drivers/md/md-autodetect.c

   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,device-list      reads a RAID superblock from the devices
  53  *             elements in device-list are read by name_to_kdev_t so can be
  54  *             a hex number or something like /dev/hda1 /dev/sdb
  55  * 2001-06-03: Dave Cinege <dcinege@psychosis.com>
  56  *              Shifted name_to_kdev_t() and related operations to md_set_drive()
  57  *              for later execution. Rewrote section to make devfs compatible.
  58  */
  59 static int __init md_setup(char *str)
  60 {
  61         int minor, level, factor, fault, partitioned = 0;
  62         char *pername = "";
  63         char *str1;
  64         int ent;
  65
  66         if (*str == 'd') {
  67                 partitioned = 1;
  68                 str++;
  69         }
  70         if (get_option(&str, &minor) != 2) {    /* MD Number */
  71                 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
  72                 return 0;
  73         }
  74         str1 = str;
  75         for (ent=0 ; ent< md_setup_ents ; ent++)
  76                 if (md_setup_args[ent].minor == minor &&
  77                     md_setup_args[ent].partitioned == partitioned) {
  78                         printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
  79                                "Replacing previous definition.\n", partitioned?"d":"", minor);
  80                         break;
  81                 }
  82         if (ent >= ARRAY_SIZE(md_setup_args)) {
  83                 printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
  84                 return 0;
  85         }
  86         if (ent >= md_setup_ents)
  87                 md_setup_ents++;
  88         switch (get_option(&str, &level)) {     /* RAID level */
  89         case 2: /* could be 0 or -1.. */
  90                 if (level == 0) {
  91                         if (get_option(&str, &factor) != 2 ||   /* Chunk Size */
  92                                         get_option(&str, &fault) != 2) {
  93                                 printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
  94                                 return 0;
  95                         }
  96                         md_setup_args[ent].level = level;
  97                         md_setup_args[ent].chunk = 1 << (factor+12);
  98                         pername = "raid0";
  99                         break;
 100                 }
 101                 fallthrough;
 102         case 1: /* the first device is numeric */
 103                 str = str1;
 104                 fallthrough;
 105         case 0:
 106                 md_setup_args[ent].level = LEVEL_NONE;
 107                 pername="super-block";
 108         }
 109
 110         printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
 111                 minor, pername, str);
 112         md_setup_args[ent].device_names = str;
 113         md_setup_args[ent].partitioned = partitioned;
 114         md_setup_args[ent].minor = minor;
 115
 116         return 1;
 117 }
 118
 119 static void __init md_setup_drive(struct md_setup_args *args)
 120 {
 121         char *devname = args->device_names;
 122         dev_t devices[MD_SB_DISKS + 1], mdev;
 123         struct mdu_array_info_s ainfo = { };
 124         struct mddev *mddev;
 125         int err = 0, i;
 126         char name[16];
 127
 128         if (args->partitioned) {
 129                 mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
 130                 sprintf(name, "md_d%d", args->minor);
 131         } else {
 132                 mdev = MKDEV(MD_MAJOR, args->minor);
 133                 sprintf(name, "md%d", args->minor);
 134         }
 135
 136         for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
 137                 struct kstat stat;
 138                 char *p;
 139                 char comp_name[64];
 140                 dev_t dev;
 141
 142                 p = strchr(devname, ',');
 143                 if (p)
 144                         *p++ = 0;
 145
 146                 if (early_lookup_bdev(devname, &dev))
 147                         dev = 0;
 148                 if (strncmp(devname, "/dev/", 5) == 0)
 149                         devname += 5;
 150                 snprintf(comp_name, 63, "/dev/%s", devname);
 151                 if (init_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
 152                         dev = new_decode_dev(stat.rdev);
 153                 if (!dev) {
 154                         pr_warn("md: Unknown device name: %s\n", devname);
 155                         break;
 156                 }
 157
 158                 devices[i] = dev;
 159                 devname = p;
 160         }
 161         devices[i] = 0;
 162
 163         if (!i)
 164                 return;
 165
 166         pr_info("md: Loading %s: %s\n", name, args->device_names);
 167
 168         mddev = md_alloc(mdev, name);
 169         if (IS_ERR(mddev)) {
 170                 pr_err("md: md_alloc failed - cannot start array %s\n", name);
 171                 return;
 172         }
 173
 174         err = mddev_suspend_and_lock(mddev);
 175         if (err) {
 176                 pr_err("md: failed to lock array %s\n", name);
 177                 goto out_mddev_put;
 178         }
 179
 180         if (!list_empty(&mddev->disks) || mddev->raid_disks) {
 181                 pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
 182                        name);
 183                 goto out_unlock;
 184         }
 185
 186         if (args->level != LEVEL_NONE) {
 187                 /* non-persistent */
 188                 ainfo.level = args->level;
 189                 ainfo.md_minor = args->minor;
 190                 ainfo.not_persistent = 1;
 191                 ainfo.state = (1 << MD_SB_CLEAN);
 192                 ainfo.chunk_size = args->chunk;
 193                 while (devices[ainfo.raid_disks])
 194                         ainfo.raid_disks++;
 195         }
 196
 197         err = md_set_array_info(mddev, &ainfo);
 198
 199         for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
 200                 struct mdu_disk_info_s dinfo = {
 201                         .major  = MAJOR(devices[i]),
 202                         .minor  = MINOR(devices[i]),
 203                 };
 204
 205                 if (args->level != LEVEL_NONE) {
 206                         dinfo.number = i;
 207                         dinfo.raid_disk = i;
 208                         dinfo.state =
 209                                 (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
 210                 }
 211
 212                 md_add_new_disk(mddev, &dinfo);
 213         }
 214
 215         if (!err)
 216                 err = do_md_run(mddev);
 217         if (err)
 218                 pr_warn("md: starting %s failed\n", name);
 219 out_unlock:
 220         mddev_unlock_and_resume(mddev);
 221 out_mddev_put:
 222         mddev_put(mddev);
 223 }
 224
 225 static int __init raid_setup(char *str)
 226 {
 227         int len, pos;
 228
 229         len = strlen(str) + 1;
 230         pos = 0;
 231
 232         while (pos < len) {
 233                 char *comma = strchr(str+pos, ',');
 234                 int wlen;
 235                 if (comma)
 236                         wlen = (comma-str)-pos;
 237                 else    wlen = (len-1)-pos;
 238
 239                 if (!strncmp(str, "noautodetect", wlen))
 240                         raid_noautodetect = 1;
 241                 if (!strncmp(str, "autodetect", wlen))
 242                         raid_noautodetect = 0;
 243                 if (strncmp(str, "partitionable", wlen)==0)
 244                         raid_autopart = 1;
 245                 if (strncmp(str, "part", wlen)==0)
 246                         raid_autopart = 1;
 247                 pos += wlen+1;
 248         }
 249         return 1;
 250 }
 251
 252 __setup("raid=", raid_setup);
 253 __setup("md=", md_setup);
 254
 255 static void __init autodetect_raid(void)
 256 {
 257         /*
 258          * Since we don't want to detect and use half a raid array, we need to
 259          * wait for the known devices to complete their probing
 260          */
 261         printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
 262         printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
 263
 264         wait_for_device_probe();
 265         md_autostart_arrays(raid_autopart);
 266 }
 267
 268 void __init md_run_setup(void)
 269 {
 270         int ent;
 271
 272         if (raid_noautodetect)
 273                 printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
 274         else
 275                 autodetect_raid();
 276
 277         for (ent = 0; ent < md_setup_ents; ent++)
 278                 md_setup_drive(&md_setup_args[ent]);
 279 }