vdo: support vdo_pool_header_size

Add profilable configurable setting for vdo pool header size, that is used as 'extra' empty space at the front and end of vdo-pool device to avoid having a disk in the system the may have same data is real vdo LV. For some conversion cases however we may need to allow using '0' header size. TODO: in this case we may eventually avoid adding 'linear' mapping layer in future - but this requires further modification over lvm code base.
lvmteam · Jun 28, 2021 · 2c6a2b6 · 2c6a2b6
1 parent 5fcbc3b
commit 2c6a2b6
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Showing 8 changed files with 28 additions and 12 deletions.
diff --git a/conf/example.conf.in b/conf/example.conf.in
@@ -733,6 +733,11 @@ allocation {
 	# The default and minimum is 1. The maximum is UINT_MAX / 4096.
 	# This configuration option has an automatic default value.
 	# vdo_max_discard = 1
+
+	# Configuration option allocation/vdo_pool_header_size.
+	# Specified the emptry header size in KiB at the front and end of vdo pool device.
+	# This configuration option has an automatic default value.
+	# vdo_pool_header_size = 512
 }
 
 # Configuration section log.

diff --git a/lib/config/config_settings.h b/lib/config/config_settings.h
@@ -816,6 +816,9 @@ cfg(allocation_vdo_max_discard_CFG, "vdo_max_discard", allocation_CFG_SECTION, C
 	"increased latency for the individual discard requests.\n"
 	"The default and minimum is 1. The maximum is UINT_MAX / 4096.\n")
 
+cfg(allocation_vdo_pool_header_size_CFG, "vdo_pool_header_size", allocation_CFG_SECTION, CFG_PROFILABLE | CFG_PROFILABLE_METADATA | CFG_DEFAULT_COMMENTED, CFG_TYPE_INT, DEFAULT_VDO_POOL_HEADER_SIZE_KB, vsn(2, 3, 12), NULL, 0, NULL,
+	"Specified the emptry header size in KiB at the front and end of vdo pool device.\n")
+
 cfg(log_report_command_log_CFG, "report_command_log", log_CFG_SECTION, CFG_PROFILABLE | CFG_DEFAULT_COMMENTED | CFG_DISALLOW_INTERACTIVE, CFG_TYPE_BOOL, DEFAULT_COMMAND_LOG_REPORT, vsn(2, 2, 158), NULL, 0, NULL,
 	"Enable or disable LVM log reporting.\n"
 	"If enabled, LVM will collect a log of operations, messages,\n"

diff --git a/lib/config/defaults.h b/lib/config/defaults.h
@@ -181,8 +181,7 @@
  * VDO pool will reverve some sectors in the front and the back of pool device to avoid
  * seeing same device twice in the system.
  */
-#define DEFAULT_VDO_POOL_HEADER_SIZE  (1024)   // 512KiB
-
+#define DEFAULT_VDO_POOL_HEADER_SIZE_KB  (512)
 
 
 #define DEFAULT_FSADM_PATH FSADM_PATH

diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
@@ -8739,7 +8739,8 @@ static struct logical_volume *_lv_create_an_lv(struct volume_group *vg,
 	}
 
 	if (seg_is_vdo_pool(lp)) {
-		if (!convert_vdo_pool_lv(lv, &lp->vdo_params, &lp->virtual_extents, 1)) {
+		if (!convert_vdo_pool_lv(lv, &lp->vdo_params, &lp->virtual_extents,
+					 1, lp->vdo_pool_header_size)) {
 			stack;
 			goto deactivate_and_revert_new_lv;
 		}

diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
@@ -1034,6 +1034,7 @@ struct lvcreate_params {
 	int approx_alloc;     /* all */
 	alloc_policy_t alloc; /* all */
 	struct dm_vdo_target_params vdo_params; /* vdo */
+	uint64_t vdo_pool_header_size; /* VDO */
 
 	int raidintegrity;
 	const char *raidintegritymode;
@@ -1368,10 +1369,12 @@ int parse_vdo_pool_status(struct dm_pool *mem, const struct logical_volume *vdo_
 struct logical_volume *convert_vdo_pool_lv(struct logical_volume *data_lv,
 					   const struct dm_vdo_target_params *vtp,
 					   uint32_t *virtual_extents,
-					   int format);
+					   int format,
+					   uint64_t vdo_pool_header_size);
 int set_vdo_write_policy(enum dm_vdo_write_policy *vwp, const char *policy);
 int fill_vdo_target_params(struct cmd_context *cmd,
 			   struct dm_vdo_target_params *vtp,
+			   uint64_t *vdo_pool_header_size,
 			   struct profile *profile);
 /* --  metadata/vdo_manip.c */
 

diff --git a/lib/metadata/vdo_manip.c b/lib/metadata/vdo_manip.c
@@ -356,9 +356,9 @@ static int _format_vdo_pool_data_lv(struct logical_volume *data_lv,
 struct logical_volume *convert_vdo_pool_lv(struct logical_volume *data_lv,
 					   const struct dm_vdo_target_params *vtp,
 					   uint32_t *virtual_extents,
-					   int format)
+					   int format,
+					   uint64_t vdo_pool_header_size)
 {
-	const uint64_t header_size = DEFAULT_VDO_POOL_HEADER_SIZE;
 	const uint32_t extent_size = data_lv->vg->extent_size;
 	struct cmd_context *cmd = data_lv->vg->cmd;
 	struct logical_volume *vdo_pool_lv = data_lv;
@@ -379,7 +379,7 @@ struct logical_volume *convert_vdo_pool_lv(struct logical_volume *data_lv,
 
 	if (*virtual_extents)
 		vdo_logical_size =
-			_get_virtual_size(*virtual_extents, extent_size, header_size);
+			_get_virtual_size(*virtual_extents, extent_size, vdo_pool_header_size);
 
 	if (!dm_vdo_validate_target_params(vtp, vdo_logical_size))
 		return_0;
@@ -403,7 +403,7 @@ struct logical_volume *convert_vdo_pool_lv(struct logical_volume *data_lv,
 		return NULL;
 	}
 
-	vdo_logical_size -= 2 * header_size;
+	vdo_logical_size -= 2 * vdo_pool_header_size;
 
 	if (vdo_logical_size < extent_size) {
 		if (!*virtual_extents)
@@ -426,7 +426,7 @@ struct logical_volume *convert_vdo_pool_lv(struct logical_volume *data_lv,
 	vdo_pool_seg = first_seg(vdo_pool_lv);
 	vdo_pool_seg->segtype = vdo_pool_segtype;
 	vdo_pool_seg->vdo_params = *vtp;
-	vdo_pool_seg->vdo_pool_header_size = DEFAULT_VDO_POOL_HEADER_SIZE;
+	vdo_pool_seg->vdo_pool_header_size = vdo_pool_header_size;
 	vdo_pool_seg->vdo_pool_virtual_extents = *virtual_extents;
 
 	vdo_pool_lv->status |= LV_VDO_POOL;
@@ -453,6 +453,7 @@ int set_vdo_write_policy(enum dm_vdo_write_policy *vwp, const char *policy)
 
 int fill_vdo_target_params(struct cmd_context *cmd,
 			   struct dm_vdo_target_params *vtp,
+			   uint64_t *vdo_pool_header_size,
 			   struct profile *profile)
 {
 	const char *policy;
@@ -501,5 +502,7 @@ int fill_vdo_target_params(struct cmd_context *cmd,
 	if (!set_vdo_write_policy(&vtp->write_policy, policy))
 		return_0;
 
+	*vdo_pool_header_size = 2 * find_config_tree_int64(cmd, allocation_vdo_pool_header_size_CFG, profile);
+
 	return 1;
 }
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
@@ -5405,6 +5405,7 @@ static int _lvconvert_to_vdopool_single(struct cmd_context *cmd,
 {
 	const char *vg_name = NULL;
 	unsigned int vdo_pool_zero;
+	uint64_t vdo_pool_header_size;
 	struct volume_group *vg = lv->vg;
 	struct logical_volume *vdo_lv;
 	struct dm_vdo_target_params vdo_params; /* vdo */
@@ -5447,7 +5448,7 @@ static int _lvconvert_to_vdopool_single(struct cmd_context *cmd,
 		goto out;
 	}
 
-	if (!fill_vdo_target_params(cmd, &vdo_params, vg->profile))
+	if (!fill_vdo_target_params(cmd, &vdo_params, &vdo_pool_header_size, vg->profile))
 		goto_out;
 
 	if (arg_is_set(cmd, compression_ARG))
@@ -5489,7 +5490,8 @@ static int _lvconvert_to_vdopool_single(struct cmd_context *cmd,
 		}
 	}
 
-	if (!convert_vdo_pool_lv(lv, &vdo_params, &lvc.virtual_extents, vdo_pool_zero))
+	if (!convert_vdo_pool_lv(lv, &vdo_params, &lvc.virtual_extents,
+				 vdo_pool_zero, vdo_pool_header_size))
 		goto_out;
 
 	dm_list_init(&lvc.tags);

diff --git a/tools/lvcreate.c b/tools/lvcreate.c
@@ -1097,7 +1097,7 @@ static int _lvcreate_params(struct cmd_context *cmd,
 
 		// FIXME: prefiling here - this is wrong place
 		// but will work for this moment
-		if (!fill_vdo_target_params(cmd, &lp->vdo_params, NULL))
+		if (!fill_vdo_target_params(cmd, &lp->vdo_params, &lp->vdo_pool_header_size, NULL))
 			return_0;
 
 		if (arg_is_set(cmd, compression_ARG))