On 03/10/2014 09:49 AM, Sage Weil wrote: > On Sat, 8 Mar 2014, Yan, Zheng wrote: >> how about the below patch and corresponding mds change in >> https://github.com/ceph/ceph/commit/617ce6761edd7264893f3638c33fd229c71751a0 >> >> Regards >> Yan, Zheng >> >> --- >> >From 0fa1971741b1d3c236ee6fa3a7feb5a74fbd7f2f Mon Sep 17 00:00:00 2001 >> From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx> >> Date: Thu, 6 Mar 2014 16:40:32 +0800 >> Subject: [PATCH 1/3] ceph: add get_name() NFS export callback >> >> Use the newly introduced LOOKUPNAME MDS request to connect child >> inode to its parent directory. >> >> Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx> >> --- >> fs/ceph/export.c | 40 ++++++++++++++++++++++++++++++++++ >> fs/ceph/inode.c | 51 +++++++++++++++++++++++++++++++++++++++++++- >> fs/ceph/strings.c | 1 + >> include/linux/ceph/ceph_fs.h | 1 + >> 4 files changed, 92 insertions(+), 1 deletion(-) >> >> diff --git a/fs/ceph/export.c b/fs/ceph/export.c >> index 6e611e7..bf36e7f 100644 >> --- a/fs/ceph/export.c >> +++ b/fs/ceph/export.c >> @@ -195,9 +195,49 @@ static struct dentry *ceph_fh_to_parent(struct super_block *sb, >> return dentry; >> } >> >> +static int ceph_get_name(struct dentry *parent, char *name, >> + struct dentry *child) >> +{ >> + struct ceph_mds_client *mdsc; >> + struct ceph_mds_request *req; >> + int err; >> + >> + mdsc = ceph_inode_to_client(child->d_inode)->mdsc; >> + req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, >> + USE_ANY_MDS); >> + if (IS_ERR(req)) >> + return PTR_ERR(req); >> + >> + mutex_lock(&parent->d_inode->i_mutex); >> + >> + req->r_inode = child->d_inode; >> + ihold(child->d_inode); >> + req->r_ino2 = ceph_vino(parent->d_inode); >> + req->r_locked_dir = parent->d_inode; >> + req->r_num_caps = 1; >> + err = ceph_mdsc_do_request(mdsc, NULL, req); >> + >> + mutex_unlock(&parent->d_inode->i_mutex); >> + >> + if (!err) { >> + struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; >> + memcpy(name, rinfo->dname, rinfo->dname_len); >> + name[rinfo->dname_len] = 0; >> + dout("get_name %p ino %llx.%llx name %s\n", >> + child, ceph_vinop(child->d_inode), name); > > One other oddity here: the MDS is returning a bunch of metadata about the > dentry, including (in most cases) a lease. The client is ignoring all of > that and only needs the name itself to feed back into exportfs. I believe > at this point that is fine: the client can forget leases at any time and > will respond to MDS revocations accordingly. > > It would probably require a bit of a kludge on the MDS side to make the > reply_request() respond with the dentry name but prevent a lease from > being issued. Might be worth it though? Maybe a generic "no lease" flag > that even regular LOOKUP could use (if for some reason the client didn't > want a lease)? > > This needn't hold up the other patches, but I'm curious what you think > about it. > the nfsd does a dentry lookup after it has got the name. the lease can avoid sending another 'lookup' request to the MDS. Regards Yan, Zheng > > >> + } else { >> + dout("get_name %p ino %llx.%llx err %d\n", >> + child, ceph_vinop(child->d_inode), err); >> + } >> + >> + ceph_mdsc_put_request(req); >> + return err; >> +} >> + >> const struct export_operations ceph_export_ops = { >> .encode_fh = ceph_encode_fh, >> .fh_to_dentry = ceph_fh_to_dentry, >> .fh_to_parent = ceph_fh_to_parent, >> .get_parent = ceph_get_parent, >> + .get_name = ceph_get_name, >> }; >> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c >> index 8bf2384..91d6c9d 100644 >> --- a/fs/ceph/inode.c >> +++ b/fs/ceph/inode.c >> @@ -1044,10 +1044,59 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req, >> session, req->r_request_started, -1, >> &req->r_caps_reservation); >> if (err < 0) >> - return err; >> + goto done; >> } else { >> WARN_ON_ONCE(1); >> } >> + >> + if (dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME) { >> + struct qstr dname; >> + struct dentry *dn, *parent; >> + >> + BUG_ON(!rinfo->head->is_target); >> + BUG_ON(req->r_dentry); >> + >> + parent = d_find_any_alias(dir); >> + BUG_ON(!parent); >> + >> + dname.name = rinfo->dname; >> + dname.len = rinfo->dname_len; >> + dname.hash = full_name_hash(dname.name, dname.len); >> + vino.ino = le64_to_cpu(rinfo->targeti.in->ino); >> + vino.snap = le64_to_cpu(rinfo->targeti.in->snapid); >> +retry_lookup: >> + dn = d_lookup(parent, &dname); >> + dout("d_lookup on parent=%p name=%.*s got %p\n", >> + parent, dname.len, dname.name, dn); >> + >> + if (!dn) { >> + dn = d_alloc(parent, &dname); >> + dout("d_alloc %p '%.*s' = %p\n", parent, >> + dname.len, dname.name, dn); >> + if (dn == NULL) { >> + dput(parent); >> + err = -ENOMEM; >> + goto done; >> + } >> + err = ceph_init_dentry(dn); >> + if (err < 0) { >> + dput(dn); >> + dput(parent); >> + goto done; >> + } >> + } else if (dn->d_inode && >> + (ceph_ino(dn->d_inode) != vino.ino || >> + ceph_snap(dn->d_inode) != vino.snap)) { >> + dout(" dn %p points to wrong inode %p\n", >> + dn, dn->d_inode); >> + d_delete(dn); >> + dput(dn); >> + goto retry_lookup; >> + } >> + >> + req->r_dentry = dn; >> + dput(parent); >> + } >> } >> >> if (rinfo->head->is_target) { >> diff --git a/fs/ceph/strings.c b/fs/ceph/strings.c >> index 4440f447..51cc23e 100644 >> --- a/fs/ceph/strings.c >> +++ b/fs/ceph/strings.c >> @@ -54,6 +54,7 @@ const char *ceph_mds_op_name(int op) >> case CEPH_MDS_OP_LOOKUPHASH: return "lookuphash"; >> case CEPH_MDS_OP_LOOKUPPARENT: return "lookupparent"; >> case CEPH_MDS_OP_LOOKUPINO: return "lookupino"; >> + case CEPH_MDS_OP_LOOKUPNAME: return "lookupname"; >> case CEPH_MDS_OP_GETATTR: return "getattr"; >> case CEPH_MDS_OP_SETXATTR: return "setxattr"; >> case CEPH_MDS_OP_SETATTR: return "setattr"; >> diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h >> index 25bfb0e..35f345f 100644 >> --- a/include/linux/ceph/ceph_fs.h >> +++ b/include/linux/ceph/ceph_fs.h >> @@ -332,6 +332,7 @@ enum { >> CEPH_MDS_OP_LOOKUPHASH = 0x00102, >> CEPH_MDS_OP_LOOKUPPARENT = 0x00103, >> CEPH_MDS_OP_LOOKUPINO = 0x00104, >> + CEPH_MDS_OP_LOOKUPNAME = 0x00105, >> >> CEPH_MDS_OP_SETXATTR = 0x01105, >> CEPH_MDS_OP_RMXATTR = 0x01106, >> -- >> 1.8.5.3 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
