On Fri, 2019-09-06 at 17:26 +0100, Luis Henriques wrote: > "Jeff Layton" <jlayton@xxxxxxxxxx> writes: > > > On Fri, 2019-09-06 at 14:57 +0100, Luis Henriques wrote: > > > OSDs are able to perform object copies across different pools. Thus, > > > there's no need to prevent copy_file_range from doing remote copies if the > > > source and destination superblocks are different. Only return -EXDEV if > > > they have different fsid (the cluster ID). > > > > > > Signed-off-by: Luis Henriques <lhenriques@xxxxxxxx> > > > --- > > > fs/ceph/file.c | 23 +++++++++++++++++++---- > > > 1 file changed, 19 insertions(+), 4 deletions(-) > > > > > > Hi! > > > > > > I've finally managed to run some tests using multiple filesystems, both > > > within a single cluster and also using two different clusters. The > > > behaviour of copy_file_range (with this patch, of course) was what I > > > expected: > > > > > > - Object copies work fine across different filesystems within the same > > > cluster (even with pools in different PGs); > > > - -EXDEV is returned if the fsid is different > > > > > > (OT: I wonder why the cluster ID is named 'fsid'; historical reasons? > > > Because this is actually what's in ceph.conf fsid in "[global]" > > > section. Anyway...) > > > > > > So, what's missing right now is (I always mention this when I have the > > > opportunity!) to merge https://github.com/ceph/ceph/pull/25374 :-) > > > And add the corresponding support for the new flag to the kernel > > > client, of course. > > > > > > Cheers, > > > -- > > > Luis > > > > > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > > > index 685a03cc4b77..88d116893c2b 100644 > > > --- a/fs/ceph/file.c > > > +++ b/fs/ceph/file.c > > > @@ -1904,6 +1904,7 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, > > > struct ceph_inode_info *src_ci = ceph_inode(src_inode); > > > struct ceph_inode_info *dst_ci = ceph_inode(dst_inode); > > > struct ceph_cap_flush *prealloc_cf; > > > + struct ceph_fs_client *src_fsc = ceph_inode_to_client(src_inode); > > > struct ceph_object_locator src_oloc, dst_oloc; > > > struct ceph_object_id src_oid, dst_oid; > > > loff_t endoff = 0, size; > > > @@ -1915,8 +1916,22 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off, > > > > > > if (src_inode == dst_inode) > > > return -EINVAL; > > > - if (src_inode->i_sb != dst_inode->i_sb) > > > - return -EXDEV; > > > + if (src_inode->i_sb != dst_inode->i_sb) { > > > + struct ceph_fs_client *dst_fsc = ceph_inode_to_client(dst_inode); > > > + > > > + if (!src_fsc->client->have_fsid || !dst_fsc->client->have_fsid) { > > > + dout("No fsid in a fs client\n"); > > > + return -EXDEV; > > > + } > > > > In what situation is there no fsid? Old cluster version? > > > > If there is no fsid, can we take that to indicate that there is only a > > single filesystem possible in the cluster and that we should attempt the > > copy anyway? > > TBH I'm not sure if 'have_fsid' can ever be 'false' in this call. It is > set to 'true' when handling the monmap, and it's never changed back to > 'false'. Since I don't think copy_file_range will be invoked *before* > we get the monmap, it should be safe to drop this check. Maybe it could > be replaced it by a WARN_ON()? > Yeah. I think the have_fsid flag just allows us to avoid the pr_err msg in ceph_check_fsid when the client is initially created. Maybe there is some better way to achieve that? In any case, I'd just drop that condition here. -- Jeff Layton <jlayton@xxxxxxxxxx>
