filter: use wwid for mpath filterdev-dct-stable-filter-wwid

5 files changed, 181 insertions, 7 deletions

diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c
index a429b100a..53b42d09c 100644
--- a/lib/device/dev-cache.c
+++ b/lib/device/dev-cache.c
@@ -163,6 +163,50 @@ void dev_set_preferred_name(struct dm_str_list *sl, struct device *dev)
 	dm_list_add_h(&dev->aliases, &sl->list);
 }
 
+static void _dev_cache_set_wwids(void)
+{
+	struct btree_iter *iter;
+	struct device *dev;
+	char buf[WWID_BUF_SIZE];
+	int already = 0;
+	int found = 0;
+	int notfound = 0;
+
+	if (!_cache.devices)
+		return;
+
+	log_debug("Reading wwid for all devices.");
+
+	iter = btree_first(_cache.devices);
+
+	while (iter) {
+		dev = btree_get_data(iter);
+
+		if (dev->wwid) {
+			already++;
+			goto next;
+		}
+
+		memset(buf, 0, sizeof(buf));
+
+		if (dev_read_wwid(dev, buf, sizeof(buf))) {
+			if (buf[0]) {
+				dev->wwid = dm_pool_strdup(_cache.mem, buf);
+				found++;
+			} else
+				notfound++;
+		} else {
+			notfound++;
+		}
+
+ next:
+		iter = btree_next(iter);
+	}
+
+	log_debug("Found wwid for %d devs not found for %d already set for %d.",
+		  found, notfound, already);
+}
+
 /*
  * Check whether path0 or path1 contains the subpath. The path that
  * *does not* contain the subpath wins (return 0 or 1). If both paths
@@ -1218,6 +1262,8 @@ void dev_cache_scan(void)
 
 	dm_list_iterate_items(dl, &_cache.files)
 		_insert_file(dl->dir);
+
+	_dev_cache_set_wwids();
 }
 
 int dev_cache_has_scanned(void)
diff --git a/lib/device/dev-type.c b/lib/device/dev-type.c
index 14a28dc37..343af9997 100644
--- a/lib/device/dev-type.c
+++ b/lib/device/dev-type.c
@@ -269,6 +269,46 @@ const char *dev_subsystem_name(struct dev_types *dt, struct device *dev)
 	return "";
 }
 
+#define WWID_BUF_SIZE 512
+
+int dev_read_wwid(struct device *dev, char *outbuf, int outsize)
+{
+	FILE *fp;
+	char path[PATH_MAX];
+	char buf[WWID_BUF_SIZE];
+	int len;
+
+	if (dm_snprintf(path, sizeof(path), "%sdev/block/%d:%d/device/wwid",
+			dm_sysfs_dir(),
+			(int) MAJOR(dev->dev),
+			(int) MINOR(dev->dev)) < 0) {
+		log_warn("Sysfs path for wwid is too long.");
+		return 0;
+	}
+
+	if (!(fp = fopen(path, "r")))
+		return 0;
+
+	if (!fgets(buf, sizeof(buf), fp))
+		log_debug("Empty wwid for %s", dev_name(dev));
+	else {
+		len = strlen(buf);
+
+		if (len > outsize - 1) {
+			log_debug("sysfs wwid len %d too large for buffer %d for %s",
+				  len, outsize, dev_name(dev));
+			len = outsize - 1;
+		}
+
+		strncpy(outbuf, buf, outsize);
+	}
+
+	if (fclose(fp))
+		log_sys_debug("fclose", path);
+
+	return 1;
+}
+
 int major_max_partitions(struct dev_types *dt, int major)
 {
 	if (major >= NUMBER_OF_MAJORS)
diff --git a/lib/device/dev-type.h b/lib/device/dev-type.h
index bd989f8c8..4d2431d25 100644
--- a/lib/device/dev-type.h
+++ b/lib/device/dev-type.h
@@ -93,4 +93,7 @@ unsigned long dev_discard_granularity(struct dev_types *dt, struct device *dev);
 
 int dev_is_rotational(struct dev_types *dt, struct device *dev);
 
+#define WWID_BUF_SIZE 512
+int dev_read_wwid(struct device *dev, char *outbuf, int outsize);
+
 #endif
diff --git a/lib/device/device.h b/lib/device/device.h
index aafc40114..8d5f04816 100644
--- a/lib/device/device.h
+++ b/lib/device/device.h
@@ -82,6 +82,7 @@ struct device {
 
 	const char *vgid; /* if device is an LV */
 	const char *lvid; /* if device is an LV */
+	const char *wwid;
 
 	char pvid[ID_LEN + 1]; /* if device is a PV */
 	char _padding[7];
diff --git a/lib/filters/filter-mpath.c b/lib/filters/filter-mpath.c
index 6763be33c..888007db4 100644
--- a/lib/filters/filter-mpath.c
+++ b/lib/filters/filter-mpath.c
@@ -15,6 +15,7 @@
 #include "lib.h"
 #include "filter.h"
 #include "activate.h"
+#include "str_list.h"
 #ifdef UDEV_SYNC_SUPPORT
 #include <libudev.h>
 #include "dev-ext-udev-constants.h"
@@ -24,6 +25,11 @@
 
 #include <dirent.h>
 
+/* FIXME: use config setting to change or disable this wwids file. */
+static const char *_wwids_file = "/etc/multipath/wwids";
+static struct dm_list *_wwids_list; /* struct dm_str_list */ 
+static struct dm_pool *_wwids_mem;
+
 #define MPATH_PREFIX "mpath-"
 
 static const char *_get_sysfs_name(struct device *dev)
@@ -146,7 +152,7 @@ static int _get_parent_mpath(const char *dir, char *name, int max_size)
 }
 
 #ifdef UDEV_SYNC_SUPPORT
-static int _udev_dev_is_mpath(struct device *dev)
+static int _udev_dev_is_mpath_component(struct device *dev)
 {
 	const char *value;
 	struct dev_ext *ext;
@@ -165,13 +171,80 @@ static int _udev_dev_is_mpath(struct device *dev)
 	return 0;
 }
 #else
-static int _udev_dev_is_mpath(struct device *dev)
+static int _udev_dev_is_mpath_component(struct device *dev)
 {
 	return 0;
 }
 #endif
 
-static int _native_dev_is_mpath(struct dev_filter *f, struct device *dev)
+#define MAX_WWID_LINE 512
+
+/*
+ * N.B. this doesn't account for the multipath.conf blacklist.
+ */
+
+static int _read_wwids_file(void)
+{
+	FILE *fp;
+	char line[MAX_WWID_LINE];
+	char *wwid, *p;
+
+	if (!(fp = fopen(_wwids_file, "r"))) {
+		return_0;
+	}
+
+	if (!(_wwids_mem = dm_pool_create("filter mpath", 1024))) {
+		fclose(fp);
+		fp = NULL;
+		return_0;
+	}
+
+	if (!(_wwids_list = str_list_create(_wwids_mem))) {
+		fclose(fp);
+		fp = NULL;
+		dm_pool_destroy(_wwids_mem);
+		_wwids_mem = NULL;
+		return_0;
+	}
+
+	while (fgets(line, sizeof(line), fp)) {
+		if (line[0] == '#')
+			continue;
+
+		wwid = line;
+
+		if (line[0] == '/')
+			wwid++;
+
+		if ((p = strchr(wwid, '/')))
+			*p = '\0';
+
+		if (!str_list_add_no_dup_check(_wwids_mem, _wwids_list,
+				dm_pool_strdup(_wwids_mem, wwid)))
+			stack;
+	}
+
+	if (fclose(fp))
+		stack;
+
+	return 1;
+}
+
+static int _wwid_dev_is_mpath_component(struct device *dev)
+{
+	if (!_wwids_list)
+		return 0;
+
+	if (!dev->wwid)
+		return 0;
+
+	if (str_list_match_item(_wwids_list, dev->wwid))
+		return 1;
+
+	return 0;
+}
+
+static int _native_dev_is_mpath_component(struct dev_filter *f, struct device *dev)
 {
 	struct dev_types *dt = (struct dev_types *) f->private;
 	const char *part_name, *name;
@@ -186,6 +259,11 @@ static int _native_dev_is_mpath(struct dev_filter *f, struct device *dev)
 	if (!major_is_scsi_device(dt, MAJOR(dev->dev)))
 		return 0;
 
+	if (_wwid_dev_is_mpath_component(dev)) {
+		log_debug_devs("%s: wwid is mpath component %s", dev_name(dev), dev->wwid);
+		return 1;
+	}
+
 	switch (dev_get_primary_dev(dt, dev, &primary_dev)) {
 	case 2: /* The dev is partition. */
 		part_name = dev_name(dev); /* name of original dev for log_debug msg */
@@ -230,13 +308,13 @@ static int _native_dev_is_mpath(struct dev_filter *f, struct device *dev)
 	return lvm_dm_prefix_check(major, minor, MPATH_PREFIX);
 }
 
-static int _dev_is_mpath(struct dev_filter *f, struct device *dev)
+static int _dev_is_mpath_component(struct dev_filter *f, struct device *dev)
 {
 	if (dev->ext.src == DEV_EXT_NONE)
-		return _native_dev_is_mpath(f, dev);
+		return _native_dev_is_mpath_component(f, dev);
 
 	if (dev->ext.src == DEV_EXT_UDEV)
-		return _udev_dev_is_mpath(dev);
+		return _udev_dev_is_mpath_component(dev);
 
 	log_error(INTERNAL_ERROR "Missing hook for mpath recognition "
 		  "using external device info source %s", dev_ext_name(dev));
@@ -248,7 +326,7 @@ static int _dev_is_mpath(struct dev_filter *f, struct device *dev)
 
 static int _ignore_mpath(struct dev_filter *f, struct device *dev)
 {
-	if (_dev_is_mpath(f, dev) == 1) {
+	if (_dev_is_mpath_component(f, dev) == 1) {
 		if (dev->ext.src == DEV_EXT_NONE)
 			log_debug_devs(MSG_SKIPPING, dev_name(dev));
 		else
@@ -265,6 +343,10 @@ static void _destroy(struct dev_filter *f)
 	if (f->use_count)
 		log_error(INTERNAL_ERROR "Destroying mpath filter while in use %u times.", f->use_count);
 
+	dm_pool_destroy(_wwids_mem);
+	_wwids_mem = NULL;
+	_wwids_list = NULL;
+
 	dm_free(f);
 }
 
@@ -283,6 +365,8 @@ struct dev_filter *mpath_filter_create(struct dev_types *dt)
 		return NULL;
 	}
 
+	_read_wwids_file();
+
 	f->passes_filter = _ignore_mpath;
 	f->destroy = _destroy;
 	f->use_count = 0;