From: Christoph Hellwig Date: Sat, 23 Jan 2021 00:48:25 +0000 (-0800) Subject: xfs: reduce ilock acquisitions in xfs_file_fsync X-Git-Tag: io_uring-worker.v3-2021-02-25~57^2~51 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=ae29e4220fd3047b5442e7e8db8027d7745093f5;p=linux-block.git xfs: reduce ilock acquisitions in xfs_file_fsync If the inode is not pinned by the time fsync is called we don't need the ilock to protect against concurrent clearing of ili_fsync_fields as the inode won't need a log flush or clearing of these fields. Not taking the iolock allows for full concurrency of fsync and thus O_DSYNC completions with io_uring/aio write submissions. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 9441c257d86c..48f6f89a38a9 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -200,7 +200,14 @@ xfs_file_fsync( else if (mp->m_logdev_targp != mp->m_ddev_targp) xfs_blkdev_issue_flush(mp->m_ddev_targp); - error = xfs_fsync_flush_log(ip, datasync, &log_flushed); + /* + * Any inode that has dirty modifications in the log is pinned. The + * racy check here for a pinned inode while not catch modifications + * that happen concurrently to the fsync call, but fsync semantics + * only require to sync previously completed I/O. + */ + if (xfs_ipincount(ip)) + error = xfs_fsync_flush_log(ip, datasync, &log_flushed); /* * If we only have a single device, and the log force about was