[dm-devel] [PATCH 1/3] dm-raid: Add support for the MD RAID0 personality
heinzm at redhat.com
heinzm at redhat.com
Fri Apr 17 12:39:44 UTC 2015
From: Heinz Mauelshagen <heinzm at redhat.com>
This patch adds access to the MD RAID0 personality to dm-raid
(in addition to the already supported raid1/10/4/5/6 personalities)
to enable single zone striping.
The following changes enable that access:
- add type definition to raid_types array
- make bitmap creation conditonal in super_validat(), because
it is not allowed in RAID0
- set rdev->sectors to the data image size in super_validate()
to allow the RAID0 personality to calculate the MD array
size properly
- set rs->md.gendisk, because it is required by RAID0
to set disk stack limits
- enhance raid_resume() to not load bitmap in case of "raid0"
- enhance raid_status() to always report full sync for "raid0"
so that userspace checks for 100% sync will succeed and allow
for resize (and takeover/reshape once added in future paches)
- use mdddev(un)lock() functions instead of direct mutex_(un)lock()
(wrapped in here because it's a trivial change)
Signed-off-by: Heinz Mauelshagen <heinzm at redhat.com>
Tested-by: Heinz Mauelshagen <heinzm at redhat.com>
---
drivers/md/dm-raid.c | 115 ++++++++++++++++++++++++++++++---------------------
1 file changed, 68 insertions(+), 47 deletions(-)
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 88e4c7f..14890dd 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -18,6 +18,7 @@
#define DM_MSG_PREFIX "raid"
+
static bool devices_handle_discard_safely = false;
/*
@@ -81,6 +82,7 @@ static struct raid_type {
const unsigned level; /* RAID level. */
const unsigned algorithm; /* RAID algorithm. */
} raid_types[] = {
+ {"raid0", "RAID0 (striping)", 0, 2, 0, 0 /* NONE */},
{"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
{"raid10", "RAID10 (striped mirrors)", 0, 2, 10, UINT_MAX /* Varies */},
{"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
@@ -720,7 +722,7 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
rs->md.layout = raid10_format_to_md_layout(raid10_format,
raid10_copies);
rs->md.new_layout = rs->md.layout;
- } else if ((rs->raid_type->level > 1) &&
+ } else if ((!rs->raid_type->level || rs->raid_type->level > 1) &&
sector_div(sectors_per_dev,
(rs->md.raid_disks - rs->raid_type->parity_devs))) {
rs->ti->error = "Target length not divisible by number of data devices";
@@ -1026,8 +1028,9 @@ static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
return 0;
}
-static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
+static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
{
+ struct mddev *mddev = &rs->md;
struct dm_raid_superblock *sb = page_address(rdev->sb_page);
/*
@@ -1037,8 +1040,10 @@ static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
if (!mddev->events && super_init_validation(mddev, rdev))
return -EINVAL;
- mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
- rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
+ /* Enable bitmap creation for RAID levels != 0 */
+ mddev->bitmap_info.offset = (rs->raid_type->level) ? 4096 >> 9 : 0;
+ rdev->mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
+
if (!test_bit(FirstUse, &rdev->flags)) {
rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
if (rdev->recovery_offset != MaxSector)
@@ -1082,6 +1087,8 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
* that the "sync" directive is disallowed during the
* reshape.
*/
+ rdev->sectors = to_sector(i_size_read(rdev->bdev->bd_inode));
+
if (rs->print_flags & DMPF_SYNC)
continue;
@@ -1140,11 +1147,11 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
* validation for the remaining devices.
*/
ti->error = "Unable to assemble array: Invalid superblocks";
- if (super_validate(mddev, freshest))
+ if (super_validate(rs, freshest))
return -EINVAL;
rdev_for_each(rdev, mddev)
- if ((rdev != freshest) && super_validate(mddev, rdev))
+ if ((rdev != freshest) && super_validate(rs, rdev))
return -EINVAL;
return 0;
@@ -1282,10 +1289,14 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
*/
configure_discard_support(ti, rs);
- mutex_lock(&rs->md.reconfig_mutex);
+ /* "raid0" calls disk_stack_limits() requiring gendisk access */
+ rs->md.gendisk = dm_disk(dm_table_get_md(ti->table));
+
+ /* Has to be held on running the array */
+ mddev_lock_nointr(&rs->md);
ret = md_run(&rs->md);
rs->md.in_sync = 0; /* Assume already marked dirty */
- mutex_unlock(&rs->md.reconfig_mutex);
+ mddev_unlock(&rs->md);
if (ret) {
ti->error = "Fail to run raid array";
@@ -1368,34 +1379,40 @@ static void raid_status(struct dm_target *ti, status_type_t type,
case STATUSTYPE_INFO:
DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
- if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
- sync = rs->md.curr_resync_completed;
- else
- sync = rs->md.recovery_cp;
-
- if (sync >= rs->md.resync_max_sectors) {
- /*
- * Sync complete.
- */
+ if (rs->raid_type->level) {
+ if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
+ sync = rs->md.curr_resync_completed;
+ else
+ sync = rs->md.recovery_cp;
+
+ if (sync >= rs->md.resync_max_sectors) {
+ /*
+ * Sync complete.
+ */
+ array_in_sync = 1;
+ sync = rs->md.resync_max_sectors;
+ } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
+ /*
+ * If "check" or "repair" is occurring, the array has
+ * undergone and initial sync and the health characters
+ * should not be 'a' anymore.
+ */
+ array_in_sync = 1;
+ } else {
+ /*
+ * The array may be doing an initial sync, or it may
+ * be rebuilding individual components. If all the
+ * devices are In_sync, then it is the array that is
+ * being initialized.
+ */
+ for (i = 0; i < rs->md.raid_disks; i++)
+ if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
+ array_in_sync = 1;
+ }
+ } else {
+ /* RAID0 */
array_in_sync = 1;
sync = rs->md.resync_max_sectors;
- } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
- /*
- * If "check" or "repair" is occurring, the array has
- * undergone and initial sync and the health characters
- * should not be 'a' anymore.
- */
- array_in_sync = 1;
- } else {
- /*
- * The array may be doing an initial sync, or it may
- * be rebuilding individual components. If all the
- * devices are In_sync, then it is the array that is
- * being initialized.
- */
- for (i = 0; i < rs->md.raid_disks; i++)
- if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
- array_in_sync = 1;
}
/*
@@ -1684,26 +1701,30 @@ static void raid_resume(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
- set_bit(MD_CHANGE_DEVS, &rs->md.flags);
- if (!rs->bitmap_loaded) {
- bitmap_load(&rs->md);
- rs->bitmap_loaded = 1;
- } else {
- /*
- * A secondary resume while the device is active.
- * Take this opportunity to check whether any failed
- * devices are reachable again.
- */
- attempt_restore_of_faulty_devices(rs);
+ if (rs->raid_type->level) {
+ set_bit(MD_CHANGE_DEVS, &rs->md.flags);
+
+ if (!rs->bitmap_loaded) {
+ bitmap_load(&rs->md);
+ rs->bitmap_loaded = 1;
+ } else {
+ /*
+ * A secondary resume while the device is active.
+ * Take this opportunity to check whether any failed
+ * devices are reachable again.
+ */
+ attempt_restore_of_faulty_devices(rs);
+ }
+
+ clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
}
- clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
mddev_resume(&rs->md);
}
static struct target_type raid_target = {
.name = "raid",
- .version = {1, 6, 0},
+ .version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = raid_ctr,
.dtr = raid_dtr,
--
2.1.0
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