block: tell drivers about an image resize

Extend the change_cb callback with a reason argument, and use it
to tell drivers about size changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -645,7 +645,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
         /* call the change callback */
         bs->media_changed = 1;
         if (bs->change_cb)
-            bs->change_cb(bs->change_opaque);
+            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
     }
 
     return 0;
@@ -684,7 +684,7 @@ void bdrv_close(BlockDriverState *bs)
         /* call the change callback */
         bs->media_changed = 1;
         if (bs->change_cb)
-            bs->change_cb(bs->change_opaque);
+            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
     }
 }
 
@@ -1135,6 +1135,9 @@ 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);
+        }
     }
     return ret;
 }
@@ -1366,7 +1369,8 @@ int bdrv_enable_write_cache(BlockDriverState *bs)
 
 /* XXX: no longer used */
 void bdrv_set_change_cb(BlockDriverState *bs,
-                        void (*change_cb)(void *opaque), void *opaque)
+                        void (*change_cb)(void *opaque, int reason),
+                        void *opaque)
 {
     bs->change_cb = change_cb;
     bs->change_opaque = opaque;
@@ -1411,7 +1415,7 @@ int bdrv_set_key(BlockDriverState *bs, const char *key)
         /* call the change callback now, we skipped it on open */
         bs->media_changed = 1;
         if (bs->change_cb)
-            bs->change_cb(bs->change_opaque);
+            bs->change_cb(bs->change_opaque, CHANGE_MEDIA);
     }
     return ret;
 }

block.h

@@ -182,7 +182,8 @@ 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), void *opaque);
+                        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

@@ -153,7 +153,7 @@ struct BlockDriverState {
     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);
+    void (*change_cb)(void *opaque, int reason);
     void *change_opaque;
 
     BlockDriver *drv; /* NULL means no media */
@@ -203,6 +203,9 @@ struct BlockDriverState {
     void *private;
 };
 
+#define CHANGE_MEDIA	0x01
+#define CHANGE_SIZE	0x02
+
 struct BlockDriverAIOCB {
     AIOPool *pool;
     BlockDriverState *bs;

hw/ide/core.c

@@ -1584,11 +1584,15 @@ static void ide_cfata_metadata_write(IDEState *s)
 }
 
 /* called when the inserted state of the media has changed */
-static void cdrom_change_cb(void *opaque)
+static void cdrom_change_cb(void *opaque, int reason)
 {
     IDEState *s = opaque;
     uint64_t nb_sectors;
 
+    if (!(reason & CHANGE_MEDIA)) {
+        return;
+    }
+
     bdrv_get_geometry(s->bs, &nb_sectors);
     s->nb_sectors = nb_sectors;
 

hw/sd.c

@@ -422,9 +422,14 @@ static void sd_reset(SDState *sd, BlockDriverState *bdrv)
     sd->pwd_len = 0;
 }
 
-static void sd_cardchange(void *opaque)
+static void sd_cardchange(void *opaque, int reason)
 {
     SDState *sd = opaque;
+
+    if (!(reason & CHANGE_MEDIA)) {
+        return;
+    }
+
     qemu_set_irq(sd->inserted_cb, bdrv_is_inserted(sd->bdrv));
     if (bdrv_is_inserted(sd->bdrv)) {
         sd_reset(sd, sd->bdrv);