fsync.c

   1 #include "compat-util.h"
   2 #include <dirent.h>
   3 #include <libgen.h>
   4
   5 #if defined(_POSIX_SYNCHRONIZED_IO) && _POSIX_SYNCHRONIZED_IO > 0
   6 static int have_fdatasync = 1;
   7 #else
   8 static int have_fdatasync;
   9 #endif
  10
  11 /* TODO: sync_file_range() if on Linux */
  12
  13 static int usage(const char * argv0)
  14 {
  15         fprintf(stderr, "Usage: %s [-d] [-D] FILE...\n", argv0);
  16         return 1;
  17 }
  18
  19 static int do_sync(const char *path, int data_only, int directory)
  20 {
  21         int fd;
  22         const char *errfunc = "";
  23
  24         if ((fd = open(path, O_RDWR|O_NOATIME)) < 0) {
  25                 if (errno == EISDIR) {
  26                         directory = 1;
  27                         goto sync_dir;
  28                 }
  29                 errfunc = "open";
  30                 goto err;
  31         }
  32
  33         if (data_only && have_fdatasync) {
  34                 if (fdatasync(fd) < 0) {
  35                         errfunc = "fdatasync";
  36                         goto err;
  37                 }
  38         } else {
  39                 if (fsync(fd) < 0) {
  40                         errfunc = "fsync";
  41                         goto err;
  42                 }
  43         }
  44
  45         if (close(fd) < 0) {
  46                 errfunc = "close";
  47                 goto err;
  48         }
  49
  50 sync_dir:
  51         if (directory) {
  52                 char *dpath;
  53                 DIR *dir;
  54
  55                 if (!(dpath = strdup(path))){
  56                         errfunc = "strdup";
  57                         goto err;
  58                 }
  59                 if (!(dir = opendir(dirname(dpath)))) {
  60                         errfunc = "opendir";
  61                         goto err;
  62                 }
  63                 if (fsync(dirfd(dir)) < 0) {
  64                         errfunc = "(directory) fsync";
  65                         goto err;
  66                 }
  67                 if (closedir(dir) < 0) {
  68                         errfunc = "closedir";
  69                         goto err;
  70                 }
  71                 free(dpath);
  72         }
  73
  74         return 0;
  75 err:
  76         fprintf(stderr, "%s: %s(): %s\n", path, errfunc, strerror(errno));
  77         return -1;
  78 }
  79
  80 int main(int argc, char * const argv[])
  81 {
  82         int data_only = 0;
  83         int directory = 0;
  84         int opt;
  85         int argi = 1;
  86
  87         while ((opt = getopt(argc, argv, "dD")) != -1) {
  88                 ++argi;
  89                 switch(opt) {
  90                 case 'd':
  91                         data_only = 1;
  92                         break;
  93                 case 'D':
  94                         directory = 1;
  95                         break;
  96                 default:
  97                         return usage(argv[0]);
  98                 }
  99         }
 100
 101         if (argi >= argc)
 102                 return usage(argv[0]);
 103
 104         for (; argi < argc; ++argi) {
 105                 if (do_sync(argv[argi], data_only, directory) < 0)
 106                         return 1;
 107         }
 108
 109         return 0;
 110 }