blob: 8392cb85bd54401d27028f0ed2932dceb4dd98bf [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090010#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/types.h>
12#include <linux/errno.h>
13#include <linux/fs.h>
14#include <linux/nfs_fs.h>
15#include <linux/utsname.h>
Nigel Cunningham7dfb7102006-12-06 20:34:23 -080016#include <linux/freezer.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/sunrpc/clnt.h>
18#include <linux/sunrpc/svc.h>
19#include <linux/lockd/lockd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
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);
Chuck Lever8ea6ecc2010-12-14 15:05:52 +000061 nlmclnt_release_host(lockowner->host);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 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);
Josef Sipek225a7192006-12-08 02:37:18 -0800130 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 -0700131 lock->caller = utsname()->nodename;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 lock->oh.data = req->a_owner;
Trond Myklebust7bab3772006-03-20 13:44:06 -0500133 lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
134 (unsigned int)fl->fl_u.nfs_fl.owner->pid,
Serge E. Hallyne9ff3992006-10-02 02:18:11 -0700135 utsname()->nodename);
Trond Myklebust7bab3772006-03-20 13:44:06 -0500136 lock->svid = fl->fl_u.nfs_fl.owner->pid;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500137 lock->fl.fl_start = fl->fl_start;
138 lock->fl.fl_end = fl->fl_end;
139 lock->fl.fl_type = fl->fl_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
142static void nlmclnt_release_lockargs(struct nlm_rqst *req)
143{
Trond Myklebust3a649b82006-03-20 13:44:44 -0500144 BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145}
146
Chuck Lever1093a602008-01-11 17:09:59 -0500147/**
148 * nlmclnt_proc - Perform a single client-side lock request
149 * @host: address of a valid nlm_host context representing the NLM server
150 * @cmd: fcntl-style file lock operation to perform
151 * @fl: address of arguments for the lock operation
152 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 */
Chuck Lever1093a602008-01-11 17:09:59 -0500154int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Trond Myklebust92737232006-03-20 13:44:45 -0500156 struct nlm_rqst *call;
Chuck Lever1093a602008-01-11 17:09:59 -0500157 int status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Chuck Lever1093a602008-01-11 17:09:59 -0500159 nlm_get_host(host);
Trond Myklebust92737232006-03-20 13:44:45 -0500160 call = nlm_alloc_call(host);
161 if (call == NULL)
162 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Trond Myklebust92737232006-03-20 13:44:45 -0500164 nlmclnt_locks_init_private(fl, host);
165 /* Set up the argument struct */
166 nlmclnt_setlockargs(call, fl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
169 if (fl->fl_type != F_UNLCK) {
170 call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
171 status = nlmclnt_lock(call, fl);
172 } else
173 status = nlmclnt_unlock(call, fl);
174 } else if (IS_GETLK(cmd))
175 status = nlmclnt_test(call, fl);
176 else
177 status = -EINVAL;
Trond Myklebust92737232006-03-20 13:44:45 -0500178 fl->fl_ops->fl_release_private(fl);
179 fl->fl_ops = NULL;
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 dprintk("lockd: clnt proc returns %d\n", status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 return status;
183}
Chuck Lever1093a602008-01-11 17:09:59 -0500184EXPORT_SYMBOL_GPL(nlmclnt_proc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186/*
187 * Allocate an NLM RPC call struct
Trond Myklebust92737232006-03-20 13:44:45 -0500188 *
189 * Note: the caller must hold a reference to host. In case of failure,
190 * this reference will be released.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 */
Trond Myklebust92737232006-03-20 13:44:45 -0500192struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
194 struct nlm_rqst *call;
195
Trond Myklebust36943fa2006-03-20 13:44:05 -0500196 for(;;) {
197 call = kzalloc(sizeof(*call), GFP_KERNEL);
198 if (call != NULL) {
Trond Myklebust5e7f37a2008-04-01 18:58:49 -0400199 atomic_set(&call->a_count, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 locks_init_lock(&call->a_args.lock.fl);
201 locks_init_lock(&call->a_res.lock.fl);
Trond Myklebust92737232006-03-20 13:44:45 -0500202 call->a_host = host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 return call;
204 }
Trond Myklebust36943fa2006-03-20 13:44:05 -0500205 if (signalled())
206 break;
Trond Myklebust92737232006-03-20 13:44:45 -0500207 printk("nlm_alloc_call: failed, waiting for memory\n");
Nishanth Aravamudan041e0e32005-09-10 00:27:23 -0700208 schedule_timeout_interruptible(5*HZ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 }
Chuck Lever8ea6ecc2010-12-14 15:05:52 +0000210 nlmclnt_release_host(host);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 return NULL;
212}
213
Chuck Lever7db836d2010-12-14 15:05:42 +0000214void nlmclnt_release_call(struct nlm_rqst *call)
Trond Myklebust92737232006-03-20 13:44:45 -0500215{
Trond Myklebust5e7f37a2008-04-01 18:58:49 -0400216 if (!atomic_dec_and_test(&call->a_count))
217 return;
Chuck Lever8ea6ecc2010-12-14 15:05:52 +0000218 nlmclnt_release_host(call->a_host);
Trond Myklebust92737232006-03-20 13:44:45 -0500219 nlmclnt_release_lockargs(call);
220 kfree(call);
221}
222
223static void nlmclnt_rpc_release(void *data)
224{
Chuck Lever7db836d2010-12-14 15:05:42 +0000225 nlmclnt_release_call(data);
Trond Myklebust92737232006-03-20 13:44:45 -0500226}
227
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228static int nlm_wait_on_grace(wait_queue_head_t *queue)
229{
230 DEFINE_WAIT(wait);
231 int status = -EINTR;
232
233 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
234 if (!signalled ()) {
235 schedule_timeout(NLMCLNT_GRACE_WAIT);
Christoph Lameter3e1d1d22005-06-24 23:13:50 -0700236 try_to_freeze();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 if (!signalled ())
238 status = 0;
239 }
240 finish_wait(queue, &wait);
241 return status;
242}
243
244/*
245 * Generic NLM call
246 */
247static int
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400248nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249{
250 struct nlm_host *host = req->a_host;
251 struct rpc_clnt *clnt;
252 struct nlm_args *argp = &req->a_args;
253 struct nlm_res *resp = &req->a_res;
254 struct rpc_message msg = {
255 .rpc_argp = argp,
256 .rpc_resp = resp,
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400257 .rpc_cred = cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 };
259 int status;
260
261 dprintk("lockd: call procedure %d on %s\n",
262 (int)proc, host->h_name);
263
264 do {
265 if (host->h_reclaiming && !argp->reclaim)
266 goto in_grace_period;
267
268 /* If we have no RPC client yet, create one. */
269 if ((clnt = nlm_bind_host(host)) == NULL)
270 return -ENOLCK;
271 msg.rpc_proc = &clnt->cl_procinfo[proc];
272
273 /* Perform the RPC call. If an error occurs, try again */
274 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
275 dprintk("lockd: rpc_call returned error %d\n", -status);
276 switch (status) {
277 case -EPROTONOSUPPORT:
278 status = -EINVAL;
279 break;
280 case -ECONNREFUSED:
281 case -ETIMEDOUT:
282 case -ENOTCONN:
283 nlm_rebind_host(host);
284 status = -EAGAIN;
285 break;
286 case -ERESTARTSYS:
287 return signalled () ? -EINTR : status;
288 default:
289 break;
290 }
291 break;
292 } else
Al Viroe8c5c042006-12-13 00:35:03 -0800293 if (resp->status == nlm_lck_denied_grace_period) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 dprintk("lockd: server in grace period\n");
295 if (argp->reclaim) {
296 printk(KERN_WARNING
297 "lockd: spurious grace period reject?!\n");
298 return -ENOLCK;
299 }
300 } else {
301 if (!argp->reclaim) {
302 /* We appear to be out of the grace period */
303 wake_up_all(&host->h_gracewait);
304 }
Vasily Averin82c2c8b2011-06-01 16:54:32 +0400305 dprintk("lockd: server returns status %d\n",
306 ntohl(resp->status));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 return 0; /* Okay, call complete */
308 }
309
310in_grace_period:
311 /*
312 * The server has rebooted and appears to be in the grace
313 * period during which locks are only allowed to be
314 * reclaimed.
315 * We can only back off and try again later.
316 */
317 status = nlm_wait_on_grace(&host->h_gracewait);
318 } while (status == 0);
319
320 return status;
321}
322
323/*
324 * Generic NLM call, async version.
325 */
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400326static 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 -0700327{
328 struct nlm_host *host = req->a_host;
329 struct rpc_clnt *clnt;
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400330 struct rpc_task_setup task_setup_data = {
331 .rpc_message = msg,
332 .callback_ops = tk_ops,
333 .callback_data = req,
334 .flags = RPC_TASK_ASYNC,
335 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 dprintk("lockd: call procedure %d on %s (async)\n",
338 (int)proc, host->h_name);
339
340 /* If we have no RPC client yet, create one. */
Trond Myklebust92737232006-03-20 13:44:45 -0500341 clnt = nlm_bind_host(host);
342 if (clnt == NULL)
343 goto out_err;
Trond Myklebustd4716622006-03-20 13:44:45 -0500344 msg->rpc_proc = &clnt->cl_procinfo[proc];
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400345 task_setup_data.rpc_client = clnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
347 /* bootstrap and kick off the async RPC call */
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400348 return rpc_run_task(&task_setup_data);
Trond Myklebust92737232006-03-20 13:44:45 -0500349out_err:
Trond Myklebusta995e9e2007-02-02 15:37:43 -0800350 tk_ops->rpc_release(req);
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400351 return ERR_PTR(-ENOLCK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352}
353
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400354static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
355{
356 struct rpc_task *task;
357
358 task = __nlm_async_call(req, proc, msg, tk_ops);
359 if (IS_ERR(task))
360 return PTR_ERR(task);
361 rpc_put_task(task);
362 return 0;
363}
364
365/*
366 * NLM asynchronous call.
367 */
Trond Myklebustd4716622006-03-20 13:44:45 -0500368int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
369{
370 struct rpc_message msg = {
371 .rpc_argp = &req->a_args,
372 .rpc_resp = &req->a_res,
373 };
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400374 return nlm_do_async_call(req, proc, &msg, tk_ops);
Trond Myklebustd4716622006-03-20 13:44:45 -0500375}
376
377int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
378{
379 struct rpc_message msg = {
380 .rpc_argp = &req->a_res,
381 };
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400382 return nlm_do_async_call(req, proc, &msg, tk_ops);
383}
384
385/*
386 * NLM client asynchronous call.
387 *
388 * Note that although the calls are asynchronous, and are therefore
389 * guaranteed to complete, we still always attempt to wait for
390 * completion in order to be able to correctly track the lock
391 * state.
392 */
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400393static 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 -0400394{
395 struct rpc_message msg = {
396 .rpc_argp = &req->a_args,
397 .rpc_resp = &req->a_res,
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400398 .rpc_cred = cred,
Trond Myklebustdc9d8d02008-03-28 16:04:36 -0400399 };
400 struct rpc_task *task;
401 int err;
402
403 task = __nlm_async_call(req, proc, &msg, tk_ops);
404 if (IS_ERR(task))
405 return PTR_ERR(task);
406 err = rpc_wait_for_completion_task(task);
407 rpc_put_task(task);
408 return err;
Trond Myklebustd4716622006-03-20 13:44:45 -0500409}
410
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411/*
412 * TEST for the presence of a conflicting lock
413 */
414static int
415nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
416{
417 int status;
418
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400419 status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 if (status < 0)
Trond Myklebust92737232006-03-20 13:44:45 -0500421 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Trond Myklebust92737232006-03-20 13:44:45 -0500423 switch (req->a_res.status) {
Al Viroe8c5c042006-12-13 00:35:03 -0800424 case nlm_granted:
Trond Myklebust92737232006-03-20 13:44:45 -0500425 fl->fl_type = F_UNLCK;
426 break;
Al Viroe8c5c042006-12-13 00:35:03 -0800427 case nlm_lck_denied:
Trond Myklebust92737232006-03-20 13:44:45 -0500428 /*
429 * Report the conflicting lock back to the application.
430 */
431 fl->fl_start = req->a_res.lock.fl.fl_start;
Felix Blyakherd67d1c72008-07-15 12:40:22 -0500432 fl->fl_end = req->a_res.lock.fl.fl_end;
Trond Myklebust92737232006-03-20 13:44:45 -0500433 fl->fl_type = req->a_res.lock.fl.fl_type;
434 fl->fl_pid = 0;
435 break;
436 default:
437 status = nlm_stat_to_errno(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 }
Trond Myklebust92737232006-03-20 13:44:45 -0500439out:
Chuck Lever7db836d2010-12-14 15:05:42 +0000440 nlmclnt_release_call(req);
Trond Myklebust92737232006-03-20 13:44:45 -0500441 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442}
443
444static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
445{
Bryan Schumaker63185942010-09-22 09:50:35 -0400446 spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
Trond Myklebust4c060b52006-03-20 13:44:41 -0500447 new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
448 new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
449 list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
Bryan Schumaker63185942010-09-22 09:50:35 -0400450 spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
452
453static void nlmclnt_locks_release_private(struct file_lock *fl)
454{
Bryan Schumaker63185942010-09-22 09:50:35 -0400455 spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
Trond Myklebust4c060b52006-03-20 13:44:41 -0500456 list_del(&fl->fl_u.nfs_fl.list);
Bryan Schumaker63185942010-09-22 09:50:35 -0400457 spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459}
460
Alexey Dobriyan6aed6282009-09-21 17:01:11 -0700461static const struct file_lock_operations nlmclnt_lock_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 .fl_copy_lock = nlmclnt_locks_copy_lock,
463 .fl_release_private = nlmclnt_locks_release_private,
464};
465
466static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
467{
468 BUG_ON(fl->fl_ops != NULL);
469 fl->fl_u.nfs_fl.state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
Trond Myklebust4c060b52006-03-20 13:44:41 -0500471 INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 fl->fl_ops = &nlmclnt_lock_ops;
473}
474
Trond Myklebust9b073572006-06-29 16:38:34 -0400475static int do_vfs_lock(struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476{
477 int res = 0;
478 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
479 case FL_POSIX:
480 res = posix_lock_file_wait(fl->fl_file, fl);
481 break;
482 case FL_FLOCK:
483 res = flock_lock_file_wait(fl->fl_file, fl);
484 break;
485 default:
486 BUG();
487 }
Trond Myklebust9b073572006-06-29 16:38:34 -0400488 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489}
490
491/*
492 * LOCK: Try to create a lock
493 *
494 * Programmer Harassment Alert
495 *
496 * When given a blocking lock request in a sync RPC call, the HPUX lockd
497 * will faithfully return LCK_BLOCKED but never cares to notify us when
498 * the lock could be granted. This way, our local process could hang
499 * around forever waiting for the callback.
500 *
501 * Solution A: Implement busy-waiting
502 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
503 *
504 * For now I am implementing solution A, because I hate the idea of
505 * re-implementing lockd for a third time in two months. The async
506 * calls shouldn't be too hard to do, however.
507 *
508 * This is one of the lovely things about standards in the NFS area:
509 * they're so soft and squishy you can't really blame HP for doing this.
510 */
511static int
512nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
513{
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400514 struct rpc_cred *cred = nfs_file_cred(fl->fl_file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 struct nlm_host *host = req->a_host;
516 struct nlm_res *resp = &req->a_res;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500517 struct nlm_wait *block = NULL;
Trond Myklebust01c3b862006-06-29 16:38:39 -0400518 unsigned char fl_flags = fl->fl_flags;
Trond Myklebust5f50c0c2008-04-01 20:26:22 -0400519 unsigned char fl_type;
Trond Myklebust3a649b82006-03-20 13:44:44 -0500520 int status = -ENOLCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Chuck Lever501c1ed2008-12-04 14:21:01 -0500522 if (nsm_monitor(host) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 goto out;
Chuck Lever6c9dc4252009-06-17 18:02:10 -0700524 req->a_args.state = nsm_local_state;
Chuck Lever501c1ed2008-12-04 14:21:01 -0500525
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:
Chuck Lever7db836d2010-12-14 15:05:42 +0000597 nlmclnt_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)
Vasily Averin82c2c8b2011-06-01 16:54:32 +0400694 printk("lockd: unexpected unlock status: %d\n",
695 ntohl(resp->status));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 /* What to do now? I'm out of my depth... */
Trond Myklebust92737232006-03-20 13:44:45 -0500697 status = -ENOLCK;
698out:
Chuck Lever7db836d2010-12-14 15:05:42 +0000699 nlmclnt_release_call(req);
Trond Myklebust92737232006-03-20 13:44:45 -0500700 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701}
702
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100703static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100705 struct nlm_rqst *req = data;
Al Viroe8c5c042006-12-13 00:35:03 -0800706 u32 status = ntohl(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707
708 if (RPC_ASSASSINATED(task))
709 goto die;
710
711 if (task->tk_status < 0) {
712 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
Trond Myklebust0b760112011-05-31 15:15:34 -0400713 switch (task->tk_status) {
714 case -EACCES:
715 case -EIO:
716 goto die;
717 default:
718 goto retry_rebind;
719 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 }
721 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
722 rpc_delay(task, NLMCLNT_GRACE_WAIT);
723 goto retry_unlock;
724 }
725 if (status != NLM_LCK_GRANTED)
726 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
727die:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 return;
729 retry_rebind:
730 nlm_rebind_host(req->a_host);
731 retry_unlock:
732 rpc_restart_call(task);
733}
734
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100735static const struct rpc_call_ops nlmclnt_unlock_ops = {
736 .rpc_call_done = nlmclnt_unlock_callback,
Trond Myklebust92737232006-03-20 13:44:45 -0500737 .rpc_release = nlmclnt_rpc_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100738};
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740/*
741 * Cancel a blocked lock request.
742 * We always use an async RPC call for this in order not to hang a
743 * process that has been Ctrl-C'ed.
744 */
Trond Myklebust16fb2422006-02-01 12:18:22 -0500745static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746{
747 struct nlm_rqst *req;
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400748 int status;
749
750 dprintk("lockd: blocking lock attempt was interrupted by a signal.\n"
751 " Attempting to cancel lock.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
Trond Myklebust92737232006-03-20 13:44:45 -0500753 req = nlm_alloc_call(nlm_get_host(host));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 if (!req)
755 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 req->a_flags = RPC_TASK_ASYNC;
757
758 nlmclnt_setlockargs(req, fl);
Trond Myklebust16fb2422006-02-01 12:18:22 -0500759 req->a_args.block = block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400761 atomic_inc(&req->a_count);
Trond Myklebustd11d10c2008-04-02 14:44:05 -0400762 status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req,
763 NLMPROC_CANCEL, &nlmclnt_cancel_ops);
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400764 if (status == 0 && req->a_res.status == nlm_lck_denied)
765 status = -ENOLCK;
Chuck Lever7db836d2010-12-14 15:05:42 +0000766 nlmclnt_release_call(req);
Trond Myklebust6b4b3a72008-04-02 14:40:53 -0400767 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768}
769
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100770static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771{
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100772 struct nlm_rqst *req = data;
Al Viroe8c5c042006-12-13 00:35:03 -0800773 u32 status = ntohl(req->a_res.status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774
775 if (RPC_ASSASSINATED(task))
776 goto die;
777
778 if (task->tk_status < 0) {
779 dprintk("lockd: CANCEL call error %d, retrying.\n",
780 task->tk_status);
781 goto retry_cancel;
782 }
783
Chuck Leverc041b5f2006-12-05 16:36:03 -0500784 dprintk("lockd: cancel status %u (task %u)\n",
Al Viroe8c5c042006-12-13 00:35:03 -0800785 status, task->tk_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
Al Viroe8c5c042006-12-13 00:35:03 -0800787 switch (status) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 case NLM_LCK_GRANTED:
789 case NLM_LCK_DENIED_GRACE_PERIOD:
Trond Myklebust35576cb2006-03-20 13:44:41 -0500790 case NLM_LCK_DENIED:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 /* Everything's good */
792 break;
793 case NLM_LCK_DENIED_NOLOCKS:
794 dprintk("lockd: CANCEL failed (server has no locks)\n");
795 goto retry_cancel;
796 default:
797 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
Al Viroe8c5c042006-12-13 00:35:03 -0800798 status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 }
800
801die:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 return;
803
804retry_cancel:
Trond Myklebustaaaa9942006-02-01 12:18:25 -0500805 /* Don't ever retry more than 3 times */
806 if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
807 goto die;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 nlm_rebind_host(req->a_host);
809 rpc_restart_call(task);
810 rpc_delay(task, 30 * HZ);
811}
812
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100813static const struct rpc_call_ops nlmclnt_cancel_ops = {
814 .rpc_call_done = nlmclnt_cancel_callback,
Trond Myklebust92737232006-03-20 13:44:45 -0500815 .rpc_release = nlmclnt_rpc_release,
Trond Myklebust963d8fe2006-01-03 09:55:04 +0100816};
817
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818/*
819 * Convert an NLM status code to a generic kernel errno
820 */
821static int
Al Viroe8c5c042006-12-13 00:35:03 -0800822nlm_stat_to_errno(__be32 status)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823{
Al Viroe8c5c042006-12-13 00:35:03 -0800824 switch(ntohl(status)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 case NLM_LCK_GRANTED:
826 return 0;
827 case NLM_LCK_DENIED:
828 return -EAGAIN;
829 case NLM_LCK_DENIED_NOLOCKS:
830 case NLM_LCK_DENIED_GRACE_PERIOD:
831 return -ENOLCK;
832 case NLM_LCK_BLOCKED:
833 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
834 return -ENOLCK;
835#ifdef CONFIG_LOCKD_V4
836 case NLM_DEADLCK:
837 return -EDEADLK;
838 case NLM_ROFS:
839 return -EROFS;
840 case NLM_STALE_FH:
841 return -ESTALE;
842 case NLM_FBIG:
843 return -EOVERFLOW;
844 case NLM_FAILED:
845 return -ENOLCK;
846#endif
847 }
Vasily Averin82c2c8b2011-06-01 16:54:32 +0400848 printk(KERN_NOTICE "lockd: unexpected server status %d\n",
849 ntohl(status));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 return -ENOLCK;
851}