ref: af36a8b50ad95196fdc21deac251919cd7bbd18a
dir: /sys/src/cmd/replica/applylog.c/
#include "all.h" #define Nwork 16 int localdirstat(char*, Dir*); int ismatch(char*); void conflict(char*, char*, ...); void error(char*, ...); int isdir(char*); void worker(int fdf, int fdt, char *from, char *to); vlong nextoff(void); void failure(void *, char *note); QLock lk; vlong off; int errors; int nconf; int donothing; int verbose; char **match; int nmatch; int tempspool = 1; int safeinstall = 1; char *lroot; char *rroot; Db *clientdb; int skip; int douid; char *mkname(char*, int, char*, char*); char localbuf[10240]; char remotebuf[10240]; int copyfile(char*, char*, char*, Dir*, int, int*); ulong maxnow; int maxn; char *timefile; int timefd; int samecontents(char*, char*); Db *copyerr; typedef struct Res Res; struct Res { char c; char *name; }; Res *res; int nres; void addresolve(int c, char *name) { if(name[0] == '/') name++; res = erealloc(res, (nres+1)*sizeof res[0]); res[nres].c = c; res[nres].name = name; nres++; } int resolve(char *name) { int i, len; for(i=0; i<nres; i++){ len = strlen(res[i].name); if(len == 0) return res[i].c; if(strncmp(name, res[i].name, len) == 0 && (name[len]=='/' || name[len] == 0)) return res[i].c; } return '?'; } void readtimefile(void) { int n; char buf[24]; if((timefd = open(timefile, ORDWR)) < 0 && (timefd = create(timefile, ORDWR|OEXCL, 0666)) < 0) return; n = readn(timefd, buf, sizeof buf); if(n < sizeof buf) return; maxnow = atoi(buf); maxn = atoi(buf+12); } void writetimefile(void) { char buf[24+1]; snprint(buf, sizeof buf, "%11lud %11d ", maxnow, maxn); pwrite(timefd, buf, 24, 0); } static void membogus(char**); void addce(char *local) { char e[ERRMAX]; Dir d; memset(&d, 0, sizeof d); rerrstr(e, sizeof e); d.name = atom(e); d.uid = ""; d.gid = ""; insertdb(copyerr, atom(local), &d); } void delce(char *local) { removedb(copyerr, local); } void chat(char *f, ...) { Fmt fmt; char buf[256]; va_list arg; if(!verbose) return; fmtfdinit(&fmt, 1, buf, sizeof buf); va_start(arg, f); fmtvprint(&fmt, f, arg); va_end(arg); fmtfdflush(&fmt); } void usage(void) { fprint(2, "usage: replica/applylog [-cnSstuv] [-T timefile] clientdb clientroot serverroot [path ...]\n"); exits("usage"); } int notexists(char *path) { char buf[ERRMAX]; if(access(path, AEXIST) >= 0) return 0; rerrstr(buf, sizeof buf); if(strstr(buf, "entry not found") || strstr(buf, "not exist")) return 1; /* some other error, like network hangup */ return 0; } void main(int argc, char **argv) { char *f[10], *local, *name, *remote, *s, *t, verb; int fd, havedb, havelocal, i, k, n, nf, resolve1, skip; int checkedmatch1, checkedmatch2, checkedmatch3, checkedmatch4; ulong now; Biobuf bin; Dir dbd, ld, nd, rd; Entry *e; membogus(argv); quotefmtinstall(); ARGBEGIN{ case 's': case 'c': i = ARGC(); addresolve(i, EARGF(usage())); break; case 'n': donothing = 1; verbose = 1; break; case 'S': safeinstall = 0; break; case 'T': timefile = EARGF(usage()); break; case 't': tempspool = 0; break; case 'u': douid = 1; break; case 'v': verbose++; break; default: usage(); }ARGEND if(argc < 3) usage(); if(timefile) readtimefile(); lroot = argv[1]; if(!isdir(lroot)) sysfatal("bad local root directory"); rroot = argv[2]; if(!isdir(rroot)) sysfatal("bad remote root directory"); match = argv+3; nmatch = argc-3; for(i=0; i<nmatch; i++) if(match[i][0] == '/') match[i]++; if((clientdb = opendb(argv[0])) == nil) sysfatal("opendb %q: %r", argv[2]); copyerr = opendb(nil); skip = 0; Binit(&bin, 0, OREAD); for(; s=Brdstr(&bin, '\n', 1); free(s)){ t = estrdup(s); nf = tokenize(s, f, nelem(f)); if(nf != 10 || strlen(f[2]) != 1){ skip = 1; fprint(2, "warning: skipping bad log entry <%s>\n", t); free(t); continue; } free(t); now = strtoul(f[0], 0, 0); n = atoi(f[1]); verb = f[2][0]; name = f[3]; if(now < maxnow || (now==maxnow && n <= maxn)) continue; local = mkname(localbuf, sizeof localbuf, lroot, name); if(strcmp(f[4], "-") == 0) f[4] = f[3]; remote = mkname(remotebuf, sizeof remotebuf, rroot, f[4]); rd.name = f[4]; rd.mode = strtoul(f[5], 0, 8); rd.uid = f[6]; rd.gid = f[7]; rd.mtime = strtoul(f[8], 0, 10); rd.length = strtoll(f[9], 0, 10); havedb = finddb(clientdb, name, &dbd)>=0; havelocal = localdirstat(local, &ld)>=0; resolve1 = resolve(name); /* * if(!ismatch(name)){ * skip = 1; * continue; * } * * This check used to be right here, but we want * the time to be able to move forward past entries * that don't match and have already been applied. * So now every path below must checked !ismatch(name) * before making any changes to the local file * system. The fake variable checkedmatch * tracks whether !ismatch(name) has been checked. * If the compiler doesn't produce any used/set * warnings, then all the paths should be okay. * Even so, we have the asserts to fall back on. */ switch(verb){ case 'd': /* delete file */ delce(local); if(!havelocal) /* doesn't exist; who cares? */ break; if(access(remote, AEXIST) >= 0) /* got recreated! */ break; if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch1); if(!havedb){ if(resolve1 == 's') goto DoRemove; else if(resolve1 == 'c') goto DoRemoveDb; conflict(name, "locally created; will not remove"); skip = 1; continue; } assert(havelocal && havedb); if(dbd.mtime > rd.mtime) /* we have a newer file than what was deleted */ break; if(samecontents(local, remote) > 0){ /* going to get recreated */ chat("= %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); break; } if(!(dbd.mode&DMDIR) && (dbd.mtime != ld.mtime || dbd.length != ld.length)){ /* locally modified since we downloaded it */ if(resolve1 == 's') goto DoRemove; else if(resolve1 == 'c') break; conflict(name, "locally modified; will not remove"); skip = 1; continue; } DoRemove: USED(checkedmatch1); assert(ismatch(name)); chat("d %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); if(donothing) break; if(remove(local) < 0){ error("removing %q: %r", name); skip = 1; continue; } DoRemoveDb: USED(checkedmatch1); assert(ismatch(name)); removedb(clientdb, name); break; case 'a': /* add file */ if(!havedb){ if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch2); if(!havelocal) goto DoCreate; if((ld.mode&DMDIR) && (rd.mode&DMDIR)) break; if(samecontents(local, remote) > 0){ chat("= %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); goto DoCreateDb; } if(resolve1 == 's') goto DoCreate; else if(resolve1 == 'c') goto DoCreateDb; conflict(name, "locally created; will not overwrite"); skip = 1; continue; } assert(havedb); if(dbd.mtime >= rd.mtime) /* already created this file; ignore */ break; if(havelocal){ if((ld.mode&DMDIR) && (rd.mode&DMDIR)) break; if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch2); if(samecontents(local, remote) > 0){ chat("= %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); goto DoCreateDb; } if(dbd.mtime==ld.mtime && dbd.length==ld.length) goto DoCreate; if(resolve1=='s') goto DoCreate; else if(resolve1 == 'c') break; conflict(name, "locally modified; will not overwrite"); skip = 1; continue; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch2); DoCreate: USED(checkedmatch2); assert(ismatch(name)); if(notexists(remote)){ addce(local); /* no skip=1 */ break;; } chat("a %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); if(donothing) break; if(rd.mode&DMDIR){ fd = create(local, OREAD, DMDIR); if(fd < 0 && isdir(local)) fd = open(local, OREAD); if(fd < 0){ error("mkdir %q: %r", name); skip = 1; continue; } nulldir(&nd); nd.mode = rd.mode; if(dirfwstat(fd, &nd) < 0) fprint(2, "warning: cannot set mode on %q\n", local); nulldir(&nd); nd.gid = rd.gid; if(dirfwstat(fd, &nd) < 0) fprint(2, "warning: cannot set gid on %q\n", local); if(douid){ nulldir(&nd); nd.uid = rd.uid; if(dirfwstat(fd, &nd) < 0) fprint(2, "warning: cannot set uid on %q\n", local); } close(fd); rd.mtime = now; }else{ if(copyfile(local, remote, name, &rd, 1, &k) < 0){ if(k) addce(local); skip = 1; continue; } } DoCreateDb: USED(checkedmatch2); assert(ismatch(name)); insertdb(clientdb, name, &rd); break; case 'c': /* change contents */ if(!havedb){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch3); if(resolve1 == 's') goto DoCopy; else if(resolve1=='c') goto DoCopyDb; if(samecontents(local, remote) > 0){ chat("= %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); goto DoCopyDb; } if(havelocal) conflict(name, "locally created; will not update"); else conflict(name, "not replicated; will not update"); skip = 1; continue; } if(dbd.mtime >= rd.mtime) /* already have/had this version; ignore */ break; if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch3); if(!havelocal){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(resolve1 == 's') goto DoCopy; else if(resolve1 == 'c') break; conflict(name, "locally removed; will not update"); skip = 1; continue; } assert(havedb && havelocal); if(dbd.mtime != ld.mtime || dbd.length != ld.length){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(samecontents(local, remote) > 0){ chat("= %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); goto DoCopyDb; } if(resolve1 == 's') goto DoCopy; else if(resolve1 == 'c') break; conflict(name, "locally modified; will not update [%llud %lud -> %llud %lud]", dbd.length, dbd.mtime, ld.length, ld.mtime); skip = 1; continue; } DoCopy: USED(checkedmatch3); assert(ismatch(name)); if(notexists(remote)){ addce(local); /* no skip=1 */ break; } chat("c %q\n", name); if(donothing) break; if(copyfile(local, remote, name, &rd, 0, &k) < 0){ if(k) addce(local); skip = 1; continue; } DoCopyDb: USED(checkedmatch3); assert(ismatch(name)); if(!havedb){ if(havelocal) dbd = ld; else dbd = rd; } dbd.mtime = rd.mtime; dbd.length = rd.length; insertdb(clientdb, name, &dbd); break; case 'm': /* change metadata */ if(!havedb){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch4); if(resolve1 == 's'){ USED(checkedmatch4); SET(checkedmatch2); goto DoCreate; } else if(resolve1 == 'c') goto DoMetaDb; if(havelocal) conflict(name, "locally created; will not update metadata"); else conflict(name, "not replicated; will not update metadata"); skip = 1; continue; } if(!(dbd.mode&DMDIR) && dbd.mtime > rd.mtime) /* have newer version; ignore */ break; if((dbd.mode&DMDIR) && dbd.mtime > now) break; if(havelocal && (!douid || strcmp(ld.uid, rd.uid)==0) && strcmp(ld.gid, rd.gid)==0 && ld.mode==rd.mode) break; if(!havelocal){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch4); if(resolve1 == 's'){ USED(checkedmatch4); SET(checkedmatch2); goto DoCreate; } else if(resolve1 == 'c') break; conflict(name, "locally removed; will not update metadata"); skip = 1; continue; } if(!(dbd.mode&DMDIR) && (dbd.mtime != ld.mtime || dbd.length != ld.length)){ /* this check might be overkill */ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch4); if(resolve1 == 's' || samecontents(local, remote) > 0) goto DoMeta; else if(resolve1 == 'c') break; conflict(name, "contents locally modified (%s); will not update metadata to %s %s %luo", dbd.mtime != ld.mtime ? "mtime" : dbd.length != ld.length ? "length" : "unknown", rd.uid, rd.gid, rd.mode); skip = 1; continue; } if((douid && strcmp(ld.uid, dbd.uid)!=0) || strcmp(ld.gid, dbd.gid)!=0 || ld.mode!=dbd.mode){ if(notexists(remote)){ addce(local); /* no skip=1 */ break; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch4); if(resolve1 == 's') goto DoMeta; else if(resolve1 == 'c') break; conflict(name, "metadata locally changed; will not update metadata to %s %s %luo", rd.uid, rd.gid, rd.mode); skip = 1; continue; } if(!ismatch(name)){ if(!skip) fprint(2, "stopped updating log apply time because of %s\n", name); skip = 1; continue; } SET(checkedmatch4); DoMeta: USED(checkedmatch4); assert(ismatch(name)); if(notexists(remote)){ addce(local); /* no skip=1 */ break; } chat("m %q %luo %q %q %lud\n", name, rd.mode, rd.uid, rd.gid, rd.mtime); if(donothing) break; nulldir(&nd); nd.gid = rd.gid; nd.mode = rd.mode; if(douid) nd.uid = rd.uid; if(dirwstat(local, &nd) < 0){ error("dirwstat %q: %r", name); skip = 1; continue; } DoMetaDb: USED(checkedmatch4); assert(ismatch(name)); if(!havedb){ if(havelocal) dbd = ld; else dbd = rd; } if(dbd.mode&DMDIR) dbd.mtime = now; dbd.gid = rd.gid; dbd.mode = rd.mode; if(douid) dbd.uid = rd.uid; insertdb(clientdb, name, &dbd); break; } if(!skip && !donothing){ maxnow = now; maxn = n; } } for(e = (Entry*)avlmin(copyerr->avl); e != nil; e = (Entry*)avlnext(e)) error("copying %q: %s\n", e->name, e->d.name); if(timefile) writetimefile(); if(nconf) exits("conflicts"); if(errors) exits("errors"); exits(nil); } char* mkname(char *buf, int nbuf, char *a, char *b) { if(strlen(a)+strlen(b)+2 > nbuf) sysfatal("name too long"); strcpy(buf, a); if(a[strlen(a)-1] != '/') strcat(buf, "/"); strcat(buf, b); return buf; } int isdir(char *s) { ulong m; Dir *d; if((d = dirstat(s)) == nil) return 0; m = d->mode; free(d); return (m&DMDIR) != 0; } void conflict(char *name, char *f, ...) { char *s; va_list arg; va_start(arg, f); s = vsmprint(f, arg); va_end(arg); fprint(2, "! %s: %s\n", name, s); free(s); nconf++; } void error(char *f, ...) { char *s; va_list arg; va_start(arg, f); s = vsmprint(f, arg); va_end(arg); fprint(2, "error: %s\n", s); free(s); errors = 1; } int ismatch(char *s) { int i, len; if(nmatch == 0) return 1; for(i=0; i<nmatch; i++){ len = strlen(match[i]); if(len == 0) return 1; if(strncmp(s, match[i], len) == 0 && (s[len]=='/' || s[len] == 0)) return 1; } return 0; } int localdirstat(char *name, Dir *d) { static Dir *d2; free(d2); if((d2 = dirstat(name)) == nil) return -1; *d = *d2; return 0; } enum { DEFB = 8192 }; static int cmp1(int fd1, int fd2) { char buf1[DEFB]; char buf2[DEFB]; int n1, n2; for(;;){ n1 = readn(fd1, buf1, DEFB); n2 = readn(fd2, buf2, DEFB); if(n1 < 0 || n2 < 0) return -1; if(n1 != n2) return 0; if(n1 == 0) return 1; if(memcmp(buf1, buf2, n1) != 0) return 0; } } static int copy1(int fdf, int fdt, char *from, char *to) { int i, n, rv, pid[Nwork]; Waitmsg *w; n = 0; off = 0; for(i=0; i<Nwork; i++){ switch(pid[n] = rfork(RFPROC|RFMEM)){ case 0: notify(failure); worker(fdf, fdt, from, to); case -1: break; default: n++; break; } } if(n == 0){ fprint(2, "cp: rfork: %r\n"); return -1; } rv = 0; while((w = wait()) != nil){ if(w->msg[0]){ rv = -1; for(i=0; i<n; i++) if(pid[i] > 0) postnote(PNPROC, pid[i], "failure"); } free(w); } return rv; } void worker(int fdf, int fdt, char *from, char *to) { char buf[DEFB], *bp; long len, n; vlong o; len = sizeof(buf); bp = buf; o = nextoff(); while(n = pread(fdf, bp, len, o)){ if(n < 0){ fprint(2, "reading %s: %r\n", from); _exits("bad"); } if(pwrite(fdt, buf, n, o) != n){ fprint(2, "writing %s: %r\n", to); _exits("bad"); } bp += n; o += n; len -= n; if(len == 0){ len = sizeof buf; bp = buf; o = nextoff(); } } _exits(nil); } vlong nextoff(void) { vlong o; qlock(&lk); o = off; off += DEFB; qunlock(&lk); return o; } void failure(void*, char *note) { if(strcmp(note, "failure") == 0) _exits(nil); noted(NDFLT); } static int opentemp(char *template) { int fd, i; char *p; p = estrdup(template); fd = -1; for(i=0; i<10; i++){ mktemp(p); if((fd=create(p, ORDWR|OEXCL|ORCLOSE, 0000)) >= 0) break; strcpy(p, template); } if(fd < 0) return -1; strcpy(template, p); free(p); return fd; } int copyfile(char *local, char *remote, char *name, Dir *d, int dowstat, int *printerror) { Dir *d0, *d1, *dl; Dir nd; int rfd, tfd, wfd, didcreate; char tmp[32], *p, *safe; char err[ERRMAX]; Again: *printerror = 0; if((rfd = open(remote, OREAD)) < 0) return -1; d0 = dirfstat(rfd); if(d0 == nil){ close(rfd); return -1; } *printerror = 1; if(!tempspool){ tfd = rfd; goto DoCopy; } strcpy(tmp, "/tmp/replicaXXXXXXXX"); tfd = opentemp(tmp); if(tfd < 0){ close(rfd); free(d0); return -1; } if(copy1(rfd, tfd, remote, tmp) < 0 || (d1 = dirfstat(rfd)) == nil){ close(rfd); close(tfd); free(d0); return -1; } close(rfd); if(d0->qid.path != d1->qid.path || d0->qid.vers != d1->qid.vers || d0->mtime != d1->mtime || d0->length != d1->length){ /* file changed underfoot; go around again */ close(tfd); free(d0); free(d1); goto Again; } free(d1); if(seek(tfd, 0, 0) != 0){ close(tfd); free(d0); return -1; } DoCopy: /* * clumsy but important hack to do safeinstall-like installs. */ p = strchr(name, '/'); if(safeinstall && p && strncmp(p, "/bin/", 5) == 0 && access(local, AEXIST) >= 0){ /* * remove bin/_targ */ safe = emalloc(strlen(local)+2); strcpy(safe, local); p = strrchr(safe, '/')+1; memmove(p+1, p, strlen(p)+1); p[0] = '_'; remove(safe); /* ignore failure */ /* * rename bin/targ to bin/_targ */ nulldir(&nd); nd.name = p; if(dirwstat(local, &nd) < 0) fprint(2, "warning: rename %s to %s: %r\n", local, p); } didcreate = 0; if((dl = dirstat(local)) == nil){ if((wfd = create(local, OWRITE, 0)) >= 0){ didcreate = 1; goto okay; } goto err; }else{ if((wfd = open(local, OTRUNC|OWRITE)) >= 0) goto okay; rerrstr(err, sizeof err); if(strstr(err, "permission") == nil) goto err; nulldir(&nd); /* * Assume the person running pull is in the appropriate * groups. We could set 0666 instead, but I'm worried * about leaving the file world-readable or world-writable * when it shouldn't be. */ nd.mode = dl->mode | 0660; if(nd.mode == dl->mode) goto err; if(dirwstat(local, &nd) < 0) goto err; if((wfd = open(local, OTRUNC|OWRITE)) >= 0){ nd.mode = dl->mode; if(dirfwstat(wfd, &nd) < 0) fprint(2, "warning: set mode on %s to 0660 to open; cannot set back to %luo: %r\n", local, nd.mode); goto okay; } nd.mode = dl->mode; if(dirwstat(local, &nd) < 0) fprint(2, "warning: set mode on %s to %luo to open; open failed; cannot set mode back to %luo: %r\n", local, nd.mode|0660, nd.mode); goto err; } err: close(tfd); free(d0); free(dl); return -1; okay: free(dl); if(copy1(tfd, wfd, tmp, local) < 0){ close(tfd); close(wfd); free(d0); return -1; } close(tfd); if(didcreate || dowstat){ nulldir(&nd); nd.mode = d->mode; if(dirfwstat(wfd, &nd) < 0) fprint(2, "warning: cannot set mode on %s\n", local); nulldir(&nd); nd.gid = d->gid; if(dirfwstat(wfd, &nd) < 0) fprint(2, "warning: cannot set gid on %s\n", local); if(douid){ nulldir(&nd); nd.uid = d->uid; if(dirfwstat(wfd, &nd) < 0) fprint(2, "warning: cannot set uid on %s\n", local); } } d->mtime = d0->mtime; d->length = d0->length; nulldir(&nd); nd.mtime = d->mtime; if(dirfwstat(wfd, &nd) < 0) fprint(2, "warning: cannot set mtime on %s\n", local); free(d0); close(wfd); return 0; } int samecontents(char *local, char *remote) { Dir *d0, *d1; int rfd, tfd, lfd, ret; char tmp[32]; /* quick check: sizes must match */ d1 = nil; if((d0 = dirstat(local)) == nil || (d1 = dirstat(remote)) == nil){ free(d0); free(d1); return -1; } if(d0->length != d1->length){ free(d0); free(d1); return 0; } Again: if((rfd = open(remote, OREAD)) < 0) return -1; d0 = dirfstat(rfd); if(d0 == nil){ close(rfd); return -1; } strcpy(tmp, "/tmp/replicaXXXXXXXX"); tfd = opentemp(tmp); if(tfd < 0){ close(rfd); free(d0); return -1; } if(copy1(rfd, tfd, remote, tmp) < 0 || (d1 = dirfstat(rfd)) == nil){ close(rfd); close(tfd); free(d0); return -1; } close(rfd); if(d0->qid.path != d1->qid.path || d0->qid.vers != d1->qid.vers || d0->mtime != d1->mtime || d0->length != d1->length){ /* file changed underfoot; go around again */ close(tfd); free(d0); free(d1); goto Again; } free(d1); free(d0); if(seek(tfd, 0, 0) != 0){ close(tfd); return -1; } /* * now compare */ if((lfd = open(local, OREAD)) < 0){ close(tfd); return -1; } ret = cmp1(lfd, tfd); close(lfd); close(tfd); return ret; } /* * Applylog might try to overwrite itself. * To avoid problems with this, we copy ourselves * into /tmp and then re-exec. */ char *rmargv0; static void rmself(void) { remove(rmargv0); } static int genopentemp(char *template, int mode, int perm) { int fd, i; char *p; p = estrdup(template); fd = -1; for(i=0; i<10; i++){ mktemp(p); if(access(p, 0) < 0 && (fd=create(p, mode, perm)) >= 0) break; strcpy(p, template); } if(fd < 0) sysfatal("could not create temporary file"); strcpy(template, p); free(p); return fd; } static void membogus(char **argv) { int n, fd, wfd; char template[50], buf[1024]; if(strncmp(argv[0], "/tmp/_applylog_", 1+3+1+1+8+1)==0) { rmargv0 = argv[0]; atexit(rmself); return; } if((fd = open(argv[0], OREAD)) < 0) return; strcpy(template, "/tmp/_applylog_XXXXXX"); if((wfd = genopentemp(template, OWRITE, 0700)) < 0) return; while((n = read(fd, buf, sizeof buf)) > 0) if(write(wfd, buf, n) != n) goto Error; if(n != 0) goto Error; close(fd); close(wfd); argv[0] = template; exec(template, argv); fprint(2, "exec error %r\n"); Error: close(fd); close(wfd); remove(template); return; }