1 /*
2 * Code extracted from
3 * linux/kernel/hd.c
4 *
5 * Copyright (C) 1991-1998 Linus Torvalds
6 *
7 * devfs support - jj, rgooch, 980122
8 *
9 * Moved partition checking code to fs/partitions* - Russell King
10 * (linux@arm.uk.linux.org)
11 */
12
13 /*
14 * TODO: rip out the remaining init crap from this file --hch
15 */
16
17 #include <linux/config.h>
18 #include <linux/module.h>
19 #include <linux/fs.h>
20 #include <linux/genhd.h>
21 #include <linux/kernel.h>
22 #include <linux/blk.h>
23 #include <linux/init.h>
24 #include <linux/spinlock.h>
25 #include <linux/seq_file.h>
26
27
28 /*
29 * Global kernel list of partitioning information.
30 *
31 * XXX: you should _never_ access this directly.
32 * the only reason this is exported is source compatiblity.
33 */
34 /*static*/ struct gendisk *gendisk_head;
35 static struct gendisk *gendisk_array[MAX_BLKDEV];
36 static rwlock_t gendisk_lock = RW_LOCK_UNLOCKED;
37
38 EXPORT_SYMBOL(gendisk_head);
39
40
41 /**
42 * add_gendisk - add partitioning information to kernel list
43 * @gp: per-device partitioning information
44 *
45 * This function registers the partitioning information in @gp
46 * with the kernel.
47 */
48 void
add_gendisk(struct gendisk * gp)49 add_gendisk(struct gendisk *gp)
50 {
51 struct gendisk *sgp;
52 unsigned long flags;
53
54 write_lock_irqsave(&gendisk_lock, flags);
55
56 /*
57 * In 2.5 this will go away. Fix the drivers who rely on
58 * old behaviour.
59 */
60
61 for (sgp = gendisk_head; sgp; sgp = sgp->next)
62 {
63 if (sgp == gp)
64 {
65 // printk(KERN_ERR "add_gendisk: device major %d is buggy and added a live gendisk!\n",
66 // sgp->major)
67 goto out;
68 }
69 }
70 gendisk_array[gp->major] = gp;
71 gp->next = gendisk_head;
72 gendisk_head = gp;
73 out:
74 write_unlock_irqrestore(&gendisk_lock, flags);
75 }
76
77 EXPORT_SYMBOL(add_gendisk);
78
79
80 /**
81 * del_gendisk - remove partitioning information from kernel list
82 * @gp: per-device partitioning information
83 *
84 * This function unregisters the partitioning information in @gp
85 * with the kernel.
86 */
87 void
del_gendisk(struct gendisk * gp)88 del_gendisk(struct gendisk *gp)
89 {
90 struct gendisk **gpp;
91 unsigned long flags;
92
93 write_lock_irqsave(&gendisk_lock, flags);
94 gendisk_array[gp->major] = NULL;
95 for (gpp = &gendisk_head; *gpp; gpp = &((*gpp)->next))
96 if (*gpp == gp)
97 break;
98 if (*gpp)
99 *gpp = (*gpp)->next;
100 write_unlock_irqrestore(&gendisk_lock, flags);
101 }
102
103 EXPORT_SYMBOL(del_gendisk);
104
105
106 /**
107 * get_gendisk - get partitioning information for a given device
108 * @dev: device to get partitioning information for
109 *
110 * This function gets the structure containing partitioning
111 * information for the given device @dev.
112 */
113 struct gendisk *
get_gendisk(kdev_t dev)114 get_gendisk(kdev_t dev)
115 {
116 struct gendisk *gp = NULL;
117 int maj = MAJOR(dev);
118 unsigned long flags;
119
120 read_lock_irqsave(&gendisk_lock, flags);
121 if ((gp = gendisk_array[maj]))
122 goto out;
123
124 /* This is needed for early 2.4 source compatiblity. --hch */
125 for (gp = gendisk_head; gp; gp = gp->next)
126 if (gp->major == maj)
127 break;
128 out:
129 read_unlock_irqrestore(&gendisk_lock, flags);
130 return gp;
131 }
132
133 EXPORT_SYMBOL(get_gendisk);
134
135
136 /**
137 * walk_gendisk - issue a command for every registered gendisk
138 * @walk: user-specified callback
139 * @data: opaque data for the callback
140 *
141 * This function walks through the gendisk chain and calls back
142 * into @walk for every element.
143 */
144 int
walk_gendisk(int (* walk)(struct gendisk *,void *),void * data)145 walk_gendisk(int (*walk)(struct gendisk *, void *), void *data)
146 {
147 struct gendisk *gp;
148 int error = 0;
149 unsigned long flags;
150
151 read_lock_irqsave(&gendisk_lock, flags);
152 for (gp = gendisk_head; gp; gp = gp->next)
153 if ((error = walk(gp, data)))
154 break;
155 read_unlock_irqrestore(&gendisk_lock, flags);
156
157 return error;
158 }
159
160 #ifdef CONFIG_PROC_FS
161 /* iterator */
part_start(struct seq_file * s,loff_t * ppos)162 static void *part_start(struct seq_file *s, loff_t *ppos)
163 {
164 struct gendisk *gp;
165 loff_t pos = *ppos;
166
167 read_lock_irq(&gendisk_lock);
168 for (gp = gendisk_head; gp; gp = gp->next)
169 if (!pos--)
170 return gp;
171 return NULL;
172 }
173
part_next(struct seq_file * s,void * v,loff_t * pos)174 static void *part_next(struct seq_file *s, void *v, loff_t *pos)
175 {
176 ++*pos;
177 return ((struct gendisk *)v)->next;
178 }
179
part_stop(struct seq_file * s,void * v)180 static void part_stop(struct seq_file *s, void *v)
181 {
182 read_unlock_irq(&gendisk_lock);
183 }
184
part_show(struct seq_file * s,void * v)185 static int part_show(struct seq_file *s, void *v)
186 {
187 struct gendisk *gp = v;
188 char buf[64];
189 int n;
190
191 if (gp == gendisk_head) {
192 seq_puts(s, "major minor #blocks name"
193 #ifdef CONFIG_BLK_STATS
194 " rio rmerge rsect ruse wio wmerge "
195 "wsect wuse running use aveq"
196 #endif
197 "\n\n");
198 }
199
200 /* show the full disk and all non-0 size partitions of it */
201 for (n = 0; n < (gp->nr_real << gp->minor_shift); n++) {
202 if (gp->part[n].nr_sects) {
203 #ifdef CONFIG_BLK_STATS
204 struct hd_struct *hd = &gp->part[n];
205
206 disk_round_stats(hd);
207 seq_printf(s, "%4d %4d %10d %s "
208 "%u %u %u %u %u %u %u %u %d %u %u\n",
209 gp->major, n, gp->sizes[n],
210 disk_name(gp, n, buf),
211 hd->rd_ios, hd->rd_merges,
212 #define MSEC(x) ((x) * 1000 / HZ)
213 hd->rd_sectors, MSEC(hd->rd_ticks),
214 hd->wr_ios, hd->wr_merges,
215 hd->wr_sectors, MSEC(hd->wr_ticks),
216 hd->ios_in_flight, MSEC(hd->io_ticks),
217 MSEC(hd->aveq));
218 #else
219 seq_printf(s, "%4d %4d %10d %s\n",
220 gp->major, n, gp->sizes[n],
221 disk_name(gp, n, buf));
222 #endif /* CONFIG_BLK_STATS */
223 }
224 }
225
226 return 0;
227 }
228
229 struct seq_operations partitions_op = {
230 .start = part_start,
231 .next = part_next,
232 .stop = part_stop,
233 .show = part_show,
234 };
235 #endif
236
237 extern int blk_dev_init(void);
238 extern int net_dev_init(void);
239 extern void console_map_init(void);
240 extern int atmdev_init(void);
241
device_init(void)242 int __init device_init(void)
243 {
244 blk_dev_init();
245 sti();
246 #ifdef CONFIG_NET
247 net_dev_init();
248 #endif
249 #ifdef CONFIG_ATM
250 (void) atmdev_init();
251 #endif
252 #ifdef CONFIG_VT
253 console_map_init();
254 #endif
255 return 0;
256 }
257
258 __initcall(device_init);
259