bcache: handle c->uuids properly for bucket size > 8MB

Bcache allocates a whole bucket to store c->uuids on cache device, and
allocates continuous pages to store it in-memory. When the bucket size
exceeds maximum allocable continuous pages, bch_cache_set_alloc() will
fail and cache device registration will fail.

This patch allocates c->uuids by alloc_meta_bucket_pages(), and uses
ilog2(meta_bucket_pages(c)) to indicate order of c->uuids pages when
free it. When writing c->uuids to cache device, its size is decided
by meta_bucket_pages(c) * PAGE_SECTORS. Now c->uuids is properly handled
for bucket size > 8MB.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f2bab57..2ddc41c 100644 (file)
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -466,6 +466,7 @@ static int __uuid_write(struct cache_set *c)
        BKEY_PADDED(key) k;
        struct closure cl;
        struct cache *ca;
+       unsigned int size;
 
        closure_init_stack(&cl);
        lockdep_assert_held(&bch_register_lock);
@@ -473,7 +474,8 @@ static int __uuid_write(struct cache_set *c)
        if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true))
                return 1;
 
-       SET_KEY_SIZE(&k.key, c->sb.bucket_size);
+       size =  meta_bucket_pages(&c->sb) * PAGE_SECTORS;
+       SET_KEY_SIZE(&k.key, size);
        uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl);
        closure_sync(&cl);
 
@@ -1664,7 +1666,7 @@ static void cache_set_free(struct closure *cl)
                }
 
        bch_bset_sort_state_free(&c->sort);
-       free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
+       free_pages((unsigned long) c->uuids, ilog2(meta_bucket_pages(&c->sb)));
 
        if (c->moving_gc_wq)
                destroy_workqueue(c->moving_gc_wq);
@@ -1870,7 +1872,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
 
        c->bucket_bits          = ilog2(sb->bucket_size);
        c->block_bits           = ilog2(sb->block_size);
-       c->nr_uuids             = bucket_bytes(c) / sizeof(struct uuid_entry);
+       c->nr_uuids             = meta_bucket_bytes(&c->sb) / sizeof(struct uuid_entry);
        c->devices_max_used     = 0;
        atomic_set(&c->attached_dev_nr, 0);
        c->btree_pages          = bucket_pages(c);
@@ -1921,7 +1923,7 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
                        BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER))
                goto err;
 
-       c->uuids = alloc_bucket_pages(GFP_KERNEL, c);
+       c->uuids = alloc_meta_bucket_pages(GFP_KERNEL, &c->sb);
        if (!c->uuids)
                goto err;