Use wait_for_completion_timeout() instead of using a timer (as
Christoph Hellwig did for aic7xxx).
That lets me eliminate the sym_eh_wait structure; the struct completion,
the old_done pointer and the to_do flag can be folded into the sym_ucmd
(which overrides the scsi_pointer in scsi_cmnd).
The sym_eh_done() function becomes much simpler as the timeout handling
is done in sym_eh_handler() directly.
The host_lock can be unlocked earlier, and I cache the host in
a local variable to make accesses to it quicker.
Signed-off-by: Matthew Wilcox <matthew@xxxxxx>
---
drivers/scsi/sym53c8xx_2/sym_glue.c | 84 +++++++++--------------------------
1 files changed, 22 insertions(+), 62 deletions(-)
af228733a867db9f4eaf37002667932a247cfc9f
diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index a27dd66..e48409e 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -137,24 +137,14 @@ static void sym2_setup_params(void)
static struct scsi_transport_template *sym2_transport_template = NULL;
/*
- * Used by the eh thread to wait for command completion.
- * It is allocated on the eh thread stack.
- */
-struct sym_eh_wait {
- struct completion done;
- struct timer_list timer;
- void (*old_done)(struct scsi_cmnd *);
- int to_do;
- int timed_out;
-};
-
-/*
* Driver private area in the SCSI command structure.
*/
struct sym_ucmd { /* Override the SCSI pointer structure */
+ struct completion done;
+ void (*old_done)(struct scsi_cmnd *);
dma_addr_t data_mapping;
- u_char data_mapped;
- struct sym_eh_wait *eh_wait;
+ int to_do;
+ u_char data_mapped; /* corresponds to data_mapping above */
};
#define SYM_UCMD_PTR(cmd) ((struct sym_ucmd *)(&(cmd)->SCp))
@@ -713,55 +703,35 @@ static void sym53c8xx_timer(unsigned lon
#define SYM_EH_DO_WAIT 2
/*
- * Our general completion handler.
+ * scsi_done() alias when error recovery is in progress.
*/
-static void __sym_eh_done(struct scsi_cmnd *cmd, int timed_out)
+static void sym_eh_done(struct scsi_cmnd *cmd)
{
- struct sym_eh_wait *ep = SYM_UCMD_PTR(cmd)->eh_wait;
- if (!ep)
- return;
-
- /* Try to avoid a race here (not 100% safe) */
- if (!timed_out) {
- ep->timed_out = 0;
- if (ep->to_do == SYM_EH_DO_WAIT && !del_timer(&ep->timer))
- return;
- }
+ struct sym_ucmd *ucmd = SYM_UCMD_PTR(cmd);
+ BUILD_BUG_ON(sizeof(struct scsi_pointer) < sizeof(struct sym_ucmd));
- /* Revert everything */
- SYM_UCMD_PTR(cmd)->eh_wait = NULL;
- cmd->scsi_done = ep->old_done;
+ cmd->scsi_done = ucmd->old_done;
- /* Wake up the eh thread if it wants to sleep */
- if (ep->to_do == SYM_EH_DO_WAIT)
- complete(&ep->done);
+ if (ucmd->to_do == SYM_EH_DO_WAIT)
+ complete(&ucmd->done);
}
/*
- * scsi_done() alias when error recovery is in progress.
- */
-static void sym_eh_done(struct scsi_cmnd *cmd) { __sym_eh_done(cmd, 0); }
-
-/*
- * Some timeout handler to avoid waiting too long.
- */
-static void sym_eh_timeout(u_long p) { __sym_eh_done((struct scsi_cmnd *)p, 1); }
-
-/*
* Generic method for our eh processing.
* The 'op' argument tells what we have to do.
*/
static int sym_eh_handler(int op, char *opname, struct scsi_cmnd *cmd)
{
struct sym_hcb *np = SYM_SOFTC_PTR(cmd);
+ struct sym_ucmd *ucmd = SYM_UCMD_PTR(cmd);
+ struct Scsi_Host *host = cmd->device->host;
SYM_QUEHEAD *qp;
int to_do = SYM_EH_DO_IGNORE;
int sts = -1;
- struct sym_eh_wait eh, *ep = &eh;
dev_warn(&cmd->device->sdev_gendev, "%s operation started.\n", opname);
- spin_lock_irq(cmd->device->host->host_lock);
+ spin_lock_irq(host->host_lock);
/* This one is queued in some place -> to wait for completion */
FOR_EACH_QUEUED_ELEMENT(&np->busy_ccbq, qp) {
struct sym_ccb *cp = sym_que_entry(qp, struct sym_ccb, link_ccbq);
@@ -772,10 +742,9 @@ static int sym_eh_handler(int op, char *
}
if (to_do == SYM_EH_DO_WAIT) {
- init_completion(&ep->done);
- ep->old_done = cmd->scsi_done;
+ init_completion(&ucmd->done);
+ ucmd->old_done = cmd->scsi_done;
cmd->scsi_done = sym_eh_done;
- SYM_UCMD_PTR(cmd)->eh_wait = ep;
}
/* Try to proceed the operation we have been asked for */
@@ -802,28 +771,19 @@ static int sym_eh_handler(int op, char *
/* On error, restore everything and cross fingers :) */
if (sts) {
- SYM_UCMD_PTR(cmd)->eh_wait = NULL;
- cmd->scsi_done = ep->old_done;
+ cmd->scsi_done = ucmd->old_done;
to_do = SYM_EH_DO_IGNORE;
}
- ep->to_do = to_do;
+ ucmd->to_do = to_do;
+ spin_unlock_irq(host->host_lock);
- /* Wait for completion with locks released, as required by kernel */
if (to_do == SYM_EH_DO_WAIT) {
- init_timer(&ep->timer);
- ep->timer.expires = jiffies + (5*HZ);
- ep->timer.function = sym_eh_timeout;
- ep->timer.data = (u_long)cmd;
- ep->timed_out = 1; /* Be pessimistic for once :) */
- add_timer(&ep->timer);
- spin_unlock_irq(np->s.host->host_lock);
- wait_for_completion(&ep->done);
- spin_lock_irq(np->s.host->host_lock);
- if (ep->timed_out)
+ if (!wait_for_completion_timeout(&ucmd->done, 5*HZ)) {
+ ucmd->to_do = SYM_EH_DO_IGNORE;
sts = -2;
+ }
}
- spin_unlock_irq(cmd->device->host->host_lock);
dev_warn(&cmd->device->sdev_gendev, "%s operation %s.\n", opname,
sts==0 ? "complete" :sts==-2 ? "timed-out" : "failed");
return sts ? SCSI_FAILED : SCSI_SUCCESS;
--
1.2.4.g375a5
-
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