Changeset b17186d in mainline

Timestamp:

2008-11-29T15:39:24Z (15 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

dfd77382

Parents:

abd36f7

Message:

Hold the namespace_rwlock during readdir().

Location:

uspace/srv/vfs

Files:

• vfs.h (modified) (2 diffs)
• vfs_lookup.c (modified) (1 diff)
• vfs_node.c (modified) (2 diffs)
• vfs_ops.c (modified) (5 diffs)

uspace/srv/vfs/vfs.h

@@ -191 +191 @@
 #define L_PARENT        64      
 
+typedef enum vfs_node_type {
+        VFS_NODE_UNKNOWN,
+        VFS_NODE_FILE,
+        VFS_NODE_DIRECTORY,
+} vfs_node_type_t;
+
 typedef struct {
         vfs_triplet_t triplet;
+        vfs_node_type_t type;
         size_t size;
         unsigned lnkcnt;
@@ -214 +221 @@
 
         link_t nh_link;         /**< Node hash-table link. */
+
+        vfs_node_type_t type;   /**< Partial info about the node type. */
+
         size_t size;            /**< Cached size if the node is a file. */
 

uspace/srv/vfs/vfs_lookup.c

@@ -183 +183 @@
                 result->size = (size_t) IPC_GET_ARG4(answer);
                 result->lnkcnt = (unsigned) IPC_GET_ARG5(answer);
+                if (lflag & L_FILE)
+                        result->type = VFS_NODE_FILE;
+                else if (lflag & L_DIRECTORY)
+                        result->type = VFS_NODE_DIRECTORY;
+                else
+                        result->type = VFS_NODE_UNKNOWN;
         }
 

uspace/srv/vfs/vfs_node.c

@@ -176 +176 @@
                 node->size = result->size;
                 node->lnkcnt = result->lnkcnt;
+                node->type = result->type;
                 link_initialize(&node->nh_link);
                 rwlock_initialize(&node->contents_rwlock);
@@ -181 +182 @@
         } else {
                 node = hash_table_get_instance(tmp, vfs_node_t, nh_link);       
+                if (node->type == VFS_NODE_UNKNOWN &&
+                    result->type != VFS_NODE_UNKNOWN) {
+                        /* Upgrade the node type. */
+                        node->type = result->type;
+                }
         }
 
         assert(node->size == result->size);
         assert(node->lnkcnt == result->lnkcnt);
+        assert(node->type == result->type || result->type == VFS_NODE_UNKNOWN);
 
         _vfs_node_addref(node);

uspace/srv/vfs/vfs_ops.c

@@ -235 +235 @@
                         mr_res.size = (size_t) rsize;
                         mr_res.lnkcnt = (unsigned) rlnkcnt;
+                        mr_res.type = VFS_NODE_DIRECTORY;
 
                         rootfs.fs_handle = fs_handle;
@@ -302 +303 @@
         int mode = IPC_GET_ARG3(*request);
         size_t len;
+
+        /*
+         * Make sure that we are called with exactly one of L_FILE and
+         * L_DIRECTORY.
+         */
+        if ((lflag & (L_FILE | L_DIRECTORY)) == 0 ||
+            (lflag & (L_FILE | L_DIRECTORY)) == (L_FILE | L_DIRECTORY)) {
+                ipc_answer_0(rid, EINVAL);
+                return;
+        }
 
         if (oflag & O_CREAT)
@@ -457 +468 @@
          */
         futex_down(&file->lock);
-        
+
         /*
          * Lock the file's node so that no other client can read/write to it at
@@ -466 +477 @@
         else
                 rwlock_write_lock(&file->node->contents_rwlock);
+
+        if (file->node->type == VFS_NODE_DIRECTORY) {
+                /*
+                 * Make sure that no one is modifying the namespace
+                 * while we are in readdir().
+                 */
+                assert(read);
+                rwlock_read_lock(&namespace_rwlock);
+        }
         
         int fs_phone = vfs_grab_phone(file->node->fs_handle);   
@@ -491 +511 @@
         async_wait_for(msg, &rc);
         size_t bytes = IPC_GET_ARG1(answer);
+
+        if (file->node->type == VFS_NODE_DIRECTORY)
+                rwlock_read_unlock(&namespace_rwlock);
         
         /* Unlock the VFS node. */