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Commit 845b9e22 authored by Artur Paszkiewicz's avatar Artur Paszkiewicz Committed by Shaohua Li
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raid5-ppl: use resize_stripes() when enabling or disabling ppl 



Use resize_stripes() instead of raid5_reset_stripe_cache() to allocate
or free sh->ppl_page at runtime for all stripes in the stripe cache.
raid5_reset_stripe_cache() required suspending the mddev and could
deadlock because of GFP_KERNEL allocations.

Move the 'newsize' check to check_reshape() to allow reallocating the
stripes with the same number of disks. Allocate sh->ppl_page in
alloc_stripe() instead of grow_buffers(). Pass 'struct r5conf *conf' as
a parameter to alloc_stripe() because it is needed to check whether to
allocate ppl_page. Add free_stripe() and use it to free stripes rather
than directly call kmem_cache_free(). Also free sh->ppl_page in
free_stripe().

Set MD_HAS_PPL at the end of ppl_init_log() instead of explicitly
setting it in advance and add another parameter to log_init() to allow
calling ppl_init_log() without the bit set. Don't try to calculate
partial parity or add a stripe to log if it does not have ppl_page set.

Enabling ppl can now be performed without suspending the mddev, because
the log won't be used until new stripes are allocated with ppl_page.
Calling mddev_suspend/resume is still necessary when disabling ppl,
because we want all stripes to finish before stopping the log, but
resize_stripes() can be called after mddev_resume() when ppl is no
longer active.

Suggested-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarArtur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 94568f64

drivers/md/raid5-log.h

+3 −2
Original line number Diff line number Diff line
@@ -93,11 +93,12 @@ static inline void log_exit(struct r5conf *conf) 
		ppl_exit_log(conf);

}



static inline int log_init(struct r5conf *conf, struct md_rdev *journal_dev)

static inline int log_init(struct r5conf *conf, struct md_rdev *journal_dev,

			   bool ppl)

{

	if (journal_dev)

		return r5l_init_log(conf, journal_dev);

	else if (raid5_has_ppl(conf))

	else if (ppl)

		return ppl_init_log(conf);



	return 0;

drivers/md/raid5-ppl.c

+2 −1
Original line number Diff line number Diff line
@@ -328,7 +328,7 @@ int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh) 
	struct ppl_io_unit *io = sh->ppl_io;

	struct ppl_log *log;



	if (io || test_bit(STRIPE_SYNCING, &sh->state) ||

	if (io || test_bit(STRIPE_SYNCING, &sh->state) || !sh->ppl_page ||

	    !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||

	    !test_bit(R5_Insync, &sh->dev[sh->pd_idx].flags)) {

		clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
@@ -1204,6 +1204,7 @@ int ppl_init_log(struct r5conf *conf) 
	}



	conf->log_private = ppl_conf;

	set_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);



	return 0;

err:

drivers/md/raid5.c

+38 −50
Original line number Diff line number Diff line
@@ -471,11 +471,6 @@ static void shrink_buffers(struct stripe_head *sh) 
		sh->dev[i].page = NULL;

		put_page(p);

	}



	if (sh->ppl_page) {

		put_page(sh->ppl_page);

		sh->ppl_page = NULL;

	}

}



static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
@@ -493,12 +488,6 @@ static int grow_buffers(struct stripe_head *sh, gfp_t gfp) 
		sh->dev[i].orig_page = page;

	}



	if (raid5_has_ppl(sh->raid_conf)) {

		sh->ppl_page = alloc_page(gfp);

		if (!sh->ppl_page)

			return 1;

	}



	return 0;

}
@@ -2132,8 +2121,15 @@ static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request) 
	put_cpu();

}



static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)

{

	if (sh->ppl_page)

		__free_page(sh->ppl_page);

	kmem_cache_free(sc, sh);

}



static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp,

	int disks)

	int disks, struct r5conf *conf)

{

	struct stripe_head *sh;

	int i;
@@ -2147,6 +2143,7 @@ static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp, 
		INIT_LIST_HEAD(&sh->r5c);

		INIT_LIST_HEAD(&sh->log_list);

		atomic_set(&sh->count, 1);

		sh->raid_conf = conf;

		sh->log_start = MaxSector;

		for (i = 0; i < disks; i++) {

			struct r5dev *dev = &sh->dev[i];
@@ -2154,6 +2151,14 @@ static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp, 
			bio_init(&dev->req, &dev->vec, 1);

			bio_init(&dev->rreq, &dev->rvec, 1);

		}



		if (raid5_has_ppl(conf)) {

			sh->ppl_page = alloc_page(gfp);

			if (!sh->ppl_page) {

				free_stripe(sc, sh);

				sh = NULL;

			}

		}

	}

	return sh;

}
@@ -2161,15 +2166,13 @@ static int grow_one_stripe(struct r5conf *conf, gfp_t gfp) 
{

	struct stripe_head *sh;



	sh = alloc_stripe(conf->slab_cache, gfp, conf->pool_size);

	sh = alloc_stripe(conf->slab_cache, gfp, conf->pool_size, conf);

	if (!sh)

		return 0;



	sh->raid_conf = conf;



	if (grow_buffers(sh, gfp)) {

		shrink_buffers(sh);

		kmem_cache_free(conf->slab_cache, sh);

		free_stripe(conf->slab_cache, sh);

		return 0;

	}

	sh->hash_lock_index =
@@ -2314,9 +2317,6 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
	int i;

	int hash, cnt;



	if (newsize <= conf->pool_size)

		return 0; /* never bother to shrink */



	err = md_allow_write(conf->mddev);

	if (err)

		return err;
@@ -2332,11 +2332,10 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
	mutex_lock(&conf->cache_size_mutex);



	for (i = conf->max_nr_stripes; i; i--) {

		nsh = alloc_stripe(sc, GFP_KERNEL, newsize);

		nsh = alloc_stripe(sc, GFP_KERNEL, newsize, conf);

		if (!nsh)

			break;



		nsh->raid_conf = conf;

		list_add(&nsh->lru, &newstripes);

	}

	if (i) {
@@ -2344,7 +2343,7 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
		while (!list_empty(&newstripes)) {

			nsh = list_entry(newstripes.next, struct stripe_head, lru);

			list_del(&nsh->lru);

			kmem_cache_free(sc, nsh);

			free_stripe(sc, nsh);

		}

		kmem_cache_destroy(sc);

		mutex_unlock(&conf->cache_size_mutex);
@@ -2370,7 +2369,7 @@ static int resize_stripes(struct r5conf *conf, int newsize) 
			nsh->dev[i].orig_page = osh->dev[i].page;

		}

		nsh->hash_lock_index = hash;

		kmem_cache_free(conf->slab_cache, osh);

		free_stripe(conf->slab_cache, osh);

		cnt++;

		if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +

		    !!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
@@ -2447,7 +2446,7 @@ static int drop_one_stripe(struct r5conf *conf) 
		return 0;

	BUG_ON(atomic_read(&sh->count));

	shrink_buffers(sh);

	kmem_cache_free(conf->slab_cache, sh);

	free_stripe(conf->slab_cache, sh);

	atomic_dec(&conf->active_stripes);

	conf->max_nr_stripes--;

	return 1;
@@ -3170,7 +3169,7 @@ schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s, 
		s->locked++;

	}



	if (raid5_has_ppl(sh->raid_conf) &&

	if (raid5_has_ppl(sh->raid_conf) && sh->ppl_page &&

	    test_bit(STRIPE_OP_BIODRAIN, &s->ops_request) &&

	    !test_bit(STRIPE_FULL_WRITE, &sh->state) &&

	    test_bit(R5_Insync, &sh->dev[pd_idx].flags))
@@ -7427,7 +7426,7 @@ static int raid5_run(struct mddev *mddev) 
		blk_queue_max_hw_sectors(mddev->queue, UINT_MAX);

	}



	if (log_init(conf, journal_dev))

	if (log_init(conf, journal_dev, raid5_has_ppl(conf)))

		goto abort;



	return 0;
@@ -7636,7 +7635,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev) 
		 * The array is in readonly mode if journal is missing, so no

		 * write requests running. We should be safe

		 */

		log_init(conf, rdev);

		log_init(conf, rdev, false);

		return 0;

	}

	if (mddev->recovery_disabled == conf->recovery_disabled)
@@ -7786,6 +7785,9 @@ static int check_reshape(struct mddev *mddev) 
				      mddev->chunk_sectors)

			    ) < 0)

			return -ENOMEM;



	if (conf->previous_raid_disks + mddev->delta_disks <= conf->pool_size)

		return 0; /* never bother to shrink */

	return resize_stripes(conf, (conf->previous_raid_disks

				     + mddev->delta_disks));

}
@@ -8276,20 +8278,6 @@ static void *raid6_takeover(struct mddev *mddev) 
	return setup_conf(mddev);

}



static void raid5_reset_stripe_cache(struct mddev *mddev)

{

	struct r5conf *conf = mddev->private;



	mutex_lock(&conf->cache_size_mutex);

	while (conf->max_nr_stripes &&

	       drop_one_stripe(conf))

		;

	while (conf->min_nr_stripes > conf->max_nr_stripes &&

	       grow_one_stripe(conf, GFP_KERNEL))

		;

	mutex_unlock(&conf->cache_size_mutex);

}



static int raid5_change_consistency_policy(struct mddev *mddev, const char *buf)

{

	struct r5conf *conf;
@@ -8304,23 +8292,23 @@ static int raid5_change_consistency_policy(struct mddev *mddev, const char *buf) 
		return -ENODEV;

	}



	if (strncmp(buf, "ppl", 3) == 0 && !raid5_has_ppl(conf)) {

	if (strncmp(buf, "ppl", 3) == 0) {

		/* ppl only works with RAID 5 */

		if (conf->level == 5) {

			mddev_suspend(mddev);

			set_bit(MD_HAS_PPL, &mddev->flags);

			err = log_init(conf, NULL);

			if (!err)

				raid5_reset_stripe_cache(mddev);

			mddev_resume(mddev);

		if (!raid5_has_ppl(conf) && conf->level == 5) {

			err = log_init(conf, NULL, true);

			if (!err) {

				err = resize_stripes(conf, conf->pool_size);

				if (err)

					log_exit(conf);

			}

		} else

			err = -EINVAL;

	} else if (strncmp(buf, "resync", 6) == 0) {

		if (raid5_has_ppl(conf)) {

			mddev_suspend(mddev);

			log_exit(conf);

			raid5_reset_stripe_cache(mddev);

			mddev_resume(mddev);

			err = resize_stripes(conf, conf->pool_size);

		} else if (test_bit(MD_HAS_JOURNAL, &conf->mddev->flags) &&

			   r5l_log_disk_error(conf)) {

			bool journal_dev_exists = false;