| Message ID | 20200715143015.14957-12-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bcache: extend bucket size to 32bit width | expand |
On 7/15/20 4:30 PM, colyli@suse.de wrote: > From: Coly Li <colyli@suse.de> > > In bch_btree_cache_alloc() when CONFIG_BCACHE_DEBUG is configured, > allocate memory for c->verify_ondisk may fail if the bucket size > 8MB, > which will require __get_free_pages() to allocate continuous pages > with order > 11 (the default MAX_ORDER of Linux buddy allocator). Such > over size allocation will fail, and cause 2 problems, > - When CONFIG_BCACHE_DEBUG is configured, bch_btree_verify() does not > work, because c->verify_ondisk is NULL and bch_btree_verify() returns > immediately. > - bch_btree_cache_alloc() will fail due to c->verify_ondisk allocation > failed, then the whole cache device registration fails. And because of > this failure, the first problem of bch_btree_verify() has no chance to > be triggered. > > This patch fixes the above problem by two means, > 1) If pages allocation of c->verify_ondisk fails, set it to NULL and > returns bch_btree_cache_alloc() with -ENOMEM. > 2) When calling __get_free_pages() to allocate c->verify_ondisk pages, > use ilog2(meta_bucket_pages(&c->sb)) to make sure ilog2() will always > generate a pages order <= MAX_ORDER (or CONFIG_FORCE_MAX_ZONEORDER). > Then the buddy system won't directly reject the allocation request. > > Signed-off-by: Coly Li <colyli@suse.de> > --- > drivers/md/bcache/btree.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index dd116c83de80..79716ac9fb5d 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -738,7 +738,7 @@ void bch_btree_cache_free(struct cache_set *c) if (c->verify_data) list_move(&c->verify_data->list, &c->btree_cache); - free_pages((unsigned long) c->verify_ondisk, ilog2(bucket_pages(c))); + free_pages((unsigned long) c->verify_ondisk, ilog2(meta_bucket_pages(&c->sb))); #endif list_splice(&c->btree_cache_freeable, @@ -785,7 +785,15 @@ int bch_btree_cache_alloc(struct cache_set *c) mutex_init(&c->verify_lock); c->verify_ondisk = (void *) - __get_free_pages(GFP_KERNEL|__GFP_COMP, ilog2(bucket_pages(c))); + __get_free_pages(GFP_KERNEL|__GFP_COMP, ilog2(meta_bucket_pages(&c->sb))); + if (!c->verify_ondisk) { + /* + * Don't worry about the mca_rereserve buckets + * allocated in previous for-loop, they will be + * handled properly in bch_cache_set_unregister(). + */ + return -ENOMEM; + } c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL);