From d0cc3f4ade36a651ada0001b18bcd04ada8d44a1 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 24 Jun 2008 18:59:59 +0000 Subject: [PATCH] mount: code shrink without logic changes. Added a comment on possible mismatch with util-linux in -o remount handling. function old new delta mount_main 995 953 -42 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-42) Total: -42 bytes --- util-linux/mount.c | 186 +++++++++++++++++++++------------------------ 1 file changed, 87 insertions(+), 99 deletions(-) diff --git a/util-linux/mount.c b/util-linux/mount.c index de0558024..61ad23528 100644 --- a/util-linux/mount.c +++ b/util-linux/mount.c @@ -407,7 +407,7 @@ static int mount_it_now(struct mntent *mp, long vfsflags, char *filteropts) vfsflags, filteropts); // If mount failed, try - // helper program + // helper program mount. if (ENABLE_FEATURE_MOUNT_HELPERS && rc) { char *args[6]; int errno_save = errno; @@ -1727,11 +1727,11 @@ static int singlemount(struct mntent *mp, int ignore_busy) static const char must_be_root[] ALIGN1 = "you must be root"; int mount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int mount_main(int argc, char **argv) +int mount_main(int argc ATTRIBUTE_UNUSED, char **argv) { char *cmdopts = xstrdup(""); char *fstype = NULL; - char *storage_path = NULL; + char *storage_path; char *opt_o; const char *fstabname; FILE *fstab; @@ -1740,43 +1740,35 @@ int mount_main(int argc, char **argv) struct mntent mtpair[2], *mtcur = mtpair; SKIP_DESKTOP(const int nonroot = 0;) - USE_DESKTOP( int nonroot = ) sanitize_env_if_suid(); + USE_DESKTOP(int nonroot = ) sanitize_env_if_suid(); // Parse long options, like --bind and --move. Note that -o option // and --option are synonymous. Yes, this means --remount,rw works. - - for (i = j = 0; i < argc; i++) { - if (argv[i][0] == '-' && argv[i][1] == '-') { - append_mount_options(&cmdopts, argv[i]+2); - } else argv[j++] = argv[i]; + for (i = j = 1; argv[i]; i++) { + if (argv[i][0] == '-' && argv[i][1] == '-') + append_mount_options(&cmdopts, argv[i] + 2); + else + argv[j++] = argv[i]; } argv[j] = NULL; - argc = j; // Parse remaining options - -#if ENABLE_FEATURE_MOUNT_VERBOSE - opt_complementary = "vv"; // -v is a counter -#endif + // Max 2 params; -v is a counter + opt_complementary = "?2" USE_FEATURE_MOUNT_VERBOSE(":vv"); opt = getopt32(argv, OPTION_STR, &opt_o, &fstype USE_FEATURE_MOUNT_VERBOSE(, &verbose)); if (opt & OPT_o) append_mount_options(&cmdopts, opt_o); // -o if (opt & OPT_r) append_mount_options(&cmdopts, "ro"); // -r if (opt & OPT_w) append_mount_options(&cmdopts, "rw"); // -w argv += optind; - argc -= optind; - - // Three or more non-option arguments? Die with a usage message. - - if (argc > 2) bb_show_usage(); // If we have no arguments, show currently mounted filesystems - - if (!argc) { + if (!argv[0]) { if (!(opt & OPT_a)) { FILE *mountTable = setmntent(bb_path_mtab_file, "r"); - if (!mountTable) bb_error_msg_and_die("no %s", bb_path_mtab_file); + if (!mountTable) + bb_error_msg_and_die("no %s", bb_path_mtab_file); while (getmntent_r(mountTable, &mtpair[0], getmntent_buf, GETMNTENT_BUFSIZE)) @@ -1790,152 +1782,148 @@ int mount_main(int argc, char **argv) mtpair->mnt_dir, mtpair->mnt_type, mtpair->mnt_opts); } - if (ENABLE_FEATURE_CLEAN_UP) endmntent(mountTable); + if (ENABLE_FEATURE_CLEAN_UP) + endmntent(mountTable); return EXIT_SUCCESS; } - } else storage_path = bb_simplify_path(argv[0]); - - // When we have two arguments, the second is the directory and we can - // skip looking at fstab entirely. We can always abspath() the directory - // argument when we get it. - - if (argc == 2) { - if (nonroot) - bb_error_msg_and_die(must_be_root); - mtpair->mnt_fsname = argv[0]; - mtpair->mnt_dir = argv[1]; - mtpair->mnt_type = fstype; - mtpair->mnt_opts = cmdopts; - if (ENABLE_FEATURE_MOUNT_LABEL) { - resolve_mount_spec(&mtpair->mnt_fsname); + storage_path = NULL; + } else { + // When we have two arguments, the second is the directory and we can + // skip looking at fstab entirely. We can always abspath() the directory + // argument when we get it. + if (argv[1]) { + if (nonroot) + bb_error_msg_and_die(must_be_root); + mtpair->mnt_fsname = argv[0]; + mtpair->mnt_dir = argv[1]; + mtpair->mnt_type = fstype; + mtpair->mnt_opts = cmdopts; + if (ENABLE_FEATURE_MOUNT_LABEL) { + resolve_mount_spec(&mtpair->mnt_fsname); + } + rc = singlemount(mtpair, 0); + return rc; } - rc = singlemount(mtpair, 0); - goto clean_up; + storage_path = bb_simplify_path(argv[0]); // malloced } + // Past this point, we are handling either "mount -a [opts]" + // or "mount [opts] single_param" + i = parse_mount_options(cmdopts, 0); // FIXME: should be "long", not "int" if (nonroot && (i & ~MS_SILENT)) // Non-root users cannot specify flags bb_error_msg_and_die(must_be_root); // If we have a shared subtree flag, don't worry about fstab or mtab. - if (ENABLE_FEATURE_MOUNT_FLAGS && (i & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) ) { - rc = verbose_mount("", argv[0], "", i, ""); - if (rc) bb_simple_perror_msg_and_die(argv[0]); - goto clean_up; + rc = verbose_mount(/*source:*/ "", /*target:*/ argv[0], + /*type:*/ "", /*flags:*/ i, /*data:*/ ""); + if (rc) + bb_simple_perror_msg_and_die(argv[0]); + return rc; } // Open either fstab or mtab - fstabname = "/etc/fstab"; if (i & MS_REMOUNT) { + // WARNING. I am not sure this matches util-linux's + // behavior. It's possible util-linux does not + // take -o opts from mtab (takes only mount source). fstabname = bb_path_mtab_file; } fstab = setmntent(fstabname, "r"); if (!fstab) bb_perror_msg_and_die("cannot read %s", fstabname); - // Loop through entries until we find what we're looking for. - + // Loop through entries until we find what we're looking for memset(mtpair, 0, sizeof(mtpair)); for (;;) { - struct mntent *mtnext = (mtcur==mtpair ? mtpair+1 : mtpair); + struct mntent *mtother = (mtcur==mtpair ? mtpair+1 : mtpair); // Get next fstab entry - if (!getmntent_r(fstab, mtcur, getmntent_buf + (mtcur==mtpair ? GETMNTENT_BUFSIZE/2 : 0), - GETMNTENT_BUFSIZE/2)) - { - // Were we looking for something specific? - - if (argc) { - - // If we didn't find anything, complain. - - if (!mtnext->mnt_fsname) - bb_error_msg_and_die("can't find %s in %s", - argv[0], fstabname); - - mtcur = mtnext; - if (nonroot) { - // fstab must have "users" or "user" - if (!(parse_mount_options(mtcur->mnt_opts, 0) & MOUNT_USERS)) - bb_error_msg_and_die(must_be_root); - } - - // Mount the last thing we found. - - mtcur->mnt_opts = xstrdup(mtcur->mnt_opts); - append_mount_options(&(mtcur->mnt_opts), cmdopts); - if (ENABLE_FEATURE_MOUNT_LABEL) { - resolve_mount_spec(&mtpair->mnt_fsname); - } - rc = singlemount(mtcur, 0); - free(mtcur->mnt_opts); - } - goto clean_up; + GETMNTENT_BUFSIZE/2) + ) { // End of fstab/mtab is reached + mtcur = mtother; // the thing we found last time + break; } - /* If we're trying to mount something specific and this isn't it, - * skip it. Note we must match both the exact text in fstab (ala - * "proc") or a full path from root */ - - if (argc) { + // If we're trying to mount something specific and this isn't it, + // skip it. Note we must match the exact text in fstab (ala + // "proc") or a full path from root + if (argv[0]) { // Is this what we're looking for? - if (strcmp(argv[0], mtcur->mnt_fsname) && strcmp(storage_path, mtcur->mnt_fsname) && strcmp(argv[0], mtcur->mnt_dir) && strcmp(storage_path, mtcur->mnt_dir)) continue; - // Remember this entry. Something later may have overmounted - // it, and we want the _last_ match. - - mtcur = mtnext; - - // If we're mounting all. + // Remember this entry. Something later may have + // overmounted it, and we want the _last_ match. + mtcur = mtother; + // If we're mounting all } else { // Do we need to match a filesystem type? if (fstype && match_fstype(mtcur, fstype)) continue; // Skip noauto and swap anyway. - if (parse_mount_options(mtcur->mnt_opts, 0) & (MOUNT_NOAUTO | MOUNT_SWAP)) continue; // No, mount -a won't mount anything, - // even user mounts, for mere humans. - + // even user mounts, for mere humans if (nonroot) bb_error_msg_and_die(must_be_root); - // Mount this thing. + // Mount this thing if (ENABLE_FEATURE_MOUNT_LABEL) resolve_mount_spec(&mtpair->mnt_fsname); // NFS mounts want this to be xrealloc-able mtcur->mnt_opts = xstrdup(mtcur->mnt_opts); if (singlemount(mtcur, 1)) { - /* Count number of failed mounts */ + // Count number of failed mounts rc++; } free(mtcur->mnt_opts); } } - if (ENABLE_FEATURE_CLEAN_UP) endmntent(fstab); - clean_up: + // End of fstab/mtab is reached. + // Were we looking for something specific? + if (argv[0]) { + // If we didn't find anything, complain + if (!mtcur->mnt_fsname) + bb_error_msg_and_die("can't find %s in %s", + argv[0], fstabname); + if (nonroot) { + // fstab must have "users" or "user" + if (!(parse_mount_options(mtcur->mnt_opts, 0) & MOUNT_USERS)) + bb_error_msg_and_die(must_be_root); + } + // Mount the last thing we found + mtcur->mnt_opts = xstrdup(mtcur->mnt_opts); + append_mount_options(&(mtcur->mnt_opts), cmdopts); + if (ENABLE_FEATURE_MOUNT_LABEL) { + resolve_mount_spec(&mtpair->mnt_fsname); + } + rc = singlemount(mtcur, 0); + if (ENABLE_FEATURE_CLEAN_UP) + free(mtcur->mnt_opts); + } + + if (ENABLE_FEATURE_CLEAN_UP) + endmntent(fstab); if (ENABLE_FEATURE_CLEAN_UP) { free(storage_path); free(cmdopts); } - return rc; }