Reviewed the code, and did not find any generic issues (other than what
Mike Christie has stated).
On Wed, 2007-10-10 at 14:55 +0200, Hannes Reinecke wrote:
> Hi Alasdair,
>
> this is a patch to add a SPC-3 hardware handler. SPC-3 ALUA has
> provisioning for 'explicit' port group state change via the
> SET TARGET GROUP STATES command, and some newer storage
> arrays do benefit from this.
> Eg HP EVAs and newer EMC Clariions already support explicit ALUA.
>
> Please apply.
>
> Cheers,
>
> Hannes
> plain text document attachment (dm-mpath-alua-support)
> diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
> index 531d4d1..3fa9df3 100644
> --- a/drivers/md/Kconfig
> +++ b/drivers/md/Kconfig
> @@ -267,6 +267,13 @@ config DM_MULTIPATH_RDAC
> ---help---
> Multipath support for LSI/Engenio RDAC.
>
> +config DM_MULTIPATH_ALUA
> + tristate "SPC-3 ALUA multipath support (EXPERIMENTAL)"
> + depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL
> + ---help---
> + Multipath support for SPC-3 Asymmetric Logical Unit
> + Access (ALUA).
> +
> config DM_DELAY
> tristate "I/O delaying target (EXPERIMENTAL)"
> depends on BLK_DEV_DM && EXPERIMENTAL
> diff --git a/drivers/md/Makefile b/drivers/md/Makefile
> index c49366c..5013920 100644
> --- a/drivers/md/Makefile
> +++ b/drivers/md/Makefile
> @@ -8,6 +8,7 @@ dm-multipath-objs := dm-hw-handler.o dm-path-selector.o
> dm-mpath.o
> dm-snapshot-objs := dm-snap.o dm-exception-store.o
> dm-mirror-objs := dm-log.o dm-raid1.o
> dm-rdac-objs := dm-mpath-rdac.o
> +dm-alua-objs := dm-mpath-alua.o
> md-mod-objs := md.o bitmap.o
> raid456-objs := raid5.o raid6algos.o raid6recov.o raid6tables.o \
> raid6int1.o raid6int2.o raid6int4.o \
> @@ -36,6 +37,7 @@ obj-$(CONFIG_DM_DELAY) += dm-delay.o
> obj-$(CONFIG_DM_MULTIPATH) += dm-multipath.o dm-round-robin.o
> obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc.o
> obj-$(CONFIG_DM_MULTIPATH_RDAC) += dm-rdac.o
> +obj-$(CONFIG_DM_MULTIPATH_ALUA) += dm-alua.o
> obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o
> obj-$(CONFIG_DM_MIRROR) += dm-mirror.o
> obj-$(CONFIG_DM_ZERO) += dm-zero.o
> diff --git a/drivers/md/dm-mpath-alua.c b/drivers/md/dm-mpath-alua.c
> new file mode 100644
> index 0000000..40b9d4d
> --- /dev/null
> +++ b/drivers/md/dm-mpath-alua.c
> @@ -0,0 +1,662 @@
> +/*
> + * Generic SCSI-3 ALUA DM HW handler
> + *
> + * Copyright (C) 2007 Hannes Reinecke. All rights reserved.
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
> + *
> + */
> +#include <scsi/scsi.h>
> +#include <scsi/scsi_cmnd.h>
> +#include <scsi/scsi_eh.h>
> +
> +#define DM_MSG_PREFIX "multipath alua"
> +
> +#include "dm.h"
> +#include "dm-hw-handler.h"
> +
> +#define ALUA_DM_HWH_NAME "alua"
> +#define ALUA_DM_HWH_VER "0.2"
> +
> +enum tpgs_state {
> + TPGS_STATE_UNKNOWN = -1,
> + TPGS_STATE_OPTIMIZED = 0x0,
> + TPGS_STATE_NONOPTIMIZED,
> + TPGS_STATE_STANDBY,
> + TPGS_STATE_UNAVAILABLE,
> + TPGS_STATE_OFFLINE = 0xe,
> + TPGS_STATE_TRANSITIONING,
> +};
> +
> +#define TPGS_SUPPORT_NONE 0x00
> +#define TPGS_SUPPORT_OPTIMIZED 0x01
> +#define TPGS_SUPPORT_NONOPTIMIZED 0x02
> +#define TPGS_SUPPORT_STANDBY 0x04
> +#define TPGS_SUPPORT_UNAVAILABLE 0x08
> +#define TPGS_SUPPORT_OFFLINE 0x40
> +#define TPGS_SUPPORT_TRANSITION 0x80
> +
> +#define TPGS_MODE_UNINITIALIZED -1
> +#define TPGS_MODE_NONE 0x0
> +#define TPGS_MODE_IMPLICIT 0x1
> +#define TPGS_MODE_EXPLICIT 0x2
> +
> +#define TPGS_INQUIRY_SIZE 36
> +#define TPGS_FAILOVER_TIMEOUT (60 * HZ)
> +
> +struct alua_handler {
> + struct dm_path *path;
> + int debug;
> + int group_id;
> + int rel_port;
> + int tpgs;
> + enum tpgs_state state;
> + unsigned char inq[TPGS_INQUIRY_SIZE];
> + unsigned char *buff;
> + int bufflen;
> + unsigned char sense[SCSI_SENSE_BUFFERSIZE];
> +};
> +
> +#define ALUA_POLICY_SWITCH_CURRENT 0
> +#define ALUA_POLICY_SWITCH_ALL 1
> +
> +#define DPRINT(h, f, arg...) \
> + if (h->debug) DMINFO("%s: " f, h->path->dev->name, arg)
> +
> +static inline int had_failures(int error)
> +{
> + return (host_byte(error) != DID_OK ||
> + msg_byte(error) != COMMAND_COMPLETE);
> +}
> +
> +static int realloc_buffer(struct alua_handler *h, unsigned len)
> +{
> + if (h->buff && h->buff != h->inq)
> + kfree(h->buff);
> +
> + h->buff = kmalloc(len, GFP_ATOMIC);
> + if (!h->buff) {
> + DMINFO("%s: kmalloc buffer failed",__FUNCTION__);
> + h->buff = h->inq;
> + h->bufflen = TPGS_INQUIRY_SIZE;
> + return 1;
> + }
> + h->bufflen = len;
> + return 0;
> +}
> +
> +static struct request *prepare_req(struct alua_handler *h,
> + void *buffer, unsigned buflen, int rw)
> +{
> + struct request *rq;
> + struct request_queue *q = bdev_get_queue(h->path->dev->bdev);
> +
> + if (!q) {
> + DMWARN("%s: no queue", __FUNCTION__);
> + return NULL;
> + }
> +
> + rq = blk_get_request(q, rw, GFP_KERNEL);
> +
> + if (!rq) {
> + DMINFO("%s: blk_get_request failed", __FUNCTION__);
> + return NULL;
> + }
> +
> + if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_KERNEL)) {
> + blk_put_request(rq);
> + DMINFO("%s: blk_rq_map_kern failed", __FUNCTION__);
> + return NULL;
> + }
> +
> + memset(&rq->cmd, 0, BLK_MAX_CDB);
> + rq->sense = h->sense;
> + memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
> + rq->sense_len = 0;
> +
> + rq->timeout = TPGS_FAILOVER_TIMEOUT;
> + rq->cmd_type = REQ_TYPE_BLOCK_PC;
> + rq->cmd_flags |= REQ_FAILFAST | REQ_NOMERGE;
> + rq->end_io_data = h;
> +
> + return rq;
> +}
> +
> +/*
> + * Issue a standard INQUIRY command
> + */
> +static int submit_std_inquiry(struct alua_handler *h)
> +{
> + struct request *rq;
> + unsigned err = (DRIVER_ERROR << 24);
> +
> + rq = prepare_req(h, h->inq, TPGS_INQUIRY_SIZE, READ);
> + if (!rq)
> + return err;
> +
> + /* Prepare the command. */
> + rq->cmd[0] = INQUIRY;
> + rq->cmd[1] = 0;
> + rq->cmd[2] = 0;
> + rq->cmd[4] = TPGS_INQUIRY_SIZE;
> + rq->cmd_len = COMMAND_SIZE(INQUIRY);
> +
> + blk_execute_rq(rq->q, NULL, rq, 1);
> + err = rq->errors;
> + blk_put_request(rq);
> +
> + return err;
> +}
> +
> +/*
> + * Issue an INQUIRY VPD page 0x83 command
> + */
> +static int submit_vpd_inquiry(struct alua_handler *h)
> +{
> + struct request *rq;
> + unsigned err = (DRIVER_ERROR << 24);
> +
> + rq = prepare_req(h, h->buff, h->bufflen, READ);
> + if (!rq) {
> + DMWARN("failed to send INQUIRY VPD page 0x83");
> + return err;
> + }
> +
> + /* Prepare the command. */
> + rq->cmd[0] = INQUIRY;
> + rq->cmd[1] = 1;
> + rq->cmd[2] = 0x83;
> + rq->cmd[4] = h->bufflen;
> + rq->cmd_len = COMMAND_SIZE(INQUIRY);
> +
> + DPRINT(h, "submit INQUIRY VPD page 0x83 len %d", h->bufflen);
> + blk_execute_rq(rq->q, NULL, rq, 1);
> + err = rq->errors;
> + blk_put_request(rq);
> +
> + return err;
> +}
> +
> +/*
> + * Issue a REPORT TARGET GROUP STATES command.
> + */
> +static unsigned submit_rtpg(struct alua_handler *h)
> +{
> + struct request *rq;
> + unsigned err = (DRIVER_ERROR << 24);
> +
> + rq = prepare_req(h, h->buff, h->bufflen, READ);
> + if (!rq)
> + return err;
> +
> + /* Prepare the command. */
> + rq->cmd[0] = MAINTENANCE_IN;
> + rq->cmd[1] = MI_REPORT_TARGET_PGS;
> + rq->cmd[6] = (h->bufflen >> 24) & 0xff;
> + rq->cmd[7] = (h->bufflen >> 16) & 0xff;
> + rq->cmd[8] = (h->bufflen >> 8) & 0xff;
> + rq->cmd[9] = h->bufflen & 0xff;
> + rq->cmd_len = COMMAND_SIZE(MAINTENANCE_IN);
> +
> + DPRINT(h, "submit REPORT TARGET GROUP STATES len %d", h->bufflen);
> + blk_execute_rq(rq->q, NULL, rq, 1);
> + err = rq->errors;
> + blk_put_request(rq);
> +
> + return err;
> +}
> +
> +/*
> + * Issue a SET TARGET GROUP STATES command.
> + *
> + * Currently we're only setting the current target port group state
> + * to 'active/optimized' and let the array firmware figure out
> + * the states of the remaining groups.
> + */
> +static unsigned submit_stpg(struct alua_handler *h)
> +{
> + struct request *rq;
> + int stpg_len = 8;
> + unsigned err = (DRIVER_ERROR << 24);
> +
> + /* Prepare the data buffer */
> + memset(h->buff, 0, stpg_len);
> + h->buff[4] = TPGS_STATE_OPTIMIZED & 0x0f;
> + h->buff[6] = (h->group_id >> 8) & 0x0f;
> + h->buff[7] = h->group_id & 0x0f;
> +
> + rq = prepare_req(h, h->buff, stpg_len, WRITE);
> + if (!rq)
> + return err;
> +
> + /* Prepare the command. */
> + rq->cmd[0] = MAINTENANCE_OUT;
> + rq->cmd[1] = MO_SET_TARGET_PGS;
> + rq->cmd[6] = (stpg_len >> 24) & 0xff;
> + rq->cmd[7] = (stpg_len >> 16) & 0xff;
> + rq->cmd[8] = (stpg_len >> 8) & 0xff;
> + rq->cmd[9] = stpg_len & 0xff;
> + rq->cmd_len = COMMAND_SIZE(MAINTENANCE_OUT);
> +
> + if (h->debug)
> + DMINFO("%s: submit SET TARGET GROUP STATES",
> + h->path->dev->name);
> +
> + blk_execute_rq(rq->q, NULL, rq, 1);
> + err = rq->errors;
> + blk_put_request(rq);
> +
> + return err;
> +}
> +
> +/*
> + * Evaluate standard INQUIRY command
> + *
> + * Just extract the TPGS setting to find out if ALUA
> + * is supported.
> + */
> +static void alua_std_inquiry(struct alua_handler *h)
> +{
> + int error;
> +
> + error = submit_std_inquiry(h);
> +
> + if (had_failures(error)) {
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + return;
> + }
> +
> + /* Check TPGS setting */
> + h->tpgs = (h->inq[5] >> 4) & 0x3;
> + switch (h->tpgs) {
> + case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
> + DMWARN("%s: supports implicit and explicit TPGS",
> + h->path->dev->name);
> + break;
> + case TPGS_MODE_EXPLICIT:
> + DMWARN("%s: supports explicit TPGS",
> + h->path->dev->name);
> + break;
> + case TPGS_MODE_IMPLICIT:
> + DMWARN("%s: supports implicit TPGS",
> + h->path->dev->name);
> + break;
> + default:
> + DMWARN("%s:TPGS not supported",
> + h->path->dev->name);
> + break;
> + }
> +
> + if (h->tpgs == TPGS_MODE_NONE) {
> + /*
> + * ALUA not supported
> + */
> + dm_pg_init_complete(h->path, 0);
> + }
> + /*
> + * Don't call dm_pg_init_complete, continue
> + * with INQUIRY VPD page 0x83 command.
> + */
> + return;
> +}
> +
> +/*
> + * Evaluate INQUIRY vpd page 0x83
> + *
> + * Extract the relative target port and the target port group
> + * descriptor from the list of identificators.
> + */
> +static void alua_vpd_inquiry(struct alua_handler *h)
> +{
> + int len;
> + unsigned error;
> + unsigned char *d;
> +
> + retry:
> + error = submit_vpd_inquiry(h);
> +
> + if (had_failures(error)) {
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + return;
> + }
> +
> + /* Check if vpd page exceeds initial buffer */
> + len = (h->buff[2] << 8) + h->buff[3] + 4;
> + if (len > h->bufflen) {
> + /* Resubmit with the correct length */
> + if (realloc_buffer(h, len)) {
> + DMINFO("%s: kmalloc buffer failed",__FUNCTION__);
> + /* Temporary failure, bypass */
> + dm_pg_init_complete(h->path, MP_BYPASS_PG);
> + return;
> + }
> + goto retry;
> + }
> +
> + /*
> + * Now look for the correct descriptor.
> + */
> + d = h->buff + 4;
> + while (d < h->buff + len) {
> + switch (d[1] & 0xf) {
> + case 0x4:
> + /* Relative target port */
> + h->rel_port = (d[6] << 8) + d[7];
> + break;
> + case 0x5:
> + /* Target port group */
> + h->group_id = (d[6] << 8) + d[7];
> + break;
> + default:
> + break;
> + }
> + d += d[3] + 4;
> + }
> +
> + if (h->group_id == -1) {
> + /*
> + * Internal error; TPGS supported but required
> + * VPD identification descriptors not present.
> + * Disable ALUA support
> + */
> + DMWARN("%s: No target port descriptors in VPD page 0x83\n",
> + h->path->dev->name);
> + h->state = TPGS_STATE_OPTIMIZED;
> + h->tpgs = TPGS_MODE_NONE;
> + dm_pg_init_complete(h->path, 0);
> + } else {
> + DMWARN("%s: port group %02x rel port %02x",
> + h->path->dev->name, h->group_id, h->rel_port);
> + }
> +
> + /*
> + * Don't call dm_pg_init_complete, continue
> + * with REPORT TARGET GROUP STATES command.
> + */
> + return;
> +}
> +
> +static char print_alua_state(enum tpgs_state s)
> +{
> + switch (s) {
> + case TPGS_STATE_OPTIMIZED:
> + return 'A';
> + case TPGS_STATE_NONOPTIMIZED:
> + return 'N';
> + case TPGS_STATE_STANDBY:
> + return 'S';
> + case TPGS_STATE_UNAVAILABLE:
> + return 'U';
> + case TPGS_STATE_OFFLINE:
> + return 'O';
> + case TPGS_STATE_TRANSITIONING:
> + return 'T';
> + default:
> + return 'X';
> + }
> +}
> +
> +/*
> + * Evaluate SET TARGET GROUP STATES
> + *
> + * We only have to test here if we should resubmit the command;
> + * any other error is assumed as a failure.
> + * Maybe we should analyze the sensebuffer here, too.
> + */
> +static void alua_stpg(struct alua_handler *h, enum tpgs_state n)
> +{
> + unsigned error;
> + int retry = 5;
> +
> + retry:
> + error = submit_stpg(h);
> + switch(host_byte(error)) {
> + case DID_BUS_BUSY:
> + if (!retry)
> + break;
> + retry++;
> + case DID_REQUEUE:
> + case DID_IMM_RETRY:
> + goto retry;
> + }
> +
> + if (had_failures(error)) {
> + DMWARN("%s: stpg failed %x, disable path",
> + h->path->dev->name, error);
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + } else {
> + h-state = n;
> + DMWARN("%s: port group %02x new state %c",
> + h->path->dev->name, h->group_id,
> + print_alua_state(h->state) );
> + dm_pg_init_complete(h->path, 0);
> + }
> +}
> +
> +/*
> + * Evaluate REPORT TARGET GROUP STATES
> + *
> + * Set the Target Port Group State. If the state
> + * is not 'active/optimized' we will try to activate
> + * this group by sending a 'SET TARGET GROUP STATES'
> + * command.
> + * If the state is 'offline' we will just fail the
> + * path.
> + */
> +static void alua_rtpg(struct alua_handler *h)
> +{
> + struct scsi_sense_hdr sense_hdr;
> + int len, k, off, valid_states = 0, sense = 0;
> + char *ucp;
> + unsigned error;
> +
> + retry:
> + error = submit_rtpg(h);
> +
> + if (had_failures(error)) {
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + return;
> + }
> +
> + if (status_byte(error) == CHECK_CONDITION) {
> + scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
> + &sense_hdr);
> + /* Retry if not ready */
> + if (sense_hdr.sense_key == NOT_READY) {
> + DMWARN("%s: device not ready, retry",
> + h->path->dev->name);
> + goto retry;
> + }
> + /* Retry on Unit Attention */
> + sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) |
> + sense_hdr.ascq;
> + if (sense == 0x62a06) {
> + DMWARN("%s: unit attention after state transition",
> + h->path->dev->name);
> + goto retry;
> + }
> + }
> +
> + len = (h->buff[0] << 24) + (h->buff[1] << 16) +
> + (h->buff[2] << 8) + h->buff[3] + 4;
> +
> + if (len > h->bufflen) {
> + /* Resubmit with the correct length */
> + if (realloc_buffer(h, len)) {
> + DMINFO("%s: kmalloc buffer failed",__FUNCTION__);
> + /* Temporary failure, bypass */
> + dm_pg_init_complete(h->path, MP_BYPASS_PG);
> + return;
> + }
> + goto retry;
> + }
> +
> + for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
> + if (h->group_id == (ucp[2] << 8) + ucp[3]) {
> + h->state = ucp[0] & 0x0f;
> + valid_states = ucp[1];
> + }
> + off = 8 + (ucp[7] * 4);
> + }
> +
> + DMWARN("%s: port group %02x state %c supports %c%c%c%c%c%c",
> + h->path->dev->name, h->group_id, print_alua_state(h->state),
> + valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
> + valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
> + valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
> + valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
> + valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
> + valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
> +
> + if (h->tpgs & TPGS_MODE_EXPLICIT) {
> + switch (h->state) {
> + case TPGS_STATE_TRANSITIONING:
> + /* State transition, retry */
> + goto retry;
> + break;
> + case TPGS_STATE_OPTIMIZED:
> + /* Path in Active/Optmized state, all done */
> + dm_pg_init_complete(h->path, 0);
> + break;
> + case TPGS_STATE_OFFLINE:
> + /* Path is offline, fail */
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + break;
> + default:
> + /* Switch path to Active/Optimized */
> + alua_stpg(h, TPGS_STATE_OPTIMIZED);
> + break;
> + }
> + } else {
> + /* Only Implicit ALUA support */
> + if (h->state == TPGS_STATE_OPTIMIZED ||
> + h->state == TPGS_STATE_NONOPTIMIZED ||
> + h->state == TPGS_STATE_STANDBY)
> + /* Useable path if active */
> + dm_pg_init_complete(h->path, 0);
> + else
> + /* Path unuseable for unavailable/offline */
> + dm_pg_init_complete(h->path, MP_FAIL_PATH);
> + }
> +}
> +
> +/*
> + * We're currently switching the port group to be activated only and
> + * let the array figure out the rest.
> + * There may be others arrays which require us to switch all port groups
> + * based on a certain policy. But until we actually encounter them this
> + * should be okay.
> + */
> +static int alua_create(struct hw_handler *hwh, unsigned argc, char **argv)
> +{
> + struct alua_handler *h;
> + int debug = 0;
> +
> + if (argc == 0) {
> + /* No arguments: use defaults */
> + debug = 0;
> + } else if (argc != 1) {
> + DMWARN("incorrect number of arguments");
> + return -EINVAL;
> + } else {
> + if (sscanf(argv[1], "%u", &debug) != 1) {
> + DMWARN("invalid debug value");
> + return -EINVAL;
> + }
> + }
> +
> + h = kzalloc(sizeof(*h), GFP_KERNEL);
> + if (!h)
> + return -ENOMEM;
> +
> + hwh->context = h;
> + h->debug = debug;
> + h->tpgs = TPGS_MODE_UNINITIALIZED;
> + h->group_id = -1;
> + h->rel_port = -1;
> + h->state = TPGS_STATE_UNKNOWN;
> + h->buff = h->inq;
> + h->bufflen = TPGS_INQUIRY_SIZE;
> +
> + return 0;
> +}
> +
> +static void alua_destroy(struct hw_handler *hwh)
> +{
> + struct alua_handler *h = hwh->context;
> +
> + if (h->buff && h->inq != h->buff)
> + kfree(h->buff);
> + kfree(h);
> + hwh->context = NULL;
> +}
> +
> +static unsigned alua_error(struct hw_handler *hwh, struct bio *bio)
> +{
> + /* Try default handler */
> + return dm_scsi_err_handler(hwh, bio);
> +}
> +
> +static void alua_pg_init(struct hw_handler *hwh, unsigned bypassed,
> + struct dm_path *path)
> +{
> + struct alua_handler *h = hwh->context;
> +
> + h->path = path;
> + if (h->tpgs == TPGS_MODE_UNINITIALIZED)
> + alua_std_inquiry(h);
> + if (h->tpgs & (TPGS_MODE_IMPLICIT | TPGS_MODE_EXPLICIT))
> + alua_vpd_inquiry(h);
> + if (h->group_id != -1)
> + alua_rtpg(h);
> +}
> +
> +static struct hw_handler_type alua_handler = {
> + .name = ALUA_DM_HWH_NAME,
> + .module = THIS_MODULE,
> + .create = alua_create,
> + .destroy = alua_destroy,
> + .pg_init = alua_pg_init,
> + .error = alua_error,
> +};
> +
> +static int __init alua_init(void)
> +{
> + int r = dm_register_hw_handler(&alua_handler);
> +
> + if (r < 0) {
> + DMERR("%s: register failed %d", ALUA_DM_HWH_NAME, r);
> + return r;
> + }
> +
> + DMINFO("%s: version %s loaded", ALUA_DM_HWH_NAME, ALUA_DM_HWH_VER);
> + return 0;
> +}
> +
> +static void __exit alua_exit(void)
> +{
> + int r = dm_unregister_hw_handler(&alua_handler);
> +
> + if (r < 0)
> + DMERR("%s: unregister failed %d", ALUA_DM_HWH_NAME, r);
> +}
> +
> +module_init(alua_init);
> +module_exit(alua_exit);
> +
> +MODULE_DESCRIPTION("DM Multipath ALUA support");
> +MODULE_AUTHOR("Hannes Reinecke");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION(ALUA_DM_HWH_VER);
> diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
> index 9f8f80a..4e87c84 100644
> --- a/include/scsi/scsi.h
> +++ b/include/scsi/scsi.h
> @@ -98,6 +98,7 @@ extern const unsigned char scsi_command_size[8];
> #define PERSISTENT_RESERVE_OUT 0x5f
> #define REPORT_LUNS 0xa0
> #define MAINTENANCE_IN 0xa3
> +#define MAINTENANCE_OUT 0xa4
> #define MOVE_MEDIUM 0xa5
> #define EXCHANGE_MEDIUM 0xa6
> #define READ_12 0xa8
> @@ -117,6 +118,8 @@ extern const unsigned char scsi_command_size[8];
> #define SAI_READ_CAPACITY_16 0x10
> /* values for maintenance in */
> #define MI_REPORT_TARGET_PGS 0x0a
> +/* values for maintenance out */
> +#define MO_SET_TARGET_PGS 0x0a
>
> /* Values for T10/04-262r7 */
> #define ATA_16 0x85 /* 16-byte pass-thru */
> --
> dm-devel mailing list
> [EMAIL PROTECTED]
> https://www.redhat.com/mailman/listinfo/dm-devel
--
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Chandra Seetharaman | Be careful what you choose....
- [EMAIL PROTECTED] | .......you may get it.
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