[SCSI] implement scsi_data_buffer
In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.
- Group all IO members of scsi_cmnd into a scsi_data_buffer
structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
scsi_cmnd. And work on it.
- Adjust scsi_init_io() and scsi_release_buffers() for above
change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
accessors where appropriate.
- fix Documentation about scsi_cmnd in scsi_host.h
- scsi_error.c
* Changed needed members of struct scsi_eh_save.
* Careful considerations in scsi_eh_prep/restore_cmnd.
- sd.c and sr.c
* sd and sr would adjust IO size to align on device's block
size so code needs to change once we move to scsi_data_buff
implementation.
* Convert code to use scsi_for_each_sg
* Use data accessors where appropriate.
- tgt: convert libsrp to use scsi_data_buffer
- isd200: This driver still bangs on scsi_cmnd IO members,
so need changing
[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 09d44f9..c6478bb 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -11,6 +11,11 @@
struct Scsi_Host;
struct scsi_device;
+struct scsi_data_buffer {
+ struct sg_table table;
+ unsigned length;
+ int resid;
+};
/* embedded in scsi_cmnd */
struct scsi_pointer {
@@ -61,15 +66,11 @@
/* These elements define the operation we are about to perform */
#define MAX_COMMAND_SIZE 16
unsigned char cmnd[MAX_COMMAND_SIZE];
- unsigned request_bufflen; /* Actual request size */
struct timer_list eh_timeout; /* Used to time out the command. */
- void *request_buffer; /* Actual requested buffer */
/* These elements define the operation we ultimately want to perform */
- struct sg_table sg_table;
- unsigned short use_sg; /* Number of pieces of scatter-gather */
-
+ struct scsi_data_buffer sdb;
unsigned underflow; /* Return error if less than
this amount is transferred */
@@ -79,10 +80,6 @@
reconnects. Probably == sector
size */
- int resid; /* Number of bytes requested to be
- transferred less actual number
- transferred (0 if not supported) */
-
struct request *request; /* The command we are
working on */
@@ -133,18 +130,29 @@
extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
-#define scsi_sg_count(cmd) ((cmd)->use_sg)
-#define scsi_sglist(cmd) ((cmd)->sg_table.sgl)
-#define scsi_bufflen(cmd) ((cmd)->request_bufflen)
+static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.table.nents;
+}
+
+static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.table.sgl;
+}
+
+static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
+{
+ return cmd->sdb.length;
+}
static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
{
- cmd->resid = resid;
+ cmd->sdb.resid = resid;
}
static inline int scsi_get_resid(struct scsi_cmnd *cmd)
{
- return cmd->resid;
+ return cmd->sdb.resid;
}
#define scsi_for_each_sg(cmd, sg, nseg, __i) \