[S390] dasd: improve dasd statistics proc interface
[safe/jmp/linux-2.6] / drivers / s390 / block / dasd_proc.c
1 /*
2  * File...........: linux/drivers/s390/block/dasd_proc.c
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  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2002
9  *
10  * /proc interface for the dasd driver.
11  *
12  */
13
14 #include <linux/ctype.h>
15 #include <linux/seq_file.h>
16 #include <linux/vmalloc.h>
17 #include <linux/proc_fs.h>
18
19 #include <asm/debug.h>
20 #include <asm/uaccess.h>
21
22 /* This is ugly... */
23 #define PRINTK_HEADER "dasd_proc:"
24
25 #include "dasd_int.h"
26
27 static struct proc_dir_entry *dasd_proc_root_entry = NULL;
28 static struct proc_dir_entry *dasd_devices_entry = NULL;
29 static struct proc_dir_entry *dasd_statistics_entry = NULL;
30
31 #ifdef CONFIG_DASD_PROFILE
32 static char *
33 dasd_get_user_string(const char __user *user_buf, size_t user_len)
34 {
35         char *buffer;
36
37         buffer = kmalloc(user_len + 1, GFP_KERNEL);
38         if (buffer == NULL)
39                 return ERR_PTR(-ENOMEM);
40         if (copy_from_user(buffer, user_buf, user_len) != 0) {
41                 kfree(buffer);
42                 return ERR_PTR(-EFAULT);
43         }
44         /* got the string, now strip linefeed. */
45         if (buffer[user_len - 1] == '\n')
46                 buffer[user_len - 1] = 0;
47         else
48                 buffer[user_len] = 0;
49         return buffer;
50 }
51 #endif /* CONFIG_DASD_PROFILE */
52
53 static int
54 dasd_devices_show(struct seq_file *m, void *v)
55 {
56         struct dasd_device *device;
57         struct dasd_block *block;
58         char *substr;
59
60         device = dasd_device_from_devindex((unsigned long) v - 1);
61         if (IS_ERR(device))
62                 return 0;
63         if (device->block)
64                 block = device->block;
65         else {
66                 dasd_put_device(device);
67                 return 0;
68         }
69         /* Print device number. */
70         seq_printf(m, "%s", dev_name(&device->cdev->dev));
71         /* Print discipline string. */
72         if (device != NULL && device->discipline != NULL)
73                 seq_printf(m, "(%s)", device->discipline->name);
74         else
75                 seq_printf(m, "(none)");
76         /* Print kdev. */
77         if (block->gdp)
78                 seq_printf(m, " at (%3d:%6d)",
79                            MAJOR(disk_devt(block->gdp)),
80                            MINOR(disk_devt(block->gdp)));
81         else
82                 seq_printf(m, "  at (???:??????)");
83         /* Print device name. */
84         if (block->gdp)
85                 seq_printf(m, " is %-8s", block->gdp->disk_name);
86         else
87                 seq_printf(m, " is ????????");
88         /* Print devices features. */
89         substr = (device->features & DASD_FEATURE_READONLY) ? "(ro)" : " ";
90         seq_printf(m, "%4s: ", substr);
91         /* Print device status information. */
92         switch ((device != NULL) ? device->state : -1) {
93         case -1:
94                 seq_printf(m, "unknown");
95                 break;
96         case DASD_STATE_NEW:
97                 seq_printf(m, "new");
98                 break;
99         case DASD_STATE_KNOWN:
100                 seq_printf(m, "detected");
101                 break;
102         case DASD_STATE_BASIC:
103                 seq_printf(m, "basic");
104                 break;
105         case DASD_STATE_UNFMT:
106                 seq_printf(m, "unformatted");
107                 break;
108         case DASD_STATE_READY:
109         case DASD_STATE_ONLINE:
110                 seq_printf(m, "active ");
111                 if (dasd_check_blocksize(block->bp_block))
112                         seq_printf(m, "n/f       ");
113                 else
114                         seq_printf(m,
115                                    "at blocksize: %d, %ld blocks, %ld MB",
116                                    block->bp_block, block->blocks,
117                                    ((block->bp_block >> 9) *
118                                     block->blocks) >> 11);
119                 break;
120         default:
121                 seq_printf(m, "no stat");
122                 break;
123         }
124         dasd_put_device(device);
125         if (dasd_probeonly)
126                 seq_printf(m, "(probeonly)");
127         seq_printf(m, "\n");
128         return 0;
129 }
130
131 static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
132 {
133         if (*pos >= dasd_max_devindex)
134                 return NULL;
135         return (void *)((unsigned long) *pos + 1);
136 }
137
138 static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
139 {
140         ++*pos;
141         return dasd_devices_start(m, pos);
142 }
143
144 static void dasd_devices_stop(struct seq_file *m, void *v)
145 {
146 }
147
148 static const struct seq_operations dasd_devices_seq_ops = {
149         .start          = dasd_devices_start,
150         .next           = dasd_devices_next,
151         .stop           = dasd_devices_stop,
152         .show           = dasd_devices_show,
153 };
154
155 static int dasd_devices_open(struct inode *inode, struct file *file)
156 {
157         return seq_open(file, &dasd_devices_seq_ops);
158 }
159
160 static const struct file_operations dasd_devices_file_ops = {
161         .owner          = THIS_MODULE,
162         .open           = dasd_devices_open,
163         .read           = seq_read,
164         .llseek         = seq_lseek,
165         .release        = seq_release,
166 };
167
168 static int
169 dasd_calc_metrics(char *page, char **start, off_t off,
170                   int count, int *eof, int len)
171 {
172         len = (len > off) ? len - off : 0;
173         if (len > count)
174                 len = count;
175         if (len < count)
176                 *eof = 1;
177         *start = page + off;
178         return len;
179 }
180
181 #ifdef CONFIG_DASD_PROFILE
182 static char *
183 dasd_statistics_array(char *str, unsigned int *array, int factor)
184 {
185         int i;
186
187         for (i = 0; i < 32; i++) {
188                 str += sprintf(str, "%7d ", array[i] / factor);
189                 if (i == 15)
190                         str += sprintf(str, "\n");
191         }
192         str += sprintf(str,"\n");
193         return str;
194 }
195 #endif /* CONFIG_DASD_PROFILE */
196
197 static int
198 dasd_statistics_read(char *page, char **start, off_t off,
199                      int count, int *eof, void *data)
200 {
201         unsigned long len;
202 #ifdef CONFIG_DASD_PROFILE
203         struct dasd_profile_info_t *prof;
204         char *str;
205         int factor;
206
207         /* check for active profiling */
208         if (dasd_profile_level == DASD_PROFILE_OFF) {
209                 len = sprintf(page, "Statistics are off - they might be "
210                                     "switched on using 'echo set on > "
211                                     "/proc/dasd/statistics'\n");
212                 return dasd_calc_metrics(page, start, off, count, eof, len);
213         }
214
215         prof = &dasd_global_profile;
216         /* prevent couter 'overflow' on output */
217         for (factor = 1; (prof->dasd_io_reqs / factor) > 9999999;
218              factor *= 10);
219
220         str = page;
221         str += sprintf(str, "%d dasd I/O requests\n", prof->dasd_io_reqs);
222         str += sprintf(str, "with %u sectors(512B each)\n",
223                        prof->dasd_io_sects);
224         str += sprintf(str, "Scale Factor is  %d\n", factor);
225         str += sprintf(str,
226                        "   __<4    ___8    __16    __32    __64    _128 "
227                        "   _256    _512    __1k    __2k    __4k    __8k "
228                        "   _16k    _32k    _64k    128k\n");
229         str += sprintf(str,
230                        "   _256    _512    __1M    __2M    __4M    __8M "
231                        "   _16M    _32M    _64M    128M    256M    512M "
232                        "   __1G    __2G    __4G " "   _>4G\n");
233
234         str += sprintf(str, "Histogram of sizes (512B secs)\n");
235         str = dasd_statistics_array(str, prof->dasd_io_secs, factor);
236         str += sprintf(str, "Histogram of I/O times (microseconds)\n");
237         str = dasd_statistics_array(str, prof->dasd_io_times, factor);
238         str += sprintf(str, "Histogram of I/O times per sector\n");
239         str = dasd_statistics_array(str, prof->dasd_io_timps, factor);
240         str += sprintf(str, "Histogram of I/O time till ssch\n");
241         str = dasd_statistics_array(str, prof->dasd_io_time1, factor);
242         str += sprintf(str, "Histogram of I/O time between ssch and irq\n");
243         str = dasd_statistics_array(str, prof->dasd_io_time2, factor);
244         str += sprintf(str, "Histogram of I/O time between ssch "
245                             "and irq per sector\n");
246         str = dasd_statistics_array(str, prof->dasd_io_time2ps, factor);
247         str += sprintf(str, "Histogram of I/O time between irq and end\n");
248         str = dasd_statistics_array(str, prof->dasd_io_time3, factor);
249         str += sprintf(str, "# of req in chanq at enqueuing (1..32) \n");
250         str = dasd_statistics_array(str, prof->dasd_io_nr_req, factor);
251         len = str - page;
252 #else
253         len = sprintf(page, "Statistics are not activated in this kernel\n");
254 #endif
255         return dasd_calc_metrics(page, start, off, count, eof, len);
256 }
257
258 static int
259 dasd_statistics_write(struct file *file, const char __user *user_buf,
260                       unsigned long user_len, void *data)
261 {
262 #ifdef CONFIG_DASD_PROFILE
263         char *buffer, *str;
264
265         if (user_len > 65536)
266                 user_len = 65536;
267         buffer = dasd_get_user_string(user_buf, user_len);
268         if (IS_ERR(buffer))
269                 return PTR_ERR(buffer);
270         MESSAGE_LOG(KERN_INFO, "/proc/dasd/statictics: '%s'", buffer);
271
272         /* check for valid verbs */
273         for (str = buffer; isspace(*str); str++);
274         if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
275                 /* 'set xxx' was given */
276                 for (str = str + 4; isspace(*str); str++);
277                 if (strcmp(str, "on") == 0) {
278                         /* switch on statistics profiling */
279                         dasd_profile_level = DASD_PROFILE_ON;
280                         MESSAGE(KERN_INFO, "%s", "Statistics switched on");
281                 } else if (strcmp(str, "off") == 0) {
282                         /* switch off and reset statistics profiling */
283                         memset(&dasd_global_profile,
284                                0, sizeof (struct dasd_profile_info_t));
285                         dasd_profile_level = DASD_PROFILE_OFF;
286                         MESSAGE(KERN_INFO, "%s", "Statistics switched off");
287                 } else
288                         goto out_error;
289         } else if (strncmp(str, "reset", 5) == 0) {
290                 /* reset the statistics */
291                 memset(&dasd_global_profile, 0,
292                        sizeof (struct dasd_profile_info_t));
293                 MESSAGE(KERN_INFO, "%s", "Statistics reset");
294         } else
295                 goto out_error;
296         kfree(buffer);
297         return user_len;
298 out_error:
299         MESSAGE(KERN_WARNING, "%s",
300                 "/proc/dasd/statistics: only 'set on', 'set off' "
301                 "and 'reset' are supported verbs");
302         kfree(buffer);
303         return -EINVAL;
304 #else
305         MESSAGE(KERN_WARNING, "%s",
306                 "/proc/dasd/statistics: is not activated in this kernel");
307         return user_len;
308 #endif                          /* CONFIG_DASD_PROFILE */
309 }
310
311 /*
312  * Create dasd proc-fs entries.
313  * In case creation failed, cleanup and return -ENOENT.
314  */
315 int
316 dasd_proc_init(void)
317 {
318         dasd_proc_root_entry = proc_mkdir("dasd", NULL);
319         if (!dasd_proc_root_entry)
320                 goto out_nodasd;
321         dasd_proc_root_entry->owner = THIS_MODULE;
322         dasd_devices_entry = proc_create("devices",
323                                          S_IFREG | S_IRUGO | S_IWUSR,
324                                          dasd_proc_root_entry,
325                                          &dasd_devices_file_ops);
326         if (!dasd_devices_entry)
327                 goto out_nodevices;
328         dasd_statistics_entry = create_proc_entry("statistics",
329                                                   S_IFREG | S_IRUGO | S_IWUSR,
330                                                   dasd_proc_root_entry);
331         if (!dasd_statistics_entry)
332                 goto out_nostatistics;
333         dasd_statistics_entry->read_proc = dasd_statistics_read;
334         dasd_statistics_entry->write_proc = dasd_statistics_write;
335         dasd_statistics_entry->owner = THIS_MODULE;
336         return 0;
337
338  out_nostatistics:
339         remove_proc_entry("devices", dasd_proc_root_entry);
340  out_nodevices:
341         remove_proc_entry("dasd", NULL);
342  out_nodasd:
343         return -ENOENT;
344 }
345
346 void
347 dasd_proc_exit(void)
348 {
349         remove_proc_entry("devices", dasd_proc_root_entry);
350         remove_proc_entry("statistics", dasd_proc_root_entry);
351         remove_proc_entry("dasd", NULL);
352 }