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v6.9.4
  1/*
  2 *  Device operations for the pnfs client.
  3 *
  4 *  Copyright (c) 2002
  5 *  The Regents of the University of Michigan
  6 *  All Rights Reserved
  7 *
  8 *  Dean Hildebrand <dhildebz@umich.edu>
  9 *  Garth Goodson   <Garth.Goodson@netapp.com>
 10 *
 11 *  Permission is granted to use, copy, create derivative works, and
 12 *  redistribute this software and such derivative works for any purpose,
 13 *  so long as the name of the University of Michigan is not used in
 14 *  any advertising or publicity pertaining to the use or distribution
 15 *  of this software without specific, written prior authorization. If
 16 *  the above copyright notice or any other identification of the
 17 *  University of Michigan is included in any copy of any portion of
 18 *  this software, then the disclaimer below must also be included.
 19 *
 20 *  This software is provided as is, without representation or warranty
 21 *  of any kind either express or implied, including without limitation
 22 *  the implied warranties of merchantability, fitness for a particular
 23 *  purpose, or noninfringement.  The Regents of the University of
 24 *  Michigan shall not be liable for any damages, including special,
 25 *  indirect, incidental, or consequential damages, with respect to any
 26 *  claim arising out of or in connection with the use of the software,
 27 *  even if it has been or is hereafter advised of the possibility of
 28 *  such damages.
 29 */
 30
 31#include <linux/export.h>
 32#include <linux/nfs_fs.h>
 33#include "nfs4session.h"
 34#include "internal.h"
 35#include "pnfs.h"
 36
 37#include "nfs4trace.h"
 38
 39#define NFSDBG_FACILITY		NFSDBG_PNFS
 40
 41/*
 42 * Device ID RCU cache. A device ID is unique per server and layout type.
 43 */
 44#define NFS4_DEVICE_ID_HASH_BITS	5
 45#define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
 46#define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)
 47
 48
 49static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
 50static DEFINE_SPINLOCK(nfs4_deviceid_lock);
 51
 52#ifdef NFS_DEBUG
 53void
 54nfs4_print_deviceid(const struct nfs4_deviceid *id)
 55{
 56	u32 *p = (u32 *)id;
 57
 58	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
 59		p[0], p[1], p[2], p[3]);
 60}
 61EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
 62#endif
 63
 64static inline u32
 65nfs4_deviceid_hash(const struct nfs4_deviceid *id)
 66{
 67	unsigned char *cptr = (unsigned char *)id->data;
 68	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
 69	u32 x = 0;
 70
 71	while (nbytes--) {
 72		x *= 37;
 73		x += *cptr++;
 74	}
 75	return x & NFS4_DEVICE_ID_HASH_MASK;
 76}
 77
 78static struct nfs4_deviceid_node *
 79_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
 80		 const struct nfs_client *clp, const struct nfs4_deviceid *id,
 81		 long hash)
 82{
 83	struct nfs4_deviceid_node *d;
 84
 85	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
 86		if (d->ld == ld && d->nfs_client == clp &&
 87		    !memcmp(&d->deviceid, id, sizeof(*id))) {
 88			if (atomic_read(&d->ref))
 89				return d;
 90			else
 91				continue;
 92		}
 93	return NULL;
 94}
 95
 96static struct nfs4_deviceid_node *
 97nfs4_get_device_info(struct nfs_server *server,
 98		const struct nfs4_deviceid *dev_id,
 99		const struct cred *cred, gfp_t gfp_flags)
100{
101	struct nfs4_deviceid_node *d = NULL;
102	struct pnfs_device *pdev = NULL;
103	struct page **pages = NULL;
104	u32 max_resp_sz;
105	int max_pages;
106	int rc, i;
107
108	/*
109	 * Use the session max response size as the basis for setting
110	 * GETDEVICEINFO's maxcount
111	 */
112	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
113	if (server->pnfs_curr_ld->max_deviceinfo_size &&
114	    server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz)
115		max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size;
116	max_pages = nfs_page_array_len(0, max_resp_sz);
117	dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
118		__func__, server, max_resp_sz, max_pages);
119
120	pdev = kzalloc(sizeof(*pdev), gfp_flags);
121	if (!pdev)
122		return NULL;
123
124	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
125	if (!pages)
126		goto out_free_pdev;
127
128	for (i = 0; i < max_pages; i++) {
129		pages[i] = alloc_page(gfp_flags);
130		if (!pages[i])
131			goto out_free_pages;
132	}
133
134	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
135	pdev->layout_type = server->pnfs_curr_ld->id;
136	pdev->pages = pages;
137	pdev->pgbase = 0;
138	pdev->pglen = max_resp_sz;
139	pdev->mincount = 0;
140	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
141
142	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
143	dprintk("%s getdevice info returns %d\n", __func__, rc);
144	if (rc)
145		goto out_free_pages;
146
147	/*
148	 * Found new device, need to decode it and then add it to the
149	 * list of known devices for this mountpoint.
150	 */
151	d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
152			gfp_flags);
153	if (d && pdev->nocache)
154		set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
155
156out_free_pages:
157	while (--i >= 0)
158		__free_page(pages[i]);
159	kfree(pages);
160out_free_pdev:
161	kfree(pdev);
162	dprintk("<-- %s d %p\n", __func__, d);
163	return d;
164}
165
166/*
167 * Lookup a deviceid in cache and get a reference count on it if found
168 *
169 * @clp nfs_client associated with deviceid
170 * @id deviceid to look up
171 */
172static struct nfs4_deviceid_node *
173__nfs4_find_get_deviceid(struct nfs_server *server,
174		const struct nfs4_deviceid *id, long hash)
175{
176	struct nfs4_deviceid_node *d;
177
178	rcu_read_lock();
179	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
180			hash);
181	if (d != NULL && !atomic_inc_not_zero(&d->ref))
182		d = NULL;
183	rcu_read_unlock();
184	return d;
185}
186
187struct nfs4_deviceid_node *
188nfs4_find_get_deviceid(struct nfs_server *server,
189		const struct nfs4_deviceid *id, const struct cred *cred,
190		gfp_t gfp_mask)
191{
192	long hash = nfs4_deviceid_hash(id);
193	struct nfs4_deviceid_node *d, *new;
194
195	d = __nfs4_find_get_deviceid(server, id, hash);
196	if (d)
197		goto found;
198
199	new = nfs4_get_device_info(server, id, cred, gfp_mask);
200	if (!new) {
201		trace_nfs4_find_deviceid(server, id, -ENOENT);
202		return new;
203	}
204
205	spin_lock(&nfs4_deviceid_lock);
206	d = __nfs4_find_get_deviceid(server, id, hash);
207	if (d) {
208		spin_unlock(&nfs4_deviceid_lock);
209		server->pnfs_curr_ld->free_deviceid_node(new);
210	} else {
211		atomic_inc(&new->ref);
212		hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
213		spin_unlock(&nfs4_deviceid_lock);
214		d = new;
215	}
216found:
217	trace_nfs4_find_deviceid(server, id, 0);
218	return d;
219}
220EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
221
222/*
223 * Remove a deviceid from cache
224 *
225 * @clp nfs_client associated with deviceid
226 * @id the deviceid to unhash
227 *
228 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
229 */
230void
231nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
232			 const struct nfs_client *clp, const struct nfs4_deviceid *id)
233{
234	struct nfs4_deviceid_node *d;
235
236	spin_lock(&nfs4_deviceid_lock);
237	rcu_read_lock();
238	d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
239	rcu_read_unlock();
240	if (!d) {
241		spin_unlock(&nfs4_deviceid_lock);
242		return;
243	}
244	hlist_del_init_rcu(&d->node);
245	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
246	spin_unlock(&nfs4_deviceid_lock);
247
248	/* balance the initial ref set in pnfs_insert_deviceid */
249	nfs4_put_deviceid_node(d);
250}
251EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
252
253void
254nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
255			const struct nfs4_deviceid *id)
256{
257	INIT_HLIST_NODE(&d->node);
258	INIT_HLIST_NODE(&d->tmpnode);
259	d->ld = server->pnfs_curr_ld;
260	d->nfs_client = server->nfs_client;
261	d->flags = 0;
262	d->deviceid = *id;
263	atomic_set(&d->ref, 1);
264}
265EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
266
267/*
268 * Dereference a deviceid node and delete it when its reference count drops
269 * to zero.
270 *
271 * @d deviceid node to put
272 *
273 * return true iff the node was deleted
274 * Note that since the test for d->ref == 0 is sufficient to establish
275 * that the node is no longer hashed in the global device id cache.
276 */
277bool
278nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
279{
280	if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
281		if (atomic_add_unless(&d->ref, -1, 2))
282			return false;
283		nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
284	}
285	if (!atomic_dec_and_test(&d->ref))
286		return false;
287	trace_nfs4_deviceid_free(d->nfs_client, &d->deviceid);
288	d->ld->free_deviceid_node(d);
289	return true;
290}
291EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
292
293void
294nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node)
295{
296	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
297		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
298		smp_mb__after_atomic();
299	}
300}
301EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);
302
303void
304nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
305{
306	node->timestamp_unavailable = jiffies;
307	smp_mb__before_atomic();
308	set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
309	smp_mb__after_atomic();
310}
311EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
312
313bool
314nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
315{
316	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
317		unsigned long start, end;
318
319		end = jiffies;
320		start = end - PNFS_DEVICE_RETRY_TIMEOUT;
321		if (time_in_range(node->timestamp_unavailable, start, end))
322			return true;
323		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
324		smp_mb__after_atomic();
325	}
326	return false;
327}
328EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
329
330static void
331_deviceid_purge_client(const struct nfs_client *clp, long hash)
332{
333	struct nfs4_deviceid_node *d;
334	HLIST_HEAD(tmp);
335
336	spin_lock(&nfs4_deviceid_lock);
337	rcu_read_lock();
338	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
339		if (d->nfs_client == clp && atomic_read(&d->ref)) {
340			hlist_del_init_rcu(&d->node);
341			hlist_add_head(&d->tmpnode, &tmp);
342			clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
343		}
344	rcu_read_unlock();
345	spin_unlock(&nfs4_deviceid_lock);
346
347	if (hlist_empty(&tmp))
348		return;
349
350	while (!hlist_empty(&tmp)) {
351		d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
352		hlist_del(&d->tmpnode);
353		nfs4_put_deviceid_node(d);
354	}
355}
356
357void
358nfs4_deviceid_purge_client(const struct nfs_client *clp)
359{
360	long h;
361
362	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
363		return;
364	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
365		_deviceid_purge_client(clp, h);
366}
367
368/*
369 * Stop use of all deviceids associated with an nfs_client
370 */
371void
372nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
373{
374	struct nfs4_deviceid_node *d;
375	int i;
376
377	rcu_read_lock();
378	for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
379		hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
380			if (d->nfs_client == clp)
381				set_bit(NFS_DEVICEID_INVALID, &d->flags);
382	}
383	rcu_read_unlock();
384}
v6.13.7
  1/*
  2 *  Device operations for the pnfs client.
  3 *
  4 *  Copyright (c) 2002
  5 *  The Regents of the University of Michigan
  6 *  All Rights Reserved
  7 *
  8 *  Dean Hildebrand <dhildebz@umich.edu>
  9 *  Garth Goodson   <Garth.Goodson@netapp.com>
 10 *
 11 *  Permission is granted to use, copy, create derivative works, and
 12 *  redistribute this software and such derivative works for any purpose,
 13 *  so long as the name of the University of Michigan is not used in
 14 *  any advertising or publicity pertaining to the use or distribution
 15 *  of this software without specific, written prior authorization. If
 16 *  the above copyright notice or any other identification of the
 17 *  University of Michigan is included in any copy of any portion of
 18 *  this software, then the disclaimer below must also be included.
 19 *
 20 *  This software is provided as is, without representation or warranty
 21 *  of any kind either express or implied, including without limitation
 22 *  the implied warranties of merchantability, fitness for a particular
 23 *  purpose, or noninfringement.  The Regents of the University of
 24 *  Michigan shall not be liable for any damages, including special,
 25 *  indirect, incidental, or consequential damages, with respect to any
 26 *  claim arising out of or in connection with the use of the software,
 27 *  even if it has been or is hereafter advised of the possibility of
 28 *  such damages.
 29 */
 30
 31#include <linux/export.h>
 32#include <linux/nfs_fs.h>
 33#include "nfs4session.h"
 34#include "internal.h"
 35#include "pnfs.h"
 36
 37#include "nfs4trace.h"
 38
 39#define NFSDBG_FACILITY		NFSDBG_PNFS
 40
 41/*
 42 * Device ID RCU cache. A device ID is unique per server and layout type.
 43 */
 44#define NFS4_DEVICE_ID_HASH_BITS	5
 45#define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
 46#define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)
 47
 48
 49static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
 50static DEFINE_SPINLOCK(nfs4_deviceid_lock);
 51
 52#ifdef NFS_DEBUG
 53void
 54nfs4_print_deviceid(const struct nfs4_deviceid *id)
 55{
 56	u32 *p = (u32 *)id;
 57
 58	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
 59		p[0], p[1], p[2], p[3]);
 60}
 61EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
 62#endif
 63
 64static inline u32
 65nfs4_deviceid_hash(const struct nfs4_deviceid *id)
 66{
 67	unsigned char *cptr = (unsigned char *)id->data;
 68	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
 69	u32 x = 0;
 70
 71	while (nbytes--) {
 72		x *= 37;
 73		x += *cptr++;
 74	}
 75	return x & NFS4_DEVICE_ID_HASH_MASK;
 76}
 77
 78static struct nfs4_deviceid_node *
 79_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
 80		 const struct nfs_client *clp, const struct nfs4_deviceid *id,
 81		 long hash)
 82{
 83	struct nfs4_deviceid_node *d;
 84
 85	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
 86		if (d->ld == ld && d->nfs_client == clp &&
 87		    !memcmp(&d->deviceid, id, sizeof(*id))) {
 88			if (atomic_read(&d->ref))
 89				return d;
 90			else
 91				continue;
 92		}
 93	return NULL;
 94}
 95
 96static struct nfs4_deviceid_node *
 97nfs4_get_device_info(struct nfs_server *server,
 98		const struct nfs4_deviceid *dev_id,
 99		const struct cred *cred, gfp_t gfp_flags)
100{
101	struct nfs4_deviceid_node *d = NULL;
102	struct pnfs_device *pdev = NULL;
103	struct page **pages = NULL;
104	u32 max_resp_sz;
105	int max_pages;
106	int rc, i;
107
108	/*
109	 * Use the session max response size as the basis for setting
110	 * GETDEVICEINFO's maxcount
111	 */
112	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
 
 
 
113	max_pages = nfs_page_array_len(0, max_resp_sz);
114	dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
115		__func__, server, max_resp_sz, max_pages);
116
117	pdev = kzalloc(sizeof(*pdev), gfp_flags);
118	if (!pdev)
119		return NULL;
120
121	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
122	if (!pages)
123		goto out_free_pdev;
124
125	for (i = 0; i < max_pages; i++) {
126		pages[i] = alloc_page(gfp_flags);
127		if (!pages[i])
128			goto out_free_pages;
129	}
130
131	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
132	pdev->layout_type = server->pnfs_curr_ld->id;
133	pdev->pages = pages;
134	pdev->pgbase = 0;
135	pdev->pglen = max_resp_sz;
136	pdev->mincount = 0;
137	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
138
139	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
140	dprintk("%s getdevice info returns %d\n", __func__, rc);
141	if (rc)
142		goto out_free_pages;
143
144	/*
145	 * Found new device, need to decode it and then add it to the
146	 * list of known devices for this mountpoint.
147	 */
148	d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
149			gfp_flags);
150	if (d && pdev->nocache)
151		set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
152
153out_free_pages:
154	while (--i >= 0)
155		__free_page(pages[i]);
156	kfree(pages);
157out_free_pdev:
158	kfree(pdev);
159	dprintk("<-- %s d %p\n", __func__, d);
160	return d;
161}
162
163/*
164 * Lookup a deviceid in cache and get a reference count on it if found
165 *
166 * @clp nfs_client associated with deviceid
167 * @id deviceid to look up
168 */
169static struct nfs4_deviceid_node *
170__nfs4_find_get_deviceid(struct nfs_server *server,
171		const struct nfs4_deviceid *id, long hash)
172{
173	struct nfs4_deviceid_node *d;
174
175	rcu_read_lock();
176	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
177			hash);
178	if (d != NULL && !atomic_inc_not_zero(&d->ref))
179		d = NULL;
180	rcu_read_unlock();
181	return d;
182}
183
184struct nfs4_deviceid_node *
185nfs4_find_get_deviceid(struct nfs_server *server,
186		const struct nfs4_deviceid *id, const struct cred *cred,
187		gfp_t gfp_mask)
188{
189	long hash = nfs4_deviceid_hash(id);
190	struct nfs4_deviceid_node *d, *new;
191
192	d = __nfs4_find_get_deviceid(server, id, hash);
193	if (d)
194		goto found;
195
196	new = nfs4_get_device_info(server, id, cred, gfp_mask);
197	if (!new) {
198		trace_nfs4_find_deviceid(server, id, -ENOENT);
199		return new;
200	}
201
202	spin_lock(&nfs4_deviceid_lock);
203	d = __nfs4_find_get_deviceid(server, id, hash);
204	if (d) {
205		spin_unlock(&nfs4_deviceid_lock);
206		server->pnfs_curr_ld->free_deviceid_node(new);
207	} else {
208		atomic_inc(&new->ref);
209		hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
210		spin_unlock(&nfs4_deviceid_lock);
211		d = new;
212	}
213found:
214	trace_nfs4_find_deviceid(server, id, 0);
215	return d;
216}
217EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
218
219/*
220 * Remove a deviceid from cache
221 *
222 * @clp nfs_client associated with deviceid
223 * @id the deviceid to unhash
224 *
225 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
226 */
227void
228nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
229			 const struct nfs_client *clp, const struct nfs4_deviceid *id)
230{
231	struct nfs4_deviceid_node *d;
232
233	spin_lock(&nfs4_deviceid_lock);
234	rcu_read_lock();
235	d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
236	rcu_read_unlock();
237	if (!d) {
238		spin_unlock(&nfs4_deviceid_lock);
239		return;
240	}
241	hlist_del_init_rcu(&d->node);
242	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
243	spin_unlock(&nfs4_deviceid_lock);
244
245	/* balance the initial ref set in pnfs_insert_deviceid */
246	nfs4_put_deviceid_node(d);
247}
248EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
249
250void
251nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
252			const struct nfs4_deviceid *id)
253{
254	INIT_HLIST_NODE(&d->node);
255	INIT_HLIST_NODE(&d->tmpnode);
256	d->ld = server->pnfs_curr_ld;
257	d->nfs_client = server->nfs_client;
258	d->flags = 0;
259	d->deviceid = *id;
260	atomic_set(&d->ref, 1);
261}
262EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
263
264/*
265 * Dereference a deviceid node and delete it when its reference count drops
266 * to zero.
267 *
268 * @d deviceid node to put
269 *
270 * return true iff the node was deleted
271 * Note that since the test for d->ref == 0 is sufficient to establish
272 * that the node is no longer hashed in the global device id cache.
273 */
274bool
275nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
276{
277	if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
278		if (atomic_add_unless(&d->ref, -1, 2))
279			return false;
280		nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
281	}
282	if (!atomic_dec_and_test(&d->ref))
283		return false;
284	trace_nfs4_deviceid_free(d->nfs_client, &d->deviceid);
285	d->ld->free_deviceid_node(d);
286	return true;
287}
288EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
289
290void
291nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node)
292{
293	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
294		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
295		smp_mb__after_atomic();
296	}
297}
298EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);
299
300void
301nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
302{
303	node->timestamp_unavailable = jiffies;
304	smp_mb__before_atomic();
305	set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
306	smp_mb__after_atomic();
307}
308EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
309
310bool
311nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
312{
313	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
314		unsigned long start, end;
315
316		end = jiffies;
317		start = end - PNFS_DEVICE_RETRY_TIMEOUT;
318		if (time_in_range(node->timestamp_unavailable, start, end))
319			return true;
320		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
321		smp_mb__after_atomic();
322	}
323	return false;
324}
325EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
326
327static void
328_deviceid_purge_client(const struct nfs_client *clp, long hash)
329{
330	struct nfs4_deviceid_node *d;
331	HLIST_HEAD(tmp);
332
333	spin_lock(&nfs4_deviceid_lock);
334	rcu_read_lock();
335	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
336		if (d->nfs_client == clp && atomic_read(&d->ref)) {
337			hlist_del_init_rcu(&d->node);
338			hlist_add_head(&d->tmpnode, &tmp);
339			clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
340		}
341	rcu_read_unlock();
342	spin_unlock(&nfs4_deviceid_lock);
343
344	if (hlist_empty(&tmp))
345		return;
346
347	while (!hlist_empty(&tmp)) {
348		d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
349		hlist_del(&d->tmpnode);
350		nfs4_put_deviceid_node(d);
351	}
352}
353
354void
355nfs4_deviceid_purge_client(const struct nfs_client *clp)
356{
357	long h;
358
359	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
360		return;
361	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
362		_deviceid_purge_client(clp, h);
363}
364
365/*
366 * Stop use of all deviceids associated with an nfs_client
367 */
368void
369nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
370{
371	struct nfs4_deviceid_node *d;
372	int i;
373
374	rcu_read_lock();
375	for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
376		hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
377			if (d->nfs_client == clp)
378				set_bit(NFS_DEVICEID_INVALID, &d->flags);
379	}
380	rcu_read_unlock();
381}