1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/blkdev.h>
4 #include <linux/init.h>
5 #include <linux/mount.h>
6 #include <linux/major.h>
7 #include <linux/delay.h>
8 #include <linux/init_syscalls.h>
9 #include <linux/raid/detect.h>
10 #include <linux/raid/md_u.h>
11 #include <linux/raid/md_p.h>
12 #include "md.h"
13
14 /*
15 * When md (and any require personalities) are compiled into the kernel
16 * (not a module), arrays can be assembles are boot time using with AUTODETECT
17 * where specially marked partitions are registered with md_autodetect_dev(),
18 * and with MD_BOOT where devices to be collected are given on the boot line
19 * with md=.....
20 * The code for that is here.
21 */
22
23 #ifdef CONFIG_MD_AUTODETECT
24 static int __initdata raid_noautodetect;
25 #else
26 static int __initdata raid_noautodetect=1;
27 #endif
28 static int __initdata raid_autopart;
29
30 static struct md_setup_args {
31 int minor;
32 int partitioned;
33 int level;
34 int chunk;
35 char *device_names;
36 } md_setup_args[256] __initdata;
37
38 static int md_setup_ents __initdata;
39
40 /*
41 * Parse the command-line parameters given our kernel, but do not
42 * actually try to invoke the MD device now; that is handled by
43 * md_setup_drive after the low-level disk drivers have initialised.
44 *
45 * 27/11/1999: Fixed to work correctly with the 2.3 kernel (which
46 * assigns the task of parsing integer arguments to the
47 * invoked program now). Added ability to initialise all
48 * the MD devices (by specifying multiple "md=" lines)
49 * instead of just one. -- KTK
50 * 18May2000: Added support for persistent-superblock arrays:
51 * md=n,0,factor,fault,device-list uses RAID0 for device n
52 * md=n,-1,factor,fault,device-list uses LINEAR for device n
53 * md=n,device-list reads a RAID superblock from the devices
54 * elements in device-list are read by name_to_kdev_t so can be
55 * a hex number or something like /dev/hda1 /dev/sdb
56 * 2001-06-03: Dave Cinege <dcinege@psychosis.com>
57 * Shifted name_to_kdev_t() and related operations to md_set_drive()
58 * for later execution. Rewrote section to make devfs compatible.
59 */
md_setup(char * str)60 static int __init md_setup(char *str)
61 {
62 int minor, level, factor, fault, partitioned = 0;
63 char *pername = "";
64 char *str1;
65 int ent;
66
67 if (*str == 'd') {
68 partitioned = 1;
69 str++;
70 }
71 if (get_option(&str, &minor) != 2) { /* MD Number */
72 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
73 return 0;
74 }
75 str1 = str;
76 for (ent=0 ; ent< md_setup_ents ; ent++)
77 if (md_setup_args[ent].minor == minor &&
78 md_setup_args[ent].partitioned == partitioned) {
79 printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
80 "Replacing previous definition.\n", partitioned?"d":"", minor);
81 break;
82 }
83 if (ent >= ARRAY_SIZE(md_setup_args)) {
84 printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
85 return 0;
86 }
87 if (ent >= md_setup_ents)
88 md_setup_ents++;
89 switch (get_option(&str, &level)) { /* RAID level */
90 case 2: /* could be 0 or -1.. */
91 if (level == 0 || level == LEVEL_LINEAR) {
92 if (get_option(&str, &factor) != 2 || /* Chunk Size */
93 get_option(&str, &fault) != 2) {
94 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
95 return 0;
96 }
97 md_setup_args[ent].level = level;
98 md_setup_args[ent].chunk = 1 << (factor+12);
99 if (level == LEVEL_LINEAR)
100 pername = "linear";
101 else
102 pername = "raid0";
103 break;
104 }
105 fallthrough;
106 case 1: /* the first device is numeric */
107 str = str1;
108 fallthrough;
109 case 0:
110 md_setup_args[ent].level = LEVEL_NONE;
111 pername="super-block";
112 }
113
114 printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
115 minor, pername, str);
116 md_setup_args[ent].device_names = str;
117 md_setup_args[ent].partitioned = partitioned;
118 md_setup_args[ent].minor = minor;
119
120 return 1;
121 }
122
md_setup_drive(struct md_setup_args * args)123 static void __init md_setup_drive(struct md_setup_args *args)
124 {
125 char *devname = args->device_names;
126 dev_t devices[MD_SB_DISKS + 1], mdev;
127 struct mdu_array_info_s ainfo = { };
128 struct mddev *mddev;
129 int err = 0, i;
130 char name[16];
131
132 if (args->partitioned) {
133 mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
134 sprintf(name, "md_d%d", args->minor);
135 } else {
136 mdev = MKDEV(MD_MAJOR, args->minor);
137 sprintf(name, "md%d", args->minor);
138 }
139
140 for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
141 struct kstat stat;
142 char *p;
143 char comp_name[64];
144 dev_t dev;
145
146 p = strchr(devname, ',');
147 if (p)
148 *p++ = 0;
149
150 if (early_lookup_bdev(devname, &dev))
151 dev = 0;
152 if (strncmp(devname, "/dev/", 5) == 0)
153 devname += 5;
154 snprintf(comp_name, 63, "/dev/%s", devname);
155 if (init_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
156 dev = new_decode_dev(stat.rdev);
157 if (!dev) {
158 pr_warn("md: Unknown device name: %s\n", devname);
159 break;
160 }
161
162 devices[i] = dev;
163 devname = p;
164 }
165 devices[i] = 0;
166
167 if (!i)
168 return;
169
170 pr_info("md: Loading %s: %s\n", name, args->device_names);
171
172 mddev = md_alloc(mdev, name);
173 if (IS_ERR(mddev)) {
174 pr_err("md: md_alloc failed - cannot start array %s\n", name);
175 return;
176 }
177
178 err = mddev_lock(mddev);
179 if (err) {
180 pr_err("md: failed to lock array %s\n", name);
181 goto out_mddev_put;
182 }
183
184 if (!list_empty(&mddev->disks) || mddev->raid_disks) {
185 pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
186 name);
187 goto out_unlock;
188 }
189
190 if (args->level != LEVEL_NONE) {
191 /* non-persistent */
192 ainfo.level = args->level;
193 ainfo.md_minor = args->minor;
194 ainfo.not_persistent = 1;
195 ainfo.state = (1 << MD_SB_CLEAN);
196 ainfo.chunk_size = args->chunk;
197 while (devices[ainfo.raid_disks])
198 ainfo.raid_disks++;
199 }
200
201 err = md_set_array_info(mddev, &ainfo);
202
203 for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
204 struct mdu_disk_info_s dinfo = {
205 .major = MAJOR(devices[i]),
206 .minor = MINOR(devices[i]),
207 };
208
209 if (args->level != LEVEL_NONE) {
210 dinfo.number = i;
211 dinfo.raid_disk = i;
212 dinfo.state =
213 (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
214 }
215
216 md_add_new_disk(mddev, &dinfo);
217 }
218
219 if (!err)
220 err = do_md_run(mddev);
221 if (err)
222 pr_warn("md: starting %s failed\n", name);
223 out_unlock:
224 mddev_unlock(mddev);
225 out_mddev_put:
226 mddev_put(mddev);
227 }
228
raid_setup(char * str)229 static int __init raid_setup(char *str)
230 {
231 int len, pos;
232
233 len = strlen(str) + 1;
234 pos = 0;
235
236 while (pos < len) {
237 char *comma = strchr(str+pos, ',');
238 int wlen;
239 if (comma)
240 wlen = (comma-str)-pos;
241 else wlen = (len-1)-pos;
242
243 if (!strncmp(str, "noautodetect", wlen))
244 raid_noautodetect = 1;
245 if (!strncmp(str, "autodetect", wlen))
246 raid_noautodetect = 0;
247 if (strncmp(str, "partitionable", wlen)==0)
248 raid_autopart = 1;
249 if (strncmp(str, "part", wlen)==0)
250 raid_autopart = 1;
251 pos += wlen+1;
252 }
253 return 1;
254 }
255
256 __setup("raid=", raid_setup);
257 __setup("md=", md_setup);
258
autodetect_raid(void)259 static void __init autodetect_raid(void)
260 {
261 /*
262 * Since we don't want to detect and use half a raid array, we need to
263 * wait for the known devices to complete their probing
264 */
265 printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
266 printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
267
268 wait_for_device_probe();
269 md_autostart_arrays(raid_autopart);
270 }
271
md_run_setup(void)272 void __init md_run_setup(void)
273 {
274 int ent;
275
276 if (raid_noautodetect)
277 printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
278 else
279 autodetect_raid();
280
281 for (ent = 0; ent < md_setup_ents; ent++)
282 md_setup_drive(&md_setup_args[ent]);
283 }
284