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authorGoldwyn Rodrigues <rgoldwyn@suse.com>2015-07-22 12:09:17 -0500
committerNeilBrown <neilb@suse.com>2015-07-23 09:22:00 +1000
commitd3b178adb3a3adf54ecf77758138b654c3ee7f09 (patch)
tree018d2ba212c10f10a6e3bbfcd3d2197918805017 /drivers/md/bitmap.c
parentee5d004fd0591536a061451eba2b187092e9127c (diff)
downloadlinux-d3b178adb3a3adf54ecf77758138b654c3ee7f09.tar.bz2
md: Skip cluster setup for dm-raid
There is a bug that the bitmap superblock isn't initialised properly for dm-raid, so a new field can have garbage in new fields. (dm-raid does initialisation in the kernel - md initialised the superblock in mdadm). This means that for dm-raid we cannot currently trust the new ->nodes field. So: - use __GFP_ZERO to initialise the superblock properly for all new arrays - initialise all fields in bitmap_info in bitmap_new_disk_sb - ignore ->nodes for dm arrays (yes, this is a hack) This bug exposes dm-raid to bug in the (still experimental) md-cluster code, so it is suitable for -stable. It does cause crashes. References: https://bugzilla.kernel.org/show_bug.cgi?id=100491 Cc: stable@vger.kernel.org (v4.1) Signed-off-By: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers/md/bitmap.c')
-rw-r--r--drivers/md/bitmap.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 135a0907e9de..c90118e90708 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -494,7 +494,7 @@ static int bitmap_new_disk_sb(struct bitmap *bitmap)
bitmap_super_t *sb;
unsigned long chunksize, daemon_sleep, write_behind;
- bitmap->storage.sb_page = alloc_page(GFP_KERNEL);
+ bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (bitmap->storage.sb_page == NULL)
return -ENOMEM;
bitmap->storage.sb_page->index = 0;
@@ -541,6 +541,7 @@ static int bitmap_new_disk_sb(struct bitmap *bitmap)
sb->state = cpu_to_le32(bitmap->flags);
bitmap->events_cleared = bitmap->mddev->events;
sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
+ bitmap->mddev->bitmap_info.nodes = 0;
kunmap_atomic(sb);
@@ -611,8 +612,16 @@ re_read:
daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
write_behind = le32_to_cpu(sb->write_behind);
sectors_reserved = le32_to_cpu(sb->sectors_reserved);
- nodes = le32_to_cpu(sb->nodes);
- strlcpy(bitmap->mddev->bitmap_info.cluster_name, sb->cluster_name, 64);
+ /* XXX: This is a hack to ensure that we don't use clustering
+ * in case:
+ * - dm-raid is in use and
+ * - the nodes written in bitmap_sb is erroneous.
+ */
+ if (!bitmap->mddev->sync_super) {
+ nodes = le32_to_cpu(sb->nodes);
+ strlcpy(bitmap->mddev->bitmap_info.cluster_name,
+ sb->cluster_name, 64);
+ }
/* verify that the bitmap-specific fields are valid */
if (sb->magic != cpu_to_le32(BITMAP_MAGIC))