ceph: quota: don't allow cross-quota renames

This patch changes ceph_rename so that -EXDEV is returned if an attempt is
made to mv a file between two different dir trees with different quotas
setup.

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 7d9851cd51bb4f96cfefee85c6a5ff180d956031..1f60498c4631702c14105ac224748e6bba5f529c 100644 (file)
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1080,6 +1080,11 @@ static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
                else
                        return -EROFS;
        }
+       /* don't allow cross-quota renames */
+       if ((old_dir != new_dir) &&
+           (!ceph_quota_is_same_realm(old_dir, new_dir)))
+               return -EXDEV;
+
        dout("rename dir %p dentry %p to dir %p dentry %p\n",
             old_dir, old_dentry, new_dir, new_dentry);
        req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);

diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index cf1c78c4a4d29ac574afda868b8e53f5321c714b..5d7dada91a572cc7aab8f24e62a3a7d63b2562e8 100644 (file)
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -21,6 +21,11 @@
 #include "super.h"
 #include "mds_client.h"
 
+static inline bool ceph_has_quota(struct ceph_inode_info *ci)
+{
+       return (ci && (ci->i_max_files || ci->i_max_bytes));
+}
+
 void ceph_handle_quota(struct ceph_mds_client *mdsc,
                       struct ceph_mds_session *session,
                       struct ceph_msg *msg)
@@ -64,6 +69,70 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
        iput(inode);
 }
 
+/*
+ * This function walks through the snaprealm for an inode and returns the
+ * ceph_snap_realm for the first snaprealm that has quotas set (either max_files
+ * or max_bytes).  If the root is reached, return the root ceph_snap_realm
+ * instead.
+ *
+ * Note that the caller is responsible for calling ceph_put_snap_realm() on the
+ * returned realm.
+ */
+static struct ceph_snap_realm *get_quota_realm(struct ceph_mds_client *mdsc,
+                                              struct inode *inode)
+{
+       struct ceph_inode_info *ci = NULL;
+       struct ceph_snap_realm *realm, *next;
+       struct ceph_vino vino;
+       struct inode *in;
+
+       realm = ceph_inode(inode)->i_snap_realm;
+       ceph_get_snap_realm(mdsc, realm);
+       while (realm) {
+               vino.ino = realm->ino;
+               vino.snap = CEPH_NOSNAP;
+               in = ceph_find_inode(inode->i_sb, vino);
+               if (!in) {
+                       pr_warn("Failed to find inode for %llu\n", vino.ino);
+                       break;
+               }
+               ci = ceph_inode(in);
+               if (ceph_has_quota(ci) || (ci->i_vino.ino == CEPH_INO_ROOT)) {
+                       iput(in);
+                       return realm;
+               }
+               iput(in);
+               next = realm->parent;
+               ceph_get_snap_realm(mdsc, next);
+               ceph_put_snap_realm(mdsc, realm);
+               realm = next;
+       }
+       if (realm)
+               ceph_put_snap_realm(mdsc, realm);
+
+       return NULL;
+}
+
+bool ceph_quota_is_same_realm(struct inode *old, struct inode *new)
+{
+       struct ceph_mds_client *mdsc = ceph_inode_to_client(old)->mdsc;
+       struct ceph_snap_realm *old_realm, *new_realm;
+       bool is_same;
+
+       down_read(&mdsc->snap_rwsem);
+       old_realm = get_quota_realm(mdsc, old);
+       new_realm = get_quota_realm(mdsc, new);
+       is_same = (old_realm == new_realm);
+       up_read(&mdsc->snap_rwsem);
+
+       if (old_realm)
+               ceph_put_snap_realm(mdsc, old_realm);
+       if (new_realm)
+               ceph_put_snap_realm(mdsc, new_realm);
+
+       return is_same;
+}
+
 enum quota_check_op {
        QUOTA_CHECK_MAX_FILES_OP        /* check quota max_files limit */
 };

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 4afc6cca878673e40186d3360e0a36c77eb7910b..eea6f70f3bf95308e53503326efb2a106321152e 100644 (file)
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1078,5 +1078,6 @@ extern void ceph_handle_quota(struct ceph_mds_client *mdsc,
                              struct ceph_mds_session *session,
                              struct ceph_msg *msg);
 extern bool ceph_quota_is_max_files_exceeded(struct inode *inode);
+extern bool ceph_quota_is_same_realm(struct inode *old, struct inode *new);
 
 #endif /* _FS_CEPH_SUPER_H */