diff options
| -rw-r--r-- | block/parallels.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/block/parallels.c b/block/parallels.c index 76e3a4e311..5ff74e8a0f 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -103,6 +103,35 @@ static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num, return MIN(nb_sectors, ret); } +static int64_t block_status(BDRVParallelsState *s, int64_t sector_num, + int nb_sectors, int *pnum) +{ + int64_t start_off = -2, prev_end_off = -2; + + *pnum = 0; + while (nb_sectors > 0 || start_off == -2) { + int64_t offset = seek_to_sector(s, sector_num); + int to_end; + + if (start_off == -2) { + start_off = offset; + prev_end_off = offset; + } else if (offset != prev_end_off) { + break; + } + + to_end = cluster_remainder(s, sector_num, nb_sectors); + nb_sectors -= to_end; + sector_num += to_end; + *pnum += to_end; + + if (offset > 0) { + prev_end_off += to_end; + } + } + return start_off; +} + static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num) { BDRVParallelsState *s = bs->opaque; @@ -148,11 +177,9 @@ static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs, int64_t offset; qemu_co_mutex_lock(&s->lock); - offset = seek_to_sector(s, sector_num); + offset = block_status(s, sector_num, nb_sectors, pnum); qemu_co_mutex_unlock(&s->lock); - *pnum = cluster_remainder(s, sector_num, nb_sectors); - if (offset < 0) { return 0; } @@ -218,10 +245,9 @@ static coroutine_fn int parallels_co_readv(BlockDriverState *bs, int n, nbytes; qemu_co_mutex_lock(&s->lock); - position = seek_to_sector(s, sector_num); + position = block_status(s, sector_num, nb_sectors, &n); qemu_co_mutex_unlock(&s->lock); - n = cluster_remainder(s, sector_num, nb_sectors); nbytes = n << BDRV_SECTOR_BITS; if (position < 0) { |