md: add feature flag MD_FEATURE_RAID0_LAYOUT
[ Upstream commit 33f2c35a54dfd75ad0e7e86918dcbe4de799a56c ]
Due to a bug introduced in Linux 3.14 we cannot determine the
correctly layout for a multi-zone RAID0 array - there are two
possibilities.
It is possible to tell the kernel which to chose using a module
parameter, but this can be clumsy to use. It would be best if
the choice were recorded in the metadata.
So add a feature flag for this purpose.
If it is set, then the 'layout' field of the superblock is used
to determine which layout to use.
If this flag is not set, then mddev->layout gets set to -1,
which causes the module parameter to be required.
Acked-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index a6db4fd..a4e7e6c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1182,6 +1182,8 @@
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
+ if (mddev->level == 0)
+ mddev->layout = -1;
if (sb->state & (1<<MD_SB_CLEAN))
mddev->recovery_cp = MaxSector;
@@ -1598,6 +1600,10 @@
rdev->ppl.sector = rdev->sb_start + rdev->ppl.offset;
}
+ if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT) &&
+ sb->level != 0)
+ return -EINVAL;
+
if (!refdev) {
ret = 1;
} else {
@@ -1708,6 +1714,10 @@
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
+ if (mddev->level == 0 &&
+ !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT))
+ mddev->layout = -1;
+
if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
set_bit(MD_HAS_JOURNAL, &mddev->flags);
@@ -6784,6 +6794,9 @@
mddev->external = 0;
mddev->layout = info->layout;
+ if (mddev->level == 0)
+ /* Cannot trust RAID0 layout info here */
+ mddev->layout = -1;
mddev->chunk_sectors = info->chunk_size >> 9;
if (mddev->persistent) {
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index efa9df2..0272102 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -152,6 +152,9 @@
if (conf->nr_strip_zones == 1) {
conf->layout = RAID0_ORIG_LAYOUT;
+ } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
+ mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
+ conf->layout = mddev->layout;
} else if (default_layout == RAID0_ORIG_LAYOUT ||
default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
conf->layout = default_layout;
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index b0d15c7..1f2d8c8 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -329,6 +329,7 @@
#define MD_FEATURE_JOURNAL 512 /* support write cache */
#define MD_FEATURE_PPL 1024 /* support PPL */
#define MD_FEATURE_MULTIPLE_PPLS 2048 /* support for multiple PPLs */
+#define MD_FEATURE_RAID0_LAYOUT 4096 /* layout is meaningful for RAID0 */
#define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \
|MD_FEATURE_RECOVERY_OFFSET \
|MD_FEATURE_RESHAPE_ACTIVE \
@@ -341,6 +342,7 @@
|MD_FEATURE_JOURNAL \
|MD_FEATURE_PPL \
|MD_FEATURE_MULTIPLE_PPLS \
+ |MD_FEATURE_RAID0_LAYOUT \
)
struct r5l_payload_header {