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[fs/lustre-release.git] / lustre / lov / lov_pool.c
1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see [sun.com URL with a
18  * copy of GPLv2].
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2012, 2014, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  *
36  * lustre/lov/lov_pool.c
37  *
38  * OST pool methods
39  *
40  * Author: Jacques-Charles LAFOUCRIERE <jc.lafoucriere@cea.fr>
41  * Author: Alex Lyashkov <Alexey.Lyashkov@Sun.COM>
42  * Author: Nathaniel Rutman <Nathan.Rutman@Sun.COM>
43  */
44
45 #define DEBUG_SUBSYSTEM S_LOV
46
47 #include <libcfs/libcfs.h>
48
49 #include <obd.h>
50 #include "lov_internal.h"
51
52 #define pool_tgt(_p, _i) \
53                 _p->pool_lobd->u.lov.lov_tgts[_p->pool_obds.op_array[_i]]
54
55 static void lov_pool_getref(struct pool_desc *pool)
56 {
57         CDEBUG(D_INFO, "pool %p\n", pool);
58         atomic_inc(&pool->pool_refcount);
59 }
60
61 static void lov_pool_putref(struct pool_desc *pool)
62 {
63         CDEBUG(D_INFO, "pool %p\n", pool);
64         if (atomic_dec_and_test(&pool->pool_refcount)) {
65                 LASSERT(hlist_unhashed(&pool->pool_hash));
66                 LASSERT(list_empty(&pool->pool_list));
67                 LASSERT(pool->pool_proc_entry == NULL);
68                 lov_ost_pool_free(&(pool->pool_obds));
69                 OBD_FREE_PTR(pool);
70                 EXIT;
71         }
72 }
73
74 static void lov_pool_putref_locked(struct pool_desc *pool)
75 {
76         CDEBUG(D_INFO, "pool %p\n", pool);
77         LASSERT(atomic_read(&pool->pool_refcount) > 1);
78
79         atomic_dec(&pool->pool_refcount);
80 }
81
82 /*
83  * hash function using a Rotating Hash algorithm
84  * Knuth, D. The Art of Computer Programming,
85  * Volume 3: Sorting and Searching,
86  * Chapter 6.4.
87  * Addison Wesley, 1973
88  */
89 static __u32 pool_hashfn(struct cfs_hash *hash_body, const void *key,
90                          unsigned mask)
91 {
92         int i;
93         __u32 result;
94         char *poolname;
95
96         result = 0;
97         poolname = (char *)key;
98         for (i = 0; i < LOV_MAXPOOLNAME; i++) {
99                 if (poolname[i] == '\0')
100                         break;
101                 result = (result << 4)^(result >> 28) ^  poolname[i];
102         }
103         return (result % mask);
104 }
105
106 static void *pool_key(struct hlist_node *hnode)
107 {
108         struct pool_desc *pool;
109
110         pool = hlist_entry(hnode, struct pool_desc, pool_hash);
111         return (pool->pool_name);
112 }
113
114 static int
115 pool_hashkey_keycmp(const void *key, struct hlist_node *compared_hnode)
116 {
117         char *pool_name;
118         struct pool_desc *pool;
119
120         pool_name = (char *)key;
121         pool = hlist_entry(compared_hnode, struct pool_desc, pool_hash);
122         return !strncmp(pool_name, pool->pool_name, LOV_MAXPOOLNAME);
123 }
124
125 static void *pool_hashobject(struct hlist_node *hnode)
126 {
127         return hlist_entry(hnode, struct pool_desc, pool_hash);
128 }
129
130 static void pool_hashrefcount_get(struct cfs_hash *hs, struct hlist_node *hnode)
131 {
132         struct pool_desc *pool;
133
134         pool = hlist_entry(hnode, struct pool_desc, pool_hash);
135         lov_pool_getref(pool);
136 }
137
138 static void pool_hashrefcount_put_locked(struct cfs_hash *hs,
139                                          struct hlist_node *hnode)
140 {
141         struct pool_desc *pool;
142
143         pool = hlist_entry(hnode, struct pool_desc, pool_hash);
144         lov_pool_putref_locked(pool);
145 }
146
147 struct cfs_hash_ops pool_hash_operations = {
148         .hs_hash        = pool_hashfn,
149         .hs_key         = pool_key,
150         .hs_keycmp      = pool_hashkey_keycmp,
151         .hs_object      = pool_hashobject,
152         .hs_get         = pool_hashrefcount_get,
153         .hs_put_locked  = pool_hashrefcount_put_locked,
154
155 };
156
157 #ifdef CONFIG_PROC_FS
158 /* ifdef needed for liblustre support */
159 /*
160  * pool /proc seq_file methods
161  */
162 /*
163  * iterator is used to go through the target pool entries
164  * index is the current entry index in the lp_array[] array
165  * index >= pos returned to the seq_file interface
166  * pos is from 0 to (pool->pool_obds.op_count - 1)
167  */
168 #define POOL_IT_MAGIC 0xB001CEA0
169 struct pool_iterator {
170         int magic;
171         struct pool_desc *pool;
172         int idx;        /* from 0 to pool_tgt_size - 1 */
173 };
174
175 static void *pool_proc_next(struct seq_file *s, void *v, loff_t *pos)
176 {
177         struct pool_iterator *iter = (struct pool_iterator *)s->private;
178         int prev_idx;
179
180         LASSERTF(iter->magic == POOL_IT_MAGIC, "%08X\n", iter->magic);
181
182         /* test if end of file */
183         if (*pos >= pool_tgt_count(iter->pool))
184                 return NULL;
185
186         /* iterate to find a non empty entry */
187         prev_idx = iter->idx;
188         down_read(&pool_tgt_rw_sem(iter->pool));
189         iter->idx++;
190         if (iter->idx == pool_tgt_count(iter->pool)) {
191                 iter->idx = prev_idx; /* we stay on the last entry */
192                 up_read(&pool_tgt_rw_sem(iter->pool));
193                 return NULL;
194         }
195         up_read(&pool_tgt_rw_sem(iter->pool));
196         (*pos)++;
197         /* return != NULL to continue */
198         return iter;
199 }
200
201 static void *pool_proc_start(struct seq_file *s, loff_t *pos)
202 {
203         struct pool_desc *pool = (struct pool_desc *)s->private;
204         struct pool_iterator *iter;
205
206         lov_pool_getref(pool);
207         if ((pool_tgt_count(pool) == 0) ||
208             (*pos >= pool_tgt_count(pool))) {
209                 /* iter is not created, so stop() has no way to
210                  * find pool to dec ref */
211                 lov_pool_putref(pool);
212                 return NULL;
213         }
214
215         OBD_ALLOC_PTR(iter);
216         if (!iter)
217                 return ERR_PTR(-ENOMEM);
218         iter->magic = POOL_IT_MAGIC;
219         iter->pool = pool;
220         iter->idx = 0;
221
222         /* we use seq_file private field to memorized iterator so
223          * we can free it at stop() */
224         /* /!\ do not forget to restore it to pool before freeing it */
225         s->private = iter;
226         if (*pos > 0) {
227                 loff_t i;
228                 void *ptr;
229
230                 i = 0;
231                 do {
232                      ptr = pool_proc_next(s, &iter, &i);
233                 } while ((i < *pos) && (ptr != NULL));
234                 return ptr;
235         }
236         return iter;
237 }
238
239 static void pool_proc_stop(struct seq_file *s, void *v)
240 {
241         struct pool_iterator *iter = (struct pool_iterator *)s->private;
242
243         /* in some cases stop() method is called 2 times, without
244          * calling start() method (see seq_read() from fs/seq_file.c)
245          * we have to free only if s->private is an iterator */
246         if ((iter) && (iter->magic == POOL_IT_MAGIC)) {
247                 /* we restore s->private so next call to pool_proc_start()
248                  * will work */
249                 s->private = iter->pool;
250                 lov_pool_putref(iter->pool);
251                 OBD_FREE_PTR(iter);
252         }
253         return;
254 }
255
256 static int pool_proc_show(struct seq_file *s, void *v)
257 {
258         struct pool_iterator *iter = (struct pool_iterator *)v;
259         struct lov_tgt_desc *tgt;
260
261         LASSERTF(iter->magic == POOL_IT_MAGIC, "%08X\n", iter->magic);
262         LASSERT(iter->pool != NULL);
263         LASSERT(iter->idx <= pool_tgt_count(iter->pool));
264
265         down_read(&pool_tgt_rw_sem(iter->pool));
266         tgt = pool_tgt(iter->pool, iter->idx);
267         up_read(&pool_tgt_rw_sem(iter->pool));
268         if (tgt)
269                 seq_printf(s, "%s\n", obd_uuid2str(&(tgt->ltd_uuid)));
270
271         return 0;
272 }
273
274 static struct seq_operations pool_proc_ops = {
275         .start          = pool_proc_start,
276         .next           = pool_proc_next,
277         .stop           = pool_proc_stop,
278         .show           = pool_proc_show,
279 };
280
281 static int pool_proc_open(struct inode *inode, struct file *file)
282 {
283         int rc;
284
285         rc = seq_open(file, &pool_proc_ops);
286         if (!rc) {
287                 struct seq_file *s = file->private_data;
288                 s->private = PDE_DATA(inode);
289         }
290         return rc;
291 }
292
293 static struct file_operations pool_proc_operations = {
294         .open           = pool_proc_open,
295         .read           = seq_read,
296         .llseek         = seq_lseek,
297         .release        = seq_release,
298 };
299 #endif /* CONFIG_PROC_FS */
300
301 void lov_dump_pool(int level, struct pool_desc *pool)
302 {
303         int i;
304
305         lov_pool_getref(pool);
306
307         CDEBUG(level, "pool "LOV_POOLNAMEF" has %d members\n",
308                pool->pool_name, pool->pool_obds.op_count);
309         down_read(&pool_tgt_rw_sem(pool));
310
311         for (i = 0; i < pool_tgt_count(pool) ; i++) {
312                 if (!pool_tgt(pool, i) || !(pool_tgt(pool, i))->ltd_exp)
313                         continue;
314                 CDEBUG(level, "pool "LOV_POOLNAMEF"[%d] = %s\n",
315                        pool->pool_name, i,
316                        obd_uuid2str(&((pool_tgt(pool, i))->ltd_uuid)));
317         }
318
319         up_read(&pool_tgt_rw_sem(pool));
320         lov_pool_putref(pool);
321 }
322
323 #define LOV_POOL_INIT_COUNT 2
324 int lov_ost_pool_init(struct ost_pool *op, unsigned int count)
325 {
326         ENTRY;
327
328         if (count == 0)
329                 count = LOV_POOL_INIT_COUNT;
330         op->op_array = NULL;
331         op->op_count = 0;
332         init_rwsem(&op->op_rw_sem);
333         op->op_size = count;
334         OBD_ALLOC(op->op_array, op->op_size * sizeof(op->op_array[0]));
335         if (op->op_array == NULL) {
336                 op->op_size = 0;
337                 RETURN(-ENOMEM);
338         }
339         EXIT;
340         return 0;
341 }
342
343 /* Caller must hold write op_rwlock */
344 int lov_ost_pool_extend(struct ost_pool *op, unsigned int min_count)
345 {
346         __u32 *new;
347         int new_size;
348
349         LASSERT(min_count != 0);
350
351         if (op->op_count < op->op_size)
352                 return 0;
353
354         new_size = max(min_count, 2 * op->op_size);
355         OBD_ALLOC(new, new_size * sizeof(op->op_array[0]));
356         if (new == NULL)
357                 return -ENOMEM;
358
359         /* copy old array to new one */
360         memcpy(new, op->op_array, op->op_size * sizeof(op->op_array[0]));
361         OBD_FREE(op->op_array, op->op_size * sizeof(op->op_array[0]));
362         op->op_array = new;
363         op->op_size = new_size;
364         return 0;
365 }
366
367 int lov_ost_pool_add(struct ost_pool *op, __u32 idx, unsigned int min_count)
368 {
369         int rc = 0, i;
370         ENTRY;
371
372         down_write(&op->op_rw_sem);
373
374         rc = lov_ost_pool_extend(op, min_count);
375         if (rc)
376                 GOTO(out, rc);
377
378         /* search ost in pool array */
379         for (i = 0; i < op->op_count; i++) {
380                 if (op->op_array[i] == idx)
381                         GOTO(out, rc = -EEXIST);
382         }
383         /* ost not found we add it */
384         op->op_array[op->op_count] = idx;
385         op->op_count++;
386         EXIT;
387 out:
388         up_write(&op->op_rw_sem);
389         return rc;
390 }
391
392 int lov_ost_pool_remove(struct ost_pool *op, __u32 idx)
393 {
394         int i;
395         ENTRY;
396
397         down_write(&op->op_rw_sem);
398
399         for (i = 0; i < op->op_count; i++) {
400                 if (op->op_array[i] == idx) {
401                         memmove(&op->op_array[i], &op->op_array[i + 1],
402                                 (op->op_count - i - 1) * sizeof(op->op_array[0]));
403                         op->op_count--;
404                         up_write(&op->op_rw_sem);
405                         EXIT;
406                         return 0;
407                 }
408         }
409
410         up_write(&op->op_rw_sem);
411         RETURN(-EINVAL);
412 }
413
414 int lov_ost_pool_free(struct ost_pool *op)
415 {
416         ENTRY;
417
418         if (op->op_size == 0)
419                 RETURN(0);
420
421         down_write(&op->op_rw_sem);
422
423         OBD_FREE(op->op_array, op->op_size * sizeof(op->op_array[0]));
424         op->op_array = NULL;
425         op->op_count = 0;
426         op->op_size = 0;
427
428         up_write(&op->op_rw_sem);
429         RETURN(0);
430 }
431
432
433 int lov_pool_new(struct obd_device *obd, char *poolname)
434 {
435         struct lov_obd *lov;
436         struct pool_desc *new_pool;
437         int rc;
438         ENTRY;
439
440         lov = &(obd->u.lov);
441
442         if (strlen(poolname) > LOV_MAXPOOLNAME)
443                 RETURN(-ENAMETOOLONG);
444
445         OBD_ALLOC_PTR(new_pool);
446         if (new_pool == NULL)
447                 RETURN(-ENOMEM);
448
449         strlcpy(new_pool->pool_name, poolname, sizeof(new_pool->pool_name));
450         new_pool->pool_lobd = obd;
451         /* ref count init to 1 because when created a pool is always used
452          * up to deletion
453          */
454         atomic_set(&new_pool->pool_refcount, 1);
455         rc = lov_ost_pool_init(&new_pool->pool_obds, 0);
456         if (rc)
457                 GOTO(out_err, rc);
458
459         INIT_HLIST_NODE(&new_pool->pool_hash);
460
461 #ifdef CONFIG_PROC_FS
462         /* get ref for /proc file */
463         lov_pool_getref(new_pool);
464         new_pool->pool_proc_entry = lprocfs_add_simple(lov->lov_pool_proc_entry,
465                                                        poolname, new_pool,
466                                                        &pool_proc_operations);
467         if (IS_ERR(new_pool->pool_proc_entry)) {
468                 CWARN("Cannot add proc pool entry "LOV_POOLNAMEF"\n", poolname);
469                 new_pool->pool_proc_entry = NULL;
470                 lov_pool_putref(new_pool);
471         }
472         CDEBUG(D_INFO, "pool %p - proc %p\n",
473                new_pool, new_pool->pool_proc_entry);
474 #endif
475
476         spin_lock(&obd->obd_dev_lock);
477         list_add_tail(&new_pool->pool_list, &lov->lov_pool_list);
478         lov->lov_pool_count++;
479         spin_unlock(&obd->obd_dev_lock);
480
481         /* add to find only when it fully ready  */
482         rc = cfs_hash_add_unique(lov->lov_pools_hash_body, poolname,
483                                  &new_pool->pool_hash);
484         if (rc)
485                 GOTO(out_err, rc = -EEXIST);
486
487         CDEBUG(D_CONFIG, LOV_POOLNAMEF" is pool #%d\n",
488                poolname, lov->lov_pool_count);
489
490         RETURN(0);
491
492 out_err:
493         spin_lock(&obd->obd_dev_lock);
494         list_del_init(&new_pool->pool_list);
495         lov->lov_pool_count--;
496         spin_unlock(&obd->obd_dev_lock);
497         lprocfs_remove(&new_pool->pool_proc_entry);
498         lov_ost_pool_free(&new_pool->pool_obds);
499         OBD_FREE_PTR(new_pool);
500
501         return rc;
502 }
503
504 int lov_pool_del(struct obd_device *obd, char *poolname)
505 {
506         struct lov_obd *lov;
507         struct pool_desc *pool;
508         ENTRY;
509
510         lov = &(obd->u.lov);
511
512         /* lookup and kill hash reference */
513         pool = cfs_hash_del_key(lov->lov_pools_hash_body, poolname);
514         if (pool == NULL)
515                 RETURN(-ENOENT);
516
517         if (pool->pool_proc_entry != NULL) {
518                 CDEBUG(D_INFO, "proc entry %p\n", pool->pool_proc_entry);
519                 lprocfs_remove(&pool->pool_proc_entry);
520                 lov_pool_putref(pool);
521         }
522
523         spin_lock(&obd->obd_dev_lock);
524         list_del_init(&pool->pool_list);
525         lov->lov_pool_count--;
526         spin_unlock(&obd->obd_dev_lock);
527
528         /* release last reference */
529         lov_pool_putref(pool);
530
531         RETURN(0);
532 }
533
534
535 int lov_pool_add(struct obd_device *obd, char *poolname, char *ostname)
536 {
537         struct obd_uuid ost_uuid;
538         struct lov_obd *lov;
539         struct pool_desc *pool;
540         unsigned int lov_idx;
541         int rc;
542         ENTRY;
543
544         lov = &(obd->u.lov);
545
546         pool = cfs_hash_lookup(lov->lov_pools_hash_body, poolname);
547         if (pool == NULL)
548                 RETURN(-ENOENT);
549
550         obd_str2uuid(&ost_uuid, ostname);
551
552
553         /* search ost in lov array */
554         obd_getref(obd);
555         for (lov_idx = 0; lov_idx < lov->desc.ld_tgt_count; lov_idx++) {
556                 if (!lov->lov_tgts[lov_idx])
557                         continue;
558                 if (obd_uuid_equals(&ost_uuid,
559                                     &(lov->lov_tgts[lov_idx]->ltd_uuid)))
560                         break;
561         }
562         /* test if ost found in lov */
563         if (lov_idx == lov->desc.ld_tgt_count)
564                 GOTO(out, rc = -EINVAL);
565
566         rc = lov_ost_pool_add(&pool->pool_obds, lov_idx, lov->lov_tgt_size);
567         if (rc)
568                 GOTO(out, rc);
569
570         CDEBUG(D_CONFIG, "Added %s to "LOV_POOLNAMEF" as member %d\n",
571                ostname, poolname,  pool_tgt_count(pool));
572
573         EXIT;
574 out:
575         obd_putref(obd);
576         lov_pool_putref(pool);
577         return rc;
578 }
579
580 int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
581 {
582         struct obd_uuid ost_uuid;
583         struct lov_obd *lov;
584         struct pool_desc *pool;
585         unsigned int lov_idx;
586         int rc = 0;
587         ENTRY;
588
589         lov = &(obd->u.lov);
590
591         pool = cfs_hash_lookup(lov->lov_pools_hash_body, poolname);
592         if (pool == NULL)
593                 RETURN(-ENOENT);
594
595         obd_str2uuid(&ost_uuid, ostname);
596
597         obd_getref(obd);
598         /* search ost in lov array, to get index */
599         for (lov_idx = 0; lov_idx < lov->desc.ld_tgt_count; lov_idx++) {
600                 if (!lov->lov_tgts[lov_idx])
601                         continue;
602
603                 if (obd_uuid_equals(&ost_uuid,
604                                     &(lov->lov_tgts[lov_idx]->ltd_uuid)))
605                         break;
606         }
607
608         /* test if ost found in lov */
609         if (lov_idx == lov->desc.ld_tgt_count)
610                 GOTO(out, rc = -EINVAL);
611
612         lov_ost_pool_remove(&pool->pool_obds, lov_idx);
613
614         CDEBUG(D_CONFIG, "%s removed from "LOV_POOLNAMEF"\n", ostname,
615                poolname);
616
617         EXIT;
618 out:
619         obd_putref(obd);
620         lov_pool_putref(pool);
621         return rc;
622 }