mirror of
https://github.com/AetherDroid/android_kernel_samsung_on5xelte.git
synced 2025-09-08 09:08:05 -04:00
Fixed MTP to work with TWRP
This commit is contained in:
awab228
commit
f6dfaef42e
50820 changed files with 20846062 additions and 0 deletions
443
drivers/base/devtmpfs.c
Normal file
443
drivers/base/devtmpfs.c
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@ -0,0 +1,443 @@
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/*
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* devtmpfs - kernel-maintained tmpfs-based /dev
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*
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* Copyright (C) 2009, Kay Sievers <kay.sievers@vrfy.org>
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*
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* During bootup, before any driver core device is registered,
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* devtmpfs, a tmpfs-based filesystem is created. Every driver-core
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* device which requests a device node, will add a node in this
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* filesystem.
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* By default, all devices are named after the name of the device,
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* owned by root and have a default mode of 0600. Subsystems can
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* overwrite the default setting if needed.
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*/
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#include <linux/kernel.h>
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#include <linux/syscalls.h>
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#include <linux/mount.h>
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#include <linux/device.h>
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#include <linux/genhd.h>
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#include <linux/namei.h>
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#include <linux/fs.h>
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#include <linux/shmem_fs.h>
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#include <linux/ramfs.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/kthread.h>
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#include "base.h"
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static struct task_struct *thread;
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#if defined CONFIG_DEVTMPFS_MOUNT
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static int mount_dev = 1;
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#else
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static int mount_dev;
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#endif
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static DEFINE_SPINLOCK(req_lock);
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static struct req {
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struct req *next;
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struct completion done;
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int err;
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const char *name;
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umode_t mode; /* 0 => delete */
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kuid_t uid;
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kgid_t gid;
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struct device *dev;
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} *requests;
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static int __init mount_param(char *str)
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{
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mount_dev = simple_strtoul(str, NULL, 0);
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return 1;
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}
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__setup("devtmpfs.mount=", mount_param);
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static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
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const char *dev_name, void *data)
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{
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#ifdef CONFIG_TMPFS
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return mount_single(fs_type, flags, data, shmem_fill_super);
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#else
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return mount_single(fs_type, flags, data, ramfs_fill_super);
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#endif
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}
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static struct file_system_type dev_fs_type = {
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.name = "devtmpfs",
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.mount = dev_mount,
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.kill_sb = kill_litter_super,
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};
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#ifdef CONFIG_BLOCK
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static inline int is_blockdev(struct device *dev)
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{
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return dev->class == &block_class;
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}
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#else
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static inline int is_blockdev(struct device *dev) { return 0; }
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#endif
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int devtmpfs_create_node(struct device *dev)
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{
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const char *tmp = NULL;
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struct req req;
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if (!thread)
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return 0;
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req.mode = 0;
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req.uid = GLOBAL_ROOT_UID;
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req.gid = GLOBAL_ROOT_GID;
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req.name = device_get_devnode(dev, &req.mode, &req.uid, &req.gid, &tmp);
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if (!req.name)
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return -ENOMEM;
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if (req.mode == 0)
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req.mode = 0600;
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if (is_blockdev(dev))
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req.mode |= S_IFBLK;
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else
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req.mode |= S_IFCHR;
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req.dev = dev;
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init_completion(&req.done);
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spin_lock(&req_lock);
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req.next = requests;
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requests = &req;
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spin_unlock(&req_lock);
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wake_up_process(thread);
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wait_for_completion(&req.done);
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kfree(tmp);
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return req.err;
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}
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int devtmpfs_delete_node(struct device *dev)
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{
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const char *tmp = NULL;
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struct req req;
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if (!thread)
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return 0;
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req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp);
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if (!req.name)
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return -ENOMEM;
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req.mode = 0;
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req.dev = dev;
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init_completion(&req.done);
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spin_lock(&req_lock);
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req.next = requests;
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requests = &req;
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spin_unlock(&req_lock);
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wake_up_process(thread);
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wait_for_completion(&req.done);
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kfree(tmp);
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return req.err;
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}
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static int dev_mkdir(const char *name, umode_t mode)
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{
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struct dentry *dentry;
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struct path path;
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int err;
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dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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err = vfs_mkdir(path.dentry->d_inode, dentry, mode);
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if (!err)
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/* mark as kernel-created inode */
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dentry->d_inode->i_private = &thread;
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done_path_create(&path, dentry);
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return err;
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}
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static int create_path(const char *nodepath)
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{
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char *path;
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char *s;
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int err = 0;
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/* parent directories do not exist, create them */
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path = kstrdup(nodepath, GFP_KERNEL);
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if (!path)
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return -ENOMEM;
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s = path;
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for (;;) {
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s = strchr(s, '/');
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if (!s)
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break;
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s[0] = '\0';
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err = dev_mkdir(path, 0755);
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if (err && err != -EEXIST)
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break;
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s[0] = '/';
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s++;
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}
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kfree(path);
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return err;
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}
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static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
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kgid_t gid, struct device *dev)
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{
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struct dentry *dentry;
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struct path path;
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int err;
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dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
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if (dentry == ERR_PTR(-ENOENT)) {
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create_path(nodename);
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dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
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}
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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err = vfs_mknod(path.dentry->d_inode, dentry, mode, dev->devt);
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if (!err) {
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struct iattr newattrs;
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newattrs.ia_mode = mode;
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newattrs.ia_uid = uid;
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newattrs.ia_gid = gid;
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newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID;
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mutex_lock(&dentry->d_inode->i_mutex);
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notify_change(dentry, &newattrs, NULL);
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mutex_unlock(&dentry->d_inode->i_mutex);
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/* mark as kernel-created inode */
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dentry->d_inode->i_private = &thread;
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}
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done_path_create(&path, dentry);
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return err;
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}
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static int dev_rmdir(const char *name)
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{
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struct path parent;
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struct dentry *dentry;
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int err;
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dentry = kern_path_locked(name, &parent);
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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if (dentry->d_inode) {
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if (dentry->d_inode->i_private == &thread)
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err = vfs_rmdir(parent.dentry->d_inode, dentry);
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else
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err = -EPERM;
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} else {
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err = -ENOENT;
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}
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dput(dentry);
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mutex_unlock(&parent.dentry->d_inode->i_mutex);
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path_put(&parent);
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return err;
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}
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static int delete_path(const char *nodepath)
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{
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const char *path;
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int err = 0;
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path = kstrdup(nodepath, GFP_KERNEL);
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if (!path)
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return -ENOMEM;
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for (;;) {
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char *base;
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base = strrchr(path, '/');
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if (!base)
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break;
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base[0] = '\0';
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err = dev_rmdir(path);
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if (err)
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break;
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}
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kfree(path);
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return err;
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}
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static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat)
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{
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/* did we create it */
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if (inode->i_private != &thread)
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return 0;
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/* does the dev_t match */
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if (is_blockdev(dev)) {
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if (!S_ISBLK(stat->mode))
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return 0;
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} else {
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if (!S_ISCHR(stat->mode))
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return 0;
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}
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if (stat->rdev != dev->devt)
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return 0;
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/* ours */
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return 1;
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}
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static int handle_remove(const char *nodename, struct device *dev)
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{
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struct path parent;
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struct dentry *dentry;
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int deleted = 0;
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int err;
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dentry = kern_path_locked(nodename, &parent);
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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if (dentry->d_inode) {
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struct kstat stat;
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struct path p = {.mnt = parent.mnt, .dentry = dentry};
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err = vfs_getattr(&p, &stat);
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if (!err && dev_mynode(dev, dentry->d_inode, &stat)) {
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struct iattr newattrs;
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/*
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* before unlinking this node, reset permissions
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* of possible references like hardlinks
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*/
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newattrs.ia_uid = GLOBAL_ROOT_UID;
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newattrs.ia_gid = GLOBAL_ROOT_GID;
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newattrs.ia_mode = stat.mode & ~0777;
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newattrs.ia_valid =
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ATTR_UID|ATTR_GID|ATTR_MODE;
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mutex_lock(&dentry->d_inode->i_mutex);
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notify_change(dentry, &newattrs, NULL);
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mutex_unlock(&dentry->d_inode->i_mutex);
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err = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
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if (!err || err == -ENOENT)
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deleted = 1;
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}
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} else {
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err = -ENOENT;
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}
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dput(dentry);
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mutex_unlock(&parent.dentry->d_inode->i_mutex);
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path_put(&parent);
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if (deleted && strchr(nodename, '/'))
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delete_path(nodename);
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return err;
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}
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/*
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* If configured, or requested by the commandline, devtmpfs will be
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* auto-mounted after the kernel mounted the root filesystem.
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*/
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int devtmpfs_mount(const char *mntdir)
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{
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int err;
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if (!mount_dev)
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return 0;
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if (!thread)
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return 0;
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err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL);
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if (err)
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printk(KERN_INFO "devtmpfs: error mounting %i\n", err);
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else
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printk(KERN_INFO "devtmpfs: mounted\n");
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return err;
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}
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static DECLARE_COMPLETION(setup_done);
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static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid,
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struct device *dev)
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{
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if (mode)
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return handle_create(name, mode, uid, gid, dev);
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else
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return handle_remove(name, dev);
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}
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static int devtmpfsd(void *p)
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{
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char options[] = "mode=0755";
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int *err = p;
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*err = sys_unshare(CLONE_NEWNS);
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if (*err)
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goto out;
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*err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
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if (*err)
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goto out;
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sys_chdir("/.."); /* will traverse into overmounted root */
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sys_chroot(".");
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complete(&setup_done);
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while (1) {
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spin_lock(&req_lock);
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while (requests) {
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struct req *req = requests;
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requests = NULL;
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spin_unlock(&req_lock);
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while (req) {
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struct req *next = req->next;
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req->err = handle(req->name, req->mode,
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req->uid, req->gid, req->dev);
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complete(&req->done);
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req = next;
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}
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spin_lock(&req_lock);
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}
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__set_current_state(TASK_INTERRUPTIBLE);
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spin_unlock(&req_lock);
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schedule();
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}
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return 0;
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out:
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complete(&setup_done);
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return *err;
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}
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/*
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* Create devtmpfs instance, driver-core devices will add their device
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* nodes here.
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*/
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int __init devtmpfs_init(void)
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{
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int err = register_filesystem(&dev_fs_type);
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if (err) {
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printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
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"type %i\n", err);
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return err;
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}
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thread = kthread_run(devtmpfsd, &err, "kdevtmpfs");
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if (!IS_ERR(thread)) {
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wait_for_completion(&setup_done);
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} else {
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err = PTR_ERR(thread);
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thread = NULL;
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}
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if (err) {
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printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err);
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unregister_filesystem(&dev_fs_type);
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return err;
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}
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printk(KERN_INFO "devtmpfs: initialized\n");
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return 0;
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}
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