On 03/10/2014 09:43 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
> 
> I like this better, thanks!
> 
> One question, though: in the LOOKUPNAME case, the client will already have 
> a cap on both the parent and child inode, right?  (IIUC, it will have done 
> a LOOKUPINO on the fh/child, then LOOKUPPARENT to get a cap for the 
> parent inode, and then a LOOKUPNAME to validate the name.
> 
> Is the reason you still do MDCache::open_ino() because we can't assume 
> that the parent and child are on the same MDS?

For the LOOKUPNAME case, MDCache::open_ino() is not needed. I'm lazy to write
separate function for LOOKUPNAME.

Regards
Yan, Zheng

> 
> Thanks!
> sage
> 
> 
>>
>> Regards
>> Yan, Zheng
>>
>> ---
>> >From 0fa1971741b1d3c236ee6fa3a7feb5a74fbd7f2f Mon Sep 17 00:00:00 2001
>> From: "Yan, Zheng" <[email protected]>
>> 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 <[email protected]>
>> ---
>>  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);
>> +    } 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
>>
>>

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