X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=util-linux%2Fmkswap.c;h=e203f0db683443f405d3d4e4c57fb58fadcf0849;hb=248d2220f9985754268f4492278758052494b80a;hp=f797d1395bef45a86a571efc369c1f0eb5a33067;hpb=cc8ed39b240180b58810784f844e253263594ac3;p=oweals%2Fbusybox.git diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c index f797d1395..e203f0db6 100644 --- a/util-linux/mkswap.c +++ b/util-linux/mkswap.c @@ -1,4 +1,4 @@ -#include "internal.h" +/* vi: set sw=4 ts=4: */ /* * mkswap.c - set up a linux swap device * @@ -9,15 +9,30 @@ /* * 20.12.91 - time began. Got VM working yesterday by doing this by hand. * - * Usage: mkswap [-c] device [size-in-blocks] + * Usage: mkswap [-c] [-vN] [-f] device [size-in-blocks] * - * -c for readablility checking (use it unless you are SURE!) + * -c for readability checking. (Use it unless you are SURE!) + * -vN for swap areas version N. (Only N=0,1 known today.) + * -f for forcing swap creation even if it would smash partition table. * - * The device may be a block device or a image of one, but this isn't + * The device may be a block device or an image of one, but this isn't * enforced (but it's not much fun on a character device :-). * * Patches from jaggy@purplet.demon.co.uk (Mike Jagdis) to make the * size-in-blocks parameter optional added Wed Feb 8 10:33:43 1995. + * + * Version 1 swap area code (for kernel 2.1.117), aeb, 981010. + * + * Sparc fixes, jj@ultra.linux.cz (Jakub Jelinek), 981201 - mangled by aeb. + * V1_MAX_PAGES fixes, jj, 990325. + * + * 1999-02-22 Arkadiusz Mi¶kiewicz + * - added Native Language Support + * + * from util-linux -- adapted for busybox by + * Erik Andersen . I ripped out Native Language + * Support, made some stuff smaller, and fitted for life in busybox. + * */ #include @@ -25,229 +40,379 @@ #include #include #include -#include -#include +#include /* for _IO */ +#include +#include /* for PAGE_SIZE and PAGE_SHIFT */ + /* we also get PAGE_SIZE via getpagesize() */ +#include "busybox.h" -#include -#include - -#ifndef __linux__ -# define volatile +#ifndef _IO +/* pre-1.3.45 */ +static const int BLKGETSIZE = 0x1260; +#else +/* same on i386, m68k, arm; different on alpha, mips, sparc, ppc */ +#define BLKGETSIZE _IO(0x12,96) #endif -#define TEST_BUFFER_PAGES 8 - -const char mkswap_usage[] = "mkswap [-c] partition [block-count]\n" -"\n" -"\tPrepare a disk partition to be used as a swap partition.\n" -"\tThe default block count is the size of the entire partition.\n" -"\n" -"\t-c:\tCheck for read-ability.\n" -"\tblock-count\tUse only this many blocks.\n"; - -static const char * program_name = "mkswap"; -static const char * device_name = NULL; +static char *device_name = NULL; static int DEV = -1; static long PAGES = 0; -static int do_check = 0; +static int check = 0; static int badpages = 0; +static int version = -1; + +#define MAKE_VERSION(p,q,r) (65536*(p) + 256*(q) + (r)) + +/* + * The definition of the union swap_header uses the constant PAGE_SIZE. + * Unfortunately, on some architectures this depends on the hardware model, + * and can only be found at run time -- we use getpagesize(). + */ + +static int pagesize; +static unsigned int *signature_page; + +static struct swap_header_v1 { + char bootbits[1024]; /* Space for disklabel etc. */ + unsigned int version; + unsigned int last_page; + unsigned int nr_badpages; + unsigned int padding[125]; + unsigned int badpages[1]; +} *p; + +static inline void init_signature_page(void) +{ + pagesize = getpagesize(); + +#ifdef PAGE_SIZE + if (pagesize != PAGE_SIZE) + bb_error_msg("Assuming pages of size %d", pagesize); +#endif + signature_page = (unsigned int *) xmalloc(pagesize); + memset(signature_page, 0, pagesize); + p = (struct swap_header_v1 *) signature_page; +} +static inline void write_signature(char *sig) +{ + char *sp = (char *) signature_page; + + strncpy(sp + pagesize - 10, sig, 10); +} + +#define V0_MAX_PAGES (8 * (pagesize - 10)) +/* Before 2.2.0pre9 */ +#define V1_OLD_MAX_PAGES ((0x7fffffff / pagesize) - 1) +/* Since 2.2.0pre9: + error if nr of pages >= SWP_OFFSET(SWP_ENTRY(0,~0UL)) + with variations on + #define SWP_ENTRY(type,offset) (((type) << 1) | ((offset) << 8)) + #define SWP_OFFSET(entry) ((entry) >> 8) + on the various architectures. Below the result - yuk. + + Machine pagesize SWP_ENTRY SWP_OFFSET bound+1 oldbound+2 + i386 2^12 o<<8 e>>8 1<<24 1<<19 + mips 2^12 o<<15 e>>15 1<<17 1<<19 + alpha 2^13 o<<40 e>>40 1<<24 1<<18 + m68k 2^12 o<<12 e>>12 1<<20 1<<19 + sparc 2^{12,13} (o&0x3ffff)<<9 (e>>9)&0x3ffff 1<<18 1<<{19,18} + sparc64 2^13 o<<13 e>>13 1<<51 1<<18 + ppc 2^12 o<<8 e>>8 1<<24 1<<19 + armo 2^{13,14,15} o<<8 e>>8 1<<24 1<<{18,17,16} + armv 2^12 o<<9 e>>9 1<<23 1<<19 -static long bit_test_and_set (unsigned int *addr, unsigned int nr) + assuming that longs have 64 bits on alpha and sparc64 and 32 bits elsewhere. + + The bad part is that we need to know this since the kernel will + refuse a swap space if it is too large. +*/ +/* patch from jj - why does this differ from the above? */ +#if defined(__alpha__) +#define V1_MAX_PAGES ((1 << 24) - 1) +#elif defined(__mips__) +#define V1_MAX_PAGES ((1 << 17) - 1) +#elif defined(__sparc_v9__) +#define V1_MAX_PAGES ((3 << 29) - 1) +#elif defined(__sparc__) +#define V1_MAX_PAGES (pagesize == 8192 ? ((3 << 29) - 1) : ((1 << 18) - 1)) +#else +#define V1_MAX_PAGES V1_OLD_MAX_PAGES +#endif +/* man page now says: +The maximum useful size of a swap area now depends on the architecture. +It is roughly 2GB on i386, PPC, m68k, ARM, 1GB on sparc, 512MB on mips, +128GB on alpha and 3TB on sparc64. +*/ + +#define MAX_BADPAGES ((pagesize-1024-128*sizeof(int)-10)/sizeof(int)) + +static inline void bit_set(unsigned int *addr, unsigned int nr) { unsigned int r, m; addr += nr / (8 * sizeof(int)); + r = *addr; m = 1 << (nr & (8 * sizeof(int) - 1)); + *addr = r | m; - return (r & m) != 0; } -static int bit_test_and_clear (unsigned int *addr, unsigned int nr) +static int bit_test_and_clear(unsigned int *addr, unsigned int nr) { unsigned int r, m; addr += nr / (8 * sizeof(int)); + r = *addr; m = 1 << (nr & (8 * sizeof(int) - 1)); + *addr = r & ~m; return (r & m) != 0; } -/* - * Volatile to let gcc know that this doesn't return. When trying - * to compile this under minix, volatile gives a warning, as - * exit() isn't defined as volatile under minix. - */ -volatile void fatal_error(const char * fmt_string) + +static void page_ok(int page) { - fprintf(stderr,fmt_string,program_name,device_name); - exit(1); + if (version == 0) + bit_set(signature_page, page); } -#define die(str) fatal_error("%s: " str "\n") +static inline void page_bad(int page) +{ + if (version == 0) + bit_test_and_clear(signature_page, page); + else { + if (badpages == MAX_BADPAGES) + bb_error_msg_and_die("too many bad pages"); + p->badpages[badpages] = page; + } + badpages++; +} -static void check_blocks(int * signature_page) +static void check_blocks(void) { unsigned int current_page; int do_seek = 1; - char buffer[PAGE_SIZE]; + char *buffer; + buffer = xmalloc(pagesize); current_page = 0; while (current_page < PAGES) { - if (!do_check) { - bit_test_and_set(signature_page,current_page++); + if (!check) { + page_ok(current_page++); continue; - } else { - printf("\r%d", current_page); } - if (do_seek && lseek(DEV,current_page*PAGE_SIZE,SEEK_SET) != - current_page*PAGE_SIZE) - die("seek failed in check_blocks"); - if ( (do_seek = (PAGE_SIZE != read(DEV, buffer, PAGE_SIZE))) ) { - bit_test_and_clear(signature_page,current_page++); - badpages++; + if (do_seek && lseek(DEV, current_page * pagesize, SEEK_SET) != + current_page * pagesize) + bb_error_msg_and_die("seek failed in check_blocks"); + if ((do_seek = (pagesize != read(DEV, buffer, pagesize)))) { + page_bad(current_page++); continue; } - bit_test_and_set(signature_page,current_page++); + page_ok(current_page++); } - if (do_check) - printf("\n"); - if (badpages) - printf("%d bad page%s\n",badpages,(badpages>1)?"s":""); + if (badpages == 1) + printf("one bad page\n"); + else if (badpages > 1) + printf("%d bad pages\n", badpages); } -static long valid_offset (int fd, int offset) +static long valid_offset(int fd, int offset) { char ch; - if (lseek (fd, offset, 0) < 0) + if (lseek(fd, offset, 0) < 0) return 0; - if (read (fd, &ch, 1) < 1) + if (read(fd, &ch, 1) < 1) return 0; return 1; } -static int count_blocks (int fd) +static int find_size(int fd) { - int high, low; + unsigned int high, low; low = 0; - for (high = 1; valid_offset (fd, high); high *= 2) + for (high = 1; high > 0 && valid_offset(fd, high); high *= 2) low = high; - while (low < high - 1) - { + while (low < high - 1) { const int mid = (low + high) / 2; - if (valid_offset (fd, mid)) + if (valid_offset(fd, mid)) low = mid; else high = mid; } - valid_offset (fd, 0); return (low + 1); } -static int get_size(const char *file) +/* return size in pages, to avoid integer overflow */ +static long get_size(const char *file) { - int fd; - int size; + int fd; + long size; - fd = open(file, O_RDWR); - if (fd < 0) { - perror(file); - exit(1); - } + if ((fd = open(file, O_RDONLY)) < 0) + bb_perror_msg_and_die("%s", file); if (ioctl(fd, BLKGETSIZE, &size) >= 0) { - close(fd); - return (size * 512); + int sectors_per_page = pagesize / 512; + + size /= sectors_per_page; + } else { + size = find_size(fd) / pagesize; } - - size = count_blocks(fd); close(fd); return size; } -int -mkswap(char *device_name, int pages, int check) - { +int mkswap_main(int argc, char **argv) +{ + char *tmp; struct stat statbuf; + int sz; + int maxpages; int goodpages; - int signature_page[PAGE_SIZE/sizeof(int)]; + int offset; + int force = 0; - PAGES = pages; - do_check = check; + init_signature_page(); /* get pagesize */ - memset(signature_page,0,PAGE_SIZE); + while (argc-- > 1) { + argv++; + if (argv[0][0] != '-') { + if (device_name) { + int blocks_per_page = pagesize / 1024; - if (device_name && !PAGES) { - PAGES = get_size(device_name) / PAGE_SIZE; + PAGES = strtol(argv[0], &tmp, 0) / blocks_per_page; + if (*tmp) + bb_show_usage(); + } else + device_name = argv[0]; + } else { + switch (argv[0][1]) { + case 'c': + check = 1; + break; + case 'f': + force = 1; + break; + case 'v': + version = atoi(argv[0] + 2); + break; + default: + bb_show_usage(); + } + } + } + if (!device_name) { + bb_error_msg("error: Nowhere to set up swap on?"); + bb_show_usage(); } - if (!device_name || PAGES<10) { - fprintf(stderr, - "%s: error: swap area needs to be at least %ldkB\n", - program_name, 10 * PAGE_SIZE / 1024); - /* usage(mkswap_usage); */ - exit(1); + sz = get_size(device_name); + if (!PAGES) { + PAGES = sz; + } else if (PAGES > sz && !force) { + bb_error_msg("error: size %ld is larger than device size %d", + PAGES * (pagesize / 1024), sz * (pagesize / 1024)); + return EXIT_FAILURE; } - if (PAGES > 8 * (PAGE_SIZE - 10)) { - PAGES = 8 * (PAGE_SIZE - 10); - fprintf(stderr, "%s: warning: truncating swap area to %ldkB\n", - program_name, PAGES * PAGE_SIZE / 1024); + + if (version == -1) { + if (get_kernel_revision() < MAKE_VERSION(2, 1, 117)) + version = 0; + else + version = 1; } - DEV = open(device_name,O_RDWR); - if (DEV < 0 || fstat(DEV, &statbuf) < 0) { - perror(device_name); - exit(1); + if (version != 0 && version != 1) { + bb_error_msg("error: unknown version %d", version); + bb_show_usage(); + } + if (PAGES < 10) { + bb_error_msg("error: swap area needs to be at least %ldkB", + (long) (10 * pagesize / 1024)); + bb_show_usage(); + } +#if 0 + maxpages = ((version == 0) ? V0_MAX_PAGES : V1_MAX_PAGES); +#else + if (!version) + maxpages = V0_MAX_PAGES; + else if (get_kernel_revision() >= MAKE_VERSION(2, 2, 1)) + maxpages = V1_MAX_PAGES; + else { + maxpages = V1_OLD_MAX_PAGES; + if (maxpages > V1_MAX_PAGES) + maxpages = V1_MAX_PAGES; + } +#endif + if (PAGES > maxpages) { + PAGES = maxpages; + bb_error_msg("warning: truncating swap area to %ldkB", + PAGES * pagesize / 1024); } + + DEV = open(device_name, O_RDWR); + if (DEV < 0 || fstat(DEV, &statbuf) < 0) + bb_perror_msg_and_die("%s", device_name); if (!S_ISBLK(statbuf.st_mode)) - do_check=0; + check = 0; else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340) - die("Will not try to make swapdevice on '%s'"); - check_blocks(signature_page); - if (!bit_test_and_clear(signature_page,0)) - die("fatal: first page unreadable"); - goodpages = PAGES - badpages - 1; - if (goodpages <= 0) - die("Unable to set up swap-space: unreadable"); - printf("Setting up swapspace, size = %ld bytes\n",goodpages*PAGE_SIZE); - strncpy((char*)signature_page+PAGE_SIZE-10,"SWAP-SPACE",10); - if (lseek(DEV, 0, SEEK_SET)) - die("unable to rewind swap-device"); - if (PAGE_SIZE != write(DEV, signature_page, PAGE_SIZE)) - die("unable to write signature page"); - - close(DEV); - return 0; -} + bb_error_msg_and_die("Will not try to make swapdevice on '%s'", device_name); -int mkswap_main(struct FileInfo * unnecessary, int argc, char ** argv) -{ - char * tmp; - long int pages=0; - int check=0; +#ifdef __sparc__ + if (!force && version == 0) { + /* Don't overwrite partition table unless forced */ + unsigned char *buffer = (unsigned char *) signature_page; + unsigned short *q, sum; - if (argc && *argv) - program_name = *argv; - while (argc > 1) { - argv++; - argc--; - if (argv[0][0] != '-') - if (device_name) { - pages = strtol(argv[0],&tmp,0)>>(PAGE_SHIFT-10); - if (*tmp) { - usage(mkswap_usage); - exit(1); - } - } else - device_name = argv[0]; - else while (*++argv[0]) - switch (argv[0][0]) { - case 'c': check=1; break; - default: usage(mkswap_usage); - exit(1); + if (read(DEV, buffer, 512) != 512) + bb_error_msg_and_die("fatal: first page unreadable"); + if (buffer[508] == 0xDA && buffer[509] == 0xBE) { + q = (unsigned short *) (buffer + 510); + for (sum = 0; q >= (unsigned short *) buffer;) + sum ^= *q--; + if (!sum) { + bb_error_msg("Device '%s' contains a valid Sun disklabel.\n" +"This probably means creating v0 swap would destroy your partition table\n" +"No swap created. If you really want to create swap v0 on that device, use\n" +"the -f option to force it.", device_name); + return EXIT_FAILURE; } + } } - return mkswap(device_name, pages, check); +#endif + + if (version == 0 || check) + check_blocks(); + if (version == 0 && !bit_test_and_clear(signature_page, 0)) + bb_error_msg_and_die("fatal: first page unreadable"); + if (version == 1) { + p->version = version; + p->last_page = PAGES - 1; + p->nr_badpages = badpages; + } + + goodpages = PAGES - badpages - 1; + if (goodpages <= 0) + bb_error_msg_and_die("Unable to set up swap-space: unreadable"); + printf("Setting up swapspace version %d, size = %ld bytes\n", + version, (long) (goodpages * pagesize)); + write_signature((version == 0) ? "SWAP-SPACE" : "SWAPSPACE2"); + + offset = ((version == 0) ? 0 : 1024); + if (lseek(DEV, offset, SEEK_SET) != offset) + bb_error_msg_and_die("unable to rewind swap-device"); + if (write(DEV, (char *) signature_page + offset, pagesize - offset) + != pagesize - offset) + bb_error_msg_and_die("unable to write signature page"); + + /* + * A subsequent swapon() will fail if the signature + * is not actually on disk. (This is a kernel bug.) + */ + if (fsync(DEV)) + bb_error_msg_and_die("fsync failed"); + return EXIT_SUCCESS; }