[RFC PATCH v8 20/24] ceph: add fscrypt support to ceph_fill_trace

[Jeff Layton <jlayton@kernel.org>]

When we get a dentry in a trace, decrypt the name so we can properly
instantiate the dentry.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/inode.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 3cb941fc334c..b8abbb0cdb83 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1395,8 +1395,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 		if (dir && req->r_op == CEPH_MDS_OP_LOOKUPNAME &&
 		    test_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags) &&
 		    !test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
+			bool is_nokey = false;
 			struct qstr dname;
 			struct dentry *dn, *parent;
+			struct fscrypt_str oname = FSTR_INIT(NULL, 0);
+			struct ceph_fname fname = { .dir	= dir,
+						    .name	= rinfo->dname,
+						    .ctext	= rinfo->altname,
+						    .name_len	= rinfo->dname_len,
+						    .ctext_len	= rinfo->altname_len };
 
 			BUG_ON(!rinfo->head->is_target);
 			BUG_ON(req->r_dentry);
@@ -1404,8 +1411,20 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 			parent = d_find_any_alias(dir);
 			BUG_ON(!parent);
 
-			dname.name = rinfo->dname;
-			dname.len = rinfo->dname_len;
+			err = ceph_fname_alloc_buffer(dir, &oname);
+			if (err < 0) {
+				dput(parent);
+				goto done;
+			}
+
+			err = ceph_fname_to_usr(&fname, NULL, &oname, &is_nokey);
+			if (err < 0) {
+				dput(parent);
+				ceph_fname_free_buffer(dir, &oname);
+				goto done;
+			}
+			dname.name = oname.name;
+			dname.len = oname.len;
 			dname.hash = full_name_hash(parent, dname.name, dname.len);
 			tvino.ino = le64_to_cpu(rinfo->targeti.in->ino);
 			tvino.snap = le64_to_cpu(rinfo->targeti.in->snapid);
@@ -1420,9 +1439,15 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 				     dname.len, dname.name, dn);
 				if (!dn) {
 					dput(parent);
+					ceph_fname_free_buffer(dir, &oname);
 					err = -ENOMEM;
 					goto done;
 				}
+				if (is_nokey) {
+					spin_lock(&dn->d_lock);
+					dn->d_flags |= DCACHE_NOKEY_NAME;
+					spin_unlock(&dn->d_lock);
+				}
 				err = 0;
 			} else if (d_really_is_positive(dn) &&
 				   (ceph_ino(d_inode(dn)) != tvino.ino ||
@@ -1434,6 +1459,7 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req)
 				dput(dn);
 				goto retry_lookup;
 			}
+			ceph_fname_free_buffer(dir, &oname);
 
 			req->r_dentry = dn;
 			dput(parent);
-- 
2.31.1