target/sbc: Add sbc_dif_read_strip software emulation

Split up __sbc_dif_verify_read() so that VERIFY READ emulation can perform target-core specific READ_STRIP, seperate from the existing FILEIO/RAMDISK backend emulation code. Also add sbc_dif_read_strip() in order to determine number of sectors using cmd->prot_length, and skip the extra sbc_dif_copy_prot(). Reviewed-by: Sagi Grimberg <[email protected]> Cc: Martin K. Petersen <[email protected]> Cc: Or Gerlitz <[email protected]> Cc: Quinn Tran <[email protected]> Cc: Giridhar Malavali <[email protected]> Signed-off-by: Nicholas Bellinger <[email protected]>
josf · Apr 7, 2014 · 395ccb2 · 395ccb2
1 parent a84bf9e
commit 395ccb2
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Showing 2 changed files with 28 additions and 4 deletions.
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
@@ -1271,9 +1271,9 @@ sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
 }
 EXPORT_SYMBOL(sbc_dif_verify_write);
 
-sense_reason_t
-sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
-		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
+static sense_reason_t
+__sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
+		      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
 {
 	struct se_device *dev = cmd->se_dev;
 	struct se_dif_v1_tuple *sdt;
@@ -1326,8 +1326,31 @@ sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
 		kunmap_atomic(paddr);
 		kunmap_atomic(daddr);
 	}
-	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
 
 	return 0;
 }
+
+sense_reason_t
+sbc_dif_read_strip(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	u32 sectors = cmd->prot_length / dev->prot_length;
+
+	return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
+				     cmd->t_prot_sg, 0);
+}
+
+sense_reason_t
+sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
+		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
+{
+	sense_reason_t rc;
+
+	rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
+	if (rc)
+		return rc;
+
+	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
+	return 0;
+}
 EXPORT_SYMBOL(sbc_dif_verify_read);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
@@ -78,6 +78,7 @@ sense_reason_t	sbc_dif_verify_write(struct se_cmd *, sector_t, unsigned int,
 				     unsigned int, struct scatterlist *, int);
 sense_reason_t	sbc_dif_verify_read(struct se_cmd *, sector_t, unsigned int,
 				    unsigned int, struct scatterlist *, int);
+sense_reason_t	sbc_dif_read_strip(struct se_cmd *);
 
 void	transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
 int	transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);