blob: 31668b690e03d4e482a8affb7657a310cffac1c0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/lockd/clntproc.c
3 *
4 * RPC procedures for the client side NLM implementation
5 *
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/errno.h>
12#include <linux/fs.h>
13#include <linux/nfs_fs.h>
14#include <linux/utsname.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080015#include <linux/freezer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/svc.h>
18#include <linux/lockd/lockd.h>
19#include <linux/lockd/sm_inter.h>
20
21#define NLMDBG_FACILITY NLMDBG_CLIENT
22#define NLMCLNT_GRACE_WAIT (5*HZ)
Trond Myklebustecdbf762005-06-22 17:16:31 +000023#define NLMCLNT_POLL_TIMEOUT (30*HZ)
Trond Myklebustaaaa9942006-02-01 12:18:25 -050024#define NLMCLNT_MAX_RETRIES 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26static int nlmclnt_test(struct nlm_rqst *, struct file_lock *);
27static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
28static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
Al Viroe8c5c042006-12-13 00:35:03 -080029static int nlm_stat_to_errno(__be32 stat);
Linus Torvalds1da177e2005-04-16 15:20:36 -070030static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
Trond Myklebust16fb2422006-02-01 12:18:22 -050031static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Trond Myklebust963d8fe2006-01-03 09:55:04 +010033static const struct rpc_call_ops nlmclnt_unlock_ops;
34static const struct rpc_call_ops nlmclnt_cancel_ops;
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036/*
37 * Cookie counter for NLM requests
38 */
Olaf Kirch031d8692006-10-04 02:16:02 -070039static atomic_t nlm_cookie = ATOMIC_INIT(0x1234);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Olaf Kirch031d8692006-10-04 02:16:02 -070041void nlmclnt_next_cookie(struct nlm_cookie *c)
Linus Torvalds1da177e2005-04-16 15:20:36 -070042{
Olaf Kirch031d8692006-10-04 02:16:02 -070043 u32 cookie = atomic_inc_return(&nlm_cookie);
44
45 memcpy(c->data, &cookie, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 c->len=4;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047}
48
49static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
50{
51 atomic_inc(&lockowner->count);
52 return lockowner;
53}
54
55static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
56{
57 if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
58 return;
59 list_del(&lockowner->list);
60 spin_unlock(&lockowner->host->h_lock);
61 nlm_release_host(lockowner->host);
62 kfree(lockowner);
63}
64
65static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
66{
67 struct nlm_lockowner *lockowner;
68 list_for_each_entry(lockowner, &host->h_lockowners, list) {
69 if (lockowner->pid == pid)
70 return -EBUSY;
71 }
72 return 0;
73}
74
75static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
76{
77 uint32_t res;
78 do {
79 res = host->h_pidcount++;
80 } while (nlm_pidbusy(host, res) < 0);
81 return res;
82}
83
84static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
85{
86 struct nlm_lockowner *lockowner;
87 list_for_each_entry(lockowner, &host->h_lockowners, list) {
88 if (lockowner->owner != owner)
89 continue;
90 return nlm_get_lockowner(lockowner);
91 }
92 return NULL;
93}
94
95static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
96{
97 struct nlm_lockowner *res, *new = NULL;
98
99 spin_lock(&host->h_lock);
100 res = __nlm_find_lockowner(host, owner);
101 if (res == NULL) {
102 spin_unlock(&host->h_lock);
Panagiotis Issarisf52720c2006-09-27 01:49:39 -0700103 new = kmalloc(sizeof(*new), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 spin_lock(&host->h_lock);
105 res = __nlm_find_lockowner(host, owner);
106 if (res == NULL && new != NULL) {
107 res = new;
108 atomic_set(&new->count, 1);
109 new->owner = owner;
110 new->pid = __nlm_alloc_pid(host);
111 new->host = nlm_get_host(host);
112 list_add(&new->list, &host->h_lockowners);
113 new = NULL;
114 }
115 }
116 spin_unlock(&host->h_lock);
Jesper Juhlf99d49a2005-11-07 01:01:34 -0800117 kfree(new);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 return res;
119}
120
121/*
122 * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
123 */
124static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
125{
126 struct nlm_args *argp = &req->a_args;
127 struct nlm_lock *lock = &argp->lock;
128
129 nlmclnt_next_cookie(&argp->cookie);
130 argp->state = nsm_local_state;
Josef Sipek225a7192006-12-08 02:37:18 -0800131 memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh));
Serge E. Hallyne9ff3992006-10-02 02:18:11 -0700132 lock->caller = utsname()->nodename;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 lock->oh.data = req->a_owner;
Trond Myklebust7bab3772006-03-20 13:44:06 -0500134 lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
135 (unsigned int)fl->fl_u.nfs_fl.owner->pid,
Serge E. Hallyne9ff3992006-10-02 02:18:11 -0700136 utsname()->nodename);
Trond Myklebust7bab3772006-03-20 13:44:06 -0500137 lock->svid = fl->fl_u.nfs_fl.owner->pid;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500138 lock->fl.fl_start = fl->fl_start;
139 lock->fl.fl_end = fl->fl_end;
140 lock->fl.fl_type = fl->fl_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
143static void nlmclnt_release_lockargs(struct nlm_rqst *req)
144{
Trond Myklebust3a649b82006-03-20 13:44:44 -0500145 BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146}
147
Chuck Lever1093a602008-01-11 17:09:59 -0500148/**
149 * nlmclnt_proc - Perform a single client-side lock request
150 * @host: address of a valid nlm_host context representing the NLM server
151 * @cmd: fcntl-style file lock operation to perform
152 * @fl: address of arguments for the lock operation
153 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 */
Chuck Lever1093a602008-01-11 17:09:59 -0500155int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156{
Trond Myklebust92737232006-03-20 13:44:45 -0500157 struct nlm_rqst *call;
Chuck Lever1093a602008-01-11 17:09:59 -0500158 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
Chuck Lever1093a602008-01-11 17:09:59 -0500160 nlm_get_host(host);
Trond Myklebust92737232006-03-20 13:44:45 -0500161 call = nlm_alloc_call(host);
162 if (call == NULL)
163 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Trond Myklebust92737232006-03-20 13:44:45 -0500165 nlmclnt_locks_init_private(fl, host);
166 /* Set up the argument struct */
167 nlmclnt_setlockargs(call, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
170 if (fl->fl_type != F_UNLCK) {
171 call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
172 status = nlmclnt_lock(call, fl);
173 } else
174 status = nlmclnt_unlock(call, fl);
175 } else if (IS_GETLK(cmd))
176 status = nlmclnt_test(call, fl);
177 else
178 status = -EINVAL;
179
Trond Myklebust92737232006-03-20 13:44:45 -0500180 fl->fl_ops->fl_release_private(fl);
181 fl->fl_ops = NULL;
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 dprintk("lockd: clnt proc returns %d\n", status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 return status;
185}
Chuck Lever1093a602008-01-11 17:09:59 -0500186EXPORT_SYMBOL_GPL(nlmclnt_proc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188/*
189 * Allocate an NLM RPC call struct
Trond Myklebust92737232006-03-20 13:44:45 -0500190 *
191 * Note: the caller must hold a reference to host. In case of failure,
192 * this reference will be released.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 */
Trond Myklebust92737232006-03-20 13:44:45 -0500194struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195{
196 struct nlm_rqst *call;
197
Trond Myklebust36943fa2006-03-20 13:44:05 -0500198 for(;;) {
199 call = kzalloc(sizeof(*call), GFP_KERNEL);
200 if (call != NULL) {
Trond Myklebust5e7f37a2008-04-01 18:58:49 -0400201 atomic_set(&call->a_count, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 locks_init_lock(&call->a_args.lock.fl);
203 locks_init_lock(&call->a_res.lock.fl);
Trond Myklebust92737232006-03-20 13:44:45 -0500204 call->a_host = host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 return call;
206 }
Trond Myklebust36943fa2006-03-20 13:44:05 -0500207 if (signalled())
208 break;
Trond Myklebust92737232006-03-20 13:44:45 -0500209 printk("nlm_alloc_call: failed, waiting for memory\n");
Nishanth Aravamudan041e0e32005-09-10 00:27:23 -0700210 schedule_timeout_interruptible(5*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 }
Trond Myklebust92737232006-03-20 13:44:45 -0500212 nlm_release_host(host);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 return NULL;
214}
215
Trond Myklebust92737232006-03-20 13:44:45 -0500216void nlm_release_call(struct nlm_rqst *call)
217{
Trond Myklebust5e7f37a2008-04-01 18:58:49 -0400218 if (!atomic_dec_and_test(&call->a_count))
219 return;
Trond Myklebust92737232006-03-20 13:44:45 -0500220 nlm_release_host(call->a_host);
221 nlmclnt_release_lockargs(call);
222 kfree(call);
223}
224
225static void nlmclnt_rpc_release(void *data)
226{
Trond Myklebusta86dc492008-06-11 13:37:09 -0400227 lock_kernel();
Trond Myklebust65fdf7d2008-01-11 17:41:29 -0500228 nlm_release_call(data);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400229 unlock_kernel();
Trond Myklebust92737232006-03-20 13:44:45 -0500230}
231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232static int nlm_wait_on_grace(wait_queue_head_t *queue)
233{
234 DEFINE_WAIT(wait);
235 int status = -EINTR;
236
237 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
238 if (!signalled ()) {
239 schedule_timeout(NLMCLNT_GRACE_WAIT);
Christoph Lameter3e1d1d22005-06-24 23:13:50 -0700240 try_to_freeze();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 if (!signalled ())
242 status = 0;
243 }
244 finish_wait(queue, &wait);
245 return status;
246}
247
248/*
249 * Generic NLM call
250 */
251static int
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400252nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
254 struct nlm_host *host = req->a_host;
255 struct rpc_clnt *clnt;
256 struct nlm_args *argp = &req->a_args;
257 struct nlm_res *resp = &req->a_res;
258 struct rpc_message msg = {
259 .rpc_argp = argp,
260 .rpc_resp = resp,
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400261 .rpc_cred = cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 };
263 int status;
264
265 dprintk("lockd: call procedure %d on %s\n",
266 (int)proc, host->h_name);
267
268 do {
269 if (host->h_reclaiming && !argp->reclaim)
270 goto in_grace_period;
271
272 /* If we have no RPC client yet, create one. */
273 if ((clnt = nlm_bind_host(host)) == NULL)
274 return -ENOLCK;
275 msg.rpc_proc = &clnt->cl_procinfo[proc];
276
277 /* Perform the RPC call. If an error occurs, try again */
278 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
279 dprintk("lockd: rpc_call returned error %d\n", -status);
280 switch (status) {
281 case -EPROTONOSUPPORT:
282 status = -EINVAL;
283 break;
284 case -ECONNREFUSED:
285 case -ETIMEDOUT:
286 case -ENOTCONN:
287 nlm_rebind_host(host);
288 status = -EAGAIN;
289 break;
290 case -ERESTARTSYS:
291 return signalled () ? -EINTR : status;
292 default:
293 break;
294 }
295 break;
296 } else
Al Viroe8c5c042006-12-13 00:35:03 -0800297 if (resp->status == nlm_lck_denied_grace_period) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 dprintk("lockd: server in grace period\n");
299 if (argp->reclaim) {
300 printk(KERN_WARNING
301 "lockd: spurious grace period reject?!\n");
302 return -ENOLCK;
303 }
304 } else {
305 if (!argp->reclaim) {
306 /* We appear to be out of the grace period */
307 wake_up_all(&host->h_gracewait);
308 }
309 dprintk("lockd: server returns status %d\n", resp->status);
310 return 0; /* Okay, call complete */
311 }
312
313in_grace_period:
314 /*
315 * The server has rebooted and appears to be in the grace
316 * period during which locks are only allowed to be
317 * reclaimed.
318 * We can only back off and try again later.
319 */
320 status = nlm_wait_on_grace(&host->h_gracewait);
321 } while (status == 0);
322
323 return status;
324}
325
326/*
327 * Generic NLM call, async version.
328 */
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400329static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330{
331 struct nlm_host *host = req->a_host;
332 struct rpc_clnt *clnt;
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400333 struct rpc_task_setup task_setup_data = {
334 .rpc_message = msg,
335 .callback_ops = tk_ops,
336 .callback_data = req,
337 .flags = RPC_TASK_ASYNC,
338 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
340 dprintk("lockd: call procedure %d on %s (async)\n",
341 (int)proc, host->h_name);
342
343 /* If we have no RPC client yet, create one. */
Trond Myklebust92737232006-03-20 13:44:45 -0500344 clnt = nlm_bind_host(host);
345 if (clnt == NULL)
346 goto out_err;
Trond Myklebustd4716622006-03-20 13:44:45 -0500347 msg->rpc_proc = &clnt->cl_procinfo[proc];
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400348 task_setup_data.rpc_client = clnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
350 /* bootstrap and kick off the async RPC call */
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400351 return rpc_run_task(&task_setup_data);
Trond Myklebust92737232006-03-20 13:44:45 -0500352out_err:
Trond Myklebusta995e9e2007-02-02 15:37:43 -0800353 tk_ops->rpc_release(req);
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400354 return ERR_PTR(-ENOLCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355}
356
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400357static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
358{
359 struct rpc_task *task;
360
361 task = __nlm_async_call(req, proc, msg, tk_ops);
362 if (IS_ERR(task))
363 return PTR_ERR(task);
364 rpc_put_task(task);
365 return 0;
366}
367
368/*
369 * NLM asynchronous call.
370 */
Trond Myklebustd4716622006-03-20 13:44:45 -0500371int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
372{
373 struct rpc_message msg = {
374 .rpc_argp = &req->a_args,
375 .rpc_resp = &req->a_res,
376 };
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400377 return nlm_do_async_call(req, proc, &msg, tk_ops);
Trond Myklebustd4716622006-03-20 13:44:45 -0500378}
379
380int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
381{
382 struct rpc_message msg = {
383 .rpc_argp = &req->a_res,
384 };
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400385 return nlm_do_async_call(req, proc, &msg, tk_ops);
386}
387
388/*
389 * NLM client asynchronous call.
390 *
391 * Note that although the calls are asynchronous, and are therefore
392 * guaranteed to complete, we still always attempt to wait for
393 * completion in order to be able to correctly track the lock
394 * state.
395 */
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400396static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400397{
398 struct rpc_message msg = {
399 .rpc_argp = &req->a_args,
400 .rpc_resp = &req->a_res,
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400401 .rpc_cred = cred,
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400402 };
403 struct rpc_task *task;
404 int err;
405
406 task = __nlm_async_call(req, proc, &msg, tk_ops);
407 if (IS_ERR(task))
408 return PTR_ERR(task);
409 err = rpc_wait_for_completion_task(task);
410 rpc_put_task(task);
411 return err;
Trond Myklebustd4716622006-03-20 13:44:45 -0500412}
413
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414/*
415 * TEST for the presence of a conflicting lock
416 */
417static int
418nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
419{
420 int status;
421
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400422 status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 if (status < 0)
Trond Myklebust92737232006-03-20 13:44:45 -0500424 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
Trond Myklebust92737232006-03-20 13:44:45 -0500426 switch (req->a_res.status) {
Al Viroe8c5c042006-12-13 00:35:03 -0800427 case nlm_granted:
Trond Myklebust92737232006-03-20 13:44:45 -0500428 fl->fl_type = F_UNLCK;
429 break;
Al Viroe8c5c042006-12-13 00:35:03 -0800430 case nlm_lck_denied:
Trond Myklebust92737232006-03-20 13:44:45 -0500431 /*
432 * Report the conflicting lock back to the application.
433 */
434 fl->fl_start = req->a_res.lock.fl.fl_start;
Felix Blyakherd67d1c72008-07-15 12:40:22 -0500435 fl->fl_end = req->a_res.lock.fl.fl_end;
Trond Myklebust92737232006-03-20 13:44:45 -0500436 fl->fl_type = req->a_res.lock.fl.fl_type;
437 fl->fl_pid = 0;
438 break;
439 default:
440 status = nlm_stat_to_errno(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 }
Trond Myklebust92737232006-03-20 13:44:45 -0500442out:
443 nlm_release_call(req);
444 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445}
446
447static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
448{
Trond Myklebust4c060b52006-03-20 13:44:41 -0500449 new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
450 new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
451 list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452}
453
454static void nlmclnt_locks_release_private(struct file_lock *fl)
455{
Trond Myklebust4c060b52006-03-20 13:44:41 -0500456 list_del(&fl->fl_u.nfs_fl.list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458}
459
460static struct file_lock_operations nlmclnt_lock_ops = {
461 .fl_copy_lock = nlmclnt_locks_copy_lock,
462 .fl_release_private = nlmclnt_locks_release_private,
463};
464
465static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
466{
467 BUG_ON(fl->fl_ops != NULL);
468 fl->fl_u.nfs_fl.state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
Trond Myklebust4c060b52006-03-20 13:44:41 -0500470 INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 fl->fl_ops = &nlmclnt_lock_ops;
472}
473
Trond Myklebust9b073572006-06-29 16:38:34 -0400474static int do_vfs_lock(struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475{
476 int res = 0;
477 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
478 case FL_POSIX:
479 res = posix_lock_file_wait(fl->fl_file, fl);
480 break;
481 case FL_FLOCK:
482 res = flock_lock_file_wait(fl->fl_file, fl);
483 break;
484 default:
485 BUG();
486 }
Trond Myklebust9b073572006-06-29 16:38:34 -0400487 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488}
489
490/*
491 * LOCK: Try to create a lock
492 *
493 * Programmer Harassment Alert
494 *
495 * When given a blocking lock request in a sync RPC call, the HPUX lockd
496 * will faithfully return LCK_BLOCKED but never cares to notify us when
497 * the lock could be granted. This way, our local process could hang
498 * around forever waiting for the callback.
499 *
500 * Solution A: Implement busy-waiting
501 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
502 *
503 * For now I am implementing solution A, because I hate the idea of
504 * re-implementing lockd for a third time in two months. The async
505 * calls shouldn't be too hard to do, however.
506 *
507 * This is one of the lovely things about standards in the NFS area:
508 * they're so soft and squishy you can't really blame HP for doing this.
509 */
510static int
511nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
512{
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400513 struct rpc_cred *cred = nfs_file_cred(fl->fl_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 struct nlm_host *host = req->a_host;
515 struct nlm_res *resp = &req->a_res;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500516 struct nlm_wait *block = NULL;
Trond Myklebust01c3b862006-06-29 16:38:39 -0400517 unsigned char fl_flags = fl->fl_flags;
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400518 unsigned char fl_type;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500519 int status = -ENOLCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Olaf Kirch977faf32006-10-04 02:15:51 -0700521 if (nsm_monitor(host) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
523 host->h_name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 goto out;
525 }
Trond Myklebust01c3b862006-06-29 16:38:39 -0400526 fl->fl_flags |= FL_ACCESS;
527 status = do_vfs_lock(fl);
Trond Myklebust4a9af592008-04-01 18:57:06 -0400528 fl->fl_flags = fl_flags;
Trond Myklebust01c3b862006-06-29 16:38:39 -0400529 if (status < 0)
530 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
Trond Myklebust3a649b82006-03-20 13:44:44 -0500532 block = nlmclnt_prepare_block(host, fl);
Trond Myklebust28df9552006-06-09 09:40:27 -0400533again:
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400534 /*
535 * Initialise resp->status to a valid non-zero value,
536 * since 0 == nlm_lck_granted
537 */
538 resp->status = nlm_lck_blocked;
Trond Myklebustecdbf762005-06-22 17:16:31 +0000539 for(;;) {
Trond Myklebust28df9552006-06-09 09:40:27 -0400540 /* Reboot protection */
541 fl->fl_u.nfs_fl.state = host->h_state;
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400542 status = nlmclnt_call(cred, req, NLMPROC_LOCK);
Trond Myklebustecdbf762005-06-22 17:16:31 +0000543 if (status < 0)
Trond Myklebustecdbf762005-06-22 17:16:31 +0000544 break;
Trond Myklebustecdbf762005-06-22 17:16:31 +0000545 /* Did a reclaimer thread notify us of a server reboot? */
Al Viroe8c5c042006-12-13 00:35:03 -0800546 if (resp->status == nlm_lck_denied_grace_period)
Trond Myklebustecdbf762005-06-22 17:16:31 +0000547 continue;
Al Viroe8c5c042006-12-13 00:35:03 -0800548 if (resp->status != nlm_lck_blocked)
Trond Myklebustecdbf762005-06-22 17:16:31 +0000549 break;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500550 /* Wait on an NLM blocking lock */
551 status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT);
Trond Myklebust3a649b82006-03-20 13:44:44 -0500552 if (status < 0)
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400553 break;
Al Viroe8c5c042006-12-13 00:35:03 -0800554 if (resp->status != nlm_lck_blocked)
Trond Myklebust3a649b82006-03-20 13:44:44 -0500555 break;
Trond Myklebustecdbf762005-06-22 17:16:31 +0000556 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400558 /* if we were interrupted while blocking, then cancel the lock request
559 * and exit
560 */
561 if (resp->status == nlm_lck_blocked) {
562 if (!req->a_args.block)
563 goto out_unlock;
564 if (nlmclnt_cancel(host, req->a_args.block, fl) == 0)
565 goto out_unblock;
566 }
567
Al Viroe8c5c042006-12-13 00:35:03 -0800568 if (resp->status == nlm_granted) {
Trond Myklebust28df9552006-06-09 09:40:27 -0400569 down_read(&host->h_rwsem);
570 /* Check whether or not the server has rebooted */
571 if (fl->fl_u.nfs_fl.state != host->h_state) {
572 up_read(&host->h_rwsem);
573 goto again;
574 }
Trond Myklebust4c060b52006-03-20 13:44:41 -0500575 /* Ensure the resulting lock will get added to granted list */
Trond Myklebust4a9af592008-04-01 18:57:06 -0400576 fl->fl_flags |= FL_SLEEP;
Trond Myklebust9b073572006-06-29 16:38:34 -0400577 if (do_vfs_lock(fl) < 0)
Harvey Harrison8e24eea2008-04-30 00:55:09 -0700578 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);
Trond Myklebust28df9552006-06-09 09:40:27 -0400579 up_read(&host->h_rwsem);
Trond Myklebust4a9af592008-04-01 18:57:06 -0400580 fl->fl_flags = fl_flags;
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400581 status = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 }
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400583 if (status < 0)
584 goto out_unlock;
Miklos Szeredicc77b152008-07-25 01:48:55 -0700585 /*
586 * EAGAIN doesn't make sense for sleeping locks, and in some
587 * cases NLM_LCK_DENIED is returned for a permanent error. So
588 * turn it into an ENOLCK.
589 */
590 if (resp->status == nlm_lck_denied && (fl_flags & FL_SLEEP))
591 status = -ENOLCK;
592 else
593 status = nlm_stat_to_errno(resp->status);
Trond Myklebustecdbf762005-06-22 17:16:31 +0000594out_unblock:
Trond Myklebust3a649b82006-03-20 13:44:44 -0500595 nlmclnt_finish_block(block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596out:
Trond Myklebust92737232006-03-20 13:44:45 -0500597 nlm_release_call(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 return status;
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400599out_unlock:
600 /* Fatal error: ensure that we remove the lock altogether */
601 dprintk("lockd: lock attempt ended in fatal error.\n"
602 " Attempting to unlock.\n");
603 nlmclnt_finish_block(block);
604 fl_type = fl->fl_type;
605 fl->fl_type = F_UNLCK;
606 down_read(&host->h_rwsem);
607 do_vfs_lock(fl);
608 up_read(&host->h_rwsem);
609 fl->fl_type = fl_type;
610 fl->fl_flags = fl_flags;
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400611 nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400612 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613}
614
615/*
616 * RECLAIM: Try to reclaim a lock
617 */
618int
619nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
620{
621 struct nlm_rqst reqst, *req;
622 int status;
623
624 req = &reqst;
625 memset(req, 0, sizeof(*req));
626 locks_init_lock(&req->a_args.lock.fl);
627 locks_init_lock(&req->a_res.lock.fl);
628 req->a_host = host;
629 req->a_flags = 0;
630
631 /* Set up the argument struct */
632 nlmclnt_setlockargs(req, fl);
633 req->a_args.reclaim = 1;
634
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400635 status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK);
636 if (status >= 0 && req->a_res.status == nlm_granted)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 return 0;
638
639 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
640 "(errno %d, status %d)\n", fl->fl_pid,
Al Viroe8c5c042006-12-13 00:35:03 -0800641 status, ntohl(req->a_res.status));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 /*
644 * FIXME: This is a serious failure. We can
645 *
646 * a. Ignore the problem
647 * b. Send the owning process some signal (Linux doesn't have
648 * SIGLOST, though...)
649 * c. Retry the operation
650 *
651 * Until someone comes up with a simple implementation
652 * for b or c, I'll choose option a.
653 */
654
655 return -ENOLCK;
656}
657
658/*
659 * UNLOCK: remove an existing lock
660 */
661static int
662nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
663{
Trond Myklebust28df9552006-06-09 09:40:27 -0400664 struct nlm_host *host = req->a_host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 struct nlm_res *resp = &req->a_res;
Trond Myklebust4a9af592008-04-01 18:57:06 -0400666 int status;
667 unsigned char fl_flags = fl->fl_flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Christoph Hellwig26bcbf92006-03-20 13:44:40 -0500669 /*
Trond Myklebust30f4e202006-03-13 21:20:49 -0800670 * Note: the server is supposed to either grant us the unlock
671 * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
672 * case, we want to unlock.
673 */
Trond Myklebust9b073572006-06-29 16:38:34 -0400674 fl->fl_flags |= FL_EXISTS;
Trond Myklebust28df9552006-06-09 09:40:27 -0400675 down_read(&host->h_rwsem);
Trond Myklebust4a9af592008-04-01 18:57:06 -0400676 status = do_vfs_lock(fl);
677 up_read(&host->h_rwsem);
678 fl->fl_flags = fl_flags;
679 if (status == -ENOENT) {
680 status = 0;
Trond Myklebust9b073572006-06-29 16:38:34 -0400681 goto out;
682 }
Trond Myklebust30f4e202006-03-13 21:20:49 -0800683
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400684 atomic_inc(&req->a_count);
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400685 status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
686 NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 if (status < 0)
Trond Myklebust92737232006-03-20 13:44:45 -0500688 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
Al Viroe8c5c042006-12-13 00:35:03 -0800690 if (resp->status == nlm_granted)
Trond Myklebust92737232006-03-20 13:44:45 -0500691 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692
Al Viroe8c5c042006-12-13 00:35:03 -0800693 if (resp->status != nlm_lck_denied_nolocks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 printk("lockd: unexpected unlock status: %d\n", resp->status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 /* What to do now? I'm out of my depth... */
Trond Myklebust92737232006-03-20 13:44:45 -0500696 status = -ENOLCK;
697out:
698 nlm_release_call(req);
699 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700}
701
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100702static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100704 struct nlm_rqst *req = data;
Al Viroe8c5c042006-12-13 00:35:03 -0800705 u32 status = ntohl(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
707 if (RPC_ASSASSINATED(task))
708 goto die;
709
710 if (task->tk_status < 0) {
711 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
712 goto retry_rebind;
713 }
714 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
715 rpc_delay(task, NLMCLNT_GRACE_WAIT);
716 goto retry_unlock;
717 }
718 if (status != NLM_LCK_GRANTED)
719 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
720die:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 return;
722 retry_rebind:
Trond Myklebusta86dc492008-06-11 13:37:09 -0400723 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 nlm_rebind_host(req->a_host);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400725 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 retry_unlock:
727 rpc_restart_call(task);
728}
729
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100730static const struct rpc_call_ops nlmclnt_unlock_ops = {
731 .rpc_call_done = nlmclnt_unlock_callback,
Trond Myklebust92737232006-03-20 13:44:45 -0500732 .rpc_release = nlmclnt_rpc_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100733};
734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735/*
736 * Cancel a blocked lock request.
737 * We always use an async RPC call for this in order not to hang a
738 * process that has been Ctrl-C'ed.
739 */
Trond Myklebust16fb2422006-02-01 12:18:22 -0500740static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741{
742 struct nlm_rqst *req;
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400743 int status;
744
745 dprintk("lockd: blocking lock attempt was interrupted by a signal.\n"
746 " Attempting to cancel lock.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
Trond Myklebust92737232006-03-20 13:44:45 -0500748 req = nlm_alloc_call(nlm_get_host(host));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 if (!req)
750 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 req->a_flags = RPC_TASK_ASYNC;
752
753 nlmclnt_setlockargs(req, fl);
Trond Myklebust16fb2422006-02-01 12:18:22 -0500754 req->a_args.block = block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400756 atomic_inc(&req->a_count);
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400757 status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
758 NLMPROC_CANCEL, &nlmclnt_cancel_ops);
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400759 if (status == 0 && req->a_res.status == nlm_lck_denied)
760 status = -ENOLCK;
761 nlm_release_call(req);
762 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763}
764
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100765static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100767 struct nlm_rqst *req = data;
Al Viroe8c5c042006-12-13 00:35:03 -0800768 u32 status = ntohl(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
770 if (RPC_ASSASSINATED(task))
771 goto die;
772
773 if (task->tk_status < 0) {
774 dprintk("lockd: CANCEL call error %d, retrying.\n",
775 task->tk_status);
776 goto retry_cancel;
777 }
778
Chuck Leverc041b5f2006-12-05 16:36:03 -0500779 dprintk("lockd: cancel status %u (task %u)\n",
Al Viroe8c5c042006-12-13 00:35:03 -0800780 status, task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
Al Viroe8c5c042006-12-13 00:35:03 -0800782 switch (status) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 case NLM_LCK_GRANTED:
784 case NLM_LCK_DENIED_GRACE_PERIOD:
Trond Myklebust35576cb2006-03-20 13:44:41 -0500785 case NLM_LCK_DENIED:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 /* Everything's good */
787 break;
788 case NLM_LCK_DENIED_NOLOCKS:
789 dprintk("lockd: CANCEL failed (server has no locks)\n");
790 goto retry_cancel;
791 default:
792 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
Al Viroe8c5c042006-12-13 00:35:03 -0800793 status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 }
795
796die:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 return;
798
799retry_cancel:
Trond Myklebustaaaa9942006-02-01 12:18:25 -0500800 /* Don't ever retry more than 3 times */
801 if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
802 goto die;
Trond Myklebusta86dc492008-06-11 13:37:09 -0400803 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 nlm_rebind_host(req->a_host);
Trond Myklebusta86dc492008-06-11 13:37:09 -0400805 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 rpc_restart_call(task);
807 rpc_delay(task, 30 * HZ);
808}
809
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100810static const struct rpc_call_ops nlmclnt_cancel_ops = {
811 .rpc_call_done = nlmclnt_cancel_callback,
Trond Myklebust92737232006-03-20 13:44:45 -0500812 .rpc_release = nlmclnt_rpc_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100813};
814
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815/*
816 * Convert an NLM status code to a generic kernel errno
817 */
818static int
Al Viroe8c5c042006-12-13 00:35:03 -0800819nlm_stat_to_errno(__be32 status)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820{
Al Viroe8c5c042006-12-13 00:35:03 -0800821 switch(ntohl(status)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 case NLM_LCK_GRANTED:
823 return 0;
824 case NLM_LCK_DENIED:
825 return -EAGAIN;
826 case NLM_LCK_DENIED_NOLOCKS:
827 case NLM_LCK_DENIED_GRACE_PERIOD:
828 return -ENOLCK;
829 case NLM_LCK_BLOCKED:
830 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
831 return -ENOLCK;
832#ifdef CONFIG_LOCKD_V4
833 case NLM_DEADLCK:
834 return -EDEADLK;
835 case NLM_ROFS:
836 return -EROFS;
837 case NLM_STALE_FH:
838 return -ESTALE;
839 case NLM_FBIG:
840 return -EOVERFLOW;
841 case NLM_FAILED:
842 return -ENOLCK;
843#endif
844 }
845 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);
846 return -ENOLCK;
847}