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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
Copyright (c) 2010 Gluster, Inc. <http://www.gluster.com>
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB.
*/
#include "mount-gluster-compat.h"
/*
* These functions (and gf_fuse_umount() in mount.c)
* were originally taken from libfuse as of commit 7960e99e
* (http://fuse.git.sourceforge.net/git/gitweb.cgi?p=fuse/fuse;a=commit;h=7960e99e)
* almost verbatim. What has been changed upon adoption:
* - style adopted to that of glusterfs
* - s/fprintf/gf_log/
* - s/free/FREE/, s/malloc/MALLOC/
* - there are some other minor things
*
* For changes that were made later and syncs with upstream,
* see the commit log and per-function comments.
*/
#ifdef GF_LINUX_HOST_OS
/* FUSE: cherry-picked bd99f9cf */
static int
mtab_needs_update (const char *mnt)
{
int res;
struct stat stbuf;
/* If mtab is within new mount, don't touch it */
if (strncmp (mnt, _PATH_MOUNTED, strlen (mnt)) == 0 &&
_PATH_MOUNTED[strlen (mnt)] == '/')
return 0;
/*
* Skip mtab update if /etc/mtab:
*
* - doesn't exist,
* - is a symlink,
* - is on a read-only filesystem.
*/
res = lstat (_PATH_MOUNTED, &stbuf);
if (res == -1) {
if (errno == ENOENT)
return 0;
} else {
uid_t ruid;
int err;
if (S_ISLNK (stbuf.st_mode))
return 0;
ruid = getuid ();
if (ruid != 0)
setreuid (0, -1);
res = access (_PATH_MOUNTED, W_OK);
err = (res == -1) ? errno : 0;
if (ruid != 0)
setreuid (ruid, -1);
if (err == EROFS)
return 0;
}
return 1;
}
#else /* GF_LINUX_HOST_OS */
#define mtab_needs_update(x) 1
#endif /* GF_LINUX_HOST_OS */
/* FUSE: called add_mount_legacy(); R.I.P. as of cbd3a2a8 */
int
fuse_mnt_add_mount (const char *progname, const char *fsname,
const char *mnt, const char *type, const char *opts)
{
int res;
int status;
sigset_t blockmask;
sigset_t oldmask;
if (!mtab_needs_update (mnt))
return 0;
sigemptyset (&blockmask);
sigaddset (&blockmask, SIGCHLD);
res = sigprocmask (SIG_BLOCK, &blockmask, &oldmask);
if (res == -1) {
GFFUSE_LOGERR ("%s: sigprocmask: %s",
progname, strerror (errno));
return -1;
}
res = fork ();
if (res == -1) {
GFFUSE_LOGERR ("%s: fork: %s", progname, strerror (errno));
goto out_restore;
}
if (res == 0) {
char templ[] = "/tmp/fusermountXXXXXX";
char *tmp;
sigprocmask (SIG_SETMASK, &oldmask, NULL);
res = setuid (geteuid ());
if (res != 0) {
GFFUSE_LOGERR ("%s: setuid: %s", progname, strerror (errno));
exit (1);
}
/*
* hide in a directory, where mount isn't able to resolve
* fsname as a valid path
*/
tmp = mkdtemp (templ);
if (!tmp) {
GFFUSE_LOGERR ("%s: failed to create temporary directory",
progname);
exit (1);
}
if (chdir (tmp)) {
GFFUSE_LOGERR ("%s: failed to chdir to %s: %s",
progname, tmp, strerror (errno));
exit (1);
}
rmdir (tmp);
execl (_PATH_MOUNT, _PATH_MOUNT, "-i", "-f", "-t", type,
"-o", opts, fsname, mnt, NULL);
GFFUSE_LOGERR ("%s: failed to execute %s: %s",
progname, _PATH_MOUNT, strerror (errno));
exit (1);
}
res = waitpid (res, &status, 0);
if (res == -1)
GFFUSE_LOGERR ("%s: waitpid: %s", progname, strerror (errno));
res = (res != -1 && status == 0) ? 0 : -1;
out_restore:
sigprocmask (SIG_SETMASK, &oldmask, NULL);
return res;
}
char *
fuse_mnt_resolve_path (const char *progname, const char *orig)
{
char buf[PATH_MAX];
char *copy;
char *dst;
char *end;
char *lastcomp;
const char *toresolv;
if (!orig[0]) {
GFFUSE_LOGERR ("%s: invalid mountpoint '%s'", progname, orig);
return NULL;
}
copy = strdup (orig);
if (copy == NULL) {
GFFUSE_LOGERR ("%s: failed to allocate memory", progname);
return NULL;
}
toresolv = copy;
lastcomp = NULL;
for (end = copy + strlen (copy) - 1; end > copy && *end == '/'; end --);
if (end[0] != '/') {
char *tmp;
end[1] = '\0';
tmp = strrchr (copy, '/');
if (tmp == NULL) {
lastcomp = copy;
toresolv = ".";
} else {
lastcomp = tmp + 1;
if (tmp == copy)
toresolv = "/";
}
if (strcmp (lastcomp, ".") == 0 || strcmp (lastcomp, "..") == 0) {
lastcomp = NULL;
toresolv = copy;
}
else if (tmp)
tmp[0] = '\0';
}
if (realpath (toresolv, buf) == NULL) {
GFFUSE_LOGERR ("%s: bad mount point %s: %s", progname, orig,
strerror (errno));
FREE (copy);
return NULL;
}
if (lastcomp == NULL)
dst = strdup (buf);
else {
dst = (char *) MALLOC (strlen (buf) + 1 + strlen (lastcomp) + 1);
if (dst) {
unsigned buflen = strlen (buf);
if (buflen && buf[buflen-1] == '/')
sprintf (dst, "%s%s", buf, lastcomp);
else
sprintf (dst, "%s/%s", buf, lastcomp);
}
}
FREE (copy);
if (dst == NULL)
GFFUSE_LOGERR ("%s: failed to allocate memory", progname);
return dst;
}
/* FUSE: to support some changes that were reverted since
* then, it was split in two (fuse_mnt_umount() and
* exec_umount()); however the actual code is same as here
* since 0197ce40
*/
int
fuse_mnt_umount (const char *progname, const char *abs_mnt,
const char *rel_mnt, int lazy)
{
int res;
int status;
sigset_t blockmask;
sigset_t oldmask;
if (!mtab_needs_update (abs_mnt)) {
res = umount2 (rel_mnt, lazy ? 2 : 0);
if (res == -1)
GFFUSE_LOGERR ("%s: failed to unmount %s: %s",
progname, abs_mnt, strerror (errno));
return res;
}
sigemptyset (&blockmask);
sigaddset (&blockmask, SIGCHLD);
res = sigprocmask (SIG_BLOCK, &blockmask, &oldmask);
if (res == -1) {
GFFUSE_LOGERR ("%s: sigprocmask: %s", progname,
strerror (errno));
return -1;
}
res = fork ();
if (res == -1) {
GFFUSE_LOGERR ("%s: fork: %s", progname, strerror (errno));
goto out_restore;
}
if (res == 0) {
sigprocmask (SIG_SETMASK, &oldmask, NULL);
res = setuid (geteuid ());
if (res != 0) {
GFFUSE_LOGERR ("%s: setuid: %s", progname, strerror (errno));
exit (1);
}
#ifdef GF_LINUX_HOST_OS
execl ("/bin/umount", "/bin/umount", "-i", rel_mnt,
lazy ? "-l" : NULL, NULL);
GFFUSE_LOGERR ("%s: failed to execute /bin/umount: %s",
progname, strerror (errno));
#elif __NetBSD__
/* exitting the filesystem causes the umount */
exit (0);
#else
execl ("/sbin/umount", "/sbin/umount", "-f", rel_mnt, NULL);
GFFUSE_LOGERR ("%s: failed to execute /sbin/umount: %s",
progname, strerror (errno));
#endif /* GF_LINUX_HOST_OS */
exit (1);
}
res = waitpid (res, &status, 0);
if (res == -1)
GFFUSE_LOGERR ("%s: waitpid: %s", progname, strerror (errno));
if (status != 0)
res = -1;
out_restore:
sigprocmask (SIG_SETMASK, &oldmask, NULL);
return res;
}
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