diff options
| -rw-r--r-- | src/server/image.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/server/image.c b/src/server/image.c index b349058..484a28f 100644 --- a/src/server/image.c +++ b/src/server/image.c @@ -126,11 +126,15 @@ void image_updateCachemap(dnbd3_image_t *image, uint64_t start, uint64_t end, co fb |= bit_mask; } // Last byte - for ( pos = lastByteInMap << 15; pos < end; pos += DNBD3_BLOCK_SIZE ) { - const int map_x = (pos >> 12) & 7; // mod 8 - const uint8_t bit_mask = (uint8_t)( 1 << map_x ); - lb |= bit_mask; + if ( lastByteInMap != firstByteInMap ) { + for ( pos = lastByteInMap << 15; pos < end; pos += DNBD3_BLOCK_SIZE ) { + assert( lastByteInMap == (pos >> 15) ); + const int map_x = (pos >> 12) & 7; // mod 8 + const uint8_t bit_mask = (uint8_t)( 1 << map_x ); + lb |= bit_mask; + } } + atomic_thread_fence( memory_order_acquire ); if ( set ) { uint8_t fo = atomic_fetch_or_explicit( &cache->map[firstByteInMap], fb, memory_order_relaxed ); uint8_t lo = atomic_fetch_or_explicit( &cache->map[lastByteInMap], lb, memory_order_relaxed ); |