Changeset 5ca5eaa7 in mainline for uspace/srv/fs/fat/fat_ops.c

Timestamp:

2011-02-27T19:25:11Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

05155a1, 5716e9a

Parents:

89e780d

Message:

Create an extra reference to an unlinked FAT node. This keeps the node
resident in memory until the node is eventually destroyed. The extra
reference especially prevents the unlinked node from being put onto the
node free list in the meantime. Otherwise the node structure can be
recycled for instantiating some unrelated node.

File:

• uspace/srv/fs/fat/fat_ops.c (modified) (3 diffs)

uspace/srv/fs/fat/fat_ops.c

@@ -812 +812 @@
         fibril_mutex_unlock(&childp->idx->lock);
         childp->lnkcnt = 0;
+        childp->refcnt++;       /* keep the node in memory until destroyed */
         childp->dirty = true;
         fibril_mutex_unlock(&childp->lock);
@@ -1489 +1490 @@
         fs_index_t index = (fs_index_t)IPC_GET_ARG2(*request);
         fs_node_t *fn;
+        fat_node_t *nodep;
         int rc;
 
@@ -1500 +1502 @@
                 return;
         }
+
+        nodep = FAT_NODE(fn);
+        /*
+         * We should have exactly two references. One for the above
+         * call to fat_node_get() and one from fat_unlink().
+         */
+        assert(nodep->refcnt == 2);
 
         rc = fat_destroy_node(fn);