btrfs: Fix slab accounting flags

BTRFS is using a variety of slab caches to satisfy internal needs.
Those slab caches are always allocated with the SLAB_RECLAIM_ACCOUNT,
meaning allocations from the caches are going to be accounted as
SReclaimable. At the same time btrfs is not registering any shrinkers
whatsoever, thus preventing memory from the slabs to be shrunk. This
means those caches are not in fact reclaimable.

To fix this remove the SLAB_RECLAIM_ACCOUNT on all caches apart from the
inode cache, since this one is being freed by the generic VFS super_block
shrinker. Also set the transaction related caches as SLAB_TEMPORARY,
to better document the lifetime of the objects (it just translates
to SLAB_RECLAIM_ACCOUNT).

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5c2c076bc552..01c6fca925f7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9392,25 +9392,25 @@ int btrfs_init_cachep(void)
 
         btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
                         sizeof(struct btrfs_trans_handle), 0,
-                        SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                        SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
         if (!btrfs_trans_handle_cachep)
                 goto fail;
 
         btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
                         sizeof(struct btrfs_transaction), 0,
-                        SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                        SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
         if (!btrfs_transaction_cachep)
                 goto fail;
 
         btrfs_path_cachep = kmem_cache_create("btrfs_path",
                         sizeof(struct btrfs_path), 0,
-                        SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                        SLAB_MEM_SPREAD, NULL);
         if (!btrfs_path_cachep)
                 goto fail;
 
         btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
                         sizeof(struct btrfs_free_space), 0,
-                        SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                        SLAB_MEM_SPREAD, NULL);
         if (!btrfs_free_space_cachep)
                 goto fail;