Re: [PATCH] Get rid of scsi_cmnd->done

Boaz Harrosh
2007-09-25T17:05:20Z

On Tue, Sep 25 2007 at 18:42 +0200, Matthew Wilcox <willy@linux.intel.com> wrote:
> 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;
Please use scsi_bufflen(cmd) this file was already converted to
accessors.

> + 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, \

Thanks otherwise looks very good
Boaz