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![Tejun Heo](/assets/img/avatar_default.png)
This patch adds default module loading and uses it to load the default block elevator. During boot, it's called right after initramfs or initrd is made available and right before control is passed to userland. This ensures that as long as the modules are available in the usual places in initramfs, initrd or the root filesystem, the default modules are loaded as soon as possible. This will replace the on-demand elevator module loading from elevator init path. v2: Fixed build breakage when !CONFIG_BLOCK. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alex Riesen <raa.lkml@gmail.com> Cc: Fengguang We <fengguang.wu@intel.com>
627 lines
13 KiB
C
627 lines
13 KiB
C
/*
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* Many of the syscalls used in this file expect some of the arguments
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* to be __user pointers not __kernel pointers. To limit the sparse
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* noise, turn off sparse checking for this file.
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*/
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#ifdef __CHECKER__
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#undef __CHECKER__
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#warning "Sparse checking disabled for this file"
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#endif
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/fcntl.h>
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#include <linux/delay.h>
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#include <linux/string.h>
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#include <linux/dirent.h>
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#include <linux/syscalls.h>
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#include <linux/utime.h>
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static __initdata char *message;
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static void __init error(char *x)
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{
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if (!message)
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message = x;
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}
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/* link hash */
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#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
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static __initdata struct hash {
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int ino, minor, major;
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umode_t mode;
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struct hash *next;
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char name[N_ALIGN(PATH_MAX)];
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} *head[32];
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static inline int hash(int major, int minor, int ino)
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{
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unsigned long tmp = ino + minor + (major << 3);
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tmp += tmp >> 5;
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return tmp & 31;
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}
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static char __init *find_link(int major, int minor, int ino,
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umode_t mode, char *name)
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{
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struct hash **p, *q;
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for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
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if ((*p)->ino != ino)
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continue;
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if ((*p)->minor != minor)
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continue;
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if ((*p)->major != major)
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continue;
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if (((*p)->mode ^ mode) & S_IFMT)
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continue;
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return (*p)->name;
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}
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q = kmalloc(sizeof(struct hash), GFP_KERNEL);
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if (!q)
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panic("can't allocate link hash entry");
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q->major = major;
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q->minor = minor;
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q->ino = ino;
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q->mode = mode;
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strcpy(q->name, name);
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q->next = NULL;
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*p = q;
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return NULL;
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}
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static void __init free_hash(void)
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{
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struct hash **p, *q;
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for (p = head; p < head + 32; p++) {
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while (*p) {
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q = *p;
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*p = q->next;
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kfree(q);
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}
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}
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}
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static long __init do_utime(char *filename, time_t mtime)
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{
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struct timespec t[2];
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t[0].tv_sec = mtime;
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t[0].tv_nsec = 0;
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t[1].tv_sec = mtime;
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t[1].tv_nsec = 0;
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return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
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}
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static __initdata LIST_HEAD(dir_list);
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struct dir_entry {
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struct list_head list;
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char *name;
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time_t mtime;
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};
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static void __init dir_add(const char *name, time_t mtime)
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{
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struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
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if (!de)
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panic("can't allocate dir_entry buffer");
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INIT_LIST_HEAD(&de->list);
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de->name = kstrdup(name, GFP_KERNEL);
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de->mtime = mtime;
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list_add(&de->list, &dir_list);
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}
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static void __init dir_utime(void)
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{
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struct dir_entry *de, *tmp;
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list_for_each_entry_safe(de, tmp, &dir_list, list) {
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list_del(&de->list);
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do_utime(de->name, de->mtime);
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kfree(de->name);
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kfree(de);
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}
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}
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static __initdata time_t mtime;
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/* cpio header parsing */
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static __initdata unsigned long ino, major, minor, nlink;
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static __initdata umode_t mode;
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static __initdata unsigned long body_len, name_len;
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static __initdata uid_t uid;
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static __initdata gid_t gid;
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static __initdata unsigned rdev;
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static void __init parse_header(char *s)
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{
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unsigned long parsed[12];
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char buf[9];
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int i;
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buf[8] = '\0';
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for (i = 0, s += 6; i < 12; i++, s += 8) {
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memcpy(buf, s, 8);
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parsed[i] = simple_strtoul(buf, NULL, 16);
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}
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ino = parsed[0];
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mode = parsed[1];
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uid = parsed[2];
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gid = parsed[3];
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nlink = parsed[4];
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mtime = parsed[5];
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body_len = parsed[6];
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major = parsed[7];
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minor = parsed[8];
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rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
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name_len = parsed[11];
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}
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/* FSM */
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static __initdata enum state {
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Start,
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Collect,
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GotHeader,
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SkipIt,
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GotName,
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CopyFile,
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GotSymlink,
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Reset
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} state, next_state;
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static __initdata char *victim;
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static __initdata unsigned count;
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static __initdata loff_t this_header, next_header;
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static inline void __init eat(unsigned n)
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{
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victim += n;
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this_header += n;
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count -= n;
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}
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static __initdata char *vcollected;
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static __initdata char *collected;
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static __initdata int remains;
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static __initdata char *collect;
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static void __init read_into(char *buf, unsigned size, enum state next)
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{
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if (count >= size) {
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collected = victim;
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eat(size);
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state = next;
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} else {
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collect = collected = buf;
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remains = size;
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next_state = next;
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state = Collect;
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}
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}
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static __initdata char *header_buf, *symlink_buf, *name_buf;
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static int __init do_start(void)
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{
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read_into(header_buf, 110, GotHeader);
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return 0;
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}
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static int __init do_collect(void)
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{
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unsigned n = remains;
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if (count < n)
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n = count;
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memcpy(collect, victim, n);
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eat(n);
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collect += n;
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if ((remains -= n) != 0)
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return 1;
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state = next_state;
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return 0;
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}
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static int __init do_header(void)
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{
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if (memcmp(collected, "070707", 6)==0) {
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error("incorrect cpio method used: use -H newc option");
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return 1;
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}
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if (memcmp(collected, "070701", 6)) {
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error("no cpio magic");
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return 1;
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}
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parse_header(collected);
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next_header = this_header + N_ALIGN(name_len) + body_len;
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next_header = (next_header + 3) & ~3;
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state = SkipIt;
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if (name_len <= 0 || name_len > PATH_MAX)
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return 0;
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if (S_ISLNK(mode)) {
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if (body_len > PATH_MAX)
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return 0;
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collect = collected = symlink_buf;
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remains = N_ALIGN(name_len) + body_len;
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next_state = GotSymlink;
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state = Collect;
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return 0;
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}
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if (S_ISREG(mode) || !body_len)
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read_into(name_buf, N_ALIGN(name_len), GotName);
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return 0;
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}
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static int __init do_skip(void)
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{
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if (this_header + count < next_header) {
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eat(count);
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return 1;
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} else {
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eat(next_header - this_header);
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state = next_state;
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return 0;
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}
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}
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static int __init do_reset(void)
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{
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while(count && *victim == '\0')
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eat(1);
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if (count && (this_header & 3))
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error("broken padding");
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return 1;
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}
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static int __init maybe_link(void)
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{
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if (nlink >= 2) {
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char *old = find_link(major, minor, ino, mode, collected);
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if (old)
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return (sys_link(old, collected) < 0) ? -1 : 1;
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}
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return 0;
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}
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static void __init clean_path(char *path, umode_t mode)
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{
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struct stat st;
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if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
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if (S_ISDIR(st.st_mode))
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sys_rmdir(path);
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else
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sys_unlink(path);
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}
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}
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static __initdata int wfd;
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static int __init do_name(void)
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{
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state = SkipIt;
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next_state = Reset;
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if (strcmp(collected, "TRAILER!!!") == 0) {
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free_hash();
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return 0;
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}
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clean_path(collected, mode);
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if (S_ISREG(mode)) {
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int ml = maybe_link();
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if (ml >= 0) {
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int openflags = O_WRONLY|O_CREAT;
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if (ml != 1)
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openflags |= O_TRUNC;
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wfd = sys_open(collected, openflags, mode);
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if (wfd >= 0) {
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sys_fchown(wfd, uid, gid);
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sys_fchmod(wfd, mode);
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if (body_len)
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sys_ftruncate(wfd, body_len);
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vcollected = kstrdup(collected, GFP_KERNEL);
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state = CopyFile;
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}
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}
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} else if (S_ISDIR(mode)) {
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sys_mkdir(collected, mode);
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sys_chown(collected, uid, gid);
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sys_chmod(collected, mode);
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dir_add(collected, mtime);
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} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
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S_ISFIFO(mode) || S_ISSOCK(mode)) {
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if (maybe_link() == 0) {
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sys_mknod(collected, mode, rdev);
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sys_chown(collected, uid, gid);
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sys_chmod(collected, mode);
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do_utime(collected, mtime);
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}
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}
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return 0;
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}
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static int __init do_copy(void)
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{
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if (count >= body_len) {
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sys_write(wfd, victim, body_len);
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sys_close(wfd);
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do_utime(vcollected, mtime);
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kfree(vcollected);
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eat(body_len);
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state = SkipIt;
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return 0;
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} else {
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sys_write(wfd, victim, count);
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body_len -= count;
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eat(count);
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return 1;
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}
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}
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static int __init do_symlink(void)
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{
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collected[N_ALIGN(name_len) + body_len] = '\0';
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clean_path(collected, 0);
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sys_symlink(collected + N_ALIGN(name_len), collected);
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sys_lchown(collected, uid, gid);
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do_utime(collected, mtime);
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state = SkipIt;
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next_state = Reset;
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return 0;
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}
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static __initdata int (*actions[])(void) = {
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[Start] = do_start,
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[Collect] = do_collect,
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[GotHeader] = do_header,
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[SkipIt] = do_skip,
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[GotName] = do_name,
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[CopyFile] = do_copy,
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[GotSymlink] = do_symlink,
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[Reset] = do_reset,
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};
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static int __init write_buffer(char *buf, unsigned len)
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{
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count = len;
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victim = buf;
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while (!actions[state]())
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;
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return len - count;
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}
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static int __init flush_buffer(void *bufv, unsigned len)
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{
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char *buf = (char *) bufv;
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int written;
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int origLen = len;
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if (message)
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return -1;
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while ((written = write_buffer(buf, len)) < len && !message) {
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char c = buf[written];
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if (c == '0') {
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buf += written;
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len -= written;
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state = Start;
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} else if (c == 0) {
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buf += written;
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len -= written;
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state = Reset;
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} else
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error("junk in compressed archive");
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}
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return origLen;
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}
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static unsigned my_inptr; /* index of next byte to be processed in inbuf */
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#include <linux/decompress/generic.h>
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static char * __init unpack_to_rootfs(char *buf, unsigned len)
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{
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int written, res;
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decompress_fn decompress;
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const char *compress_name;
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static __initdata char msg_buf[64];
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header_buf = kmalloc(110, GFP_KERNEL);
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symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
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name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
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if (!header_buf || !symlink_buf || !name_buf)
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panic("can't allocate buffers");
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state = Start;
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this_header = 0;
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message = NULL;
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while (!message && len) {
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loff_t saved_offset = this_header;
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if (*buf == '0' && !(this_header & 3)) {
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state = Start;
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written = write_buffer(buf, len);
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buf += written;
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len -= written;
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continue;
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}
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if (!*buf) {
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buf++;
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len--;
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this_header++;
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continue;
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}
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this_header = 0;
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decompress = decompress_method(buf, len, &compress_name);
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if (decompress) {
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res = decompress(buf, len, NULL, flush_buffer, NULL,
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&my_inptr, error);
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if (res)
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error("decompressor failed");
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} else if (compress_name) {
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if (!message) {
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snprintf(msg_buf, sizeof msg_buf,
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"compression method %s not configured",
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compress_name);
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message = msg_buf;
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}
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} else
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error("junk in compressed archive");
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if (state != Reset)
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error("junk in compressed archive");
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this_header = saved_offset + my_inptr;
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buf += my_inptr;
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len -= my_inptr;
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}
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dir_utime();
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kfree(name_buf);
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kfree(symlink_buf);
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kfree(header_buf);
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return message;
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}
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static int __initdata do_retain_initrd;
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static int __init retain_initrd_param(char *str)
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{
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if (*str)
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return 0;
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do_retain_initrd = 1;
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return 1;
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}
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__setup("retain_initrd", retain_initrd_param);
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extern char __initramfs_start[];
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extern unsigned long __initramfs_size;
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#include <linux/initrd.h>
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#include <linux/kexec.h>
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static void __init free_initrd(void)
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{
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#ifdef CONFIG_KEXEC
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unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
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unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
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#endif
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if (do_retain_initrd)
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goto skip;
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#ifdef CONFIG_KEXEC
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/*
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* If the initrd region is overlapped with crashkernel reserved region,
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* free only memory that is not part of crashkernel region.
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*/
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if (initrd_start < crashk_end && initrd_end > crashk_start) {
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/*
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* Initialize initrd memory region since the kexec boot does
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* not do.
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*/
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memset((void *)initrd_start, 0, initrd_end - initrd_start);
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if (initrd_start < crashk_start)
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free_initrd_mem(initrd_start, crashk_start);
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if (initrd_end > crashk_end)
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free_initrd_mem(crashk_end, initrd_end);
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} else
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#endif
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free_initrd_mem(initrd_start, initrd_end);
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skip:
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initrd_start = 0;
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initrd_end = 0;
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}
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#ifdef CONFIG_BLK_DEV_RAM
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#define BUF_SIZE 1024
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static void __init clean_rootfs(void)
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{
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int fd;
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void *buf;
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struct linux_dirent64 *dirp;
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int num;
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|
|
fd = sys_open("/", O_RDONLY, 0);
|
|
WARN_ON(fd < 0);
|
|
if (fd < 0)
|
|
return;
|
|
buf = kzalloc(BUF_SIZE, GFP_KERNEL);
|
|
WARN_ON(!buf);
|
|
if (!buf) {
|
|
sys_close(fd);
|
|
return;
|
|
}
|
|
|
|
dirp = buf;
|
|
num = sys_getdents64(fd, dirp, BUF_SIZE);
|
|
while (num > 0) {
|
|
while (num > 0) {
|
|
struct stat st;
|
|
int ret;
|
|
|
|
ret = sys_newlstat(dirp->d_name, &st);
|
|
WARN_ON_ONCE(ret);
|
|
if (!ret) {
|
|
if (S_ISDIR(st.st_mode))
|
|
sys_rmdir(dirp->d_name);
|
|
else
|
|
sys_unlink(dirp->d_name);
|
|
}
|
|
|
|
num -= dirp->d_reclen;
|
|
dirp = (void *)dirp + dirp->d_reclen;
|
|
}
|
|
dirp = buf;
|
|
memset(buf, 0, BUF_SIZE);
|
|
num = sys_getdents64(fd, dirp, BUF_SIZE);
|
|
}
|
|
|
|
sys_close(fd);
|
|
kfree(buf);
|
|
}
|
|
#endif
|
|
|
|
static int __init populate_rootfs(void)
|
|
{
|
|
char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size);
|
|
if (err)
|
|
panic(err); /* Failed to decompress INTERNAL initramfs */
|
|
if (initrd_start) {
|
|
#ifdef CONFIG_BLK_DEV_RAM
|
|
int fd;
|
|
printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
|
|
err = unpack_to_rootfs((char *)initrd_start,
|
|
initrd_end - initrd_start);
|
|
if (!err) {
|
|
free_initrd();
|
|
goto done;
|
|
} else {
|
|
clean_rootfs();
|
|
unpack_to_rootfs(__initramfs_start, __initramfs_size);
|
|
}
|
|
printk(KERN_INFO "rootfs image is not initramfs (%s)"
|
|
"; looks like an initrd\n", err);
|
|
fd = sys_open("/initrd.image",
|
|
O_WRONLY|O_CREAT, 0700);
|
|
if (fd >= 0) {
|
|
sys_write(fd, (char *)initrd_start,
|
|
initrd_end - initrd_start);
|
|
sys_close(fd);
|
|
free_initrd();
|
|
}
|
|
done:
|
|
#else
|
|
printk(KERN_INFO "Unpacking initramfs...\n");
|
|
err = unpack_to_rootfs((char *)initrd_start,
|
|
initrd_end - initrd_start);
|
|
if (err)
|
|
printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
|
|
free_initrd();
|
|
#endif
|
|
/*
|
|
* Try loading default modules from initramfs. This gives
|
|
* us a chance to load before device_initcalls.
|
|
*/
|
|
load_default_modules();
|
|
}
|
|
return 0;
|
|
}
|
|
rootfs_initcall(populate_rootfs);
|