[net-next-2.6.git] / fs / afs / volume.c

/* AFS volume management
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include "internal.h"

static const char *afs_voltypes[] = { "R/W", "R/O", "BAK" };

/*
 * lookup a volume by name
 * - this 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_volume_lookup(struct afs_mount_params *params)
{
	struct afs_vlocation *vlocation = NULL;
	struct afs_volume *volume = NULL;
	struct afs_server *server = NULL;
	char srvtmask;
	int ret, loop;

	_enter("{%*.*s,%d}",
	       params->volnamesz, params->volnamesz, params->volname, params->rwpath);

	/* lookup the volume location record */
	vlocation = afs_vlocation_lookup(params->cell, params->key,
					 params->volname, params->volnamesz);
	if (IS_ERR(vlocation)) {
		ret = PTR_ERR(vlocation);
		vlocation = NULL;
		goto error;
	}

	/* make the final decision on the type we want */
	ret = -ENOMEDIUM;
	if (params->force && !(vlocation->vldb.vidmask & (1 << params->type)))
		goto error;

	srvtmask = 0;
	for (loop = 0; loop < vlocation->vldb.nservers; loop++)
		srvtmask |= vlocation->vldb.srvtmask[loop];

	if (params->force) {
		if (!(srvtmask & (1 << params->type)))
			goto error;
	} else if (srvtmask & AFS_VOL_VTM_RO) {
		params->type = AFSVL_ROVOL;
	} else if (srvtmask & AFS_VOL_VTM_RW) {
		params->type = AFSVL_RWVOL;
	} else {
		goto error;
	}

	down_write(&params->cell->vl_sem);

	/* is the volume already active? */
	if (vlocation->vols[params->type]) {
		/* yes - re-use it */
		volume = vlocation->vols[params->type];
		afs_get_volume(volume);
		goto success;
	}

	/* create a new volume record */
	_debug("creating new volume record");

	ret = -ENOMEM;
	volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
	if (!volume)
		goto error_up;

	atomic_set(&volume->usage, 1);
	volume->type		= params->type;
	volume->type_force	= params->force;
	volume->cell		= params->cell;
	volume->vid		= vlocation->vldb.vid[params->type];

	ret = bdi_setup_and_register(&volume->bdi, "afs", BDI_CAP_MAP_COPY);
	if (ret)
		goto error_bdi;

	init_rwsem(&volume->server_sem);

	/* look up all the applicable server records */
	for (loop = 0; loop < 8; loop++) {
		if (vlocation->vldb.srvtmask[loop] & (1 << volume->type)) {
			server = afs_lookup_server(
			       volume->cell, &vlocation->vldb.servers[loop]);
			if (IS_ERR(server)) {
				ret = PTR_ERR(server);
				goto error_discard;
			}

			volume->servers[volume->nservers] = server;
			volume->nservers++;
		}
	}

	/* attach the cache and volume location */
#ifdef CONFIG_AFS_FSCACHE
	volume->cache = fscache_acquire_cookie(vlocation->cache,
					       &afs_volume_cache_index_def,
					       volume);
#endif
	afs_get_vlocation(vlocation);
	volume->vlocation = vlocation;

	vlocation->vols[volume->type] = volume;

success:
	_debug("kAFS selected %s volume %08x",
	       afs_voltypes[volume->type], volume->vid);
	up_write(&params->cell->vl_sem);
	afs_put_vlocation(vlocation);
	_leave(" = %p", volume);
	return volume;

	/* clean up */
error_up:
	up_write(&params->cell->vl_sem);
error:
	afs_put_vlocation(vlocation);
	_leave(" = %d", ret);
	return ERR_PTR(ret);

error_discard:
	bdi_destroy(&volume->bdi);
error_bdi:
	up_write(&params->cell->vl_sem);

	for (loop = volume->nservers - 1; loop >= 0; loop--)
		afs_put_server(volume->servers[loop]);

	kfree(volume);
	goto error;
}

/*
 * destroy a volume record
 */
void afs_put_volume(struct afs_volume *volume)
{
	struct afs_vlocation *vlocation;
	int loop;

	if (!volume)
		return;

	_enter("%p", volume);

	ASSERTCMP(atomic_read(&volume->usage), >, 0);

	vlocation = volume->vlocation;

	/* to prevent a race, the decrement and the dequeue must be effectively
	 * atomic */
	down_write(&vlocation->cell->vl_sem);

	if (likely(!atomic_dec_and_test(&volume->usage))) {
		up_write(&vlocation->cell->vl_sem);
		_leave("");
		return;
	}

	vlocation->vols[volume->type] = NULL;

	up_write(&vlocation->cell->vl_sem);

	/* finish cleaning up the volume */
#ifdef CONFIG_AFS_FSCACHE
	fscache_relinquish_cookie(volume->cache, 0);
#endif
	afs_put_vlocation(vlocation);

	for (loop = volume->nservers - 1; loop >= 0; loop--)
		afs_put_server(volume->servers[loop]);

	bdi_destroy(&volume->bdi);
	kfree(volume);

	_leave(" [destroyed]");
}

/*
 * pick a server to use to try accessing this volume
 * - returns with an elevated usage count on the server chosen
 */
struct afs_server *afs_volume_pick_fileserver(struct afs_vnode *vnode)
{
	struct afs_volume *volume = vnode->volume;
	struct afs_server *server;
	int ret, state, loop;

	_enter("%s", volume->vlocation->vldb.name);

	/* stick with the server we're already using if we can */
	if (vnode->server && vnode->server->fs_state == 0) {
		afs_get_server(vnode->server);
		_leave(" = %p [current]", vnode->server);
		return vnode->server;
	}

	down_read(&volume->server_sem);

	/* handle the no-server case */
	if (volume->nservers == 0) {
		ret = volume->rjservers ? -ENOMEDIUM : -ESTALE;
		up_read(&volume->server_sem);
		_leave(" = %d [no servers]", ret);
		return ERR_PTR(ret);
	}

	/* basically, just search the list for the first live server and use
	 * that */
	ret = 0;
	for (loop = 0; loop < volume->nservers; loop++) {
		server = volume->servers[loop];
		state = server->fs_state;

		_debug("consider %d [%d]", loop, state);

		switch (state) {
			/* found an apparently healthy server */
		case 0:
			afs_get_server(server);
			up_read(&volume->server_sem);
			_leave(" = %p (picked %08x)",
			       server, ntohl(server->addr.s_addr));
			return server;

		case -ENETUNREACH:
			if (ret == 0)
				ret = state;
			break;

		case -EHOSTUNREACH:
			if (ret == 0 ||
			    ret == -ENETUNREACH)
				ret = state;
			break;

		case -ECONNREFUSED:
			if (ret == 0 ||
			    ret == -ENETUNREACH ||
			    ret == -EHOSTUNREACH)
				ret = state;
			break;

		default:
		case -EREMOTEIO:
			if (ret == 0 ||
			    ret == -ENETUNREACH ||
			    ret == -EHOSTUNREACH ||
			    ret == -ECONNREFUSED)
				ret = state;
			break;
		}
	}

	/* no available servers
	 * - TODO: handle the no active servers case better
	 */
	up_read(&volume->server_sem);
	_leave(" = %d", ret);
	return ERR_PTR(ret);
}

/*
 * release a server after use
 * - releases the ref on the server struct that was acquired by picking
 * - records result of using a particular server to access a volume
 * - return 0 to try again, 1 if okay or to issue error
 * - the caller must release the server struct if result was 0
 */
int afs_volume_release_fileserver(struct afs_vnode *vnode,
				  struct afs_server *server,
				  int result)
{
	struct afs_volume *volume = vnode->volume;
	unsigned loop;

	_enter("%s,%08x,%d",
	       volume->vlocation->vldb.name, ntohl(server->addr.s_addr),
	       result);

	switch (result) {
		/* success */
	case 0:
		server->fs_act_jif = jiffies;
		server->fs_state = 0;
		_leave("");
		return 1;

		/* the fileserver denied all knowledge of the volume */
	case -ENOMEDIUM:
		server->fs_act_jif = jiffies;
		down_write(&volume->server_sem);

		/* firstly, find where the server is in the active list (if it
		 * is) */
		for (loop = 0; loop < volume->nservers; loop++)
			if (volume->servers[loop] == server)
				goto present;

		/* no longer there - may have been discarded by another op */
		goto try_next_server_upw;

	present:
		volume->nservers--;
		memmove(&volume->servers[loop],
			&volume->servers[loop + 1],
			sizeof(volume->servers[loop]) *
			(volume->nservers - loop));
		volume->servers[volume->nservers] = NULL;
		afs_put_server(server);
		volume->rjservers++;

		if (volume->nservers > 0)
			/* another server might acknowledge its existence */
			goto try_next_server_upw;

		/* handle the case where all the fileservers have rejected the
		 * volume
		 * - TODO: try asking the fileservers for volume information
		 * - TODO: contact the VL server again to see if the volume is
		 *         no longer registered
		 */
		up_write(&volume->server_sem);
		afs_put_server(server);
		_leave(" [completely rejected]");
		return 1;

		/* problem reaching the server */
	case -ENETUNREACH:
	case -EHOSTUNREACH:
	case -ECONNREFUSED:
	case -ETIME:
	case -ETIMEDOUT:
	case -EREMOTEIO:
		/* mark the server as dead
		 * TODO: vary dead timeout depending on error
		 */
		spin_lock(&server->fs_lock);
		if (!server->fs_state) {
			server->fs_dead_jif = jiffies + HZ * 10;
			server->fs_state = result;
			printk("kAFS: SERVER DEAD state=%d\n", result);
		}
		spin_unlock(&server->fs_lock);
		goto try_next_server;

		/* miscellaneous error */
	default:
		server->fs_act_jif = jiffies;
	case -ENOMEM:
	case -ENONET:
		/* tell the caller to accept the result */
		afs_put_server(server);
		_leave(" [local failure]");
		return 1;
	}

	/* tell the caller to loop around and try the next server */
try_next_server_upw:
	up_write(&volume->server_sem);
try_next_server:
	afs_put_server(server);
	_leave(" [try next server]");
	return 0;
}
Commit	Line	Data
ec26815a	1	/* AFS volume management
1da177e4	2	*
08e0e7c8	3	* Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
1da177e4 LT	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/slab.h>
	16	#include <linux/fs.h>
	17	#include <linux/pagemap.h>
e8edc6e0	18	#include <linux/sched.h>
1da177e4 LT	19	#include "internal.h"
1da177e4 LT	20
1da177e4	21	static const char *afs_voltypes[] = { "R/W", "R/O", "BAK" };
1da177e4	22
1da177e4 LT	23	/*
	24	* lookup a volume by name
	25	* - this can be one of the following:
	26	* "%[cell:]volume[.]" R/W volume
	27	* "#[cell:]volume[.]" R/O or R/W volume (rwparent=0),
	28	* or R/W (rwparent=1) volume
	29	* "%[cell:]volume.readonly" R/O volume
	30	* "#[cell:]volume.readonly" R/O volume
	31	* "%[cell:]volume.backup" Backup volume
	32	* "#[cell:]volume.backup" Backup volume
	33	*
	34	* The cell name is optional, and defaults to the current cell.
	35	*
	36	* See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
	37	* Guide
	38	* - Rule 1: Explicit type suffix forces access of that type or nothing
	39	* (no suffix, then use Rule 2 & 3)
	40	* - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
	41	* if not available
	42	* - Rule 3: If parent volume is R/W, then only mount R/W volume unless
	43	* explicitly told otherwise
	44	*/
00d3b7a4	45	struct afs_volume afs_volume_lookup(struct afs_mount_params params)
1da177e4 LT	46	{
	47	struct afs_vlocation *vlocation = NULL;
	48	struct afs_volume *volume = NULL;
08e0e7c8	49	struct afs_server *server = NULL;
1da177e4	50	char srvtmask;
00d3b7a4	51	int ret, loop;
1da177e4	52
00d3b7a4 DH	53	_enter("{%.s,%d}",
00d3b7a4 DH	54	params->volnamesz, params->volnamesz, params->volname, params->rwpath);
1da177e4 LT	55
1da177e4 LT	56	/* lookup the volume location record */
00d3b7a4 DH	57	vlocation = afs_vlocation_lookup(params->cell, params->key,
00d3b7a4 DH	58	params->volname, params->volnamesz);
08e0e7c8 DH	59	if (IS_ERR(vlocation)) {
	60	ret = PTR_ERR(vlocation);
	61	vlocation = NULL;
1da177e4	62	goto error;
08e0e7c8	63	}
1da177e4 LT	64
	65	/* make the final decision on the type we want */
	66	ret = -ENOMEDIUM;
00d3b7a4	67	if (params->force && !(vlocation->vldb.vidmask & (1 << params->type)))
1da177e4 LT	68	goto error;
	69
	70	srvtmask = 0;
	71	for (loop = 0; loop < vlocation->vldb.nservers; loop++)
	72	srvtmask \|= vlocation->vldb.srvtmask[loop];
	73
00d3b7a4 DH	74	if (params->force) {
00d3b7a4 DH	75	if (!(srvtmask & (1 << params->type)))
1da177e4	76	goto error;
ec26815a	77	} else if (srvtmask & AFS_VOL_VTM_RO) {
00d3b7a4	78	params->type = AFSVL_ROVOL;
ec26815a	79	} else if (srvtmask & AFS_VOL_VTM_RW) {
00d3b7a4	80	params->type = AFSVL_RWVOL;
ec26815a	81	} else {
1da177e4 LT	82	goto error;
	83	}
	84
00d3b7a4	85	down_write(&params->cell->vl_sem);
1da177e4 LT	86
1da177e4 LT	87	/* is the volume already active? */
00d3b7a4	88	if (vlocation->vols[params->type]) {
1da177e4	89	/* yes - re-use it */
00d3b7a4	90	volume = vlocation->vols[params->type];
1da177e4 LT	91	afs_get_volume(volume);
	92	goto success;
	93	}
	94
	95	/* create a new volume record */
	96	_debug("creating new volume record");
	97
	98	ret = -ENOMEM;
f8314dc6	99	volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
1da177e4 LT	100	if (!volume)
	101	goto error_up;
	102
1da177e4	103	atomic_set(&volume->usage, 1);
00d3b7a4 DH	104	volume->type = params->type;
	105	volume->type_force = params->force;
	106	volume->cell = params->cell;
	107	volume->vid = vlocation->vldb.vid[params->type];
1da177e4	108
e1da0222 JA	109	ret = bdi_setup_and_register(&volume->bdi, "afs", BDI_CAP_MAP_COPY);
	110	if (ret)
	111	goto error_bdi;
	112
1da177e4 LT	113	init_rwsem(&volume->server_sem);
	114
	115	/* look up all the applicable server records */
	116	for (loop = 0; loop < 8; loop++) {
	117	if (vlocation->vldb.srvtmask[loop] & (1 << volume->type)) {
08e0e7c8 DH	118	server = afs_lookup_server(
	119	volume->cell, &vlocation->vldb.servers[loop]);
	120	if (IS_ERR(server)) {
	121	ret = PTR_ERR(server);
1da177e4	122	goto error_discard;
08e0e7c8	123	}
1da177e4	124
08e0e7c8	125	volume->servers[volume->nservers] = server;
1da177e4 LT	126	volume->nservers++;
	127	}
	128	}
	129
	130	/* attach the cache and volume location */
9b3f26c9 DH	131	#ifdef CONFIG_AFS_FSCACHE
	132	volume->cache = fscache_acquire_cookie(vlocation->cache,
	133	&afs_volume_cache_index_def,
	134	volume);
1da177e4	135	#endif
1da177e4 LT	136	afs_get_vlocation(vlocation);
	137	volume->vlocation = vlocation;
	138
00d3b7a4	139	vlocation->vols[volume->type] = volume;
1da177e4	140
ec26815a	141	success:
1da177e4 LT	142	_debug("kAFS selected %s volume %08x",
1da177e4 LT	143	afs_voltypes[volume->type], volume->vid);
00d3b7a4	144	up_write(&params->cell->vl_sem);
08e0e7c8	145	afs_put_vlocation(vlocation);
08e0e7c8 DH	146	_leave(" = %p", volume);
08e0e7c8 DH	147	return volume;
1da177e4 LT	148
1da177e4 LT	149	/* clean up */
ec26815a	150	error_up:
00d3b7a4	151	up_write(&params->cell->vl_sem);
ec26815a	152	error:
1da177e4	153	afs_put_vlocation(vlocation);
08e0e7c8 DH	154	_leave(" = %d", ret);
08e0e7c8 DH	155	return ERR_PTR(ret);
1da177e4	156
ec26815a	157	error_discard:
e1da0222 JA	158	bdi_destroy(&volume->bdi);
e1da0222 JA	159	error_bdi:
00d3b7a4	160	up_write(&params->cell->vl_sem);
1da177e4 LT	161
	162	for (loop = volume->nservers - 1; loop >= 0; loop--)
	163	afs_put_server(volume->servers[loop]);
	164
	165	kfree(volume);
	166	goto error;
ec26815a	167	}
1da177e4	168
1da177e4 LT	169	/*
	170	* destroy a volume record
	171	*/
	172	void afs_put_volume(struct afs_volume *volume)
	173	{
	174	struct afs_vlocation *vlocation;
	175	int loop;
	176
	177	if (!volume)
	178	return;
	179
	180	_enter("%p", volume);
	181
08e0e7c8	182	ASSERTCMP(atomic_read(&volume->usage), >, 0);
1da177e4	183
08e0e7c8	184	vlocation = volume->vlocation;
1da177e4 LT	185
	186	/* to prevent a race, the decrement and the dequeue must be effectively
	187	* atomic */
	188	down_write(&vlocation->cell->vl_sem);
	189
	190	if (likely(!atomic_dec_and_test(&volume->usage))) {
	191	up_write(&vlocation->cell->vl_sem);
	192	_leave("");
	193	return;
	194	}
	195
	196	vlocation->vols[volume->type] = NULL;
	197
	198	up_write(&vlocation->cell->vl_sem);
	199
	200	/* finish cleaning up the volume */
9b3f26c9 DH	201	#ifdef CONFIG_AFS_FSCACHE
9b3f26c9 DH	202	fscache_relinquish_cookie(volume->cache, 0);
1da177e4 LT	203	#endif
	204	afs_put_vlocation(vlocation);
	205
	206	for (loop = volume->nservers - 1; loop >= 0; loop--)
	207	afs_put_server(volume->servers[loop]);
	208
e1da0222	209	bdi_destroy(&volume->bdi);
1da177e4 LT	210	kfree(volume);
	211
	212	_leave(" [destroyed]");
ec26815a	213	}
1da177e4	214
1da177e4 LT	215	/*
	216	* pick a server to use to try accessing this volume
	217	* - returns with an elevated usage count on the server chosen
	218	*/
08e0e7c8	219	struct afs_server afs_volume_pick_fileserver(struct afs_vnode vnode)
1da177e4	220	{
08e0e7c8	221	struct afs_volume *volume = vnode->volume;
1da177e4 LT	222	struct afs_server *server;
	223	int ret, state, loop;
	224
	225	_enter("%s", volume->vlocation->vldb.name);
	226
08e0e7c8 DH	227	/* stick with the server we're already using if we can */
	228	if (vnode->server && vnode->server->fs_state == 0) {
	229	afs_get_server(vnode->server);
	230	_leave(" = %p [current]", vnode->server);
	231	return vnode->server;
	232	}
	233
1da177e4 LT	234	down_read(&volume->server_sem);
	235
	236	/* handle the no-server case */
	237	if (volume->nservers == 0) {
	238	ret = volume->rjservers ? -ENOMEDIUM : -ESTALE;
	239	up_read(&volume->server_sem);
	240	_leave(" = %d [no servers]", ret);
08e0e7c8	241	return ERR_PTR(ret);
1da177e4 LT	242	}
	243
	244	/* basically, just search the list for the first live server and use
	245	* that */
	246	ret = 0;
	247	for (loop = 0; loop < volume->nservers; loop++) {
	248	server = volume->servers[loop];
	249	state = server->fs_state;
	250
08e0e7c8 DH	251	_debug("consider %d [%d]", loop, state);
08e0e7c8 DH	252
1da177e4 LT	253	switch (state) {
	254	/* found an apparently healthy server */
	255	case 0:
	256	afs_get_server(server);
	257	up_read(&volume->server_sem);
08e0e7c8 DH	258	_leave(" = %p (picked %08x)",
	259	server, ntohl(server->addr.s_addr));
	260	return server;
1da177e4 LT	261
	262	case -ENETUNREACH:
	263	if (ret == 0)
	264	ret = state;
	265	break;
	266
	267	case -EHOSTUNREACH:
	268	if (ret == 0 \|\|
	269	ret == -ENETUNREACH)
	270	ret = state;
	271	break;
	272
	273	case -ECONNREFUSED:
	274	if (ret == 0 \|\|
	275	ret == -ENETUNREACH \|\|
	276	ret == -EHOSTUNREACH)
	277	ret = state;
	278	break;
	279
	280	default:
	281	case -EREMOTEIO:
	282	if (ret == 0 \|\|
	283	ret == -ENETUNREACH \|\|
	284	ret == -EHOSTUNREACH \|\|
	285	ret == -ECONNREFUSED)
	286	ret = state;
	287	break;
	288	}
	289	}
	290
	291	/* no available servers
	292	* - TODO: handle the no active servers case better
	293	*/
	294	up_read(&volume->server_sem);
	295	_leave(" = %d", ret);
08e0e7c8	296	return ERR_PTR(ret);
ec26815a	297	}
1da177e4	298
1da177e4 LT	299	/*
	300	* release a server after use
	301	* - releases the ref on the server struct that was acquired by picking
	302	* - records result of using a particular server to access a volume
	303	* - return 0 to try again, 1 if okay or to issue error
260a9803	304	* - the caller must release the server struct if result was 0
1da177e4	305	*/
08e0e7c8	306	int afs_volume_release_fileserver(struct afs_vnode *vnode,
1da177e4 LT	307	struct afs_server *server,
	308	int result)
	309	{
08e0e7c8	310	struct afs_volume *volume = vnode->volume;
1da177e4 LT	311	unsigned loop;
	312
	313	_enter("%s,%08x,%d",
	314	volume->vlocation->vldb.name, ntohl(server->addr.s_addr),
	315	result);
	316
	317	switch (result) {
	318	/* success */
	319	case 0:
	320	server->fs_act_jif = jiffies;
08e0e7c8	321	server->fs_state = 0;
260a9803 DH	322	_leave("");
260a9803 DH	323	return 1;
1da177e4 LT	324
	325	/* the fileserver denied all knowledge of the volume */
	326	case -ENOMEDIUM:
	327	server->fs_act_jif = jiffies;
	328	down_write(&volume->server_sem);
	329
08e0e7c8	330	/* firstly, find where the server is in the active list (if it
1da177e4 LT	331	* is) */
	332	for (loop = 0; loop < volume->nservers; loop++)
	333	if (volume->servers[loop] == server)
	334	goto present;
	335
	336	/* no longer there - may have been discarded by another op */
	337	goto try_next_server_upw;
	338
	339	present:
	340	volume->nservers--;
	341	memmove(&volume->servers[loop],
	342	&volume->servers[loop + 1],
	343	sizeof(volume->servers[loop]) *
	344	(volume->nservers - loop));
	345	volume->servers[volume->nservers] = NULL;
	346	afs_put_server(server);
	347	volume->rjservers++;
	348
	349	if (volume->nservers > 0)
	350	/* another server might acknowledge its existence */
	351	goto try_next_server_upw;
	352
	353	/* handle the case where all the fileservers have rejected the
	354	* volume
	355	* - TODO: try asking the fileservers for volume information
	356	* - TODO: contact the VL server again to see if the volume is
	357	* no longer registered
	358	*/
	359	up_write(&volume->server_sem);
	360	afs_put_server(server);
	361	_leave(" [completely rejected]");
	362	return 1;
	363
	364	/* problem reaching the server */
	365	case -ENETUNREACH:
	366	case -EHOSTUNREACH:
	367	case -ECONNREFUSED:
08e0e7c8	368	case -ETIME:
1da177e4 LT	369	case -ETIMEDOUT:
	370	case -EREMOTEIO:
	371	/* mark the server as dead
	372	* TODO: vary dead timeout depending on error
	373	*/
	374	spin_lock(&server->fs_lock);
	375	if (!server->fs_state) {
	376	server->fs_dead_jif = jiffies + HZ * 10;
	377	server->fs_state = result;
	378	printk("kAFS: SERVER DEAD state=%d\n", result);
	379	}
	380	spin_unlock(&server->fs_lock);
	381	goto try_next_server;
	382
	383	/* miscellaneous error */
	384	default:
	385	server->fs_act_jif = jiffies;
	386	case -ENOMEM:
	387	case -ENONET:
260a9803 DH	388	/* tell the caller to accept the result */
	389	afs_put_server(server);
	390	_leave(" [local failure]");
	391	return 1;
1da177e4 LT	392	}
1da177e4 LT	393
1da177e4	394	/* tell the caller to loop around and try the next server */
ec26815a	395	try_next_server_upw:
1da177e4	396	up_write(&volume->server_sem);
ec26815a	397	try_next_server:
1da177e4 LT	398	afs_put_server(server);
	399	_leave(" [try next server]");
	400	return 0;
ec26815a	401	}