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Create shared API to access on-disk NSM data

PATCH In review Chuck Lever 2 participants 5 messages Jan 8, 2010 – Jan 12, 2010 1 message not in the archive

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#0 lore raw

cover Create shared API to access on-disk NSM data

The goal of these patches is to replace duplicate code in statd and sm-notify that accesses the local NSM state number and the on-disk monitor and notify lists. This change allows us to fix bugs and add IPv6 support in one place instead of two.

There should be little behavioral change, since the new code in libnsm.a is by and large copied from existing code in statd and sm-notify. Some error checking is enhanced. The sync(2) system call done after an NSM state number update is removed, since the update is already performed with POSIX file system calls that are all synchronous with permanent storage.

---

Chuck Lever (3):
statd: Use the new nsm_ file.c calls in rpc.statd
statd: Use the new nsm_ file.c calls in sm_notify libnsm.a: Introduce common routines to handle persistent storage

 support/include/Makefile.am |    2 
 support/include/nsm.h       |   64 +++
 support/nsm/Makefile.am     |    2 
 support/nsm/file.c          |  819 +++++++++++++++++++++++++++++++++++++++++++
 utils/statd/misc.c          |   24 -
 utils/statd/monitor.c       |  140 ++-----
 utils/statd/sm-notify.c     |  288 +++------------
 utils/statd/statd.c         |  116 +-----
 utils/statd/statd.h         |   23 -
 9 files changed, 1006 insertions(+), 472 deletions(-)
 create mode 100644 support/include/nsm.h
 create mode 100644 support/nsm/file.c
Signature · 1 line
Chuck Lever <[email protected]>

A message that is not in the archive (sent off-list or not yet received): 20100108180144.452.14970.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/[email protected]

#2 lore raw

PATCH 1/3 libnsm.a: Introduce common routines to handle persistent storage

rpc.statd and sm-notify access the same set of files under /var/lib/nfs/statd, but both have their own code base to handle this. They should share this code.

In addition, the on-disk format used by statd and friends is considered a formal interface, so this new code will codify the API and provide documentation for it.

The shared code handles switching from the default parent statd directory, reducing privileges at start-up, and managing the NSM state files, in addition to handling normal operations on the monitored host and notification lists on disk.

The new code is simply a copy of the same logic that was used in rpc.statd and sm-notify, but wrapped in a nice API. There should be minimal behavioral and no on-disk format changes with the new libnsm.a code.

The new code is more careful to check for bad corner cases. Occassionally this code may not allow an operation that was permitted in the past, but hopefully the error reporting has improved enough that it should be easy to track down any problems.

---

 support/include/Makefile.am |    2 
 support/include/nsm.h       |   64 +++
 support/nsm/Makefile.am     |    2 
 support/nsm/file.c          |  819 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 886 insertions(+), 1 deletions(-)
 create mode 100644 support/include/nsm.h
 create mode 100644 support/nsm/file.c
support/include/Makefile.am +2 -0
index f5a77ec..4b33ee9 100644
@@ -9,6 +9,8 @@ noinst_HEADERS = \
 	nfs_mntent.h \
 	nfs_paths.h \
 	nfslib.h \
+	nfsrpc.h \
+	nsm.h \
 	rpcmisc.h \
 	tcpwrapper.h \
 	xio.h \
support/include/nsm.h new file +64 -0

64 lines not on this page · raw message

support/nsm/Makefile.am +1 -1
index 4b8110d..e359a43 100644
@@ -10,7 +10,7 @@ GENFILES	= $(GENFILES_CLNT) $(GENFILES_SVC) $(GENFILES_XDR) $(GENFILES_H)
 EXTRA_DIST	= sm_inter.x
 
 noinst_LIBRARIES = libnsm.a
-libnsm_a_SOURCES = $(GENFILES)
+libnsm_a_SOURCES = $(GENFILES) file.c
 
 BUILT_SOURCES = $(GENFILES)
 
support/nsm/file.c new file +819 -0

819 lines not on this page · raw message

#3 lore raw

PATCH 2/3 statd: Use the new nsm_ file.c calls in sm_notify

In reply to a message not in the archive

Replace open-coded accesses to on-disk NSM data with calls to the new libnsm.a API.

One major change is that sync(2) is no longer called when the NSM state number is updated at boot time. Otherwise sm-notify should behave much the same as it did before.

---

 utils/statd/sm-notify.c |  288 ++++++++++-------------------------------------
 1 files changed, 63 insertions(+), 225 deletions(-)
utils/statd/sm-notify.c +63 -225
index 0dba891..581234e 100644
@@ -8,6 +8,7 @@
 #include <config.h>
 #endif
 
+#include <err.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
@@ -29,25 +30,9 @@
 #include <grp.h>
 
 #include "xlog.h"
+#include "nsm.h"
 #include "nfsrpc.h"
 
-#ifndef BASEDIR
-# ifdef NFS_STATEDIR
-#  define BASEDIR		NFS_STATEDIR
-# else
-#  define BASEDIR		"/var/lib/nfs"
-# endif
-#endif
-
-#define DEFAULT_SM_STATE_PATH	BASEDIR "/state"
-#define	DEFAULT_SM_DIR_PATH	BASEDIR "/sm"
-#define	DEFAULT_SM_BAK_PATH	DEFAULT_SM_DIR_PATH ".bak"
-
-char *_SM_BASE_PATH = BASEDIR;
-char *_SM_STATE_PATH = DEFAULT_SM_STATE_PATH;
-char *_SM_DIR_PATH = DEFAULT_SM_DIR_PATH;
-char *_SM_BAK_PATH = DEFAULT_SM_BAK_PATH;
-
 #define NSM_PROG	100024
 #define NSM_PROGRAM	100024
 #define NSM_VERSION	1
@@ -59,7 +44,6 @@ char *_SM_BAK_PATH = DEFAULT_SM_BAK_PATH;
 struct nsm_host {
 	struct nsm_host *	next;
 	char *			name;
-	char *			path;
 	struct sockaddr_storage	addr;
 	struct addrinfo		*ai;
 	time_t			last_used;
@@ -70,24 +54,19 @@ struct nsm_host {
 };
 
 static char		nsm_hostname[256];
-static uint32_t		nsm_state;
+static int		nsm_state;
 static int		opt_debug = 0;
-static int		opt_update_state = 1;
+static _Bool		opt_update_state = true;
 static unsigned int	opt_max_retry = 15 * 60;
 static char *		opt_srcaddr = 0;
 static uint16_t		opt_srcport = 0;
 
-static unsigned int	nsm_get_state(int);
 static void		notify(void);
 static int		notify_host(int, struct nsm_host *);
 static void		recv_reply(int);
-static void		backup_hosts(const char *, const char *);
-static void		get_hosts(const char *);
 static void		insert_host(struct nsm_host *);
 static struct nsm_host *find_host(uint32_t);
 static int		record_pid(void);
-static void		drop_privs(void);
-static void		set_kernel_nsm_state(int state);
 
 static struct nsm_host *	hosts = NULL;
 
@@ -111,10 +90,39 @@ static struct addrinfo *smn_lookup(const char *name)
 	return ai;
 }
 
+__attribute_malloc__
+static struct nsm_host *
+smn_alloc_host(const char *hostname, const time_t timestamp)
+{
+	struct nsm_host	*host;
+
+	host = calloc(1, sizeof(*host));
+	if (host == NULL)
+		goto out_nomem;
+
+	host->name = strdup(hostname);
+	if (host->name == NULL) {
+		free(host);
+		goto out_nomem;
+	}
+
+	host->last_used = timestamp;
+	host->timeout = NSM_TIMEOUT;
+	host->retries = 100;		/* force address retry */
+
+	return host;
+
+out_nomem:
+	xlog_warn("Unable to allocate memory");
+	return NULL;
+}
+
 static void smn_forget_host(struct nsm_host *host)
 {
-	unlink(host->path);
-	free(host->path);
+	xlog(D_CALL, "Removing %s from notify list", host->name);
+
+	nsm_delete_notified_host(host->name);
+
 	free(host->name);
 	if (host->ai)
 		freeaddrinfo(host->ai);
@@ -122,6 +130,23 @@ static void smn_forget_host(struct nsm_host *host)
 	free(host);
 }
 
+static unsigned int
+smn_get_host(const char *hostname,
+		__attribute__ ((unused)) const struct sockaddr *sap,
+		__attribute__ ((unused)) const struct mon *m,
+		const time_t timestamp)
+{
+	struct nsm_host	*host;
+
+	host = smn_alloc_host(hostname, timestamp);
+	if (host == NULL)
+		return 0;
+
+	insert_host(host);
+	xlog(D_GENERAL, "Added host %s to notify list", hostname);
+	return 1;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -147,7 +172,7 @@ main(int argc, char **argv)
 			opt_max_retry = atoi(optarg) * 60;
 			break;
 		case 'n':
-			opt_update_state = 0;
+			opt_update_state = false;
 			break;
 		case 'p':
 			opt_srcport = atoi(optarg);
@@ -156,20 +181,8 @@ main(int argc, char **argv)
 			opt_srcaddr = optarg;
 			break;
 		case 'P':
-			_SM_BASE_PATH = strdup(optarg);
-			_SM_STATE_PATH = malloc(strlen(optarg)+1+sizeof("state"));
-			_SM_DIR_PATH = malloc(strlen(optarg)+1+sizeof("sm"));
-			_SM_BAK_PATH = malloc(strlen(optarg)+1+sizeof("sm.bak"));
-			if (_SM_BASE_PATH == NULL ||
-			    _SM_STATE_PATH == NULL ||
-			    _SM_DIR_PATH == NULL ||
-			    _SM_BAK_PATH == NULL) {
-				fprintf(stderr, "unable to allocate memory");
+			if (!nsm_setup_pathnames(argv[0], optarg))
 				exit(1);
-			}
-			strcat(strcpy(_SM_STATE_PATH, _SM_BASE_PATH), "/state");
-			strcat(strcpy(_SM_DIR_PATH, _SM_BASE_PATH), "/sm");
-			strcat(strcpy(_SM_BAK_PATH, _SM_BASE_PATH), "/sm.bak");
 			break;
 
 		default:
@@ -195,8 +208,8 @@ usage:		fprintf(stderr,
 	xlog_open(progname);
 	xlog(L_NOTICE, "Version " VERSION " starting");
 
-	if (strcmp(_SM_BASE_PATH, BASEDIR) == 0) {
-		if (record_pid() == 0 && force == 0 && opt_update_state == 1) {
+	if (nsm_is_default_parentdir()) {
+		if (record_pid() == 0 && force == 0 && opt_update_state) {
 			/* already run, don't try again */
 			xlog(L_NOTICE, "Already notifying clients; Exiting!");
 			exit(0);
@@ -211,18 +224,16 @@ usage:		fprintf(stderr,
 		exit(1);
 	}
 
-	backup_hosts(_SM_DIR_PATH, _SM_BAK_PATH);
-	get_hosts(_SM_BAK_PATH);
-
-	/* If there are not hosts to notify, just exit */
-	if (!hosts) {
+	(void)nsm_retire_monitored_hosts();
+	if (nsm_load_notify_list(smn_get_host) == 0) {
 		xlog(D_GENERAL, "No hosts to notify; exiting");
 		return 0;
 	}
 
-	/* Get and update the NSM state. This will call sync() */
 	nsm_state = nsm_get_state(opt_update_state);
-	set_kernel_nsm_state(nsm_state);
+	if (nsm_state == 0)
+		exit(1);
+	nsm_update_kernel_state(nsm_state);
 
 	if (!opt_debug) {
 		xlog(L_NOTICE, "Backgrounding to notify hosts...\n");
@@ -316,7 +327,8 @@ notify(void)
 	if (opt_max_retry)
 		failtime = time(NULL) + opt_max_retry;
 
-	drop_privs();
+	if (!nsm_drop_privileges(-1))
+		exit(1);
 
 	while (hosts) {
 		struct pollfd	pfd;
@@ -554,82 +566,6 @@ fail:	/* Re-insert the host */
 }
 
 /*
- * Back up all hosts from the sm directory to sm.bak
- */
-static void
-backup_hosts(const char *dirname, const char *bakname)
-{
-	struct dirent	*de;
-	DIR		*dir;
-
-	if (!(dir = opendir(dirname))) {
-		xlog_warn("Failed to open %s: %m", dirname);
-		return;
-	}
-
-	while ((de = readdir(dir)) != NULL) {
-		char	src[1024], dst[1024];
-
-		if (de->d_name[0] == '.')
-			continue;
-
-		snprintf(src, sizeof(src), "%s/%s", dirname, de->d_name);
-		snprintf(dst, sizeof(dst), "%s/%s", bakname, de->d_name);
-		if (rename(src, dst) < 0)
-			xlog_warn("Failed to rename %s -> %s: %m", src, dst);
-	}
-	closedir(dir);
-}
-
-/*
- * Get all entries from sm.bak and convert them to host entries
- */
-static void
-get_hosts(const char *dirname)
-{
-	struct nsm_host	*host;
-	struct dirent	*de;
-	DIR		*dir;
-
-	if (!(dir = opendir(dirname))) {
-		xlog_warn("Failed to open %s: %m", dirname);
-		return;
-	}
-
-	host = NULL;
-	while ((de = readdir(dir)) != NULL) {
-		struct stat	stb;
-		char		path[1024];
-
-		if (de->d_name[0] == '.')
-			continue;
-		if (host == NULL)
-			host = calloc(1, sizeof(*host));
-		if (host == NULL) {
-			xlog_warn("Unable to allocate memory");
-			return;
-		}
-
-		snprintf(path, sizeof(path), "%s/%s", dirname, de->d_name);
-		if (stat(path, &stb) < 0)
-			continue;
-
-		host->last_used = stb.st_mtime;
-		host->timeout = NSM_TIMEOUT;
-		host->path = strdup(path);
-		host->name = strdup(de->d_name);
-		host->retries = 100; /* force address retry */
-
-		insert_host(host);
-		host = NULL;
-	}
-	closedir(dir);
-
-	if (host)
-		free(host);
-}
-
-/*
  * Insert host into sorted list
  */
 static void
@@ -676,60 +612,6 @@ find_host(uint32_t xid)
 	return NULL;
 }
 
-
-/*
- * Retrieve the current NSM state
- */
-static unsigned int
-nsm_get_state(int update)
-{
-	char		newfile[PATH_MAX];
-	int		fd, state;
-
-	if ((fd = open(_SM_STATE_PATH, O_RDONLY)) < 0) {
-		xlog_warn("%s: %m", _SM_STATE_PATH);
-		xlog_warn("Creating %s, set initial state 1",
-			_SM_STATE_PATH);
-		state = 1;
-		update = 1;
-	} else {
-		if (read(fd, &state, sizeof(state)) != sizeof(state)) {
-			xlog_warn("%s: bad file size, setting state = 1",
-				_SM_STATE_PATH);
-			state = 1;
-			update = 1;
-		} else {
-			if (!(state & 1))
-				state += 1;
-		}
-		close(fd);
-	}
-
-	if (update) {
-		state += 2;
-		snprintf(newfile, sizeof(newfile),
-				"%s.new", _SM_STATE_PATH);
-		if ((fd = open(newfile, O_CREAT|O_WRONLY, 0644)) < 0) {
-			xlog(L_ERROR, "Cannot create %s: %m", newfile);
-			exit(1);
-		}
-		if (write(fd, &state, sizeof(state)) != sizeof(state)) {
-			xlog(L_ERROR,
-				"Failed to write state to %s", newfile);
-			exit(1);
-		}
-		close(fd);
-		if (rename(newfile, _SM_STATE_PATH) < 0) {
-			xlog(L_ERROR,
-				"Cannot create %s: %m", _SM_STATE_PATH);
-			exit(1);
-		}
-		sync();
-	}
-
-	return state;
-}
-
 /*
  * Record pid in /var/run/sm-notify.pid
  * This file should remain until a reboot, even if the
@@ -756,47 +638,3 @@ static int record_pid(void)
 	(void)close(fd);
 	return 1;
 }
-
-/* Drop privileges to match owner of state-directory
- * (in case a reply triggers some unknown bug).
- */
-static void drop_privs(void)
-{
-	struct stat st;
-
-	if (stat(_SM_DIR_PATH, &st) == -1 &&
-	    stat(_SM_BASE_PATH, &st) == -1) {
-		st.st_uid = 0;
-		st.st_gid = 0;
-	}
-
-	if (st.st_uid == 0) {
-		xlog_warn("Running as 'root'.  "
-			"chown %s to choose different user", _SM_DIR_PATH);
-		return;
-	}
-
-	setgroups(0, NULL);
-	if (setgid(st.st_gid) == -1
-	    || setuid(st.st_uid) == -1) {
-		xlog(L_ERROR, "Fail to drop privileges");
-		exit(1);
-	}
-}
-
-static void set_kernel_nsm_state(int state)
-{
-	int fd;
-	const char *file = "/proc/sys/fs/nfs/nsm_local_state";
-
-	fd = open(file ,O_WRONLY);
-	if (fd >= 0) {
-		char buf[20];
-		snprintf(buf, sizeof(buf), "%d", state);
-		if (write(fd, buf, strlen(buf)) != strlen(buf)) {
-			xlog_warn("Writing to '%s' failed: errno %d (%m)",
-				file, errno);
-		}
-		close(fd);
-	}
-}
#4 lore raw

PATCH 3/3 statd: Use the new nsm_ file.c calls in rpc.statd

In reply to a message not in the archive

Replace open-coded accesses to on-disk NSM information in rpc.statd with calls to the new API.

Behavior should be much the same as it was before.

---

 utils/statd/misc.c    |   24 --------
 utils/statd/monitor.c |  140 ++++++++++++++++---------------------------------
 utils/statd/statd.c   |  116 ++++-------------------------------------
 utils/statd/statd.h   |   23 --------
 4 files changed, 57 insertions(+), 246 deletions(-)
utils/statd/misc.c +0 -24
index 44af30e..f2a086f 100644
@@ -49,27 +49,3 @@ xstrdup (const char *string)
 
   return (result);
 }
-
-
-/*
- * Unlinking a file.
- */
-void
-xunlink (char *path, char *host)
-{
-	char *tozap;
-
-	tozap = malloc(strlen(path)+strlen(host)+2);
-	if (tozap == NULL) {
-		xlog(L_ERROR, "xunlink: malloc failed: errno %d (%m)", errno);
-		return;
-	}
-	sprintf (tozap, "%s/%s", path, host);
-
-	if (unlink (tozap) == -1)
-		xlog(L_ERROR, "unlink (%s): %m", tozap);
-	else
-		xlog(D_GENERAL, "Unlinked %s", tozap);
-
-	free(tozap);
-}
utils/statd/monitor.c +45 -95

208 lines not on this page · raw message

utils/statd/statd.c +12 -104

169 lines not on this page · raw message

utils/statd/statd.h +0 -23
index 085f32d..542a877 100644
@@ -14,28 +14,6 @@
 #include "xlog.h"
 
 /*
- * Paths and filenames.
- */
-#if defined(NFS_STATEDIR)
-# define DEFAULT_DIR_BASE	NFS_STATEDIR "/"
-#else
-# define DEFAULT_DIR_BASE	"/var/lib/nfs/"
-#endif
-
-#define DEFAULT_SM_DIR		DEFAULT_DIR_BASE "sm"
-#define DEFAULT_SM_BAK_DIR	DEFAULT_DIR_BASE "sm.bak"
-#define DEFAULT_SM_STAT_PATH	DEFAULT_DIR_BASE "state"
-
-/* Added to support run-time specification of state directory path.
- * [email protected]
- */
-
-extern char * DIR_BASE;
-extern char *  SM_DIR;
-extern char *  SM_BAK_DIR;
-extern char *  SM_STAT_PATH;
-
-/*
  * Status definitions.
  */
 #define STAT_FAIL	stat_fail
@@ -53,7 +31,6 @@ extern int	process_notify_list(void);
 extern int	process_reply(FD_SET_TYPE *);
 extern char *	xstrdup(const char *);
 extern void *	xmalloc(size_t);
-extern void	xunlink (char *, char *);
 extern void	load_state(void);
 
 /*
#5 lore raw
In reply to a message not in the archive
Quoted 12 lines · Chuck Lever

The goal of these patches is to replace duplicate code in statd and sm-notify that accesses the local NSM state number and the on-disk monitor and notify lists. This change allows us to fix bugs and add IPv6 support in one place instead of two.

There should be little behavioral change, since the new code in libnsm.a is by and large copied from existing code in statd and sm-notify. Some error checking is enhanced. The sync(2) system call done after an NSM state number update is removed, since the update is already performed with POSIX file system calls that are all synchronous with permanent storage.

Quoted 6 lines

---

Chuck Lever (3):
statd: Use the new nsm_ file.c calls in rpc.statd
statd: Use the new nsm_ file.c calls in sm_notify libnsm.a: Introduce common routines to handle persistent storage

Committed...

steved.