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1// SPDX-License-Identifier: GPL-2.02#include <linux/fs.h>3#include <linux/init.h>4#include <linux/proc_fs.h>5#include <linux/seq_file.h>6#include <linux/blkdev.h>7#include "internal.h"8 9static int devinfo_show(struct seq_file *f, void *v)10{11 int i = *(loff_t *) v;12 13 if (i < CHRDEV_MAJOR_MAX) {14 if (i == 0)15 seq_puts(f, "Character devices:\n");16 chrdev_show(f, i);17 }18#ifdef CONFIG_BLOCK19 else {20 i -= CHRDEV_MAJOR_MAX;21 if (i == 0)22 seq_puts(f, "\nBlock devices:\n");23 blkdev_show(f, i);24 }25#endif26 return 0;27}28 29static void *devinfo_start(struct seq_file *f, loff_t *pos)30{31 if (*pos < (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))32 return pos;33 return NULL;34}35 36static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)37{38 (*pos)++;39 if (*pos >= (BLKDEV_MAJOR_MAX + CHRDEV_MAJOR_MAX))40 return NULL;41 return pos;42}43 44static void devinfo_stop(struct seq_file *f, void *v)45{46 /* Nothing to do */47}48 49static const struct seq_operations devinfo_ops = {50 .start = devinfo_start,51 .next = devinfo_next,52 .stop = devinfo_stop,53 .show = devinfo_show54};55 56static int __init proc_devices_init(void)57{58 struct proc_dir_entry *pde;59 60 pde = proc_create_seq("devices", 0, NULL, &devinfo_ops);61 pde_make_permanent(pde);62 return 0;63}64fs_initcall(proc_devices_init);65