| /* |
| * fs/cifs/transport.c |
| * |
| * Copyright (C) International Business Machines Corp., 2002,2008 |
| * Author(s): Steve French (sfrench@us.ibm.com) |
| * Jeremy Allison (jra@samba.org) 2006. |
| * |
| * 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/gfp.h> |
| #include <linux/wait.h> |
| #include <linux/net.h> |
| #include <linux/delay.h> |
| #include <linux/freezer.h> |
| #include <linux/tcp.h> |
| #include <linux/bvec.h> |
| #include <linux/highmem.h> |
| #include <linux/uaccess.h> |
| #include <asm/processor.h> |
| #include <linux/mempool.h> |
| #include <linux/sched/signal.h> |
| #include "cifspdu.h" |
| #include "cifsglob.h" |
| #include "cifsproto.h" |
| #include "cifs_debug.h" |
| #include "smb2proto.h" |
| #include "smbdirect.h" |
| |
| /* Max number of iovectors we can use off the stack when sending requests. */ |
| #define CIFS_MAX_IOV_SIZE 8 |
| |
| void |
| cifs_wake_up_task(struct mid_q_entry *mid) |
| { |
| wake_up_process(mid->callback_data); |
| } |
| |
| struct mid_q_entry * |
| AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server) |
| { |
| struct mid_q_entry *temp; |
| |
| if (server == NULL) { |
| cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n"); |
| return NULL; |
| } |
| |
| temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS); |
| memset(temp, 0, sizeof(struct mid_q_entry)); |
| kref_init(&temp->refcount); |
| temp->mid = get_mid(smb_buffer); |
| temp->pid = current->pid; |
| temp->command = cpu_to_le16(smb_buffer->Command); |
| cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command); |
| /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */ |
| /* when mid allocated can be before when sent */ |
| temp->when_alloc = jiffies; |
| temp->server = server; |
| |
| /* |
| * The default is for the mid to be synchronous, so the |
| * default callback just wakes up the current task. |
| */ |
| get_task_struct(current); |
| temp->creator = current; |
| temp->callback = cifs_wake_up_task; |
| temp->callback_data = current; |
| |
| atomic_inc(&midCount); |
| temp->mid_state = MID_REQUEST_ALLOCATED; |
| return temp; |
| } |
| |
| static void _cifs_mid_q_entry_release(struct kref *refcount) |
| { |
| struct mid_q_entry *midEntry = |
| container_of(refcount, struct mid_q_entry, refcount); |
| #ifdef CONFIG_CIFS_STATS2 |
| __le16 command = midEntry->server->vals->lock_cmd; |
| __u16 smb_cmd = le16_to_cpu(midEntry->command); |
| unsigned long now; |
| unsigned long roundtrip_time; |
| #endif |
| struct TCP_Server_Info *server = midEntry->server; |
| |
| if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) && |
| midEntry->mid_state == MID_RESPONSE_RECEIVED && |
| server->ops->handle_cancelled_mid) |
| server->ops->handle_cancelled_mid(midEntry->resp_buf, server); |
| |
| midEntry->mid_state = MID_FREE; |
| atomic_dec(&midCount); |
| if (midEntry->large_buf) |
| cifs_buf_release(midEntry->resp_buf); |
| else |
| cifs_small_buf_release(midEntry->resp_buf); |
| #ifdef CONFIG_CIFS_STATS2 |
| now = jiffies; |
| if (now < midEntry->when_alloc) |
| cifs_server_dbg(VFS, "Invalid mid allocation time\n"); |
| roundtrip_time = now - midEntry->when_alloc; |
| |
| if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) { |
| if (atomic_read(&server->num_cmds[smb_cmd]) == 0) { |
| server->slowest_cmd[smb_cmd] = roundtrip_time; |
| server->fastest_cmd[smb_cmd] = roundtrip_time; |
| } else { |
| if (server->slowest_cmd[smb_cmd] < roundtrip_time) |
| server->slowest_cmd[smb_cmd] = roundtrip_time; |
| else if (server->fastest_cmd[smb_cmd] > roundtrip_time) |
| server->fastest_cmd[smb_cmd] = roundtrip_time; |
| } |
| cifs_stats_inc(&server->num_cmds[smb_cmd]); |
| server->time_per_cmd[smb_cmd] += roundtrip_time; |
| } |
| /* |
| * commands taking longer than one second (default) can be indications |
| * that something is wrong, unless it is quite a slow link or a very |
| * busy server. Note that this calc is unlikely or impossible to wrap |
| * as long as slow_rsp_threshold is not set way above recommended max |
| * value (32767 ie 9 hours) and is generally harmless even if wrong |
| * since only affects debug counters - so leaving the calc as simple |
| * comparison rather than doing multiple conversions and overflow |
| * checks |
| */ |
| if ((slow_rsp_threshold != 0) && |
| time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) && |
| (midEntry->command != command)) { |
| /* |
| * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command |
| * NB: le16_to_cpu returns unsigned so can not be negative below |
| */ |
| if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) |
| cifs_stats_inc(&server->smb2slowcmd[smb_cmd]); |
| |
| trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid, |
| midEntry->when_sent, midEntry->when_received); |
| if (cifsFYI & CIFS_TIMER) { |
| pr_debug("slow rsp: cmd %d mid %llu", |
| midEntry->command, midEntry->mid); |
| cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n", |
| now - midEntry->when_alloc, |
| now - midEntry->when_sent, |
| now - midEntry->when_received); |
| } |
| } |
| #endif |
| put_task_struct(midEntry->creator); |
| |
| mempool_free(midEntry, cifs_mid_poolp); |
| } |
| |
| void cifs_mid_q_entry_release(struct mid_q_entry *midEntry) |
| { |
| spin_lock(&GlobalMid_Lock); |
| kref_put(&midEntry->refcount, _cifs_mid_q_entry_release); |
| spin_unlock(&GlobalMid_Lock); |
| } |
| |
| void DeleteMidQEntry(struct mid_q_entry *midEntry) |
| { |
| cifs_mid_q_entry_release(midEntry); |
| } |
| |
| void |
| cifs_delete_mid(struct mid_q_entry *mid) |
| { |
| spin_lock(&GlobalMid_Lock); |
| if (!(mid->mid_flags & MID_DELETED)) { |
| list_del_init(&mid->qhead); |
| mid->mid_flags |= MID_DELETED; |
| } |
| spin_unlock(&GlobalMid_Lock); |
| |
| DeleteMidQEntry(mid); |
| } |
| |
| /* |
| * smb_send_kvec - send an array of kvecs to the server |
| * @server: Server to send the data to |
| * @smb_msg: Message to send |
| * @sent: amount of data sent on socket is stored here |
| * |
| * Our basic "send data to server" function. Should be called with srv_mutex |
| * held. The caller is responsible for handling the results. |
| */ |
| static int |
| smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg, |
| size_t *sent) |
| { |
| int rc = 0; |
| int retries = 0; |
| struct socket *ssocket = server->ssocket; |
| |
| *sent = 0; |
| |
| smb_msg->msg_name = (struct sockaddr *) &server->dstaddr; |
| smb_msg->msg_namelen = sizeof(struct sockaddr); |
| smb_msg->msg_control = NULL; |
| smb_msg->msg_controllen = 0; |
| if (server->noblocksnd) |
| smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL; |
| else |
| smb_msg->msg_flags = MSG_NOSIGNAL; |
| |
| while (msg_data_left(smb_msg)) { |
| /* |
| * If blocking send, we try 3 times, since each can block |
| * for 5 seconds. For nonblocking we have to try more |
| * but wait increasing amounts of time allowing time for |
| * socket to clear. The overall time we wait in either |
| * case to send on the socket is about 15 seconds. |
| * Similarly we wait for 15 seconds for a response from |
| * the server in SendReceive[2] for the server to send |
| * a response back for most types of requests (except |
| * SMB Write past end of file which can be slow, and |
| * blocking lock operations). NFS waits slightly longer |
| * than CIFS, but this can make it take longer for |
| * nonresponsive servers to be detected and 15 seconds |
| * is more than enough time for modern networks to |
| * send a packet. In most cases if we fail to send |
| * after the retries we will kill the socket and |
| * reconnect which may clear the network problem. |
| */ |
| rc = sock_sendmsg(ssocket, smb_msg); |
| if (rc == -EAGAIN) { |
| retries++; |
| if (retries >= 14 || |
| (!server->noblocksnd && (retries > 2))) { |
| cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n", |
| ssocket); |
| return -EAGAIN; |
| } |
| msleep(1 << retries); |
| continue; |
| } |
| |
| if (rc < 0) |
| return rc; |
| |
| if (rc == 0) { |
| /* should never happen, letting socket clear before |
| retrying is our only obvious option here */ |
| cifs_server_dbg(VFS, "tcp sent no data\n"); |
| msleep(500); |
| continue; |
| } |
| |
| /* send was at least partially successful */ |
| *sent += rc; |
| retries = 0; /* in case we get ENOSPC on the next send */ |
| } |
| return 0; |
| } |
| |
| unsigned long |
| smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst) |
| { |
| unsigned int i; |
| struct kvec *iov; |
| int nvec; |
| unsigned long buflen = 0; |
| |
| if (server->vals->header_preamble_size == 0 && |
| rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) { |
| iov = &rqst->rq_iov[1]; |
| nvec = rqst->rq_nvec - 1; |
| } else { |
| iov = rqst->rq_iov; |
| nvec = rqst->rq_nvec; |
| } |
| |
| /* total up iov array first */ |
| for (i = 0; i < nvec; i++) |
| buflen += iov[i].iov_len; |
| |
| /* |
| * Add in the page array if there is one. The caller needs to make |
| * sure rq_offset and rq_tailsz are set correctly. If a buffer of |
| * multiple pages ends at page boundary, rq_tailsz needs to be set to |
| * PAGE_SIZE. |
| */ |
| if (rqst->rq_npages) { |
| if (rqst->rq_npages == 1) |
| buflen += rqst->rq_tailsz; |
| else { |
| /* |
| * If there is more than one page, calculate the |
| * buffer length based on rq_offset and rq_tailsz |
| */ |
| buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) - |
| rqst->rq_offset; |
| buflen += rqst->rq_tailsz; |
| } |
| } |
| |
| return buflen; |
| } |
| |
| static int |
| __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, |
| struct smb_rqst *rqst) |
| { |
| int rc = 0; |
| struct kvec *iov; |
| int n_vec; |
| unsigned int send_length = 0; |
| unsigned int i, j; |
| sigset_t mask, oldmask; |
| size_t total_len = 0, sent, size; |
| struct socket *ssocket = server->ssocket; |
| struct msghdr smb_msg; |
| __be32 rfc1002_marker; |
| |
| if (cifs_rdma_enabled(server)) { |
| /* return -EAGAIN when connecting or reconnecting */ |
| rc = -EAGAIN; |
| if (server->smbd_conn) |
| rc = smbd_send(server, num_rqst, rqst); |
| goto smbd_done; |
| } |
| |
| if (ssocket == NULL) |
| return -EAGAIN; |
| |
| if (signal_pending(current)) { |
| cifs_dbg(FYI, "signal is pending before sending any data\n"); |
| return -EINTR; |
| } |
| |
| /* cork the socket */ |
| tcp_sock_set_cork(ssocket->sk, true); |
| |
| for (j = 0; j < num_rqst; j++) |
| send_length += smb_rqst_len(server, &rqst[j]); |
| rfc1002_marker = cpu_to_be32(send_length); |
| |
| /* |
| * We should not allow signals to interrupt the network send because |
| * any partial send will cause session reconnects thus increasing |
| * latency of system calls and overload a server with unnecessary |
| * requests. |
| */ |
| |
| sigfillset(&mask); |
| sigprocmask(SIG_BLOCK, &mask, &oldmask); |
| |
| /* Generate a rfc1002 marker for SMB2+ */ |
| if (server->vals->header_preamble_size == 0) { |
| struct kvec hiov = { |
| .iov_base = &rfc1002_marker, |
| .iov_len = 4 |
| }; |
| iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4); |
| rc = smb_send_kvec(server, &smb_msg, &sent); |
| if (rc < 0) |
| goto unmask; |
| |
| total_len += sent; |
| send_length += 4; |
| } |
| |
| cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length); |
| |
| for (j = 0; j < num_rqst; j++) { |
| iov = rqst[j].rq_iov; |
| n_vec = rqst[j].rq_nvec; |
| |
| size = 0; |
| for (i = 0; i < n_vec; i++) { |
| dump_smb(iov[i].iov_base, iov[i].iov_len); |
| size += iov[i].iov_len; |
| } |
| |
| iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size); |
| |
| rc = smb_send_kvec(server, &smb_msg, &sent); |
| if (rc < 0) |
| goto unmask; |
| |
| total_len += sent; |
| |
| /* now walk the page array and send each page in it */ |
| for (i = 0; i < rqst[j].rq_npages; i++) { |
| struct bio_vec bvec; |
| |
| bvec.bv_page = rqst[j].rq_pages[i]; |
| rqst_page_get_length(&rqst[j], i, &bvec.bv_len, |
| &bvec.bv_offset); |
| |
| iov_iter_bvec(&smb_msg.msg_iter, WRITE, |
| &bvec, 1, bvec.bv_len); |
| rc = smb_send_kvec(server, &smb_msg, &sent); |
| if (rc < 0) |
| break; |
| |
| total_len += sent; |
| } |
| } |
| |
| unmask: |
| sigprocmask(SIG_SETMASK, &oldmask, NULL); |
| |
| /* |
| * If signal is pending but we have already sent the whole packet to |
| * the server we need to return success status to allow a corresponding |
| * mid entry to be kept in the pending requests queue thus allowing |
| * to handle responses from the server by the client. |
| * |
| * If only part of the packet has been sent there is no need to hide |
| * interrupt because the session will be reconnected anyway, so there |
| * won't be any response from the server to handle. |
| */ |
| |
| if (signal_pending(current) && (total_len != send_length)) { |
| cifs_dbg(FYI, "signal is pending after attempt to send\n"); |
| rc = -EINTR; |
| } |
| |
| /* uncork it */ |
| tcp_sock_set_cork(ssocket->sk, false); |
| |
| if ((total_len > 0) && (total_len != send_length)) { |
| cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n", |
| send_length, total_len); |
| /* |
| * If we have only sent part of an SMB then the next SMB could |
| * be taken as the remainder of this one. We need to kill the |
| * socket so the server throws away the partial SMB |
| */ |
| server->tcpStatus = CifsNeedReconnect; |
| trace_smb3_partial_send_reconnect(server->CurrentMid, |
| server->hostname); |
| } |
| smbd_done: |
| if (rc < 0 && rc != -EINTR) |
| cifs_server_dbg(VFS, "Error %d sending data on socket to server\n", |
| rc); |
| else if (rc > 0) |
| rc = 0; |
| |
| return rc; |
| } |
| |
| static int |
| smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, |
| struct smb_rqst *rqst, int flags) |
| { |
| struct kvec iov; |
| struct smb2_transform_hdr *tr_hdr; |
| struct smb_rqst cur_rqst[MAX_COMPOUND]; |
| int rc; |
| |
| if (!(flags & CIFS_TRANSFORM_REQ)) |
| return __smb_send_rqst(server, num_rqst, rqst); |
| |
| if (num_rqst > MAX_COMPOUND - 1) |
| return -ENOMEM; |
| |
| if (!server->ops->init_transform_rq) { |
| cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n"); |
| return -EIO; |
| } |
| |
| tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS); |
| if (!tr_hdr) |
| return -ENOMEM; |
| |
| memset(&cur_rqst[0], 0, sizeof(cur_rqst)); |
| memset(&iov, 0, sizeof(iov)); |
| memset(tr_hdr, 0, sizeof(*tr_hdr)); |
| |
| iov.iov_base = tr_hdr; |
| iov.iov_len = sizeof(*tr_hdr); |
| cur_rqst[0].rq_iov = &iov; |
| cur_rqst[0].rq_nvec = 1; |
| |
| rc = server->ops->init_transform_rq(server, num_rqst + 1, |
| &cur_rqst[0], rqst); |
| if (rc) |
| goto out; |
| |
| rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]); |
| smb3_free_compound_rqst(num_rqst, &cur_rqst[1]); |
| out: |
| kfree(tr_hdr); |
| return rc; |
| } |
| |
| int |
| smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer, |
| unsigned int smb_buf_length) |
| { |
| struct kvec iov[2]; |
| struct smb_rqst rqst = { .rq_iov = iov, |
| .rq_nvec = 2 }; |
| |
| iov[0].iov_base = smb_buffer; |
| iov[0].iov_len = 4; |
| iov[1].iov_base = (char *)smb_buffer + 4; |
| iov[1].iov_len = smb_buf_length; |
| |
| return __smb_send_rqst(server, 1, &rqst); |
| } |
| |
| static int |
| wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits, |
| const int timeout, const int flags, |
| unsigned int *instance) |
| { |
| int rc; |
| int *credits; |
| int optype; |
| long int t; |
| |
| if (timeout < 0) |
| t = MAX_JIFFY_OFFSET; |
| else |
| t = msecs_to_jiffies(timeout); |
| |
| optype = flags & CIFS_OP_MASK; |
| |
| *instance = 0; |
| |
| credits = server->ops->get_credits_field(server, optype); |
| /* Since an echo is already inflight, no need to wait to send another */ |
| if (*credits <= 0 && optype == CIFS_ECHO_OP) |
| return -EAGAIN; |
| |
| spin_lock(&server->req_lock); |
| if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) { |
| /* oplock breaks must not be held up */ |
| server->in_flight++; |
| if (server->in_flight > server->max_in_flight) |
| server->max_in_flight = server->in_flight; |
| *credits -= 1; |
| *instance = server->reconnect_instance; |
| spin_unlock(&server->req_lock); |
| return 0; |
| } |
| |
| while (1) { |
| if (*credits < num_credits) { |
| spin_unlock(&server->req_lock); |
| cifs_num_waiters_inc(server); |
| rc = wait_event_killable_timeout(server->request_q, |
| has_credits(server, credits, num_credits), t); |
| cifs_num_waiters_dec(server); |
| if (!rc) { |
| trace_smb3_credit_timeout(server->CurrentMid, |
| server->hostname, num_credits); |
| cifs_server_dbg(VFS, "wait timed out after %d ms\n", |
| timeout); |
| return -ENOTSUPP; |
| } |
| if (rc == -ERESTARTSYS) |
| return -ERESTARTSYS; |
| spin_lock(&server->req_lock); |
| } else { |
| if (server->tcpStatus == CifsExiting) { |
| spin_unlock(&server->req_lock); |
| return -ENOENT; |
| } |
| |
| /* |
| * For normal commands, reserve the last MAX_COMPOUND |
| * credits to compound requests. |
| * Otherwise these compounds could be permanently |
| * starved for credits by single-credit requests. |
| * |
| * To prevent spinning CPU, block this thread until |
| * there are >MAX_COMPOUND credits available. |
| * But only do this is we already have a lot of |
| * credits in flight to avoid triggering this check |
| * for servers that are slow to hand out credits on |
| * new sessions. |
| */ |
| if (!optype && num_credits == 1 && |
| server->in_flight > 2 * MAX_COMPOUND && |
| *credits <= MAX_COMPOUND) { |
| spin_unlock(&server->req_lock); |
| cifs_num_waiters_inc(server); |
| rc = wait_event_killable_timeout( |
| server->request_q, |
| has_credits(server, credits, |
| MAX_COMPOUND + 1), |
| t); |
| cifs_num_waiters_dec(server); |
| if (!rc) { |
| trace_smb3_credit_timeout( |
| server->CurrentMid, |
| server->hostname, num_credits); |
| cifs_server_dbg(VFS, "wait timed out after %d ms\n", |
| timeout); |
| return -ENOTSUPP; |
| } |
| if (rc == -ERESTARTSYS) |
| return -ERESTARTSYS; |
| spin_lock(&server->req_lock); |
| continue; |
| } |
| |
| /* |
| * Can not count locking commands against total |
| * as they are allowed to block on server. |
| */ |
| |
| /* update # of requests on the wire to server */ |
| if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) { |
| *credits -= num_credits; |
| server->in_flight += num_credits; |
| if (server->in_flight > server->max_in_flight) |
| server->max_in_flight = server->in_flight; |
| *instance = server->reconnect_instance; |
| } |
| spin_unlock(&server->req_lock); |
| break; |
| } |
| } |
| return 0; |
| } |
| |
| static int |
| wait_for_free_request(struct TCP_Server_Info *server, const int flags, |
| unsigned int *instance) |
| { |
| return wait_for_free_credits(server, 1, -1, flags, |
| instance); |
| } |
| |
| static int |
| wait_for_compound_request(struct TCP_Server_Info *server, int num, |
| const int flags, unsigned int *instance) |
| { |
| int *credits; |
| |
| credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK); |
| |
| spin_lock(&server->req_lock); |
| if (*credits < num) { |
| /* |
| * Return immediately if not too many requests in flight since |
| * we will likely be stuck on waiting for credits. |
| */ |
| if (server->in_flight < num - *credits) { |
| spin_unlock(&server->req_lock); |
| return -ENOTSUPP; |
| } |
| } |
| spin_unlock(&server->req_lock); |
| |
| return wait_for_free_credits(server, num, 60000, flags, |
| instance); |
| } |
| |
| int |
| cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size, |
| unsigned int *num, struct cifs_credits *credits) |
| { |
| *num = size; |
| credits->value = 0; |
| credits->instance = server->reconnect_instance; |
| return 0; |
| } |
| |
| static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf, |
| struct mid_q_entry **ppmidQ) |
| { |
| if (ses->server->tcpStatus == CifsExiting) { |
| return -ENOENT; |
| } |
| |
| if (ses->server->tcpStatus == CifsNeedReconnect) { |
| cifs_dbg(FYI, "tcp session dead - return to caller to retry\n"); |
| return -EAGAIN; |
| } |
| |
| if (ses->status == CifsNew) { |
| if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) && |
| (in_buf->Command != SMB_COM_NEGOTIATE)) |
| return -EAGAIN; |
| /* else ok - we are setting up session */ |
| } |
| |
| if (ses->status == CifsExiting) { |
| /* check if SMB session is bad because we are setting it up */ |
| if (in_buf->Command != SMB_COM_LOGOFF_ANDX) |
| return -EAGAIN; |
| /* else ok - we are shutting down session */ |
| } |
| |
| *ppmidQ = AllocMidQEntry(in_buf, ses->server); |
| if (*ppmidQ == NULL) |
| return -ENOMEM; |
| spin_lock(&GlobalMid_Lock); |
| list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q); |
| spin_unlock(&GlobalMid_Lock); |
| return 0; |
| } |
| |
| static int |
| wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ) |
| { |
| int error; |
| |
| error = wait_event_freezekillable_unsafe(server->response_q, |
| midQ->mid_state != MID_REQUEST_SUBMITTED); |
| if (error < 0) |
| return -ERESTARTSYS; |
| |
| return 0; |
| } |
| |
| struct mid_q_entry * |
| cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst) |
| { |
| int rc; |
| struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base; |
| struct mid_q_entry *mid; |
| |
| if (rqst->rq_iov[0].iov_len != 4 || |
| rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) |
| return ERR_PTR(-EIO); |
| |
| /* enable signing if server requires it */ |
| if (server->sign) |
| hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; |
| |
| mid = AllocMidQEntry(hdr, server); |
| if (mid == NULL) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = cifs_sign_rqst(rqst, server, &mid->sequence_number); |
| if (rc) { |
| DeleteMidQEntry(mid); |
| return ERR_PTR(rc); |
| } |
| |
| return mid; |
| } |
| |
| /* |
| * Send a SMB request and set the callback function in the mid to handle |
| * the result. Caller is responsible for dealing with timeouts. |
| */ |
| int |
| cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst, |
| mid_receive_t *receive, mid_callback_t *callback, |
| mid_handle_t *handle, void *cbdata, const int flags, |
| const struct cifs_credits *exist_credits) |
| { |
| int rc; |
| struct mid_q_entry *mid; |
| struct cifs_credits credits = { .value = 0, .instance = 0 }; |
| unsigned int instance; |
| int optype; |
| |
| optype = flags & CIFS_OP_MASK; |
| |
| if ((flags & CIFS_HAS_CREDITS) == 0) { |
| rc = wait_for_free_request(server, flags, &instance); |
| if (rc) |
| return rc; |
| credits.value = 1; |
| credits.instance = instance; |
| } else |
| instance = exist_credits->instance; |
| |
| mutex_lock(&server->srv_mutex); |
| |
| /* |
| * We can't use credits obtained from the previous session to send this |
| * request. Check if there were reconnects after we obtained credits and |
| * return -EAGAIN in such cases to let callers handle it. |
| */ |
| if (instance != server->reconnect_instance) { |
| mutex_unlock(&server->srv_mutex); |
| add_credits_and_wake_if(server, &credits, optype); |
| return -EAGAIN; |
| } |
| |
| mid = server->ops->setup_async_request(server, rqst); |
| if (IS_ERR(mid)) { |
| mutex_unlock(&server->srv_mutex); |
| add_credits_and_wake_if(server, &credits, optype); |
| return PTR_ERR(mid); |
| } |
| |
| mid->receive = receive; |
| mid->callback = callback; |
| mid->callback_data = cbdata; |
| mid->handle = handle; |
| mid->mid_state = MID_REQUEST_SUBMITTED; |
| |
| /* put it on the pending_mid_q */ |
| spin_lock(&GlobalMid_Lock); |
| list_add_tail(&mid->qhead, &server->pending_mid_q); |
| spin_unlock(&GlobalMid_Lock); |
| |
| /* |
| * Need to store the time in mid before calling I/O. For call_async, |
| * I/O response may come back and free the mid entry on another thread. |
| */ |
| cifs_save_when_sent(mid); |
| cifs_in_send_inc(server); |
| rc = smb_send_rqst(server, 1, rqst, flags); |
| cifs_in_send_dec(server); |
| |
| if (rc < 0) { |
| revert_current_mid(server, mid->credits); |
| server->sequence_number -= 2; |
| cifs_delete_mid(mid); |
| } |
| |
| mutex_unlock(&server->srv_mutex); |
| |
| if (rc == 0) |
| return 0; |
| |
| add_credits_and_wake_if(server, &credits, optype); |
| return rc; |
| } |
| |
| /* |
| * |
| * Send an SMB Request. No response info (other than return code) |
| * needs to be parsed. |
| * |
| * flags indicate the type of request buffer and how long to wait |
| * and whether to log NT STATUS code (error) before mapping it to POSIX error |
| * |
| */ |
| int |
| SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses, |
| char *in_buf, int flags) |
| { |
| int rc; |
| struct kvec iov[1]; |
| struct kvec rsp_iov; |
| int resp_buf_type; |
| |
| iov[0].iov_base = in_buf; |
| iov[0].iov_len = get_rfc1002_length(in_buf) + 4; |
| flags |= CIFS_NO_RSP_BUF; |
| rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov); |
| cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc); |
| |
| return rc; |
| } |
| |
| static int |
| cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server) |
| { |
| int rc = 0; |
| |
| cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n", |
| __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state); |
| |
| spin_lock(&GlobalMid_Lock); |
| switch (mid->mid_state) { |
| case MID_RESPONSE_RECEIVED: |
| spin_unlock(&GlobalMid_Lock); |
| return rc; |
| case MID_RETRY_NEEDED: |
| rc = -EAGAIN; |
| break; |
| case MID_RESPONSE_MALFORMED: |
| rc = -EIO; |
| break; |
| case MID_SHUTDOWN: |
| rc = -EHOSTDOWN; |
| break; |
| default: |
| if (!(mid->mid_flags & MID_DELETED)) { |
| list_del_init(&mid->qhead); |
| mid->mid_flags |= MID_DELETED; |
| } |
| cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n", |
| __func__, mid->mid, mid->mid_state); |
| rc = -EIO; |
| } |
| spin_unlock(&GlobalMid_Lock); |
| |
| DeleteMidQEntry(mid); |
| return rc; |
| } |
| |
| static inline int |
| send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst, |
| struct mid_q_entry *mid) |
| { |
| return server->ops->send_cancel ? |
| server->ops->send_cancel(server, rqst, mid) : 0; |
| } |
| |
| int |
| cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, |
| bool log_error) |
| { |
| unsigned int len = get_rfc1002_length(mid->resp_buf) + 4; |
| |
| dump_smb(mid->resp_buf, min_t(u32, 92, len)); |
| |
| /* convert the length into a more usable form */ |
| if (server->sign) { |
| struct kvec iov[2]; |
| int rc = 0; |
| struct smb_rqst rqst = { .rq_iov = iov, |
| .rq_nvec = 2 }; |
| |
| iov[0].iov_base = mid->resp_buf; |
| iov[0].iov_len = 4; |
| iov[1].iov_base = (char *)mid->resp_buf + 4; |
| iov[1].iov_len = len - 4; |
| /* FIXME: add code to kill session */ |
| rc = cifs_verify_signature(&rqst, server, |
| mid->sequence_number); |
| if (rc) |
| cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n", |
| rc); |
| } |
| |
| /* BB special case reconnect tid and uid here? */ |
| return map_smb_to_linux_error(mid->resp_buf, log_error); |
| } |
| |
| struct mid_q_entry * |
| cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored, |
| struct smb_rqst *rqst) |
| { |
| int rc; |
| struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base; |
| struct mid_q_entry *mid; |
| |
| if (rqst->rq_iov[0].iov_len != 4 || |
| rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base) |
| return ERR_PTR(-EIO); |
| |
| rc = allocate_mid(ses, hdr, &mid); |
| if (rc) |
| return ERR_PTR(rc); |
| rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number); |
| if (rc) { |
| cifs_delete_mid(mid); |
| return ERR_PTR(rc); |
| } |
| return mid; |
| } |
| |
| static void |
| cifs_compound_callback(struct mid_q_entry *mid) |
| { |
| struct TCP_Server_Info *server = mid->server; |
| struct cifs_credits credits; |
| |
| credits.value = server->ops->get_credits(mid); |
| credits.instance = server->reconnect_instance; |
| |
| add_credits(server, &credits, mid->optype); |
| } |
| |
| static void |
| cifs_compound_last_callback(struct mid_q_entry *mid) |
| { |
| cifs_compound_callback(mid); |
| cifs_wake_up_task(mid); |
| } |
| |
| static void |
| cifs_cancelled_callback(struct mid_q_entry *mid) |
| { |
| cifs_compound_callback(mid); |
| DeleteMidQEntry(mid); |
| } |
| |
| /* |
| * Return a channel (master if none) of @ses that can be used to send |
| * regular requests. |
| * |
| * If we are currently binding a new channel (negprot/sess.setup), |
| * return the new incomplete channel. |
| */ |
| struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses) |
| { |
| uint index = 0; |
| |
| if (!ses) |
| return NULL; |
| |
| if (!ses->binding) { |
| /* round robin */ |
| if (ses->chan_count > 1) { |
| index = (uint)atomic_inc_return(&ses->chan_seq); |
| index %= ses->chan_count; |
| } |
| return ses->chans[index].server; |
| } else { |
| return cifs_ses_server(ses); |
| } |
| } |
| |
| int |
| compound_send_recv(const unsigned int xid, struct cifs_ses *ses, |
| struct TCP_Server_Info *server, |
| const int flags, const int num_rqst, struct smb_rqst *rqst, |
| int *resp_buf_type, struct kvec *resp_iov) |
| { |
| int i, j, optype, rc = 0; |
| struct mid_q_entry *midQ[MAX_COMPOUND]; |
| bool cancelled_mid[MAX_COMPOUND] = {false}; |
| struct cifs_credits credits[MAX_COMPOUND] = { |
| { .value = 0, .instance = 0 } |
| }; |
| unsigned int instance; |
| char *buf; |
| |
| optype = flags & CIFS_OP_MASK; |
| |
| for (i = 0; i < num_rqst; i++) |
| resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */ |
| |
| if (!ses || !ses->server || !server) { |
| cifs_dbg(VFS, "Null session\n"); |
| return -EIO; |
| } |
| |
| if (server->tcpStatus == CifsExiting) |
| return -ENOENT; |
| |
| /* |
| * Wait for all the requests to become available. |
| * This approach still leaves the possibility to be stuck waiting for |
| * credits if the server doesn't grant credits to the outstanding |
| * requests and if the client is completely idle, not generating any |
| * other requests. |
| * This can be handled by the eventual session reconnect. |
| */ |
| rc = wait_for_compound_request(server, num_rqst, flags, |
| &instance); |
| if (rc) |
| return rc; |
| |
| for (i = 0; i < num_rqst; i++) { |
| credits[i].value = 1; |
| credits[i].instance = instance; |
| } |
| |
| /* |
| * 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. |
| */ |
| |
| mutex_lock(&server->srv_mutex); |
| |
| /* |
| * All the parts of the compound chain belong obtained credits from the |
| * same session. We can not use credits obtained from the previous |
| * session to send this request. Check if there were reconnects after |
| * we obtained credits and return -EAGAIN in such cases to let callers |
| * handle it. |
| */ |
| if (instance != server->reconnect_instance) { |
| mutex_unlock(&server->srv_mutex); |
| for (j = 0; j < num_rqst; j++) |
| add_credits(server, &credits[j], optype); |
| return -EAGAIN; |
| } |
| |
| for (i = 0; i < num_rqst; i++) { |
| midQ[i] = server->ops->setup_request(ses, server, &rqst[i]); |
| if (IS_ERR(midQ[i])) { |
| revert_current_mid(server, i); |
| for (j = 0; j < i; j++) |
| cifs_delete_mid(midQ[j]); |
| mutex_unlock(&server->srv_mutex); |
| |
| /* Update # of requests on wire to server */ |
| for (j = 0; j < num_rqst; j++) |
| add_credits(server, &credits[j], optype); |
| return PTR_ERR(midQ[i]); |
| } |
| |
| midQ[i]->mid_state = MID_REQUEST_SUBMITTED; |
| midQ[i]->optype = optype; |
| /* |
| * Invoke callback for every part of the compound chain |
| * to calculate credits properly. Wake up this thread only when |
| * the last element is received. |
| */ |
| if (i < num_rqst - 1) |
| midQ[i]->callback = cifs_compound_callback; |
| else |
| midQ[i]->callback = cifs_compound_last_callback; |
| } |
| cifs_in_send_inc(server); |
| rc = smb_send_rqst(server, num_rqst, rqst, flags); |
| cifs_in_send_dec(server); |
| |
| for (i = 0; i < num_rqst; i++) |
| cifs_save_when_sent(midQ[i]); |
| |
| if (rc < 0) { |
| revert_current_mid(server, num_rqst); |
| server->sequence_number -= 2; |
| } |
| |
| mutex_unlock(&server->srv_mutex); |
| |
| /* |
| * If sending failed for some reason or it is an oplock break that we |
| * will not receive a response to - return credits back |
| */ |
| if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) { |
| for (i = 0; i < num_rqst; i++) |
| add_credits(server, &credits[i], optype); |
| goto out; |
| } |
| |
| /* |
| * At this point the request is passed to the network stack - we assume |
| * that any credits taken from the server structure on the client have |
| * been spent and we can't return them back. Once we receive responses |
| * we will collect credits granted by the server in the mid callbacks |
| * and add those credits to the server structure. |
| */ |
| |
| /* |
| * Compounding is never used during session establish. |
| */ |
| if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) |
| smb311_update_preauth_hash(ses, rqst[0].rq_iov, |
| rqst[0].rq_nvec); |
| |
| for (i = 0; i < num_rqst; i++) { |
| rc = wait_for_response(server, midQ[i]); |
| if (rc != 0) |
| break; |
| } |
| if (rc != 0) { |
| for (; i < num_rqst; i++) { |
| cifs_server_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n", |
| midQ[i]->mid, le16_to_cpu(midQ[i]->command)); |
| send_cancel(server, &rqst[i], midQ[i]); |
| spin_lock(&GlobalMid_Lock); |
| midQ[i]->mid_flags |= MID_WAIT_CANCELLED; |
| if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) { |
| midQ[i]->callback = cifs_cancelled_callback; |
| cancelled_mid[i] = true; |
| credits[i].value = 0; |
| } |
| spin_unlock(&GlobalMid_Lock); |
| } |
| } |
| |
| for (i = 0; i < num_rqst; i++) { |
| if (rc < 0) |
| goto out; |
| |
| rc = cifs_sync_mid_result(midQ[i], server); |
| if (rc != 0) { |
| /* mark this mid as cancelled to not free it below */ |
| cancelled_mid[i] = true; |
| goto out; |
| } |
| |
| if (!midQ[i]->resp_buf || |
| midQ[i]->mid_state != MID_RESPONSE_RECEIVED) { |
| rc = -EIO; |
| cifs_dbg(FYI, "Bad MID state?\n"); |
| goto out; |
| } |
| |
| buf = (char *)midQ[i]->resp_buf; |
| resp_iov[i].iov_base = buf; |
| resp_iov[i].iov_len = midQ[i]->resp_buf_size + |
| server->vals->header_preamble_size; |
| |
| if (midQ[i]->large_buf) |
| resp_buf_type[i] = CIFS_LARGE_BUFFER; |
| else |
| resp_buf_type[i] = CIFS_SMALL_BUFFER; |
| |
| rc = server->ops->check_receive(midQ[i], server, |
| flags & CIFS_LOG_ERROR); |
| |
| /* mark it so buf will not be freed by cifs_delete_mid */ |
| if ((flags & CIFS_NO_RSP_BUF) == 0) |
| midQ[i]->resp_buf = NULL; |
| |
| } |
| |
| /* |
| * Compounding is never used during session establish. |
| */ |
| if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) { |
| struct kvec iov = { |
| .iov_base = resp_iov[0].iov_base, |
| .iov_len = resp_iov[0].iov_len |
| }; |
| smb311_update_preauth_hash(ses, &iov, 1); |
| } |
| |
| out: |
| /* |
| * This will dequeue all mids. After this it is important that the |
| * demultiplex_thread will not process any of these mids any futher. |
| * This is prevented above by using a noop callback that will not |
| * wake this thread except for the very last PDU. |
| */ |
| for (i = 0; i < num_rqst; i++) { |
| if (!cancelled_mid[i]) |
| cifs_delete_mid(midQ[i]); |
| } |
| |
| return rc; |
| } |
| |
| int |
| cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, |
| struct TCP_Server_Info *server, |
| struct smb_rqst *rqst, int *resp_buf_type, const int flags, |
| struct kvec *resp_iov) |
| { |
| return compound_send_recv(xid, ses, server, flags, 1, |
| rqst, resp_buf_type, resp_iov); |
| } |
| |
| int |
| SendReceive2(const unsigned int xid, struct cifs_ses *ses, |
| struct kvec *iov, int n_vec, int *resp_buf_type /* ret */, |
| const int flags, struct kvec *resp_iov) |
| { |
| struct smb_rqst rqst; |
| struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov; |
| int rc; |
| |
| if (n_vec + 1 > CIFS_MAX_IOV_SIZE) { |
| new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec), |
| GFP_KERNEL); |
| if (!new_iov) { |
| /* otherwise cifs_send_recv below sets resp_buf_type */ |
| *resp_buf_type = CIFS_NO_BUFFER; |
| return -ENOMEM; |
| } |
| } else |
| new_iov = s_iov; |
| |
| /* 1st iov is a RFC1001 length followed by the rest of the packet */ |
| memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec)); |
| |
| new_iov[0].iov_base = new_iov[1].iov_base; |
| new_iov[0].iov_len = 4; |
| new_iov[1].iov_base += 4; |
| new_iov[1].iov_len -= 4; |
| |
| memset(&rqst, 0, sizeof(struct smb_rqst)); |
| rqst.rq_iov = new_iov; |
| rqst.rq_nvec = n_vec + 1; |
| |
| rc = cifs_send_recv(xid, ses, ses->server, |
| &rqst, resp_buf_type, flags, resp_iov); |
| if (n_vec + 1 > CIFS_MAX_IOV_SIZE) |
| kfree(new_iov); |
| return rc; |
| } |
| |
| int |
| SendReceive(const unsigned int xid, struct cifs_ses *ses, |
| struct smb_hdr *in_buf, struct smb_hdr *out_buf, |
| int *pbytes_returned, const int flags) |
| { |
| int rc = 0; |
| struct mid_q_entry *midQ; |
| unsigned int len = be32_to_cpu(in_buf->smb_buf_length); |
| struct kvec iov = { .iov_base = in_buf, .iov_len = len }; |
| struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; |
| struct cifs_credits credits = { .value = 1, .instance = 0 }; |
| struct TCP_Server_Info *server; |
| |
| if (ses == NULL) { |
| cifs_dbg(VFS, "Null smb session\n"); |
| return -EIO; |
| } |
| server = ses->server; |
| if (server == NULL) { |
| cifs_dbg(VFS, "Null tcp session\n"); |
| return -EIO; |
| } |
| |
| if (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 (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) { |
| cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n", |
| len); |
| return -EIO; |
| } |
| |
| rc = wait_for_free_request(server, flags, &credits.instance); |
| if (rc) |
| return rc; |
| |
| /* 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 */ |
| |
| mutex_lock(&server->srv_mutex); |
| |
| rc = allocate_mid(ses, in_buf, &midQ); |
| if (rc) { |
| mutex_unlock(&server->srv_mutex); |
| /* Update # of requests on wire to server */ |
| add_credits(server, &credits, 0); |
| return rc; |
| } |
| |
| rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number); |
| if (rc) { |
| mutex_unlock(&server->srv_mutex); |
| goto out; |
| } |
| |
| midQ->mid_state = MID_REQUEST_SUBMITTED; |
| |
| cifs_in_send_inc(server); |
| rc = smb_send(server, in_buf, len); |
| cifs_in_send_dec(server); |
| cifs_save_when_sent(midQ); |
| |
| if (rc < 0) |
| server->sequence_number -= 2; |
| |
| mutex_unlock(&server->srv_mutex); |
| |
| if (rc < 0) |
| goto out; |
| |
| rc = wait_for_response(server, midQ); |
| if (rc != 0) { |
| send_cancel(server, &rqst, midQ); |
| spin_lock(&GlobalMid_Lock); |
| if (midQ->mid_state == MID_REQUEST_SUBMITTED) { |
| /* no longer considered to be "in-flight" */ |
| midQ->callback = DeleteMidQEntry; |
| spin_unlock(&GlobalMid_Lock); |
| add_credits(server, &credits, 0); |
| return rc; |
| } |
| spin_unlock(&GlobalMid_Lock); |
| } |
| |
| rc = cifs_sync_mid_result(midQ, server); |
| if (rc != 0) { |
| add_credits(server, &credits, 0); |
| return rc; |
| } |
| |
| if (!midQ->resp_buf || !out_buf || |
| midQ->mid_state != MID_RESPONSE_RECEIVED) { |
| rc = -EIO; |
| cifs_server_dbg(VFS, "Bad MID state?\n"); |
| goto out; |
| } |
| |
| *pbytes_returned = get_rfc1002_length(midQ->resp_buf); |
| memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); |
| rc = cifs_check_receive(midQ, server, 0); |
| out: |
| cifs_delete_mid(midQ); |
| add_credits(server, &credits, 0); |
| |
| return rc; |
| } |
| |
| /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows |
| blocking lock to return. */ |
| |
| static int |
| send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon, |
| struct smb_hdr *in_buf, |
| struct smb_hdr *out_buf) |
| { |
| int bytes_returned; |
| struct cifs_ses *ses = tcon->ses; |
| LOCK_REQ *pSMB = (LOCK_REQ *)in_buf; |
| |
| /* We just modify the current in_buf to change |
| the type of lock from LOCKING_ANDX_SHARED_LOCK |
| or LOCKING_ANDX_EXCLUSIVE_LOCK to |
| LOCKING_ANDX_CANCEL_LOCK. */ |
| |
| pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES; |
| pSMB->Timeout = 0; |
| pSMB->hdr.Mid = get_next_mid(ses->server); |
| |
| return SendReceive(xid, ses, in_buf, out_buf, |
| &bytes_returned, 0); |
| } |
| |
| int |
| SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon, |
| struct smb_hdr *in_buf, struct smb_hdr *out_buf, |
| int *pbytes_returned) |
| { |
| int rc = 0; |
| int rstart = 0; |
| struct mid_q_entry *midQ; |
| struct cifs_ses *ses; |
| unsigned int len = be32_to_cpu(in_buf->smb_buf_length); |
| struct kvec iov = { .iov_base = in_buf, .iov_len = len }; |
| struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 }; |
| unsigned int instance; |
| struct TCP_Server_Info *server; |
| |
| if (tcon == NULL || tcon->ses == NULL) { |
| cifs_dbg(VFS, "Null smb session\n"); |
| return -EIO; |
| } |
| ses = tcon->ses; |
| server = ses->server; |
| |
| if (server == NULL) { |
| cifs_dbg(VFS, "Null tcp session\n"); |
| return -EIO; |
| } |
| |
| if (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 (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) { |
| cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n", |
| len); |
| return -EIO; |
| } |
| |
| rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance); |
| if (rc) |
| return rc; |
| |
| /* 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 */ |
| |
| mutex_lock(&server->srv_mutex); |
| |
| rc = allocate_mid(ses, in_buf, &midQ); |
| if (rc) { |
| mutex_unlock(&server->srv_mutex); |
| return rc; |
| } |
| |
| rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number); |
| if (rc) { |
| cifs_delete_mid(midQ); |
| mutex_unlock(&server->srv_mutex); |
| return rc; |
| } |
| |
| midQ->mid_state = MID_REQUEST_SUBMITTED; |
| cifs_in_send_inc(server); |
| rc = smb_send(server, in_buf, len); |
| cifs_in_send_dec(server); |
| cifs_save_when_sent(midQ); |
| |
| if (rc < 0) |
| server->sequence_number -= 2; |
| |
| mutex_unlock(&server->srv_mutex); |
| |
| if (rc < 0) { |
| cifs_delete_mid(midQ); |
| return rc; |
| } |
| |
| /* Wait for a reply - allow signals to interrupt. */ |
| rc = wait_event_interruptible(server->response_q, |
| (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) || |
| ((server->tcpStatus != CifsGood) && |
| (server->tcpStatus != CifsNew))); |
| |
| /* Were we interrupted by a signal ? */ |
| if ((rc == -ERESTARTSYS) && |
| (midQ->mid_state == MID_REQUEST_SUBMITTED) && |
| ((server->tcpStatus == CifsGood) || |
| (server->tcpStatus == CifsNew))) { |
| |
| if (in_buf->Command == SMB_COM_TRANSACTION2) { |
| /* POSIX lock. We send a NT_CANCEL SMB to cause the |
| blocking lock to return. */ |
| rc = send_cancel(server, &rqst, midQ); |
| if (rc) { |
| cifs_delete_mid(midQ); |
| return rc; |
| } |
| } else { |
| /* Windows lock. We send a LOCKINGX_CANCEL_LOCK |
| to cause the blocking lock to return. */ |
| |
| rc = send_lock_cancel(xid, tcon, in_buf, out_buf); |
| |
| /* If we get -ENOLCK back the lock may have |
| already been removed. Don't exit in this case. */ |
| if (rc && rc != -ENOLCK) { |
| cifs_delete_mid(midQ); |
| return rc; |
| } |
| } |
| |
| rc = wait_for_response(server, midQ); |
| if (rc) { |
| send_cancel(server, &rqst, midQ); |
| spin_lock(&GlobalMid_Lock); |
| if (midQ->mid_state == MID_REQUEST_SUBMITTED) { |
| /* no longer considered to be "in-flight" */ |
| midQ->callback = DeleteMidQEntry; |
| spin_unlock(&GlobalMid_Lock); |
| return rc; |
| } |
| spin_unlock(&GlobalMid_Lock); |
| } |
| |
| /* We got the response - restart system call. */ |
| rstart = 1; |
| } |
| |
| rc = cifs_sync_mid_result(midQ, server); |
| if (rc != 0) |
| return rc; |
| |
| /* rcvd frame is ok */ |
| if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) { |
| rc = -EIO; |
| cifs_tcon_dbg(VFS, "Bad MID state?\n"); |
| goto out; |
| } |
| |
| *pbytes_returned = get_rfc1002_length(midQ->resp_buf); |
| memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4); |
| rc = cifs_check_receive(midQ, server, 0); |
| out: |
| cifs_delete_mid(midQ); |
| if (rstart && rc == -EACCES) |
| return -ERESTARTSYS; |
| return rc; |
| } |