Re: [PATCH v3 4/6] scsi: Retry unaligned zoned writes

On 7/27/23 00:02, Bart Van Assche wrote:

On 7/26/23 01:47, Damien Le Moal wrote:

quoted

On 7/26/23 09:57, Bart Van Assche wrote:

quoted

+/*
+ * Returns a negative value if @_a has a lower LBA than @_b, zero if
+ * both have the same LBA and a positive value otherwise.
+ */
+static int scsi_cmp_lba(void *priv, const struct list_head *_a,
+            const struct list_head *_b)

The argument priv is unused.

I cannot remove the 'priv' argument. From include/linux/list_sort.h:

typedef int __attribute__((nonnull(2,3))) (*list_cmp_func_t)(void *,
        const struct list_head *, const struct list_head *);

__attribute__((nonnull(2,3)))
void list_sort(void *priv, struct list_head *head, list_cmp_func_t cmp);

Yes. I missed that this is a callbalck. Sorry for the noise.

quoted

quoted

  /**
   * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
   * @shost:    Host to unjam.

@@ -2258,6 +2289,12 @@ static void scsi_unjam_host(struct Scsi_Host *shost)

        SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
  +    /*
+     * Sort pending SCSI commands in LBA order. This is important if zone
+     * write locking is disabled for a zoned SCSI device.
+     */
+    list_sort(NULL, &eh_work_q, scsi_cmp_lba);

Should we do this only for zoned devices ?

I'm not sure this is possible. Error handling happens per SCSI host. Some of
the logical units associated with a host may be zoned while others may
represent conventional storage or have no storage associated with them (WLUN).

Thanks,

Bart.

-- 
Damien Le Moal
Western Digital Research