diff options
Diffstat (limited to 'fs/smb/client/transport.c')
| -rw-r--r-- | fs/smb/client/transport.c | 1810 |
1 files changed, 1810 insertions, 0 deletions
diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c new file mode 100644 index 000000000000..0474d0bba0a2 --- /dev/null +++ b/fs/smb/client/transport.c @@ -0,0 +1,1810 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * + * Copyright (C) International Business Machines Corp., 2002,2008 + * Author(s): Steve French (sfrench@us.ibm.com) + * Jeremy Allison (jra@samba.org) 2006. + * + */ + +#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 <linux/task_io_accounting_ops.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); +} + +static struct mid_q_entry * +alloc_mid(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server) +{ + struct mid_q_entry *temp; + + if (server == NULL) { + cifs_dbg(VFS, "%s: null TCP session\n", __func__); + 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); + /* 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(&mid_count); + temp->mid_state = MID_REQUEST_ALLOCATED; + return temp; +} + +static void __release_mid(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, server); + + midEntry->mid_state = MID_FREE; + atomic_dec(&mid_count); + 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 release_mid(struct mid_q_entry *mid) +{ + struct TCP_Server_Info *server = mid->server; + + spin_lock(&server->mid_lock); + kref_put(&mid->refcount, __release_mid); + spin_unlock(&server->mid_lock); +} + +void +delete_mid(struct mid_q_entry *mid) +{ + spin_lock(&mid->server->mid_lock); + if (!(mid->mid_flags & MID_DELETED)) { + list_del_init(&mid->qhead); + mid->mid_flags |= MID_DELETED; + } + spin_unlock(&mid->server->mid_lock); + + release_mid(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; + + 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 (!is_smb1(server) && 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; + + buflen += iov_iter_count(&rqst->rq_iter); + return buflen; +} + +static int +__smb_send_rqst(struct TCP_Server_Info *server, int num_rqst, + struct smb_rqst *rqst) +{ + int rc; + 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; + + cifs_in_send_inc(server); + 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; + } + + rc = -EAGAIN; + if (ssocket == NULL) + goto out; + + rc = -ERESTARTSYS; + if (fatal_signal_pending(current)) { + cifs_dbg(FYI, "signal pending before send request\n"); + goto out; + } + + rc = 0; + /* 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 (!is_smb1(server)) { + struct kvec hiov = { + .iov_base = &rfc1002_marker, + .iov_len = 4 + }; + iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &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, ITER_SOURCE, iov, n_vec, size); + + rc = smb_send_kvec(server, &smb_msg, &sent); + if (rc < 0) + goto unmask; + + total_len += sent; + + if (iov_iter_count(&rqst[j].rq_iter) > 0) { + smb_msg.msg_iter = rqst[j].rq_iter; + 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 = -ERESTARTSYS; + } + + /* 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 + */ + cifs_signal_cifsd_for_reconnect(server, false); + trace_smb3_partial_send_reconnect(server->CurrentMid, + server->conn_id, 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; +out: + cifs_in_send_dec(server); + 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 = kzalloc(sizeof(*tr_hdr), GFP_NOFS); + if (!tr_hdr) + return -ENOMEM; + + memset(&cur_rqst[0], 0, sizeof(cur_rqst)); + memset(&iov, 0, sizeof(iov)); + + 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) +{ + long rc; + int *credits; + int optype; + long int t; + int scredits, in_flight; + + 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; + scredits = *credits; + in_flight = server->in_flight; + spin_unlock(&server->req_lock); + + trace_smb3_nblk_credits(server->CurrentMid, + server->conn_id, server->hostname, scredits, -1, in_flight); + cifs_dbg(FYI, "%s: remove %u credits total=%d\n", + __func__, 1, scredits); + + return 0; + } + + while (1) { + if (*credits < num_credits) { + scredits = *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) { + spin_lock(&server->req_lock); + scredits = *credits; + in_flight = server->in_flight; + spin_unlock(&server->req_lock); + + trace_smb3_credit_timeout(server->CurrentMid, + server->conn_id, server->hostname, scredits, + num_credits, in_flight); + cifs_server_dbg(VFS, "wait timed out after %d ms\n", + timeout); + return -EBUSY; + } + if (rc == -ERESTARTSYS) + return -ERESTARTSYS; + spin_lock(&server->req_lock); + } else { + spin_unlock(&server->req_lock); + + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsExiting) { + spin_unlock(&server->srv_lock); + return -ENOENT; + } + spin_unlock(&server->srv_lock); + + /* + * 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. + */ + spin_lock(&server->req_lock); + 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) { + spin_lock(&server->req_lock); + scredits = *credits; + in_flight = server->in_flight; + spin_unlock(&server->req_lock); + + trace_smb3_credit_timeout( + server->CurrentMid, + server->conn_id, server->hostname, + scredits, num_credits, in_flight); + cifs_server_dbg(VFS, "wait timed out after %d ms\n", + timeout); + return -EBUSY; + } + 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; + } + scredits = *credits; + in_flight = server->in_flight; + spin_unlock(&server->req_lock); + + trace_smb3_waitff_credits(server->CurrentMid, + server->conn_id, server->hostname, scredits, + -(num_credits), in_flight); + cifs_dbg(FYI, "%s: remove %u credits total=%d\n", + __func__, num_credits, scredits); + 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; + int scredits, in_flight; + + credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK); + + spin_lock(&server->req_lock); + scredits = *credits; + in_flight = server->in_flight; + + if (*credits < num) { + /* + * If the server is tight on resources or just gives us less + * credits for other reasons (e.g. requests are coming out of + * order and the server delays granting more credits until it + * processes a missing mid) and we exhausted most available + * credits there may be situations when we try to send + * a compound request but we don't have enough credits. At this + * point the client needs to decide if it should wait for + * additional credits or fail the request. If at least one + * request is in flight there is a high probability that the + * server will return enough credits to satisfy this compound + * request. + * + * Return immediately if no requests in flight since we will be + * stuck on waiting for credits. + */ + if (server->in_flight == 0) { + spin_unlock(&server->req_lock); + trace_smb3_insufficient_credits(server->CurrentMid, + server->conn_id, server->hostname, scredits, + num, in_flight); + cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n", + __func__, in_flight, num, scredits); + return -EDEADLK; + } + } + 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) +{ + spin_lock(&ses->ses_lock); + if (ses->ses_status == SES_NEW) { + if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) && + (in_buf->Command != SMB_COM_NEGOTIATE)) { + spin_unlock(&ses->ses_lock); + return -EAGAIN; + } + /* else ok - we are setting up session */ + } + + if (ses->ses_status == SES_EXITING) { + /* check if SMB session is bad because we are setting it up */ + if (in_buf->Command != SMB_COM_LOGOFF_ANDX) { + spin_unlock(&ses->ses_lock); + return -EAGAIN; + } + /* else ok - we are shutting down session */ + } + spin_unlock(&ses->ses_lock); + + *ppmidQ = alloc_mid(in_buf, ses->server); + if (*ppmidQ == NULL) + return -ENOMEM; + spin_lock(&ses->server->mid_lock); + list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q); + spin_unlock(&ses->server->mid_lock); + return 0; +} + +static int +wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ) +{ + int error; + + error = wait_event_state(server->response_q, + midQ->mid_state != MID_REQUEST_SUBMITTED, + (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE)); + 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 = alloc_mid(hdr, server); + if (mid == NULL) + return ERR_PTR(-ENOMEM); + + rc = cifs_sign_rqst(rqst, server, &mid->sequence_number); + if (rc) { + release_mid(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; + + cifs_server_lock(server); + + /* + * 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) { + cifs_server_unlock(server); + add_credits_and_wake_if(server, &credits, optype); + return -EAGAIN; + } + + mid = server->ops->setup_async_request(server, rqst); + if (IS_ERR(mid)) { + cifs_server_unlock(server); + 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(&server->mid_lock); + list_add_tail(&mid->qhead, &server->pending_mid_q); + spin_unlock(&server->mid_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); + rc = smb_send_rqst(server, 1, rqst, flags); + + if (rc < 0) { + revert_current_mid(server, mid->credits); + server->sequence_number -= 2; + delete_mid(mid); + } + + cifs_server_unlock(server); + + 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(&server->mid_lock); + switch (mid->mid_state) { + case MID_RESPONSE_RECEIVED: + spin_unlock(&server->mid_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(&server->mid_lock); + + release_mid(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_and_check_smb_error(mid, 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) { + 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); + release_mid(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; + unsigned int min_in_flight = UINT_MAX, max_in_flight = 0; + struct TCP_Server_Info *server = NULL; + int i; + + if (!ses) + return NULL; + + spin_lock(&ses->chan_lock); + for (i = 0; i < ses->chan_count; i++) { + server = ses->chans[i].server; + if (!server) + continue; + + /* + * strictly speaking, we should pick up req_lock to read + * server->in_flight. But it shouldn't matter much here if we + * race while reading this data. The worst that can happen is + * that we could use a channel that's not least loaded. Avoiding + * taking the lock could help reduce wait time, which is + * important for this function + */ + if (server->in_flight < min_in_flight) { + min_in_flight = server->in_flight; + index = i; + } + if (server->in_flight > max_in_flight) + max_in_flight = server->in_flight; + } + + /* if all channels are equally loaded, fall back to round-robin */ + if (min_in_flight == max_in_flight) { + index = (uint)atomic_inc_return(&ses->chan_seq); + index %= ses->chan_count; + } + spin_unlock(&ses->chan_lock); + + return ses->chans[index].server; +} + +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; + } + + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsExiting) { + spin_unlock(&server->srv_lock); + return -ENOENT; + } + spin_unlock(&server->srv_lock); + + /* + * 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. + */ + + cifs_server_lock(server); + + /* + * 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) { + cifs_server_unlock(server); + 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++) + delete_mid(midQ[j]); + cifs_server_unlock(server); + + /* 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; + } + rc = smb_send_rqst(server, num_rqst, rqst, flags); + + 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; + } + + cifs_server_unlock(server); + + /* + * 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. + */ + spin_lock(&ses->ses_lock); + if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) { + spin_unlock(&ses->ses_lock); + + cifs_server_lock(server); + smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec); + cifs_server_unlock(server); + + spin_lock(&ses->ses_lock); + } + spin_unlock(&ses->ses_lock); + + 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(FYI, "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(&server->mid_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(&server->mid_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 + + HEADER_PREAMBLE_SIZE(server); + + 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 delete_mid */ + if ((flags & CIFS_NO_RSP_BUF) == 0) + midQ[i]->resp_buf = NULL; + + } + + /* + * Compounding is never used during session establish. + */ + spin_lock(&ses->ses_lock); + if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) { + struct kvec iov = { + .iov_base = resp_iov[0].iov_base, + .iov_len = resp_iov[0].iov_len + }; + spin_unlock(&ses->ses_lock); + cifs_server_lock(server); + smb311_update_preauth_hash(ses, server, &iov, 1); + cifs_server_unlock(server); + spin_lock(&ses->ses_lock); + } + spin_unlock(&ses->ses_lock); + +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]) + 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; + } + + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsExiting) { + spin_unlock(&server->srv_lock); + return -ENOENT; + } + spin_unlock(&server->srv_lock); + + /* 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 */ + + cifs_server_lock(server); + + rc = allocate_mid(ses, in_buf, &midQ); + if (rc) { + cifs_server_unlock(server); + /* 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) { + cifs_server_unlock(server); + goto out; + } + + midQ->mid_state = MID_REQUEST_SUBMITTED; + + rc = smb_send(server, in_buf, len); + cifs_save_when_sent(midQ); + + if (rc < 0) + server->sequence_number -= 2; + + cifs_server_unlock(server); + + if (rc < 0) + goto out; + + rc = wait_for_response(server, midQ); + if (rc != 0) { + send_cancel(server, &rqst, midQ); + spin_lock(&server->mid_lock); + if (midQ->mid_state == MID_REQUEST_SUBMITTED) { + /* no longer considered to be "in-flight" */ + midQ->callback = release_mid; + spin_unlock(&server->mid_lock); + add_credits(server, &credits, 0); + return rc; + } + spin_unlock(&server->mid_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: + 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; + } + + spin_lock(&server->srv_lock); + if (server->tcpStatus == CifsExiting) { + spin_unlock(&server->srv_lock); + return -ENOENT; + } + spin_unlock(&server->srv_lock); + + /* 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 */ + + cifs_server_lock(server); + + rc = allocate_mid(ses, in_buf, &midQ); + if (rc) { + cifs_server_unlock(server); + return rc; + } + + rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number); + if (rc) { + delete_mid(midQ); + cifs_server_unlock(server); + return rc; + } + + midQ->mid_state = MID_REQUEST_SUBMITTED; + rc = smb_send(server, in_buf, len); + cifs_save_when_sent(midQ); + + if (rc < 0) + server->sequence_number -= 2; + + cifs_server_unlock(server); + + if (rc < 0) { + 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 ? */ + spin_lock(&server->srv_lock); + if ((rc == -ERESTARTSYS) && + (midQ->mid_state == MID_REQUEST_SUBMITTED) && + ((server->tcpStatus == CifsGood) || + (server->tcpStatus == CifsNew))) { + spin_unlock(&server->srv_lock); + + 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) { + 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) { + delete_mid(midQ); + return rc; + } + } + + rc = wait_for_response(server, midQ); + if (rc) { + send_cancel(server, &rqst, midQ); + spin_lock(&server->mid_lock); + if (midQ->mid_state == MID_REQUEST_SUBMITTED) { + /* no longer considered to be "in-flight" */ + midQ->callback = release_mid; + spin_unlock(&server->mid_lock); + return rc; + } + spin_unlock(&server->mid_lock); + } + + /* We got the response - restart system call. */ + rstart = 1; + spin_lock(&server->srv_lock); + } + spin_unlock(&server->srv_lock); + + 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: + delete_mid(midQ); + if (rstart && rc == -EACCES) + return -ERESTARTSYS; + return rc; +} + +/* + * Discard any remaining data in the current SMB. To do this, we borrow the + * current bigbuf. + */ +int +cifs_discard_remaining_data(struct TCP_Server_Info *server) +{ + unsigned int rfclen = server->pdu_size; + size_t remaining = rfclen + HEADER_PREAMBLE_SIZE(server) - + server->total_read; + + while (remaining > 0) { + ssize_t length; + + length = cifs_discard_from_socket(server, + min_t(size_t, remaining, + CIFSMaxBufSize + MAX_HEADER_SIZE(server))); + if (length < 0) + return length; + server->total_read += length; + remaining -= length; + } + + return 0; +} + +static int +__cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid, + bool malformed) +{ + int length; + + length = cifs_discard_remaining_data(server); + dequeue_mid(mid, malformed); + mid->resp_buf = server->smallbuf; + server->smallbuf = NULL; + return length; +} + +static int +cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid) +{ + struct cifs_readdata *rdata = mid->callback_data; + + return __cifs_readv_discard(server, mid, rdata->result); +} + +int +cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) +{ + int length, len; + unsigned int data_offset, data_len; + struct cifs_readdata *rdata = mid->callback_data; + char *buf = server->smallbuf; + unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server); + bool use_rdma_mr = false; + + cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n", + __func__, mid->mid, rdata->offset, rdata->bytes); + + /* + * read the rest of READ_RSP header (sans Data array), or whatever we + * can if there's not enough data. At this point, we've read down to + * the Mid. + */ + len = min_t(unsigned int, buflen, server->vals->read_rsp_size) - + HEADER_SIZE(server) + 1; + + length = cifs_read_from_socket(server, + buf + HEADER_SIZE(server) - 1, len); + if (length < 0) + return length; + server->total_read += length; + + if (server->ops->is_session_expired && + server->ops->is_session_expired(buf)) { + cifs_reconnect(server, true); + return -1; + } + + if (server->ops->is_status_pending && + server->ops->is_status_pending(buf, server)) { + cifs_discard_remaining_data(server); + return -1; + } + + /* set up first two iov for signature check and to get credits */ + rdata->iov[0].iov_base = buf; + rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server); + rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server); + rdata->iov[1].iov_len = + server->total_read - HEADER_PREAMBLE_SIZE(server); + cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n", + rdata->iov[0].iov_base, rdata->iov[0].iov_len); + cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n", + rdata->iov[1].iov_base, rdata->iov[1].iov_len); + + /* Was the SMB read successful? */ + rdata->result = server->ops->map_error(buf, false); + if (rdata->result != 0) { + cifs_dbg(FYI, "%s: server returned error %d\n", + __func__, rdata->result); + /* normal error on read response */ + return __cifs_readv_discard(server, mid, false); + } + + /* Is there enough to get to the rest of the READ_RSP header? */ + if (server->total_read < server->vals->read_rsp_size) { + cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n", + __func__, server->total_read, + server->vals->read_rsp_size); + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + + data_offset = server->ops->read_data_offset(buf) + + HEADER_PREAMBLE_SIZE(server); + if (data_offset < server->total_read) { + /* + * win2k8 sometimes sends an offset of 0 when the read + * is beyond the EOF. Treat it as if the data starts just after + * the header. + */ + cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n", + __func__, data_offset); + data_offset = server->total_read; + } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) { + /* data_offset is beyond the end of smallbuf */ + cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n", + __func__, data_offset); + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + + cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n", + __func__, server->total_read, data_offset); + + len = data_offset - server->total_read; + if (len > 0) { + /* read any junk before data into the rest of smallbuf */ + length = cifs_read_from_socket(server, + buf + server->total_read, len); + if (length < 0) + return length; + server->total_read += length; + } + + /* how much data is in the response? */ +#ifdef CONFIG_CIFS_SMB_DIRECT + use_rdma_mr = rdata->mr; +#endif + data_len = server->ops->read_data_length(buf, use_rdma_mr); + if (!use_rdma_mr && (data_offset + data_len > buflen)) { + /* data_len is corrupt -- discard frame */ + rdata->result = -EIO; + return cifs_readv_discard(server, mid); + } + +#ifdef CONFIG_CIFS_SMB_DIRECT + if (rdata->mr) + length = data_len; /* An RDMA read is already done. */ + else +#endif + length = cifs_read_iter_from_socket(server, &rdata->iter, + data_len); + if (length > 0) + rdata->got_bytes += length; + server->total_read += length; + + cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n", + server->total_read, buflen, data_len); + + /* discard anything left over */ + if (server->total_read < buflen) + return cifs_readv_discard(server, mid); + + dequeue_mid(mid, false); + mid->resp_buf = server->smallbuf; + server->smallbuf = NULL; + return length; +} |