diff options
Diffstat (limited to 'utils/mount/mount_libmount.c')
| -rw-r--r-- | utils/mount/mount_libmount.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/utils/mount/mount_libmount.c b/utils/mount/mount_libmount.c new file mode 100644 index 0000000..aa4ac5c --- /dev/null +++ b/utils/mount/mount_libmount.c @@ -0,0 +1,461 @@ +/* + * mount_libmount.c -- Linux NFS [u]mount based on libmount + * + * Copyright (C) 2011 Karel Zak <kzak@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 0211-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <getopt.h> +#include <libgen.h> + +#include <libmount/libmount.h> + +#include "nls.h" +#include "mount_config.h" + +#include "nfs_mount.h" +#include "nfs4_mount.h" +#include "stropts.h" +#include "version.h" +#include "xcommon.h" + +#include "error.h" +#include "utils.h" + +char *retrieve_mount_options(struct libmnt_fs *fs); + +char *progname; +int nfs_mount_data_version; +int verbose; +int sloppy; +int string; +int nomtab; + +#define FOREGROUND (0) +#define BACKGROUND (1) + +/* + * Store mount options to mtab (or /dev/.mount/utab), called from mount.nfs. + * + * Note that on systems without /etc/mtab the fs-specific options are not + * managed by libmount at all. We have to use "mount attributes" that are + * private for mount.<type> helpers. + */ +static void store_mount_options(struct libmnt_fs *fs, const char *nfs_opts) +{ + char *o = NULL; + + mnt_fs_set_attributes(fs, nfs_opts); /* for non-mtab systems */ + + /* for mtab create a new options list */ + mnt_optstr_append_option(&o, mnt_fs_get_vfs_options(fs), NULL); + mnt_optstr_append_option(&o, nfs_opts, NULL); + mnt_optstr_append_option(&o, mnt_fs_get_user_options(fs), NULL); + + mnt_fs_set_options(fs, o); + free(o); +} + +/* + * Retrieve mount options from mtab (or /dev/.mount/utab) called from umount.nfs. + * + * The result can passed to free(). + */ +char *retrieve_mount_options(struct libmnt_fs *fs) +{ + const char *opts; + + if (!fs) + return NULL; + + opts = mnt_fs_get_attributes(fs); /* /dev/.mount/utab */ + if (opts) + return strdup(opts); + + return mnt_fs_strdup_options(fs); /* /etc/mtab */ +} + +static int try_mount(struct libmnt_context *cxt, int bg) +{ + struct libmnt_fs *fs; + const char *p; + char *src = NULL, *tgt = NULL, *type = NULL, *opts = NULL; + unsigned long flags = 0; + int fake, ret = 0; + + fs = mnt_context_get_fs(cxt); + + /* libmount returns read-only pointers (const char) + * so, reallocate for nfsmount() functions. + */ + if ((p = mnt_fs_get_source(fs))) /* spec */ + src = strdup(p); + if ((p = mnt_fs_get_target(fs))) /* mountpoint */ + tgt = strdup(p); + if ((p = mnt_fs_get_fstype(fs))) /* FS type */ + type = strdup(p); + if ((p = mnt_fs_get_fs_options(fs))) /* mount options */ + opts = strdup(p); + + mnt_context_get_mflags(cxt, &flags); /* mount(2) flags */ + fake = mnt_context_is_fake(cxt); + + if (string) + ret = nfsmount_string(src, tgt, type, flags, &opts, fake, bg); + + else if (strcmp(type, "nfs4") == 0) + ret = nfs4mount(src, tgt, flags, &opts, fake, bg); + else + ret = nfsmount(src, tgt, flags, &opts, fake, bg); + + /* Store mount options if not called with mount --no-mtab */ + if (!ret && !mnt_context_is_nomtab(cxt)) + store_mount_options(fs, opts); + + free(src); + free(tgt); + free(type); + free(opts); + + return ret; +} + +/* returns: error = -1, success = 1 , not vers4 == 0 */ +static int is_vers4(struct libmnt_context *cxt) +{ + struct libmnt_fs *fs = mnt_context_get_fs(cxt); + struct libmnt_table *tb = NULL; + const char *src = mnt_context_get_source(cxt), + *tgt = mnt_context_get_target(cxt); + int rc = 0; + + if (!src || !tgt) + return -1; + + if (!mnt_fs_is_kernel(fs)) { + struct libmnt_table *tb = mnt_new_table_from_file("/proc/mounts"); + + if (!tb) + return -1; + fs = mnt_table_find_pair(tb, src, tgt, MNT_ITER_BACKWARD); + } + + if (fs) { + const char *type = mnt_fs_get_fstype(fs); + if (type && strcmp(type, "nfs4") == 0) + rc = 1; + } + mnt_free_table(tb); + return rc; +} + +static int umount_main(struct libmnt_context *cxt, int argc, char **argv) +{ + int rc, c; + char *spec = NULL, *opts = NULL; + int ret = EX_FAIL, verbose = 0; + + static const struct option longopts[] = { + { "force", 0, 0, 'f' }, + { "help", 0, 0, 'h' }, + { "no-mtab", 0, 0, 'n' }, + { "verbose", 0, 0, 'v' }, + { "read-only", 0, 0, 'r' }, + { "lazy", 0, 0, 'l' }, + { "types", 1, 0, 't' }, + { NULL, 0, 0, 0 } + }; + + mnt_context_init_helper(cxt, MNT_ACT_UMOUNT, 0); + mnt_context_disable_canonicalize(cxt, 1); + + while ((c = getopt_long (argc, argv, "fvnrlh", longopts, NULL)) != -1) { + + rc = mnt_context_helper_setopt(cxt, c, optarg); + if (rc == 0) /* valid option */ + continue; + if (rc < 0) /* error (probably ENOMEM) */ + goto err; + /* rc==1 means unknow option */ + umount_usage(); + return EX_USAGE; + } + + verbose = mnt_context_is_verbose(cxt); + + if (optind < argc) + spec = argv[optind++]; + + if (!spec || (*spec != '/' && strchr(spec,':') == NULL)) { + nfs_error(_("%s: no mount point provided"), progname); + umount_usage(); + return EX_USAGE; + } + + if (mnt_context_set_target(cxt, spec)) + goto err; + + /* read mtab/fstab, evaluate permissions, etc. */ + rc = mnt_context_prepare_umount(cxt); + if (rc) { + nfs_error(_("%s: failed to prepare umount: %s\n"), + progname, strerror(-rc)); + goto err; + } + + if (mnt_context_get_fstype(cxt) && + !mnt_match_fstype(mnt_context_get_fstype(cxt), "nfs,nfs4")) { + + nfs_error(_("%s: %s: is not an NFS filesystem"), progname, spec); + ret = EX_USAGE; + goto err; + } + + if (verbose) + printf(_("%s: %s mount point detected\n"), spec, + mnt_context_get_fstype(cxt)); + + opts = retrieve_mount_options(mnt_context_get_fs(cxt)); + + if (!mnt_context_is_lazy(cxt)) { + if (opts) { + /* we have full FS description (e.g. from mtab or /proc) */ + switch (is_vers4(cxt)) { + case 0: + /* We ignore the error from nfs_umount23. + * If the actual umount succeeds (in del_mtab), + * we don't want to signal an error, as that + * could cause /sbin/mount to retry! + */ + nfs_umount23(mnt_context_get_source(cxt), opts); + break; + case 1: /* unknown */ + break; + default: /* error */ + goto err; + } + } else + /* strange, no entry in mtab or /proc not mounted */ + nfs_umount23(spec, "tcp,v3"); + } + + ret = EX_FILEIO; + rc = mnt_context_do_umount(cxt); /* call umount(2) syscall */ + mnt_context_finalize_mount(cxt); /* mtab update */ + + if (rc && !mnt_context_get_status(cxt)) { + /* mnt_context_do_umount() returns errno if umount(2) failed */ + umount_error(rc, spec); + goto err; + } + ret = EX_SUCCESS; +err: + if (verbose) { + if (ret == EX_SUCCESS) + printf(_("%s: umounted\n"), spec); + else + printf(_("%s: umount failed\n"), spec); + } + free(opts); + return ret; +} + +static int mount_main(struct libmnt_context *cxt, int argc, char **argv) +{ + int rc, c; + struct libmnt_fs *fs; + char *spec = NULL, *mount_point = NULL, *opts = NULL; + + static const struct option longopts[] = { + { "fake", 0, 0, 'f' }, + { "help", 0, 0, 'h' }, + { "no-mtab", 0, 0, 'n' }, + { "read-only", 0, 0, 'r' }, + { "ro", 0, 0, 'r' }, + { "verbose", 0, 0, 'v' }, + { "version", 0, 0, 'V' }, + { "read-write", 0, 0, 'w' }, + { "rw", 0, 0, 'w' }, + { "options", 1, 0, 'o' }, + { "sloppy", 0, 0, 's' }, + { NULL, 0, 0, 0 } + }; + + mount_config_init(progname); + mnt_context_init_helper(cxt, MNT_ACT_MOUNT, 0); + + while ((c = getopt_long(argc, argv, "fhnrVvwo:s", longopts, NULL)) != -1) { + + rc = mnt_context_helper_setopt(cxt, c, optarg); + if (rc == 0) /* valid option */ + continue; + if (rc < 0) /* error (probably ENOMEM) */ + goto err; + /* rc==1 means unknow option */ + switch (c) { + case 'V': + printf("%s: ("PACKAGE_STRING")\n", progname); + return EX_SUCCESS; + case 'h': + default: + mount_usage(); + return EX_USAGE; + } + } + + if (optind < argc) + spec = argv[optind++]; + if (optind < argc) + mount_point = argv[optind++]; + + if (!mount_point) { + nfs_error(_("%s: no mount point provided"), progname); + mount_usage(); + goto err; + } + if (!spec) { + nfs_error(_("%s: no mount spec provided"), progname); + goto err; + } + + if (geteuid() != 0) { + nfs_error(_("%s: not installed setuid - " + "\"user\" NFS mounts not supported."), progname); + goto err; + } + + verbose = mnt_context_is_verbose(cxt); + sloppy = mnt_context_is_sloppy(cxt); + nomtab = mnt_context_is_nomtab(cxt); + + if (strcmp(progname, "mount.nfs4") == 0) + mnt_context_set_fstype(cxt, "nfs4"); + else + mnt_context_set_fstype(cxt, "nfs"); /* default */ + + rc = mnt_context_set_source(cxt, spec); + if (!rc) + mnt_context_set_target(cxt, mount_point); + if (rc) { + nfs_error(_("%s: failed to set spec or mountpoint: %s"), + progname, strerror(errno)); + goto err; + } + + mount_point = mnt_resolve_path(mount_point, + mnt_context_get_cache(cxt)); + + if (chk_mountpoint(mount_point)) + goto err; + + /* + * The libmount strictly uses only options from fstab if running in + * restricted mode (suid, non-root user). This is done in + * mnt_context_prepare_mount() by default. + * + * We have to read fstab before nfsmount.conf, otherwise the options + * from nfsmount.conf will be ignored (overwrited). + */ + rc = mnt_context_apply_fstab(cxt); + if (rc) { + nfs_error(_("%s: failed to apply fstab options\n"), progname); + goto err; + } + + /* + * Concatenate mount options from the configuration file + */ + fs = mnt_context_get_fs(cxt); + if (fs) { + opts = mnt_fs_strdup_options(fs); + + opts = mount_config_opts(spec, mount_point, opts); + mnt_fs_set_options(fs, opts); + } + + rc = mnt_context_prepare_mount(cxt); + if (rc) { + nfs_error(_("%s: failed to prepare mount: %s\n"), + progname, strerror(-rc)); + goto err; + } + + rc = try_mount(cxt, FOREGROUND); + + if (rc == EX_BG) { + printf(_("%s: backgrounding \"%s\"\n"), + progname, mnt_context_get_source(cxt)); + printf(_("%s: mount options: \"%s\"\n"), + progname, opts); + + fflush(stdout); + + if (daemon(0, 0)) { + nfs_error(_("%s: failed to start " + "background process: %s\n"), + progname, strerror(errno)); + exit(EX_FAIL); + } + + rc = try_mount(cxt, BACKGROUND); + + if (verbose && rc) + printf(_("%s: giving up \"%s\"\n"), + progname, mnt_context_get_source(cxt)); + } + + mnt_context_set_syscall_status(cxt, rc == EX_SUCCESS ? 0 : -1); + mnt_context_finalize_mount(cxt); /* mtab update */ + return rc; +err: + return EX_FAIL; +} + +int main(int argc, char *argv[]) +{ + struct libmnt_context *cxt; + int rc; + + mnt_init_debug(0); + cxt = mnt_new_context(); + if (!cxt) { + nfs_error(_("Can't initilize libmount: %s"), + strerror(errno)); + rc = EX_FAIL; + goto done; + } + + progname = basename(argv[0]); + nfs_mount_data_version = discover_nfs_mount_data_version(&string); + + if(strncmp(progname, "umount", 6) == 0) + rc = umount_main(cxt, argc, argv); + else + rc = mount_main(cxt, argc, argv); +done: + mnt_free_context(cxt); + return rc; +} |