1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds #include <linux/module.h> 31da177e4SLinus Torvalds #include <linux/sched.h> 41da177e4SLinus Torvalds #include <linux/ctype.h> 51da177e4SLinus Torvalds #include <linux/fd.h> 61da177e4SLinus Torvalds #include <linux/tty.h> 71da177e4SLinus Torvalds #include <linux/suspend.h> 81da177e4SLinus Torvalds #include <linux/root_dev.h> 91da177e4SLinus Torvalds #include <linux/security.h> 101da177e4SLinus Torvalds #include <linux/delay.h> 11dd2a345fSDave Gilbert #include <linux/genhd.h> 12d53d9f16SAndrew Morton #include <linux/mount.h> 13d779249eSGreg Kroah-Hartman #include <linux/device.h> 1446595390SAdrian Bunk #include <linux/init.h> 15011e3fcdSAdrian Bunk #include <linux/fs.h> 1682c8253aSAdrian Bunk #include <linux/initrd.h> 1722a9d645SArjan van de Ven #include <linux/async.h> 185ad4e53bSAl Viro #include <linux/fs_struct.h> 195a0e3ad6STejun Heo #include <linux/slab.h> 2057f150a5SRob Landley #include <linux/ramfs.h> 2116203a7aSRob Landley #include <linux/shmem_fs.h> 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds #include <linux/nfs_fs.h> 241da177e4SLinus Torvalds #include <linux/nfs_fs_sb.h> 251da177e4SLinus Torvalds #include <linux/nfs_mount.h> 264f5b246bSChristoph Hellwig #include <linux/raid/detect.h> 27e262e32dSDavid Howells #include <uapi/linux/mount.h> 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds #include "do_mounts.h" 301da177e4SLinus Torvalds 319b04c997STheodore Ts'o int root_mountflags = MS_RDONLY | MS_SILENT; 32f56f6d30SAdrian Bunk static char * __initdata root_device_name; 331da177e4SLinus Torvalds static char __initdata saved_root_name[64]; 3479975f13SWill Drewry static int root_wait; 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds dev_t ROOT_DEV; 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds static int __init load_ramdisk(char *str) 391da177e4SLinus Torvalds { 40c8376994SChristoph Hellwig pr_warn("ignoring the deprecated load_ramdisk= option\n"); 411da177e4SLinus Torvalds return 1; 421da177e4SLinus Torvalds } 431da177e4SLinus Torvalds __setup("load_ramdisk=", load_ramdisk); 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds static int __init readonly(char *str) 461da177e4SLinus Torvalds { 471da177e4SLinus Torvalds if (*str) 481da177e4SLinus Torvalds return 0; 491da177e4SLinus Torvalds root_mountflags |= MS_RDONLY; 501da177e4SLinus Torvalds return 1; 511da177e4SLinus Torvalds } 521da177e4SLinus Torvalds 531da177e4SLinus Torvalds static int __init readwrite(char *str) 541da177e4SLinus Torvalds { 551da177e4SLinus Torvalds if (*str) 561da177e4SLinus Torvalds return 0; 571da177e4SLinus Torvalds root_mountflags &= ~MS_RDONLY; 581da177e4SLinus Torvalds return 1; 591da177e4SLinus Torvalds } 601da177e4SLinus Torvalds 611da177e4SLinus Torvalds __setup("ro", readonly); 621da177e4SLinus Torvalds __setup("rw", readwrite); 631da177e4SLinus Torvalds 646d0aed7aSJens Axboe #ifdef CONFIG_BLOCK 651ad7e899SStephen Warren struct uuidcmp { 661ad7e899SStephen Warren const char *uuid; 671ad7e899SStephen Warren int len; 681ad7e899SStephen Warren }; 691ad7e899SStephen Warren 70b5af921eSWill Drewry /** 71b5af921eSWill Drewry * match_dev_by_uuid - callback for finding a partition using its uuid 72b5af921eSWill Drewry * @dev: device passed in by the caller 731ad7e899SStephen Warren * @data: opaque pointer to the desired struct uuidcmp to match 74b5af921eSWill Drewry * 75b5af921eSWill Drewry * Returns 1 if the device matches, and 0 otherwise. 76b5af921eSWill Drewry */ 779f3b795aSMichał Mirosław static int match_dev_by_uuid(struct device *dev, const void *data) 78b5af921eSWill Drewry { 799f3b795aSMichał Mirosław const struct uuidcmp *cmp = data; 80b5af921eSWill Drewry struct hd_struct *part = dev_to_part(dev); 81b5af921eSWill Drewry 82*013b0e96SChristoph Hellwig if (!part->info || 83*013b0e96SChristoph Hellwig strncasecmp(cmp->uuid, part->info->uuid, cmp->len)) 84b5af921eSWill Drewry return 0; 85*013b0e96SChristoph Hellwig return 1; 86b5af921eSWill Drewry } 87b5af921eSWill Drewry 88b5af921eSWill Drewry /** 89b5af921eSWill Drewry * devt_from_partuuid - looks up the dev_t of a partition by its UUID 90a68b3108Schishanmingshen * @uuid_str: char array containing ascii UUID 91b5af921eSWill Drewry * 92b5af921eSWill Drewry * The function will return the first partition which contains a matching 93b5af921eSWill Drewry * UUID value in its partition_meta_info struct. This does not search 94b5af921eSWill Drewry * by filesystem UUIDs. 95b5af921eSWill Drewry * 96a68b3108Schishanmingshen * If @uuid_str is followed by a "/PARTNROFF=%d", then the number will be 9779975f13SWill Drewry * extracted and used as an offset from the partition identified by the UUID. 9879975f13SWill Drewry * 99b5af921eSWill Drewry * Returns the matching dev_t on success or 0 on failure. 100b5af921eSWill Drewry */ 1011ad7e899SStephen Warren static dev_t devt_from_partuuid(const char *uuid_str) 102b5af921eSWill Drewry { 1031ad7e899SStephen Warren struct uuidcmp cmp; 104b5af921eSWill Drewry struct device *dev = NULL; 105e036bb8eSChristoph Hellwig dev_t devt = 0; 10679975f13SWill Drewry int offset = 0; 107283f8fc0SStephen Warren char *slash; 10879975f13SWill Drewry 1091ad7e899SStephen Warren cmp.uuid = uuid_str; 1101ad7e899SStephen Warren 111283f8fc0SStephen Warren slash = strchr(uuid_str, '/'); 11279975f13SWill Drewry /* Check for optional partition number offset attributes. */ 113283f8fc0SStephen Warren if (slash) { 11479975f13SWill Drewry char c = 0; 115e036bb8eSChristoph Hellwig 11679975f13SWill Drewry /* Explicitly fail on poor PARTUUID syntax. */ 117e036bb8eSChristoph Hellwig if (sscanf(slash + 1, "PARTNROFF=%d%c", &offset, &c) != 1) 118e036bb8eSChristoph Hellwig goto clear_root_wait; 119283f8fc0SStephen Warren cmp.len = slash - uuid_str; 120283f8fc0SStephen Warren } else { 121283f8fc0SStephen Warren cmp.len = strlen(uuid_str); 122283f8fc0SStephen Warren } 123283f8fc0SStephen Warren 124e036bb8eSChristoph Hellwig if (!cmp.len) 125e036bb8eSChristoph Hellwig goto clear_root_wait; 126b5af921eSWill Drewry 127e036bb8eSChristoph Hellwig dev = class_find_device(&block_class, NULL, &cmp, &match_dev_by_uuid); 128b5af921eSWill Drewry if (!dev) 129e036bb8eSChristoph Hellwig return 0; 130b5af921eSWill Drewry 131e036bb8eSChristoph Hellwig if (offset) { 132e036bb8eSChristoph Hellwig /* 133e036bb8eSChristoph Hellwig * Attempt to find the requested partition by adding an offset 134e036bb8eSChristoph Hellwig * to the partition number found by UUID. 135e036bb8eSChristoph Hellwig */ 136e036bb8eSChristoph Hellwig struct hd_struct *part; 137b5af921eSWill Drewry 138e036bb8eSChristoph Hellwig part = disk_get_part(dev_to_disk(dev), 139e036bb8eSChristoph Hellwig dev_to_part(dev)->partno + offset); 14079975f13SWill Drewry if (part) { 141e036bb8eSChristoph Hellwig devt = part_devt(part); 14279975f13SWill Drewry put_device(part_to_dev(part)); 14379975f13SWill Drewry } 144e036bb8eSChristoph Hellwig } else { 145e036bb8eSChristoph Hellwig devt = dev->devt; 146e036bb8eSChristoph Hellwig } 14779975f13SWill Drewry 14879975f13SWill Drewry put_device(dev); 149e036bb8eSChristoph Hellwig return devt; 150e036bb8eSChristoph Hellwig 151e036bb8eSChristoph Hellwig clear_root_wait: 152283f8fc0SStephen Warren pr_err("VFS: PARTUUID= is invalid.\n" 153283f8fc0SStephen Warren "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n"); 154283f8fc0SStephen Warren if (root_wait) 155283f8fc0SStephen Warren pr_err("Disabling rootwait; root= is invalid.\n"); 156283f8fc0SStephen Warren root_wait = 0; 157e036bb8eSChristoph Hellwig return 0; 158b5af921eSWill Drewry } 159f027c34dSNikolaus Voss 160f027c34dSNikolaus Voss /** 161f027c34dSNikolaus Voss * match_dev_by_label - callback for finding a partition using its label 162f027c34dSNikolaus Voss * @dev: device passed in by the caller 163f027c34dSNikolaus Voss * @data: opaque pointer to the label to match 164f027c34dSNikolaus Voss * 165f027c34dSNikolaus Voss * Returns 1 if the device matches, and 0 otherwise. 166f027c34dSNikolaus Voss */ 167f027c34dSNikolaus Voss static int match_dev_by_label(struct device *dev, const void *data) 168f027c34dSNikolaus Voss { 169f027c34dSNikolaus Voss const char *label = data; 170f027c34dSNikolaus Voss struct hd_struct *part = dev_to_part(dev); 171f027c34dSNikolaus Voss 172*013b0e96SChristoph Hellwig if (!part->info || strcmp(label, part->info->volname)) 173f027c34dSNikolaus Voss return 0; 174*013b0e96SChristoph Hellwig return 1; 175f027c34dSNikolaus Voss } 176c2637e80SChristoph Hellwig 177c2637e80SChristoph Hellwig static dev_t devt_from_partlabel(const char *label) 178c2637e80SChristoph Hellwig { 179c2637e80SChristoph Hellwig struct device *dev; 180c2637e80SChristoph Hellwig dev_t devt = 0; 181c2637e80SChristoph Hellwig 182c2637e80SChristoph Hellwig dev = class_find_device(&block_class, NULL, label, &match_dev_by_label); 183c2637e80SChristoph Hellwig if (dev) { 184c2637e80SChristoph Hellwig devt = dev->devt; 185c2637e80SChristoph Hellwig put_device(dev); 186c2637e80SChristoph Hellwig } 187c2637e80SChristoph Hellwig 188c2637e80SChristoph Hellwig return devt; 189c2637e80SChristoph Hellwig } 190c2637e80SChristoph Hellwig 191c2637e80SChristoph Hellwig static dev_t devt_from_devname(const char *name) 192c2637e80SChristoph Hellwig { 193c2637e80SChristoph Hellwig dev_t devt = 0; 194c2637e80SChristoph Hellwig int part; 195c2637e80SChristoph Hellwig char s[32]; 196c2637e80SChristoph Hellwig char *p; 197c2637e80SChristoph Hellwig 198c2637e80SChristoph Hellwig if (strlen(name) > 31) 199c2637e80SChristoph Hellwig return 0; 200c2637e80SChristoph Hellwig strcpy(s, name); 201c2637e80SChristoph Hellwig for (p = s; *p; p++) { 202c2637e80SChristoph Hellwig if (*p == '/') 203c2637e80SChristoph Hellwig *p = '!'; 204c2637e80SChristoph Hellwig } 205c2637e80SChristoph Hellwig 206c2637e80SChristoph Hellwig devt = blk_lookup_devt(s, 0); 207c2637e80SChristoph Hellwig if (devt) 208c2637e80SChristoph Hellwig return devt; 209c2637e80SChristoph Hellwig 210c2637e80SChristoph Hellwig /* 211c2637e80SChristoph Hellwig * Try non-existent, but valid partition, which may only exist after 212c2637e80SChristoph Hellwig * opening the device, like partitioned md devices. 213c2637e80SChristoph Hellwig */ 214c2637e80SChristoph Hellwig while (p > s && isdigit(p[-1])) 215c2637e80SChristoph Hellwig p--; 216c2637e80SChristoph Hellwig if (p == s || !*p || *p == '0') 217c2637e80SChristoph Hellwig return 0; 218c2637e80SChristoph Hellwig 219c2637e80SChristoph Hellwig /* try disk name without <part number> */ 220c2637e80SChristoph Hellwig part = simple_strtoul(p, NULL, 10); 221c2637e80SChristoph Hellwig *p = '\0'; 222c2637e80SChristoph Hellwig devt = blk_lookup_devt(s, part); 223c2637e80SChristoph Hellwig if (devt) 224c2637e80SChristoph Hellwig return devt; 225c2637e80SChristoph Hellwig 226c2637e80SChristoph Hellwig /* try disk name without p<part number> */ 227c2637e80SChristoph Hellwig if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') 228c2637e80SChristoph Hellwig return 0; 229c2637e80SChristoph Hellwig p[-1] = '\0'; 230c2637e80SChristoph Hellwig return blk_lookup_devt(s, part); 231c2637e80SChristoph Hellwig } 232c2637e80SChristoph Hellwig #endif /* CONFIG_BLOCK */ 233c2637e80SChristoph Hellwig 234c2637e80SChristoph Hellwig static dev_t devt_from_devnum(const char *name) 235c2637e80SChristoph Hellwig { 236c2637e80SChristoph Hellwig unsigned maj, min, offset; 237c2637e80SChristoph Hellwig dev_t devt = 0; 238c2637e80SChristoph Hellwig char *p, dummy; 239c2637e80SChristoph Hellwig 240c2637e80SChristoph Hellwig if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 || 241c2637e80SChristoph Hellwig sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset, &dummy) == 3) { 242c2637e80SChristoph Hellwig devt = MKDEV(maj, min); 243c2637e80SChristoph Hellwig if (maj != MAJOR(devt) || min != MINOR(devt)) 244c2637e80SChristoph Hellwig return 0; 245c2637e80SChristoph Hellwig } else { 246c2637e80SChristoph Hellwig devt = new_decode_dev(simple_strtoul(name, &p, 16)); 247c2637e80SChristoph Hellwig if (*p) 248c2637e80SChristoph Hellwig return 0; 249c2637e80SChristoph Hellwig } 250c2637e80SChristoph Hellwig 251c2637e80SChristoph Hellwig return devt; 252c2637e80SChristoph Hellwig } 253b5af921eSWill Drewry 2541da177e4SLinus Torvalds /* 2551da177e4SLinus Torvalds * Convert a name into device number. We accept the following variants: 2561da177e4SLinus Torvalds * 2570bf37ae4SPavel Machek * 1) <hex_major><hex_minor> device number in hexadecimal represents itself 2580bf37ae4SPavel Machek * no leading 0x, for example b302. 2591da177e4SLinus Torvalds * 2) /dev/nfs represents Root_NFS (0xff) 2601da177e4SLinus Torvalds * 3) /dev/<disk_name> represents the device number of disk 2611da177e4SLinus Torvalds * 4) /dev/<disk_name><decimal> represents the device number 2621da177e4SLinus Torvalds * of partition - device number of disk plus the partition number 2631da177e4SLinus Torvalds * 5) /dev/<disk_name>p<decimal> - same as the above, that form is 2641da177e4SLinus Torvalds * used when disk name of partitioned disk ends on a digit. 265b5af921eSWill Drewry * 6) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 266b5af921eSWill Drewry * unique id of a partition if the partition table provides it. 267d33b98fcSStephen Warren * The UUID may be either an EFI/GPT UUID, or refer to an MSDOS 268d33b98fcSStephen Warren * partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- 269d33b98fcSStephen Warren * filled hex representation of the 32-bit "NT disk signature", and PP 270d33b98fcSStephen Warren * is a zero-filled hex representation of the 1-based partition number. 27179975f13SWill Drewry * 7) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation to 27279975f13SWill Drewry * a partition with a known unique id. 2736c251611SSebastian Capella * 8) <major>:<minor> major and minor number of the device separated by 2746c251611SSebastian Capella * a colon. 275f027c34dSNikolaus Voss * 9) PARTLABEL=<name> with name being the GPT partition label. 276f027c34dSNikolaus Voss * MSDOS partitions do not support labels! 2778902dd52SPaulo Alcantara (SUSE) * 10) /dev/cifs represents Root_CIFS (0xfe) 2781da177e4SLinus Torvalds * 279edfaa7c3SKay Sievers * If name doesn't have fall into the categories above, we return (0,0). 280edfaa7c3SKay Sievers * block_class is used to check if something is a disk name. If the disk 281edfaa7c3SKay Sievers * name contains slashes, the device name has them replaced with 282edfaa7c3SKay Sievers * bangs. 2831da177e4SLinus Torvalds */ 284e6e20a7aSDan Ehrenberg dev_t name_to_dev_t(const char *name) 2851da177e4SLinus Torvalds { 286c2637e80SChristoph Hellwig if (strcmp(name, "/dev/nfs") == 0) 287c2637e80SChristoph Hellwig return Root_NFS; 288c2637e80SChristoph Hellwig if (strcmp(name, "/dev/cifs") == 0) 289c2637e80SChristoph Hellwig return Root_CIFS; 290c2637e80SChristoph Hellwig if (strcmp(name, "/dev/ram") == 0) 291c2637e80SChristoph Hellwig return Root_RAM0; 2926d0aed7aSJens Axboe #ifdef CONFIG_BLOCK 293c2637e80SChristoph Hellwig if (strncmp(name, "PARTUUID=", 9) == 0) 294c2637e80SChristoph Hellwig return devt_from_partuuid(name + 9); 295c2637e80SChristoph Hellwig if (strncmp(name, "PARTLABEL=", 10) == 0) 296c2637e80SChristoph Hellwig return devt_from_partlabel(name + 10); 297c2637e80SChristoph Hellwig if (strncmp(name, "/dev/", 5) == 0) 298c2637e80SChristoph Hellwig return devt_from_devname(name + 5); 2996d0aed7aSJens Axboe #endif 300c2637e80SChristoph Hellwig return devt_from_devnum(name); 3011da177e4SLinus Torvalds } 302e6e20a7aSDan Ehrenberg EXPORT_SYMBOL_GPL(name_to_dev_t); 3031da177e4SLinus Torvalds 3041da177e4SLinus Torvalds static int __init root_dev_setup(char *line) 3051da177e4SLinus Torvalds { 3061da177e4SLinus Torvalds strlcpy(saved_root_name, line, sizeof(saved_root_name)); 3071da177e4SLinus Torvalds return 1; 3081da177e4SLinus Torvalds } 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds __setup("root=", root_dev_setup); 3111da177e4SLinus Torvalds 312cc1ed754SPierre Ossman static int __init rootwait_setup(char *str) 313cc1ed754SPierre Ossman { 314cc1ed754SPierre Ossman if (*str) 315cc1ed754SPierre Ossman return 0; 316cc1ed754SPierre Ossman root_wait = 1; 317cc1ed754SPierre Ossman return 1; 318cc1ed754SPierre Ossman } 319cc1ed754SPierre Ossman 320cc1ed754SPierre Ossman __setup("rootwait", rootwait_setup); 321cc1ed754SPierre Ossman 3221da177e4SLinus Torvalds static char * __initdata root_mount_data; 3231da177e4SLinus Torvalds static int __init root_data_setup(char *str) 3241da177e4SLinus Torvalds { 3251da177e4SLinus Torvalds root_mount_data = str; 3261da177e4SLinus Torvalds return 1; 3271da177e4SLinus Torvalds } 3281da177e4SLinus Torvalds 3291da177e4SLinus Torvalds static char * __initdata root_fs_names; 3301da177e4SLinus Torvalds static int __init fs_names_setup(char *str) 3311da177e4SLinus Torvalds { 3321da177e4SLinus Torvalds root_fs_names = str; 3331da177e4SLinus Torvalds return 1; 3341da177e4SLinus Torvalds } 3351da177e4SLinus Torvalds 3361da177e4SLinus Torvalds static unsigned int __initdata root_delay; 3371da177e4SLinus Torvalds static int __init root_delay_setup(char *str) 3381da177e4SLinus Torvalds { 3391da177e4SLinus Torvalds root_delay = simple_strtoul(str, NULL, 0); 3401da177e4SLinus Torvalds return 1; 3411da177e4SLinus Torvalds } 3421da177e4SLinus Torvalds 3431da177e4SLinus Torvalds __setup("rootflags=", root_data_setup); 3441da177e4SLinus Torvalds __setup("rootfstype=", fs_names_setup); 3451da177e4SLinus Torvalds __setup("rootdelay=", root_delay_setup); 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds static void __init get_fs_names(char *page) 3481da177e4SLinus Torvalds { 3491da177e4SLinus Torvalds char *s = page; 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvalds if (root_fs_names) { 3521da177e4SLinus Torvalds strcpy(page, root_fs_names); 3531da177e4SLinus Torvalds while (*s++) { 3541da177e4SLinus Torvalds if (s[-1] == ',') 3551da177e4SLinus Torvalds s[-1] = '\0'; 3561da177e4SLinus Torvalds } 3571da177e4SLinus Torvalds } else { 3581da177e4SLinus Torvalds int len = get_filesystem_list(page); 3591da177e4SLinus Torvalds char *p, *next; 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds page[len] = '\0'; 3621da177e4SLinus Torvalds for (p = page-1; p; p = next) { 3631da177e4SLinus Torvalds next = strchr(++p, '\n'); 3641da177e4SLinus Torvalds if (*p++ != '\t') 3651da177e4SLinus Torvalds continue; 3661da177e4SLinus Torvalds while ((*s++ = *p++) != '\n') 3671da177e4SLinus Torvalds ; 3681da177e4SLinus Torvalds s[-1] = '\0'; 3691da177e4SLinus Torvalds } 3701da177e4SLinus Torvalds } 3711da177e4SLinus Torvalds *s = '\0'; 3721da177e4SLinus Torvalds } 3731da177e4SLinus Torvalds 374cccaa5e3SDominik Brodowski static int __init do_mount_root(const char *name, const char *fs, 375cccaa5e3SDominik Brodowski const int flags, const void *data) 3761da177e4SLinus Torvalds { 377d8c9584eSAl Viro struct super_block *s; 3787de7de7cSLinus Torvalds struct page *p = NULL; 3797de7de7cSLinus Torvalds char *data_page = NULL; 380cccaa5e3SDominik Brodowski int ret; 381cccaa5e3SDominik Brodowski 3827de7de7cSLinus Torvalds if (data) { 383c60166f0SChristoph Hellwig /* init_mount() requires a full page as fifth argument */ 384cccaa5e3SDominik Brodowski p = alloc_page(GFP_KERNEL); 385cccaa5e3SDominik Brodowski if (!p) 386cccaa5e3SDominik Brodowski return -ENOMEM; 387cccaa5e3SDominik Brodowski data_page = page_address(p); 388c60166f0SChristoph Hellwig /* zero-pad. init_mount() will make sure it's terminated */ 3897de7de7cSLinus Torvalds strncpy(data_page, data, PAGE_SIZE); 3907de7de7cSLinus Torvalds } 391cccaa5e3SDominik Brodowski 392c60166f0SChristoph Hellwig ret = init_mount(name, "/root", fs, flags, data_page); 393cccaa5e3SDominik Brodowski if (ret) 394cccaa5e3SDominik Brodowski goto out; 3951da177e4SLinus Torvalds 396db63f1e3SChristoph Hellwig init_chdir("/root"); 397d8c9584eSAl Viro s = current->fs->pwd.dentry->d_sb; 398d8c9584eSAl Viro ROOT_DEV = s->s_dev; 39980cdc6daSMandeep Singh Baines printk(KERN_INFO 40080cdc6daSMandeep Singh Baines "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n", 401d8c9584eSAl Viro s->s_type->name, 402bc98a42cSDavid Howells sb_rdonly(s) ? " readonly" : "", 403d8c9584eSAl Viro MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 404cccaa5e3SDominik Brodowski 405cccaa5e3SDominik Brodowski out: 4067de7de7cSLinus Torvalds if (p) 407cccaa5e3SDominik Brodowski put_page(p); 408cccaa5e3SDominik Brodowski return ret; 4091da177e4SLinus Torvalds } 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds void __init mount_block_root(char *name, int flags) 4121da177e4SLinus Torvalds { 41375f296d9SLevin, Alexander (Sasha Levin) struct page *page = alloc_page(GFP_KERNEL); 414a608ca21SJeff Layton char *fs_names = page_address(page); 4151da177e4SLinus Torvalds char *p; 4161da177e4SLinus Torvalds char b[BDEVNAME_SIZE]; 4171da177e4SLinus Torvalds 418ea3edd4dSChristoph Hellwig scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)", 419ea3edd4dSChristoph Hellwig MAJOR(ROOT_DEV), MINOR(ROOT_DEV)); 4201da177e4SLinus Torvalds get_fs_names(fs_names); 4211da177e4SLinus Torvalds retry: 4221da177e4SLinus Torvalds for (p = fs_names; *p; p += strlen(p)+1) { 4231da177e4SLinus Torvalds int err = do_mount_root(name, p, flags, root_mount_data); 4241da177e4SLinus Torvalds switch (err) { 4251da177e4SLinus Torvalds case 0: 4261da177e4SLinus Torvalds goto out; 4271da177e4SLinus Torvalds case -EACCES: 4281da177e4SLinus Torvalds case -EINVAL: 4291da177e4SLinus Torvalds continue; 4301da177e4SLinus Torvalds } 4311da177e4SLinus Torvalds /* 4321da177e4SLinus Torvalds * Allow the user to distinguish between failed sys_open 4331da177e4SLinus Torvalds * and bad superblock on root device. 434dd2a345fSDave Gilbert * and give them a list of the available devices 4351da177e4SLinus Torvalds */ 4360e0cb892SBernhard Walle printk("VFS: Cannot open root device \"%s\" or %s: error %d\n", 4370e0cb892SBernhard Walle root_device_name, b, err); 438dd2a345fSDave Gilbert printk("Please append a correct \"root=\" boot option; here are the available partitions:\n"); 4391da177e4SLinus Torvalds 440dd2a345fSDave Gilbert printk_all_partitions(); 44155dc7db7STejun Heo #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT 44255dc7db7STejun Heo printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify " 44355dc7db7STejun Heo "explicit textual name for \"root=\" boot option.\n"); 44455dc7db7STejun Heo #endif 4451da177e4SLinus Torvalds panic("VFS: Unable to mount root fs on %s", b); 4461da177e4SLinus Torvalds } 447e462ec50SDavid Howells if (!(flags & SB_RDONLY)) { 448e462ec50SDavid Howells flags |= SB_RDONLY; 44910975933SMiklos Szeredi goto retry; 45010975933SMiklos Szeredi } 451be6e028bSAndy Whitcroft 452dd2a345fSDave Gilbert printk("List of all partitions:\n"); 453dd2a345fSDave Gilbert printk_all_partitions(); 454be6e028bSAndy Whitcroft printk("No filesystem could mount root, tried: "); 455be6e028bSAndy Whitcroft for (p = fs_names; *p; p += strlen(p)+1) 456be6e028bSAndy Whitcroft printk(" %s", p); 457be6e028bSAndy Whitcroft printk("\n"); 4589361401eSDavid Howells panic("VFS: Unable to mount root fs on %s", b); 4591da177e4SLinus Torvalds out: 460a608ca21SJeff Layton put_page(page); 4611da177e4SLinus Torvalds } 4621da177e4SLinus Torvalds 4631da177e4SLinus Torvalds #ifdef CONFIG_ROOT_NFS 46443717c7dSChuck Lever 46543717c7dSChuck Lever #define NFSROOT_TIMEOUT_MIN 5 46643717c7dSChuck Lever #define NFSROOT_TIMEOUT_MAX 30 46743717c7dSChuck Lever #define NFSROOT_RETRY_MAX 5 46843717c7dSChuck Lever 4691da177e4SLinus Torvalds static int __init mount_nfs_root(void) 4701da177e4SLinus Torvalds { 47156463e50SChuck Lever char *root_dev, *root_data; 47243717c7dSChuck Lever unsigned int timeout; 47343717c7dSChuck Lever int try, err; 4741da177e4SLinus Torvalds 47543717c7dSChuck Lever err = nfs_root_data(&root_dev, &root_data); 47643717c7dSChuck Lever if (err != 0) 4771da177e4SLinus Torvalds return 0; 47843717c7dSChuck Lever 47943717c7dSChuck Lever /* 48043717c7dSChuck Lever * The server or network may not be ready, so try several 48143717c7dSChuck Lever * times. Stop after a few tries in case the client wants 48243717c7dSChuck Lever * to fall back to other boot methods. 48343717c7dSChuck Lever */ 48443717c7dSChuck Lever timeout = NFSROOT_TIMEOUT_MIN; 48543717c7dSChuck Lever for (try = 1; ; try++) { 48643717c7dSChuck Lever err = do_mount_root(root_dev, "nfs", 48743717c7dSChuck Lever root_mountflags, root_data); 48843717c7dSChuck Lever if (err == 0) 48956463e50SChuck Lever return 1; 49043717c7dSChuck Lever if (try > NFSROOT_RETRY_MAX) 49143717c7dSChuck Lever break; 49243717c7dSChuck Lever 49343717c7dSChuck Lever /* Wait, in case the server refused us immediately */ 49443717c7dSChuck Lever ssleep(timeout); 49543717c7dSChuck Lever timeout <<= 1; 49643717c7dSChuck Lever if (timeout > NFSROOT_TIMEOUT_MAX) 49743717c7dSChuck Lever timeout = NFSROOT_TIMEOUT_MAX; 49843717c7dSChuck Lever } 49943717c7dSChuck Lever return 0; 5001da177e4SLinus Torvalds } 5011da177e4SLinus Torvalds #endif 5021da177e4SLinus Torvalds 5038902dd52SPaulo Alcantara (SUSE) #ifdef CONFIG_CIFS_ROOT 5048902dd52SPaulo Alcantara (SUSE) 5058902dd52SPaulo Alcantara (SUSE) extern int cifs_root_data(char **dev, char **opts); 5068902dd52SPaulo Alcantara (SUSE) 5078902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_TIMEOUT_MIN 5 5088902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_TIMEOUT_MAX 30 5098902dd52SPaulo Alcantara (SUSE) #define CIFSROOT_RETRY_MAX 5 5108902dd52SPaulo Alcantara (SUSE) 5118902dd52SPaulo Alcantara (SUSE) static int __init mount_cifs_root(void) 5128902dd52SPaulo Alcantara (SUSE) { 5138902dd52SPaulo Alcantara (SUSE) char *root_dev, *root_data; 5148902dd52SPaulo Alcantara (SUSE) unsigned int timeout; 5158902dd52SPaulo Alcantara (SUSE) int try, err; 5168902dd52SPaulo Alcantara (SUSE) 5178902dd52SPaulo Alcantara (SUSE) err = cifs_root_data(&root_dev, &root_data); 5188902dd52SPaulo Alcantara (SUSE) if (err != 0) 5198902dd52SPaulo Alcantara (SUSE) return 0; 5208902dd52SPaulo Alcantara (SUSE) 5218902dd52SPaulo Alcantara (SUSE) timeout = CIFSROOT_TIMEOUT_MIN; 5228902dd52SPaulo Alcantara (SUSE) for (try = 1; ; try++) { 5238902dd52SPaulo Alcantara (SUSE) err = do_mount_root(root_dev, "cifs", root_mountflags, 5248902dd52SPaulo Alcantara (SUSE) root_data); 5258902dd52SPaulo Alcantara (SUSE) if (err == 0) 5268902dd52SPaulo Alcantara (SUSE) return 1; 5278902dd52SPaulo Alcantara (SUSE) if (try > CIFSROOT_RETRY_MAX) 5288902dd52SPaulo Alcantara (SUSE) break; 5298902dd52SPaulo Alcantara (SUSE) 5308902dd52SPaulo Alcantara (SUSE) ssleep(timeout); 5318902dd52SPaulo Alcantara (SUSE) timeout <<= 1; 5328902dd52SPaulo Alcantara (SUSE) if (timeout > CIFSROOT_TIMEOUT_MAX) 5338902dd52SPaulo Alcantara (SUSE) timeout = CIFSROOT_TIMEOUT_MAX; 5348902dd52SPaulo Alcantara (SUSE) } 5358902dd52SPaulo Alcantara (SUSE) return 0; 5368902dd52SPaulo Alcantara (SUSE) } 5378902dd52SPaulo Alcantara (SUSE) #endif 5388902dd52SPaulo Alcantara (SUSE) 5391da177e4SLinus Torvalds void __init mount_root(void) 5401da177e4SLinus Torvalds { 5411da177e4SLinus Torvalds #ifdef CONFIG_ROOT_NFS 542377485f6SSasha Levin if (ROOT_DEV == Root_NFS) { 543c8376994SChristoph Hellwig if (!mount_nfs_root()) 544c8376994SChristoph Hellwig printk(KERN_ERR "VFS: Unable to mount root fs via NFS.\n"); 5451da177e4SLinus Torvalds return; 5461da177e4SLinus Torvalds } 5471da177e4SLinus Torvalds #endif 5488902dd52SPaulo Alcantara (SUSE) #ifdef CONFIG_CIFS_ROOT 5498902dd52SPaulo Alcantara (SUSE) if (ROOT_DEV == Root_CIFS) { 550c8376994SChristoph Hellwig if (!mount_cifs_root()) 551c8376994SChristoph Hellwig printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n"); 5528902dd52SPaulo Alcantara (SUSE) return; 5531da177e4SLinus Torvalds } 5541da177e4SLinus Torvalds #endif 5559361401eSDavid Howells #ifdef CONFIG_BLOCK 556c69e3c3aSVishnu Pratap Singh { 557c69e3c3aSVishnu Pratap Singh int err = create_dev("/dev/root", ROOT_DEV); 558c69e3c3aSVishnu Pratap Singh 559c69e3c3aSVishnu Pratap Singh if (err < 0) 560c69e3c3aSVishnu Pratap Singh pr_emerg("Failed to create /dev/root: %d\n", err); 5611da177e4SLinus Torvalds mount_block_root("/dev/root", root_mountflags); 562c69e3c3aSVishnu Pratap Singh } 5639361401eSDavid Howells #endif 5641da177e4SLinus Torvalds } 5651da177e4SLinus Torvalds 5661da177e4SLinus Torvalds /* 5671da177e4SLinus Torvalds * Prepare the namespace - decide what/where to mount, load ramdisks, etc. 5681da177e4SLinus Torvalds */ 5691da177e4SLinus Torvalds void __init prepare_namespace(void) 5701da177e4SLinus Torvalds { 5711da177e4SLinus Torvalds if (root_delay) { 5721da177e4SLinus Torvalds printk(KERN_INFO "Waiting %d sec before mounting root device...\n", 5731da177e4SLinus Torvalds root_delay); 5741da177e4SLinus Torvalds ssleep(root_delay); 5751da177e4SLinus Torvalds } 5761da177e4SLinus Torvalds 577216773a7SArjan van de Ven /* 578216773a7SArjan van de Ven * wait for the known devices to complete their probing 579216773a7SArjan van de Ven * 580216773a7SArjan van de Ven * Note: this is a potential source of long boot delays. 581216773a7SArjan van de Ven * For example, it is not atypical to wait 5 seconds here 582216773a7SArjan van de Ven * for the touchpad of a laptop to initialize. 583216773a7SArjan van de Ven */ 584216773a7SArjan van de Ven wait_for_device_probe(); 585d779249eSGreg Kroah-Hartman 5861da177e4SLinus Torvalds md_run_setup(); 5871da177e4SLinus Torvalds 5881da177e4SLinus Torvalds if (saved_root_name[0]) { 5891da177e4SLinus Torvalds root_device_name = saved_root_name; 5902d62f488SAdrian Hunter if (!strncmp(root_device_name, "mtd", 3) || 5912d62f488SAdrian Hunter !strncmp(root_device_name, "ubi", 3)) { 592e9482b43SJoern Engel mount_block_root(root_device_name, root_mountflags); 593e9482b43SJoern Engel goto out; 594e9482b43SJoern Engel } 5951da177e4SLinus Torvalds ROOT_DEV = name_to_dev_t(root_device_name); 5961da177e4SLinus Torvalds if (strncmp(root_device_name, "/dev/", 5) == 0) 5971da177e4SLinus Torvalds root_device_name += 5; 5981da177e4SLinus Torvalds } 5991da177e4SLinus Torvalds 6001da177e4SLinus Torvalds if (initrd_load()) 6011da177e4SLinus Torvalds goto out; 6021da177e4SLinus Torvalds 603cc1ed754SPierre Ossman /* wait for any asynchronous scanning to complete */ 604cc1ed754SPierre Ossman if ((ROOT_DEV == 0) && root_wait) { 605cc1ed754SPierre Ossman printk(KERN_INFO "Waiting for root device %s...\n", 606cc1ed754SPierre Ossman saved_root_name); 607cc1ed754SPierre Ossman while (driver_probe_done() != 0 || 608cc1ed754SPierre Ossman (ROOT_DEV = name_to_dev_t(saved_root_name)) == 0) 60939a0e975SJungseung Lee msleep(5); 610216773a7SArjan van de Ven async_synchronize_full(); 611cc1ed754SPierre Ossman } 612cc1ed754SPierre Ossman 6131da177e4SLinus Torvalds mount_root(); 6141da177e4SLinus Torvalds out: 6155e787dbfSDominik Brodowski devtmpfs_mount(); 616c60166f0SChristoph Hellwig init_mount(".", "/", NULL, MS_MOVE, NULL); 6174b7ca501SChristoph Hellwig init_chroot("."); 6181da177e4SLinus Torvalds } 61957f150a5SRob Landley 6206e19ededSRob Landley static bool is_tmpfs; 621f3235626SDavid Howells static int rootfs_init_fs_context(struct fs_context *fc) 62257f150a5SRob Landley { 6236e19ededSRob Landley if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs) 624f3235626SDavid Howells return shmem_init_fs_context(fc); 6256e19ededSRob Landley 626f3235626SDavid Howells return ramfs_init_fs_context(fc); 62757f150a5SRob Landley } 62857f150a5SRob Landley 629fd3e007fSAl Viro struct file_system_type rootfs_fs_type = { 63057f150a5SRob Landley .name = "rootfs", 631f3235626SDavid Howells .init_fs_context = rootfs_init_fs_context, 63257f150a5SRob Landley .kill_sb = kill_litter_super, 63357f150a5SRob Landley }; 63457f150a5SRob Landley 635037f11b4SAl Viro void __init init_rootfs(void) 63657f150a5SRob Landley { 6376e19ededSRob Landley if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] && 638037f11b4SAl Viro (!root_fs_names || strstr(root_fs_names, "tmpfs"))) 6396e19ededSRob Landley is_tmpfs = true; 64057f150a5SRob Landley } 641