From: Jeff Layton Subject: [PATCH v4 16/19] fs: only set S_VERSION when updating times if necessary Date: Fri, 22 Dec 2017 07:05:53 -0500 Message-ID: <20171222120556.7435-17-jlayton@kernel.org> References: <20171222120556.7435-1-jlayton@kernel.org> Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-nfs@vger.kernel.org, bfields@fieldses.org, neilb@suse.de, jack@suse.de, linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, linux-xfs@vger.kernel.org, darrick.wong@oracle.com, david@fromorbit.com, linux-btrfs@vger.kernel.org, clm@fb.com, jbacik@fb.com, dsterba@suse.com, linux-integrity@vger.kernel.org, zohar@linux.vnet.ibm.com, dmitry.kasatkin@gmail.com, linux-afs@lists.infradead.org, dhowells@redhat.com, jaltman@auristor.com To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <20171222120556.7435-1-jlayton@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Jeff Layton We only really need to update i_version if someone has queried for it since we last incremented it. By doing that, we can avoid having to update the inode if the times haven't changed. If the times have changed, then we go ahead and forcibly increment the counter, under the assumption that we'll be going to the storage anyway, and the increment itself is relatively cheap. Signed-off-by: Jeff Layton --- fs/inode.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 19e72f500f71..2fa920188759 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1635,17 +1635,21 @@ static int relatime_need_update(const struct path *path, struct inode *inode, int generic_update_time(struct inode *inode, struct timespec *time, int flags) { int iflags = I_DIRTY_TIME; + bool dirty = false; if (flags & S_ATIME) inode->i_atime = *time; if (flags & S_VERSION) - inode_inc_iversion(inode); + dirty |= inode_maybe_inc_iversion(inode, dirty); if (flags & S_CTIME) inode->i_ctime = *time; if (flags & S_MTIME) inode->i_mtime = *time; + if ((flags & (S_ATIME | S_CTIME | S_MTIME)) && + !(inode->i_sb->s_flags & SB_LAZYTIME)) + dirty = true; - if (!(inode->i_sb->s_flags & SB_LAZYTIME) || (flags & S_VERSION)) + if (dirty) iflags |= I_DIRTY_SYNC; __mark_inode_dirty(inode, iflags); return 0; @@ -1864,7 +1868,7 @@ int file_update_time(struct file *file) if (!timespec_equal(&inode->i_ctime, &now)) sync_it |= S_CTIME; - if (IS_I_VERSION(inode)) + if (IS_I_VERSION(inode) && inode_iversion_need_inc(inode)) sync_it |= S_VERSION; if (!sync_it) -- 2.14.3