From 1ff20307393e17dc57fde62226df625a3a3c36e9 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@kernel.org>
Date: Wed, 24 Aug 2022 18:03:49 +0200
Subject: [PATCH] ext4: unconditionally enable the i_version counter
Git-commit: 1ff20307393e17dc57fde62226df625a3a3c36e9
Patch-mainline: v6.1-rc1
References: bsc#1211299

The original i_version implementation was pretty expensive, requiring a
log flush on every change. Because of this, it was gated behind a mount
option (implemented via the MS_I_VERSION mountoption flag).

Commit ae5e165d855d (fs: new API for handling inode->i_version) made the
i_version flag much less expensive, so there is no longer a performance
penalty from enabling it. xfs and btrfs already enable it
unconditionally when the on-disk format can support it.

Have ext4 ignore the SB_I_VERSION flag, and just enable it
unconditionally.  While we're in here, mark the i_version mount
option Opt_removed.

[ Removed leftover bits of i_version from ext4_apply_options() since it
  now can't ever be set in ctx->mask_s_flags -- lczerner ]

Cc: stable@kernel.org
Cc: Dave Chinner <david@fromorbit.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220824160349.39664-3-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/ext4/inode.c |    5 ++---
 fs/ext4/super.c |   14 ++++++--------
 2 files changed, 8 insertions(+), 11 deletions(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5421,7 +5421,7 @@ int ext4_setattr(struct user_namespace *
 			return -EINVAL;
 		}
 
-		if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size)
+		if (attr->ia_size != inode->i_size)
 			inode_inc_iversion(inode);
 
 		if (shrink) {
@@ -5731,8 +5731,7 @@ int ext4_mark_iloc_dirty(handle_t *handl
 	 * ea_inodes are using i_version for storing reference count, don't
 	 * mess with it
 	 */
-	if (IS_I_VERSION(inode) &&
-	    !(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
+	if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
 		inode_inc_iversion(inode);
 
 	/* the do_update_inode consumes one bh->b_count */
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1673,7 +1673,7 @@ enum {
 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
-	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version,
+	Opt_usrquota, Opt_grpquota, Opt_prjquota,
 	Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never,
 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
 	Opt_nowarn_on_error, Opt_mblk_io_submit,
@@ -1743,7 +1743,7 @@ static const match_table_t tokens = {
 	{Opt_barrier, "barrier=%u"},
 	{Opt_barrier, "barrier"},
 	{Opt_nobarrier, "nobarrier"},
-	{Opt_i_version, "i_version"},
+	{Opt_removed, "i_version"},
 	{Opt_dax, "dax"},
 	{Opt_dax_always, "dax=always"},
 	{Opt_dax_inode, "dax=inode"},
@@ -2130,9 +2130,6 @@ static int handle_mount_opt(struct super
 	case Opt_abort:
 		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
 		return 1;
-	case Opt_i_version:
-		sb->s_flags |= SB_I_VERSION;
-		return 1;
 	case Opt_lazytime:
 		sb->s_flags |= SB_LAZYTIME;
 		return 1;
@@ -2593,8 +2590,6 @@ static int _ext4_show_options(struct seq
 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
-	if (sb->s_flags & SB_I_VERSION)
-		SEQ_OPTS_PUTS("i_version");
 	if (nodefs || sbi->s_stripe)
 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
@@ -4381,6 +4376,9 @@ static int ext4_fill_super(struct super_
 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
 
+	/* i_version is always enabled now */
+	sb->s_flags |= SB_I_VERSION;
+
 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
 	    (ext4_has_compat_features(sb) ||
 	     ext4_has_ro_compat_features(sb) ||
@@ -5931,7 +5929,7 @@ static int ext4_remount(struct super_blo
 	 * either way we need to make sure it matches in both *flags and
 	 * s_flags. Copy those selected flags from *flags to s_flags
 	 */
-	vfs_flags = SB_LAZYTIME | SB_I_VERSION;
+	vfs_flags = SB_LAZYTIME;
 	sb->s_flags = (sb->s_flags & ~vfs_flags) | (*flags & vfs_flags);
 
 	if (!parse_options(data, sb, &parsed_opts, 1)) {