[dm-devel] [PATCH V2 22/26] dm raid: enhance reshape check and factor out reshape setup
heinzm at redhat.com
heinzm at redhat.com
Thu Jul 7 14:25:43 UTC 2016
From: Heinz Mauelshagen <heinzm at redhat.com>
Enhance rs_reshape_requested() check function to be
more transparent and fix its raid10 check.
Streamline the constructor by factoring out reshaping
preparation into fucntion rs_prepare_reshape().
Signed-off-by: Heinz Mauelshagen <heinzm at redhat.com>
---
drivers/md/dm-raid.c | 167 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 106 insertions(+), 61 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 846c58d..473c6d9 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -1700,16 +1700,30 @@ static bool rs_takeover_requested(struct raid_set *rs)
/* True if @rs is requested to reshape by ctr */
static bool rs_reshape_requested(struct raid_set *rs)
{
+ bool change;
struct mddev *mddev = &rs->md;
+ if (rs_takeover_requested(rs))
+ return false;
+
if (!mddev->level)
return false;
- return !__is_raid10_far(mddev->new_layout) &&
- mddev->new_level == mddev->level &&
- (mddev->new_layout != mddev->layout ||
- mddev->new_chunk_sectors != mddev->chunk_sectors ||
- rs->raid_disks + rs->delta_disks != mddev->raid_disks);
+ change = mddev->new_layout != mddev->layout ||
+ mddev->new_chunk_sectors != mddev->chunk_sectors ||
+ rs->delta_disks;
+
+ /* Historical case to support raid1 reshape without delta disks */
+ if (mddev->level == 1)
+ return !change &&
+ mddev->raid_disks != rs->raid_disks;
+
+ if (mddev->level == 10)
+ return change &&
+ !__is_raid10_far(mddev->new_layout) &&
+ rs->delta_disks >= 0;
+
+ return change;
}
/* Features */
@@ -1821,7 +1835,7 @@ static int rs_check_reshape(struct raid_set *rs)
rs->ti->error = "Can't reshape degraded raid set";
else if (rs_is_recovering(rs))
rs->ti->error = "Convert request on recovering raid set prohibited";
- else if (mddev->reshape_position && rs_is_reshaping(rs))
+ else if (rs_is_reshaping(rs))
rs->ti->error = "raid set already reshaping!";
else if (!(rs_is_raid10(rs) || rs_is_raid456(rs)))
rs->ti->error = "Reshaping only supported for raid4/5/6/10";
@@ -2518,6 +2532,69 @@ static int rs_setup_takeover(struct raid_set *rs)
return 0;
}
+/* Prepare @rs for reshape */
+static int rs_prepare_reshape(struct raid_set *rs)
+{
+ bool reshape;
+ struct mddev *mddev = &rs->md;
+
+ if (rs_is_raid10(rs)) {
+ if (rs->raid_disks != mddev->raid_disks &&
+ __is_raid10_near(mddev->layout) &&
+ rs->raid10_copies &&
+ rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
+ /*
+ * raid disk have to be multiple of data copies to allow this conversion,
+ *
+ * This is actually not a reshape it is a
+ * rebuild of any additional mirrors per group
+ */
+ if (rs->raid_disks % rs->raid10_copies) {
+ rs->ti->error = "Can't reshape raid10 mirror groups";
+ return -EINVAL;
+ }
+
+ /* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
+ __reorder_raid_disk_indexes(rs);
+ mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
+ rs->raid10_copies);
+ mddev->new_layout = mddev->layout;
+ reshape = false;
+ } else
+ reshape = true;
+
+ } else if (rs_is_raid456(rs))
+ reshape = true;
+
+ /*
+ * HM FIXME: process raid1 via delta_disks as well?
+ * Would cause allocations in raid1->check_reshape
+ * though, thus more issues with potential failures
+ */
+ else if (rs_is_raid1(rs)) {
+ set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
+ mddev->raid_disks = rs->raid_disks;
+ reshape = false;
+
+ } else {
+ rs->ti->error = "Called with bogus raid type";
+ return -EINVAL;
+ }
+
+ if (reshape) {
+ set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
+ set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
+ set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
+ }
+ /* Create new superblocks and bitmaps, if any */
+ if (mddev->raid_disks < rs->raid_disks) {
+ set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
+ rs_set_cur(rs);
+ }
+
+ return 0;
+}
+
/*
*
* - change raid layout
@@ -2682,7 +2759,7 @@ static void configure_discard_support(struct raid_set *rs)
static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
{
int r;
- bool resize = false;
+ bool resize;
struct raid_type *rt;
unsigned num_raid_params, num_raid_devs;
sector_t calculated_dev_sectors;
@@ -2770,6 +2847,12 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
/* Restore any requested new layout for conversion decision */
rs_config_restore(rs, &rs_layout);
+ /*
+ * Now that we have any superblock metadata available,
+ * check for new, recovering, reshaping, to be taken over,
+ * to be reshaped or an existing, unchanged raid set to
+ * run in sequence.
+ */
if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
if (rs_is_raid6(rs) &&
@@ -2782,6 +2865,7 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
rs_set_new(rs);
} else if (rs_is_recovering(rs)) {
+ /* A recovering raid set may be resized */
; /* skip setup rs */
} else if (rs_is_reshaping(rs)) {
/* Have to reject size change request during reshape */
@@ -2790,7 +2874,7 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
r = -EPERM;
goto bad;
}
- ; /* skip setup rs */
+ /* skip setup rs */
} else if (rs_takeover_requested(rs)) {
if (rs_is_reshaping(rs)) {
ti->error = "Can't takeover a reshaping raid set";
@@ -2800,7 +2884,9 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
/*
* If a takeover is needed, userspace sets any additional
- * devices to rebuild, so set the level to the new requested
+ * devices to rebuild and we can check for a valid request here.
+ *
+ * If acceptible, set the level to the new requested
* one, prohibit requesting recovery, allow the raid
* set to run and store superblocks during resume.
*/
@@ -2814,63 +2900,22 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
+ /* Takeover ain't recovery, so disable recovery */
rs_setup_recovery(rs, MaxSector);
rs_set_new(rs);
} else if (rs_reshape_requested(rs)) {
- if (rs_is_reshaping(rs)) {
- ti->error = "raid set already reshaping!";
- r = -EPERM;
- goto bad;
- }
-
- if (rs_is_raid10(rs)) {
- if (rs->raid_disks != rs->md.raid_disks &&
- __is_raid10_near(rs->md.layout) &&
- rs->raid10_copies &&
- rs->raid10_copies != __raid10_near_copies(rs->md.layout)) {
- /*
- * raid disk have to be multiple of data copies to allow this conversion,
- *
- * This is actually not a reshape it is a
- * rebuild of any additional mirrors per group
- */
- if (rs->raid_disks % rs->raid10_copies) {
- ti->error = "Can't reshape raid10 mirror groups";
- r = -EINVAL;
- goto bad;
- }
-
- /* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
- __reorder_raid_disk_indexes(rs);
- rs->md.layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
- rs->raid10_copies);
- rs->md.new_layout = rs->md.layout;
-
- } else
- set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
-
- } else if (rs_is_raid456(rs))
- set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
-
/*
- * HM FIXME: process raid1 via delta_disks as well?
- * Would cause allocations in raid1->check_reshape
- * though, thus more issues with potential failures
- */
- else if (rs_is_raid1(rs)) {
- set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
- rs->md.raid_disks = rs->raid_disks;
- }
-
- if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
- set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
- set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
- }
-
- /* Create new superblocks and bitmaps, if any */
- if (rs->md.raid_disks < rs->raid_disks)
- set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
+ * We can only prepare for a reshape here, because the
+ * raid set needs to run to provide the repective reshape
+ * check functions via its MD personality instance.
+ *
+ * So do the reshape check after md_run() succeeded.
+ */
+ r = rs_prepare_reshape(rs);
+ if (r)
+ return r;
+ /* Reshaping ain't recovery, so disable recovery */
rs_setup_recovery(rs, MaxSector);
rs_set_cur(rs);
} else {
--
2.5.5
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