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| author | Goldwyn Rodrigues <rgoldwyn@suse.com> | 2015-07-22 19:09:17 +0200 |
|---|---|---|
| committer | NeilBrown <neilb@suse.com> | 2015-07-23 01:22:00 +0200 |
| commit | d3b178adb3a3adf54ecf77758138b654c3ee7f09 (patch) | |
| tree | 018d2ba212c10f10a6e3bbfcd3d2197918805017 /drivers/md/bitmap.c | |
| parent | md: flush ->event_work before stopping array. (diff) | |
| download | linux-d3b178adb3a3adf54ecf77758138b654c3ee7f09.tar.xz linux-d3b178adb3a3adf54ecf77758138b654c3ee7f09.zip | |
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.c | 15 |
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)) |