On Mon, 2024-07-01 at 09:49 -0400, Josef Bacik wrote:
> On Mon, Jul 01, 2024 at 06:26:45AM -0400, Jeff Layton wrote:
> > Enable multigrain timestamps, which should ensure that there is an
> > apparent change to the timestamp whenever it has been written after
> > being actively observed via getattr.
> >
> > Beyond enabling the FS_MGTIME flag, this patch eliminates
> > update_time_for_write, which goes to great pains to avoid in-memory
> > stores. Just have it overwrite the timestamps unconditionally.
> >
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > fs/btrfs/file.c | 25 ++++---------------------
> > fs/btrfs/super.c | 3 ++-
> > 2 files changed, 6 insertions(+), 22 deletions(-)
> >
> > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> > index d90138683a0a..409628c0c3cc 100644
> > --- a/fs/btrfs/file.c
> > +++ b/fs/btrfs/file.c
> > @@ -1120,26 +1120,6 @@ void btrfs_check_nocow_unlock(struct
> > btrfs_inode *inode)
> > btrfs_drew_write_unlock(&inode->root->snapshot_lock);
> > }
> >
> > -static void update_time_for_write(struct inode *inode)
> > -{
> > - struct timespec64 now, ts;
> > -
> > - if (IS_NOCMTIME(inode))
> > - return;
> > -
> > - now = current_time(inode);
> > - ts = inode_get_mtime(inode);
> > - if (!timespec64_equal(&ts, &now))
> > - inode_set_mtime_to_ts(inode, now);
> > -
> > - ts = inode_get_ctime(inode);
> > - if (!timespec64_equal(&ts, &now))
> > - inode_set_ctime_to_ts(inode, now);
> > -
> > - if (IS_I_VERSION(inode))
> > - inode_inc_iversion(inode);
> > -}
> > -
> > static int btrfs_write_check(struct kiocb *iocb, struct iov_iter
> > *from,
> > size_t count)
> > {
> > @@ -1171,7 +1151,10 @@ static int btrfs_write_check(struct kiocb
> > *iocb, struct iov_iter *from,
> > * need to start yet another transaction to update the
> > inode as we will
> > * update the inode when we finish writing whatever data
> > we write.
> > */
> > - update_time_for_write(inode);
> > + if (!IS_NOCMTIME(inode)) {
> > + inode_set_mtime_to_ts(inode,
> > inode_set_ctime_current(inode));
> > + inode_inc_iversion(inode);
>
> You've dropped the
>
> if (IS_I_VERSION(inode))
>
> check here, and it doesn't appear to be in inode_inc_iversion. Is
> there a
> reason for this? Thanks,
>
AFAICT, btrfs always sets SB_I_VERSION. Are there any cases where it
isn't? If so, then I can put this check back. I'll make a note about it
in the changelog if not.
--
Jeff Layton <jlayton@xxxxxxxxxx>
