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,-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  */
  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
 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 block_device *bdev;
 129         struct mddev *mddev;
 130         int err = 0, i;
 131         char name[16];
 132
 133         if (args->partitioned) {
 134                 mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
 135                 sprintf(name, "md_d%d", args->minor);
 136         } else {
 137                 mdev = MKDEV(MD_MAJOR, args->minor);
 138                 sprintf(name, "md%d", args->minor);
 139         }
 140
 141         for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
 142                 struct kstat stat;
 143                 char *p;
 144                 char comp_name[64];
 145                 dev_t dev;
 146
 147                 p = strchr(devname, ',');
 148                 if (p)
 149                         *p++ = 0;
 150
 151                 dev = name_to_dev_t(devname);
 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         bdev = blkdev_get_by_dev(mdev, FMODE_READ, NULL);
 173         if (IS_ERR(bdev)) {
 174                 pr_err("md: open failed - cannot start array %s\n", name);
 175                 return;
 176         }
 177
 178         err = -EIO;
 179         if (WARN(bdev->bd_disk->fops != &md_fops,
 180                         "Opening block device %x resulted in non-md device\n",
 181                         mdev))
 182                 goto out_blkdev_put;
 183
 184         mddev = bdev->bd_disk->private_data;
 185
 186         err = mddev_lock(mddev);
 187         if (err) {
 188                 pr_err("md: failed to lock array %s\n", name);
 189                 goto out_blkdev_put;
 190         }
 191
 192         if (!list_empty(&mddev->disks) || mddev->raid_disks) {
 193                 pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
 194                        name);
 195                 goto out_unlock;
 196         }
 197
 198         if (args->level != LEVEL_NONE) {
 199                 /* non-persistent */
 200                 ainfo.level = args->level;
 201                 ainfo.md_minor = args->minor;
 202                 ainfo.not_persistent = 1;
 203                 ainfo.state = (1 << MD_SB_CLEAN);
 204                 ainfo.chunk_size = args->chunk;
 205                 while (devices[ainfo.raid_disks])
 206                         ainfo.raid_disks++;
 207         }
 208
 209         err = md_set_array_info(mddev, &ainfo);
 210
 211         for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
 212                 struct mdu_disk_info_s dinfo = {
 213                         .major  = MAJOR(devices[i]),
 214                         .minor  = MINOR(devices[i]),
 215                 };
 216
 217                 if (args->level != LEVEL_NONE) {
 218                         dinfo.number = i;
 219                         dinfo.raid_disk = i;
 220                         dinfo.state =
 221                                 (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
 222                 }
 223
 224                 md_add_new_disk(mddev, &dinfo);
 225         }
 226
 227         if (!err)
 228                 err = do_md_run(mddev);
 229         if (err)
 230                 pr_warn("md: starting %s failed\n", name);
 231 out_unlock:
 232         mddev_unlock(mddev);
 233 out_blkdev_put:
 234         blkdev_put(bdev, FMODE_READ);
 235 }
 236
 237 static int __init raid_setup(char *str)
 238 {
 239         int len, pos;
 240
 241         len = strlen(str) + 1;
 242         pos = 0;
 243
 244         while (pos < len) {
 245                 char *comma = strchr(str+pos, ',');
 246                 int wlen;
 247                 if (comma)
 248                         wlen = (comma-str)-pos;
 249                 else    wlen = (len-1)-pos;
 250
 251                 if (!strncmp(str, "noautodetect", wlen))
 252                         raid_noautodetect = 1;
 253                 if (!strncmp(str, "autodetect", wlen))
 254                         raid_noautodetect = 0;
 255                 if (strncmp(str, "partitionable", wlen)==0)
 256                         raid_autopart = 1;
 257                 if (strncmp(str, "part", wlen)==0)
 258                         raid_autopart = 1;
 259                 pos += wlen+1;
 260         }
 261         return 1;
 262 }
 263
 264 __setup("raid=", raid_setup);
 265 __setup("md=", md_setup);
 266
 267 static void __init autodetect_raid(void)
 268 {
 269         /*
 270          * Since we don't want to detect and use half a raid array, we need to
 271          * wait for the known devices to complete their probing
 272          */
 273         printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
 274         printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
 275
 276         wait_for_device_probe();
 277         md_autostart_arrays(raid_autopart);
 278 }
 279
 280 void __init md_run_setup(void)
 281 {
 282         int ent;
 283
 284         if (raid_noautodetect)
 285                 printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
 286         else
 287                 autodetect_raid();
 288
 289         for (ent = 0; ent < md_setup_ents; ent++)
 290                 md_setup_drive(&md_setup_args[ent]);
 291 }