+/**
+ * @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
static struct cake_pile* inode_pile;
static struct cake_pile* file_pile;
static struct cake_pile* superblock_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 hstr vfs_empty = HSTR("", 0);
+
struct v_dnode*
vfs_d_alloc();
// 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);
- inode_pile = cake_new_pile("file_cache", sizeof(struct v_file), 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("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));
+
+ hstr_rehash(&vfs_ddot, HSTR_FULL_HASH);
+ hstr_rehash(&vfs_dot, HSTR_FULL_HASH);
- // 挂载Lunaix的根文件系统，TwiFS！
- struct filesystem* rootfs = fsm_get("twifs");
+ // 创建一个根superblock，用来蕴含我们的根目录。
root_sb = vfs_sb_alloc();
- rootfs->mount(root_sb, NULL);
+ 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 || HSTR_EQ(str, &vfs_dot))
+ return parent;
+
+ if (HSTR_EQ(str, &vfs_ddot)) {
+ return parent->parent ? parent->parent : parent;
+ }
+
struct hbucket* slot = __dcache_get_bucket(parent, str->hash);
struct v_dnode *pos, *n;
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) {
- if ((walk_options & VFS_WALK_FSRELATIVE)) {
+ if (path[0] == PATH_DELIM || !start) {
+ if ((walk_options & VFS_WALK_FSRELATIVE) && start) {
start = start->super_block->root;
} else {
start = root_sb->root;
lookahead = path[i++];
if (current != PATH_DELIM) {
if (j >= VFS_NAME_MAXLEN - 1) {
- return VFS_ETOOLONG;
+ return ENAMETOOLONG;
}
if (!VFS_VALID_CHAR(current)) {
return VFS_EINVLD;
}
name_content[j] = 0;
+ 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) {
errno =
current_level->inode->ops.dir_lookup(current_level->inode, dnode);
- if (errno == VFS_ENOTFOUND &&
- ((walk_options & VFS_WALK_MKPARENT) ||
- ((walk_options & VFS_WALK_MKDIR) && !lookahead))) {
- /*
- 两种创建文件夹的情况：
- 1) VFS_WALK_MKPARENT：沿路创建所有不存在的文件夹
- 2) VFS_WALK_MKDIR：仅创建路径最后一级的不存在文件夹
- */
+ if (errno == ENOENT && (walk_options & VFS_WALK_MKPARENT)) {
if (!current_level->inode->ops.mkdir) {
- errno = VFS_ENOOPS;
+ errno = ENOTSUP;
} else {
errno = current_level->inode->ops.mkdir(
current_level->inode, dnode);
error:
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)
}
int
-vfs_mkdir(const char* parent_path,
- const char* component,
- struct v_dnode** dentry)
-{
- return vfs_walk(root_sb->root, parent_path, dentry, VFS_WALK_MKDIR);
-}
-
-int
-vfs_unmount(struct v_dnode* mnt_point)
+vfs_unmount_at(struct v_dnode* mnt_point)
{
int errno = 0;
struct v_superblock* sb = mnt_point->super_block;
vfs_open(struct v_dnode* dnode, struct v_file** file)
{
if (!dnode->inode || !dnode->inode->ops.open) {
- return VFS_ENOOPS;
+ return ENOTSUP;
}
struct v_file* vfile = cake_grab(file_pile);
memset(vfile, 0, sizeof(*vfile));
+ vfile->dnode = dnode;
+ vfile->inode = dnode->inode;
+
int errno = dnode->inode->ops.open(dnode->inode, vfile);
if (errno) {
cake_release(file_pile, vfile);
vfs_close(struct v_file* file)
{
if (!file->ops.close) {
- return VFS_ENOOPS;
+ return ENOTSUP;
}
int errno = file->ops.close(file);
int
vfs_fsync(struct v_file* file)
{
- int errno = VFS_ENOOPS;
+ int errno = ENOTSUP;
if (file->ops.sync) {
errno = file->ops.sync(file);
}
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*
vfs_sb_alloc()
{
vfs_d_alloc()
{
struct v_dnode* dnode = cake_grab(dnode_pile);
+ memset(dnode, 0, sizeof(*dnode));
llist_init_head(&dnode->children);
+ dnode->name = vfs_empty;
+ return dnode;
}
void
{
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;
+
+ 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;
+ }
+
+ __current->k_status = errno;
+ 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 (dent->d_offset == 0) {
+ __vfs_readdir_callback(&dctx, vfs_dot.value, vfs_dot.len, 0);
+ } else if (dent->d_offset == 1) {
+ __vfs_readdir_callback(&dctx, vfs_ddot.value, vfs_ddot.len, 0);
+ } else {
+ dctx.index -= 2;
+ if ((errno = fd_s->file->ops.readdir(fd_s->file, &dctx))) {
+ goto done;
+ }
+ }
+ errno = 0;
+ dent->d_offset++;
+ }
+
+done:
+ __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);
+}
+
+int
+vfs_readlink(struct v_dnode* dnode, char* buf, size_t size, int depth)
+{
+ if (!dnode) {
+ return 0;
+ }
+
+ if (depth > 64) {
+ return ELOOP;
+ }
+
+ size_t len = vfs_readlink(dnode->parent, buf, size, depth + 1);
+
+ if (len >= size) {
+ return len;
+ }
+
+ size_t cpy_size = MIN(dnode->name.len, size - len);
+ strncpy(buf + len, dnode->name.value, cpy_size);
+ len += cpy_size;
+
+ if (len < size) {
+ buf[len++] = PATH_DELIM;
+ }
+
+ return len;
+}
+
+__DEFINE_LXSYSCALL3(int, readlink, const char*, path, char*, buf, size_t, size)
+{
+ int errno;
+ struct v_dnode* dnode;
+ if (!(errno = vfs_walk(NULL, path, &dnode, NULL, 0))) {
+ errno = vfs_readlink(dnode, buf, size, 0);
+ }
+
+ if (errno >= 0) {
+ return errno;
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
+
+__DEFINE_LXSYSCALL4(int,
+ readlinkat,
+ int,
+ dirfd,
+ const char*,
+ pathname,
+ char*,
+ buf,
+ size_t,
+ size)
+{
+ int errno;
+ struct v_fd* fd_s;
+ if (!GET_FD(dirfd, fd_s)) {
+ errno = EBADF;
+ } else {
+ struct v_dnode* dnode;
+ if (!(errno = vfs_walk(fd_s->file->dnode, pathname, &dnode, NULL, 0))) {
+ errno = vfs_readlink(fd_s->file->dnode, buf, size, 0);
+ }
+ }
+
+ if (errno >= 0) {
+ return errno;
+ }
+
+ __current->k_status = errno;
+ return SYSCALL_ESTATUS(errno);
+}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff