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Diffstat (limited to 'fs/gfs2/locking/dlm/thread.c')
-rw-r--r--fs/gfs2/locking/dlm/thread.c331
1 files changed, 12 insertions, 319 deletions
diff --git a/fs/gfs2/locking/dlm/thread.c b/fs/gfs2/locking/dlm/thread.c
index e53db6fd28ab..38823efd698c 100644
--- a/fs/gfs2/locking/dlm/thread.c
+++ b/fs/gfs2/locking/dlm/thread.c
@@ -9,367 +9,60 @@
9 9
10#include "lock_dlm.h" 10#include "lock_dlm.h"
11 11
12/* A lock placed on this queue is re-submitted to DLM as soon as the lock_dlm 12static inline int no_work(struct gdlm_ls *ls)
13 thread gets to it. */
14
15static void queue_submit(struct gdlm_lock *lp)
16{
17 struct gdlm_ls *ls = lp->ls;
18
19 spin_lock(&ls->async_lock);
20 list_add_tail(&lp->delay_list, &ls->submit);
21 spin_unlock(&ls->async_lock);
22 wake_up(&ls->thread_wait);
23}
24
25static void process_blocking(struct gdlm_lock *lp, int bast_mode)
26{
27 struct gdlm_ls *ls = lp->ls;
28 unsigned int cb = 0;
29
30 switch (gdlm_make_lmstate(bast_mode)) {
31 case LM_ST_EXCLUSIVE:
32 cb = LM_CB_NEED_E;
33 break;
34 case LM_ST_DEFERRED:
35 cb = LM_CB_NEED_D;
36 break;
37 case LM_ST_SHARED:
38 cb = LM_CB_NEED_S;
39 break;
40 default:
41 gdlm_assert(0, "unknown bast mode %u", lp->bast_mode);
42 }
43
44 ls->fscb(ls->sdp, cb, &lp->lockname);
45}
46
47static void wake_up_ast(struct gdlm_lock *lp)
48{
49 clear_bit(LFL_AST_WAIT, &lp->flags);
50 smp_mb__after_clear_bit();
51 wake_up_bit(&lp->flags, LFL_AST_WAIT);
52}
53
54static void process_complete(struct gdlm_lock *lp)
55{
56 struct gdlm_ls *ls = lp->ls;
57 struct lm_async_cb acb;
58 s16 prev_mode = lp->cur;
59
60 memset(&acb, 0, sizeof(acb));
61
62 if (lp->lksb.sb_status == -DLM_ECANCEL) {
63 log_info("complete dlm cancel %x,%llx flags %lx",
64 lp->lockname.ln_type,
65 (unsigned long long)lp->lockname.ln_number,
66 lp->flags);
67
68 lp->req = lp->cur;
69 acb.lc_ret |= LM_OUT_CANCELED;
70 if (lp->cur == DLM_LOCK_IV)
71 lp->lksb.sb_lkid = 0;
72 goto out;
73 }
74
75 if (test_and_clear_bit(LFL_DLM_UNLOCK, &lp->flags)) {
76 if (lp->lksb.sb_status != -DLM_EUNLOCK) {
77 log_info("unlock sb_status %d %x,%llx flags %lx",
78 lp->lksb.sb_status, lp->lockname.ln_type,
79 (unsigned long long)lp->lockname.ln_number,
80 lp->flags);
81 return;
82 }
83
84 lp->cur = DLM_LOCK_IV;
85 lp->req = DLM_LOCK_IV;
86 lp->lksb.sb_lkid = 0;
87
88 if (test_and_clear_bit(LFL_UNLOCK_DELETE, &lp->flags)) {
89 gdlm_delete_lp(lp);
90 return;
91 }
92 goto out;
93 }
94
95 if (lp->lksb.sb_flags & DLM_SBF_VALNOTVALID)
96 memset(lp->lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
97
98 if (lp->lksb.sb_flags & DLM_SBF_ALTMODE) {
99 if (lp->req == DLM_LOCK_PR)
100 lp->req = DLM_LOCK_CW;
101 else if (lp->req == DLM_LOCK_CW)
102 lp->req = DLM_LOCK_PR;
103 }
104
105 /*
106 * A canceled lock request. The lock was just taken off the delayed
107 * list and was never even submitted to dlm.
108 */
109
110 if (test_and_clear_bit(LFL_CANCEL, &lp->flags)) {
111 log_info("complete internal cancel %x,%llx",
112 lp->lockname.ln_type,
113 (unsigned long long)lp->lockname.ln_number);
114 lp->req = lp->cur;
115 acb.lc_ret |= LM_OUT_CANCELED;
116 goto out;
117 }
118
119 /*
120 * An error occured.
121 */
122
123 if (lp->lksb.sb_status) {
124 /* a "normal" error */
125 if ((lp->lksb.sb_status == -EAGAIN) &&
126 (lp->lkf & DLM_LKF_NOQUEUE)) {
127 lp->req = lp->cur;
128 if (lp->cur == DLM_LOCK_IV)
129 lp->lksb.sb_lkid = 0;
130 goto out;
131 }
132
133 /* this could only happen with cancels I think */
134 log_info("ast sb_status %d %x,%llx flags %lx",
135 lp->lksb.sb_status, lp->lockname.ln_type,
136 (unsigned long long)lp->lockname.ln_number,
137 lp->flags);
138 if (lp->lksb.sb_status == -EDEADLOCK &&
139 lp->ls->fsflags & LM_MFLAG_CONV_NODROP) {
140 lp->req = lp->cur;
141 acb.lc_ret |= LM_OUT_CONV_DEADLK;
142 if (lp->cur == DLM_LOCK_IV)
143 lp->lksb.sb_lkid = 0;
144 goto out;
145 } else
146 return;
147 }
148
149 /*
150 * This is an AST for an EX->EX conversion for sync_lvb from GFS.
151 */
152
153 if (test_and_clear_bit(LFL_SYNC_LVB, &lp->flags)) {
154 wake_up_ast(lp);
155 return;
156 }
157
158 /*
159 * A lock has been demoted to NL because it initially completed during
160 * BLOCK_LOCKS. Now it must be requested in the originally requested
161 * mode.
162 */
163
164 if (test_and_clear_bit(LFL_REREQUEST, &lp->flags)) {
165 gdlm_assert(lp->req == DLM_LOCK_NL, "%x,%llx",
166 lp->lockname.ln_type,
167 (unsigned long long)lp->lockname.ln_number);
168 gdlm_assert(lp->prev_req > DLM_LOCK_NL, "%x,%llx",
169 lp->lockname.ln_type,
170 (unsigned long long)lp->lockname.ln_number);
171
172 lp->cur = DLM_LOCK_NL;
173 lp->req = lp->prev_req;
174 lp->prev_req = DLM_LOCK_IV;
175 lp->lkf &= ~DLM_LKF_CONVDEADLK;
176
177 set_bit(LFL_NOCACHE, &lp->flags);
178
179 if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
180 !test_bit(LFL_NOBLOCK, &lp->flags))
181 gdlm_queue_delayed(lp);
182 else
183 queue_submit(lp);
184 return;
185 }
186
187 /*
188 * A request is granted during dlm recovery. It may be granted
189 * because the locks of a failed node were cleared. In that case,
190 * there may be inconsistent data beneath this lock and we must wait
191 * for recovery to complete to use it. When gfs recovery is done this
192 * granted lock will be converted to NL and then reacquired in this
193 * granted state.
194 */
195
196 if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
197 !test_bit(LFL_NOBLOCK, &lp->flags) &&
198 lp->req != DLM_LOCK_NL) {
199
200 lp->cur = lp->req;
201 lp->prev_req = lp->req;
202 lp->req = DLM_LOCK_NL;
203 lp->lkf |= DLM_LKF_CONVERT;
204 lp->lkf &= ~DLM_LKF_CONVDEADLK;
205
206 log_debug("rereq %x,%llx id %x %d,%d",
207 lp->lockname.ln_type,
208 (unsigned long long)lp->lockname.ln_number,
209 lp->lksb.sb_lkid, lp->cur, lp->req);
210
211 set_bit(LFL_REREQUEST, &lp->flags);
212 queue_submit(lp);
213 return;
214 }
215
216 /*
217 * DLM demoted the lock to NL before it was granted so GFS must be
218 * told it cannot cache data for this lock.
219 */
220
221 if (lp->lksb.sb_flags & DLM_SBF_DEMOTED)
222 set_bit(LFL_NOCACHE, &lp->flags);
223
224out:
225 /*
226 * This is an internal lock_dlm lock
227 */
228
229 if (test_bit(LFL_INLOCK, &lp->flags)) {
230 clear_bit(LFL_NOBLOCK, &lp->flags);
231 lp->cur = lp->req;
232 wake_up_ast(lp);
233 return;
234 }
235
236 /*
237 * Normal completion of a lock request. Tell GFS it now has the lock.
238 */
239
240 clear_bit(LFL_NOBLOCK, &lp->flags);
241 lp->cur = lp->req;
242
243 acb.lc_name = lp->lockname;
244 acb.lc_ret |= gdlm_make_lmstate(lp->cur);
245
246 if (!test_and_clear_bit(LFL_NOCACHE, &lp->flags) &&
247 (lp->cur > DLM_LOCK_NL) && (prev_mode > DLM_LOCK_NL))
248 acb.lc_ret |= LM_OUT_CACHEABLE;
249
250 ls->fscb(ls->sdp, LM_CB_ASYNC, &acb);
251}
252
253static inline int no_work(struct gdlm_ls *ls, int blocking)
254{ 13{
255 int ret; 14 int ret;
256 15
257 spin_lock(&ls->async_lock); 16 spin_lock(&ls->async_lock);
258 ret = list_empty(&ls->complete) && list_empty(&ls->submit); 17 ret = list_empty(&ls->submit);
259 if (ret && blocking)
260 ret = list_empty(&ls->blocking);
261 spin_unlock(&ls->async_lock); 18 spin_unlock(&ls->async_lock);
262 19
263 return ret; 20 return ret;
264} 21}
265 22
266static inline int check_drop(struct gdlm_ls *ls) 23static int gdlm_thread(void *data)
267{
268 if (!ls->drop_locks_count)
269 return 0;
270
271 if (time_after(jiffies, ls->drop_time + ls->drop_locks_period * HZ)) {
272 ls->drop_time = jiffies;
273 if (ls->all_locks_count >= ls->drop_locks_count)
274 return 1;
275 }
276 return 0;
277}
278
279static int gdlm_thread(void *data, int blist)
280{ 24{
281 struct gdlm_ls *ls = (struct gdlm_ls *) data; 25 struct gdlm_ls *ls = (struct gdlm_ls *) data;
282 struct gdlm_lock *lp = NULL; 26 struct gdlm_lock *lp = NULL;
283 uint8_t complete, blocking, submit, drop;
284
285 /* Only thread1 is allowed to do blocking callbacks since gfs
286 may wait for a completion callback within a blocking cb. */
287 27
288 while (!kthread_should_stop()) { 28 while (!kthread_should_stop()) {
289 wait_event_interruptible(ls->thread_wait, 29 wait_event_interruptible(ls->thread_wait,
290 !no_work(ls, blist) || kthread_should_stop()); 30 !no_work(ls) || kthread_should_stop());
291
292 complete = blocking = submit = drop = 0;
293 31
294 spin_lock(&ls->async_lock); 32 spin_lock(&ls->async_lock);
295 33
296 if (blist && !list_empty(&ls->blocking)) { 34 if (!list_empty(&ls->submit)) {
297 lp = list_entry(ls->blocking.next, struct gdlm_lock,
298 blist);
299 list_del_init(&lp->blist);
300 blocking = lp->bast_mode;
301 lp->bast_mode = 0;
302 } else if (!list_empty(&ls->complete)) {
303 lp = list_entry(ls->complete.next, struct gdlm_lock,
304 clist);
305 list_del_init(&lp->clist);
306 complete = 1;
307 } else if (!list_empty(&ls->submit)) {
308 lp = list_entry(ls->submit.next, struct gdlm_lock, 35 lp = list_entry(ls->submit.next, struct gdlm_lock,
309 delay_list); 36 delay_list);
310 list_del_init(&lp->delay_list); 37 list_del_init(&lp->delay_list);
311 submit = 1; 38 spin_unlock(&ls->async_lock);
39 gdlm_do_lock(lp);
40 spin_lock(&ls->async_lock);
312 } 41 }
313
314 drop = check_drop(ls);
315 spin_unlock(&ls->async_lock); 42 spin_unlock(&ls->async_lock);
316
317 if (complete)
318 process_complete(lp);
319
320 else if (blocking)
321 process_blocking(lp, blocking);
322
323 else if (submit)
324 gdlm_do_lock(lp);
325
326 if (drop)
327 ls->fscb(ls->sdp, LM_CB_DROPLOCKS, NULL);
328
329 schedule();
330 } 43 }
331 44
332 return 0; 45 return 0;
333} 46}
334 47
335static int gdlm_thread1(void *data)
336{
337 return gdlm_thread(data, 1);
338}
339
340static int gdlm_thread2(void *data)
341{
342 return gdlm_thread(data, 0);
343}
344
345int gdlm_init_threads(struct gdlm_ls *ls) 48int gdlm_init_threads(struct gdlm_ls *ls)
346{ 49{
347 struct task_struct *p; 50 struct task_struct *p;
348 int error; 51 int error;
349 52
350 p = kthread_run(gdlm_thread1, ls, "lock_dlm1"); 53 p = kthread_run(gdlm_thread, ls, "lock_dlm");
351 error = IS_ERR(p);
352 if (error) {
353 log_error("can't start lock_dlm1 thread %d", error);
354 return error;
355 }
356 ls->thread1 = p;
357
358 p = kthread_run(gdlm_thread2, ls, "lock_dlm2");
359 error = IS_ERR(p); 54 error = IS_ERR(p);
360 if (error) { 55 if (error) {
361 log_error("can't start lock_dlm2 thread %d", error); 56 log_error("can't start lock_dlm thread %d", error);
362 kthread_stop(ls->thread1);
363 return error; 57 return error;
364 } 58 }
365 ls->thread2 = p; 59 ls->thread = p;
366 60
367 return 0; 61 return 0;
368} 62}
369 63
370void gdlm_release_threads(struct gdlm_ls *ls) 64void gdlm_release_threads(struct gdlm_ls *ls)
371{ 65{
372 kthread_stop(ls->thread1); 66 kthread_stop(ls->thread);
373 kthread_stop(ls->thread2);
374} 67}
375 68
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