Added very basic vfs

4 files changed, 213 insertions, 2 deletions

diff --git a/src/kernel/fs/ext2.c b/src/kernel/fs/ext2.c
index c95c134..ce8338a 100644
--- a/src/kernel/fs/ext2.c
+++ b/src/kernel/fs/ext2.c
@@ -7,6 +7,7 @@
 #include <kernel/memory/alloc.h>
 #include <kernel/lib/lib.h>
 #include <kernel/lib/stdlib.h>
+#include <kernel/fs/vfs.h>
 
 static struct ext2_superblock superblock;
 static struct bgd *bgdt;
@@ -231,4 +232,97 @@ uint32_t ext2_look_up_path(char *path)
 		return 0;
 
 	return inode;
-}
\ No newline at end of file
+}
+
+// VFS Implementation
+
+void ext2_vfs_open(struct fs_node *node)
+{
+	node->inode = ext2_look_up_path(node->name);
+
+	if (node->inode != 0) {
+		struct ext2_file *file = kmalloc(sizeof *file);
+		ext2_open_inode(node->inode, file);
+
+		node->impl = file;
+
+		// TODO: More file metadata
+	}
+}
+
+static void ext2_vfs_close(struct fs_node *node)
+{
+	kfree(node->impl);
+}
+
+static uint32_t ext2_vfs_read(struct fs_node *node, size_t offset, size_t size, char *buf)
+{
+	if (offset != ((struct ext2_file *)node->impl)->pos) {
+		panic("Seeking is currently unsupported for Ext2 files");
+		return 0;
+	}
+
+	return (uint32_t)ext2_read(node->impl, (uint8_t *)buf, size);
+}
+
+static uint32_t ext2_vfs_write(struct fs_node *node, size_t offset, size_t size, char *buf)
+{
+	panic("Writing to Ext2 is currently unsupported");
+
+	return 0;
+}
+
+static struct dir_entry *ext2_vfs_read_dir(struct fs_node *node, size_t index)
+{
+	struct ext2_dirent ext2_dir;
+
+	if (ext2_next_dirent(node->impl, &ext2_dir)) {
+		struct dir_entry *dir = kmalloc(sizeof *dir);
+
+		dir->inode = ext2_dir.inode_num;
+		strcpy(dir->name, (char *)ext2_dir.name);
+
+		return dir;
+	} else {
+		return NULL;
+	}
+}
+
+static struct fs_node *ext2_vfs_find_dir(struct fs_node *node, char *name)
+{
+	uint32_t inode = ext2_find_in_dir(node->inode, name);
+	if (inode == 0) {
+		return NULL;
+	} else {
+		struct fs_node *found = kmalloc(sizeof *found);
+		found->inode = inode;
+
+		return found;
+	}
+}
+
+void ext2_mount(struct fs_node *mountpoint)
+{
+	assert(mountpoint->node_ptr == NULL && (mountpoint->type & MOUNTPOINT_NODE) == 0);
+	assert((mountpoint->type & DIR_NODE) != 0);
+
+	struct fs_node *ext2_root = (struct fs_node *)kmalloc(sizeof(struct fs_node));
+	ext2_root->name[0] = '\0';
+	ext2_root->permissions = 0;
+	ext2_root->uid = 0;
+	ext2_root->gid = 0;
+	ext2_root->inode = ROOT_INODE;
+	ext2_root->length = 0;
+	ext2_root->type = DIR_NODE;
+	ext2_root->read = ext2_vfs_read;
+	ext2_root->write = ext2_vfs_write;
+	ext2_root->open = ext2_vfs_open;
+	ext2_root->close = ext2_vfs_close;
+	ext2_root->read_dir = ext2_vfs_read_dir;
+	ext2_root->find_dir = ext2_vfs_find_dir;
+	ext2_root->node_ptr = NULL;
+	ext2_root->impl = NULL;
+
+	mountpoint->type |= MOUNTPOINT_NODE;
+	mountpoint->node_ptr = ext2_root;
+}
diff --git a/src/kernel/fs/ext2.h b/src/kernel/fs/ext2.h
index e5e0f1c..f3ea4a0 100644
--- a/src/kernel/fs/ext2.h
+++ b/src/kernel/fs/ext2.h
@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <kernel/fs/vfs.h>
 
 #define ROOT_INODE 2
 
@@ -137,4 +138,6 @@ bool ext2_next_dirent(struct ext2_file *file, struct ext2_dirent *dir);
 uint32_t ext2_find_in_dir(uint32_t dir_inode, const char *name);
 uint32_t ext2_look_up_path(char *path);
 
-#endif
\ No newline at end of file
+void ext2_mount(struct fs_node *mountpoint);
+
+#endif
diff --git a/src/kernel/fs/vfs.c b/src/kernel/fs/vfs.c
new file mode 100644
index 0000000..075117e
--- /dev/null
+++ b/src/kernel/fs/vfs.c
@@ -0,0 +1,48 @@
+#include <stddef.h>
+#include <kernel/fs/vfs.h>
+
+struct fs_node *fs_root = NULL;
+
+uint32_t read_fs_node(struct fs_node *node, size_t offset, size_t size, char *buf)
+{
+	if (node->read != NULL)
+		return node->read(node, offset, size, buf);
+	else
+		return 0;
+}
+
+uint32_t write_fs_node(struct fs_node *node, size_t offset, size_t size, char *buf)
+{
+	if (node->write != NULL)
+		return node->write(node, offset, size, buf);
+	else
+		return 0;
+}
+
+void open_fs_node(struct fs_node *node, bool read, bool write)
+{
+	if (node->open != NULL)
+		node->open(node);
+}
+
+void close_fs_node(struct fs_node *node)
+{
+	if (node->close != NULL)
+		node->close(node);
+}
+
+struct dir_entry *read_dir_node(struct fs_node *node, size_t index)
+{
+	if ((node->type & DIR_NODE) != 0 && node->read_dir != NULL)
+		return node->read_dir(node, index);
+	else
+		return NULL;
+}
+
+struct fs_node *find_dir_node(struct fs_node *node, char *name)
+{
+	if ((node->type & DIR_NODE) != 0 && node->find_dir != NULL)
+		return node->find_dir(node, name);
+	else
+		return NULL;
+}
diff --git a/src/kernel/fs/vfs.h b/src/kernel/fs/vfs.h
new file mode 100644
index 0000000..41d80eb
--- /dev/null
+++ b/src/kernel/fs/vfs.h
@@ -0,0 +1,66 @@
+#ifndef MELVIX_VFS_H
+#define MELVIX_VFS_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define MAX_NAME_LENGTH 128
+
+enum node_type {
+	FILE_NODE = 1,
+	DIR_NODE,
+	CHAR_DEV_NODE,
+	BLOCK_DEV_NODE,
+	PIPE_NODE,
+	SYMLINK_NODE,
+	MOUNTPOINT_NODE = 8
+};
+
+struct fs_node;
+struct dir_entry;
+
+typedef uint32_t (*read)(struct fs_node *, size_t, size_t, char *);
+typedef uint32_t (*write)(struct fs_node *, size_t, size_t, char *);
+typedef void (*open)(struct fs_node *);
+typedef void (*close)(struct fs_node *);
+
+typedef struct dir_entry *(*read_dir)(struct fs_node *, size_t);
+typedef struct fs_node *(*find_dir)(struct fs_node *, char *);
+
+struct fs_node {
+	char name[MAX_NAME_LENGTH];
+	uint32_t length;
+	uint32_t inode;
+	uint32_t permissions;
+	uint32_t uid;
+	uint32_t gid;
+	enum node_type type;
+
+	struct fs_node *node_ptr;
+
+	void *impl;
+
+	read read;
+	write write;
+	open open;
+	close close;
+	read_dir read_dir;
+	find_dir find_dir;
+};
+
+struct dir_entry {
+	char name[MAX_NAME_LENGTH];
+	uint32_t inode;
+};
+
+struct fs_node *fs_root;
+
+uint32_t read_fs_node(struct fs_node *node, size_t offset, size_t size, char *buf);
+uint32_t write_fs_node(struct fs_node *node, size_t offset, size_t size, char *buf);
+void open_fs_node(struct fs_node *node, bool read, bool write);
+void close_fs_node(struct fs_node *node);
+struct dir_entry *read_dir_node(struct fs_node *node, size_t index);
+struct fs_node *find_dir_node(struct fs_node *node, char *name);
+
+#endif