Re: [PATCH] ceph: set pool_ns in new inode layout for async creates

[Ilya Dryomov <idryomov@gmail.com>]

On Tue, Jan 25, 2022 at 10:10 PM Jeff Layton <jlayton@kernel.org> wrote:
>
> Dan reported that he was unable to write to files that had been
> asynchronously created when the client's OSD caps are restricted to a
> particular namespace.
>
> The issue is that the layout for the new inode is only partially being
> filled. Ensure that we populate the pool_ns_data and pool_ns_len in the
> iinfo before calling ceph_fill_inode.
>
> Reported-by: Dan van der Ster <dan@vanderster.com>
> Fixes: 9a8d03ca2e2c ("ceph: attempt to do async create when possible")
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/ceph/file.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index cbe4d5a5cde5..efea321ff643 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -599,6 +599,7 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
>         struct ceph_inode_info *ci = ceph_inode(dir);
>         struct inode *inode;
>         struct timespec64 now;
> +       struct ceph_string *pool_ns;
>         struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
>         struct ceph_vino vino = { .ino = req->r_deleg_ino,
>                                   .snap = CEPH_NOSNAP };
> @@ -648,11 +649,17 @@ static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
>         in.max_size = cpu_to_le64(lo->stripe_unit);
>
>         ceph_file_layout_to_legacy(lo, &in.layout);
> +       pool_ns = ceph_try_get_string(lo->pool_ns);
> +       if (pool_ns) {
> +               iinfo.pool_ns_len = pool_ns->len;
> +               iinfo.pool_ns_data = pool_ns->str;
> +       }

Considering that we have a reference from try_prep_async_create(), do
we actually need to bother with ceph_try_get_string() here?

Thanks,

                Ilya