Re: module development

[Jordi Prats <jprats@cesca.es>]

[-- Attachment #1: Type: text/plain, Size: 1464 bytes --]

Hi,
Ok, No problem! Here it is with the only changes of my proposal.

Jordi

Ian Kent wrote:
> On Wed, 2007-02-28 at 15:34 +0100, Jordi Prats wrote:
>   
>> Hi all,
>> I have modified autofs's source code to create an entry point for the 
>> umount operation. Here I attach a patch for autofs-4.1.4
>>
>> This patch will allow to create a custom umount operation. In my case I 
>> need to perform an operation before mounting the fs and after. So, I 
>> think this could help others.
>>
>> What I need to do to contribute this code?
>>     
>
> Sorry, you've got a bit of work to do on that patch.
>
> When you make a patch please make the diff from a clean source tree.
> The reason for this is that the diff should contain only the changes
> that you're proposing so the possibility of mistakes getting through is
> minimized. As it is this patch contains a more unrelated stuff than the
> changes for the proposal itself. I can't really follow it well enough to
> know what you're trying to do.
>
> Ian
>
>
>
>   


-- 
......................................................................
         __
        / /          Jordi Prats
  C E / S / C A      Dept. de Sistemes
      /_/            Centre de Supercomputació de Catalunya

  Gran Capità, 2-4 (Edifici Nexus) · 08034 Barcelona
  T. 93 205 6464 · F.  93 205 6979 · jprats@cesca.es
...................................................................... 


[-- Attachment #2: patch-umount --]
[-- Type: text/plain, Size: 11147 bytes --]

diff -Naur autofs-4.1.4/daemon/automount.c autofs-modificat/daemon/automount.c
--- autofs-4.1.4/daemon/automount.c	2005-03-06 10:43:55.000000000 +0100
+++ autofs-modificat/daemon/automount.c	2007-02-28 11:55:00.000000000 +0100
@@ -139,31 +139,7 @@
 
 static int umount_ent(const char *root, const char *name, const char *type)
 {
-	char path_buf[PATH_MAX];
-	struct stat st;
-	int sav_errno;
-	int is_smbfs = (strcmp(type, "smbfs") == 0);
-	int status;
-	int rv = 0;
-
-	sprintf(path_buf, "%s/%s", root, name);
-	status =  lstat(path_buf, &st);
-	sav_errno = errno;
-
-	/* EIO appears to correspond to an smb mount that has gone away */
-	if (!status ||
-	    (is_smbfs && (sav_errno == EIO || sav_errno == EBADSLT))) {
-		int umount_ok = 0;
-
-		if (!status && (S_ISDIR(st.st_mode) && (st.st_dev != ap.dev)))
-			umount_ok = 1;
-
-		if (umount_ok || is_smbfs) {
-			rv = spawnll(LOG_DEBUG, 
-				    PATH_UMOUNT, PATH_UMOUNT, path_buf, NULL);
-		}
-	}
-	return rv;
+  return do_umount(root, name, type);
 }
 
 /* Like ftw, except fn gets called twice: before a directory is
diff -Naur autofs-4.1.4/daemon/Makefile autofs-modificat/daemon/Makefile
--- autofs-4.1.4/daemon/Makefile	2004-04-03 09:14:33.000000000 +0200
+++ autofs-modificat/daemon/Makefile	2007-02-28 11:03:47.000000000 +0100
@@ -6,8 +6,8 @@
 -include ../Makefile.conf
 include ../Makefile.rules
 
-SRCS = automount.c spawn.c module.c mount.c
-OBJS = automount.o spawn.o module.o mount.o
+SRCS = automount.c spawn.c module.c mount.c umount.c
+OBJS = automount.o spawn.o module.o mount.o umount.o
 
 version := $(shell cat ../.version)
 
diff -Naur autofs-4.1.4/daemon/module.c autofs-modificat/daemon/module.c
--- autofs-4.1.4/daemon/module.c	2004-01-29 17:01:22.000000000 +0100
+++ autofs-modificat/daemon/module.c	2007-02-28 13:27:28.000000000 +0100
@@ -240,6 +240,75 @@
 	return mod;
 }
 
+
+struct mount_mod *open_umount(const char *name, const char *err_prefix)
+{
+	struct mount_mod *mod;
+	char *fnbuf;
+	size_t size_name;
+	size_t size_fnbuf;
+	void *dh;
+	int *ver;
+	
+	size_name = _strlen(name, PATH_MAX + 1);
+	if (!size_name)
+		return NULL;
+
+	mod = malloc(sizeof(struct mount_mod));
+	if (!mod) {
+		if (err_prefix)
+			crit("%s%m", err_prefix);
+		return NULL;
+	}
+
+	size_fnbuf = size_name + strlen(AUTOFS_LIB_DIR) + 13;
+	fnbuf = alloca(size_fnbuf);
+	if (!fnbuf) {
+		free(mod);
+		if (err_prefix)
+			crit("%s%m", err_prefix);
+		return NULL;
+	}
+	snprintf(fnbuf, size_fnbuf, "%s/umount_%s.so", AUTOFS_LIB_DIR, name);
+	
+	if (!(dh = dlopen(fnbuf, RTLD_NOW))) {
+		if (err_prefix)
+			crit("%scannot open umount module %s (%s)",
+			       err_prefix, name, dlerror());
+		free(mod);
+		return NULL;
+	}
+
+	if (!(ver = (int *) dlsym(dh, "mount_version"))
+	    || *ver != AUTOFS_MOUNT_VERSION) {
+		if (err_prefix)
+			crit("%smount module %s version mismatch",
+			     err_prefix, name);
+		dlclose(dh);
+		free(mod);
+		return NULL;
+	}
+
+	if (!(mod->mount_init = (mount_init_t) dlsym(dh, "mount_init")) ||
+	    !(mod->mount_umount = (mount_umount_t) dlsym(dh, "mount_umount")) ||
+	    !(mod->mount_done = (mount_done_t) dlsym(dh, "mount_done"))) {
+		if (err_prefix)
+			crit("%smount module %s corrupt", err_prefix, name);
+		dlclose(dh);
+		free(mod);
+		return NULL;
+	}
+
+	if (mod->mount_init(&mod->context)) {
+		dlclose(dh);
+		free(mod);
+		return NULL;
+	}
+	mod->dlhandle = dh;
+	return mod;
+}
+
+
 int close_mount(struct mount_mod *mod)
 {
 	int rv = mod->mount_done(mod->context);
diff -Naur autofs-4.1.4/daemon/umount.c autofs-modificat/daemon/umount.c
--- autofs-4.1.4/daemon/umount.c	1970-01-01 01:00:00.000000000 +0100
+++ autofs-modificat/daemon/umount.c	2007-02-28 15:05:30.000000000 +0100
@@ -0,0 +1,63 @@
+/* ----------------------------------------------------------------------- *
+ *   
+ *   umount.c - Abstract umount code used by modules for an unexpected
+ *            filesystem type
+ *
+ *   Copyright 2007 Jordi Prats - CESCA - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ *   USA; either version 2 of the License, or (at your option) any later
+ *   version.
+ *   
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <syslog.h>
+#include <stdlib.h>
+#include <string.h>
+#include "automount.h"
+
+/* These filesystems are known not to work with the "generic" module */
+static char *not_generic[] = { "ext3lvm",
+			       NULL
+};
+
+// (const char *root, const char *name, int name_len,
+// const char *what, const char *fstype, const char *options)
+
+int do_umount(const char *root, const char *name, const char *type)
+{
+	struct mount_mod *mod;
+	const char *modstr;
+	char **ngp;
+	int rv;
+		
+	mod = open_umount(modstr = type, NULL);
+	if (!mod) {
+		for (ngp = not_generic; *ngp; ngp++) {
+			if (!strcmp(type, *ngp))
+				break;
+		}
+		if (!*ngp)
+			mod = open_umount(modstr = "generic", NULL);
+		if (!mod) {
+			error("cannot find umount method for filesystem %s",
+			       type);
+			return -1;
+		}
+	}
+
+	debug("do_umount root %s name type %s",
+		  root, name, type);
+
+	rv = mod->mount_umount(root, name, strlen(name), type, mod->context);
+	close_mount(mod);
+
+	return rv;
+}
diff -Naur autofs-4.1.4/include/automount.h autofs-modificat/include/automount.h
--- autofs-4.1.4/include/automount.h	2005-01-26 14:03:02.000000000 +0100
+++ autofs-modificat/include/automount.h	2007-02-28 11:54:07.000000000 +0100
@@ -130,6 +130,9 @@
 int signal_children(int sig);
 int do_mount(const char *root, const char *name, int name_len,
 	     const char *what, const char *fstype, const char *options);
+
+int do_umount(const char *root, const char *name, const char *type);
+
 int mkdir_path(const char *path, mode_t mode);
 int rmdir_path(const char *path);
 
@@ -200,22 +203,32 @@
 int mount_init(void **context);
 int mount_mount(const char *root, const char *name, int name_len,
 		const char *what, const char *fstype, const char *options, void *context);
+
+int mount_umount(const char *root, const char *name, int name_len,
+		 const char *fstype, void *context);
+
 int mount_done(void *context);
 #endif
 typedef int (*mount_init_t) (void **);
 typedef int (*mount_mount_t) (const char *, const char *, int, const char *, const char *,
 			      const char *, void *);
+
+typedef int (*mount_umount_t) (const char *, const char *, int, const char *,
+			      void *);
+
 typedef int (*mount_done_t) (void *);
 
 struct mount_mod {
 	mount_init_t mount_init;
 	mount_mount_t mount_mount;
+	mount_umount_t mount_umount;
 	mount_done_t mount_done;
 	void *dlhandle;
 	void *context;
 };
 
 struct mount_mod *open_mount(const char *name, const char *err_prefix);
+struct mount_mod *open_umount(const char *name, const char *err_prefix);
 int close_mount(struct mount_mod *);
 
 /* mapent cache definition */
diff -Naur autofs-4.1.4/include/config.h autofs-modificat/include/config.h
--- autofs-4.1.4/include/config.h	1970-01-01 01:00:00.000000000 +0100
+++ autofs-modificat/include/config.h	2007-02-28 10:46:55.000000000 +0100
@@ -0,0 +1,28 @@
+/* include/config.h.  Generated by configure.  */
+#ident "$Id: config.h.in,v 1.4 2004/02/03 15:23:21 raven Exp $"
+/* -*- c -*-
+ *
+ * config.h.in: Pattern file for autofs to be filled in by configure
+ *
+ */
+
+/* Program paths */
+#define HAVE_MOUNT 1
+#define PATH_MOUNT "/bin/mount"
+
+#define HAVE_UMOUNT 1
+#define PATH_UMOUNT "/bin/umount"
+
+/* #undef HAVE_SMBMOUNT */
+/* #undef PATH_SMBMOUNT */
+
+#define HAVE_E2FSCK 1
+#define PATH_E2FSCK "/sbin/fsck.ext2"
+
+#define HAVE_E3FSCK 1
+#define PATH_E3FSCK "/sbin/fsck.ext3"
+
+/* Define this option if mount(8) supports the -s (sloppy) option */
+#define HAVE_SLOPPY_MOUNT 1
+
+/* #undef ENABLE_EXT_ENV */
diff -Naur autofs-4.1.4/modules/Makefile autofs-modificat/modules/Makefile
--- autofs-4.1.4/modules/Makefile	2004-08-29 14:46:23.000000000 +0200
+++ autofs-modificat/modules/Makefile	2007-02-28 13:03:49.000000000 +0100
@@ -10,13 +10,13 @@
 	lookup_multi.c \
 	parse_sun.c    \
 	mount_generic.c  mount_nfs.c  mount_afs.c  mount_autofs.c \
-	mount_changer.c  mount_bind.c
+	mount_changer.c  mount_bind.c umount_generic.c
 
 MODS :=	lookup_yp.so lookup_file.so lookup_program.so lookup_userhome.so \
 	lookup_multi.so \
 	parse_sun.so \
 	mount_generic.so mount_nfs.so mount_afs.so mount_autofs.so \
-	mount_changer.so mount_bind.so
+	mount_changer.so mount_bind.so umount_generic.so
 
 ifeq ($(EXT2FS), 1)
   SRCS += mount_ext2.c
diff -Naur autofs-4.1.4/modules/umount_generic.c autofs-modificat/modules/umount_generic.c
--- autofs-4.1.4/modules/umount_generic.c	1970-01-01 01:00:00.000000000 +0100
+++ autofs-modificat/modules/umount_generic.c	2007-02-28 15:06:18.000000000 +0100
@@ -0,0 +1,73 @@
+/* ----------------------------------------------------------------------- *
+ *   
+ *  umount_generic.c - module for Linux automountd to umount filesystems
+ *                    for which no special magic is required
+ *
+ *   Copyright 2007 Jordi Prats - CESCA - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ *   USA; either version 2 of the License, or (at your option) any later
+ *   version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <stdio.h>
+#include <malloc.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#define MODULE_MOUNT
+#include "automount.h"
+
+#define MODPREFIX "umount(generic): "
+
+int mount_version = AUTOFS_MOUNT_VERSION;	/* Required by protocol */
+
+int mount_init(void **context)
+{
+	return 0;
+}
+
+int mount_umount(const char *root, const char *name, int name_len,
+		 const char *fstype, void *context)
+{
+	char path_buf[PATH_MAX];
+	struct stat st;
+	int sav_errno;
+	int is_smbfs = (strcmp(fstype, "smbfs") == 0);
+	int status;
+	int rv = 0;
+	
+	sprintf(path_buf, "%s/%s", root, name);
+	status =  lstat(path_buf, &st);
+	sav_errno = errno;
+
+	/* EIO appears to correspond to an smb mount that has gone away */
+	if (!status ||
+	    (is_smbfs && (sav_errno == EIO || sav_errno == EBADSLT))) {
+		int umount_ok = 0;
+
+		if (!status && (S_ISDIR(st.st_mode) && (st.st_dev != ap.dev)))
+			umount_ok = 1;
+
+		if (umount_ok || is_smbfs) {
+			rv = spawnll(LOG_DEBUG, 
+				    PATH_UMOUNT, PATH_UMOUNT, path_buf, NULL);
+		}
+	}
+	return rv;
+}
+
+int mount_done(void *context)
+{
+	return 0;
+}

[-- Attachment #3: Type: text/plain, Size: 140 bytes --]

_______________________________________________
autofs mailing list
autofs@linux.kernel.org
http://linux.kernel.org/mailman/listinfo/autofs