[PATCH 2/2] xfs: reduce ilock acquisitions in xfs_file_fsync
From: Christoph Hellwig <hch@lst.de>
Date: 2021-01-22 17:50:19
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
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 <hch@lst.de> --- fs/xfs/xfs_file.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 588232c77f11e0..ffe2d7c37e26cd 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
--
2.29.2