linux-imx

#include <linux/export.h>

#include <linux/sched/signal.h>

#include <linux/sched/task.h>

#include <linux/fs.h>

#include <linux/path.h>

#include <linux/slab.h>

#include <linux/fs_struct.h>

#include "internal.h"

​

/*

 * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.

 * It can block.

 */

void set_fs_root(struct fs_struct *fs, const struct path *path)

{

    struct path old_root;

​

    path_get(path);

    spin_lock(&fs->lock);

    write_seqcount_begin(&fs->seq);

    old_root = fs->root;

    fs->root = *path;

    write_seqcount_end(&fs->seq);

    spin_unlock(&fs->lock);

    if (old_root.dentry)

        path_put(&old_root);

}

​

/*

 * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.

 * It can block.

 */

void set_fs_pwd(struct fs_struct *fs, const struct path *path)

{

    struct path old_pwd;

​

    path_get(path);

    spin_lock(&fs->lock);

    write_seqcount_begin(&fs->seq);

    old_pwd = fs->pwd;

    fs->pwd = *path;

    write_seqcount_end(&fs->seq);

    spin_unlock(&fs->lock);

​

    if (old_pwd.dentry)

        path_put(&old_pwd);

}

​

static inline int replace_path(struct path *p, const struct path *old, const struct path *new)

{

    if (likely(p->dentry != old->dentry || p->mnt != old->mnt))

        return 0;

    *p = *new;

    return 1;

}

​

void chroot_fs_refs(const struct path *old_root, const struct path *new_root)

{

    struct task_struct *g, *p;

    struct fs_struct *fs;

    int count = 0;

​

    read_lock(&tasklist_lock);