#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify_backend.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/inotify.h>
#include <linux/fanotify.h>
#include <linux/kernel.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/exportfs.h>

#include "inotify/inotify.h"
#include "../fs/mount.h"

#if defined(CONFIG_PROC_FS)

#if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)

static void show_fdinfo(struct seq_file *m, struct file *f,
                        void (*show)(struct seq_file *m,
                                     struct fsnotify_mark *mark))
{
        struct fsnotify_group *group = f->private_data;
        struct fsnotify_mark *mark;

        mutex_lock(&group->mark_mutex);
        list_for_each_entry(mark, &group->marks_list, g_list) {
                show(m, mark);
                if (seq_has_overflowed(m))
                        break;
        }
        mutex_unlock(&group->mark_mutex);
}

#if defined(CONFIG_EXPORTFS)
static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
{
        struct {
                struct file_handle handle;
                u8 pad[MAX_HANDLE_SZ];
        } f;
        int size, ret, i;

        f.handle.handle_bytes = sizeof(f.pad);
        size = f.handle.handle_bytes >> 2;

        ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, &size, 0);
        if ((ret == FILEID_INVALID) || (ret < 0)) {
                WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", ret);
                return;
        }

        f.handle.handle_type = ret;
        f.handle.handle_bytes = size * sizeof(u32);

        seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
                   f.handle.handle_bytes, f.handle.handle_type);

        for (i = 0; i < f.handle.handle_bytes; i++)
                seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
}
#else
static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
{
}
#endif

#ifdef CONFIG_INOTIFY_USER

static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
{
        struct inotify_inode_mark *inode_mark;
        struct inode *inode;

        if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE) ||
            !(mark->flags & FSNOTIFY_MARK_FLAG_INODE))
                return;

        inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
        inode = igrab(mark->inode);
        if (inode) {
                /*
                 * IN_ALL_EVENTS represents all of the mask bits
                 * that we expose to userspace.  There is at
                 * least one bit (FS_EVENT_ON_CHILD) which is
                 * used only internally to the kernel.
                 */
                u32 mask = mark->mask & IN_ALL_EVENTS;
                seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:%x ",
                           inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
                           mask, mark->ignored_mask);
                show_mark_fhandle(m, inode);
                seq_putc(m, '\n');
                iput(inode);
        }
}

void inotify_show_fdinfo(struct seq_file *m, struct file *f)
{
        show_fdinfo(m, f, inotify_fdinfo);
}

#endif /* CONFIG_INOTIFY_USER */

#ifdef CONFIG_FANOTIFY

static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
{
        unsigned int mflags = 0;
        struct inode *inode;

        if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE))
                return;

        if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
                mflags |= FAN_MARK_IGNORED_SURV_MODIFY;

        if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
                inode = igrab(mark->inode);
                if (!inode)
                        return;
                seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x ignored_mask:%x ",
                           inode->i_ino, inode->i_sb->s_dev,
                           mflags, mark->mask, mark->ignored_mask);
                show_mark_fhandle(m, inode);
                seq_putc(m, '\n');
                iput(inode);
        } else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) {
                struct mount *mnt = real_mount(mark->mnt);

                seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x ignored_mask:%x\n",
                           mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
        }
}

void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
{
        struct fsnotify_group *group = f->private_data;
        unsigned int flags = 0;

        switch (group->priority) {
        case FS_PRIO_0:
                flags |= FAN_CLASS_NOTIF;
                break;
        case FS_PRIO_1:
                flags |= FAN_CLASS_CONTENT;
                break;
        case FS_PRIO_2:
                flags |= FAN_CLASS_PRE_CONTENT;
                break;
        }

        if (group->max_events == UINT_MAX)
                flags |= FAN_UNLIMITED_QUEUE;

        if (group->fanotify_data.max_marks == UINT_MAX)
                flags |= FAN_UNLIMITED_MARKS;

        seq_printf(m, "fanotify flags:%x event-flags:%x\n",
                   flags, group->fanotify_data.f_flags);

        show_fdinfo(m, f, fanotify_fdinfo);
}

#endif /* CONFIG_FANOTIFY */

#endif /* CONFIG_INOTIFY_USER || CONFIG_FANOTIFY */

#endif /* CONFIG_PROC_FS */