[Qemu-devel][Patch] Fix QEMU failure for disk image on readonly filesystem

[Qemu-devel][Patch] Fix QEMU failure for disk image on readonly filesystem

[Stefan Weil]

Hello,

qemu fails when the disk image file is writable but on
a readonly filesystem (so it is not really writable).

The patch below fixes this. It also declares a local
function "static" (maybe this part of the patch is a
matter of taste).

Regards,
Stefan


--- block.c     19 Aug 2006 11:45:59 -0000      1.34
+++ block.c     21 Aug 2006 16:46:21 -0000
@@ -110,7 +110,7 @@
 }


-void bdrv_register(BlockDriver *bdrv)
+static void bdrv_register(BlockDriver *bdrv)
 {
     if (!bdrv->bdrv_aio_read) {
         /* add AIO emulation layer */
@@ -359,7 +359,7 @@
     else
         open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
     ret = drv->bdrv_open(bs, filename, open_flags);
-    if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
+    if ((ret == -EACCES || ret == -EROFS) && !(flags & BDRV_O_FILE)) {
         ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
         bs->read_only = 1;
     }

Re: [Qemu-devel][Patch] Fix QEMU failure for disk image on readonly filesystem

[Fabrice Bellard]

Stefan Weil wrote:
> Hello,
> 
> qemu fails when the disk image file is writable but on
> a readonly filesystem (so it is not really writable).
> 
> The patch below fixes this. It also declares a local
> function "static" (maybe this part of the patch is a
> matter of taste).

Are you sure it is needed ? I made a different fix a few days ago.

Regards,

Fabrice.

Re: [Qemu-devel][Patch] Fix QEMU failure for disk image on readonly filesystem

[Stefan Weil]

> Are you sure it is needed ? I made a different fix a few days ago.
>
> Regards,
>
> Fabrice.
>
>
I wrote my fix before your fix was available.

At least for raw disk images, your fix also works,
so at the moment, there is no need for my patch
(this should be checked with other kinds of disk
images).

Regards,
Stefan