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>

1 files changed, 7 insertions, 37 deletions

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index ac74cbde7adf..88bfe0fb72ee 100644
--- 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,