blob: 088d1328e14a1a9edbbc52cfb4038b3d932d4c44 [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* This file is part of libmount from util-linux project.
*
* Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com>
*
* libmount is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*/
/**
* SECTION: context-mount
* @title: Mount context
* @short_description: high-level API to mount operation.
*/
#ifdef HAVE_LIBSELINUX
#include <selinux/selinux.h>
#include <selinux/context.h>
#endif
#include <sys/wait.h>
#include <sys/mount.h>
#include "linux_version.h"
#include "mountP.h"
#include "strutils.h"
/*
* Kernel supports only one MS_PROPAGATION flag change by one mount(2) syscall,
* to bypass this restriction we call mount(2) per flag. It's really not a perfect
* solution, but it's the same like to execute multiple mount(8) commands.
*
* We use cxt->addmounts (additional mounts) list to keep order of the requested
* flags changes.
*/
struct libmnt_addmount *mnt_new_addmount(void)
{
struct libmnt_addmount *ad = calloc(1, sizeof(*ad));
if (!ad)
return NULL;
INIT_LIST_HEAD(&ad->mounts);
return ad;
}
void mnt_free_addmount(struct libmnt_addmount *ad)
{
if (!ad)
return;
list_del(&ad->mounts);
free(ad);
}
static int mnt_context_append_additional_mount(struct libmnt_context *cxt,
struct libmnt_addmount *ad)
{
assert(cxt);
assert(ad);
if (!list_empty(&ad->mounts))
return -EINVAL;
DBG(CXT, ul_debugobj(cxt,
"mount: add additional flag: 0x%08lx",
ad->mountflags));
list_add_tail(&ad->mounts, &cxt->addmounts);
return 0;
}
/*
* add additional mount(2) syscall requests when necessary to set propagation flags
* after regular mount(2).
*/
static int init_propagation(struct libmnt_context *cxt)
{
char *name;
char *opts = (char *) mnt_fs_get_vfs_options(cxt->fs);
size_t namesz;
struct libmnt_optmap const *maps[1];
int rec_count = 0;
if (!opts)
return 0;
DBG(CXT, ul_debugobj(cxt, "mount: initialize additional propagation mounts"));
maps[0] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
while (!mnt_optstr_next_option(&opts, &name, &namesz, NULL, NULL)) {
const struct libmnt_optmap *ent;
struct libmnt_addmount *ad;
int rc;
if (!mnt_optmap_get_entry(maps, 1, name, namesz, &ent) || !ent)
continue;
DBG(CXT, ul_debugobj(cxt, " checking %s", ent->name));
/* Note that MS_REC may be used for more flags, so we have to keep
* track about number of recursive options to keep the MS_REC in the
* mountflags if necessary.
*/
if (ent->id & MS_REC)
rec_count++;
if (!(ent->id & MS_PROPAGATION))
continue;
ad = mnt_new_addmount();
if (!ad)
return -ENOMEM;
ad->mountflags = ent->id;
DBG(CXT, ul_debugobj(cxt, " adding extra mount(2) call for %s", ent->name));
rc = mnt_context_append_additional_mount(cxt, ad);
if (rc)
return rc;
DBG(CXT, ul_debugobj(cxt, " removing %s from primary mount(2) call", ent->name));
cxt->mountflags &= ~ent->id;
if (ent->id & MS_REC)
rec_count--;
}
if (rec_count)
cxt->mountflags |= MS_REC;
return 0;
}
/*
* add additional mount(2) syscall request to implement "bind,<flags>", the first regular
* mount(2) is the "bind" operation, the second is "remount,bind,<flags>" call.
*/
static int init_bind_remount(struct libmnt_context *cxt)
{
struct libmnt_addmount *ad;
int rc;
assert(cxt);
assert(cxt->mountflags & MS_BIND);
assert(!(cxt->mountflags & MS_REMOUNT));
DBG(CXT, ul_debugobj(cxt, "mount: initialize additional ro,bind mount"));
ad = mnt_new_addmount();
if (!ad)
return -ENOMEM;
ad->mountflags = cxt->mountflags;
ad->mountflags |= (MS_REMOUNT | MS_BIND);
rc = mnt_context_append_additional_mount(cxt, ad);
if (rc)
return rc;
return 0;
}
#if defined(HAVE_LIBSELINUX) || defined(HAVE_SMACK)
struct libmnt_optname {
const char *name;
size_t namesz;
};
#define DEF_OPTNAME(n) { .name = n, .namesz = sizeof(n) - 1 }
#define DEF_OPTNAME_LAST { .name = NULL }
static int is_option(const char *name, size_t namesz,
const struct libmnt_optname *names)
{
const struct libmnt_optname *p;
for (p = names; p && p->name; p++) {
if (p->namesz == namesz
&& strncmp(name, p->name, namesz) == 0)
return 1;
}
return 0;
}
#endif /* HAVE_LIBSELINUX || HAVE_SMACK */
/*
* this has to be called after mnt_context_evaluate_permissions()
*/
static int fix_optstr(struct libmnt_context *cxt)
{
int rc = 0;
struct libmnt_ns *ns_old;
char *next;
char *name, *val;
size_t namesz, valsz;
struct libmnt_fs *fs;
#ifdef HAVE_LIBSELINUX
int se_fix = 0, se_rem = 0;
static const struct libmnt_optname selinux_options[] = {
DEF_OPTNAME("context"),
DEF_OPTNAME("fscontext"),
DEF_OPTNAME("defcontext"),
DEF_OPTNAME("rootcontext"),
DEF_OPTNAME("seclabel"),
DEF_OPTNAME_LAST
};
#endif
#ifdef HAVE_SMACK
int sm_rem = 0;
static const struct libmnt_optname smack_options[] = {
DEF_OPTNAME("smackfsdef"),
DEF_OPTNAME("smackfsfloor"),
DEF_OPTNAME("smackfshat"),
DEF_OPTNAME("smackfsroot"),
DEF_OPTNAME("smackfstransmute"),
DEF_OPTNAME_LAST
};
#endif
assert(cxt);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!cxt->fs || (cxt->flags & MNT_FL_MOUNTOPTS_FIXED))
return 0;
fs = cxt->fs;
DBG(CXT, ul_debugobj(cxt, "mount: fixing options, current "
"vfs: '%s' fs: '%s' user: '%s', optstr: '%s'",
fs->vfs_optstr, fs->fs_optstr, fs->user_optstr, fs->optstr));
/*
* The "user" options is our business (so we can modify the option),
* the exception is command line for /sbin/mount.<type> helpers. Let's
* save the original user=<name> to call the helpers with an unchanged
* "user" setting.
*/
if (cxt->user_mountflags & MNT_MS_USER) {
if (!mnt_optstr_get_option(fs->user_optstr,
"user", &val, &valsz) && val) {
cxt->orig_user = strndup(val, valsz);
if (!cxt->orig_user) {
rc = -ENOMEM;
goto done;
}
}
cxt->flags |= MNT_FL_SAVED_USER;
}
/*
* Sync mount options with mount flags
*/
DBG(CXT, ul_debugobj(cxt, "mount: fixing vfs optstr"));
rc = mnt_optstr_apply_flags(&fs->vfs_optstr, cxt->mountflags,
mnt_get_builtin_optmap(MNT_LINUX_MAP));
if (rc)
goto done;
DBG(CXT, ul_debugobj(cxt, "mount: fixing user optstr"));
rc = mnt_optstr_apply_flags(&fs->user_optstr, cxt->user_mountflags,
mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
if (rc)
goto done;
if (fs->vfs_optstr && *fs->vfs_optstr == '\0') {
free(fs->vfs_optstr);
fs->vfs_optstr = NULL;
}
if (fs->user_optstr && *fs->user_optstr == '\0') {
free(fs->user_optstr);
fs->user_optstr = NULL;
}
if (cxt->mountflags & MS_PROPAGATION) {
rc = init_propagation(cxt);
if (rc)
return rc;
}
if ((cxt->mountflags & MS_BIND)
&& (cxt->mountflags & MNT_BIND_SETTABLE)
&& !(cxt->mountflags & MS_REMOUNT)) {
rc = init_bind_remount(cxt);
if (rc)
return rc;
}
next = fs->fs_optstr;
#ifdef HAVE_LIBSELINUX
if (!is_selinux_enabled())
/* Always remove SELinux garbage if SELinux disabled */
se_rem = 1;
else if (cxt->mountflags & MS_REMOUNT)
/*
* Linux kernel < 2.6.39 does not allow to remount with any
* selinux specific mount options.
*
* Kernel 2.6.39 commits: ff36fe2c845cab2102e4826c1ffa0a6ebf487c65
* 026eb167ae77244458fa4b4b9fc171209c079ba7
* fix this odd behavior, so we don't have to care about it in
* userspace.
*/
se_rem = get_linux_version() < KERNEL_VERSION(2, 6, 39);
else
/* For normal mount, contexts are translated */
se_fix = 1;
if (!se_rem) {
/* de-duplicate SELinux options */
const struct libmnt_optname *p;
for (p = selinux_options; p && p->name; p++)
mnt_optstr_deduplicate_option(&fs->fs_optstr, p->name);
}
#endif
#ifdef HAVE_SMACK
if (access("/sys/fs/smackfs", F_OK) != 0)
sm_rem = 1;
#endif
while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
if (namesz == 3 && !strncmp(name, "uid", 3))
rc = mnt_optstr_fix_uid(&fs->fs_optstr, val, valsz, &next);
else if (namesz == 3 && !strncmp(name, "gid", 3))
rc = mnt_optstr_fix_gid(&fs->fs_optstr, val, valsz, &next);
#ifdef HAVE_LIBSELINUX
else if ((se_rem || se_fix)
&& is_option(name, namesz, selinux_options)) {
if (se_rem) {
/* remove context= option */
next = name;
rc = mnt_optstr_remove_option_at(&fs->fs_optstr,
name,
val ? val + valsz :
name + namesz);
} else if (se_fix && val && valsz)
/* translate selinux contexts */
rc = mnt_optstr_fix_secontext(&fs->fs_optstr,
val, valsz, &next);
}
#endif
#ifdef HAVE_SMACK
else if (sm_rem && is_option(name, namesz, smack_options)) {
next = name;
rc = mnt_optstr_remove_option_at(&fs->fs_optstr,
name,
val ? val + valsz : name + namesz);
}
#endif
if (rc)
goto done;
}
if (!rc && mnt_context_is_restricted(cxt) && (cxt->user_mountflags & MNT_MS_USER)) {
ns_old = mnt_context_switch_origin_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
rc = mnt_optstr_fix_user(&fs->user_optstr);
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
}
/* refresh merged optstr */
free(fs->optstr);
fs->optstr = NULL;
fs->optstr = mnt_fs_strdup_options(fs);
done:
cxt->flags |= MNT_FL_MOUNTOPTS_FIXED;
DBG(CXT, ul_debugobj(cxt, "fixed options [rc=%d]: "
"vfs: '%s' fs: '%s' user: '%s', optstr: '%s'", rc,
fs->vfs_optstr, fs->fs_optstr, fs->user_optstr, fs->optstr));
if (rc)
rc = -MNT_ERR_MOUNTOPT;
return rc;
}
/*
* Converts the already evaluated and fixed options to the form that is compatible
* with /sbin/mount.type helpers.
*/
static int generate_helper_optstr(struct libmnt_context *cxt, char **optstr)
{
struct libmnt_optmap const *maps[2];
char *next, *name, *val;
size_t namesz, valsz;
int rc = 0;
assert(cxt);
assert(cxt->fs);
assert(optstr);
DBG(CXT, ul_debugobj(cxt, "mount: generate helper mount options"));
*optstr = mnt_fs_strdup_options(cxt->fs);
if (!*optstr)
return -ENOMEM;
if ((cxt->user_mountflags & MNT_MS_USER) ||
(cxt->user_mountflags & MNT_MS_USERS)) {
/*
* This is unnecessary for real user-mounts as mount.<type>
* helpers always have to follow fstab rather than mount
* options on the command line.
*
* However, if you call mount.<type> as root, then the helper follows
* the command line. If there is (for example) "user,exec" in fstab,
* then we have to manually append the "exec" back to the options
* string, because there is nothing like MS_EXEC (we only have
* MS_NOEXEC in mount flags and we don't care about the original
* mount string in libmount for VFS options).
*/
if (!(cxt->mountflags & MS_NOEXEC))
mnt_optstr_append_option(optstr, "exec", NULL);
if (!(cxt->mountflags & MS_NOSUID))
mnt_optstr_append_option(optstr, "suid", NULL);
if (!(cxt->mountflags & MS_NODEV))
mnt_optstr_append_option(optstr, "dev", NULL);
}
if (cxt->flags & MNT_FL_SAVED_USER)
rc = mnt_optstr_set_option(optstr, "user", cxt->orig_user);
if (rc)
goto err;
/* remove userspace options with MNT_NOHLPS flag */
maps[0] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
maps[1] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
next = *optstr;
while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
const struct libmnt_optmap *ent;
mnt_optmap_get_entry(maps, 2, name, namesz, &ent);
if (ent && ent->id && (ent->mask & MNT_NOHLPS)) {
next = name;
rc = mnt_optstr_remove_option_at(optstr, name,
val ? val + valsz : name + namesz);
if (rc)
goto err;
}
}
return rc;
err:
free(*optstr);
*optstr = NULL;
return rc;
}
/*
* this has to be called before fix_optstr()
*
* Note that user=<name> may be used by some filesystems as a filesystem
* specific option (e.g. cifs). Yes, developers of such filesystems have
* allocated pretty hot place in hell...
*/
static int evaluate_permissions(struct libmnt_context *cxt)
{
unsigned long u_flags = 0;
assert(cxt);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (!cxt->fs)
return 0;
DBG(CXT, ul_debugobj(cxt, "mount: evaluating permissions"));
mnt_context_get_user_mflags(cxt, &u_flags);
if (!mnt_context_is_restricted(cxt)) {
/*
* superuser mount
*/
cxt->user_mountflags &= ~MNT_MS_OWNER;
cxt->user_mountflags &= ~MNT_MS_GROUP;
} else {
/*
* user mount
*/
if (!mnt_context_tab_applied(cxt))
{
DBG(CXT, ul_debugobj(cxt, "perms: fstab not applied, ignore user mount"));
return -EPERM;
}
/*
* MS_OWNERSECURE and MS_SECURE mount options are already
* applied by mnt_optstr_get_flags() in mnt_context_merge_mflags()
* if "user" (but no user=<name> !) options is set.
*
* Let's ignore all user=<name> (if <name> is set) requests.
*/
if (cxt->user_mountflags & MNT_MS_USER) {
size_t valsz = 0;
if (!mnt_optstr_get_option(cxt->fs->user_optstr,
"user", NULL, &valsz) && valsz) {
DBG(CXT, ul_debugobj(cxt, "perms: user=<name> detected, ignore"));
cxt->user_mountflags &= ~MNT_MS_USER;
}
}
/*
* MS_OWNER: Allow owners to mount when fstab contains the
* owner option. Note that this should never be used in a high
* security environment, but may be useful to give people at
* the console the possibility of mounting a floppy. MS_GROUP:
* Allow members of device group to mount. (Martin Dickopp)
*/
if (u_flags & (MNT_MS_OWNER | MNT_MS_GROUP)) {
struct stat sb;
struct libmnt_cache *cache = NULL;
char *xsrc = NULL;
const char *srcpath = mnt_fs_get_srcpath(cxt->fs);
if (!srcpath) { /* Ah... source is TAG */
cache = mnt_context_get_cache(cxt);
xsrc = mnt_resolve_spec(
mnt_context_get_source(cxt),
cache);
srcpath = xsrc;
}
if (!srcpath) {
DBG(CXT, ul_debugobj(cxt, "perms: src undefined"));
return -EPERM;
}
if (strncmp(srcpath, "/dev/", 5) == 0 &&
stat(srcpath, &sb) == 0 &&
(((u_flags & MNT_MS_OWNER) && getuid() == sb.st_uid) ||
((u_flags & MNT_MS_GROUP) && mnt_in_group(sb.st_gid))))
cxt->user_mountflags |= MNT_MS_USER;
if (!cache)
free(xsrc);
}
if (!(cxt->user_mountflags & (MNT_MS_USER | MNT_MS_USERS))) {
DBG(CXT, ul_debugobj(cxt, "permissions evaluation ends with -EPERMS"));
return -EPERM;
}
}
return 0;
}
/*
* mnt_context_helper_setopt() backend
*
* This function applies the mount.type command line option (for example parsed
* by getopt() or getopt_long()) to @cxt. All unknown options are ignored and
* then 1 is returned.
*
* Returns: negative number on error, 1 if @c is unknown option, 0 on success.
*/
int mnt_context_mount_setopt(struct libmnt_context *cxt, int c, char *arg)
{
int rc = -EINVAL;
assert(cxt);
assert(cxt->action == MNT_ACT_MOUNT);
switch(c) {
case 'f':
rc = mnt_context_enable_fake(cxt, TRUE);
break;
case 'n':
rc = mnt_context_disable_mtab(cxt, TRUE);
break;
case 'r':
rc = mnt_context_append_options(cxt, "ro");
break;
case 'v':
rc = mnt_context_enable_verbose(cxt, TRUE);
break;
case 'w':
rc = mnt_context_append_options(cxt, "rw");
break;
case 'o':
if (arg)
rc = mnt_context_append_options(cxt, arg);
break;
case 's':
rc = mnt_context_enable_sloppy(cxt, TRUE);
break;
case 't':
if (arg)
rc = mnt_context_set_fstype(cxt, arg);
break;
case 'N':
if (arg)
rc = mnt_context_set_target_ns(cxt, arg);
break;
default:
return 1;
}
return rc;
}
static int exec_helper(struct libmnt_context *cxt)
{
char *o = NULL, *namespace = NULL;
struct libmnt_ns *ns_tgt = mnt_context_get_target_ns(cxt);
int rc;
pid_t pid;
assert(cxt);
assert(cxt->fs);
assert(cxt->helper);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
DBG(CXT, ul_debugobj(cxt, "mount: executing helper %s", cxt->helper));
rc = generate_helper_optstr(cxt, &o);
if (rc)
return -EINVAL;
if (ns_tgt->fd != -1
&& asprintf(&namespace, "/proc/%i/fd/%i",
getpid(), ns_tgt->fd) == -1) {
free(o);
return -ENOMEM;
}
DBG_FLUSH;
pid = fork();
switch (pid) {
case 0:
{
const char *args[14], *type;
int i = 0;
if (setgid(getgid()) < 0)
_exit(EXIT_FAILURE);
if (setuid(getuid()) < 0)
_exit(EXIT_FAILURE);
if (!mnt_context_switch_origin_ns(cxt))
_exit(EXIT_FAILURE);
type = mnt_fs_get_fstype(cxt->fs);
args[i++] = cxt->helper; /* 1 */
args[i++] = mnt_fs_get_srcpath(cxt->fs);/* 2 */
args[i++] = mnt_fs_get_target(cxt->fs); /* 3 */
if (mnt_context_is_sloppy(cxt))
args[i++] = "-s"; /* 4 */
if (mnt_context_is_fake(cxt))
args[i++] = "-f"; /* 5 */
if (mnt_context_is_nomtab(cxt))
args[i++] = "-n"; /* 6 */
if (mnt_context_is_verbose(cxt))
args[i++] = "-v"; /* 7 */
if (o) {
args[i++] = "-o"; /* 8 */
args[i++] = o; /* 9 */
}
if (type
&& strchr(type, '.')
&& !endswith(cxt->helper, type)) {
args[i++] = "-t"; /* 10 */
args[i++] = type; /* 11 */
}
if (namespace) {
args[i++] = "-N"; /* 11 */
args[i++] = namespace; /* 12 */
}
args[i] = NULL; /* 13 */
for (i = 0; args[i]; i++)
DBG(CXT, ul_debugobj(cxt, "argv[%d] = \"%s\"",
i, args[i]));
DBG_FLUSH;
execv(cxt->helper, (char * const *) args);
_exit(EXIT_FAILURE);
}
default:
{
int st;
if (waitpid(pid, &st, 0) == (pid_t) -1) {
cxt->helper_status = -1;
rc = -errno;
} else {
cxt->helper_status = WIFEXITED(st) ? WEXITSTATUS(st) : -1;
cxt->helper_exec_status = rc = 0;
}
DBG(CXT, ul_debugobj(cxt, "%s executed [status=%d, rc=%d%s]",
cxt->helper,
cxt->helper_status, rc,
rc ? " waitpid failed" : ""));
break;
}
case -1:
cxt->helper_exec_status = rc = -errno;
DBG(CXT, ul_debugobj(cxt, "fork() failed"));
break;
}
free(o);
return rc;
}
static int do_mount_additional(struct libmnt_context *cxt,
const char *target,
unsigned long flags,
int *syserr)
{
struct list_head *p;
assert(cxt);
assert(target);
if (syserr)
*syserr = 0;
list_for_each(p, &cxt->addmounts) {
int rc;
struct libmnt_addmount *ad =
list_entry(p, struct libmnt_addmount, mounts);
DBG(CXT, ul_debugobj(cxt, "mount(2) changing flag: 0x%08lx %s",
ad->mountflags,
ad->mountflags & MS_REC ? " (recursive)" : ""));
rc = mount("none", target, NULL,
ad->mountflags | (flags & MS_SILENT), NULL);
if (rc) {
if (syserr)
*syserr = -errno;
DBG(CXT, ul_debugobj(cxt,
"mount(2) failed [errno=%d %m]",
errno));
return rc;
}
}
return 0;
}
/*
* The default is to use fstype from cxt->fs, this could be overwritten by
* @try_type argument. If @try_type is specified then mount with MS_SILENT.
*
* Returns: 0 on success,
* >0 in case of mount(2) error (returns syscall errno),
* <0 in case of other errors.
*/
static int do_mount(struct libmnt_context *cxt, const char *try_type)
{
int rc = 0;
const char *src, *target, *type;
unsigned long flags;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
if (try_type && !cxt->helper) {
rc = mnt_context_prepare_helper(cxt, "mount", try_type);
if (rc)
return rc;
}
flags = cxt->mountflags;
src = mnt_fs_get_srcpath(cxt->fs);
target = mnt_fs_get_target(cxt->fs);
if (cxt->helper) {
rc = exec_helper(cxt);
if (mnt_context_helper_executed(cxt)
&& mnt_context_get_helper_status(cxt) == 0
&& !list_empty(&cxt->addmounts)
&& do_mount_additional(cxt, target, flags, NULL))
return -MNT_ERR_APPLYFLAGS;
return rc;
}
if (!target)
return -EINVAL;
if (!src) {
/* unnecessary, should be already resolved in
* mnt_context_prepare_srcpath(), but to be sure... */
DBG(CXT, ul_debugobj(cxt, "WARNING: source is NULL -- using \"none\"!"));
src = "none";
}
type = try_type ? : mnt_fs_get_fstype(cxt->fs);
if (try_type)
flags |= MS_SILENT;
DBG(CXT, ul_debugobj(cxt, "%smount(2) "
"[source=%s, target=%s, type=%s, "
" mountflags=0x%08lx, mountdata=%s]",
mnt_context_is_fake(cxt) ? "(FAKE) " : "",
src, target, type,
flags, cxt->mountdata ? "yes" : "<none>"));
if (mnt_context_is_fake(cxt)) {
/*
* fake
*/
cxt->syscall_status = 0;
} else if (mnt_context_propagation_only(cxt)) {
/*
* propagation flags *only*
*/
if (do_mount_additional(cxt, target, flags, &cxt->syscall_status))
return -MNT_ERR_APPLYFLAGS;
} else {
/*
* regular mount
*/
if (mount(src, target, type, flags, cxt->mountdata)) {
cxt->syscall_status = -errno;
DBG(CXT, ul_debugobj(cxt, "mount(2) failed [errno=%d %m]",
-cxt->syscall_status));
return -cxt->syscall_status;
}
DBG(CXT, ul_debugobj(cxt, " success"));
cxt->syscall_status = 0;
/*
* additional mounts for extra propagation flags
*/
if (!list_empty(&cxt->addmounts)
&& do_mount_additional(cxt, target, flags, NULL)) {
/* TODO: call umount? */
return -MNT_ERR_APPLYFLAGS;
}
}
if (try_type && cxt->update) {
struct libmnt_fs *fs = mnt_update_get_fs(cxt->update);
if (fs)
rc = mnt_fs_set_fstype(fs, try_type);
}
return rc;
}
/* try mount(2) for all items in comma separated list of the filesystem @types */
static int do_mount_by_types(struct libmnt_context *cxt, const char *types)
{
int rc = -EINVAL;
char *p, *p0;
assert(cxt);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
DBG(CXT, ul_debugobj(cxt, "trying to mount by FS list '%s'", types));
p0 = p = strdup(types);
if (!p)
return -ENOMEM;
do {
char *autotype = NULL;
char *end = strchr(p, ',');
if (end)
*end = '\0';
DBG(CXT, ul_debugobj(cxt, "-->trying '%s'", p));
/* Let's support things like "udf,iso9660,auto" */
if (strcmp(p, "auto") == 0) {
rc = mnt_context_guess_srcpath_fstype(cxt, &autotype);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "failed to guess FS type [rc=%d]", rc));
free(p0);
free(autotype);
return rc;
}
p = autotype;
DBG(CXT, ul_debugobj(cxt, " --> '%s'", p));
}
if (p)
rc = do_mount(cxt, p);
p = end ? end + 1 : NULL;
free(autotype);
} while (!mnt_context_get_status(cxt) && p);
free(p0);
return rc;
}
static int do_mount_by_pattern(struct libmnt_context *cxt, const char *pattern)
{
int neg = pattern && strncmp(pattern, "no", 2) == 0;
int rc = -EINVAL;
char **filesystems, **fp;
struct libmnt_ns *ns_old;
assert(cxt);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
/*
* Use the pattern as list of the filesystems
*/
if (!neg && pattern) {
DBG(CXT, ul_debugobj(cxt, "use FS pattern as FS list"));
return do_mount_by_types(cxt, pattern);
}
DBG(CXT, ul_debugobj(cxt, "trying to mount by FS pattern '%s'", pattern));
/*
* Apply pattern to /etc/filesystems and /proc/filesystems
*/
ns_old = mnt_context_switch_origin_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
rc = mnt_get_filesystems(&filesystems, neg ? pattern : NULL);
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
if (rc)
return rc;
if (filesystems == NULL)
return -MNT_ERR_NOFSTYPE;
for (fp = filesystems; *fp; fp++) {
rc = do_mount(cxt, *fp);
if (mnt_context_get_status(cxt))
break;
if (mnt_context_get_syscall_errno(cxt) != EINVAL &&
mnt_context_get_syscall_errno(cxt) != ENODEV)
break;
}
mnt_free_filesystems(filesystems);
return rc;
}
/**
* mnt_context_prepare_mount:
* @cxt: context
*
* Prepare context for mounting, unnecessary for mnt_context_mount().
*
* Returns: negative number on error, zero on success
*/
int mnt_context_prepare_mount(struct libmnt_context *cxt)
{
int rc = -EINVAL;
struct libmnt_ns *ns_old;
if (!cxt || !cxt->fs || mnt_fs_is_swaparea(cxt->fs))
return -EINVAL;
if (!mnt_fs_get_source(cxt->fs) && !mnt_fs_get_target(cxt->fs))
return -EINVAL;
if (cxt->flags & MNT_FL_PREPARED)
return 0;
assert(cxt->helper_exec_status == 1);
assert(cxt->syscall_status == 1);
cxt->action = MNT_ACT_MOUNT;
ns_old = mnt_context_switch_target_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
DBG(CXT, ul_debugobj(cxt, "mount: preparing"));
rc = mnt_context_apply_fstab(cxt);
if (!rc)
rc = mnt_context_merge_mflags(cxt);
if (!rc)
rc = evaluate_permissions(cxt);
if (!rc)
rc = fix_optstr(cxt);
if (!rc)
rc = mnt_context_prepare_srcpath(cxt);
if (!rc)
rc = mnt_context_guess_fstype(cxt);
if (!rc)
rc = mnt_context_prepare_target(cxt);
if (!rc)
rc = mnt_context_prepare_helper(cxt, "mount", NULL);
if (rc) {
DBG(CXT, ul_debugobj(cxt, "mount: preparing failed"));
goto end;
}
cxt->flags |= MNT_FL_PREPARED;
end:
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
return rc;
}
/**
* mnt_context_do_mount
* @cxt: context
*
* Call mount(2) or mount.type helper. Unnecessary for mnt_context_mount().
*
* Note that this function could be called only once. If you want to mount
* another source or target, then you have to call mnt_reset_context().
*
* If you want to call mount(2) for the same source and target with different
* mount flags or fstype, then call mnt_context_reset_status() and then try
* again mnt_context_do_mount().
*
* WARNING: non-zero return code does not mean that mount(2) syscall or
* mount.type helper wasn't successfully called.
*
* Check mnt_context_get_status() after error! See mnt_context_mount() for more
* details about errors and warnings.
*
* Returns: 0 on success;
* >0 in case of mount(2) error (returns syscall errno),
* <0 in case of other errors.
*/
int mnt_context_do_mount(struct libmnt_context *cxt)
{
const char *type;
int res;
struct libmnt_ns *ns_old;
assert(cxt);
assert(cxt->fs);
assert(cxt->helper_exec_status == 1);
assert(cxt->syscall_status == 1);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
assert((cxt->flags & MNT_FL_PREPARED));
assert((cxt->action == MNT_ACT_MOUNT));
DBG(CXT, ul_debugobj(cxt, "mount: do mount"));
if (!(cxt->flags & MNT_FL_MOUNTDATA))
cxt->mountdata = (char *) mnt_fs_get_fs_options(cxt->fs);
ns_old = mnt_context_switch_target_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
type = mnt_fs_get_fstype(cxt->fs);
if (type) {
if (strchr(type, ','))
/* this only happens if fstab contains a list of filesystems */
res = do_mount_by_types(cxt, type);
else
res = do_mount(cxt, NULL);
} else
res = do_mount_by_pattern(cxt, cxt->fstype_pattern);
#ifdef USE_LIBMOUNT_SUPPORT_MTAB
if (mnt_context_get_status(cxt)
&& !mnt_context_is_fake(cxt)
&& !cxt->helper
&& mnt_context_mtab_writable(cxt)) {
int is_rdonly = -1;
DBG(CXT, ul_debugobj(cxt, "checking for RDONLY mismatch"));
/*
* Mounted by mount(2), do some post-mount checks
*
* Kernel allows to use MS_RDONLY for bind mounts, but the
* read-only request could be silently ignored. Check it to
* avoid 'ro' in mtab and 'rw' in /proc/mounts.
*/
if ((cxt->mountflags & MS_BIND)
&& (cxt->mountflags & MS_RDONLY)) {
if (is_rdonly < 0)
is_rdonly = mnt_is_readonly(mnt_context_get_target(cxt));
if (!is_rdonly)
mnt_context_set_mflags(cxt, cxt->mountflags & ~MS_RDONLY);
}
/* Kernel can silently add MS_RDONLY flag when mounting file
* system that does not have write support. Check this to avoid
* 'ro' in /proc/mounts and 'rw' in mtab.
*/
if (!(cxt->mountflags & (MS_RDONLY | MS_MOVE))
&& !mnt_context_propagation_only(cxt)) {
if (is_rdonly < 0)
is_rdonly = mnt_is_readonly(mnt_context_get_target(cxt));
if (is_rdonly)
mnt_context_set_mflags(cxt, cxt->mountflags | MS_RDONLY);
}
}
#endif
/* Cleanup will be immediate on failure, and deferred to umount on success */
if (mnt_context_is_veritydev(cxt))
mnt_context_deferred_delete_veritydev(cxt);
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
return res;
}
/**
* mnt_context_finalize_mount:
* @cxt: context
*
* Mtab update, etc. Unnecessary for mnt_context_mount(), but should be called
* after mnt_context_do_mount(). See also mnt_context_set_syscall_status().
*
* Returns: negative number on error, 0 on success.
*/
int mnt_context_finalize_mount(struct libmnt_context *cxt)
{
int rc;
assert(cxt);
assert(cxt->fs);
assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
assert((cxt->flags & MNT_FL_PREPARED));
rc = mnt_context_prepare_update(cxt);
if (!rc)
rc = mnt_context_update_tabs(cxt);
return rc;
}
/**
* mnt_context_mount:
* @cxt: mount context
*
* High-level, mounts the filesystem by mount(2) or fork()+exec(/sbin/mount.type).
*
* This is similar to:
*
* mnt_context_prepare_mount(cxt);
* mnt_context_do_mount(cxt);
* mnt_context_finalize_mount(cxt);
*
* See also mnt_context_disable_helpers().
*
* Note that this function should be called only once. If you want to mount with
* different settings, then you have to call mnt_reset_context(). It's NOT enough
* to call mnt_context_reset_status(). If you want to call this function more than
* once, the whole context has to be reset.
*
* WARNING: non-zero return code does not mean that mount(2) syscall or
* mount.type helper wasn't successfully called.
*
* Always use mnt_context_get_status():
*
* <informalexample>
* <programlisting>
* rc = mnt_context_mount(cxt);
*
* if (mnt_context_helper_executed(cxt))
* return mnt_context_get_helper_status(cxt);
* if (rc == 0 && mnt_context_get_status(cxt) == 1)
* return MNT_EX_SUCCESS;
* return MNT_EX_FAIL;
* </programlisting>
* </informalexample>
*
* or mnt_context_get_excode() to generate mount(8) compatible error
* or warning message:
*
* <informalexample>
* <programlisting>
* rc = mnt_context_mount(cxt);
* rc = mnt_context_get_excode(cxt, rc, buf, sizeof(buf));
* if (buf)
* warnx(_("%s: %s"), mnt_context_get_target(cxt), buf);
* return rc; // MNT_EX_*
* </programlisting>
* </informalexample>
*
* Returns: 0 on success;
* >0 in case of mount(2) error (returns syscall errno),
* <0 in case of other errors.
*/
int mnt_context_mount(struct libmnt_context *cxt)
{
int rc;
struct libmnt_ns *ns_old;
assert(cxt);
assert(cxt->fs);
assert(cxt->helper_exec_status == 1);
assert(cxt->syscall_status == 1);
ns_old = mnt_context_switch_target_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
again:
rc = mnt_context_prepare_mount(cxt);
if (!rc)
rc = mnt_context_prepare_update(cxt);
if (!rc)
rc = mnt_context_do_mount(cxt);
if (!rc)
rc = mnt_context_update_tabs(cxt);
/*
* Read-only device; try mount filesystem read-only
*/
if ((rc == -EROFS && !mnt_context_syscall_called(cxt)) /* before syscall; rdonly loopdev */
|| mnt_context_get_syscall_errno(cxt) == EROFS /* syscall failed with EROFS */
|| mnt_context_get_syscall_errno(cxt) == EACCES) /* syscall failed with EACCES */
{
unsigned long mflags = 0;
mnt_context_get_mflags(cxt, &mflags);
if (!(mflags & MS_RDONLY) /* not yet RDONLY */
&& !(mflags & MS_REMOUNT) /* not remount */
&& !(mflags & MS_BIND) /* not bin mount */
&& !mnt_context_is_rwonly_mount(cxt)) { /* no explicit read-write */
assert(!(cxt->flags & MNT_FL_FORCED_RDONLY));
DBG(CXT, ul_debugobj(cxt, "write-protected source, trying RDONLY."));
mnt_context_reset_status(cxt);
mnt_context_set_mflags(cxt, mflags | MS_RDONLY);
cxt->flags |= MNT_FL_FORCED_RDONLY;
goto again;
}
}
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
return rc;
}
/**
* mnt_context_next_mount:
* @cxt: context
* @itr: iterator
* @fs: returns the current filesystem
* @mntrc: returns the return code from mnt_context_mount()
* @ignored: returns 1 for non-matching and 2 for already mounted filesystems
*
* This function tries to mount the next filesystem from fstab (as returned by
* mnt_context_get_fstab()). See also mnt_context_set_fstab().
*
* You can filter out filesystems by:
* mnt_context_set_options_pattern() to simulate mount -a -O pattern
* mnt_context_set_fstype_pattern() to simulate mount -a -t pattern
*
* If the filesystem is already mounted or does not match defined criteria,
* then the mnt_context_next_mount() function returns zero, but the @ignored is
* non-zero. Note that the root filesystem and filesystems with "noauto" option
* are always ignored.
*
* If mount(2) syscall or mount.type helper failed, then the
* mnt_context_next_mount() function returns zero, but the @mntrc is non-zero.
* Use also mnt_context_get_status() to check if the filesystem was
* successfully mounted.
*
* See mnt_context_mount() for more details about errors and warnings.
*
* Returns: 0 on success,
* <0 in case of error (!= mount(2) errors)
* 1 at the end of the list.
*/
int mnt_context_next_mount(struct libmnt_context *cxt,
struct libmnt_iter *itr,
struct libmnt_fs **fs,
int *mntrc,
int *ignored)
{
struct libmnt_table *fstab, *mtab;
const char *o, *tgt;
int rc, mounted = 0;
if (ignored)
*ignored = 0;
if (mntrc)
*mntrc = 0;
if (!cxt || !fs || !itr)
return -EINVAL;
rc = mnt_context_get_fstab(cxt, &fstab);
if (rc)
return rc;
rc = mnt_table_next_fs(fstab, itr, fs);
if (rc != 0)
return rc; /* more filesystems (or error) */
o = mnt_fs_get_user_options(*fs);
tgt = mnt_fs_get_target(*fs);
DBG(CXT, ul_debugobj(cxt, "next-mount: trying %s", tgt));
/* ignore swap */
if (mnt_fs_is_swaparea(*fs) ||
/* ignore root filesystem */
(tgt && (strcmp(tgt, "/") == 0 || strcmp(tgt, "root") == 0)) ||
/* ignore noauto filesystems */
(o && mnt_optstr_get_option(o, "noauto", NULL, NULL) == 0) ||
/* ignore filesystems which don't match options patterns */
(cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
cxt->fstype_pattern)) ||
/* ignore filesystems which don't match type patterns */
(cxt->optstr_pattern && !mnt_fs_match_options(*fs,
cxt->optstr_pattern))) {
if (ignored)
*ignored = 1;
DBG(CXT, ul_debugobj(cxt, "next-mount: not-match "
"[fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]",
mnt_fs_get_fstype(*fs),
cxt->fstype_pattern,
mnt_fs_get_options(*fs),
cxt->optstr_pattern));
return 0;
}
/* ignore already mounted filesystems */
rc = mnt_context_is_fs_mounted(cxt, *fs, &mounted);
if (rc)
return rc;
if (mounted) {
if (ignored)
*ignored = 2;
return 0;
}
/* Save mount options, etc. -- this is effective for the first
* mnt_context_next_mount() call only. Make sure that cxt has not set
* source, target or fstype.
*/
if (!mnt_context_has_template(cxt)) {
mnt_context_set_source(cxt, NULL);
mnt_context_set_target(cxt, NULL);
mnt_context_set_fstype(cxt, NULL);
mnt_context_save_template(cxt);
}
/* reset context, but protect mtab */
mtab = cxt->mtab;
cxt->mtab = NULL;
mnt_reset_context(cxt);
cxt->mtab = mtab;
if (mnt_context_is_fork(cxt)) {
rc = mnt_fork_context(cxt);
if (rc)
return rc; /* fork error */
if (mnt_context_is_parent(cxt)) {
return 0; /* parent */
}
}
/*
* child or non-forked
*/
/* copy stuff from fstab to context */
rc = mnt_context_apply_fs(cxt, *fs);
if (!rc) {
/*
* "-t <pattern>" is used to filter out fstab entries, but for ordinary
* mount operation -t means "-t <type>". We have to zeroize the pattern
* to avoid misinterpretation.
*/
char *pattern = cxt->fstype_pattern;
cxt->fstype_pattern = NULL;
rc = mnt_context_mount(cxt);
cxt->fstype_pattern = pattern;
if (mntrc)
*mntrc = rc;
}
if (mnt_context_is_child(cxt)) {
DBG(CXT, ul_debugobj(cxt, "next-mount: child exit [rc=%d]", rc));
DBG_FLUSH;
_exit(rc);
}
return 0;
}
/**
* mnt_context_next_remount:
* @cxt: context
* @itr: iterator
* @fs: returns the current filesystem
* @mntrc: returns the return code from mnt_context_mount()
* @ignored: returns 1 for non-matching
*
* This function tries to remount the next mounted filesystem (as returned by
* mnt_context_get_mtab()).
*
* You can filter out filesystems by:
* mnt_context_set_options_pattern() to simulate mount -a -O pattern
* mnt_context_set_fstype_pattern() to simulate mount -a -t pattern
*
* If the filesystem does not match defined criteria, then the
* mnt_context_next_remount() function returns zero, but the @ignored is
* non-zero.
*
* IMPORTANT -- the mount operation is performed in the current context.
* The context is reset before the next mount (see mnt_reset_context()).
* The context setting related to the filesystem (e.g. mount options,
* etc.) are protected.
* If mount(2) syscall or mount.type helper failed, then the
* mnt_context_next_mount() function returns zero, but the @mntrc is non-zero.
* Use also mnt_context_get_status() to check if the filesystem was
* successfully mounted.
*
* See mnt_context_mount() for more details about errors and warnings.
*
* Returns: 0 on success,
* <0 in case of error (!= mount(2) errors)
* 1 at the end of the list.
*
* Since: 2.34
*/
int mnt_context_next_remount(struct libmnt_context *cxt,
struct libmnt_iter *itr,
struct libmnt_fs **fs,
int *mntrc,
int *ignored)
{
struct libmnt_table *mtab;
const char *tgt;
int rc;
if (ignored)
*ignored = 0;
if (mntrc)
*mntrc = 0;
if (!cxt || !fs || !itr)
return -EINVAL;
rc = mnt_context_get_mtab(cxt, &mtab);
if (rc)
return rc;
rc = mnt_table_next_fs(mtab, itr, fs);
if (rc != 0)
return rc; /* more filesystems (or error) */
tgt = mnt_fs_get_target(*fs);
DBG(CXT, ul_debugobj(cxt, "next-remount: trying %s", tgt));
/* ignore filesystems which don't match options patterns */
if ((cxt->fstype_pattern && !mnt_fs_match_fstype(*fs,
cxt->fstype_pattern)) ||
/* ignore filesystems which don't match type patterns */
(cxt->optstr_pattern && !mnt_fs_match_options(*fs,
cxt->optstr_pattern))) {
if (ignored)
*ignored = 1;
DBG(CXT, ul_debugobj(cxt, "next-remount: not-match "
"[fstype: %s, t-pattern: %s, options: %s, O-pattern: %s]",
mnt_fs_get_fstype(*fs),
cxt->fstype_pattern,
mnt_fs_get_options(*fs),
cxt->optstr_pattern));
return 0;
}
/* Save mount options, etc. -- this is effective for the first
* mnt_context_next_remount() call only. Make sure that cxt has not set
* source, target or fstype.
*/
if (!mnt_context_has_template(cxt)) {
mnt_context_set_source(cxt, NULL);
mnt_context_set_target(cxt, NULL);
mnt_context_set_fstype(cxt, NULL);
mnt_context_save_template(cxt);
}
/* restore original, but protect mtab */
cxt->mtab = NULL;
mnt_reset_context(cxt);
cxt->mtab = mtab;
rc = mnt_context_set_target(cxt, tgt);
if (!rc) {
/*
* "-t <pattern>" is used to filter out fstab entries, but for ordinary
* mount operation -t means "-t <type>". We have to zeroize the pattern
* to avoid misinterpretation.
*/
char *pattern = cxt->fstype_pattern;
cxt->fstype_pattern = NULL;
rc = mnt_context_mount(cxt);
cxt->fstype_pattern = pattern;
if (mntrc)
*mntrc = rc;
rc = 0;
}
return rc;
}
/*
* Returns 1 if @dir parent is shared
*/
static int is_shared_tree(struct libmnt_context *cxt, const char *dir)
{
struct libmnt_table *tb = NULL;
struct libmnt_fs *fs;
unsigned long mflags = 0;
char *mnt = NULL, *p;
int rc = 0;
struct libmnt_ns *ns_old;
ns_old = mnt_context_switch_target_ns(cxt);
if (!ns_old)
return -MNT_ERR_NAMESPACE;
if (!dir)
return 0;
if (mnt_context_get_mtab(cxt, &tb) || !tb)
goto done;
mnt = strdup(dir);
if (!mnt)
goto done;
p = strrchr(mnt, '/');
if (!p)
goto done;
if (p > mnt)
*p = '\0';
fs = mnt_table_find_mountpoint(tb, mnt, MNT_ITER_BACKWARD);
rc = fs && mnt_fs_is_kernel(fs)
&& mnt_fs_get_propagation(fs, &mflags) == 0
&& (mflags & MS_SHARED);
done:
free(mnt);
if (!mnt_context_switch_ns(cxt, ns_old))
return -MNT_ERR_NAMESPACE;
return rc;
}
int mnt_context_get_mount_excode(
struct libmnt_context *cxt,
int rc,
char *buf,
size_t bufsz)
{
int syserr;
struct stat st;
unsigned long uflags = 0, mflags = 0;
int restricted = mnt_context_is_restricted(cxt);
const char *tgt = mnt_context_get_target(cxt);
const char *src = mnt_context_get_source(cxt);
if (mnt_context_helper_executed(cxt)) {
/*
* /sbin/mount.<type> called, return status
*/
if (rc == -MNT_ERR_APPLYFLAGS && buf)
snprintf(buf, bufsz, _("WARNING: failed to apply propagation flags"));
return mnt_context_get_helper_status(cxt);
}
if (rc == 0 && mnt_context_get_status(cxt) == 1) {
/*
* Libmount success && syscall success.
*/
if (buf && mnt_context_forced_rdonly(cxt))
snprintf(buf, bufsz, _("WARNING: device write-protected, mounted read-only"));
return MNT_EX_SUCCESS;
}
mnt_context_get_mflags(cxt, &mflags); /* mount(2) flags */
mnt_context_get_user_mflags(cxt, &uflags); /* userspace flags */
if (!mnt_context_syscall_called(cxt)) {
/*
* libmount errors (extra library checks)
*/
switch (rc) {
case -EPERM:
if (buf)
snprintf(buf, bufsz, _("operation permitted for root only"));
return MNT_EX_USAGE;
case -EBUSY:
if (buf)
snprintf(buf, bufsz, _("%s is already mounted"), src);
return MNT_EX_USAGE;
case -MNT_ERR_NOFSTAB:
if (!buf)
return MNT_EX_USAGE;
if (mnt_context_is_swapmatch(cxt))
snprintf(buf, bufsz, _("can't find in %s"),
mnt_get_fstab_path());
else if (tgt)
snprintf(buf, bufsz, _("can't find mount point in %s"),
mnt_get_fstab_path());
else if (src)
snprintf(buf, bufsz, _("can't find mount source %s in %s"),
src, mnt_get_fstab_path());
return MNT_EX_USAGE;
case -MNT_ERR_AMBIFS:
if (buf)
snprintf(buf, bufsz, _("more filesystems detected on %s; use -t <type> or wipefs(8)"), src);
return MNT_EX_USAGE;
case -MNT_ERR_NOFSTYPE:
if (buf)
snprintf(buf, bufsz, restricted ?
_("failed to determine filesystem type") :
_("no filesystem type specified"));
return MNT_EX_USAGE;
case -MNT_ERR_NOSOURCE:
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (buf) {
if (src)
snprintf(buf, bufsz, _("can't find %s"), src);
else
snprintf(buf, bufsz, _("no mount source specified"));
}
return MNT_EX_USAGE;
case -MNT_ERR_MOUNTOPT:
if (buf)
snprintf(buf, bufsz, errno ?
_("failed to parse mount options: %m") :
_("failed to parse mount options"));
return MNT_EX_USAGE;
case -MNT_ERR_LOOPDEV:
if (buf)
snprintf(buf, bufsz, _("failed to setup loop device for %s"), src);
return MNT_EX_FAIL;
case -MNT_ERR_LOOPOVERLAP:
if (buf)
snprintf(buf, bufsz, _("overlapping loop device exists for %s"), src);
return MNT_EX_FAIL;
case -MNT_ERR_LOCK:
if (buf)
snprintf(buf, bufsz, _("locking failed"));
return MNT_EX_FILEIO;
case -MNT_ERR_NAMESPACE:
if (buf)
snprintf(buf, bufsz, _("failed to switch namespace"));
return MNT_EX_SYSERR;
default:
return mnt_context_get_generic_excode(rc, buf, bufsz, _("mount failed: %m"));
}
} else if (mnt_context_get_syscall_errno(cxt) == 0) {
/*
* mount(2) syscall success, but something else failed
* (probably error in mtab processing).
*/
if (rc == -MNT_ERR_LOCK) {
if (buf)
snprintf(buf, bufsz, _("filesystem was mounted, but failed to update userspace mount table"));
return MNT_EX_FILEIO;
} else if (rc == -MNT_ERR_NAMESPACE) {
if (buf)
snprintf(buf, bufsz, _("filesystem was mounted, but failed to switch namespace back"));
return MNT_EX_SYSERR;
} else if (rc < 0)
return mnt_context_get_generic_excode(rc, buf, bufsz,
_("filesystem was mounted, but any subsequent operation failed: %m"));
return MNT_EX_SOFTWARE; /* internal error */
}
/*
* mount(2) errors
*/
syserr = mnt_context_get_syscall_errno(cxt);
switch(syserr) {
case EPERM:
if (!buf)
break;
if (geteuid() == 0) {
if (stat(tgt, &st) || !S_ISDIR(st.st_mode))
snprintf(buf, bufsz, _("mount point is not a directory"));
else
snprintf(buf, bufsz, _("permission denied"));
} else
snprintf(buf, bufsz, _("must be superuser to use mount"));
break;
case EBUSY:
{
struct libmnt_table *tb;
if (!buf)
break;
if (mflags & MS_REMOUNT) {
snprintf(buf, bufsz, _("mount point is busy"));
break;
}
if (src && mnt_context_get_mtab(cxt, &tb) == 0) {
struct libmnt_iter itr;
struct libmnt_fs *fs;
mnt_reset_iter(&itr, MNT_ITER_FORWARD);
while (mnt_table_next_fs(tb, &itr, &fs) == 0) {
const char *s = mnt_fs_get_srcpath(fs),
*t = mnt_fs_get_target(fs);
if (t && s && mnt_fs_streq_srcpath(fs, src)) {
snprintf(buf, bufsz, _("%s already mounted on %s"), s, t);
break;
}
}
}
if (!*buf)
snprintf(buf, bufsz, _("%s already mounted or mount point busy"), src);
break;
}
case ENOENT:
if (tgt && lstat(tgt, &st)) {
if (buf)
snprintf(buf, bufsz, _("mount point does not exist"));
} else if (tgt && stat(tgt, &st)) {
if (buf)
snprintf(buf, bufsz, _("mount point is a symbolic link to nowhere"));
} else if (src && stat(src, &st)) {
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (buf)
snprintf(buf, bufsz, _("special device %s does not exist"), src);
} else if (buf) {
errno = syserr;
snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
}
break;
case ENOTDIR:
if (stat(tgt, &st) || ! S_ISDIR(st.st_mode)) {
if (buf)
snprintf(buf, bufsz, _("mount point is not a directory"));
} else if (src && stat(src, &st) && errno == ENOTDIR) {
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (buf)
snprintf(buf, bufsz, _("special device %s does not exist "
"(a path prefix is not a directory)"), src);
} else if (buf) {
errno = syserr;
snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
}
break;
case EINVAL:
if (!buf)
break;
if (mflags & MS_REMOUNT)
snprintf(buf, bufsz, _("mount point not mounted or bad option"));
else if (rc == -MNT_ERR_APPLYFLAGS)
snprintf(buf, bufsz, _("not mount point or bad option"));
else if ((mflags & MS_MOVE) && is_shared_tree(cxt, src))
snprintf(buf, bufsz,
_("bad option; moving a mount "
"residing under a shared mount is unsupported"));
else if (mnt_fs_is_netfs(mnt_context_get_fs(cxt)))
snprintf(buf, bufsz,
_("bad option; for several filesystems (e.g. nfs, cifs) "
"you might need a /sbin/mount.<type> helper program"));
else
snprintf(buf, bufsz,
_("wrong fs type, bad option, bad superblock on %s, "
"missing codepage or helper program, or other error"),
src);
break;
case EMFILE:
if (buf)
snprintf(buf, bufsz, _("mount table full"));
break;
case EIO:
if (buf)
snprintf(buf, bufsz, _("can't read superblock on %s"), src);
break;
case ENODEV:
if (!buf)
break;
if (mnt_context_get_fstype(cxt))
snprintf(buf, bufsz, _("unknown filesystem type '%s'"),
mnt_context_get_fstype(cxt));
else
snprintf(buf, bufsz, _("unknown filesystem type"));
break;
case ENOTBLK:
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (!buf)
break;
if (src && stat(src, &st))
snprintf(buf, bufsz, _("%s is not a block device, and stat(2) fails?"), src);
else if (src && S_ISBLK(st.st_mode))
snprintf(buf, bufsz,
_("the kernel does not recognize %s as a block device; "
"maybe \"modprobe driver\" is necessary"), src);
else if (src && S_ISREG(st.st_mode))
snprintf(buf, bufsz, _("%s is not a block device; try \"-o loop\""), src);
else
snprintf(buf, bufsz, _("%s is not a block device"), src);
break;
case ENXIO:
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (buf)
snprintf(buf, bufsz, _("%s is not a valid block device"), src);
break;
case EACCES:
case EROFS:
if (!buf)
break;
if (mflags & MS_RDONLY)
snprintf(buf, bufsz, _("cannot mount %s read-only"), src);
else if (mnt_context_is_rwonly_mount(cxt))
snprintf(buf, bufsz, _("%s is write-protected but explicit read-write mode requested"), src);
else if (mflags & MS_REMOUNT)
snprintf(buf, bufsz, _("cannot remount %s read-write, is write-protected"), src);
else if (mflags & MS_BIND)
snprintf(buf, bufsz, _("bind %s failed"), src);
else {
errno = syserr;
snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
}
break;
case ENOMEDIUM:
if (uflags & MNT_MS_NOFAIL)
return MNT_EX_SUCCESS;
if (buf)
snprintf(buf, bufsz, _("no medium found on %s"), src);
break;
case EBADMSG:
/* Bad CRC for classic filesystems (e.g. extN or XFS) */
if (buf && src && stat(src, &st) == 0
&& (S_ISBLK(st.st_mode) || S_ISREG(st.st_mode))) {
snprintf(buf, bufsz, _("cannot mount; probably corrupted filesystem on %s"), src);
break;
}
/* fallthrough */
default:
if (buf) {
errno = syserr;
snprintf(buf, bufsz, _("mount(2) system call failed: %m"));
}
break;
}
return MNT_EX_FAIL;
}