Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit fafc8e09 authored by Alexei Naberezhnov's avatar Alexei Naberezhnov Committed by Greg Kroah-Hartman
Browse files

md/raid5: fix 'out of memory' during raid cache recovery 



commit 483cbbeddd5fe2c80fd4141ff0748fa06c4ff146 upstream.

This fixes the case when md array assembly fails because of raid cache recovery
unable to allocate a stripe, despite attempts to replay stripes and increase
cache size. This happens because stripes released by r5c_recovery_replay_stripes
and raid5_set_cache_size don't become available for allocation immediately.
Released stripes first are placed on conf->released_stripes list and require
md thread to merge them on conf->inactive_list before they can be allocated.

Patch allows final allocation attempt during cache recovery to wait for
new stripes to become availabe for allocation.

Cc: linux-raid@vger.kernel.org
Cc: Shaohua Li <shli@kernel.org>
Cc: linux-stable <stable@vger.kernel.org> # 4.10+
Fixes: b4c625c6 ("md/r5cache: r5cache recovery: part 1")
Signed-off-by: default avatarAlexei Naberezhnov <anaberezhnov@fb.com>
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4ebbe06b

drivers/md/raid5-cache.c

+22 −11
Original line number Diff line number Diff line
@@ -1942,12 +1942,14 @@ r5l_recovery_replay_one_stripe(struct r5conf *conf, 
}



static struct stripe_head *

r5c_recovery_alloc_stripe(struct r5conf *conf,

			  sector_t stripe_sect)

r5c_recovery_alloc_stripe(

		struct r5conf *conf,

		sector_t stripe_sect,

		int noblock)

{

	struct stripe_head *sh;



	sh = raid5_get_active_stripe(conf, stripe_sect, 0, 1, 0);

	sh = raid5_get_active_stripe(conf, stripe_sect, 0, noblock, 0);

	if (!sh)

		return NULL;  /* no more stripe available */
@@ -2157,7 +2159,7 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, 
						stripe_sect);



		if (!sh) {

			sh = r5c_recovery_alloc_stripe(conf, stripe_sect);

			sh = r5c_recovery_alloc_stripe(conf, stripe_sect, 1);

			/*

			 * cannot get stripe from raid5_get_active_stripe

			 * try replay some stripes
@@ -2166,16 +2168,25 @@ r5c_recovery_analyze_meta_block(struct r5l_log *log, 
				r5c_recovery_replay_stripes(

					cached_stripe_list, ctx);

				sh = r5c_recovery_alloc_stripe(

					conf, stripe_sect);

					conf, stripe_sect, 1);

			}

			if (!sh) {

				int new_size = conf->min_nr_stripes * 2;

				pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",

					mdname(mddev),

					conf->min_nr_stripes * 2);

				raid5_set_cache_size(mddev,

						     conf->min_nr_stripes * 2);

				sh = r5c_recovery_alloc_stripe(conf,

							       stripe_sect);

					new_size);

				ret = raid5_set_cache_size(mddev, new_size);

				if (conf->min_nr_stripes <= new_size / 2) {

					pr_err("md/raid:%s: Cannot increase cache size, ret=%d, new_size=%d, min_nr_stripes=%d, max_nr_stripes=%d\n",

						mdname(mddev),

						ret,

						new_size,

						conf->min_nr_stripes,

						conf->max_nr_stripes);

					return -ENOMEM;

				}

				sh = r5c_recovery_alloc_stripe(

					conf, stripe_sect, 0);

			}

			if (!sh) {

				pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",

drivers/md/raid5.c

+6 −2
Original line number Diff line number Diff line
@@ -6336,6 +6336,7 @@ raid5_show_stripe_cache_size(struct mddev *mddev, char *page) 
int

raid5_set_cache_size(struct mddev *mddev, int size)

{

	int result = 0;

	struct r5conf *conf = mddev->private;



	if (size <= 16 || size > 32768)
@@ -6352,11 +6353,14 @@ raid5_set_cache_size(struct mddev *mddev, int size) 


	mutex_lock(&conf->cache_size_mutex);

	while (size > conf->max_nr_stripes)

		if (!grow_one_stripe(conf, GFP_KERNEL))

		if (!grow_one_stripe(conf, GFP_KERNEL)) {

			conf->min_nr_stripes = conf->max_nr_stripes;

			result = -ENOMEM;

			break;

		}

	mutex_unlock(&conf->cache_size_mutex);



	return 0;

	return result;

}

EXPORT_SYMBOL(raid5_set_cache_size);