#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
+#include <linux/kthread.h>
#include "md.h"
#include "raid10.h"
#include "raid0.h"
static void allow_barrier(struct r10conf *conf);
static void lower_barrier(struct r10conf *conf);
static int enough(struct r10conf *conf, int ignore);
+static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
+ int *skipped);
+static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio);
+static void end_reshape_write(struct bio *bio, int error);
+static void end_reshape(struct r10conf *conf);
static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
{
if (!r10_bio)
return NULL;
- if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
+ if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
+ test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
nalloc = conf->copies; /* resync */
else
nalloc = 2; /* recovery */
struct bio *rbio = r10_bio->devs[j].repl_bio;
bio = r10_bio->devs[j].bio;
for (i = 0; i < RESYNC_PAGES; i++) {
- if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
- &conf->mddev->recovery)) {
- /* we can share bv_page's during recovery */
+ if (j > 0 && !test_bit(MD_RECOVERY_SYNC,
+ &conf->mddev->recovery)) {
+ /* we can share bv_page's during recovery
+ * and reshape */
struct bio *rbio = r10_bio->devs[0].bio;
page = rbio->bi_io_vec[i].bv_page;
get_page(page);
struct r10conf *conf = mddev->private;
sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
int max;
- unsigned int chunk_sectors = mddev->chunk_sectors;
+ unsigned int chunk_sectors;
unsigned int bio_sectors = bvm->bi_size >> 9;
struct geom *geo = &conf->geo;
+ chunk_sectors = (conf->geo.chunk_mask & conf->prev.chunk_mask) + 1;
if (conf->reshape_progress != MaxSector &&
((sector >= conf->reshape_progress) !=
conf->mddev->reshape_backwards))
int plugged;
int sectors_handled;
int max_sectors;
+ int sectors;
if (unlikely(bio->bi_rw & REQ_FLUSH)) {
md_flush_request(mddev, bio);
*/
wait_barrier(conf);
+ sectors = bio->bi_size >> 9;
+ while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+ bio->bi_sector < conf->reshape_progress &&
+ bio->bi_sector + sectors > conf->reshape_progress) {
+ /* IO spans the reshape position. Need to wait for
+ * reshape to pass
+ */
+ allow_barrier(conf);
+ wait_event(conf->wait_barrier,
+ conf->reshape_progress <= bio->bi_sector ||
+ conf->reshape_progress >= bio->bi_sector + sectors);
+ wait_barrier(conf);
+ }
+ if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+ bio_data_dir(bio) == WRITE &&
+ (mddev->reshape_backwards
+ ? (bio->bi_sector < conf->reshape_safe &&
+ bio->bi_sector + sectors > conf->reshape_progress)
+ : (bio->bi_sector + sectors > conf->reshape_safe &&
+ bio->bi_sector < conf->reshape_progress))) {
+ /* Need to update reshape_position in metadata */
+ mddev->reshape_position = conf->reshape_progress;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ set_bit(MD_CHANGE_PENDING, &mddev->flags);
+ md_wakeup_thread(mddev->thread);
+ wait_event(mddev->sb_wait,
+ !test_bit(MD_CHANGE_PENDING, &mddev->flags));
+
+ conf->reshape_safe = mddev->reshape_position;
+ }
+
r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
r10_bio->master_bio = bio;
- r10_bio->sectors = bio->bi_size >> 9;
+ r10_bio->sectors = sectors;
r10_bio->mddev = mddev;
r10_bio->sector = bio->bi_sector;
struct r10conf *conf = r10_bio->mddev->private;
int d;
- d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
+ if (bio == r10_bio->master_bio) {
+ /* this is a reshape read */
+ d = r10_bio->read_slot; /* really the read dev */
+ } else
+ d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
if (test_bit(BIO_UPTODATE, &bio->bi_flags))
set_bit(R10BIO_Uptodate, &r10_bio->state);
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
handle_write_completed(conf, r10_bio);
+ else if (test_bit(R10BIO_IsReshape, &r10_bio->state))
+ reshape_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsSync, &r10_bio->state))
sync_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
skipped:
max_sector = mddev->dev_sectors;
- if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
+ test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
max_sector = mddev->resync_max_sectors;
if (sector_nr >= max_sector) {
/* If we aborted, we need to abort the
* we need to convert that to several
* virtual addresses.
*/
+ if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
+ end_reshape(conf);
+ return 0;
+ }
+
if (mddev->curr_resync < max_sector) { /* aborted */
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
*skipped = 1;
return sectors_skipped;
}
+
+ if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
+ return reshape_request(mddev, sector_nr, skipped);
+
if (chunks_skipped >= conf->geo.raid_disks) {
/* if there has been nothing to do on any drive,
* then there is nothing to do at all..
struct r10conf *conf = mddev->private;
if (!raid_disks)
- raid_disks = conf->geo.raid_disks;
+ raid_disks = min(conf->geo.raid_disks,
+ conf->prev.raid_disks);
if (!sectors)
sectors = conf->dev_sectors;
if (!conf)
goto out;
- conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+ /* FIXME calc properly */
+ conf->mirrors = kzalloc(sizeof(struct mirror_info)*(mddev->raid_disks +
+ max(0,mddev->delta_disks)),
GFP_KERNEL);
if (!conf->mirrors)
goto out;
goto out;
calc_sectors(conf, mddev->dev_sectors);
- conf->prev = conf->geo;
- conf->reshape_progress = MaxSector;
-
+ if (mddev->reshape_position == MaxSector) {
+ conf->prev = conf->geo;
+ conf->reshape_progress = MaxSector;
+ } else {
+ if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) {
+ err = -EINVAL;
+ goto out;
+ }
+ conf->reshape_progress = mddev->reshape_position;
+ if (conf->prev.far_offset)
+ conf->prev.stride = 1 << conf->prev.chunk_shift;
+ else
+ /* far_copies must be 1 */
+ conf->prev.stride = conf->dev_sectors;
+ }
spin_lock_init(&conf->device_lock);
INIT_LIST_HEAD(&conf->retry_list);
return conf;
out:
- printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
- mdname(mddev));
+ if (err == -ENOMEM)
+ printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
+ mdname(mddev));
if (conf) {
if (conf->r10bio_pool)
mempool_destroy(conf->r10bio_pool);
struct mirror_info *disk;
struct md_rdev *rdev;
sector_t size;
-
- /*
- * copy the already verified devices into our private RAID10
- * bookkeeping area. [whatever we allocate in run(),
- * should be freed in stop()]
- */
+ sector_t min_offset_diff = 0;
+ int first = 1;
if (mddev->private == NULL) {
conf = setup_conf(mddev);
(conf->geo.raid_disks / conf->geo.near_copies));
rdev_for_each(rdev, mddev) {
+ long long diff;
disk_idx = rdev->raid_disk;
if (disk_idx < 0)
goto out_free_conf;
disk->rdev = rdev;
}
+ diff = (rdev->new_data_offset - rdev->data_offset);
+ if (!mddev->reshape_backwards)
+ diff = -diff;
+ if (diff < 0)
+ diff = 0;
+ if (first || diff < min_offset_diff)
+ min_offset_diff = diff;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
disk->head_position = 0;
}
+
/* need to check that every block has at least one working mirror */
if (!enough(conf, -1)) {
printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
goto out_free_conf;
}
+ if (conf->reshape_progress != MaxSector) {
+ /* must ensure that shape change is supported */
+ if (conf->geo.far_copies != 1 &&
+ conf->geo.far_offset == 0)
+ goto out_free_conf;
+ if (conf->prev.far_copies != 1 &&
+ conf->geo.far_offset == 0)
+ goto out_free_conf;
+ }
+
mddev->degraded = 0;
for (i = 0;
i < conf->geo.raid_disks
int stripe = conf->geo.raid_disks *
((mddev->chunk_sectors << 9) / PAGE_SIZE);
stripe /= conf->geo.near_copies;
- if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
- mddev->queue->backing_dev_info.ra_pages = 2* stripe;
+ if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
+ mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
}
blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
if (md_integrity_register(mddev))
goto out_free_conf;
+ if (conf->reshape_progress != MaxSector) {
+ unsigned long before_length, after_length;
+
+ before_length = ((1 << conf->prev.chunk_shift) *
+ conf->prev.far_copies);
+ after_length = ((1 << conf->geo.chunk_shift) *
+ conf->geo.far_copies);
+
+ if (max(before_length, after_length) > min_offset_diff) {
+ /* This cannot work */
+ printk("md/raid10: offset difference not enough to continue reshape\n");
+ goto out_free_conf;
+ }
+ conf->offset_diff = min_offset_diff;
+
+ conf->reshape_safe = conf->reshape_progress;
+ clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+ clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+ set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
+ set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+ mddev->sync_thread = md_register_thread(md_do_sync, mddev,
+ "reshape");
+ }
+
return 0;
out_free_conf:
return ERR_PTR(-EINVAL);
}
+static int raid10_check_reshape(struct mddev *mddev)
+{
+ /* Called when there is a request to change
+ * - layout (to ->new_layout)
+ * - chunk size (to ->new_chunk_sectors)
+ * - raid_disks (by delta_disks)
+ * or when trying to restart a reshape that was ongoing.
+ *
+ * We need to validate the request and possibly allocate
+ * space if that might be an issue later.
+ *
+ * Currently we reject any reshape of a 'far' mode array,
+ * allow chunk size to change if new is generally acceptable,
+ * allow raid_disks to increase, and allow
+ * a switch between 'near' mode and 'offset' mode.
+ */
+ struct r10conf *conf = mddev->private;
+ struct geom geo;
+
+ if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
+ return -EINVAL;
+
+ if (setup_geo(&geo, mddev, geo_start) != conf->copies)
+ /* mustn't change number of copies */
+ return -EINVAL;
+ if (geo.far_copies > 1 && !geo.far_offset)
+ /* Cannot switch to 'far' mode */
+ return -EINVAL;
+
+ if (mddev->array_sectors & geo.chunk_mask)
+ /* not factor of array size */
+ return -EINVAL;
+
+ if (mddev->bitmap)
+ return -EBUSY;
+ if (!enough(conf, -1))
+ return -EINVAL;
+
+ kfree(conf->mirrors_new);
+ conf->mirrors_new = NULL;
+ if (mddev->delta_disks > 0) {
+ /* allocate new 'mirrors' list */
+ conf->mirrors_new = kzalloc(
+ sizeof(struct mirror_info)
+ *(mddev->raid_disks +
+ mddev->delta_disks),
+ GFP_KERNEL);
+ if (!conf->mirrors_new)
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+/*
+ * Need to check if array has failed when deciding whether to:
+ * - start an array
+ * - remove non-faulty devices
+ * - add a spare
+ * - allow a reshape
+ * This determination is simple when no reshape is happening.
+ * However if there is a reshape, we need to carefully check
+ * both the before and after sections.
+ * This is because some failed devices may only affect one
+ * of the two sections, and some non-in_sync devices may
+ * be insync in the section most affected by failed devices.
+ */
+static int calc_degraded(struct r10conf *conf)
+{
+ int degraded, degraded2;
+ int i;
+
+ rcu_read_lock();
+ degraded = 0;
+ /* 'prev' section first */
+ for (i = 0; i < conf->prev.raid_disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (!rdev || test_bit(Faulty, &rdev->flags))
+ degraded++;
+ else if (!test_bit(In_sync, &rdev->flags))
+ /* When we can reduce the number of devices in
+ * an array, this might not contribute to
+ * 'degraded'. It does now.
+ */
+ degraded++;
+ }
+ rcu_read_unlock();
+ if (conf->geo.raid_disks == conf->prev.raid_disks)
+ return degraded;
+ rcu_read_lock();
+ degraded2 = 0;
+ for (i = 0; i < conf->geo.raid_disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (!rdev || test_bit(Faulty, &rdev->flags))
+ degraded2++;
+ else if (!test_bit(In_sync, &rdev->flags)) {
+ /* If reshape is increasing the number of devices,
+ * this section has already been recovered, so
+ * it doesn't contribute to degraded.
+ * else it does.
+ */
+ if (conf->geo.raid_disks <= conf->prev.raid_disks)
+ degraded2++;
+ }
+ }
+ rcu_read_unlock();
+ if (degraded2 > degraded)
+ return degraded2;
+ return degraded;
+}
+
+static int raid10_start_reshape(struct mddev *mddev)
+{
+ /* A 'reshape' has been requested. This commits
+ * the various 'new' fields and sets MD_RECOVER_RESHAPE
+ * This also checks if there are enough spares and adds them
+ * to the array.
+ * We currently require enough spares to make the final
+ * array non-degraded. We also require that the difference
+ * between old and new data_offset - on each device - is
+ * enough that we never risk over-writing.
+ */
+
+ unsigned long before_length, after_length;
+ sector_t min_offset_diff = 0;
+ int first = 1;
+ struct geom new;
+ struct r10conf *conf = mddev->private;
+ struct md_rdev *rdev;
+ int spares = 0;
+
+ if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+ return -EBUSY;
+
+ if (setup_geo(&new, mddev, geo_start) != conf->copies)
+ return -EINVAL;
+
+ before_length = ((1 << conf->prev.chunk_shift) *
+ conf->prev.far_copies);
+ after_length = ((1 << conf->geo.chunk_shift) *
+ conf->geo.far_copies);
+
+ rdev_for_each(rdev, mddev) {
+ if (!test_bit(In_sync, &rdev->flags)
+ && !test_bit(Faulty, &rdev->flags))
+ spares++;
+ if (rdev->raid_disk >= 0) {
+ long long diff = (rdev->new_data_offset
+ - rdev->data_offset);
+ if (!mddev->reshape_backwards)
+ diff = -diff;
+ if (diff < 0)
+ diff = 0;
+ if (first || diff < min_offset_diff)
+ min_offset_diff = diff;
+ }
+ }
+
+ if (max(before_length, after_length) > min_offset_diff)
+ return -EINVAL;
+
+ if (spares < mddev->delta_disks)
+ return -EINVAL;
+
+ conf->offset_diff = min_offset_diff;
+ spin_lock_irq(&conf->device_lock);
+ if (conf->mirrors_new) {
+ memcpy(conf->mirrors_new, conf->mirrors,
+ sizeof(struct mirror_info)*conf->prev.raid_disks);
+ smp_mb();
+ kfree(conf->mirrors_old); /* FIXME and elsewhere */
+ conf->mirrors_old = conf->mirrors;
+ conf->mirrors = conf->mirrors_new;
+ conf->mirrors_new = NULL;
+ }
+ setup_geo(&conf->geo, mddev, geo_start);
+ smp_mb();
+ if (mddev->reshape_backwards) {
+ sector_t size = raid10_size(mddev, 0, 0);
+ if (size < mddev->array_sectors) {
+ spin_unlock_irq(&conf->device_lock);
+ printk(KERN_ERR "md/raid10:%s: array size must be reduce before number of disks\n",
+ mdname(mddev));
+ return -EINVAL;
+ }
+ mddev->resync_max_sectors = size;
+ conf->reshape_progress = size;
+ } else
+ conf->reshape_progress = 0;
+ spin_unlock_irq(&conf->device_lock);
+
+ if (mddev->delta_disks > 0) {
+ rdev_for_each(rdev, mddev)
+ if (rdev->raid_disk < 0 &&
+ !test_bit(Faulty, &rdev->flags)) {
+ if (raid10_add_disk(mddev, rdev) == 0) {
+ if (rdev->raid_disk >=
+ conf->prev.raid_disks)
+ set_bit(In_sync, &rdev->flags);
+ else
+ rdev->recovery_offset = 0;
+
+ if (sysfs_link_rdev(mddev, rdev))
+ /* Failure here is OK */;
+ }
+ } else if (rdev->raid_disk >= conf->prev.raid_disks
+ && !test_bit(Faulty, &rdev->flags)) {
+ /* This is a spare that was manually added */
+ set_bit(In_sync, &rdev->flags);
+ }
+ }
+ /* When a reshape changes the number of devices,
+ * ->degraded is measured against the larger of the
+ * pre and post numbers.
+ */
+ spin_lock_irq(&conf->device_lock);
+ mddev->degraded = calc_degraded(conf);
+ spin_unlock_irq(&conf->device_lock);
+ mddev->raid_disks = conf->geo.raid_disks;
+ mddev->reshape_position = conf->reshape_progress;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+
+ clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+ clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+ set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
+ set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+
+ mddev->sync_thread = md_register_thread(md_do_sync, mddev,
+ "reshape");
+ if (!mddev->sync_thread) {
+ mddev->recovery = 0;
+ spin_lock_irq(&conf->device_lock);
+ conf->geo = conf->prev;
+ mddev->raid_disks = conf->geo.raid_disks;
+ rdev_for_each(rdev, mddev)
+ rdev->new_data_offset = rdev->data_offset;
+ smp_wmb();
+ conf->reshape_progress = MaxSector;
+ mddev->reshape_position = MaxSector;
+ spin_unlock_irq(&conf->device_lock);
+ return -EAGAIN;
+ }
+ conf->reshape_checkpoint = jiffies;
+ md_wakeup_thread(mddev->sync_thread);
+ md_new_event(mddev);
+ return 0;
+}
+
+/* Calculate the last device-address that could contain
+ * any block from the chunk that includes the array-address 's'
+ * and report the next address.
+ * i.e. the address returned will be chunk-aligned and after
+ * any data that is in the chunk containing 's'.
+ */
+static sector_t last_dev_address(sector_t s, struct geom *geo)
+{
+ s = (s | geo->chunk_mask) + 1;
+ s >>= geo->chunk_shift;
+ s *= geo->near_copies;
+ s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks);
+ s *= geo->far_copies;
+ s <<= geo->chunk_shift;
+ return s;
+}
+
+/* Calculate the first device-address that could contain
+ * any block from the chunk that includes the array-address 's'.
+ * This too will be the start of a chunk
+ */
+static sector_t first_dev_address(sector_t s, struct geom *geo)
+{
+ s >>= geo->chunk_shift;
+ s *= geo->near_copies;
+ sector_div(s, geo->raid_disks);
+ s *= geo->far_copies;
+ s <<= geo->chunk_shift;
+ return s;
+}
+
+static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
+ int *skipped)
+{
+ /* We simply copy at most one chunk (smallest of old and new)
+ * at a time, possibly less if that exceeds RESYNC_PAGES,
+ * or we hit a bad block or something.
+ * This might mean we pause for normal IO in the middle of
+ * a chunk, but that is not a problem was mddev->reshape_position
+ * can record any location.
+ *
+ * If we will want to write to a location that isn't
+ * yet recorded as 'safe' (i.e. in metadata on disk) then
+ * we need to flush all reshape requests and update the metadata.
+ *
+ * When reshaping forwards (e.g. to more devices), we interpret
+ * 'safe' as the earliest block which might not have been copied
+ * down yet. We divide this by previous stripe size and multiply
+ * by previous stripe length to get lowest device offset that we
+ * cannot write to yet.
+ * We interpret 'sector_nr' as an address that we want to write to.
+ * From this we use last_device_address() to find where we might
+ * write to, and first_device_address on the 'safe' position.
+ * If this 'next' write position is after the 'safe' position,
+ * we must update the metadata to increase the 'safe' position.
+ *
+ * When reshaping backwards, we round in the opposite direction
+ * and perform the reverse test: next write position must not be
+ * less than current safe position.
+ *
+ * In all this the minimum difference in data offsets
+ * (conf->offset_diff - always positive) allows a bit of slack,
+ * so next can be after 'safe', but not by more than offset_disk
+ *
+ * We need to prepare all the bios here before we start any IO
+ * to ensure the size we choose is acceptable to all devices.
+ * The means one for each copy for write-out and an extra one for
+ * read-in.
+ * We store the read-in bio in ->master_bio and the others in
+ * ->devs[x].bio and ->devs[x].repl_bio.
+ */
+ struct r10conf *conf = mddev->private;
+ struct r10bio *r10_bio;
+ sector_t next, safe, last;
+ int max_sectors;
+ int nr_sectors;
+ int s;
+ struct md_rdev *rdev;
+ int need_flush = 0;
+ struct bio *blist;
+ struct bio *bio, *read_bio;
+ int sectors_done = 0;
+
+ if (sector_nr == 0) {
+ /* If restarting in the middle, skip the initial sectors */
+ if (mddev->reshape_backwards &&
+ conf->reshape_progress < raid10_size(mddev, 0, 0)) {
+ sector_nr = (raid10_size(mddev, 0, 0)
+ - conf->reshape_progress);
+ } else if (!mddev->reshape_backwards &&
+ conf->reshape_progress > 0)
+ sector_nr = conf->reshape_progress;
+ if (sector_nr) {
+ mddev->curr_resync_completed = sector_nr;
+ sysfs_notify(&mddev->kobj, NULL, "sync_completed");
+ *skipped = 1;
+ return sector_nr;
+ }
+ }
+
+ /* We don't use sector_nr to track where we are up to
+ * as that doesn't work well for ->reshape_backwards.
+ * So just use ->reshape_progress.
+ */
+ if (mddev->reshape_backwards) {
+ /* 'next' is the earliest device address that we might
+ * write to for this chunk in the new layout
+ */
+ next = first_dev_address(conf->reshape_progress - 1,
+ &conf->geo);
+
+ /* 'safe' is the last device address that we might read from
+ * in the old layout after a restart
+ */
+ safe = last_dev_address(conf->reshape_safe - 1,
+ &conf->prev);
+
+ if (next + conf->offset_diff < safe)
+ need_flush = 1;
+
+ last = conf->reshape_progress - 1;
+ sector_nr = last & ~(sector_t)(conf->geo.chunk_mask
+ & conf->prev.chunk_mask);
+ if (sector_nr + RESYNC_BLOCK_SIZE/512 < last)
+ sector_nr = last + 1 - RESYNC_BLOCK_SIZE/512;
+ } else {
+ /* 'next' is after the last device address that we
+ * might write to for this chunk in the new layout
+ */
+ next = last_dev_address(conf->reshape_progress, &conf->geo);
+
+ /* 'safe' is the earliest device address that we might
+ * read from in the old layout after a restart
+ */
+ safe = first_dev_address(conf->reshape_safe, &conf->prev);
+
+ /* Need to update metadata if 'next' might be beyond 'safe'
+ * as that would possibly corrupt data
+ */
+ if (next > safe + conf->offset_diff)
+ need_flush = 1;
+
+ sector_nr = conf->reshape_progress;
+ last = sector_nr | (conf->geo.chunk_mask
+ & conf->prev.chunk_mask);
+
+ if (sector_nr + RESYNC_BLOCK_SIZE/512 <= last)
+ last = sector_nr + RESYNC_BLOCK_SIZE/512 - 1;
+ }
+
+ if (need_flush ||
+ time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
+ /* Need to update reshape_position in metadata */
+ wait_barrier(conf);
+ mddev->reshape_position = conf->reshape_progress;
+ if (mddev->reshape_backwards)
+ mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
+ - conf->reshape_progress;
+ else
+ mddev->curr_resync_completed = conf->reshape_progress;
+ conf->reshape_checkpoint = jiffies;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ md_wakeup_thread(mddev->thread);
+ wait_event(mddev->sb_wait, mddev->flags == 0 ||
+ kthread_should_stop());
+ conf->reshape_safe = mddev->reshape_position;
+ allow_barrier(conf);
+ }
+
+read_more:
+ /* Now schedule reads for blocks from sector_nr to last */
+ r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
+ raise_barrier(conf, sectors_done != 0);
+ atomic_set(&r10_bio->remaining, 0);
+ r10_bio->mddev = mddev;
+ r10_bio->sector = sector_nr;
+ set_bit(R10BIO_IsReshape, &r10_bio->state);
+ r10_bio->sectors = last - sector_nr + 1;
+ rdev = read_balance(conf, r10_bio, &max_sectors);
+ BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state));
+
+ if (!rdev) {
+ /* Cannot read from here, so need to record bad blocks
+ * on all the target devices.
+ */
+ // FIXME
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ return sectors_done;
+ }
+
+ read_bio = bio_alloc_mddev(GFP_KERNEL, RESYNC_PAGES, mddev);
+
+ read_bio->bi_bdev = rdev->bdev;
+ read_bio->bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
+ + rdev->data_offset);
+ read_bio->bi_private = r10_bio;
+ read_bio->bi_end_io = end_sync_read;
+ read_bio->bi_rw = READ;
+ read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
+ read_bio->bi_flags |= 1 << BIO_UPTODATE;
+ read_bio->bi_vcnt = 0;
+ read_bio->bi_idx = 0;
+ read_bio->bi_size = 0;
+ r10_bio->master_bio = read_bio;
+ r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
+
+ /* Now find the locations in the new layout */
+ __raid10_find_phys(&conf->geo, r10_bio);
+
+ blist = read_bio;
+ read_bio->bi_next = NULL;
+
+ for (s = 0; s < conf->copies*2; s++) {
+ struct bio *b;
+ int d = r10_bio->devs[s/2].devnum;
+ struct md_rdev *rdev2;
+ if (s&1) {
+ rdev2 = conf->mirrors[d].replacement;
+ b = r10_bio->devs[s/2].repl_bio;
+ } else {
+ rdev2 = conf->mirrors[d].rdev;
+ b = r10_bio->devs[s/2].bio;
+ }
+ if (!rdev2 || test_bit(Faulty, &rdev2->flags))
+ continue;
+ b->bi_bdev = rdev2->bdev;
+ b->bi_sector = r10_bio->devs[s/2].addr + rdev2->new_data_offset;
+ b->bi_private = r10_bio;
+ b->bi_end_io = end_reshape_write;
+ b->bi_rw = WRITE;
+ b->bi_flags &= ~(BIO_POOL_MASK - 1);
+ b->bi_flags |= 1 << BIO_UPTODATE;
+ b->bi_next = blist;
+ b->bi_vcnt = 0;
+ b->bi_idx = 0;
+ b->bi_size = 0;
+ blist = b;
+ }
+
+ /* Now add as many pages as possible to all of these bios. */
+
+ nr_sectors = 0;
+ for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
+ struct page *page = r10_bio->devs[0].bio->bi_io_vec[s/(PAGE_SIZE>>9)].bv_page;
+ int len = (max_sectors - s) << 9;
+ if (len > PAGE_SIZE)
+ len = PAGE_SIZE;
+ for (bio = blist; bio ; bio = bio->bi_next) {
+ struct bio *bio2;
+ if (bio_add_page(bio, page, len, 0))
+ continue;
+
+ /* Didn't fit, must stop */
+ for (bio2 = blist;
+ bio2 && bio2 != bio;
+ bio2 = bio2->bi_next) {
+ /* Remove last page from this bio */
+ bio2->bi_vcnt--;
+ bio2->bi_size -= len;
+ bio2->bi_flags &= ~(1<<BIO_SEG_VALID);
+ }
+ goto bio_full;
+ }
+ sector_nr += len >> 9;
+ nr_sectors += len >> 9;
+ }
+bio_full:
+ r10_bio->sectors = nr_sectors;
+
+ /* Now submit the read */
+ md_sync_acct(read_bio->bi_bdev, r10_bio->sectors);
+ atomic_inc(&r10_bio->remaining);
+ read_bio->bi_next = NULL;
+ generic_make_request(read_bio);
+ sector_nr += nr_sectors;
+ sectors_done += nr_sectors;
+ if (sector_nr <= last)
+ goto read_more;
+
+ /* Now that we have done the whole section we can
+ * update reshape_progress
+ */
+ if (mddev->reshape_backwards)
+ conf->reshape_progress -= sectors_done;
+ else
+ conf->reshape_progress += sectors_done;
+
+ return sectors_done;
+}
+
+static void end_reshape_request(struct r10bio *r10_bio);
+static int handle_reshape_read_error(struct mddev *mddev,
+ struct r10bio *r10_bio);
+static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
+{
+ /* Reshape read completed. Hopefully we have a block
+ * to write out.
+ * If we got a read error then we do sync 1-page reads from
+ * elsewhere until we find the data - or give up.
+ */
+ struct r10conf *conf = mddev->private;
+ int s;
+
+ if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
+ if (handle_reshape_read_error(mddev, r10_bio) < 0) {
+ /* Reshape has been aborted */
+ md_done_sync(mddev, r10_bio->sectors, 0);
+ return;
+ }
+
+ /* We definitely have the data in the pages, schedule the
+ * writes.
+ */
+ atomic_set(&r10_bio->remaining, 1);
+ for (s = 0; s < conf->copies*2; s++) {
+ struct bio *b;
+ int d = r10_bio->devs[s/2].devnum;
+ struct md_rdev *rdev;
+ if (s&1) {
+ rdev = conf->mirrors[d].replacement;
+ b = r10_bio->devs[s/2].repl_bio;
+ } else {
+ rdev = conf->mirrors[d].rdev;
+ b = r10_bio->devs[s/2].bio;
+ }
+ if (!rdev || test_bit(Faulty, &rdev->flags))
+ continue;
+ atomic_inc(&rdev->nr_pending);
+ md_sync_acct(b->bi_bdev, r10_bio->sectors);
+ atomic_inc(&r10_bio->remaining);
+ b->bi_next = NULL;
+ generic_make_request(b);
+ }
+ end_reshape_request(r10_bio);
+}
+
+static void end_reshape(struct r10conf *conf)
+{
+ if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery))
+ return;
+
+ spin_lock_irq(&conf->device_lock);
+ conf->prev = conf->geo;
+ md_finish_reshape(conf->mddev);
+ smp_wmb();
+ conf->reshape_progress = MaxSector;
+ spin_unlock_irq(&conf->device_lock);
+
+ /* read-ahead size must cover two whole stripes, which is
+ * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
+ */
+ if (conf->mddev->queue) {
+ int stripe = conf->geo.raid_disks *
+ ((conf->mddev->chunk_sectors << 9) / PAGE_SIZE);
+ stripe /= conf->geo.near_copies;
+ if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
+ conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
+ }
+ conf->fullsync = 0;
+}
+
+
+static int handle_reshape_read_error(struct mddev *mddev,
+ struct r10bio *r10_bio)
+{
+ /* Use sync reads to get the blocks from somewhere else */
+ int sectors = r10_bio->sectors;
+ struct r10bio r10b;
+ struct r10conf *conf = mddev->private;
+ int slot = 0;
+ int idx = 0;
+ struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec;
+
+ r10b.sector = r10_bio->sector;
+ __raid10_find_phys(&conf->prev, &r10b);
+
+ while (sectors) {
+ int s = sectors;
+ int success = 0;
+ int first_slot = slot;
+
+ if (s > (PAGE_SIZE >> 9))
+ s = PAGE_SIZE >> 9;
+
+ while (!success) {
+ int d = r10b.devs[slot].devnum;
+ struct md_rdev *rdev = conf->mirrors[d].rdev;
+ sector_t addr;
+ if (rdev == NULL ||
+ test_bit(Faulty, &rdev->flags) ||
+ !test_bit(In_sync, &rdev->flags))
+ goto failed;
+
+ addr = r10b.devs[slot].addr + idx * PAGE_SIZE;
+ success = sync_page_io(rdev,
+ addr,
+ s << 9,
+ bvec[idx].bv_page,
+ READ, false);
+ if (success)
+ break;
+ failed:
+ slot++;
+ if (slot >= conf->copies)
+ slot = 0;
+ if (slot == first_slot)
+ break;
+ }
+ if (!success) {
+ /* couldn't read this block, must give up */
+ set_bit(MD_RECOVERY_INTR,
+ &mddev->recovery);
+ return -EIO;
+ }
+ sectors -= s;
+ idx++;
+ }
+ return 0;
+}
+
+static void end_reshape_write(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct r10bio *r10_bio = bio->bi_private;
+ struct mddev *mddev = r10_bio->mddev;
+ struct r10conf *conf = mddev->private;
+ int d;
+ int slot;
+ int repl;
+ struct md_rdev *rdev = NULL;
+
+ d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
+ if (repl)
+ rdev = conf->mirrors[d].replacement;
+ if (!rdev) {
+ smp_mb();
+ rdev = conf->mirrors[d].rdev;
+ }
+
+ if (!uptodate) {
+ /* FIXME should record badblock */
+ md_error(mddev, rdev);
+ }
+
+ rdev_dec_pending(rdev, mddev);
+ end_reshape_request(r10_bio);
+}
+
+static void end_reshape_request(struct r10bio *r10_bio)
+{
+ if (!atomic_dec_and_test(&r10_bio->remaining))
+ return;
+ md_done_sync(r10_bio->mddev, r10_bio->sectors, 1);
+ bio_put(r10_bio->master_bio);
+ put_buf(r10_bio);
+}
+
+static void raid10_finish_reshape(struct mddev *mddev)
+{
+ struct r10conf *conf = mddev->private;
+
+ if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
+ return;
+
+ if (mddev->delta_disks > 0) {
+ sector_t size = raid10_size(mddev, 0, 0);
+ md_set_array_sectors(mddev, size);
+ if (mddev->recovery_cp > mddev->resync_max_sectors) {
+ mddev->recovery_cp = mddev->resync_max_sectors;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ mddev->resync_max_sectors = size;
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ }
+ mddev->layout = mddev->new_layout;
+ mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
+ mddev->reshape_position = MaxSector;
+ mddev->delta_disks = 0;
+ mddev->reshape_backwards = 0;
+}
+
static struct md_personality raid10_personality =
{
.name = "raid10",
.size = raid10_size,
.resize = raid10_resize,
.takeover = raid10_takeover,
+ .check_reshape = raid10_check_reshape,
+ .start_reshape = raid10_start_reshape,
+ .finish_reshape = raid10_finish_reshape,
};
static int __init raid_init(void)