Fixed lookup return value. Now using generic_lookup directy, i.e.

not through a vnode, because it really isn't fs-specific.

tasks/fs0/main.c

@@ -27,6 +27,12 @@
  *   either high-level vfs code, or the mm0 page cache.
  * - readdir provides a posix-compliant dirent structure list in dirbuf.
  * - memfs dentries should be identical to posix struct dirents.
+ *
+ *   ALL DONE!!! But untested.
+ *
+ * - Add mkdir
+ * - Add create
+ * - Add read/write -> This will need page cache and mm0 involvement.
  */
 
 /* TODO:

tasks/fs0/src/lookup.c

@@ -57,7 +57,7 @@ struct vnode *lookup_dentry_children(struct dentry *parentdir, char *path)
 			return v;
 
 	/* Out of all children dentries, neither was a match, so we return 0 */
-	return 0;
+	return PTR_ERR(-ENOENT);
 }
 
 /* Lookup, recursive, assuming single-mountpoint */
@@ -68,7 +68,7 @@ struct vnode *generic_vnode_lookup(struct vnode *thisnode, char *path)
 	struct vnode *found;
 	int err;
 
-	/* Does this path component match with any of parent vnode's names? */
+	/* Does this path component match with any of this vnode's dentries? */
 	list_for_each_entry(d, &thisnode->dentries, vref) {
 		if (d->ops.compare(d, component)) {
 			/* Is this a directory? */

tasks/fs0/src/memfs/vnode.c

@@ -205,11 +205,13 @@ int memfs_write_vnode(struct superblock *sb, struct vnode *v)
 }
 
 /*
- * Allocates and populates all dentries and their corresponding vnodes that are
- * the direct children of vnode v. This means that by each call to readdir, the vfs
- * layer increases its cache of filesystem tree by one level beneath that directory.
+ * Reads the vnode directory contents into vnode's buffer in a posix-compliant
+ * struct dirent format.
  *
- * TODO: Returns the list of posix-compliant dirent records in the buffer.
+ * Reading the buffer, allocates and populates all dentries and their
+ * corresponding vnodes that are the direct children of vnode v. This means
+ * that by each call to readdir, the vfs layer increases its cache of filesystem
+ * tree by one level beneath that directory.
  */
 int memfs_vnode_readdir(struct vnode *v)
 {
@@ -278,7 +280,6 @@ int memfs_vnode_readdir(struct vnode *v)
 }
 
 struct vnode_ops memfs_vnode_operations = {
-	.lookup = generic_vnode_lookup,
 	.readdir = memfs_vnode_readdir,
 };
 

tasks/fs0/src/syscalls.c

@@ -78,15 +78,28 @@ int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode)
 	return do_open(sender, pathname, flags, mode);
 }
 
+int sys_mkdir(l4id_t sender, const char *pathname, unsigned int mode)
+{
+	return 0;
+}
+
 int sys_read(l4id_t sender, int fd, void *buf, int count)
 {
 	return 0;
 }
 
+int sys_write(l4id_t sender, int fd, const void *buf, int count)
+{
+	return 0;
+}
+
+int sys_lseek(l4id_t sender, int fd, int offset, int whence)
+{
+	return 0;
+}
+
 /*
- * FIXME: Read count is not considered yet. Take that into account.
- * FIXME: Do we pass this buf back to mm0. Do we get it from mm0???
- * Fix generic_vnode_lookup as well.
+ * Reads @count bytes of posix struct dirents into @buf
  */
 int sys_readdir(l4id_t sender, int fd, void *buf, int count)
 {
@@ -119,20 +132,10 @@ int sys_readdir(l4id_t sender, int fd, void *buf, int count)
 
 	/* Do we have those bytes at hand? */
 	if (v->dirbuf.buffer && (v->dirbuf.npages * PAGE_SIZE) >= nbytes) {
-		memcpy(buf, v->dirbuf.buffer, nbytes); /* Finish the job */
+		memcpy(buf, v->dirbuf.buffer, nbytes);
 		return nbytes;
 	}
 
 	return 0;
 }
 
-int sys_write(l4id_t sender, int fd, const void *buf, int count)
-{
-	return 0;
-}
-
-int sys_lseek(l4id_t sender, int fd, int offset, int whence)
-{
-	return 0;
-}
-

tasks/fs0/src/vfs.c

@@ -30,7 +30,7 @@ struct vnode *vfs_lookup_byvnum(struct superblock *sb, unsigned long vnum)
 	struct vnode *v;
 	int err;
 
-	/* Check the vnode cache by vnum */
+	/* Check the vnode flat list by vnum */
 	list_for_each_entry(v, &vnode_cache, cache_list)
 		if (v->vnum == vnum)
 			return v;
@@ -53,7 +53,7 @@ struct vnode *vfs_lookup_byvnum(struct superblock *sb, unsigned long vnum)
 		return PTR_ERR(err);
 	}
 
-	/* Add the vnode back to vnode cache */
+	/* Add the vnode back to vnode flat list */
 	list_add(&v->cache_list, &vnode_cache);
 
 	return v;
@@ -70,14 +70,10 @@ struct vnode *vfs_lookup_bypath(struct superblock *sb, char *path)
 	if (!strcmp(path, "/"))
 		return sb->root;
 
-	/* TODO: Check the vnode cache by path component
-	 *
-	 * This should split the path into components and compare
-	 * each of them with each vnode's dentry list.
+	/*
+	 * This does vfs cache + fs lookup.
 	 */
-
-	/* It's not in the cache, look it up from filesystem. */
-	return sb->root->ops.lookup(sb->root, path);
+	return generic_vnode_lookup(sb->root, path);
 }
 
 int vfs_mount_root(struct superblock *sb)