~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/dlm/user.c

Version: ~ [ linux-5.9-rc6 ] ~ [ linux-5.8.10 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.66 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.146 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.198 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.236 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.236 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright (C) 2006-2010 Red Hat, Inc.  All rights reserved.
  3  *
  4  * This copyrighted material is made available to anyone wishing to use,
  5  * modify, copy, or redistribute it subject to the terms and conditions
  6  * of the GNU General Public License v.2.
  7  */
  8 
  9 #include <linux/miscdevice.h>
 10 #include <linux/init.h>
 11 #include <linux/wait.h>
 12 #include <linux/module.h>
 13 #include <linux/file.h>
 14 #include <linux/fs.h>
 15 #include <linux/poll.h>
 16 #include <linux/signal.h>
 17 #include <linux/spinlock.h>
 18 #include <linux/dlm.h>
 19 #include <linux/dlm_device.h>
 20 #include <linux/slab.h>
 21 
 22 #include "dlm_internal.h"
 23 #include "lockspace.h"
 24 #include "lock.h"
 25 #include "lvb_table.h"
 26 #include "user.h"
 27 #include "ast.h"
 28 
 29 static const char name_prefix[] = "dlm";
 30 static const struct file_operations device_fops;
 31 static atomic_t dlm_monitor_opened;
 32 static int dlm_monitor_unused = 1;
 33 
 34 #ifdef CONFIG_COMPAT
 35 
 36 struct dlm_lock_params32 {
 37         __u8 mode;
 38         __u8 namelen;
 39         __u16 unused;
 40         __u32 flags;
 41         __u32 lkid;
 42         __u32 parent;
 43         __u64 xid;
 44         __u64 timeout;
 45         __u32 castparam;
 46         __u32 castaddr;
 47         __u32 bastparam;
 48         __u32 bastaddr;
 49         __u32 lksb;
 50         char lvb[DLM_USER_LVB_LEN];
 51         char name[0];
 52 };
 53 
 54 struct dlm_write_request32 {
 55         __u32 version[3];
 56         __u8 cmd;
 57         __u8 is64bit;
 58         __u8 unused[2];
 59 
 60         union  {
 61                 struct dlm_lock_params32 lock;
 62                 struct dlm_lspace_params lspace;
 63                 struct dlm_purge_params purge;
 64         } i;
 65 };
 66 
 67 struct dlm_lksb32 {
 68         __u32 sb_status;
 69         __u32 sb_lkid;
 70         __u8 sb_flags;
 71         __u32 sb_lvbptr;
 72 };
 73 
 74 struct dlm_lock_result32 {
 75         __u32 version[3];
 76         __u32 length;
 77         __u32 user_astaddr;
 78         __u32 user_astparam;
 79         __u32 user_lksb;
 80         struct dlm_lksb32 lksb;
 81         __u8 bast_mode;
 82         __u8 unused[3];
 83         /* Offsets may be zero if no data is present */
 84         __u32 lvb_offset;
 85 };
 86 
 87 static void compat_input(struct dlm_write_request *kb,
 88                          struct dlm_write_request32 *kb32,
 89                          int namelen)
 90 {
 91         kb->version[0] = kb32->version[0];
 92         kb->version[1] = kb32->version[1];
 93         kb->version[2] = kb32->version[2];
 94 
 95         kb->cmd = kb32->cmd;
 96         kb->is64bit = kb32->is64bit;
 97         if (kb->cmd == DLM_USER_CREATE_LOCKSPACE ||
 98             kb->cmd == DLM_USER_REMOVE_LOCKSPACE) {
 99                 kb->i.lspace.flags = kb32->i.lspace.flags;
100                 kb->i.lspace.minor = kb32->i.lspace.minor;
101                 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen);
102         } else if (kb->cmd == DLM_USER_PURGE) {
103                 kb->i.purge.nodeid = kb32->i.purge.nodeid;
104                 kb->i.purge.pid = kb32->i.purge.pid;
105         } else {
106                 kb->i.lock.mode = kb32->i.lock.mode;
107                 kb->i.lock.namelen = kb32->i.lock.namelen;
108                 kb->i.lock.flags = kb32->i.lock.flags;
109                 kb->i.lock.lkid = kb32->i.lock.lkid;
110                 kb->i.lock.parent = kb32->i.lock.parent;
111                 kb->i.lock.xid = kb32->i.lock.xid;
112                 kb->i.lock.timeout = kb32->i.lock.timeout;
113                 kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam;
114                 kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr;
115                 kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam;
116                 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr;
117                 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb;
118                 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN);
119                 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen);
120         }
121 }
122 
123 static void compat_output(struct dlm_lock_result *res,
124                           struct dlm_lock_result32 *res32)
125 {
126         res32->version[0] = res->version[0];
127         res32->version[1] = res->version[1];
128         res32->version[2] = res->version[2];
129 
130         res32->user_astaddr = (__u32)(long)res->user_astaddr;
131         res32->user_astparam = (__u32)(long)res->user_astparam;
132         res32->user_lksb = (__u32)(long)res->user_lksb;
133         res32->bast_mode = res->bast_mode;
134 
135         res32->lvb_offset = res->lvb_offset;
136         res32->length = res->length;
137 
138         res32->lksb.sb_status = res->lksb.sb_status;
139         res32->lksb.sb_flags = res->lksb.sb_flags;
140         res32->lksb.sb_lkid = res->lksb.sb_lkid;
141         res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr;
142 }
143 #endif
144 
145 /* Figure out if this lock is at the end of its life and no longer
146    available for the application to use.  The lkb still exists until
147    the final ast is read.  A lock becomes EOL in three situations:
148      1. a noqueue request fails with EAGAIN
149      2. an unlock completes with EUNLOCK
150      3. a cancel of a waiting request completes with ECANCEL/EDEADLK
151    An EOL lock needs to be removed from the process's list of locks.
152    And we can't allow any new operation on an EOL lock.  This is
153    not related to the lifetime of the lkb struct which is managed
154    entirely by refcount. */
155 
156 static int lkb_is_endoflife(int mode, int status)
157 {
158         switch (status) {
159         case -DLM_EUNLOCK:
160                 return 1;
161         case -DLM_ECANCEL:
162         case -ETIMEDOUT:
163         case -EDEADLK:
164         case -EAGAIN:
165                 if (mode == DLM_LOCK_IV)
166                         return 1;
167                 break;
168         }
169         return 0;
170 }
171 
172 /* we could possibly check if the cancel of an orphan has resulted in the lkb
173    being removed and then remove that lkb from the orphans list and free it */
174 
175 void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode,
176                       int status, uint32_t sbflags, uint64_t seq)
177 {
178         struct dlm_ls *ls;
179         struct dlm_user_args *ua;
180         struct dlm_user_proc *proc;
181         int rv;
182 
183         if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
184                 return;
185 
186         ls = lkb->lkb_resource->res_ls;
187         mutex_lock(&ls->ls_clear_proc_locks);
188 
189         /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast
190            can't be delivered.  For ORPHAN's, dlm_clear_proc_locks() freed
191            lkb->ua so we can't try to use it.  This second check is necessary
192            for cases where a completion ast is received for an operation that
193            began before clear_proc_locks did its cancel/unlock. */
194 
195         if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD))
196                 goto out;
197 
198         DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb););
199         ua = lkb->lkb_ua;
200         proc = ua->proc;
201 
202         if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL)
203                 goto out;
204 
205         if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status))
206                 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE;
207 
208         spin_lock(&proc->asts_spin);
209 
210         rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, seq);
211         if (rv < 0) {
212                 spin_unlock(&proc->asts_spin);
213                 goto out;
214         }
215 
216         if (list_empty(&lkb->lkb_cb_list)) {
217                 kref_get(&lkb->lkb_ref);
218                 list_add_tail(&lkb->lkb_cb_list, &proc->asts);
219                 wake_up_interruptible(&proc->wait);
220         }
221         spin_unlock(&proc->asts_spin);
222 
223         if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) {
224                 /* N.B. spin_lock locks_spin, not asts_spin */
225                 spin_lock(&proc->locks_spin);
226                 if (!list_empty(&lkb->lkb_ownqueue)) {
227                         list_del_init(&lkb->lkb_ownqueue);
228                         dlm_put_lkb(lkb);
229                 }
230                 spin_unlock(&proc->locks_spin);
231         }
232  out:
233         mutex_unlock(&ls->ls_clear_proc_locks);
234 }
235 
236 static int device_user_lock(struct dlm_user_proc *proc,
237                             struct dlm_lock_params *params)
238 {
239         struct dlm_ls *ls;
240         struct dlm_user_args *ua;
241         int error = -ENOMEM;
242 
243         ls = dlm_find_lockspace_local(proc->lockspace);
244         if (!ls)
245                 return -ENOENT;
246 
247         if (!params->castaddr || !params->lksb) {
248                 error = -EINVAL;
249                 goto out;
250         }
251 
252         ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
253         if (!ua)
254                 goto out;
255         ua->proc = proc;
256         ua->user_lksb = params->lksb;
257         ua->castparam = params->castparam;
258         ua->castaddr = params->castaddr;
259         ua->bastparam = params->bastparam;
260         ua->bastaddr = params->bastaddr;
261         ua->xid = params->xid;
262 
263         if (params->flags & DLM_LKF_CONVERT)
264                 error = dlm_user_convert(ls, ua,
265                                          params->mode, params->flags,
266                                          params->lkid, params->lvb,
267                                          (unsigned long) params->timeout);
268         else {
269                 error = dlm_user_request(ls, ua,
270                                          params->mode, params->flags,
271                                          params->name, params->namelen,
272                                          (unsigned long) params->timeout);
273                 if (!error)
274                         error = ua->lksb.sb_lkid;
275         }
276  out:
277         dlm_put_lockspace(ls);
278         return error;
279 }
280 
281 static int device_user_unlock(struct dlm_user_proc *proc,
282                               struct dlm_lock_params *params)
283 {
284         struct dlm_ls *ls;
285         struct dlm_user_args *ua;
286         int error = -ENOMEM;
287 
288         ls = dlm_find_lockspace_local(proc->lockspace);
289         if (!ls)
290                 return -ENOENT;
291 
292         ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS);
293         if (!ua)
294                 goto out;
295         ua->proc = proc;
296         ua->user_lksb = params->lksb;
297         ua->castparam = params->castparam;
298         ua->castaddr = params->castaddr;
299 
300         if (params->flags & DLM_LKF_CANCEL)
301                 error = dlm_user_cancel(ls, ua, params->flags, params->lkid);
302         else
303                 error = dlm_user_unlock(ls, ua, params->flags, params->lkid,
304                                         params->lvb);
305  out:
306         dlm_put_lockspace(ls);
307         return error;
308 }
309 
310 static int device_user_deadlock(struct dlm_user_proc *proc,
311                                 struct dlm_lock_params *params)
312 {
313         struct dlm_ls *ls;
314         int error;
315 
316         ls = dlm_find_lockspace_local(proc->lockspace);
317         if (!ls)
318                 return -ENOENT;
319 
320         error = dlm_user_deadlock(ls, params->flags, params->lkid);
321 
322         dlm_put_lockspace(ls);
323         return error;
324 }
325 
326 static int dlm_device_register(struct dlm_ls *ls, char *name)
327 {
328         int error, len;
329 
330         /* The device is already registered.  This happens when the
331            lockspace is created multiple times from userspace. */
332         if (ls->ls_device.name)
333                 return 0;
334 
335         error = -ENOMEM;
336         len = strlen(name) + strlen(name_prefix) + 2;
337         ls->ls_device.name = kzalloc(len, GFP_NOFS);
338         if (!ls->ls_device.name)
339                 goto fail;
340 
341         snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
342                  name);
343         ls->ls_device.fops = &device_fops;
344         ls->ls_device.minor = MISC_DYNAMIC_MINOR;
345 
346         error = misc_register(&ls->ls_device);
347         if (error) {
348                 kfree(ls->ls_device.name);
349         }
350 fail:
351         return error;
352 }
353 
354 int dlm_device_deregister(struct dlm_ls *ls)
355 {
356         int error;
357 
358         /* The device is not registered.  This happens when the lockspace
359            was never used from userspace, or when device_create_lockspace()
360            calls dlm_release_lockspace() after the register fails. */
361         if (!ls->ls_device.name)
362                 return 0;
363 
364         error = misc_deregister(&ls->ls_device);
365         if (!error)
366                 kfree(ls->ls_device.name);
367         return error;
368 }
369 
370 static int device_user_purge(struct dlm_user_proc *proc,
371                              struct dlm_purge_params *params)
372 {
373         struct dlm_ls *ls;
374         int error;
375 
376         ls = dlm_find_lockspace_local(proc->lockspace);
377         if (!ls)
378                 return -ENOENT;
379 
380         error = dlm_user_purge(ls, proc, params->nodeid, params->pid);
381 
382         dlm_put_lockspace(ls);
383         return error;
384 }
385 
386 static int device_create_lockspace(struct dlm_lspace_params *params)
387 {
388         dlm_lockspace_t *lockspace;
389         struct dlm_ls *ls;
390         int error;
391 
392         if (!capable(CAP_SYS_ADMIN))
393                 return -EPERM;
394 
395         error = dlm_new_lockspace(params->name, NULL, params->flags,
396                                   DLM_USER_LVB_LEN, NULL, NULL, NULL,
397                                   &lockspace);
398         if (error)
399                 return error;
400 
401         ls = dlm_find_lockspace_local(lockspace);
402         if (!ls)
403                 return -ENOENT;
404 
405         error = dlm_device_register(ls, params->name);
406         dlm_put_lockspace(ls);
407 
408         if (error)
409                 dlm_release_lockspace(lockspace, 0);
410         else
411                 error = ls->ls_device.minor;
412 
413         return error;
414 }
415 
416 static int device_remove_lockspace(struct dlm_lspace_params *params)
417 {
418         dlm_lockspace_t *lockspace;
419         struct dlm_ls *ls;
420         int error, force = 0;
421 
422         if (!capable(CAP_SYS_ADMIN))
423                 return -EPERM;
424 
425         ls = dlm_find_lockspace_device(params->minor);
426         if (!ls)
427                 return -ENOENT;
428 
429         if (params->flags & DLM_USER_LSFLG_FORCEFREE)
430                 force = 2;
431 
432         lockspace = ls->ls_local_handle;
433         dlm_put_lockspace(ls);
434 
435         /* The final dlm_release_lockspace waits for references to go to
436            zero, so all processes will need to close their device for the
437            ls before the release will proceed.  release also calls the
438            device_deregister above.  Converting a positive return value
439            from release to zero means that userspace won't know when its
440            release was the final one, but it shouldn't need to know. */
441 
442         error = dlm_release_lockspace(lockspace, force);
443         if (error > 0)
444                 error = 0;
445         return error;
446 }
447 
448 /* Check the user's version matches ours */
449 static int check_version(struct dlm_write_request *req)
450 {
451         if (req->version[0] != DLM_DEVICE_VERSION_MAJOR ||
452             (req->version[0] == DLM_DEVICE_VERSION_MAJOR &&
453              req->version[1] > DLM_DEVICE_VERSION_MINOR)) {
454 
455                 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch "
456                        "user (%d.%d.%d) kernel (%d.%d.%d)\n",
457                        current->comm,
458                        task_pid_nr(current),
459                        req->version[0],
460                        req->version[1],
461                        req->version[2],
462                        DLM_DEVICE_VERSION_MAJOR,
463                        DLM_DEVICE_VERSION_MINOR,
464                        DLM_DEVICE_VERSION_PATCH);
465                 return -EINVAL;
466         }
467         return 0;
468 }
469 
470 /*
471  * device_write
472  *
473  *   device_user_lock
474  *     dlm_user_request -> request_lock
475  *     dlm_user_convert -> convert_lock
476  *
477  *   device_user_unlock
478  *     dlm_user_unlock -> unlock_lock
479  *     dlm_user_cancel -> cancel_lock
480  *
481  *   device_create_lockspace
482  *     dlm_new_lockspace
483  *
484  *   device_remove_lockspace
485  *     dlm_release_lockspace
486  */
487 
488 /* a write to a lockspace device is a lock or unlock request, a write
489    to the control device is to create/remove a lockspace */
490 
491 static ssize_t device_write(struct file *file, const char __user *buf,
492                             size_t count, loff_t *ppos)
493 {
494         struct dlm_user_proc *proc = file->private_data;
495         struct dlm_write_request *kbuf;
496         int error;
497 
498 #ifdef CONFIG_COMPAT
499         if (count < sizeof(struct dlm_write_request32))
500 #else
501         if (count < sizeof(struct dlm_write_request))
502 #endif
503                 return -EINVAL;
504 
505         /*
506          * can't compare against COMPAT/dlm_write_request32 because
507          * we don't yet know if is64bit is zero
508          */
509         if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN)
510                 return -EINVAL;
511 
512         kbuf = kzalloc(count + 1, GFP_NOFS);
513         if (!kbuf)
514                 return -ENOMEM;
515 
516         if (copy_from_user(kbuf, buf, count)) {
517                 error = -EFAULT;
518                 goto out_free;
519         }
520 
521         if (check_version(kbuf)) {
522                 error = -EBADE;
523                 goto out_free;
524         }
525 
526 #ifdef CONFIG_COMPAT
527         if (!kbuf->is64bit) {
528                 struct dlm_write_request32 *k32buf;
529                 int namelen = 0;
530 
531                 if (count > sizeof(struct dlm_write_request32))
532                         namelen = count - sizeof(struct dlm_write_request32);
533 
534                 k32buf = (struct dlm_write_request32 *)kbuf;
535 
536                 /* add 1 after namelen so that the name string is terminated */
537                 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1,
538                                GFP_NOFS);
539                 if (!kbuf) {
540                         kfree(k32buf);
541                         return -ENOMEM;
542                 }
543 
544                 if (proc)
545                         set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags);
546 
547                 compat_input(kbuf, k32buf, namelen);
548                 kfree(k32buf);
549         }
550 #endif
551 
552         /* do we really need this? can a write happen after a close? */
553         if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) &&
554             (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) {
555                 error = -EINVAL;
556                 goto out_free;
557         }
558 
559         error = -EINVAL;
560 
561         switch (kbuf->cmd)
562         {
563         case DLM_USER_LOCK:
564                 if (!proc) {
565                         log_print("no locking on control device");
566                         goto out_free;
567                 }
568                 error = device_user_lock(proc, &kbuf->i.lock);
569                 break;
570 
571         case DLM_USER_UNLOCK:
572                 if (!proc) {
573                         log_print("no locking on control device");
574                         goto out_free;
575                 }
576                 error = device_user_unlock(proc, &kbuf->i.lock);
577                 break;
578 
579         case DLM_USER_DEADLOCK:
580                 if (!proc) {
581                         log_print("no locking on control device");
582                         goto out_free;
583                 }
584                 error = device_user_deadlock(proc, &kbuf->i.lock);
585                 break;
586 
587         case DLM_USER_CREATE_LOCKSPACE:
588                 if (proc) {
589                         log_print("create/remove only on control device");
590                         goto out_free;
591                 }
592                 error = device_create_lockspace(&kbuf->i.lspace);
593                 break;
594 
595         case DLM_USER_REMOVE_LOCKSPACE:
596                 if (proc) {
597                         log_print("create/remove only on control device");
598                         goto out_free;
599                 }
600                 error = device_remove_lockspace(&kbuf->i.lspace);
601                 break;
602 
603         case DLM_USER_PURGE:
604                 if (!proc) {
605                         log_print("no locking on control device");
606                         goto out_free;
607                 }
608                 error = device_user_purge(proc, &kbuf->i.purge);
609                 break;
610 
611         default:
612                 log_print("Unknown command passed to DLM device : %d\n",
613                           kbuf->cmd);
614         }
615 
616  out_free:
617         kfree(kbuf);
618         return error;
619 }
620 
621 /* Every process that opens the lockspace device has its own "proc" structure
622    hanging off the open file that's used to keep track of locks owned by the
623    process and asts that need to be delivered to the process. */
624 
625 static int device_open(struct inode *inode, struct file *file)
626 {
627         struct dlm_user_proc *proc;
628         struct dlm_ls *ls;
629 
630         ls = dlm_find_lockspace_device(iminor(inode));
631         if (!ls)
632                 return -ENOENT;
633 
634         proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS);
635         if (!proc) {
636                 dlm_put_lockspace(ls);
637                 return -ENOMEM;
638         }
639 
640         proc->lockspace = ls->ls_local_handle;
641         INIT_LIST_HEAD(&proc->asts);
642         INIT_LIST_HEAD(&proc->locks);
643         INIT_LIST_HEAD(&proc->unlocking);
644         spin_lock_init(&proc->asts_spin);
645         spin_lock_init(&proc->locks_spin);
646         init_waitqueue_head(&proc->wait);
647         file->private_data = proc;
648 
649         return 0;
650 }
651 
652 static int device_close(struct inode *inode, struct file *file)
653 {
654         struct dlm_user_proc *proc = file->private_data;
655         struct dlm_ls *ls;
656 
657         ls = dlm_find_lockspace_local(proc->lockspace);
658         if (!ls)
659                 return -ENOENT;
660 
661         set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags);
662 
663         dlm_clear_proc_locks(ls, proc);
664 
665         /* at this point no more lkb's should exist for this lockspace,
666            so there's no chance of dlm_user_add_ast() being called and
667            looking for lkb->ua->proc */
668 
669         kfree(proc);
670         file->private_data = NULL;
671 
672         dlm_put_lockspace(ls);
673         dlm_put_lockspace(ls);  /* for the find in device_open() */
674 
675         /* FIXME: AUTOFREE: if this ls is no longer used do
676            device_remove_lockspace() */
677 
678         return 0;
679 }
680 
681 static int copy_result_to_user(struct dlm_user_args *ua, int compat,
682                                uint32_t flags, int mode, int copy_lvb,
683                                char __user *buf, size_t count)
684 {
685 #ifdef CONFIG_COMPAT
686         struct dlm_lock_result32 result32;
687 #endif
688         struct dlm_lock_result result;
689         void *resultptr;
690         int error=0;
691         int len;
692         int struct_len;
693 
694         memset(&result, 0, sizeof(struct dlm_lock_result));
695         result.version[0] = DLM_DEVICE_VERSION_MAJOR;
696         result.version[1] = DLM_DEVICE_VERSION_MINOR;
697         result.version[2] = DLM_DEVICE_VERSION_PATCH;
698         memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb));
699         result.user_lksb = ua->user_lksb;
700 
701         /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated
702            in a conversion unless the conversion is successful.  See code
703            in dlm_user_convert() for updating ua from ua_tmp.  OpenVMS, though,
704            notes that a new blocking AST address and parameter are set even if
705            the conversion fails, so maybe we should just do that. */
706 
707         if (flags & DLM_CB_BAST) {
708                 result.user_astaddr = ua->bastaddr;
709                 result.user_astparam = ua->bastparam;
710                 result.bast_mode = mode;
711         } else {
712                 result.user_astaddr = ua->castaddr;
713                 result.user_astparam = ua->castparam;
714         }
715 
716 #ifdef CONFIG_COMPAT
717         if (compat)
718                 len = sizeof(struct dlm_lock_result32);
719         else
720 #endif
721                 len = sizeof(struct dlm_lock_result);
722         struct_len = len;
723 
724         /* copy lvb to userspace if there is one, it's been updated, and
725            the user buffer has space for it */
726 
727         if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) {
728                 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr,
729                                  DLM_USER_LVB_LEN)) {
730                         error = -EFAULT;
731                         goto out;
732                 }
733 
734                 result.lvb_offset = len;
735                 len += DLM_USER_LVB_LEN;
736         }
737 
738         result.length = len;
739         resultptr = &result;
740 #ifdef CONFIG_COMPAT
741         if (compat) {
742                 compat_output(&result, &result32);
743                 resultptr = &result32;
744         }
745 #endif
746 
747         if (copy_to_user(buf, resultptr, struct_len))
748                 error = -EFAULT;
749         else
750                 error = len;
751  out:
752         return error;
753 }
754 
755 static int copy_version_to_user(char __user *buf, size_t count)
756 {
757         struct dlm_device_version ver;
758 
759         memset(&ver, 0, sizeof(struct dlm_device_version));
760         ver.version[0] = DLM_DEVICE_VERSION_MAJOR;
761         ver.version[1] = DLM_DEVICE_VERSION_MINOR;
762         ver.version[2] = DLM_DEVICE_VERSION_PATCH;
763 
764         if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version)))
765                 return -EFAULT;
766         return sizeof(struct dlm_device_version);
767 }
768 
769 /* a read returns a single ast described in a struct dlm_lock_result */
770 
771 static ssize_t device_read(struct file *file, char __user *buf, size_t count,
772                            loff_t *ppos)
773 {
774         struct dlm_user_proc *proc = file->private_data;
775         struct dlm_lkb *lkb;
776         DECLARE_WAITQUEUE(wait, current);
777         struct dlm_callback cb;
778         int rv, resid, copy_lvb = 0;
779 
780         if (count == sizeof(struct dlm_device_version)) {
781                 rv = copy_version_to_user(buf, count);
782                 return rv;
783         }
784 
785         if (!proc) {
786                 log_print("non-version read from control device %zu", count);
787                 return -EINVAL;
788         }
789 
790 #ifdef CONFIG_COMPAT
791         if (count < sizeof(struct dlm_lock_result32))
792 #else
793         if (count < sizeof(struct dlm_lock_result))
794 #endif
795                 return -EINVAL;
796 
797  try_another:
798 
799         /* do we really need this? can a read happen after a close? */
800         if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))
801                 return -EINVAL;
802 
803         spin_lock(&proc->asts_spin);
804         if (list_empty(&proc->asts)) {
805                 if (file->f_flags & O_NONBLOCK) {
806                         spin_unlock(&proc->asts_spin);
807                         return -EAGAIN;
808                 }
809 
810                 add_wait_queue(&proc->wait, &wait);
811 
812         repeat:
813                 set_current_state(TASK_INTERRUPTIBLE);
814                 if (list_empty(&proc->asts) && !signal_pending(current)) {
815                         spin_unlock(&proc->asts_spin);
816                         schedule();
817                         spin_lock(&proc->asts_spin);
818                         goto repeat;
819                 }
820                 set_current_state(TASK_RUNNING);
821                 remove_wait_queue(&proc->wait, &wait);
822 
823                 if (signal_pending(current)) {
824                         spin_unlock(&proc->asts_spin);
825                         return -ERESTARTSYS;
826                 }
827         }
828 
829         /* if we empty lkb_callbacks, we don't want to unlock the spinlock
830            without removing lkb_cb_list; so empty lkb_cb_list is always
831            consistent with empty lkb_callbacks */
832 
833         lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_cb_list);
834 
835         rv = dlm_rem_lkb_callback(lkb->lkb_resource->res_ls, lkb, &cb, &resid);
836         if (rv < 0) {
837                 /* this shouldn't happen; lkb should have been removed from
838                    list when resid was zero */
839                 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id);
840                 list_del_init(&lkb->lkb_cb_list);
841                 spin_unlock(&proc->asts_spin);
842                 /* removes ref for proc->asts, may cause lkb to be freed */
843                 dlm_put_lkb(lkb);
844                 goto try_another;
845         }
846         if (!resid)
847                 list_del_init(&lkb->lkb_cb_list);
848         spin_unlock(&proc->asts_spin);
849 
850         if (cb.flags & DLM_CB_SKIP) {
851                 /* removes ref for proc->asts, may cause lkb to be freed */
852                 if (!resid)
853                         dlm_put_lkb(lkb);
854                 goto try_another;
855         }
856 
857         if (cb.flags & DLM_CB_CAST) {
858                 int old_mode, new_mode;
859 
860                 old_mode = lkb->lkb_last_cast.mode;
861                 new_mode = cb.mode;
862 
863                 if (!cb.sb_status && lkb->lkb_lksb->sb_lvbptr &&
864                     dlm_lvb_operations[old_mode + 1][new_mode + 1])
865                         copy_lvb = 1;
866 
867                 lkb->lkb_lksb->sb_status = cb.sb_status;
868                 lkb->lkb_lksb->sb_flags = cb.sb_flags;
869         }
870 
871         rv = copy_result_to_user(lkb->lkb_ua,
872                                  test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags),
873                                  cb.flags, cb.mode, copy_lvb, buf, count);
874 
875         /* removes ref for proc->asts, may cause lkb to be freed */
876         if (!resid)
877                 dlm_put_lkb(lkb);
878 
879         return rv;
880 }
881 
882 static unsigned int device_poll(struct file *file, poll_table *wait)
883 {
884         struct dlm_user_proc *proc = file->private_data;
885 
886         poll_wait(file, &proc->wait, wait);
887 
888         spin_lock(&proc->asts_spin);
889         if (!list_empty(&proc->asts)) {
890                 spin_unlock(&proc->asts_spin);
891                 return POLLIN | POLLRDNORM;
892         }
893         spin_unlock(&proc->asts_spin);
894         return 0;
895 }
896 
897 int dlm_user_daemon_available(void)
898 {
899         /* dlm_controld hasn't started (or, has started, but not
900            properly populated configfs) */
901 
902         if (!dlm_our_nodeid())
903                 return 0;
904 
905         /* This is to deal with versions of dlm_controld that don't
906            know about the monitor device.  We assume that if the
907            dlm_controld was started (above), but the monitor device
908            was never opened, that it's an old version.  dlm_controld
909            should open the monitor device before populating configfs. */
910 
911         if (dlm_monitor_unused)
912                 return 1;
913 
914         return atomic_read(&dlm_monitor_opened) ? 1 : 0;
915 }
916 
917 static int ctl_device_open(struct inode *inode, struct file *file)
918 {
919         file->private_data = NULL;
920         return 0;
921 }
922 
923 static int ctl_device_close(struct inode *inode, struct file *file)
924 {
925         return 0;
926 }
927 
928 static int monitor_device_open(struct inode *inode, struct file *file)
929 {
930         atomic_inc(&dlm_monitor_opened);
931         dlm_monitor_unused = 0;
932         return 0;
933 }
934 
935 static int monitor_device_close(struct inode *inode, struct file *file)
936 {
937         if (atomic_dec_and_test(&dlm_monitor_opened))
938                 dlm_stop_lockspaces();
939         return 0;
940 }
941 
942 static const struct file_operations device_fops = {
943         .open    = device_open,
944         .release = device_close,
945         .read    = device_read,
946         .write   = device_write,
947         .poll    = device_poll,
948         .owner   = THIS_MODULE,
949         .llseek  = noop_llseek,
950 };
951 
952 static const struct file_operations ctl_device_fops = {
953         .open    = ctl_device_open,
954         .release = ctl_device_close,
955         .read    = device_read,
956         .write   = device_write,
957         .owner   = THIS_MODULE,
958         .llseek  = noop_llseek,
959 };
960 
961 static struct miscdevice ctl_device = {
962         .name  = "dlm-control",
963         .fops  = &ctl_device_fops,
964         .minor = MISC_DYNAMIC_MINOR,
965 };
966 
967 static const struct file_operations monitor_device_fops = {
968         .open    = monitor_device_open,
969         .release = monitor_device_close,
970         .owner   = THIS_MODULE,
971         .llseek  = noop_llseek,
972 };
973 
974 static struct miscdevice monitor_device = {
975         .name  = "dlm-monitor",
976         .fops  = &monitor_device_fops,
977         .minor = MISC_DYNAMIC_MINOR,
978 };
979 
980 int __init dlm_user_init(void)
981 {
982         int error;
983 
984         atomic_set(&dlm_monitor_opened, 0);
985 
986         error = misc_register(&ctl_device);
987         if (error) {
988                 log_print("misc_register failed for control device");
989                 goto out;
990         }
991 
992         error = misc_register(&monitor_device);
993         if (error) {
994                 log_print("misc_register failed for monitor device");
995                 misc_deregister(&ctl_device);
996         }
997  out:
998         return error;
999 }
1000 
1001 void dlm_user_exit(void)
1002 {
1003         misc_deregister(&ctl_device);
1004         misc_deregister(&monitor_device);
1005 }
1006 
1007 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp