[PATCH 1/2] xfs: stop advertising SB_I_VERSION

[Dave Chinner <david@fromorbit.com>]

From: Dave Chinner <dchinner@redhat.com>

The redefinition of how NFS wants inode->i_version to be updated is
incomaptible with the XFS i_version mechanism. The VFS now wants
inode->i_version to only change when ctime changes (i.e. it has
become a ctime change counter, not an inode change counter). XFS has
fine grained timestamps, so it can just use ctime for the NFS change
cookie like it still does for V4 XFS filesystems.

We still want XFS to update the inode change counter as it currently
does, so convert all the code that checks SB_I_VERSION to check for
v5 format support. Then we can remove the SB_I_VERSION flag from the
VFS superblock to indicate that inode->i_version is not a valid
change counter and should not be used as such.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
---
 fs/xfs/libxfs/xfs_trans_inode.c | 15 +++++----------
 fs/xfs/xfs_iops.c               | 16 +++-------------
 fs/xfs/xfs_super.c              |  8 --------
 3 files changed, 8 insertions(+), 31 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c
index 69fc5b981352..b82f9c7ff2d5 100644
--- a/fs/xfs/libxfs/xfs_trans_inode.c
+++ b/fs/xfs/libxfs/xfs_trans_inode.c
@@ -97,17 +97,12 @@ xfs_trans_log_inode(
 
 	/*
 	 * First time we log the inode in a transaction, bump the inode change
-	 * counter if it is configured for this to occur. While we have the
-	 * inode locked exclusively for metadata modification, we can usually
-	 * avoid setting XFS_ILOG_CORE if no one has queried the value since
-	 * the last time it was incremented. If we have XFS_ILOG_CORE already
-	 * set however, then go ahead and bump the i_version counter
-	 * unconditionally.
+	 * counter if it is configured for this to occur.
 	 */
-	if (!test_and_set_bit(XFS_LI_DIRTY, &iip->ili_item.li_flags)) {
-		if (IS_I_VERSION(inode) &&
-		    inode_maybe_inc_iversion(inode, flags & XFS_ILOG_CORE))
-			flags |= XFS_ILOG_IVERSION;
+	if (!test_and_set_bit(XFS_LI_DIRTY, &iip->ili_item.li_flags) &&
+	    xfs_has_crc(ip->i_mount)) {
+		atomic64_inc(&inode->i_version);
+		flags |= XFS_ILOG_IVERSION;
 	}
 
 	iip->ili_dirty_flags |= flags;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 66f8c47642e8..3940ad1ee66e 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -584,11 +584,6 @@ xfs_vn_getattr(
 		}
 	}
 
-	if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) {
-		stat->change_cookie = inode_query_iversion(inode);
-		stat->result_mask |= STATX_CHANGE_COOKIE;
-	}
-
 	/*
 	 * Note: If you add another clause to set an attribute flag, please
 	 * update attributes_mask below.
@@ -1043,16 +1038,11 @@ xfs_vn_update_time(
 	struct timespec64	now;
 
 	trace_xfs_update_time(ip);
+	ASSERT(!(flags & S_VERSION));
 
 	if (inode->i_sb->s_flags & SB_LAZYTIME) {
-		if (!((flags & S_VERSION) &&
-		      inode_maybe_inc_iversion(inode, false))) {
-			generic_update_time(inode, flags);
-			return 0;
-		}
-
-		/* Capture the iversion update that just occurred */
-		log_flags |= XFS_ILOG_CORE;
+		generic_update_time(inode, flags);
+		return 0;
 	}
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index c21f10ab0f5d..bfc5f3a27451 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1690,10 +1690,6 @@ xfs_fs_fill_super(
 
 	set_posix_acl_flag(sb);
 
-	/* version 5 superblocks support inode version counters. */
-	if (xfs_has_crc(mp))
-		sb->s_flags |= SB_I_VERSION;
-
 	if (xfs_has_dax_always(mp)) {
 		error = xfs_setup_dax_always(mp);
 		if (error)
@@ -1915,10 +1911,6 @@ xfs_fs_reconfigure(
 	int			flags = fc->sb_flags;
 	int			error;
 
-	/* version 5 superblocks always support version counters. */
-	if (xfs_has_crc(mp))
-		fc->sb_flags |= SB_I_VERSION;
-
 	error = xfs_fs_validate_params(new_mp);
 	if (error)
 		return error;
-- 
2.43.0