scsi_debug: ignore host lock option

Remove logic to optionally hold host_lock while each command is
queued. Keep module and sysfs host_lock parameters for backward
compatibility. Note in module parameter description that host_lock is
ignored.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index ac74cbde7adfb68977a1537a8f05ad40584f11ba..88bfe0fb72ee1103f013c5488fe56b6e8e0a1424 100644 (file)
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4040,7 +4040,7 @@ MODULE_PARM_DESC(dsense, "use descriptor sense format(def=0 -> fixed)");
 MODULE_PARM_DESC(every_nth, "timeout every nth command(def=0)");
 MODULE_PARM_DESC(fake_rw, "fake reads/writes instead of copying (def=0)");
 MODULE_PARM_DESC(guard, "protection checksum: 0=crc, 1=ip (def=0)");
-MODULE_PARM_DESC(host_lock, "use host_lock around all commands (def=0)");
+MODULE_PARM_DESC(host_lock, "host_lock is ignored (def=0)");
 MODULE_PARM_DESC(lbpu, "enable LBP, support UNMAP command (def=0)");
 MODULE_PARM_DESC(lbpws, "enable LBP, support WRITE SAME(16) with UNMAP bit (def=0)");
 MODULE_PARM_DESC(lbpws10, "enable LBP, support WRITE SAME(10) with UNMAP bit (def=0)");
@@ -4592,30 +4592,15 @@ static ssize_t host_lock_show(struct device_driver *ddp, char *buf)
 {
        return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_host_lock);
 }
-/* Returns -EBUSY if host_lock is being changed and commands are queued */
+/* N.B. sdebug_host_lock does nothing, kept for backward compatibility */
 static ssize_t host_lock_store(struct device_driver *ddp, const char *buf,
                               size_t count)
 {
-       int n, res;
+       int n;
 
        if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
-               bool new_host_lock = (n > 0);
-
-               res = count;
-               if (new_host_lock != sdebug_host_lock) {
-                       unsigned long iflags;
-                       int k;
-
-                       spin_lock_irqsave(&queued_arr_lock, iflags);
-                       k = find_first_bit(queued_in_use_bm,
-                                          sdebug_max_queue);
-                       if (k != sdebug_max_queue)
-                               res = -EBUSY;   /* have queued commands */
-                       else
-                               sdebug_host_lock = new_host_lock;
-                       spin_unlock_irqrestore(&queued_arr_lock, iflags);
-               }
-               return res;
+               sdebug_host_lock = (n > 0);
+               return count;
        }
        return -EINVAL;
 }
@@ -5035,7 +5020,7 @@ check_inject(struct scsi_cmnd *scp)
 }
 
 static int
-scsi_debug_queuecommand(struct scsi_cmnd *scp)
+scsi_debug_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scp)
 {
        u8 sdeb_i;
        struct scsi_device *sdp = scp->device;
@@ -5170,21 +5155,6 @@ check_cond:
        return schedule_resp(scp, devip, check_condition_result, 0);
 }
 
-static int
-sdebug_queuecommand_lock_or_not(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
-{
-       if (sdebug_host_lock) {
-               unsigned long iflags;
-               int rc;
-
-               spin_lock_irqsave(shost->host_lock, iflags);
-               rc = scsi_debug_queuecommand(cmd);
-               spin_unlock_irqrestore(shost->host_lock, iflags);
-               return rc;
-       } else
-               return scsi_debug_queuecommand(cmd);
-}
-
 static struct scsi_host_template sdebug_driver_template = {
        .show_info =            scsi_debug_show_info,
        .write_info =           scsi_debug_write_info,
@@ -5195,7 +5165,7 @@ static struct scsi_host_template sdebug_driver_template = {
        .slave_configure =      scsi_debug_slave_configure,
        .slave_destroy =        scsi_debug_slave_destroy,
        .ioctl =                scsi_debug_ioctl,
-       .queuecommand =         sdebug_queuecommand_lock_or_not,
+       .queuecommand =         scsi_debug_queuecommand,
        .change_queue_depth =   sdebug_change_qdepth,
        .eh_abort_handler =     scsi_debug_abort,
        .eh_device_reset_handler = scsi_debug_device_reset,