block: move integrity information into queue_limits

Move the integrity information into the queue limits so that it can be
set atomically with other queue limits, and that the sysfs changes to
the read_verify and write_generate flags are properly synchronized.
This also allows to provide a more useful helper to stack the integrity
fields, although it still is separate from the main stacking function
as not all stackable devices want to inherit the integrity settings.
Even with that it greatly simplifies the code in md and dm.

Note that the integrity field is moved as-is into the queue limits.
While there are good arguments for removing the separate blk_integrity
structure, this would cause a lot of churn and might better be done at a
later time if desired.  However the integrity field in the queue_limits
structure is now unconditional so that various ifdefs can be avoided or
replaced with IS_ENABLED().  Given that tiny size of it that seems like
a worthwhile trade off.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

3 files changed, 20 insertions, 34 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d957e29b17a9..e01393ed4207 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2482,11 +2482,13 @@ static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer
 	return 0;
 }
 
-static void sd_config_protection(struct scsi_disk *sdkp)
+static void sd_config_protection(struct scsi_disk *sdkp,
+		struct queue_limits *lim)
 {
 	struct scsi_device *sdp = sdkp->device;
 
-	sd_dif_config_host(sdkp);
+	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY))
+		sd_dif_config_host(sdkp, lim);
 
 	if (!sdkp->protection_type)
 		return;
@@ -3677,7 +3679,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 		sd_read_app_tag_own(sdkp, buffer);
 		sd_read_write_same(sdkp, buffer);
 		sd_read_security(sdkp, buffer);
-		sd_config_protection(sdkp);
+		sd_config_protection(sdkp, &lim);
 	}
 
 	/*
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index b4170b17bad4..726f1613f6cb 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -220,17 +220,7 @@ static inline sector_t sectors_to_logical(struct scsi_device *sdev, sector_t sec
 	return sector >> (ilog2(sdev->sector_size) - 9);
 }
 
-#ifdef CONFIG_BLK_DEV_INTEGRITY
-
-extern void sd_dif_config_host(struct scsi_disk *);
-
-#else /* CONFIG_BLK_DEV_INTEGRITY */
-
-static inline void sd_dif_config_host(struct scsi_disk *disk)
-{
-}
-
-#endif /* CONFIG_BLK_DEV_INTEGRITY */
+void sd_dif_config_host(struct scsi_disk *sdkp, struct queue_limits *lim);
 
 static inline int sd_is_zoned(struct scsi_disk *sdkp)
 {
diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index 6f0921c7db78..ae6ce6f5d622 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -24,14 +24,15 @@
 /*
  * Configure exchange of protection information between OS and HBA.
  */
-void sd_dif_config_host(struct scsi_disk *sdkp)
+void sd_dif_config_host(struct scsi_disk *sdkp, struct queue_limits *lim)
 {
 	struct scsi_device *sdp = sdkp->device;
-	struct gendisk *disk = sdkp->disk;
 	u8 type = sdkp->protection_type;
-	struct blk_integrity bi;
+	struct blk_integrity *bi = &lim->integrity;
 	int dif, dix;
 
+	memset(bi, 0, sizeof(*bi));
+
 	dif = scsi_host_dif_capable(sdp->host, type);
 	dix = scsi_host_dix_capable(sdp->host, type);
 
@@ -39,40 +40,33 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 		dif = 0; dix = 1;
 	}
 
-	if (!dix) {
-		blk_integrity_unregister(disk);
+	if (!dix)
 		return;
-	}
-
-	memset(&bi, 0, sizeof(bi));
 
 	/* Enable DMA of protection information */
 	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
-		bi.csum_type = BLK_INTEGRITY_CSUM_IP;
+		bi->csum_type = BLK_INTEGRITY_CSUM_IP;
 	else
-		bi.csum_type = BLK_INTEGRITY_CSUM_CRC;
+		bi->csum_type = BLK_INTEGRITY_CSUM_CRC;
 
 	if (type != T10_PI_TYPE3_PROTECTION)
-		bi.flags |= BLK_INTEGRITY_REF_TAG;
+		bi->flags |= BLK_INTEGRITY_REF_TAG;
 
-	bi.tuple_size = sizeof(struct t10_pi_tuple);
+	bi->tuple_size = sizeof(struct t10_pi_tuple);
 
 	if (dif && type) {
-		bi.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+		bi->flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
 
 		if (!sdkp->ATO)
-			goto out;
+			return;
 
 		if (type == T10_PI_TYPE3_PROTECTION)
-			bi.tag_size = sizeof(u16) + sizeof(u32);
+			bi->tag_size = sizeof(u16) + sizeof(u32);
 		else
-			bi.tag_size = sizeof(u16);
+			bi->tag_size = sizeof(u16);
 	}
 
 	sd_first_printk(KERN_NOTICE, sdkp,
 			"Enabling DIX %s, application tag size %u bytes\n",
-			blk_integrity_profile_name(&bi), bi.tag_size);
-out:
-	blk_integrity_register(disk, &bi);
+			blk_integrity_profile_name(bi), bi->tag_size);
 }
-