fsync,sync: make them similar
authorDenys Vlasenko <vda.linux@googlemail.com>
Tue, 2 Apr 2019 12:39:56 +0000 (14:39 +0200)
committerDenys Vlasenko <vda.linux@googlemail.com>
Tue, 2 Apr 2019 12:39:56 +0000 (14:39 +0200)
sync: add O_NOCTTY
fsync: drop O_NOATIME, add O_NONBLOCK, set exitcode to 1 if fsync() fails,
    update --help message to be similar to sync.
both: reformat code to minimize "diff -u sync.c fsync.c":
    in particular, they use same open() flags now

function                                             old     new   delta
fsync_main                                           126     130      +4
packed_usage                                       33316   33317      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 5/0)                 Total: 5 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
coreutils/fsync.c
coreutils/sync.c

index c7cba9f610d083bccde4ba7c7463e3d7e6ce49c3..216cbcf415da9ae55154a3a1971e66f09c88bb2b 100644 (file)
@@ -12,6 +12,7 @@
 //config:      help
 //config:      fsync is used to flush file-related cached blocks to disk.
 
+//                APPLET_NOFORK:name   main   location    suid_type     help
 //applet:IF_FSYNC(APPLET_NOFORK(fsync, fsync, BB_DIR_BIN, BB_SUID_DROP, fsync))
 
 //kbuild:lib-$(CONFIG_FSYNC) += fsync.o
 //usage:#define fsync_trivial_usage
 //usage:       "[-d] FILE..."
 //usage:#define fsync_full_usage "\n\n"
-//usage:       "Write files' buffered blocks to disk\n"
+//usage:       "Write all buffered blocks in FILEs to disk\n"
 //usage:     "\n       -d      Avoid syncing metadata"
 
 #include "libbb.h"
-#ifndef O_NOATIME
-# define O_NOATIME 0
-#endif
 
 /* This is a NOFORK applet. Be very careful! */
 
 int fsync_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int fsync_main(int argc UNUSED_PARAM, char **argv)
 {
-       int status;
+       int ret;
        int opts;
 
        opts = getopt32(argv, "d"); /* fdatasync */
@@ -41,20 +39,24 @@ int fsync_main(int argc UNUSED_PARAM, char **argv)
                bb_show_usage();
        }
 
-       status = EXIT_SUCCESS;
+       ret = EXIT_SUCCESS;
        do {
-               int fd = open_or_warn(*argv, O_NOATIME | O_NOCTTY | O_RDONLY);
+               /* GNU "sync FILE" uses O_NONBLOCK open */
+               int fd = open_or_warn(*argv, /*O_NOATIME |*/ O_NOCTTY | O_RDONLY | O_NONBLOCK);
+               /* open(NOATIME) can only be used by owner or root, don't use NOATIME here */
 
-               if (fd == -1) {
-                       status = EXIT_FAILURE;
-                       continue;
+               if (fd < 0) {
+                       ret = EXIT_FAILURE;
+                       goto next;
                }
-               if ((opts ? fdatasync(fd) : fsync(fd))) {
-                       //status = EXIT_FAILURE; - do we want this?
+               if ((opts ? fdatasync(fd) : fsync(fd)) != 0) {
                        bb_simple_perror_msg(*argv);
+                       ret = EXIT_FAILURE;
                }
                close(fd);
-       } while (*++argv);
+ next:
+               argv++;
+       } while (*argv);
 
-       return status;
+       return ret;
 }
index b93476aee3c4ccf7e7af770843466e7b7a807345..e60e553a34dee15bdb0dfd6a6374cbb5f7d5f028 100644 (file)
@@ -20,6 +20,7 @@
 //config:      sync -d FILE... executes fdatasync() on each FILE.
 //config:      sync -f FILE... executes syncfs() on each FILE.
 
+//               APPLET_NOFORK:name  main  location    suid_type     help
 //applet:IF_SYNC(APPLET_NOFORK(sync, sync, BB_DIR_BIN, BB_SUID_DROP, sync))
 
 //kbuild:lib-$(CONFIG_SYNC) += sync.o
@@ -52,7 +53,7 @@ int sync_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
        return EXIT_SUCCESS;
 #else
        unsigned opts;
-       int ret = EXIT_SUCCESS;
+       int ret;
 
        enum {
                OPT_DATASYNC = (1 << 0),
@@ -66,35 +67,30 @@ int sync_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
        if (!argv[0])
                sync();
 
+       ret = EXIT_SUCCESS;
        while (*argv) {
-               int fd = open_or_warn(*argv, O_RDONLY);
+               /* GNU "sync FILE" uses O_NONBLOCK open */
+               int fd = open_or_warn(*argv, /*O_NOATIME |*/ O_NOCTTY | O_RDONLY | O_NONBLOCK);
+               /* open(NOATIME) can only be used by owner or root, don't use NOATIME here */
 
                if (fd < 0) {
                        ret = EXIT_FAILURE;
                        goto next;
                }
-               if (opts & OPT_DATASYNC) {
-                       if (fdatasync(fd))
-                               goto err;
-                       goto do_close;
-               }
                if (opts & OPT_SYNCFS) {
                        /*
                         * syncfs is documented to only fail with EBADF,
                         * which can't happen here. So, no error checks.
                         */
                        syncfs(fd);
-                       goto do_close;
-               }
-               if (fsync(fd)) {
- err:
+               } else
+               if (((opts & OPT_DATASYNC) ? fdatasync(fd) : fsync(fd)) != 0) {
                        bb_simple_perror_msg(*argv);
                        ret = EXIT_FAILURE;
                }
- do_close:
                close(fd);
  next:
-               ++argv;
+               argv++;
        }
 
        return ret;