2 * pNFS functions to call and manage layout drivers.
4 * Copyright (c) 2002 [year of first publication]
5 * The Regents of the University of Michigan
8 * Dean Hildebrand <dhildebz@umich.edu>
10 * Permission is granted to use, copy, create derivative works, and
11 * redistribute this software and such derivative works for any purpose,
12 * so long as the name of the University of Michigan is not used in
13 * any advertising or publicity pertaining to the use or distribution
14 * of this software without specific, written prior authorization. If
15 * the above copyright notice or any other identification of the
16 * University of Michigan is included in any copy of any portion of
17 * this software, then the disclaimer below must also be included.
19 * This software is provided as is, without representation or warranty
20 * of any kind either express or implied, including without limitation
21 * the implied warranties of merchantability, fitness for a particular
22 * purpose, or noninfringement. The Regents of the University of
23 * Michigan shall not be liable for any damages, including special,
24 * indirect, incidental, or consequential damages, with respect to any
25 * claim arising out of or in connection with the use of the software,
26 * even if it has been or is hereafter advised of the possibility of
30 #include <linux/nfs_fs.h>
34 #define NFSDBG_FACILITY NFSDBG_PNFS
39 * protects pnfs_modules_tbl.
41 static DEFINE_SPINLOCK(pnfs_spinlock);
44 * pnfs_modules_tbl holds all pnfs modules
46 static LIST_HEAD(pnfs_modules_tbl);
48 /* Return the registered pnfs layout driver module matching given id */
49 static struct pnfs_layoutdriver_type *
50 find_pnfs_driver_locked(u32 id)
52 struct pnfs_layoutdriver_type *local;
54 list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
59 dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
63 static struct pnfs_layoutdriver_type *
64 find_pnfs_driver(u32 id)
66 struct pnfs_layoutdriver_type *local;
68 spin_lock(&pnfs_spinlock);
69 local = find_pnfs_driver_locked(id);
70 spin_unlock(&pnfs_spinlock);
75 unset_pnfs_layoutdriver(struct nfs_server *nfss)
77 if (nfss->pnfs_curr_ld) {
78 nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
79 module_put(nfss->pnfs_curr_ld->owner);
81 nfss->pnfs_curr_ld = NULL;
85 * Try to set the server's pnfs module to the pnfs layout type specified by id.
86 * Currently only one pNFS layout driver per filesystem is supported.
88 * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
91 set_pnfs_layoutdriver(struct nfs_server *server, u32 id)
93 struct pnfs_layoutdriver_type *ld_type = NULL;
97 if (!(server->nfs_client->cl_exchange_flags &
98 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
99 printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__,
100 id, server->nfs_client->cl_exchange_flags);
103 ld_type = find_pnfs_driver(id);
105 request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
106 ld_type = find_pnfs_driver(id);
108 dprintk("%s: No pNFS module found for %u.\n",
113 if (!try_module_get(ld_type->owner)) {
114 dprintk("%s: Could not grab reference on module\n", __func__);
117 server->pnfs_curr_ld = ld_type;
118 if (ld_type->set_layoutdriver(server)) {
120 "%s: Error initializing mount point for layout driver %u.\n",
122 module_put(ld_type->owner);
125 dprintk("%s: pNFS module for %u set\n", __func__, id);
129 dprintk("%s: Using NFSv4 I/O\n", __func__);
130 server->pnfs_curr_ld = NULL;
134 pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
136 int status = -EINVAL;
137 struct pnfs_layoutdriver_type *tmp;
139 if (ld_type->id == 0) {
140 printk(KERN_ERR "%s id 0 is reserved\n", __func__);
143 if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
144 printk(KERN_ERR "%s Layout driver must provide "
145 "alloc_lseg and free_lseg.\n", __func__);
149 spin_lock(&pnfs_spinlock);
150 tmp = find_pnfs_driver_locked(ld_type->id);
152 list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
154 dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
157 printk(KERN_ERR "%s Module with id %d already loaded!\n",
158 __func__, ld_type->id);
160 spin_unlock(&pnfs_spinlock);
164 EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
167 pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
169 dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
170 spin_lock(&pnfs_spinlock);
171 list_del(&ld_type->pnfs_tblid);
172 spin_unlock(&pnfs_spinlock);
174 EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
177 * pNFS client layout cache
180 /* Need to hold i_lock if caller does not already hold reference */
182 get_layout_hdr(struct pnfs_layout_hdr *lo)
184 atomic_inc(&lo->plh_refcount);
188 destroy_layout_hdr(struct pnfs_layout_hdr *lo)
190 dprintk("%s: freeing layout cache %p\n", __func__, lo);
191 BUG_ON(!list_empty(&lo->plh_layouts));
192 NFS_I(lo->plh_inode)->layout = NULL;
197 put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
199 if (atomic_dec_and_test(&lo->plh_refcount))
200 destroy_layout_hdr(lo);
204 put_layout_hdr(struct pnfs_layout_hdr *lo)
206 struct inode *inode = lo->plh_inode;
208 if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
209 destroy_layout_hdr(lo);
210 spin_unlock(&inode->i_lock);
215 init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
217 INIT_LIST_HEAD(&lseg->pls_list);
218 atomic_set(&lseg->pls_refcount, 1);
220 set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
221 lseg->pls_layout = lo;
224 static void free_lseg(struct pnfs_layout_segment *lseg)
226 struct inode *ino = lseg->pls_layout->plh_inode;
228 NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
229 /* Matched by get_layout_hdr in pnfs_insert_layout */
230 put_layout_hdr(NFS_I(ino)->layout);
233 /* The use of tmp_list is necessary because pnfs_curr_ld->free_lseg
234 * could sleep, so must be called outside of the lock.
235 * Returns 1 if object was removed, otherwise return 0.
238 put_lseg_locked(struct pnfs_layout_segment *lseg,
239 struct list_head *tmp_list)
241 dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
242 atomic_read(&lseg->pls_refcount),
243 test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
244 if (atomic_dec_and_test(&lseg->pls_refcount)) {
245 struct inode *ino = lseg->pls_layout->plh_inode;
247 BUG_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
248 list_del(&lseg->pls_list);
249 if (list_empty(&lseg->pls_layout->plh_segs)) {
250 struct nfs_client *clp;
252 clp = NFS_SERVER(ino)->nfs_client;
253 spin_lock(&clp->cl_lock);
254 /* List does not take a reference, so no need for put here */
255 list_del_init(&lseg->pls_layout->plh_layouts);
256 spin_unlock(&clp->cl_lock);
257 clear_bit(NFS_LAYOUT_BULK_RECALL, &lseg->pls_layout->plh_flags);
259 list_add(&lseg->pls_list, tmp_list);
266 should_free_lseg(u32 lseg_iomode, u32 recall_iomode)
268 return (recall_iomode == IOMODE_ANY ||
269 lseg_iomode == recall_iomode);
272 /* Returns 1 if lseg is removed from list, 0 otherwise */
273 static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
274 struct list_head *tmp_list)
278 if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
279 /* Remove the reference keeping the lseg in the
280 * list. It will now be removed when all
281 * outstanding io is finished.
283 rv = put_lseg_locked(lseg, tmp_list);
288 /* Returns count of number of matching invalid lsegs remaining in list
292 mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
293 struct list_head *tmp_list,
296 struct pnfs_layout_segment *lseg, *next;
297 int invalid = 0, removed = 0;
299 dprintk("%s:Begin lo %p\n", __func__, lo);
301 list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
302 if (should_free_lseg(lseg->pls_range.iomode, iomode)) {
303 dprintk("%s: freeing lseg %p iomode %d "
304 "offset %llu length %llu\n", __func__,
305 lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
306 lseg->pls_range.length);
308 removed += mark_lseg_invalid(lseg, tmp_list);
310 dprintk("%s:Return %i\n", __func__, invalid - removed);
311 return invalid - removed;
315 pnfs_free_lseg_list(struct list_head *free_me)
317 struct pnfs_layout_segment *lseg, *tmp;
319 list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
320 list_del(&lseg->pls_list);
326 pnfs_destroy_layout(struct nfs_inode *nfsi)
328 struct pnfs_layout_hdr *lo;
331 spin_lock(&nfsi->vfs_inode.i_lock);
334 set_bit(NFS_LAYOUT_DESTROYED, &nfsi->layout->plh_flags);
335 mark_matching_lsegs_invalid(lo, &tmp_list, IOMODE_ANY);
336 /* Matched by refcount set to 1 in alloc_init_layout_hdr */
337 put_layout_hdr_locked(lo);
339 spin_unlock(&nfsi->vfs_inode.i_lock);
340 pnfs_free_lseg_list(&tmp_list);
344 * Called by the state manger to remove all layouts established under an
348 pnfs_destroy_all_layouts(struct nfs_client *clp)
350 struct pnfs_layout_hdr *lo;
353 spin_lock(&clp->cl_lock);
354 list_splice_init(&clp->cl_layouts, &tmp_list);
355 spin_unlock(&clp->cl_lock);
357 while (!list_empty(&tmp_list)) {
358 lo = list_entry(tmp_list.next, struct pnfs_layout_hdr,
360 dprintk("%s freeing layout for inode %lu\n", __func__,
361 lo->plh_inode->i_ino);
362 pnfs_destroy_layout(NFS_I(lo->plh_inode));
366 /* update lo->plh_stateid with new if is more recent */
368 pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
373 oldseq = be32_to_cpu(lo->plh_stateid.stateid.seqid);
374 newseq = be32_to_cpu(new->stateid.seqid);
375 if ((int)(newseq - oldseq) > 0) {
376 memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
377 if (update_barrier) {
378 u32 new_barrier = be32_to_cpu(new->stateid.seqid);
380 if ((int)(new_barrier - lo->plh_barrier))
381 lo->plh_barrier = new_barrier;
383 /* Because of wraparound, we want to keep the barrier
384 * "close" to the current seqids. It needs to be
385 * within 2**31 to count as "behind", so if it
386 * gets too near that limit, give us a litle leeway
387 * and bring it to within 2**30.
388 * NOTE - and yes, this is all unsigned arithmetic.
390 if (unlikely((newseq - lo->plh_barrier) > (3 << 29)))
391 lo->plh_barrier = newseq - (1 << 30);
396 /* lget is set to 1 if called from inside send_layoutget call chain */
398 pnfs_layoutgets_blocked(struct pnfs_layout_hdr *lo, nfs4_stateid *stateid,
402 (int)(lo->plh_barrier - be32_to_cpu(stateid->stateid.seqid)) >= 0)
404 return test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
405 (list_empty(&lo->plh_segs) &&
406 (atomic_read(&lo->plh_outstanding) > lget));
410 pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
411 struct nfs4_state *open_state)
415 dprintk("--> %s\n", __func__);
416 spin_lock(&lo->plh_inode->i_lock);
417 if (pnfs_layoutgets_blocked(lo, NULL, 1)) {
419 } else if (list_empty(&lo->plh_segs)) {
423 seq = read_seqbegin(&open_state->seqlock);
424 memcpy(dst->data, open_state->stateid.data,
425 sizeof(open_state->stateid.data));
426 } while (read_seqretry(&open_state->seqlock, seq));
428 memcpy(dst->data, lo->plh_stateid.data, sizeof(lo->plh_stateid.data));
429 spin_unlock(&lo->plh_inode->i_lock);
430 dprintk("<-- %s\n", __func__);
435 * Get layout from server.
436 * for now, assume that whole file layouts are requested.
438 * arg->length: all ones
440 static struct pnfs_layout_segment *
441 send_layoutget(struct pnfs_layout_hdr *lo,
442 struct nfs_open_context *ctx,
445 struct inode *ino = lo->plh_inode;
446 struct nfs_server *server = NFS_SERVER(ino);
447 struct nfs4_layoutget *lgp;
448 struct pnfs_layout_segment *lseg = NULL;
450 dprintk("--> %s\n", __func__);
453 lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
456 lgp->args.minlength = NFS4_MAX_UINT64;
457 lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
458 lgp->args.range.iomode = iomode;
459 lgp->args.range.offset = 0;
460 lgp->args.range.length = NFS4_MAX_UINT64;
461 lgp->args.type = server->pnfs_curr_ld->id;
462 lgp->args.inode = ino;
463 lgp->args.ctx = get_nfs_open_context(ctx);
466 /* Synchronously retrieve layout information from server and
469 nfs4_proc_layoutget(lgp);
471 /* remember that LAYOUTGET failed and suspend trying */
472 set_bit(lo_fail_bit(iomode), &lo->plh_flags);
478 * Compare two layout segments for sorting into layout cache.
479 * We want to preferentially return RW over RO layouts, so ensure those
483 cmp_layout(u32 iomode1, u32 iomode2)
485 /* read > read/write */
486 return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ);
490 pnfs_insert_layout(struct pnfs_layout_hdr *lo,
491 struct pnfs_layout_segment *lseg)
493 struct pnfs_layout_segment *lp;
496 dprintk("%s:Begin\n", __func__);
498 assert_spin_locked(&lo->plh_inode->i_lock);
499 list_for_each_entry(lp, &lo->plh_segs, pls_list) {
500 if (cmp_layout(lp->pls_range.iomode, lseg->pls_range.iomode) > 0)
502 list_add_tail(&lseg->pls_list, &lp->pls_list);
503 dprintk("%s: inserted lseg %p "
504 "iomode %d offset %llu length %llu before "
505 "lp %p iomode %d offset %llu length %llu\n",
506 __func__, lseg, lseg->pls_range.iomode,
507 lseg->pls_range.offset, lseg->pls_range.length,
508 lp, lp->pls_range.iomode, lp->pls_range.offset,
509 lp->pls_range.length);
514 list_add_tail(&lseg->pls_list, &lo->plh_segs);
515 dprintk("%s: inserted lseg %p "
516 "iomode %d offset %llu length %llu at tail\n",
517 __func__, lseg, lseg->pls_range.iomode,
518 lseg->pls_range.offset, lseg->pls_range.length);
522 dprintk("%s:Return\n", __func__);
525 static struct pnfs_layout_hdr *
526 alloc_init_layout_hdr(struct inode *ino)
528 struct pnfs_layout_hdr *lo;
530 lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL);
533 atomic_set(&lo->plh_refcount, 1);
534 INIT_LIST_HEAD(&lo->plh_layouts);
535 INIT_LIST_HEAD(&lo->plh_segs);
536 INIT_LIST_HEAD(&lo->plh_bulk_recall);
541 static struct pnfs_layout_hdr *
542 pnfs_find_alloc_layout(struct inode *ino)
544 struct nfs_inode *nfsi = NFS_I(ino);
545 struct pnfs_layout_hdr *new = NULL;
547 dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
549 assert_spin_locked(&ino->i_lock);
551 if (test_bit(NFS_LAYOUT_DESTROYED, &nfsi->layout->plh_flags))
556 spin_unlock(&ino->i_lock);
557 new = alloc_init_layout_hdr(ino);
558 spin_lock(&ino->i_lock);
560 if (likely(nfsi->layout == NULL)) /* Won the race? */
568 * iomode matching rules:
579 is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode)
581 return (iomode != IOMODE_RW || lseg->pls_range.iomode == IOMODE_RW);
585 * lookup range in layout
587 static struct pnfs_layout_segment *
588 pnfs_find_lseg(struct pnfs_layout_hdr *lo, u32 iomode)
590 struct pnfs_layout_segment *lseg, *ret = NULL;
592 dprintk("%s:Begin\n", __func__);
594 assert_spin_locked(&lo->plh_inode->i_lock);
595 list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
596 if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
597 is_matching_lseg(lseg, iomode)) {
601 if (cmp_layout(iomode, lseg->pls_range.iomode) > 0)
605 dprintk("%s:Return lseg %p ref %d\n",
606 __func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
611 * Layout segment is retreived from the server if not cached.
612 * The appropriate layout segment is referenced and returned to the caller.
614 struct pnfs_layout_segment *
615 pnfs_update_layout(struct inode *ino,
616 struct nfs_open_context *ctx,
617 enum pnfs_iomode iomode)
619 struct nfs_inode *nfsi = NFS_I(ino);
620 struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
621 struct pnfs_layout_hdr *lo;
622 struct pnfs_layout_segment *lseg = NULL;
624 if (!pnfs_enabled_sb(NFS_SERVER(ino)))
626 spin_lock(&ino->i_lock);
627 lo = pnfs_find_alloc_layout(ino);
629 dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__);
633 /* Do we even need to bother with this? */
634 if (test_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state) ||
635 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
636 dprintk("%s matches recall, use MDS\n", __func__);
639 /* Check to see if the layout for the given range already exists */
640 lseg = pnfs_find_lseg(lo, iomode);
644 /* if LAYOUTGET already failed once we don't try again */
645 if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
648 if (pnfs_layoutgets_blocked(lo, NULL, 0))
650 atomic_inc(&lo->plh_outstanding);
653 if (list_empty(&lo->plh_segs)) {
654 /* The lo must be on the clp list if there is any
655 * chance of a CB_LAYOUTRECALL(FILE) coming in.
657 spin_lock(&clp->cl_lock);
658 BUG_ON(!list_empty(&lo->plh_layouts));
659 list_add_tail(&lo->plh_layouts, &clp->cl_layouts);
660 spin_unlock(&clp->cl_lock);
662 spin_unlock(&ino->i_lock);
664 lseg = send_layoutget(lo, ctx, iomode);
666 spin_lock(&ino->i_lock);
667 if (list_empty(&lo->plh_segs)) {
668 spin_lock(&clp->cl_lock);
669 list_del_init(&lo->plh_layouts);
670 spin_unlock(&clp->cl_lock);
671 clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
673 spin_unlock(&ino->i_lock);
675 atomic_dec(&lo->plh_outstanding);
678 dprintk("%s end, state 0x%lx lseg %p\n", __func__,
679 nfsi->layout->plh_flags, lseg);
682 spin_unlock(&ino->i_lock);
687 pnfs_layout_process(struct nfs4_layoutget *lgp)
689 struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
690 struct nfs4_layoutget_res *res = &lgp->res;
691 struct pnfs_layout_segment *lseg;
692 struct inode *ino = lo->plh_inode;
693 struct nfs_client *clp = NFS_SERVER(ino)->nfs_client;
696 /* Verify we got what we asked for.
697 * Note that because the xdr parsing only accepts a single
698 * element array, this can fail even if the server is behaving
701 if (lgp->args.range.iomode > res->range.iomode ||
702 res->range.offset != 0 ||
703 res->range.length != NFS4_MAX_UINT64) {
707 /* Inject layout blob into I/O device driver */
708 lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res);
709 if (!lseg || IS_ERR(lseg)) {
713 status = PTR_ERR(lseg);
714 dprintk("%s: Could not allocate layout: error %d\n",
719 spin_lock(&ino->i_lock);
720 if (test_bit(NFS4CLNT_LAYOUTRECALL, &clp->cl_state) ||
721 test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
722 dprintk("%s forget reply due to recall\n", __func__);
723 goto out_forget_reply;
726 if (pnfs_layoutgets_blocked(lo, &res->stateid, 1)) {
727 dprintk("%s forget reply due to state\n", __func__);
728 goto out_forget_reply;
731 lseg->pls_range = res->range;
733 pnfs_insert_layout(lo, lseg);
735 /* Done processing layoutget. Set the layout stateid */
736 pnfs_set_layout_stateid(lo, &res->stateid, false);
737 spin_unlock(&ino->i_lock);
742 spin_unlock(&ino->i_lock);
743 lseg->pls_layout = lo;
744 NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
749 * Device ID cache. Currently supports one layout type per struct nfs_client.
750 * Add layout type to the lookup key to expand to support multiple types.
753 pnfs_alloc_init_deviceid_cache(struct nfs_client *clp,
754 void (*free_callback)(struct pnfs_deviceid_node *))
756 struct pnfs_deviceid_cache *c;
758 c = kzalloc(sizeof(struct pnfs_deviceid_cache), GFP_KERNEL);
761 spin_lock(&clp->cl_lock);
762 if (clp->cl_devid_cache != NULL) {
763 atomic_inc(&clp->cl_devid_cache->dc_ref);
764 dprintk("%s [kref [%d]]\n", __func__,
765 atomic_read(&clp->cl_devid_cache->dc_ref));
768 /* kzalloc initializes hlists */
769 spin_lock_init(&c->dc_lock);
770 atomic_set(&c->dc_ref, 1);
771 c->dc_free_callback = free_callback;
772 clp->cl_devid_cache = c;
773 dprintk("%s [new]\n", __func__);
775 spin_unlock(&clp->cl_lock);
778 EXPORT_SYMBOL_GPL(pnfs_alloc_init_deviceid_cache);
781 * Called from pnfs_layoutdriver_type->free_lseg
782 * last layout segment reference frees deviceid
785 pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
786 struct pnfs_deviceid_node *devid)
788 struct nfs4_deviceid *id = &devid->de_id;
789 struct pnfs_deviceid_node *d;
790 struct hlist_node *n;
791 long h = nfs4_deviceid_hash(id);
793 dprintk("%s [%d]\n", __func__, atomic_read(&devid->de_ref));
794 if (!atomic_dec_and_lock(&devid->de_ref, &c->dc_lock))
797 hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[h], de_node)
798 if (!memcmp(&d->de_id, id, sizeof(*id))) {
799 hlist_del_rcu(&d->de_node);
800 spin_unlock(&c->dc_lock);
802 c->dc_free_callback(devid);
805 spin_unlock(&c->dc_lock);
806 /* Why wasn't it found in the list? */
809 EXPORT_SYMBOL_GPL(pnfs_put_deviceid);
811 /* Find and reference a deviceid */
812 struct pnfs_deviceid_node *
813 pnfs_find_get_deviceid(struct pnfs_deviceid_cache *c, struct nfs4_deviceid *id)
815 struct pnfs_deviceid_node *d;
816 struct hlist_node *n;
817 long hash = nfs4_deviceid_hash(id);
819 dprintk("--> %s hash %ld\n", __func__, hash);
821 hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) {
822 if (!memcmp(&d->de_id, id, sizeof(*id))) {
823 if (!atomic_inc_not_zero(&d->de_ref)) {
835 EXPORT_SYMBOL_GPL(pnfs_find_get_deviceid);
838 * Add a deviceid to the cache.
839 * GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new
841 struct pnfs_deviceid_node *
842 pnfs_add_deviceid(struct pnfs_deviceid_cache *c, struct pnfs_deviceid_node *new)
844 struct pnfs_deviceid_node *d;
845 long hash = nfs4_deviceid_hash(&new->de_id);
847 dprintk("--> %s hash %ld\n", __func__, hash);
848 spin_lock(&c->dc_lock);
849 d = pnfs_find_get_deviceid(c, &new->de_id);
851 spin_unlock(&c->dc_lock);
852 dprintk("%s [discard]\n", __func__);
853 c->dc_free_callback(new);
856 INIT_HLIST_NODE(&new->de_node);
857 atomic_set(&new->de_ref, 1);
858 hlist_add_head_rcu(&new->de_node, &c->dc_deviceids[hash]);
859 spin_unlock(&c->dc_lock);
860 dprintk("%s [new]\n", __func__);
863 EXPORT_SYMBOL_GPL(pnfs_add_deviceid);
866 pnfs_put_deviceid_cache(struct nfs_client *clp)
868 struct pnfs_deviceid_cache *local = clp->cl_devid_cache;
870 dprintk("--> %s cl_devid_cache %p\n", __func__, clp->cl_devid_cache);
871 if (atomic_dec_and_lock(&local->dc_ref, &clp->cl_lock)) {
873 /* Verify cache is empty */
874 for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++)
875 BUG_ON(!hlist_empty(&local->dc_deviceids[i]));
876 clp->cl_devid_cache = NULL;
877 spin_unlock(&clp->cl_lock);
881 EXPORT_SYMBOL_GPL(pnfs_put_deviceid_cache);