[PATCH v4 3/6] ext4: unconditionally enable the i_version counter

Jeff Layton
2022-09-07T11:33:51Z

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, remove the handling of
Opt_i_version as well since it's due for deprecation anyway.

Ideally, we'd couple this change with a way to disable the i_version
counter (just in case), but the way the iversion mount option was
implemented makes that difficult to do. We'd need to add a new mount
option altogether or do something with tune2fs. That's probably best
left to later patches if it turns out to be needed.

Cc: Dave Chinner <david@fromorbit.com>
Cc: Lukas Czerner <lczerner@redhat.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>
---
fs/ext4/inode.c | 2 +-
fs/ext4/ioctl.c | 12 ++++--------
fs/ext4/move_extent.c | 6 ++----
fs/ext4/super.c | 13 ++++---------
fs/ext4/xattr.c | 3 +--
5 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index aa37bce4c541..6ef37269e7c0 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5342,7 +5342,7 @@ int ext4_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
int error, rc = 0;
int orphan = 0;
const unsigned int ia_valid = attr->ia_valid;
- bool inc_ivers = IS_I_VERSION(inode);
+ bool inc_ivers = true;

if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 60e77ae9342d..ad3a294a88eb 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -452,8 +452,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
swap_inode_data(inode, inode_bl);

inode->i_ctime = inode_bl->i_ctime = current_time(inode);
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
+ inode_inc_iversion(inode);

inode->i_generation = prandom_u32();
inode_bl->i_generation = prandom_u32();
@@ -667,8 +666,7 @@ static int ext4_ioctl_setflags(struct inode *inode,
ext4_set_inode_flags(inode, false);

inode->i_ctime = current_time(inode);
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
+ inode_inc_iversion(inode);

err = ext4_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
@@ -779,8 +777,7 @@ static int ext4_ioctl_setproject(struct inode *inode, __u32 projid)

EXT4_I(inode)->i_projid = kprojid;
inode->i_ctime = current_time(inode);
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
+ inode_inc_iversion(inode);
out_dirty:
rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
if (!err)
@@ -1263,8 +1260,7 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
inode->i_ctime = current_time(inode);
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
+ inode_inc_iversion(inode);
inode->i_generation = generation;
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
}
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index d73ab3153218..285700b00d38 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -687,10 +687,8 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,

orig_inode->i_ctime = current_time(orig_inode);
donor_inode->i_ctime = current_time(donor_inode);
- if (IS_I_VERSION(orig_inode))
- inode_inc_iversion(orig_inode);
- if (IS_I_VERSION(donor_inode))
- inode_inc_iversion(donor_inode);
+ inode_inc_iversion(orig_inode);
+ inode_inc_iversion(donor_inode);
}
*moved_len = o_start - orig_blk;
if (*moved_len > len)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9a66abcca1a8..e7cf5361245a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1585,7 +1585,7 @@ enum {
Opt_inlinecrypt,
Opt_usrjquota, Opt_grpjquota, 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, Opt_debug_want_extra_isize,
@@ -1694,7 +1694,6 @@ static const struct fs_parameter_spec ext4_param_specs[] = {
fsparam_flag ("barrier", Opt_barrier),
fsparam_u32 ("barrier", Opt_barrier),
fsparam_flag ("nobarrier", Opt_nobarrier),
- fsparam_flag ("i_version", Opt_i_version),
fsparam_flag ("dax", Opt_dax),
fsparam_enum ("dax", Opt_dax_type, ext4_param_dax),
fsparam_u32 ("stripe", Opt_stripe),
@@ -2140,11 +2139,6 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
case Opt_abort:
ctx_set_mount_flag(ctx, EXT4_MF_FS_ABORTED);
return 0;
- case Opt_i_version:
- ext4_msg(NULL, KERN_WARNING, deprecated_msg, param->key, "5.20");
- ext4_msg(NULL, KERN_WARNING, "Use iversion instead\n");
- ctx_set_flags(ctx, SB_I_VERSION);
- return 0;
case Opt_inlinecrypt:
#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
ctx_set_flags(ctx, SB_INLINECRYPT);
@@ -2970,8 +2964,6 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
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 &
@@ -4640,6 +4632,9 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
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) ||
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index e975442e4ab2..36d6ba7190b6 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2412,8 +2412,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
if (!error) {
ext4_xattr_update_super_block(handle, inode->i_sb);
inode->i_ctime = current_time(inode);
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
+ inode_inc_iversion(inode);
if (!value)
no_expand = 0;
error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
--
2.37.3