[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Jeff Layton]

I've been working on a patchset to change how the inode->i_ctime is
accessed in order to give us conditional, high-res timestamps for the
ctime and mtime. struct timespec64 has unused bits in it that we can use
to implement this. In order to do that however, we need to wrap all
accesses of inode->i_ctime to ensure that bits used as flags are
appropriately handled.

This patchset first adds some new inode_ctime_* accessor functions. It
then converts all in-tree accesses of inode->i_ctime to use those new
functions and then renames the i_ctime field to __i_ctime to help ensure
that use of the accessors.

Most of this conversion was done via coccinelle, with a few of the more
non-standard accesses done by hand. There should be no behavioral
changes with this set. That will come later, as we convert individual
filesystems to use multigrain timestamps.

Some of these patches depend on the set I sent recently to add missing
ctime updates in various subsystems:

    https://lore.kernel.org/linux-fsdevel/20230612104524.17058-1-jlayton at kernel.org/T/#m25399f903cc9526e46b2e0f5a35713c80b52fde9

Since this patchset is so large, I'm only going to send individual
conversion patches to the appropriate maintainers. Please send
Acked-by's or Reviewed-by's if you can. The intent is to merge these as
a set (probably in v6.6). Let me know if that causes conflicts though,
and we can work it out.

This is based on top of linux-next as of yesterday.

Jeff Layton (79):
  fs: add ctime accessors infrastructure
  spufs: switch to new ctime accessors
  s390: switch to new ctime accessors
  binderfs: switch to new ctime accessors
  qib_fs: switch to new ctime accessors
  ibm: switch to new ctime accessors
  usb: switch to new ctime accessors
  9p: switch to new ctime accessors
  adfs: switch to new ctime accessors
  affs: switch to new ctime accessors
  afs: switch to new ctime accessors
  fs: switch to new ctime accessors
  autofs: switch to new ctime accessors
  befs: switch to new ctime accessors
  bfs: switch to new ctime accessors
  btrfs: switch to new ctime accessors
  ceph: switch to new ctime accessors
  coda: switch to new ctime accessors
  configfs: switch to new ctime accessors
  cramfs: switch to new ctime accessors
  debugfs: switch to new ctime accessors
  devpts: switch to new ctime accessors
  ecryptfs: switch to new ctime accessors
  efivarfs: switch to new ctime accessors
  efs: switch to new ctime accessors
  erofs: switch to new ctime accessors
  exfat: switch to new ctime accessors
  ext2: switch to new ctime accessors
  ext4: switch to new ctime accessors
  f2fs: switch to new ctime accessors
  fat: switch to new ctime accessors
  freevxfs: switch to new ctime accessors
  fuse: switch to new ctime accessors
  gfs2: switch to new ctime accessors
  hfs: switch to new ctime accessors
  hfsplus: switch to new ctime accessors
  hostfs: switch to new ctime accessors
  hpfs: switch to new ctime accessors
  hugetlbfs: switch to new ctime accessors
  isofs: switch to new ctime accessors
  jffs2: switch to new ctime accessors
  jfs: switch to new ctime accessors
  kernfs: switch to new ctime accessors
  minix: switch to new ctime accessors
  nfs: switch to new ctime accessors
  nfsd: switch to new ctime accessors
  nilfs2: switch to new ctime accessors
  ntfs: switch to new ctime accessors
  ntfs3: switch to new ctime accessors
  ocfs2: switch to new ctime accessors
  omfs: switch to new ctime accessors
  openpromfs: switch to new ctime accessors
  orangefs: switch to new ctime accessors
  overlayfs: switch to new ctime accessors
  proc: switch to new ctime accessors
  pstore: switch to new ctime accessors
  qnx4: switch to new ctime accessors
  qnx6: switch to new ctime accessors
  ramfs: switch to new ctime accessors
  reiserfs: switch to new ctime accessors
  romfs: switch to new ctime accessors
  smb: switch to new ctime accessors
  squashfs: switch to new ctime accessors
  sysv: switch to new ctime accessors
  tracefs: switch to new ctime accessors
  ubifs: switch to new ctime accessors
  udf: switch to new ctime accessors
  ufs: switch to new ctime accessors
  vboxsf: switch to new ctime accessors
  xfs: switch to new ctime accessors
  zonefs: switch to new ctime accessors
  mqueue: switch to new ctime accessors
  bpf: switch to new ctime accessors
  shmem: switch to new ctime accessors
  rpc_pipefs: switch to new ctime accessors
  apparmor: switch to new ctime accessors
  security: switch to new ctime accessors
  selinux: switch to new ctime accessors
  fs: rename i_ctime field to __i_ctime

 arch/powerpc/platforms/cell/spufs/inode.c |  2 +-
 arch/s390/hypfs/inode.c                   |  4 +-
 drivers/android/binderfs.c                |  8 +--
 drivers/infiniband/hw/qib/qib_fs.c        |  4 +-
 drivers/misc/ibmasm/ibmasmfs.c            |  2 +-
 drivers/misc/ibmvmc.c                     |  2 +-
 drivers/usb/core/devio.c                  | 16 +++---
 drivers/usb/gadget/function/f_fs.c        |  6 +--
 drivers/usb/gadget/legacy/inode.c         |  3 +-
 fs/9p/vfs_inode.c                         |  6 ++-
 fs/9p/vfs_inode_dotl.c                    | 11 ++--
 fs/adfs/inode.c                           |  4 +-
 fs/affs/amigaffs.c                        |  6 +--
 fs/affs/inode.c                           | 17 +++---
 fs/afs/dynroot.c                          |  2 +-
 fs/afs/inode.c                            |  6 +--
 fs/attr.c                                 |  2 +-
 fs/autofs/inode.c                         |  2 +-
 fs/autofs/root.c                          |  6 +--
 fs/bad_inode.c                            |  3 +-
 fs/befs/linuxvfs.c                        |  2 +-
 fs/bfs/dir.c                              | 16 +++---
 fs/bfs/inode.c                            |  6 +--
 fs/binfmt_misc.c                          |  3 +-
 fs/btrfs/delayed-inode.c                  | 10 ++--
 fs/btrfs/file.c                           | 24 +++------
 fs/btrfs/inode.c                          | 66 +++++++++--------------
 fs/btrfs/ioctl.c                          |  2 +-
 fs/btrfs/reflink.c                        |  7 ++-
 fs/btrfs/transaction.c                    |  3 +-
 fs/btrfs/tree-log.c                       |  4 +-
 fs/btrfs/xattr.c                          |  4 +-
 fs/ceph/acl.c                             |  2 +-
 fs/ceph/caps.c                            |  2 +-
 fs/ceph/inode.c                           | 17 +++---
 fs/ceph/snap.c                            |  2 +-
 fs/ceph/xattr.c                           |  2 +-
 fs/coda/coda_linux.c                      |  2 +-
 fs/coda/dir.c                             |  2 +-
 fs/coda/file.c                            |  2 +-
 fs/coda/inode.c                           |  2 +-
 fs/configfs/inode.c                       |  6 +--
 fs/cramfs/inode.c                         |  2 +-
 fs/debugfs/inode.c                        |  2 +-
 fs/devpts/inode.c                         |  6 +--
 fs/ecryptfs/inode.c                       |  2 +-
 fs/efivarfs/file.c                        |  2 +-
 fs/efivarfs/inode.c                       |  2 +-
 fs/efs/inode.c                            |  5 +-
 fs/erofs/inode.c                          | 16 +++---
 fs/exfat/file.c                           |  4 +-
 fs/exfat/inode.c                          |  6 +--
 fs/exfat/namei.c                          | 29 +++++-----
 fs/exfat/super.c                          |  4 +-
 fs/ext2/acl.c                             |  2 +-
 fs/ext2/dir.c                             |  6 +--
 fs/ext2/ialloc.c                          |  2 +-
 fs/ext2/inode.c                           | 11 ++--
 fs/ext2/ioctl.c                           |  4 +-
 fs/ext2/namei.c                           |  8 +--
 fs/ext2/super.c                           |  2 +-
 fs/ext2/xattr.c                           |  2 +-
 fs/ext4/acl.c                             |  2 +-
 fs/ext4/ext4.h                            | 20 +++++++
 fs/ext4/extents.c                         | 12 ++---
 fs/ext4/ialloc.c                          |  2 +-
 fs/ext4/inline.c                          |  4 +-
 fs/ext4/inode.c                           | 16 +++---
 fs/ext4/ioctl.c                           |  9 ++--
 fs/ext4/namei.c                           | 26 +++++----
 fs/ext4/super.c                           |  2 +-
 fs/ext4/xattr.c                           |  6 +--
 fs/f2fs/dir.c                             |  8 +--
 fs/f2fs/f2fs.h                            |  5 +-
 fs/f2fs/file.c                            | 16 +++---
 fs/f2fs/inline.c                          |  2 +-
 fs/f2fs/inode.c                           | 10 ++--
 fs/f2fs/namei.c                           | 12 ++---
 fs/f2fs/recovery.c                        |  4 +-
 fs/f2fs/super.c                           |  2 +-
 fs/f2fs/xattr.c                           |  2 +-
 fs/fat/inode.c                            |  8 +--
 fs/fat/misc.c                             |  7 ++-
 fs/freevxfs/vxfs_inode.c                  |  4 +-
 fs/fuse/control.c                         |  2 +-
 fs/fuse/dir.c                             |  8 +--
 fs/fuse/inode.c                           | 18 ++++---
 fs/gfs2/acl.c                             |  2 +-
 fs/gfs2/bmap.c                            | 11 ++--
 fs/gfs2/dir.c                             | 15 +++---
 fs/gfs2/file.c                            |  2 +-
 fs/gfs2/glops.c                           |  4 +-
 fs/gfs2/inode.c                           |  8 +--
 fs/gfs2/super.c                           |  4 +-
 fs/gfs2/xattr.c                           |  8 +--
 fs/hfs/catalog.c                          |  8 +--
 fs/hfs/dir.c                              |  2 +-
 fs/hfs/inode.c                            | 13 +++--
 fs/hfs/sysdep.c                           |  2 +-
 fs/hfsplus/catalog.c                      |  8 +--
 fs/hfsplus/dir.c                          |  6 +--
 fs/hfsplus/inode.c                        | 14 ++---
 fs/hostfs/hostfs_kern.c                   |  4 +-
 fs/hpfs/dir.c                             |  8 +--
 fs/hpfs/inode.c                           |  6 +--
 fs/hpfs/namei.c                           | 26 +++++----
 fs/hpfs/super.c                           |  5 +-
 fs/hugetlbfs/inode.c                      | 12 ++---
 fs/inode.c                                | 26 +++++++--
 fs/isofs/inode.c                          |  4 +-
 fs/isofs/rock.c                           | 16 +++---
 fs/jffs2/dir.c                            | 19 +++----
 fs/jffs2/file.c                           |  3 +-
 fs/jffs2/fs.c                             | 10 ++--
 fs/jffs2/os-linux.h                       |  2 +-
 fs/jfs/acl.c                              |  2 +-
 fs/jfs/inode.c                            |  2 +-
 fs/jfs/ioctl.c                            |  2 +-
 fs/jfs/jfs_imap.c                         |  8 +--
 fs/jfs/jfs_inode.c                        |  4 +-
 fs/jfs/namei.c                            | 25 ++++-----
 fs/jfs/super.c                            |  2 +-
 fs/jfs/xattr.c                            |  2 +-
 fs/kernfs/inode.c                         |  4 +-
 fs/libfs.c                                | 32 +++++------
 fs/minix/bitmap.c                         |  2 +-
 fs/minix/dir.c                            |  6 +--
 fs/minix/inode.c                          | 11 ++--
 fs/minix/itree_common.c                   |  4 +-
 fs/minix/namei.c                          |  6 +--
 fs/nfs/callback_proc.c                    |  2 +-
 fs/nfs/fscache.h                          |  4 +-
 fs/nfs/inode.c                            | 21 ++++----
 fs/nfsd/nfsctl.c                          |  2 +-
 fs/nfsd/vfs.c                             |  2 +-
 fs/nilfs2/dir.c                           |  6 +--
 fs/nilfs2/inode.c                         | 12 ++---
 fs/nilfs2/ioctl.c                         |  2 +-
 fs/nilfs2/namei.c                         |  8 +--
 fs/nsfs.c                                 |  2 +-
 fs/ntfs/inode.c                           | 15 +++---
 fs/ntfs/mft.c                             |  3 +-
 fs/ntfs3/file.c                           |  6 +--
 fs/ntfs3/frecord.c                        |  4 +-
 fs/ntfs3/inode.c                          | 14 ++---
 fs/ntfs3/namei.c                          | 10 ++--
 fs/ntfs3/xattr.c                          |  4 +-
 fs/ocfs2/acl.c                            |  6 +--
 fs/ocfs2/alloc.c                          |  6 +--
 fs/ocfs2/aops.c                           |  2 +-
 fs/ocfs2/dir.c                            |  8 +--
 fs/ocfs2/dlmfs/dlmfs.c                    |  4 +-
 fs/ocfs2/dlmglue.c                        | 10 ++--
 fs/ocfs2/file.c                           | 16 +++---
 fs/ocfs2/inode.c                          | 14 ++---
 fs/ocfs2/move_extents.c                   |  6 +--
 fs/ocfs2/namei.c                          | 22 ++++----
 fs/ocfs2/refcounttree.c                   | 14 ++---
 fs/ocfs2/xattr.c                          |  6 +--
 fs/omfs/dir.c                             |  4 +-
 fs/omfs/inode.c                           | 10 ++--
 fs/openpromfs/inode.c                     |  4 +-
 fs/orangefs/namei.c                       |  2 +-
 fs/orangefs/orangefs-utils.c              |  6 +--
 fs/overlayfs/file.c                       |  7 ++-
 fs/overlayfs/util.c                       |  2 +-
 fs/pipe.c                                 |  2 +-
 fs/posix_acl.c                            |  2 +-
 fs/proc/base.c                            |  2 +-
 fs/proc/inode.c                           |  2 +-
 fs/proc/proc_sysctl.c                     |  2 +-
 fs/proc/self.c                            |  2 +-
 fs/proc/thread_self.c                     |  2 +-
 fs/pstore/inode.c                         |  4 +-
 fs/qnx4/inode.c                           |  4 +-
 fs/qnx6/inode.c                           |  4 +-
 fs/ramfs/inode.c                          |  6 +--
 fs/reiserfs/inode.c                       | 14 ++---
 fs/reiserfs/ioctl.c                       |  4 +-
 fs/reiserfs/namei.c                       | 21 ++++----
 fs/reiserfs/stree.c                       |  4 +-
 fs/reiserfs/super.c                       |  2 +-
 fs/reiserfs/xattr.c                       |  5 +-
 fs/reiserfs/xattr_acl.c                   |  2 +-
 fs/romfs/super.c                          |  4 +-
 fs/smb/client/file.c                      |  4 +-
 fs/smb/client/fscache.h                   |  5 +-
 fs/smb/client/inode.c                     | 15 +++---
 fs/smb/client/smb2ops.c                   |  2 +-
 fs/smb/server/smb2pdu.c                   |  8 +--
 fs/squashfs/inode.c                       |  2 +-
 fs/stack.c                                |  2 +-
 fs/stat.c                                 |  2 +-
 fs/sysv/dir.c                             |  6 +--
 fs/sysv/ialloc.c                          |  2 +-
 fs/sysv/inode.c                           |  6 +--
 fs/sysv/itree.c                           |  4 +-
 fs/sysv/namei.c                           |  6 +--
 fs/tracefs/inode.c                        |  2 +-
 fs/ubifs/debug.c                          |  4 +-
 fs/ubifs/dir.c                            | 39 +++++++-------
 fs/ubifs/file.c                           | 16 +++---
 fs/ubifs/ioctl.c                          |  2 +-
 fs/ubifs/journal.c                        |  4 +-
 fs/ubifs/super.c                          |  4 +-
 fs/ubifs/xattr.c                          |  6 +--
 fs/udf/ialloc.c                           |  2 +-
 fs/udf/inode.c                            | 17 +++---
 fs/udf/namei.c                            | 24 ++++-----
 fs/ufs/dir.c                              |  6 +--
 fs/ufs/ialloc.c                           |  2 +-
 fs/ufs/inode.c                            | 23 ++++----
 fs/ufs/namei.c                            |  8 +--
 fs/vboxsf/utils.c                         |  4 +-
 fs/xfs/libxfs/xfs_inode_buf.c             |  4 +-
 fs/xfs/libxfs/xfs_trans_inode.c           |  2 +-
 fs/xfs/xfs_acl.c                          |  2 +-
 fs/xfs/xfs_bmap_util.c                    |  6 ++-
 fs/xfs/xfs_inode.c                        |  2 +-
 fs/xfs/xfs_inode_item.c                   |  2 +-
 fs/xfs/xfs_iops.c                         |  4 +-
 fs/xfs/xfs_itable.c                       |  4 +-
 fs/zonefs/super.c                         |  8 +--
 include/linux/fs.h                        | 55 ++++++++++++++++++-
 include/linux/fs_stack.h                  |  2 +-
 ipc/mqueue.c                              | 20 ++++---
 kernel/bpf/inode.c                        |  4 +-
 mm/shmem.c                                | 28 +++++-----
 net/sunrpc/rpc_pipe.c                     |  2 +-
 security/apparmor/apparmorfs.c            |  6 +--
 security/apparmor/policy_unpack.c         |  4 +-
 security/inode.c                          |  2 +-
 security/selinux/selinuxfs.c              |  2 +-
 233 files changed, 914 insertions(+), 808 deletions(-)

-- 
2.41.0

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Jeff Layton]

struct timespec64 has unused bits in the tv_nsec field that can be used
for other purposes. In future patches, we're going to change how the
inode->i_ctime is accessed in certain inodes in order to make use of
them. In order to do that safely though, we'll need to eradicate raw
accesses of the inode->i_ctime field from the kernel.

Add new accessor functions for the ctime that we can use to replace them.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/inode.c         | 16 ++++++++++++++
 include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/fs/inode.c b/fs/inode.c
index d37fad91c8da..c005e7328fbb 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
 }
 EXPORT_SYMBOL(current_time);
 
+/**
+ * inode_ctime_set_current - set the ctime to current_time
+ * @inode: inode
+ *
+ * Set the inode->i_ctime to the current value for the inode. Returns
+ * the current value that was assigned to i_ctime.
+ */
+struct timespec64 inode_ctime_set_current(struct inode *inode)
+{
+	struct timespec64 now = current_time(inode);
+
+	inode_set_ctime(inode, now);
+	return now;
+}
+EXPORT_SYMBOL(inode_ctime_set_current);
+
 /**
  * in_group_or_capable - check whether caller is CAP_FSETID privileged
  * @idmap:	idmap of the mount @inode was found from
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6867512907d6..9afb30606373 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
 	       kgid_has_mapping(fs_userns, kgid);
 }
 
-extern struct timespec64 current_time(struct inode *inode);
+struct timespec64 current_time(struct inode *inode);
+struct timespec64 inode_ctime_set_current(struct inode *inode);
+
+/**
+ * inode_ctime_peek - fetch the current ctime from the inode
+ * @inode: inode from which to fetch ctime
+ *
+ * Grab the current ctime from the inode and return it.
+ */
+static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
+{
+	return inode->i_ctime;
+}
+
+/**
+ * inode_ctime_set - set the ctime in the inode to the given value
+ * @inode: inode in which to set the ctime
+ * @ts: timespec value to set the ctime
+ *
+ * Set the ctime in @inode to @ts.
+ */
+static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
+{
+	inode->i_ctime = ts;
+	return ts;
+}
+
+/**
+ * inode_ctime_set_sec - set only the tv_sec field in the inode ctime
+ * @inode: inode in which to set the ctime
+ * @sec:  value to set the tv_sec field
+ *
+ * Set the sec field in the ctime. Returns @sec.
+ */
+static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
+{
+	inode->i_ctime.tv_sec = sec;
+	return sec;
+}
+
+/**
+ * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
+ * @inode: inode in which to set the ctime
+ * @nsec:  value to set the tv_nsec field
+ *
+ * Set the nsec field in the ctime. Returns @nsec.
+ */
+static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
+{
+	inode->i_ctime.tv_nsec = nsec;
+	return nsec;
+}
 
 /*
  * Snapshotting support.
-- 
2.41.0

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Jan Kara]

On Wed 21-06-23 10:45:06, Jeff Layton wrote:
> struct timespec64 has unused bits in the tv_nsec field that can be used
> for other purposes. In future patches, we're going to change how the
> inode->i_ctime is accessed in certain inodes in order to make use of
> them. In order to do that safely though, we'll need to eradicate raw
> accesses of the inode->i_ctime field from the kernel.
> 
> Add new accessor functions for the ctime that we can use to replace them.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/inode.c         | 16 ++++++++++++++
>  include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 68 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/inode.c b/fs/inode.c
> index d37fad91c8da..c005e7328fbb 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
>  }
>  EXPORT_SYMBOL(current_time);
>  
> +/**
> + * inode_ctime_set_current - set the ctime to current_time
> + * @inode: inode
> + *
> + * Set the inode->i_ctime to the current value for the inode. Returns
> + * the current value that was assigned to i_ctime.
> + */
> +struct timespec64 inode_ctime_set_current(struct inode *inode)
> +{
> +	struct timespec64 now = current_time(inode);
> +
> +	inode_set_ctime(inode, now);
> +	return now;
> +}
> +EXPORT_SYMBOL(inode_ctime_set_current);
> +
>  /**
>   * in_group_or_capable - check whether caller is CAP_FSETID privileged
>   * @idmap:	idmap of the mount @inode was found from
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 6867512907d6..9afb30606373 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
>  	       kgid_has_mapping(fs_userns, kgid);
>  }
>  
> -extern struct timespec64 current_time(struct inode *inode);
> +struct timespec64 current_time(struct inode *inode);
> +struct timespec64 inode_ctime_set_current(struct inode *inode);
> +
> +/**
> + * inode_ctime_peek - fetch the current ctime from the inode
> + * @inode: inode from which to fetch ctime
> + *
> + * Grab the current ctime from the inode and return it.
> + */
> +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
> +{
> +	return inode->i_ctime;
> +}
> +
> +/**
> + * inode_ctime_set - set the ctime in the inode to the given value
> + * @inode: inode in which to set the ctime
> + * @ts: timespec value to set the ctime
> + *
> + * Set the ctime in @inode to @ts.
> + */
> +static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
> +{
> +	inode->i_ctime = ts;
> +	return ts;
> +}
> +
> +/**
> + * inode_ctime_set_sec - set only the tv_sec field in the inode ctime
> + * @inode: inode in which to set the ctime
> + * @sec:  value to set the tv_sec field
> + *
> + * Set the sec field in the ctime. Returns @sec.
> + */
> +static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
> +{
> +	inode->i_ctime.tv_sec = sec;
> +	return sec;
> +}
> +
> +/**
> + * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
> + * @inode: inode in which to set the ctime
> + * @nsec:  value to set the tv_nsec field
> + *
> + * Set the nsec field in the ctime. Returns @nsec.
> + */
> +static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
> +{
> +	inode->i_ctime.tv_nsec = nsec;
> +	return nsec;
> +}
>  
>  /*
>   * Snapshotting support.
> -- 
> 2.41.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Tom Talpey]

On 6/21/2023 10:45 AM, Jeff Layton wrote:
> struct timespec64 has unused bits in the tv_nsec field that can be used
> for other purposes. In future patches, we're going to change how the
> inode->i_ctime is accessed in certain inodes in order to make use of
> them. In order to do that safely though, we'll need to eradicate raw
> accesses of the inode->i_ctime field from the kernel.
> 
> Add new accessor functions for the ctime that we can use to replace them.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>   fs/inode.c         | 16 ++++++++++++++
>   include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
>   2 files changed, 68 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/inode.c b/fs/inode.c
> index d37fad91c8da..c005e7328fbb 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
>   }
>   EXPORT_SYMBOL(current_time);
>   
> +/**
> + * inode_ctime_set_current - set the ctime to current_time
> + * @inode: inode
> + *
> + * Set the inode->i_ctime to the current value for the inode. Returns
> + * the current value that was assigned to i_ctime.
> + */
> +struct timespec64 inode_ctime_set_current(struct inode *inode)
> +{
> +	struct timespec64 now = current_time(inode);
> +
> +	inode_set_ctime(inode, now);
> +	return now;
> +}
> +EXPORT_SYMBOL(inode_ctime_set_current);
> +
>   /**
>    * in_group_or_capable - check whether caller is CAP_FSETID privileged
>    * @idmap:	idmap of the mount @inode was found from
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 6867512907d6..9afb30606373 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
>   	       kgid_has_mapping(fs_userns, kgid);
>   }
>   
> -extern struct timespec64 current_time(struct inode *inode);
> +struct timespec64 current_time(struct inode *inode);
> +struct timespec64 inode_ctime_set_current(struct inode *inode);
> +
> +/**
> + * inode_ctime_peek - fetch the current ctime from the inode
> + * @inode: inode from which to fetch ctime
> + *
> + * Grab the current ctime from the inode and return it.
> + */
> +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
> +{
> +	return inode->i_ctime;
> +}
> +
> +/**
> + * inode_ctime_set - set the ctime in the inode to the given value
> + * @inode: inode in which to set the ctime
> + * @ts: timespec value to set the ctime
> + *
> + * Set the ctime in @inode to @ts.
> + */
> +static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
> +{
> +	inode->i_ctime = ts;
> +	return ts;
> +}
> +
> +/**
> + * inode_ctime_set_sec - set only the tv_sec field in the inode ctime

I'm curious about why you choose to split the tv_sec and tv_nsec
set_ functions. Do any callers not set them both? Wouldn't a
single call enable a more atomic behavior someday?

   inode_ctime_set_sec_nsec(struct inode *, time64_t, time64_t)

(or simply initialize a timespec64 and use inode_ctime_spec() )

Tom.

> + * @inode: inode in which to set the ctime
> + * @sec:  value to set the tv_sec field
> + *
> + * Set the sec field in the ctime. Returns @sec.
> + */
> +static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
> +{
> +	inode->i_ctime.tv_sec = sec;
> +	return sec;
> +}
> +
> +/**
> + * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
> + * @inode: inode in which to set the ctime
> + * @nsec:  value to set the tv_nsec field
> + *
> + * Set the nsec field in the ctime. Returns @nsec.
> + */
> +static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
> +{
> +	inode->i_ctime.tv_nsec = nsec;
> +	return nsec;
> +}
>   
>   /*
>    * Snapshotting support.

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Jeff Layton]

On Wed, 2023-06-21 at 13:29 -0400, Tom Talpey wrote:
> On 6/21/2023 10:45 AM, Jeff Layton wrote:
> > struct timespec64 has unused bits in the tv_nsec field that can be used
> > for other purposes. In future patches, we're going to change how the
> > inode->i_ctime is accessed in certain inodes in order to make use of
> > them. In order to do that safely though, we'll need to eradicate raw
> > accesses of the inode->i_ctime field from the kernel.
> > 
> > Add new accessor functions for the ctime that we can use to replace them.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> >   fs/inode.c         | 16 ++++++++++++++
> >   include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
> >   2 files changed, 68 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/inode.c b/fs/inode.c
> > index d37fad91c8da..c005e7328fbb 100644
> > --- a/fs/inode.c
> > +++ b/fs/inode.c
> > @@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
> >   }
> >   EXPORT_SYMBOL(current_time);
> >   
> > +/**
> > + * inode_ctime_set_current - set the ctime to current_time
> > + * @inode: inode
> > + *
> > + * Set the inode->i_ctime to the current value for the inode. Returns
> > + * the current value that was assigned to i_ctime.
> > + */
> > +struct timespec64 inode_ctime_set_current(struct inode *inode)
> > +{
> > +	struct timespec64 now = current_time(inode);
> > +
> > +	inode_set_ctime(inode, now);
> > +	return now;
> > +}
> > +EXPORT_SYMBOL(inode_ctime_set_current);
> > +
> >   /**
> >    * in_group_or_capable - check whether caller is CAP_FSETID privileged
> >    * @idmap:	idmap of the mount @inode was found from
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index 6867512907d6..9afb30606373 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
> >   	       kgid_has_mapping(fs_userns, kgid);
> >   }
> >   
> > -extern struct timespec64 current_time(struct inode *inode);
> > +struct timespec64 current_time(struct inode *inode);
> > +struct timespec64 inode_ctime_set_current(struct inode *inode);
> > +
> > +/**
> > + * inode_ctime_peek - fetch the current ctime from the inode
> > + * @inode: inode from which to fetch ctime
> > + *
> > + * Grab the current ctime from the inode and return it.
> > + */
> > +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
> > +{
> > +	return inode->i_ctime;
> > +}
> > +
> > +/**
> > + * inode_ctime_set - set the ctime in the inode to the given value
> > + * @inode: inode in which to set the ctime
> > + * @ts: timespec value to set the ctime
> > + *
> > + * Set the ctime in @inode to @ts.
> > + */
> > +static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
> > +{
> > +	inode->i_ctime = ts;
> > +	return ts;
> > +}
> > +
> > +/**
> > + * inode_ctime_set_sec - set only the tv_sec field in the inode ctime
> 
> I'm curious about why you choose to split the tv_sec and tv_nsec
> set_ functions. Do any callers not set them both? Wouldn't a
> single call enable a more atomic behavior someday?
> 
>    inode_ctime_set_sec_nsec(struct inode *, time64_t, time64_t)
> 
> (or simply initialize a timespec64 and use inode_ctime_spec() )
> 

Yes, quite a few places set the fields individually. For example, when
loading a value from disk that doesn't have sufficient granularity to
set the nsecs field to anything but 0.

Could I have done it by declaring a local timespec64 variable and just
use the inode_ctime_set function in these places? Absolutely.

That's a bit more difficult to handle with coccinelle though. If someone
wants to suggest a way to do that without having to change all of these
call sites manually, then I'm open to redoing the set.

That might be better left for a later cleanup though.

> > + * @inode: inode in which to set the ctime
> > + * @sec:  value to set the tv_sec field
> > + *
> > + * Set the sec field in the ctime. Returns @sec.
> > + */
> > +static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
> > +{
> > +	inode->i_ctime.tv_sec = sec;
> > +	return sec;
> > +}
> > +
> > +/**
> > + * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
> > + * @inode: inode in which to set the ctime
> > + * @nsec:  value to set the tv_nsec field
> > + *
> > + * Set the nsec field in the ctime. Returns @nsec.
> > + */
> > +static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
> > +{
> > +	inode->i_ctime.tv_nsec = nsec;
> > +	return nsec;
> > +}
> >   
> >   /*
> >    * Snapshotting support.

-- 
Jeff Layton <jlayton@kernel.org>

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Tom Talpey]

On 6/21/2023 2:01 PM, Jeff Layton wrote:
> On Wed, 2023-06-21 at 13:29 -0400, Tom Talpey wrote:
>> On 6/21/2023 10:45 AM, Jeff Layton wrote:
>>> struct timespec64 has unused bits in the tv_nsec field that can be used
>>> for other purposes. In future patches, we're going to change how the
>>> inode->i_ctime is accessed in certain inodes in order to make use of
>>> them. In order to do that safely though, we'll need to eradicate raw
>>> accesses of the inode->i_ctime field from the kernel.
>>>
>>> Add new accessor functions for the ctime that we can use to replace them.
>>>
>>> Signed-off-by: Jeff Layton <jlayton@kernel.org>
>>> ---
>>>    fs/inode.c         | 16 ++++++++++++++
>>>    include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
>>>    2 files changed, 68 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/inode.c b/fs/inode.c
>>> index d37fad91c8da..c005e7328fbb 100644
>>> --- a/fs/inode.c
>>> +++ b/fs/inode.c
>>> @@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
>>>    }
>>>    EXPORT_SYMBOL(current_time);
>>>    
>>> +/**
>>> + * inode_ctime_set_current - set the ctime to current_time
>>> + * @inode: inode
>>> + *
>>> + * Set the inode->i_ctime to the current value for the inode. Returns
>>> + * the current value that was assigned to i_ctime.
>>> + */
>>> +struct timespec64 inode_ctime_set_current(struct inode *inode)
>>> +{
>>> +	struct timespec64 now = current_time(inode);
>>> +
>>> +	inode_set_ctime(inode, now);
>>> +	return now;
>>> +}
>>> +EXPORT_SYMBOL(inode_ctime_set_current);
>>> +
>>>    /**
>>>     * in_group_or_capable - check whether caller is CAP_FSETID privileged
>>>     * @idmap:	idmap of the mount @inode was found from
>>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>>> index 6867512907d6..9afb30606373 100644
>>> --- a/include/linux/fs.h
>>> +++ b/include/linux/fs.h
>>> @@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
>>>    	       kgid_has_mapping(fs_userns, kgid);
>>>    }
>>>    
>>> -extern struct timespec64 current_time(struct inode *inode);
>>> +struct timespec64 current_time(struct inode *inode);
>>> +struct timespec64 inode_ctime_set_current(struct inode *inode);
>>> +
>>> +/**
>>> + * inode_ctime_peek - fetch the current ctime from the inode
>>> + * @inode: inode from which to fetch ctime
>>> + *
>>> + * Grab the current ctime from the inode and return it.
>>> + */
>>> +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
>>> +{
>>> +	return inode->i_ctime;
>>> +}
>>> +
>>> +/**
>>> + * inode_ctime_set - set the ctime in the inode to the given value
>>> + * @inode: inode in which to set the ctime
>>> + * @ts: timespec value to set the ctime
>>> + *
>>> + * Set the ctime in @inode to @ts.
>>> + */
>>> +static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
>>> +{
>>> +	inode->i_ctime = ts;
>>> +	return ts;
>>> +}
>>> +
>>> +/**
>>> + * inode_ctime_set_sec - set only the tv_sec field in the inode ctime
>>
>> I'm curious about why you choose to split the tv_sec and tv_nsec
>> set_ functions. Do any callers not set them both? Wouldn't a
>> single call enable a more atomic behavior someday?
>>
>>     inode_ctime_set_sec_nsec(struct inode *, time64_t, time64_t)
>>
>> (or simply initialize a timespec64 and use inode_ctime_spec() )
>>
> 
> Yes, quite a few places set the fields individually. For example, when
> loading a value from disk that doesn't have sufficient granularity to
> set the nsecs field to anything but 0.

Well, they still need to set the tv_nsec so they could just pass 0.
But ok.

> Could I have done it by declaring a local timespec64 variable and just
> use the inode_ctime_set function in these places? Absolutely.
> 
> That's a bit more difficult to handle with coccinelle though. If someone
> wants to suggest a way to do that without having to change all of these
> call sites manually, then I'm open to redoing the set.
> 
> That might be better left for a later cleanup though.

Acked-by: Tom Talpey <tom@talpey.com>

>>> + * @inode: inode in which to set the ctime
>>> + * @sec:  value to set the tv_sec field
>>> + *
>>> + * Set the sec field in the ctime. Returns @sec.
>>> + */
>>> +static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
>>> +{
>>> +	inode->i_ctime.tv_sec = sec;
>>> +	return sec;
>>> +}
>>> +
>>> +/**
>>> + * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
>>> + * @inode: inode in which to set the ctime
>>> + * @nsec:  value to set the tv_nsec field
>>> + *
>>> + * Set the nsec field in the ctime. Returns @nsec.
>>> + */
>>> +static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
>>> +{
>>> +	inode->i_ctime.tv_nsec = nsec;
>>> +	return nsec;
>>> +}
>>>    
>>>    /*
>>>     * Snapshotting support.
> 

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Jeff Layton]

On Wed, 2023-06-21 at 14:19 -0400, Tom Talpey wrote:
> On 6/21/2023 2:01 PM, Jeff Layton wrote:
> > On Wed, 2023-06-21 at 13:29 -0400, Tom Talpey wrote:
> > > On 6/21/2023 10:45 AM, Jeff Layton wrote:
> > > > struct timespec64 has unused bits in the tv_nsec field that can be used
> > > > for other purposes. In future patches, we're going to change how the
> > > > inode->i_ctime is accessed in certain inodes in order to make use of
> > > > them. In order to do that safely though, we'll need to eradicate raw
> > > > accesses of the inode->i_ctime field from the kernel.
> > > > 
> > > > Add new accessor functions for the ctime that we can use to replace them.
> > > > 
> > > > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > > > ---
> > > >    fs/inode.c         | 16 ++++++++++++++
> > > >    include/linux/fs.h | 53 +++++++++++++++++++++++++++++++++++++++++++++-
> > > >    2 files changed, 68 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/fs/inode.c b/fs/inode.c
> > > > index d37fad91c8da..c005e7328fbb 100644
> > > > --- a/fs/inode.c
> > > > +++ b/fs/inode.c
> > > > @@ -2499,6 +2499,22 @@ struct timespec64 current_time(struct inode *inode)
> > > >    }
> > > >    EXPORT_SYMBOL(current_time);
> > > >    
> > > > +/**
> > > > + * inode_ctime_set_current - set the ctime to current_time
> > > > + * @inode: inode
> > > > + *
> > > > + * Set the inode->i_ctime to the current value for the inode. Returns
> > > > + * the current value that was assigned to i_ctime.
> > > > + */
> > > > +struct timespec64 inode_ctime_set_current(struct inode *inode)
> > > > +{
> > > > +	struct timespec64 now = current_time(inode);
> > > > +
> > > > +	inode_set_ctime(inode, now);
> > > > +	return now;
> > > > +}
> > > > +EXPORT_SYMBOL(inode_ctime_set_current);
> > > > +
> > > >    /**
> > > >     * in_group_or_capable - check whether caller is CAP_FSETID privileged
> > > >     * @idmap:	idmap of the mount @inode was found from
> > > > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > > > index 6867512907d6..9afb30606373 100644
> > > > --- a/include/linux/fs.h
> > > > +++ b/include/linux/fs.h
> > > > @@ -1474,7 +1474,58 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,
> > > >    	       kgid_has_mapping(fs_userns, kgid);
> > > >    }
> > > >    
> > > > -extern struct timespec64 current_time(struct inode *inode);
> > > > +struct timespec64 current_time(struct inode *inode);
> > > > +struct timespec64 inode_ctime_set_current(struct inode *inode);
> > > > +
> > > > +/**
> > > > + * inode_ctime_peek - fetch the current ctime from the inode
> > > > + * @inode: inode from which to fetch ctime
> > > > + *
> > > > + * Grab the current ctime from the inode and return it.
> > > > + */
> > > > +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
> > > > +{
> > > > +	return inode->i_ctime;
> > > > +}
> > > > +
> > > > +/**
> > > > + * inode_ctime_set - set the ctime in the inode to the given value
> > > > + * @inode: inode in which to set the ctime
> > > > + * @ts: timespec value to set the ctime
> > > > + *
> > > > + * Set the ctime in @inode to @ts.
> > > > + */
> > > > +static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
> > > > +{
> > > > +	inode->i_ctime = ts;
> > > > +	return ts;
> > > > +}
> > > > +
> > > > +/**
> > > > + * inode_ctime_set_sec - set only the tv_sec field in the inode ctime
> > > 
> > > I'm curious about why you choose to split the tv_sec and tv_nsec
> > > set_ functions. Do any callers not set them both? Wouldn't a
> > > single call enable a more atomic behavior someday?
> > > 
> > >     inode_ctime_set_sec_nsec(struct inode *, time64_t, time64_t)
> > > 
> > > (or simply initialize a timespec64 and use inode_ctime_spec() )
> > > 
> > 
> > Yes, quite a few places set the fields individually. For example, when
> > loading a value from disk that doesn't have sufficient granularity to
> > set the nsecs field to anything but 0.
> 
> Well, they still need to set the tv_nsec so they could just pass 0.
> But ok.
> 

Sure. The difficulty is in trying to do this in an automated way. For
instance, look at the hfsplus patch; it has separate assignments in
place already:

-       result->i_ctime.tv_sec = result->i_mtime.tv_sec = result->i_atime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date));
-       result->i_ctime.tv_nsec = 0;
+       inode_ctime_set_sec(result,
+                           result->i_mtime.tv_sec = result->i_atime.tv_sec = local_to_gmt(dir->i_sb, le32_to_cpu(dee.creation_date)));
+       inode_ctime_set_nsec(result, 0);

Granted the new code is pretty ugly, but it compiles!

Transforming that into what you're suggesting is a tougher proposition
to do with coccinelle. I didn't see a way to conditionally catch cases
like this, declare a new variable in the appropriate spot and then
transform two assignments (that may not be next to one another!) into a
single one.

Maybe it's possible, but my grasp of SMPL is not that great. The docs
and examples (including Kees' vey helpful ones!) cover fairly simple
changes well, but I didn't quite grasp how to do that complex an
evolution.

> > Could I have done it by declaring a local timespec64 variable and just
> > use the inode_ctime_set function in these places? Absolutely.
> > 
> > That's a bit more difficult to handle with coccinelle though. If someone
> > wants to suggest a way to do that without having to change all of these
> > call sites manually, then I'm open to redoing the set.
> > 
> > That might be better left for a later cleanup though.
> 
> Acked-by: Tom Talpey <tom@talpey.com>
> 

Many thanks!

> > > > + * @inode: inode in which to set the ctime
> > > > + * @sec:  value to set the tv_sec field
> > > > + *
> > > > + * Set the sec field in the ctime. Returns @sec.
> > > > + */
> > > > +static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
> > > > +{
> > > > +	inode->i_ctime.tv_sec = sec;
> > > > +	return sec;
> > > > +}
> > > > +
> > > > +/**
> > > > + * inode_ctime_set_nsec - set only the tv_nsec field in the inode ctime
> > > > + * @inode: inode in which to set the ctime
> > > > + * @nsec:  value to set the tv_nsec field
> > > > + *
> > > > + * Set the nsec field in the ctime. Returns @nsec.
> > > > + */
> > > > +static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
> > > > +{
> > > > +	inode->i_ctime.tv_nsec = nsec;
> > > > +	return nsec;
> > > > +}
> > > >    
> > > >    /*
> > > >     * Snapshotting support.
> > 

-- 
Jeff Layton <jlayton@kernel.org>

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Damien Le Moal]

On 6/21/23 23:45, Jeff Layton wrote:
> struct timespec64 has unused bits in the tv_nsec field that can be used
> for other purposes. In future patches, we're going to change how the
> inode->i_ctime is accessed in certain inodes in order to make use of
> them. In order to do that safely though, we'll need to eradicate raw
> accesses of the inode->i_ctime field from the kernel.
> 
> Add new accessor functions for the ctime that we can use to replace them.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

[...]

> +/**
> + * inode_ctime_peek - fetch the current ctime from the inode
> + * @inode: inode from which to fetch ctime
> + *
> + * Grab the current ctime from the inode and return it.
> + */
> +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)

To be consistent with inode_ctime_set(), why not call this one inode_ctime_get()
? Also, inode_set_ctime() & inode_get_ctime() may be a little more natural. But
no strong opinion about that though.

-- 
Damien Le Moal
Western Digital Research

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Jeff Layton]

On Thu, 2023-06-22 at 09:46 +0900, Damien Le Moal wrote:
> On 6/21/23 23:45, Jeff Layton wrote:
> > struct timespec64 has unused bits in the tv_nsec field that can be used
> > for other purposes. In future patches, we're going to change how the
> > inode->i_ctime is accessed in certain inodes in order to make use of
> > them. In order to do that safely though, we'll need to eradicate raw
> > accesses of the inode->i_ctime field from the kernel.
> > 
> > Add new accessor functions for the ctime that we can use to replace them.
> > 
> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> 
> [...]
> 
> > +/**
> > + * inode_ctime_peek - fetch the current ctime from the inode
> > + * @inode: inode from which to fetch ctime
> > + *
> > + * Grab the current ctime from the inode and return it.
> > + */
> > +static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
> 
> To be consistent with inode_ctime_set(), why not call this one inode_ctime_get()

In later patches fetching the ctime for presentation may have side
effects on certain filesystems. Using "peek" here is a hint that we want
to avoid those side effects in these calls.

> ? Also, inode_set_ctime() & inode_get_ctime() may be a little more natural. But
> no strong opinion about that though.
> 

I like the consistency of the inode_ctime_* prefix. It makes it simpler
to find these calls when grepping, etc.

That said, my opinions on naming are pretty loosely-held, so if the
consensus is that the names should as you suggest, I'll go along with
it.
-- 
Jeff Layton <jlayton@kernel.org>

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Luis Chamberlain]

On Wed, Jun 21, 2023 at 10:45:06AM -0400, Jeff Layton wrote:
> struct timespec64 has unused bits in the tv_nsec field that can be used
> for other purposes. In future patches, we're going to change how the
> inode->i_ctime is accessed in certain inodes in order to make use of
> them. In order to do that safely though, we'll need to eradicate raw
> accesses of the inode->i_ctime field from the kernel.
> 
> Add new accessor functions for the ctime that we can use to replace them.
> 
> Signed-off-by: Jeff Layton <jlayton@kernel.org>

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>

  Luis

[Cluster-devel] [PATCH 01/79] fs: add ctime accessors infrastructure

[Randy Dunlap]

Hi Jeff,

On arch/um/, (subarch i386 or x86_64), hostfs build fails with:

../fs/hostfs/hostfs_kern.c:520:36: error: incompatible type for arg
ument 2 of 'inode_set_ctime_to_ts'
../include/linux/fs.h:1499:73: note: expected 'struct timespec64' b
ut argument is of type 'const struct hostfs_timespec *'


-- 
~Randy

[Cluster-devel] [PATCH 34/79] gfs2: switch to new ctime accessors

[Jeff Layton]

In later patches, we're going to change how the ctime.tv_nsec field is
utilized. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/gfs2/acl.c   |  2 +-
 fs/gfs2/bmap.c  | 11 +++++------
 fs/gfs2/dir.c   | 15 ++++++++-------
 fs/gfs2/file.c  |  2 +-
 fs/gfs2/glops.c |  4 ++--
 fs/gfs2/inode.c |  8 ++++----
 fs/gfs2/super.c |  4 ++--
 fs/gfs2/xattr.c |  8 ++++----
 8 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index a392aa0f041d..b267dae0dc63 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -142,7 +142,7 @@ int gfs2_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
 
 	ret = __gfs2_set_acl(inode, acl, type);
 	if (!ret && mode != inode->i_mode) {
-		inode->i_ctime = current_time(inode);
+		inode_ctime_set_current(inode);
 		inode->i_mode = mode;
 		mark_inode_dirty(inode);
 	}
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 8d611fbcf0bd..743b09a0b196 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1386,7 +1386,7 @@ static int trunc_start(struct inode *inode, u64 newsize)
 		ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG;
 
 	i_size_write(inode, newsize);
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode->i_mtime = inode_ctime_set_current(inode);
 	gfs2_dinode_out(ip, dibh->b_data);
 
 	if (journaled)
@@ -1583,8 +1583,7 @@ static int sweep_bh_for_rgrps(struct gfs2_inode *ip, struct gfs2_holder *rd_gh,
 
 			/* Every transaction boundary, we rewrite the dinode
 			   to keep its di_blocks current in case of failure. */
-			ip->i_inode.i_mtime = ip->i_inode.i_ctime =
-				current_time(&ip->i_inode);
+			ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 			gfs2_trans_add_meta(ip->i_gl, dibh);
 			gfs2_dinode_out(ip, dibh->b_data);
 			brelse(dibh);
@@ -1950,7 +1949,7 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length)
 		gfs2_statfs_change(sdp, 0, +btotal, 0);
 		gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid,
 				  ip->i_inode.i_gid);
-		ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+		ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 		gfs2_trans_add_meta(ip->i_gl, dibh);
 		gfs2_dinode_out(ip, dibh->b_data);
 		up_write(&ip->i_rw_mutex);
@@ -1993,7 +1992,7 @@ static int trunc_end(struct gfs2_inode *ip)
 		gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 		gfs2_ordered_del_inode(ip);
 	}
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 	ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG;
 
 	gfs2_trans_add_meta(ip->i_gl, dibh);
@@ -2094,7 +2093,7 @@ static int do_grow(struct inode *inode, u64 size)
 		goto do_end_trans;
 
 	truncate_setsize(inode, size);
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 	gfs2_trans_add_meta(ip->i_gl, dibh);
 	gfs2_dinode_out(ip, dibh->b_data);
 	brelse(dibh);
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 54a6d17b8c25..c07cb9883ea1 100644
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -130,7 +130,7 @@ static int gfs2_dir_write_stuffed(struct gfs2_inode *ip, const char *buf,
 	memcpy(dibh->b_data + offset + sizeof(struct gfs2_dinode), buf, size);
 	if (ip->i_inode.i_size < offset + size)
 		i_size_write(&ip->i_inode, offset + size);
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 	gfs2_dinode_out(ip, dibh->b_data);
 
 	brelse(dibh);
@@ -227,7 +227,7 @@ static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 
 	if (ip->i_inode.i_size < offset + copied)
 		i_size_write(&ip->i_inode, offset + copied);
-	ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	ip->i_inode.i_mtime = inode_ctime_set_current(&ip->i_inode);
 
 	gfs2_trans_add_meta(ip->i_gl, dibh);
 	gfs2_dinode_out(ip, dibh->b_data);
@@ -1814,7 +1814,7 @@ int gfs2_dir_add(struct inode *inode, const struct qstr *name,
 			gfs2_inum_out(nip, dent);
 			dent->de_type = cpu_to_be16(IF2DT(nip->i_inode.i_mode));
 			dent->de_rahead = cpu_to_be16(gfs2_inode_ra_len(nip));
-			tv = current_time(&ip->i_inode);
+			tv = inode_ctime_set_current(&ip->i_inode);
 			if (ip->i_diskflags & GFS2_DIF_EXHASH) {
 				leaf = (struct gfs2_leaf *)bh->b_data;
 				be16_add_cpu(&leaf->lf_entries, 1);
@@ -1825,7 +1825,7 @@ int gfs2_dir_add(struct inode *inode, const struct qstr *name,
 			da->bh = NULL;
 			brelse(bh);
 			ip->i_entries++;
-			ip->i_inode.i_mtime = ip->i_inode.i_ctime = tv;
+			ip->i_inode.i_mtime = tv;
 			if (S_ISDIR(nip->i_inode.i_mode))
 				inc_nlink(&ip->i_inode);
 			mark_inode_dirty(inode);
@@ -1876,7 +1876,7 @@ int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
 	const struct qstr *name = &dentry->d_name;
 	struct gfs2_dirent *dent, *prev = NULL;
 	struct buffer_head *bh;
-	struct timespec64 tv = current_time(&dip->i_inode);
+	struct timespec64 tv;
 
 	/* Returns _either_ the entry (if its first in block) or the
 	   previous entry otherwise */
@@ -1895,6 +1895,7 @@ int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
 		dent = (struct gfs2_dirent *)((char *)dent + be16_to_cpu(prev->de_rec_len));
 	}
 
+	tv = inode_ctime_set_current(&dip->i_inode);
 	dirent_del(dip, bh, prev, dent);
 	if (dip->i_diskflags & GFS2_DIF_EXHASH) {
 		struct gfs2_leaf *leaf = (struct gfs2_leaf *)bh->b_data;
@@ -1910,7 +1911,7 @@ int gfs2_dir_del(struct gfs2_inode *dip, const struct dentry *dentry)
 	if (!dip->i_entries)
 		gfs2_consist_inode(dip);
 	dip->i_entries--;
-	dip->i_inode.i_mtime = dip->i_inode.i_ctime = tv;
+	dip->i_inode.i_mtime = tv;
 	if (d_is_dir(dentry))
 		drop_nlink(&dip->i_inode);
 	mark_inode_dirty(&dip->i_inode);
@@ -1951,7 +1952,7 @@ int gfs2_dir_mvino(struct gfs2_inode *dip, const struct qstr *filename,
 	dent->de_type = cpu_to_be16(new_type);
 	brelse(bh);
 
-	dip->i_inode.i_mtime = dip->i_inode.i_ctime = current_time(&dip->i_inode);
+	dip->i_inode.i_mtime = inode_ctime_set_current(&dip->i_inode);
 	mark_inode_dirty_sync(&dip->i_inode);
 	return 0;
 }
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 1bf3c4453516..cb754c5f1d2d 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -260,7 +260,7 @@ static int do_gfs2_set_flags(struct inode *inode, u32 reqflags, u32 mask)
 	error = gfs2_meta_inode_buffer(ip, &bh);
 	if (error)
 		goto out_trans_end;
-	inode->i_ctime = current_time(inode);
+	inode_ctime_set_current(inode);
 	gfs2_trans_add_meta(ip->i_gl, bh);
 	ip->i_diskflags = new_flags;
 	gfs2_dinode_out(ip, bh->b_data);
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 7c48c7afd6a4..2aba6f82194f 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -437,8 +437,8 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
 		inode->i_atime = atime;
 	inode->i_mtime.tv_sec = be64_to_cpu(str->di_mtime);
 	inode->i_mtime.tv_nsec = be32_to_cpu(str->di_mtime_nsec);
-	inode->i_ctime.tv_sec = be64_to_cpu(str->di_ctime);
-	inode->i_ctime.tv_nsec = be32_to_cpu(str->di_ctime_nsec);
+	inode_ctime_set_sec(inode, be64_to_cpu(str->di_ctime));
+	inode_ctime_set_nsec(inode, be32_to_cpu(str->di_ctime_nsec));
 
 	ip->i_goal = be64_to_cpu(str->di_goal_meta);
 	ip->i_generation = be64_to_cpu(str->di_generation);
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 17c994a0c0d0..3a9c9b6ea456 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -690,7 +690,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
 	inode->i_rdev = dev;
 	inode->i_size = size;
-	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+	inode->i_atime = inode->i_mtime = inode_ctime_set_current(inode);
 	munge_mode_uid_gid(dip, inode);
 	check_and_update_goal(dip);
 	ip->i_goal = dip->i_goal;
@@ -1029,7 +1029,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 
 	gfs2_trans_add_meta(ip->i_gl, dibh);
 	inc_nlink(&ip->i_inode);
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	ihold(inode);
 	d_instantiate(dentry, inode);
 	mark_inode_dirty(inode);
@@ -1114,7 +1114,7 @@ static int gfs2_unlink_inode(struct gfs2_inode *dip,
 		return error;
 
 	ip->i_entries = 0;
-	inode->i_ctime = current_time(inode);
+	inode_ctime_set_current(inode);
 	if (S_ISDIR(inode->i_mode))
 		clear_nlink(inode);
 	else
@@ -1371,7 +1371,7 @@ static int update_moved_ino(struct gfs2_inode *ip, struct gfs2_inode *ndip,
 	if (dir_rename)
 		return gfs2_dir_mvino(ip, &gfs2_qdotdot, ndip, DT_DIR);
 
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	mark_inode_dirty_sync(&ip->i_inode);
 	return 0;
 }
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 9be72d5aafea..fc495df15e71 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -412,7 +412,7 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
 	str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(inode));
 	str->di_atime = cpu_to_be64(inode->i_atime.tv_sec);
 	str->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec);
-	str->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec);
+	str->di_ctime = cpu_to_be64(inode_ctime_peek(inode).tv_sec);
 
 	str->di_goal_meta = cpu_to_be64(ip->i_goal);
 	str->di_goal_data = cpu_to_be64(ip->i_goal);
@@ -429,7 +429,7 @@ void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
 	str->di_eattr = cpu_to_be64(ip->i_eattr);
 	str->di_atime_nsec = cpu_to_be32(inode->i_atime.tv_nsec);
 	str->di_mtime_nsec = cpu_to_be32(inode->i_mtime.tv_nsec);
-	str->di_ctime_nsec = cpu_to_be32(inode->i_ctime.tv_nsec);
+	str->di_ctime_nsec = cpu_to_be32(inode_ctime_peek(inode).tv_nsec);
 }
 
 /**
diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
index 93b36d026bb4..8f807d18ec52 100644
--- a/fs/gfs2/xattr.c
+++ b/fs/gfs2/xattr.c
@@ -311,7 +311,7 @@ static int ea_dealloc_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
 		ea->ea_num_ptrs = 0;
 	}
 
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
 
 	gfs2_trans_end(sdp);
@@ -763,7 +763,7 @@ static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
 	if (error)
 		goto out_end_trans;
 
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
 
 out_end_trans:
@@ -888,7 +888,7 @@ static int ea_set_simple_noalloc(struct gfs2_inode *ip, struct buffer_head *bh,
 	if (es->es_el)
 		ea_set_remove_stuffed(ip, es->es_el);
 
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
 
 	gfs2_trans_end(GFS2_SB(&ip->i_inode));
@@ -1106,7 +1106,7 @@ static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
 		ea->ea_type = GFS2_EATYPE_UNUSED;
 	}
 
-	ip->i_inode.i_ctime = current_time(&ip->i_inode);
+	inode_ctime_set_current(&ip->i_inode);
 	__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
 
 	gfs2_trans_end(GFS2_SB(&ip->i_inode));
-- 
2.41.0

[Cluster-devel] [PATCH 79/79] fs: rename i_ctime field to __i_ctime

[Jeff Layton]

Now that everything in-tree is converted to use the accessor functions,
rename the i_ctime field in the inode to make its accesses more
self-documenting.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 include/linux/fs.h | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9afb30606373..2ca46c532b49 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -642,7 +642,7 @@ struct inode {
 	loff_t			i_size;
 	struct timespec64	i_atime;
 	struct timespec64	i_mtime;
-	struct timespec64	i_ctime;
+	struct timespec64	__i_ctime; /* use inode_ctime_* accessors! */
 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
 	unsigned short          i_bytes;
 	u8			i_blkbits;
@@ -1485,7 +1485,7 @@ struct timespec64 inode_ctime_set_current(struct inode *inode);
  */
 static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
 {
-	return inode->i_ctime;
+	return inode->__i_ctime;
 }
 
 /**
@@ -1497,7 +1497,7 @@ static inline struct timespec64 inode_ctime_peek(const struct inode *inode)
  */
 static inline struct timespec64 inode_ctime_set(struct inode *inode, struct timespec64 ts)
 {
-	inode->i_ctime = ts;
+	inode->__i_ctime = ts;
 	return ts;
 }
 
@@ -1510,7 +1510,7 @@ static inline struct timespec64 inode_ctime_set(struct inode *inode, struct time
  */
 static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
 {
-	inode->i_ctime.tv_sec = sec;
+	inode->__i_ctime.tv_sec = sec;
 	return sec;
 }
 
@@ -1523,7 +1523,7 @@ static inline time64_t inode_ctime_set_sec(struct inode *inode, time64_t sec)
  */
 static inline long inode_ctime_set_nsec(struct inode *inode, long nsec)
 {
-	inode->i_ctime.tv_nsec = nsec;
+	inode->__i_ctime.tv_nsec = nsec;
 	return nsec;
 }
 
-- 
2.41.0

[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Steven Rostedt]

On Wed, 21 Jun 2023 10:45:05 -0400
Jeff Layton <jlayton@kernel.org> wrote:

> Most of this conversion was done via coccinelle, with a few of the more
> non-standard accesses done by hand. There should be no behavioral
> changes with this set. That will come later, as we convert individual
> filesystems to use multigrain timestamps.

BTW, Linus has suggested to me that whenever a conccinelle script is used,
it should be included in the change log.

-- Steve

[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Jeff Layton]

On Wed, 2023-06-21 at 15:21 -0400, Steven Rostedt wrote:
> On Wed, 21 Jun 2023 10:45:05 -0400
> Jeff Layton <jlayton@kernel.org> wrote:
> 
> > Most of this conversion was done via coccinelle, with a few of the more
> > non-standard accesses done by hand. There should be no behavioral
> > changes with this set. That will come later, as we convert individual
> > filesystems to use multigrain timestamps.
> 
> BTW, Linus has suggested to me that whenever a conccinelle script is used,
> it should be included in the change log.
> 

Ok, here's what I have. I note again that my usage of coccinelle is
pretty primitive, so I ended up doing a fair bit of by-hand fixing after
applying these.

Given the way that this change is broken up into 77 patches by
subsystem, to which changelogs should I add it? I could add it to the
"infrastructure" patch, but that's the one where I _didn't_ use it.?

Maybe to patch #79 (the one that renames i_ctime)?


------------------------8<------------------------------
@@
expression inode;
@@

- inode->i_ctime = current_time(inode)
+ inode_set_current_ctime(inode)

@@
expression inode;
@@

- inode->i_ctime = inode->i_mtime = current_time(inode)
+ inode->i_mtime = inode_set_current_ctime(inode)

@@
struct inode *inode;
expression value;
@@

- inode->i_ctime = value;
+ inode_set_ctime(inode, value);

@@
struct inode *inode;
expression val;
@@
- inode->i_ctime.tv_sec = val
+ inode_set_ctime_sec(inode, val)

@@
struct inode *inode;
expression val;
@@
- inode->i_ctime.tv_nsec = val
+ inode_set_ctime_nsec(inode, val)

@@
struct inode *inode;
@@
- inode->i_ctime
+ inode_ctime_peek(inode)

[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Christian Brauner]

On Wed, Jun 21, 2023 at 03:52:27PM -0400, Jeff Layton wrote:
> On Wed, 2023-06-21 at 15:21 -0400, Steven Rostedt wrote:
> > On Wed, 21 Jun 2023 10:45:05 -0400
> > Jeff Layton <jlayton@kernel.org> wrote:
> > 
> > > Most of this conversion was done via coccinelle, with a few of the more
> > > non-standard accesses done by hand. There should be no behavioral
> > > changes with this set. That will come later, as we convert individual
> > > filesystems to use multigrain timestamps.
> > 
> > BTW, Linus has suggested to me that whenever a conccinelle script is used,
> > it should be included in the change log.
> > 
> 
> Ok, here's what I have. I note again that my usage of coccinelle is
> pretty primitive, so I ended up doing a fair bit of by-hand fixing after
> applying these.
> 
> Given the way that this change is broken up into 77 patches by
> subsystem, to which changelogs should I add it? I could add it to the
> "infrastructure" patch, but that's the one where I _didn't_ use it.?
> 
> Maybe to patch #79 (the one that renames i_ctime)?

That works. I can also put this into a merge commit or pr message.

[Cluster-devel] [PATCH 00/79] fs: new accessors for inode->i_ctime

[Luis Chamberlain]

On Wed, Jun 21, 2023 at 03:21:41PM -0400, Steven Rostedt wrote:
> On Wed, 21 Jun 2023 10:45:05 -0400
> Jeff Layton <jlayton@kernel.org> wrote:
> 
> > Most of this conversion was done via coccinelle, with a few of the more
> > non-standard accesses done by hand. There should be no behavioral
> > changes with this set. That will come later, as we convert individual
> > filesystems to use multigrain timestamps.
> 
> BTW, Linus has suggested to me that whenever a conccinelle script is used,
> it should be included in the change log.

Sometimes people like the coccinelle included in the commit, sometimes
people don't [0], it really ends up being up to a subjective maintainer
preference. A compromise could be to use git notes as these are
optional, however if we want to go down that path we should try to make
a general consensus on it so we can send a consistent message.

[0] https://lore.kernel.org/all/20230512073100.GC32559 at twin.jikos.cz/

  Luis