From 18be4fc257bf2f6932b85ec901eab43fa22af1be Mon Sep 17 00:00:00 2001 From: aliguori Date: Fri, 13 Mar 2009 03:12:03 +0000 Subject: [PATCH] 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 Reported-by: Herve Poussineau Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6828 c046a42c-6fe2-441c-8c8c-71466251a162 --- block-raw-posix.c | 13 +++++++++++-- block-raw-win32.c | 4 ++++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/block-raw-posix.c b/block-raw-posix.c index 696128b..1a1a178 100644 --- a/block-raw-posix.c +++ b/block-raw-posix.c @@ -361,7 +361,12 @@ static int raw_pread(BlockDriverState *bs, int64_t offset, static int raw_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { - return raw_pread(bs, sector_num * 512, buf, (uint64_t)nb_sectors * 512); + int ret; + + ret = raw_pread(bs, sector_num * 512, buf, nb_sectors * 512); + if (ret == (nb_sectors * 512)) + ret = 0; + return ret; } /* @@ -445,7 +450,11 @@ static int raw_pwrite(BlockDriverState *bs, int64_t offset, static int raw_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { - return raw_pwrite(bs, sector_num * 512, buf, (uint64_t)nb_sectors * 512); + int ret; + ret = raw_pwrite(bs, sector_num * 512, buf, nb_sectors * 512); + if (ret == (nb_sectors * 512)) + ret = 0; + return ret; } #ifdef CONFIG_AIO diff --git a/block-raw-win32.c b/block-raw-win32.c index 8564a72..d034b4a 100644 --- a/block-raw-win32.c +++ b/block-raw-win32.c @@ -145,6 +145,8 @@ static int raw_read(BlockDriverState *bs, int64_t sector_num, #endif return ret_count; } + if (ret_count == count) + ret_count = 0; return ret_count; } @@ -171,6 +173,8 @@ static int raw_write(BlockDriverState *bs, int64_t sector_num, #endif return ret_count; } + if (ret_count == count) + ret_count = 0; return ret_count; } -- 2.7.4