File 0158-super1-allow-reshape-that-hasn-t-really-started-to-b.patch of Package mdadm.5365
From d5ff855d477cea9c8f242721923982aeb81a6dbc Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.com>
Date: Thu, 28 Jan 2016 12:57:08 +1100
Subject: [PATCH 218/359] super1: allow reshape that hasn't really started to
be reverted.
References: bsc#1081910
A simple revert doesn't work here because the reshape_position is
in the critical section.
The best approach is to let the reshape progress a bit and then
go backwards.
If that isn't possible, assembling with --update=revert-reshape and
--invalid-backup should work.
Reported-by-tested-by: George Rapp <george.rapp@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
Assemble.c | 9 ++++++++-
super1.c | 21 ++++++++++++++++++++-
2 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/Assemble.c b/Assemble.c
index a7cd163..25a14be 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -643,7 +643,14 @@ static int load_devices(struct devs *devices, char *devmap,
} else if (strcmp(c->update, "nodes") == 0) {
tst->nodes = c->nodes;
err = tst->ss->write_bitmap(tst, dfd, NodeNumUpdate);
- } else
+ } else if (strcmp(c->update, "revert-reshape") == 0 &&
+ c->invalid_backup)
+ err = tst->ss->update_super(tst, content,
+ "revert-reshape-nobackup",
+ devname, c->verbose,
+ ident->uuid_set,
+ c->homehost);
+ else
err = tst->ss->update_super(tst, content, c->update,
devname, c->verbose,
ident->uuid_set,
diff --git a/super1.c b/super1.c
index 5d08d4d..0f6797a 100644
--- a/super1.c
+++ b/super1.c
@@ -1307,7 +1307,7 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
(st->sb + MAX_SB_SIZE + BM_SUPER_SIZE);
sb->data_size = __cpu_to_le64(
misc->device_size - __le64_to_cpu(sb->data_offset));
- } else if (strcmp(update, "revert-reshape") == 0) {
+ } else if (strncmp(update, "revert-reshape", 14) == 0) {
rv = -2;
if (!(sb->feature_map & __cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE)))
pr_err("No active reshape to revert on %s\n",
@@ -1317,6 +1317,24 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
unsigned long long reshape_sectors;
long reshape_chunk;
rv = 0;
+ /* If the reshape hasn't started, just stop it.
+ * It is conceivable that a stripe was modified but
+ * the metadata not updated. In that case the backup
+ * should have been used to get passed the critical stage.
+ * If that couldn't happen, the "-nobackup" version
+ * will be used.
+ */
+ if (strcmp(update, "revert-reshape-nobackup") == 0 &&
+ sb->reshape_position == 0 &&
+ (__le32_to_cpu(sb->delta_disks) > 0 ||
+ (__le32_to_cpu(sb->delta_disks) == 0 &&
+ !(sb->feature_map & __cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS))))) {
+ sb->feature_map &= ~__cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
+ sb->raid_disks = __cpu_to_le32(__le32_to_cpu(sb->raid_disks) -
+ __le32_to_cpu(sb->delta_disks));
+ sb->delta_disks = 0;
+ goto done;
+ }
/* reshape_position is a little messy.
* Its value must be a multiple of the larger
* chunk size, and of the "after" data disks.
@@ -1363,6 +1381,7 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
sb->new_offset = __cpu_to_le32(-offset_delta);
sb->data_size = __cpu_to_le64(__le64_to_cpu(sb->data_size) - offset_delta);
}
+ done:;
}
} else if (strcmp(update, "_reshape_progress")==0)
sb->reshape_position = __cpu_to_le64(info->reshape_progress);
--
2.16.1
