Quelle  dasd_proc.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *     Horst Hummel <Horst.Hummel@de.ibm.com>
 *     Carsten Otte <Cotte@de.ibm.com>
 *     Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2002
 *
 * /proc interface for the dasd driver.
 *
 */

#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>

#include <asm/debug.h>
#include <linux/uaccess.h>

#include "dasd_int.h"

static struct proc_dir_entry *dasd_proc_root_entry = NULL;
static struct proc_dir_entry *dasd_devices_entry = NULL;
static struct proc_dir_entry *dasd_statistics_entry = NULL;

static int
dasd_devices_show(struct seq_file *m, void *v)
{
 struct dasd_device *device;
 struct dasd_block *block;
 char *substr;

 device = dasd_device_from_devindex((unsigned long) v - 1);
 if (IS_ERR(device))
  return 0;
 if (device->block)
  block = device->block;
 else {
  dasd_put_device(device);
  return 0;
 }
 /* Print device number. */
 seq_printf(m, "%s", dev_name(&device->cdev->dev));
 /* Print discipline string. */
 if (device->discipline != NULL)
  seq_printf(m, "(%s)", device->discipline->name);
 else
  seq_printf(m, "(none)");
 /* Print kdev. */
 if (block->gdp)
  seq_printf(m, " at (%3d:%6d)",
      MAJOR(disk_devt(block->gdp)),
      MINOR(disk_devt(block->gdp)));
 else
  seq_printf(m, " at (???:??????)");
 /* Print device name. */
 if (block->gdp)
  seq_printf(m, " is %-8s", block->gdp->disk_name);
 else
  seq_printf(m, " is ????????");
 /* Print devices features. */
 substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
 seq_printf(m, "%4s: ", substr);
 /* Print device status information. */
 switch (device->state) {
 case DASD_STATE_NEW:
  seq_printf(m, "new");
  break;
 case DASD_STATE_KNOWN:
  seq_printf(m, "detected");
  break;
 case DASD_STATE_BASIC:
  seq_printf(m, "basic");
  break;
 case DASD_STATE_UNFMT:
  seq_printf(m, "unformatted");
  break;
 case DASD_STATE_READY:
 case DASD_STATE_ONLINE:
  seq_printf(m, "active ");
  if (dasd_check_blocksize(block->bp_block))
   seq_printf(m, "n/f ");
  else
   seq_printf(m,
       "at blocksize: %u, %lu blocks, %lu MB",
       block->bp_block, block->blocks,
       ((block->bp_block >> 9) *
        block->blocks) >> 11);
  break;
 default:
  seq_printf(m, "no stat");
  break;
 }
 dasd_put_device(device);
 if (dasd_probeonly)
  seq_printf(m, "(probeonly)");
 seq_printf(m, "\n");
 return 0;
}

static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
{
 if (*pos >= dasd_max_devindex)
  return NULL;
 return (void *)((unsigned long) *pos + 1);
}

static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
{
 ++*pos;
 return dasd_devices_start(m, pos);
}

static void dasd_devices_stop(struct seq_file *m, void *v)
{
}

static const struct seq_operations dasd_devices_seq_ops = {
 .start  = dasd_devices_start,
 .next  = dasd_devices_next,
 .stop  = dasd_devices_stop,
 .show  = dasd_devices_show,
};

#ifdef CONFIG_DASD_PROFILE
static int dasd_stats_all_block_on(void)
{
 int i, rc;
 struct dasd_device *device;

 rc = 0;
 for (i = 0; i < dasd_max_devindex; ++i) {
  device = dasd_device_from_devindex(i);
  if (IS_ERR(device))
   continue;
  if (device->block)
   rc = dasd_profile_on(&device->block->profile);
  dasd_put_device(device);
  if (rc)
   return rc;
 }
 return 0;
}

static void dasd_stats_all_block_off(void)
{
 int i;
 struct dasd_device *device;

 for (i = 0; i < dasd_max_devindex; ++i) {
  device = dasd_device_from_devindex(i);
  if (IS_ERR(device))
   continue;
  if (device->block)
   dasd_profile_off(&device->block->profile);
  dasd_put_device(device);
 }
}

static void dasd_stats_all_block_reset(void)
{
 int i;
 struct dasd_device *device;

 for (i = 0; i < dasd_max_devindex; ++i) {
  device = dasd_device_from_devindex(i);
  if (IS_ERR(device))
   continue;
  if (device->block)
   dasd_profile_reset(&device->block->profile);
  dasd_put_device(device);
 }
}

static void dasd_statistics_array(struct seq_file *m, unsigned int *array, int factor)
{
 int i;

 for (i = 0; i < 32; i++) {
  seq_printf(m, "%7d ", array[i] / factor);
  if (i == 15)
   seq_putc(m, '\n');
 }
 seq_putc(m, '\n');
}
#endif /* CONFIG_DASD_PROFILE */

static int dasd_stats_proc_show(struct seq_file *m, void *v)
{
#ifdef CONFIG_DASD_PROFILE
 struct dasd_profile_info *prof;
 int factor;

 spin_lock_bh(&dasd_global_profile.lock);
 prof = dasd_global_profile.data;
 if (!prof) {
  spin_unlock_bh(&dasd_global_profile.lock);
  seq_printf(m, "Statistics are off - they might be "
        "switched on using 'echo set on > "
        "/proc/dasd/statistics'\n");
  return 0;
 }

 /* prevent counter 'overflow' on output */
 for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
      factor *= 10);

 seq_printf(m, "%d dasd I/O requests\n", prof->dasd_io_reqs);
 seq_printf(m, "with %u sectors(512B each)\n",
         prof->dasd_io_sects);
 seq_printf(m, "Scale Factor is %d\n", factor);
 seq_printf(m,
         " __<4 ___8 __16 __32 __64 _128 "
         " _256 _512 __1k __2k __4k __8k "
         " _16k _32k _64k 128k\n");
 seq_printf(m,
         " _256 _512 __1M __2M __4M __8M "
         " _16M _32M _64M 128M 256M 512M "
         " __1G __2G __4G " " _>4G\n");

 seq_printf(m, "Histogram of sizes (512B secs)\n");
 dasd_statistics_array(m, prof->dasd_io_secs, factor);
 seq_printf(m, "Histogram of I/O times (microseconds)\n");
 dasd_statistics_array(m, prof->dasd_io_times, factor);
 seq_printf(m, "Histogram of I/O times per sector\n");
 dasd_statistics_array(m, prof->dasd_io_timps, factor);
 seq_printf(m, "Histogram of I/O time till ssch\n");
 dasd_statistics_array(m, prof->dasd_io_time1, factor);
 seq_printf(m, "Histogram of I/O time between ssch and irq\n");
 dasd_statistics_array(m, prof->dasd_io_time2, factor);
 seq_printf(m, "Histogram of I/O time between ssch "
       "and irq per sector\n");
 dasd_statistics_array(m, prof->dasd_io_time2ps, factor);
 seq_printf(m, "Histogram of I/O time between irq and end\n");
 dasd_statistics_array(m, prof->dasd_io_time3, factor);
 seq_printf(m, "# of req in chanq at enqueuing (1..32) \n");
 dasd_statistics_array(m, prof->dasd_io_nr_req, factor);
 spin_unlock_bh(&dasd_global_profile.lock);
#else
 seq_printf(m, "Statistics are not activated in this kernel\n");
#endif
 return 0;
}

static int dasd_stats_proc_open(struct inode *inode, struct file *file)
{
 return single_open(file, dasd_stats_proc_show, NULL);
}

static ssize_t dasd_stats_proc_write(struct file *file,
  const char __user *user_buf, size_t user_len, loff_t *pos)
{
#ifdef CONFIG_DASD_PROFILE
 char *buffer, *str;
 int rc;

 if (user_len > 65536)
  user_len = 65536;
 buffer = dasd_get_user_string(user_buf, user_len);
 if (IS_ERR(buffer))
  return PTR_ERR(buffer);

 /* check for valid verbs */
 str = skip_spaces(buffer);
 if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
  /* 'set xxx' was given */
  str = skip_spaces(str + 4);
  if (strcmp(str, "on") == 0) {
   /* switch on statistics profiling */
   rc = dasd_stats_all_block_on();
   if (rc) {
    dasd_stats_all_block_off();
    goto out_error;
   }
   rc = dasd_profile_on(&dasd_global_profile);
   if (rc) {
    dasd_stats_all_block_off();
    goto out_error;
   }
   dasd_profile_reset(&dasd_global_profile);
   dasd_global_profile_level = DASD_PROFILE_ON;
   pr_info("The statistics feature has been switched "
    "on\n");
  } else if (strcmp(str, "off") == 0) {
   /* switch off statistics profiling */
   dasd_global_profile_level = DASD_PROFILE_OFF;
   dasd_profile_off(&dasd_global_profile);
   dasd_stats_all_block_off();
   pr_info("The statistics feature has been switched "
    "off\n");
  } else
   goto out_parse_error;
 } else if (strncmp(str, "reset", 5) == 0) {
  /* reset the statistics */
  dasd_profile_reset(&dasd_global_profile);
  dasd_stats_all_block_reset();
  pr_info("The statistics have been reset\n");
 } else
  goto out_parse_error;
 vfree(buffer);
 return user_len;
out_parse_error:
 rc = -EINVAL;
 pr_warn("%s is not a supported value for /proc/dasd/statistics\n", str);
out_error:
 vfree(buffer);
 return rc;
#else
 pr_warn("/proc/dasd/statistics: is not activated in this kernel\n");
 return user_len;
#endif    /* CONFIG_DASD_PROFILE */
}

static const struct proc_ops dasd_stats_proc_ops = {
 .proc_open = dasd_stats_proc_open,
 .proc_read = seq_read,
 .proc_lseek = seq_lseek,
 .proc_release = single_release,
 .proc_write = dasd_stats_proc_write,
};

/*
 * Create dasd proc-fs entries.
 * In case creation failed, cleanup and return -ENOENT.
 */
int
dasd_proc_init(void)
{
 dasd_proc_root_entry = proc_mkdir("dasd", NULL);
 if (!dasd_proc_root_entry)
  goto out_nodasd;
 dasd_devices_entry = proc_create_seq("devices", 0444,
      dasd_proc_root_entry,
      &dasd_devices_seq_ops);
 if (!dasd_devices_entry)
  goto out_nodevices;
 dasd_statistics_entry = proc_create("statistics",
         S_IFREG | S_IRUGO | S_IWUSR,
         dasd_proc_root_entry,
         &dasd_stats_proc_ops);
 if (!dasd_statistics_entry)
  goto out_nostatistics;
 return 0;

 out_nostatistics:
 remove_proc_entry("devices", dasd_proc_root_entry);
 out_nodevices:
 remove_proc_entry("dasd", NULL);
 dasd_proc_root_entry = NULL;
 out_nodasd:
 return -ENOENT;
}

void
dasd_proc_exit(void)
{
 if (!dasd_proc_root_entry)
  return;

 remove_proc_entry("devices", dasd_proc_root_entry);
 remove_proc_entry("statistics", dasd_proc_root_entry);
 remove_proc_entry("dasd", NULL);
 dasd_proc_root_entry = NULL;
}