/*------------------------------------------------------------------------- * * dirmod.c * rename/unlink() * * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * These are replacement versions of unlink and rename that work on * Win32 (NT, Win2k, XP). replace() doesn't work on Win95/98/Me. * * IDENTIFICATION * $PostgreSQL: pgsql/src/port/dirmod.c,v 1.13 2004/08/01 06:19:26 momjian Exp $ * *------------------------------------------------------------------------- */ #ifndef FRONTEND #include "postgres.h" #else #include "postgres_fe.h" #endif #include #include #include #define _(x) gettext((x)) #ifndef TEST_VERSION #if defined(WIN32) || defined(__CYGWIN__) #include "miscadmin.h" #undef rename #undef unlink int pgrename(const char *from, const char *to) { int loops = 0; #ifdef WIN32 while (!MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING)) #endif #ifdef __CYGWIN__ while (rename(from, to) < 0) #endif { #ifdef WIN32 if (GetLastError() != ERROR_ACCESS_DENIED) #endif #ifdef __CYGWIN__ if (errno != EACCES) #endif /* set errno? */ return -1; pg_usleep(100000); /* us */ if (loops == 30) #ifndef FRONTEND elog(LOG, "could not rename \"%s\" to \"%s\", continuing to try", from, to); #else fprintf(stderr, "could not rename \"%s\" to \"%s\", continuing to try\n", from, to); #endif loops++; } if (loops > 30) #ifndef FRONTEND elog(LOG, "completed rename of \"%s\" to \"%s\"", from, to); #else fprintf(stderr, "completed rename of \"%s\" to \"%s\"\n", from, to); #endif return 0; } int pgunlink(const char *path) { int loops = 0; while (unlink(path)) { if (errno != EACCES) /* set errno? */ return -1; pg_usleep(100000); /* us */ if (loops == 30) #ifndef FRONTEND elog(LOG, "could not unlink \"%s\", continuing to try", path); #else fprintf(stderr, "could not unlink \"%s\", continuing to try\n", path); #endif loops++; } if (loops > 30) #ifndef FRONTEND elog(LOG, "completed unlink of \"%s\"", path); #else fprintf(stderr, "completed unlink of \"%s\"\n", path); #endif return 0; } #endif #if defined(WIN32) || defined(__CYGWIN__) #define rmt_unlink(path) pgunlink(path) #else #define rmt_unlink(path) unlink(path) #endif #ifdef FRONTEND static void * xmalloc(size_t size) { void *result; result = malloc(size); if (!result) { fprintf(stderr, _("out of memory\n")); exit(1); } return result; } static char * xstrdup(const char *s) { char *result; result = strdup(s); if (!result) { fprintf(stderr, _("out of memory\n")); exit(1); } return result; } #define xfree(n) free(n) #else /* on the backend, use palloc and friends */ #define xmalloc(n) palloc(n) #define xstrdup(n) pstrdup(n) #define xfree(n) pfree(n) #endif /* * deallocate memory used for filenames */ static void rmt_cleanup(char ** filenames) { char ** fn; for (fn = filenames; *fn; fn++) xfree(*fn); xfree(filenames); } /* * delete a directory tree recursively * assumes path points to a valid directory * deletes everything under path * if rmtopdir is true deletes the directory too * */ bool rmtree(char *path, bool rmtopdir) { char filepath[MAXPGPATH]; DIR *dir; struct dirent *file; char **filenames; char **filename; int numnames = 0; struct stat statbuf; /* * we copy all the names out of the directory before we start * modifying it. */ dir = opendir(path); if (dir == NULL) return false; while ((file = readdir(dir)) != NULL) { if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0) numnames++; } rewinddir(dir); filenames = xmalloc((numnames + 2) * sizeof(char *)); numnames = 0; while ((file = readdir(dir)) != NULL) { if (strcmp(file->d_name, ".") != 0 && strcmp(file->d_name, "..") != 0) filenames[numnames++] = xstrdup(file->d_name); } filenames[numnames] = NULL; closedir(dir); /* now we have the names we can start removing things */ for (filename = filenames; *filename; filename++) { snprintf(filepath, MAXPGPATH, "%s/%s", path, *filename); if (stat(filepath, &statbuf) != 0) { rmt_cleanup(filenames); return false; } if (S_ISDIR(statbuf.st_mode)) { /* call ourselves recursively for a directory */ if (!rmtree(filepath, true)) { rmt_cleanup(filenames); return false; } } else { if (rmt_unlink(filepath) != 0) { rmt_cleanup(filenames); return false; } } } if (rmtopdir) { if (rmdir(path) != 0) { rmt_cleanup(filenames); return false; } } rmt_cleanup(filenames); return true; } #else /* * Illustrates problem with Win32 rename() and unlink() * under concurrent access. * * Run with arg '1', then less than 5 seconds later, run with * arg '2' (rename) or '3'(unlink) to see the problem. */ #include #include #include #include #define halt(str) \ do { \ fputs(str, stderr); \ exit(1); \ } while (0) int main(int argc, char *argv[]) { FILE *fd; if (argc != 2) halt("Arg must be '1' (test), '2' (rename), or '3' (unlink)\n" "Run '1' first, then less than 5 seconds later, run\n" "'2' to test rename, or '3' to test unlink.\n"); if (atoi(argv[1]) == 1) { if ((fd = fopen("/rtest.txt", "w")) == NULL) halt("Can not create file\n"); fclose(fd); if ((fd = fopen("/rtest.txt", "r")) == NULL) halt("Can not open file\n"); Sleep(5000); } else if (atoi(argv[1]) == 2) { unlink("/rtest.new"); if ((fd = fopen("/rtest.new", "w")) == NULL) halt("Can not create file\n"); fclose(fd); while (!MoveFileEx("/rtest.new", "/rtest.txt", MOVEFILE_REPLACE_EXISTING)) { if (GetLastError() != ERROR_ACCESS_DENIED) halt("Unknown failure\n"); else fprintf(stderr, "move failed\n"); Sleep(500); } halt("move successful\n"); } else if (atoi(argv[1]) == 3) { while (unlink("/rtest.txt")) { if (errno != EACCES) halt("Unknown failure\n"); else fprintf(stderr, "unlink failed\n"); Sleep(500); } halt("unlink successful\n"); } else halt("invalid arg\n"); return 0; } #endif