From patchwork Fri Jun 18 15:03:25 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [2/6] cow: Use bdrv_(p)write_sync for metadata writes From: Kevin Wolf X-Patchwork-Id: 56196 Message-Id: <1276873409-8235-3-git-send-email-kwolf@redhat.com> To: qemu-devel@nongnu.org Cc: kwolf@redhat.com Date: Fri, 18 Jun 2010 17:03:25 +0200 Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash. While at it, correct the wrong usage of errno. Signed-off-by: Kevin Wolf --- block/cow.c | 20 +++++++++++--------- 1 files changed, 11 insertions(+), 9 deletions(-) diff --git a/block/cow.c b/block/cow.c index d146434..eedcc48 100644 --- a/block/cow.c +++ b/block/cow.c @@ -97,17 +97,18 @@ static inline int cow_set_bit(BlockDriverState *bs, int64_t bitnum) { uint64_t offset = sizeof(struct cow_header_v2) + bitnum / 8; uint8_t bitmap; + int ret; - if (bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } bitmap |= (1 << (bitnum % 8)); - if (bdrv_pwrite(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pwrite_sync(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } return 0; } @@ -116,10 +117,11 @@ static inline int is_bit_set(BlockDriverState *bs, int64_t bitnum) { uint64_t offset = sizeof(struct cow_header_v2) + bitnum / 8; uint8_t bitmap; + int ret; - if (bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } return !!(bitmap & (1 << (bitnum % 8)));