Iterating over all possible bus number in scsi_eh_bus_reset() is
inefficient as not all busses may be affected during SCSI EH.
So rewrite the loop in scsi_eh_bus_reset() to match the loop
in scsi_eh_target_reset() and only loop over failed commands.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/scsi/scsi_error.c | 62 ++++++++++++++++-----------------------
1 file changed, 25 insertions(+), 37 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 42e12756d6f4..7c9c376affda 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1694,21 +1694,20 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
struct list_head *work_q,
struct list_head *done_q)
{
- struct scsi_cmnd *scmd, *chan_scmd, *next;
+ LIST_HEAD(tmp_list);
LIST_HEAD(check_list);
- unsigned int channel;
- enum scsi_disposition rtn;
- /*
- * we really want to loop over the various channels, and do this on
- * a channel by channel basis. we should also check to see if any
- * of the failed commands are on soft_reset devices, and if so, skip
- * the reset.
- */
+ list_splice_init(work_q, &tmp_list);
+
+ while (!list_empty(&tmp_list)) {
+ struct scsi_cmnd *next, *scmd;
+ enum scsi_disposition rtn;
+ unsigned int channel;
- for (channel = 0; channel <= shost->max_channel; channel++) {
if (scsi_host_eh_past_deadline(shost)) {
+ /* push back on work queue for further processing */
list_splice_init(&check_list, work_q);
+ list_splice_init(&tmp_list, work_q);
SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, shost,
"%s: skip BRST, past eh deadline\n",
@@ -1716,43 +1715,32 @@ static int scsi_eh_bus_reset(struct Scsi_Host *shost,
return list_empty(work_q);
}
- chan_scmd = NULL;
- list_for_each_entry(scmd, work_q, eh_entry) {
- if (channel == scmd_channel(scmd)) {
- chan_scmd = scmd;
- break;
- /*
- * FIXME add back in some support for
- * soft_reset devices.
- */
- }
- }
+ scmd = list_first_entry(&tmp_list, struct scsi_cmnd, eh_entry);
+ channel = scmd_channel(scmd);
- if (!chan_scmd)
- continue;
SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, shost,
"%s: Sending BRST chan: %d\n",
current->comm, channel));
- rtn = scsi_try_bus_reset(chan_scmd);
- if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
- list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
- if (channel == scmd_channel(scmd)) {
- if (rtn == FAST_IO_FAIL) {
- set_host_byte(scmd,
- DID_TRANSPORT_FAILFAST);
- scsi_eh_finish_cmd(scmd, done_q);
- } else
- list_move_tail(&scmd->eh_entry,
- &check_list);
- }
- }
- } else {
+ rtn = scsi_try_bus_reset(scmd);
+ if (rtn != SUCCESS && rtn != FAST_IO_FAIL) {
SCSI_LOG_ERROR_RECOVERY(3,
shost_printk(KERN_INFO, shost,
"%s: BRST failed chan: %d\n",
current->comm, channel));
}
+ list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
+ if (scmd_channel(scmd) != channel)
+ continue;
+
+ if (rtn == SUCCESS)
+ list_move_tail(&scmd->eh_entry, &check_list);
+ else if (rtn == FAST_IO_FAIL) {
+ set_host_byte(scmd, DID_TRANSPORT_FAILFAST);
+ scsi_eh_finish_cmd(scmd, done_q);
+ } else
+ list_move_tail(&scmd->eh_entry, work_q);
+ }
}
return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
}
--
2.35.3
