kernel: Add initial VFS implementation

Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 227 insertions, 0 deletions

diff --git a/sys/include/fs/initramfs.h b/sys/include/fs/initramfs.h
new file mode 100644
index 0000000..c507e3d
--- /dev/null
+++ b/sys/include/fs/initramfs.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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_INITRAMFS_H_
+#define _FS_INITRAMFS_H_
+
+#include <sys/mount.h>
+
+extern struct vfsops g_initramfs_ops;
+
+const char *initramfs_open(const char *path);
+
+#endif  /* !_FS_INITRAMFS_H_ */
diff --git a/sys/include/sys/mount.h b/sys/include/sys/mount.h
new file mode 100644
index 0000000..014ce89
--- /dev/null
+++ b/sys/include/sys/mount.h
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 _SYS_MOUNT_H_
+#define _SYS_MOUNT_H_
+
+#include <sys/types.h>
+#include <sys/queue.h>
+
+#define FS_NAME_MAX 16 /* Max length of FS type name including nul */
+
+struct fs_info;
+struct mount;
+
+struct vfsops {
+    int(*init)(struct fs_info *info);
+    int(*vget_name)(struct fs_info *info, const char *name);
+};
+
+struct mount {
+    int flags;
+    size_t phash;               /* Path hash */
+    TAILQ_ENTRY(mount) link;
+};
+
+struct fs_info {
+    char name[FS_NAME_MAX];     /* Filesystem type name */
+    struct vfsops *vfsops;      /* Filesystem operations */
+    struct mount *mp_root;
+};
+
+/*
+ * Mount flags
+ */
+#define MNT_RDONLY  0x00000001
+
+#if defined(_KERNEL)
+
+/* For caching */
+#define MOUNTLIST_SIZE 8
+
+/* Mountlist cache entry */
+struct mountlist_entry {
+    TAILQ_HEAD(, mount) buckets;
+};
+
+int vfs_mount(struct mount **mp_out, const char *path, int mnt_flags);
+#endif  /* defined(_KERNEL) */
+
+#endif  /* !_SYS_MOUNT_H_ */
diff --git a/sys/include/sys/vfs.h b/sys/include/sys/vfs.h
new file mode 100644
index 0000000..2c056a1
--- /dev/null
+++ b/sys/include/sys/vfs.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 _SYS_VFS_H_
+#define _SYS_VFS_H_
+
+#include <sys/mount.h>
+#include <sys/vnode.h>
+#include <sys/types.h>
+
+#if defined(_KERNEL)
+void vfs_init(void);
+struct fs_info *vfs_byname(const char *name);
+
+struct vnode *vfs_path_to_node(const char *path);
+char *vfs_get_fname_at(const char *path, size_t idx);
+bool vfs_is_valid_path(const char *path);
+size_t vfs_hash_path(const char *path);
+
+void vfs_init_cache(void);
+int vfs_cache_mp(struct mount *mp, const char *path);
+int vfs_cache_fetch_mp(const char *path, struct mount **mp);
+#endif /* defined(_KERNEL) */
+
+#endif  /* !_SYS_VFS_H_ */
diff --git a/sys/include/sys/vnode.h b/sys/include/sys/vnode.h
new file mode 100644
index 0000000..3cfcc7a
--- /dev/null
+++ b/sys/include/sys/vnode.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * 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 Hyra 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 _SYS_VNODE_H_
+#define _SYS_VNODE_H_
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/mount.h>
+
+/* Vnode cache entry */
+struct vnode_cache {
+    const char *path;
+    struct vnode *vnode;
+};
+
+struct vnode {
+    int type;
+    int flags;
+    int usecount;       /* Ref count of uses */
+    struct mount *mp;   /* Ptr to vfs vnode is in */
+    TAILQ_ENTRY(vnode) freelist;
+};
+
+/*
+ * Vnode v_type flags
+ */
+#define VREG    0x01    /* Regular file */
+#define VDIR    0x02    /* Directory */
+
+#if defined(_KERNEL)
+int vfs_alloc_vnode(struct vnode **vnode, struct mount *mp, int type);
+#endif
+
+#endif