ceph: initialize inode before instantiating dentry

commit b18825a7c8 (Put a small type field into struct dentry::d_flags)
put a type field into struct dentry::d_flags. __d_instantiate() set the
field by checking inode->i_mode. So we should initialize inode before
instantiating dentry when handling mds reply.

Fixes: http://tracker.ceph.com/issues/6930
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 9a8e396aed89a43a0c824c3b682f96ac817ebc1c..278fd28912880b5cc09989ed7dcb8e7fbbfcb3ef 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -978,7 +978,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
        struct ceph_mds_reply_inode *ininfo;
        struct ceph_vino vino;
        struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
-       int i = 0;
        int err = 0;
 
        dout("fill_trace %p is_dentry %d is_target %d\n", req,
@@ -1039,6 +1038,29 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                }
        }
 
+       if (rinfo->head->is_target) {
+               vino.ino = le64_to_cpu(rinfo->targeti.in->ino);
+               vino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
+
+               in = ceph_get_inode(sb, vino);
+               if (IS_ERR(in)) {
+                       err = PTR_ERR(in);
+                       goto done;
+               }
+               req->r_target_inode = in;
+
+               err = fill_inode(in, &rinfo->targeti, NULL,
+                               session, req->r_request_started,
+                               (le32_to_cpu(rinfo->head->result) == 0) ?
+                               req->r_fmode : -1,
+                               &req->r_caps_reservation);
+               if (err < 0) {
+                       pr_err("fill_inode badness %p %llx.%llx\n",
+                               in, ceph_vinop(in));
+                       goto done;
+               }
+       }
+
        /*
         * ignore null lease/binding on snapdir ENOENT, or else we
         * will have trouble splicing in the virtual snapdir later
@@ -1108,7 +1130,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                             ceph_dentry(req->r_old_dentry)->offset);
 
                        dn = req->r_old_dentry;  /* use old_dentry */
-                       in = dn->d_inode;
                }
 
                /* null dentry? */
@@ -1130,44 +1151,28 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                }
 
                /* attach proper inode */
-               ininfo = rinfo->targeti.in;
-               vino.ino = le64_to_cpu(ininfo->ino);
-               vino.snap = le64_to_cpu(ininfo->snapid);
-               in = dn->d_inode;
-               if (!in) {
-                       in = ceph_get_inode(sb, vino);
-                       if (IS_ERR(in)) {
-                               pr_err("fill_trace bad get_inode "
-                                      "%llx.%llx\n", vino.ino, vino.snap);
-                               err = PTR_ERR(in);
-                               d_drop(dn);
-                               goto done;
-                       }
+               if (!dn->d_inode) {
+                       ihold(in);
                        dn = splice_dentry(dn, in, &have_lease, true);
                        if (IS_ERR(dn)) {
                                err = PTR_ERR(dn);
                                goto done;
                        }
                        req->r_dentry = dn;  /* may have spliced */
-                       ihold(in);
-               } else if (ceph_ino(in) == vino.ino &&
-                          ceph_snap(in) == vino.snap) {
-                       ihold(in);
-               } else {
+               } else if (dn->d_inode && dn->d_inode != in) {
                        dout(" %p links to %p %llx.%llx, not %llx.%llx\n",
-                            dn, in, ceph_ino(in), ceph_snap(in),
-                            vino.ino, vino.snap);
+                            dn, dn->d_inode, ceph_vinop(dn->d_inode),
+                            ceph_vinop(in));
                        have_lease = false;
-                       in = NULL;
                }
 
                if (have_lease)
                        update_dentry_lease(dn, rinfo->dlease, session,
                                            req->r_request_started);
                dout(" final dn %p\n", dn);
-               i++;
-       } else if ((req->r_op == CEPH_MDS_OP_LOOKUPSNAP ||
-                  req->r_op == CEPH_MDS_OP_MKSNAP) && !req->r_aborted) {
+       } else if (!req->r_aborted &&
+                  (req->r_op == CEPH_MDS_OP_LOOKUPSNAP ||
+                   req->r_op == CEPH_MDS_OP_MKSNAP)) {
                struct dentry *dn = req->r_dentry;
 
                /* fill out a snapdir LOOKUPSNAP dentry */
@@ -1177,52 +1182,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
                ininfo = rinfo->targeti.in;
                vino.ino = le64_to_cpu(ininfo->ino);
                vino.snap = le64_to_cpu(ininfo->snapid);
-               in = ceph_get_inode(sb, vino);
-               if (IS_ERR(in)) {
-                       pr_err("fill_inode get_inode badness %llx.%llx\n",
-                              vino.ino, vino.snap);
-                       err = PTR_ERR(in);
-                       d_delete(dn);
-                       goto done;
-               }
                dout(" linking snapped dir %p to dn %p\n", in, dn);
+               ihold(in);
                dn = splice_dentry(dn, in, NULL, true);
                if (IS_ERR(dn)) {
                        err = PTR_ERR(dn);
                        goto done;
                }
                req->r_dentry = dn;  /* may have spliced */
-               ihold(in);
-               rinfo->head->is_dentry = 1;  /* fool notrace handlers */
-       }
-
-       if (rinfo->head->is_target) {
-               vino.ino = le64_to_cpu(rinfo->targeti.in->ino);
-               vino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
-
-               if (in == NULL || ceph_ino(in) != vino.ino ||
-                   ceph_snap(in) != vino.snap) {
-                       in = ceph_get_inode(sb, vino);
-                       if (IS_ERR(in)) {
-                               err = PTR_ERR(in);
-                               goto done;
-                       }
-               }
-               req->r_target_inode = in;
-
-               err = fill_inode(in,
-                                &rinfo->targeti, NULL,
-                                session, req->r_request_started,
-                                (le32_to_cpu(rinfo->head->result) == 0) ?
-                                req->r_fmode : -1,
-                                &req->r_caps_reservation);
-               if (err < 0) {
-                       pr_err("fill_inode badness %p %llx.%llx\n",
-                              in, ceph_vinop(in));
-                       goto done;
-               }
        }
-
 done:
        dout("fill_trace done err=%d\n", err);
        return err;
@@ -1272,7 +1240,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
        struct qstr dname;
        struct dentry *dn;
        struct inode *in;
-       int err = 0, i;
+       int err = 0, ret, i;
        struct inode *snapdir = NULL;
        struct ceph_mds_request_head *rhead = req->r_request->front.iov_base;
        struct ceph_dentry_info *di;
@@ -1305,6 +1273,7 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req,
                        ceph_fill_dirfrag(parent->d_inode, rinfo->dir_dir);
        }
 
+       /* FIXME: release caps/leases if error occurs */
        for (i = 0; i < rinfo->dir_nr; i++) {
                struct ceph_vino vino;
 
@@ -1329,9 +1298,10 @@ retry_lookup:
                                err = -ENOMEM;
                                goto out;
                        }
-                       err = ceph_init_dentry(dn);
-                       if (err < 0) {
+                       ret = ceph_init_dentry(dn);
+                       if (ret < 0) {
                                dput(dn);
+                               err = ret;
                                goto out;
                        }
                } else if (dn->d_inode &&
@@ -1351,9 +1321,6 @@ retry_lookup:
                        spin_unlock(&parent->d_lock);
                }
 
-               di = dn->d_fsdata;
-               di->offset = ceph_make_fpos(frag, i + r_readdir_offset);
-
                /* inode */
                if (dn->d_inode) {
                        in = dn->d_inode;
@@ -1366,26 +1333,39 @@ retry_lookup:
                                err = PTR_ERR(in);
                                goto out;
                        }
-                       dn = splice_dentry(dn, in, NULL, false);
-                       if (IS_ERR(dn))
-                               dn = NULL;
                }
 
                if (fill_inode(in, &rinfo->dir_in[i], NULL, session,
                               req->r_request_started, -1,
                               &req->r_caps_reservation) < 0) {
                        pr_err("fill_inode badness on %p\n", in);
+                       if (!dn->d_inode)
+                               iput(in);
+                       d_drop(dn);
                        goto next_item;
                }
-               if (dn)
-                       update_dentry_lease(dn, rinfo->dir_dlease[i],
-                                           req->r_session,
-                                           req->r_request_started);
+
+               if (!dn->d_inode) {
+                       dn = splice_dentry(dn, in, NULL, false);
+                       if (IS_ERR(dn)) {
+                               err = PTR_ERR(dn);
+                               dn = NULL;
+                               goto next_item;
+                       }
+               }
+
+               di = dn->d_fsdata;
+               di->offset = ceph_make_fpos(frag, i + r_readdir_offset);
+
+               update_dentry_lease(dn, rinfo->dir_dlease[i],
+                                   req->r_session,
+                                   req->r_request_started);
 next_item:
                if (dn)
                        dput(dn);
        }
-       req->r_did_prepopulate = true;
+       if (err == 0)
+               req->r_did_prepopulate = true;
 
 out:
        if (snapdir) {