[thirdparty/mdadm.git] / msg.c

/*
 * Copyright (C) 2008 Intel Corporation
 *
 * 	mdmon socket / message handling
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include "mdadm.h"
#include "mdmon.h"

static const __u32 start_magic = 0x5a5aa5a5;
static const __u32 end_magic = 0xa5a55a5a;

static int send_buf(int fd, const void* buf, int len, int tmo)
{
	fd_set set;
	int rv;
	struct timeval timeout = {tmo, 0};
	struct timeval *ptmo = tmo ? &timeout : NULL;

	while (len) {
		FD_ZERO(&set);
		FD_SET(fd, &set);
		rv = select(fd+1, NULL, &set, NULL, ptmo);
		if (rv <= 0)
			return -1;
		rv = write(fd, buf, len);
		if (rv <= 0)
			return -1;
		len -= rv;
		buf += rv;
	}
	return 0;
}

static int recv_buf(int fd, void* buf, int len, int tmo)
{
	fd_set set;
	int rv;
	struct timeval timeout = {tmo, 0};
	struct timeval *ptmo = tmo ? &timeout : NULL;

	while (len) {
		FD_ZERO(&set);
		FD_SET(fd, &set);
		rv = select(fd+1, &set, NULL, NULL, ptmo);
		if (rv <= 0)
			return -1;
		rv = read(fd, buf, len);
		if (rv <= 0)
			return -1;
		len -= rv;
		buf += rv;
	}
	return 0;
}


int send_message(int fd, struct metadata_update *msg, int tmo)
{
	__s32 len = msg->len;
	int rv;

	rv = send_buf(fd, &start_magic, 4, tmo);
	rv = rv ?: send_buf(fd, &len, 4, tmo);
	if (len > 0)
		rv = rv ?: send_buf(fd, msg->buf, msg->len, tmo);
	rv = send_buf(fd, &end_magic, 4, tmo);

	return rv;
}

int receive_message(int fd, struct metadata_update *msg, int tmo)
{
	__u32 magic;
	__s32 len;
	int rv;

	rv = recv_buf(fd, &magic, 4, tmo);
	if (rv < 0 || magic != start_magic)
		return -1;
	rv = recv_buf(fd, &len, 4, tmo);
	if (rv < 0 || len > MSG_MAX_LEN)
		return -1;
	if (len > 0) {
		msg->buf = malloc(len);
		if (msg->buf == NULL)
			return -1;
		rv = recv_buf(fd, msg->buf, len, tmo);
		if (rv < 0) {
			free(msg->buf);
			return -1;
		}
	} else
		msg->buf = NULL;
	rv = recv_buf(fd, &magic, 4, tmo);
	if (rv < 0 || magic != end_magic) {
		free(msg->buf);
		return -1;
	}
	msg->len = len;
	return 0;
}

int ack(int fd, int tmo)
{
	struct metadata_update msg = { .len = 0 };

	return send_message(fd, &msg, tmo);
}

int wait_reply(int fd, int tmo)
{
	struct metadata_update msg;
	int err = receive_message(fd, &msg, tmo);

	/* mdmon sent extra data, but caller only cares that we got a
	 * successful reply
	 */
	if (err == 0 && msg.len > 0)
		free(msg.buf);

	return err;
}

int connect_monitor(char *devname)
{
	char path[100];
	int sfd;
	long fl;
	struct sockaddr_un addr;
	int pos;
	char *c;

	pos = sprintf(path, "%s/", MDMON_DIR);
	if (is_subarray(devname)) {
		devname++;
		c = strchr(devname, '/');
		if (!c)
			return -1;
		snprintf(&path[pos], c - devname + 1, "%s", devname);
		pos += c - devname;
	} else
		pos += sprintf(&path[pos], "%s", devname);
	sprintf(&path[pos], ".sock");

	sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	if (sfd < 0)
		return -1;

	addr.sun_family = PF_LOCAL;
	strcpy(addr.sun_path, path);
	if (connect(sfd, &addr, sizeof(addr)) < 0) {
		close(sfd);
		return -1;
	}

	fl = fcntl(sfd, F_GETFL, 0);
	fl |= O_NONBLOCK;
	fcntl(sfd, F_SETFL, fl);

	return sfd;
}

int fping_monitor(int sfd)
{
	int err = 0;

	if (sfd < 0)
		return sfd;

	/* try to ping existing socket */
	if (ack(sfd, 20) != 0)
		err = -1;

	/* check the reply */
	if (!err && wait_reply(sfd, 20) != 0)
		err = -1;

	return err;
}

/* give the monitor a chance to update the metadata */
int ping_monitor(char *devname)
{
	int sfd = connect_monitor(devname);
	int err = fping_monitor(sfd);

	close(sfd);
	return err;
}

/* ping monitor using device number */
int ping_monitor_by_id(int devnum)
{
	int err = -1;
	char *container = devnum2devname(devnum);

	if (container) {
		err = ping_monitor(container);
		free(container);
	}

	return err;
}

static char *ping_monitor_version(char *devname)
{
	int sfd = connect_monitor(devname);
	struct metadata_update msg;
	int err = 0;

	if (sfd < 0)
		return NULL;

	if (ack(sfd, 20) != 0)
		err = -1;

	if (!err && receive_message(sfd, &msg, 20) != 0)
		err = -1;

	close(sfd);

	if (err || !msg.len || !msg.buf)
		return NULL;
	return msg.buf;
}

int unblock_subarray(struct mdinfo *sra, const int unfreeze)
{
	char buf[64];
	int rc = 0;

	if (sra) {
		sprintf(buf, "external:%s\n", sra->text_version);
		buf[9] = '/';
	} else
		buf[9] = '-';

	if (buf[9] == '-' ||
	    sysfs_set_str(sra, NULL, "metadata_version", buf) ||
	    (unfreeze &&
	     sysfs_attribute_available(sra, NULL, "sync_action") &&
	     sysfs_set_str(sra, NULL, "sync_action", "idle")))
		rc = -1;
	return rc;
}

int block_subarray(struct mdinfo *sra)
{
	char buf[64];
	int rc = 0;

	sprintf(buf, "external:%s\n", sra->text_version);
	buf[9] = '-';
	if (sysfs_set_str(sra, NULL, "metadata_version", buf))
		rc = -1;

	return rc;
}

/* check mdmon version if it supports
 * array blocking mechanism
 */
int check_mdmon_version(char *container)
{
	char *version = NULL;
	int devnum = devname2devnum(container);

	if (!mdmon_running(devnum)) {
		/* if mdmon is not active we assume that any instance that is
		 * later started will match the current mdadm version, if this
		 * assumption is violated we may inadvertantly rebuild an array
		 * that was meant for reshape, or start rebuild on a spare that
		 * was to be moved to another container
		 */
		/* pass */;
	} else {
		int ver;

		version = ping_monitor_version(container);
		ver = version ? mdadm_version(version) : -1;
		free(version);
		if (ver < 3002000) {
			fprintf(stderr, Name
				": mdmon instance for %s cannot be disabled\n",
				container);
			return -1;
		}
	}

	return 0;
}

/**
 * block_monitor - prevent mdmon spare assignment
 * @container - container to block
 * @freeze - flag to additionally freeze sync_action
 *
 * This is used by the reshape code to freeze the container, and the
 * auto-rebuild implementation to atomically move spares.
 * In both cases we need to stop mdmon from assigning spares to replace
 * failed devices as we might have other plans for the spare.
 * For the reshape case we also need to 'freeze' sync_action so that
 * no recovery happens until we have fully prepared for the reshape.
 *
 * We tell mdmon that the array is frozen by marking the 'metadata' name
 * with a leading '-'.  The previously told mdmon "Don't make this array
 * read/write, leave it readonly".  Now it means a more general "Don't
 * reconfigure this array at all".
 * As older versions of mdmon (which might run from initrd) don't understand
 * this, we first check that the running mdmon is new enough.
 */
int block_monitor(char *container, const int freeze)
{
	struct mdstat_ent *ent, *e, *e2;
	struct mdinfo *sra = NULL;
	char buf[64];
	int rv = 0;

	if (check_mdmon_version(container))
		return -1;

	ent = mdstat_read(0, 0);
	if (!ent) {
		fprintf(stderr, Name
			": failed to read /proc/mdstat while disabling mdmon\n");
		return -1;
	}

	/* freeze container contents */
	for (e = ent; e; e = e->next) {
		if (!is_container_member(e, container))
			continue;
		sysfs_free(sra);
		sra = sysfs_read(-1, e->devnum, GET_VERSION);
		if (!sra) {
			fprintf(stderr, Name
				": failed to read sysfs for subarray%s\n",
				to_subarray(e, container));
			break;
		}
		/* can't reshape an array that we can't monitor */
		if (sra->text_version[0] == '-')
			break;

		if (freeze && sysfs_freeze_array(sra) < 1)
			break;
		/* flag this array to not be modified by mdmon (close race with
		 * takeover in reshape case and spare reassignment in the
		 * auto-rebuild case)
		 */
		if (block_subarray(sra))
			break;
		ping_monitor(container);

		/* check that we did not race with recovery */
		if ((freeze &&
		     !sysfs_attribute_available(sra, NULL, "sync_action")) ||
		    (freeze &&
		     sysfs_attribute_available(sra, NULL, "sync_action") &&
		     sysfs_get_str(sra, NULL, "sync_action", buf, 20) > 0 &&
		     strcmp(buf, "frozen\n") == 0))
			/* pass */;
		else {
			unblock_subarray(sra, 0);
			break;
		}
		/* Double check against races - there should be no spares
		 * or part-spares
		 */
		sysfs_free(sra);
		sra = sysfs_read(-1, e->devnum, GET_DEVS | GET_STATE);
		if (sra && sra->array.spare_disks > 0) {
			unblock_subarray(sra, freeze);
			break;
		}
	}

	if (e) {
		fprintf(stderr, Name ": failed to freeze subarray%s\n",
			to_subarray(e, container));

		/* thaw the partially frozen container */
		for (e2 = ent; e2 && e2 != e; e2 = e2->next) {
			if (!is_container_member(e2, container))
				continue;
			sysfs_free(sra);
			sra = sysfs_read(-1, e2->devnum, GET_VERSION);
			if (unblock_subarray(sra, freeze))
				fprintf(stderr, Name ": Failed to unfreeze %s\n", e2->dev);
		}

		ping_monitor(container); /* cleared frozen */
		rv = -1;
	}

	sysfs_free(sra);
	free_mdstat(ent);

	return rv;
}

void unblock_monitor(char *container, const int unfreeze)
{
	struct mdstat_ent *ent, *e;
	struct mdinfo *sra = NULL;
	int to_ping = 0;

	ent = mdstat_read(0, 0);
	if (!ent) {
		fprintf(stderr, Name
			": failed to read /proc/mdstat while unblocking container\n");
		return;
	}

	/* unfreeze container contents */
	for (e = ent; e; e = e->next) {
		if (!is_container_member(e, container))
			continue;
		sysfs_free(sra);
		sra = sysfs_read(-1, e->devnum, GET_VERSION|GET_LEVEL);
		if (sra->array.level > 0)
			to_ping++;
		if (unblock_subarray(sra, unfreeze))
			fprintf(stderr, Name ": Failed to unfreeze %s\n", e->dev);
	}
	if (to_ping)
		ping_monitor(container);

	sysfs_free(sra);
	free_mdstat(ent);
}


/* give the manager a chance to view the updated container state.  This
 * would naturally happen due to the manager noticing a change in
 * /proc/mdstat; however, pinging encourages this detection to happen
 * while an exclusive open() on the container is active
 */
int ping_manager(char *devname)
{
	int sfd = connect_monitor(devname);
	struct metadata_update msg = { .len = -1 };
	int err = 0;

	if (sfd < 0)
		return sfd;

	err = send_message(sfd, &msg, 20);

	/* check the reply */
	if (!err && wait_reply(sfd, 20) != 0)
		err = -1;

	close(sfd);
	return err;
}
Commit	Line	Data
f7dd881f DW	1	/*
	2	* Copyright (C) 2008 Intel Corporation
	3	*
	4	* mdmon socket / message handling
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along with
	16	* this program; if not, write to the Free Software Foundation, Inc.,
	17	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	18	*/
	19	#ifndef _GNU_SOURCE
	20	#define _GNU_SOURCE
	21	#endif
	22	#include <unistd.h>
	23	#include <stdio.h>
	24	#include <string.h>
	25	#include <stdlib.h>
	26	#include <errno.h>
	27	#include <fcntl.h>
	28	#include <sys/types.h>
	29	#include <sys/socket.h>
	30	#include <sys/un.h>
	31	#include "mdadm.h"
bfa44e2e	32	#include "mdmon.h"
f7dd881f	33
bfa44e2e NB	34	static const __u32 start_magic = 0x5a5aa5a5;
	35	static const __u32 end_magic = 0xa5a55a5a;
	36
	37	static int send_buf(int fd, const void* buf, int len, int tmo)
f7dd881f	38	{
bfa44e2e NB	39	fd_set set;
	40	int rv;
	41	struct timeval timeout = {tmo, 0};
	42	struct timeval *ptmo = tmo ? &timeout : NULL;
	43
	44	while (len) {
	45	FD_ZERO(&set);
	46	FD_SET(fd, &set);
	47	rv = select(fd+1, NULL, &set, NULL, ptmo);
	48	if (rv <= 0)
	49	return -1;
	50	rv = write(fd, buf, len);
	51	if (rv <= 0)
	52	return -1;
	53	len -= rv;
	54	buf += rv;
	55	}
	56	return 0;
	57	}
f7dd881f	58
bfa44e2e NB	59	static int recv_buf(int fd, void* buf, int len, int tmo)
	60	{
	61	fd_set set;
	62	int rv;
	63	struct timeval timeout = {tmo, 0};
	64	struct timeval *ptmo = tmo ? &timeout : NULL;
	65
	66	while (len) {
	67	FD_ZERO(&set);
	68	FD_SET(fd, &set);
	69	rv = select(fd+1, &set, NULL, NULL, ptmo);
	70	if (rv <= 0)
	71	return -1;
	72	rv = read(fd, buf, len);
	73	if (rv <= 0)
	74	return -1;
	75	len -= rv;
	76	buf += rv;
	77	}
	78	return 0;
f7dd881f DW	79	}
	80
	81
bfa44e2e	82	int send_message(int fd, struct metadata_update *msg, int tmo)
f7dd881f	83	{
313a4a82	84	__s32 len = msg->len;
bfa44e2e NB	85	int rv;
	86
	87	rv = send_buf(fd, &start_magic, 4, tmo);
	88	rv = rv ?: send_buf(fd, &len, 4, tmo);
313a4a82	89	if (len > 0)
bfa44e2e NB	90	rv = rv ?: send_buf(fd, msg->buf, msg->len, tmo);
	91	rv = send_buf(fd, &end_magic, 4, tmo);
	92
	93	return rv;
f7dd881f DW	94	}
f7dd881f DW	95
bfa44e2e	96	int receive_message(int fd, struct metadata_update *msg, int tmo)
f7dd881f	97	{
bfa44e2e	98	__u32 magic;
313a4a82	99	__s32 len;
bfa44e2e NB	100	int rv;
	101
	102	rv = recv_buf(fd, &magic, 4, tmo);
	103	if (rv < 0 \|\| magic != start_magic)
	104	return -1;
	105	rv = recv_buf(fd, &len, 4, tmo);
	106	if (rv < 0 \|\| len > MSG_MAX_LEN)
f7dd881f	107	return -1;
313a4a82	108	if (len > 0) {
bfa44e2e NB	109	msg->buf = malloc(len);
	110	if (msg->buf == NULL)
	111	return -1;
	112	rv = recv_buf(fd, msg->buf, len, tmo);
	113	if (rv < 0) {
	114	free(msg->buf);
	115	return -1;
	116	}
	117	} else
	118	msg->buf = NULL;
	119	rv = recv_buf(fd, &magic, 4, tmo);
	120	if (rv < 0 \|\| magic != end_magic) {
	121	free(msg->buf);
	122	return -1;
	123	}
	124	msg->len = len;
	125	return 0;
f7dd881f DW	126	}
f7dd881f DW	127
bfa44e2e	128	int ack(int fd, int tmo)
f7dd881f	129	{
bfa44e2e	130	struct metadata_update msg = { .len = 0 };
f7dd881f DW	131
	132	return send_message(fd, &msg, tmo);
	133	}
	134
bfa44e2e	135	int wait_reply(int fd, int tmo)
f7dd881f	136	{
bfa44e2e	137	struct metadata_update msg;
bc77ed53 DW	138	int err = receive_message(fd, &msg, tmo);
	139
	140	/* mdmon sent extra data, but caller only cares that we got a
	141	* successful reply
	142	*/
	143	if (err == 0 && msg.len > 0)
	144	free(msg.buf);
	145
	146	return err;
f7dd881f DW	147	}
f7dd881f DW	148
f7dd881f DW	149	int connect_monitor(char *devname)
	150	{
	151	char path[100];
	152	int sfd;
	153	long fl;
	154	struct sockaddr_un addr;
c94709e8 DW	155	int pos;
	156	char *c;
	157
753cf905	158	pos = sprintf(path, "%s/", MDMON_DIR);
c94709e8 DW	159	if (is_subarray(devname)) {
	160	devname++;
	161	c = strchr(devname, '/');
	162	if (!c)
	163	return -1;
	164	snprintf(&path[pos], c - devname + 1, "%s", devname);
	165	pos += c - devname;
	166	} else
	167	pos += sprintf(&path[pos], "%s", devname);
	168	sprintf(&path[pos], ".sock");
f7dd881f	169
f7dd881f DW	170	sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	171	if (sfd < 0)
	172	return -1;
	173
	174	addr.sun_family = PF_LOCAL;
	175	strcpy(addr.sun_path, path);
	176	if (connect(sfd, &addr, sizeof(addr)) < 0) {
	177	close(sfd);
	178	return -1;
	179	}
	180
	181	fl = fcntl(sfd, F_GETFL, 0);
	182	fl \|= O_NONBLOCK;
	183	fcntl(sfd, F_SETFL, fl);
	184
	185	return sfd;
	186	}
	187
9f1da824	188	int fping_monitor(int sfd)
f7dd881f	189	{
f7dd881f DW	190	int err = 0;
	191
	192	if (sfd < 0)
	193	return sfd;
	194
	195	/* try to ping existing socket */
eb2c876f	196	if (ack(sfd, 20) != 0)
f7dd881f DW	197	err = -1;
	198
	199	/* check the reply */
eb2c876f	200	if (!err && wait_reply(sfd, 20) != 0)
f7dd881f DW	201	err = -1;
f7dd881f DW	202
9f1da824 DW	203	return err;
	204	}
	205
9f1da824 DW	206	/* give the monitor a chance to update the metadata */
	207	int ping_monitor(char *devname)
	208	{
	209	int sfd = connect_monitor(devname);
	210	int err = fping_monitor(sfd);
	211
f7dd881f DW	212	close(sfd);
	213	return err;
	214	}
313a4a82	215
983fff45 AK	216	/* ping monitor using device number */
	217	int ping_monitor_by_id(int devnum)
	218	{
	219	int err = -1;
	220	char *container = devnum2devname(devnum);
	221
	222	if (container) {
	223	err = ping_monitor(container);
	224	free(container);
	225	}
	226
	227	return err;
	228	}
	229
bc77ed53 DW	230	static char ping_monitor_version(char devname)
	231	{
	232	int sfd = connect_monitor(devname);
	233	struct metadata_update msg;
	234	int err = 0;
	235
	236	if (sfd < 0)
	237	return NULL;
	238
	239	if (ack(sfd, 20) != 0)
	240	err = -1;
	241
	242	if (!err && receive_message(sfd, &msg, 20) != 0)
	243	err = -1;
	244
	245	close(sfd);
	246
	247	if (err \|\| !msg.len \|\| !msg.buf)
	248	return NULL;
	249	return msg.buf;
	250	}
	251
2a093697	252	int unblock_subarray(struct mdinfo *sra, const int unfreeze)
bc77ed53 DW	253	{
	254	char buf[64];
	255	int rc = 0;
	256
	257	if (sra) {
	258	sprintf(buf, "external:%s\n", sra->text_version);
	259	buf[9] = '/';
	260	} else
	261	buf[9] = '-';
	262
	263	if (buf[9] == '-' \|\|
	264	sysfs_set_str(sra, NULL, "metadata_version", buf) \|\|
	265	(unfreeze &&
	266	sysfs_attribute_available(sra, NULL, "sync_action") &&
	267	sysfs_set_str(sra, NULL, "sync_action", "idle")))
	268	rc = -1;
	269	return rc;
	270	}
	271
2a093697 AK	272	int block_subarray(struct mdinfo *sra)
	273	{
	274	char buf[64];
	275	int rc = 0;
	276
	277	sprintf(buf, "external:%s\n", sra->text_version);
	278	buf[9] = '-';
	279	if (sysfs_set_str(sra, NULL, "metadata_version", buf))
	280	rc = -1;
	281
	282	return rc;
	283	}
7aa437c2 AK	284
	285	/* check mdmon version if it supports
	286	* array blocking mechanism
	287	*/
	288	int check_mdmon_version(char *container)
	289	{
	290	char *version = NULL;
	291	int devnum = devname2devnum(container);
	292
	293	if (!mdmon_running(devnum)) {
	294	/* if mdmon is not active we assume that any instance that is
	295	* later started will match the current mdadm version, if this
	296	* assumption is violated we may inadvertantly rebuild an array
	297	* that was meant for reshape, or start rebuild on a spare that
	298	* was to be moved to another container
	299	*/
	300	/* pass */;
	301	} else {
	302	int ver;
	303
	304	version = ping_monitor_version(container);
	305	ver = version ? mdadm_version(version) : -1;
	306	free(version);
	307	if (ver < 3002000) {
	308	fprintf(stderr, Name
	309	": mdmon instance for %s cannot be disabled\n",
	310	container);
	311	return -1;
	312	}
	313	}
	314
	315	return 0;
	316	}
	317
bc77ed53 DW	318	/**
	319	* block_monitor - prevent mdmon spare assignment
	320	* @container - container to block
	321	* @freeze - flag to additionally freeze sync_action
	322	*
	323	* This is used by the reshape code to freeze the container, and the
746a6567 N	324	* auto-rebuild implementation to atomically move spares.
	325	* In both cases we need to stop mdmon from assigning spares to replace
	326	* failed devices as we might have other plans for the spare.
	327	* For the reshape case we also need to 'freeze' sync_action so that
	328	* no recovery happens until we have fully prepared for the reshape.
	329	*
	330	* We tell mdmon that the array is frozen by marking the 'metadata' name
	331	* with a leading '-'. The previously told mdmon "Don't make this array
	332	* read/write, leave it readonly". Now it means a more general "Don't
	333	* reconfigure this array at all".
	334	* As older versions of mdmon (which might run from initrd) don't understand
	335	* this, we first check that the running mdmon is new enough.
bc77ed53 DW	336	*/
	337	int block_monitor(char *container, const int freeze)
	338	{
bc77ed53 DW	339	struct mdstat_ent ent, e, *e2;
bc77ed53 DW	340	struct mdinfo *sra = NULL;
bc77ed53 DW	341	char buf[64];
	342	int rv = 0;
	343
7aa437c2 AK	344	if (check_mdmon_version(container))
7aa437c2 AK	345	return -1;
bc77ed53 DW	346
	347	ent = mdstat_read(0, 0);
	348	if (!ent) {
	349	fprintf(stderr, Name
	350	": failed to read /proc/mdstat while disabling mdmon\n");
	351	return -1;
	352	}
	353
	354	/* freeze container contents */
	355	for (e = ent; e; e = e->next) {
	356	if (!is_container_member(e, container))
	357	continue;
	358	sysfs_free(sra);
	359	sra = sysfs_read(-1, e->devnum, GET_VERSION);
	360	if (!sra) {
	361	fprintf(stderr, Name
	362	": failed to read sysfs for subarray%s\n",
	363	to_subarray(e, container));
	364	break;
	365	}
	366	/* can't reshape an array that we can't monitor */
	367	if (sra->text_version[0] == '-')
	368	break;
	369
	370	if (freeze && sysfs_freeze_array(sra) < 1)
	371	break;
	372	/* flag this array to not be modified by mdmon (close race with
	373	* takeover in reshape case and spare reassignment in the
	374	* auto-rebuild case)
	375	*/
2a093697	376	if (block_subarray(sra))
bc77ed53 DW	377	break;
	378	ping_monitor(container);
	379
	380	/* check that we did not race with recovery */
	381	if ((freeze &&
	382	!sysfs_attribute_available(sra, NULL, "sync_action")) \|\|
	383	(freeze &&
	384	sysfs_attribute_available(sra, NULL, "sync_action") &&
	385	sysfs_get_str(sra, NULL, "sync_action", buf, 20) > 0 &&
	386	strcmp(buf, "frozen\n") == 0))
	387	/* pass */;
885f9845 N	388	else {
885f9845 N	389	unblock_subarray(sra, 0);
bc77ed53	390	break;
885f9845 N	391	}
	392	/* Double check against races - there should be no spares
	393	* or part-spares
	394	*/
	395	sysfs_free(sra);
	396	sra = sysfs_read(-1, e->devnum, GET_DEVS \| GET_STATE);
	397	if (sra && sra->array.spare_disks > 0) {
	398	unblock_subarray(sra, freeze);
	399	break;
	400	}
bc77ed53 DW	401	}
	402
	403	if (e) {
	404	fprintf(stderr, Name ": failed to freeze subarray%s\n",
	405	to_subarray(e, container));
	406
	407	/* thaw the partially frozen container */
	408	for (e2 = ent; e2 && e2 != e; e2 = e2->next) {
	409	if (!is_container_member(e2, container))
	410	continue;
	411	sysfs_free(sra);
	412	sra = sysfs_read(-1, e2->devnum, GET_VERSION);
	413	if (unblock_subarray(sra, freeze))
	414	fprintf(stderr, Name ": Failed to unfreeze %s\n", e2->dev);
	415	}
	416
	417	ping_monitor(container); /* cleared frozen */
	418	rv = -1;
	419	}
	420
	421	sysfs_free(sra);
	422	free_mdstat(ent);
bc77ed53 DW	423
	424	return rv;
	425	}
	426
	427	void unblock_monitor(char *container, const int unfreeze)
	428	{
	429	struct mdstat_ent ent, e;
	430	struct mdinfo *sra = NULL;
5158aef1	431	int to_ping = 0;
bc77ed53 DW	432
	433	ent = mdstat_read(0, 0);
	434	if (!ent) {
	435	fprintf(stderr, Name
	436	": failed to read /proc/mdstat while unblocking container\n");
	437	return;
	438	}
	439
	440	/* unfreeze container contents */
	441	for (e = ent; e; e = e->next) {
	442	if (!is_container_member(e, container))
	443	continue;
	444	sysfs_free(sra);
5158aef1 AK	445	sra = sysfs_read(-1, e->devnum, GET_VERSION\|GET_LEVEL);
	446	if (sra->array.level > 0)
	447	to_ping++;
bc77ed53 DW	448	if (unblock_subarray(sra, unfreeze))
	449	fprintf(stderr, Name ": Failed to unfreeze %s\n", e->dev);
	450	}
5158aef1 AK	451	if (to_ping)
5158aef1 AK	452	ping_monitor(container);
bc77ed53 DW	453
	454	sysfs_free(sra);
	455	free_mdstat(ent);
	456	}
	457
	458
	459
313a4a82 DW	460	/* give the manager a chance to view the updated container state. This
	461	* would naturally happen due to the manager noticing a change in
	462	* /proc/mdstat; however, pinging encourages this detection to happen
	463	* while an exclusive open() on the container is active
	464	*/
	465	int ping_manager(char *devname)
	466	{
	467	int sfd = connect_monitor(devname);
	468	struct metadata_update msg = { .len = -1 };
	469	int err = 0;
	470
	471	if (sfd < 0)
	472	return sfd;
	473
	474	err = send_message(sfd, &msg, 20);
	475
	476	/* check the reply */
	477	if (!err && wait_reply(sfd, 20) != 0)
	478	err = -1;
	479
	480	close(sfd);
	481	return err;
	482	}