On Mon, Jan 11, 2021 at 05:15:44PM +0100, Christoph Hellwig wrote: > 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@xxxxxx> > --- So this changes fsync semantics for when a concurrent modification might already be in progress (but not yet complete) to essentially skip the log force rather than serialize/wait and force. This seems.. reasonable I suppose since nothign has committed at that point, but I feel like could use more documentation and justification around that and why this might be acceptable behavior. Brian > fs/xfs/xfs_file.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 414d856e2e755a..ba02780dee6439 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -200,7 +200,8 @@ 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); > + 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 >
