Jeff Mahoney
2008-Aug-12 15:18 UTC
[Ocfs2-devel] [PATCH] ocfs2console: Allow ocfs2console to enumerate device mapper devices
ocfs2console will currently display device mapper devices as dm-#, where
the number can be dynamic across reboots making it non-obvious which
device the user is using. While LVM volumes aren't safe to use across
physical nodes, they are often used with virtual machines. Many ocfs2
users also use dm-multipath.
This patch refactors partition_info_fill to separate hashing from
enumeration so that it is trivial to add a device-mapper enumerator.
The device mapper enumerator is automatically enabled if libdevmapper
is present at build time. When enabled, it suppresses the dm-# devices
from enumeration. If disabled, the dm-# devices are used instead.
I have a bug report for this (Novell Bugzilla 414756) and it was easy
enough to bang out quickly.
Signed-off-by: Jeff Mahoney <jeffm at suse.com>
---
Config.make.in | 2
configure.in | 5 +
ocfs2console/ocfs2interface/Makefile | 7 +
ocfs2console/ocfs2interface/ocfsplist.c | 148 ++++++++++++++++++++++----------
4 files changed, 118 insertions(+), 44 deletions(-)
--- a/Config.make.in
+++ b/Config.make.in
@@ -72,6 +72,8 @@ HAVE_BLKID = @HAVE_BLKID@
LIBDLM_FOUND = @LIBDLM_FOUND@
+LIBDEVMAPPER_FOUND = @LIBDEVMAPPER_FOUND@
+
BUILD_OCFS2CONSOLE = @BUILD_OCFS2CONSOLE@
BUILD_DEBUGOCFS2 = @BUILD_DEBUGOCFS2@
--- a/configure.in
+++ b/configure.in
@@ -289,6 +289,11 @@ if test "x$cman_found" = "xyes" -a
"x$cp
fi
AC_SUBST(BUILD_CMAN_SUPPORT)
+LIBDEVMAPPER_FOUND+AC_CHECK_HEADER(libdevmapper.h, LIBDEVMAPPER_FOUND=yes,
+ [AC_MSG_WARN([libdevmapper.h not found, device-mapper support will not be
built])])
+AC_SUBST(LIBDEVMAPPER_FOUND)
+
BUILD_OCFS2CONSOLE AC_ARG_ENABLE(ocfs2console, [
--enable-ocfs2console=[yes/no] Build GUI frontend
[default=yes]],,enable_ocfs2console=yes)
--- a/ocfs2console/ocfs2interface/Makefile
+++ b/ocfs2console/ocfs2interface/Makefile
@@ -48,6 +48,11 @@ OCFS2_CFILES = ocfs2module.c
ocfs2module_CPPFLAGS = $(OCFS2_CPPFLAGS)
ocfs2module_CFLAGS = $(PYMOD_CFLAGS)
+ifneq ($(LIBDEVMAPPER_FOUND),)
+ocfsplist_CPPFLAGS += -DHAVE_DEVICE_MAPPER
+LIBDEVMAPPER_LIBS = -ldevmapper
+endif
+
PLIST_OBJS = $(subst .c,.o,$(PLIST_CFILES))
GIDLE_OBJS = $(subst .c,.o,$(GIDLE_CFILES))
OCFS2_OBJS = $(subst .c,.o,$(OCFS2_CFILES))
@@ -90,7 +95,7 @@ INSTALL_RULES = install-pylib
DIST_FILES = $(PLIST_CFILES) $(PLIST_HFILES) $(GIDLE_CFILES) $(OCFS2_CFILES)
$(O2CB_CFILES) $(PYSRC) $(addsuffix .in,$(BUILT_PYSRC))
plistmodule.so: $(PLIST_OBJS) $(LIBOCFS2_DEPS) $(LIBO2DLM_DEPS) $(LIBO2CB_DEPS)
$(BLKID_DEPS)
- $(LINK) -shared $(LIBOCFS2_LIBS) $(LIBO2DLM_LIBS) $(LIBO2CB_LIBS)
$(BLKID_LIBS) $(COM_ERR_LIBS) $(GLIB_LIBS)
+ $(LINK) -shared $(LIBOCFS2_LIBS) $(LIBO2DLM_LIBS) $(LIBO2CB_LIBS)
$(BLKID_LIBS) $(COM_ERR_LIBS) $(GLIB_LIBS) $(LIBDEVMAPPER_LIBS)
gidlemodule.so: $(GIDLE_OBJS)
$(LINK) -shared $(GLIB_LIBS)
--- a/ocfs2console/ocfs2interface/ocfsplist.c
+++ b/ocfs2console/ocfs2interface/ocfsplist.c
@@ -37,6 +37,11 @@
#include <blkid/blkid.h>
+#ifdef HAVE_DEVICE_MAPPER
+#include <libdevmapper.h>
+#include <limits.h>
+#endif
+
#include "ocfsplist.h"
@@ -214,15 +219,91 @@ get_device_fstype (const gchar *device,
}
static void
-partition_info_fill (GHashTable *info,
- gboolean async)
+partition_add_one(GHashTable *info, gboolean async, const char *name,
+ guint *count)
+{
+ GSList *list = NULL;
+ gchar *device = g_strconcat ("/dev/", name, NULL);
+ gint i = strlen (device) - 1;
+
+ if (g_ascii_isdigit (device[i]))
+ {
+ gchar *p;
+ while (i > 0 && g_ascii_isdigit (device[i]))
+ i--;
+
+ p = g_strndup (device, i + 1);
+ list = g_hash_table_lookup (info, p);
+
+ if (list == NULL)
+ {
+ list = g_slist_prepend (NULL, device);
+ g_hash_table_insert (info, p, list);
+ }
+ else
+ {
+ if (strcmp (p, list->data) == 0)
+ {
+ g_free (list->data);
+ list->data = device;
+ }
+ else
+ g_slist_append (list, device);
+
+ g_free (p);
+ }
+ }
+ else if (!g_hash_table_lookup (info, device))
+ {
+ list = g_slist_prepend (NULL, g_strdup (device));
+ g_hash_table_insert (info, device, list);
+ }
+ else
+ g_free (device);
+
+ async_loop_run (async, count, FILL_ASYNC_ITERATIONS);
+}
+
+#ifdef HAVE_DEVICE_MAPPER
+static void
+partition_add_dm(GHashTable *info, gboolean async, guint *count)
+{
+ struct dm_names *names;
+ struct dm_task *dmt;
+ unsigned int next = 0;
+
+ if (!(dmt = dm_task_create(DM_DEVICE_LIST)))
+ return;
+
+ if (!dm_task_run(dmt))
+ goto out;
+
+ if (!(names = dm_task_get_names(dmt)))
+ goto out;
+
+ if (!names->dev)
+ goto out;
+
+ do
+ {
+ char name[PATH_MAX];
+ names = (void *) names + next;
+ snprintf(name, PATH_MAX, "mapper/%s", names->name);
+ partition_add_one(info, async, name, count);
+ next = names->next;
+ }
+ while (next);
+
+out:
+ dm_task_destroy(dmt);
+}
+#endif
+
+static void
+partition_add_partitions(GHashTable *info, gboolean async, guint *count)
{
FILE *proc;
- gchar line[100], name[100], *device;
- GSList *list;
- gint i;
- gchar *p;
- guint count = 0;
+ gchar line[100], name[100];
proc = fopen ("/proc/partitions", "r");
if (proc == NULL)
@@ -233,47 +314,28 @@ partition_info_fill (GHashTable *info,
if (sscanf(line, "%*d %*d %*d %99[^ \t\n]", name) != 1)
continue;
- device = g_strconcat ("/dev/", name, NULL);
-
- i = strlen (device) - 1;
- if (g_ascii_isdigit (device[i]))
- {
- while (i > 0 && g_ascii_isdigit (device[i]))
- i--;
+#ifdef HAVE_DEVICE_MAPPER
+ if (strstr(name, "dm-") == name)
+ continue;
+#endif
- p = g_strndup (device, i + 1);
- list = g_hash_table_lookup (info, p);
+ partition_add_one(info, async, name, count);
- if (list == NULL)
- {
- list = g_slist_prepend (NULL, device);
- g_hash_table_insert (info, p, list);
- }
- else
- {
- if (strcmp (p, list->data) == 0)
- {
- g_free (list->data);
- list->data = device;
- }
- else
- g_slist_append (list, device);
+ }
+ fclose (proc);
+}
- g_free (p);
- }
- }
- else if (!g_hash_table_lookup (info, device))
- {
- list = g_slist_prepend (NULL, g_strdup (device));
- g_hash_table_insert (info, device, list);
- }
- else
- g_free (device);
+static void
+partition_info_fill (GHashTable *info,
+ gboolean async)
+{
+ guint count = 0;
- async_loop_run (async, &count, FILL_ASYNC_ITERATIONS);
- }
+ partition_add_partitions(info, async, &count);
- fclose (proc);
+#ifdef HAVE_DEVICE_MAPPER
+ partition_add_dm(info, async, &count);
+#endif
}
static gboolean
--
Jeff Mahoney
SUSE Labs
Joel Becker
2008-Aug-12 19:25 UTC
[Ocfs2-devel] [PATCH] ocfs2console: Allow ocfs2console to enumerate device mapper devices
[Cc'ing ocfs2-tools-devel] On Tue, Aug 12, 2008 at 11:18:31AM -0400, Jeff Mahoney wrote:> ocfs2console will currently display device mapper devices as dm-#, where > the number can be dynamic across reboots making it non-obvious which > device the user is using. While LVM volumes aren't safe to use across > physical nodes, they are often used with virtual machines. Many ocfs2 > users also use dm-multipath. > > This patch refactors partition_info_fill to separate hashing from > enumeration so that it is trivial to add a device-mapper enumerator. > > The device mapper enumerator is automatically enabled if libdevmapper > is present at build time. When enabled, it suppresses the dm-# devices > from enumeration. If disabled, the dm-# devices are used instead. > > I have a bug report for this (Novell Bugzilla 414756) and it was easy > enough to bang out quickly.Nice! I've not played with libdevmapper - I assume that the enumerator returns "preferred" names when there are 10 different symlinks for the same volume? :-) Joel> +LIBDEVMAPPER_FOUND> +AC_CHECK_HEADER(libdevmapper.h, LIBDEVMAPPER_FOUND=yes, > + [AC_MSG_WARN([libdevmapper.h not found, device-mapper support will not be built])]) > +AC_SUBST(LIBDEVMAPPER_FOUND)Please check for the lib too: LIBDEVMAPPER_FOUNDAC_CHECK_LIB(devmapper, dm_task_create, [AC_CHECK_HEADER(libdevmapper.h, LIBDEVMAPPER_FOUND=yes, [AC_MSG_WARN([libdevmapper.h not found, device-mapper support will not be built])])], [AC_MSG_WARN([libdevmapper not found, device-mapper support will not be built])]) AC_SUBST(LIBDEVMAPPER_FOUND) Otherwise, it looks good. Joel -- "The nice thing about egotists is that they don't talk about other people." - Lucille S. Harper Joel Becker Principal Software Developer Oracle E-mail: joel.becker at oracle.com Phone: (650) 506-8127