dasd_proc.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
  4 *		    Horst Hummel <Horst.Hummel@de.ibm.com>
  5 *		    Carsten Otte <Cotte@de.ibm.com>
  6 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
  7 * Bugreports.to..: <Linux390@de.ibm.com>
  8 * Copyright IBM Corp. 1999, 2002
  9 *
 10 * /proc interface for the dasd driver.
 11 *
 12 */
 13
 14#include <linux/ctype.h>
 15#include <linux/slab.h>
 16#include <linux/string.h>
 17#include <linux/seq_file.h>
 18#include <linux/vmalloc.h>
 19#include <linux/proc_fs.h>
 20
 21#include <asm/debug.h>
 22#include <linux/uaccess.h>
 23
 24#include "dasd_int.h"
 25
 26static struct proc_dir_entry *dasd_proc_root_entry = NULL;
 27static struct proc_dir_entry *dasd_devices_entry = NULL;
 28static struct proc_dir_entry *dasd_statistics_entry = NULL;
 29
 30static int
 31dasd_devices_show(struct seq_file *m, void *v)
 32{
 33	struct dasd_device *device;
 34	struct dasd_block *block;
 35	char *substr;
 36
 37	device = dasd_device_from_devindex((unsigned long) v - 1);
 38	if (IS_ERR(device))
 39		return 0;
 40	if (device->block)
 41		block = device->block;
 42	else {
 43		dasd_put_device(device);
 44		return 0;
 45	}
 46	/* Print device number. */
 47	seq_printf(m, "%s", dev_name(&device->cdev->dev));
 48	/* Print discipline string. */
 49	if (device->discipline != NULL)
 50		seq_printf(m, "(%s)", device->discipline->name);
 51	else
 52		seq_printf(m, "(none)");
 53	/* Print kdev. */
 54	if (block->gdp)
 55		seq_printf(m, " at (%3d:%6d)",
 56			   MAJOR(disk_devt(block->gdp)),
 57			   MINOR(disk_devt(block->gdp)));
 58	else
 59		seq_printf(m, "  at (???:??????)");
 60	/* Print device name. */
 61	if (block->gdp)
 62		seq_printf(m, " is %-8s", block->gdp->disk_name);
 63	else
 64		seq_printf(m, " is ????????");
 65	/* Print devices features. */
 66	substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
 67	seq_printf(m, "%4s: ", substr);
 68	/* Print device status information. */
 69	switch (device->state) {
 70	case DASD_STATE_NEW:
 71		seq_printf(m, "new");
 72		break;
 73	case DASD_STATE_KNOWN:
 74		seq_printf(m, "detected");
 75		break;
 76	case DASD_STATE_BASIC:
 77		seq_printf(m, "basic");
 78		break;
 79	case DASD_STATE_UNFMT:
 80		seq_printf(m, "unformatted");
 81		break;
 82	case DASD_STATE_READY:
 83	case DASD_STATE_ONLINE:
 84		seq_printf(m, "active ");
 85		if (dasd_check_blocksize(block->bp_block))
 86			seq_printf(m, "n/f	 ");
 87		else
 88			seq_printf(m,
 89				   "at blocksize: %u, %lu blocks, %lu MB",
 90				   block->bp_block, block->blocks,
 91				   ((block->bp_block >> 9) *
 92				    block->blocks) >> 11);
 93		break;
 94	default:
 95		seq_printf(m, "no stat");
 96		break;
 97	}
 98	dasd_put_device(device);
 99	if (dasd_probeonly)
100		seq_printf(m, "(probeonly)");
101	seq_printf(m, "\n");
102	return 0;
103}
104
105static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
106{
107	if (*pos >= dasd_max_devindex)
108		return NULL;
109	return (void *)((unsigned long) *pos + 1);
110}
111
112static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
113{
114	++*pos;
115	return dasd_devices_start(m, pos);
116}
117
118static void dasd_devices_stop(struct seq_file *m, void *v)
119{
120}
121
122static const struct seq_operations dasd_devices_seq_ops = {
123	.start		= dasd_devices_start,
124	.next		= dasd_devices_next,
125	.stop		= dasd_devices_stop,
126	.show		= dasd_devices_show,
127};
128
129#ifdef CONFIG_DASD_PROFILE
130static int dasd_stats_all_block_on(void)
131{
132	int i, rc;
133	struct dasd_device *device;
134
135	rc = 0;
136	for (i = 0; i < dasd_max_devindex; ++i) {
137		device = dasd_device_from_devindex(i);
138		if (IS_ERR(device))
139			continue;
140		if (device->block)
141			rc = dasd_profile_on(&device->block->profile);
142		dasd_put_device(device);
143		if (rc)
144			return rc;
145	}
146	return 0;
147}
148
149static void dasd_stats_all_block_off(void)
150{
151	int i;
152	struct dasd_device *device;
153
154	for (i = 0; i < dasd_max_devindex; ++i) {
155		device = dasd_device_from_devindex(i);
156		if (IS_ERR(device))
157			continue;
158		if (device->block)
159			dasd_profile_off(&device->block->profile);
160		dasd_put_device(device);
161	}
162}
163
164static void dasd_stats_all_block_reset(void)
165{
166	int i;
167	struct dasd_device *device;
168
169	for (i = 0; i < dasd_max_devindex; ++i) {
170		device = dasd_device_from_devindex(i);
171		if (IS_ERR(device))
172			continue;
173		if (device->block)
174			dasd_profile_reset(&device->block->profile);
175		dasd_put_device(device);
176	}
177}
178
179static void dasd_statistics_array(struct seq_file *m, unsigned int *array, int factor)
180{
181	int i;
182
183	for (i = 0; i < 32; i++) {
184		seq_printf(m, "%7d ", array[i] / factor);
185		if (i == 15)
186			seq_putc(m, '\n');
187	}
188	seq_putc(m, '\n');
189}
190#endif /* CONFIG_DASD_PROFILE */
191
192static int dasd_stats_proc_show(struct seq_file *m, void *v)
193{
194#ifdef CONFIG_DASD_PROFILE
195	struct dasd_profile_info *prof;
196	int factor;
197
198	spin_lock_bh(&dasd_global_profile.lock);
199	prof = dasd_global_profile.data;
200	if (!prof) {
201		spin_unlock_bh(&dasd_global_profile.lock);
202		seq_printf(m, "Statistics are off - they might be "
203				    "switched on using 'echo set on > "
204				    "/proc/dasd/statistics'\n");
205		return 0;
206	}
207
208	/* prevent counter 'overflow' on output */
209	for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
210	     factor *= 10);
211
212	seq_printf(m, "%d dasd I/O requests\n", prof->dasd_io_reqs);
213	seq_printf(m, "with %u sectors(512B each)\n",
214		       prof->dasd_io_sects);
215	seq_printf(m, "Scale Factor is  %d\n", factor);
216	seq_printf(m,
217		       "   __<4	   ___8	   __16	   __32	   __64	   _128	"
218		       "   _256	   _512	   __1k	   __2k	   __4k	   __8k	"
219		       "   _16k	   _32k	   _64k	   128k\n");
220	seq_printf(m,
221		       "   _256	   _512	   __1M	   __2M	   __4M	   __8M	"
222		       "   _16M	   _32M	   _64M	   128M	   256M	   512M	"
223		       "   __1G	   __2G	   __4G " "   _>4G\n");
224
225	seq_printf(m, "Histogram of sizes (512B secs)\n");
226	dasd_statistics_array(m, prof->dasd_io_secs, factor);
227	seq_printf(m, "Histogram of I/O times (microseconds)\n");
228	dasd_statistics_array(m, prof->dasd_io_times, factor);
229	seq_printf(m, "Histogram of I/O times per sector\n");
230	dasd_statistics_array(m, prof->dasd_io_timps, factor);
231	seq_printf(m, "Histogram of I/O time till ssch\n");
232	dasd_statistics_array(m, prof->dasd_io_time1, factor);
233	seq_printf(m, "Histogram of I/O time between ssch and irq\n");
234	dasd_statistics_array(m, prof->dasd_io_time2, factor);
235	seq_printf(m, "Histogram of I/O time between ssch "
236			    "and irq per sector\n");
237	dasd_statistics_array(m, prof->dasd_io_time2ps, factor);
238	seq_printf(m, "Histogram of I/O time between irq and end\n");
239	dasd_statistics_array(m, prof->dasd_io_time3, factor);
240	seq_printf(m, "# of req in chanq at enqueuing (1..32) \n");
241	dasd_statistics_array(m, prof->dasd_io_nr_req, factor);
242	spin_unlock_bh(&dasd_global_profile.lock);
243#else
244	seq_printf(m, "Statistics are not activated in this kernel\n");
245#endif
246	return 0;
247}
248
249static int dasd_stats_proc_open(struct inode *inode, struct file *file)
250{
251	return single_open(file, dasd_stats_proc_show, NULL);
252}
253
254static ssize_t dasd_stats_proc_write(struct file *file,
255		const char __user *user_buf, size_t user_len, loff_t *pos)
256{
257#ifdef CONFIG_DASD_PROFILE
258	char *buffer, *str;
259	int rc;
260
261	if (user_len > 65536)
262		user_len = 65536;
263	buffer = dasd_get_user_string(user_buf, user_len);
264	if (IS_ERR(buffer))
265		return PTR_ERR(buffer);
266
267	/* check for valid verbs */
268	str = skip_spaces(buffer);
269	if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
270		/* 'set xxx' was given */
271		str = skip_spaces(str + 4);
272		if (strcmp(str, "on") == 0) {
273			/* switch on statistics profiling */
274			rc = dasd_stats_all_block_on();
275			if (rc) {
276				dasd_stats_all_block_off();
277				goto out_error;
278			}
279			rc = dasd_profile_on(&dasd_global_profile);
280			if (rc) {
281				dasd_stats_all_block_off();
282				goto out_error;
283			}
284			dasd_profile_reset(&dasd_global_profile);
285			dasd_global_profile_level = DASD_PROFILE_ON;
286			pr_info("The statistics feature has been switched "
287				"on\n");
288		} else if (strcmp(str, "off") == 0) {
289			/* switch off statistics profiling */
290			dasd_global_profile_level = DASD_PROFILE_OFF;
291			dasd_profile_off(&dasd_global_profile);
292			dasd_stats_all_block_off();
293			pr_info("The statistics feature has been switched "
294				"off\n");
295		} else
296			goto out_parse_error;
297	} else if (strncmp(str, "reset", 5) == 0) {
298		/* reset the statistics */
299		dasd_profile_reset(&dasd_global_profile);
300		dasd_stats_all_block_reset();
301		pr_info("The statistics have been reset\n");
302	} else
303		goto out_parse_error;
304	vfree(buffer);
305	return user_len;
306out_parse_error:
307	rc = -EINVAL;
308	pr_warn("%s is not a supported value for /proc/dasd/statistics\n", str);
309out_error:
310	vfree(buffer);
311	return rc;
312#else
313	pr_warn("/proc/dasd/statistics: is not activated in this kernel\n");
314	return user_len;
315#endif				/* CONFIG_DASD_PROFILE */
316}
317
318static const struct proc_ops dasd_stats_proc_ops = {
319	.proc_open	= dasd_stats_proc_open,
320	.proc_read	= seq_read,
321	.proc_lseek	= seq_lseek,
322	.proc_release	= single_release,
323	.proc_write	= dasd_stats_proc_write,
324};
325
326/*
327 * Create dasd proc-fs entries.
328 * In case creation failed, cleanup and return -ENOENT.
329 */
330int
331dasd_proc_init(void)
332{
333	dasd_proc_root_entry = proc_mkdir("dasd", NULL);
334	if (!dasd_proc_root_entry)
335		goto out_nodasd;
336	dasd_devices_entry = proc_create_seq("devices", 0444,
337					 dasd_proc_root_entry,
338					 &dasd_devices_seq_ops);
339	if (!dasd_devices_entry)
340		goto out_nodevices;
341	dasd_statistics_entry = proc_create("statistics",
342					    S_IFREG | S_IRUGO | S_IWUSR,
343					    dasd_proc_root_entry,
344					    &dasd_stats_proc_ops);
345	if (!dasd_statistics_entry)
346		goto out_nostatistics;
347	return 0;
348
349 out_nostatistics:
350	remove_proc_entry("devices", dasd_proc_root_entry);
351 out_nodevices:
352	remove_proc_entry("dasd", NULL);
353	dasd_proc_root_entry = NULL;
354 out_nodasd:
355	return -ENOENT;
356}
357
358void
359dasd_proc_exit(void)
360{
361	if (!dasd_proc_root_entry)
362		return;
363
364	remove_proc_entry("devices", dasd_proc_root_entry);
365	remove_proc_entry("statistics", dasd_proc_root_entry);
366	remove_proc_entry("dasd", NULL);
367	dasd_proc_root_entry = NULL;
368}