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-cd.c b/drivers/ide/ide-cd.c
index 4e73aeee4053..8f253e5f26a8 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -57,23 +57,29 @@ static DEFINE_MUTEX(idecd_ref_mutex);
 #define ide_cd_g(disk) \
         container_of((disk)->private_data, struct cdrom_info, driver)
 
+static void ide_cd_release(struct kref *);
+
 static struct cdrom_info *ide_cd_get(struct gendisk *disk)
 {
         struct cdrom_info *cd = NULL;
 
         mutex_lock(&idecd_ref_mutex);
         cd = ide_cd_g(disk);
-        if (cd)
+        if (cd) {
                 kref_get(&cd->kref);
+                if (ide_device_get(cd->drive)) {
+                        kref_put(&cd->kref, ide_cd_release);
+                        cd = NULL;
+                }
+        }
         mutex_unlock(&idecd_ref_mutex);
         return cd;
 }
 
-static void ide_cd_release(struct kref *);
-
 static void ide_cd_put(struct cdrom_info *cd)
 {
         mutex_lock(&idecd_ref_mutex);
+        ide_device_put(cd->drive);
         kref_put(&cd->kref, ide_cd_release);
         mutex_unlock(&idecd_ref_mutex);
 }