Fix regression introduced by r6824
commit537a1d4bb02b7c5d21c8f3c853f7c7ae3782bc3f
authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Fri, 13 Mar 2009 03:12:03 +0000 (13 03:12 +0000)
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>
Fri, 13 Mar 2009 03:12:03 +0000 (13 03:12 +0000)
tree93f68beb4ac7fc625c08cd06a690bf170c0fba0e
parent610626af30fc142e3d420cbce6ac8bdb70377b50
Fix regression introduced by r6824

The changes introduced by r6824 broke a subtle, and admittedly obscure, aspect
of the block API.  While bdrv_{pread,pwrite} return the number of bytes read
or written upon success, bdrv_{read,write} returns a zero upon success.

When using bdrv_pread for bdrv_read, special care must be taken to handle this
case.

This fixes certain guest images (notably linux-0.2 provided on the qemu
website).

Reported-by: malc <av1474@comtv.ru>
Reported-by: Herve Poussineau <hpoussin@reactos.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6828 c046a42c-6fe2-441c-8c8c-71466251a162
block-raw-posix.c
block-raw-win32.c