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13 * General Public License version 2 for more details (a copy is included
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20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2012, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * lustre/lov/lov_pool.c
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>
45 #define DEBUG_SUBSYSTEM S_LOV
47 #include "../../include/linux/libcfs/libcfs.h"
49 #include "../include/obd.h"
50 #include "lov_internal.h"
52 #define pool_tgt(_p, _i) \
53 _p->pool_lobd->u.lov.lov_tgts[_p->pool_obds.op_array[_i]]
55 static void lov_pool_getref(struct pool_desc *pool)
57 CDEBUG(D_INFO, "pool %p\n", pool);
58 atomic_inc(&pool->pool_refcount);
61 void lov_pool_putref(struct pool_desc *pool)
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_debugfs_entry);
68 lov_ost_pool_free(&(pool->pool_rr.lqr_pool));
69 lov_ost_pool_free(&(pool->pool_obds));
74 static void lov_pool_putref_locked(struct pool_desc *pool)
76 CDEBUG(D_INFO, "pool %p\n", pool);
77 LASSERT(atomic_read(&pool->pool_refcount) > 1);
79 atomic_dec(&pool->pool_refcount);
83 * hash function using a Rotating Hash algorithm
84 * Knuth, D. The Art of Computer Programming,
85 * Volume 3: Sorting and Searching,
87 * Addison Wesley, 1973
89 static __u32 pool_hashfn(struct cfs_hash *hash_body, const void *key, unsigned mask)
96 poolname = (char *)key;
97 for (i = 0; i < LOV_MAXPOOLNAME; i++) {
98 if (poolname[i] == '\0')
100 result = (result << 4)^(result >> 28) ^ poolname[i];
102 return (result % mask);
105 static void *pool_key(struct hlist_node *hnode)
107 struct pool_desc *pool;
109 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
110 return pool->pool_name;
113 static int pool_hashkey_keycmp(const void *key, struct hlist_node *compared_hnode)
116 struct pool_desc *pool;
118 pool_name = (char *)key;
119 pool = hlist_entry(compared_hnode, struct pool_desc, pool_hash);
120 return !strncmp(pool_name, pool->pool_name, LOV_MAXPOOLNAME);
123 static void *pool_hashobject(struct hlist_node *hnode)
125 return hlist_entry(hnode, struct pool_desc, pool_hash);
128 static void pool_hashrefcount_get(struct cfs_hash *hs, struct hlist_node *hnode)
130 struct pool_desc *pool;
132 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
133 lov_pool_getref(pool);
136 static void pool_hashrefcount_put_locked(struct cfs_hash *hs,
137 struct hlist_node *hnode)
139 struct pool_desc *pool;
141 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
142 lov_pool_putref_locked(pool);
145 struct cfs_hash_ops pool_hash_operations = {
146 .hs_hash = pool_hashfn,
148 .hs_keycmp = pool_hashkey_keycmp,
149 .hs_object = pool_hashobject,
150 .hs_get = pool_hashrefcount_get,
151 .hs_put_locked = pool_hashrefcount_put_locked,
156 * pool debugfs seq_file methods
159 * iterator is used to go through the target pool entries
160 * index is the current entry index in the lp_array[] array
161 * index >= pos returned to the seq_file interface
162 * pos is from 0 to (pool->pool_obds.op_count - 1)
164 #define POOL_IT_MAGIC 0xB001CEA0
165 struct pool_iterator {
167 struct pool_desc *pool;
168 int idx; /* from 0 to pool_tgt_size - 1 */
171 static void *pool_proc_next(struct seq_file *s, void *v, loff_t *pos)
173 struct pool_iterator *iter = (struct pool_iterator *)s->private;
176 LASSERTF(iter->magic == POOL_IT_MAGIC, "%08X\n", iter->magic);
178 /* test if end of file */
179 if (*pos >= pool_tgt_count(iter->pool))
182 /* iterate to find a non empty entry */
183 prev_idx = iter->idx;
184 down_read(&pool_tgt_rw_sem(iter->pool));
186 if (iter->idx == pool_tgt_count(iter->pool)) {
187 iter->idx = prev_idx; /* we stay on the last entry */
188 up_read(&pool_tgt_rw_sem(iter->pool));
191 up_read(&pool_tgt_rw_sem(iter->pool));
193 /* return != NULL to continue */
197 static void *pool_proc_start(struct seq_file *s, loff_t *pos)
199 struct pool_desc *pool = (struct pool_desc *)s->private;
200 struct pool_iterator *iter;
202 lov_pool_getref(pool);
203 if ((pool_tgt_count(pool) == 0) ||
204 (*pos >= pool_tgt_count(pool))) {
205 /* iter is not created, so stop() has no way to
206 * find pool to dec ref
208 lov_pool_putref(pool);
212 iter = kzalloc(sizeof(*iter), GFP_NOFS);
214 return ERR_PTR(-ENOMEM);
215 iter->magic = POOL_IT_MAGIC;
219 /* we use seq_file private field to memorized iterator so
220 * we can free it at stop()
222 /* /!\ do not forget to restore it to pool before freeing it */
230 ptr = pool_proc_next(s, &iter, &i);
231 } while ((i < *pos) && ptr);
237 static void pool_proc_stop(struct seq_file *s, void *v)
239 struct pool_iterator *iter = (struct pool_iterator *)s->private;
241 /* in some cases stop() method is called 2 times, without
242 * calling start() method (see seq_read() from fs/seq_file.c)
243 * we have to free only if s->private is an iterator
245 if ((iter) && (iter->magic == POOL_IT_MAGIC)) {
246 /* we restore s->private so next call to pool_proc_start()
249 s->private = iter->pool;
250 lov_pool_putref(iter->pool);
255 static int pool_proc_show(struct seq_file *s, void *v)
257 struct pool_iterator *iter = (struct pool_iterator *)v;
258 struct lov_tgt_desc *tgt;
260 LASSERTF(iter->magic == POOL_IT_MAGIC, "%08X\n", iter->magic);
262 LASSERT(iter->idx <= pool_tgt_count(iter->pool));
264 down_read(&pool_tgt_rw_sem(iter->pool));
265 tgt = pool_tgt(iter->pool, iter->idx);
266 up_read(&pool_tgt_rw_sem(iter->pool));
268 seq_printf(s, "%s\n", obd_uuid2str(&(tgt->ltd_uuid)));
273 static const struct seq_operations pool_proc_ops = {
274 .start = pool_proc_start,
275 .next = pool_proc_next,
276 .stop = pool_proc_stop,
277 .show = pool_proc_show,
280 static int pool_proc_open(struct inode *inode, struct file *file)
284 rc = seq_open(file, &pool_proc_ops);
286 struct seq_file *s = file->private_data;
288 s->private = inode->i_private;
293 static struct file_operations pool_proc_operations = {
294 .open = pool_proc_open,
297 .release = seq_release,
300 #define LOV_POOL_INIT_COUNT 2
301 int lov_ost_pool_init(struct ost_pool *op, unsigned int count)
304 count = LOV_POOL_INIT_COUNT;
307 init_rwsem(&op->op_rw_sem);
309 op->op_array = kcalloc(op->op_size, sizeof(op->op_array[0]), GFP_NOFS);
317 /* Caller must hold write op_rwlock */
318 int lov_ost_pool_extend(struct ost_pool *op, unsigned int min_count)
323 LASSERT(min_count != 0);
325 if (op->op_count < op->op_size)
328 new_size = max(min_count, 2 * op->op_size);
329 new = kcalloc(new_size, sizeof(op->op_array[0]), GFP_NOFS);
333 /* copy old array to new one */
334 memcpy(new, op->op_array, op->op_size * sizeof(op->op_array[0]));
337 op->op_size = new_size;
341 int lov_ost_pool_add(struct ost_pool *op, __u32 idx, unsigned int min_count)
345 down_write(&op->op_rw_sem);
347 rc = lov_ost_pool_extend(op, min_count);
351 /* search ost in pool array */
352 for (i = 0; i < op->op_count; i++) {
353 if (op->op_array[i] == idx) {
358 /* ost not found we add it */
359 op->op_array[op->op_count] = idx;
362 up_write(&op->op_rw_sem);
366 int lov_ost_pool_remove(struct ost_pool *op, __u32 idx)
370 down_write(&op->op_rw_sem);
372 for (i = 0; i < op->op_count; i++) {
373 if (op->op_array[i] == idx) {
374 memmove(&op->op_array[i], &op->op_array[i + 1],
375 (op->op_count - i - 1) * sizeof(op->op_array[0]));
377 up_write(&op->op_rw_sem);
382 up_write(&op->op_rw_sem);
386 int lov_ost_pool_free(struct ost_pool *op)
388 if (op->op_size == 0)
391 down_write(&op->op_rw_sem);
398 up_write(&op->op_rw_sem);
402 int lov_pool_new(struct obd_device *obd, char *poolname)
405 struct pool_desc *new_pool;
410 if (strlen(poolname) > LOV_MAXPOOLNAME)
411 return -ENAMETOOLONG;
413 new_pool = kzalloc(sizeof(*new_pool), GFP_NOFS);
417 strlcpy(new_pool->pool_name, poolname, sizeof(new_pool->pool_name));
418 new_pool->pool_lobd = obd;
419 /* ref count init to 1 because when created a pool is always used
422 atomic_set(&new_pool->pool_refcount, 1);
423 rc = lov_ost_pool_init(&new_pool->pool_obds, 0);
427 memset(&(new_pool->pool_rr), 0, sizeof(struct lov_qos_rr));
428 rc = lov_ost_pool_init(&new_pool->pool_rr.lqr_pool, 0);
430 goto out_free_pool_obds;
432 INIT_HLIST_NODE(&new_pool->pool_hash);
434 /* get ref for debugfs file */
435 lov_pool_getref(new_pool);
436 new_pool->pool_debugfs_entry = ldebugfs_add_simple(
437 lov->lov_pool_debugfs_entry,
439 &pool_proc_operations);
440 if (IS_ERR_OR_NULL(new_pool->pool_debugfs_entry)) {
441 CWARN("Cannot add debugfs pool entry "LOV_POOLNAMEF"\n",
443 new_pool->pool_debugfs_entry = NULL;
444 lov_pool_putref(new_pool);
446 CDEBUG(D_INFO, "pool %p - proc %p\n",
447 new_pool, new_pool->pool_debugfs_entry);
449 spin_lock(&obd->obd_dev_lock);
450 list_add_tail(&new_pool->pool_list, &lov->lov_pool_list);
451 lov->lov_pool_count++;
452 spin_unlock(&obd->obd_dev_lock);
454 /* add to find only when it fully ready */
455 rc = cfs_hash_add_unique(lov->lov_pools_hash_body, poolname,
456 &new_pool->pool_hash);
462 CDEBUG(D_CONFIG, LOV_POOLNAMEF" is pool #%d\n",
463 poolname, lov->lov_pool_count);
468 spin_lock(&obd->obd_dev_lock);
469 list_del_init(&new_pool->pool_list);
470 lov->lov_pool_count--;
471 spin_unlock(&obd->obd_dev_lock);
473 ldebugfs_remove(&new_pool->pool_debugfs_entry);
475 lov_ost_pool_free(&new_pool->pool_rr.lqr_pool);
477 lov_ost_pool_free(&new_pool->pool_obds);
482 int lov_pool_del(struct obd_device *obd, char *poolname)
485 struct pool_desc *pool;
489 /* lookup and kill hash reference */
490 pool = cfs_hash_del_key(lov->lov_pools_hash_body, poolname);
494 if (!IS_ERR_OR_NULL(pool->pool_debugfs_entry)) {
495 CDEBUG(D_INFO, "proc entry %p\n", pool->pool_debugfs_entry);
496 ldebugfs_remove(&pool->pool_debugfs_entry);
497 lov_pool_putref(pool);
500 spin_lock(&obd->obd_dev_lock);
501 list_del_init(&pool->pool_list);
502 lov->lov_pool_count--;
503 spin_unlock(&obd->obd_dev_lock);
505 /* release last reference */
506 lov_pool_putref(pool);
511 int lov_pool_add(struct obd_device *obd, char *poolname, char *ostname)
513 struct obd_uuid ost_uuid;
515 struct pool_desc *pool;
516 unsigned int lov_idx;
521 pool = cfs_hash_lookup(lov->lov_pools_hash_body, poolname);
525 obd_str2uuid(&ost_uuid, ostname);
527 /* search ost in lov array */
529 for (lov_idx = 0; lov_idx < lov->desc.ld_tgt_count; lov_idx++) {
530 if (!lov->lov_tgts[lov_idx])
532 if (obd_uuid_equals(&ost_uuid,
533 &(lov->lov_tgts[lov_idx]->ltd_uuid)))
536 /* test if ost found in lov */
537 if (lov_idx == lov->desc.ld_tgt_count) {
542 rc = lov_ost_pool_add(&pool->pool_obds, lov_idx, lov->lov_tgt_size);
546 pool->pool_rr.lqr_dirty = 1;
548 CDEBUG(D_CONFIG, "Added %s to "LOV_POOLNAMEF" as member %d\n",
549 ostname, poolname, pool_tgt_count(pool));
553 lov_pool_putref(pool);
557 int lov_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
559 struct obd_uuid ost_uuid;
561 struct pool_desc *pool;
562 unsigned int lov_idx;
567 pool = cfs_hash_lookup(lov->lov_pools_hash_body, poolname);
571 obd_str2uuid(&ost_uuid, ostname);
574 /* search ost in lov array, to get index */
575 for (lov_idx = 0; lov_idx < lov->desc.ld_tgt_count; lov_idx++) {
576 if (!lov->lov_tgts[lov_idx])
579 if (obd_uuid_equals(&ost_uuid,
580 &(lov->lov_tgts[lov_idx]->ltd_uuid)))
584 /* test if ost found in lov */
585 if (lov_idx == lov->desc.ld_tgt_count) {
590 lov_ost_pool_remove(&pool->pool_obds, lov_idx);
592 pool->pool_rr.lqr_dirty = 1;
594 CDEBUG(D_CONFIG, "%s removed from "LOV_POOLNAMEF"\n", ostname,
599 lov_pool_putref(pool);
603 int lov_check_index_in_pool(__u32 idx, struct pool_desc *pool)
607 /* caller may no have a ref on pool if it got the pool
608 * without calling lov_find_pool() (e.g. go through the lov pool
611 lov_pool_getref(pool);
613 down_read(&pool_tgt_rw_sem(pool));
615 for (i = 0; i < pool_tgt_count(pool); i++) {
616 if (pool_tgt_array(pool)[i] == idx) {
623 up_read(&pool_tgt_rw_sem(pool));
625 lov_pool_putref(pool);
629 struct pool_desc *lov_find_pool(struct lov_obd *lov, char *poolname)
631 struct pool_desc *pool;
634 if (poolname[0] != '\0') {
635 pool = cfs_hash_lookup(lov->lov_pools_hash_body, poolname);
637 CWARN("Request for an unknown pool ("LOV_POOLNAMEF")\n",
639 if (pool && (pool_tgt_count(pool) == 0)) {
640 CWARN("Request for an empty pool ("LOV_POOLNAMEF")\n",
642 /* pool is ignored, so we remove ref on it */
643 lov_pool_putref(pool);