[linux.git] / fs / nfs / pnfs_dev.c

/*
 *  Device operations for the pnfs client.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <[email protected]>
 *  Garth Goodson   <[email protected]>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#include <linux/export.h>
#include <linux/nfs_fs.h>
#include "nfs4session.h"
#include "internal.h"
#include "pnfs.h"

#include "nfs4trace.h"

#define NFSDBG_FACILITY		NFSDBG_PNFS

/*
 * Device ID RCU cache. A device ID is unique per server and layout type.
 */
#define NFS4_DEVICE_ID_HASH_BITS	5
#define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
#define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)


static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
static DEFINE_SPINLOCK(nfs4_deviceid_lock);

#ifdef NFS_DEBUG
void
nfs4_print_deviceid(const struct nfs4_deviceid *id)
{
	u32 *p = (u32 *)id;

	dprintk("%s: device id= [%x%x%x%x]\n", __func__,
		p[0], p[1], p[2], p[3]);
}
EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
#endif

static inline u32
nfs4_deviceid_hash(const struct nfs4_deviceid *id)
{
	unsigned char *cptr = (unsigned char *)id->data;
	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
	u32 x = 0;

	while (nbytes--) {
		x *= 37;
		x += *cptr++;
	}
	return x & NFS4_DEVICE_ID_HASH_MASK;
}

static struct nfs4_deviceid_node *
_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
		 const struct nfs_client *clp, const struct nfs4_deviceid *id,
		 long hash)
{
	struct nfs4_deviceid_node *d;

	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
		if (d->ld == ld && d->nfs_client == clp &&
		    !memcmp(&d->deviceid, id, sizeof(*id))) {
			if (atomic_read(&d->ref))
				return d;
			else
				continue;
		}
	return NULL;
}

static struct nfs4_deviceid_node *
nfs4_get_device_info(struct nfs_server *server,
		const struct nfs4_deviceid *dev_id,
		const struct cred *cred, gfp_t gfp_flags)
{
	struct nfs4_deviceid_node *d = NULL;
	struct pnfs_device *pdev = NULL;
	struct page **pages = NULL;
	u32 max_resp_sz;
	int max_pages;
	int rc, i;

	/*
	 * Use the session max response size as the basis for setting
	 * GETDEVICEINFO's maxcount
	 */
	max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
	max_pages = nfs_page_array_len(0, max_resp_sz);
	dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
		__func__, server, max_resp_sz, max_pages);

	pdev = kzalloc(sizeof(*pdev), gfp_flags);
	if (!pdev)
		return NULL;

	pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
	if (!pages)
		goto out_free_pdev;

	for (i = 0; i < max_pages; i++) {
		pages[i] = alloc_page(gfp_flags);
		if (!pages[i])
			goto out_free_pages;
	}

	memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
	pdev->layout_type = server->pnfs_curr_ld->id;
	pdev->pages = pages;
	pdev->pgbase = 0;
	pdev->pglen = max_resp_sz;
	pdev->mincount = 0;
	pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;

	rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
	dprintk("%s getdevice info returns %d\n", __func__, rc);
	if (rc)
		goto out_free_pages;

	/*
	 * Found new device, need to decode it and then add it to the
	 * list of known devices for this mountpoint.
	 */
	d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
			gfp_flags);
	if (d && pdev->nocache)
		set_bit(NFS_DEVICEID_NOCACHE, &d->flags);

out_free_pages:
	while (--i >= 0)
		__free_page(pages[i]);
	kfree(pages);
out_free_pdev:
	kfree(pdev);
	dprintk("<-- %s d %p\n", __func__, d);
	return d;
}

/*
 * Lookup a deviceid in cache and get a reference count on it if found
 *
 * @clp nfs_client associated with deviceid
 * @id deviceid to look up
 */
static struct nfs4_deviceid_node *
__nfs4_find_get_deviceid(struct nfs_server *server,
		const struct nfs4_deviceid *id, long hash)
{
	struct nfs4_deviceid_node *d;

	rcu_read_lock();
	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
			hash);
	if (d != NULL && !atomic_inc_not_zero(&d->ref))
		d = NULL;
	rcu_read_unlock();
	return d;
}

struct nfs4_deviceid_node *
nfs4_find_get_deviceid(struct nfs_server *server,
		const struct nfs4_deviceid *id, const struct cred *cred,
		gfp_t gfp_mask)
{
	long hash = nfs4_deviceid_hash(id);
	struct nfs4_deviceid_node *d, *new;

	d = __nfs4_find_get_deviceid(server, id, hash);
	if (d)
		goto found;

	new = nfs4_get_device_info(server, id, cred, gfp_mask);
	if (!new) {
		trace_nfs4_find_deviceid(server, id, -ENOENT);
		return new;
	}

	spin_lock(&nfs4_deviceid_lock);
	d = __nfs4_find_get_deviceid(server, id, hash);
	if (d) {
		spin_unlock(&nfs4_deviceid_lock);
		server->pnfs_curr_ld->free_deviceid_node(new);
	} else {
		atomic_inc(&new->ref);
		hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
		spin_unlock(&nfs4_deviceid_lock);
		d = new;
	}
found:
	trace_nfs4_find_deviceid(server, id, 0);
	return d;
}
EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);

/*
 * Remove a deviceid from cache
 *
 * @clp nfs_client associated with deviceid
 * @id the deviceid to unhash
 *
 * @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
 */
void
nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
			 const struct nfs_client *clp, const struct nfs4_deviceid *id)
{
	struct nfs4_deviceid_node *d;

	spin_lock(&nfs4_deviceid_lock);
	rcu_read_lock();
	d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
	rcu_read_unlock();
	if (!d) {
		spin_unlock(&nfs4_deviceid_lock);
		return;
	}
	hlist_del_init_rcu(&d->node);
	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
	spin_unlock(&nfs4_deviceid_lock);

	/* balance the initial ref set in pnfs_insert_deviceid */
	nfs4_put_deviceid_node(d);
}
EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);

void
nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
			const struct nfs4_deviceid *id)
{
	INIT_HLIST_NODE(&d->node);
	INIT_HLIST_NODE(&d->tmpnode);
	d->ld = server->pnfs_curr_ld;
	d->nfs_client = server->nfs_client;
	d->flags = 0;
	d->deviceid = *id;
	atomic_set(&d->ref, 1);
}
EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);

/*
 * Dereference a deviceid node and delete it when its reference count drops
 * to zero.
 *
 * @d deviceid node to put
 *
 * return true iff the node was deleted
 * Note that since the test for d->ref == 0 is sufficient to establish
 * that the node is no longer hashed in the global device id cache.
 */
bool
nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
{
	if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
		if (atomic_add_unless(&d->ref, -1, 2))
			return false;
		nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
	}
	if (!atomic_dec_and_test(&d->ref))
		return false;
	trace_nfs4_deviceid_free(d->nfs_client, &d->deviceid);
	d->ld->free_deviceid_node(d);
	return true;
}
EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);

void
nfs4_mark_deviceid_available(struct nfs4_deviceid_node *node)
{
	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
		smp_mb__after_atomic();
	}
}
EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);

void
nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
{
	node->timestamp_unavailable = jiffies;
	smp_mb__before_atomic();
	set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
	smp_mb__after_atomic();
}
EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);

bool
nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
{
	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
		unsigned long start, end;

		end = jiffies;
		start = end - PNFS_DEVICE_RETRY_TIMEOUT;
		if (time_in_range(node->timestamp_unavailable, start, end))
			return true;
		clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
		smp_mb__after_atomic();
	}
	return false;
}
EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);

static void
_deviceid_purge_client(const struct nfs_client *clp, long hash)
{
	struct nfs4_deviceid_node *d;
	HLIST_HEAD(tmp);

	spin_lock(&nfs4_deviceid_lock);
	rcu_read_lock();
	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
		if (d->nfs_client == clp && atomic_read(&d->ref)) {
			hlist_del_init_rcu(&d->node);
			hlist_add_head(&d->tmpnode, &tmp);
			clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
		}
	rcu_read_unlock();
	spin_unlock(&nfs4_deviceid_lock);

	if (hlist_empty(&tmp))
		return;

	while (!hlist_empty(&tmp)) {
		d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
		hlist_del(&d->tmpnode);
		nfs4_put_deviceid_node(d);
	}
}

void
nfs4_deviceid_purge_client(const struct nfs_client *clp)
{
	long h;

	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
		return;
	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
		_deviceid_purge_client(clp, h);
}

/*
 * Stop use of all deviceids associated with an nfs_client
 */
void
nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
{
	struct nfs4_deviceid_node *d;
	int i;

	rcu_read_lock();
	for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
		hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
			if (d->nfs_client == clp)
				set_bit(NFS_DEVICEID_INVALID, &d->flags);
	}
	rcu_read_unlock();
}
Commit	Line	Data
a1eaecbc BH	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 <[email protected]>
	9	* Garth Goodson <[email protected]>
	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
afeacc8c	31	#include <linux/export.h>
661373b1 CH	32	#include <linux/nfs_fs.h>
	33	#include "nfs4session.h"
	34	#include "internal.h"
a1eaecbc BH	35	#include "pnfs.h"
a1eaecbc BH	36
cac1d3a2 TM	37	#include "nfs4trace.h"
cac1d3a2 TM	38
a1eaecbc BH	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
1dfed273	48
a1eaecbc BH	49	static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
	50	static DEFINE_SPINLOCK(nfs4_deviceid_lock);
	51
6f00866d	52	#ifdef NFS_DEBUG
a1eaecbc BH	53	void
	54	nfs4_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	}
	61	EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
6f00866d	62	#endif
a1eaecbc BH	63
	64	static inline u32
	65	nfs4_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
1be5683b	78	static struct nfs4_deviceid_node *
35c8bb54 BH	79	_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
35c8bb54 BH	80	const struct nfs_client clp, const struct nfs4_deviceid id,
1be5683b ME	81	long hash)
	82	{
	83	struct nfs4_deviceid_node *d;
1be5683b	84
b67bfe0d	85	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
35c8bb54 BH	86	if (d->ld == ld && d->nfs_client == clp &&
35c8bb54 BH	87	!memcmp(&d->deviceid, id, sizeof(*id))) {
1be5683b ME	88	if (atomic_read(&d->ref))
	89	return d;
	90	else
	91	continue;
	92	}
	93	return NULL;
	94	}
	95
661373b1 CH	96	static struct nfs4_deviceid_node *
	97	nfs4_get_device_info(struct nfs_server *server,
	98	const struct nfs4_deviceid *dev_id,
a52458b4	99	const struct cred *cred, gfp_t gfp_flags)
661373b1 CH	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;
661373b1 CH	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);
df52699e TM	150	if (d && pdev->nocache)
df52699e TM	151	set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
661373b1 CH	152
661373b1 CH	153	out_free_pages:
96562c45	154	while (--i >= 0)
661373b1 CH	155	__free_page(pages[i]);
	156	kfree(pages);
	157	out_free_pdev:
	158	kfree(pdev);
	159	dprintk("<-- %s d %p\n", __func__, d);
	160	return d;
	161	}
	162
a1eaecbc BH	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	*/
17280175	169	static struct nfs4_deviceid_node *
661373b1 CH	170	__nfs4_find_get_deviceid(struct nfs_server *server,
661373b1 CH	171	const struct nfs4_deviceid *id, long hash)
1be5683b ME	172	{
	173	struct nfs4_deviceid_node *d;
	174
	175	rcu_read_lock();
661373b1 CH	176	d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
661373b1 CH	177	hash);
84a80f62 TM	178	if (d != NULL && !atomic_inc_not_zero(&d->ref))
84a80f62 TM	179	d = NULL;
1be5683b ME	180	rcu_read_unlock();
	181	return d;
	182	}
	183
a1eaecbc	184	struct nfs4_deviceid_node *
661373b1	185	nfs4_find_get_deviceid(struct nfs_server *server,
a52458b4	186	const struct nfs4_deviceid id, const struct cred cred,
661373b1	187	gfp_t gfp_mask)
1be5683b	188	{
661373b1 CH	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)
cac1d3a2	194	goto found;
661373b1 CH	195
661373b1 CH	196	new = nfs4_get_device_info(server, id, cred, gfp_mask);
cac1d3a2 TM	197	if (!new) {
cac1d3a2 TM	198	trace_nfs4_find_deviceid(server, id, -ENOENT);
661373b1	199	return new;
cac1d3a2	200	}
661373b1 CH	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);
cac1d3a2 TM	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;
661373b1	212	}
cac1d3a2 TM	213	found:
	214	trace_nfs4_find_deviceid(server, id, 0);
	215	return d;
1be5683b ME	216	}
	217	EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
	218
	219	/*
47cb498e	220	* Remove a deviceid from cache
1be5683b ME	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	*/
47cb498e TM	227	void
47cb498e TM	228	nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
35c8bb54	229	const struct nfs_client clp, const struct nfs4_deviceid id)
a1eaecbc BH	230	{
a1eaecbc BH	231	struct nfs4_deviceid_node *d;
a1eaecbc	232
1be5683b	233	spin_lock(&nfs4_deviceid_lock);
a1eaecbc	234	rcu_read_lock();
35c8bb54	235	d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
a1eaecbc	236	rcu_read_unlock();
1be5683b ME	237	if (!d) {
1be5683b ME	238	spin_unlock(&nfs4_deviceid_lock);
47cb498e	239	return;
1be5683b ME	240	}
1be5683b ME	241	hlist_del_init_rcu(&d->node);
df52699e	242	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
1be5683b	243	spin_unlock(&nfs4_deviceid_lock);
1be5683b ME	244
1be5683b ME	245	/* balance the initial ref set in pnfs_insert_deviceid */
fb1458f4	246	nfs4_put_deviceid_node(d);
1be5683b ME	247	}
1be5683b ME	248	EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
a1eaecbc BH	249
a1eaecbc BH	250	void
661373b1	251	nfs4_init_deviceid_node(struct nfs4_deviceid_node d, struct nfs_server server,
a1eaecbc BH	252	const struct nfs4_deviceid *id)
a1eaecbc BH	253	{
1775bc34	254	INIT_HLIST_NODE(&d->node);
9e3bd4e2	255	INIT_HLIST_NODE(&d->tmpnode);
661373b1 CH	256	d->ld = server->pnfs_curr_ld;
661373b1 CH	257	d->nfs_client = server->nfs_client;
c47abcf8	258	d->flags = 0;
a1eaecbc	259	d->deviceid = *id;
1775bc34	260	atomic_set(&d->ref, 1);
a1eaecbc BH	261	}
	262	EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
	263
a1eaecbc BH	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	*
47cb498e TM	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.
a1eaecbc BH	273	*/
	274	bool
	275	nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
	276	{
df52699e TM	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	}
47cb498e	282	if (!atomic_dec_and_test(&d->ref))
a1eaecbc	283	return false;
cac1d3a2	284	trace_nfs4_deviceid_free(d->nfs_client, &d->deviceid);
1775bc34	285	d->ld->free_deviceid_node(d);
a1eaecbc BH	286	return true;
	287	}
	288	EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
1775bc34	289
76c66905 TM	290	void
	291	nfs4_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	}
	298	EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_available);
	299
1dfed273 TM	300	void
	301	nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
	302	{
	303	node->timestamp_unavailable = jiffies;
39a5201a	304	smp_mb__before_atomic();
1dfed273	305	set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
39a5201a	306	smp_mb__after_atomic();
1dfed273 TM	307	}
	308	EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
	309
	310	bool
	311	nfs4_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);
39a5201a	321	smp_mb__after_atomic();
1dfed273 TM	322	}
	323	return false;
	324	}
	325	EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
	326
1775bc34 BH	327	static void
	328	_deviceid_purge_client(const struct nfs_client *clp, long hash)
	329	{
	330	struct nfs4_deviceid_node *d;
1775bc34 BH	331	HLIST_HEAD(tmp);
1775bc34 BH	332
9e3bd4e2	333	spin_lock(&nfs4_deviceid_lock);
1775bc34	334	rcu_read_lock();
b67bfe0d	335	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
1775bc34 BH	336	if (d->nfs_client == clp && atomic_read(&d->ref)) {
1775bc34 BH	337	hlist_del_init_rcu(&d->node);
9e3bd4e2	338	hlist_add_head(&d->tmpnode, &tmp);
df52699e	339	clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
1775bc34 BH	340	}
1775bc34 BH	341	rcu_read_unlock();
9e3bd4e2	342	spin_unlock(&nfs4_deviceid_lock);
1775bc34 BH	343
	344	if (hlist_empty(&tmp))
	345	return;
	346
9e3bd4e2 WAA	347	while (!hlist_empty(&tmp)) {
	348	d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
	349	hlist_del(&d->tmpnode);
fb1458f4	350	nfs4_put_deviceid_node(d);
9e3bd4e2	351	}
1775bc34 BH	352	}
	353
	354	void
	355	nfs4_deviceid_purge_client(const struct nfs_client *clp)
	356	{
	357	long h;
	358
9e3bd4e2 WAA	359	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
9e3bd4e2 WAA	360	return;
1775bc34 BH	361	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
1775bc34 BH	362	_deviceid_purge_client(clp, h);
1775bc34	363	}
c47abcf8 AA	364
	365	/*
	366	* Stop use of all deviceids associated with an nfs_client
	367	*/
	368	void
	369	nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
	370	{
	371	struct nfs4_deviceid_node *d;
c47abcf8 AA	372	int i;
	373
	374	rcu_read_lock();
	375	for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
b67bfe0d	376	hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
c47abcf8 AA	377	if (d->nfs_client == clp)
	378	set_bit(NFS_DEVICEID_INVALID, &d->flags);
	379	}
	380	rcu_read_unlock();
	381	}