+/**
+ * @file vfs.c
+ * @author Lunaixsky (zelong56@gmail.com)
+ * @brief Lunaix virtual file system - an abstraction layer for all file system.
+ * @version 0.1
+ * @date 2022-07-24
+ *
+ * @copyright Copyright (c) 2022
+ *
+ */
+
#include <klibc/string.h>
+#include <lunaix/dirent.h>
+#include <lunaix/foptions.h>
#include <lunaix/fs.h>
#include <lunaix/mm/cake.h>
+#include <lunaix/mm/page.h>
#include <lunaix/mm/valloc.h>
+#include <lunaix/process.h>
+#include <lunaix/spike.h>
+#include <lunaix/syscall.h>
#define PATH_DELIM '/'
#define DNODE_HASHTABLE_BITS 10
#define DNODE_HASH_MASK (DNODE_HASHTABLE_SIZE - 1)
#define DNODE_HASHBITS (32 - DNODE_HASHTABLE_BITS)
-#define VFS_ETOOLONG -1
-#define VFS_ENOFS -2
-
static struct cake_pile* dnode_pile;
static struct cake_pile* inode_pile;
+static struct cake_pile* file_pile;
static struct cake_pile* superblock_pile;
-static struct cake_pile* name_pile;
+static struct cake_pile* fd_pile;
static struct v_superblock* root_sb;
static struct hbucket* dnode_cache;
static int fs_id = 0;
+struct hstr vfs_ddot = HSTR("..", 2);
+struct hstr vfs_dot = HSTR(".", 1);
+
struct v_dnode*
-__new_dnode();
+vfs_d_alloc();
void
-__free_dnode(struct v_dnode* dnode);
+vfs_d_free(struct v_dnode* dnode);
struct v_superblock*
-__new_superblock();
+vfs_sb_alloc();
void
-__free_superblock(struct v_superblock* sb);
+vfs_sb_free(struct v_superblock* sb);
void
vfs_init()
{
- // 为他们专门创建一个蛋糕堆，而不使用valloc，这样我们可以最小化内部碎片的产生
- dnode_pile = cake_new_pile("dnode", sizeof(struct v_dnode), 1, 0);
- inode_pile = cake_new_pile("inode", sizeof(struct v_inode), 1, 0);
- name_pile = cake_new_pile("dname", VFS_NAME_MAXLEN, 1, 0);
+ // 为他们专门创建一个蛋糕堆，而不使用valloc，这样我们可以最小化内碎片的产生
+ dnode_pile = cake_new_pile("dnode_cache", sizeof(struct v_dnode), 1, 0);
+ inode_pile = cake_new_pile("inode_cache", sizeof(struct v_inode), 1, 0);
+ file_pile = cake_new_pile("file_cache", sizeof(struct v_file), 1, 0);
+ fd_pile = cake_new_pile("fd_cache", sizeof(struct v_fd), 1, 0);
superblock_pile =
- cake_new_pile("superblock", sizeof(struct v_superblock), 1, 0);
+ cake_new_pile("sb_cache", sizeof(struct v_superblock), 1, 0);
- dnode_cache = valloc(DNODE_HASHTABLE_SIZE * sizeof(struct hbucket));
+ dnode_cache = vzalloc(DNODE_HASHTABLE_SIZE * sizeof(struct hbucket));
- // 挂载Lunaix的根文件系统，TwiFS！
- struct filesystem* rootfs = fsm_get("twifs");
- root_sb = __new_superblock();
- rootfs->mount(root_sb, NULL);
+ hstr_rehash(&vfs_ddot, HSTR_FULL_HASH);
+ hstr_rehash(&vfs_dot, HSTR_FULL_HASH);
+
+ // 创建一个根superblock，用来蕴含我们的根目录。
+ root_sb = vfs_sb_alloc();
+ root_sb->root = vfs_d_alloc();
}
inline struct hbucket*
struct v_dnode*
vfs_dcache_lookup(struct v_dnode* parent, struct hstr* str)
{
+ if (!str->len)
+ return parent;
+
struct hbucket* slot = __dcache_get_bucket(parent, str->hash);
struct v_dnode *pos, *n;
}
int
-vfs_walk(struct v_dnode* start, const char* path, struct v_dnode** dentry)
+vfs_walk(struct v_dnode* start,
+ const char* path,
+ struct v_dnode** dentry,
+ struct hstr* component,
+ int walk_options)
{
int errno = 0;
int i = 0, j = 0;
- if (path[0] == PATH_DELIM) {
- start = start->super_block->root;
+ if (path[0] == PATH_DELIM || !start) {
+ if ((walk_options & VFS_WALK_FSRELATIVE) && start) {
+ start = start->super_block->root;
+ } else {
+ start = root_sb->root;
+ }
i++;
}
char name_content[VFS_NAME_MAXLEN];
struct hstr name = HSTR(name_content, 0);
- char current, lookahead;
- do {
- current = path[i++];
+ char current = path[i++], lookahead;
+ while (current) {
lookahead = path[i++];
if (current != PATH_DELIM) {
if (j >= VFS_NAME_MAXLEN - 1) {
- errno = VFS_ETOOLONG;
- goto error;
+ return ENAMETOOLONG;
+ }
+ if (!VFS_VALID_CHAR(current)) {
+ return VFS_EINVLD;
}
name_content[j++] = current;
if (lookahead) {
- continue;
+ goto cont;
}
}
+ // handling cases like /^.*(\/+).*$/
+ if (lookahead == PATH_DELIM) {
+ goto cont;
+ }
+
name_content[j] = 0;
- hstr_rehash(&name, 32);
+ name.len = j;
+ hstr_rehash(&name, HSTR_FULL_HASH);
+
+ if (!lookahead && (walk_options & VFS_WALK_PARENT)) {
+ if (component) {
+ component->hash = name.hash;
+ component->len = j;
+ strcpy(component->value, name_content);
+ }
+ break;
+ }
dnode = vfs_dcache_lookup(current_level, &name);
if (!dnode) {
- dnode = __new_dnode();
- strcpy(dnode->name.value, name_content);
+ dnode = vfs_d_alloc();
+ dnode->name = HSTR(valloc(VFS_NAME_MAXLEN), j);
dnode->name.hash = name.hash;
- dnode->name.len = j;
- if ((errno =
- dnode->inode->ops.dir_lookup(current_level->inode, dnode))) {
+ strcpy(dnode->name.value, name_content);
+
+ errno =
+ current_level->inode->ops.dir_lookup(current_level->inode, dnode);
+
+ if (errno == ENOENT && (walk_options & VFS_WALK_MKPARENT)) {
+ if (!current_level->inode->ops.mkdir) {
+ errno = ENOTSUP;
+ } else {
+ errno = current_level->inode->ops.mkdir(
+ current_level->inode, dnode);
+ }
+ }
+
+ if (errno) {
goto error;
}
j = 0;
current_level = dnode;
- } while (lookahead);
+ cont:
+ current = lookahead;
+ };
- *dentry = dnode;
+ *dentry = current_level;
return 0;
error:
- __free_dnode(dnode);
+ vfree(dnode->name.value);
+ vfs_d_free(dnode);
+ *dentry = NULL;
return errno;
}
int
-vfs_mount(const char* fs_name, bdev_t device, struct v_dnode* mnt_point)
+vfs_mount(const char* target, const char* fs_name, bdev_t device)
+{
+ int errno;
+ struct v_dnode* mnt;
+
+ if (!(errno = vfs_walk(NULL, target, &mnt, NULL, 0))) {
+ errno = vfs_mount_at(fs_name, device, mnt);
+ }
+
+ return errno;
+}
+
+int
+vfs_unmount(const char* target)
+{
+ int errno;
+ struct v_dnode* mnt;
+
+ if (!(errno = vfs_walk(NULL, target, &mnt, NULL, 0))) {
+ errno = vfs_unmount_at(mnt);
+ }
+
+ return errno;
+}
+
+int
+vfs_mount_at(const char* fs_name, bdev_t device, struct v_dnode* mnt_point)
{
struct filesystem* fs = fsm_get(fs_name);
if (!fs)
return VFS_ENOFS;
- struct v_superblock* sb = __new_superblock();
+ struct v_superblock* sb = vfs_sb_alloc();
sb->dev = device;
sb->fs_id = fs_id++;
int errno = 0;
if (!(errno = fs->mount(sb, mnt_point))) {
sb->fs = fs;
+ sb->root = mnt_point;
+ mnt_point->super_block = sb;
llist_append(&root_sb->sb_list, &sb->sb_list);
}
}
int
-vfs_unmount(const int fs_id)
+vfs_unmount_at(struct v_dnode* mnt_point)
{
int errno = 0;
- struct v_superblock *pos, *n;
- llist_for_each(pos, n, &root_sb->sb_list, sb_list)
- {
- if (pos->fs_id != fs_id) {
- continue;
- }
- if (!(errno = pos->fs->unmount(pos))) {
- llist_delete(&pos->sb_list);
- __free_superblock(pos);
- }
- break;
+ struct v_superblock* sb = mnt_point->super_block;
+ if (!sb) {
+ return VFS_EBADMNT;
+ }
+ if (!(errno = sb->fs->unmount(sb))) {
+ struct v_dnode* fs_root = sb->root;
+ llist_delete(&fs_root->siblings);
+ llist_delete(&sb->sb_list);
+ vfs_sb_free(sb);
+ }
+ return errno;
+}
+
+int
+vfs_open(struct v_dnode* dnode, struct v_file** file)
+{
+ if (!dnode->inode || !dnode->inode->ops.open) {
+ return ENOTSUP;
+ }
+
+ struct v_file* vfile = cake_grab(file_pile);
+ memset(vfile, 0, sizeof(*vfile));
+
+ int errno = dnode->inode->ops.open(dnode->inode, vfile);
+ if (errno) {
+ cake_release(file_pile, vfile);
+ } else {
+ *file = vfile;
}
return errno;
}
+int
+vfs_close(struct v_file* file)
+{
+ if (!file->ops.close) {
+ return ENOTSUP;
+ }
+
+ int errno = file->ops.close(file);
+ if (!errno) {
+ cake_release(file_pile, file);
+ }
+ return errno;
+}
+
+int
+vfs_fsync(struct v_file* file)
+{
+ int errno = ENOTSUP;
+ if (file->ops.sync) {
+ errno = file->ops.sync(file);
+ }
+ if (!errno && file->inode->ops.sync) {
+ return file->inode->ops.sync(file->inode);
+ }
+ return errno;
+}
+
+int
+vfs_alloc_fdslot(int* fd)
+{
+ for (size_t i = 0; i < VFS_MAX_FD; i++) {
+ if (!__current->fdtable->fds[i]) {
+ *fd = i;
+ return 0;
+ }
+ }
+ return EMFILE;
+}
+
struct v_superblock*
-__new_superblock()
+vfs_sb_alloc()
{
struct v_superblock* sb = cake_grab(superblock_pile);
memset(sb, 0, sizeof(*sb));
llist_init_head(&sb->sb_list);
- sb->root = __new_dnode();
+ return sb;
}
void
-__free_superblock(struct v_superblock* sb)
+vfs_sb_free(struct v_superblock* sb)
{
- __free_dnode(sb->root);
cake_release(superblock_pile, sb);
}
struct v_dnode*
-__new_dnode()
+vfs_d_alloc()
{
struct v_dnode* dnode = cake_grab(dnode_pile);
- dnode->inode = cake_grab(inode_pile);
- dnode->name.value = cake_grab(name_pile);
+ memset(dnode, 0, sizeof(*dnode));
+ llist_init_head(&dnode->children);
+ return dnode;
}
void
-__free_dnode(struct v_dnode* dnode)
+vfs_d_free(struct v_dnode* dnode)
{
- cake_release(inode_pile, dnode->inode);
- cake_release(name_pile, dnode->name.value);
+ if (dnode->ops.destruct) {
+ dnode->ops.destruct(dnode);
+ }
cake_release(dnode_pile, dnode);
+}
+
+struct v_inode*
+vfs_i_alloc()
+{
+ struct v_inode* inode = cake_grab(inode_pile);
+ memset(inode, 0, sizeof(*inode));
+
+ return inode;
+}
+
+void
+vfs_i_free(struct v_inode* inode)
+{
+ cake_release(inode_pile, inode);
+}
+
+int
+__vfs_do_open(struct v_file** file_out, const char* path, int options)
+{
+ char name_str[VFS_NAME_MAXLEN];
+ struct hstr name = HSTR(name_str, 0);
+ struct v_dnode *dentry, *file;
+ int errno;
+ if ((errno = vfs_walk(NULL, path, &dentry, &name, VFS_WALK_PARENT))) {
+ return ENOENT;
+ }
+
+ vfs_walk(dentry, name.value, &file, NULL, 0);
+
+ struct v_file* opened_file = 0;
+ if (!file) {
+ if ((options & FO_CREATE)) {
+ errno = dentry->inode->ops.create(dentry->inode, opened_file);
+ } else {
+ errno = ENOENT;
+ }
+ } else {
+ errno = vfs_open(file, &opened_file);
+ }
+
+ *file_out = opened_file;
+ return errno;
+}
+
+__DEFINE_LXSYSCALL2(int, open, const char*, path, int, options)
+{
+ struct v_file* opened_file;
+ int errno = __vfs_do_open(&opened_file, path, options), fd;
+
+ __current->k_status = errno;
+
+ if (!errno && !(errno = vfs_alloc_fdslot(&fd))) {
+ struct v_fd* fd_s = vzalloc(sizeof(*fd_s));
+ fd_s->file = opened_file;
+ fd_s->pos = opened_file->inode->fsize & -((options & FO_APPEND) != 0);
+ __current->fdtable->fds[fd] = fd_s;
+ return fd;
+ }
+
+ return SYSCALL_ESTATUS(errno);
+}
+
+#define GET_FD(fd, fd_s) \
+ (fd >= 0 && fd < VFS_MAX_FD && (fd_s = __current->fdtable->fds[fd]))
+
+__DEFINE_LXSYSCALL1(int, close, int, fd)
+{
+ struct v_fd* fd_s;
+ int errno;
+ if (!GET_FD(fd, fd_s)) {
+ errno = EBADF;
+ } else if (!(errno = vfs_close(fd_s->file))) {
+ vfree(fd_s);
+ __current->fdtable->fds[fd] = 0;
+ }
+
+ __current->k_status = errno;
+
+ return SYSCALL_ESTATUS(errno);
+}
+
+void
+__vfs_readdir_callback(struct dir_context* dctx,
+ const char* name,
+ const int len,
+ const int dtype)
+{
+ struct dirent* dent = (struct dirent*)dctx->cb_data;
+ strncpy(dent->d_name, name, DIRENT_NAME_MAX_LEN);
+ dent->d_nlen = len;
+ dent->d_type = dtype;
+}
+
+__DEFINE_LXSYSCALL2(int, readdir, int, fd, struct dirent*, dent)
+{
+ struct v_fd* fd_s;
+ int errno;
+ if (!GET_FD(fd, fd_s)) {
+ errno = EBADF;
+ } else if (!(fd_s->file->inode->itype & VFS_INODE_TYPE_DIR)) {
+ errno = ENOTDIR;
+ } else {
+ struct dir_context dctx =
+ (struct dir_context){ .cb_data = dent,
+ .index = dent->d_offset,
+ .read_complete_callback =
+ __vfs_readdir_callback };
+ if (!(errno = fd_s->file->ops.readdir(fd_s->file, &dctx))) {
+ dent->d_offset++;
+ }
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
+
+__DEFINE_LXSYSCALL1(int, mkdir, const char*, path)
+{
+ struct v_dnode *parent, *dir;
+ struct hstr component = HSTR(valloc(VFS_NAME_MAXLEN), 0);
+ int errno = vfs_walk(NULL, path, &parent, &component, VFS_WALK_PARENT);
+ if (errno) {
+ goto done;
+ }
+
+ if ((parent->super_block->fs->types & FSTYPE_ROFS)) {
+ errno = ENOTSUP;
+ } else if (!parent->inode->ops.mkdir) {
+ errno = ENOTSUP;
+ } else if (!(parent->inode->itype & VFS_INODE_TYPE_DIR)) {
+ errno = ENOTDIR;
+ } else {
+ dir = vfs_d_alloc();
+ dir->name = component;
+ if (!(errno = parent->inode->ops.mkdir(parent->inode, dir))) {
+ llist_append(&parent->children, &dir->siblings);
+ } else {
+ vfs_d_free(dir);
+ vfree(component.value);
+ }
+ }
+
+done:
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
+
+__DEFINE_LXSYSCALL3(int, read, int, fd, void*, buf, size_t, count)
+{
+ int errno = 0;
+ struct v_fd* fd_s;
+ if (!GET_FD(fd, fd_s)) {
+ errno = EBADF;
+ } else {
+ struct v_file* file = fd_s->file;
+ file->f_pos = fd_s->pos;
+ if ((errno = file->ops.read(file, buf, count)) >= 0) {
+ fd_s->pos += errno;
+ }
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
+
+__DEFINE_LXSYSCALL3(int, write, int, fd, void*, buf, size_t, count)
+{
+ int errno = 0;
+ struct v_fd* fd_s;
+ if (!GET_FD(fd, fd_s)) {
+ errno = EBADF;
+ } else {
+ struct v_file* file = fd_s->file;
+ file->f_pos = fd_s->pos;
+ if ((errno = file->ops.write(file, buf, count)) >= 0) {
+ fd_s->pos += errno;
+ }
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
+
+__DEFINE_LXSYSCALL3(int, lseek, int, fd, int, offset, int, options)
+{
+ int errno = 0;
+ struct v_fd* fd_s;
+ if (!GET_FD(fd, fd_s)) {
+ errno = EBADF;
+ } else {
+ size_t fpos = fd_s->file->f_pos;
+ switch (options) {
+ case FSEEK_CUR:
+ fpos = (size_t)((int)fd_s->file->f_pos + offset);
+ break;
+ case FSEEK_END:
+ fpos = (size_t)((int)fd_s->file->inode->fsize + offset);
+ break;
+ case FSEEK_SET:
+ fpos = offset;
+ break;
+
+ default:
+ break;
+ }
+ fd_s->pos = fpos;
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff