Re: [PATCHv5 7/8] scsi: make asynchronous aborts mandatory

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig 

[PATCHv5 7/8] scsi: make asynchronous aborts mandatory

[Hannes Reinecke]

There hasn't been any reports for HBAs where asynchronous abort
would not work, so we should make it mandatory and remove
the fallback.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Bart Van Assche 
---
 Documentation/scsi/scsi_eh.txt | 18 --
 drivers/scsi/scsi_error.c  | 81 --
 drivers/scsi/scsi_lib.c|  2 +-
 drivers/scsi/scsi_priv.h   |  3 +-
 include/scsi/scsi_host.h   |  5 ---
 5 files changed, 15 insertions(+), 94 deletions(-)

diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt
index 4edb9c1c..11e447b 100644
--- a/Documentation/scsi/scsi_eh.txt
+++ b/Documentation/scsi/scsi_eh.txt
@@ -70,7 +70,7 @@ with the command.
scmd is requeued to blk queue.
 
  - otherwise
-   scsi_eh_scmd_add(scmd, 0) is invoked for the command.  See
+   scsi_eh_scmd_add(scmd) is invoked for the command.  See
[1-3] for details of this function.
 
 
@@ -103,9 +103,7 @@ function
 eh_timed_out() callback did not handle the command.
Step #2 is taken.
 
- 2. If the host supports asynchronous completion (as indicated by the
-no_async_abort setting in the host template) scsi_abort_command()
-is invoked to schedule an asynchrous abort.
+ 2. scsi_abort_command() is invoked to schedule an asynchrous abort.
 Asynchronous abort are not invoked for commands which the
 SCSI_EH_ABORT_SCHEDULED flag is set (this indicates that the command
 already had been aborted once, and this is a retry which failed),
@@ -127,16 +125,13 @@ function
 
  scmds enter EH via scsi_eh_scmd_add(), which does the following.
 
- 1. Turns on scmd->eh_eflags as requested.  It's 0 for error
-completions and SCSI_EH_CANCEL_CMD for timeouts.
+ 1. Links scmd->eh_entry to shost->eh_cmd_q
 
- 2. Links scmd->eh_entry to shost->eh_cmd_q
+ 2. Sets SHOST_RECOVERY bit in shost->shost_state
 
- 3. Sets SHOST_RECOVERY bit in shost->shost_state
+ 3. Increments shost->host_failed
 
- 4. Increments shost->host_failed
-
- 5. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed
+ 4. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed
 
  As can be seen above, once any scmd is added to shost->eh_cmd_q,
 SHOST_RECOVERY shost_state bit is turned on.  This prevents any new
@@ -252,7 +247,6 @@ scmd->allowed.
 
  1. Error completion / time out
 ACTION: scsi_eh_scmd_add() is invoked for scmd
-   - set scmd->eh_eflags
- add scmd to shost->eh_cmd_q
- set SHOST_RECOVERY
- shost->host_failed++
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index bbc4318..53e3343 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -162,7 +162,7 @@ static int scsi_host_eh_past_deadline(struct Scsi_Host 
*shost)
}
}
 
-   scsi_eh_scmd_add(scmd, 0);
+   scsi_eh_scmd_add(scmd);
 }
 
 /**
@@ -221,9 +221,8 @@ static void scsi_eh_reset(struct scsi_cmnd *scmd)
 /**
  * scsi_eh_scmd_add - add scsi cmd to error handling.
  * @scmd:  scmd to run eh on.
- * @eh_flag:   optional SCSI_EH flag.
  */
-void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
+void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
 {
struct Scsi_Host *shost = scmd->device->host;
unsigned long flags;
@@ -239,9 +238,6 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
if (shost->eh_deadline != -1 && !shost->last_reset)
shost->last_reset = jiffies;
 
-   if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
-   eh_flag &= ~SCSI_EH_CANCEL_CMD;
-   scmd->eh_eflags |= eh_flag;
scsi_eh_reset(scmd);
list_add_tail(>eh_entry, >eh_cmd_q);
shost->host_failed++;
@@ -275,10 +271,9 @@ enum blk_eh_timer_return scsi_times_out(struct request 
*req)
rtn = host->hostt->eh_timed_out(scmd);
 
if (rtn == BLK_EH_NOT_HANDLED) {
-   if (host->hostt->no_async_abort ||
-   scsi_abort_command(scmd) != SUCCESS) {
+   if (scsi_abort_command(scmd) != SUCCESS) {
set_host_byte(scmd, DID_TIME_OUT);
-   scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD);
+   scsi_eh_scmd_add(scmd);
}
}
 
@@ -331,7 +326,7 @@ static inline void scsi_eh_prt_fail_stats(struct Scsi_Host 
*shost,
list_for_each_entry(scmd, work_q, eh_entry) {
if (scmd->device == sdev) {
++total_failures;
-   if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
+   if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
++cmd_cancel;
else
++cmd_failed;
@@ -1154,8 +1149,7 @@ int scsi_eh_get_sense(struct