4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
24 * Use is subject to license terms.
26 * Copyright (c) 2012, 2014, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
33 * lustre/lod/lod_pool.c
37 * This file provides code related to the Logical Object Device (LOD)
38 * handling of OST Pools on the MDT. Pools are named lists of targets
39 * that allow userspace to group targets that share a particlar property
40 * together so that users or kernel helpers can make decisions about file
41 * allocation based on these properties. For example, pools could be
42 * defined based on fault domains (e.g. separate racks of server nodes) so
43 * that RAID-1 mirroring could select targets from independent fault
44 * domains, or pools could define target performance characteristics so
45 * that applicatins could select IOP-optimized storage or stream-optimized
46 * storage for a particular output file.
48 * This file handles creation, lookup, and removal of pools themselves, as
49 * well as adding and removing targets to pools. It also handles lprocfs
50 * display of configured pool. The pools are accessed by name in the pool
51 * hash, and are refcounted to ensure proper pool structure lifetimes.
53 * Author: Jacques-Charles LAFOUCRIERE <jc.lafoucriere@cea.fr>
54 * Author: Alex Lyashkov <Alexey.Lyashkov@Sun.COM>
55 * Author: Nathaniel Rutman <Nathan.Rutman@Sun.COM>
58 #define DEBUG_SUBSYSTEM S_LOV
60 #include <libcfs/libcfs.h>
62 #include "lod_internal.h"
64 #define pool_tgt(_p, _i) OST_TGT(lu2lod_dev((_p)->pool_lobd->obd_lu_dev), \
65 (_p)->pool_obds.op_array[_i])
68 * Get a reference on the specified pool.
70 * To ensure the pool descriptor is not freed before the caller is finished
71 * with it. Any process that is accessing \a pool directly needs to hold
72 * reference on it, including /proc since a userspace thread may be holding
73 * the /proc file open and busy in the kernel.
75 * \param[in] pool pool descriptor on which to gain reference
77 static void pool_getref(struct pool_desc *pool)
79 CDEBUG(D_INFO, "pool %p\n", pool);
80 atomic_inc(&pool->pool_refcount);
84 * Drop a reference on the specified pool and free its memory if needed.
86 * One reference is held by the LOD OBD device while it is configured, from
87 * the time the configuration log defines the pool until the time when it is
88 * dropped when the LOD OBD is cleaned up or the pool is deleted. This means
89 * that the pool will not be freed while the LOD device is configured, unless
90 * it is explicitly destroyed by the sysadmin. The pool structure is freed
91 * after the last reference on the structure is released.
93 * \param[in] pool pool descriptor to drop reference on and possibly free
95 void lod_pool_putref(struct pool_desc *pool)
97 CDEBUG(D_INFO, "pool %p\n", pool);
98 if (atomic_dec_and_test(&pool->pool_refcount)) {
99 LASSERT(hlist_unhashed(&pool->pool_hash));
100 LASSERT(list_empty(&pool->pool_list));
101 LASSERT(pool->pool_proc_entry == NULL);
102 lod_ost_pool_free(&(pool->pool_rr.lqr_pool));
103 lod_ost_pool_free(&(pool->pool_obds));
110 * Drop the refcount in cases where the caller holds a spinlock.
112 * This is needed if the caller cannot be blocked while freeing memory.
113 * It assumes that there is some other known refcount held on the \a pool
114 * and the memory cannot actually be freed, but the refcounting needs to
117 * \param[in] pool pool descriptor on which to drop reference
119 static void pool_putref_locked(struct pool_desc *pool)
121 CDEBUG(D_INFO, "pool %p\n", pool);
122 LASSERT(atomic_read(&pool->pool_refcount) > 1);
124 atomic_dec(&pool->pool_refcount);
128 * Group of functions needed for cfs_hash implementation. This
129 * includes pool lookup, refcounting, and cleanup.
133 * Hash the pool name for use by the cfs_hash handlers.
135 * Use the standard DJB2 hash function for ASCII strings in Lustre.
137 * \param[in] hash_body hash structure where this key is embedded (unused)
138 * \param[in] key key to be hashed (in this case the pool name)
139 * \param[in] mask bitmask to limit the hash value to the desired size
141 * \retval computed hash value from \a key and limited by \a mask
143 static __u32 pool_hashfn(struct cfs_hash *hash_body, const void *key,
146 return cfs_hash_djb2_hash(key, strnlen(key, LOV_MAXPOOLNAME), mask);
150 * Return the actual key (pool name) from the hashed \a hnode.
152 * Allows extracting the key name when iterating over all hash entries.
154 * \param[in] hnode hash node found by lookup or iteration
156 * \retval char array referencing the pool name (no refcount)
158 static void *pool_key(struct hlist_node *hnode)
160 struct pool_desc *pool;
162 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
163 return pool->pool_name;
167 * Check if the specified hash key matches the hash node.
169 * This is needed in case there is a hash key collision, allowing the hash
170 * table lookup/iteration to distinguish between the two entries.
172 * \param[in] key key (pool name) being searched for
173 * \param[in] compared current entry being compared
175 * \retval 0 if \a key is the same as the key of \a compared
176 * \retval 1 if \a key is different from the key of \a compared
178 static int pool_hashkey_keycmp(const void *key, struct hlist_node *compared)
180 return !strncmp(key, pool_key(compared), LOV_MAXPOOLNAME);
184 * Return the actual pool data structure from the hash table entry.
186 * Once the hash table entry is found, extract the pool data from it.
187 * The return type of this function is void * because it needs to be
188 * assigned to the generic hash operations table.
190 * \param[in] hnode hash table entry
192 * \retval struct pool_desc for the specified \a hnode
194 static void *pool_hashobject(struct hlist_node *hnode)
196 return hlist_entry(hnode, struct pool_desc, pool_hash);
199 static void pool_hashrefcount_get(struct cfs_hash *hs, struct hlist_node *hnode)
201 struct pool_desc *pool;
203 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
207 static void pool_hashrefcount_put_locked(struct cfs_hash *hs,
208 struct hlist_node *hnode)
210 struct pool_desc *pool;
212 pool = hlist_entry(hnode, struct pool_desc, pool_hash);
213 pool_putref_locked(pool);
216 struct cfs_hash_ops pool_hash_operations = {
217 .hs_hash = pool_hashfn,
219 .hs_keycmp = pool_hashkey_keycmp,
220 .hs_object = pool_hashobject,
221 .hs_get = pool_hashrefcount_get,
222 .hs_put_locked = pool_hashrefcount_put_locked,
226 * Methods for /proc seq_file iteration of the defined pools.
229 #define POOL_IT_MAGIC 0xB001CEA0
230 struct lod_pool_iterator {
231 unsigned int lpi_magic; /* POOL_IT_MAGIC */
232 unsigned int lpi_idx; /* from 0 to pool_tgt_size - 1 */
233 struct pool_desc *lpi_pool;
237 * Return the next configured target within one pool for seq_file iteration.
239 * Iterator is used to go through the target entries of a single pool
240 * (i.e. the list of OSTs configured for a named pool).
241 * lpi_idx is the current target index in the pool's op_array[].
243 * The return type is a void * because this function is one of the
244 * struct seq_operations methods and must match the function template.
246 * \param[in] seq /proc sequence file iteration tracking structure
247 * \param[in] v unused
248 * \param[in] pos position within iteration; 0 to number of targets - 1
250 * \retval struct pool_iterator of the next pool descriptor
252 static void *pool_proc_next(struct seq_file *seq, void *v, loff_t *pos)
254 struct lod_pool_iterator *iter = seq->private;
257 LASSERTF(iter->lpi_magic == POOL_IT_MAGIC, "%08X\n", iter->lpi_magic);
259 /* test if end of file */
260 if (*pos >= pool_tgt_count(iter->lpi_pool))
263 /* iterate to find a non empty entry */
264 prev_idx = iter->lpi_idx;
266 if (iter->lpi_idx >= pool_tgt_count(iter->lpi_pool)) {
267 iter->lpi_idx = prev_idx; /* we stay on the last entry */
271 /* return != NULL to continue */
276 * Start seq_file iteration via /proc for a single pool.
278 * The \a pos parameter may be non-zero, indicating that the iteration
279 * is starting at some offset in the target list. Use the seq_file
280 * private field to memorize the iterator so we can free it at stop().
281 * Need to restore the private pointer to the pool before freeing it.
283 * \param[in] seq new sequence file structure to initialize
284 * \param[in] pos initial target number at which to start iteration
286 * \retval initialized pool iterator private structure
287 * \retval NULL if \a pos exceeds the number of targets in \a pool
288 * \retval negative error number on failure
290 static void *pool_proc_start(struct seq_file *seq, loff_t *pos)
292 struct pool_desc *pool = seq->private;
293 struct lod_pool_iterator *iter;
296 if ((pool_tgt_count(pool) == 0) ||
297 (*pos >= pool_tgt_count(pool))) {
298 /* iter is not created, so stop() has no way to
299 * find pool to dec ref */
300 lod_pool_putref(pool);
306 return ERR_PTR(-ENOMEM);
307 iter->lpi_magic = POOL_IT_MAGIC;
308 iter->lpi_pool = pool;
312 down_read(&pool_tgt_rw_sem(pool));
319 ptr = pool_proc_next(seq, &iter, &i);
320 } while ((i < *pos) && (ptr != NULL));
329 * Finish seq_file iteration for a single pool.
331 * Once iteration has been completed, the pool_iterator struct must be
332 * freed, and the seq_file private pointer restored to the pool, as it
333 * was initially when pool_proc_start() was called.
335 * In some cases the stop() method may be called 2 times, without calling
336 * the start() method (see seq_read() from fs/seq_file.c). We have to free
337 * the private iterator struct only if seq->private points to the iterator.
339 * \param[in] seq sequence file structure to clean up
340 * \param[in] v (unused)
342 static void pool_proc_stop(struct seq_file *seq, void *v)
344 struct lod_pool_iterator *iter = seq->private;
346 if (iter != NULL && iter->lpi_magic == POOL_IT_MAGIC) {
347 up_read(&pool_tgt_rw_sem(iter->lpi_pool));
348 seq->private = iter->lpi_pool;
349 lod_pool_putref(iter->lpi_pool);
355 * Print out one target entry from the pool for seq_file iteration.
357 * The currently referenced pool target is given by op_array[lpi_idx].
359 * \param[in] seq new sequence file structure to initialize
360 * \param[in] v (unused)
362 static int pool_proc_show(struct seq_file *seq, void *v)
364 struct lod_pool_iterator *iter = v;
365 struct lod_tgt_desc *tgt;
367 LASSERTF(iter->lpi_magic == POOL_IT_MAGIC, "%08X\n", iter->lpi_magic);
368 LASSERT(iter->lpi_pool != NULL);
369 LASSERT(iter->lpi_idx <= pool_tgt_count(iter->lpi_pool));
371 tgt = pool_tgt(iter->lpi_pool, iter->lpi_idx);
373 seq_printf(seq, "%s\n", obd_uuid2str(&(tgt->ltd_uuid)));
378 static const struct seq_operations pool_proc_ops = {
379 .start = pool_proc_start,
380 .next = pool_proc_next,
381 .stop = pool_proc_stop,
382 .show = pool_proc_show,
386 * Open a new /proc file for seq_file iteration of targets in one pool.
388 * Initialize the seq_file private pointer to reference the pool.
390 * \param inode inode to store iteration state for /proc
391 * \param file file descriptor to store iteration methods
393 * \retval 0 for success
394 * \retval negative error number on failure
396 static int pool_proc_open(struct inode *inode, struct file *file)
400 rc = seq_open(file, &pool_proc_ops);
402 struct seq_file *seq = file->private_data;
403 seq->private = PDE_DATA(inode);
408 static struct file_operations pool_proc_operations = {
409 .open = pool_proc_open,
412 .release = seq_release,
416 * Dump the pool target list into the Lustre debug log.
418 * This is a debugging function to allow dumping the list of targets
419 * in \a pool to the Lustre kernel debug log at the given \a level.
421 * This is not currently called by any existing code, but can be called
422 * from within gdb/crash to display the contents of the pool, or from
423 * code under development.
425 * \param[in] level Lustre debug level (D_INFO, D_WARN, D_ERROR, etc)
426 * \param[in] pool pool descriptor to be dumped
428 void lod_dump_pool(int level, struct pool_desc *pool)
434 CDEBUG(level, "pool "LOV_POOLNAMEF" has %d members\n",
435 pool->pool_name, pool->pool_obds.op_count);
436 down_read(&pool_tgt_rw_sem(pool));
438 for (i = 0; i < pool_tgt_count(pool) ; i++) {
439 if (!pool_tgt(pool, i) || !(pool_tgt(pool, i))->ltd_exp)
441 CDEBUG(level, "pool "LOV_POOLNAMEF"[%d] = %s\n",
443 obd_uuid2str(&((pool_tgt(pool, i))->ltd_uuid)));
446 up_read(&pool_tgt_rw_sem(pool));
447 lod_pool_putref(pool);
451 * Initialize the pool data structures at startup.
453 * Allocate and initialize the pool data structures with the specified
454 * array size. If pool count is not specified (\a count == 0), then
455 * POOL_INIT_COUNT will be used. Allocating a non-zero initial array
456 * size avoids the need to reallocate as new pools are added.
458 * \param[in] op pool structure
459 * \param[in] count initial size of the target op_array[] array
461 * \retval 0 indicates successful pool initialization
462 * \retval negative error number on failure
464 #define POOL_INIT_COUNT 2
465 int lod_ost_pool_init(struct ost_pool *op, unsigned int count)
470 count = POOL_INIT_COUNT;
473 init_rwsem(&op->op_rw_sem);
474 op->op_size = count * sizeof(op->op_array[0]);
475 OBD_ALLOC(op->op_array, op->op_size);
476 if (op->op_array == NULL) {
485 * Increase the op_array size to hold more targets in this pool.
487 * The size is increased to at least \a min_count, but may be larger
488 * for an existing pool since ->op_array[] is growing exponentially.
489 * Caller must hold write op_rwlock.
491 * \param[in] op pool structure
492 * \param[in] min_count minimum number of entries to handle
494 * \retval 0 on success
495 * \retval negative error number on failure.
497 int lod_ost_pool_extend(struct ost_pool *op, unsigned int min_count)
502 LASSERT(min_count != 0);
504 if (op->op_count * sizeof(op->op_array[0]) < op->op_size)
507 new_size = max_t(__u32, min_count * sizeof(op->op_array[0]),
509 OBD_ALLOC(new, new_size);
513 /* copy old array to new one */
514 memcpy(new, op->op_array, op->op_size);
515 OBD_FREE(op->op_array, op->op_size);
517 op->op_size = new_size;
523 * Add a new target to an existing pool.
525 * Add a new target device to the pool previously created and returned by
526 * lod_pool_new(). Each target can only be in each pool at most one time.
528 * \param[in] op target pool to add new entry
529 * \param[in] idx pool index number to add to the \a op array
530 * \param[in] min_count minimum number of entries to expect in the pool
532 * \retval 0 if target could be added to the pool
533 * \retval negative error if target \a idx was not added
535 int lod_ost_pool_add(struct ost_pool *op, __u32 idx, unsigned int min_count)
541 down_write(&op->op_rw_sem);
543 rc = lod_ost_pool_extend(op, min_count);
547 /* search ost in pool array */
548 for (i = 0; i < op->op_count; i++) {
549 if (op->op_array[i] == idx)
550 GOTO(out, rc = -EEXIST);
552 /* ost not found we add it */
553 op->op_array[op->op_count] = idx;
557 up_write(&op->op_rw_sem);
562 * Remove an existing pool from the system.
564 * The specified pool must have previously been allocated by
565 * lod_pool_new() and not have any target members in the pool.
566 * If the removed target is not the last, compact the array
567 * to remove empty spaces.
569 * \param[in] op pointer to the original data structure
570 * \param[in] idx target index to be removed
572 * \retval 0 on success
573 * \retval negative error number on failure
575 int lod_ost_pool_remove(struct ost_pool *op, __u32 idx)
580 down_write(&op->op_rw_sem);
582 for (i = 0; i < op->op_count; i++) {
583 if (op->op_array[i] == idx) {
584 memmove(&op->op_array[i], &op->op_array[i + 1],
585 (op->op_count - i - 1) *
586 sizeof(op->op_array[0]));
588 up_write(&op->op_rw_sem);
594 up_write(&op->op_rw_sem);
599 * Free the pool after it was emptied and removed from /proc.
601 * Note that all of the child/target entries referenced by this pool
602 * must have been removed by lod_ost_pool_remove() before it can be
603 * deleted from memory.
605 * \param[in] op pool to be freed.
607 * \retval 0 on success or if pool was already freed
609 int lod_ost_pool_free(struct ost_pool *op)
613 if (op->op_size == 0)
616 down_write(&op->op_rw_sem);
618 OBD_FREE(op->op_array, op->op_size);
623 up_write(&op->op_rw_sem);
628 * Allocate a new pool for the specified device.
630 * Allocate a new pool_desc structure for the specified \a new_pool
631 * device to create a pool with the given \a poolname. The new pool
632 * structure is created with a single reference, and is freed when the
633 * reference count drops to zero.
635 * \param[in] obd Lustre OBD device on which to add a pool iterator
636 * \param[in] poolname the name of the pool to be created
638 * \retval 0 in case of success
639 * \retval negative error code in case of error
641 int lod_pool_new(struct obd_device *obd, char *poolname)
643 struct lod_device *lod = lu2lod_dev(obd->obd_lu_dev);
644 struct pool_desc *new_pool;
648 if (strlen(poolname) > LOV_MAXPOOLNAME)
649 RETURN(-ENAMETOOLONG);
651 OBD_ALLOC_PTR(new_pool);
652 if (new_pool == NULL)
655 strlcpy(new_pool->pool_name, poolname, sizeof(new_pool->pool_name));
656 new_pool->pool_lobd = obd;
657 atomic_set(&new_pool->pool_refcount, 1);
658 rc = lod_ost_pool_init(&new_pool->pool_obds, 0);
662 lod_qos_rr_init(&new_pool->pool_rr);
663 rc = lod_ost_pool_init(&new_pool->pool_rr.lqr_pool, 0);
665 GOTO(out_free_pool_obds, rc);
667 INIT_HLIST_NODE(&new_pool->pool_hash);
669 #ifdef CONFIG_PROC_FS
670 pool_getref(new_pool);
671 new_pool->pool_proc_entry = lprocfs_add_simple(lod->lod_pool_proc_entry,
673 &pool_proc_operations);
674 if (IS_ERR(new_pool->pool_proc_entry)) {
675 CDEBUG(D_CONFIG, "%s: cannot add proc entry "LOV_POOLNAMEF"\n",
676 obd->obd_name, poolname);
677 new_pool->pool_proc_entry = NULL;
678 lod_pool_putref(new_pool);
680 CDEBUG(D_INFO, "pool %p - proc %p\n", new_pool,
681 new_pool->pool_proc_entry);
684 spin_lock(&obd->obd_dev_lock);
685 list_add_tail(&new_pool->pool_list, &lod->lod_pool_list);
686 lod->lod_pool_count++;
687 spin_unlock(&obd->obd_dev_lock);
689 /* add to find only when it fully ready */
690 rc = cfs_hash_add_unique(lod->lod_pools_hash_body, poolname,
691 &new_pool->pool_hash);
693 GOTO(out_err, rc = -EEXIST);
695 CDEBUG(D_CONFIG, LOV_POOLNAMEF" is pool #%d\n",
696 poolname, lod->lod_pool_count);
701 spin_lock(&obd->obd_dev_lock);
702 list_del_init(&new_pool->pool_list);
703 lod->lod_pool_count--;
704 spin_unlock(&obd->obd_dev_lock);
706 lprocfs_remove(&new_pool->pool_proc_entry);
708 lod_ost_pool_free(&new_pool->pool_rr.lqr_pool);
710 lod_ost_pool_free(&new_pool->pool_obds);
711 OBD_FREE_PTR(new_pool);
716 * Remove the named pool from the OBD device.
718 * \param[in] obd OBD device on which pool was previously created
719 * \param[in] poolname name of pool to remove from \a obd
721 * \retval 0 on successfully removing the pool
722 * \retval negative error numbers for failures
724 int lod_pool_del(struct obd_device *obd, char *poolname)
726 struct lod_device *lod = lu2lod_dev(obd->obd_lu_dev);
727 struct pool_desc *pool;
730 /* lookup and kill hash reference */
731 pool = cfs_hash_del_key(lod->lod_pools_hash_body, poolname);
735 if (pool->pool_proc_entry != NULL) {
736 CDEBUG(D_INFO, "proc entry %p\n", pool->pool_proc_entry);
737 lprocfs_remove(&pool->pool_proc_entry);
738 lod_pool_putref(pool);
741 spin_lock(&obd->obd_dev_lock);
742 list_del_init(&pool->pool_list);
743 lod->lod_pool_count--;
744 spin_unlock(&obd->obd_dev_lock);
746 /* release last reference */
747 lod_pool_putref(pool);
753 * Add a single target device to the named pool.
755 * Add the target specified by \a ostname to the specified \a poolname.
757 * \param[in] obd OBD device on which to add the pool
758 * \param[in] poolname name of the pool to which to add the target \a ostname
759 * \param[in] ostname name of the target device to be added
761 * \retval 0 if \a ostname was (previously) added to the named pool
762 * \retval negative error number on failure
764 int lod_pool_add(struct obd_device *obd, char *poolname, char *ostname)
766 struct lod_device *lod = lu2lod_dev(obd->obd_lu_dev);
767 struct obd_uuid ost_uuid;
768 struct pool_desc *pool;
773 pool = cfs_hash_lookup(lod->lod_pools_hash_body, poolname);
777 obd_str2uuid(&ost_uuid, ostname);
779 /* search ost in lod array */
780 lod_getref(&lod->lod_ost_descs);
781 lod_foreach_ost(lod, idx) {
782 if (obd_uuid_equals(&ost_uuid, &OST_TGT(lod, idx)->ltd_uuid)) {
791 rc = lod_ost_pool_add(&pool->pool_obds, idx, lod->lod_osts_size);
795 pool->pool_rr.lqr_dirty = 1;
797 CDEBUG(D_CONFIG, "Added %s to "LOV_POOLNAMEF" as member %d\n",
798 ostname, poolname, pool_tgt_count(pool));
802 lod_putref(lod, &lod->lod_ost_descs);
803 lod_pool_putref(pool);
808 * Remove the named target from the specified pool.
810 * Remove one target named \a ostname from \a poolname. The \a ostname
811 * is searched for in the lod_device lod_ost_bitmap array, to ensure the
812 * specified name actually exists in the pool.
814 * \param[in] obd OBD device from which to remove \a poolname
815 * \param[in] poolname name of the pool to be changed
816 * \param[in] ostname name of the target to remove from \a poolname
818 * \retval 0 on successfully removing \a ostname from the pool
819 * \retval negative number on error (e.g. \a ostname not in pool)
821 int lod_pool_remove(struct obd_device *obd, char *poolname, char *ostname)
823 struct lod_device *lod = lu2lod_dev(obd->obd_lu_dev);
824 struct obd_uuid ost_uuid;
825 struct pool_desc *pool;
830 pool = cfs_hash_lookup(lod->lod_pools_hash_body, poolname);
834 obd_str2uuid(&ost_uuid, ostname);
836 lod_getref(&lod->lod_ost_descs);
837 cfs_foreach_bit(lod->lod_ost_bitmap, idx) {
838 if (obd_uuid_equals(&ost_uuid, &OST_TGT(lod, idx)->ltd_uuid)) {
844 /* test if ost found in lod array */
848 lod_ost_pool_remove(&pool->pool_obds, idx);
850 pool->pool_rr.lqr_dirty = 1;
852 CDEBUG(D_CONFIG, "%s removed from "LOV_POOLNAMEF"\n", ostname,
857 lod_putref(lod, &lod->lod_ost_descs);
858 lod_pool_putref(pool);
863 * Check if the specified target exists in the pool.
865 * The caller may not have a reference on \a pool if it got the pool without
866 * calling lod_find_pool() (e.g. directly from the lod pool list)
868 * \param[in] idx Target index to check
869 * \param[in] pool Pool in which to check if target is added.
871 * \retval 0 successfully found index in \a pool
872 * \retval negative error if device not found in \a pool
874 int lod_check_index_in_pool(__u32 idx, struct pool_desc *pool)
882 down_read(&pool_tgt_rw_sem(pool));
884 for (i = 0; i < pool_tgt_count(pool); i++) {
885 if (pool_tgt_array(pool)[i] == idx)
891 up_read(&pool_tgt_rw_sem(pool));
893 lod_pool_putref(pool);
898 * Find the pool descriptor for the specified pool and return it with a
899 * reference to the caller if found.
901 * \param[in] lod LOD on which the pools are configured
902 * \param[in] poolname NUL-terminated name of the pool
904 * \retval pointer to pool descriptor on success
905 * \retval NULL if \a poolname could not be found or poolname is empty
907 struct pool_desc *lod_find_pool(struct lod_device *lod, char *poolname)
909 struct pool_desc *pool;
912 if (poolname[0] != '\0') {
913 pool = cfs_hash_lookup(lod->lod_pools_hash_body, poolname);
915 CDEBUG(D_CONFIG, "%s: request for an unknown pool ("
917 lod->lod_child_exp->exp_obd->obd_name, poolname);
918 if (pool != NULL && pool_tgt_count(pool) == 0) {
919 CDEBUG(D_CONFIG, "%s: request for an empty pool ("
921 lod->lod_child_exp->exp_obd->obd_name, poolname);
922 /* pool is ignored, so we remove ref on it */
923 lod_pool_putref(pool);