Revert "Btrfs: do not do filemap_write_and_wait_range in fsync" (90abccf2) · Commits · 戴 / test

This reverts commit After applying the above patch, the performance slowed down because the dirty page flush can only be done by one task, so revert it. The following is the test result of sysbench: Before After 24MB/s 39MB/s Signed-off-by:

Miao Xie <miaox@cn.fujitsu.com>

fs/btrfs/file.c

+11 −3

Original line number	Diff line number	Diff line
		@@ -1544,12 +1544,20 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)

		trace_btrfs_sync_file(file, datasync);

		/*
		* We write the dirty pages in the range and wait until they complete
		* out of the ->i_mutex. If so, we can flush the dirty pages by
		* multi-task, and make the performance up.
		*/
		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
		if (ret)
		return ret;

		mutex_lock(&inode->i_mutex);

		/*
		* we wait first, since the writeback may change the inode, also wait
		* ordered range does a filemape_write_and_wait_range which is why we
		* don't do it above like other file systems.
		* We flush the dirty pages again to avoid some dirty pages in the
		* range being left.
		*/
		atomic_inc(&root->log_batch);
		btrfs_wait_ordered_range(inode, start, end);

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