On Fri, 2023-09-08 at 12:42 +0200, Jan Kara wrote: > On Thu 07-09-23 12:33:47, Jeff Layton wrote: > > With the advent of multigrain timestamps, we use inode_set_ctime_current > > to set the ctime, which can skip updating if the existing ctime appears > > to be in the future. Because we don't initialize this field at > > allocation time, that could prevent the ctime from being initialized > > properly when the inode is instantiated. > > > > Always initialize the ctime field to the epoch so that the filesystem > > can set the timestamps properly later. > > > > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > > Closes: https://lore.kernel.org/oe-lkp/202309071017.a64aca5e-oliver.sang@xxxxxxxxx > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > > Looks good but don't you need the same treatment to atime after your patch > 2/2? > > I don't think so. Most filesystems are doing something along the lines of this when allocating a new inode: inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode); ...and I think they pretty much all have to initialize i_atime properly, since someone could stat the inode before an atime update occurs. > > --- > > fs/inode.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/fs/inode.c b/fs/inode.c > > index 35fd688168c5..54237f4242ff 100644 > > --- a/fs/inode.c > > +++ b/fs/inode.c > > @@ -168,6 +168,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode) > > inode->i_fop = &no_open_fops; > > inode->i_ino = 0; > > inode->__i_nlink = 1; > > + inode->__i_ctime.tv_sec = 0; > > + inode->__i_ctime.tv_nsec = 0; > > inode->i_opflags = 0; > > if (sb->s_xattr) > > inode->i_opflags |= IOP_XATTR; > > > > -- > > 2.41.0 > > -- Jeff Layton <jlayton@xxxxxxxxxx>
