transport.c 42 KB

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  1. /*
  2. * fs/cifs/transport.c
  3. *
  4. * Copyright (C) International Business Machines Corp., 2002,2008
  5. * Author(s): Steve French (sfrench@us.ibm.com)
  6. * Jeremy Allison (jra@samba.org) 2006.
  7. *
  8. * This library is free software; you can redistribute it and/or modify
  9. * it under the terms of the GNU Lesser General Public License as published
  10. * by the Free Software Foundation; either version 2.1 of the License, or
  11. * (at your option) any later version.
  12. *
  13. * This library is distributed in the hope that it will be useful,
  14. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  16. * the GNU Lesser General Public License for more details.
  17. *
  18. * You should have received a copy of the GNU Lesser General Public License
  19. * along with this library; if not, write to the Free Software
  20. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21. */
  22. #include <linux/fs.h>
  23. #include <linux/list.h>
  24. #include <linux/gfp.h>
  25. #include <linux/wait.h>
  26. #include <linux/net.h>
  27. #include <linux/delay.h>
  28. #include <linux/freezer.h>
  29. #include <linux/tcp.h>
  30. #include <linux/bvec.h>
  31. #include <linux/highmem.h>
  32. #include <linux/uaccess.h>
  33. #include <asm/processor.h>
  34. #include <linux/mempool.h>
  35. #include <linux/sched/signal.h>
  36. #include "cifspdu.h"
  37. #include "cifsglob.h"
  38. #include "cifsproto.h"
  39. #include "cifs_debug.h"
  40. #include "smb2proto.h"
  41. #include "smbdirect.h"
  42. /* Max number of iovectors we can use off the stack when sending requests. */
  43. #define CIFS_MAX_IOV_SIZE 8
  44. void
  45. cifs_wake_up_task(struct mid_q_entry *mid)
  46. {
  47. wake_up_process(mid->callback_data);
  48. }
  49. struct mid_q_entry *
  50. AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
  51. {
  52. struct mid_q_entry *temp;
  53. if (server == NULL) {
  54. cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
  55. return NULL;
  56. }
  57. temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
  58. memset(temp, 0, sizeof(struct mid_q_entry));
  59. kref_init(&temp->refcount);
  60. temp->mid = get_mid(smb_buffer);
  61. temp->pid = current->pid;
  62. temp->command = cpu_to_le16(smb_buffer->Command);
  63. cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
  64. /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
  65. /* when mid allocated can be before when sent */
  66. temp->when_alloc = jiffies;
  67. temp->server = server;
  68. /*
  69. * The default is for the mid to be synchronous, so the
  70. * default callback just wakes up the current task.
  71. */
  72. get_task_struct(current);
  73. temp->creator = current;
  74. temp->callback = cifs_wake_up_task;
  75. temp->callback_data = current;
  76. atomic_inc(&midCount);
  77. temp->mid_state = MID_REQUEST_ALLOCATED;
  78. return temp;
  79. }
  80. static void _cifs_mid_q_entry_release(struct kref *refcount)
  81. {
  82. struct mid_q_entry *midEntry =
  83. container_of(refcount, struct mid_q_entry, refcount);
  84. #ifdef CONFIG_CIFS_STATS2
  85. __le16 command = midEntry->server->vals->lock_cmd;
  86. __u16 smb_cmd = le16_to_cpu(midEntry->command);
  87. unsigned long now;
  88. unsigned long roundtrip_time;
  89. #endif
  90. struct TCP_Server_Info *server = midEntry->server;
  91. if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
  92. midEntry->mid_state == MID_RESPONSE_RECEIVED &&
  93. server->ops->handle_cancelled_mid)
  94. server->ops->handle_cancelled_mid(midEntry, server);
  95. midEntry->mid_state = MID_FREE;
  96. atomic_dec(&midCount);
  97. if (midEntry->large_buf)
  98. cifs_buf_release(midEntry->resp_buf);
  99. else
  100. cifs_small_buf_release(midEntry->resp_buf);
  101. #ifdef CONFIG_CIFS_STATS2
  102. now = jiffies;
  103. if (now < midEntry->when_alloc)
  104. cifs_server_dbg(VFS, "Invalid mid allocation time\n");
  105. roundtrip_time = now - midEntry->when_alloc;
  106. if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
  107. if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
  108. server->slowest_cmd[smb_cmd] = roundtrip_time;
  109. server->fastest_cmd[smb_cmd] = roundtrip_time;
  110. } else {
  111. if (server->slowest_cmd[smb_cmd] < roundtrip_time)
  112. server->slowest_cmd[smb_cmd] = roundtrip_time;
  113. else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
  114. server->fastest_cmd[smb_cmd] = roundtrip_time;
  115. }
  116. cifs_stats_inc(&server->num_cmds[smb_cmd]);
  117. server->time_per_cmd[smb_cmd] += roundtrip_time;
  118. }
  119. /*
  120. * commands taking longer than one second (default) can be indications
  121. * that something is wrong, unless it is quite a slow link or a very
  122. * busy server. Note that this calc is unlikely or impossible to wrap
  123. * as long as slow_rsp_threshold is not set way above recommended max
  124. * value (32767 ie 9 hours) and is generally harmless even if wrong
  125. * since only affects debug counters - so leaving the calc as simple
  126. * comparison rather than doing multiple conversions and overflow
  127. * checks
  128. */
  129. if ((slow_rsp_threshold != 0) &&
  130. time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
  131. (midEntry->command != command)) {
  132. /*
  133. * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
  134. * NB: le16_to_cpu returns unsigned so can not be negative below
  135. */
  136. if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
  137. cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
  138. trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
  139. midEntry->when_sent, midEntry->when_received);
  140. if (cifsFYI & CIFS_TIMER) {
  141. pr_debug("slow rsp: cmd %d mid %llu",
  142. midEntry->command, midEntry->mid);
  143. cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
  144. now - midEntry->when_alloc,
  145. now - midEntry->when_sent,
  146. now - midEntry->when_received);
  147. }
  148. }
  149. #endif
  150. put_task_struct(midEntry->creator);
  151. mempool_free(midEntry, cifs_mid_poolp);
  152. }
  153. void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
  154. {
  155. spin_lock(&GlobalMid_Lock);
  156. kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
  157. spin_unlock(&GlobalMid_Lock);
  158. }
  159. void DeleteMidQEntry(struct mid_q_entry *midEntry)
  160. {
  161. cifs_mid_q_entry_release(midEntry);
  162. }
  163. void
  164. cifs_delete_mid(struct mid_q_entry *mid)
  165. {
  166. spin_lock(&GlobalMid_Lock);
  167. if (!(mid->mid_flags & MID_DELETED)) {
  168. list_del_init(&mid->qhead);
  169. mid->mid_flags |= MID_DELETED;
  170. }
  171. spin_unlock(&GlobalMid_Lock);
  172. DeleteMidQEntry(mid);
  173. }
  174. /*
  175. * smb_send_kvec - send an array of kvecs to the server
  176. * @server: Server to send the data to
  177. * @smb_msg: Message to send
  178. * @sent: amount of data sent on socket is stored here
  179. *
  180. * Our basic "send data to server" function. Should be called with srv_mutex
  181. * held. The caller is responsible for handling the results.
  182. */
  183. static int
  184. smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
  185. size_t *sent)
  186. {
  187. int rc = 0;
  188. int retries = 0;
  189. struct socket *ssocket = server->ssocket;
  190. *sent = 0;
  191. smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
  192. smb_msg->msg_namelen = sizeof(struct sockaddr);
  193. smb_msg->msg_control = NULL;
  194. smb_msg->msg_controllen = 0;
  195. if (server->noblocksnd)
  196. smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
  197. else
  198. smb_msg->msg_flags = MSG_NOSIGNAL;
  199. while (msg_data_left(smb_msg)) {
  200. /*
  201. * If blocking send, we try 3 times, since each can block
  202. * for 5 seconds. For nonblocking we have to try more
  203. * but wait increasing amounts of time allowing time for
  204. * socket to clear. The overall time we wait in either
  205. * case to send on the socket is about 15 seconds.
  206. * Similarly we wait for 15 seconds for a response from
  207. * the server in SendReceive[2] for the server to send
  208. * a response back for most types of requests (except
  209. * SMB Write past end of file which can be slow, and
  210. * blocking lock operations). NFS waits slightly longer
  211. * than CIFS, but this can make it take longer for
  212. * nonresponsive servers to be detected and 15 seconds
  213. * is more than enough time for modern networks to
  214. * send a packet. In most cases if we fail to send
  215. * after the retries we will kill the socket and
  216. * reconnect which may clear the network problem.
  217. */
  218. rc = sock_sendmsg(ssocket, smb_msg);
  219. if (rc == -EAGAIN) {
  220. retries++;
  221. if (retries >= 14 ||
  222. (!server->noblocksnd && (retries > 2))) {
  223. cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
  224. ssocket);
  225. return -EAGAIN;
  226. }
  227. msleep(1 << retries);
  228. continue;
  229. }
  230. if (rc < 0)
  231. return rc;
  232. if (rc == 0) {
  233. /* should never happen, letting socket clear before
  234. retrying is our only obvious option here */
  235. cifs_server_dbg(VFS, "tcp sent no data\n");
  236. msleep(500);
  237. continue;
  238. }
  239. /* send was at least partially successful */
  240. *sent += rc;
  241. retries = 0; /* in case we get ENOSPC on the next send */
  242. }
  243. return 0;
  244. }
  245. unsigned long
  246. smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
  247. {
  248. unsigned int i;
  249. struct kvec *iov;
  250. int nvec;
  251. unsigned long buflen = 0;
  252. if (server->vals->header_preamble_size == 0 &&
  253. rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
  254. iov = &rqst->rq_iov[1];
  255. nvec = rqst->rq_nvec - 1;
  256. } else {
  257. iov = rqst->rq_iov;
  258. nvec = rqst->rq_nvec;
  259. }
  260. /* total up iov array first */
  261. for (i = 0; i < nvec; i++)
  262. buflen += iov[i].iov_len;
  263. /*
  264. * Add in the page array if there is one. The caller needs to make
  265. * sure rq_offset and rq_tailsz are set correctly. If a buffer of
  266. * multiple pages ends at page boundary, rq_tailsz needs to be set to
  267. * PAGE_SIZE.
  268. */
  269. if (rqst->rq_npages) {
  270. if (rqst->rq_npages == 1)
  271. buflen += rqst->rq_tailsz;
  272. else {
  273. /*
  274. * If there is more than one page, calculate the
  275. * buffer length based on rq_offset and rq_tailsz
  276. */
  277. buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
  278. rqst->rq_offset;
  279. buflen += rqst->rq_tailsz;
  280. }
  281. }
  282. return buflen;
  283. }
  284. static int
  285. __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
  286. struct smb_rqst *rqst)
  287. {
  288. int rc = 0;
  289. struct kvec *iov;
  290. int n_vec;
  291. unsigned int send_length = 0;
  292. unsigned int i, j;
  293. sigset_t mask, oldmask;
  294. size_t total_len = 0, sent, size;
  295. struct socket *ssocket = server->ssocket;
  296. struct msghdr smb_msg;
  297. __be32 rfc1002_marker;
  298. if (cifs_rdma_enabled(server)) {
  299. /* return -EAGAIN when connecting or reconnecting */
  300. rc = -EAGAIN;
  301. if (server->smbd_conn)
  302. rc = smbd_send(server, num_rqst, rqst);
  303. goto smbd_done;
  304. }
  305. if (ssocket == NULL)
  306. return -EAGAIN;
  307. if (fatal_signal_pending(current)) {
  308. cifs_dbg(FYI, "signal pending before send request\n");
  309. return -ERESTARTSYS;
  310. }
  311. /* cork the socket */
  312. tcp_sock_set_cork(ssocket->sk, true);
  313. for (j = 0; j < num_rqst; j++)
  314. send_length += smb_rqst_len(server, &rqst[j]);
  315. rfc1002_marker = cpu_to_be32(send_length);
  316. /*
  317. * We should not allow signals to interrupt the network send because
  318. * any partial send will cause session reconnects thus increasing
  319. * latency of system calls and overload a server with unnecessary
  320. * requests.
  321. */
  322. sigfillset(&mask);
  323. sigprocmask(SIG_BLOCK, &mask, &oldmask);
  324. /* Generate a rfc1002 marker for SMB2+ */
  325. if (server->vals->header_preamble_size == 0) {
  326. struct kvec hiov = {
  327. .iov_base = &rfc1002_marker,
  328. .iov_len = 4
  329. };
  330. iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
  331. rc = smb_send_kvec(server, &smb_msg, &sent);
  332. if (rc < 0)
  333. goto unmask;
  334. total_len += sent;
  335. send_length += 4;
  336. }
  337. cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
  338. for (j = 0; j < num_rqst; j++) {
  339. iov = rqst[j].rq_iov;
  340. n_vec = rqst[j].rq_nvec;
  341. size = 0;
  342. for (i = 0; i < n_vec; i++) {
  343. dump_smb(iov[i].iov_base, iov[i].iov_len);
  344. size += iov[i].iov_len;
  345. }
  346. iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
  347. rc = smb_send_kvec(server, &smb_msg, &sent);
  348. if (rc < 0)
  349. goto unmask;
  350. total_len += sent;
  351. /* now walk the page array and send each page in it */
  352. for (i = 0; i < rqst[j].rq_npages; i++) {
  353. struct bio_vec bvec;
  354. bvec.bv_page = rqst[j].rq_pages[i];
  355. rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
  356. &bvec.bv_offset);
  357. iov_iter_bvec(&smb_msg.msg_iter, WRITE,
  358. &bvec, 1, bvec.bv_len);
  359. rc = smb_send_kvec(server, &smb_msg, &sent);
  360. if (rc < 0)
  361. break;
  362. total_len += sent;
  363. }
  364. }
  365. unmask:
  366. sigprocmask(SIG_SETMASK, &oldmask, NULL);
  367. /*
  368. * If signal is pending but we have already sent the whole packet to
  369. * the server we need to return success status to allow a corresponding
  370. * mid entry to be kept in the pending requests queue thus allowing
  371. * to handle responses from the server by the client.
  372. *
  373. * If only part of the packet has been sent there is no need to hide
  374. * interrupt because the session will be reconnected anyway, so there
  375. * won't be any response from the server to handle.
  376. */
  377. if (signal_pending(current) && (total_len != send_length)) {
  378. cifs_dbg(FYI, "signal is pending after attempt to send\n");
  379. rc = -ERESTARTSYS;
  380. }
  381. /* uncork it */
  382. tcp_sock_set_cork(ssocket->sk, false);
  383. if ((total_len > 0) && (total_len != send_length)) {
  384. cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
  385. send_length, total_len);
  386. /*
  387. * If we have only sent part of an SMB then the next SMB could
  388. * be taken as the remainder of this one. We need to kill the
  389. * socket so the server throws away the partial SMB
  390. */
  391. server->tcpStatus = CifsNeedReconnect;
  392. trace_smb3_partial_send_reconnect(server->CurrentMid,
  393. server->hostname);
  394. }
  395. smbd_done:
  396. if (rc < 0 && rc != -EINTR)
  397. cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
  398. rc);
  399. else if (rc > 0)
  400. rc = 0;
  401. return rc;
  402. }
  403. static int
  404. smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
  405. struct smb_rqst *rqst, int flags)
  406. {
  407. struct kvec iov;
  408. struct smb2_transform_hdr *tr_hdr;
  409. struct smb_rqst cur_rqst[MAX_COMPOUND];
  410. int rc;
  411. if (!(flags & CIFS_TRANSFORM_REQ))
  412. return __smb_send_rqst(server, num_rqst, rqst);
  413. if (num_rqst > MAX_COMPOUND - 1)
  414. return -ENOMEM;
  415. if (!server->ops->init_transform_rq) {
  416. cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
  417. return -EIO;
  418. }
  419. tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
  420. if (!tr_hdr)
  421. return -ENOMEM;
  422. memset(&cur_rqst[0], 0, sizeof(cur_rqst));
  423. memset(&iov, 0, sizeof(iov));
  424. memset(tr_hdr, 0, sizeof(*tr_hdr));
  425. iov.iov_base = tr_hdr;
  426. iov.iov_len = sizeof(*tr_hdr);
  427. cur_rqst[0].rq_iov = &iov;
  428. cur_rqst[0].rq_nvec = 1;
  429. rc = server->ops->init_transform_rq(server, num_rqst + 1,
  430. &cur_rqst[0], rqst);
  431. if (rc)
  432. goto out;
  433. rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
  434. smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
  435. out:
  436. kfree(tr_hdr);
  437. return rc;
  438. }
  439. int
  440. smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
  441. unsigned int smb_buf_length)
  442. {
  443. struct kvec iov[2];
  444. struct smb_rqst rqst = { .rq_iov = iov,
  445. .rq_nvec = 2 };
  446. iov[0].iov_base = smb_buffer;
  447. iov[0].iov_len = 4;
  448. iov[1].iov_base = (char *)smb_buffer + 4;
  449. iov[1].iov_len = smb_buf_length;
  450. return __smb_send_rqst(server, 1, &rqst);
  451. }
  452. static int
  453. wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
  454. const int timeout, const int flags,
  455. unsigned int *instance)
  456. {
  457. long rc;
  458. int *credits;
  459. int optype;
  460. long int t;
  461. if (timeout < 0)
  462. t = MAX_JIFFY_OFFSET;
  463. else
  464. t = msecs_to_jiffies(timeout);
  465. optype = flags & CIFS_OP_MASK;
  466. *instance = 0;
  467. credits = server->ops->get_credits_field(server, optype);
  468. /* Since an echo is already inflight, no need to wait to send another */
  469. if (*credits <= 0 && optype == CIFS_ECHO_OP)
  470. return -EAGAIN;
  471. spin_lock(&server->req_lock);
  472. if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
  473. /* oplock breaks must not be held up */
  474. server->in_flight++;
  475. if (server->in_flight > server->max_in_flight)
  476. server->max_in_flight = server->in_flight;
  477. *credits -= 1;
  478. *instance = server->reconnect_instance;
  479. spin_unlock(&server->req_lock);
  480. return 0;
  481. }
  482. while (1) {
  483. if (*credits < num_credits) {
  484. spin_unlock(&server->req_lock);
  485. cifs_num_waiters_inc(server);
  486. rc = wait_event_killable_timeout(server->request_q,
  487. has_credits(server, credits, num_credits), t);
  488. cifs_num_waiters_dec(server);
  489. if (!rc) {
  490. trace_smb3_credit_timeout(server->CurrentMid,
  491. server->hostname, num_credits, 0);
  492. cifs_server_dbg(VFS, "wait timed out after %d ms\n",
  493. timeout);
  494. return -ENOTSUPP;
  495. }
  496. if (rc == -ERESTARTSYS)
  497. return -ERESTARTSYS;
  498. spin_lock(&server->req_lock);
  499. } else {
  500. if (server->tcpStatus == CifsExiting) {
  501. spin_unlock(&server->req_lock);
  502. return -ENOENT;
  503. }
  504. /*
  505. * For normal commands, reserve the last MAX_COMPOUND
  506. * credits to compound requests.
  507. * Otherwise these compounds could be permanently
  508. * starved for credits by single-credit requests.
  509. *
  510. * To prevent spinning CPU, block this thread until
  511. * there are >MAX_COMPOUND credits available.
  512. * But only do this is we already have a lot of
  513. * credits in flight to avoid triggering this check
  514. * for servers that are slow to hand out credits on
  515. * new sessions.
  516. */
  517. if (!optype && num_credits == 1 &&
  518. server->in_flight > 2 * MAX_COMPOUND &&
  519. *credits <= MAX_COMPOUND) {
  520. spin_unlock(&server->req_lock);
  521. cifs_num_waiters_inc(server);
  522. rc = wait_event_killable_timeout(
  523. server->request_q,
  524. has_credits(server, credits,
  525. MAX_COMPOUND + 1),
  526. t);
  527. cifs_num_waiters_dec(server);
  528. if (!rc) {
  529. trace_smb3_credit_timeout(
  530. server->CurrentMid,
  531. server->hostname, num_credits,
  532. 0);
  533. cifs_server_dbg(VFS, "wait timed out after %d ms\n",
  534. timeout);
  535. return -ENOTSUPP;
  536. }
  537. if (rc == -ERESTARTSYS)
  538. return -ERESTARTSYS;
  539. spin_lock(&server->req_lock);
  540. continue;
  541. }
  542. /*
  543. * Can not count locking commands against total
  544. * as they are allowed to block on server.
  545. */
  546. /* update # of requests on the wire to server */
  547. if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
  548. *credits -= num_credits;
  549. server->in_flight += num_credits;
  550. if (server->in_flight > server->max_in_flight)
  551. server->max_in_flight = server->in_flight;
  552. *instance = server->reconnect_instance;
  553. }
  554. spin_unlock(&server->req_lock);
  555. break;
  556. }
  557. }
  558. return 0;
  559. }
  560. static int
  561. wait_for_free_request(struct TCP_Server_Info *server, const int flags,
  562. unsigned int *instance)
  563. {
  564. return wait_for_free_credits(server, 1, -1, flags,
  565. instance);
  566. }
  567. static int
  568. wait_for_compound_request(struct TCP_Server_Info *server, int num,
  569. const int flags, unsigned int *instance)
  570. {
  571. int *credits;
  572. credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
  573. spin_lock(&server->req_lock);
  574. if (*credits < num) {
  575. /*
  576. * If the server is tight on resources or just gives us less
  577. * credits for other reasons (e.g. requests are coming out of
  578. * order and the server delays granting more credits until it
  579. * processes a missing mid) and we exhausted most available
  580. * credits there may be situations when we try to send
  581. * a compound request but we don't have enough credits. At this
  582. * point the client needs to decide if it should wait for
  583. * additional credits or fail the request. If at least one
  584. * request is in flight there is a high probability that the
  585. * server will return enough credits to satisfy this compound
  586. * request.
  587. *
  588. * Return immediately if no requests in flight since we will be
  589. * stuck on waiting for credits.
  590. */
  591. if (server->in_flight == 0) {
  592. spin_unlock(&server->req_lock);
  593. return -ENOTSUPP;
  594. }
  595. }
  596. spin_unlock(&server->req_lock);
  597. return wait_for_free_credits(server, num, 60000, flags,
  598. instance);
  599. }
  600. int
  601. cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
  602. unsigned int *num, struct cifs_credits *credits)
  603. {
  604. *num = size;
  605. credits->value = 0;
  606. credits->instance = server->reconnect_instance;
  607. return 0;
  608. }
  609. static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
  610. struct mid_q_entry **ppmidQ)
  611. {
  612. if (ses->server->tcpStatus == CifsExiting) {
  613. return -ENOENT;
  614. }
  615. if (ses->server->tcpStatus == CifsNeedReconnect) {
  616. cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
  617. return -EAGAIN;
  618. }
  619. if (ses->status == CifsNew) {
  620. if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
  621. (in_buf->Command != SMB_COM_NEGOTIATE))
  622. return -EAGAIN;
  623. /* else ok - we are setting up session */
  624. }
  625. if (ses->status == CifsExiting) {
  626. /* check if SMB session is bad because we are setting it up */
  627. if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
  628. return -EAGAIN;
  629. /* else ok - we are shutting down session */
  630. }
  631. *ppmidQ = AllocMidQEntry(in_buf, ses->server);
  632. if (*ppmidQ == NULL)
  633. return -ENOMEM;
  634. spin_lock(&GlobalMid_Lock);
  635. list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
  636. spin_unlock(&GlobalMid_Lock);
  637. return 0;
  638. }
  639. static int
  640. wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
  641. {
  642. int error;
  643. error = wait_event_freezekillable_unsafe(server->response_q,
  644. midQ->mid_state != MID_REQUEST_SUBMITTED);
  645. if (error < 0)
  646. return -ERESTARTSYS;
  647. return 0;
  648. }
  649. struct mid_q_entry *
  650. cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
  651. {
  652. int rc;
  653. struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
  654. struct mid_q_entry *mid;
  655. if (rqst->rq_iov[0].iov_len != 4 ||
  656. rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
  657. return ERR_PTR(-EIO);
  658. /* enable signing if server requires it */
  659. if (server->sign)
  660. hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
  661. mid = AllocMidQEntry(hdr, server);
  662. if (mid == NULL)
  663. return ERR_PTR(-ENOMEM);
  664. rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
  665. if (rc) {
  666. DeleteMidQEntry(mid);
  667. return ERR_PTR(rc);
  668. }
  669. return mid;
  670. }
  671. /*
  672. * Send a SMB request and set the callback function in the mid to handle
  673. * the result. Caller is responsible for dealing with timeouts.
  674. */
  675. int
  676. cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
  677. mid_receive_t *receive, mid_callback_t *callback,
  678. mid_handle_t *handle, void *cbdata, const int flags,
  679. const struct cifs_credits *exist_credits)
  680. {
  681. int rc;
  682. struct mid_q_entry *mid;
  683. struct cifs_credits credits = { .value = 0, .instance = 0 };
  684. unsigned int instance;
  685. int optype;
  686. optype = flags & CIFS_OP_MASK;
  687. if ((flags & CIFS_HAS_CREDITS) == 0) {
  688. rc = wait_for_free_request(server, flags, &instance);
  689. if (rc)
  690. return rc;
  691. credits.value = 1;
  692. credits.instance = instance;
  693. } else
  694. instance = exist_credits->instance;
  695. mutex_lock(&server->srv_mutex);
  696. /*
  697. * We can't use credits obtained from the previous session to send this
  698. * request. Check if there were reconnects after we obtained credits and
  699. * return -EAGAIN in such cases to let callers handle it.
  700. */
  701. if (instance != server->reconnect_instance) {
  702. mutex_unlock(&server->srv_mutex);
  703. add_credits_and_wake_if(server, &credits, optype);
  704. return -EAGAIN;
  705. }
  706. mid = server->ops->setup_async_request(server, rqst);
  707. if (IS_ERR(mid)) {
  708. mutex_unlock(&server->srv_mutex);
  709. add_credits_and_wake_if(server, &credits, optype);
  710. return PTR_ERR(mid);
  711. }
  712. mid->receive = receive;
  713. mid->callback = callback;
  714. mid->callback_data = cbdata;
  715. mid->handle = handle;
  716. mid->mid_state = MID_REQUEST_SUBMITTED;
  717. /* put it on the pending_mid_q */
  718. spin_lock(&GlobalMid_Lock);
  719. list_add_tail(&mid->qhead, &server->pending_mid_q);
  720. spin_unlock(&GlobalMid_Lock);
  721. /*
  722. * Need to store the time in mid before calling I/O. For call_async,
  723. * I/O response may come back and free the mid entry on another thread.
  724. */
  725. cifs_save_when_sent(mid);
  726. cifs_in_send_inc(server);
  727. rc = smb_send_rqst(server, 1, rqst, flags);
  728. cifs_in_send_dec(server);
  729. if (rc < 0) {
  730. revert_current_mid(server, mid->credits);
  731. server->sequence_number -= 2;
  732. cifs_delete_mid(mid);
  733. }
  734. mutex_unlock(&server->srv_mutex);
  735. if (rc == 0)
  736. return 0;
  737. add_credits_and_wake_if(server, &credits, optype);
  738. return rc;
  739. }
  740. /*
  741. *
  742. * Send an SMB Request. No response info (other than return code)
  743. * needs to be parsed.
  744. *
  745. * flags indicate the type of request buffer and how long to wait
  746. * and whether to log NT STATUS code (error) before mapping it to POSIX error
  747. *
  748. */
  749. int
  750. SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
  751. char *in_buf, int flags)
  752. {
  753. int rc;
  754. struct kvec iov[1];
  755. struct kvec rsp_iov;
  756. int resp_buf_type;
  757. iov[0].iov_base = in_buf;
  758. iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
  759. flags |= CIFS_NO_RSP_BUF;
  760. rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
  761. cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
  762. return rc;
  763. }
  764. static int
  765. cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
  766. {
  767. int rc = 0;
  768. cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
  769. __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
  770. spin_lock(&GlobalMid_Lock);
  771. switch (mid->mid_state) {
  772. case MID_RESPONSE_RECEIVED:
  773. spin_unlock(&GlobalMid_Lock);
  774. return rc;
  775. case MID_RETRY_NEEDED:
  776. rc = -EAGAIN;
  777. break;
  778. case MID_RESPONSE_MALFORMED:
  779. rc = -EIO;
  780. break;
  781. case MID_SHUTDOWN:
  782. rc = -EHOSTDOWN;
  783. break;
  784. default:
  785. if (!(mid->mid_flags & MID_DELETED)) {
  786. list_del_init(&mid->qhead);
  787. mid->mid_flags |= MID_DELETED;
  788. }
  789. cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
  790. __func__, mid->mid, mid->mid_state);
  791. rc = -EIO;
  792. }
  793. spin_unlock(&GlobalMid_Lock);
  794. DeleteMidQEntry(mid);
  795. return rc;
  796. }
  797. static inline int
  798. send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
  799. struct mid_q_entry *mid)
  800. {
  801. return server->ops->send_cancel ?
  802. server->ops->send_cancel(server, rqst, mid) : 0;
  803. }
  804. int
  805. cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
  806. bool log_error)
  807. {
  808. unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
  809. dump_smb(mid->resp_buf, min_t(u32, 92, len));
  810. /* convert the length into a more usable form */
  811. if (server->sign) {
  812. struct kvec iov[2];
  813. int rc = 0;
  814. struct smb_rqst rqst = { .rq_iov = iov,
  815. .rq_nvec = 2 };
  816. iov[0].iov_base = mid->resp_buf;
  817. iov[0].iov_len = 4;
  818. iov[1].iov_base = (char *)mid->resp_buf + 4;
  819. iov[1].iov_len = len - 4;
  820. /* FIXME: add code to kill session */
  821. rc = cifs_verify_signature(&rqst, server,
  822. mid->sequence_number);
  823. if (rc)
  824. cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
  825. rc);
  826. }
  827. /* BB special case reconnect tid and uid here? */
  828. return map_and_check_smb_error(mid, log_error);
  829. }
  830. struct mid_q_entry *
  831. cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
  832. struct smb_rqst *rqst)
  833. {
  834. int rc;
  835. struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
  836. struct mid_q_entry *mid;
  837. if (rqst->rq_iov[0].iov_len != 4 ||
  838. rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
  839. return ERR_PTR(-EIO);
  840. rc = allocate_mid(ses, hdr, &mid);
  841. if (rc)
  842. return ERR_PTR(rc);
  843. rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
  844. if (rc) {
  845. cifs_delete_mid(mid);
  846. return ERR_PTR(rc);
  847. }
  848. return mid;
  849. }
  850. static void
  851. cifs_compound_callback(struct mid_q_entry *mid)
  852. {
  853. struct TCP_Server_Info *server = mid->server;
  854. struct cifs_credits credits;
  855. credits.value = server->ops->get_credits(mid);
  856. credits.instance = server->reconnect_instance;
  857. add_credits(server, &credits, mid->optype);
  858. }
  859. static void
  860. cifs_compound_last_callback(struct mid_q_entry *mid)
  861. {
  862. cifs_compound_callback(mid);
  863. cifs_wake_up_task(mid);
  864. }
  865. static void
  866. cifs_cancelled_callback(struct mid_q_entry *mid)
  867. {
  868. cifs_compound_callback(mid);
  869. DeleteMidQEntry(mid);
  870. }
  871. /*
  872. * Return a channel (master if none) of @ses that can be used to send
  873. * regular requests.
  874. *
  875. * If we are currently binding a new channel (negprot/sess.setup),
  876. * return the new incomplete channel.
  877. */
  878. struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
  879. {
  880. uint index = 0;
  881. if (!ses)
  882. return NULL;
  883. if (!ses->binding) {
  884. /* round robin */
  885. if (ses->chan_count > 1) {
  886. index = (uint)atomic_inc_return(&ses->chan_seq);
  887. index %= ses->chan_count;
  888. }
  889. return ses->chans[index].server;
  890. } else {
  891. return cifs_ses_server(ses);
  892. }
  893. }
  894. int
  895. compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
  896. struct TCP_Server_Info *server,
  897. const int flags, const int num_rqst, struct smb_rqst *rqst,
  898. int *resp_buf_type, struct kvec *resp_iov)
  899. {
  900. int i, j, optype, rc = 0;
  901. struct mid_q_entry *midQ[MAX_COMPOUND];
  902. bool cancelled_mid[MAX_COMPOUND] = {false};
  903. struct cifs_credits credits[MAX_COMPOUND] = {
  904. { .value = 0, .instance = 0 }
  905. };
  906. unsigned int instance;
  907. char *buf;
  908. optype = flags & CIFS_OP_MASK;
  909. for (i = 0; i < num_rqst; i++)
  910. resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
  911. if (!ses || !ses->server || !server) {
  912. cifs_dbg(VFS, "Null session\n");
  913. return -EIO;
  914. }
  915. if (server->tcpStatus == CifsExiting)
  916. return -ENOENT;
  917. /*
  918. * Wait for all the requests to become available.
  919. * This approach still leaves the possibility to be stuck waiting for
  920. * credits if the server doesn't grant credits to the outstanding
  921. * requests and if the client is completely idle, not generating any
  922. * other requests.
  923. * This can be handled by the eventual session reconnect.
  924. */
  925. rc = wait_for_compound_request(server, num_rqst, flags,
  926. &instance);
  927. if (rc)
  928. return rc;
  929. for (i = 0; i < num_rqst; i++) {
  930. credits[i].value = 1;
  931. credits[i].instance = instance;
  932. }
  933. /*
  934. * Make sure that we sign in the same order that we send on this socket
  935. * and avoid races inside tcp sendmsg code that could cause corruption
  936. * of smb data.
  937. */
  938. mutex_lock(&server->srv_mutex);
  939. /*
  940. * All the parts of the compound chain belong obtained credits from the
  941. * same session. We can not use credits obtained from the previous
  942. * session to send this request. Check if there were reconnects after
  943. * we obtained credits and return -EAGAIN in such cases to let callers
  944. * handle it.
  945. */
  946. if (instance != server->reconnect_instance) {
  947. mutex_unlock(&server->srv_mutex);
  948. for (j = 0; j < num_rqst; j++)
  949. add_credits(server, &credits[j], optype);
  950. return -EAGAIN;
  951. }
  952. for (i = 0; i < num_rqst; i++) {
  953. midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
  954. if (IS_ERR(midQ[i])) {
  955. revert_current_mid(server, i);
  956. for (j = 0; j < i; j++)
  957. cifs_delete_mid(midQ[j]);
  958. mutex_unlock(&server->srv_mutex);
  959. /* Update # of requests on wire to server */
  960. for (j = 0; j < num_rqst; j++)
  961. add_credits(server, &credits[j], optype);
  962. return PTR_ERR(midQ[i]);
  963. }
  964. midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
  965. midQ[i]->optype = optype;
  966. /*
  967. * Invoke callback for every part of the compound chain
  968. * to calculate credits properly. Wake up this thread only when
  969. * the last element is received.
  970. */
  971. if (i < num_rqst - 1)
  972. midQ[i]->callback = cifs_compound_callback;
  973. else
  974. midQ[i]->callback = cifs_compound_last_callback;
  975. }
  976. cifs_in_send_inc(server);
  977. rc = smb_send_rqst(server, num_rqst, rqst, flags);
  978. cifs_in_send_dec(server);
  979. for (i = 0; i < num_rqst; i++)
  980. cifs_save_when_sent(midQ[i]);
  981. if (rc < 0) {
  982. revert_current_mid(server, num_rqst);
  983. server->sequence_number -= 2;
  984. }
  985. mutex_unlock(&server->srv_mutex);
  986. /*
  987. * If sending failed for some reason or it is an oplock break that we
  988. * will not receive a response to - return credits back
  989. */
  990. if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
  991. for (i = 0; i < num_rqst; i++)
  992. add_credits(server, &credits[i], optype);
  993. goto out;
  994. }
  995. /*
  996. * At this point the request is passed to the network stack - we assume
  997. * that any credits taken from the server structure on the client have
  998. * been spent and we can't return them back. Once we receive responses
  999. * we will collect credits granted by the server in the mid callbacks
  1000. * and add those credits to the server structure.
  1001. */
  1002. /*
  1003. * Compounding is never used during session establish.
  1004. */
  1005. if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
  1006. mutex_lock(&server->srv_mutex);
  1007. smb311_update_preauth_hash(ses, rqst[0].rq_iov,
  1008. rqst[0].rq_nvec);
  1009. mutex_unlock(&server->srv_mutex);
  1010. }
  1011. for (i = 0; i < num_rqst; i++) {
  1012. rc = wait_for_response(server, midQ[i]);
  1013. if (rc != 0)
  1014. break;
  1015. }
  1016. if (rc != 0) {
  1017. for (; i < num_rqst; i++) {
  1018. cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
  1019. midQ[i]->mid, le16_to_cpu(midQ[i]->command));
  1020. send_cancel(server, &rqst[i], midQ[i]);
  1021. spin_lock(&GlobalMid_Lock);
  1022. midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
  1023. if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
  1024. midQ[i]->callback = cifs_cancelled_callback;
  1025. cancelled_mid[i] = true;
  1026. credits[i].value = 0;
  1027. }
  1028. spin_unlock(&GlobalMid_Lock);
  1029. }
  1030. }
  1031. for (i = 0; i < num_rqst; i++) {
  1032. if (rc < 0)
  1033. goto out;
  1034. rc = cifs_sync_mid_result(midQ[i], server);
  1035. if (rc != 0) {
  1036. /* mark this mid as cancelled to not free it below */
  1037. cancelled_mid[i] = true;
  1038. goto out;
  1039. }
  1040. if (!midQ[i]->resp_buf ||
  1041. midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
  1042. rc = -EIO;
  1043. cifs_dbg(FYI, "Bad MID state?\n");
  1044. goto out;
  1045. }
  1046. buf = (char *)midQ[i]->resp_buf;
  1047. resp_iov[i].iov_base = buf;
  1048. resp_iov[i].iov_len = midQ[i]->resp_buf_size +
  1049. server->vals->header_preamble_size;
  1050. if (midQ[i]->large_buf)
  1051. resp_buf_type[i] = CIFS_LARGE_BUFFER;
  1052. else
  1053. resp_buf_type[i] = CIFS_SMALL_BUFFER;
  1054. rc = server->ops->check_receive(midQ[i], server,
  1055. flags & CIFS_LOG_ERROR);
  1056. /* mark it so buf will not be freed by cifs_delete_mid */
  1057. if ((flags & CIFS_NO_RSP_BUF) == 0)
  1058. midQ[i]->resp_buf = NULL;
  1059. }
  1060. /*
  1061. * Compounding is never used during session establish.
  1062. */
  1063. if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
  1064. struct kvec iov = {
  1065. .iov_base = resp_iov[0].iov_base,
  1066. .iov_len = resp_iov[0].iov_len
  1067. };
  1068. mutex_lock(&server->srv_mutex);
  1069. smb311_update_preauth_hash(ses, &iov, 1);
  1070. mutex_unlock(&server->srv_mutex);
  1071. }
  1072. out:
  1073. /*
  1074. * This will dequeue all mids. After this it is important that the
  1075. * demultiplex_thread will not process any of these mids any futher.
  1076. * This is prevented above by using a noop callback that will not
  1077. * wake this thread except for the very last PDU.
  1078. */
  1079. for (i = 0; i < num_rqst; i++) {
  1080. if (!cancelled_mid[i])
  1081. cifs_delete_mid(midQ[i]);
  1082. }
  1083. return rc;
  1084. }
  1085. int
  1086. cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
  1087. struct TCP_Server_Info *server,
  1088. struct smb_rqst *rqst, int *resp_buf_type, const int flags,
  1089. struct kvec *resp_iov)
  1090. {
  1091. return compound_send_recv(xid, ses, server, flags, 1,
  1092. rqst, resp_buf_type, resp_iov);
  1093. }
  1094. int
  1095. SendReceive2(const unsigned int xid, struct cifs_ses *ses,
  1096. struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
  1097. const int flags, struct kvec *resp_iov)
  1098. {
  1099. struct smb_rqst rqst;
  1100. struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
  1101. int rc;
  1102. if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
  1103. new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
  1104. GFP_KERNEL);
  1105. if (!new_iov) {
  1106. /* otherwise cifs_send_recv below sets resp_buf_type */
  1107. *resp_buf_type = CIFS_NO_BUFFER;
  1108. return -ENOMEM;
  1109. }
  1110. } else
  1111. new_iov = s_iov;
  1112. /* 1st iov is a RFC1001 length followed by the rest of the packet */
  1113. memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
  1114. new_iov[0].iov_base = new_iov[1].iov_base;
  1115. new_iov[0].iov_len = 4;
  1116. new_iov[1].iov_base += 4;
  1117. new_iov[1].iov_len -= 4;
  1118. memset(&rqst, 0, sizeof(struct smb_rqst));
  1119. rqst.rq_iov = new_iov;
  1120. rqst.rq_nvec = n_vec + 1;
  1121. rc = cifs_send_recv(xid, ses, ses->server,
  1122. &rqst, resp_buf_type, flags, resp_iov);
  1123. if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
  1124. kfree(new_iov);
  1125. return rc;
  1126. }
  1127. int
  1128. SendReceive(const unsigned int xid, struct cifs_ses *ses,
  1129. struct smb_hdr *in_buf, struct smb_hdr *out_buf,
  1130. int *pbytes_returned, const int flags)
  1131. {
  1132. int rc = 0;
  1133. struct mid_q_entry *midQ;
  1134. unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
  1135. struct kvec iov = { .iov_base = in_buf, .iov_len = len };
  1136. struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
  1137. struct cifs_credits credits = { .value = 1, .instance = 0 };
  1138. struct TCP_Server_Info *server;
  1139. if (ses == NULL) {
  1140. cifs_dbg(VFS, "Null smb session\n");
  1141. return -EIO;
  1142. }
  1143. server = ses->server;
  1144. if (server == NULL) {
  1145. cifs_dbg(VFS, "Null tcp session\n");
  1146. return -EIO;
  1147. }
  1148. if (server->tcpStatus == CifsExiting)
  1149. return -ENOENT;
  1150. /* Ensure that we do not send more than 50 overlapping requests
  1151. to the same server. We may make this configurable later or
  1152. use ses->maxReq */
  1153. if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
  1154. cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
  1155. len);
  1156. return -EIO;
  1157. }
  1158. rc = wait_for_free_request(server, flags, &credits.instance);
  1159. if (rc)
  1160. return rc;
  1161. /* make sure that we sign in the same order that we send on this socket
  1162. and avoid races inside tcp sendmsg code that could cause corruption
  1163. of smb data */
  1164. mutex_lock(&server->srv_mutex);
  1165. rc = allocate_mid(ses, in_buf, &midQ);
  1166. if (rc) {
  1167. mutex_unlock(&server->srv_mutex);
  1168. /* Update # of requests on wire to server */
  1169. add_credits(server, &credits, 0);
  1170. return rc;
  1171. }
  1172. rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
  1173. if (rc) {
  1174. mutex_unlock(&server->srv_mutex);
  1175. goto out;
  1176. }
  1177. midQ->mid_state = MID_REQUEST_SUBMITTED;
  1178. cifs_in_send_inc(server);
  1179. rc = smb_send(server, in_buf, len);
  1180. cifs_in_send_dec(server);
  1181. cifs_save_when_sent(midQ);
  1182. if (rc < 0)
  1183. server->sequence_number -= 2;
  1184. mutex_unlock(&server->srv_mutex);
  1185. if (rc < 0)
  1186. goto out;
  1187. rc = wait_for_response(server, midQ);
  1188. if (rc != 0) {
  1189. send_cancel(server, &rqst, midQ);
  1190. spin_lock(&GlobalMid_Lock);
  1191. if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
  1192. /* no longer considered to be "in-flight" */
  1193. midQ->callback = DeleteMidQEntry;
  1194. spin_unlock(&GlobalMid_Lock);
  1195. add_credits(server, &credits, 0);
  1196. return rc;
  1197. }
  1198. spin_unlock(&GlobalMid_Lock);
  1199. }
  1200. rc = cifs_sync_mid_result(midQ, server);
  1201. if (rc != 0) {
  1202. add_credits(server, &credits, 0);
  1203. return rc;
  1204. }
  1205. if (!midQ->resp_buf || !out_buf ||
  1206. midQ->mid_state != MID_RESPONSE_RECEIVED) {
  1207. rc = -EIO;
  1208. cifs_server_dbg(VFS, "Bad MID state?\n");
  1209. goto out;
  1210. }
  1211. *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
  1212. memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
  1213. rc = cifs_check_receive(midQ, server, 0);
  1214. out:
  1215. cifs_delete_mid(midQ);
  1216. add_credits(server, &credits, 0);
  1217. return rc;
  1218. }
  1219. /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
  1220. blocking lock to return. */
  1221. static int
  1222. send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
  1223. struct smb_hdr *in_buf,
  1224. struct smb_hdr *out_buf)
  1225. {
  1226. int bytes_returned;
  1227. struct cifs_ses *ses = tcon->ses;
  1228. LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
  1229. /* We just modify the current in_buf to change
  1230. the type of lock from LOCKING_ANDX_SHARED_LOCK
  1231. or LOCKING_ANDX_EXCLUSIVE_LOCK to
  1232. LOCKING_ANDX_CANCEL_LOCK. */
  1233. pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
  1234. pSMB->Timeout = 0;
  1235. pSMB->hdr.Mid = get_next_mid(ses->server);
  1236. return SendReceive(xid, ses, in_buf, out_buf,
  1237. &bytes_returned, 0);
  1238. }
  1239. int
  1240. SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
  1241. struct smb_hdr *in_buf, struct smb_hdr *out_buf,
  1242. int *pbytes_returned)
  1243. {
  1244. int rc = 0;
  1245. int rstart = 0;
  1246. struct mid_q_entry *midQ;
  1247. struct cifs_ses *ses;
  1248. unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
  1249. struct kvec iov = { .iov_base = in_buf, .iov_len = len };
  1250. struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
  1251. unsigned int instance;
  1252. struct TCP_Server_Info *server;
  1253. if (tcon == NULL || tcon->ses == NULL) {
  1254. cifs_dbg(VFS, "Null smb session\n");
  1255. return -EIO;
  1256. }
  1257. ses = tcon->ses;
  1258. server = ses->server;
  1259. if (server == NULL) {
  1260. cifs_dbg(VFS, "Null tcp session\n");
  1261. return -EIO;
  1262. }
  1263. if (server->tcpStatus == CifsExiting)
  1264. return -ENOENT;
  1265. /* Ensure that we do not send more than 50 overlapping requests
  1266. to the same server. We may make this configurable later or
  1267. use ses->maxReq */
  1268. if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
  1269. cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
  1270. len);
  1271. return -EIO;
  1272. }
  1273. rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
  1274. if (rc)
  1275. return rc;
  1276. /* make sure that we sign in the same order that we send on this socket
  1277. and avoid races inside tcp sendmsg code that could cause corruption
  1278. of smb data */
  1279. mutex_lock(&server->srv_mutex);
  1280. rc = allocate_mid(ses, in_buf, &midQ);
  1281. if (rc) {
  1282. mutex_unlock(&server->srv_mutex);
  1283. return rc;
  1284. }
  1285. rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
  1286. if (rc) {
  1287. cifs_delete_mid(midQ);
  1288. mutex_unlock(&server->srv_mutex);
  1289. return rc;
  1290. }
  1291. midQ->mid_state = MID_REQUEST_SUBMITTED;
  1292. cifs_in_send_inc(server);
  1293. rc = smb_send(server, in_buf, len);
  1294. cifs_in_send_dec(server);
  1295. cifs_save_when_sent(midQ);
  1296. if (rc < 0)
  1297. server->sequence_number -= 2;
  1298. mutex_unlock(&server->srv_mutex);
  1299. if (rc < 0) {
  1300. cifs_delete_mid(midQ);
  1301. return rc;
  1302. }
  1303. /* Wait for a reply - allow signals to interrupt. */
  1304. rc = wait_event_interruptible(server->response_q,
  1305. (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
  1306. ((server->tcpStatus != CifsGood) &&
  1307. (server->tcpStatus != CifsNew)));
  1308. /* Were we interrupted by a signal ? */
  1309. if ((rc == -ERESTARTSYS) &&
  1310. (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
  1311. ((server->tcpStatus == CifsGood) ||
  1312. (server->tcpStatus == CifsNew))) {
  1313. if (in_buf->Command == SMB_COM_TRANSACTION2) {
  1314. /* POSIX lock. We send a NT_CANCEL SMB to cause the
  1315. blocking lock to return. */
  1316. rc = send_cancel(server, &rqst, midQ);
  1317. if (rc) {
  1318. cifs_delete_mid(midQ);
  1319. return rc;
  1320. }
  1321. } else {
  1322. /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
  1323. to cause the blocking lock to return. */
  1324. rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
  1325. /* If we get -ENOLCK back the lock may have
  1326. already been removed. Don't exit in this case. */
  1327. if (rc && rc != -ENOLCK) {
  1328. cifs_delete_mid(midQ);
  1329. return rc;
  1330. }
  1331. }
  1332. rc = wait_for_response(server, midQ);
  1333. if (rc) {
  1334. send_cancel(server, &rqst, midQ);
  1335. spin_lock(&GlobalMid_Lock);
  1336. if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
  1337. /* no longer considered to be "in-flight" */
  1338. midQ->callback = DeleteMidQEntry;
  1339. spin_unlock(&GlobalMid_Lock);
  1340. return rc;
  1341. }
  1342. spin_unlock(&GlobalMid_Lock);
  1343. }
  1344. /* We got the response - restart system call. */
  1345. rstart = 1;
  1346. }
  1347. rc = cifs_sync_mid_result(midQ, server);
  1348. if (rc != 0)
  1349. return rc;
  1350. /* rcvd frame is ok */
  1351. if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
  1352. rc = -EIO;
  1353. cifs_tcon_dbg(VFS, "Bad MID state?\n");
  1354. goto out;
  1355. }
  1356. *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
  1357. memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
  1358. rc = cifs_check_receive(midQ, server, 0);
  1359. out:
  1360. cifs_delete_mid(midQ);
  1361. if (rstart && rc == -EACCES)
  1362. return -ERESTARTSYS;
  1363. return rc;
  1364. }