From f450ffed18936a3b9a6249ad46b24741f7e7b2a3 Mon Sep 17 00:00:00 2001

From: David Teigland <teigland@redhat.com>

Date: Thu, 1 Aug 2019 10:06:47 -0500

Subject: [PATCH 2/6] vgcreate/vgextend: restrict PVs with mixed block sizes

Avoid having PVs with different logical block sizes in the same VG.

This prevents LVs from having mixed block sizes, which can produce

file system errors.

The new config setting devices/allow_mixed_block_sizes (default 0)

can be changed to 1 to return to the unrestricted mode.

(cherry picked from commit 0404539edb25e4a9d3456bb3e6b402aa2767af6b)

Conflicts:

	tools/lvmcmdline.c

	tools/toollib.c

(cherry picked from commit a57b92dec396ac79c57e02e54c04e205aa85f084)

---

 lib/commands/toolcontext.h       |  1 +

 lib/config/config_settings.h     |  5 +++++

 lib/metadata/metadata-exported.h |  1 +

 lib/metadata/metadata.c          | 44 +++++++++++++++++++++++++++++++++++++

 tools/lvmcmdline.c               |  2 ++

 tools/toollib.c                  | 47 ++++++++++++++++++++++++++++++++++++++++

 tools/vgcreate.c                 |  2 ++

 7 files changed, 102 insertions(+)

diff --git a/lib/commands/toolcontext.h b/lib/commands/toolcontext.h

index 4b2a079..497f4bd 100644

--- a/lib/commands/toolcontext.h

+++ b/lib/commands/toolcontext.h

@@ -155,6 +155,7 @@ struct cmd_context {

 	unsigned include_shared_vgs:1;		/* report/display cmds can reveal lockd VGs */

 	unsigned include_active_foreign_vgs:1;	/* cmd should process foreign VGs with active LVs */

 	unsigned vg_read_print_access_error:1;	/* print access errors from vg_read */

+	unsigned allow_mixed_block_sizes:1;

 	unsigned force_access_clustered:1;

 	unsigned lockd_gl_disable:1;

 	unsigned lockd_vg_disable:1;

diff --git a/lib/config/config_settings.h b/lib/config/config_settings.h

index 9904a62..622e982 100644

--- a/lib/config/config_settings.h

+++ b/lib/config/config_settings.h

@@ -470,6 +470,11 @@ cfg(devices_allow_changes_with_duplicate_pvs_CFG, "allow_changes_with_duplicate_

 	"Enabling this setting allows the VG to be used as usual even with\n"

 	"uncertain devices.\n")

+cfg(devices_allow_mixed_block_sizes_CFG, "allow_mixed_block_sizes", devices_CFG_SECTION, 0, CFG_TYPE_BOOL, 0, vsn(2, 3, 6), NULL, 0, NULL,

+	"Allow PVs in the same VG with different logical block sizes.\n"

+	"When allowed, the user is responsible to ensure that an LV is\n"

+	"using PVs with matching block sizes when necessary.\n")

+

 cfg_array(allocation_cling_tag_list_CFG, "cling_tag_list", allocation_CFG_SECTION, CFG_DEFAULT_UNDEFINED, CFG_TYPE_STRING, NULL, vsn(2, 2, 77), NULL, 0, NULL,

 	"Advise LVM which PVs to use when searching for new space.\n"

 	"When searching for free space to extend an LV, the 'cling' allocation\n"

diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h

index 2245c29..5674545 100644

--- a/lib/metadata/metadata-exported.h

+++ b/lib/metadata/metadata-exported.h

@@ -593,6 +593,7 @@ struct pvcreate_params {

 	unsigned is_remove : 1;         /* is removing PVs, not creating */

 	unsigned preserve_existing : 1;

 	unsigned check_failed : 1;

+	unsigned check_consistent_block_size : 1;

 };

 struct lvresize_params {

diff --git a/lib/metadata/metadata.c b/lib/metadata/metadata.c

index 3620240..123f7f5 100644

--- a/lib/metadata/metadata.c

+++ b/lib/metadata/metadata.c

@@ -699,12 +699,40 @@ int vg_extend_each_pv(struct volume_group *vg, struct pvcreate_params *pp)

 {

 	struct pv_list *pvl;

 	unsigned int max_phys_block_size = 0;

+	unsigned int physical_block_size, logical_block_size;

+	unsigned int prev_lbs = 0;

+	int inconsistent_existing_lbs = 0;

 	log_debug_metadata("Adding PVs to VG %s.", vg->name);

 	if (vg_bad_status_bits(vg, RESIZEABLE_VG))

 		return_0;

+	/*

+	 * Check if existing PVs have inconsistent block sizes.

+	 * If so, do not enforce new devices to be consistent.

+	 */

+	dm_list_iterate_items(pvl, &vg->pvs) {

+		logical_block_size = 0;

+		physical_block_size = 0;

+

+		if (!dev_get_direct_block_sizes(pvl->pv->dev, &physical_block_size, &logical_block_size))

+			continue;

+

+		if (!logical_block_size)

+			continue;

+

+		if (!prev_lbs) {

+			prev_lbs = logical_block_size;

+			continue;

+		}

+		

+		if (prev_lbs != logical_block_size) {

+			inconsistent_existing_lbs = 1;

+			break;

+		}

+	}

+

 	dm_list_iterate_items(pvl, &pp->pvs) {

 		log_debug_metadata("Adding PV %s to VG %s.", pv_dev_name(pvl->pv), vg->name);

@@ -715,6 +743,22 @@ int vg_extend_each_pv(struct volume_group *vg, struct pvcreate_params *pp)

 			return 0;

 		}

+		logical_block_size = 0;

+		physical_block_size = 0;

+

+		if (!dev_get_direct_block_sizes(pvl->pv->dev, &physical_block_size, &logical_block_size))

+			log_warn("WARNING: PV %s has unknown block size.", pv_dev_name(pvl->pv));

+

+		else if (prev_lbs && logical_block_size && (logical_block_size != prev_lbs)) {

+			if (vg->cmd->allow_mixed_block_sizes || inconsistent_existing_lbs)

+				log_debug("Devices have inconsistent block sizes (%u and %u)", prev_lbs, logical_block_size);

+			else {

+				log_error("Devices have inconsistent logical block sizes (%u and %u).",

+					  prev_lbs, logical_block_size);

+				return 0;

+			}

+		}

+

 		if (!add_pv_to_vg(vg, pv_dev_name(pvl->pv), pvl->pv, 0)) {

 			log_error("PV %s cannot be added to VG %s.",

 				  pv_dev_name(pvl->pv), vg->name);

diff --git a/tools/lvmcmdline.c b/tools/lvmcmdline.c

index f238b64..f82827d 100644

--- a/tools/lvmcmdline.c

+++ b/tools/lvmcmdline.c

@@ -2308,6 +2308,8 @@ static int _get_current_settings(struct cmd_context *cmd)

 	if (cmd->cname->flags & CAN_USE_ONE_SCAN)

 		cmd->can_use_one_scan = 1;

+	cmd->allow_mixed_block_sizes = find_config_tree_bool(cmd, devices_allow_mixed_block_sizes_CFG, NULL);

+

 	cmd->partial_activation = 0;

 	cmd->degraded_activation = 0;

 	activation_mode = find_config_tree_str(cmd, activation_mode_CFG, NULL);

diff --git a/tools/toollib.c b/tools/toollib.c

index 81953ee..0b957cc 100644

--- a/tools/toollib.c

+++ b/tools/toollib.c

@@ -5506,6 +5506,8 @@ int pvcreate_each_device(struct cmd_context *cmd,

 	struct device_list *devl;

 	const char *pv_name;

 	int consistent = 0;

+	unsigned int physical_block_size, logical_block_size;

+	unsigned int prev_pbs = 0, prev_lbs = 0;

 	int must_use_all = (cmd->cname->flags & MUST_USE_ALL_ARGS);

 	int found;

 	unsigned i;

@@ -5584,6 +5586,51 @@ int pvcreate_each_device(struct cmd_context *cmd,

 		pd->dev = dev_cache_get(pd->name, cmd->full_filter);

 	/*

+	 * Check for consistent block sizes.

+	 */

+	if (pp->check_consistent_block_size) {

+		dm_list_iterate_items(pd, &pp->arg_devices) {

+			if (!pd->dev)

+				continue;

+

+			logical_block_size = 0;

+			physical_block_size = 0;

+

+			if (!dev_get_direct_block_sizes(pd->dev, &physical_block_size, &logical_block_size)) {

+				log_warn("WARNING: Unknown block size for device %s.", dev_name(pd->dev));

+				continue;

+			}

+

+			if (!logical_block_size) {

+				log_warn("WARNING: Unknown logical_block_size for device %s.", dev_name(pd->dev));

+				continue;

+			}

+

+			if (!prev_lbs) {

+				prev_lbs = logical_block_size;

+				prev_pbs = physical_block_size;

+				continue;

+			}

+

+			if (prev_lbs == logical_block_size) {

+				/* Require lbs to match, just warn about unmatching pbs. */

+				if (!cmd->allow_mixed_block_sizes && prev_pbs && physical_block_size &&

+				    (prev_pbs != physical_block_size))

+					log_warn("WARNING: Devices have inconsistent physical block sizes (%u and %u).",

+						  prev_pbs, physical_block_size);

+				continue;

+			}

+

+			if (!cmd->allow_mixed_block_sizes) {

+				log_error("Devices have inconsistent logical block sizes (%u and %u).",

+					  prev_lbs, logical_block_size);

+				log_print("See lvm.conf allow_mixed_block_sizes.");

+				return 0;

+			}

+		}

+	}

+

+	/*

 	 * Use process_each_pv to search all existing PVs and devices.

 	 *

 	 * This is a slightly different way to use process_each_pv, because the

diff --git a/tools/vgcreate.c b/tools/vgcreate.c

index 4356d99..7add53b 100644

--- a/tools/vgcreate.c

+++ b/tools/vgcreate.c

@@ -48,6 +48,8 @@ int vgcreate(struct cmd_context *cmd, int argc, char **argv)

 	/* Don't create a new PV on top of an existing PV like pvcreate does. */

 	pp.preserve_existing = 1;

+	pp.check_consistent_block_size = 1;

+

 	if (!vgcreate_params_set_defaults(cmd, &vp_def, NULL))

 		return EINVALID_CMD_LINE;

 	vp_def.vg_name = vg_name;

-- 

1.8.3.1