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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-13 03:12:03 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-13 03:12:03 +0000
commit537a1d4bb02b7c5d21c8f3c853f7c7ae3782bc3f (patch)
tree93f68beb4ac7fc625c08cd06a690bf170c0fba0e
parent610626af30fc142e3d420cbce6ac8bdb70377b50 (diff)
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
-rw-r--r--block-raw-posix.c13
-rw-r--r--block-raw-win32.c4
2 files changed, 15 insertions, 2 deletions
diff --git a/block-raw-posix.c b/block-raw-posix.c
index 696128b80b..1a1a1781bc 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 8564a72762..d034b4a069 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;
}