lib: fs: add library for implementing a filesystem service

lib/libfs/include/fs/allocator.h

@@ -0,0 +1,19 @@
+#ifndef FS_ALLOCATOR_H_
+#define FS_ALLOCATOR_H_
+
+#include <stddef.h>
+
+struct fs_allocator {
+	void *fs_arg;
+	void *(*fs_alloc)(struct fs_allocator *, size_t);
+	void *(*fs_calloc)(struct fs_allocator *, size_t, size_t);
+	void *(*fs_realloc)(struct fs_allocator *, void *, size_t);
+	void (*fs_free)(struct fs_allocator *, void *);
+};
+
+extern void *fs_alloc(struct fs_allocator *alloc, size_t count);
+extern void *fs_calloc(struct fs_allocator *alloc, size_t count, size_t sz);
+extern void *fs_realloc(struct fs_allocator *alloc, void *p, size_t count);
+extern void fs_free(struct fs_allocator *alloc, void *p);
+
+#endif

lib/libfs/include/fs/context.h

@@ -0,0 +1,31 @@
+#ifndef FS_CONTEXT_H_
+#define FS_CONTEXT_H_
+
+#include <rosetta/fs.h>
+
+struct fs_file;
+struct fs_context;
+struct fs_allocator;
+struct fs_superblock;
+
+extern struct fs_context *fs_context_create(
+	struct fs_allocator *alloc,
+	struct fs_superblock *sb);
+extern void fs_context_destroy(struct fs_context *ctx);
+
+extern struct fs_file *fs_context_open_file(
+	struct fs_context *ctx,
+	unsigned long id);
+extern void fs_context_close_file(struct fs_context *ctx, struct fs_file *f);
+
+extern struct fs_dentry *fs_context_resolve_path(
+	struct fs_context *ctx,
+	const char *path);
+
+extern kern_status_t fs_context_dispatch_msg(
+	struct fs_context *ctx,
+	kern_handle_t channel,
+	struct msg_endpoint *sender,
+	struct msg_header *hdr);
+
+#endif

lib/libfs/include/fs/dentry.h

@@ -0,0 +1,18 @@
+#ifndef FS_DENTRY_H_
+#define FS_DENTRY_H_
+
+struct fs_inode;
+struct fs_superblock;
+
+struct fs_dentry_ops {
+};
+
+struct fs_dentry {
+	struct fs_inode *d_inode;
+	struct fs_dentry *d_parent;
+	struct fs_superblock *d_sb;
+	const struct fs_dentry_ops *d_ops;
+	void *d_fsdata;
+};
+
+#endif

lib/libfs/include/fs/file.h

@@ -0,0 +1,15 @@
+#ifndef FS_FILE_H_
+#define FS_FILE_H_
+
+#include <mango/types.h>
+#include <stddef.h>
+
+struct fs_file;
+
+struct fs_file_ops {
+	ssize_t (*f_read)(struct fs_file *, void *, size_t);
+	ssize_t (*f_write)(struct fs_file *, const void *, size_t);
+	off_t (*f_seek)(struct fs_file *, off_t, int);
+};
+
+#endif

lib/libfs/include/fs/inode.h

@@ -0,0 +1,17 @@
+#ifndef FS_INODE_H_
+#define FS_INODE_H_
+
+struct fs_inode;
+struct fs_dentry;
+struct fs_superblock;
+
+struct fs_inode_ops {
+	int (*i_lookup)(struct fs_inode *, struct fs_dentry *);
+};
+
+struct fs_inode {
+	struct fs_superblock *i_sb;
+	const struct fs_inode_ops *i_ops;
+};
+
+#endif

lib/libfs/include/fs/superblock.h

@@ -0,0 +1,20 @@
+#ifndef FS_SUPERBLOCK_H_
+#define FS_SUPERBLOCK_H_
+
+struct fs_inode;
+struct fs_dentry;
+struct fs_superblock;
+
+struct fs_superblock_ops {
+	struct fs_inode *(*s_alloc_inode)(struct fs_superblock *);
+};
+
+struct fs_superblock {
+	const struct fs_superblock_ops *s_ops;
+
+	struct fs_dentry *s_root;
+};
+
+extern struct fs_inode *fs_superblock_alloc_inode(struct fs_superblock *sb);
+
+#endif