This fixes scsi_get_lba() helper function for PC commands.
Only the block layer is supposed to touch rq->__sector. We could
create a new accessor for it. But it seems overdoing a bit? Jens?
=
From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Subject: [PATCH] scsi: fix scsi_get_lba helper function for pc command
scsi_get_lba() can be used to get the lba info from
scsi_cmnd. scsi_get_lba() gets the lba info from rq->__sector so
scsi_get_lba() returns a bogus value for PC commands (we don't use
rq->__sector for PC commands).
This patch sets rq->__sector in scsi_setup_blk_pc_cmnd() so that
scsi_get_lba() works with PC commands.
scsi_get_data_transfer_info() is taken from
scsi_debug. scsi_get_data_transfer_info() looks useful for some
(scsi_debug, scsi_trace, libata, etc). So I export it. I'll convert
them to use scsi_get_data_transfer_info().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 54 +++++++++++++++++++++++++++++++++++++++++++++-
include/scsi/scsi_cmnd.h | 4 +++
2 files changed, 57 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1646fe7..b9b7f40 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -19,6 +19,7 @@
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/scatterlist.h>
+#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
@@ -69,6 +70,52 @@ struct kmem_cache *scsi_sdb_cache;
static void scsi_run_queue(struct request_queue *q);
+int scsi_get_data_transfer_info(unsigned char *cmd, unsigned long long *lba,
+ unsigned int *num, unsigned int *ei_lba)
+{
+ int ret = 0;
+
+ switch (*cmd) {
+ case VARIABLE_LENGTH_CMD:
+ *lba = get_unaligned_be64(&cmd[12]);
+ *num = get_unaligned_be32(&cmd[28]);
+ *ei_lba = get_unaligned_be32(&cmd[20]);
+ break;
+ case WRITE_16:
+ case READ_16:
+ case VERIFY_16:
+ case WRITE_SAME_16:
+ *lba = get_unaligned_be64(&cmd[2]);
+ *num = get_unaligned_be32(&cmd[10]);
+ break;
+ case WRITE_12:
+ case READ_12:
+ case VERIFY_12:
+ *lba = get_unaligned_be32(&cmd[2]);
+ *num = get_unaligned_be32(&cmd[6]);
+ break;
+ case WRITE_10:
+ case READ_10:
+ case XDWRITEREAD_10:
+ case VERIFY:
+ case WRITE_SAME:
+ *lba = get_unaligned_be32(&cmd[2]);
+ *num = get_unaligned_be16(&cmd[7]);
+ break;
+ case WRITE_6:
+ case READ_6:
+ *lba = (u32)cmd[3] | (u32)cmd[2] << 8 |
+ (u32)(cmd[1] & 0x1f) << 16;
+ *num = (0 == cmd[4]) ? 256 : cmd[4];
+ break;
+ default:
+ ret = -1;
+ break;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(scsi_get_data_transfer_info);
+
/*
* Function: scsi_unprep_request()
*
@@ -1046,6 +1093,8 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
int ret = scsi_prep_state_check(sdev, req);
+ unsigned int num, ei_lba;
+ unsigned long long lba;
if (ret != BLKPREP_OK)
return ret;
@@ -1082,7 +1131,10 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
cmd->sc_data_direction = DMA_TO_DEVICE;
else
cmd->sc_data_direction = DMA_FROM_DEVICE;
-
+
+ scsi_get_data_transfer_info(cmd->cmnd, &lba, &num, &ei_lba);
+ req->__sector = lba;
+
cmd->transfersize = blk_rq_bytes(req);
cmd->allowed = req->retries;
return BLKPREP_OK;
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index a5e885a..be3c785 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -151,6 +151,10 @@ extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
+extern int scsi_get_data_transfer_info(unsigned char *cmd,
+ unsigned long long *lba,
+ unsigned int *num, unsigned int *ei_lba);
+
static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
{
return cmd->sdb.table.nents;
--
1.6.5
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