[PATCH v13 29/59] ceph: add fscrypt support to ceph_fill_trace

From: Jeff Layton
Date: Tue Apr 05 2022 - 21:49:44 EST


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

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
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 4cbc303730ef..37c2c2977235 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1405,8 +1405,15 @@ 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);
@@ -1414,8 +1421,20 @@ 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);
@@ -1430,9 +1449,15 @@ 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 ||
@@ -1444,6 +1469,7 @@ 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);
--
2.35.1