Made mkdir a backend op, fixed link count bugs in rmdir.

3 files changed, 33 insertions, 13 deletions

diff --git a/src/clojure/foofs/filesystem.clj b/src/clojure/foofs/filesystem.clj
index b11dbc4..a6579de 100644
--- a/src/clojure/foofs/filesystem.clj
+++ b/src/clojure/foofs/filesystem.clj
@@ -132,19 +132,12 @@
           (continuation! inode)
           (continuation! (fill-entry inode))))))
   (mkdir [_ {:keys [nodeid arg]} continuation!]
-    ;; TODO: this probably should be a backend op. the parent dir could go
-    ;; away before we can ref it with the .. link.
-    (.mknod
-      backend nodeid (:filename arg)
-      (bit-or stat-type-directory (:mode arg))
+    (.mkdir
+      backend nodeid (:filename arg) (:mode arg)
       (fn [inode]
         (if (integer? inode)
           (continuation! inode)
-          (let [child-nodeid (:nodeid inode)]
-            ;; do we need to wait for these to finish?
-            (.link backend child-nodeid "." child-nodeid skip)
-            (.link backend child-nodeid ".." nodeid skip)
-            (continuation! (fill-entry inode)))))))
+          (continuation! (fill-entry inode))))))
   (unlink [_ {:keys [nodeid arg]} continuation!]
     (.unlink backend nodeid arg continuation!))
   (rmdir [_ {:keys [nodeid arg]} continuation!]
diff --git a/src/clojure/foofs/filesystembackend.clj b/src/clojure/foofs/filesystembackend.clj
index 4b64a8b..ae61625 100644
--- a/src/clojure/foofs/filesystembackend.clj
+++ b/src/clojure/foofs/filesystembackend.clj
@@ -33,6 +33,8 @@
              "Writes a ByteBuffer to a file.")
   (mknod [this nodeid filename mode continuation!]
          "Create an inode and return it.")
+  (mkdir [this nodeid filename mode continuation!]
+         "Create a directory and return its inode.")
   (link [this nodeid filename target-nodeid continuation!]
         "Create a hardlink and return the target inode.")
   (unlink [this nodeid filename continuation!]
diff --git a/src/clojure/foofs/memorybackend.clj b/src/clojure/foofs/memorybackend.clj
index 24e6f13..3cbaddd 100644
--- a/src/clojure/foofs/memorybackend.clj
+++ b/src/clojure/foofs/memorybackend.clj
@@ -126,6 +126,30 @@
             (agent-do state-agent
                       (continuation! (assoc inode :nodeid child-nodeid)))
             state)))))
+  (mkdir [_ nodeid filename mode continuation!]
+    (send
+      state-agent
+      (fn [state]
+        (if (contains? (get-in state [:lookup-table nodeid]) filename)
+          (do (continuation! errno-exist) state)
+          (let [child-nodeid (next-key (:inode-table state)
+                                       (:next-nodeid state)
+                                       Long/MIN_VALUE Long/MAX_VALUE)
+                inode (assoc empty-inode
+                             :mode (bit-or stat-type-directory mode)
+                             :nlink 2)
+                state (assoc-in state [:inode-table child-nodeid] inode)
+                state (assoc-in state [:lookup-table nodeid filename]
+                                child-nodeid)
+                state (assoc-in state [:lookup-table child-nodeid]
+                                {"." child-nodeid ".." nodeid})
+                nlink (get-in state [:inode-table nodeid :nlink])
+                state (assoc-in state [:inode-table nodeid :nlink]
+                                (inc nlink))
+                state (assoc state :next-nodeid (inc child-nodeid))]
+            (agent-do state-agent
+                      (continuation! (assoc inode :nodeid child-nodeid)))
+            state)))))
   (link [_ nodeid filename target-nodeid continuation!]
     (send
       state-agent
@@ -205,9 +229,7 @@
             (not (empty? (dissoc child-children "." "..")))
             (do (continuation! errno-notempty) state)
             true
-            ;; TODO: 3 is wrong if . or .. don't exist
-            ;;       and we need to (dec (:nlink inode))
-            (let [nlink (- (:nlink child-inode) 3)
+            (let [nlink (- (:nlink child-inode) 2)
                   lookup-table (assoc lookup-table nodeid
                                       (dissoc children filename))
                   lookup-table (dissoc lookup-table child-nodeid)
@@ -216,6 +238,9 @@
                                 (dissoc inode-table child-nodeid)
                                 (assoc-in inode-table [child-nodeid :nlink]
                                           nlink))
+                  inode-table (assoc-in inode-table [nodeid :nlink]
+                                        (dec (get-in inode-table
+                                                     [nodeid :nlink])))
                   state (assoc state :inode-table inode-table)]
               (agent-do state-agent (continuation! 0))
               state))))))