blob: 27cb9cca9c086a7cca70eede9c52d482ef2ffc85 [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)
Harvey Harrison55ba4742008-10-24 11:31:12 -0700296__releases(&gl->gl_spin)
297__acquires(&gl->gl_spin)
Steven Whitehouse6802e342008-05-21 17:03:22 +0100298{
299 const struct gfs2_glock_operations *glops = gl->gl_ops;
300 struct gfs2_holder *gh, *tmp;
301 int ret;
302
303restart:
304 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
305 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
306 continue;
307 if (may_grant(gl, gh)) {
308 if (gh->gh_list.prev == &gl->gl_holders &&
309 glops->go_lock) {
310 spin_unlock(&gl->gl_spin);
311 /* FIXME: eliminate this eventually */
312 ret = glops->go_lock(gh);
313 spin_lock(&gl->gl_spin);
314 if (ret) {
315 gh->gh_error = ret;
316 list_del_init(&gh->gh_list);
317 gfs2_holder_wake(gh);
318 goto restart;
319 }
320 set_bit(HIF_HOLDER, &gh->gh_iflags);
321 gfs2_holder_wake(gh);
322 goto restart;
323 }
324 set_bit(HIF_HOLDER, &gh->gh_iflags);
325 gfs2_holder_wake(gh);
326 continue;
327 }
328 if (gh->gh_list.prev == &gl->gl_holders)
329 return 1;
330 break;
331 }
332 return 0;
333}
334
335/**
336 * do_error - Something unexpected has happened during a lock request
337 *
338 */
339
340static inline void do_error(struct gfs2_glock *gl, const int ret)
341{
342 struct gfs2_holder *gh, *tmp;
343
344 list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
345 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
346 continue;
347 if (ret & LM_OUT_ERROR)
348 gh->gh_error = -EIO;
349 else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))
350 gh->gh_error = GLR_TRYFAILED;
351 else
352 continue;
353 list_del_init(&gh->gh_list);
354 gfs2_holder_wake(gh);
355 }
356}
357
358/**
359 * find_first_waiter - find the first gh that's waiting for the glock
360 * @gl: the glock
361 */
362
363static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl)
364{
365 struct gfs2_holder *gh;
366
367 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
368 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
369 return gh;
370 }
371 return NULL;
372}
373
374/**
375 * state_change - record that the glock is now in a different state
376 * @gl: the glock
377 * @new_state the new state
378 *
379 */
380
381static void state_change(struct gfs2_glock *gl, unsigned int new_state)
382{
383 int held1, held2;
384
385 held1 = (gl->gl_state != LM_ST_UNLOCKED);
386 held2 = (new_state != LM_ST_UNLOCKED);
387
388 if (held1 != held2) {
389 if (held2)
390 gfs2_glock_hold(gl);
391 else
392 gfs2_glock_put(gl);
393 }
394
395 gl->gl_state = new_state;
396 gl->gl_tchange = jiffies;
397}
398
399static void gfs2_demote_wake(struct gfs2_glock *gl)
400{
401 gl->gl_demote_state = LM_ST_EXCLUSIVE;
402 clear_bit(GLF_DEMOTE, &gl->gl_flags);
403 smp_mb__after_clear_bit();
404 wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
405}
406
407/**
408 * finish_xmote - The DLM has replied to one of our lock requests
409 * @gl: The glock
410 * @ret: The status from the DLM
411 *
412 */
413
414static void finish_xmote(struct gfs2_glock *gl, unsigned int ret)
415{
416 const struct gfs2_glock_operations *glops = gl->gl_ops;
417 struct gfs2_holder *gh;
418 unsigned state = ret & LM_OUT_ST_MASK;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500419
420 spin_lock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100421 state_change(gl, state);
422 gh = find_first_waiter(gl);
423
424 /* Demote to UN request arrived during demote to SH or DF */
425 if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) &&
426 state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED)
427 gl->gl_target = LM_ST_UNLOCKED;
428
429 /* Check for state != intended state */
430 if (unlikely(state != gl->gl_target)) {
431 if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) {
432 /* move to back of queue and try next entry */
433 if (ret & LM_OUT_CANCELED) {
434 if ((gh->gh_flags & LM_FLAG_PRIORITY) == 0)
435 list_move_tail(&gh->gh_list, &gl->gl_holders);
436 gh = find_first_waiter(gl);
437 gl->gl_target = gh->gh_state;
438 goto retry;
439 }
440 /* Some error or failed "try lock" - report it */
441 if ((ret & LM_OUT_ERROR) ||
442 (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) {
443 gl->gl_target = gl->gl_state;
444 do_error(gl, ret);
445 goto out;
446 }
447 }
448 switch(state) {
449 /* Unlocked due to conversion deadlock, try again */
450 case LM_ST_UNLOCKED:
451retry:
452 do_xmote(gl, gh, gl->gl_target);
453 break;
454 /* Conversion fails, unlock and try again */
455 case LM_ST_SHARED:
456 case LM_ST_DEFERRED:
457 do_xmote(gl, gh, LM_ST_UNLOCKED);
458 break;
459 default: /* Everything else */
460 printk(KERN_ERR "GFS2: wanted %u got %u\n", gl->gl_target, state);
461 GLOCK_BUG_ON(gl, 1);
462 }
463 spin_unlock(&gl->gl_spin);
464 gfs2_glock_put(gl);
465 return;
466 }
467
468 /* Fast path - we got what we asked for */
469 if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags))
470 gfs2_demote_wake(gl);
471 if (state != LM_ST_UNLOCKED) {
472 if (glops->go_xmote_bh) {
473 int rv;
474 spin_unlock(&gl->gl_spin);
475 rv = glops->go_xmote_bh(gl, gh);
476 if (rv == -EAGAIN)
477 return;
478 spin_lock(&gl->gl_spin);
479 if (rv) {
480 do_error(gl, rv);
481 goto out;
482 }
483 }
484 do_promote(gl);
485 }
486out:
487 clear_bit(GLF_LOCK, &gl->gl_flags);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500488 spin_unlock(&gl->gl_spin);
489 gfs2_glock_put(gl);
490}
491
Steven Whitehouse6802e342008-05-21 17:03:22 +0100492static unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, void *lock,
493 unsigned int cur_state, unsigned int req_state,
494 unsigned int flags)
495{
496 int ret = LM_OUT_ERROR;
Steven Whitehouse048bca22008-05-23 14:46:04 +0100497
498 if (!sdp->sd_lockstruct.ls_ops->lm_lock)
499 return req_state == LM_ST_UNLOCKED ? 0 : req_state;
500
Steven Whitehouse6802e342008-05-21 17:03:22 +0100501 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
502 ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state,
503 req_state, flags);
504 return ret;
505}
506
507/**
508 * do_xmote - Calls the DLM to change the state of a lock
509 * @gl: The lock state
510 * @gh: The holder (only for promotes)
511 * @target: The target lock state
512 *
513 */
514
515static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
Harvey Harrison55ba4742008-10-24 11:31:12 -0700516__releases(&gl->gl_spin)
517__acquires(&gl->gl_spin)
Steven Whitehouse6802e342008-05-21 17:03:22 +0100518{
519 const struct gfs2_glock_operations *glops = gl->gl_ops;
520 struct gfs2_sbd *sdp = gl->gl_sbd;
521 unsigned int lck_flags = gh ? gh->gh_flags : 0;
522 int ret;
523
524 lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
525 LM_FLAG_PRIORITY);
526 BUG_ON(gl->gl_state == target);
527 BUG_ON(gl->gl_state == gl->gl_target);
528 if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) &&
529 glops->go_inval) {
530 set_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
531 do_error(gl, 0); /* Fail queued try locks */
532 }
533 spin_unlock(&gl->gl_spin);
534 if (glops->go_xmote_th)
535 glops->go_xmote_th(gl);
536 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
537 glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA);
538 clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags);
539
540 gfs2_glock_hold(gl);
541 if (target != LM_ST_UNLOCKED && (gl->gl_state == LM_ST_SHARED ||
542 gl->gl_state == LM_ST_DEFERRED) &&
543 !(lck_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
544 lck_flags |= LM_FLAG_TRY_1CB;
545 ret = gfs2_lm_lock(sdp, gl->gl_lock, gl->gl_state, target, lck_flags);
546
547 if (!(ret & LM_OUT_ASYNC)) {
548 finish_xmote(gl, ret);
549 gfs2_glock_hold(gl);
550 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
551 gfs2_glock_put(gl);
552 } else {
553 GLOCK_BUG_ON(gl, ret != LM_OUT_ASYNC);
554 }
555 spin_lock(&gl->gl_spin);
556}
557
558/**
559 * find_first_holder - find the first "holder" gh
560 * @gl: the glock
561 */
562
563static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl)
564{
565 struct gfs2_holder *gh;
566
567 if (!list_empty(&gl->gl_holders)) {
568 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
569 if (test_bit(HIF_HOLDER, &gh->gh_iflags))
570 return gh;
571 }
572 return NULL;
573}
574
575/**
576 * run_queue - do all outstanding tasks related to a glock
577 * @gl: The glock in question
578 * @nonblock: True if we must not block in run_queue
579 *
580 */
581
582static void run_queue(struct gfs2_glock *gl, const int nonblock)
Harvey Harrison55ba4742008-10-24 11:31:12 -0700583__releases(&gl->gl_spin)
584__acquires(&gl->gl_spin)
Steven Whitehouse6802e342008-05-21 17:03:22 +0100585{
586 struct gfs2_holder *gh = NULL;
587
588 if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
589 return;
590
591 GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags));
592
593 if (test_bit(GLF_DEMOTE, &gl->gl_flags) &&
594 gl->gl_demote_state != gl->gl_state) {
595 if (find_first_holder(gl))
596 goto out;
597 if (nonblock)
598 goto out_sched;
599 set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
Steven Whitehouse265d529c2008-07-07 10:02:36 +0100600 GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100601 gl->gl_target = gl->gl_demote_state;
602 } else {
603 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
604 gfs2_demote_wake(gl);
605 if (do_promote(gl) == 0)
606 goto out;
607 gh = find_first_waiter(gl);
608 gl->gl_target = gh->gh_state;
609 if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
610 do_error(gl, 0); /* Fail queued try locks */
611 }
612 do_xmote(gl, gh, gl->gl_target);
613 return;
614
615out_sched:
616 gfs2_glock_hold(gl);
617 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
618 gfs2_glock_put(gl);
619out:
620 clear_bit(GLF_LOCK, &gl->gl_flags);
621}
622
623static void glock_work_func(struct work_struct *work)
624{
625 unsigned long delay = 0;
626 struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
627
628 if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags))
629 finish_xmote(gl, gl->gl_reply);
630 spin_lock(&gl->gl_spin);
Steven Whitehouse265d529c2008-07-07 10:02:36 +0100631 if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
632 gl->gl_state != LM_ST_UNLOCKED &&
633 gl->gl_demote_state != LM_ST_EXCLUSIVE) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100634 unsigned long holdtime, now = jiffies;
635 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
636 if (time_before(now, holdtime))
637 delay = holdtime - now;
638 set_bit(delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE, &gl->gl_flags);
639 }
640 run_queue(gl, 0);
641 spin_unlock(&gl->gl_spin);
642 if (!delay ||
643 queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
644 gfs2_glock_put(gl);
645}
646
Steven Whitehouseda755fd2008-01-30 15:34:04 +0000647static int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
648 void **lockp)
649{
650 int error = -EIO;
Steven Whitehouse048bca22008-05-23 14:46:04 +0100651 if (!sdp->sd_lockstruct.ls_ops->lm_get_lock)
652 return 0;
Steven Whitehouseda755fd2008-01-30 15:34:04 +0000653 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
654 error = sdp->sd_lockstruct.ls_ops->lm_get_lock(
655 sdp->sd_lockstruct.ls_lockspace, name, lockp);
656 return error;
657}
658
David Teiglandb3b94fa2006-01-16 16:50:04 +0000659/**
660 * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
661 * @sdp: The GFS2 superblock
662 * @number: the lock number
663 * @glops: The glock_operations to use
664 * @create: If 0, don't create the glock if it doesn't exist
665 * @glp: the glock is returned here
666 *
667 * This does not lock a glock, just finds/creates structures for one.
668 *
669 * Returns: errno
670 */
671
Steven Whitehousecd915492006-09-04 12:49:07 -0400672int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
Steven Whitehouse8fb4b532006-08-30 09:30:00 -0400673 const struct gfs2_glock_operations *glops, int create,
David Teiglandb3b94fa2006-01-16 16:50:04 +0000674 struct gfs2_glock **glp)
675{
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400676 struct lm_lockname name = { .ln_number = number, .ln_type = glops->go_type };
David Teiglandb3b94fa2006-01-16 16:50:04 +0000677 struct gfs2_glock *gl, *tmp;
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400678 unsigned int hash = gl_hash(sdp, &name);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000679 int error;
680
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400681 read_lock(gl_lock_addr(hash));
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400682 gl = search_bucket(hash, sdp, &name);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400683 read_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000684
685 if (gl || !create) {
686 *glp = gl;
687 return 0;
688 }
689
690 gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_KERNEL);
691 if (!gl)
692 return -ENOMEM;
693
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400694 gl->gl_flags = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000695 gl->gl_name = name;
Steven Whitehouse16feb9f2006-09-13 10:43:37 -0400696 atomic_set(&gl->gl_ref, 1);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000697 gl->gl_state = LM_ST_UNLOCKED;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100698 gl->gl_target = LM_ST_UNLOCKED;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500699 gl->gl_demote_state = LM_ST_EXCLUSIVE;
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400700 gl->gl_hash = hash;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000701 gl->gl_ops = glops;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400702 gl->gl_stamp = jiffies;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500703 gl->gl_tchange = jiffies;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400704 gl->gl_object = NULL;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000705 gl->gl_sbd = sdp;
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400706 gl->gl_aspace = NULL;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500707 INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000708
709 /* If this glock protects actual on-disk data or metadata blocks,
710 create a VFS inode to manage the pages/buffers holding them. */
Steven Whitehouse50299962006-09-04 09:49:55 -0400711 if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
David Teiglandb3b94fa2006-01-16 16:50:04 +0000712 gl->gl_aspace = gfs2_aspace_get(sdp);
713 if (!gl->gl_aspace) {
714 error = -ENOMEM;
715 goto fail;
716 }
717 }
718
719 error = gfs2_lm_get_lock(sdp, &name, &gl->gl_lock);
720 if (error)
721 goto fail_aspace;
722
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400723 write_lock(gl_lock_addr(hash));
Steven Whitehouse37b2fa62006-09-08 13:35:56 -0400724 tmp = search_bucket(hash, sdp, &name);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000725 if (tmp) {
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400726 write_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000727 glock_free(gl);
728 gl = tmp;
729 } else {
Steven Whitehouseb6397892006-09-12 10:10:01 -0400730 hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
Steven Whitehouse087efdd2006-09-09 16:59:11 -0400731 write_unlock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000732 }
733
734 *glp = gl;
735
736 return 0;
737
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400738fail_aspace:
David Teiglandb3b94fa2006-01-16 16:50:04 +0000739 if (gl->gl_aspace)
740 gfs2_aspace_put(gl->gl_aspace);
Steven Whitehouseec45d9f2006-08-30 10:36:52 -0400741fail:
Steven Whitehouse907b9bc2006-09-25 09:26:04 -0400742 kmem_cache_free(gfs2_glock_cachep, gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000743 return error;
744}
745
746/**
747 * gfs2_holder_init - initialize a struct gfs2_holder in the default way
748 * @gl: the glock
749 * @state: the state we're requesting
750 * @flags: the modifier flags
751 * @gh: the holder structure
752 *
753 */
754
Steven Whitehouse190562b2006-04-20 16:57:23 -0400755void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
David Teiglandb3b94fa2006-01-16 16:50:04 +0000756 struct gfs2_holder *gh)
757{
758 INIT_LIST_HEAD(&gh->gh_list);
759 gh->gh_gl = gl;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500760 gh->gh_ip = (unsigned long)__builtin_return_address(0);
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800761 gh->gh_owner_pid = get_pid(task_pid(current));
David Teiglandb3b94fa2006-01-16 16:50:04 +0000762 gh->gh_state = state;
763 gh->gh_flags = flags;
764 gh->gh_error = 0;
765 gh->gh_iflags = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000766 gfs2_glock_hold(gl);
767}
768
769/**
770 * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it
771 * @state: the state we're requesting
772 * @flags: the modifier flags
773 * @gh: the holder structure
774 *
775 * Don't mess with the glock.
776 *
777 */
778
Steven Whitehouse190562b2006-04-20 16:57:23 -0400779void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000780{
781 gh->gh_state = state;
Steven Whitehouse579b78a2006-04-26 14:58:26 -0400782 gh->gh_flags = flags;
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000783 gh->gh_iflags = 0;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500784 gh->gh_ip = (unsigned long)__builtin_return_address(0);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000785}
786
787/**
788 * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference)
789 * @gh: the holder structure
790 *
791 */
792
793void gfs2_holder_uninit(struct gfs2_holder *gh)
794{
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800795 put_pid(gh->gh_owner_pid);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000796 gfs2_glock_put(gh->gh_gl);
797 gh->gh_gl = NULL;
Steven Whitehoused0dc80d2006-03-29 14:36:49 -0500798 gh->gh_ip = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000799}
800
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100801static int just_schedule(void *word)
Steven Whitehousefee852e2007-01-17 15:33:23 +0000802{
803 schedule();
804 return 0;
805}
806
807static void wait_on_holder(struct gfs2_holder *gh)
808{
809 might_sleep();
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100810 wait_on_bit(&gh->gh_iflags, HIF_WAIT, just_schedule, TASK_UNINTERRUPTIBLE);
811}
812
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100813static void wait_on_demote(struct gfs2_glock *gl)
814{
815 might_sleep();
816 wait_on_bit(&gl->gl_flags, GLF_DEMOTE, just_schedule, TASK_UNINTERRUPTIBLE);
Steven Whitehousefee852e2007-01-17 15:33:23 +0000817}
818
David Teiglandb3b94fa2006-01-16 16:50:04 +0000819/**
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000820 * handle_callback - process a demote request
David Teiglandb3b94fa2006-01-16 16:50:04 +0000821 * @gl: the glock
822 * @state: the state the caller wants us to change to
823 *
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000824 * There are only two requests that we are going to see in actual
825 * practise: LM_ST_SHARED and LM_ST_UNLOCKED
David Teiglandb3b94fa2006-01-16 16:50:04 +0000826 */
827
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500828static void handle_callback(struct gfs2_glock *gl, unsigned int state,
829 int remote, unsigned long delay)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000830{
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500831 int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
832
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -0500833 set_bit(bit, &gl->gl_flags);
834 if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
Steven Whitehouse3b8249f2007-03-16 09:40:31 +0000835 gl->gl_demote_state = state;
836 gl->gl_demote_time = jiffies;
Abhijith Dasd93cfa92007-06-11 08:22:32 +0100837 if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
Steven Whitehouse6802e342008-05-21 17:03:22 +0100838 gl->gl_object)
Wendy Cheng49e61f22007-09-13 17:52:42 -0400839 gfs2_glock_schedule_for_reclaim(gl);
Josef Whiter26caee52007-07-23 10:02:40 +0100840 } else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
841 gl->gl_demote_state != state) {
Steven Whitehouse6802e342008-05-21 17:03:22 +0100842 gl->gl_demote_state = LM_ST_UNLOCKED;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000843 }
David Teiglandb3b94fa2006-01-16 16:50:04 +0000844}
845
846/**
Steven Whitehouse6802e342008-05-21 17:03:22 +0100847 * gfs2_glock_wait - wait on a glock acquisition
David Teiglandb3b94fa2006-01-16 16:50:04 +0000848 * @gh: the glock holder
849 *
850 * Returns: 0 on success
851 */
852
Steven Whitehouse6802e342008-05-21 17:03:22 +0100853int gfs2_glock_wait(struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000854{
Steven Whitehousefee852e2007-01-17 15:33:23 +0000855 wait_on_holder(gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000856 return gh->gh_error;
857}
858
Steven Whitehouse6802e342008-05-21 17:03:22 +0100859void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...)
Robert Peterson7c52b162007-03-16 10:26:37 +0000860{
861 va_list args;
862
863 va_start(args, fmt);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100864 if (seq) {
865 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +0000866 vsprintf(gi->string, fmt, args);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100867 seq_printf(seq, gi->string);
868 } else {
869 printk(KERN_ERR " ");
Robert Peterson7c52b162007-03-16 10:26:37 +0000870 vprintk(fmt, args);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100871 }
Robert Peterson7c52b162007-03-16 10:26:37 +0000872 va_end(args);
873}
874
David Teiglandb3b94fa2006-01-16 16:50:04 +0000875/**
David Teiglandb3b94fa2006-01-16 16:50:04 +0000876 * add_to_queue - Add a holder to the wait queue (but look for recursion)
877 * @gh: the holder structure to add
878 *
Steven Whitehouse6802e342008-05-21 17:03:22 +0100879 * Eventually we should move the recursive locking trap to a
880 * debugging option or something like that. This is the fast
881 * path and needs to have the minimum number of distractions.
882 *
David Teiglandb3b94fa2006-01-16 16:50:04 +0000883 */
884
Steven Whitehouse6802e342008-05-21 17:03:22 +0100885static inline void add_to_queue(struct gfs2_holder *gh)
Harvey Harrison55ba4742008-10-24 11:31:12 -0700886__releases(&gl->gl_spin)
887__acquires(&gl->gl_spin)
David Teiglandb3b94fa2006-01-16 16:50:04 +0000888{
889 struct gfs2_glock *gl = gh->gh_gl;
Steven Whitehouse6802e342008-05-21 17:03:22 +0100890 struct gfs2_sbd *sdp = gl->gl_sbd;
891 struct list_head *insert_pt = NULL;
892 struct gfs2_holder *gh2;
893 int try_lock = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000894
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -0800895 BUG_ON(gh->gh_owner_pid == NULL);
Steven Whitehousefee852e2007-01-17 15:33:23 +0000896 if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
897 BUG();
Steven Whitehouse190562b2006-04-20 16:57:23 -0400898
Steven Whitehouse6802e342008-05-21 17:03:22 +0100899 if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
900 if (test_bit(GLF_LOCK, &gl->gl_flags))
901 try_lock = 1;
902 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
903 goto fail;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000904 }
905
Steven Whitehouse6802e342008-05-21 17:03:22 +0100906 list_for_each_entry(gh2, &gl->gl_holders, gh_list) {
907 if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid &&
908 (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK)))
909 goto trap_recursive;
910 if (try_lock &&
911 !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) &&
912 !may_grant(gl, gh)) {
913fail:
914 gh->gh_error = GLR_TRYFAILED;
915 gfs2_holder_wake(gh);
916 return;
917 }
918 if (test_bit(HIF_HOLDER, &gh2->gh_iflags))
919 continue;
920 if (unlikely((gh->gh_flags & LM_FLAG_PRIORITY) && !insert_pt))
921 insert_pt = &gh2->gh_list;
922 }
923 if (likely(insert_pt == NULL)) {
924 list_add_tail(&gh->gh_list, &gl->gl_holders);
925 if (unlikely(gh->gh_flags & LM_FLAG_PRIORITY))
926 goto do_cancel;
927 return;
928 }
929 list_add_tail(&gh->gh_list, insert_pt);
930do_cancel:
931 gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);
932 if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {
933 spin_unlock(&gl->gl_spin);
Steven Whitehouse048bca22008-05-23 14:46:04 +0100934 if (sdp->sd_lockstruct.ls_ops->lm_cancel)
935 sdp->sd_lockstruct.ls_ops->lm_cancel(gl->gl_lock);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100936 spin_lock(&gl->gl_spin);
937 }
938 return;
939
940trap_recursive:
941 print_symbol(KERN_ERR "original: %s\n", gh2->gh_ip);
942 printk(KERN_ERR "pid: %d\n", pid_nr(gh2->gh_owner_pid));
943 printk(KERN_ERR "lock type: %d req lock state : %d\n",
944 gh2->gh_gl->gl_name.ln_type, gh2->gh_state);
945 print_symbol(KERN_ERR "new: %s\n", gh->gh_ip);
946 printk(KERN_ERR "pid: %d\n", pid_nr(gh->gh_owner_pid));
947 printk(KERN_ERR "lock type: %d req lock state : %d\n",
948 gh->gh_gl->gl_name.ln_type, gh->gh_state);
949 __dump_glock(NULL, gl);
950 BUG();
David Teiglandb3b94fa2006-01-16 16:50:04 +0000951}
952
953/**
954 * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock)
955 * @gh: the holder structure
956 *
957 * if (gh->gh_flags & GL_ASYNC), this never returns an error
958 *
959 * Returns: 0, GLR_TRYFAILED, or errno on failure
960 */
961
962int gfs2_glock_nq(struct gfs2_holder *gh)
963{
964 struct gfs2_glock *gl = gh->gh_gl;
965 struct gfs2_sbd *sdp = gl->gl_sbd;
966 int error = 0;
967
Steven Whitehouse6802e342008-05-21 17:03:22 +0100968 if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
David Teiglandb3b94fa2006-01-16 16:50:04 +0000969 return -EIO;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000970
David Teiglandb3b94fa2006-01-16 16:50:04 +0000971 spin_lock(&gl->gl_spin);
972 add_to_queue(gh);
Steven Whitehouse6802e342008-05-21 17:03:22 +0100973 run_queue(gl, 1);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000974 spin_unlock(&gl->gl_spin);
975
Steven Whitehouse6802e342008-05-21 17:03:22 +0100976 if (!(gh->gh_flags & GL_ASYNC))
977 error = gfs2_glock_wait(gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +0000978
David Teiglandb3b94fa2006-01-16 16:50:04 +0000979 return error;
980}
981
982/**
983 * gfs2_glock_poll - poll to see if an async request has been completed
984 * @gh: the holder
985 *
986 * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on
987 */
988
989int gfs2_glock_poll(struct gfs2_holder *gh)
990{
Steven Whitehouse6802e342008-05-21 17:03:22 +0100991 return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +0000992}
993
994/**
995 * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock)
996 * @gh: the glock holder
997 *
998 */
999
1000void gfs2_glock_dq(struct gfs2_holder *gh)
1001{
1002 struct gfs2_glock *gl = gh->gh_gl;
Steven Whitehouse8fb4b532006-08-30 09:30:00 -04001003 const struct gfs2_glock_operations *glops = gl->gl_ops;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001004 unsigned delay = 0;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001005 int fast_path = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001006
Steven Whitehouse6802e342008-05-21 17:03:22 +01001007 spin_lock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001008 if (gh->gh_flags & GL_NOCACHE)
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001009 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001010
David Teiglandb3b94fa2006-01-16 16:50:04 +00001011 list_del_init(&gh->gh_list);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001012 if (find_first_holder(gl) == NULL) {
Steven Whitehouse3042a2cc2007-11-02 08:39:34 +00001013 if (glops->go_unlock) {
Steven Whitehouse6802e342008-05-21 17:03:22 +01001014 GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));
Steven Whitehouse3042a2cc2007-11-02 08:39:34 +00001015 spin_unlock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001016 glops->go_unlock(gh);
Steven Whitehouse3042a2cc2007-11-02 08:39:34 +00001017 spin_lock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001018 clear_bit(GLF_LOCK, &gl->gl_flags);
Steven Whitehouse3042a2cc2007-11-02 08:39:34 +00001019 }
Steven Whitehouse3b8249f2007-03-16 09:40:31 +00001020 gl->gl_stamp = jiffies;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001021 if (list_empty(&gl->gl_holders) &&
1022 !test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1023 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1024 fast_path = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001025 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001026 spin_unlock(&gl->gl_spin);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001027 if (likely(fast_path))
1028 return;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001029
1030 gfs2_glock_hold(gl);
1031 if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
1032 !test_bit(GLF_DEMOTE, &gl->gl_flags))
1033 delay = gl->gl_ops->go_min_hold_time;
1034 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1035 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001036}
1037
Abhijith Dasd93cfa92007-06-11 08:22:32 +01001038void gfs2_glock_dq_wait(struct gfs2_holder *gh)
1039{
1040 struct gfs2_glock *gl = gh->gh_gl;
1041 gfs2_glock_dq(gh);
1042 wait_on_demote(gl);
1043}
1044
David Teiglandb3b94fa2006-01-16 16:50:04 +00001045/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001046 * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
1047 * @gh: the holder structure
1048 *
1049 */
1050
1051void gfs2_glock_dq_uninit(struct gfs2_holder *gh)
1052{
1053 gfs2_glock_dq(gh);
1054 gfs2_holder_uninit(gh);
1055}
1056
1057/**
1058 * gfs2_glock_nq_num - acquire a glock based on lock number
1059 * @sdp: the filesystem
1060 * @number: the lock number
1061 * @glops: the glock operations for the type of glock
1062 * @state: the state to acquire the glock in
1063 * @flags: modifier flags for the aquisition
1064 * @gh: the struct gfs2_holder
1065 *
1066 * Returns: errno
1067 */
1068
Steven Whitehousecd915492006-09-04 12:49:07 -04001069int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
Steven Whitehouse8fb4b532006-08-30 09:30:00 -04001070 const struct gfs2_glock_operations *glops,
1071 unsigned int state, int flags, struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001072{
1073 struct gfs2_glock *gl;
1074 int error;
1075
1076 error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
1077 if (!error) {
1078 error = gfs2_glock_nq_init(gl, state, flags, gh);
1079 gfs2_glock_put(gl);
1080 }
1081
1082 return error;
1083}
1084
1085/**
1086 * glock_compare - Compare two struct gfs2_glock structures for sorting
1087 * @arg_a: the first structure
1088 * @arg_b: the second structure
1089 *
1090 */
1091
1092static int glock_compare(const void *arg_a, const void *arg_b)
1093{
Steven Whitehousea5e08a9e2006-09-09 17:07:05 -04001094 const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
1095 const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
1096 const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
1097 const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001098
1099 if (a->ln_number > b->ln_number)
Steven Whitehousea5e08a9e2006-09-09 17:07:05 -04001100 return 1;
1101 if (a->ln_number < b->ln_number)
1102 return -1;
Steven Whitehouse1c0f4872007-01-22 12:10:39 -05001103 BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
Steven Whitehousea5e08a9e2006-09-09 17:07:05 -04001104 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001105}
1106
1107/**
1108 * nq_m_sync - synchonously acquire more than one glock in deadlock free order
1109 * @num_gh: the number of structures
1110 * @ghs: an array of struct gfs2_holder structures
1111 *
1112 * Returns: 0 on success (all glocks acquired),
1113 * errno on failure (no glocks acquired)
1114 */
1115
1116static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs,
1117 struct gfs2_holder **p)
1118{
1119 unsigned int x;
1120 int error = 0;
1121
1122 for (x = 0; x < num_gh; x++)
1123 p[x] = &ghs[x];
1124
1125 sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
1126
1127 for (x = 0; x < num_gh; x++) {
1128 p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1129
1130 error = gfs2_glock_nq(p[x]);
1131 if (error) {
1132 while (x--)
1133 gfs2_glock_dq(p[x]);
1134 break;
1135 }
1136 }
1137
1138 return error;
1139}
1140
1141/**
1142 * gfs2_glock_nq_m - acquire multiple glocks
1143 * @num_gh: the number of structures
1144 * @ghs: an array of struct gfs2_holder structures
1145 *
David Teiglandb3b94fa2006-01-16 16:50:04 +00001146 *
1147 * Returns: 0 on success (all glocks acquired),
1148 * errno on failure (no glocks acquired)
1149 */
1150
1151int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1152{
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001153 struct gfs2_holder *tmp[4];
1154 struct gfs2_holder **pph = tmp;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001155 int error = 0;
1156
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001157 switch(num_gh) {
1158 case 0:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001159 return 0;
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001160 case 1:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001161 ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
1162 return gfs2_glock_nq(ghs);
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001163 default:
1164 if (num_gh <= 4)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001165 break;
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001166 pph = kmalloc(num_gh * sizeof(struct gfs2_holder *), GFP_NOFS);
1167 if (!pph)
1168 return -ENOMEM;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001169 }
1170
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001171 error = nq_m_sync(num_gh, ghs, pph);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001172
Steven Whitehouseeaf5bd32007-06-19 15:38:17 +01001173 if (pph != tmp)
1174 kfree(pph);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001175
1176 return error;
1177}
1178
1179/**
1180 * gfs2_glock_dq_m - release multiple glocks
1181 * @num_gh: the number of structures
1182 * @ghs: an array of struct gfs2_holder structures
1183 *
1184 */
1185
1186void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs)
1187{
1188 unsigned int x;
1189
1190 for (x = 0; x < num_gh; x++)
1191 gfs2_glock_dq(&ghs[x]);
1192}
1193
1194/**
1195 * gfs2_glock_dq_uninit_m - release multiple glocks
1196 * @num_gh: the number of structures
1197 * @ghs: an array of struct gfs2_holder structures
1198 *
1199 */
1200
1201void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
1202{
1203 unsigned int x;
1204
1205 for (x = 0; x < num_gh; x++)
1206 gfs2_glock_dq_uninit(&ghs[x]);
1207}
1208
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001209static int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, void *lock, char **lvbp)
1210{
1211 int error = -EIO;
Steven Whitehouse048bca22008-05-23 14:46:04 +01001212 if (!sdp->sd_lockstruct.ls_ops->lm_hold_lvb)
1213 return 0;
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001214 if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
1215 error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp);
1216 return error;
1217}
1218
David Teiglandb3b94fa2006-01-16 16:50:04 +00001219/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001220 * gfs2_lvb_hold - attach a LVB from a glock
1221 * @gl: The glock in question
1222 *
1223 */
1224
1225int gfs2_lvb_hold(struct gfs2_glock *gl)
1226{
1227 int error;
1228
David Teiglandb3b94fa2006-01-16 16:50:04 +00001229 if (!atomic_read(&gl->gl_lvb_count)) {
1230 error = gfs2_lm_hold_lvb(gl->gl_sbd, gl->gl_lock, &gl->gl_lvb);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001231 if (error)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001232 return error;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001233 gfs2_glock_hold(gl);
1234 }
1235 atomic_inc(&gl->gl_lvb_count);
1236
David Teiglandb3b94fa2006-01-16 16:50:04 +00001237 return 0;
1238}
1239
1240/**
1241 * gfs2_lvb_unhold - detach a LVB from a glock
1242 * @gl: The glock in question
1243 *
1244 */
1245
1246void gfs2_lvb_unhold(struct gfs2_glock *gl)
1247{
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001248 struct gfs2_sbd *sdp = gl->gl_sbd;
1249
David Teiglandb3b94fa2006-01-16 16:50:04 +00001250 gfs2_glock_hold(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001251 gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count) > 0);
1252 if (atomic_dec_and_test(&gl->gl_lvb_count)) {
Steven Whitehouse048bca22008-05-23 14:46:04 +01001253 if (sdp->sd_lockstruct.ls_ops->lm_unhold_lvb)
Steven Whitehouseda755fd2008-01-30 15:34:04 +00001254 sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(gl->gl_lock, gl->gl_lvb);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001255 gl->gl_lvb = NULL;
1256 gfs2_glock_put(gl);
1257 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001258 gfs2_glock_put(gl);
1259}
1260
David Teiglandb3b94fa2006-01-16 16:50:04 +00001261static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
1262 unsigned int state)
1263{
1264 struct gfs2_glock *gl;
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001265 unsigned long delay = 0;
1266 unsigned long holdtime;
1267 unsigned long now = jiffies;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001268
1269 gl = gfs2_glock_find(sdp, name);
1270 if (!gl)
1271 return;
1272
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001273 holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
1274 if (time_before(now, holdtime))
1275 delay = holdtime - now;
Steven Whitehousedff52572008-09-02 13:33:17 +01001276 if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags))
1277 delay = gl->gl_ops->go_min_hold_time;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001278
Steven Whitehouse6802e342008-05-21 17:03:22 +01001279 spin_lock(&gl->gl_spin);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001280 handle_callback(gl, state, 1, delay);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001281 spin_unlock(&gl->gl_spin);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001282 if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
1283 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001284}
1285
1286/**
1287 * gfs2_glock_cb - Callback used by locking module
Steven Whitehouse1c089c32006-09-07 15:50:20 -04001288 * @sdp: Pointer to the superblock
David Teiglandb3b94fa2006-01-16 16:50:04 +00001289 * @type: Type of callback
1290 * @data: Type dependent data pointer
1291 *
1292 * Called by the locking module when it wants to tell us something.
1293 * Either we need to drop a lock, one of our ASYNC requests completed, or
1294 * a journal from another client needs to be recovered.
1295 */
1296
Steven Whitehouse9b47c112006-09-08 10:17:58 -04001297void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001298{
Steven Whitehouse9b47c112006-09-08 10:17:58 -04001299 struct gfs2_sbd *sdp = cb_data;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001300
David Teiglandb3b94fa2006-01-16 16:50:04 +00001301 switch (type) {
1302 case LM_CB_NEED_E:
David Teiglande7f5c012006-04-27 11:25:45 -04001303 blocking_cb(sdp, data, LM_ST_UNLOCKED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001304 return;
1305
1306 case LM_CB_NEED_D:
David Teiglande7f5c012006-04-27 11:25:45 -04001307 blocking_cb(sdp, data, LM_ST_DEFERRED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001308 return;
1309
1310 case LM_CB_NEED_S:
David Teiglande7f5c012006-04-27 11:25:45 -04001311 blocking_cb(sdp, data, LM_ST_SHARED);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001312 return;
1313
1314 case LM_CB_ASYNC: {
David Teiglande7f5c012006-04-27 11:25:45 -04001315 struct lm_async_cb *async = data;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001316 struct gfs2_glock *gl;
1317
Steven Whitehouse61be0842007-01-29 11:51:45 +00001318 down_read(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001319 gl = gfs2_glock_find(sdp, &async->lc_name);
1320 if (gfs2_assert_warn(sdp, gl))
1321 return;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001322 gl->gl_reply = async->lc_ret;
1323 set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001324 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1325 gfs2_glock_put(gl);
Steven Whitehouse61be0842007-01-29 11:51:45 +00001326 up_read(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001327 return;
1328 }
1329
1330 case LM_CB_NEED_RECOVERY:
1331 gfs2_jdesc_make_dirty(sdp, *(unsigned int *)data);
1332 if (sdp->sd_recoverd_process)
1333 wake_up_process(sdp->sd_recoverd_process);
1334 return;
1335
David Teiglandb3b94fa2006-01-16 16:50:04 +00001336 default:
1337 gfs2_assert_warn(sdp, 0);
1338 return;
1339 }
1340}
1341
1342/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001343 * demote_ok - Check to see if it's ok to unlock a glock
1344 * @gl: the glock
1345 *
1346 * Returns: 1 if it's ok
1347 */
1348
1349static int demote_ok(struct gfs2_glock *gl)
1350{
Steven Whitehouse8fb4b532006-08-30 09:30:00 -04001351 const struct gfs2_glock_operations *glops = gl->gl_ops;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001352 int demote = 1;
1353
1354 if (test_bit(GLF_STICKY, &gl->gl_flags))
1355 demote = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001356 else if (glops->go_demote_ok)
1357 demote = glops->go_demote_ok(gl);
1358
1359 return demote;
1360}
1361
1362/**
1363 * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
1364 * @gl: the glock
1365 *
1366 */
1367
1368void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
1369{
1370 struct gfs2_sbd *sdp = gl->gl_sbd;
1371
1372 spin_lock(&sdp->sd_reclaim_lock);
1373 if (list_empty(&gl->gl_reclaim)) {
1374 gfs2_glock_hold(gl);
1375 list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
1376 atomic_inc(&sdp->sd_reclaim_count);
Bob Petersonef8c4412008-01-28 14:54:16 -06001377 spin_unlock(&sdp->sd_reclaim_lock);
1378 wake_up(&sdp->sd_reclaim_wq);
1379 } else
1380 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001381}
1382
1383/**
1384 * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
1385 * @sdp: the filesystem
1386 *
1387 * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
1388 * different glock and we notice that there are a lot of glocks in the
1389 * reclaim list.
1390 *
1391 */
1392
1393void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
1394{
1395 struct gfs2_glock *gl;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001396 int done_callback = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001397
1398 spin_lock(&sdp->sd_reclaim_lock);
1399 if (list_empty(&sdp->sd_reclaim_list)) {
1400 spin_unlock(&sdp->sd_reclaim_lock);
1401 return;
1402 }
1403 gl = list_entry(sdp->sd_reclaim_list.next,
1404 struct gfs2_glock, gl_reclaim);
1405 list_del_init(&gl->gl_reclaim);
1406 spin_unlock(&sdp->sd_reclaim_lock);
1407
1408 atomic_dec(&sdp->sd_reclaim_count);
1409 atomic_inc(&sdp->sd_reclaimed);
1410
Steven Whitehouse6802e342008-05-21 17:03:22 +01001411 spin_lock(&gl->gl_spin);
1412 if (find_first_holder(gl) == NULL &&
1413 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) {
1414 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1415 done_callback = 1;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001416 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001417 spin_unlock(&gl->gl_spin);
1418 if (!done_callback ||
1419 queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1420 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001421}
1422
1423/**
1424 * examine_bucket - Call a function for glock in a hash bucket
1425 * @examiner: the function
1426 * @sdp: the filesystem
1427 * @bucket: the bucket
1428 *
1429 * Returns: 1 if the bucket has entries
1430 */
1431
1432static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
Steven Whitehouse37b2fa62006-09-08 13:35:56 -04001433 unsigned int hash)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001434{
Steven Whitehouse24264432006-09-11 21:40:30 -04001435 struct gfs2_glock *gl, *prev = NULL;
1436 int has_entries = 0;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001437 struct hlist_head *head = &gl_hash_table[hash].hb_list;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001438
Steven Whitehouse24264432006-09-11 21:40:30 -04001439 read_lock(gl_lock_addr(hash));
Steven Whitehouseb6397892006-09-12 10:10:01 -04001440 /* Can't use hlist_for_each_entry - don't want prefetch here */
1441 if (hlist_empty(head))
Steven Whitehouse24264432006-09-11 21:40:30 -04001442 goto out;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001443 gl = list_entry(head->first, struct gfs2_glock, gl_list);
1444 while(1) {
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001445 if (!sdp || gl->gl_sbd == sdp) {
David Teiglandb3b94fa2006-01-16 16:50:04 +00001446 gfs2_glock_hold(gl);
Steven Whitehouse24264432006-09-11 21:40:30 -04001447 read_unlock(gl_lock_addr(hash));
1448 if (prev)
1449 gfs2_glock_put(prev);
1450 prev = gl;
1451 examiner(gl);
Steven Whitehousea8336342006-09-14 13:57:38 -04001452 has_entries = 1;
Steven Whitehouse24264432006-09-11 21:40:30 -04001453 read_lock(gl_lock_addr(hash));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001454 }
Steven Whitehouseb6397892006-09-12 10:10:01 -04001455 if (gl->gl_list.next == NULL)
1456 break;
Steven Whitehouse24264432006-09-11 21:40:30 -04001457 gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001458 }
Steven Whitehouse24264432006-09-11 21:40:30 -04001459out:
1460 read_unlock(gl_lock_addr(hash));
1461 if (prev)
1462 gfs2_glock_put(prev);
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001463 cond_resched();
Steven Whitehouse24264432006-09-11 21:40:30 -04001464 return has_entries;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001465}
1466
1467/**
1468 * scan_glock - look at a glock and see if we can reclaim it
1469 * @gl: the glock to look at
1470 *
1471 */
1472
1473static void scan_glock(struct gfs2_glock *gl)
1474{
Steven Whitehouseb0041572006-11-23 10:51:34 -05001475 if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
Steven Whitehouse24264432006-09-11 21:40:30 -04001476 return;
Steven Whitehouse6802e342008-05-21 17:03:22 +01001477 if (test_bit(GLF_LOCK, &gl->gl_flags))
1478 return;
Steven Whitehousea2242db2006-08-24 17:03:05 -04001479
Steven Whitehouse6802e342008-05-21 17:03:22 +01001480 spin_lock(&gl->gl_spin);
1481 if (find_first_holder(gl) == NULL &&
1482 gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
1483 gfs2_glock_schedule_for_reclaim(gl);
1484 spin_unlock(&gl->gl_spin);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001485}
1486
1487/**
David Teiglandb3b94fa2006-01-16 16:50:04 +00001488 * clear_glock - look at a glock and see if we can free it from glock cache
1489 * @gl: the glock to look at
1490 *
1491 */
1492
1493static void clear_glock(struct gfs2_glock *gl)
1494{
1495 struct gfs2_sbd *sdp = gl->gl_sbd;
1496 int released;
1497
1498 spin_lock(&sdp->sd_reclaim_lock);
1499 if (!list_empty(&gl->gl_reclaim)) {
1500 list_del_init(&gl->gl_reclaim);
1501 atomic_dec(&sdp->sd_reclaim_count);
Steven Whitehouse190562b2006-04-20 16:57:23 -04001502 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001503 released = gfs2_glock_put(gl);
1504 gfs2_assert(sdp, !released);
Steven Whitehouse190562b2006-04-20 16:57:23 -04001505 } else {
1506 spin_unlock(&sdp->sd_reclaim_lock);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001507 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001508
Steven Whitehouse6802e342008-05-21 17:03:22 +01001509 spin_lock(&gl->gl_spin);
1510 if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
1511 handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
1512 spin_unlock(&gl->gl_spin);
1513 gfs2_glock_hold(gl);
1514 if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
1515 gfs2_glock_put(gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001516}
1517
1518/**
1519 * gfs2_gl_hash_clear - Empty out the glock hash table
1520 * @sdp: the filesystem
1521 * @wait: wait until it's all gone
1522 *
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001523 * Called when unmounting the filesystem.
David Teiglandb3b94fa2006-01-16 16:50:04 +00001524 */
1525
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001526void gfs2_gl_hash_clear(struct gfs2_sbd *sdp)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001527{
1528 unsigned long t;
1529 unsigned int x;
1530 int cont;
1531
1532 t = jiffies;
1533
1534 for (;;) {
1535 cont = 0;
Steven Whitehouse24264432006-09-11 21:40:30 -04001536 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
Steven Whitehouse907b9bc2006-09-25 09:26:04 -04001537 if (examine_bucket(clear_glock, sdp, x))
David Teiglandb3b94fa2006-01-16 16:50:04 +00001538 cont = 1;
Steven Whitehouse24264432006-09-11 21:40:30 -04001539 }
David Teiglandb3b94fa2006-01-16 16:50:04 +00001540
Steven Whitehouse1bdad602008-06-03 14:09:53 +01001541 if (!cont)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001542 break;
1543
1544 if (time_after_eq(jiffies,
1545 t + gfs2_tune_get(sdp, gt_stall_secs) * HZ)) {
1546 fs_warn(sdp, "Unmount seems to be stalled. "
1547 "Dumping lock state...\n");
1548 gfs2_dump_lockstate(sdp);
1549 t = jiffies;
1550 }
1551
Steven Whitehouse61be0842007-01-29 11:51:45 +00001552 down_write(&gfs2_umount_flush_sem);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001553 invalidate_inodes(sdp->sd_vfs);
Steven Whitehouse61be0842007-01-29 11:51:45 +00001554 up_write(&gfs2_umount_flush_sem);
Steven Whitehousefd88de562006-05-05 16:59:11 -04001555 msleep(10);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001556 }
1557}
1558
Steven Whitehouse6802e342008-05-21 17:03:22 +01001559static const char *state2str(unsigned state)
Robert Peterson04b933f2007-03-23 17:05:15 -05001560{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001561 switch(state) {
1562 case LM_ST_UNLOCKED:
1563 return "UN";
1564 case LM_ST_SHARED:
1565 return "SH";
1566 case LM_ST_DEFERRED:
1567 return "DF";
1568 case LM_ST_EXCLUSIVE:
1569 return "EX";
1570 }
1571 return "??";
1572}
Robert Peterson04b933f2007-03-23 17:05:15 -05001573
Steven Whitehouse6802e342008-05-21 17:03:22 +01001574static const char *hflags2str(char *buf, unsigned flags, unsigned long iflags)
1575{
1576 char *p = buf;
1577 if (flags & LM_FLAG_TRY)
1578 *p++ = 't';
1579 if (flags & LM_FLAG_TRY_1CB)
1580 *p++ = 'T';
1581 if (flags & LM_FLAG_NOEXP)
1582 *p++ = 'e';
1583 if (flags & LM_FLAG_ANY)
1584 *p++ = 'a';
1585 if (flags & LM_FLAG_PRIORITY)
1586 *p++ = 'p';
1587 if (flags & GL_ASYNC)
1588 *p++ = 'a';
1589 if (flags & GL_EXACT)
1590 *p++ = 'E';
Steven Whitehouse6802e342008-05-21 17:03:22 +01001591 if (flags & GL_NOCACHE)
1592 *p++ = 'c';
1593 if (test_bit(HIF_HOLDER, &iflags))
1594 *p++ = 'H';
1595 if (test_bit(HIF_WAIT, &iflags))
1596 *p++ = 'W';
1597 if (test_bit(HIF_FIRST, &iflags))
1598 *p++ = 'F';
1599 *p = 0;
1600 return buf;
Robert Peterson04b933f2007-03-23 17:05:15 -05001601}
1602
David Teiglandb3b94fa2006-01-16 16:50:04 +00001603/**
1604 * dump_holder - print information about a glock holder
Steven Whitehouse6802e342008-05-21 17:03:22 +01001605 * @seq: the seq_file struct
David Teiglandb3b94fa2006-01-16 16:50:04 +00001606 * @gh: the glock holder
1607 *
1608 * Returns: 0 on success, -ENOBUFS when we run out of space
1609 */
1610
Steven Whitehouse6802e342008-05-21 17:03:22 +01001611static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001612{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001613 struct task_struct *gh_owner = NULL;
1614 char buffer[KSYM_SYMBOL_LEN];
1615 char flags_buf[32];
David Teiglandb3b94fa2006-01-16 16:50:04 +00001616
Steven Whitehouse6802e342008-05-21 17:03:22 +01001617 sprint_symbol(buffer, gh->gh_ip);
1618 if (gh->gh_owner_pid)
Pavel Emelyanovb1e058d2008-02-07 00:13:19 -08001619 gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001620 gfs2_print_dbg(seq, " H: s:%s f:%s e:%d p:%ld [%s] %s\n",
1621 state2str(gh->gh_state),
1622 hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags),
1623 gh->gh_error,
1624 gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1,
1625 gh_owner ? gh_owner->comm : "(ended)", buffer);
Robert Peterson7c52b162007-03-16 10:26:37 +00001626 return 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001627}
1628
Steven Whitehouse6802e342008-05-21 17:03:22 +01001629static const char *gflags2str(char *buf, const unsigned long *gflags)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001630{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001631 char *p = buf;
1632 if (test_bit(GLF_LOCK, gflags))
1633 *p++ = 'l';
1634 if (test_bit(GLF_STICKY, gflags))
1635 *p++ = 's';
1636 if (test_bit(GLF_DEMOTE, gflags))
1637 *p++ = 'D';
1638 if (test_bit(GLF_PENDING_DEMOTE, gflags))
1639 *p++ = 'd';
1640 if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags))
1641 *p++ = 'p';
1642 if (test_bit(GLF_DIRTY, gflags))
1643 *p++ = 'y';
1644 if (test_bit(GLF_LFLUSH, gflags))
1645 *p++ = 'f';
1646 if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags))
1647 *p++ = 'i';
1648 if (test_bit(GLF_REPLY_PENDING, gflags))
1649 *p++ = 'r';
1650 *p = 0;
1651 return buf;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001652}
1653
1654/**
Steven Whitehouse6802e342008-05-21 17:03:22 +01001655 * __dump_glock - print information about a glock
1656 * @seq: The seq_file struct
David Teiglandb3b94fa2006-01-16 16:50:04 +00001657 * @gl: the glock
Steven Whitehouse6802e342008-05-21 17:03:22 +01001658 *
1659 * The file format is as follows:
1660 * One line per object, capital letters are used to indicate objects
1661 * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented,
1662 * other objects are indented by a single space and follow the glock to
1663 * which they are related. Fields are indicated by lower case letters
1664 * followed by a colon and the field value, except for strings which are in
1665 * [] so that its possible to see if they are composed of spaces for
1666 * example. The field's are n = number (id of the object), f = flags,
1667 * t = type, s = state, r = refcount, e = error, p = pid.
David Teiglandb3b94fa2006-01-16 16:50:04 +00001668 *
1669 * Returns: 0 on success, -ENOBUFS when we run out of space
1670 */
1671
Steven Whitehouse6802e342008-05-21 17:03:22 +01001672static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001673{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001674 const struct gfs2_glock_operations *glops = gl->gl_ops;
1675 unsigned long long dtime;
1676 const struct gfs2_holder *gh;
1677 char gflags_buf[32];
1678 int error = 0;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001679
Steven Whitehouse6802e342008-05-21 17:03:22 +01001680 dtime = jiffies - gl->gl_demote_time;
1681 dtime *= 1000000/HZ; /* demote time in uSec */
1682 if (!test_bit(GLF_DEMOTE, &gl->gl_flags))
1683 dtime = 0;
1684 gfs2_print_dbg(seq, "G: s:%s n:%u/%llu f:%s t:%s d:%s/%llu l:%d a:%d r:%d\n",
1685 state2str(gl->gl_state),
1686 gl->gl_name.ln_type,
1687 (unsigned long long)gl->gl_name.ln_number,
1688 gflags2str(gflags_buf, &gl->gl_flags),
1689 state2str(gl->gl_target),
1690 state2str(gl->gl_demote_state), dtime,
1691 atomic_read(&gl->gl_lvb_count),
1692 atomic_read(&gl->gl_ail_count),
1693 atomic_read(&gl->gl_ref));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001694
David Teiglandb3b94fa2006-01-16 16:50:04 +00001695 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
Steven Whitehouse6802e342008-05-21 17:03:22 +01001696 error = dump_holder(seq, gh);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001697 if (error)
1698 goto out;
1699 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001700 if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump)
1701 error = glops->go_dump(seq, gl);
Steven Whitehousea91ea692006-09-04 12:04:26 -04001702out:
David Teiglandb3b94fa2006-01-16 16:50:04 +00001703 return error;
1704}
1705
Steven Whitehouse6802e342008-05-21 17:03:22 +01001706static int dump_glock(struct seq_file *seq, struct gfs2_glock *gl)
1707{
1708 int ret;
1709 spin_lock(&gl->gl_spin);
1710 ret = __dump_glock(seq, gl);
1711 spin_unlock(&gl->gl_spin);
1712 return ret;
1713}
1714
David Teiglandb3b94fa2006-01-16 16:50:04 +00001715/**
1716 * gfs2_dump_lockstate - print out the current lockstate
1717 * @sdp: the filesystem
1718 * @ub: the buffer to copy the information into
1719 *
1720 * If @ub is NULL, dump the lockstate to the console.
1721 *
1722 */
1723
Adrian Bunk08bc2db2006-04-28 10:59:12 -04001724static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
David Teiglandb3b94fa2006-01-16 16:50:04 +00001725{
David Teiglandb3b94fa2006-01-16 16:50:04 +00001726 struct gfs2_glock *gl;
Steven Whitehouseb6397892006-09-12 10:10:01 -04001727 struct hlist_node *h;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001728 unsigned int x;
1729 int error = 0;
1730
1731 for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
David Teiglandb3b94fa2006-01-16 16:50:04 +00001732
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001733 read_lock(gl_lock_addr(x));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001734
Steven Whitehouseb6397892006-09-12 10:10:01 -04001735 hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001736 if (gl->gl_sbd != sdp)
1737 continue;
David Teiglandb3b94fa2006-01-16 16:50:04 +00001738
Robert Peterson7c52b162007-03-16 10:26:37 +00001739 error = dump_glock(NULL, gl);
David Teiglandb3b94fa2006-01-16 16:50:04 +00001740 if (error)
1741 break;
1742 }
1743
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001744 read_unlock(gl_lock_addr(x));
David Teiglandb3b94fa2006-01-16 16:50:04 +00001745
1746 if (error)
1747 break;
1748 }
1749
1750
1751 return error;
1752}
1753
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001754/**
1755 * gfs2_scand - Look for cached glocks and inodes to toss from memory
1756 * @sdp: Pointer to GFS2 superblock
1757 *
1758 * One of these daemons runs, finding candidates to add to sd_reclaim_list.
1759 * See gfs2_glockd()
1760 */
1761
1762static int gfs2_scand(void *data)
1763{
1764 unsigned x;
1765 unsigned delay;
1766
1767 while (!kthread_should_stop()) {
1768 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
1769 examine_bucket(scan_glock, NULL, x);
1770 if (freezing(current))
1771 refrigerator();
1772 delay = scand_secs;
1773 if (delay < 1)
1774 delay = 1;
1775 schedule_timeout_interruptible(delay * HZ);
1776 }
1777
1778 return 0;
1779}
1780
1781
1782
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001783int __init gfs2_glock_init(void)
1784{
1785 unsigned i;
1786 for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
Steven Whitehouseb6397892006-09-12 10:10:01 -04001787 INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001788 }
Steven Whitehouse087efdd2006-09-09 16:59:11 -04001789#ifdef GL_HASH_LOCK_SZ
1790 for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
1791 rwlock_init(&gl_hash_locks[i]);
1792 }
1793#endif
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001794
1795 scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand");
1796 if (IS_ERR(scand_process))
1797 return PTR_ERR(scand_process);
1798
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001799 glock_workqueue = create_workqueue("glock_workqueue");
1800 if (IS_ERR(glock_workqueue)) {
1801 kthread_stop(scand_process);
1802 return PTR_ERR(glock_workqueue);
1803 }
1804
Steven Whitehouse85d1da62006-09-07 14:40:21 -04001805 return 0;
1806}
1807
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001808void gfs2_glock_exit(void)
1809{
Benjamin Marzinskic4f68a12007-08-23 13:19:05 -05001810 destroy_workqueue(glock_workqueue);
Steven Whitehouse8fbbfd22007-08-01 13:57:10 +01001811 kthread_stop(scand_process);
1812}
1813
1814module_param(scand_secs, uint, S_IRUGO|S_IWUSR);
1815MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs");
1816
Steven Whitehouse6802e342008-05-21 17:03:22 +01001817static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
Robert Peterson7c52b162007-03-16 10:26:37 +00001818{
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001819 struct gfs2_glock *gl;
1820
Abhijith Dasa947e032007-08-21 09:57:29 -05001821restart:
Robert Peterson7a0079d2007-04-17 11:37:11 -05001822 read_lock(gl_lock_addr(gi->hash));
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001823 gl = gi->gl;
1824 if (gl) {
Abhijith Dasa947e032007-08-21 09:57:29 -05001825 gi->gl = hlist_entry(gl->gl_list.next,
1826 struct gfs2_glock, gl_list);
Steven Whitehousec1e817d02008-07-22 22:58:03 +01001827 } else {
1828 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1829 struct gfs2_glock, gl_list);
Robert Peterson7c52b162007-03-16 10:26:37 +00001830 }
Steven Whitehousec1e817d02008-07-22 22:58:03 +01001831 if (gi->gl)
1832 gfs2_glock_hold(gi->gl);
Robert Peterson7a0079d2007-04-17 11:37:11 -05001833 read_unlock(gl_lock_addr(gi->hash));
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001834 if (gl)
1835 gfs2_glock_put(gl);
Steven Whitehouse6802e342008-05-21 17:03:22 +01001836 while (gi->gl == NULL) {
Steven Whitehousec1e817d02008-07-22 22:58:03 +01001837 gi->hash++;
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001838 if (gi->hash >= GFS2_GL_HASH_SIZE)
1839 return 1;
1840 read_lock(gl_lock_addr(gi->hash));
1841 gi->gl = hlist_entry(gl_hash_table[gi->hash].hb_list.first,
1842 struct gfs2_glock, gl_list);
1843 if (gi->gl)
1844 gfs2_glock_hold(gi->gl);
1845 read_unlock(gl_lock_addr(gi->hash));
1846 }
Abhijith Dasa947e032007-08-21 09:57:29 -05001847
1848 if (gi->sdp != gi->gl->gl_sbd)
1849 goto restart;
1850
Robert Peterson7c52b162007-03-16 10:26:37 +00001851 return 0;
1852}
1853
Steven Whitehouse6802e342008-05-21 17:03:22 +01001854static void gfs2_glock_iter_free(struct gfs2_glock_iter *gi)
Robert Peterson7c52b162007-03-16 10:26:37 +00001855{
Steven Whitehouse7b08fc62007-07-24 13:53:36 +01001856 if (gi->gl)
1857 gfs2_glock_put(gi->gl);
Abhijith Dasa947e032007-08-21 09:57:29 -05001858 gi->gl = NULL;
Robert Peterson7c52b162007-03-16 10:26:37 +00001859}
1860
Steven Whitehouse6802e342008-05-21 17:03:22 +01001861static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos)
Robert Peterson7c52b162007-03-16 10:26:37 +00001862{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001863 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +00001864 loff_t n = *pos;
1865
Steven Whitehouse6802e342008-05-21 17:03:22 +01001866 gi->hash = 0;
Robert Peterson7c52b162007-03-16 10:26:37 +00001867
Steven Whitehouse6802e342008-05-21 17:03:22 +01001868 do {
Robert Peterson7c52b162007-03-16 10:26:37 +00001869 if (gfs2_glock_iter_next(gi)) {
1870 gfs2_glock_iter_free(gi);
1871 return NULL;
1872 }
Steven Whitehouse6802e342008-05-21 17:03:22 +01001873 } while (n--);
Robert Peterson7c52b162007-03-16 10:26:37 +00001874
Steven Whitehouse6802e342008-05-21 17:03:22 +01001875 return gi->gl;
Robert Peterson7c52b162007-03-16 10:26:37 +00001876}
1877
Steven Whitehouse6802e342008-05-21 17:03:22 +01001878static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr,
Robert Peterson7c52b162007-03-16 10:26:37 +00001879 loff_t *pos)
1880{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001881 struct gfs2_glock_iter *gi = seq->private;
Robert Peterson7c52b162007-03-16 10:26:37 +00001882
1883 (*pos)++;
1884
1885 if (gfs2_glock_iter_next(gi)) {
1886 gfs2_glock_iter_free(gi);
1887 return NULL;
1888 }
1889
Steven Whitehouse6802e342008-05-21 17:03:22 +01001890 return gi->gl;
Robert Peterson7c52b162007-03-16 10:26:37 +00001891}
1892
Steven Whitehouse6802e342008-05-21 17:03:22 +01001893static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr)
Robert Peterson7c52b162007-03-16 10:26:37 +00001894{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001895 struct gfs2_glock_iter *gi = seq->private;
1896 gfs2_glock_iter_free(gi);
Robert Peterson7c52b162007-03-16 10:26:37 +00001897}
1898
Steven Whitehouse6802e342008-05-21 17:03:22 +01001899static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr)
Robert Peterson7c52b162007-03-16 10:26:37 +00001900{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001901 return dump_glock(seq, iter_ptr);
Robert Peterson7c52b162007-03-16 10:26:37 +00001902}
1903
Denis Cheng4ef29002007-07-31 18:31:11 +08001904static const struct seq_operations gfs2_glock_seq_ops = {
Robert Peterson7c52b162007-03-16 10:26:37 +00001905 .start = gfs2_glock_seq_start,
1906 .next = gfs2_glock_seq_next,
1907 .stop = gfs2_glock_seq_stop,
1908 .show = gfs2_glock_seq_show,
1909};
1910
1911static int gfs2_debugfs_open(struct inode *inode, struct file *file)
1912{
Steven Whitehouse6802e342008-05-21 17:03:22 +01001913 int ret = seq_open_private(file, &gfs2_glock_seq_ops,
1914 sizeof(struct gfs2_glock_iter));
1915 if (ret == 0) {
1916 struct seq_file *seq = file->private_data;
1917 struct gfs2_glock_iter *gi = seq->private;
1918 gi->sdp = inode->i_private;
1919 }
1920 return ret;
Robert Peterson7c52b162007-03-16 10:26:37 +00001921}
1922
1923static const struct file_operations gfs2_debug_fops = {
1924 .owner = THIS_MODULE,
1925 .open = gfs2_debugfs_open,
1926 .read = seq_read,
1927 .llseek = seq_lseek,
Steven Whitehouse6802e342008-05-21 17:03:22 +01001928 .release = seq_release_private,
Robert Peterson7c52b162007-03-16 10:26:37 +00001929};
1930
1931int gfs2_create_debugfs_file(struct gfs2_sbd *sdp)
1932{
Robert Peterson5f882092007-04-18 11:41:11 -05001933 sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root);
1934 if (!sdp->debugfs_dir)
1935 return -ENOMEM;
1936 sdp->debugfs_dentry_glocks = debugfs_create_file("glocks",
1937 S_IFREG | S_IRUGO,
1938 sdp->debugfs_dir, sdp,
1939 &gfs2_debug_fops);
1940 if (!sdp->debugfs_dentry_glocks)
Robert Peterson7c52b162007-03-16 10:26:37 +00001941 return -ENOMEM;
1942
1943 return 0;
1944}
1945
1946void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp)
1947{
Robert Peterson5f882092007-04-18 11:41:11 -05001948 if (sdp && sdp->debugfs_dir) {
1949 if (sdp->debugfs_dentry_glocks) {
1950 debugfs_remove(sdp->debugfs_dentry_glocks);
1951 sdp->debugfs_dentry_glocks = NULL;
1952 }
1953 debugfs_remove(sdp->debugfs_dir);
1954 sdp->debugfs_dir = NULL;
1955 }
Robert Peterson7c52b162007-03-16 10:26:37 +00001956}
1957
1958int gfs2_register_debugfs(void)
1959{
1960 gfs2_root = debugfs_create_dir("gfs2", NULL);
1961 return gfs2_root ? 0 : -ENOMEM;
1962}
1963
1964void gfs2_unregister_debugfs(void)
1965{
1966 debugfs_remove(gfs2_root);
Robert Peterson5f882092007-04-18 11:41:11 -05001967 gfs2_root = NULL;
Robert Peterson7c52b162007-03-16 10:26:37 +00001968}