Re: [PATCH v3 06/26] xfs: Expose init_xattrs in xfs_create_tmpfile

["Darrick J. Wong" <djwong@kernel.org>]

On Fri, Sep 23, 2022 at 08:45:22PM +0000, Allison Henderson wrote:
> On Fri, 2022-09-23 at 12:25 -0700, Darrick J. Wong wrote:
> > On Wed, Sep 21, 2022 at 10:44:38PM -0700,
> > allison.henderson@oracle.com wrote:
> > > From: Allison Henderson <allison.henderson@oracle.com>
> > > 
> > > Tmp files are used as part of rename operations and will need attr
> > > forks
> > > initialized for parent pointers.  Expose the init_xattrs parameter
> > > to
> > > the calling function to initialize the fork.
> > > 
> > > Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
> > > ---
> > >  fs/xfs/xfs_inode.c | 8 +++++---
> > >  fs/xfs/xfs_inode.h | 2 +-
> > >  fs/xfs/xfs_iops.c  | 3 ++-
> > >  3 files changed, 8 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > > index 4bfa4a1579f0..ff680de560d2 100644
> > > --- a/fs/xfs/xfs_inode.c
> > > +++ b/fs/xfs/xfs_inode.c
> > > @@ -1108,6 +1108,7 @@ xfs_create_tmpfile(
> > >         struct user_namespace   *mnt_userns,
> > >         struct xfs_inode        *dp,
> > >         umode_t                 mode,
> > > +       bool                    init_xattrs,
> > >         struct xfs_inode        **ipp)
> > >  {
> > >         struct xfs_mount        *mp = dp->i_mount;
> > > @@ -1148,7 +1149,7 @@ xfs_create_tmpfile(
> > >         error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
> > >         if (!error)
> > >                 error = xfs_init_new_inode(mnt_userns, tp, dp, ino,
> > > mode,
> > > -                               0, 0, prid, false, &ip);
> > > +                               0, 0, prid, init_xattrs, &ip);
> > >         if (error)
> > >                 goto out_trans_cancel;
> > >  
> > > @@ -2726,6 +2727,7 @@ xfs_rename_alloc_whiteout(
> > >         struct user_namespace   *mnt_userns,
> > >         struct xfs_name         *src_name,
> > >         struct xfs_inode        *dp,
> > > +       bool                    init_xattrs,
> > >         struct xfs_inode        **wip)
> > >  {
> > >         struct xfs_inode        *tmpfile;
> > > @@ -2733,7 +2735,7 @@ xfs_rename_alloc_whiteout(
> > >         int                     error;
> > >  
> > >         error = xfs_create_tmpfile(mnt_userns, dp, S_IFCHR |
> > > WHITEOUT_MODE,
> > > -                                  &tmpfile);
> > > +                                  init_xattrs, &tmpfile);
> > 
> > Whiteouts are created prior to being added to a directory, right?
> > If so, shouldn't this be s/init_xattrs/true/g to save time?
> well, replaced with xfs_has_parent(mp) if we want to retain the non
> parent code functionality.  I dont know that it really saves that much
> time, but we can implement it that way of folks prefer.

I didn't used to think it would make much difference, but the reason why
the init_xattrs thing got added is that Dave benchmarked file creation
on a system that has selinux enabled (and hence sets selinux security
xattrs on every file created) and discovered that it /did/ make a
difference.

--D

> > 
> > Everything else in here looks good though!
> Thanks!
> Allison
> 
> > 
> > --D
> > 
> > >         if (error)
> > >                 return error;
> > >  
> > > @@ -2797,7 +2799,7 @@ xfs_rename(
> > >          */
> > >         if (flags & RENAME_WHITEOUT) {
> > >                 error = xfs_rename_alloc_whiteout(mnt_userns,
> > > src_name,
> > > -                                                 target_dp, &wip);
> > > +                                                 target_dp, false,
> > > &wip);
> > >                 if (error)
> > >                         return error;
> > >  
> > > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> > > index 2eaed98af814..5735de32beeb 100644
> > > --- a/fs/xfs/xfs_inode.h
> > > +++ b/fs/xfs/xfs_inode.h
> > > @@ -478,7 +478,7 @@ int         xfs_create(struct user_namespace
> > > *mnt_userns,
> > >                            umode_t mode, dev_t rdev, bool
> > > need_xattr,
> > >                            struct xfs_inode **ipp);
> > >  int            xfs_create_tmpfile(struct user_namespace
> > > *mnt_userns,
> > > -                          struct xfs_inode *dp, umode_t mode,
> > > +                          struct xfs_inode *dp, umode_t mode, bool
> > > init_xattrs,
> > >                            struct xfs_inode **ipp);
> > >  int            xfs_remove(struct xfs_inode *dp, struct xfs_name
> > > *name,
> > >                            struct xfs_inode *ip);
> > > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> > > index 5d670c85dcc2..07a26f4f6348 100644
> > > --- a/fs/xfs/xfs_iops.c
> > > +++ b/fs/xfs/xfs_iops.c
> > > @@ -200,7 +200,8 @@ xfs_generic_create(
> > >                                 xfs_create_need_xattr(dir,
> > > default_acl, acl),
> > >                                 &ip);
> > >         } else {
> > > -               error = xfs_create_tmpfile(mnt_userns, XFS_I(dir),
> > > mode, &ip);
> > > +               error = xfs_create_tmpfile(mnt_userns, XFS_I(dir),
> > > mode, false,
> > > +                                          &ip);
> > >         }
> > >         if (unlikely(error))
> > >                 goto out_free_acl;
> > > -- 
> > > 2.25.1
> > > 
>