cregit-Linux how code gets into the kernel

Release 4.14 init/do_mounts_md.c

Directory: init
// SPDX-License-Identifier: GPL-2.0
/*
 * Many of the syscalls used in this file expect some of the arguments
 * to be __user pointers not __kernel pointers.  To limit the sparse
 * noise, turn off sparse checking for this file.
 */
#ifdef __CHECKER__

#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif

#include <linux/delay.h>
#include <linux/raid/md_u.h>
#include <linux/raid/md_p.h>

#include "do_mounts.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 {
	
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; }

Contributors

PersonTokensPropCommitsCommitProp
Kai Germaschewski21261.63%125.00%
Andrew Morton12436.05%125.00%
Neil Brown82.33%250.00%
Total344100.00%4100.00%


static void __init md_setup_drive(void) { int minor, i, ent, partitioned; dev_t dev; dev_t devices[MD_SB_DISKS+1]; for (ent = 0; ent < md_setup_ents ; ent++) { int fd; int err = 0; char *devname; mdu_disk_info_t dinfo; char name[16]; minor = md_setup_args[ent].minor; partitioned = md_setup_args[ent].partitioned; devname = md_setup_args[ent].device_names; sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor); if (partitioned) dev = MKDEV(mdp_major, minor << MdpMinorShift); else dev = MKDEV(MD_MAJOR, minor); create_dev(name, dev); for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) { char *p; char comp_name[64]; u32 rdev; 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); rdev = bstat(comp_name); if (rdev) dev = new_decode_dev(rdev); if (!dev) { printk(KERN_WARNING "md: Unknown device name: %s\n", devname); break; } devices[i] = dev; devname = p; } devices[i] = 0; if (!i) continue; printk(KERN_INFO "md: Loading md%s%d: %s\n", partitioned ? "_d" : "", minor, md_setup_args[ent].device_names); fd = sys_open(name, 0, 0); if (fd < 0) { printk(KERN_ERR "md: open failed - cannot start " "array %s\n", name); continue; } if (sys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) { printk(KERN_WARNING "md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n", minor); sys_close(fd); continue; } if (md_setup_args[ent].level != LEVEL_NONE) { /* non-persistent */ mdu_array_info_t ainfo; ainfo.level = md_setup_args[ent].level; ainfo.size = 0; ainfo.nr_disks =0; ainfo.raid_disks =0; while (devices[ainfo.raid_disks]) ainfo.raid_disks++; ainfo.md_minor =minor; ainfo.not_persistent = 1; ainfo.state = (1 << MD_SB_CLEAN); ainfo.layout = 0; ainfo.chunk_size = md_setup_args[ent].chunk; err = sys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo); for (i = 0; !err && i <= MD_SB_DISKS; i++) { dev = devices[i]; if (!dev) break; dinfo.number = i; dinfo.raid_disk = i; dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC); dinfo.major = MAJOR(dev); dinfo.minor = MINOR(dev); err = sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); } } else { /* persistent */ for (i = 0; i <= MD_SB_DISKS; i++) { dev = devices[i]; if (!dev) break; dinfo.major = MAJOR(dev); dinfo.minor = MINOR(dev); sys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo); } } if (!err) err = sys_ioctl(fd, RUN_ARRAY, 0); if (err) printk(KERN_WARNING "md: starting md%d failed\n", minor); else { /* reread the partition table. * I (neilb) and not sure why this is needed, but I cannot * boot a kernel with devfs compiled in from partitioned md * array without it */ sys_close(fd); fd = sys_open(name, 0, 0); sys_ioctl(fd, BLKRRPART, 0); } sys_close(fd); } }

Contributors

PersonTokensPropCommitsCommitProp
Kai Germaschewski56481.27%222.22%
Andrew Morton8311.96%222.22%
Neil Brown334.76%222.22%
Al Viro131.87%222.22%
Harvey Harrison10.14%111.11%
Total694100.00%9100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Kai Germaschewski10367.32%250.00%
Andrew Morton3422.22%125.00%
Arjan van de Ven1610.46%125.00%
Total153100.00%4100.00%

__setup("raid=", raid_setup); __setup("md=", md_setup);
static void __init autodetect_raid(void) { int fd; /* * 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(); fd = sys_open("/dev/md0", 0, 0); if (fd >= 0) { sys_ioctl(fd, RAID_AUTORUN, raid_autopart); sys_close(fd); } }

Contributors

PersonTokensPropCommitsCommitProp
Kai Germaschewski3455.74%112.50%
Arjan van de Ven1524.59%337.50%
Ingo Molnar813.11%112.50%
Andrew Morton34.92%225.00%
Mike Frysinger11.64%112.50%
Total61100.00%8100.00%


void __init md_run_setup(void) { create_dev("/dev/md0", MKDEV(MD_MAJOR, 0)); if (raid_noautodetect) printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n"); else autodetect_raid(); md_setup_drive(); }

Contributors

PersonTokensPropCommitsCommitProp
Ingo Molnar3286.49%133.33%
Kai Germaschewski410.81%133.33%
Arjan van de Ven12.70%133.33%
Total37100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Kai Germaschewski96069.31%210.00%
Andrew Morton25718.56%210.00%
Arjan van de Ven503.61%420.00%
Neil Brown473.39%420.00%
Ingo Molnar402.89%15.00%
Al Viro130.94%210.00%
H Hartley Sweeten120.87%15.00%
Alexey Dobriyan30.22%15.00%
Greg Kroah-Hartman10.07%15.00%
Harvey Harrison10.07%15.00%
Mike Frysinger10.07%15.00%
Total1385100.00%20100.00%
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