From: Martin K. Petersen <martin.petersen@oracle.com>
Date: Wed, 13 Jun 2012 04:05:30 +0000 (-0400)
Subject: sd: Avoid remapping bad reference tags
X-Git-Tag: v2.6.39-400.9.0~516^2~18^2~5
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0e4bc5cde0abb288a63d2c341183e61e43d15a36;p=users%2Fjedix%2Flinux-maple.git

sd: Avoid remapping bad reference tags

It does not make sense to translate ref tags with unexpected values.
Instead we simply ignore them and let the upper layers catch the
problem. Ref tags that contain the expected value are still remapped.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index c7f29defe4f1..1a903b09496a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -772,9 +772,8 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 		SCpnt->cmnd[0] = WRITE_6;
 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
 
-		if (blk_integrity_rq(rq) &&
-		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
-			goto out;
+		if (blk_integrity_rq(rq))
+			sd_dif_prepare(rq, block, sdp->sector_size);
 
 	} else if (rq_data_dir(rq) == READ) {
 		SCpnt->cmnd[0] = READ_6;
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index d039e53913ed..eea88182e9d1 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -127,7 +127,7 @@ struct sd_dif_tuple {
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 
 extern void sd_dif_config_host(struct scsi_disk *);
-extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
+extern void sd_dif_prepare(struct request *rq, sector_t, unsigned int);
 extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
 
 #else /* CONFIG_BLK_DEV_INTEGRITY */
diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index 0cb39ff21171..1c47fa4ee1cf 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -366,7 +366,8 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
  *
  * Type 3 does not have a reference tag so no remapping is required.
  */
-int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_sz)
+void sd_dif_prepare(struct request *rq, sector_t hw_sector,
+		    unsigned int sector_sz)
 {
 	const int tuple_sz = sizeof(struct sd_dif_tuple);
 	struct bio *bio;
@@ -378,7 +379,7 @@ int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_s
 	sdkp = rq->bio->bi_bdev->bd_disk->private_data;
 
 	if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
-		return 0;
+		return;
 
 	phys = hw_sector & 0xffffffff;
 
@@ -397,10 +398,9 @@ int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_s
 
 			for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
 
-				if (be32_to_cpu(sdt->ref_tag) != virt)
-					goto error;
+				if (be32_to_cpu(sdt->ref_tag) == virt)
+					sdt->ref_tag = cpu_to_be32(phys);
 
-				sdt->ref_tag = cpu_to_be32(phys);
 				virt++;
 				phys++;
 			}
@@ -410,16 +410,6 @@ int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_s
 
 		bio->bi_flags |= BIO_MAPPED_INTEGRITY;
 	}
-
-	return 0;
-
-error:
-	kunmap_atomic(sdt, KM_USER0);
-	sd_printk(KERN_ERR, sdkp, "%s: virt %u, phys %u, ref %u, app %4x\n",
-		  __func__, virt, phys, be32_to_cpu(sdt->ref_tag),
-		  be16_to_cpu(sdt->app_tag));
-
-	return -EILSEQ;
 }
 
 /*
@@ -463,10 +453,7 @@ void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
 					return;
 				}
 
-				if (be32_to_cpu(sdt->ref_tag) != phys &&
-				    sdt->app_tag != 0xffff)
-					sdt->ref_tag = 0xffffffff; /* Bad ref */
-				else
+				if (be32_to_cpu(sdt->ref_tag) == phys)
 					sdt->ref_tag = cpu_to_be32(virt);
 
 				virt++;