Created student weenix repository

1 files changed, 162 insertions, 0 deletions

diff --git a/kernel/include/fs/vfs.h b/kernel/include/fs/vfs.h
new file mode 100644
index 0000000..23f418a
--- /dev/null
+++ b/kernel/include/fs/vfs.h
@@ -0,0 +1,162 @@
+#pragma once
+
+#include "types.h"
+
+#include "fs/open.h"
+#include "proc/kmutex.h"
+#include "util/list.h"
+
+struct vnode;
+struct file;
+struct vfs;
+struct fs;
+struct slab_allocator;
+
+/* name_match: fname should be null-terminated, name is namelen long */
+#define name_match(fname, name, namelen) \
+    (strlen(fname) == namelen && !strncmp((fname), (name), (namelen)))
+
+typedef struct fs_ops
+{
+    /*
+     * Initialize vn_ops, vn_mode, vn_devid and vn_len.
+     * If the filesystem wishes, it may initialize and use vn_i.
+     */
+    void (*read_vnode)(struct fs *fs, struct vnode *vn);
+
+    /*
+     * Called when the vnode's reference count drops to 0.
+     * Perform any necessary cleanup for the corresponding inode.
+     */
+    void (*delete_vnode)(struct fs *fs, struct vnode *vn);
+
+    /*
+     * Optional. Default behavior is to vput() fs_root.
+     * Unmount the filesystem, performing any desired sanity checks
+     * and/or necessary cleanup.
+     * Return 0 on success; negative number on error.
+     */
+    long (*umount)(struct fs *fs);
+
+    void (*sync)(struct fs *fs);
+} fs_ops_t;
+
+#ifndef STR_MAX
+#define STR_MAX 32
+#endif
+
+/* similar to Linux's super_block. */
+typedef struct fs
+{
+    /*
+     * The string name of the device from which this file system should
+     * be mounted. This may be used by the mount function of some file
+     * systems which need to know which device they are mounting.
+     */
+    char fs_dev[STR_MAX];
+    /*
+     * The type of file system this structure represents (given as a
+     * well-defined string). This is used by the generic VFS mount
+     * function to decide which filesystem-specific mount function to
+     * call.  Valid values are hard-coded in vfs.c.
+     */
+    char fs_type[STR_MAX];
+
+#ifdef __MOUNTING__
+    /*
+     * If mounting is implemented then this should point to the vnode
+     * of the file that this file system is mounted on. For the root file
+     * system this will just point to the root of that file system.
+     */
+    struct vnode *fs_mtpt;
+
+    /*
+     * An identifier for the mounted file system. This should be enlisted
+     * by the the kernel to keep track of all mounted file systems.
+     */
+    list_link_t fs_link;
+#endif
+
+    /*
+     * The following members are initialized by the filesystem
+     * implementation's mount routine:
+     */
+
+    /*
+     * The struct of operations that define which filesystem-specific
+     * functions to call to perform filesystem manipulation.
+     */
+    fs_ops_t *fs_ops;
+
+    /*
+     * The root vnode for this filesystem (not to be confused with
+     * either / (the root of VFS) or the vnode where the filesystem is
+     * mounted, which is on a different file system.
+     */
+    struct vnode *fs_root;
+
+    /* Filesystem-specific data. */
+    void *fs_i;
+
+    struct slab_allocator *fs_vnode_allocator;
+    list_t vnode_list;
+    kmutex_t vnode_list_mutex;
+    kmutex_t vnode_rename_mutex;
+
+} fs_t;
+
+/* - this is the vnode on which we will mount the vfsroot fs.
+ */
+extern fs_t vfs_root_fs;
+
+void do_sync();
+
+/* VFS {{{ */
+/*
+ * - called by the init process at system shutdown
+ * - at this point, init process is the only process running
+ *     => so, there should be no "live" vnodes
+ *
+ * unmount the root filesystem (and first unmount any filesystems mounted
+ * on the root filesystem in the proper order (bottom up)).
+ *
+ */
+
+/* VFS }}} */
+/* VFS Shutdown: */
+/*
+ *    Called by the init process at system shutdown.
+ *     
+ *    At this point, the init process is the only process running
+ *     => so, there should be no "live" vnodes
+ */
+long vfs_shutdown();
+
+/* Pathname resolution: */
+/* (the corresponding definitions live in namev.c) */
+long namev_lookup(struct vnode *dir, const char *name, size_t namelen,
+                  struct vnode **out);
+
+long namev_dir(struct vnode *base, const char *path, struct vnode **res_vnode,
+               const char **name, size_t *namelen);
+
+long namev_open(struct vnode *base, const char *path, int oflags, int mode,
+                devid_t devid, struct vnode **res_vnode);
+
+long namev_resolve(struct vnode *base, const char *path,
+                   struct vnode **res_vnode);
+
+long namev_get_child(struct vnode *dir, char *name, size_t namelen,
+                     struct vnode **out);
+
+long namev_get_parent(struct vnode *dir, struct vnode **out);
+
+long namev_is_descendant(struct vnode *a, struct vnode *b);
+
+#ifdef __GETCWD__
+long lookup_name(struct vnode *dir, struct vnode *entry, char *buf,
+                 size_t size);
+long lookup_dirpath(struct vnode *dir, char *buf, size_t size);
+#endif /* __GETCWD__ */
+
+long mountfunc(fs_t *fs);