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scsi: scsi_debug: Do not sleep in atomic sections

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Function stop_qc_helper() is called while the debug_scsi_cmd lock is held,
and from here we may call cancel_work_sync(), which may sleep.

Sleeping in atomic sections is not allowed.

Hence change the cancel_work_sync() call into a cancel_work() call.

However now it is not possible to know if the work callback is running when
we return. This is relevant for eh_abort_handler handling, as the semantics
of that callback are that success means that we do not keep a reference to
the scsi_cmnd - now this is not possible. So return FAIL when we are unsure
if the callback still running.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
jpg: return FAILED from scsi_debug_abort() when possible callback running
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20250224115517.495899-5-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Bart Van Assche
2025-02-24 20:53:07 -05:00
committed by Martin K. Petersen
parent b441eafbd1
commit ac0fb4a55b
1 changed files with 10 additions and 6 deletions
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drivers/scsi/scsi_debug.c
+10 -6
View File
@@ -6655,7 +6655,7 @@ static void scsi_debug_sdev_destroy(struct scsi_device *sdp)
sdp->hostdata = NULL;
}
/* Returns true if it is safe to complete @cmnd. */
/* Returns true if cancelled or not running callback. */
static bool scsi_debug_stop_cmnd(struct scsi_cmnd *cmnd)
{
struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmnd);
@@ -6668,18 +6668,18 @@ static bool scsi_debug_stop_cmnd(struct scsi_cmnd *cmnd)
int res = hrtimer_try_to_cancel(&sd_dp->hrt);
switch (res) {
case 0: /* Not active, it must have already run */
case -1: /* -1 It's executing the CB */
return false;
case 0: /* Not active, it must have already run */
case 1: /* Was active, we've now cancelled */
default:
return true;
}
} else if (defer_t == SDEB_DEFER_WQ) {
/* Cancel if pending */
if (cancel_work_sync(&sd_dp->ew.work))
if (cancel_work(&sd_dp->ew.work))
return true;
/* Was not pending, so it must have run */
/* callback may be running, so return false */
return false;
} else if (defer_t == SDEB_DEFER_POLL) {
return true;
@@ -6759,7 +6759,7 @@ static int sdebug_fail_abort(struct scsi_cmnd *cmnd)
static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
{
bool ok = scsi_debug_abort_cmnd(SCpnt);
bool aborted = scsi_debug_abort_cmnd(SCpnt);
u8 *cmd = SCpnt->cmnd;
u8 opcode = cmd[0];
@@ -6768,7 +6768,8 @@ static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
sdev_printk(KERN_INFO, SCpnt->device,
"%s: command%s found\n", __func__,
ok ? "" : " not");
aborted ? "" : " not");
if (sdebug_fail_abort(SCpnt)) {
scmd_printk(KERN_INFO, SCpnt, "fail abort command 0x%x\n",
@@ -6776,6 +6777,9 @@ static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
return FAILED;
}
if (aborted == false)
return FAILED;
return SUCCESS;
}