diff options
Diffstat (limited to 'drivers/md/md-autodetect.c')
| -rw-r--r-- | drivers/md/md-autodetect.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c new file mode 100644 index 000000000000..6bbec89976a7 --- /dev/null +++ b/drivers/md/md-autodetect.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/blkdev.h> +#include <linux/init.h> +#include <linux/mount.h> +#include <linux/major.h> +#include <linux/delay.h> +#include <linux/init_syscalls.h> +#include <linux/raid/detect.h> +#include <linux/raid/md_u.h> +#include <linux/raid/md_p.h> +#include "md.h" + +/* + * When md (and any require personalities) are compiled into the kernel + * (not a module), arrays can be assembles are boot time using with AUTODETECT + * where specially marked partitions are registered with md_autodetect_dev(), + * and with MD_BOOT where devices to be collected are given on the boot line + * with md=..... + * The code for that is here. + */ + +#ifdef CONFIG_MD_AUTODETECT +static int __initdata raid_noautodetect; +#else +static int __initdata raid_noautodetect=1; +#endif +static int __initdata raid_autopart; + +static struct md_setup_args { + int minor; + int partitioned; + int level; + int chunk; + char *device_names; +} md_setup_args[256] __initdata; + +static int md_setup_ents __initdata; + +/* + * Parse the command-line parameters given our kernel, but do not + * actually try to invoke the MD device now; that is handled by + * md_setup_drive after the low-level disk drivers have initialised. + * + * 27/11/1999: Fixed to work correctly with the 2.3 kernel (which + * assigns the task of parsing integer arguments to the + * invoked program now). Added ability to initialise all + * the MD devices (by specifying multiple "md=" lines) + * instead of just one. -- KTK + * 18May2000: Added support for persistent-superblock arrays: + * md=n,0,factor,fault,device-list uses RAID0 for device n + * md=n,-1,factor,fault,device-list uses LINEAR for device n + * md=n,device-list reads a RAID superblock from the devices + * elements in device-list are read by name_to_kdev_t so can be + * a hex number or something like /dev/hda1 /dev/sdb + * 2001-06-03: Dave Cinege <dcinege@psychosis.com> + * Shifted name_to_kdev_t() and related operations to md_set_drive() + * for later execution. Rewrote section to make devfs compatible. + */ +static int __init md_setup(char *str) +{ + int minor, level, factor, fault, partitioned = 0; + char *pername = ""; + char *str1; + int ent; + + if (*str == 'd') { + partitioned = 1; + str++; + } + if (get_option(&str, &minor) != 2) { /* MD Number */ + printk(KERN_WARNING "md: Too few arguments supplied to md=.\n"); + return 0; + } + str1 = str; + for (ent=0 ; ent< md_setup_ents ; ent++) + if (md_setup_args[ent].minor == minor && + md_setup_args[ent].partitioned == partitioned) { + printk(KERN_WARNING "md: md=%s%d, Specified more than once. " + "Replacing previous definition.\n", partitioned?"d":"", minor); + break; + } + if (ent >= ARRAY_SIZE(md_setup_args)) { + printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor); + return 0; + } + if (ent >= md_setup_ents) + md_setup_ents++; + switch (get_option(&str, &level)) { /* RAID level */ + case 2: /* could be 0 or -1.. */ + if (level == 0 || level == LEVEL_LINEAR) { + if (get_option(&str, &factor) != 2 || /* Chunk Size */ + get_option(&str, &fault) != 2) { + printk(KERN_WARNING "md: Too few arguments supplied to md=.\n"); + return 0; + } + md_setup_args[ent].level = level; + md_setup_args[ent].chunk = 1 << (factor+12); + if (level == LEVEL_LINEAR) + pername = "linear"; + else + pername = "raid0"; + break; + } + /* FALL THROUGH */ + case 1: /* the first device is numeric */ + str = str1; + /* FALL THROUGH */ + case 0: + md_setup_args[ent].level = LEVEL_NONE; + pername="super-block"; + } + + printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n", + minor, pername, str); + md_setup_args[ent].device_names = str; + md_setup_args[ent].partitioned = partitioned; + md_setup_args[ent].minor = minor; + + return 1; +} + +static void __init md_setup_drive(struct md_setup_args *args) +{ + char *devname = args->device_names; + dev_t devices[MD_SB_DISKS + 1], mdev; + struct mdu_array_info_s ainfo = { }; + struct block_device *bdev; + struct mddev *mddev; + int err = 0, i; + char name[16]; + + if (args->partitioned) { + mdev = MKDEV(mdp_major, args->minor << MdpMinorShift); + sprintf(name, "md_d%d", args->minor); + } else { + mdev = MKDEV(MD_MAJOR, args->minor); + sprintf(name, "md%d", args->minor); + } + + for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) { + struct kstat stat; + char *p; + char comp_name[64]; + dev_t dev; + + p = strchr(devname, ','); + if (p) + *p++ = 0; + + dev = name_to_dev_t(devname); + if (strncmp(devname, "/dev/", 5) == 0) + devname += 5; + snprintf(comp_name, 63, "/dev/%s", devname); + if (init_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode)) + dev = new_decode_dev(stat.rdev); + if (!dev) { + pr_warn("md: Unknown device name: %s\n", devname); + break; + } + + devices[i] = dev; + devname = p; + } + devices[i] = 0; + + if (!i) + return; + + pr_info("md: Loading %s: %s\n", name, args->device_names); + + bdev = blkdev_get_by_dev(mdev, FMODE_READ, NULL); + if (IS_ERR(bdev)) { + pr_err("md: open failed - cannot start array %s\n", name); + return; + } + + err = -EIO; + if (WARN(bdev->bd_disk->fops != &md_fops, + "Opening block device %x resulted in non-md device\n", + mdev)) + goto out_blkdev_put; + + mddev = bdev->bd_disk->private_data; + + err = mddev_lock(mddev); + if (err) { + pr_err("md: failed to lock array %s\n", name); + goto out_blkdev_put; + } + + if (!list_empty(&mddev->disks) || mddev->raid_disks) { + pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n", + name); + goto out_unlock; + } + + if (args->level != LEVEL_NONE) { + /* non-persistent */ + ainfo.level = args->level; + ainfo.md_minor = args->minor; + ainfo.not_persistent = 1; + ainfo.state = (1 << MD_SB_CLEAN); + ainfo.chunk_size = args->chunk; + while (devices[ainfo.raid_disks]) + ainfo.raid_disks++; + } + + err = md_set_array_info(mddev, &ainfo); + + for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) { + struct mdu_disk_info_s dinfo = { + .major = MAJOR(devices[i]), + .minor = MINOR(devices[i]), + }; + + if (args->level != LEVEL_NONE) { + dinfo.number = i; + dinfo.raid_disk = i; + dinfo.state = + (1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC); + } + + md_add_new_disk(mddev, &dinfo); + } + + if (!err) + err = do_md_run(mddev); + if (err) + pr_warn("md: starting %s failed\n", name); +out_unlock: + mddev_unlock(mddev); +out_blkdev_put: + blkdev_put(bdev, FMODE_READ); +} + +static int __init raid_setup(char *str) +{ + int len, pos; + + len = strlen(str) + 1; + pos = 0; + + while (pos < len) { + char *comma = strchr(str+pos, ','); + int wlen; + if (comma) + wlen = (comma-str)-pos; + else wlen = (len-1)-pos; + + if (!strncmp(str, "noautodetect", wlen)) + raid_noautodetect = 1; + if (!strncmp(str, "autodetect", wlen)) + raid_noautodetect = 0; + if (strncmp(str, "partitionable", wlen)==0) + raid_autopart = 1; + if (strncmp(str, "part", wlen)==0) + raid_autopart = 1; + pos += wlen+1; + } + return 1; +} + +__setup("raid=", raid_setup); +__setup("md=", md_setup); + +static void __init autodetect_raid(void) +{ + /* + * Since we don't want to detect and use half a raid array, we need to + * wait for the known devices to complete their probing + */ + printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n"); + printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n"); + + wait_for_device_probe(); + md_autostart_arrays(raid_autopart); +} + +void __init md_run_setup(void) +{ + int ent; + + if (raid_noautodetect) + printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n"); + else + autodetect_raid(); + + for (ent = 0; ent < md_setup_ents; ent++) + md_setup_drive(&md_setup_args[ent]); +} |