circuitpython/shared-module/storage/__init__.c

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/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2015 Josef Gajdusek
* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
*
* 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 <string.h>
#include "extmod/vfs.h"
#include "py/mperrno.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "shared-bindings/os/__init__.h"
#include "shared-bindings/storage/__init__.h"
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) {
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[n_args + 2];
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);
}
void common_hal_storage_mount(mp_obj_t vfs_obj, const char* mount_path, bool readonly) {
// create new object
mp_vfs_mount_t *vfs = m_new_obj(mp_vfs_mount_t);
vfs->str = mount_path;
vfs->len = strlen(mount_path);
vfs->obj = vfs_obj;
vfs->next = NULL;
mp_obj_t args[2];
args[0] = readonly ? mp_const_true : mp_const_false;
args[1] = mp_const_false; // Don't make the file system automatically when mounting.
// Check that there's no file or directory with the same name as the mount point.
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
common_hal_os_stat(mount_path);
nlr_pop();
// Something with the same name exists.
mp_raise_OSError(MP_EEXIST);
}
// check that the destination mount point is unused
const char *path_out;
mp_vfs_mount_t *existing_mount = mp_vfs_lookup_path(mount_path, &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);
}
}
// call the underlying object to do any mounting operation
mp_vfs_proxy_call(vfs, MP_QSTR_mount, 2, (mp_obj_t*)&args);
// Insert the vfs into the mount table by pushing it onto the front of the
// mount table.
mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table);
vfs->next = *vfsp;
*vfsp = vfs;
}
void common_hal_storage_umount_object(mp_obj_t vfs_obj) {
// remove vfs from the mount table
mp_vfs_mount_t *vfs = NULL;
for (mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table); *vfsp != NULL; vfsp = &(*vfsp)->next) {
if ((*vfsp)->obj == vfs_obj) {
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);
}
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STATIC mp_obj_t storage_object_from_path(const char* mount_path) {
for (mp_vfs_mount_t **vfsp = &MP_STATE_VM(vfs_mount_table); *vfsp != NULL; vfsp = &(*vfsp)->next) {
if (strcmp(mount_path, (*vfsp)->str) == 0) {
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return (*vfsp)->obj;
}
}
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mp_raise_OSError(MP_EINVAL);
}
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void common_hal_storage_umount_path(const char* mount_path) {
common_hal_storage_umount_object(storage_object_from_path(mount_path));
}
mp_obj_t common_hal_storage_getmount(const char *mount_path) {
return storage_object_from_path(mount_path);
}