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circuitpython/extmod/vfs.c

466 lines
17 KiB

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdint.h>
#include <string.h>
#include "py/runtime.h"
#include "py/objstr.h"
#include "py/mperrno.h"
#include "extmod/vfs.h"
#if MICROPY_VFS
#if MICROPY_VFS_FAT
#include "extmod/vfs_fat.h"
#endif
// For mp_vfs_proxy_call, the maximum number of additional args that can be passed.
// A fixed maximum size is used to avoid the need for a costly variable array.
#define PROXY_MAX_ARGS (2)
// path is the path to lookup and *path_out holds the path within the VFS
// object (starts with / if an absolute path).
// Returns MP_VFS_ROOT for root dir (and then path_out is undefined) and
// MP_VFS_NONE for path not found.
mp_vfs_mount_t *mp_vfs_lookup_path(const char *path, const char **path_out) {
if (*path == '/' || MP_STATE_VM(vfs_cur) == MP_VFS_ROOT) {
// an absolute path, or the current volume is root, so search root dir
bool is_abs = 0;
if (*path == '/') {
++path;
is_abs = 1;
}
if (*path == '\0') {
// path is "" or "/" so return virtual root
return MP_VFS_ROOT;
}
for (mp_vfs_mount_t *vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) {
size_t len = vfs->len - 1;
if (len == 0) {
*path_out = path - is_abs;
return vfs;
}
if (strncmp(path, vfs->str + 1, len) == 0) {
if (path[len] == '/') {
*path_out = path + len;
return vfs;
} else if (path[len] == '\0') {
*path_out = "/";
return vfs;
}
}
}
// if we get here then there's nothing mounted on /
if (is_abs) {
// path began with / and was not found
return MP_VFS_NONE;
}
}
// a relative path within a mounted device
*path_out = path;
return MP_STATE_VM(vfs_cur);
}
// Version of mp_vfs_lookup_path that takes and returns uPy string objects.
STATIC mp_vfs_mount_t *lookup_path(mp_obj_t path_in, mp_obj_t *path_out) {
const char *path = mp_obj_str_get_str(path_in);
const char *p_out;
mp_vfs_mount_t *vfs = mp_vfs_lookup_path(path, &p_out);
if (vfs != MP_VFS_NONE && vfs != MP_VFS_ROOT) {
*path_out = mp_obj_new_str_of_type(mp_obj_get_type(path_in),
(const byte*)p_out, strlen(p_out));
}
return vfs;
}
STATIC mp_obj_t mp_vfs_proxy_call(mp_vfs_mount_t *vfs, qstr meth_name, size_t n_args, const mp_obj_t *args) {
assert(n_args <= PROXY_MAX_ARGS);
if (vfs == MP_VFS_NONE) {
// mount point not found
mp_raise_OSError(MP_ENODEV);
}
if (vfs == MP_VFS_ROOT) {
// can't do operation on root dir
mp_raise_OSError(MP_EPERM);
}
mp_obj_t meth[2 + PROXY_MAX_ARGS];
mp_load_method(vfs->obj, meth_name, meth);
if (args != NULL) {
memcpy(meth + 2, args, n_args * sizeof(*args));
}
return mp_call_method_n_kw(n_args, 0, meth);
}
mp_import_stat_t mp_vfs_import_stat(const char *path) {
const char *path_out;
mp_vfs_mount_t *vfs = mp_vfs_lookup_path(path, &path_out);
if (vfs == MP_VFS_NONE || vfs == MP_VFS_ROOT) {
return MP_IMPORT_STAT_NO_EXIST;
}
// If the mounted object has the VFS protocol, call its import_stat helper
const mp_vfs_proto_t *proto = (mp_vfs_proto_t*)mp_proto_get(MP_QSTR_protocol_vfs, vfs->obj);
if (proto != NULL) {
return proto->import_stat(MP_OBJ_TO_PTR(vfs->obj), path_out);
}
// delegate to vfs.stat() method
mp_obj_t path_o = mp_obj_new_str(path_out, strlen(path_out));
mp_obj_t stat;
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
stat = mp_vfs_proxy_call(vfs, MP_QSTR_stat, 1, &path_o);
nlr_pop();
} else {
// assume an exception means that the path is not found
return MP_IMPORT_STAT_NO_EXIST;
}
mp_obj_t *items;
mp_obj_get_array_fixed_n(stat, 10, &items);
mp_int_t st_mode = mp_obj_get_int(items[0]);
if (st_mode & MP_S_IFDIR) {
return MP_IMPORT_STAT_DIR;
} else {
return MP_IMPORT_STAT_FILE;
}
}
mp_obj_t mp_vfs_mount(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_readonly, ARG_mkfs };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_readonly, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_PTR(&mp_const_false_obj)} },
{ MP_QSTR_mkfs, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_PTR(&mp_const_false_obj)} },
};
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 2, pos_args + 2, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// get the mount point
size_t mnt_len;
const char *mnt_str = mp_obj_str_get_data(pos_args[1], &mnt_len);
// see if we need to auto-detect and create the filesystem
mp_obj_t vfs_obj = pos_args[0];
mp_obj_t dest[2];
mp_load_method_maybe(vfs_obj, MP_QSTR_mount, dest);
if (dest[0] == MP_OBJ_NULL) {
// Input object has no mount method, assume it's a block device and try to
// auto-detect the filesystem and create the corresponding VFS entity.
// (At the moment we only support FAT filesystems.)
#if MICROPY_VFS_FAT
vfs_obj = mp_fat_vfs_type.make_new(&mp_fat_vfs_type, 1, &vfs_obj, NULL);
#endif
}
// create new object
mp_vfs_mount_t *vfs = m_new_obj(mp_vfs_mount_t);
vfs->str = mnt_str;
vfs->len = mnt_len;
vfs->obj = vfs_obj;
vfs->next = NULL;
// call the underlying object to do any mounting operation
mp_vfs_proxy_call(vfs, MP_QSTR_mount, 2, (mp_obj_t*)&args);
// check that the destination mount point is unused
const char *path_out;
mp_vfs_mount_t *existing_mount = mp_vfs_lookup_path(mp_obj_str_get_str(pos_args[1]), &path_out);
if (existing_mount != MP_VFS_NONE && existing_mount != MP_VFS_ROOT) {
if (vfs->len != 1 && existing_mount->len == 1) {
// if root dir is mounted, still allow to mount something within a subdir of root
} else {
// mount point in use
mp_raise_OSError(MP_EPERM);
}
}
// insert the vfs into the mount table
mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table);
while (*vfsp != NULL) {
if ((*vfsp)->len == 1) {
// make sure anything mounted at the root stays at the end of the list
vfs->next = *vfsp;
break;
}
vfsp = &(*vfsp)->next;
}
*vfsp = vfs;
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(mp_vfs_mount_obj, 2, mp_vfs_mount);
mp_obj_t mp_vfs_umount(mp_obj_t mnt_in) {
// remove vfs from the mount table
mp_vfs_mount_t *vfs = NULL;
size_t mnt_len;
const char *mnt_str = NULL;
if (MP_OBJ_IS_STR(mnt_in)) {
mnt_str = mp_obj_str_get_data(mnt_in, &mnt_len);
}
for (mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table); *vfsp != NULL; vfsp = &(*vfsp)->next) {
if ((mnt_str != NULL && !memcmp(mnt_str, (*vfsp)->str, mnt_len + 1)) || (*vfsp)->obj == mnt_in) {
vfs = *vfsp;
*vfsp = (*vfsp)->next;
break;
}
}
if (vfs == NULL) {
mp_raise_OSError(MP_EINVAL);
}
// if we unmounted the current device then set current to root
if (MP_STATE_VM(vfs_cur) == vfs) {
MP_STATE_VM(vfs_cur) = MP_VFS_ROOT;
}
// call the underlying object to do any unmounting operation
mp_vfs_proxy_call(vfs, MP_QSTR_umount, 0, NULL);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_umount_obj, mp_vfs_umount);
// Note: buffering and encoding args are currently ignored
mp_obj_t mp_vfs_open(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_file, ARG_mode, ARG_encoding };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_rom_obj = MP_ROM_PTR(&mp_const_none_obj)} },
{ MP_QSTR_mode, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_QSTR(MP_QSTR_r)} },
{ MP_QSTR_buffering, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_encoding, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_PTR(&mp_const_none_obj)} },
};
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_vfs_mount_t *vfs = lookup_path(args[ARG_file].u_obj, &args[ARG_file].u_obj);
return mp_vfs_proxy_call(vfs, MP_QSTR_open, 2, (mp_obj_t*)&args);
}
MP_DEFINE_CONST_FUN_OBJ_KW(mp_vfs_open_obj, 0, mp_vfs_open);
mp_obj_t mp_vfs_chdir(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
MP_STATE_VM(vfs_cur) = vfs;
if (vfs == MP_VFS_ROOT) {
// If we change to the root dir and a VFS is mounted at the root then
// we must change that VFS's current dir to the root dir so that any
// subsequent relative paths begin at the root of that VFS.
for (vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) {
if (vfs->len == 1) {
mp_obj_t root = MP_OBJ_NEW_QSTR(MP_QSTR__slash_);
mp_vfs_proxy_call(vfs, MP_QSTR_chdir, 1, &root);
break;
}
}
} else {
mp_vfs_proxy_call(vfs, MP_QSTR_chdir, 1, &path_out);
}
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_chdir_obj, mp_vfs_chdir);
mp_obj_t mp_vfs_getcwd(void) {
if (MP_STATE_VM(vfs_cur) == MP_VFS_ROOT) {
return MP_OBJ_NEW_QSTR(MP_QSTR__slash_);
}
mp_obj_t cwd_o = mp_vfs_proxy_call(MP_STATE_VM(vfs_cur), MP_QSTR_getcwd, 0, NULL);
if (MP_STATE_VM(vfs_cur)->len == 1) {
// don't prepend "/" for vfs mounted at root
return cwd_o;
}
const char *cwd = mp_obj_str_get_str(cwd_o);
vstr_t vstr;
vstr_init(&vstr, MP_STATE_VM(vfs_cur)->len + strlen(cwd) + 1);
vstr_add_strn(&vstr, MP_STATE_VM(vfs_cur)->str, MP_STATE_VM(vfs_cur)->len);
if (!(cwd[0] == '/' && cwd[1] == 0)) {
vstr_add_str(&vstr, cwd);
}
return mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_0(mp_vfs_getcwd_obj, mp_vfs_getcwd);
mp_obj_t mp_vfs_ilistdir_it_iternext(mp_obj_t self_in) {
mp_vfs_ilistdir_it_t *self = MP_OBJ_TO_PTR(self_in);
if (self->is_iter) {
// continue delegating to root dir
return mp_iternext(self->cur.iter);
} else if (self->cur.vfs == NULL) {
// finished iterating mount points and no root dir is mounted
return MP_OBJ_STOP_ITERATION;
} else {
// continue iterating mount points
mp_vfs_mount_t *vfs = self->cur.vfs;
self->cur.vfs = vfs->next;
if (vfs->len == 1) {
// vfs is mounted at root dir, delegate to it
mp_obj_t root = MP_OBJ_NEW_QSTR(MP_QSTR__slash_);
self->is_iter = true;
self->cur.iter = mp_vfs_proxy_call(vfs, MP_QSTR_ilistdir, 1, &root);
return mp_iternext(self->cur.iter);
} else {
// a mounted directory
mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(3, NULL));
t->items[0] = mp_obj_new_str_of_type(
self->is_str ? &mp_type_str : &mp_type_bytes,
(const byte*)vfs->str + 1, vfs->len - 1);
t->items[1] = MP_OBJ_NEW_SMALL_INT(MP_S_IFDIR);
t->items[2] = MP_OBJ_NEW_SMALL_INT(0); // no inode number
return MP_OBJ_FROM_PTR(t);
}
}
}
mp_obj_t mp_vfs_ilistdir(size_t n_args, const mp_obj_t *args) {
mp_obj_t path_in;
if (n_args == 1) {
path_in = args[0];
} else {
path_in = MP_OBJ_NEW_QSTR(MP_QSTR_);
}
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
if (vfs == MP_VFS_ROOT) {
// list the root directory
mp_vfs_ilistdir_it_t *iter = m_new_obj(mp_vfs_ilistdir_it_t);
iter->base.type = &mp_type_polymorph_iter;
iter->iternext = mp_vfs_ilistdir_it_iternext;
iter->cur.vfs = MP_STATE_VM(vfs_mount_table);
iter->is_str = mp_obj_get_type(path_in) == &mp_type_str;
iter->is_iter = false;
return MP_OBJ_FROM_PTR(iter);
}
return mp_vfs_proxy_call(vfs, MP_QSTR_ilistdir, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_vfs_ilistdir_obj, 0, 1, mp_vfs_ilistdir);
mp_obj_t mp_vfs_listdir(size_t n_args, const mp_obj_t *args) {
mp_obj_t iter = mp_vfs_ilistdir(n_args, args);
mp_obj_t dir_list = mp_obj_new_list(0, NULL);
mp_obj_t next;
while ((next = mp_iternext(iter)) != MP_OBJ_STOP_ITERATION) {
mp_obj_list_append(dir_list, mp_obj_subscr(next, MP_OBJ_NEW_SMALL_INT(0), MP_OBJ_SENTINEL));
}
return dir_list;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_vfs_listdir_obj, 0, 1, mp_vfs_listdir);
mp_obj_t mp_vfs_mkdir(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
if (vfs == MP_VFS_ROOT || (vfs != MP_VFS_NONE && !strcmp(mp_obj_str_get_str(path_out), "/"))) {
mp_raise_OSError(MP_EEXIST);
}
return mp_vfs_proxy_call(vfs, MP_QSTR_mkdir, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_mkdir_obj, mp_vfs_mkdir);
mp_obj_t mp_vfs_remove(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
return mp_vfs_proxy_call(vfs, MP_QSTR_remove, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_remove_obj, mp_vfs_remove);
mp_obj_t mp_vfs_rename(mp_obj_t old_path_in, mp_obj_t new_path_in) {
mp_obj_t args[2];
mp_vfs_mount_t *old_vfs = lookup_path(old_path_in, &args[0]);
mp_vfs_mount_t *new_vfs = lookup_path(new_path_in, &args[1]);
if (old_vfs != new_vfs) {
// can't rename across filesystems
mp_raise_OSError(MP_EPERM);
}
return mp_vfs_proxy_call(old_vfs, MP_QSTR_rename, 2, args);
}
MP_DEFINE_CONST_FUN_OBJ_2(mp_vfs_rename_obj, mp_vfs_rename);
mp_obj_t mp_vfs_rmdir(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
return mp_vfs_proxy_call(vfs, MP_QSTR_rmdir, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_rmdir_obj, mp_vfs_rmdir);
mp_obj_t mp_vfs_stat(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
if (vfs == MP_VFS_ROOT) {
mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(10, NULL));
t->items[0] = MP_OBJ_NEW_SMALL_INT(MP_S_IFDIR); // st_mode
for (int i = 1; i <= 9; ++i) {
t->items[i] = MP_OBJ_NEW_SMALL_INT(0); // dev, nlink, uid, gid, size, atime, mtime, ctime
}
return MP_OBJ_FROM_PTR(t);
}
return mp_vfs_proxy_call(vfs, MP_QSTR_stat, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_stat_obj, mp_vfs_stat);
mp_obj_t mp_vfs_statvfs(mp_obj_t path_in) {
mp_obj_t path_out;
mp_vfs_mount_t *vfs = lookup_path(path_in, &path_out);
if (vfs == MP_VFS_ROOT) {
// statvfs called on the root directory, see if there's anything mounted there
for (vfs = MP_STATE_VM(vfs_mount_table); vfs != NULL; vfs = vfs->next) {
if (vfs->len == 1) {
break;
}
}
// If there's nothing mounted at root then return a mostly-empty tuple
if (vfs == NULL) {
mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(10, NULL));
// fill in: bsize, frsize, blocks, bfree, bavail, files, ffree, favail, flags
for (int i = 0; i <= 8; ++i) {
t->items[i] = MP_OBJ_NEW_SMALL_INT(0);
}
// Put something sensible in f_namemax
t->items[9] = MP_OBJ_NEW_SMALL_INT(MICROPY_ALLOC_PATH_MAX);
return MP_OBJ_FROM_PTR(t);
}
// VFS mounted at root so delegate the call to it
path_out = MP_OBJ_NEW_QSTR(MP_QSTR__slash_);
}
return mp_vfs_proxy_call(vfs, MP_QSTR_statvfs, 1, &path_out);
}
MP_DEFINE_CONST_FUN_OBJ_1(mp_vfs_statvfs_obj, mp_vfs_statvfs);
#endif // MICROPY_VFS