From 2c8890e926a4c7f9169b5054e3dbf84426fe1025 Mon Sep 17 00:00:00 2001
From: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Date: Thu, 28 Sep 2017 14:41:07 +0200
Subject: [PATCH 01/12] Don't abort starting the array if kernel does
 not support ppl

Change the behavior of assemble and create for consistency-policy=ppl
for external metadata arrays. If the kernel does not support ppl, don't
abort but print a warning and start the array without ppl
(consistency-policy=resync). No change for native md arrays because the
kernel will not allow starting the array if it finds an unsupported
feature bit in the superblock.

In sysfs_add_disk() check consistency_policy in the mdinfo structure
that represents the array, not the disk and read the current consistency
policy from sysfs in mdmon's manage_member(). This is necessary to make
sysfs_add_disk() honor the actual consistency policy and not what is in
the metadata. Also remove all the places where consistency_policy is set
for a disk's mdinfo - it is a property of the array, not the disk.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>
---
 managemon.c   | 11 ++++++++---
 super-intel.c |  4 +---
 sysfs.c       |  6 +++---
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/managemon.c b/managemon.c
index 68f0c2d..cc3c6f1 100644
--- a/managemon.c
+++ b/managemon.c
@@ -477,7 +477,7 @@ static void manage_member(struct mdstat_ent *mdstat,
 	char buf[64];
 	int frozen;
 	struct supertype *container = a->container;
-	unsigned long long int component_size = 0;
+	struct mdinfo *mdi;
 
 	if (container == NULL)
 		/* Raced with something */
@@ -489,8 +489,13 @@ static void manage_member(struct mdstat_ent *mdstat,
 		// MORE
 	}
 
-	if (sysfs_get_ll(&a->info, NULL, "component_size", &component_size) >= 0)
-		a->info.component_size = component_size << 1;
+	mdi = sysfs_read(-1, mdstat->devnm,
+			 GET_COMPONENT|GET_CONSISTENCY_POLICY);
+	if (mdi) {
+		a->info.component_size = mdi->component_size;
+		a->info.consistency_policy = mdi->consistency_policy;
+		sysfs_free(mdi);
+	}
 
 	/* honor 'frozen' */
 	if (sysfs_get_str(&a->info, NULL, "metadata_version", buf, sizeof(buf)) > 0)
diff --git a/super-intel.c b/super-intel.c
index bbe7bc7..e3dcd3d 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -7669,7 +7669,6 @@ static struct mdinfo *container_content_imsm(struct supertype *st, char *subarra
 			} else {
 				info_d->component_size = blocks_per_member(map);
 			}
-			info_d->consistency_policy = this->consistency_policy;
 
 			info_d->bb.supported = 1;
 			get_volume_badblocks(super->bbm_log, ord_to_idx(ord),
@@ -8758,8 +8757,7 @@ static struct mdinfo *imsm_activate_spare(struct active_array *a,
 		di->component_size = a->info.component_size;
 		di->container_member = inst;
 		di->bb.supported = 1;
-		if (dev->rwh_policy == RWH_DISTRIBUTED) {
-			di->consistency_policy = CONSISTENCY_POLICY_PPL;
+		if (a->info.consistency_policy == CONSISTENCY_POLICY_PPL) {
 			di->ppl_sector = get_ppl_sector(super, inst);
 			di->ppl_size = (PPL_HEADER_SIZE + PPL_ENTRY_SPACE) >> 9;
 		}
diff --git a/sysfs.c b/sysfs.c
index 68ddd5f..bf5c8c5 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -709,8 +709,8 @@ int sysfs_set_array(struct mdinfo *info, int vers)
 		if (sysfs_set_str(info, NULL, "consistency_policy",
 				  map_num(consistency_policies,
 					  info->consistency_policy))) {
-			pr_err("This kernel does not support PPL\n");
-			return 1;
+			pr_err("This kernel does not support PPL. Falling back to consistency-policy=resync.\n");
+			info->consistency_policy = CONSISTENCY_POLICY_RESYNC;
 		}
 	}
 
@@ -745,7 +745,7 @@ int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
 	rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 	rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 	if (sra->array.level != LEVEL_CONTAINER) {
-		if (sd->consistency_policy == CONSISTENCY_POLICY_PPL) {
+		if (sra->consistency_policy == CONSISTENCY_POLICY_PPL) {
 			rv |= sysfs_set_num(sra, sd, "ppl_sector", sd->ppl_sector);
 			rv |= sysfs_set_num(sra, sd, "ppl_size", sd->ppl_size);
 		}
-- 
2.7.4