[SRU][G/oracle][PATCH 1/2] scsi: core: Add limitless cmd retry support
Khalid Elmously
khalid.elmously at canonical.com
Tue Jun 15 05:23:19 UTC 2021
From: Mike Christie <michael.christie at oracle.com>
BugLink: https://bugs.launchpad.net/bugs/1931959
Add infinite retry support to SCSI midlayer by combining common checks for
retries into some helper functions, and then checking for the
-1/SCSI_CMD_RETRIES_NO_LIMIT.
Link: https://lore.kernel.org/r/1601566554-26752-2-git-send-email-michael.christie@oracle.com
Reviewed-by: Bart Van Assche <bvanassche at acm.org>
Signed-off-by: Mike Christie <michael.christie at oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit 2a242d59d6b908341c0d426bc6e7f8e28871cbd0)
Signed-off-by: Khalid Elmously <khalid.elmously at canonical.com>
---
drivers/scsi/scsi_error.c | 33 +++++++++++++++++++++++----------
drivers/scsi/scsi_lib.c | 29 +++++++++++++++++++----------
drivers/scsi/scsi_priv.h | 1 +
3 files changed, 43 insertions(+), 20 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 927b1e641842..1588f19b7f69 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -116,6 +116,14 @@ static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
return 1;
}
+static bool scsi_cmd_retry_allowed(struct scsi_cmnd *cmd)
+{
+ if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
+ return true;
+
+ return ++cmd->retries <= cmd->allowed;
+}
+
/**
* scmd_eh_abort_handler - Handle command aborts
* @work: command to be aborted.
@@ -151,7 +159,7 @@ scmd_eh_abort_handler(struct work_struct *work)
"eh timeout, not retrying "
"aborted command\n"));
} else if (!scsi_noretry_cmd(scmd) &&
- (++scmd->retries <= scmd->allowed)) {
+ scsi_cmd_retry_allowed(scmd)) {
SCSI_LOG_ERROR_RECOVERY(3,
scmd_printk(KERN_WARNING, scmd,
"retry aborted command\n"));
@@ -1264,11 +1272,18 @@ int scsi_eh_get_sense(struct list_head *work_q,
* upper level.
*/
if (rtn == SUCCESS)
- /* we don't want this command reissued, just
- * finished with the sense data, so set
- * retries to the max allowed to ensure it
- * won't get reissued */
- scmd->retries = scmd->allowed;
+ /*
+ * We don't want this command reissued, just finished
+ * with the sense data, so set retries to the max
+ * allowed to ensure it won't get reissued. If the user
+ * has requested infinite retries, we also want to
+ * finish this command, so force completion by setting
+ * retries and allowed to the same value.
+ */
+ if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
+ scmd->retries = scmd->allowed = 1;
+ else
+ scmd->retries = scmd->allowed;
else if (rtn != NEEDS_RETRY)
continue;
@@ -1944,8 +1959,7 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
* the request was not marked fast fail. Note that above,
* even if the request is marked fast fail, we still requeue
* for queue congestion conditions (QUEUE_FULL or BUSY) */
- if ((++scmd->retries) <= scmd->allowed
- && !scsi_noretry_cmd(scmd)) {
+ if (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) {
return NEEDS_RETRY;
} else {
/*
@@ -2091,8 +2105,7 @@ void scsi_eh_flush_done_q(struct list_head *done_q)
list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
list_del_init(&scmd->eh_entry);
if (scsi_device_online(scmd->device) &&
- !scsi_noretry_cmd(scmd) &&
- (++scmd->retries <= scmd->allowed)) {
+ !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd)) {
SCSI_LOG_ERROR_RECOVERY(3,
scmd_printk(KERN_INFO, scmd,
"%s: flush retry cmd\n",
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 67597db1d900..dc285ebba361 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -655,6 +655,23 @@ static void scsi_io_completion_reprep(struct scsi_cmnd *cmd,
scsi_mq_requeue_cmd(cmd);
}
+static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd)
+{
+ struct request *req = cmd->request;
+ unsigned long wait_for;
+
+ if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
+ return false;
+
+ wait_for = (cmd->allowed + 1) * req->timeout;
+ if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
+ scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n",
+ wait_for/HZ);
+ return true;
+ }
+ return false;
+}
+
/* Helper for scsi_io_completion() when special action required. */
static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
{
@@ -663,7 +680,6 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
int level = 0;
enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
ACTION_DELAYED_RETRY} action;
- unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
struct scsi_sense_hdr sshdr;
bool sense_valid;
bool sense_current = true; /* false implies "deferred sense" */
@@ -768,8 +784,7 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
} else
action = ACTION_FAIL;
- if (action != ACTION_FAIL &&
- time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
+ if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd))
action = ACTION_FAIL;
switch (action) {
@@ -1437,7 +1452,6 @@ static bool scsi_mq_lld_busy(struct request_queue *q)
static void scsi_softirq_done(struct request *rq)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
int disposition;
INIT_LIST_HEAD(&cmd->eh_entry);
@@ -1447,13 +1461,8 @@ static void scsi_softirq_done(struct request *rq)
atomic_inc(&cmd->device->ioerr_cnt);
disposition = scsi_decide_disposition(cmd);
- if (disposition != SUCCESS &&
- time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
- scmd_printk(KERN_ERR, cmd,
- "timing out command, waited %lus\n",
- wait_for/HZ);
+ if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd))
disposition = SUCCESS;
- }
scsi_log_completion(cmd, disposition);
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 22b6585e28b4..f8c46cc82e9f 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -15,6 +15,7 @@ struct scsi_host_template;
struct Scsi_Host;
struct scsi_nl_hdr;
+#define SCSI_CMD_RETRIES_NO_LIMIT -1
/*
* Scsi Error Handler Flags
--
2.17.1
More information about the kernel-team
mailing list