[linux-block.git] / fs / afs / volume.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* AFS volume management
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include "internal.h"

unsigned __read_mostly afs_volume_gc_delay = 10;
unsigned __read_mostly afs_volume_record_life = 60 * 60;

/*
 * Insert a volume into a cell.  If there's an existing volume record, that is
 * returned instead with a ref held.
 */
static struct afs_volume *afs_insert_volume_into_cell(struct afs_cell *cell,
						      struct afs_volume *volume)
{
	struct afs_volume *p;
	struct rb_node *parent = NULL, **pp;

	write_seqlock(&cell->volume_lock);

	pp = &cell->volumes.rb_node;
	while (*pp) {
		parent = *pp;
		p = rb_entry(parent, struct afs_volume, cell_node);
		if (p->vid < volume->vid) {
			pp = &(*pp)->rb_left;
		} else if (p->vid > volume->vid) {
			pp = &(*pp)->rb_right;
		} else {
			volume = afs_get_volume(p, afs_volume_trace_get_cell_insert);
			goto found;
		}
	}

	rb_link_node_rcu(&volume->cell_node, parent, pp);
	rb_insert_color(&volume->cell_node, &cell->volumes);
	hlist_add_head_rcu(&volume->proc_link, &cell->proc_volumes);

found:
	write_sequnlock(&cell->volume_lock);
	return volume;

}

static void afs_remove_volume_from_cell(struct afs_volume *volume)
{
	struct afs_cell *cell = volume->cell;

	if (!hlist_unhashed(&volume->proc_link)) {
		trace_afs_volume(volume->vid, atomic_read(&volume->usage),
				 afs_volume_trace_remove);
		write_seqlock(&cell->volume_lock);
		hlist_del_rcu(&volume->proc_link);
		rb_erase(&volume->cell_node, &cell->volumes);
		write_sequnlock(&cell->volume_lock);
	}
}

/*
 * Allocate a volume record and load it up from a vldb record.
 */
static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
					   struct afs_vldb_entry *vldb,
					   unsigned long type_mask)
{
	struct afs_server_list *slist;
	struct afs_volume *volume;
	int ret = -ENOMEM, nr_servers = 0, i;

	for (i = 0; i < vldb->nr_servers; i++)
		if (vldb->fs_mask[i] & type_mask)
			nr_servers++;

	volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
	if (!volume)
		goto error_0;

	volume->vid		= vldb->vid[params->type];
	volume->update_at	= ktime_get_real_seconds() + afs_volume_record_life;
	volume->cell		= afs_get_cell(params->cell, afs_cell_trace_get_vol);
	volume->type		= params->type;
	volume->type_force	= params->force;
	volume->name_len	= vldb->name_len;

	atomic_set(&volume->usage, 1);
	INIT_HLIST_NODE(&volume->proc_link);
	rwlock_init(&volume->servers_lock);
	rwlock_init(&volume->cb_v_break_lock);
	memcpy(volume->name, vldb->name, vldb->name_len + 1);

	slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask);
	if (IS_ERR(slist)) {
		ret = PTR_ERR(slist);
		goto error_1;
	}

	refcount_set(&slist->usage, 1);
	rcu_assign_pointer(volume->servers, slist);
	trace_afs_volume(volume->vid, 1, afs_volume_trace_alloc);
	return volume;

error_1:
	afs_put_cell(volume->cell, afs_cell_trace_put_vol);
	kfree(volume);
error_0:
	return ERR_PTR(ret);
}

/*
 * Look up or allocate a volume record.
 */
static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params,
					    struct afs_vldb_entry *vldb,
					    unsigned long type_mask)
{
	struct afs_volume *candidate, *volume;

	candidate = afs_alloc_volume(params, vldb, type_mask);
	if (IS_ERR(candidate))
		return candidate;

	volume = afs_insert_volume_into_cell(params->cell, candidate);
	if (volume != candidate)
		afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup);
	return volume;
}

/*
 * Look up a VLDB record for a volume.
 */
static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
						 struct key *key,
						 const char *volname,
						 size_t volnamesz)
{
	struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ);
	struct afs_vl_cursor vc;
	int ret;

	if (!afs_begin_vlserver_operation(&vc, cell, key))
		return ERR_PTR(-ERESTARTSYS);

	while (afs_select_vlserver(&vc)) {
		vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz);
	}

	ret = afs_end_vlserver_operation(&vc);
	return ret < 0 ? ERR_PTR(ret) : vldb;
}

/*
 * Look up a volume in the VL server and create a candidate volume record for
 * it.
 *
 * The volume name can be one of the following:
 *	"%[cell:]volume[.]"		R/W volume
 *	"#[cell:]volume[.]"		R/O or R/W volume (rwparent=0),
 *					 or R/W (rwparent=1) volume
 *	"%[cell:]volume.readonly"	R/O volume
 *	"#[cell:]volume.readonly"	R/O volume
 *	"%[cell:]volume.backup"		Backup volume
 *	"#[cell:]volume.backup"		Backup volume
 *
 * The cell name is optional, and defaults to the current cell.
 *
 * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
 * Guide
 * - Rule 1: Explicit type suffix forces access of that type or nothing
 *           (no suffix, then use Rule 2 & 3)
 * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
 *           if not available
 * - Rule 3: If parent volume is R/W, then only mount R/W volume unless
 *           explicitly told otherwise
 */
struct afs_volume *afs_create_volume(struct afs_fs_context *params)
{
	struct afs_vldb_entry *vldb;
	struct afs_volume *volume;
	unsigned long type_mask = 1UL << params->type;

	vldb = afs_vl_lookup_vldb(params->cell, params->key,
				  params->volname, params->volnamesz);
	if (IS_ERR(vldb))
		return ERR_CAST(vldb);

	if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) {
		volume = ERR_PTR(vldb->error);
		goto error;
	}

	/* Make the final decision on the type we want */
	volume = ERR_PTR(-ENOMEDIUM);
	if (params->force) {
		if (!(vldb->flags & type_mask))
			goto error;
	} else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) {
		params->type = AFSVL_ROVOL;
	} else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) {
		params->type = AFSVL_RWVOL;
	} else {
		goto error;
	}

	type_mask = 1UL << params->type;
	volume = afs_lookup_volume(params, vldb, type_mask);

error:
	kfree(vldb);
	return volume;
}

/*
 * Destroy a volume record
 */
static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
{
	_enter("%p", volume);

#ifdef CONFIG_AFS_FSCACHE
	ASSERTCMP(volume->cache, ==, NULL);
#endif

	afs_remove_volume_from_cell(volume);
	afs_put_serverlist(net, rcu_access_pointer(volume->servers));
	afs_put_cell(volume->cell, afs_cell_trace_put_vol);
	trace_afs_volume(volume->vid, atomic_read(&volume->usage),
			 afs_volume_trace_free);
	kfree_rcu(volume, rcu);

	_leave(" [destroyed]");
}

/*
 * Get a reference on a volume record.
 */
struct afs_volume *afs_get_volume(struct afs_volume *volume,
				  enum afs_volume_trace reason)
{
	if (volume) {
		int u = atomic_inc_return(&volume->usage);
		trace_afs_volume(volume->vid, u, reason);
	}
	return volume;
}


/*
 * Drop a reference on a volume record.
 */
void afs_put_volume(struct afs_net *net, struct afs_volume *volume,
		    enum afs_volume_trace reason)
{
	if (volume) {
		afs_volid_t vid = volume->vid;
		int u = atomic_dec_return(&volume->usage);
		trace_afs_volume(vid, u, reason);
		if (u == 0)
			afs_destroy_volume(net, volume);
	}
}

/*
 * Activate a volume.
 */
void afs_activate_volume(struct afs_volume *volume)
{
#ifdef CONFIG_AFS_FSCACHE
	volume->cache = fscache_acquire_cookie(volume->cell->cache,
					       &afs_volume_cache_index_def,
					       &volume->vid, sizeof(volume->vid),
					       NULL, 0,
					       volume, 0, true);
#endif
}

/*
 * Deactivate a volume.
 */
void afs_deactivate_volume(struct afs_volume *volume)
{
	_enter("%s", volume->name);

#ifdef CONFIG_AFS_FSCACHE
	fscache_relinquish_cookie(volume->cache, NULL,
				  test_bit(AFS_VOLUME_DELETED, &volume->flags));
	volume->cache = NULL;
#endif

	_leave("");
}

/*
 * Query the VL service to update the volume status.
 */
static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
{
	struct afs_server_list *new, *old, *discard;
	struct afs_vldb_entry *vldb;
	char idbuf[16];
	int ret, idsz;

	_enter("");

	/* We look up an ID by passing it as a decimal string in the
	 * operation's name parameter.
	 */
	idsz = sprintf(idbuf, "%llu", volume->vid);

	vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz);
	if (IS_ERR(vldb)) {
		ret = PTR_ERR(vldb);
		goto error;
	}

	/* See if the volume got renamed. */
	if (vldb->name_len != volume->name_len ||
	    memcmp(vldb->name, volume->name, vldb->name_len) != 0) {
		/* TODO: Use RCU'd string. */
		memcpy(volume->name, vldb->name, AFS_MAXVOLNAME);
		volume->name_len = vldb->name_len;
	}

	/* See if the volume's server list got updated. */
	new = afs_alloc_server_list(volume->cell, key,
				    vldb, (1 << volume->type));
	if (IS_ERR(new)) {
		ret = PTR_ERR(new);
		goto error_vldb;
	}

	write_lock(&volume->servers_lock);

	discard = new;
	old = rcu_dereference_protected(volume->servers,
					lockdep_is_held(&volume->servers_lock));
	if (afs_annotate_server_list(new, old)) {
		new->seq = volume->servers_seq + 1;
		rcu_assign_pointer(volume->servers, new);
		smp_wmb();
		volume->servers_seq++;
		discard = old;
	}

	volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
	write_unlock(&volume->servers_lock);
	ret = 0;

	afs_put_serverlist(volume->cell->net, discard);
error_vldb:
	kfree(vldb);
error:
	_leave(" = %d", ret);
	return ret;
}

/*
 * Make sure the volume record is up to date.
 */
int afs_check_volume_status(struct afs_volume *volume, struct afs_operation *op)
{
	int ret, retries = 0;

	_enter("");

retry:
	if (test_bit(AFS_VOLUME_WAIT, &volume->flags))
		goto wait;
	if (volume->update_at <= ktime_get_real_seconds() ||
	    test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags))
		goto update;
	_leave(" = 0");
	return 0;

update:
	if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) {
		clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
		ret = afs_update_volume_status(volume, op->key);
		if (ret < 0)
			set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
		clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags);
		clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags);
		wake_up_bit(&volume->flags, AFS_VOLUME_WAIT);
		_leave(" = %d", ret);
		return ret;
	}

wait:
	if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) {
		_leave(" = 0 [no wait]");
		return 0;
	}

	ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT,
			  (op->flags & AFS_OPERATION_UNINTR) ?
			  TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
	if (ret == -ERESTARTSYS) {
		_leave(" = %d", ret);
		return ret;
	}

	retries++;
	if (retries == 4) {
		_leave(" = -ESTALE");
		return -ESTALE;
	}
	goto retry;
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
ec26815a	2	/* AFS volume management
1da177e4	3	*
08e0e7c8	4	* Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
1da177e4	5	* Written by David Howells (dhowells@redhat.com)
1da177e4 LT	6	*/
	7
	8	#include <linux/kernel.h>
1da177e4	9	#include <linux/slab.h>
1da177e4 LT	10	#include "internal.h"
1da177e4 LT	11
d2ddc776 DH	12	unsigned __read_mostly afs_volume_gc_delay = 10;
	13	unsigned __read_mostly afs_volume_record_life = 60 * 60;
	14
20325960 DH	15	/*
	16	* Insert a volume into a cell. If there's an existing volume record, that is
	17	* returned instead with a ref held.
	18	*/
	19	static struct afs_volume afs_insert_volume_into_cell(struct afs_cell cell,
	20	struct afs_volume *volume)
	21	{
	22	struct afs_volume *p;
	23	struct rb_node parent = NULL, *pp;
	24
	25	write_seqlock(&cell->volume_lock);
	26
	27	pp = &cell->volumes.rb_node;
	28	while (*pp) {
	29	parent = *pp;
	30	p = rb_entry(parent, struct afs_volume, cell_node);
	31	if (p->vid < volume->vid) {
	32	pp = &(*pp)->rb_left;
	33	} else if (p->vid > volume->vid) {
	34	pp = &(*pp)->rb_right;
	35	} else {
	36	volume = afs_get_volume(p, afs_volume_trace_get_cell_insert);
	37	goto found;
	38	}
	39	}
	40
	41	rb_link_node_rcu(&volume->cell_node, parent, pp);
	42	rb_insert_color(&volume->cell_node, &cell->volumes);
	43	hlist_add_head_rcu(&volume->proc_link, &cell->proc_volumes);
	44
	45	found:
	46	write_sequnlock(&cell->volume_lock);
	47	return volume;
	48
	49	}
	50
	51	static void afs_remove_volume_from_cell(struct afs_volume *volume)
	52	{
	53	struct afs_cell *cell = volume->cell;
	54
	55	if (!hlist_unhashed(&volume->proc_link)) {
	56	trace_afs_volume(volume->vid, atomic_read(&volume->usage),
	57	afs_volume_trace_remove);
	58	write_seqlock(&cell->volume_lock);
	59	hlist_del_rcu(&volume->proc_link);
	60	rb_erase(&volume->cell_node, &cell->volumes);
	61	write_sequnlock(&cell->volume_lock);
	62	}
	63	}
	64
1da177e4	65	/*
d2ddc776 DH	66	* Allocate a volume record and load it up from a vldb record.
d2ddc776 DH	67	*/
13fcc683	68	static struct afs_volume afs_alloc_volume(struct afs_fs_context params,
d2ddc776 DH	69	struct afs_vldb_entry *vldb,
	70	unsigned long type_mask)
	71	{
	72	struct afs_server_list *slist;
d2ddc776	73	struct afs_volume *volume;
45df8462	74	int ret = -ENOMEM, nr_servers = 0, i;
d2ddc776 DH	75
	76	for (i = 0; i < vldb->nr_servers; i++)
	77	if (vldb->fs_mask[i] & type_mask)
	78	nr_servers++;
	79
	80	volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
	81	if (!volume)
	82	goto error_0;
	83
	84	volume->vid = vldb->vid[params->type];
	85	volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
dca54a7b	86	volume->cell = afs_get_cell(params->cell, afs_cell_trace_get_vol);
d2ddc776 DH	87	volume->type = params->type;
	88	volume->type_force = params->force;
	89	volume->name_len = vldb->name_len;
	90
	91	atomic_set(&volume->usage, 1);
20325960	92	INIT_HLIST_NODE(&volume->proc_link);
d2ddc776	93	rwlock_init(&volume->servers_lock);
90fa9b64	94	rwlock_init(&volume->cb_v_break_lock);
d2ddc776 DH	95	memcpy(volume->name, vldb->name, vldb->name_len + 1);
	96
	97	slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask);
	98	if (IS_ERR(slist)) {
	99	ret = PTR_ERR(slist);
	100	goto error_1;
	101	}
	102
	103	refcount_set(&slist->usage, 1);
8a070a96	104	rcu_assign_pointer(volume->servers, slist);
cca37d45	105	trace_afs_volume(volume->vid, 1, afs_volume_trace_alloc);
d2ddc776 DH	106	return volume;
d2ddc776 DH	107
d2ddc776	108	error_1:
dca54a7b	109	afs_put_cell(volume->cell, afs_cell_trace_put_vol);
d2ddc776 DH	110	kfree(volume);
	111	error_0:
	112	return ERR_PTR(ret);
	113	}
	114
20325960 DH	115	/*
	116	* Look up or allocate a volume record.
	117	*/
	118	static struct afs_volume afs_lookup_volume(struct afs_fs_context params,
	119	struct afs_vldb_entry *vldb,
	120	unsigned long type_mask)
	121	{
	122	struct afs_volume candidate, volume;
	123
	124	candidate = afs_alloc_volume(params, vldb, type_mask);
	125	if (IS_ERR(candidate))
	126	return candidate;
	127
	128	volume = afs_insert_volume_into_cell(params->cell, candidate);
	129	if (volume != candidate)
	130	afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup);
	131	return volume;
	132	}
	133
d2ddc776 DH	134	/*
	135	* Look up a VLDB record for a volume.
	136	*/
	137	static struct afs_vldb_entry afs_vl_lookup_vldb(struct afs_cell cell,
	138	struct key *key,
	139	const char *volname,
	140	size_t volnamesz)
	141	{
0a5143f2 DH	142	struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ);
0a5143f2 DH	143	struct afs_vl_cursor vc;
d2ddc776 DH	144	int ret;
d2ddc776 DH	145
0a5143f2 DH	146	if (!afs_begin_vlserver_operation(&vc, cell, key))
0a5143f2 DH	147	return ERR_PTR(-ERESTARTSYS);
d2ddc776	148
0a5143f2	149	while (afs_select_vlserver(&vc)) {
0a5143f2	150	vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz);
d2ddc776 DH	151	}
d2ddc776 DH	152
0a5143f2 DH	153	ret = afs_end_vlserver_operation(&vc);
0a5143f2 DH	154	return ret < 0 ? ERR_PTR(ret) : vldb;
d2ddc776 DH	155	}
	156
	157	/*
	158	* Look up a volume in the VL server and create a candidate volume record for
	159	* it.
	160	*
	161	* The volume name can be one of the following:
1da177e4 LT	162	* "%[cell:]volume[.]" R/W volume
	163	* "#[cell:]volume[.]" R/O or R/W volume (rwparent=0),
	164	* or R/W (rwparent=1) volume
	165	* "%[cell:]volume.readonly" R/O volume
	166	* "#[cell:]volume.readonly" R/O volume
	167	* "%[cell:]volume.backup" Backup volume
	168	* "#[cell:]volume.backup" Backup volume
	169	*
	170	* The cell name is optional, and defaults to the current cell.
	171	*
	172	* See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
	173	* Guide
	174	* - Rule 1: Explicit type suffix forces access of that type or nothing
	175	* (no suffix, then use Rule 2 & 3)
	176	* - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
	177	* if not available
	178	* - Rule 3: If parent volume is R/W, then only mount R/W volume unless
	179	* explicitly told otherwise
	180	*/
13fcc683	181	struct afs_volume afs_create_volume(struct afs_fs_context params)
1da177e4	182	{
d2ddc776 DH	183	struct afs_vldb_entry *vldb;
	184	struct afs_volume *volume;
	185	unsigned long type_mask = 1UL << params->type;
1da177e4	186
d2ddc776 DH	187	vldb = afs_vl_lookup_vldb(params->cell, params->key,
	188	params->volname, params->volnamesz);
	189	if (IS_ERR(vldb))
	190	return ERR_CAST(vldb);
1da177e4	191
d2ddc776 DH	192	if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) {
	193	volume = ERR_PTR(vldb->error);
	194	goto error;
	195	}
1da177e4	196
d2ddc776 DH	197	/* Make the final decision on the type we want */
d2ddc776 DH	198	volume = ERR_PTR(-ENOMEDIUM);
00d3b7a4	199	if (params->force) {
d2ddc776	200	if (!(vldb->flags & type_mask))
1da177e4	201	goto error;
d2ddc776	202	} else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) {
00d3b7a4	203	params->type = AFSVL_ROVOL;
d2ddc776	204	} else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) {
00d3b7a4	205	params->type = AFSVL_RWVOL;
ec26815a	206	} else {
1da177e4 LT	207	goto error;
	208	}
	209
d2ddc776	210	type_mask = 1UL << params->type;
20325960	211	volume = afs_lookup_volume(params, vldb, type_mask);
1da177e4	212
d2ddc776 DH	213	error:
	214	kfree(vldb);
	215	return volume;
	216	}
1da177e4	217
d2ddc776 DH	218	/*
	219	* Destroy a volume record
	220	*/
	221	static void afs_destroy_volume(struct afs_net net, struct afs_volume volume)
	222	{
	223	_enter("%p", volume);
1da177e4	224
d2ddc776 DH	225	#ifdef CONFIG_AFS_FSCACHE
	226	ASSERTCMP(volume->cache, ==, NULL);
	227	#endif
1da177e4	228
20325960	229	afs_remove_volume_from_cell(volume);
8a070a96	230	afs_put_serverlist(net, rcu_access_pointer(volume->servers));
dca54a7b	231	afs_put_cell(volume->cell, afs_cell_trace_put_vol);
cca37d45 DH	232	trace_afs_volume(volume->vid, atomic_read(&volume->usage),
cca37d45 DH	233	afs_volume_trace_free);
20325960	234	kfree_rcu(volume, rcu);
1da177e4	235
d2ddc776 DH	236	_leave(" [destroyed]");
	237	}
	238
	239	/*
cca37d45	240	* Get a reference on a volume record.
d2ddc776	241	*/
cca37d45 DH	242	struct afs_volume afs_get_volume(struct afs_volume volume,
cca37d45 DH	243	enum afs_volume_trace reason)
d2ddc776 DH	244	{
d2ddc776 DH	245	if (volume) {
cca37d45 DH	246	int u = atomic_inc_return(&volume->usage);
	247	trace_afs_volume(volume->vid, u, reason);
	248	}
	249	return volume;
	250	}
	251
d2ddc776	252
cca37d45 DH	253	/*
	254	* Drop a reference on a volume record.
	255	*/
	256	void afs_put_volume(struct afs_net net, struct afs_volume volume,
	257	enum afs_volume_trace reason)
	258	{
	259	if (volume) {
	260	afs_volid_t vid = volume->vid;
	261	int u = atomic_dec_return(&volume->usage);
	262	trace_afs_volume(vid, u, reason);
	263	if (u == 0)
e49c7b2f	264	afs_destroy_volume(net, volume);
1da177e4	265	}
d2ddc776	266	}
1da177e4	267
d2ddc776 DH	268	/*
	269	* Activate a volume.
	270	*/
	271	void afs_activate_volume(struct afs_volume *volume)
	272	{
9b3f26c9	273	#ifdef CONFIG_AFS_FSCACHE
ad6a942a	274	volume->cache = fscache_acquire_cookie(volume->cell->cache,
9b3f26c9	275	&afs_volume_cache_index_def,
402cb8dd DH	276	&volume->vid, sizeof(volume->vid),
402cb8dd DH	277	NULL, 0,
ee1235a9	278	volume, 0, true);
1da177e4	279	#endif
d2ddc776	280	}
1da177e4	281
d2ddc776 DH	282	/*
	283	* Deactivate a volume.
	284	*/
	285	void afs_deactivate_volume(struct afs_volume *volume)
	286	{
	287	_enter("%s", volume->name);
1da177e4	288
d2ddc776	289	#ifdef CONFIG_AFS_FSCACHE
402cb8dd	290	fscache_relinquish_cookie(volume->cache, NULL,
d2ddc776 DH	291	test_bit(AFS_VOLUME_DELETED, &volume->flags));
	292	volume->cache = NULL;
	293	#endif
1da177e4	294
d2ddc776	295	_leave("");
ec26815a	296	}
1da177e4	297
1da177e4	298	/*
d2ddc776	299	* Query the VL service to update the volume status.
1da177e4	300	*/
d2ddc776	301	static int afs_update_volume_status(struct afs_volume volume, struct key key)
1da177e4	302	{
d2ddc776 DH	303	struct afs_server_list new, old, *discard;
	304	struct afs_vldb_entry *vldb;
	305	char idbuf[16];
	306	int ret, idsz;
1da177e4	307
d2ddc776	308	_enter("");
1da177e4	309
d2ddc776 DH	310	/* We look up an ID by passing it as a decimal string in the
	311	* operation's name parameter.
	312	*/
3b6492df	313	idsz = sprintf(idbuf, "%llu", volume->vid);
1da177e4	314
d2ddc776 DH	315	vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz);
	316	if (IS_ERR(vldb)) {
	317	ret = PTR_ERR(vldb);
	318	goto error;
	319	}
1da177e4	320
d2ddc776 DH	321	/* See if the volume got renamed. */
	322	if (vldb->name_len != volume->name_len \|\|
	323	memcmp(vldb->name, volume->name, vldb->name_len) != 0) {
	324	/* TODO: Use RCU'd string. */
	325	memcpy(volume->name, vldb->name, AFS_MAXVOLNAME);
	326	volume->name_len = vldb->name_len;
	327	}
	328
	329	/* See if the volume's server list got updated. */
	330	new = afs_alloc_server_list(volume->cell, key,
45df8462	331	vldb, (1 << volume->type));
d2ddc776 DH	332	if (IS_ERR(new)) {
	333	ret = PTR_ERR(new);
	334	goto error_vldb;
	335	}
1da177e4	336
d2ddc776	337	write_lock(&volume->servers_lock);
1da177e4	338
d2ddc776	339	discard = new;
8a070a96 DH	340	old = rcu_dereference_protected(volume->servers,
8a070a96 DH	341	lockdep_is_held(&volume->servers_lock));
d2ddc776 DH	342	if (afs_annotate_server_list(new, old)) {
d2ddc776 DH	343	new->seq = volume->servers_seq + 1;
8a070a96	344	rcu_assign_pointer(volume->servers, new);
d2ddc776 DH	345	smp_wmb();
	346	volume->servers_seq++;
	347	discard = old;
1da177e4 LT	348	}
1da177e4 LT	349
d2ddc776	350	volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
d2ddc776 DH	351	write_unlock(&volume->servers_lock);
d2ddc776 DH	352	ret = 0;
1da177e4	353
d2ddc776 DH	354	afs_put_serverlist(volume->cell->net, discard);
	355	error_vldb:
	356	kfree(vldb);
	357	error:
	358	_leave(" = %d", ret);
	359	return ret;
	360	}
1da177e4	361
d2ddc776 DH	362	/*
	363	* Make sure the volume record is up to date.
	364	*/
e49c7b2f	365	int afs_check_volume_status(struct afs_volume volume, struct afs_operation op)
d2ddc776	366	{
d2ddc776	367	int ret, retries = 0;
1da177e4	368
d2ddc776 DH	369	_enter("");
d2ddc776 DH	370
d2ddc776	371	retry:
f6cbb368 DH	372	if (test_bit(AFS_VOLUME_WAIT, &volume->flags))
	373	goto wait;
	374	if (volume->update_at <= ktime_get_real_seconds() \|\|
	375	test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags))
	376	goto update;
	377	_leave(" = 0");
	378	return 0;
	379
	380	update:
d2ddc776	381	if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) {
f6cbb368	382	clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
e49c7b2f	383	ret = afs_update_volume_status(volume, op->key);
f6cbb368 DH	384	if (ret < 0)
f6cbb368 DH	385	set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
d2ddc776 DH	386	clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags);
	387	clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags);
	388	wake_up_bit(&volume->flags, AFS_VOLUME_WAIT);
	389	_leave(" = %d", ret);
	390	return ret;
	391	}
1da177e4	392
f6cbb368	393	wait:
d2ddc776 DH	394	if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) {
	395	_leave(" = 0 [no wait]");
	396	return 0;
	397	}
	398
c4bfda16	399	ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT,
e49c7b2f DH	400	(op->flags & AFS_OPERATION_UNINTR) ?
e49c7b2f DH	401	TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
d2ddc776 DH	402	if (ret == -ERESTARTSYS) {
	403	_leave(" = %d", ret);
	404	return ret;
	405	}
	406
	407	retries++;
	408	if (retries == 4) {
	409	_leave(" = -ESTALE");
	410	return -ESTALE;
	411	}
	412	goto retry;
ec26815a	413	}