block: Generalize change_cb() to BlockDevOps

So we can more easily add device model callbacks.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -44,6 +44,7 @@
 #include <windows.h>
 #endif
 
+static void bdrv_dev_change_cb(BlockDriverState *bs, int reason);
 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
         BlockDriverCompletionFunc *cb, void *opaque);
@@ -688,10 +689,8 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
     }
 
     if (!bdrv_key_required(bs)) {
-        /* call the change callback */
         bs->media_changed = 1;
-        if (bs->change_cb)
-            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
+        bdrv_dev_change_cb(bs, CHANGE_MEDIA);
     }
 
     return 0;
@@ -727,10 +726,8 @@ void bdrv_close(BlockDriverState *bs)
             bdrv_close(bs->file);
         }
 
-        /* call the change callback */
         bs->media_changed = 1;
-        if (bs->change_cb)
-            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
+        bdrv_dev_change_cb(bs, CHANGE_MEDIA);
     }
 }
 
@@ -792,8 +789,8 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev)
 {
     assert(bs->dev == dev);
     bs->dev = NULL;
-    bs->change_cb = NULL;
-    bs->change_opaque = NULL;
+    bs->dev_ops = NULL;
+    bs->dev_opaque = NULL;
 }
 
 /* TODO change to return DeviceState * when all users are qdevified */
@@ -802,6 +799,20 @@ void *bdrv_get_attached_dev(BlockDriverState *bs)
     return bs->dev;
 }
 
+void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
+                      void *opaque)
+{
+    bs->dev_ops = ops;
+    bs->dev_opaque = opaque;
+}
+
+static void bdrv_dev_change_cb(BlockDriverState *bs, int reason)
+{
+    if (bs->dev_ops && bs->dev_ops->change_cb) {
+        bs->dev_ops->change_cb(bs->dev_opaque, reason);
+    }
+}
+
 /*
  * Run consistency checks on an image
  *
@@ -1272,9 +1283,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset)
     ret = drv->bdrv_truncate(bs, offset);
     if (ret == 0) {
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
-        if (bs->change_cb) {
-            bs->change_cb(bs->change_opaque, CHANGE_SIZE);
-        }
+        bdrv_dev_change_cb(bs, CHANGE_SIZE);
     }
     return ret;
 }
@@ -1612,15 +1621,6 @@ int bdrv_enable_write_cache(BlockDriverState *bs)
     return bs->enable_write_cache;
 }
 
-/* XXX: no longer used */
-void bdrv_set_change_cb(BlockDriverState *bs,
-                        void (*change_cb)(void *opaque, int reason),
-                        void *opaque)
-{
-    bs->change_cb = change_cb;
-    bs->change_opaque = opaque;
-}
-
 int bdrv_is_encrypted(BlockDriverState *bs)
 {
     if (bs->backing_hd && bs->backing_hd->encrypted)
@@ -1659,8 +1659,7 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
         bs->valid_key = 1;
         /* call the change callback now, we skipped it on open */
         bs->media_changed = 1;
-        if (bs->change_cb)
-            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
+        bdrv_dev_change_cb(bs, CHANGE_MEDIA);
     }
     return ret;
 }

block.h

@@ -28,6 +28,10 @@ typedef struct QEMUSnapshotInfo {
     uint64_t vm_clock_nsec; /* VM clock relative to boot */
 } QEMUSnapshotInfo;
 
+typedef struct BlockDevOps {
+    void (*change_cb)(void *opaque, int reason);
+} BlockDevOps;
+
 #define BDRV_O_RDWR        0x0002
 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
@@ -78,6 +82,8 @@ int bdrv_attach_dev(BlockDriverState *bs, void *dev);
 void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev);
 void bdrv_detach_dev(BlockDriverState *bs, void *dev);
 void *bdrv_get_attached_dev(BlockDriverState *bs);
+void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
+                      void *opaque);
 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
               uint8_t *buf, int nb_sectors);
 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
@@ -193,9 +199,6 @@ int bdrv_media_changed(BlockDriverState *bs);
 int bdrv_is_locked(BlockDriverState *bs);
 void bdrv_set_locked(BlockDriverState *bs, int locked);
 int bdrv_eject(BlockDriverState *bs, int eject_flag);
-void bdrv_set_change_cb(BlockDriverState *bs,
-                        void (*change_cb)(void *opaque, int reason),
-                        void *opaque);
 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size);
 BlockDriverState *bdrv_find(const char *name);
 BlockDriverState *bdrv_next(BlockDriverState *bs);

block_int.h

@@ -161,15 +161,14 @@ struct BlockDriverState {
     int encrypted; /* if true, the media is encrypted */
     int valid_key; /* if true, a valid encryption key has been set */
     int sg;        /* if true, the device is a /dev/sg* */
-    /* event callback when inserting/removing */
-    void (*change_cb)(void *opaque, int reason);
-    void *change_opaque;
 
     BlockDriver *drv; /* NULL means no media */
     void *opaque;
 
     void *dev;                  /* attached device model, if any */
     /* TODO change to DeviceState when all users are qdevified */
+    const BlockDevOps *dev_ops;
+    void *dev_opaque;
 
     char filename[1024];
     char backing_file[1024]; /* if non zero, the image is a diff of

hw/ide/core.c

@@ -1742,6 +1742,10 @@ void ide_bus_reset(IDEBus *bus)
     bus->dma->ops->reset(bus->dma);
 }
 
+static const BlockDevOps ide_cd_block_ops = {
+    .change_cb = cdrom_change_cb,
+};
+
 int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,
                    const char *version, const char *serial)
 {
@@ -1776,7 +1780,7 @@ int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,
     s->smart_errors = 0;
     s->smart_selftest_count = 0;
     if (kind == IDE_CD) {
-        bdrv_set_change_cb(bs, cdrom_change_cb, s);
+        bdrv_set_dev_ops(bs, &ide_cd_block_ops, s);
         bs->buffer_alignment = 2048;
     } else {
         if (!bdrv_is_inserted(s->bs)) {

hw/sd.c

@@ -435,6 +435,10 @@ static void sd_cardchange(void *opaque, int reason)
     }
 }
 
+static const BlockDevOps sd_block_ops = {
+    .change_cb = sd_cardchange,
+};
+
 /* We do not model the chip select pin, so allow the board to select
    whether card should be in SSI or MMC/SD mode.  It is also up to the
    board to ensure that ssi transfers only occur when the chip select
@@ -450,7 +454,7 @@ SDState *sd_init(BlockDriverState *bs, int is_spi)
     sd_reset(sd, bs);
     if (sd->bdrv) {
         bdrv_attach_dev_nofail(sd->bdrv, sd);
-        bdrv_set_change_cb(sd->bdrv, sd_cardchange, sd);
+        bdrv_set_dev_ops(sd->bdrv, &sd_block_ops, sd);
     }
     return sd;
 }

hw/virtio-blk.c

@@ -552,6 +552,10 @@ static void virtio_blk_change_cb(void *opaque, int reason)
     }
 }
 
+static const BlockDevOps virtio_block_ops = {
+    .change_cb = virtio_blk_change_cb,
+};
+
 VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf,
                               char **serial)
 {
@@ -598,7 +602,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf,
     register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                     virtio_blk_save, virtio_blk_load, s);
     bdrv_set_removable(s->bs, 0);
-    bdrv_set_change_cb(s->bs, virtio_blk_change_cb, s);
+    bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
     s->bs->buffer_alignment = conf->logical_block_size;
 
     add_boot_device_path(conf->bootindex, dev, "/disk@0,0");