[PATCH v2] xfs: don't bump the i_version on an atime update in xfs_vn_update_time

Jeff Layton
2022-08-22T13:40:41Z

xfs will update the i_version when updating only the atime value, which
is not desirable for any of the current consumers of i_version. Doing so
leads to unnecessary cache invalidations on NFS and extra measurement
activity in IMA.

Add a new XFS_ILOG_NOIVER flag, and use that to indicate that the
transaction should not update the i_version. Set that value in
xfs_vn_update_time if we're only updating the atime.

Cc: Dave Chinner <david@fromorbit.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Trond Myklebust <trondmy@hammerspace.com>
Cc: David Wysochanski <dwysocha@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/xfs/libxfs/xfs_log_format.h | 2 +-
fs/xfs/libxfs/xfs_trans_inode.c | 2 +-
fs/xfs/xfs_iops.c | 11 +++++++++--
3 files changed, 11 insertions(+), 4 deletions(-)

v2: don't set the NOIVERS flag if S_VERSION is set

diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
index b351b9dc6561..866a4c5cf70c 100644
--- a/fs/xfs/libxfs/xfs_log_format.h
+++ b/fs/xfs/libxfs/xfs_log_format.h
@@ -323,7 +323,7 @@ struct xfs_inode_log_format_32 {
#define XFS_ILOG_ABROOT 0x100 /* log i_af.i_broot */
#define XFS_ILOG_DOWNER 0x200 /* change the data fork owner on replay */
#define XFS_ILOG_AOWNER 0x400 /* change the attr fork owner on replay */
-
+#define XFS_ILOG_NOIVER 0x800 /* don't bump i_version */

/*
* The timestamps are dirty, but not necessarily anything else in the inode
diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c
index 8b5547073379..ffe6d296e7f9 100644
--- a/fs/xfs/libxfs/xfs_trans_inode.c
+++ b/fs/xfs/libxfs/xfs_trans_inode.c
@@ -126,7 +126,7 @@ xfs_trans_log_inode(
* unconditionally.
*/
if (!test_and_set_bit(XFS_LI_DIRTY, &iip->ili_item.li_flags)) {
- if (IS_I_VERSION(inode) &&
+ if (!(flags & XFS_ILOG_NOIVER) && IS_I_VERSION(inode) &&
inode_maybe_inc_iversion(inode, flags & XFS_ILOG_CORE))
iversion_flags = XFS_ILOG_CORE;
}
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 45518b8c613c..94f14d96641b 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1041,10 +1041,17 @@ xfs_vn_update_time(
return error;

xfs_ilock(ip, XFS_ILOCK_EXCL);
- if (flags & S_CTIME)
+
+ if (!(flags & S_VERSION))
+ log_flags |= XFS_ILOG_NOIVER;
+ if (flags & S_CTIME) {
inode->i_ctime = *now;
- if (flags & S_MTIME)
+ log_flags &= ~XFS_ILOG_NOIVER;
+ }
+ if (flags & S_MTIME) {
inode->i_mtime = *now;
+ log_flags &= ~XFS_ILOG_NOIVER;
+ }
if (flags & S_ATIME)
inode->i_atime = *now;

--
2.37.2