blob: c962283d4e7ff174ffe9d2eb719319f863eca2c2 [file] [log] [blame]
David Teiglandb3b94fa2006-01-16 16:50:04 +00001/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
Bob Petersoncf45b752008-01-31 10:31:39 -06003 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
David Teiglandb3b94fa2006-01-16 16:50:04 +00004 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
Steven Whitehousee9fc2aa2006-09-01 11:05:15 -04007 * of the GNU General Public License version 2.
David Teiglandb3b94fa2006-01-16 16:50:04 +00008 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/delay.h>
16#include <linux/sort.h>
17#include <linux/jhash.h>
Steven Whitehoused0dc80d2006-03-29 14:36:49 -050018#include <linux/kallsyms.h>
Steven Whitehouse5c676f62006-02-27 17:23:27 -050019#include <linux/gfs2_ondisk.h>
Steven Whitehouse24264432006-09-11 21:40:30 -040020#include <linux/list.h>
Fabio Massimo Di Nitto7d308592006-09-19 07:56:29 +020021#include <linux/lm_interface.h>
Steven Whitehousefee852e2007-01-17 15:33:23 +000022#include <linux/wait.h>
akpm@linux-foundation.org95d97b72007-03-05 23:10:39 -080023#include <linux/module.h>
Steven Whitehouse61be0842007-01-29 11:51:45 +000024#include <linux/rwsem.h>
David Teiglandb3b94fa2006-01-16 16:50:04 +000025#include <asm/uaccess.h>
Robert Peterson7c52b162007-03-16 10:26:37 +000026#include <linux/seq_file.h>
27#include <linux/debugfs.h>
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +010028#include <linux/kthread.h>
29#include <linux/freezer.h>
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -050030#include <linux/workqueue.h>
31#include <linux/jiffies.h>
David Teiglandb3b94fa2006-01-16 16:50:04 +000032
33#include "gfs2.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050034#include "incore.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000035#include "glock.h"
36#include "glops.h"
37#include "inode.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000038#include "lops.h"
39#include "meta_io.h"
40#include "quota.h"
41#include "super.h"
Steven Whitehouse5c676f62006-02-27 17:23:27 -050042#include "util.h"
David Teiglandb3b94fa2006-01-16 16:50:04 +000043
Steven Whitehouse37b2fa62006-09-08 13:35:56 -040044struct gfs2_gl_hash_bucket {
Steven Whitehouseb6397892006-09-12 10:10:01 -040045 struct hlist_head hb_list;
Steven Whitehouse37b2fa62006-09-08 13:35:56 -040046};
47
Steven Whitehouse6802e342008-05-21 17:03:22 +010048struct gfs2_glock_iter {
49 int hash; /* hash bucket index */
50 struct gfs2_sbd *sdp; /* incore superblock */
51 struct gfs2_glock *gl; /* current glock struct */
52 char string[512]; /* scratch space */
Robert Peterson7c52b162007-03-16 10:26:37 +000053};
54
David Teiglandb3b94fa2006-01-16 16:50:04 +000055typedef void (*glock_examiner) (struct gfs2_glock * gl);
56
Adrian Bunk08bc2db2006-04-28 10:59:12 -040057static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
Steven Whitehouse6802e342008-05-21 17:03:22 +010058static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
59#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { __dump_glock(NULL, gl); BUG(); } } while(0)
60static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -050061
Steven Whitehouse61be0842007-01-29 11:51:45 +000062static DECLARE_RWSEM(gfs2_umount_flush_sem);
Robert Peterson7c52b162007-03-16 10:26:37 +000063static struct dentry *gfs2_root;
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +010064static struct task_struct *scand_process;
65static unsigned int scand_secs = 5;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -050066static struct workqueue_struct *glock_workqueue;
Adrian Bunk08bc2db2006-04-28 10:59:12 -040067
Steven Whitehouseb6397892006-09-12 10:10:01 -040068#define GFS2_GL_HASH_SHIFT 15
Steven Whitehouse087efdd2006-09-09 16:59:11 -040069#define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
70#define GFS2_GL_HASH_MASK (GFS2_GL_HASH_SIZE - 1)
71
Steven Whitehouse85d1da62006-09-07 14:40:21 -040072static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
Robert Peterson04b933f2007-03-23 17:05:15 -050073static struct dentry *gfs2_root;
Steven Whitehouse087efdd2006-09-09 16:59:11 -040074
75/*
76 * Despite what you might think, the numbers below are not arbitrary :-)
77 * They are taken from the ipv4 routing hash code, which is well tested
78 * and thus should be nearly optimal. Later on we might tweek the numbers
79 * but for now this should be fine.
80 *
81 * The reason for putting the locks in a separate array from the list heads
82 * is that we can have fewer locks than list heads and save memory. We use
83 * the same hash function for both, but with a different hash mask.
84 */
85#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
86 defined(CONFIG_PROVE_LOCKING)
87
88#ifdef CONFIG_LOCKDEP
89# define GL_HASH_LOCK_SZ 256
90#else
91# if NR_CPUS >= 32
92# define GL_HASH_LOCK_SZ 4096
93# elif NR_CPUS >= 16
94# define GL_HASH_LOCK_SZ 2048
95# elif NR_CPUS >= 8
96# define GL_HASH_LOCK_SZ 1024
97# elif NR_CPUS >= 4
98# define GL_HASH_LOCK_SZ 512
99# else
100# define GL_HASH_LOCK_SZ 256
101# endif
102#endif
103
104/* We never want more locks than chains */
105#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
106# undef GL_HASH_LOCK_SZ
107# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
108#endif
109
110static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
111
112static inline rwlock_t *gl_lock_addr(unsigned int x)
113{
Steven Whitehouse94610612006-09-09 18:59:27 -0400114 return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400115}
116#else /* not SMP, so no spinlocks required */
Randy Dunlap0ac23062006-11-28 22:29:19 -0800117static inline rwlock_t *gl_lock_addr(unsigned int x)
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400118{
119 return NULL;
120}
121#endif
Steven Whitehouse85d1da62006-09-07 14:40:21 -0400122
David Teiglandb3b94fa2006-01-16 16:50:04 +0000123/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000124 * gl_hash() - Turn glock number into hash bucket number
125 * @lock: The glock number
126 *
127 * Returns: The number of the corresponding hash bucket
128 */
129
Steven Whitehouseb8547852006-09-07 13:12:27 -0400130static unsigned int gl_hash(const struct gfs2_sbd *sdp,
131 const struct lm_lockname *name)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000132{
133 unsigned int h;
134
Steven Whitehousecd915492006-09-04 12:49:07 -0400135 h = jhash(&name->ln_number, sizeof(u64), 0);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000136 h = jhash(&name->ln_type, sizeof(unsigned int), h);
Steven Whitehouseb8547852006-09-07 13:12:27 -0400137 h = jhash(&sdp, sizeof(struct gfs2_sbd *), h);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000138 h &= GFS2_GL_HASH_MASK;
139
140 return h;
141}
142
143/**
144 * glock_free() - Perform a few checks and then release struct gfs2_glock
145 * @gl: The glock to release
146 *
147 * Also calls lock module to release its internal structure for this glock.
148 *
149 */
150
151static void glock_free(struct gfs2_glock *gl)
152{
153 struct gfs2_sbd *sdp = gl->gl_sbd;
154 struct inode *aspace = gl->gl_aspace;
155
Steven Whitehouse048bca22008-05-23 14:46:04 +0100156 if (sdp->sd_lockstruct.ls_ops->lm_put_lock)
Steven Whitehouseda755fd2008-01-30 15:34:04 +0000157 sdp->sd_lockstruct.ls_ops->lm_put_lock(gl->gl_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000158
159 if (aspace)
160 gfs2_aspace_put(aspace);
161
162 kmem_cache_free(gfs2_glock_cachep, gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000163}
164
165/**
166 * gfs2_glock_hold() - increment reference count on glock
167 * @gl: The glock to hold
168 *
169 */
170
Adrian Bunk048786f2008-01-29 00:11:34 +0200171static void gfs2_glock_hold(struct gfs2_glock *gl)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000172{
Steven Whitehouse16feb9f2006-09-13 10:43:37 -0400173 atomic_inc(&gl->gl_ref);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000174}
175
176/**
177 * gfs2_glock_put() - Decrement reference count on glock
178 * @gl: The glock to put
179 *
180 */
181
182int gfs2_glock_put(struct gfs2_glock *gl)
183{
David Teiglandb3b94fa2006-01-16 16:50:04 +0000184 int rv = 0;
185
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400186 write_lock(gl_lock_addr(gl->gl_hash));
Steven Whitehouse16feb9f2006-09-13 10:43:37 -0400187 if (atomic_dec_and_test(&gl->gl_ref)) {
Steven Whitehouseb6397892006-09-12 10:10:01 -0400188 hlist_del(&gl->gl_list);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400189 write_unlock(gl_lock_addr(gl->gl_hash));
Steven Whitehouse6802e342008-05-21 17:03:22 +0100190 GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED);
191 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim));
192 GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000193 glock_free(gl);
194 rv = 1;
195 goto out;
196 }
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400197 write_unlock(gl_lock_addr(gl->gl_hash));
Steven Whitehousea2242db2006-08-24 17:03:05 -0400198out:
David Teiglandb3b94fa2006-01-16 16:50:04 +0000199 return rv;
200}
201
202/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000203 * search_bucket() - Find struct gfs2_glock by lock number
204 * @bucket: the bucket to search
205 * @name: The lock name
206 *
207 * Returns: NULL, or the struct gfs2_glock with the requested number
208 */
209
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400210static struct gfs2_glock *search_bucket(unsigned int hash,
Steven Whitehouse899be4d2006-08-30 12:50:28 -0400211 const struct gfs2_sbd *sdp,
Steven Whitehoused6a53722006-08-30 11:16:23 -0400212 const struct lm_lockname *name)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000213{
214 struct gfs2_glock *gl;
Steven Whitehouseb6397892006-09-12 10:10:01 -0400215 struct hlist_node *h;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000216
Steven Whitehouseb6397892006-09-12 10:10:01 -0400217 hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
David Teiglandb3b94fa2006-01-16 16:50:04 +0000218 if (!lm_name_equal(&gl->gl_name, name))
219 continue;
Steven Whitehouse899be4d2006-08-30 12:50:28 -0400220 if (gl->gl_sbd != sdp)
221 continue;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000222
Steven Whitehouse16feb9f2006-09-13 10:43:37 -0400223 atomic_inc(&gl->gl_ref);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000224
225 return gl;
226 }
227
228 return NULL;
229}
230
231/**
232 * gfs2_glock_find() - Find glock by lock number
233 * @sdp: The GFS2 superblock
234 * @name: The lock name
235 *
236 * Returns: NULL, or the struct gfs2_glock with the requested number
237 */
238
Steven Whitehouse85d1da62006-09-07 14:40:21 -0400239static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
Steven Whitehoused6a53722006-08-30 11:16:23 -0400240 const struct lm_lockname *name)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000241{
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400242 unsigned int hash = gl_hash(sdp, name);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000243 struct gfs2_glock *gl;
244
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400245 read_lock(gl_lock_addr(hash));
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400246 gl = search_bucket(hash, sdp, name);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400247 read_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000248
249 return gl;
250}
251
Steven Whitehouse6802e342008-05-21 17:03:22 +0100252/**
253 * may_grant - check if its ok to grant a new lock
254 * @gl: The glock
255 * @gh: The lock request which we wish to grant
256 *
257 * Returns: true if its ok to grant the lock
258 */
259
260static inline int may_grant(const struct gfs2_glock *gl, const struct gfs2_holder *gh)
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500261{
Steven Whitehouse6802e342008-05-21 17:03:22 +0100262 const struct gfs2_holder *gh_head = list_entry(gl->gl_holders.next, const struct gfs2_holder, gh_list);
263 if ((gh->gh_state == LM_ST_EXCLUSIVE ||
264 gh_head->gh_state == LM_ST_EXCLUSIVE) && gh != gh_head)
265 return 0;
266 if (gl->gl_state == gh->gh_state)
267 return 1;
268 if (gh->gh_flags & GL_EXACT)
269 return 0;
Steven Whitehouse209806a2008-07-07 10:07:28 +0100270 if (gl->gl_state == LM_ST_EXCLUSIVE) {
271 if (gh->gh_state == LM_ST_SHARED && gh_head->gh_state == LM_ST_SHARED)
272 return 1;
273 if (gh->gh_state == LM_ST_DEFERRED && gh_head->gh_state == LM_ST_DEFERRED)
274 return 1;
275 }
Steven Whitehouse6802e342008-05-21 17:03:22 +0100276 if (gl->gl_state != LM_ST_UNLOCKED && (gh->gh_flags & LM_FLAG_ANY))
277 return 1;
278 return 0;
279}
280
281static void gfs2_holder_wake(struct gfs2_holder *gh)
282{
283 clear_bit(HIF_WAIT, &gh->gh_iflags);
284 smp_mb__after_clear_bit();
285 wake_up_bit(&gh->gh_iflags, HIF_WAIT);
286}
287
288/**
289 * do_promote - promote as many requests as possible on the current queue
290 * @gl: The glock
291 *
292 * Returns: true if there is a blocked holder at the head of the list
293 */
294
295static int do_promote(struct gfs2_glock *gl)
296{
297 const struct gfs2_glock_operations *glops = gl->gl_ops;
298 struct gfs2_holder *gh, *tmp;
299 int ret;
300
301restart:
302 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
303 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
304 continue;
305 if (may_grant(gl, gh)) {
306 if (gh->gh_list.prev == &gl->gl_holders &&
307 glops->go_lock) {
308 spin_unlock(&gl->gl_spin);
309 /* FIXME: eliminate this eventually */
310 ret = glops->go_lock(gh);
311 spin_lock(&gl->gl_spin);
312 if (ret) {
313 gh->gh_error = ret;
314 list_del_init(&gh->gh_list);
315 gfs2_holder_wake(gh);
316 goto restart;
317 }
318 set_bit(HIF_HOLDER, &gh->gh_iflags);
319 gfs2_holder_wake(gh);
320 goto restart;
321 }
322 set_bit(HIF_HOLDER, &gh->gh_iflags);
323 gfs2_holder_wake(gh);
324 continue;
325 }
326 if (gh->gh_list.prev == &gl->gl_holders)
327 return 1;
328 break;
329 }
330 return 0;
331}
332
333/**
334 * do_error - Something unexpected has happened during a lock request
335 *
336 */
337
338static inline void do_error(struct gfs2_glock *gl, const int ret)
339{
340 struct gfs2_holder *gh, *tmp;
341
342 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
343 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
344 continue;
345 if (ret & LM_OUT_ERROR)
346 gh->gh_error = -EIO;
347 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
348 gh->gh_error = GLR_TRYFAILED;
349 else
350 continue;
351 list_del_init(&gh->gh_list);
352 gfs2_holder_wake(gh);
353 }
354}
355
356/**
357 * find_first_waiter - find the first gh that's waiting for the glock
358 * @gl: the glock
359 */
360
361static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
362{
363 struct gfs2_holder *gh;
364
365 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
366 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
367 return gh;
368 }
369 return NULL;
370}
371
372/**
373 * state_change - record that the glock is now in a different state
374 * @gl: the glock
375 * @new_state the new state
376 *
377 */
378
379static void state_change(struct gfs2_glock *gl, unsigned int new_state)
380{
381 int held1, held2;
382
383 held1 = (gl->gl_state != LM_ST_UNLOCKED);
384 held2 = (new_state != LM_ST_UNLOCKED);
385
386 if (held1 != held2) {
387 if (held2)
388 gfs2_glock_hold(gl);
389 else
390 gfs2_glock_put(gl);
391 }
392
393 gl->gl_state = new_state;
394 gl->gl_tchange = jiffies;
395}
396
397static void gfs2_demote_wake(struct gfs2_glock *gl)
398{
399 gl->gl_demote_state = LM_ST_EXCLUSIVE;
400 clear_bit(GLF_DEMOTE, &gl->gl_flags);
401 smp_mb__after_clear_bit();
402 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
403}
404
405/**
406 * finish_xmote - The DLM has replied to one of our lock requests
407 * @gl: The glock
408 * @ret: The status from the DLM
409 *
410 */
411
412static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
413{
414 const struct gfs2_glock_operations *glops = gl->gl_ops;
415 struct gfs2_holder *gh;
416 unsigned state = ret & LM_OUT_ST_MASK;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500417
418 spin_lock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100419 state_change(gl, state);
420 gh = find_first_waiter(gl);
421
422 /* Demote to UN request arrived during demote to SH or DF */
423 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
424 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
425 gl->gl_target = LM_ST_UNLOCKED;
426
427 /* Check for state != intended state */
428 if (unlikely(state != gl->gl_target)) {
429 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
430 /* move to back of queue and try next entry */
431 if (ret & LM_OUT_CANCELED) {
432 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
433 list_move_tail(&gh->gh_list, &gl->gl_holders);
434 gh = find_first_waiter(gl);
435 gl->gl_target = gh->gh_state;
436 goto retry;
437 }
438 /* Some error or failed "try lock" - report it */
439 if ((ret & LM_OUT_ERROR) ||
440 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
441 gl->gl_target = gl->gl_state;
442 do_error(gl, ret);
443 goto out;
444 }
445 }
446 switch(state) {
447 /* Unlocked due to conversion deadlock, try again */
448 case LM_ST_UNLOCKED:
449retry:
450 do_xmote(gl, gh, gl->gl_target);
451 break;
452 /* Conversion fails, unlock and try again */
453 case LM_ST_SHARED:
454 case LM_ST_DEFERRED:
455 do_xmote(gl, gh, LM_ST_UNLOCKED);
456 break;
457 default: /* Everything else */
458 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
459 GLOCK_BUG_ON(gl, 1);
460 }
461 spin_unlock(&gl->gl_spin);
462 gfs2_glock_put(gl);
463 return;
464 }
465
466 /* Fast path - we got what we asked for */
467 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
468 gfs2_demote_wake(gl);
469 if (state != LM_ST_UNLOCKED) {
470 if (glops->go_xmote_bh) {
471 int rv;
472 spin_unlock(&gl->gl_spin);
473 rv = glops->go_xmote_bh(gl, gh);
474 if (rv == -EAGAIN)
475 return;
476 spin_lock(&gl->gl_spin);
477 if (rv) {
478 do_error(gl, rv);
479 goto out;
480 }
481 }
482 do_promote(gl);
483 }
484out:
485 clear_bit(GLF_LOCK, &gl->gl_flags);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500486 spin_unlock(&gl->gl_spin);
487 gfs2_glock_put(gl);
488}
489
Steven Whitehouse6802e342008-05-21 17:03:22 +0100490static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
491 unsigned int cur_state, unsigned int req_state,
492 unsigned int flags)
493{
494 int ret = LM_OUT_ERROR;
Steven Whitehouse048bca22008-05-23 14:46:04 +0100495
496 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
497 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
498
Steven Whitehouse6802e342008-05-21 17:03:22 +0100499 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
500 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state,
501 req_state, flags);
502 return ret;
503}
504
505/**
506 * do_xmote - Calls the DLM to change the state of a lock
507 * @gl: The lock state
508 * @gh: The holder (only for promotes)
509 * @target: The target lock state
510 *
511 */
512
513static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
514{
515 const struct gfs2_glock_operations *glops = gl->gl_ops;
516 struct gfs2_sbd *sdp = gl->gl_sbd;
517 unsigned int lck_flags = gh ? gh->gh_flags : 0;
518 int ret;
519
520 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
521 LM_FLAG_PRIORITY);
522 BUG_ON(gl->gl_state == target);
523 BUG_ON(gl->gl_state == gl->gl_target);
524 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
525 glops->go_inval) {
526 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
527 do_error(gl, 0); /* Fail queued try locks */
528 }
529 spin_unlock(&gl->gl_spin);
530 if (glops->go_xmote_th)
531 glops->go_xmote_th(gl);
532 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
533 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
534 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
535
536 gfs2_glock_hold(gl);
537 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
538 gl->gl_state == LM_ST_DEFERRED) &&
539 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
540 lck_flags |= LM_FLAG_TRY_1CB;
541 ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags);
542
543 if (!(ret & LM_OUT_ASYNC)) {
544 finish_xmote(gl, ret);
545 gfs2_glock_hold(gl);
546 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
547 gfs2_glock_put(gl);
548 } else {
549 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
550 }
551 spin_lock(&gl->gl_spin);
552}
553
554/**
555 * find_first_holder - find the first "holder" gh
556 * @gl: the glock
557 */
558
559static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
560{
561 struct gfs2_holder *gh;
562
563 if (!list_empty(&gl->gl_holders)) {
564 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
565 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
566 return gh;
567 }
568 return NULL;
569}
570
571/**
572 * run_queue - do all outstanding tasks related to a glock
573 * @gl: The glock in question
574 * @nonblock: True if we must not block in run_queue
575 *
576 */
577
578static void run_queue(struct gfs2_glock *gl, const int nonblock)
579{
580 struct gfs2_holder *gh = NULL;
581
582 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
583 return;
584
585 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
586
587 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
588 gl->gl_demote_state != gl->gl_state) {
589 if (find_first_holder(gl))
590 goto out;
591 if (nonblock)
592 goto out_sched;
593 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
Steven Whitehouse265d529c2008-07-07 10:02:36 +0100594 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100595 gl->gl_target = gl->gl_demote_state;
596 } else {
597 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
598 gfs2_demote_wake(gl);
599 if (do_promote(gl) == 0)
600 goto out;
601 gh = find_first_waiter(gl);
602 gl->gl_target = gh->gh_state;
603 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
604 do_error(gl, 0); /* Fail queued try locks */
605 }
606 do_xmote(gl, gh, gl->gl_target);
607 return;
608
609out_sched:
610 gfs2_glock_hold(gl);
611 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
612 gfs2_glock_put(gl);
613out:
614 clear_bit(GLF_LOCK, &gl->gl_flags);
615}
616
617static void glock_work_func(struct work_struct *work)
618{
619 unsigned long delay = 0;
620 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
621
622 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags))
623 finish_xmote(gl, gl->gl_reply);
624 spin_lock(&gl->gl_spin);
Steven Whitehouse265d529c2008-07-07 10:02:36 +0100625 if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
626 gl->gl_state != LM_ST_UNLOCKED &&
627 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100628 unsigned long holdtime, now = jiffies;
629 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
630 if (time_before(now, holdtime))
631 delay = holdtime - now;
632 set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
633 }
634 run_queue(gl, 0);
635 spin_unlock(&gl->gl_spin);
636 if (!delay ||
637 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
638 gfs2_glock_put(gl);
639}
640
Steven Whitehouseda755fd2008-01-30 15:34:04 +0000641static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
642 void **lockp)
643{
644 int error = -EIO;
Steven Whitehouse048bca22008-05-23 14:46:04 +0100645 if (!sdp->sd_lockstruct.ls_ops->lm_get_lock)
646 return 0;
Steven Whitehouseda755fd2008-01-30 15:34:04 +0000647 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
648 error = sdp->sd_lockstruct.ls_ops->lm_get_lock(
649 sdp->sd_lockstruct.ls_lockspace, name, lockp);
650 return error;
651}
652
David Teiglandb3b94fa2006-01-16 16:50:04 +0000653/**
654 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
655 * @sdp: The GFS2 superblock
656 * @number: the lock number
657 * @glops: The glock_operations to use
658 * @create: If 0, don't create the glock if it doesn't exist
659 * @glp: the glock is returned here
660 *
661 * This does not lock a glock, just finds/creates structures for one.
662 *
663 * Returns: errno
664 */
665
Steven Whitehousecd915492006-09-04 12:49:07 -0400666int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
Steven Whitehouse8fb4b532006-08-30 09:30:00 -0400667 const struct gfs2_glock_operations *glops, int create,
David Teiglandb3b94fa2006-01-16 16:50:04 +0000668 struct gfs2_glock **glp)
669{
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400670 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
David Teiglandb3b94fa2006-01-16 16:50:04 +0000671 struct gfs2_glock *gl, *tmp;
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400672 unsigned int hash = gl_hash(sdp, &name);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000673 int error;
674
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400675 read_lock(gl_lock_addr(hash));
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400676 gl = search_bucket(hash, sdp, &name);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400677 read_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000678
679 if (gl || !create) {
680 *glp = gl;
681 return 0;
682 }
683
684 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
685 if (!gl)
686 return -ENOMEM;
687
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400688 gl->gl_flags = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000689 gl->gl_name = name;
Steven Whitehouse16feb9f2006-09-13 10:43:37 -0400690 atomic_set(&gl->gl_ref, 1);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000691 gl->gl_state = LM_ST_UNLOCKED;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100692 gl->gl_target = LM_ST_UNLOCKED;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500693 gl->gl_demote_state = LM_ST_EXCLUSIVE;
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400694 gl->gl_hash = hash;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000695 gl->gl_ops = glops;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400696 gl->gl_stamp = jiffies;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500697 gl->gl_tchange = jiffies;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400698 gl->gl_object = NULL;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000699 gl->gl_sbd = sdp;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400700 gl->gl_aspace = NULL;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500701 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000702
703 /* If this glock protects actual on-disk data or metadata blocks,
704 create a VFS inode to manage the pages/buffers holding them. */
Steven Whitehouse50299962006-09-04 09:49:55 -0400705 if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
David Teiglandb3b94fa2006-01-16 16:50:04 +0000706 gl->gl_aspace = gfs2_aspace_get(sdp);
707 if (!gl->gl_aspace) {
708 error = -ENOMEM;
709 goto fail;
710 }
711 }
712
713 error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
714 if (error)
715 goto fail_aspace;
716
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400717 write_lock(gl_lock_addr(hash));
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400718 tmp = search_bucket(hash, sdp, &name);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000719 if (tmp) {
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400720 write_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000721 glock_free(gl);
722 gl = tmp;
723 } else {
Steven Whitehouseb6397892006-09-12 10:10:01 -0400724 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400725 write_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000726 }
727
728 *glp = gl;
729
730 return 0;
731
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400732fail_aspace:
David Teiglandb3b94fa2006-01-16 16:50:04 +0000733 if (gl->gl_aspace)
734 gfs2_aspace_put(gl->gl_aspace);
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400735fail:
Steven Whitehouse907b9bc2006-09-25 09:26:04 -0400736 kmem_cache_free(gfs2_glock_cachep, gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000737 return error;
738}
739
740/**
741 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
742 * @gl: the glock
743 * @state: the state we're requesting
744 * @flags: the modifier flags
745 * @gh: the holder structure
746 *
747 */
748
Steven Whitehouse190562b2006-04-20 16:57:23 -0400749void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
David Teiglandb3b94fa2006-01-16 16:50:04 +0000750 struct gfs2_holder *gh)
751{
752 INIT_LIST_HEAD(&gh->gh_list);
753 gh->gh_gl = gl;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500754 gh->gh_ip = (unsigned long)__builtin_return_address(0);
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800755 gh->gh_owner_pid = get_pid(task_pid(current));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000756 gh->gh_state = state;
757 gh->gh_flags = flags;
758 gh->gh_error = 0;
759 gh->gh_iflags = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000760 gfs2_glock_hold(gl);
761}
762
763/**
764 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
765 * @state: the state we're requesting
766 * @flags: the modifier flags
767 * @gh: the holder structure
768 *
769 * Don't mess with the glock.
770 *
771 */
772
Steven Whitehouse190562b2006-04-20 16:57:23 -0400773void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000774{
775 gh->gh_state = state;
Steven Whitehouse579b78a2006-04-26 14:58:26 -0400776 gh->gh_flags = flags;
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000777 gh->gh_iflags = 0;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500778 gh->gh_ip = (unsigned long)__builtin_return_address(0);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000779}
780
781/**
782 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
783 * @gh: the holder structure
784 *
785 */
786
787void gfs2_holder_uninit(struct gfs2_holder *gh)
788{
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800789 put_pid(gh->gh_owner_pid);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000790 gfs2_glock_put(gh->gh_gl);
791 gh->gh_gl = NULL;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500792 gh->gh_ip = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000793}
794
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100795static int just_schedule(void *word)
Steven Whitehousefee852e2007-01-17 15:33:23 +0000796{
797 schedule();
798 return 0;
799}
800
801static void wait_on_holder(struct gfs2_holder *gh)
802{
803 might_sleep();
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100804 wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
805}
806
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100807static void wait_on_demote(struct gfs2_glock *gl)
808{
809 might_sleep();
810 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
Steven Whitehousefee852e2007-01-17 15:33:23 +0000811}
812
David Teiglandb3b94fa2006-01-16 16:50:04 +0000813/**
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000814 * handle_callback - process a demote request
David Teiglandb3b94fa2006-01-16 16:50:04 +0000815 * @gl: the glock
816 * @state: the state the caller wants us to change to
817 *
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000818 * There are only two requests that we are going to see in actual
819 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
David Teiglandb3b94fa2006-01-16 16:50:04 +0000820 */
821
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500822static void handle_callback(struct gfs2_glock *gl, unsigned int state,
823 int remote, unsigned long delay)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000824{
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500825 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
826
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500827 set_bit(bit, &gl->gl_flags);
828 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000829 gl->gl_demote_state = state;
830 gl->gl_demote_time = jiffies;
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100831 if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
Steven Whitehouse6802e342008-05-21 17:03:22 +0100832 gl->gl_object)
Wendy Cheng49e61f22007-09-13 17:52:42 -0400833 gfs2_glock_schedule_for_reclaim(gl);
Josef Whiter26caee52007-07-23 10:02:40 +0100834 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
835 gl->gl_demote_state != state) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100836 gl->gl_demote_state = LM_ST_UNLOCKED;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000837 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000838}
839
840/**
Steven Whitehouse6802e342008-05-21 17:03:22 +0100841 * gfs2_glock_wait - wait on a glock acquisition
David Teiglandb3b94fa2006-01-16 16:50:04 +0000842 * @gh: the glock holder
843 *
844 * Returns: 0 on success
845 */
846
Steven Whitehouse6802e342008-05-21 17:03:22 +0100847int gfs2_glock_wait(struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000848{
Steven Whitehousefee852e2007-01-17 15:33:23 +0000849 wait_on_holder(gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000850 return gh->gh_error;
851}
852
Steven Whitehouse6802e342008-05-21 17:03:22 +0100853void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
Robert Peterson7c52b162007-03-16 10:26:37 +0000854{
855 va_list args;
856
857 va_start(args, fmt);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100858 if (seq) {
859 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +0000860 vsprintf(gi->string, fmt, args);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100861 seq_printf(seq, gi->string);
862 } else {
863 printk(KERN_ERR " ");
Robert Peterson7c52b162007-03-16 10:26:37 +0000864 vprintk(fmt, args);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100865 }
Robert Peterson7c52b162007-03-16 10:26:37 +0000866 va_end(args);
867}
868
David Teiglandb3b94fa2006-01-16 16:50:04 +0000869/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000870 * add_to_queue - Add a holder to the wait queue (but look for recursion)
871 * @gh: the holder structure to add
872 *
Steven Whitehouse6802e342008-05-21 17:03:22 +0100873 * Eventually we should move the recursive locking trap to a
874 * debugging option or something like that. This is the fast
875 * path and needs to have the minimum number of distractions.
876 *
David Teiglandb3b94fa2006-01-16 16:50:04 +0000877 */
878
Steven Whitehouse6802e342008-05-21 17:03:22 +0100879static inline void add_to_queue(struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000880{
881 struct gfs2_glock *gl = gh->gh_gl;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100882 struct gfs2_sbd *sdp = gl->gl_sbd;
883 struct list_head *insert_pt = NULL;
884 struct gfs2_holder *gh2;
885 int try_lock = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000886
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800887 BUG_ON(gh->gh_owner_pid == NULL);
Steven Whitehousefee852e2007-01-17 15:33:23 +0000888 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
889 BUG();
Steven Whitehouse190562b2006-04-20 16:57:23 -0400890
Steven Whitehouse6802e342008-05-21 17:03:22 +0100891 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
892 if (test_bit(GLF_LOCK, &gl->gl_flags))
893 try_lock = 1;
894 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
895 goto fail;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000896 }
897
Steven Whitehouse6802e342008-05-21 17:03:22 +0100898 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
899 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
900 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
901 goto trap_recursive;
902 if (try_lock &&
903 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
904 !may_grant(gl, gh)) {
905fail:
906 gh->gh_error = GLR_TRYFAILED;
907 gfs2_holder_wake(gh);
908 return;
909 }
910 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
911 continue;
912 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
913 insert_pt = &gh2->gh_list;
914 }
915 if (likely(insert_pt == NULL)) {
916 list_add_tail(&gh->gh_list, &gl->gl_holders);
917 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
918 goto do_cancel;
919 return;
920 }
921 list_add_tail(&gh->gh_list, insert_pt);
922do_cancel:
923 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
924 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
925 spin_unlock(&gl->gl_spin);
Steven Whitehouse048bca22008-05-23 14:46:04 +0100926 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
927 sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100928 spin_lock(&gl->gl_spin);
929 }
930 return;
931
932trap_recursive:
933 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
934 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
935 printk(KERN_ERR "lock type: %d req lock state : %d\n",
936 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
937 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
938 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
939 printk(KERN_ERR "lock type: %d req lock state : %d\n",
940 gh->gh_gl->gl_name.ln_type, gh->gh_state);
941 __dump_glock(NULL, gl);
942 BUG();
David Teiglandb3b94fa2006-01-16 16:50:04 +0000943}
944
945/**
946 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
947 * @gh: the holder structure
948 *
949 * if (gh->gh_flags & GL_ASYNC), this never returns an error
950 *
951 * Returns: 0, GLR_TRYFAILED, or errno on failure
952 */
953
954int gfs2_glock_nq(struct gfs2_holder *gh)
955{
956 struct gfs2_glock *gl = gh->gh_gl;
957 struct gfs2_sbd *sdp = gl->gl_sbd;
958 int error = 0;
959
Steven Whitehouse6802e342008-05-21 17:03:22 +0100960 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
David Teiglandb3b94fa2006-01-16 16:50:04 +0000961 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000962
David Teiglandb3b94fa2006-01-16 16:50:04 +0000963 spin_lock(&gl->gl_spin);
964 add_to_queue(gh);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100965 run_queue(gl, 1);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000966 spin_unlock(&gl->gl_spin);
967
Steven Whitehouse6802e342008-05-21 17:03:22 +0100968 if (!(gh->gh_flags & GL_ASYNC))
969 error = gfs2_glock_wait(gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000970
David Teiglandb3b94fa2006-01-16 16:50:04 +0000971 return error;
972}
973
974/**
975 * gfs2_glock_poll - poll to see if an async request has been completed
976 * @gh: the holder
977 *
978 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
979 */
980
981int gfs2_glock_poll(struct gfs2_holder *gh)
982{
Steven Whitehouse6802e342008-05-21 17:03:22 +0100983 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000984}
985
986/**
987 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
988 * @gh: the glock holder
989 *
990 */
991
992void gfs2_glock_dq(struct gfs2_holder *gh)
993{
994 struct gfs2_glock *gl = gh->gh_gl;
Steven Whitehouse8fb4b532006-08-30 09:30:00 -0400995 const struct gfs2_glock_operations *glops = gl->gl_ops;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500996 unsigned delay = 0;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100997 int fast_path = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000998
Steven Whitehouse6802e342008-05-21 17:03:22 +0100999 spin_lock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001000 if (gh->gh_flags & GL_NOCACHE)
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001001 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001002
David Teiglandb3b94fa2006-01-16 16:50:04 +00001003 list_del_init(&gh->gh_list);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001004 if (find_first_holder(gl) == NULL) {
Steven Whitehouse3042a2c2007-11-02 08:39:34 +00001005 if (glops->go_unlock) {
Steven Whitehouse6802e342008-05-21 17:03:22 +01001006 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
Steven Whitehouse3042a2c2007-11-02 08:39:34 +00001007 spin_unlock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001008 glops->go_unlock(gh);
Steven Whitehouse3042a2c2007-11-02 08:39:34 +00001009 spin_lock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001010 clear_bit(GLF_LOCK, &gl->gl_flags);
Steven Whitehouse3042a2c2007-11-02 08:39:34 +00001011 }
Steven Whitehouse3b8249f2007-03-16 09:40:31 +00001012 gl->gl_stamp = jiffies;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001013 if (list_empty(&gl->gl_holders) &&
1014 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1015 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1016 fast_path = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001017 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001018 spin_unlock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001019 if (likely(fast_path))
1020 return;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001021
1022 gfs2_glock_hold(gl);
1023 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1024 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1025 delay = gl->gl_ops->go_min_hold_time;
1026 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1027 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001028}
1029
Abhijith Dasd93cfa92007-06-11 08:22:32 +01001030void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1031{
1032 struct gfs2_glock *gl = gh->gh_gl;
1033 gfs2_glock_dq(gh);
1034 wait_on_demote(gl);
1035}
1036
David Teiglandb3b94fa2006-01-16 16:50:04 +00001037/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001038 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1039 * @gh: the holder structure
1040 *
1041 */
1042
1043void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1044{
1045 gfs2_glock_dq(gh);
1046 gfs2_holder_uninit(gh);
1047}
1048
1049/**
1050 * gfs2_glock_nq_num - acquire a glock based on lock number
1051 * @sdp: the filesystem
1052 * @number: the lock number
1053 * @glops: the glock operations for the type of glock
1054 * @state: the state to acquire the glock in
1055 * @flags: modifier flags for the aquisition
1056 * @gh: the struct gfs2_holder
1057 *
1058 * Returns: errno
1059 */
1060
Steven Whitehousecd915492006-09-04 12:49:07 -04001061int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
Steven Whitehouse8fb4b532006-08-30 09:30:00 -04001062 const struct gfs2_glock_operations *glops,
1063 unsigned int state, int flags, struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001064{
1065 struct gfs2_glock *gl;
1066 int error;
1067
1068 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1069 if (!error) {
1070 error = gfs2_glock_nq_init(gl, state, flags, gh);
1071 gfs2_glock_put(gl);
1072 }
1073
1074 return error;
1075}
1076
1077/**
1078 * glock_compare - Compare two struct gfs2_glock structures for sorting
1079 * @arg_a: the first structure
1080 * @arg_b: the second structure
1081 *
1082 */
1083
1084static int glock_compare(const void *arg_a, const void *arg_b)
1085{
Steven Whitehousea5e08a92006-09-09 17:07:05 -04001086 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1087 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1088 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1089 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001090
1091 if (a->ln_number > b->ln_number)
Steven Whitehousea5e08a92006-09-09 17:07:05 -04001092 return 1;
1093 if (a->ln_number < b->ln_number)
1094 return -1;
Steven Whitehouse1c0f4872007-01-22 12:10:39 -05001095 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
Steven Whitehousea5e08a92006-09-09 17:07:05 -04001096 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001097}
1098
1099/**
1100 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1101 * @num_gh: the number of structures
1102 * @ghs: an array of struct gfs2_holder structures
1103 *
1104 * Returns: 0 on success (all glocks acquired),
1105 * errno on failure (no glocks acquired)
1106 */
1107
1108static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1109 struct gfs2_holder **p)
1110{
1111 unsigned int x;
1112 int error = 0;
1113
1114 for (x = 0; x < num_gh; x++)
1115 p[x] = &ghs[x];
1116
1117 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1118
1119 for (x = 0; x < num_gh; x++) {
1120 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1121
1122 error = gfs2_glock_nq(p[x]);
1123 if (error) {
1124 while (x--)
1125 gfs2_glock_dq(p[x]);
1126 break;
1127 }
1128 }
1129
1130 return error;
1131}
1132
1133/**
1134 * gfs2_glock_nq_m - acquire multiple glocks
1135 * @num_gh: the number of structures
1136 * @ghs: an array of struct gfs2_holder structures
1137 *
David Teiglandb3b94fa2006-01-16 16:50:04 +00001138 *
1139 * Returns: 0 on success (all glocks acquired),
1140 * errno on failure (no glocks acquired)
1141 */
1142
1143int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1144{
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001145 struct gfs2_holder *tmp[4];
1146 struct gfs2_holder **pph = tmp;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001147 int error = 0;
1148
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001149 switch(num_gh) {
1150 case 0:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001151 return 0;
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001152 case 1:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001153 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1154 return gfs2_glock_nq(ghs);
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001155 default:
1156 if (num_gh <= 4)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001157 break;
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001158 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1159 if (!pph)
1160 return -ENOMEM;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001161 }
1162
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001163 error = nq_m_sync(num_gh, ghs, pph);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001164
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001165 if (pph != tmp)
1166 kfree(pph);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001167
1168 return error;
1169}
1170
1171/**
1172 * gfs2_glock_dq_m - release multiple glocks
1173 * @num_gh: the number of structures
1174 * @ghs: an array of struct gfs2_holder structures
1175 *
1176 */
1177
1178void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1179{
1180 unsigned int x;
1181
1182 for (x = 0; x < num_gh; x++)
1183 gfs2_glock_dq(&ghs[x]);
1184}
1185
1186/**
1187 * gfs2_glock_dq_uninit_m - release multiple glocks
1188 * @num_gh: the number of structures
1189 * @ghs: an array of struct gfs2_holder structures
1190 *
1191 */
1192
1193void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1194{
1195 unsigned int x;
1196
1197 for (x = 0; x < num_gh; x++)
1198 gfs2_glock_dq_uninit(&ghs[x]);
1199}
1200
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001201static int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, void *lock, char **lvbp)
1202{
1203 int error = -EIO;
Steven Whitehouse048bca22008-05-23 14:46:04 +01001204 if (!sdp->sd_lockstruct.ls_ops->lm_hold_lvb)
1205 return 0;
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001206 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1207 error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp);
1208 return error;
1209}
1210
David Teiglandb3b94fa2006-01-16 16:50:04 +00001211/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001212 * gfs2_lvb_hold - attach a LVB from a glock
1213 * @gl: The glock in question
1214 *
1215 */
1216
1217int gfs2_lvb_hold(struct gfs2_glock *gl)
1218{
1219 int error;
1220
David Teiglandb3b94fa2006-01-16 16:50:04 +00001221 if (!atomic_read(&gl->gl_lvb_count)) {
1222 error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001223 if (error)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001224 return error;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001225 gfs2_glock_hold(gl);
1226 }
1227 atomic_inc(&gl->gl_lvb_count);
1228
David Teiglandb3b94fa2006-01-16 16:50:04 +00001229 return 0;
1230}
1231
1232/**
1233 * gfs2_lvb_unhold - detach a LVB from a glock
1234 * @gl: The glock in question
1235 *
1236 */
1237
1238void gfs2_lvb_unhold(struct gfs2_glock *gl)
1239{
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001240 struct gfs2_sbd *sdp = gl->gl_sbd;
1241
David Teiglandb3b94fa2006-01-16 16:50:04 +00001242 gfs2_glock_hold(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001243 gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
1244 if (atomic_dec_and_test(&gl->gl_lvb_count)) {
Steven Whitehouse048bca22008-05-23 14:46:04 +01001245 if (sdp->sd_lockstruct.ls_ops->lm_unhold_lvb)
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001246 sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(gl->gl_lock, gl->gl_lvb);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001247 gl->gl_lvb = NULL;
1248 gfs2_glock_put(gl);
1249 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001250 gfs2_glock_put(gl);
1251}
1252
David Teiglandb3b94fa2006-01-16 16:50:04 +00001253static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
1254 unsigned int state)
1255{
1256 struct gfs2_glock *gl;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001257 unsigned long delay = 0;
1258 unsigned long holdtime;
1259 unsigned long now = jiffies;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001260
1261 gl = gfs2_glock_find(sdp, name);
1262 if (!gl)
1263 return;
1264
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001265 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1266 if (time_before(now, holdtime))
1267 delay = holdtime - now;
Steven Whitehousedff52572008-09-02 13:33:17 +01001268 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1269 delay = gl->gl_ops->go_min_hold_time;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001270
Steven Whitehouse6802e342008-05-21 17:03:22 +01001271 spin_lock(&gl->gl_spin);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001272 handle_callback(gl, state, 1, delay);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001273 spin_unlock(&gl->gl_spin);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001274 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1275 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001276}
1277
1278/**
1279 * gfs2_glock_cb - Callback used by locking module
Steven Whitehouse1c089c32006-09-07 15:50:20 -04001280 * @sdp: Pointer to the superblock
David Teiglandb3b94fa2006-01-16 16:50:04 +00001281 * @type: Type of callback
1282 * @data: Type dependent data pointer
1283 *
1284 * Called by the locking module when it wants to tell us something.
1285 * Either we need to drop a lock, one of our ASYNC requests completed, or
1286 * a journal from another client needs to be recovered.
1287 */
1288
Steven Whitehouse9b47c112006-09-08 10:17:58 -04001289void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001290{
Steven Whitehouse9b47c112006-09-08 10:17:58 -04001291 struct gfs2_sbd *sdp = cb_data;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001292
David Teiglandb3b94fa2006-01-16 16:50:04 +00001293 switch (type) {
1294 case LM_CB_NEED_E:
David Teiglande7f5c012006-04-27 11:25:45 -04001295 blocking_cb(sdp, data, LM_ST_UNLOCKED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001296 return;
1297
1298 case LM_CB_NEED_D:
David Teiglande7f5c012006-04-27 11:25:45 -04001299 blocking_cb(sdp, data, LM_ST_DEFERRED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001300 return;
1301
1302 case LM_CB_NEED_S:
David Teiglande7f5c012006-04-27 11:25:45 -04001303 blocking_cb(sdp, data, LM_ST_SHARED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001304 return;
1305
1306 case LM_CB_ASYNC: {
David Teiglande7f5c012006-04-27 11:25:45 -04001307 struct lm_async_cb *async = data;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001308 struct gfs2_glock *gl;
1309
Steven Whitehouse61be0842007-01-29 11:51:45 +00001310 down_read(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001311 gl = gfs2_glock_find(sdp, &async->lc_name);
1312 if (gfs2_assert_warn(sdp, gl))
1313 return;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001314 gl->gl_reply = async->lc_ret;
1315 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001316 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1317 gfs2_glock_put(gl);
Steven Whitehouse61be0842007-01-29 11:51:45 +00001318 up_read(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001319 return;
1320 }
1321
1322 case LM_CB_NEED_RECOVERY:
1323 gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
1324 if (sdp->sd_recoverd_process)
1325 wake_up_process(sdp->sd_recoverd_process);
1326 return;
1327
David Teiglandb3b94fa2006-01-16 16:50:04 +00001328 default:
1329 gfs2_assert_warn(sdp, 0);
1330 return;
1331 }
1332}
1333
1334/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001335 * demote_ok - Check to see if it's ok to unlock a glock
1336 * @gl: the glock
1337 *
1338 * Returns: 1 if it's ok
1339 */
1340
1341static int demote_ok(struct gfs2_glock *gl)
1342{
Steven Whitehouse8fb4b532006-08-30 09:30:00 -04001343 const struct gfs2_glock_operations *glops = gl->gl_ops;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001344 int demote = 1;
1345
1346 if (test_bit(GLF_STICKY, &gl->gl_flags))
1347 demote = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001348 else if (glops->go_demote_ok)
1349 demote = glops->go_demote_ok(gl);
1350
1351 return demote;
1352}
1353
1354/**
1355 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1356 * @gl: the glock
1357 *
1358 */
1359
1360void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
1361{
1362 struct gfs2_sbd *sdp = gl->gl_sbd;
1363
1364 spin_lock(&sdp->sd_reclaim_lock);
1365 if (list_empty(&gl->gl_reclaim)) {
1366 gfs2_glock_hold(gl);
1367 list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
1368 atomic_inc(&sdp->sd_reclaim_count);
Bob Petersonef8c4412008-01-28 14:54:16 -06001369 spin_unlock(&sdp->sd_reclaim_lock);
1370 wake_up(&sdp->sd_reclaim_wq);
1371 } else
1372 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001373}
1374
1375/**
1376 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1377 * @sdp: the filesystem
1378 *
1379 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1380 * different glock and we notice that there are a lot of glocks in the
1381 * reclaim list.
1382 *
1383 */
1384
1385void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
1386{
1387 struct gfs2_glock *gl;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001388 int done_callback = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001389
1390 spin_lock(&sdp->sd_reclaim_lock);
1391 if (list_empty(&sdp->sd_reclaim_list)) {
1392 spin_unlock(&sdp->sd_reclaim_lock);
1393 return;
1394 }
1395 gl = list_entry(sdp->sd_reclaim_list.next,
1396 struct gfs2_glock, gl_reclaim);
1397 list_del_init(&gl->gl_reclaim);
1398 spin_unlock(&sdp->sd_reclaim_lock);
1399
1400 atomic_dec(&sdp->sd_reclaim_count);
1401 atomic_inc(&sdp->sd_reclaimed);
1402
Steven Whitehouse6802e342008-05-21 17:03:22 +01001403 spin_lock(&gl->gl_spin);
1404 if (find_first_holder(gl) == NULL &&
1405 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) {
1406 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1407 done_callback = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001408 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001409 spin_unlock(&gl->gl_spin);
1410 if (!done_callback ||
1411 queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1412 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001413}
1414
1415/**
1416 * examine_bucket - Call a function for glock in a hash bucket
1417 * @examiner: the function
1418 * @sdp: the filesystem
1419 * @bucket: the bucket
1420 *
1421 * Returns: 1 if the bucket has entries
1422 */
1423
1424static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
Steven Whitehouse37b2fa62006-09-08 13:35:56 -04001425 unsigned int hash)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001426{
Steven Whitehouse24264432006-09-11 21:40:30 -04001427 struct gfs2_glock *gl, *prev = NULL;
1428 int has_entries = 0;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001429 struct hlist_head *head = &gl_hash_table[hash].hb_list;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001430
Steven Whitehouse24264432006-09-11 21:40:30 -04001431 read_lock(gl_lock_addr(hash));
Steven Whitehouseb6397892006-09-12 10:10:01 -04001432 /* Can't use hlist_for_each_entry - don't want prefetch here */
1433 if (hlist_empty(head))
Steven Whitehouse24264432006-09-11 21:40:30 -04001434 goto out;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001435 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1436 while(1) {
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001437 if (!sdp || gl->gl_sbd == sdp) {
David Teiglandb3b94fa2006-01-16 16:50:04 +00001438 gfs2_glock_hold(gl);
Steven Whitehouse24264432006-09-11 21:40:30 -04001439 read_unlock(gl_lock_addr(hash));
1440 if (prev)
1441 gfs2_glock_put(prev);
1442 prev = gl;
1443 examiner(gl);
Steven Whitehousea8336342006-09-14 13:57:38 -04001444 has_entries = 1;
Steven Whitehouse24264432006-09-11 21:40:30 -04001445 read_lock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001446 }
Steven Whitehouseb6397892006-09-12 10:10:01 -04001447 if (gl->gl_list.next == NULL)
1448 break;
Steven Whitehouse24264432006-09-11 21:40:30 -04001449 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001450 }
Steven Whitehouse24264432006-09-11 21:40:30 -04001451out:
1452 read_unlock(gl_lock_addr(hash));
1453 if (prev)
1454 gfs2_glock_put(prev);
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001455 cond_resched();
Steven Whitehouse24264432006-09-11 21:40:30 -04001456 return has_entries;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001457}
1458
1459/**
1460 * scan_glock - look at a glock and see if we can reclaim it
1461 * @gl: the glock to look at
1462 *
1463 */
1464
1465static void scan_glock(struct gfs2_glock *gl)
1466{
Steven Whitehouseb0041572006-11-23 10:51:34 -05001467 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
Steven Whitehouse24264432006-09-11 21:40:30 -04001468 return;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001469 if (test_bit(GLF_LOCK, &gl->gl_flags))
1470 return;
Steven Whitehousea2242db2006-08-24 17:03:05 -04001471
Steven Whitehouse6802e342008-05-21 17:03:22 +01001472 spin_lock(&gl->gl_spin);
1473 if (find_first_holder(gl) == NULL &&
1474 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1475 gfs2_glock_schedule_for_reclaim(gl);
1476 spin_unlock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001477}
1478
1479/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001480 * clear_glock - look at a glock and see if we can free it from glock cache
1481 * @gl: the glock to look at
1482 *
1483 */
1484
1485static void clear_glock(struct gfs2_glock *gl)
1486{
1487 struct gfs2_sbd *sdp = gl->gl_sbd;
1488 int released;
1489
1490 spin_lock(&sdp->sd_reclaim_lock);
1491 if (!list_empty(&gl->gl_reclaim)) {
1492 list_del_init(&gl->gl_reclaim);
1493 atomic_dec(&sdp->sd_reclaim_count);
Steven Whitehouse190562b2006-04-20 16:57:23 -04001494 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001495 released = gfs2_glock_put(gl);
1496 gfs2_assert(sdp, !released);
Steven Whitehouse190562b2006-04-20 16:57:23 -04001497 } else {
1498 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001499 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001500
Steven Whitehouse6802e342008-05-21 17:03:22 +01001501 spin_lock(&gl->gl_spin);
1502 if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
1503 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1504 spin_unlock(&gl->gl_spin);
1505 gfs2_glock_hold(gl);
1506 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1507 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001508}
1509
1510/**
1511 * gfs2_gl_hash_clear - Empty out the glock hash table
1512 * @sdp: the filesystem
1513 * @wait: wait until it's all gone
1514 *
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001515 * Called when unmounting the filesystem.
David Teiglandb3b94fa2006-01-16 16:50:04 +00001516 */
1517
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001518void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001519{
1520 unsigned long t;
1521 unsigned int x;
1522 int cont;
1523
1524 t = jiffies;
1525
1526 for (;;) {
1527 cont = 0;
Steven Whitehouse24264432006-09-11 21:40:30 -04001528 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
Steven Whitehouse907b9bc2006-09-25 09:26:04 -04001529 if (examine_bucket(clear_glock, sdp, x))
David Teiglandb3b94fa2006-01-16 16:50:04 +00001530 cont = 1;
Steven Whitehouse24264432006-09-11 21:40:30 -04001531 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001532
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001533 if (!cont)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001534 break;
1535
1536 if (time_after_eq(jiffies,
1537 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1538 fs_warn(sdp, "Unmount seems to be stalled. "
1539 "Dumping lock state...\n");
1540 gfs2_dump_lockstate(sdp);
1541 t = jiffies;
1542 }
1543
Steven Whitehouse61be0842007-01-29 11:51:45 +00001544 down_write(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001545 invalidate_inodes(sdp->sd_vfs);
Steven Whitehouse61be0842007-01-29 11:51:45 +00001546 up_write(&gfs2_umount_flush_sem);
Steven Whitehousefd88de562006-05-05 16:59:11 -04001547 msleep(10);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001548 }
1549}
1550
Steven Whitehouse6802e342008-05-21 17:03:22 +01001551static const char *state2str(unsigned state)
Robert Peterson04b933f2007-03-23 17:05:15 -05001552{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001553 switch(state) {
1554 case LM_ST_UNLOCKED:
1555 return "UN";
1556 case LM_ST_SHARED:
1557 return "SH";
1558 case LM_ST_DEFERRED:
1559 return "DF";
1560 case LM_ST_EXCLUSIVE:
1561 return "EX";
1562 }
1563 return "??";
1564}
Robert Peterson04b933f2007-03-23 17:05:15 -05001565
Steven Whitehouse6802e342008-05-21 17:03:22 +01001566static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1567{
1568 char *p = buf;
1569 if (flags & LM_FLAG_TRY)
1570 *p++ = 't';
1571 if (flags & LM_FLAG_TRY_1CB)
1572 *p++ = 'T';
1573 if (flags & LM_FLAG_NOEXP)
1574 *p++ = 'e';
1575 if (flags & LM_FLAG_ANY)
1576 *p++ = 'a';
1577 if (flags & LM_FLAG_PRIORITY)
1578 *p++ = 'p';
1579 if (flags & GL_ASYNC)
1580 *p++ = 'a';
1581 if (flags & GL_EXACT)
1582 *p++ = 'E';
Steven Whitehouse6802e342008-05-21 17:03:22 +01001583 if (flags & GL_NOCACHE)
1584 *p++ = 'c';
1585 if (test_bit(HIF_HOLDER, &iflags))
1586 *p++ = 'H';
1587 if (test_bit(HIF_WAIT, &iflags))
1588 *p++ = 'W';
1589 if (test_bit(HIF_FIRST, &iflags))
1590 *p++ = 'F';
1591 *p = 0;
1592 return buf;
Robert Peterson04b933f2007-03-23 17:05:15 -05001593}
1594
David Teiglandb3b94fa2006-01-16 16:50:04 +00001595/**
1596 * dump_holder - print information about a glock holder
Steven Whitehouse6802e342008-05-21 17:03:22 +01001597 * @seq: the seq_file struct
David Teiglandb3b94fa2006-01-16 16:50:04 +00001598 * @gh: the glock holder
1599 *
1600 * Returns: 0 on success, -ENOBUFS when we run out of space
1601 */
1602
Steven Whitehouse6802e342008-05-21 17:03:22 +01001603static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001604{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001605 struct task_struct *gh_owner = NULL;
1606 char buffer[KSYM_SYMBOL_LEN];
1607 char flags_buf[32];
David Teiglandb3b94fa2006-01-16 16:50:04 +00001608
Steven Whitehouse6802e342008-05-21 17:03:22 +01001609 sprint_symbol(buffer, gh->gh_ip);
1610 if (gh->gh_owner_pid)
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -08001611 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001612 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1613 state2str(gh->gh_state),
1614 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1615 gh->gh_error,
1616 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1617 gh_owner ? gh_owner->comm : "(ended)", buffer);
Robert Peterson7c52b162007-03-16 10:26:37 +00001618 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001619}
1620
Steven Whitehouse6802e342008-05-21 17:03:22 +01001621static const char *gflags2str(char *buf, const unsigned long *gflags)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001622{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001623 char *p = buf;
1624 if (test_bit(GLF_LOCK, gflags))
1625 *p++ = 'l';
1626 if (test_bit(GLF_STICKY, gflags))
1627 *p++ = 's';
1628 if (test_bit(GLF_DEMOTE, gflags))
1629 *p++ = 'D';
1630 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1631 *p++ = 'd';
1632 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1633 *p++ = 'p';
1634 if (test_bit(GLF_DIRTY, gflags))
1635 *p++ = 'y';
1636 if (test_bit(GLF_LFLUSH, gflags))
1637 *p++ = 'f';
1638 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1639 *p++ = 'i';
1640 if (test_bit(GLF_REPLY_PENDING, gflags))
1641 *p++ = 'r';
1642 *p = 0;
1643 return buf;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001644}
1645
1646/**
Steven Whitehouse6802e342008-05-21 17:03:22 +01001647 * __dump_glock - print information about a glock
1648 * @seq: The seq_file struct
David Teiglandb3b94fa2006-01-16 16:50:04 +00001649 * @gl: the glock
Steven Whitehouse6802e342008-05-21 17:03:22 +01001650 *
1651 * The file format is as follows:
1652 * One line per object, capital letters are used to indicate objects
1653 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1654 * other objects are indented by a single space and follow the glock to
1655 * which they are related. Fields are indicated by lower case letters
1656 * followed by a colon and the field value, except for strings which are in
1657 * [] so that its possible to see if they are composed of spaces for
1658 * example. The field's are n = number (id of the object), f = flags,
1659 * t = type, s = state, r = refcount, e = error, p = pid.
David Teiglandb3b94fa2006-01-16 16:50:04 +00001660 *
1661 * Returns: 0 on success, -ENOBUFS when we run out of space
1662 */
1663
Steven Whitehouse6802e342008-05-21 17:03:22 +01001664static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001665{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001666 const struct gfs2_glock_operations *glops = gl->gl_ops;
1667 unsigned long long dtime;
1668 const struct gfs2_holder *gh;
1669 char gflags_buf[32];
1670 int error = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001671
Steven Whitehouse6802e342008-05-21 17:03:22 +01001672 dtime = jiffies - gl->gl_demote_time;
1673 dtime *= 1000000/HZ; /* demote time in uSec */
1674 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1675 dtime = 0;
1676 gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n",
1677 state2str(gl->gl_state),
1678 gl->gl_name.ln_type,
1679 (unsigned long long)gl->gl_name.ln_number,
1680 gflags2str(gflags_buf, &gl->gl_flags),
1681 state2str(gl->gl_target),
1682 state2str(gl->gl_demote_state), dtime,
1683 atomic_read(&gl->gl_lvb_count),
1684 atomic_read(&gl->gl_ail_count),
1685 atomic_read(&gl->gl_ref));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001686
David Teiglandb3b94fa2006-01-16 16:50:04 +00001687 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
Steven Whitehouse6802e342008-05-21 17:03:22 +01001688 error = dump_holder(seq, gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001689 if (error)
1690 goto out;
1691 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001692 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1693 error = glops->go_dump(seq, gl);
Steven Whitehousea91ea692006-09-04 12:04:26 -04001694out:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001695 return error;
1696}
1697
Steven Whitehouse6802e342008-05-21 17:03:22 +01001698static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1699{
1700 int ret;
1701 spin_lock(&gl->gl_spin);
1702 ret = __dump_glock(seq, gl);
1703 spin_unlock(&gl->gl_spin);
1704 return ret;
1705}
1706
David Teiglandb3b94fa2006-01-16 16:50:04 +00001707/**
1708 * gfs2_dump_lockstate - print out the current lockstate
1709 * @sdp: the filesystem
1710 * @ub: the buffer to copy the information into
1711 *
1712 * If @ub is NULL, dump the lockstate to the console.
1713 *
1714 */
1715
Adrian Bunk08bc2db2006-04-28 10:59:12 -04001716static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001717{
David Teiglandb3b94fa2006-01-16 16:50:04 +00001718 struct gfs2_glock *gl;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001719 struct hlist_node *h;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001720 unsigned int x;
1721 int error = 0;
1722
1723 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
David Teiglandb3b94fa2006-01-16 16:50:04 +00001724
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001725 read_lock(gl_lock_addr(x));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001726
Steven Whitehouseb6397892006-09-12 10:10:01 -04001727 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001728 if (gl->gl_sbd != sdp)
1729 continue;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001730
Robert Peterson7c52b162007-03-16 10:26:37 +00001731 error = dump_glock(NULL, gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001732 if (error)
1733 break;
1734 }
1735
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001736 read_unlock(gl_lock_addr(x));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001737
1738 if (error)
1739 break;
1740 }
1741
1742
1743 return error;
1744}
1745
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001746/**
1747 * gfs2_scand - Look for cached glocks and inodes to toss from memory
1748 * @sdp: Pointer to GFS2 superblock
1749 *
1750 * One of these daemons runs, finding candidates to add to sd_reclaim_list.
1751 * See gfs2_glockd()
1752 */
1753
1754static int gfs2_scand(void *data)
1755{
1756 unsigned x;
1757 unsigned delay;
1758
1759 while (!kthread_should_stop()) {
1760 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1761 examine_bucket(scan_glock, NULL, x);
1762 if (freezing(current))
1763 refrigerator();
1764 delay = scand_secs;
1765 if (delay < 1)
1766 delay = 1;
1767 schedule_timeout_interruptible(delay * HZ);
1768 }
1769
1770 return 0;
1771}
1772
1773
1774
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001775int __init gfs2_glock_init(void)
1776{
1777 unsigned i;
1778 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
Steven Whitehouseb6397892006-09-12 10:10:01 -04001779 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001780 }
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001781#ifdef GL_HASH_LOCK_SZ
1782 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1783 rwlock_init(&gl_hash_locks[i]);
1784 }
1785#endif
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001786
1787 scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand");
1788 if (IS_ERR(scand_process))
1789 return PTR_ERR(scand_process);
1790
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001791 glock_workqueue = create_workqueue("glock_workqueue");
1792 if (IS_ERR(glock_workqueue)) {
1793 kthread_stop(scand_process);
1794 return PTR_ERR(glock_workqueue);
1795 }
1796
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001797 return 0;
1798}
1799
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001800void gfs2_glock_exit(void)
1801{
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001802 destroy_workqueue(glock_workqueue);
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001803 kthread_stop(scand_process);
1804}
1805
1806module_param(scand_secs, uint, S_IRUGO|S_IWUSR);
1807MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs");
1808
Steven Whitehouse6802e342008-05-21 17:03:22 +01001809static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
Robert Peterson7c52b162007-03-16 10:26:37 +00001810{
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001811 struct gfs2_glock *gl;
1812
Abhijith Dasa947e032007-08-21 09:57:29 -05001813restart:
Robert Peterson7a0079d2007-04-17 11:37:11 -05001814 read_lock(gl_lock_addr(gi->hash));
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001815 gl = gi->gl;
1816 if (gl) {
Abhijith Dasa947e032007-08-21 09:57:29 -05001817 gi->gl = hlist_entry(gl->gl_list.next,
1818 struct gfs2_glock, gl_list);
Steven Whitehousec1e817d2008-07-22 22:58:03 +01001819 } else {
1820 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1821 struct gfs2_glock, gl_list);
Robert Peterson7c52b162007-03-16 10:26:37 +00001822 }
Steven Whitehousec1e817d2008-07-22 22:58:03 +01001823 if (gi->gl)
1824 gfs2_glock_hold(gi->gl);
Robert Peterson7a0079d2007-04-17 11:37:11 -05001825 read_unlock(gl_lock_addr(gi->hash));
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001826 if (gl)
1827 gfs2_glock_put(gl);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001828 while (gi->gl == NULL) {
Steven Whitehousec1e817d2008-07-22 22:58:03 +01001829 gi->hash++;
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001830 if (gi->hash >= GFS2_GL_HASH_SIZE)
1831 return 1;
1832 read_lock(gl_lock_addr(gi->hash));
1833 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1834 struct gfs2_glock, gl_list);
1835 if (gi->gl)
1836 gfs2_glock_hold(gi->gl);
1837 read_unlock(gl_lock_addr(gi->hash));
1838 }
Abhijith Dasa947e032007-08-21 09:57:29 -05001839
1840 if (gi->sdp != gi->gl->gl_sbd)
1841 goto restart;
1842
Robert Peterson7c52b162007-03-16 10:26:37 +00001843 return 0;
1844}
1845
Steven Whitehouse6802e342008-05-21 17:03:22 +01001846static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
Robert Peterson7c52b162007-03-16 10:26:37 +00001847{
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001848 if (gi->gl)
1849 gfs2_glock_put(gi->gl);
Abhijith Dasa947e032007-08-21 09:57:29 -05001850 gi->gl = NULL;
Robert Peterson7c52b162007-03-16 10:26:37 +00001851}
1852
Steven Whitehouse6802e342008-05-21 17:03:22 +01001853static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
Robert Peterson7c52b162007-03-16 10:26:37 +00001854{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001855 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +00001856 loff_t n = *pos;
1857
Steven Whitehouse6802e342008-05-21 17:03:22 +01001858 gi->hash = 0;
Robert Peterson7c52b162007-03-16 10:26:37 +00001859
Steven Whitehouse6802e342008-05-21 17:03:22 +01001860 do {
Robert Peterson7c52b162007-03-16 10:26:37 +00001861 if (gfs2_glock_iter_next(gi)) {
1862 gfs2_glock_iter_free(gi);
1863 return NULL;
1864 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001865 } while (n--);
Robert Peterson7c52b162007-03-16 10:26:37 +00001866
Steven Whitehouse6802e342008-05-21 17:03:22 +01001867 return gi->gl;
Robert Peterson7c52b162007-03-16 10:26:37 +00001868}
1869
Steven Whitehouse6802e342008-05-21 17:03:22 +01001870static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
Robert Peterson7c52b162007-03-16 10:26:37 +00001871 loff_t *pos)
1872{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001873 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +00001874
1875 (*pos)++;
1876
1877 if (gfs2_glock_iter_next(gi)) {
1878 gfs2_glock_iter_free(gi);
1879 return NULL;
1880 }
1881
Steven Whitehouse6802e342008-05-21 17:03:22 +01001882 return gi->gl;
Robert Peterson7c52b162007-03-16 10:26:37 +00001883}
1884
Steven Whitehouse6802e342008-05-21 17:03:22 +01001885static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
Robert Peterson7c52b162007-03-16 10:26:37 +00001886{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001887 struct gfs2_glock_iter *gi = seq->private;
1888 gfs2_glock_iter_free(gi);
Robert Peterson7c52b162007-03-16 10:26:37 +00001889}
1890
Steven Whitehouse6802e342008-05-21 17:03:22 +01001891static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
Robert Peterson7c52b162007-03-16 10:26:37 +00001892{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001893 return dump_glock(seq, iter_ptr);
Robert Peterson7c52b162007-03-16 10:26:37 +00001894}
1895
Denis Cheng4ef29002007-07-31 18:31:11 +08001896static const struct seq_operations gfs2_glock_seq_ops = {
Robert Peterson7c52b162007-03-16 10:26:37 +00001897 .start = gfs2_glock_seq_start,
1898 .next = gfs2_glock_seq_next,
1899 .stop = gfs2_glock_seq_stop,
1900 .show = gfs2_glock_seq_show,
1901};
1902
1903static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1904{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001905 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1906 sizeof(struct gfs2_glock_iter));
1907 if (ret == 0) {
1908 struct seq_file *seq = file->private_data;
1909 struct gfs2_glock_iter *gi = seq->private;
1910 gi->sdp = inode->i_private;
1911 }
1912 return ret;
Robert Peterson7c52b162007-03-16 10:26:37 +00001913}
1914
1915static const struct file_operations gfs2_debug_fops = {
1916 .owner = THIS_MODULE,
1917 .open = gfs2_debugfs_open,
1918 .read = seq_read,
1919 .llseek = seq_lseek,
Steven Whitehouse6802e342008-05-21 17:03:22 +01001920 .release = seq_release_private,
Robert Peterson7c52b162007-03-16 10:26:37 +00001921};
1922
1923int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1924{
Robert Peterson5f882092007-04-18 11:41:11 -05001925 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1926 if (!sdp->debugfs_dir)
1927 return -ENOMEM;
1928 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1929 S_IFREG | S_IRUGO,
1930 sdp->debugfs_dir, sdp,
1931 &gfs2_debug_fops);
1932 if (!sdp->debugfs_dentry_glocks)
Robert Peterson7c52b162007-03-16 10:26:37 +00001933 return -ENOMEM;
1934
1935 return 0;
1936}
1937
1938void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1939{
Robert Peterson5f882092007-04-18 11:41:11 -05001940 if (sdp && sdp->debugfs_dir) {
1941 if (sdp->debugfs_dentry_glocks) {
1942 debugfs_remove(sdp->debugfs_dentry_glocks);
1943 sdp->debugfs_dentry_glocks = NULL;
1944 }
1945 debugfs_remove(sdp->debugfs_dir);
1946 sdp->debugfs_dir = NULL;
1947 }
Robert Peterson7c52b162007-03-16 10:26:37 +00001948}
1949
1950int gfs2_register_debugfs(void)
1951{
1952 gfs2_root = debugfs_create_dir("gfs2", NULL);
1953 return gfs2_root ? 0 : -ENOMEM;
1954}
1955
1956void gfs2_unregister_debugfs(void)
1957{
1958 debugfs_remove(gfs2_root);
Robert Peterson5f882092007-04-18 11:41:11 -05001959 gfs2_root = NULL;
Robert Peterson7c52b162007-03-16 10:26:37 +00001960}