Initial Spring 2016 commit.

2015-12-23 00:50:04 +00:00
commit cafa9f5690
732 changed files with 92195 additions and 0 deletions
--- a/kern/include/fs.h
+++ b/kern/include/fs.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _FS_H_
+#define _FS_H_
+
+struct vnode; /* in vnode.h */
+
+
+/*
+ * Abstract file system. (Or device accessible as a file.)
+ *
+ * fs_data is a pointer to filesystem-specific data.
+ */
+
+struct fs {
+	void *fs_data;
+	const struct fs_ops *fs_ops;
+};
+
+/*
+ * Abstraction operations on a file system:
+ *
+ *      fsop_sync       - Flush all dirty buffers to disk.
+ *      fsop_getvolname - Return volume name of filesystem.
+ *      fsop_getroot    - Return root vnode of filesystem.
+ *      fsop_unmount    - Attempt unmount of filesystem.
+ *
+ * fsop_getvolname may return NULL on filesystem types that don't
+ * support the concept of a volume name. The string returned is
+ * assumed to point into the filesystem's private storage and live
+ * until unmount time.
+ *
+ * If the volume name changes on the fly, there is no way at present
+ * to make sure such changes don't cause name conflicts. So it probably
+ * should be considered fixed.
+ *
+ * fsop_getroot should increment the refcount of the vnode returned.
+ * It should not ever return NULL.
+ *
+ * If fsop_unmount returns an error, the filesystem stays mounted, and
+ * consequently the struct fs instance should remain valid. On success,
+ * however, the filesystem object and all storage associated with the
+ * filesystem should have been discarded/released.
+ */
+struct fs_ops {
+	int           (*fsop_sync)(struct fs *);
+	const char   *(*fsop_getvolname)(struct fs *);
+	int           (*fsop_getroot)(struct fs *, struct vnode **);
+	int           (*fsop_unmount)(struct fs *);
+};
+
+/*
+ * Macros to shorten the calling sequences.
+ */
+#define FSOP_SYNC(fs)        ((fs)->fs_ops->fsop_sync(fs))
+#define FSOP_GETVOLNAME(fs)  ((fs)->fs_ops->fsop_getvolname(fs))
+#define FSOP_GETROOT(fs, ret) ((fs)->fs_ops->fsop_getroot(fs, ret))
+#define FSOP_UNMOUNT(fs)     ((fs)->fs_ops->fsop_unmount(fs))
+
+/* Initialization functions for builtin fake file systems. */
+void semfs_bootstrap(void);
+
+
+#endif /* _FS_H_ */