[PATCH] Update relatime comments to include equality

[PATCH] Update relatime comments to include equality

[Stephen Kitt]

relatime also updates atime if the previous atime is equal to one or
both of the ctime and mtime; a non-strict interpretation of "earlier
than" and "younger than" in the comments allows this, but for clarity,
this makes it explicit.

Pointed out by "epiii2" and "ctrl-alt-delor" in
https://unix.stackexchange.com/q/740862/86440.

Signed-off-by: Stephen Kitt <steve@sk2.org>
---
 fs/inode.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 4558dc2f1355..3ec5a8f7b644 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1804,8 +1804,8 @@ EXPORT_SYMBOL(bmap);
 
 /*
  * With relative atime, only update atime if the previous atime is
- * earlier than either the ctime or mtime or if at least a day has
- * passed since the last atime update.
+ * earlier than or equal to either the ctime or mtime,
+ * or if at least a day has passed since the last atime update.
  */
 static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
 			     struct timespec64 now)
@@ -1814,12 +1814,12 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
 	if (!(mnt->mnt_flags & MNT_RELATIME))
 		return 1;
 	/*
-	 * Is mtime younger than atime? If yes, update atime:
+	 * Is mtime younger than or equal to atime? If yes, update atime:
 	 */
 	if (timespec64_compare(&inode->i_mtime, &inode->i_atime) >= 0)
 		return 1;
 	/*
-	 * Is ctime younger than atime? If yes, update atime:
+	 * Is ctime younger than or equal to atime? If yes, update atime:
 	 */
 	if (timespec64_compare(&inode->i_ctime, &inode->i_atime) >= 0)
 		return 1;

base-commit: 65aca32efdcb0965502d3db2f1fa33838c070952
-- 
2.30.2

Re: [PATCH] Update relatime comments to include equality

[Christian Brauner]

On Sat, 25 Mar 2023 09:22:32 +0100, Stephen Kitt wrote:
> relatime also updates atime if the previous atime is equal to one or
> both of the ctime and mtime; a non-strict interpretation of "earlier
> than" and "younger than" in the comments allows this, but for clarity,
> this makes it explicit.
> 
> Pointed out by "epiii2" and "ctrl-alt-delor" in
> https://unix.stackexchange.com/q/740862/86440.
> 
> [...]

Seems userspace documentation has been update accordingly. So looks good to me,

tree: https://lore.kernel.org/lkml/20230325082232.2017437-1-steve@sk2.org
branch: fs.misc
[1/1] Update relatime comments to include equality
      commit: d98ffa1aca264ce547b9135135f83d81cfe4345f

Thanks!
Christian