/* diskcheck - test a disk for bad blocks Author: Andy Tanenbaum */ #include <minix/config.h> #include <minix/const.h> #include <sys/types.h> #include <sys/stat.h> #include <signal.h> #include <errno.h> #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <stdio.h> #undef ERROR /* ERROR might be defined in <errno.h> :-( */ #define ERROR (-99) #define OK 0 #define PRINTFREQ 10 #define N 30 #define SHORTS_PER_BLOCK (BLOCK_SIZE / sizeof(short)) char purgebuf[BLOCK_SIZE * N]; char buf[BLOCK_SIZE], zero[BLOCK_SIZE]; short pat1[SHORTS_PER_BLOCK], pat2[SHORTS_PER_BLOCK]; int blk = -1; /* number of the block in buf, or -1 */ int pfd; /* file descriptor for purging */ int fd; /* file descriptor for data I/O */ unsigned long initblock; /* first block to test */ unsigned long curblock; /* current block */ unsigned long limit; /* first block beyond test zone */ unsigned long errors; /* # errors so far */ unsigned long ct; /* # blocks read so far */ int intflag; /* set when signal seen */ int rawdev; /* set when I/O done on raw device */ char *purgefile = "/dev/ram"; _PROTOTYPE(int main, (int argc , char *argv [])); _PROTOTYPE(int testblock, (unsigned long b )); _PROTOTYPE(void status, (void )); _PROTOTYPE(void nonfatal, (char *s , unsigned long b )); _PROTOTYPE(void fatal, (char *s , unsigned long b )); _PROTOTYPE(void catch, (int sig )); _PROTOTYPE(void usage, (void )); _PROTOTYPE(int wtest, (off_t pos , short *pat )); _PROTOTYPE(void purge_cache, (void )); int main(argc, argv) int argc; char *argv[]; { unsigned long b; int i; struct stat s; signal(SIGINT, catch); signal(SIGQUIT, catch); if (argc != 4) usage(); if (stat(argv[1], &s)) { printf("Cannot stat %s\n", argv[1]); exit(1); } rawdev = S_ISCHR(s.st_mode); if ((fd = open(argv[1], O_RDWR)) < 0) { printf("Cannot open %s\n", argv[1]); exit(1); } if ((pfd = open(purgefile, O_RDONLY)) < 0) { printf("Cannot open %s\n", purgefile); exit(1); } initblock = atol(argv[2]); limit = initblock + atol(argv[3]); if (limit <= initblock) usage(); for (i = 0; i < SHORTS_PER_BLOCK; i++) { pat1[i] = i; pat2[i] = 1000 - i; } for (b = initblock; b < limit; b++) { if (intflag) break; if (testblock(b) == ERROR) { errors++; if (blk == b) { /* Read ok, write failed; try to restore block. */ lseek(fd, (off_t) BLOCK_SIZE * (off_t) b, SEEK_SET); write(fd, buf, BLOCK_SIZE); } } curblock = b; ct++; if (ct % PRINTFREQ == 0) status(); } status(); printf("\n"); return(0); } int testblock(b) unsigned long b; { /* Read block b in, save it in buf. Then overwrite that block with a * known test pattern and read it back. Finally, replace the block. * Return OK or ERROR. */ off_t pos; int s; blk = -1; pos = (off_t) BLOCK_SIZE * (off_t) b; purge_cache(); if (lseek(fd, pos, SEEK_SET) != pos) fatal("Cannot seek to block ", b); /* Read block b into 'buf'. */ s = read(fd, buf, BLOCK_SIZE); /* Test for various outcomes of the read. */ if (s == BLOCK_SIZE) { blk = b; if (wtest(pos, pat1) == ERROR) return(ERROR); if (wtest(pos, pat2) == ERROR) return (ERROR); lseek(fd, pos, SEEK_SET); if (write(fd, buf, BLOCK_SIZE) != BLOCK_SIZE) { nonfatal("Cannot rewrite block ", b); return(ERROR); } else { return(OK); } } if (s < 0) { if (errno == EIO) nonfatal("Read error on block ", b); else { printf("\nError. Read returned %d. errno=%d. ", s, errno); fatal("Block ", b); } return(ERROR); } if (s == 0) fatal("End of file reached trying to read block ", b); nonfatal("Read size error on block ", b); return(ERROR); } void status() { printf("%8lu blocks tested, %lu errors detected (last block tested = %5lu)\r", ct, errors, curblock); fflush(stdout); } void nonfatal(s, b) char *s; unsigned long b; { printf("\n%s%lu\n", s, b); } void fatal(s, b) char *s; unsigned long b; { printf("\n%s%lu\n", s, b); status(); exit(1); } void catch(sig) int sig; /* prototype says there has to be 1 arg */ { signal(SIGINT, catch); signal(SIGQUIT, catch); intflag = 1; } void usage() { printf("Usage: diskcheck device start-block block-count\n"); exit(1); } int wtest(pos, pat) off_t pos; short *pat; { short testb[SHORTS_PER_BLOCK]; int i; lseek(fd, pos, SEEK_SET); if (write(fd, (char *) pat, BLOCK_SIZE) != BLOCK_SIZE) return(ERROR); sync(); /* force the write to the disk */ purge_cache(); lseek(fd, pos, SEEK_SET); if (read(fd, (char *) testb, BLOCK_SIZE) != BLOCK_SIZE) return(ERROR); for (i = 0; i < SHORTS_PER_BLOCK; i++) if (testb[i] != pat[i]) { printf("%d %d\n", testb[i], pat[i]); return(ERROR); } return(OK); } void purge_cache() { /* Do enough reads that the cache is purged. */ static int warned = 0; int left, count, r; if (rawdev) return; pfd = open(purgefile, O_RDONLY); #ifdef NR_BUFS left = NR_BUFS; #else /* XXX - buffers are dynamically allocated and there are likely to be * several MB worth. This purge is unlikely to work. There should be * raw devices to avoid such complications. */ left = 8000; #endif while (left > 0) { count = (left < N ? left : N); r = read(pfd, purgebuf, (size_t) (count * BLOCK_SIZE)); if (r != count * BLOCK_SIZE) { if (r == 0) { if (!warned) printf("WARNING: Cannot purge cache.\n"); warned = 1; break; } printf("ERROR: count=%d left=%d r=%d. ", count, left, r); fatal("Cannot purge cache. errno= ", (unsigned long) errno); } left -= count; } close(pfd); }