4.20-stable review patch. If anyone has any objections, please let me know.
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From: Alexei Naberezhnov anaberezhnov@fb.com
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: b4c625c67362 ("md/r5cache: r5cache recovery: part 1") Signed-off-by: Alexei Naberezhnov anaberezhnov@fb.com Signed-off-by: Song Liu songliubraving@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/raid5-cache.c | 33 ++++++++++++++++++++++----------- drivers/md/raid5.c | 8 ++++++-- 2 files changed, 28 insertions(+), 13 deletions(-)
--- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1935,12 +1935,14 @@ out: }
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 */
@@ -2150,7 +2152,7 @@ r5c_recovery_analyze_meta_block(struct r 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 @@ -2159,20 +2161,29 @@ r5c_recovery_analyze_meta_block(struct r 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", - mdname(mddev)); + mdname(mddev)); return -ENOMEM; } list_add_tail(&sh->lru, cached_stripe_list); --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -6369,6 +6369,7 @@ raid5_show_stripe_cache_size(struct mdde int raid5_set_cache_size(struct mddev *mddev, int size) { + int result = 0; struct r5conf *conf = mddev->private;
if (size <= 16 || size > 32768) @@ -6385,11 +6386,14 @@ raid5_set_cache_size(struct mddev *mddev
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);