[PATCH] s390: dasd readonly attribute
[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  * $Revision: 1.31 $
13  */
14
15 #include <linux/config.h>
16 #include <linux/ctype.h>
17 #include <linux/seq_file.h>
18 #include <linux/vmalloc.h>
19
20 #include <asm/debug.h>
21 #include <asm/uaccess.h>
22
23 /* This is ugly... */
24 #define PRINTK_HEADER "dasd_proc:"
25
26 #include "dasd_int.h"
27
28 static struct proc_dir_entry *dasd_proc_root_entry = NULL;
29 static struct proc_dir_entry *dasd_devices_entry = NULL;
30 static struct proc_dir_entry *dasd_statistics_entry = NULL;
31
32 static inline 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
52 static int
53 dasd_devices_show(struct seq_file *m, void *v)
54 {
55         struct dasd_device *device;
56         char *substr;
57         int feature;
58
59         device = dasd_device_from_devindex((unsigned long) v - 1);
60         if (IS_ERR(device))
61                 return 0;
62         /* Print device number. */
63         seq_printf(m, "%s", device->cdev->dev.bus_id);
64         /* Print discipline string. */
65         if (device != NULL && device->discipline != NULL)
66                 seq_printf(m, "(%s)", device->discipline->name);
67         else
68                 seq_printf(m, "(none)");
69         /* Print kdev. */
70         if (device->gdp)
71                 seq_printf(m, " at (%3d:%6d)",
72                            device->gdp->major, device->gdp->first_minor);
73         else
74                 seq_printf(m, "  at (???:??????)");
75         /* Print device name. */
76         if (device->gdp)
77                 seq_printf(m, " is %-8s", device->gdp->disk_name);
78         else
79                 seq_printf(m, " is ????????");
80         /* Print devices features. */
81         feature = dasd_get_feature(device->cdev, DASD_FEATURE_READONLY);
82         if (feature < 0)
83                 return 0;
84         substr = feature ? "(ro)" : " ";
85         seq_printf(m, "%4s: ", substr);
86         /* Print device status information. */
87         switch ((device != NULL) ? device->state : -1) {
88         case -1:
89                 seq_printf(m, "unknown");
90                 break;
91         case DASD_STATE_NEW:
92                 seq_printf(m, "new");
93                 break;
94         case DASD_STATE_KNOWN:
95                 seq_printf(m, "detected");
96                 break;
97         case DASD_STATE_BASIC:
98                 seq_printf(m, "basic");
99                 break;
100         case DASD_STATE_READY:
101         case DASD_STATE_ONLINE:
102                 seq_printf(m, "active ");
103                 if (dasd_check_blocksize(device->bp_block))
104                         seq_printf(m, "n/f       ");
105                 else
106                         seq_printf(m,
107                                    "at blocksize: %d, %ld blocks, %ld MB",
108                                    device->bp_block, device->blocks,
109                                    ((device->bp_block >> 9) *
110                                     device->blocks) >> 11);
111                 break;
112         default:
113                 seq_printf(m, "no stat");
114                 break;
115         }
116         dasd_put_device(device);
117         if (dasd_probeonly)
118                 seq_printf(m, "(probeonly)");
119         seq_printf(m, "\n");
120         return 0;
121 }
122
123 static void *dasd_devices_start(struct seq_file *m, loff_t *pos)
124 {
125         if (*pos >= dasd_max_devindex)
126                 return NULL;
127         return (void *)((unsigned long) *pos + 1);
128 }
129
130 static void *dasd_devices_next(struct seq_file *m, void *v, loff_t *pos)
131 {
132         ++*pos;
133         return dasd_devices_start(m, pos);
134 }
135
136 static void dasd_devices_stop(struct seq_file *m, void *v)
137 {
138 }
139
140 static struct seq_operations dasd_devices_seq_ops = {
141         .start          = dasd_devices_start,
142         .next           = dasd_devices_next,
143         .stop           = dasd_devices_stop,
144         .show           = dasd_devices_show,
145 };
146
147 static int dasd_devices_open(struct inode *inode, struct file *file)
148 {
149         return seq_open(file, &dasd_devices_seq_ops);
150 }
151
152 static struct file_operations dasd_devices_file_ops = {
153         .open           = dasd_devices_open,
154         .read           = seq_read,
155         .llseek         = seq_lseek,
156         .release        = seq_release,
157 };
158
159 static inline int
160 dasd_calc_metrics(char *page, char **start, off_t off,
161                   int count, int *eof, int len)
162 {
163         len = (len > off) ? len - off : 0;
164         if (len > count)
165                 len = count;
166         if (len < count)
167                 *eof = 1;
168         *start = page + off;
169         return len;
170 }
171
172 static inline char *
173 dasd_statistics_array(char *str, int *array, int shift)
174 {
175         int i;
176
177         for (i = 0; i < 32; i++) {
178                 str += sprintf(str, "%7d ", array[i] >> shift);
179                 if (i == 15)
180                         str += sprintf(str, "\n");
181         }
182         str += sprintf(str,"\n");
183         return str;
184 }
185
186 static int
187 dasd_statistics_read(char *page, char **start, off_t off,
188                      int count, int *eof, void *data)
189 {
190         unsigned long len;
191 #ifdef CONFIG_DASD_PROFILE
192         struct dasd_profile_info_t *prof;
193         char *str;
194         int shift;
195
196         /* check for active profiling */
197         if (dasd_profile_level == DASD_PROFILE_OFF) {
198                 len = sprintf(page, "Statistics are off - they might be "
199                                     "switched on using 'echo set on > "
200                                     "/proc/dasd/statistics'\n");
201                 return dasd_calc_metrics(page, start, off, count, eof, len);
202         }
203
204         prof = &dasd_global_profile;
205         /* prevent couter 'overflow' on output */
206         for (shift = 0; (prof->dasd_io_reqs >> shift) > 9999999; shift++);
207
208         str = page;
209         str += sprintf(str, "%d dasd I/O requests\n", prof->dasd_io_reqs);
210         str += sprintf(str, "with %d sectors(512B each)\n",
211                        prof->dasd_io_sects);
212         str += sprintf(str,
213                        "   __<4    ___8    __16    __32    __64    _128 "
214                        "   _256    _512    __1k    __2k    __4k    __8k "
215                        "   _16k    _32k    _64k    128k\n");
216         str += sprintf(str,
217                        "   _256    _512    __1M    __2M    __4M    __8M "
218                        "   _16M    _32M    _64M    128M    256M    512M "
219                        "   __1G    __2G    __4G " "   _>4G\n");
220
221         str += sprintf(str, "Histogram of sizes (512B secs)\n");
222         str = dasd_statistics_array(str, prof->dasd_io_secs, shift);
223         str += sprintf(str, "Histogram of I/O times (microseconds)\n");
224         str = dasd_statistics_array(str, prof->dasd_io_times, shift);
225         str += sprintf(str, "Histogram of I/O times per sector\n");
226         str = dasd_statistics_array(str, prof->dasd_io_timps, shift);
227         str += sprintf(str, "Histogram of I/O time till ssch\n");
228         str = dasd_statistics_array(str, prof->dasd_io_time1, shift);
229         str += sprintf(str, "Histogram of I/O time between ssch and irq\n");
230         str = dasd_statistics_array(str, prof->dasd_io_time2, shift);
231         str += sprintf(str, "Histogram of I/O time between ssch "
232                             "and irq per sector\n");
233         str = dasd_statistics_array(str, prof->dasd_io_time2ps, shift);
234         str += sprintf(str, "Histogram of I/O time between irq and end\n");
235         str = dasd_statistics_array(str, prof->dasd_io_time3, shift);
236         str += sprintf(str, "# of req in chanq at enqueuing (1..32) \n");
237         str = dasd_statistics_array(str, prof->dasd_io_nr_req, shift);
238         len = str - page;
239 #else
240         len = sprintf(page, "Statistics are not activated in this kernel\n");
241 #endif
242         return dasd_calc_metrics(page, start, off, count, eof, len);
243 }
244
245 static int
246 dasd_statistics_write(struct file *file, const char __user *user_buf,
247                       unsigned long user_len, void *data)
248 {
249 #ifdef CONFIG_DASD_PROFILE
250         char *buffer, *str;
251
252         if (user_len > 65536)
253                 user_len = 65536;
254         buffer = dasd_get_user_string(user_buf, user_len);
255         if (IS_ERR(buffer))
256                 return PTR_ERR(buffer);
257         MESSAGE_LOG(KERN_INFO, "/proc/dasd/statictics: '%s'", buffer);
258
259         /* check for valid verbs */
260         for (str = buffer; isspace(*str); str++);
261         if (strncmp(str, "set", 3) == 0 && isspace(str[3])) {
262                 /* 'set xxx' was given */
263                 for (str = str + 4; isspace(*str); str++);
264                 if (strcmp(str, "on") == 0) {
265                         /* switch on statistics profiling */
266                         dasd_profile_level = DASD_PROFILE_ON;
267                         MESSAGE(KERN_INFO, "%s", "Statistics switched on");
268                 } else if (strcmp(str, "off") == 0) {
269                         /* switch off and reset statistics profiling */
270                         memset(&dasd_global_profile,
271                                0, sizeof (struct dasd_profile_info_t));
272                         dasd_profile_level = DASD_PROFILE_OFF;
273                         MESSAGE(KERN_INFO, "%s", "Statistics switched off");
274                 } else
275                         goto out_error;
276         } else if (strncmp(str, "reset", 5) == 0) {
277                 /* reset the statistics */
278                 memset(&dasd_global_profile, 0,
279                        sizeof (struct dasd_profile_info_t));
280                 MESSAGE(KERN_INFO, "%s", "Statistics reset");
281         } else
282                 goto out_error;
283         kfree(buffer);
284         return user_len;
285 out_error:
286         MESSAGE(KERN_WARNING, "%s",
287                 "/proc/dasd/statistics: only 'set on', 'set off' "
288                 "and 'reset' are supported verbs");
289         kfree(buffer);
290         return -EINVAL;
291 #else
292         MESSAGE(KERN_WARNING, "%s",
293                 "/proc/dasd/statistics: is not activated in this kernel");
294         return user_len;
295 #endif                          /* CONFIG_DASD_PROFILE */
296 }
297
298 int
299 dasd_proc_init(void)
300 {
301         dasd_proc_root_entry = proc_mkdir("dasd", &proc_root);
302         dasd_proc_root_entry->owner = THIS_MODULE;
303         dasd_devices_entry = create_proc_entry("devices",
304                                                S_IFREG | S_IRUGO | S_IWUSR,
305                                                dasd_proc_root_entry);
306         dasd_devices_entry->proc_fops = &dasd_devices_file_ops;
307         dasd_devices_entry->owner = THIS_MODULE;
308         dasd_statistics_entry = create_proc_entry("statistics",
309                                                   S_IFREG | S_IRUGO | S_IWUSR,
310                                                   dasd_proc_root_entry);
311         dasd_statistics_entry->read_proc = dasd_statistics_read;
312         dasd_statistics_entry->write_proc = dasd_statistics_write;
313         dasd_statistics_entry->owner = THIS_MODULE;
314         return 0;
315 }
316
317 void
318 dasd_proc_exit(void)
319 {
320         remove_proc_entry("devices", dasd_proc_root_entry);
321         remove_proc_entry("statistics", dasd_proc_root_entry);
322         remove_proc_entry("dasd", &proc_root);
323 }