diff mbox

[11/20] scsi_dh_alua: Use separate alua_port_group structure

Message ID 1436346378-96518-12-git-send-email-hare@suse.de (mailing list archive)
State New, archived
Headers show

Commit Message

Hannes Reinecke July 8, 2015, 9:06 a.m. UTC 
The port group needs to be a separate structure as several
LUNs might belong to the same group.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 210 +++++++++++++++++++----------
 1 file changed, 137 insertions(+), 73 deletions(-)

Comments

Christoph Hellwig July 24, 2015, 2:58 p.m. UTC | #1 
On Wed, Jul 08, 2015 at 11:06:09AM +0200, Hannes Reinecke wrote:
> +	pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
> +	if (!pg) {
> +		sdev_printk(KERN_WARNING, sdev,
> +			    "%s: kzalloc port group failed\n",
> +			    ALUA_DH_NAME);
> +		/* Temporary failure, bypass */
> +		return SCSI_DH_DEV_TEMP_BUSY;
> +	}
> +	pg->group_id = group_id;
> +	pg->buff = pg->inq;
> +	pg->bufflen = ALUA_INQUIRY_SIZE;
> +	pg->tpgs = h->tpgs;
> +	pg->state = TPGS_STATE_OPTIMIZED;
> +	kref_init(&pg->kref);
> +	spin_lock(&port_group_lock);
> +	list_add(&pg->node, &port_group_list);
> +	h->pg = pg;
> +	spin_unlock(&port_group_lock);

Is there any high level protection against someone racing to allocate
this structure, e.g. from a sysfs-initiated scan?

> -	len = (h->buff[0] << 24) + (h->buff[1] << 16) +
> -		(h->buff[2] << 8) + h->buff[3] + 4;
> +	len = get_unaligned_be32(&pg->buff[0]) + 4;

Andother spurious get/set_unaligned conversion.  I'd really recommend doing
all of them before the atual series.

> +	rcu_read_lock();
> +	pg = rcu_dereference(h->pg);
> +	if (!pg) {
> +		rcu_read_unlock();
> +		return -ENXIO;
> +	}
> +	rcu_read_unlock();
> +
>  	if (optimize)
> -		h->flags |= ALUA_OPTIMIZE_STPG;
> +		pg->flags |= ALUA_OPTIMIZE_STPG;
>  	else
> -		h->flags &= ~ALUA_OPTIMIZE_STPG;
> +		pg->flags |= ~ALUA_OPTIMIZE_STPG;

You'll need to move the rcu_read_unlock here to be safe.

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Hannes Reinecke July 25, 2015, 3:52 p.m. UTC | #2 
On 07/24/2015 04:58 PM, Christoph Hellwig wrote:
> On Wed, Jul 08, 2015 at 11:06:09AM +0200, Hannes Reinecke wrote:
>> +	pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
>> +	if (!pg) {
>> +		sdev_printk(KERN_WARNING, sdev,
>> +			    "%s: kzalloc port group failed\n",
>> +			    ALUA_DH_NAME);
>> +		/* Temporary failure, bypass */
>> +		return SCSI_DH_DEV_TEMP_BUSY;
>> +	}
>> +	pg->group_id = group_id;
>> +	pg->buff = pg->inq;
>> +	pg->bufflen = ALUA_INQUIRY_SIZE;
>> +	pg->tpgs = h->tpgs;
>> +	pg->state = TPGS_STATE_OPTIMIZED;
>> +	kref_init(&pg->kref);
>> +	spin_lock(&port_group_lock);
>> +	list_add(&pg->node, &port_group_list);
>> +	h->pg = pg;
>> +	spin_unlock(&port_group_lock);
> 
> Is there any high level protection against someone racing to allocate
> this structure, e.g. from a sysfs-initiated scan?
> 
Not in this patch, as this is called during device scan only. It is
assumed that higher levels will protect against simultaneous scans.

Real protection against concurrent updates is done in patch
'scsi_dh_alua: parse device id', as with that we can easily hit existing
port groups.

>> -	len = (h->buff[0] << 24) + (h->buff[1] << 16) +
>> -		(h->buff[2] << 8) + h->buff[3] + 4;
>> +	len = get_unaligned_be32(&pg->buff[0]) + 4;
> 
> Andother spurious get/set_unaligned conversion.  I'd really recommend doing
> all of them before the atual series.
> 
Okay, will be doing so.

>> +	rcu_read_lock();
>> +	pg = rcu_dereference(h->pg);
>> +	if (!pg) {
>> +		rcu_read_unlock();
>> +		return -ENXIO;
>> +	}
>> +	rcu_read_unlock();
>> +
>>  	if (optimize)
>> -		h->flags |= ALUA_OPTIMIZE_STPG;
>> +		pg->flags |= ALUA_OPTIMIZE_STPG;
>>  	else
>> -		h->flags &= ~ALUA_OPTIMIZE_STPG;
>> +		pg->flags |= ~ALUA_OPTIMIZE_STPG;
> 
> You'll need to move the rcu_read_unlock here to be safe.
> 
Ok.

Cheers,

Hannes
diff mbox

Patch

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index ea4a920..3f18f6b 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -64,9 +64,13 @@ 
 #define ALUA_OPTIMIZE_STPG		1
 #define ALUA_RTPG_EXT_HDR_UNSUPP	2
 
-struct alua_dh_data {
+static LIST_HEAD(port_group_list);
+static DEFINE_SPINLOCK(port_group_lock);
+
+struct alua_port_group {
+	struct kref		kref;
+	struct list_head	node;
 	int			group_id;
-	int			rel_port;
 	int			tpgs;
 	int			state;
 	int			pref;
@@ -75,6 +79,12 @@  struct alua_dh_data {
 	unsigned char		*buff;
 	int			bufflen;
 	unsigned char		transition_tmo;
+};
+
+struct alua_dh_data {
+	struct alua_port_group	*pg;
+	int			rel_port;
+	int			tpgs;
 	struct scsi_device	*sdev;
 	activate_complete	callback_fn;
 	void			*callback_data;
@@ -86,21 +96,35 @@  struct alua_dh_data {
 static char print_alua_state(int);
 static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *);
 
-static int realloc_buffer(struct alua_dh_data *h, unsigned len)
+static int realloc_buffer(struct alua_port_group *pg, unsigned len)
 {
-	if (h->buff && h->buff != h->inq)
-		kfree(h->buff);
+	if (pg->buff && pg->buff != pg->inq)
+		kfree(pg->buff);
 
-	h->buff = kmalloc(len, GFP_NOIO);
-	if (!h->buff) {
-		h->buff = h->inq;
-		h->bufflen = ALUA_INQUIRY_SIZE;
+	pg->buff = kmalloc(len, GFP_NOIO);
+	if (!pg->buff) {
+		pg->buff = pg->inq;
+		pg->bufflen = ALUA_INQUIRY_SIZE;
 		return 1;
 	}
-	h->bufflen = len;
+	pg->bufflen = len;
 	return 0;
 }
 
+static void release_port_group(struct kref *kref)
+{
+	struct alua_port_group *pg;
+
+	pg = container_of(kref, struct alua_port_group, kref);
+	printk(KERN_WARNING "alua: release port group %d\n", pg->group_id);
+	spin_lock(&port_group_lock);
+	list_del(&pg->node);
+	spin_unlock(&port_group_lock);
+	if (pg->buff && pg->inq != pg->buff)
+		kfree(pg->buff);
+	kfree(pg);
+}
+
 /*
  * submit_rtpg - Issue a REPORT TARGET GROUP STATES command
  * @sdev: sdev the command should be sent to
@@ -223,6 +247,8 @@  static int alua_check_tpgs(struct scsi_device *sdev, struct alua_dh_data *h)
 static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
 {
 	unsigned char *d;
+	int group_id = -1;
+	struct alua_port_group *pg = NULL;
 
 	if (!sdev->vpd_pg83)
 		return SCSI_DH_DEV_UNSUPP;
@@ -239,7 +265,7 @@  static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
 			break;
 		case 0x5:
 			/* Target port group */
-			h->group_id = (d[6] << 8) + d[7];
+			group_id = (d[6] << 8) + d[7];
 			break;
 		default:
 			break;
@@ -247,7 +273,7 @@  static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
 		d += d[3] + 4;
 	}
 
-	if (h->group_id == -1) {
+	if (group_id == -1) {
 		/*
 		 * Internal error; TPGS supported but required
 		 * VPD identification descriptors not present.
@@ -256,15 +282,33 @@  static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
 		sdev_printk(KERN_INFO, sdev,
 			    "%s: No target port descriptors found\n",
 			    ALUA_DH_NAME);
-		h->state = TPGS_STATE_OPTIMIZED;
 		h->tpgs = TPGS_MODE_NONE;
 		return SCSI_DH_DEV_UNSUPP;
 	}
 	sdev_printk(KERN_INFO, sdev,
 		    "%s: port group %02x rel port %02x\n",
-		    ALUA_DH_NAME, h->group_id, h->rel_port);
+		    ALUA_DH_NAME, group_id, h->rel_port);
 
-	return 0;
+	pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
+	if (!pg) {
+		sdev_printk(KERN_WARNING, sdev,
+			    "%s: kzalloc port group failed\n",
+			    ALUA_DH_NAME);
+		/* Temporary failure, bypass */
+		return SCSI_DH_DEV_TEMP_BUSY;
+	}
+	pg->group_id = group_id;
+	pg->buff = pg->inq;
+	pg->bufflen = ALUA_INQUIRY_SIZE;
+	pg->tpgs = h->tpgs;
+	pg->state = TPGS_STATE_OPTIMIZED;
+	kref_init(&pg->kref);
+	spin_lock(&port_group_lock);
+	list_add(&pg->node, &port_group_list);
+	h->pg = pg;
+	spin_unlock(&port_group_lock);
+
+	return SCSI_DH_OK;
 }
 
 static char print_alua_state(int state)
@@ -375,7 +419,7 @@  static int alua_check_sense(struct scsi_device *sdev,
  * Returns SCSI_DH_DEV_OFFLINED if the path is
  * found to be unusable.
  */
-static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_for_transition)
+static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg, int wait_for_transition)
 {
 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
 	struct scsi_sense_hdr sense_hdr;
@@ -386,13 +430,13 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 	unsigned int tpg_desc_tbl_off;
 	unsigned char orig_transition_tmo;
 
-	if (!h->transition_tmo)
+	if (!pg->transition_tmo)
 		expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT * HZ);
 	else
-		expiry = round_jiffies_up(jiffies + h->transition_tmo * HZ);
+		expiry = round_jiffies_up(jiffies + pg->transition_tmo * HZ);
 
  retry:
-	retval = submit_rtpg(sdev, h->buff, h->bufflen, sense, h->flags);
+	retval = submit_rtpg(sdev, pg->buff, pg->bufflen, sense, pg->flags);
 
 	if (retval) {
 		if (!(driver_byte(retval) & DRIVER_SENSE) ||
@@ -416,10 +460,10 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 		 * The retry without rtpg_ext_hdr_req set
 		 * handles this.
 		 */
-		if (!(h->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
+		if (!(pg->flags & ALUA_RTPG_EXT_HDR_UNSUPP) &&
 		    sense_hdr.sense_key == ILLEGAL_REQUEST &&
 		    sense_hdr.asc == 0x24 && sense_hdr.ascq == 0) {
-			h->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
+			pg->flags |= ALUA_RTPG_EXT_HDR_UNSUPP;
 			goto retry;
 		}
 
@@ -436,12 +480,11 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 		return SCSI_DH_IO;
 	}
 
-	len = (h->buff[0] << 24) + (h->buff[1] << 16) +
-		(h->buff[2] << 8) + h->buff[3] + 4;
+	len = get_unaligned_be32(&pg->buff[0]) + 4;
 
-	if (len > h->bufflen) {
+	if (len > pg->bufflen) {
 		/* Resubmit with the correct length */
-		if (realloc_buffer(h, len)) {
+		if (realloc_buffer(pg, len)) {
 			sdev_printk(KERN_WARNING, sdev,
 				    "%s: kmalloc buffer failed\n",__func__);
 			/* Temporary failure, bypass */
@@ -450,31 +493,32 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 		goto retry;
 	}
 
-	orig_transition_tmo = h->transition_tmo;
-	if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR && h->buff[5] != 0)
-		h->transition_tmo = h->buff[5];
+	orig_transition_tmo = pg->transition_tmo;
+	if ((pg->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR &&
+	    pg->buff[5] != 0)
+		pg->transition_tmo = pg->buff[5];
 	else
-		h->transition_tmo = ALUA_FAILOVER_TIMEOUT;
+		pg->transition_tmo = ALUA_FAILOVER_TIMEOUT;
 
-	if (wait_for_transition && (orig_transition_tmo != h->transition_tmo)) {
+	if (wait_for_transition && (orig_transition_tmo != pg->transition_tmo)) {
 		sdev_printk(KERN_INFO, sdev,
 			    "%s: transition timeout set to %d seconds\n",
-			    ALUA_DH_NAME, h->transition_tmo);
-		expiry = jiffies + h->transition_tmo * HZ;
+			    ALUA_DH_NAME, pg->transition_tmo);
+		expiry = jiffies + pg->transition_tmo * HZ;
 	}
 
-	if ((h->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR)
+	if ((pg->buff[4] & RTPG_FMT_MASK) == RTPG_FMT_EXT_HDR)
 		tpg_desc_tbl_off = 8;
 	else
 		tpg_desc_tbl_off = 4;
 
-	for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off;
+	for (k = tpg_desc_tbl_off, ucp = pg->buff + tpg_desc_tbl_off;
 	     k < len;
 	     k += off, ucp += off) {
 
-		if (h->group_id == (ucp[2] << 8) + ucp[3]) {
-			h->state = ucp[0] & 0x0f;
-			h->pref = ucp[0] >> 7;
+		if (pg->group_id == (ucp[2] << 8) + ucp[3]) {
+			pg->state = ucp[0] & 0x0f;
+			pg->pref = ucp[0] >> 7;
 			valid_states = ucp[1];
 		}
 		off = 8 + (ucp[7] * 4);
@@ -482,8 +526,8 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 
 	sdev_printk(KERN_INFO, sdev,
 		    "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n",
-		    ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
-		    h->pref ? "preferred" : "non-preferred",
+		    ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state),
+		    pg->pref ? "preferred" : "non-preferred",
 		    valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
 		    valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
 		    valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
@@ -492,7 +536,7 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 		    valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
 		    valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
 
-	switch (h->state) {
+	switch (pg->state) {
 	case TPGS_STATE_TRANSITIONING:
 		if (wait_for_transition) {
 			if (time_before(jiffies, expiry)) {
@@ -507,7 +551,7 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
 		}
 
 		/* Transitioning time exceeded, set port to standby */
-		h->state = TPGS_STATE_STANDBY;
+		pg->state = TPGS_STATE_STANDBY;
 		break;
 	case TPGS_STATE_OFFLINE:
 		/* Path unusable */
@@ -528,23 +572,23 @@  static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h, int wait_
  * response. Returns SCSI_DH_RETRY per default to trigger
  * a re-evaluation of the target group state.
  */
-static unsigned alua_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
+static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg)
 {
 	int retval;
 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
 	struct scsi_sense_hdr sense_hdr;
 
-	if (!(h->tpgs & TPGS_MODE_EXPLICIT)) {
+	if (!(pg->tpgs & TPGS_MODE_EXPLICIT)) {
 		/* Only implicit ALUA supported, retry */
 		return SCSI_DH_RETRY;
 	}
-	switch (h->state) {
+	switch (pg->state) {
 	case TPGS_STATE_OPTIMIZED:
 		return SCSI_DH_OK;
 	case TPGS_STATE_NONOPTIMIZED:
-		if ((h->flags & ALUA_OPTIMIZE_STPG) &&
-		    (!h->pref) &&
-		    (h->tpgs & TPGS_MODE_IMPLICIT))
+		if ((pg->flags & ALUA_OPTIMIZE_STPG) &&
+		    (!pg->pref) &&
+		    (pg->tpgs & TPGS_MODE_IMPLICIT))
 			return SCSI_DH_OK;
 		break;
 	case TPGS_STATE_STANDBY:
@@ -558,13 +602,13 @@  static unsigned alua_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
 	default:
 		sdev_printk(KERN_INFO, sdev,
 			    "%s: stpg failed, unhandled TPGS state %d",
-			    ALUA_DH_NAME, h->state);
+			    ALUA_DH_NAME, pg->state);
 		return SCSI_DH_NOSYS;
 		break;
 	}
 	/* Set state to transitioning */
-	h->state = TPGS_STATE_TRANSITIONING;
-	retval = submit_stpg(sdev, h->group_id, sense);
+	pg->state = TPGS_STATE_TRANSITIONING;
+	retval = submit_stpg(sdev, pg->group_id, sense);
 
 	if (retval) {
 		if (!(driver_byte(retval) & DRIVER_SENSE) ||
@@ -576,7 +620,7 @@  static unsigned alua_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
 			if (driver_byte(retval) == DRIVER_ERROR)
 				return SCSI_DH_DEV_TEMP_BUSY;
 		} else {
-			sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n",
+			sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n",
 				    ALUA_DH_NAME);
 			scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr);
 		}
@@ -601,13 +645,12 @@  static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
 		goto out;
 
 	err = alua_check_vpd(sdev, h);
-	if (err != SCSI_DH_OK)
-		goto out;
-
-	err = alua_rtpg(sdev, h, 0);
-	if (err != SCSI_DH_OK)
+	if (err != SCSI_DH_OK || !h->pg)
 		goto out;
 
+	kref_get(&h->pg->kref);
+	err = alua_rtpg(sdev, h->pg, 0);
+	kref_put(&h->pg->kref, release_port_group);
 out:
 	return err;
 }
@@ -623,6 +666,7 @@  out:
 static int alua_set_params(struct scsi_device *sdev, const char *params)
 {
 	struct alua_dh_data *h = sdev->handler_data;
+	struct alua_port_group *pg = NULL;
 	unsigned int optimize = 0, argc;
 	const char *p = params;
 	int result = SCSI_DH_OK;
@@ -635,10 +679,18 @@  static int alua_set_params(struct scsi_device *sdev, const char *params)
 	if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1))
 		return -EINVAL;
 
+	rcu_read_lock();
+	pg = rcu_dereference(h->pg);
+	if (!pg) {
+		rcu_read_unlock();
+		return -ENXIO;
+	}
+	rcu_read_unlock();
+
 	if (optimize)
-		h->flags |= ALUA_OPTIMIZE_STPG;
+		pg->flags |= ALUA_OPTIMIZE_STPG;
 	else
-		h->flags &= ~ALUA_OPTIMIZE_STPG;
+		pg->flags |= ~ALUA_OPTIMIZE_STPG;
 
 	return result;
 }
@@ -663,16 +715,23 @@  static int alua_activate(struct scsi_device *sdev,
 	struct alua_dh_data *h = sdev->handler_data;
 	int err = SCSI_DH_OK;
 
-	err = alua_rtpg(sdev, h, 1);
-	if (err != SCSI_DH_OK)
+	if (!h->pg)
 		goto out;
 
+	kref_get(&h->pg->kref);
+
 	if (optimize_stpg)
-		h->flags |= ALUA_OPTIMIZE_STPG;
+		h->pg->flags |= ALUA_OPTIMIZE_STPG;
 
-	err = alua_stpg(sdev, h);
+	err = alua_rtpg(sdev, h->pg, 1);
+	if (err != SCSI_DH_OK) {
+		kref_put(&h->pg->kref, release_port_group);
+		goto out;
+	}
+	err = alua_stpg(sdev, h->pg);
 	if (err == SCSI_DH_RETRY)
-		err = alua_rtpg(sdev, h, 1);
+		err = alua_rtpg(sdev, h->pg, 1);
+	kref_put(&h->pg->kref, release_port_group);
 out:
 	if (fn)
 		fn(data, err);
@@ -688,13 +747,19 @@  out:
 static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
 {
 	struct alua_dh_data *h = sdev->handler_data;
+	int state;
 	int ret = BLKPREP_OK;
 
-	if (h->state == TPGS_STATE_TRANSITIONING)
+	if (!h->pg)
+		return ret;
+	kref_get(&h->pg->kref);
+	state = h->pg->state;
+	kref_put(&h->pg->kref, release_port_group);
+	if (state == TPGS_STATE_TRANSITIONING)
 		ret = BLKPREP_DEFER;
-	else if (h->state != TPGS_STATE_OPTIMIZED &&
-		 h->state != TPGS_STATE_NONOPTIMIZED &&
-		 h->state != TPGS_STATE_LBA_DEPENDENT) {
+	else if (state != TPGS_STATE_OPTIMIZED &&
+		 state != TPGS_STATE_NONOPTIMIZED &&
+		 state != TPGS_STATE_LBA_DEPENDENT) {
 		ret = BLKPREP_KILL;
 		req->cmd_flags |= REQ_QUIET;
 	}
@@ -715,11 +780,8 @@  static int alua_bus_attach(struct scsi_device *sdev)
 	if (!h)
 		return -ENOMEM;
 	h->tpgs = TPGS_MODE_UNINITIALIZED;
-	h->state = TPGS_STATE_OPTIMIZED;
-	h->group_id = -1;
+	h->pg = NULL;
 	h->rel_port = -1;
-	h->buff = h->inq;
-	h->bufflen = ALUA_INQUIRY_SIZE;
 	h->sdev = sdev;
 
 	err = alua_initialize(sdev, h);
@@ -741,8 +803,10 @@  static void alua_bus_detach(struct scsi_device *sdev)
 {
 	struct alua_dh_data *h = sdev->handler_data;
 
-	if (h->buff && h->inq != h->buff)
-		kfree(h->buff);
+	if (h->pg) {
+		kref_put(&h->pg->kref, release_port_group);
+		h->pg = NULL;
+	}
 	sdev->handler_data = NULL;
 	kfree(h);
 }