mm: bdi: add separate writeback accounting capability

Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB.  If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().

Misc cleanups:

 - convert bdi_cap_writeback_dirty() and friends to static inline functions
 - create a flag that includes all three dirty/writeback related flags,
   since almst all users will want to have them toghether

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 4 insertions, 4 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 2a9942f5387c..bbcb916190c9 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1246,7 +1246,7 @@ int test_clear_page_writeback(struct page *page)
                         radix_tree_tag_clear(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_WRITEBACK);
-                        if (bdi_cap_writeback_dirty(bdi)) {
+                        if (bdi_cap_account_writeback(bdi)) {
                                 __dec_bdi_stat(bdi, BDI_WRITEBACK);
                                 __bdi_writeout_inc(bdi);
                         }
@@ -1275,7 +1275,7 @@ int test_set_page_writeback(struct page *page)
                         radix_tree_tag_set(&mapping->page_tree,
                                                 page_index(page),
                                                 PAGECACHE_TAG_WRITEBACK);
-                        if (bdi_cap_writeback_dirty(bdi))
+                        if (bdi_cap_account_writeback(bdi))
                                 __inc_bdi_stat(bdi, BDI_WRITEBACK);
                 }
                 if (!PageDirty(page))
diff --git a/mm/shmem.c b/mm/shmem.c
index e6d9298aa22a..e2a6ae1a44e9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -201,7 +201,7 @@ static struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
         .ra_pages       = 0,    /* No readahead */
-        .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
         .unplug_io_fn   = default_unplug_io_fn,
 };
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 50757ee3f9f3..d8aadaf2a0ba 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -33,7 +33,7 @@ static const struct address_space_operations swap_aops = {
 };
 
 static struct backing_dev_info swap_backing_dev_info = {
-        .capabilities   = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK,
+        .capabilities   = BDI_CAP_NO_ACCT_AND_WRITEBACK,
         .unplug_io_fn   = swap_unplug_io_fn,
 };