[PATCH] Get rid of scsi_cmnd->done

Matthew Wilcox
2007-09-25T16:42:07Z

From: Matthew Wilcox <matthew@wil.cx>

The ULD ->done callback moves into the scsi_driver. By moving the call
to scsi_io_completion() from scsi_blk_pc_done() to scsi_finish_command(),
we can eliminate the latter entirely. By returning 'good_bytes' from
the ->done callback (rather than invoking scsi_io_completion()), we can
stop exporting scsi_io_completion().

Also move the prototypes from sd.h to sd.c as they're all internal anyway.
Rename sd_rw_intr to sd_done and rw_intr to sr_done.

Inspired-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
drivers/scsi/scsi.c | 20 +++++++++++++++++---
drivers/scsi/scsi_error.c | 1 -
drivers/scsi/scsi_lib.c | 14 --------------
drivers/scsi/scsi_priv.h | 1 +
drivers/scsi/sd.c | 28 ++++++++++++++++++----------
drivers/scsi/sr.c | 21 ++++++---------------
include/scsi/scsi_cmnd.h | 2 --
include/scsi/scsi_driver.h | 1 +
include/scsi/sd.h | 13 -------------
9 files changed, 43 insertions(+), 58 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index a5de1a8..60799ff 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -59,6 +59,7 @@
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
@@ -367,9 +368,8 @@ void scsi_log_send(struct scsi_cmnd *cmd)
scsi_print_command(cmd);
if (level > 3) {
printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
- " done = 0x%p, queuecommand 0x%p\n",
+ " queuecommand 0x%p\n",
scsi_sglist(cmd), scsi_bufflen(cmd),
- cmd->done,
cmd->device->host->hostt->queuecommand);

}
@@ -658,6 +658,12 @@ void __scsi_done(struct scsi_cmnd *cmd)
blk_complete_request(rq);
}

+/* Move this to a header if it becomes more generally useful */
+static struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
+{
+ return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
+}
+
/*
* Function: scsi_finish_command
*
@@ -669,6 +675,8 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
{
struct scsi_device *sdev = cmd->device;
struct Scsi_Host *shost = sdev->host;
+ struct scsi_driver *drv;
+ unsigned int good_bytes;

scsi_device_unbusy(sdev);

@@ -694,7 +702,13 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
"Notifying upper driver of completion "
"(result %x)\n", cmd->result));

- cmd->done(cmd);
+ good_bytes = cmd->request_bufflen;
+ if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
+ drv = scsi_cmd_to_driver(cmd);
+ if (drv->done)
+ good_bytes = drv->done(cmd);
+ }
+ scsi_io_completion(cmd, good_bytes);
}
EXPORT_SYMBOL(scsi_finish_command);

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c05d020..10f6acc 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1671,7 +1671,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));

scmd->scsi_done = scsi_reset_provider_done_command;
- scmd->done = NULL;
scmd->request_buffer = NULL;
scmd->request_bufflen = 0;

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 94d82cb..cb8a577 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -982,7 +982,6 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
}
scsi_end_request(cmd, 0, this_count, !result);
}
-EXPORT_SYMBOL(scsi_io_completion);

/*
* Function: scsi_init_io()
@@ -1063,18 +1062,6 @@ static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
return cmd;
}

-static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
-{
- BUG_ON(!blk_pc_request(cmd->request));
- /*
- * This will complete the whole command with uptodate=1 so
- * as far as the block layer is concerned the command completed
- * successfully. Since this is a REQ_BLOCK_PC command the
- * caller should check the request's errors value
- */
- scsi_io_completion(cmd, cmd->request_bufflen);
-}
-
int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
@@ -1124,7 +1111,6 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
cmd->transfersize = req->data_len;
cmd->allowed = req->retries;
cmd->timeout_per_command = req->timeout;
- cmd->done = scsi_blk_pc_done;
return BLKPREP_OK;
}
EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index ee8efe8..eff0059 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -68,6 +68,7 @@ extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
extern void scsi_device_unbusy(struct scsi_device *sdev);
extern int scsi_queue_insert(struct scsi_cmnd *cmd, int reason);
extern void scsi_next_command(struct scsi_cmnd *cmd);
+extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_run_host_queues(struct Scsi_Host *shost);
extern struct request_queue *scsi_alloc_queue(struct scsi_device *sdev);
extern void scsi_free_queue(struct request_queue *q);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 38a4141..0a3a528 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -86,6 +86,19 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);

+static int sd_revalidate_disk(struct gendisk *);
+static int sd_probe(struct device *);
+static int sd_remove(struct device *);
+static void sd_shutdown(struct device *);
+static int sd_suspend(struct device *, pm_message_t state);
+static int sd_resume(struct device *);
+static void sd_rescan(struct device *);
+static int sd_done(struct scsi_cmnd *);
+static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
+static void scsi_disk_release(struct class_device *cdev);
+static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
+static void sd_print_result(struct scsi_disk *, int);
+
static DEFINE_IDR(sd_index_idr);
static DEFINE_SPINLOCK(sd_index_lock);

@@ -240,6 +253,7 @@ static struct scsi_driver sd_template = {
.shutdown = sd_shutdown,
},
.rescan = sd_rescan,
+ .done = sd_done,
};

/*
@@ -509,12 +523,6 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
SCpnt->timeout_per_command = timeout;

/*
- * This is the completion routine we use. This is matched in terms
- * of capability to this function.
- */
- SCpnt->done = sd_rw_intr;
-
- /*
* This indicates that the command is ready from our end to be
* queued.
*/
@@ -908,13 +916,13 @@ static struct block_device_operations sd_fops = {
};

/**
- * sd_rw_intr - bottom half handler: called when the lower level
+ * sd_done - bottom half handler: called when the lower level
* driver has completed (successfully or otherwise) a scsi command.
* @SCpnt: mid-level's per command structure.
*
* Note: potentially run from within an ISR. Must not block.
**/
-static void sd_rw_intr(struct scsi_cmnd * SCpnt)
+static int sd_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
unsigned int xfer_size = SCpnt->request_bufflen;
@@ -935,7 +943,7 @@ static void sd_rw_intr(struct scsi_cmnd * SCpnt)
SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
if (sense_valid) {
SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
- "sd_rw_intr: sb[respc,sk,asc,"
+ "sd_done: sb[respc,sk,asc,"
"ascq]=%x,%x,%x,%x\n",
sshdr.response_code,
sshdr.sense_key, sshdr.asc,
@@ -1007,7 +1015,7 @@ static void sd_rw_intr(struct scsi_cmnd * SCpnt)
break;
}
out:
- scsi_io_completion(SCpnt, good_bytes);
+ return good_bytes;
}

static int media_not_present(struct scsi_disk *sdkp,
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index a0c4e13..c619990 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -78,6 +78,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);

static int sr_probe(struct device *);
static int sr_remove(struct device *);
+static int sr_done(struct scsi_cmnd *);

static struct scsi_driver sr_template = {
.owner = THIS_MODULE,
@@ -86,6 +87,7 @@ static struct scsi_driver sr_template = {
.probe = sr_probe,
.remove = sr_remove,
},
+ .done = sr_done,
};

static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
@@ -208,12 +210,12 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot)
}

/*
- * rw_intr is the interrupt routine for the device driver.
+ * sr_done is the interrupt routine for the device driver.
*
- * It will be notified on the end of a SCSI read / write, and will take on
+ * It will be notified on the end of a SCSI read / write, and will take one
* of several actions based on success or failure.
*/
-static void rw_intr(struct scsi_cmnd * SCpnt)
+static int sr_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
int this_count = SCpnt->request_bufflen;
@@ -286,12 +288,7 @@ static void rw_intr(struct scsi_cmnd * SCpnt)
}
}

- /*
- * This calls the generic completion function, now that we know
- * how many actual sectors finished, and how many sectors we need
- * to say have failed.
- */
- scsi_io_completion(SCpnt, good_bytes);
+ return good_bytes;
}

static int sr_prep_fn(struct request_queue *q, struct request *rq)
@@ -428,12 +425,6 @@ static int sr_prep_fn(struct request_queue *q, struct request *rq)
SCpnt->timeout_per_command = timeout;

/*
- * This is the completion routine we use. This is matched in terms
- * of capability to this function.
- */
- SCpnt->done = rw_intr;
-
- /*
* This indicates that the command is ready from our end to be
* queued.
*/
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 53e1705..b2888d7 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -33,7 +33,6 @@ struct scsi_cmnd {
struct list_head list; /* scsi_cmnd participates in queue lists */
struct list_head eh_entry; /* entry for the host eh_cmd_q */
int eh_eflags; /* Used by error handlr */
- void (*done) (struct scsi_cmnd *); /* Mid-level done function */

/*
* A SCSI Command is assigned a nonzero serial_number before passed
@@ -124,7 +123,6 @@ extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
struct device *);
-extern void scsi_io_completion(struct scsi_cmnd *, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);

diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index 56a3047..1f5ca7f 100644
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -15,6 +15,7 @@ struct scsi_driver {
struct device_driver gendrv;

void (*rescan)(struct device *);
+ int (*done)(struct scsi_cmnd *);
};
#define to_scsi_driver(drv) \
container_of((drv), struct scsi_driver, gendrv)
diff --git a/include/scsi/sd.h b/include/scsi/sd.h
index aa1e716..f751331 100644
--- a/include/scsi/sd.h
+++ b/include/scsi/sd.h
@@ -47,19 +47,6 @@ struct scsi_disk {
};
#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,cdev)

-static int sd_revalidate_disk(struct gendisk *disk);
-static void sd_rw_intr(struct scsi_cmnd * SCpnt);
-static int sd_probe(struct device *);
-static int sd_remove(struct device *);
-static void sd_shutdown(struct device *dev);
-static int sd_suspend(struct device *dev, pm_message_t state);
-static int sd_resume(struct device *dev);
-static void sd_rescan(struct device *);
-static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
-static void scsi_disk_release(struct class_device *cdev);
-static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
-static void sd_print_result(struct scsi_disk *, int);
-
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_printk(prefix, (sdsk)->device, "[%s] " fmt, \
--
1.5.3.1