kernel-ark/drivers/s390/block/dasd_proc.c
Arjan van de Ven d54b1fdb1d [PATCH] mark struct file_operations const 5
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00

339 lines
9.4 KiB
C

/*
* File...........: linux/drivers/s390/block/dasd_proc.c
* 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>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2002
*
* /proc interface for the dasd driver.
*
*/
#include <linux/ctype.h>
#include <linux/seq_file.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>
#include <asm/debug.h>
#include <asm/uaccess.h>
/* This is ugly... */
#define PRINTK_HEADER "dasd_proc:"
#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 char *
dasd_get_user_string(const char __user *user_buf, size_t user_len)
{
char *buffer;
buffer = kmalloc(user_len + 1, GFP_KERNEL);
if (buffer == NULL)
return ERR_PTR(-ENOMEM);
if (copy_from_user(buffer, user_buf, user_len) != 0) {
kfree(buffer);
return ERR_PTR(-EFAULT);
}
/* got the string, now strip linefeed. */
if (buffer[user_len - 1] == '\n')
buffer[user_len - 1] = 0;
else
buffer[user_len] = 0;
return buffer;
}
static int
dasd_devices_show(struct seq_file *m, void *v)
{
struct dasd_device *device;
char *substr;
device = dasd_device_from_devindex((unsigned long) v - 1);
if (IS_ERR(device))
return 0;
/* Print device number. */
seq_printf(m, "%s", device->cdev->dev.bus_id);
/* Print discipline string. */
if (device != NULL && device->discipline != NULL)
seq_printf(m, "(%s)", device->discipline->name);
else
seq_printf(m, "(none)");
/* Print kdev. */
if (device->gdp)
seq_printf(m, " at (%3d:%6d)",
device->gdp->major, device->gdp->first_minor);
else
seq_printf(m, " at (???:??????)");
/* Print device name. */
if (device->gdp)
seq_printf(m, " is %-8s", device->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 != NULL) ? device->state : -1) {
case -1:
seq_printf(m, "unknown");
break;
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(device->bp_block))
seq_printf(m, "n/f ");
else
seq_printf(m,
"at blocksize: %d, %ld blocks, %ld MB",
device->bp_block, device->blocks,
((device->bp_block >> 9) *
device->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 struct seq_operations dasd_devices_seq_ops = {
.start = dasd_devices_start,
.next = dasd_devices_next,
.stop = dasd_devices_stop,
.show = dasd_devices_show,
};
static int dasd_devices_open(struct inode *inode, struct file *file)
{
return seq_open(file, &dasd_devices_seq_ops);
}
static const struct file_operations dasd_devices_file_ops = {
.open = dasd_devices_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int
dasd_calc_metrics(char *page, char **start, off_t off,
int count, int *eof, int len)
{
len = (len > off) ? len - off : 0;
if (len > count)
len = count;
if (len < count)
*eof = 1;
*start = page + off;
return len;
}
static char *
dasd_statistics_array(char *str, unsigned int *array, int shift)
{
int i;
for (i = 0; i < 32; i++) {
str += sprintf(str, "%7d ", array[i] >> shift);
if (i == 15)
str += sprintf(str, "\n");
}
str += sprintf(str,"\n");
return str;
}
static int
dasd_statistics_read(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
unsigned long len;
#ifdef CONFIG_DASD_PROFILE
struct dasd_profile_info_t *prof;
char *str;
int shift;
/* check for active profiling */
if (dasd_profile_level == DASD_PROFILE_OFF) {
len = sprintf(page, "Statistics are off - they might be "
"switched on using 'echo set on > "
"/proc/dasd/statistics'\n");
return dasd_calc_metrics(page, start, off, count, eof, len);
}
prof = &dasd_global_profile;
/* prevent couter 'overflow' on output */
for (shift = 0; (prof->dasd_io_reqs >> shift) > 9999999; shift++);
str = page;
str += sprintf(str, "%d dasd I/O requests\n", prof->dasd_io_reqs);
str += sprintf(str, "with %d sectors(512B each)\n",
prof->dasd_io_sects);
str += sprintf(str,
" __<4 ___8 __16 __32 __64 _128 "
" _256 _512 __1k __2k __4k __8k "
" _16k _32k _64k 128k\n");
str += sprintf(str,
" _256 _512 __1M __2M __4M __8M "
" _16M _32M _64M 128M 256M 512M "
" __1G __2G __4G " " _>4G\n");
str += sprintf(str, "Histogram of sizes (512B secs)\n");
str = dasd_statistics_array(str, prof->dasd_io_secs, shift);
str += sprintf(str, "Histogram of I/O times (microseconds)\n");
str = dasd_statistics_array(str, prof->dasd_io_times, shift);
str += sprintf(str, "Histogram of I/O times per sector\n");
str = dasd_statistics_array(str, prof->dasd_io_timps, shift);
str += sprintf(str, "Histogram of I/O time till ssch\n");
str = dasd_statistics_array(str, prof->dasd_io_time1, shift);
str += sprintf(str, "Histogram of I/O time between ssch and irq\n");
str = dasd_statistics_array(str, prof->dasd_io_time2, shift);
str += sprintf(str, "Histogram of I/O time between ssch "
"and irq per sector\n");
str = dasd_statistics_array(str, prof->dasd_io_time2ps, shift);
str += sprintf(str, "Histogram of I/O time between irq and end\n");
str = dasd_statistics_array(str, prof->dasd_io_time3, shift);
str += sprintf(str, "# of req in chanq at enqueuing (1..32) \n");
str = dasd_statistics_array(str, prof->dasd_io_nr_req, shift);
len = str - page;
#else
len = sprintf(page, "Statistics are not activated in this kernel\n");
#endif
return dasd_calc_metrics(page, start, off, count, eof, len);
}
static int
dasd_statistics_write(struct file *file, const char __user *user_buf,
unsigned long user_len, void *data)
{
#ifdef CONFIG_DASD_PROFILE
char *buffer, *str;
if (user_len > 65536)
user_len = 65536;
buffer = dasd_get_user_string(user_buf, user_len);
if (IS_ERR(buffer))
return PTR_ERR(buffer);
MESSAGE_LOG(KERN_INFO, "/proc/dasd/statictics: '%s'", buffer);
/* check for valid verbs */
for (str = buffer; isspace(*str); str++);
if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
/* 'set xxx' was given */
for (str = str + 4; isspace(*str); str++);
if (strcmp(str, "on") == 0) {
/* switch on statistics profiling */
dasd_profile_level = DASD_PROFILE_ON;
MESSAGE(KERN_INFO, "%s", "Statistics switched on");
} else if (strcmp(str, "off") == 0) {
/* switch off and reset statistics profiling */
memset(&dasd_global_profile,
0, sizeof (struct dasd_profile_info_t));
dasd_profile_level = DASD_PROFILE_OFF;
MESSAGE(KERN_INFO, "%s", "Statistics switched off");
} else
goto out_error;
} else if (strncmp(str, "reset", 5) == 0) {
/* reset the statistics */
memset(&dasd_global_profile, 0,
sizeof (struct dasd_profile_info_t));
MESSAGE(KERN_INFO, "%s", "Statistics reset");
} else
goto out_error;
kfree(buffer);
return user_len;
out_error:
MESSAGE(KERN_WARNING, "%s",
"/proc/dasd/statistics: only 'set on', 'set off' "
"and 'reset' are supported verbs");
kfree(buffer);
return -EINVAL;
#else
MESSAGE(KERN_WARNING, "%s",
"/proc/dasd/statistics: is not activated in this kernel");
return user_len;
#endif /* CONFIG_DASD_PROFILE */
}
/*
* 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", &proc_root);
if (!dasd_proc_root_entry)
goto out_nodasd;
dasd_proc_root_entry->owner = THIS_MODULE;
dasd_devices_entry = create_proc_entry("devices",
S_IFREG | S_IRUGO | S_IWUSR,
dasd_proc_root_entry);
if (!dasd_devices_entry)
goto out_nodevices;
dasd_devices_entry->proc_fops = &dasd_devices_file_ops;
dasd_devices_entry->owner = THIS_MODULE;
dasd_statistics_entry = create_proc_entry("statistics",
S_IFREG | S_IRUGO | S_IWUSR,
dasd_proc_root_entry);
if (!dasd_statistics_entry)
goto out_nostatistics;
dasd_statistics_entry->read_proc = dasd_statistics_read;
dasd_statistics_entry->write_proc = dasd_statistics_write;
dasd_statistics_entry->owner = THIS_MODULE;
return 0;
out_nostatistics:
remove_proc_entry("devices", dasd_proc_root_entry);
out_nodevices:
remove_proc_entry("dasd", &proc_root);
out_nodasd:
return -ENOENT;
}
void
dasd_proc_exit(void)
{
remove_proc_entry("devices", dasd_proc_root_entry);
remove_proc_entry("statistics", dasd_proc_root_entry);
remove_proc_entry("dasd", &proc_root);
}