ide: add ide_device_{get,put}() helpers

* Add 'struct ide_host *host' field to ide_hwif_t and set it
  in ide_host_alloc_all().

* Add ide_device_{get,put}() helpers loosely based on SCSI's
  scsi_device_{get,put}() ones.

* Convert IDE device drivers to use ide_device_{get,put}().

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index 6962ca4891a1..789f3428f072 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -322,23 +322,29 @@ static struct class *idetape_sysfs_class;
 #define ide_tape_g(disk) \
         container_of((disk)->private_data, struct ide_tape_obj, driver)
 
+static void ide_tape_release(struct kref *);
+
 static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
 {
         struct ide_tape_obj *tape = NULL;
 
         mutex_lock(&idetape_ref_mutex);
         tape = ide_tape_g(disk);
-        if (tape)
+        if (tape) {
                 kref_get(&tape->kref);
+                if (ide_device_get(tape->drive)) {
+                        kref_put(&tape->kref, ide_tape_release);
+                        tape = NULL;
+                }
+        }
         mutex_unlock(&idetape_ref_mutex);
         return tape;
 }
 
-static void ide_tape_release(struct kref *);
-
 static void ide_tape_put(struct ide_tape_obj *tape)
 {
         mutex_lock(&idetape_ref_mutex);
+        ide_device_put(tape->drive);
         kref_put(&tape->kref, ide_tape_release);
         mutex_unlock(&idetape_ref_mutex);
 }