From: Christoph Hellwig <hch@lst.de>
To: jejb@steeleye.com, michaelc@cs.wisc.edu
Cc: linux-scsi@vger.kernel.org
Subject: [PATCH] always handle REQ_BLOCK_PC requests in common code
Date: Fri, 6 Jan 2006 18:34:07 +0100 [thread overview]
Message-ID: <20060106173407.GA23658@lst.de> (raw)
LLDDs should never see REQ_BLOCK_PC requests, we can handle them just
fine in the core code. There is a small behaviour change in that some
check in sr's rw_intr are bypassed, but I consider the old behaviour
a bug.
Mike found this cleanup ooportunity and provdided early patches, so all
the credit goes to him, even if I redid the patches from scratch beause
that was easier than forward-porting the old patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Index: scsi-misc-2.6/drivers/scsi/scsi_lib.c
===================================================================
--- scsi-misc-2.6.orig/drivers/scsi/scsi_lib.c 2005-12-16 16:14:35.000000000 +0100
+++ scsi-misc-2.6/drivers/scsi/scsi_lib.c 2006-01-06 18:11:16.000000000 +0100
@@ -1247,7 +1247,7 @@
return -EOPNOTSUPP;
}
-static void scsi_generic_done(struct scsi_cmnd *cmd)
+static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
{
BUG_ON(!blk_pc_request(cmd->request));
/*
@@ -1259,7 +1259,7 @@
scsi_io_completion(cmd, cmd->bufflen, 0);
}
-void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
+static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
{
struct request *req = cmd->request;
@@ -1276,8 +1276,8 @@
cmd->transfersize = req->data_len;
cmd->allowed = req->retries;
cmd->timeout_per_command = req->timeout;
+ cmd->done = scsi_blk_pc_done;
}
-EXPORT_SYMBOL_GPL(scsi_setup_blk_pc_cmnd);
static int scsi_prep_fn(struct request_queue *q, struct request *req)
{
@@ -1374,7 +1374,6 @@
* happening now.
*/
if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
- struct scsi_driver *drv;
int ret;
/*
@@ -1406,16 +1405,17 @@
/*
* Initialize the actual SCSI command for this request.
*/
- if (req->rq_disk) {
+ if (req->flags & REQ_BLOCK_PC) {
+ scsi_setup_blk_pc_cmnd(cmd);
+ } else if (req->rq_disk) {
+ struct scsi_driver *drv;
+
drv = *(struct scsi_driver **)req->rq_disk->private_data;
if (unlikely(!drv->init_command(cmd))) {
scsi_release_buffers(cmd);
scsi_put_command(cmd);
goto kill;
}
- } else {
- scsi_setup_blk_pc_cmnd(cmd);
- cmd->done = scsi_generic_done;
}
}
Index: scsi-misc-2.6/drivers/scsi/sd.c
===================================================================
--- scsi-misc-2.6.orig/drivers/scsi/sd.c 2006-01-06 17:52:58.000000000 +0100
+++ scsi-misc-2.6/drivers/scsi/sd.c 2006-01-06 18:18:49.000000000 +0100
@@ -233,34 +233,12 @@
**/
static int sd_init_command(struct scsi_cmnd * SCpnt)
{
- unsigned int this_count, timeout;
- struct gendisk *disk;
- sector_t block;
struct scsi_device *sdp = SCpnt->device;
struct request *rq = SCpnt->request;
-
- timeout = sdp->timeout;
-
- /*
- * SG_IO from block layer already setup, just copy cdb basically
- */
- if (blk_pc_request(rq)) {
- scsi_setup_blk_pc_cmnd(SCpnt);
- if (rq->timeout)
- timeout = rq->timeout;
-
- goto queue;
- }
-
- /*
- * we only do REQ_CMD and REQ_BLOCK_PC
- */
- if (!blk_fs_request(rq))
- return 0;
-
- disk = rq->rq_disk;
- block = rq->sector;
- this_count = SCpnt->request_bufflen >> 9;
+ struct gendisk *disk = rq->rq_disk;
+ sector_t block = rq->sector;
+ unsigned int this_count = SCpnt->request_bufflen >> 9;
+ unsigned int timeout = sdp->timeout;
SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
"count=%d\n", disk->disk_name,
@@ -394,8 +372,6 @@
SCpnt->transfersize = sdp->sector_size;
SCpnt->underflow = this_count << 9;
SCpnt->allowed = SD_MAX_RETRIES;
-
-queue:
SCpnt->timeout_per_command = timeout;
/*
@@ -870,15 +846,7 @@
relatively rare error condition, no care is taken to avoid
unnecessary additional work such as memcpy's that could be avoided.
*/
-
- /*
- * If SG_IO from block layer then set good_bytes to stop retries;
- * else if errors, check them, and if necessary prepare for
- * (partial) retries.
- */
- if (blk_pc_request(SCpnt->request))
- good_bytes = this_count;
- else if (driver_byte(result) != 0 &&
+ if (driver_byte(result) != 0 &&
sense_valid && !sense_deferred) {
switch (sshdr.sense_key) {
case MEDIUM_ERROR:
Index: scsi-misc-2.6/drivers/scsi/sr.c
===================================================================
--- scsi-misc-2.6.orig/drivers/scsi/sr.c 2005-12-16 16:14:35.000000000 +0100
+++ scsi-misc-2.6/drivers/scsi/sr.c 2006-01-06 18:16:05.000000000 +0100
@@ -237,8 +237,6 @@
case ILLEGAL_REQUEST:
if (!(SCpnt->sense_buffer[0] & 0x90))
break;
- if (!blk_fs_request(SCpnt->request))
- break;
error_sector = (SCpnt->sense_buffer[3] << 24) |
(SCpnt->sense_buffer[4] << 16) |
(SCpnt->sense_buffer[5] << 8) |
@@ -317,23 +315,6 @@
}
/*
- * these are already setup, just copy cdb basically
- */
- if (SCpnt->request->flags & REQ_BLOCK_PC) {
- scsi_setup_blk_pc_cmnd(SCpnt);
-
- if (SCpnt->timeout_per_command)
- timeout = SCpnt->timeout_per_command;
-
- goto queue;
- }
-
- if (!(SCpnt->request->flags & REQ_CMD)) {
- blk_dump_rq_flags(SCpnt->request, "sr unsup command");
- return 0;
- }
-
- /*
* we do lazy blocksize switching (when reading XA sectors,
* see CDROMREADMODE2 ioctl)
*/
@@ -421,8 +402,6 @@
*/
SCpnt->transfersize = cd->device->sector_size;
SCpnt->underflow = this_count << 9;
-
-queue:
SCpnt->allowed = MAX_RETRIES;
SCpnt->timeout_per_command = timeout;
Index: scsi-misc-2.6/drivers/scsi/st.c
===================================================================
--- scsi-misc-2.6.orig/drivers/scsi/st.c 2006-01-04 12:11:46.000000000 +0100
+++ scsi-misc-2.6/drivers/scsi/st.c 2006-01-06 18:12:35.000000000 +0100
@@ -193,7 +193,6 @@
static int st_probe(struct device *);
static int st_remove(struct device *);
-static int st_init_command(struct scsi_cmnd *);
static void do_create_driverfs_files(void);
static void do_remove_driverfs_files(void);
@@ -206,7 +205,6 @@
.probe = st_probe,
.remove = st_remove,
},
- .init_command = st_init_command,
};
static int st_compression(struct scsi_tape *, int);
@@ -4180,29 +4178,6 @@
return;
}
-static void st_intr(struct scsi_cmnd *SCpnt)
-{
- /*
- * The caller should be checking the request's errors
- * value.
- */
- scsi_io_completion(SCpnt, SCpnt->bufflen, 0);
-}
-
-/*
- * st_init_command: only called via the scsi_cmd_ioctl (block SG_IO)
- * interface for REQ_BLOCK_PC commands.
- */
-static int st_init_command(struct scsi_cmnd *SCpnt)
-{
- if (!(SCpnt->request->flags & REQ_BLOCK_PC))
- return 0;
-
- scsi_setup_blk_pc_cmnd(SCpnt);
- SCpnt->done = st_intr;
- return 1;
-}
-
static int __init init_st(void)
{
validate_options();
Index: scsi-misc-2.6/include/scsi/scsi_cmnd.h
===================================================================
--- scsi-misc-2.6.orig/include/scsi/scsi_cmnd.h 2005-12-16 16:14:35.000000000 +0100
+++ scsi-misc-2.6/include/scsi/scsi_cmnd.h 2006-01-06 18:11:45.000000000 +0100
@@ -151,6 +151,5 @@
extern void scsi_put_command(struct scsi_cmnd *);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
-extern void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd);
#endif /* _SCSI_SCSI_CMND_H */
next reply other threads:[~2006-01-06 17:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-06 17:34 Christoph Hellwig [this message]
2006-01-07 6:26 ` [PATCH] always handle REQ_BLOCK_PC requests in common code Douglas Gilbert
2006-01-07 14:13 ` Christoph Hellwig
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