libshare: nfs: commonify nfs_exports_[un]lock(), FILE_HEADER

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <gwilson@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11886

lib/libshare/Makefile.am

@@ -7,6 +7,7 @@ noinst_LTLIBRARIES = libshare.la
 USER_C = \
 	libshare_impl.h \
 	libshare.c \
+	nfs.c \
 	nfs.h \
 	smb.h
 

lib/libshare/nfs.c

@@ -0,0 +1,73 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include "nfs.h"
+
+
+static int nfs_lock_fd = -1;
+
+
+/*
+ * nfs_exports_[lock|unlock] are used to guard against conconcurrent
+ * updates to the exports file. Each protocol is responsible for
+ * providing the necessary locking to ensure consistency.
+ */
+__attribute__((visibility("hidden"))) int
+nfs_exports_lock(const char *name)
+{
+	int err;
+
+	nfs_lock_fd = open(name, O_RDWR | O_CREAT | O_CLOEXEC, 0600);
+	if (nfs_lock_fd == -1) {
+		err = errno;
+		fprintf(stderr, "failed to lock %s: %s\n", name, strerror(err));
+		return (err);
+	}
+
+	if (flock(nfs_lock_fd, LOCK_EX) != 0) {
+		err = errno;
+		fprintf(stderr, "failed to lock %s: %s\n", name, strerror(err));
+		(void) close(nfs_lock_fd);
+		nfs_lock_fd = -1;
+		return (err);
+	}
+
+	return (0);
+}
+
+__attribute__((visibility("hidden"))) void
+nfs_exports_unlock(const char *name)
+{
+	verify(nfs_lock_fd > 0);
+
+	if (flock(nfs_lock_fd, LOCK_UN) != 0) {
+		fprintf(stderr, "failed to unlock %s: %s\n",
+		    name, strerror(errno));
+	}
+
+	(void) close(nfs_lock_fd);
+	nfs_lock_fd = -1;
+}

lib/libshare/nfs.h

@@ -24,4 +24,9 @@
  * Copyright (c) 2011 Gunnar Beutner
  */
 
+#define	FILE_HEADER		"# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
+
 void libshare_nfs_init(void);
+
+int nfs_exports_lock(const char *name);
+void nfs_exports_unlock(const char *name);

lib/libshare/os/freebsd/nfs.c

@@ -47,7 +47,6 @@ __FBSDID("$FreeBSD$");
 #include "nfs.h"
 
 #define	_PATH_MOUNTDPID	"/var/run/mountd.pid"
-#define	FILE_HEADER	"# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
 #define	OPTSSIZE	1024
 #define	MAXLINESIZE	(PATH_MAX + OPTSSIZE)
 #define	ZFS_EXPORTS_FILE	"/etc/zfs/exports"
@@ -55,49 +54,6 @@ __FBSDID("$FreeBSD$");
 
 static sa_fstype_t *nfs_fstype;
 
-static int nfs_lock_fd = -1;
-
-/*
- * The nfs_exports_[lock|unlock] is used to guard against conconcurrent
- * updates to the exports file. Each protocol is responsible for
- * providing the necessary locking to ensure consistency.
- */
-static int
-nfs_exports_lock(void)
-{
-	int err;
-
-	nfs_lock_fd = open(ZFS_EXPORTS_LOCK,
-	    O_RDWR | O_CREAT | O_CLOEXEC, 0600);
-	if (nfs_lock_fd == -1) {
-		err = errno;
-		fprintf(stderr, "failed to lock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(err));
-		return (err);
-	}
-	if (flock(nfs_lock_fd, LOCK_EX) != 0) {
-		err = errno;
-		fprintf(stderr, "failed to lock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(err));
-		(void) close(nfs_lock_fd);
-		return (err);
-	}
-	return (0);
-}
-
-static void
-nfs_exports_unlock(void)
-{
-	verify(nfs_lock_fd > 0);
-
-	if (flock(nfs_lock_fd, LOCK_UN) != 0) {
-		fprintf(stderr, "failed to unlock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(errno));
-	}
-	close(nfs_lock_fd);
-	nfs_lock_fd = -1;
-}
-
 /*
  * Read one line from a file. Skip comments, empty lines and a line with a
  * mountpoint specified in the 'skip' argument.
@@ -281,7 +237,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 	if ((filename = nfs_init_tmpfile()) == NULL)
 		return (SA_SYSTEM_ERR);
 
-	error = nfs_exports_lock();
+	error = nfs_exports_lock(ZFS_EXPORTS_LOCK);
 	if (error != 0) {
 		unlink(filename);
 		free(filename);
@@ -292,7 +248,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 	if (error != SA_OK) {
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (error);
 	}
 
@@ -302,7 +258,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 		    strerror(errno));
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (SA_SYSTEM_ERR);
 	}
 	char *shareopts = FSINFO(impl_share, nfs_fstype)->shareopts;
@@ -315,7 +271,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 		fclose(fp);
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (SA_SYSTEM_ERR);
 	}
 
@@ -324,11 +280,11 @@ nfs_enable_share(sa_share_impl_t impl_share)
 		    filename, strerror(errno));
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (SA_SYSTEM_ERR);
 	}
 	error = nfs_fini_tmpfile(filename);
-	nfs_exports_unlock();
+	nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 	return (error);
 }
 
@@ -341,7 +297,7 @@ nfs_disable_share(sa_share_impl_t impl_share)
 	if ((filename = nfs_init_tmpfile()) == NULL)
 		return (SA_SYSTEM_ERR);
 
-	error = nfs_exports_lock();
+	error = nfs_exports_lock(ZFS_EXPORTS_LOCK);
 	if (error != 0) {
 		unlink(filename);
 		free(filename);
@@ -352,12 +308,12 @@ nfs_disable_share(sa_share_impl_t impl_share)
 	if (error != SA_OK) {
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (error);
 	}
 
 	error = nfs_fini_tmpfile(filename);
-	nfs_exports_unlock();
+	nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 	return (error);
 }
 

lib/libshare/os/linux/nfs.c

@@ -42,7 +42,6 @@
 #include "libshare_impl.h"
 #include "nfs.h"
 
-#define	FILE_HEADER		"# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
 #define	ZFS_EXPORTS_DIR		"/etc/exports.d"
 #define	ZFS_EXPORTS_FILE	ZFS_EXPORTS_DIR"/zfs.exports"
 #define	ZFS_EXPORTS_LOCK	ZFS_EXPORTS_FILE".lock"
@@ -55,49 +54,6 @@ typedef int (*nfs_shareopt_callback_t)(const char *opt, const char *value,
 typedef int (*nfs_host_callback_t)(const char *sharepath, const char *filename,
     const char *host, const char *security, const char *access, void *cookie);
 
-static int nfs_lock_fd = -1;
-
-/*
- * The nfs_exports_[lock|unlock] is used to guard against conconcurrent
- * updates to the exports file. Each protocol is responsible for
- * providing the necessary locking to ensure consistency.
- */
-static int
-nfs_exports_lock(void)
-{
-	int err;
-
-	nfs_lock_fd = open(ZFS_EXPORTS_LOCK,
-	    O_RDWR | O_CREAT | O_CLOEXEC, 0600);
-	if (nfs_lock_fd == -1) {
-		err = errno;
-		fprintf(stderr, "failed to lock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(err));
-		return (err);
-	}
-	if (flock(nfs_lock_fd, LOCK_EX) != 0) {
-		err = errno;
-		fprintf(stderr, "failed to lock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(err));
-		(void) close(nfs_lock_fd);
-		return (err);
-	}
-	return (0);
-}
-
-static void
-nfs_exports_unlock(void)
-{
-	verify(nfs_lock_fd > 0);
-
-	if (flock(nfs_lock_fd, LOCK_UN) != 0) {
-		fprintf(stderr, "failed to unlock %s: %s\n",
-		    ZFS_EXPORTS_LOCK, strerror(errno));
-	}
-	close(nfs_lock_fd);
-	nfs_lock_fd = -1;
-}
-
 /*
  * Invokes the specified callback function for each Solaris share option
  * listed in the specified string.
@@ -563,7 +519,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 	if ((filename = nfs_init_tmpfile()) == NULL)
 		return (SA_SYSTEM_ERR);
 
-	error = nfs_exports_lock();
+	error = nfs_exports_lock(ZFS_EXPORTS_LOCK);
 	if (error != 0) {
 		unlink(filename);
 		free(filename);
@@ -574,7 +530,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 	if (error != SA_OK) {
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (error);
 	}
 
@@ -583,7 +539,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 	if (error != SA_OK) {
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (error);
 	}
 
@@ -596,7 +552,7 @@ nfs_enable_share(sa_share_impl_t impl_share)
 		unlink(filename);
 		free(filename);
 	}
-	nfs_exports_unlock();
+	nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 	return (error);
 }
 
@@ -612,7 +568,7 @@ nfs_disable_share(sa_share_impl_t impl_share)
 	if ((filename = nfs_init_tmpfile()) == NULL)
 		return (SA_SYSTEM_ERR);
 
-	error = nfs_exports_lock();
+	error = nfs_exports_lock(ZFS_EXPORTS_LOCK);
 	if (error != 0) {
 		unlink(filename);
 		free(filename);
@@ -623,11 +579,11 @@ nfs_disable_share(sa_share_impl_t impl_share)
 	if (error != SA_OK) {
 		unlink(filename);
 		free(filename);
-		nfs_exports_unlock();
+		nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 		return (error);
 	}
 	error = nfs_fini_tmpfile(filename);
-	nfs_exports_unlock();
+	nfs_exports_unlock(ZFS_EXPORTS_LOCK);
 	return (error);
 }