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dm raid: enhance status interface and fixup takeover/raid0

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The target's status interface has to provide the new 'data_offset' value
to allow userspace to retrieve the kernels offset to the data on each
raid device of a raid set.  This is the base for out-of-place reshaping
required to not write over any data during reshaping (e.g. change
raid6_zr -> raid6_nc):

 - add rs_set_cur() to be able to start up existing array in case of no
   takeover; use in ctr on takeover check

 - enhance raid_status()

 - add supporting functions to get resync/reshape progress and raid
   device status chars

 - fixup rebuild table line output race, which does miss to emit
   'rebuild N' on fully synced/rebuild devices, because it is relying on
   the transient 'In_sync' raid device flag

 - add new status line output for 'data_offset', which'll later be used
   for out-of-place reshaping

 - fixup takeover not working for all levels

 - fixup raid0 message interface oops caused by missing checks
   for the md threads, which don't exist in case of raid0

 - remove ALL_FREEZE_FLAGS not needed for takeover

 - adjust comments

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Heinz Mauelshagen 2016-05-19 18:49:34 +02:00 committed by Mike Snitzer
parent ecbfb9f118
commit 3a1c1ef2fd
1 changed files with 253 additions and 181 deletions
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434
drivers/md/dm-raid.c
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@ -98,13 +98,6 @@ struct raid_dev {
#define ALL_CTR_FLAGS (CTR_FLAG_OPTIONS_NO_ARGS | \
CTR_FLAG_OPTIONS_ONE_ARG)
/*
* All flags which cause a recovery unfreeze once they got stored in the raid metadata
*/
#define ALL_FREEZE_FLAGS (ALL_CTR_FLAGS & ~(CTR_FLAG_REGION_SIZE | CTR_FLAGS_ANY_SYNC | \
CTR_FLAG_RAID10_FORMAT | CTR_FLAG_RAID10_COPIES | \
CTR_FLAG_RAID10_USE_NEAR_SETS))
/* Invalid options definitions per raid level... */
/* "raid0" does not accept any options */
@ -617,6 +610,19 @@ static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
return NULL;
}
/*
* Set the mddev properties in @rs to the current
* ones retrieved from the freshest superblock
*/
static void rs_set_cur(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
/*
* Set the mddev properties in @rs to the new
* ones requested by the ctr
@ -628,6 +634,7 @@ static void rs_set_new(struct raid_set *rs)
mddev->level = mddev->new_level;
mddev->layout = mddev->new_layout;
mddev->chunk_sectors = mddev->new_chunk_sectors;
mddev->raid_disks = rs->raid_disks;
mddev->delta_disks = 0;
}
@ -773,7 +780,7 @@ static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
}
rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
rebuild++;
}
@ -1245,6 +1252,12 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
return rs_check_for_invalid_flags(rs);
}
/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
static unsigned int mddev_data_stripes(struct raid_set *rs)
{
return rs->md.raid_disks - rs->raid_type->parity_devs;
}
static void do_table_event(struct work_struct *ws)
{
struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
@ -1735,7 +1748,7 @@ static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
} else {
/*
* Reshaping is not allowed, because we don't have the appropriate metadata
* No takeover/reshaping, because we don't have the extended v1.8.0 metadata
*/
if (le32_to_cpu(sb->level) != mddev->level) {
DMERR("Reshaping/takeover raid sets not yet supported. (raid level/stripes/size change)");
@ -1889,7 +1902,7 @@ static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
struct mddev *mddev = &rs->md;
struct dm_raid_superblock *sb;
if (!rdev->sb_page)
if (rs_is_raid0(rs) || !rdev->sb_page)
return 0;
sb = page_address(rdev->sb_page);
@ -2084,9 +2097,6 @@ static int rs_setup_takeover(struct raid_set *rs)
rdev->new_data_offset = new_data_offset;
}
rs_set_new(rs);
set_bit(MD_CHANGE_DEVS, &mddev->flags);
return 0;
}
@ -2232,8 +2242,11 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
if (r)
return r;
/* Tell preresume to update superblocks with new layout */
_set_flag(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
}
rs_set_new(rs);
} else
rs_set_cur(rs);
/* Start raid set read-only and assumed clean to change in raid_resume() */
rs->md.ro = 1;
@ -2288,6 +2301,7 @@ static int raid_map(struct dm_target *ti, struct bio *bio)
return DM_MAPIO_SUBMITTED;
}
/* Return string describing the current sync action of @mddev */
static const char *decipher_sync_action(struct mddev *mddev)
{
if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
@ -2313,181 +2327,251 @@ static const char *decipher_sync_action(struct mddev *mddev)
return "idle";
}
/*
* Return status string @rdev
*
* Status characters:
*
* 'D' = Dead/Failed device
* 'a' = Alive but not in-sync
* 'A' = Alive and in-sync
*/
static const char *_raid_dev_status(struct md_rdev *rdev, bool array_in_sync)
{
if (test_bit(Faulty, &rdev->flags))
return "D";
else if (!array_in_sync || !test_bit(In_sync, &rdev->flags))
return "a";
else
return "A";
}
/* Helper to return resync/reshape progress for @rs and @array_in_sync */
static sector_t rs_get_progress(struct raid_set *rs,
sector_t resync_max_sectors, bool *array_in_sync)
{
sector_t r, recovery_cp, curr_resync_completed;
struct mddev *mddev = &rs->md;
curr_resync_completed = mddev->curr_resync_completed ?: mddev->recovery_cp;
recovery_cp = mddev->recovery_cp;
*array_in_sync = false;
if (rs_is_raid0(rs)) {
r = resync_max_sectors;
*array_in_sync = true;
} else {
r = mddev->reshape_position;
/* Reshape is relative to the array size */
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
r != MaxSector) {
if (r == MaxSector) {
*array_in_sync = true;
r = resync_max_sectors;
} else {
/* Got to reverse on backward reshape */
if (mddev->reshape_backwards)
r = mddev->array_sectors - r;
/* Devide by # of data stripes */
sector_div(r, mddev_data_stripes(rs));
}
/* Sync is relative to the component device size */
} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
r = curr_resync_completed;
else
r = recovery_cp;
if (r == MaxSector) {
/*
* Sync complete.
*/
*array_in_sync = true;
r = resync_max_sectors;
} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/*
* If "check" or "repair" is occurring, the raid set has
* undergone an initial sync and the health characters
* should not be 'a' anymore.
*/
*array_in_sync = true;
} else {
struct md_rdev *rdev;
/*
* The raid set may be doing an initial sync, or it may
* be rebuilding individual components. If all the
* devices are In_sync, then it is the raid set that is
* being initialized.
*/
rdev_for_each(rdev, mddev)
if (!test_bit(In_sync, &rdev->flags))
*array_in_sync = true;
#if 0
r = 0; /* HM FIXME: TESTME: https://bugzilla.redhat.com/show_bug.cgi?id=1210637 ? */
#endif
}
}
return r;
}
/* Helper to return @dev name or "-" if !@dev */
static const char *_get_dev_name(struct dm_dev *dev)
{
return dev ? dev->name : "-";
}
static void raid_status(struct dm_target *ti, status_type_t type,
unsigned status_flags, char *result, unsigned maxlen)
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct raid_set *rs = ti->private;
unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
unsigned sz = 0;
int i, array_in_sync = 0;
sector_t sync;
struct mddev *mddev = &rs->md;
struct r5conf *conf = mddev->private;
int max_nr_stripes = conf ? conf->max_nr_stripes : 0;
bool array_in_sync;
unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
unsigned int sz = 0;
unsigned int write_mostly_params = 0;
sector_t progress, resync_max_sectors, resync_mismatches;
const char *sync_action;
struct raid_type *rt;
struct md_rdev *rdev;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
/* *Should* always succeed */
rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
if (!rt)
return;
if (!rt_is_raid0(rs->raid_type)) {
if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
sync = rs->md.curr_resync_completed;
else
sync = rs->md.recovery_cp;
DMEMIT("%s %d ", rt ? rt->name : "unknown", mddev->raid_disks);
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;
}
/* Access most recent mddev properties for status output */
smp_rmb();
/* Get sensible max sectors even if raid set not yet started */
resync_max_sectors = _test_flag(RT_FLAG_RS_PRERESUMED, rs->runtime_flags) ?
mddev->resync_max_sectors : mddev->dev_sectors;
progress = rs_get_progress(rs, resync_max_sectors, &array_in_sync);
resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
(unsigned int) atomic64_read(&mddev->resync_mismatches) : 0;
sync_action = decipher_sync_action(&rs->md);
/* HM FIXME: do we want another state char for raid0? It shows 'D' or 'A' now */
rdev_for_each(rdev, mddev)
DMEMIT(_raid_dev_status(rdev, array_in_sync));
/*
* Status characters:
* 'D' = Dead/Failed device
* 'a' = Alive but not in-sync
* 'A' = Alive and in-sync
*/
for (i = 0; i < rs->md.raid_disks; i++) {
if (test_bit(Faulty, &rs->dev[i].rdev.flags))
DMEMIT("D");
else if (!array_in_sync ||
!test_bit(In_sync, &rs->dev[i].rdev.flags))
DMEMIT("a");
else
DMEMIT("A");
}
/*
* In-sync ratio:
* In-sync/Reshape ratio:
* The in-sync ratio shows the progress of:
* - Initializing the array
* - Rebuilding a subset of devices of the array
* - Initializing the raid set
* - Rebuilding a subset of devices of the raid set
* The user can distinguish between the two by referring
* to the status characters.
*
* The reshape ratio shows the progress of
* changing the raid layout or the number of
* disks of a raid set
*/
DMEMIT(" %llu/%llu",
(unsigned long long) sync,
(unsigned long long) rs->md.resync_max_sectors);
DMEMIT(" %llu/%llu", (unsigned long long) progress,
(unsigned long long) resync_max_sectors);
/*
* v1.5.0+:
*
* Sync action:
* See Documentation/device-mapper/dm-raid.c for
* See Documentation/device-mapper/dm-raid.txt for
* information on each of these states.
*/
DMEMIT(" %s", decipher_sync_action(&rs->md));
DMEMIT(" %s", sync_action);
/*
* v1.5.0+:
*
* resync_mismatches/mismatch_cnt
* This field shows the number of discrepancies found when
* performing a "check" of the array.
* performing a "check" of the raid set.
*/
DMEMIT(" %llu",
(strcmp(rs->md.last_sync_action, "check")) ? 0 :
(unsigned long long)
atomic64_read(&rs->md.resync_mismatches));
DMEMIT(" %llu", (unsigned long long) resync_mismatches);
/*
* v1.8.0+:
*
* data_offset (needed for out of space reshaping)
* This field shows the data offset into the data
* image LV where the first stripes data starts.
*
* We keep data_offset equal on all raid disks of the set,
* so retrieving it from the first raid disk is sufficient.
*/
DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
break;
case STATUSTYPE_TABLE:
/* The string you would use to construct this array */
for (i = 0; i < rs->md.raid_disks; i++) {
if (_test_flag(CTR_FLAG_REBUILD, rs->ctr_flags) &&
rs->dev[i].data_dev &&
!test_bit(In_sync, &rs->dev[i].rdev.flags))
raid_param_cnt += 2; /* for rebuilds */
if (rs->dev[i].data_dev &&
test_bit(WriteMostly, &rs->dev[i].rdev.flags))
raid_param_cnt += 2;
}
raid_param_cnt += (hweight32(rs->ctr_flags & ~CTR_FLAG_REBUILD) * 2);
if (rs->ctr_flags & (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC))
raid_param_cnt--;
DMEMIT("%s %u %u", rs->raid_type->name,
raid_param_cnt, rs->md.chunk_sectors);
if (_test_flag(CTR_FLAG_SYNC, rs->ctr_flags) &&
rs->md.recovery_cp == MaxSector)
DMEMIT(" sync");
if (_test_flag(CTR_FLAG_NOSYNC, rs->ctr_flags))
DMEMIT(" nosync");
for (i = 0; i < rs->md.raid_disks; i++)
if (_test_flag(CTR_FLAG_REBUILD, rs->ctr_flags) &&
rs->dev[i].data_dev &&
!test_bit(In_sync, &rs->dev[i].rdev.flags))
DMEMIT(" rebuild %u", i);
if (_test_flag(CTR_FLAG_DAEMON_SLEEP, rs->ctr_flags))
DMEMIT(" daemon_sleep %lu",
rs->md.bitmap_info.daemon_sleep);
if (_test_flag(CTR_FLAG_MIN_RECOVERY_RATE, rs->ctr_flags))
DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
if (_test_flag(CTR_FLAG_MAX_RECOVERY_RATE, rs->ctr_flags))
DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
for (i = 0; i < rs->md.raid_disks; i++)
if (rs->dev[i].data_dev &&
test_bit(WriteMostly, &rs->dev[i].rdev.flags))
DMEMIT(" write_mostly %u", i);
if (_test_flag(CTR_FLAG_MAX_WRITE_BEHIND, rs->ctr_flags))
DMEMIT(" max_write_behind %lu",
rs->md.bitmap_info.max_write_behind);
if (_test_flag(CTR_FLAG_STRIPE_CACHE, rs->ctr_flags)) {
struct r5conf *conf = rs->md.private;
/* convert from kiB to sectors */
DMEMIT(" stripe_cache %d",
conf ? conf->max_nr_stripes * 2 : 0);
}
if (_test_flag(CTR_FLAG_REGION_SIZE, rs->ctr_flags))
DMEMIT(" region_size %lu",
rs->md.bitmap_info.chunksize >> 9);
if (_test_flag(CTR_FLAG_RAID10_COPIES, rs->ctr_flags))
DMEMIT(" raid10_copies %u",
raid10_md_layout_to_copies(rs->md.layout));
/* Report the table line string you would use to construct this raid set */
/* Calculate raid parameter count */
rdev_for_each(rdev, mddev)
if (test_bit(WriteMostly, &rdev->flags))
write_mostly_params += 2;
raid_param_cnt += memweight(rs->rebuild_disks,
DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks)) * 2 +
write_mostly_params +
hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
/* Emit table line */
DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
if (_test_flag(CTR_FLAG_RAID10_FORMAT, rs->ctr_flags))
DMEMIT(" raid10_format %s",
raid10_md_layout_to_format(rs->md.layout));
DMEMIT(" %s %s", _argname_by_flag(CTR_FLAG_RAID10_FORMAT),
raid10_md_layout_to_format(mddev->layout));
if (_test_flag(CTR_FLAG_RAID10_COPIES, rs->ctr_flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_RAID10_COPIES),
raid10_md_layout_to_copies(mddev->layout));
if (_test_flag(CTR_FLAG_NOSYNC, rs->ctr_flags))
DMEMIT(" %s", _argname_by_flag(CTR_FLAG_NOSYNC));
if (_test_flag(CTR_FLAG_SYNC, rs->ctr_flags))
DMEMIT(" %s", _argname_by_flag(CTR_FLAG_SYNC));
if (_test_flag(CTR_FLAG_REGION_SIZE, rs->ctr_flags))
DMEMIT(" %s %llu", _argname_by_flag(CTR_FLAG_REGION_SIZE),
(unsigned long long) to_sector(mddev->bitmap_info.chunksize));
if (_test_flag(CTR_FLAG_DATA_OFFSET, rs->ctr_flags))
DMEMIT(" %s %llu", _argname_by_flag(CTR_FLAG_DATA_OFFSET),
(unsigned long long) rs->data_offset);
if (_test_flag(CTR_FLAG_DAEMON_SLEEP, rs->ctr_flags))
DMEMIT(" %s %lu", _argname_by_flag(CTR_FLAG_DAEMON_SLEEP),
mddev->bitmap_info.daemon_sleep);
if (_test_flag(CTR_FLAG_DELTA_DISKS, rs->ctr_flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_DELTA_DISKS),
mddev->delta_disks);
if (_test_flag(CTR_FLAG_STRIPE_CACHE, rs->ctr_flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_STRIPE_CACHE),
max_nr_stripes);
rdev_for_each(rdev, mddev)
if (test_bit(rdev->raid_disk, (void *) rs->rebuild_disks))
DMEMIT(" %s %u", _argname_by_flag(CTR_FLAG_REBUILD),
rdev->raid_disk);
rdev_for_each(rdev, mddev)
if (test_bit(WriteMostly, &rdev->flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_WRITE_MOSTLY),
rdev->raid_disk);
if (_test_flag(CTR_FLAG_MAX_WRITE_BEHIND, rs->ctr_flags))
DMEMIT(" %s %lu", _argname_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
mddev->bitmap_info.max_write_behind);
if (_test_flag(CTR_FLAG_MAX_RECOVERY_RATE, rs->ctr_flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
mddev->sync_speed_max);
if (_test_flag(CTR_FLAG_MIN_RECOVERY_RATE, rs->ctr_flags))
DMEMIT(" %s %d", _argname_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
mddev->sync_speed_min);
DMEMIT(" %d", rs->raid_disks);
rdev_for_each(rdev, mddev) {
struct raid_dev *rd = container_of(rdev, struct raid_dev, rdev);
DMEMIT(" %d", rs->md.raid_disks);
for (i = 0; i < rs->md.raid_disks; i++) {
if (rs->dev[i].meta_dev)
DMEMIT(" %s", rs->dev[i].meta_dev->name);
else
DMEMIT(" -");
if (rs->dev[i].data_dev)
DMEMIT(" %s", rs->dev[i].data_dev->name);
else
DMEMIT(" -");
DMEMIT(" %s %s", _get_dev_name(rd->meta_dev),
_get_dev_name(rd->data_dev));
}
}
}
@ -2519,11 +2603,10 @@ static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
return -EBUSY;
else if (!strcasecmp(argv[0], "resync"))
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
else if (!strcasecmp(argv[0], "recover")) {
; /* MD_RECOVERY_NEEDED set below */
else if (!strcasecmp(argv[0], "recover"))
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
} else {
else {
if (!strcasecmp(argv[0], "check"))
set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
else if (!!strcasecmp(argv[0], "repair"))
@ -2536,11 +2619,11 @@ static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
* canceling read-auto mode
*/
mddev->ro = 0;
if (!mddev->suspended)
if (!mddev->suspended && mddev->sync_thread)
md_wakeup_thread(mddev->sync_thread);
}
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
if (!mddev->suspended)
if (!mddev->suspended && mddev->thread)
md_wakeup_thread(mddev->thread);
return 0;
@ -2711,24 +2794,12 @@ static void raid_resume(struct dm_target *ti)
* devices are reachable again.
*/
attempt_restore_of_faulty_devices(rs);
} else {
mddev->in_sync = 0;
/*
* If any of the constructor flags got passed in
* but "region_size" (gets always passed in for
* mappings with bitmap), we expect userspace to
* reset them and reload the mapping anyway.
*
* -> don't unfreeze resynchronization until imminant
* reload of the table w/o theses flags
*/
if (!_test_flags(ALL_FREEZE_FLAGS, rs->ctr_flags))
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
}
mddev->ro = 0;
mddev->in_sync = 0;
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
if (mddev->suspended)
mddev_resume(mddev);
}
@ -2778,4 +2849,5 @@ MODULE_ALIAS("dm-raid4");
MODULE_ALIAS("dm-raid5");
MODULE_ALIAS("dm-raid6");
MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
MODULE_LICENSE("GPL");