[SCSI] Make scsi_scan_host work for drivers which find their own targets

If a driver can find its own targets, it can now fill in scan_finished and
(optionally) scan_start in the scsi_host_template.  Then, when it calls
scsi_scan_host(), it will be called back (from a thread if asynchronous
discovery is enabled), first to start the scan, and then at intervals to
check if the scan is completed.

Also make scsi_prep_async_scan and scsi_finish_async_scan static.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index e618e711ea57..6d8945d71c65 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -241,6 +241,24 @@ struct scsi_host_template {
         void (* target_destroy)(struct scsi_target *);
 
         /*
+         * If a host has the ability to discover targets on its own instead
+         * of scanning the entire bus, it can fill in this function and
+         * call scsi_scan_host().  This function will be called periodically
+         * until it returns 1 with the scsi_host and the elapsed time of
+         * the scan in jiffies.
+         *
+         * Status: OPTIONAL
+         */
+        int (* scan_finished)(struct Scsi_Host *, unsigned long);
+
+        /*
+         * If the host wants to be called before the scan starts, but
+         * after the midlayer has set up ready for the scan, it can fill
+         * in this function.
+         */
+        void (* scan_start)(struct Scsi_Host *);
+
+        /*
          * fill in this function to allow the queue depth of this host
          * to be changeable (on a per device basis).  returns either
          * the current queue depth setting (may be different from what