Commit 5036c390 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by NeilBrown
Browse files

raid5: allow r5l_io_unit allocations to fail 



And propagate the error up the stack so we can add the stripe
to no_stripes_list and retry our log operation later.  This avoids
blocking raid5d due to reclaim, an it allows to get rid of the
deadlock-prone GFP_NOFAIL allocation.

shli: add missing mempool_destroy()

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
parent e8deb638

drivers/md/raid5-cache.c

+57 −10
Original line number Diff line number Diff line
@@ -75,7 +75,10 @@ struct r5l_log { 
	struct list_head finished_ios;	/* io_units which settle down in log disk */

	struct bio flush_bio;



	struct list_head no_mem_stripes;   /* pending stripes, -ENOMEM */



	struct kmem_cache *io_kc;

	mempool_t *io_pool;

	struct bio_set *bs;

	mempool_t *meta_pool;
@@ -287,8 +290,11 @@ static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log) 
	struct r5l_io_unit *io;

	struct r5l_meta_block *block;



	/* We can't handle memory allocate failure so far */

	io = kmem_cache_zalloc(log->io_kc, GFP_NOIO | __GFP_NOFAIL);

	io = mempool_alloc(log->io_pool, GFP_ATOMIC);

	if (!io)

		return NULL;

	memset(io, 0, sizeof(*io));



	io->log = log;

	INIT_LIST_HEAD(&io->log_sibling);

	INIT_LIST_HEAD(&io->stripe_list);
@@ -326,8 +332,12 @@ static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size) 
	    log->current_io->meta_offset + payload_size > PAGE_SIZE)

		r5l_submit_current_io(log);



	if (!log->current_io)

	if (!log->current_io) {

		log->current_io = r5l_new_meta(log);

		if (!log->current_io)

			return -ENOMEM;

	}



	return 0;

}
@@ -372,11 +382,12 @@ static void r5l_append_payload_page(struct r5l_log *log, struct page *page) 
	r5_reserve_log_entry(log, io);

}



static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,

static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,

			   int data_pages, int parity_pages)

{

	int i;

	int meta_size;

	int ret;

	struct r5l_io_unit *io;



	meta_size =
@@ -385,7 +396,10 @@ static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh, 
		sizeof(struct r5l_payload_data_parity) +

		sizeof(__le32) * parity_pages;



	r5l_get_meta(log, meta_size);

	ret = r5l_get_meta(log, meta_size);

	if (ret)

		return ret;



	io = log->current_io;



	for (i = 0; i < sh->disks; i++) {
@@ -415,6 +429,8 @@ static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh, 
	list_add_tail(&sh->log_list, &io->stripe_list);

	atomic_inc(&io->pending_stripe);

	sh->log_io = io;



	return 0;

}



static void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
@@ -429,6 +445,7 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) 
	int meta_size;

	int reserve;

	int i;

	int ret = 0;



	if (!log)

		return -EAGAIN;
@@ -477,17 +494,22 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) 
	mutex_lock(&log->io_mutex);

	/* meta + data */

	reserve = (1 + write_disks) << (PAGE_SHIFT - 9);

	if (r5l_has_free_space(log, reserve))

		r5l_log_stripe(log, sh, data_pages, parity_pages);

	else {

	if (!r5l_has_free_space(log, reserve)) {

		spin_lock(&log->no_space_stripes_lock);

		list_add_tail(&sh->log_list, &log->no_space_stripes);

		spin_unlock(&log->no_space_stripes_lock);



		r5l_wake_reclaim(log, reserve);

	} else {

		ret = r5l_log_stripe(log, sh, data_pages, parity_pages);

		if (ret) {

			spin_lock_irq(&log->io_list_lock);

			list_add_tail(&sh->log_list, &log->no_mem_stripes);

			spin_unlock_irq(&log->io_list_lock);

		}

	}

	mutex_unlock(&log->io_mutex);



	mutex_unlock(&log->io_mutex);

	return 0;

}
@@ -540,6 +562,21 @@ static sector_t r5l_reclaimable_space(struct r5l_log *log) 
				 log->next_checkpoint);

}



static void r5l_run_no_mem_stripe(struct r5l_log *log)

{

	struct stripe_head *sh;



	assert_spin_locked(&log->io_list_lock);



	if (!list_empty(&log->no_mem_stripes)) {

		sh = list_first_entry(&log->no_mem_stripes,

				      struct stripe_head, log_list);

		list_del_init(&sh->log_list);

		set_bit(STRIPE_HANDLE, &sh->state);

		raid5_release_stripe(sh);

	}

}



static bool r5l_complete_finished_ios(struct r5l_log *log)

{

	struct r5l_io_unit *io, *next;
@@ -556,7 +593,8 @@ static bool r5l_complete_finished_ios(struct r5l_log *log) 
		log->next_cp_seq = io->seq;



		list_del(&io->log_sibling);

		kmem_cache_free(log->io_kc, io);

		mempool_free(io, log->io_pool);

		r5l_run_no_mem_stripe(log);



		found = true;

	}
@@ -1170,6 +1208,10 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) 
	if (!log->io_kc)

		goto io_kc;



	log->io_pool = mempool_create_slab_pool(R5L_POOL_SIZE, log->io_kc);

	if (!log->io_pool)

		goto io_pool;



	log->bs = bioset_create(R5L_POOL_SIZE, 0);

	if (!log->bs)

		goto io_bs;
@@ -1184,6 +1226,8 @@ int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev) 
		goto reclaim_thread;

	init_waitqueue_head(&log->iounit_wait);



	INIT_LIST_HEAD(&log->no_mem_stripes);



	INIT_LIST_HEAD(&log->no_space_stripes);

	spin_lock_init(&log->no_space_stripes_lock);
@@ -1200,6 +1244,8 @@ reclaim_thread: 
out_mempool:

	bioset_free(log->bs);

io_bs:

	mempool_destroy(log->io_pool);

io_pool:

	kmem_cache_destroy(log->io_kc);

io_kc:

	kfree(log);
@@ -1211,6 +1257,7 @@ void r5l_exit_log(struct r5l_log *log) 
	md_unregister_thread(&log->reclaim_thread);

	mempool_destroy(log->meta_pool);

	bioset_free(log->bs);

	mempool_destroy(log->io_pool);

	kmem_cache_destroy(log->io_kc);

	kfree(log);

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE