ceph: avoid d_parent in ceph_dentry_hash; fix ceph_encode_fh() hashing bug
Have caller pass in a safely-obtained reference to the parent directory
for calculating a dentry's hash valud.
While we're here, simpify the flow through ceph_encode_fh() so that there
is a single exit point and cleanup.
Also fix a bug with the dentry hash calculation: calculate the hash for the
dentry we were given, not its parent.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index f67b687..9fbcdeca 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -46,7 +46,7 @@
int type;
struct ceph_nfs_fh *fh = (void *)rawfh;
struct ceph_nfs_confh *cfh = (void *)rawfh;
- struct dentry *parent = dentry->d_parent;
+ struct dentry *parent;
struct inode *inode = dentry->d_inode;
int connected_handle_length = sizeof(*cfh)/4;
int handle_length = sizeof(*fh)/4;
@@ -55,26 +55,33 @@
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EINVAL;
+ spin_lock(&dentry->d_lock);
+ parent = dget(dentry->d_parent);
+ spin_unlock(&dentry->d_lock);
+
if (*max_len >= connected_handle_length) {
dout("encode_fh %p connectable\n", dentry);
cfh->ino = ceph_ino(dentry->d_inode);
cfh->parent_ino = ceph_ino(parent->d_inode);
- cfh->parent_name_hash = ceph_dentry_hash(parent);
+ cfh->parent_name_hash = ceph_dentry_hash(parent->d_inode,
+ dentry);
*max_len = connected_handle_length;
type = 2;
} else if (*max_len >= handle_length) {
if (connectable) {
*max_len = connected_handle_length;
- return 255;
+ type = 255;
+ } else {
+ dout("encode_fh %p\n", dentry);
+ fh->ino = ceph_ino(dentry->d_inode);
+ *max_len = handle_length;
+ type = 1;
}
- dout("encode_fh %p\n", dentry);
- fh->ino = ceph_ino(dentry->d_inode);
- *max_len = handle_length;
- type = 1;
} else {
*max_len = handle_length;
- return 255;
+ type = 255;
}
+ dput(parent);
return type;
}
@@ -123,7 +130,6 @@
return dentry;
}
err = ceph_init_dentry(dentry);
-
if (err < 0) {
iput(inode);
return ERR_PTR(err);