diff options
| -rw-r--r-- | block/cow.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/block/cow.c b/block/cow.c index fde066ec32..1a48ac0cba 100644 --- a/block/cow.c +++ b/block/cow.c @@ -78,7 +78,7 @@ static int cow_open(BlockDriverState *bs, const char *filename, int flags) } s->fd = fd; /* see if it is a cow image */ - if (read(fd, &cow_header, sizeof(cow_header)) != sizeof(cow_header)) { + if (pread(fd, &cow_header, sizeof(cow_header), 0) != sizeof(cow_header)) { goto fail; } @@ -159,8 +159,8 @@ static int cow_read(BlockDriverState *bs, int64_t sector_num, while (nb_sectors > 0) { if (is_changed(s->cow_bitmap, sector_num, nb_sectors, &n)) { - lseek(s->fd, s->cow_sectors_offset + sector_num * 512, SEEK_SET); - ret = read(s->fd, buf, n * 512); + ret = pread(s->fd, buf, n * 512, + s->cow_sectors_offset + sector_num * 512); if (ret != n * 512) return -1; } else { @@ -186,8 +186,8 @@ static int cow_write(BlockDriverState *bs, int64_t sector_num, BDRVCowState *s = bs->opaque; int ret, i; - lseek(s->fd, s->cow_sectors_offset + sector_num * 512, SEEK_SET); - ret = write(s->fd, buf, nb_sectors * 512); + ret = pwrite(s->fd, buf, nb_sectors * 512, + s->cow_sectors_offset + sector_num * 512); if (ret != nb_sectors * 512) return -1; for (i = 0; i < nb_sectors; i++) |