psmisc/0001-Use-mountinfo-to-be-able-to-use-the-mount-identity.patch

From d7487838d0c79bd007e63e9ba9f7933cec40e3c9 Mon Sep 17 00:00:00 2001
From: Werner Fink <werner@suse.de>
Date: Thu, 29 Jun 2017 15:18:28 +0200
Subject: [PATCH] Use mountinfo to be able to use the mount identity

which allows to distinguish different mounts with the
same device number as it happens with NFS shares.
Smaller cleanup as support of chroot environments
and older systems.

Add support for name_to_handle_at() system call to
get the real mount ID for each file

Signed-off-by: Werner Fink <werner@suse.de>
---
 configure.ac                       |  18 +-
 src/fuser.c                        | 528 +++++++++++++++++++++++++++----------
 src/fuser.h                        |  19 +-
 testsuite/Makefile.am              |   3 +-
 testsuite/killall.test/killall.exp |   4 +
 5 files changed, 424 insertions(+), 148 deletions(-)

diff --git configure.ac configure.ac
index 176a2fc..d8d3366 100644
--- configure.ac
+++ configure.ac
@@ -27,6 +27,9 @@ if test "$enable_selinux" = "yes"; then
   AC_DEFINE([WITH_SELINUX], [1], [Use Security-Enhanced Linux features])
   AC_CHECK_LIB([selinux], [getfilecon], [SELINUX_LIB=-lselinux], [
      AC_MSG_ERROR([Cannot find selinux static library]) ])
+  echo 'set has_selinux 1' > testsuite/selinux.exp
+else
+  echo 'set has_selinux 0' > testsuite/selinux.exp
 fi
 AC_SUBST([SELINUX_LIB])
 
@@ -44,6 +47,19 @@ if test "$enable_timeout_stat" = "static"; then
 fi
 AM_CONDITIONAL([WANT_TIMEOUT_STAT], [test "$enable_timeout_stat" = "static"])
 
+# Use /proc/self/mountinfo if available
+if test -e /proc/self/mountinfo ; then
+  AC_DEFINE([HAS_MOUNTINFO], [1], [System has /proc/self/mountinfo which can used instead /proc(/self)/mounts])
+fi
+# Use /proc/self/fdinfo if available
+if test -e /proc/self/fdinfo ; then
+  AC_DEFINE([HAS_FDINFO], [1], [System has /proc/self/fdinfo for informations on file descriptors])
+fi
+
+# Check for Linux specific name_to_handle_at(2) system call for getting mount IDs
+AC_CHECK_FUNC([name_to_handle_at],[
+  AC_DEFINE([HAS_NAME_TO_HANDLE_AT], [1], [System has name_to_handle_at(2) system call])])
+
 # Use string search for network based file systems but only if the system
 # has /proc/self/mountinfo
 AC_SUBST([WITH_MOUNTINFO_LIST])
@@ -85,7 +101,7 @@ dnl Checks for header files.
 AC_HEADER_DIRENT
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h langinfo.h libintl.h limits.h locale.h mntent.h netdb.h netinet/in.h stdlib.h string.h sys/ioctl.h sys/socket.h termios.h unistd.h])
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h langinfo.h libintl.h limits.h locale.h mntent.h netdb.h netinet/in.h stdlib.h string.h sys/ioctl.h sys/mount.h sys/param.h sys/stat.h sys/socket.h sys/types.h termios.h unistd.h])
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_C_CONST
diff --git src/fuser.c src/fuser.c
index 31ef30c..a204f08 100644
--- src/fuser.c
+++ src/fuser.c
@@ -32,6 +32,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <fcntl.h>
+#if defined(HAS_GETFH)
+#include <sys/mount.h>
+#endif
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -78,7 +82,7 @@ static void check_map(const pid_t pid, const char *filename,
 		      struct device_list *dev_head,
 		      struct inode_list *ino_head, const uid_t uid,
 		      const char access);
-static struct stat *get_pidstat(const pid_t pid, const char *filename);
+static struct stat *get_pidstat(const pid_t pid, const char *filename, int *id);
 static uid_t getpiduid(const pid_t pid);
 static int print_matches(struct names *names_head, const opt_type opts,
 			 const int sig_number);
@@ -88,8 +92,8 @@ static int kill_matched_proc(struct procs *pptr, const opt_type opts,
 /*int parse_mount(struct names *this_name, struct device_list **dev_list);*/
 static void add_device(struct device_list **dev_list,
 		       struct names *this_name, dev_t device);
-void fill_unix_cache(struct unixsocket_list **unixsocket_head);
-void clear_unix_cache(struct unixsocket_list **unixsocket_head);
+static void fill_unix_cache(struct unixsocket_list **unixsocket_head);
+static void clear_unix_cache(struct unixsocket_list **unixsocket_head);
 static void atexit_clear_unix_cache();
 static dev_t find_net_dev(void);
 static void scan_procs(struct names *names_head, struct inode_list *ino_head,
@@ -108,9 +112,12 @@ static void debug_match_lists(struct names *names_head,
 			      struct device_list *dev_head);
 #endif
 
-#if defined(WITH_MOUNTINFO_LIST)
+static list_t mntinfo = { &mntinfo, &mntinfo };
 static void clear_mntinfo(void) __attribute__ ((__destructor__));
 static void init_mntinfo(void) __attribute__ ((__constructor__));
+static int get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info);
+static int find_mountpoint(const char *path, mntinfo_t **mountinfo);
+#if defined(WITH_MOUNTINFO_LIST)
 static int mntstat(const char *path, struct stat *buf);
 #endif
 static stat_t thestat = stat;
@@ -198,6 +205,7 @@ scan_procs(struct names *names_head, struct inode_list *ino_head,
 		struct stat *cwd_stat = NULL;
 		struct stat *exe_stat = NULL;
 		struct stat *root_stat = NULL;
+		int cwd_id, exe_id, root_id;
 
 		if (topproc_dent->d_name[0] < '0' || topproc_dent->d_name[0] > '9')	/* Not a process */
 			continue;
@@ -207,9 +215,9 @@ scan_procs(struct names *names_head, struct inode_list *ino_head,
 			continue;
 		uid = getpiduid(pid);
 
-		cwd_stat = get_pidstat(pid, "cwd");
-		exe_stat = get_pidstat(pid, "exe");
-		root_stat = get_pidstat(pid, "root");
+		cwd_stat = get_pidstat(pid, "cwd", &cwd_id);
+		exe_stat = get_pidstat(pid, "exe", &exe_id);
+		root_stat = get_pidstat(pid, "root", &root_id);
 		cwd_dev = cwd_stat ? cwd_stat->st_dev : 0;
 		exe_dev = exe_stat ? exe_stat->st_dev : 0;
 		root_dev = root_stat ? root_stat->st_dev : 0;
@@ -217,21 +225,21 @@ scan_procs(struct names *names_head, struct inode_list *ino_head,
 		/* Scan the devices */
 		for (dev_tmp = dev_head; dev_tmp != NULL;
 		     dev_tmp = dev_tmp->next) {
-			if (exe_dev == dev_tmp->device)
-				add_matched_proc(dev_tmp->name, pid, uid,
-						 ACCESS_EXE);
-			if (root_dev == dev_tmp->device)
-				add_matched_proc(dev_tmp->name, pid, uid,
-						 ACCESS_ROOT);
-			if (cwd_dev == dev_tmp->device)
-				add_matched_proc(dev_tmp->name, pid, uid,
-						 ACCESS_CWD);
+			char access = 0;
+			if (exe_dev == dev_tmp->device && dev_tmp->mnt_id == exe_id)
+				access |= ACCESS_EXE;
+			if (root_dev == dev_tmp->device && dev_tmp->mnt_id == root_id)
+				access |= ACCESS_ROOT;
+			if (cwd_dev == dev_tmp->device && dev_tmp->mnt_id == cwd_id)
+				access |= ACCESS_CWD;
+			if (access)
+				add_matched_proc(dev_tmp->name, pid, uid, access);
 		}
 		for (ino_tmp = ino_head; ino_tmp != NULL;
 		     ino_tmp = ino_tmp->next) {
 			if (exe_dev == ino_tmp->device) {
 				if (!exe_stat)
-					exe_stat = get_pidstat(pid, "exe");
+					exe_stat = get_pidstat(pid, "exe", NULL);
 				if (exe_stat
 				    && exe_stat->st_dev == ino_tmp->device
 				    && exe_stat->st_ino == ino_tmp->inode)
@@ -240,7 +248,7 @@ scan_procs(struct names *names_head, struct inode_list *ino_head,
 			}
 			if (root_dev == ino_tmp->device) {
 				if (!root_stat)
-					root_stat = get_pidstat(pid, "root");
+					root_stat = get_pidstat(pid, "root", NULL);
 				if (root_stat
 				    && root_stat->st_dev == ino_tmp->device
 				    && root_stat->st_ino == ino_tmp->inode)
@@ -249,7 +257,7 @@ scan_procs(struct names *names_head, struct inode_list *ino_head,
 			}
 			if (cwd_dev == ino_tmp->device) {
 				if (!cwd_stat)
-					cwd_stat = get_pidstat(pid, "cwd");
+					cwd_stat = get_pidstat(pid, "cwd", NULL);
 				if (cwd_stat
 				    && cwd_stat->st_dev == ino_tmp->device
 				    && cwd_stat->st_ino == ino_tmp->inode)
@@ -290,6 +298,7 @@ add_inode(struct inode_list **ino_list, struct names *this_name,
 	ino_tmp->name = this_name;
 	ino_tmp->device = device;
 	ino_tmp->inode = inode;
+	ino_tmp->mnt_id = this_name->mnt_id;
 	ino_tmp->next = ino_head;
 	*ino_list = ino_tmp;
 }
@@ -309,6 +318,7 @@ add_device(struct device_list **dev_list, struct names *this_name, dev_t device)
 	dev_head = *dev_list;
 	dev_tmp->name = this_name;
 	dev_tmp->device = device;
+	dev_tmp->mnt_id = this_name->mnt_id;
 	dev_tmp->next = dev_head;
 	*dev_list = dev_tmp;
 }
@@ -450,13 +460,15 @@ add_special_proc(struct names *name_list, const char ptype, const uid_t uid,
 int parse_file(struct names *this_name, struct inode_list **ino_list,
 	       const opt_type opts)
 {
+	mntinfo_t *mountinfo;
 	char *new = expandpath(this_name->filename);
 	if (new) {
 		if (this_name->filename)
 			free(this_name->filename);
 		this_name->filename = strdup(new);
 	}
-	if (timeout(thestat, this_name->filename, &(this_name->st), 5) != 0) {
+	if (timeout(thestat, this_name->filename, &(this_name->st), 5) != 0 ||
+	    find_mountpoint(this_name->filename, &mountinfo) != 0) {
 		if (errno == ENOENT)
 			fprintf(stderr,
 				_("Specified filename %s does not exist.\n"),
@@ -466,10 +478,12 @@ int parse_file(struct names *this_name, struct inode_list **ino_list,
 				this_name->filename, strerror(errno));
 		return -1;
 	}
+	this_name->mnt_id = mountinfo->id;
 #ifdef DEBUG
-	printf("adding file %s %lX %lX\n", this_name->filename,
+	printf("adding file %s %lX %lX %d nfs=%s\n", this_name->filename,
 	       (unsigned long)this_name->st.st_dev,
-	       (unsigned long)this_name->st.st_ino);
+	       (unsigned long)this_name->st.st_ino,
+	       mountinfo.id, mountinfo.isnfs ? "yes" : "no");
 #endif				/* DEBUG */
 	add_inode(ino_list, this_name, this_name->st.st_dev,
 		  this_name->st.st_ino);
@@ -501,11 +515,39 @@ parse_mounts(struct names *this_name, struct device_list **dev_list,
 	     const opt_type opts)
 {
 	dev_t match_device;
+	mntinfo_t *mountinfo = NULL;
+	list_t *ptr;
+	int count;
 
 	if (S_ISBLK(this_name->st.st_mode))
 		match_device = this_name->st.st_rdev;
 	else
 		match_device = this_name->st.st_dev;
+
+	count = 0;
+	list_for_each(ptr, &mntinfo) {
+		mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
+		if (match_device != mnt->dev || this_name->mnt_id != mnt->id)
+			continue;
+		if (!mountinfo)
+			mountinfo = mnt;
+		count++;
+	}
+	if (count == 0) {
+		errno = ENOENT;
+		fprintf(stderr,
+			_("Specified filename %s has no mountpoint.\n"),
+			this_name->filename);
+		return -1;
+	}
+	if (count > 1) {
+		errno = ENOTUNIQ;
+		fprintf(stderr,
+			_("The device %u:%u is not unique. Please change!\n"),
+			major(mountinfo->dev), minor(mountinfo->dev));
+		/* return -1 */
+	}
+	this_name->mnt_id = mountinfo->id;
 	add_device(dev_list, this_name, match_device);
 	return 0;
 }
@@ -620,7 +662,7 @@ int parse_inet(struct names *this_name, struct ip_connections **ip_list)
 			fprintf(stderr, _("Unknown local port AF %d\n"),
 				res->ai_family);
 			freeaddrinfo(res);
-            free(lcl_port_str);
+			free(lcl_port_str);
 			return -1;
 		}
 		freeaddrinfo(res);
@@ -683,10 +725,12 @@ int parse_inet(struct names *this_name, struct ip_connections **ip_list)
 					break;
 #endif
 				}
-			}	/*while */
-		    freeaddrinfo(res);
+			}	/* for (;;) */
+
+			freeaddrinfo(res);
 			return 0;
-		}
+
+		}	/* if getaddrinfo */
 	}
 	return 1;
 }
@@ -1161,16 +1205,11 @@ int main(int argc, char *argv[])
 					skip_argv = 1;
 					//while(option != '\0') option++;
 					if (strcmp(argv[argc_cnt], "tcp") == 0)
-						default_namespace =
-						    NAMESPACE_TCP;
-					else if (strcmp(argv[argc_cnt], "udp")
-						 == 0)
-						default_namespace =
-						    NAMESPACE_UDP;
-					else if (strcmp(argv[argc_cnt], "file")
-						 == 0)
-						default_namespace =
-						    NAMESPACE_FILE;
+						default_namespace = NAMESPACE_TCP;
+					else if (strcmp(argv[argc_cnt], "udp") == 0)
+						default_namespace = NAMESPACE_UDP;
+					else if (strcmp(argv[argc_cnt], "file") == 0)
+						default_namespace = NAMESPACE_FILE;
 					else
 						usage(_
 						      ("Invalid namespace name"));
@@ -1210,7 +1249,7 @@ int main(int argc, char *argv[])
 		}
 
 #if defined(WITH_MOUNTINFO_LIST)
-		if ((opts & OPT_ALWAYSSTAT) == 0)
+		if ((opts & (OPT_MOUNTS|OPT_ALWAYSSTAT)) == OPT_MOUNTS)
 			thestat = mntstat;
 #endif
 		/* an option */
@@ -1524,7 +1563,7 @@ print_matches(struct names *names_head, const opt_type opts,
 
 }
 
-static struct stat *get_pidstat(const pid_t pid, const char *filename)
+static struct stat *get_pidstat(const pid_t pid, const char *filename, int *id)
 {
 	char pathname[256];
 	struct stat *st;
@@ -1536,6 +1575,15 @@ static struct stat *get_pidstat(const pid_t pid, const char *filename)
 		free(st);
 		return NULL;
 	}
+
+	if (id) {
+		mntinfo_t *info;
+		char *new = expandpath(pathname);
+		if (new && find_mountpoint(new, &info) == 0)
+			*id = info->id;
+		else	*id = -1;
+	}
+
 	return st;
 }
 
@@ -1550,18 +1598,19 @@ check_dir(const pid_t pid, const char *dirname, struct device_list *dev_head,
 	struct inode_list *ino_tmp;
 	struct device_list *dev_tmp;
 	struct unixsocket_list *sock_tmp;
-	struct stat st, lst;
-	char dirpath[MAX_PATHNAME];
-	char filepath[MAX_PATHNAME];
+	struct fdinfo fd;
+	struct stat st;
+	char dirpath[PATH_MAX+1];
+	char filepath[PATH_MAX+1];
 
-	snprintf(dirpath, MAX_PATHNAME, "/proc/%d/%s", pid, dirname);
+	snprintf(dirpath, PATH_MAX, "/proc/%d/%s", pid, dirname);
 	if ((dirp = opendir(dirpath)) == NULL)
 		return;
 	while ((direntry = readdir(dirp)) != NULL) {
 		if (direntry->d_name[0] < '0' || direntry->d_name[0] > '9')
 			continue;
 
-		snprintf(filepath, MAX_PATHNAME, "/proc/%d/%s/%s",
+		snprintf(filepath, PATH_MAX, "/proc/%d/%s/%s",
 			 pid, dirname, direntry->d_name);
 
 		if (timeout(thestat, filepath, &st, 5) != 0) {
@@ -1586,9 +1635,12 @@ check_dir(const pid_t pid, const char *dirname, struct device_list *dev_head,
 			     dev_tmp = dev_tmp->next) {
 				if (thedev != dev_tmp->device)
 					continue;
+				if (get_fdinfo(pid, direntry->d_name, &fd) != 0)
+					continue;
+				if (fd.mnt_id != dev_tmp->mnt_id)
+					continue;
 				if (access == ACCESS_FILE
-				    && (lstat(filepath, &lst) == 0)
-				    && (lst.st_mode & S_IWUSR)) {
+				    && (fd.flags & (O_WRONLY|O_RDWR))) {
 					add_matched_proc(dev_tmp->name,
 							 pid, uid,
 							 ACCESS_FILEWR |
@@ -1610,9 +1662,10 @@ check_dir(const pid_t pid, const char *dirname, struct device_list *dev_head,
 					continue;
 				}
 				if (st.st_ino == ino_tmp->inode) {
+					if (get_fdinfo(pid, direntry->d_name, &fd) != 0)
+						continue;
 					if (access == ACCESS_FILE
-					    && (lstat(filepath, &lst) == 0)
-					    && (lst.st_mode & S_IWUSR)) {
+					    && (fd.flags & (O_WRONLY|O_RDWR))) {
 						add_matched_proc(ino_tmp->name,
 								 pid, uid,
 								 ACCESS_FILEWR |
@@ -1641,18 +1694,30 @@ check_map(const pid_t pid, const char *filename,
 	FILE *fp;
 	unsigned long long tmp_inode;
 	unsigned int tmp_maj, tmp_min;
-	dev_t tmp_device;
 
 	snprintf(pathname, MAX_PATHNAME, "/proc/%d/%s", pid, filename);
 	if ((fp = fopen(pathname, "r")) == NULL)
 		return;
 	while (fgets(line, BUFSIZ, fp)) {
-		if (sscanf(line, "%*s %*s %*s %x:%x %lld",
-			   &tmp_maj, &tmp_min, &tmp_inode) == 3) {
-			tmp_device = tmp_maj * 256 + tmp_min;
+		char *scanned_path = NULL;
+		if (sscanf(line, "%*s %*s %*s %x:%x %lld %ms",
+			   &tmp_maj, &tmp_min, &tmp_inode, &scanned_path) == 4) {
+			dev_t tmp_device = makedev(tmp_maj, tmp_min);
+			int mnt_id = -1;
+
+			if (scanned_path) {
+				if (*scanned_path == '/') {
+					mntinfo_t *mountinfo;
+					if (find_mountpoint(scanned_path, &mountinfo) == 0)
+						mnt_id = mountinfo->id;
+				}
+				free(scanned_path);
+			}
+
 			for (dev_tmp = dev_head; dev_tmp != NULL;
 			     dev_tmp = dev_tmp->next)
-				if (dev_tmp->device == tmp_device)
+				if (dev_tmp->device == tmp_device &&
+				    mnt_id == dev_tmp->mnt_id)
 					add_matched_proc(dev_tmp->name, pid,
 							 uid, access);
 			for (ino_tmp = ino_head; ino_tmp != NULL;
@@ -1661,7 +1726,8 @@ check_map(const pid_t pid, const char *filename,
 				    && ino_tmp->inode == tmp_inode)
 					add_matched_proc(ino_tmp->name, pid,
 							 uid, access);
-		}
+		} else if (scanned_path)
+			free(scanned_path);
 	}
 	fclose(fp);
 }
@@ -1682,6 +1748,7 @@ static uid_t getpiduid(const pid_t pid)
  * fill_unix_cache : Create a list of Unix sockets
  *   This list is used later for matching purposes
  */
+static
 void fill_unix_cache(struct unixsocket_list **unixsocket_head)
 {
 	FILE *fp;
@@ -1698,6 +1765,8 @@ void fill_unix_cache(struct unixsocket_list **unixsocket_head)
 	while (fgets(line, BUFSIZ, fp) != NULL) {
 		char *path;
 		char *scanned_path = NULL;
+		int mnt_id = -1;
+		mntinfo_t *mountinfo;
 		if (sscanf(line, "%*x: %*x %*x %*x %*x %*d %d %ms",
 			   &scanned_inode, &scanned_path) != 2) {
 			if (scanned_path)
@@ -1713,6 +1782,8 @@ void fill_unix_cache(struct unixsocket_list **unixsocket_head)
 			free(path);
 			continue;
 		}
+		if (find_mountpoint(scanned_path, &mountinfo) == 0)
+			mnt_id = mountinfo->id;
 		if ((newsocket = (struct unixsocket_list *)
 		     malloc(sizeof(struct unixsocket_list))) == NULL) {
 			free(path);
@@ -1721,6 +1792,7 @@ void fill_unix_cache(struct unixsocket_list **unixsocket_head)
 		newsocket->sun_name = strdup(scanned_path);
 		newsocket->inode = st.st_ino;
 		newsocket->dev = st.st_dev;
+		newsocket->mnt_id = mnt_id;
 		newsocket->net_inode = scanned_inode;
 		newsocket->next = *unixsocket_head;
 		*unixsocket_head = newsocket;
@@ -1733,6 +1805,7 @@ void fill_unix_cache(struct unixsocket_list **unixsocket_head)
 /*
  * Free up the list of Unix sockets
  */
+static
 void clear_unix_cache(struct unixsocket_list **unixsocket_head)
 {
 	while(*unixsocket_head != NULL) {
@@ -1900,30 +1973,22 @@ scan_mounts(struct names *names_head, struct inode_list *ino_head,
 {
 	struct device_list *dev_tmp;
 	struct inode_list *ino_tmp;
-	FILE *fp;
-	char line[BUFSIZ];
-	char *find_mountp;
-	char *find_space;
 	struct stat st;
 
-	if ((fp = fopen(PROC_MOUNTS, "r")) == NULL) {
-		fprintf(stderr, "Cannot open %s\n", PROC_MOUNTS);
-		return;
-	}
-	while (fgets(line, BUFSIZ, fp) != NULL) {
-		if ((find_mountp = strchr(line, ' ')) == NULL)
-			continue;
-		find_mountp++;
-		if ((find_space = strchr(find_mountp, ' ')) == NULL)
-			continue;
-		*find_space = '\0';
-		if (timeout(thestat, find_mountp, &st, 5) != 0) {
+	list_t *ptr;
+
+	list_for_each(ptr, &mntinfo) {
+		mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
+		const char *find_mountp = mnt->mpoint;
+
+		if (timeout(thestat, find_mountp, &st, 5) != 0)
 			continue;
-		}
+
 		/* Scan the devices */
 		for (dev_tmp = dev_head; dev_tmp != NULL;
 		     dev_tmp = dev_tmp->next) {
-			if (st.st_dev == dev_tmp->device)
+			if (st.st_dev == dev_tmp->device &&
+			    mnt->id == dev_tmp->mnt_id)
 				add_special_proc(dev_tmp->name, PTYPE_MOUNT, 0,
 						 find_mountp);
 		}
@@ -1935,7 +2000,6 @@ scan_mounts(struct names *names_head, struct inode_list *ino_head,
 						 find_mountp);
 		}
 	}
-	fclose(fp);
 }
 
 static void
@@ -1985,16 +2049,42 @@ scan_swaps(struct names *names_head, struct inode_list *ino_head,
 	fclose(fp);
 }
 
-#if defined(WITH_MOUNTINFO_LIST)
 /*
  * Use /proc/self/mountinfo of modern linux system to determine
  * the device numbers of the mount points. Use this to avoid the
  * stat(2) system call wherever possible.
  */
 
-static list_t mntinfo = { &mntinfo, &mntinfo };
+static mntinfo_t*
+add_mntinfo(const char *mpoint, const char *type, int mid, int parid, dev_t dev)
+{
+	const size_t nlen = strlen(mpoint);
+	mntinfo_t *restrict mnt;
+	if (posix_memalign
+	    ((void *)&mnt, sizeof(void *),
+	     alignof(mntinfo_t) + (nlen + 1)) != 0) {
+		fprintf(stderr,
+			_
+			("Cannot allocate memory for matched proc: %s\n"),
+			strerror(errno));
+		exit(1);
+	}
+	append(mnt, mntinfo);
+	mnt->mpoint = ((char *)mnt) + alignof(mntinfo_t);
+	strcpy(mnt->mpoint, mpoint);
+	mnt->nlen = nlen;
+	mnt->parid = parid;
+	mnt->dev = dev;
+	mnt->id = mid;
+	if (strncmp("nfs", type, 3) == 0)
+		mnt->isnfs = 1;
+	else	mnt->isnfs = 0;
+
+	return mnt;
+}
 
-static void clear_mntinfo(void)
+static void
+clear_mntinfo(void)
 {
 	list_t *ptr, *tmp;
 
@@ -2005,72 +2095,232 @@ static void clear_mntinfo(void)
 	}
 }
 
-static void init_mntinfo(void)
+static void
+init_mntinfo(void)
 {
+	char type[256];
 	char mpoint[PATH_MAX*4 + 1]; // octal escaping takes 4 chars per 1 char
-	int mid, parid, max = 0;
+	int mid, parid;
+#if defined(HAS_MOUNTINFO)
 	uint maj, min;
-	list_t sort;
+#endif
 	FILE *mnt;
 
 	if (!list_empty(&mntinfo))
 		return;
-	if ((mnt = fopen("/proc/self/mountinfo", "r")) == (FILE *) 0)
+#if defined(HAS_MOUNTINFO)
+	if ((mnt = fopen(PROC_MOUNTINFO, "r")) == (FILE *) 0)
 		return;
 	while (fscanf
-	       (mnt, "%i %i %u:%u %*s %s %*[^\n]", &mid, &parid, &maj, &min,
-		&mpoint[0]) == 5) {
-		const size_t nlen = strlen(mpoint);
-		mntinfo_t *restrict mnt;
-		if (posix_memalign
-		    ((void *)&mnt, sizeof(void *),
-		     alignof(mntinfo_t) + (nlen + 1)) != 0) {
-			fprintf(stderr,
-				_
-				("Cannot allocate memory for matched proc: %s\n"),
-				strerror(errno));
-			exit(1);
+	       (mnt, "%i %i %u:%u %*s %s %*[^-] - %s %*[^\n]",
+		&mid, &parid, &maj, &min, &mpoint[0], &type[0]) == 6)
+		(void)add_mntinfo(mpoint, type, mid, parid, makedev(maj, min));
+#else
+	if ((mnt = fopen(PROC_MOUNTS, "r")) == (FILE *) 0)
+		return;
+	mid = 1;
+	parid = -1;
+	while (fscanf (mnt, "%*s %s %s %*[^\n]", &mpoint[0], &type[0]) == 2) {
+		struct stat st;
+		if (stat(mpoint, &st) != 0) {
+			if (errno != EACCES) {
+				fprintf(stderr, _("Cannot stat %s: %s\n"),
+					mnt->mpoint, strerror(errno));
+				exit(1);
+			}
+			st.st_dev = (dev_t)-1;
 		}
-		append(mnt, mntinfo);
-		mnt->mpoint = ((char *)mnt) + alignof(mntinfo_t);
-		strcpy(mnt->mpoint, mpoint);
-		mnt->nlen = nlen;
-		mnt->parid = parid;
-		mnt->dev = makedev(maj, min);
-		mnt->id = mid;
-		if (mid > max)
-			max = mid;
+		(void)add_mntinfo(mpoint, type, mid++, parid, st.st_dev);
 	}
+#endif
 	fclose(mnt);
+}
+
+static int
+get_fdinfo(const pid_t pid, const char *fd, struct fdinfo *info)
+{
+	int ret = 0;
+	char pathname[256];
+#if defined(HAS_FDINFO)
+	const static char delimiters[] = ": \t\n";
+	char line[BUFSIZ];
+	FILE *fp;
+	int mnt_id = 0, flags = 0;
+
+	snprintf(pathname, 256, "/proc/%d/fdinfo/%s", pid, fd);
+	if ((fp = fopen(pathname, "r")) == NULL)
+               goto out;
+	while (fgets(line, BUFSIZ, fp) && ret < 2) {
+		char *fp, *vp, *ep;
+		unsigned long ul;
+		fp = strtok(&line[0], delimiters);
+		if (!fp || *fp == 0)
+			continue;
+		vp = strtok(NULL, delimiters);
+		if (!vp || *vp == 0)
+			continue;
+		if (strcmp(fp, "flags")  == 0 && (ul = strtoul(vp, &ep, 0)) != ULONG_MAX && ep && *ep == 0) {
+			info->flags = (mode_t)ul;
+			flags++;
+			ret++;
+		}
+		if (strcmp(fp, "mnt_id") == 0 && (ul = strtoul(vp, &ep, 0)) != ULONG_MAX && ep && *ep == 0) {
+			info->mnt_id = (int)ul;
+			mnt_id++;
+			ret++;
+		}
+	}
+	fclose(fp);
+out:
+#endif
+	if (!flags || !mnt_id) {
+		struct stat lst;
+
+		snprintf(pathname, 256, "/proc/%d/fd/%s", pid, fd);
+		if (!flags && lstat(pathname, &lst) == 0) {
+			if (lst.st_mode & S_IWUSR)
+				info->flags |= O_WRONLY;
+			ret++;
+		}
+
+		if (!mnt_id) {
+			char *realname = expandpath(pathname);
+			if (realname) {
+				mntinfo_t *mountinfo;
+				if (find_mountpoint(realname, &mountinfo) == 0) {
+					info->mnt_id = mountinfo->id;
+					ret++;
+				}
+			}
+		}
+	}
+	return ret == 2 ? 0 : -1;
+}
+
+#if defined(HAS_NAME_TO_HANDLE_AT)
+static int
+get_mountid(const char *path)
+{
+	union fh_u {
+	    struct file_handle handle;
+	    char buffer[sizeof(struct file_handle) + MAX_HANDLE_SZ];
+	} fh = { .handle.handle_bytes = MAX_HANDLE_SZ };
+	int mnt_id = -1;
+
+	errno = 0;
+	if (name_to_handle_at(0, path, &fh.handle, &mnt_id, 0) == -1)
+		mnt_id = -1;
+	return mnt_id;
+}
+#endif
+
+static int
+find_mountpoint(const char *path, mntinfo_t **mountinfo)
+{
+	char *use, *end;
+	ssize_t nlen;
+#if defined(HAS_NAME_TO_HANDLE_AT)
+	int mnt_id = get_mountid(path);
+#endif
+	int ret = -1;
+
+	*mountinfo = NULL;
 
-	/* Sort mount points accordingly to the reverse mount order */
-	initial(&sort);
-	for (mid = 1; mid <= max; mid++) {
-		list_t *ptr, *tmp;
-		list_for_each_safe(ptr, tmp, &mntinfo) {
+#if defined(HAS_NAME_TO_HANDLE_AT)
+	if (mnt_id >= 0) {
+		list_t *ptr;
+
+		errno = ENOENT;
+		list_for_each(ptr, &mntinfo) {
 			mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
-			if (mid != mnt->id)
+
+			if (mnt_id != mnt->id)
 				continue;
-			move_head(ptr, &sort);
+
+			ret = 0;
+			errno = 0;
+			*mountinfo = mnt;
 			break;
 		}
-		list_for_each_safe(ptr, tmp, &mntinfo) {
+		if (*mountinfo)
+			goto out;
+
+		if (strlen(path) == 1 && path[0] == '/') {
+			struct stat st;
+
+			/* could be a chroot or a container */
+
+			if (stat(path, &st) != 0) {
+				if (errno != EACCES) {
+					fprintf(stderr, _("Cannot stat %s: %s\n"),
+						path, strerror(errno));
+					exit(1);
+				}
+				st.st_dev = (dev_t)-1;
+			}
+			ret = 0;
+			errno = 0;
+			*mountinfo = add_mntinfo(path, "unkown", mnt_id, -1, st.st_dev);
+			goto out;
+		}
+	}
+#endif
+	use = strdup(path);
+	if (!use)
+		goto out;
+
+	nlen = strlen(use);
+	end = use+nlen;
+	errno = ENOENT;
+	do {
+		list_t *ptr;
+		if (*end == '/') {
+			if (end == use)	{	/* root file system */
+				end++;
+				if (nlen == 1) {
+					struct stat st;
+
+					/* could be a chroot or a container */
+
+					if (stat(use, &st) != 0) {
+						if (errno != EACCES) {
+							fprintf(stderr, _("Cannot stat %s: %s\n"),
+								use, strerror(errno));
+							exit(1);
+						}
+						st.st_dev = (dev_t)-1;
+					}
+					ret = 0;
+					errno = 0;
+					*mountinfo = add_mntinfo(use, "unkown", 0, -1, st.st_dev);
+					break;
+				}
+			}
+		}
+		*end = '\0';
+		nlen = end-use;
+		list_for_each(ptr, &mntinfo) {
 			mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
-			if (mid != mnt->parid)
+
+			if (nlen != mnt->nlen)
 				continue;
-			move_head(ptr, &sort);
+
+			if (strcmp(use, mnt->mpoint))
+				continue;
+
+			ret = 0;
+			errno = 0;
+			*mountinfo = mnt;
+			break;
 		}
-	}
-	if (!list_empty(&mntinfo)) {
-#ifdef EBADE
-		errno = EBADE;
-#else
-		errno = ENOENT;
-#endif				/* EBADE */
-	}
-	join(&sort, &mntinfo);
+
+	} while (!*mountinfo && (end = strrchr(use, '/')));
+	free(use);
+out:
+	return ret;
 }
 
+#if defined(WITH_MOUNTINFO_LIST)
 /*
  * Determine device of links below /proc/
  */
@@ -2078,8 +2328,7 @@ static int mntstat(const char *path, struct stat *buf)
 {
 	char name[PATH_MAX + 1];
 	const char *use;
-	ssize_t nlen;
-	list_t *ptr;
+	mntinfo_t *mnt;
 
 	if ((use = realpath(path, name)) == NULL || *use != '/')
 	{
@@ -2091,27 +2340,26 @@ static int mntstat(const char *path, struct stat *buf)
 		errno = 0;
 		return stat(path, buf);
 	}
+	if (strncmp("/dev/", use, 5) == 0) {
+		/*
+		 * Could be a special file (socket, pipe, inotify)
+		 */
+		errno = 0;
+		return stat(path, buf);
+	}
 
-	nlen = strlen(use);
-	list_for_each(ptr, &mntinfo) {
-		mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
-		if (nlen < mnt->nlen)
-			continue;
-		if (mnt->nlen == 1) {	/* root fs is the last entry */
-			buf->st_dev = mnt->dev;
-			buf->st_ino = 0;
-			return 0;
-		}
-		if (use[mnt->nlen] != '\0' && use[mnt->nlen] != '/')
-			continue;
-		if (strncmp(use, mnt->mpoint, mnt->nlen) == 0) {
-			buf->st_dev = mnt->dev;
-			buf->st_ino = 0;
-			return 0;
-		}
+	if (find_mountpoint(use, &mnt) < 0) {
+		errno = ENOENT;
+		return -1;
 	}
-	errno = ENOENT;
-	return -1;
+
+	if (mnt->isnfs) {
+		buf->st_dev = mnt->dev;
+		buf->st_ino = mnt->id;	    /* inode substitute */
+		return 0;		    /* found on NFS */
+	}
+
+	return stat(path, buf);
 }
 #endif				/* WITH_MOUNTINFO_LIST */
 
diff --git src/fuser.h src/fuser.h
index a4df711..4b9b1d6 100644
--- src/fuser.h
+++ src/fuser.h
@@ -37,10 +37,16 @@ struct procs {
 #define PTYPE_KNFSD 2
 #define PTYPE_SWAP 3
 
+struct fdinfo {
+	mode_t	flags;
+	int	mnt_id;
+};
+
 struct names {
 	char *filename;
 	unsigned char name_space;
-    struct stat st;
+	struct stat st;
+	int mnt_id;
 	struct procs *matched_procs;
 	struct names *next;
 };
@@ -65,12 +71,14 @@ struct inode_list {
 	struct names *name;
 	dev_t	device;
 	ino_t	inode;
+	int	mnt_id;
 	struct inode_list *next;
 };
 
 struct device_list {
 	struct names *name;
 	dev_t	device;
+	int	mnt_id;
 	struct device_list *next;
 };
 
@@ -79,6 +87,7 @@ struct unixsocket_list {
 	ino_t	inode;
 	ino_t	net_inode;
 	dev_t	dev;
+	int	mnt_id;
 	struct unixsocket_list *next;
 };
 
@@ -87,18 +96,15 @@ struct mount_list {
 	struct mount_list *next;
 };
 
-#if defined (__GNUC__) && defined(WITH_MOUNTINFO_LIST)
-# include "lists.h"
+#include "lists.h"
 typedef struct mntinfo_s {
     list_t   this;
     int id, parid;
+    char    isnfs;
     dev_t     dev;
     size_t   nlen;
     char  *mpoint;
 } mntinfo_t;
-#else
-# undef WITH_MOUNTINFO_LIST
-#endif
 
 #define NAMESPACE_FILE 0
 #define NAMESPACE_TCP 1
@@ -108,5 +114,6 @@ typedef struct mntinfo_s {
 #define MAX_CMDNAME 16
 
 #define KNFSD_EXPORTS "/proc/fs/nfs/exports"
+#define PROC_MOUNTINFO "/proc/self/mountinfo"
 #define PROC_MOUNTS "/proc/mounts"
 #define PROC_SWAPS "/proc/swaps"
diff --git testsuite/Makefile.am testsuite/Makefile.am
index 696a44a..739237e 100644
--- testsuite/Makefile.am
+++ testsuite/Makefile.am
@@ -1,6 +1,8 @@
 AUTOMAKE_OPTIONS = dejagnu
 export DEJAGNU
 
+EXTRA_DEJAGNU_SITE_CONFIG=$(srcdir)/selinux.exp
+
 # Programs that are expected across the board.
 DEJATOOL = killall
 DEJATOOL += pslog
@@ -9,5 +11,4 @@ if WANT_FUSER
   DEJATOOL += fuser
 endif
 
-
 EXTRA_DIST =
diff --git testsuite/killall.test/killall.exp testsuite/killall.test/killall.exp
index b244893..1a10a1a 100644
--- testsuite/killall.test/killall.exp
+++ testsuite/killall.test/killall.exp
@@ -7,7 +7,11 @@ set fake_proc_name "afakeprocname"
 
 set test "killall with no arguments"
 spawn $killall
+if { $has_selinux == 0 } {
 expect_pass "$test" "^Usage: killall \\\[OPTION\\\]\\.\\.\\. \\\[--\\\] NAME\\.\\.\\."
+} else {
+expect_pass "$test" "^Usage: killall \\\[ -Z CONTEXT \\\] \\\[ -u USER \\\] \\\[ -y TIME \\\] \\\[ -o TIME \\\] \\\[ -eIgiqrvw \\\]"
+} 
 
 set test "killall list signals"
 spawn $killall -l
-- 
2.12.3