fix: Apply further code review suggestions

Changes:
- update Linux client default value of write cache size parameter
(actually not changing anything write buffer size) to show the actual
behavior of the client.
- rename beingWritten member of ChunkData to writesCount to better
represent the idea of this member.
- remove an outdated comment from ChunkJobWriter::processDataChain.

src/mount/sauna_client.h

@@ -81,11 +81,10 @@ struct FsInitParams {
 	static constexpr float    kDefaultBandwidthOveruse = 1.0;
 	static constexpr unsigned kDefaultChunkserverWriteTo = 5000;
 	static constexpr bool     kDefaultIgnoreFlush = false;
+	static constexpr unsigned kDefaultWriteCacheSize = 128;
 #ifdef _WIN32
-	static constexpr unsigned kDefaultWriteCacheSize = 50;
 	static constexpr unsigned kDefaultWriteWaveTo = 10;
 #else
-	static constexpr unsigned kDefaultWriteCacheSize = 0;
 	static constexpr unsigned kDefaultWriteWaveTo = 50;
 #endif
 	static constexpr unsigned kDefaultCachePerInodePercentage = 25;

src/mount/writedata.cc

@@ -132,7 +132,7 @@ struct ChunkData {
 	bool inQueue = false;  // true if this chunk is waiting in one of the queues or is being processed
 	bool workerWaitingForData = false;
 	std::unique_ptr<WriteChunkLocator> locator;
-	std::atomic<int> beingWritten = 0;
+	std::atomic<int> writesCount = 0;
 
 	ChunkData(uint32_t chunkIndex, inodedata *parent)
 	    : chunkIndex(chunkIndex), parent_(parent) {
@@ -467,7 +467,7 @@ void write_job_delayed_end(ChunkData* chunkData, int status, int seconds, Lock &
 		// Don't sleep if we have to write all the data immediately
 		seconds = 0;
 	}
-	if (chunkData->beingWritten) {
+	if (chunkData->writesCount) {
 		inodeLock.unlock();
 
 		gLock.lock();
@@ -719,7 +719,6 @@ void ChunkJobWriter::processDataChain(ChunkWriter& writer) {
 					SAUNAFS_ERROR_TIMEOUT);
 		}
 
-		// Let's sleep a bit shorter if we can't be woken up by the pipe to reduce the latency
 		writer.processOperations(gWaveTimeout);
 	}
 }
@@ -935,10 +934,10 @@ int write_blocks(inodedata *id, uint64_t offset, uint32_t size,
 		ChunkData *chunkData = write_get_chunkdata(chindx, id, inodeLock);
 		inodeLock.unlock();
 
-		chunkData->beingWritten++;
+		chunkData->writesCount++;
 		if (size > SFSBLOCKSIZE - from) {
 			if (write_block(chunkData, pos, from, SFSBLOCKSIZE, data, inodeLock) < 0) {
-				chunkData->beingWritten--;
+				chunkData->writesCount--;
 				return SAUNAFS_ERROR_IO;
 			}
 			size -= (SFSBLOCKSIZE - from);
@@ -951,12 +950,12 @@ int write_blocks(inodedata *id, uint64_t offset, uint32_t size,
 			}
 		} else {
 			if (write_block(chunkData, pos, from, from + size, data, inodeLock) < 0) {
-				chunkData->beingWritten--;
+				chunkData->writesCount--;
 				return SAUNAFS_ERROR_IO;
 			}
 			size = 0;
 		}
-		chunkData->beingWritten--;
+		chunkData->writesCount--;
 	}
 	return 0;
 }