Patchwork [2/3] block: tell drivers about an image resize

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Submitter Christoph Hellwig
Date Jan. 19, 2011, 5:02 p.m.
Message ID <20110119170256.GB9819@lst.de>
Download mbox | patch
Permalink /patch/79498/
State New
Headers show

Comments

Christoph Hellwig - Jan. 19, 2011, 5:02 p.m.
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>
Stefan Hajnoczi - Jan. 20, 2011, 9:14 a.m.
On Wed, Jan 19, 2011 at 5:02 PM, Christoph Hellwig <hch@lst.de> wrote:
> 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>
>
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c   2011-01-18 20:54:45.246021572 +0100
> +++ qemu/block.c        2011-01-18 20:56:54.117255612 +0100
> @@ -645,7 +645,7 @@ int bdrv_open(BlockDriverState *bs, cons
>         /* 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);

Cool, this is much nicer than stashing away state like
bs->media_changed = 1.  I just took a peek to see if we can remove
that field completely but IDE seems to use it internally.

Stefan
Christoph Hellwig - Jan. 20, 2011, 9:44 a.m.
On Thu, Jan 20, 2011 at 09:14:17AM +0000, Stefan Hajnoczi wrote:
> Cool, this is much nicer than stashing away state like
> bs->media_changed = 1.  I just took a peek to see if we can remove
> that field completely but IDE seems to use it internally.

I think we could get rid of it in generic code, but let's keep this
series simple.
Kevin Wolf - Jan. 21, 2011, 10:41 a.m.
Am 19.01.2011 18:02, schrieb Christoph Hellwig:
> 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>
> 
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c	2011-01-18 20:54:45.246021572 +0100
> +++ qemu/block.c	2011-01-18 20:56:54.117255612 +0100
> @@ -645,7 +645,7 @@ int bdrv_open(BlockDriverState *bs, cons
>          /* 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 +1135,8 @@ int bdrv_truncate(BlockDriverState *bs,
>      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);

Braces are missing here.

Apart from that and Stefan's s/id/device/ the series looks good to me.

Kevin

Patch

Index: qemu/block.c
===================================================================
--- qemu.orig/block.c	2011-01-18 20:54:45.246021572 +0100
+++ qemu/block.c	2011-01-18 20:56:54.117255612 +0100
@@ -645,7 +645,7 @@  int bdrv_open(BlockDriverState *bs, cons
         /* 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 +1135,8 @@  int bdrv_truncate(BlockDriverState *bs,
     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 +1368,8 @@  int bdrv_enable_write_cache(BlockDriverS
 
 /* 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 +1414,7 @@  int bdrv_set_key(BlockDriverState *bs, c
         /* 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;
 }
Index: qemu/block.h
===================================================================
--- qemu.orig/block.h	2011-01-18 20:57:00.792253448 +0100
+++ qemu/block.h	2011-01-18 20:57:09.771282850 +0100
@@ -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);
Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h	2011-01-18 20:55:43.783009908 +0100
+++ qemu/block_int.h	2011-01-18 20:56:58.912004806 +0100
@@ -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;
Index: qemu/hw/ide/core.c
===================================================================
--- qemu.orig/hw/ide/core.c	2011-01-18 20:57:17.321260780 +0100
+++ qemu/hw/ide/core.c	2011-01-18 20:59:46.242256451 +0100
@@ -1625,11 +1625,15 @@  static void ide_cfata_metadata_write(IDE
 }
 
 /* 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;
 
Index: qemu/hw/sd.c
===================================================================
--- qemu.orig/hw/sd.c	2011-01-18 20:57:48.978261549 +0100
+++ qemu/hw/sd.c	2011-01-18 20:59:37.000000000 +0100
@@ -422,9 +422,14 @@  static void sd_reset(SDState *sd, BlockD
     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);