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block: unify request timeout handling

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Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe
2008-09-14 05:55:09 -07:00
parent 608aeef17a
commit 242f9dcb8b
39 changed files with 399 additions and 339 deletions
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90
drivers/scsi/scsi_error.c
View File

@@ -111,70 +111,9 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
return ret;
}
/**
* scsi_add_timer - Start timeout timer for a single scsi command.
* @scmd: scsi command that is about to start running.
* @timeout: amount of time to allow this command to run.
* @complete: timeout function to call if timer isn't canceled.
*
* Notes:
* This should be turned into an inline function. Each scsi command
* has its own timer, and as it is added to the queue, we set up the
* timer. When the command completes, we cancel the timer.
*/
void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
void (*complete)(struct scsi_cmnd *))
{
/*
* If the clock was already running for this command, then
* first delete the timer. The timer handling code gets rather
* confused if we don't do this.
*/
if (scmd->eh_timeout.function)
del_timer(&scmd->eh_timeout);
scmd->eh_timeout.data = (unsigned long)scmd;
scmd->eh_timeout.expires = jiffies + timeout;
scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
" %d, (%p)\n", __func__,
scmd, timeout, complete));
add_timer(&scmd->eh_timeout);
}
/**
* scsi_delete_timer - Delete/cancel timer for a given function.
* @scmd: Cmd that we are canceling timer for
*
* Notes:
* This should be turned into an inline function.
*
* Return value:
* 1 if we were able to detach the timer. 0 if we blew it, and the
* timer function has already started to run.
*/
int scsi_delete_timer(struct scsi_cmnd *scmd)
{
int rtn;
rtn = del_timer(&scmd->eh_timeout);
SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
" rtn: %d\n", __func__,
scmd, rtn));
scmd->eh_timeout.data = (unsigned long)NULL;
scmd->eh_timeout.function = NULL;
return rtn;
}
/**
* scsi_times_out - Timeout function for normal scsi commands.
* @scmd: Cmd that is timing out.
* @req: request that is timing out.
*
* Notes:
* We do not need to lock this. There is the potential for a race
@@ -182,9 +121,11 @@ int scsi_delete_timer(struct scsi_cmnd *scmd)
* normal completion function determines that the timer has already
* fired, then it mustn't do anything.
*/
void scsi_times_out(struct scsi_cmnd *scmd)
enum blk_eh_timer_return scsi_times_out(struct request *req)
{
enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
struct scsi_cmnd *scmd = req->special;
enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
scsi_log_completion(scmd, TIMEOUT_ERROR);
@@ -196,22 +137,20 @@ void scsi_times_out(struct scsi_cmnd *scmd)
eh_timed_out = NULL;
if (eh_timed_out)
switch (eh_timed_out(scmd)) {
case EH_HANDLED:
__scsi_done(scmd);
return;
case EH_RESET_TIMER:
scsi_add_timer(scmd, scmd->timeout_per_command,
scsi_times_out);
return;
case EH_NOT_HANDLED:
rtn = eh_timed_out(scmd);
switch (rtn) {
case BLK_EH_NOT_HANDLED:
break;
default:
return rtn;
}
if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
scmd->result |= DID_TIME_OUT << 16;
__scsi_done(scmd);
return BLK_EH_HANDLED;
}
return BLK_EH_NOT_HANDLED;
}
/**
@@ -1793,7 +1732,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
blk_rq_init(NULL, &req);
scmd->request = &req;
memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
scmd->cmnd = req.cmd;
@@ -1804,8 +1742,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
scmd->sc_data_direction = DMA_BIDIRECTIONAL;
init_timer(&scmd->eh_timeout);
spin_lock_irqsave(shost->host_lock, flags);
shost->tmf_in_progress = 1;
spin_unlock_irqrestore(shost->host_lock, flags);