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

diff -ru old/configure.ac new/configure.ac
--- old/configure.ac	2019-11-12 11:23:38.000000000 +0100
+++ new/configure.ac	2020-12-31 10:49:48.159279790 +0100
@@ -27,6 +27,9 @@
   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 @@
 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 @@
 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
Only in new: .idea
diff -ru old/src/fuser.c new/src/fuser.c
--- old/src/fuser.c	2019-11-12 11:23:38.000000000 +0100
+++ new/src/fuser.c	2020-12-31 11:02:04.273256080 +0100
@@ -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>
@@ -79,7 +83,7 @@
 		      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);
@@ -88,9 +92,9 @@
 
 /*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);
+		       struct names *this_name, dev_t device, dev_t subvol);
+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,
@@ -109,9 +113,12 @@
 			      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;
@@ -202,6 +209,7 @@
 		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;
@@ -211,9 +219,9 @@
 			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;
@@ -221,21 +229,33 @@
 		/* 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);
+			struct subvol *vol_tmp;
+			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;
+			for (vol_tmp = dev_tmp->vol; vol_tmp != NULL;
+				vol_tmp = vol_tmp->next) {
+				/* For BtrFS sub volumes there are different
+				   mount ids for the same device */
+				if (exe_dev == vol_tmp->device && vol_tmp->mnt_id == exe_id)
+					access |= ACCESS_EXE;
+				if (root_dev == vol_tmp->device && vol_tmp->mnt_id == root_id)
+					access |= ACCESS_ROOT;
+				if (cwd_dev == vol_tmp->device && vol_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)
@@ -244,7 +264,7 @@
 			}
 			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)
@@ -253,7 +273,7 @@
 			}
 			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)
@@ -294,18 +314,42 @@
 	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;
 }
+	
+static void
+add_subvol(struct subvol **head, dev_t device, int mnt_id)
+{
+	struct subvol *vol_tmp, *vol_head;
+
+	if ((vol_tmp =
+	     (struct subvol *)malloc(sizeof(struct subvol))) == NULL)
+		return;
+	vol_head = *head;
+	vol_tmp->device = device;
+	vol_tmp->mnt_id = mnt_id;
+	vol_tmp->next = vol_head;
+	*head = vol_tmp;
+}
 
 static void
-add_device(struct device_list **dev_list, struct names *this_name, dev_t device)
+add_device(struct device_list **dev_list, struct names *this_name, dev_t device, dev_t subvol)
 {
 	struct device_list *dev_tmp, *dev_head;
 #ifdef DEBUG
 	fprintf(stderr, "add_device(%s %u\n", this_name->filename,
 		(unsigned int)device);
 #endif				/* DEBUG */
+	/* For BtrFS there are many sub volumes all on the same block device */
+	for (dev_tmp = *dev_list; dev_tmp != NULL; dev_tmp = dev_tmp->next)
+		if (dev_tmp->device == device) {
+			if (dev_tmp->device != subvol)
+				add_subvol(&dev_tmp->vol, subvol, this_name->mnt_id);
+			*dev_list = dev_tmp;
+			return;
+		}
 
 	if ((dev_tmp =
 	     (struct device_list *)malloc(sizeof(struct device_list))) == NULL)
@@ -313,6 +357,10 @@
 	dev_head = *dev_list;
 	dev_tmp->name = this_name;
 	dev_tmp->device = device;
+	dev_tmp->mnt_id = this_name->mnt_id;
+	dev_tmp->vol = NULL;
+	if (dev_tmp->device != subvol)
+		add_subvol(&dev_tmp->vol, subvol, this_name->mnt_id);
 	dev_tmp->next = dev_head;
 	*dev_list = dev_tmp;
 }
@@ -454,13 +502,15 @@
 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"),
@@ -470,10 +520,12 @@
 				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->isremote ? "yes" : "no");
 #endif				/* DEBUG */
 	add_inode(ino_list, this_name, this_name->st.st_dev,
 		  this_name->st.st_ino);
@@ -505,12 +557,45 @@
 	     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;
-	add_device(dev_list, this_name, match_device);
+
+	count = 0;
+	list_for_each(ptr, &mntinfo) {
+		mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
+		if (S_ISBLK(this_name->st.st_mode)) {
+			/* Skip mount IDs check if a block device
+			 * was specified */
+			this_name->mnt_id = mnt->id;
+			add_device(dev_list, this_name, match_device, mnt->dev);
+			if (mnt->dev == mnt->vol)
+				count++;
+			else	count = 1;
+			continue;
+		}
+		if (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 (S_ISBLK(this_name->st.st_mode))
+		return 0;
+	this_name->mnt_id = mountinfo->id;
+	add_device(dev_list, this_name, match_device, match_device);
 	return 0;
 }
 
@@ -624,7 +709,7 @@
 			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);
@@ -687,10 +772,12 @@
 					break;
 #endif
 				}
-			}	/*while */
-		    freeaddrinfo(res);
+			}	/* for (;;) */
+
+			freeaddrinfo(res);
 			return 0;
-		}
+
+		}	/* if getaddrinfo */
 	}
 	return 1;
 }
@@ -957,6 +1044,21 @@
 /*
  * Free up structures allocated in add_device
  */
+
+static void
+free_subvol(struct subvol **volumes)
+{
+	struct subvol *vol_tmp, *vol_next;
+
+	vol_tmp = *volumes;
+	while (vol_tmp != NULL) {
+		vol_next = vol_tmp->next;
+		free(vol_tmp);
+		vol_tmp = vol_next;
+	}
+	*volumes =NULL;
+}
+
 static void
 free_devices(struct device_list **match_devices)
 {
@@ -964,6 +1066,8 @@
 
 	device_tmp = *match_devices;
 	while(device_tmp != NULL) {
+		if (device_tmp->vol)
+			free_subvol(&device_tmp->vol);
 		device_next = device_tmp->next;
 		free(device_tmp);
 		device_tmp = device_next;
@@ -1166,16 +1270,11 @@
 					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"));
@@ -1215,7 +1314,7 @@
 		}
 
 #if defined(WITH_MOUNTINFO_LIST)
-		if ((opts & OPT_ALWAYSSTAT) == 0)
+		if ((opts & (OPT_MOUNTS|OPT_ALWAYSSTAT)) == OPT_MOUNTS)
 			thestat = mntstat;
 #endif
 		/* an option */
@@ -1529,7 +1628,7 @@
 
 }
 
-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;
@@ -1541,6 +1640,15 @@
 		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;
 }
 
@@ -1555,7 +1663,8 @@
 	struct inode_list *ino_tmp;
 	struct device_list *dev_tmp;
 	struct unixsocket_list *sock_tmp;
-	struct stat st, lst;
+	struct fdinfo fd;
+	struct stat st;
 	char *dirpath;
 	char filepath[PATH_MAX];
 
@@ -1594,11 +1703,27 @@
 			}
 			for (dev_tmp = dev_head; dev_tmp != NULL;
 			     dev_tmp = dev_tmp->next) {
-				if (thedev != dev_tmp->device)
+				if (thedev != dev_tmp->device) {
+					struct subvol *vol_tmp;
+					int found = 0;
+					for (vol_tmp = dev_tmp->vol; vol_tmp != NULL;
+					     vol_tmp = vol_tmp->next) {
+						/* Check for BtrFS sub volumes as well */
+						if (thedev == vol_tmp->device) {
+							found++;
+							break;
+						}
+					}
+ 
+					if (!found)
+						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 |
@@ -1620,9 +1745,10 @@
 					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 |
@@ -1651,31 +1777,54 @@
 	FILE *fp;
 	unsigned long long tmp_inode;
 	unsigned int tmp_maj, tmp_min;
-	dev_t tmp_device;
 
 	if (asprintf(&pathname, "/proc/%d/%s", pid, filename) < 0)
         return;
 	if ((fp = fopen(pathname, "r")) == NULL) {
-        free(pathname);
+		free(pathname);
 		return;
-    }
-    free(pathname);
+	}
+	free(pathname);
 	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)
+			     dev_tmp = dev_tmp->next) {
+				struct subvol *vol_tmp;
+				if (dev_tmp->device == tmp_device &&
+				    mnt_id == dev_tmp->mnt_id)
 					add_matched_proc(dev_tmp->name, pid,
 							 uid, access);
+				for (vol_tmp = dev_tmp->vol; vol_tmp != NULL;
+				     vol_tmp = vol_tmp->next) {
+					/* For BtrFS sub volumes there are different
+					   mount ids for the same device */
+					if (vol_tmp->device == tmp_device && mnt_id == vol_tmp->mnt_id)
+						add_matched_proc(dev_tmp->name, pid,
+								 uid, access);
+				}
+			}
 			for (ino_tmp = ino_head; ino_tmp != NULL;
 			     ino_tmp = ino_tmp->next)
 				if (ino_tmp->device == tmp_device
 				    && ino_tmp->inode == tmp_inode)
 					add_matched_proc(ino_tmp->name, pid,
 							 uid, access);
-		}
+		} else if (scanned_path)
+			free(scanned_path);
 	}
 	fclose(fp);
 }
@@ -1699,6 +1848,7 @@
  * 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;
@@ -1715,6 +1865,8 @@
 	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 %llu %ms",
 			   &scanned_inode, &scanned_path) != 2) {
 			if (scanned_path)
@@ -1730,6 +1882,8 @@
 			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);
@@ -1738,6 +1892,7 @@
 		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;
@@ -1750,6 +1905,7 @@
 /*
  * Free up the list of Unix sockets
  */
+static
 void clear_unix_cache(struct unixsocket_list **unixsocket_head)
 {
 	while(*unixsocket_head != NULL) {
@@ -1921,34 +2077,24 @@
 {
 	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 ( (ino_head == NULL) && (dev_head == NULL) )
 		return;
 
+	list_t *ptr;
+    list_for_each(ptr, &mntinfo) {
+        mntinfo_t *mnt = list_entry(ptr, mntinfo_t);
+        const char *find_mountp = mnt->mpoint;
 
-	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)
+        if (timeout(thestat, find_mountp, &st, 5) != 0)
 			continue;
-		find_mountp++;
-		if ((find_space = strchr(find_mountp, ' ')) == NULL)
-			continue;
-		*find_space = '\0';
-		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);
 		}
@@ -1960,7 +2106,6 @@
 						 find_mountp);
 		}
 	}
-	fclose(fp);
 }
 
 static void
@@ -2013,16 +2158,44 @@
 	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.
+ * stat(2) system call for remote file system.
  */
 
-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 || strncmp("afs", type, 3) == 0 || strncmp("autofs", type, 6))
+		mnt->isremote = 1;
+	else	mnt->isremote = 0;
+	/* E.g. sub volumes of BtrFS do not show main device number in
+	   /proc/self/mountinfo, for now just map the device to this */
+	mnt->vol = dev;
+	return mnt;
+}
 
-static void clear_mntinfo(void)
+static void
+clear_mntinfo(void)
 {
 	list_t *ptr, *tmp;
 
@@ -2033,72 +2206,247 @@
 	}
 }
 
-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;
+	char devname[PATH_MAX];
+	int mid, parid;
+	mntinfo_t *mntinf;
+#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);
-		}
-		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;
+	       (mnt, "%i %i %u:%u %*s %s %*[^-] - %s %s %*[^\n]",
+		&mid, &parid, &maj, &min, &mpoint[0], &type[0], &devname[0]) == 7) {
+		struct stat st;
+		mntinf = add_mntinfo(mpoint, type, mid, parid, makedev(maj, min));
+		if (mntinf && strncmp(devname, "/dev/", 5) == 0 && stat(devname, &st) == 0) {
+			if (st.st_rdev != 0 && mntinf->dev != st.st_rdev) {
+				mntinf->vol = st.st_rdev;
+				stat(mpoint, &st);
+				mntinf->dev = st.st_dev;	/* stat(2) on binary does not see subvol dev */
+			}
+		}
 	}
+#else
+	if ((mnt = fopen(PROC_MOUNTS, "r")) == (FILE *) 0)
+		return;
+	mid = 1;
+	parid = -1;
+	while (fscanf (mnt, "%s %s %s %*[^\n]", &devname[0], &mpoint[0], &type[0]) == 3) {
+		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;
+		}
+		mntinf = add_mntinfo(mpoint, type, mid++, parid, st.st_dev);
+		if (mntinf && strncmp(devname, "/dev/", 5) == 0 && stat(devname, &st) == 0) {
+			if (st.st_rdev != 0 && mntinf->dev != st.st_rdev)
+				mntinf->vol = st.st_rdev;
+		}
+	}
+#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/
  */
@@ -2106,8 +2454,7 @@
 {
 	char name[PATH_MAX + 1];
 	const char *use;
-	ssize_t nlen;
-	list_t *ptr;
+	mntinfo_t *mnt;
 
 	if ((use = realpath(path, name)) == NULL || *use != '/')
 	{
@@ -2119,27 +2466,26 @@
 		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->isremote) {
+		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 -ru old/src/fuser.h new/src/fuser.h
--- old/src/fuser.h	2019-11-12 11:23:38.000000000 +0100
+++ new/src/fuser.h	2020-12-31 10:49:48.159279790 +0100
@@ -37,10 +37,16 @@
 #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 +71,21 @@
 	struct names *name;
 	dev_t	device;
 	ino_t	inode;
+	int	mnt_id;
 	struct inode_list *next;
 };
 
+struct subvol {
+	dev_t	device;
+	int	mnt_id;
+	struct subvol *next;
+};
+
 struct device_list {
 	struct names *name;
+	struct subvol *vol;
 	dev_t	device;
+	int	mnt_id;
 	struct device_list *next;
 };
 
@@ -79,6 +94,7 @@
 	ino_t	inode;
 	ino_t	net_inode;
 	dev_t	dev;
+	int	mnt_id;
 	struct unixsocket_list *next;
 };
 
@@ -87,18 +103,16 @@
 	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 isremote;
     dev_t     dev;
     size_t   nlen;
+    dev_t     vol;
     char  *mpoint;
 } mntinfo_t;
-#else
-# undef WITH_MOUNTINFO_LIST
-#endif
 
 #define NAMESPACE_FILE 0
 #define NAMESPACE_TCP 1
@@ -109,5 +123,6 @@
 #endif /* PATH_MAX */
 
 #define KNFSD_EXPORTS "/proc/fs/nfs/exports"
+#define PROC_MOUNTINFO "/proc/self/mountinfo"
 #define PROC_MOUNTS "/proc/mounts"
 #define PROC_SWAPS "/proc/swaps"
diff -ru old/testsuite/killall.test/killall.exp new/testsuite/killall.test/killall.exp
--- old/testsuite/killall.test/killall.exp	2019-11-12 11:23:38.000000000 +0100
+++ new/testsuite/killall.test/killall.exp	2020-12-31 10:49:48.159279790 +0100
@@ -7,7 +7,11 @@
 
 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
diff -ru old/testsuite/Makefile.am new/testsuite/Makefile.am
--- old/testsuite/Makefile.am	2019-11-12 11:23:38.000000000 +0100
+++ new/testsuite/Makefile.am	2020-12-31 10:49:48.159279790 +0100
@@ -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 @@
   DEJATOOL += fuser
 endif
 
-
 EXTRA_DIST =