On Mon, Sep 18, 2023 at 10:20 AM Xiubo Li xiubli@redhat.com wrote:
On 9/18/23 16:04, Ilya Dryomov wrote:
On Sun, Sep 17, 2023 at 9:49 PM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
6.5-stable review patch. If anyone has any objections, please let me know.
From: Xiubo Li xiubli@redhat.com
[ Upstream commit 3af5ae22030cb59fab4fba35f5a2b62f47e14df9 ]
In ceph mainline it will allow to set the btime in the setattr request and just add a 'btime' member in the union 'ceph_mds_request_args' and then bump up the header version to 4. That means the total size of union 'ceph_mds_request_args' will increase sizeof(struct ceph_timespec) bytes, but in kclient it will increase the sizeof(setattr_ext) bytes for each request.
Since the MDS will always depend on the header's vesion and front_len members to decode the 'ceph_mds_request_head' struct, at the same time kclient hasn't supported the 'btime' feature yet in setattr request, so it's safe to do this change here.
This will save 48 bytes memories for each request.
Fixes: 4f1ddb1ea874 ("ceph: implement updated ceph_mds_request_head structure") Signed-off-by: Xiubo Li xiubli@redhat.com Reviewed-by: Milind Changire mchangir@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org
include/linux/ceph/ceph_fs.h | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h index 49586ff261520..b4fa2a25b7d95 100644 --- a/include/linux/ceph/ceph_fs.h +++ b/include/linux/ceph/ceph_fs.h @@ -462,17 +462,19 @@ union ceph_mds_request_args { } __attribute__ ((packed));
union ceph_mds_request_args_ext {
union ceph_mds_request_args old;struct {__le32 mode;__le32 uid;__le32 gid;struct ceph_timespec mtime;struct ceph_timespec atime;__le64 size, old_size; /* old_size needed by truncate */__le32 mask; /* CEPH_SETATTR_* */struct ceph_timespec btime;} __attribute__ ((packed)) setattr_ext;
union {union ceph_mds_request_args old;struct {__le32 mode;__le32 uid;__le32 gid;struct ceph_timespec mtime;struct ceph_timespec atime;__le64 size, old_size; /* old_size needed by truncate */__le32 mask; /* CEPH_SETATTR_* */struct ceph_timespec btime;} __attribute__ ((packed)) setattr_ext;};Hi Xiubo,
I was going to ask whether it makes sense to backport this change, but, after looking at it, the change seems bogus to me even in mainline. You added a union inside siting memory use but ceph_mds_request_args_ext was already a union before:
union ceph_mds_request_args_ext { union ceph_mds_request_args old; struct { ... } __attribute__ ((packed)) setattr_ext; }What is being achieved here?
As I remembered there has other changes in this union in the beginning. And that patch seems being abandoned and missing this one.
Let's skip backporting this one and in the upstream just revert it.
OK, I will send a revert to ceph-devel list.
Greg, please drop this one from all stable branches.
Thanks,
Ilya