rq_slen = oparam + req->rq_lparm;
if (req->rq_data) {
req->rq_iovlen += 2;
req->rq_iov[2].iov_base = padding;
req->rq_iov[2].iov_len = odata - oparam - req->rq_lparm;
req->rq_iov[3].iov_base = req->rq_data;
req->rq_iov[3].iov_len = req->rq_ldata;
req->rq_slen = odata + req->rq_ldata;
}
/* always a data part for trans2 replies */
req->rq_setup_read = smb_setup_bcc;
return 0;
}
/*
* Add a request and tell smbiod to process it
*/
int smb_add_request(struct smb_request *req)
{
long timeleft;
struct smb_sb_info *server = req->rq_server;
int result = 0;
smb_setup_request(req);
if (req->rq_trans2_command) {
if (req->rq_buffer == NULL) {
PARANOIA("trans2 attempted without response buffer!\n");
return -EIO;
}
result = smb_setup_trans2request(req);
}
if (result < 0)
return result;
#ifdef SMB_DEBUG_PACKET_SIZE
add_xmit_stats(req);
#endif
/* add 'req' to the queue of requests */
if (smb_lock_server_interruptible(server))
return -EINTR;
/*
* Try to send the request as the process. If that fails we queue the
* request and let smbiod send it later.
*/
/* FIXME: each server has a number on the maximum number of parallel
requests. 10, 50 or so. We should not allow more requests to be
active. */
if (server->mid > 0xf000)
server->mid = 0;
req->rq_mid = server->mid++;
WSET(req->rq_header, smb_mid, req->rq_mid);
result = 0;
if (server->state == CONN_VALID) {
if (list_empty(&server->xmitq))
result = smb_request_send_req(req);
if (result < 0) {
/* Connection lost? */
server->conn_error = result;
server->state = CONN_INVALID;
}
}
if (result != 1)
list_add_tail(&req->rq_queue, &server->xmitq);
smb_rget(req);
if (server->state != CONN_VALID)
smbiod_retry(server);
smb_unlock_server(server);
smbiod_wake_up();
timeleft = wait_event_interruptible_timeout(req->rq_wait,
req->rq_flags & SMB_REQ_RECEIVED, 30*HZ);
if (!timeleft || signal_pending(current)) {
/*
* On timeout or on interrupt we want to try and remove the
* request from the recvq/xmitq.
* First check if the request is still part of a queue. (May
* have been removed by some error condition)
*/
smb_lock_server(server);
if (!list_empty(&req->rq_queue)) {
list_del_init(&req->rq_queue);
smb_rput(req);
}
smb_unlock_server(server);
}
if (!timeleft) {
PARANOIA("request [%p, mid=%d] timed out!\n",
req, req->rq_mid);
VERBOSE("smb_com: %02x\n", *(req->rq_header + smb_com));
VERBOSE("smb_rcls: %02x\n", *(req->rq_header + smb_rcls));
VERBOSE("smb_flg: %02x\n", *(req->rq_header + smb_flg));
VERBOSE("smb_tid: %04x\n", WVAL(req->rq_header, smb_tid));
VERBOSE("smb_pid: %04x\n", WVAL(req->rq_header, smb_pid));
VERBOSE("smb_uid: %04x\n", WVAL(req->rq_header, smb_uid));
VERBOSE("smb_mid: %04x\n", WVAL(req->rq_header, smb_mid));
VERBOSE("smb_wct: %02x\n", *(req->rq_header + smb_wct));
req->rq_rcls = ERRSRV;
req->rq_err = ERRtimeout;
/* Just in case it was "stuck" */
smbiod_wake_up();
}
VERBOSE("woke up, rcls=%d\n", req->rq_rcls);
if (req->rq_rcls != 0)
req->rq_errno = smb_errno(req);
if (signal_pending(current))
req->rq_errno = -ERESTARTSYS;
return req->rq_errno;
}
/*
* Send a request and place it on the recvq if successfully sent.
* Must be called with the server lock held.
*/
static int smb_request_send_req(struct smb_request *req)
{
struct smb_sb_info *server = req->rq_server;
int result;
if (req->rq_bytes_sent == 0) {
WSET(req->rq_header, smb_tid, server->opt.tid);
WSET(req->rq_header, smb_pid, 1);
WSET(req->rq_header, smb_uid, server->opt.server_uid);
}
result = smb_send_request(req);
if (result < 0 && result != -EAGAIN)
goto out;
result = 0;
if (!(req->rq_flags & SMB_REQ_TRANSMITTED))
goto out;
list_move_tail(&req->rq_queue, &server->recvq);
result = 1;
out:
return result;
}
/*
* Sends one request for this server. (smbiod)
* Must be called with the server lock held.
* Returns: <0 on error
* 0 if no request could be completely sent
* 1 if all data for one request was sent
*/
int smb_request_send_server(struct smb_sb_info *server)
{
struct list_head *head;
struct smb_request *req;
int result;
if (server->state != CONN_VALID)
return 0;
/* dequeue first request, if any */
req = NULL;
head = server->xmitq.next;
if (head != &server->xmitq) {
req = list_entry(head, struct smb_request, rq_queue);
}
if (!req)
return 0;
result = smb_request_send_req(req);
if (result < 0) {
server->conn_error = result;
list_move(&req->rq_queue, &server->xmitq);
result = -EIO;
goto out;
}
out:
return result;
}
/*
* Try to find a request matching this "mid". Typically the first entry will
* be the matching one.
*/
static struct smb_request *find_request(struct smb_sb_info *server, int mid)
{
struct list_head *tmp;
struct smb_request *req = NULL;
list_for_each(tmp, &server->recvq) {
req = list_entry(tmp, struct smb_request, rq_queue);
if (req->rq_mid == mid) {
break;
}
req = NULL;
}
if (!req) {
VERBOSE("received reply with mid %d but no request!\n",
WVAL(server->header, smb_mid));
server->rstate = SMB_RECV_DROP;
}
return req;
}
/*
* Called when we have read the smb header and believe this is a response.
*/
static int smb_init_request(struct smb_sb_info *server, struct smb_request *req)
{
int hdrlen, wct;
memcpy(req->rq_header, server->header, SMB_HEADER_LEN);
wct = *(req->rq_header + smb_wct);
if (wct > 20) {
PARANOIA("wct too large, %d > 20\n", wct);
server->rstate = SMB_RECV_DROP;
return 0;
}
req->rq_resp_wct = wct;
hdrlen = SMB_HEADER_LEN + wct*2 + 2;
VERBOSE("header length: %d smb_wct: %2d\n", hdrlen, wct);
req->rq_bytes_recvd = SMB_HEADER_LEN;
req->rq_rlen = hdrlen;
req->rq_iov[0].iov_base = req->rq_header;
req->rq_iov[0].iov_len = hdrlen;
req->rq_iovlen = 1;
server->rstate = SMB_RECV_PARAM;
#ifdef SMB_DEBUG_PACKET_SIZE
add_recv_stats(smb_len(server->header));
#endif
return 0;
}
/*
* Reads the SMB parameters
*/
static int smb_recv_param(struct smb_sb_info *server, struct smb_request *req)
{
int result;
result = smb_receive(server, req);
if (result < 0)
return result;
if (req->rq_bytes_recvd < req->rq_rlen)
return 0;
VERBOSE("result: %d smb_bcc: %04x\n", result,
WVAL(req->rq_header, SMB_HEADER_LEN +
(*(req->rq_header + smb_wct) * 2)));
result = 0;
req->rq_iov[0].iov_base = NULL;
req->rq_rlen = 0;
if (req->rq_callback)
req->rq_callback(req);
else if (req->rq_setup_read)
result = req->rq_setup_read(req);
if (result < 0) {
server->rstate = SMB_RECV_DROP;
return result;
}
server->rstate = req->rq_rlen > 0 ? SMB_RECV_DATA : SMB_RECV_END;
req->rq_bytes_recvd = 0; // recvd out of the iov
VERBOSE("rlen: %d\n", req->rq_rlen);
if (req->rq_rlen < 0) {
PARANOIA("Parameters read beyond end of packet!\n");
server->rstate = SMB_RECV_END;
return -EIO;
}
return 0;
}
/*
* Reads the SMB data
*/
static int smb_recv_data(struct smb_sb_info *server, struct smb_request *req)
{
int result;
result = smb_receive(server, req);
if (result < 0)
goto out;
if (req->rq_bytes_recvd < req->rq_rlen)
goto out;
server->rstate = SMB_RECV_END;
out:
VERBOSE("result: %d\n", result);
return result;
}
/*
* Receive a transaction2 response
* Return: 0 if the response has been fully read
* 1 if there are further "fragments" to read
* <0 if there is an error
*/
static int smb_recv_trans2(struct smb_sb_info *server, struct smb_request *req)
{
unsigned char *inbuf;
unsigned int parm_disp, parm_offset, parm_count, parm_tot;
unsigned int data_disp, data_offset, data_count, data_tot;
int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;
VERBOSE("handling trans2\n");
inbuf = req->rq_header;
data_tot = WVAL(inbuf, smb_tdrcnt);
parm_tot = WVAL(inbuf, smb_tprcnt);
parm_disp = WVAL(inbuf, smb_prdisp);
parm_offset = WVAL(inbuf, smb_proff);
parm_count = WVAL(inbuf, smb_prcnt);
data_disp = WVAL(inbuf, smb_drdisp);
data_offset = WVAL(inbuf, smb_droff);
data_count = WVAL(inbuf, smb_drcnt);
/* Modify offset for the split header/buffer we use */
if (data_count || data_offset) {
if (unlikely(data_offset < hdrlen))
goto out_bad_data;
else
data_offset -= hdrlen;
}
if (parm_count || parm_offset) {
if (unlikely(parm_offset < hdrlen))
goto out_bad_parm;
else
parm_offset -= hdrlen;
}
if (parm_count == parm_tot && data_count == data_tot) {
/*
* This packet has all the trans2 data.
*
* We setup the request so that this will be the common
* case. It may be a server error to not return a
* response that fits.
*/
VERBOSE("single trans2 response "
"dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
data_count, parm_count,
data_offset, parm_offset);
req->rq_ldata = data_count;
req->rq_lparm = parm_count;
req->rq_data = req->rq_buffer + data_offset;
req->rq_parm = req->rq_buffer + parm_offset;
if (unlikely(parm_offset + parm_count > req->rq_rlen))
goto out_bad_parm;
if (unlikely(data_offset + data_count > req->rq_rlen))
goto out_bad_data;
return 0;
}
VERBOSE("multi trans2 response "
"frag=%d, dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
req->rq_fragment,
data_count, parm_count,
data_offset, parm_offset);
if (!req->rq_fragment) {
int buf_len;
/* We got the first trans2 fragment */
req->rq_fragment = 1;
req->rq_total_data = data_tot;
req->rq_total_parm = parm_tot;
req->rq_ldata = 0;
req->rq_lparm = 0;
buf_len = data_tot + parm_tot;
if (buf_len > SMB_MAX_PACKET_SIZE)
goto out_too_long;
req->rq_trans2bufsize = buf_len;
req->rq_trans2buffer = kzalloc(buf_len, GFP_NOFS);
if (!req->rq_trans2buffer)
goto out_no_mem;
req->rq_parm = req->rq_trans2buffer;
req->rq_data = req->rq_trans2buffer + parm_tot;
} else if (unlikely(req->rq_total_data < data_tot ||
req->rq_total_parm < parm_tot))
goto out_data_grew;
if (unlikely(parm_disp + parm_count > req->rq_total_parm ||
parm_offset + parm_count > req->rq_rlen))
goto out_bad_parm;
if (unlikely(data_disp + data_count > req->rq_total_data ||
data_offset + data_count > req->rq_rlen))
goto out_bad_data;
inbuf = req->rq_buffer;
memcpy(req->rq_parm + parm_disp, inbuf + parm_offset, parm_count);
memcpy(req->rq_data + data_disp, inbuf + data_offset, data_count);
req->rq_ldata += data_count;
req->rq_lparm += parm_count;
/*
* Check whether we've received all of the data. Note that
* we use the packet totals -- total lengths might shrink!
*/
if (req->rq_ldata >= data_tot && req->rq_lparm >= parm_tot) {
req->rq_ldata = data_tot;
req->rq_lparm = parm_tot;
return 0;
}
return 1;
out_too_long:
printk(KERN_ERR "smb_trans2: data/param too long, data=%u, parm=%u\n",
data_tot, parm_tot);
goto out_EIO;
out_no_mem:
printk(KERN_ERR "smb_trans2: couldn't allocate data area of %d bytes\n",
req->rq_trans2bufsize);
req->rq_errno = -ENOMEM;
goto out;
out_data_grew:
printk(KERN_ERR "smb_trans2: data/params grew!\n");
goto out_EIO;
out_bad_parm:
printk(KERN_ERR "smb_trans2: invalid parms, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
parm_disp, parm_count, parm_tot, parm_offset);
goto out_EIO;
out_bad_data:
printk(KERN_ERR "smb_trans2: invalid data, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
data_disp, data_count, data_tot, data_offset);
out_EIO:
req->rq_errno = -EIO;
out:
return req->rq_errno;
}
/*
* State machine for receiving responses. We handle the fact that we can't
* read the full response in one try by having states telling us how much we
* have read.
*
* Must be called with the server lock held (only called from smbiod).
*
* Return: <0 on error
*/
int smb_request_recv(struct smb_sb_info *server)
{
struct smb_request *req = NULL;
int result = 0;
if (smb_recv_available(server) <= 0)
return 0;
VERBOSE("state: %d\n", server->rstate);
switch (server->rstate) {
case SMB_RECV_DROP:
result = smb_receive_drop(server);
if (result < 0)
break;
if (server->rstate == SMB_RECV_DROP)
break;
server->rstate = SMB_RECV_START;
/* fallthrough */
case SMB_RECV_START:
server->smb_read = 0;
server->rstate = SMB_RECV_HEADER;
/* fallthrough */
case SMB_RECV_HEADER:
result = smb_receive_header(server);
if (result < 0)
break;
if (server->rstate == SMB_RECV_HEADER)
break;
if (! (*(server->header + smb_flg) & SMB_FLAGS_REPLY) ) {
server->rstate = SMB_RECV_REQUEST;
break;
}
if (server->rstate != SMB_RECV_HCOMPLETE)
break;
/* fallthrough */
case SMB_RECV_HCOMPLETE:
req = find_request(server, WVAL(server->header, smb_mid));
if (!req)
break;
smb_init_request(server, req);
req->rq_rcls = *(req->rq_header + smb_rcls);
req->rq_err = WVAL(req->rq_header, smb_err);
if (server->rstate != SMB_RECV_PARAM)
break;
/* fallthrough */
case SMB_RECV_PARAM:
if (!req)
req = find_request(server,WVAL(server->header,smb_mid));
if (!req)
break;
result = smb_recv_param(server, req);
if (result < 0)
break;
if (server->rstate != SMB_RECV_DATA)
break;
/* fallthrough */
case SMB_RECV_DATA:
if (!req)
req = find_request(server,WVAL(server->header,smb_mid));
if (!req)
break;
result = smb_recv_data(server, req);
if (result < 0)
break;
break;
/* We should never be called with any of these states */
case SMB_RECV_END:
case SMB_RECV_REQUEST:
BUG();
}
if (result < 0) {
/* We saw an error */
return result;
}
if (server->rstate != SMB_RECV_END)
return 0;
result = 0;
if (req->rq_trans2_command && req->rq_rcls == SUCCESS)
result = smb_recv_trans2(server, req);
/*
* Response completely read. Drop any extra bytes sent by the server.
* (Yes, servers sometimes add extra bytes to responses)
*/
VERBOSE("smb_len: %d smb_read: %d\n",
server->smb_len, server->smb_read);
if (server->smb_read < server->smb_len)
smb_receive_drop(server);
server->rstate = SMB_RECV_START;
if (!result) {
list_del_init(&req->rq_queue);
req->rq_flags |= SMB_REQ_RECEIVED;
smb_rput(req);
wake_up_interruptible(&req->rq_wait);
}
return 0;
}