Commit 27ba3e8f authored by Damien Le Moal's avatar Damien Le Moal Committed by Martin K. Petersen
Browse files

scsi: sd: sd_zbc: Fix handling of host-aware ZBC disks 

When CONFIG_BLK_DEV_ZONED is disabled, allow using host-aware ZBC disks as
regular disks. In this case, ensure that command completion is correctly
executed by changing sd_zbc_complete() to return good_bytes instead of 0
and causing a hang during device probe (endless retries).

When CONFIG_BLK_DEV_ZONED is enabled and a host-aware disk is detected to
have partitions, it will be used as a regular disk. In this case, make sure
to not do anything in sd_zbc_revalidate_zones() as that triggers warnings.

Since all these different cases result in subtle settings of the disk queue
zoned model, introduce the block layer helper function
blk_queue_set_zoned() to generically implement setting up the effective
zoned model according to the disk type, the presence of partitions on the
disk and CONFIG_BLK_DEV_ZONED configuration.

Link: https://lore.kernel.org/r/20200915073347.832424-2-damien.lemoal@wdc.com


Fixes: b7205307 ("block: allow partitions on host aware zone devices")
Cc: <stable@vger.kernel.org>
Reported-by: default avatarBorislav Petkov <bp@alien8.de>
Suggested-by: default avatarChristoph Hellwig <hch@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 7f04839e

block/blk-settings.c

+46 −0
Original line number Diff line number Diff line
@@ -801,6 +801,52 @@ bool blk_queue_can_use_dma_map_merging(struct request_queue *q, 
}

EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);



/**

 * blk_queue_set_zoned - configure a disk queue zoned model.

 * @disk:	the gendisk of the queue to configure

 * @model:	the zoned model to set

 *

 * Set the zoned model of the request queue of @disk according to @model.

 * When @model is BLK_ZONED_HM (host managed), this should be called only

 * if zoned block device support is enabled (CONFIG_BLK_DEV_ZONED option).

 * If @model specifies BLK_ZONED_HA (host aware), the effective model used

 * depends on CONFIG_BLK_DEV_ZONED settings and on the existence of partitions

 * on the disk.

 */

void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model)

{

	switch (model) {

	case BLK_ZONED_HM:

		/*

		 * Host managed devices are supported only if

		 * CONFIG_BLK_DEV_ZONED is enabled.

		 */

		WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED));

		break;

	case BLK_ZONED_HA:

		/*

		 * Host aware devices can be treated either as regular block

		 * devices (similar to drive managed devices) or as zoned block

		 * devices to take advantage of the zone command set, similarly

		 * to host managed devices. We try the latter if there are no

		 * partitions and zoned block device support is enabled, else

		 * we do nothing special as far as the block layer is concerned.

		 */

		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||

		    disk_has_partitions(disk))

			model = BLK_ZONED_NONE;

		break;

	case BLK_ZONED_NONE:

	default:

		if (WARN_ON_ONCE(model != BLK_ZONED_NONE))

			model = BLK_ZONED_NONE;

		break;

	}



	disk->queue->limits.zoned = model;

}

EXPORT_SYMBOL_GPL(blk_queue_set_zoned);



static int __init blk_settings_init(void)

{

	blk_max_low_pfn = max_low_pfn - 1;

drivers/scsi/sd.c

+18 −12
Original line number Diff line number Diff line
@@ -2964,26 +2964,32 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp) 


	if (sdkp->device->type == TYPE_ZBC) {

		/* Host-managed */

		q->limits.zoned = BLK_ZONED_HM;

		blk_queue_set_zoned(sdkp->disk, BLK_ZONED_HM);

	} else {

		sdkp->zoned = (buffer[8] >> 4) & 3;

		if (sdkp->zoned == 1 && !disk_has_partitions(sdkp->disk)) {

		if (sdkp->zoned == 1) {

			/* Host-aware */

			q->limits.zoned = BLK_ZONED_HA;

			blk_queue_set_zoned(sdkp->disk, BLK_ZONED_HA);

		} else {

			/*

			 * Treat drive-managed devices and host-aware devices

			 * with partitions as regular block devices.

			 */

			q->limits.zoned = BLK_ZONED_NONE;

			if (sdkp->zoned == 2 && sdkp->first_scan)

				sd_printk(KERN_NOTICE, sdkp,

					  "Drive-managed SMR disk\n");

			/* Regular disk or drive managed disk */

			blk_queue_set_zoned(sdkp->disk, BLK_ZONED_NONE);

		}

	}

	if (blk_queue_is_zoned(q) && sdkp->first_scan)



	if (!sdkp->first_scan)

		goto out;



	if (blk_queue_is_zoned(q)) {

		sd_printk(KERN_NOTICE, sdkp, "Host-%s zoned block device\n",

		      q->limits.zoned == BLK_ZONED_HM ? "managed" : "aware");

	} else {

		if (sdkp->zoned == 1)

			sd_printk(KERN_NOTICE, sdkp,

				  "Host-aware SMR disk used as regular disk\n");

		else if (sdkp->zoned == 2)

			sd_printk(KERN_NOTICE, sdkp,

				  "Drive-managed SMR disk\n");

	}



 out:

	kfree(buffer);

drivers/scsi/sd.h

+1 −1
Original line number Diff line number Diff line
@@ -259,7 +259,7 @@ static inline blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd, 
static inline unsigned int sd_zbc_complete(struct scsi_cmnd *cmd,

			unsigned int good_bytes, struct scsi_sense_hdr *sshdr)

{

	return 0;

	return good_bytes;

}



static inline blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd,

drivers/scsi/sd_zbc.c

+5 −1
Original line number Diff line number Diff line
@@ -667,7 +667,11 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp) 
	u32 max_append;

	int ret = 0;



	if (!sd_is_zoned(sdkp))

	/*

	 * There is nothing to do for regular disks, including host-aware disks

	 * that have partitions.

	 */

	if (!blk_queue_is_zoned(q))

		return 0;



	/*

include/linux/blkdev.h

+2 −0
Original line number Diff line number Diff line
@@ -352,6 +352,8 @@ struct queue_limits { 
typedef int (*report_zones_cb)(struct blk_zone *zone, unsigned int idx,

			       void *data);



void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model);



#ifdef CONFIG_BLK_DEV_ZONED



#define BLK_ALL_ZONES  ((unsigned int)-1)

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