bdi: replace BDI_CAP_NO_{WRITEBACK,ACCT_DIRTY} with a single flag

Replace the two negative flags that are always used together with a
single positive flag that indicates the writeback capability instead
of two related non-capabilities.  Also remove the pointless wrappers
to just check the flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

7 files changed, 14 insertions, 16 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index df18f0088dd3..408d5051d05b 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -14,9 +14,7 @@
 #include <linux/device.h>
 #include <trace/events/writeback.h>
 
-struct backing_dev_info noop_backing_dev_info = {
-	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK,
-};
+struct backing_dev_info noop_backing_dev_info;
 EXPORT_SYMBOL_GPL(noop_backing_dev_info);
 
 static struct class *bdi_class;
@@ -745,7 +743,7 @@ struct backing_dev_info *bdi_alloc(int node_id)
 		kfree(bdi);
 		return NULL;
 	}
-	bdi->capabilities = BDI_CAP_WRITEBACK_ACCT;
+	bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT;
 	bdi->ra_pages = VM_READAHEAD_PAGES;
 	bdi->io_pages = VM_READAHEAD_PAGES;
 	return bdi;
diff --git a/mm/filemap.c b/mm/filemap.c
index 1aaea26556cc..6c2a0139e22f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -414,7 +414,7 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 		.range_end = end,
 	};
 
-	if (!mapping_cap_writeback_dirty(mapping) ||
+	if (!mapping_can_writeback(mapping) ||
 	    !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
 		return 0;
 
@@ -1702,7 +1702,7 @@ repeat:
 no_page:
 	if (!page && (fgp_flags & FGP_CREAT)) {
 		int err;
-		if ((fgp_flags & FGP_WRITE) && mapping_cap_account_dirty(mapping))
+		if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping))
 			gfp_mask |= __GFP_WRITE;
 		if (fgp_flags & FGP_NOFS)
 			gfp_mask &= ~__GFP_FS;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b807952b4d43..d2352f76d651 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5643,7 +5643,7 @@ static int mem_cgroup_move_account(struct page *page,
 		if (PageDirty(page)) {
 			struct address_space *mapping = page_mapping(page);
 
-			if (mapping_cap_account_dirty(mapping)) {
+			if (mapping_can_writeback(mapping)) {
 				__mod_lruvec_state(from_vec, NR_FILE_DIRTY,
 						   -nr_pages);
 				__mod_lruvec_state(to_vec, NR_FILE_DIRTY,
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index f1aa6433f404..a1e73943445e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1006,7 +1006,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
 	 */
 	mapping = page_mapping(hpage);
 	if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping &&
-	    mapping_cap_writeback_dirty(mapping)) {
+	    mapping_can_writeback(mapping)) {
 		if (page_mkclean(hpage)) {
 			SetPageDirty(hpage);
 		} else {
diff --git a/mm/migrate.c b/mm/migrate.c
index 34a842a8eb6a..9d2f42a3a162 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -503,7 +503,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 			__dec_lruvec_state(old_lruvec, NR_SHMEM);
 			__inc_lruvec_state(new_lruvec, NR_SHMEM);
 		}
-		if (dirty && mapping_cap_account_dirty(mapping)) {
+		if (dirty && mapping_can_writeback(mapping)) {
 			__dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY);
 			__dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING);
 			__inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY);
diff --git a/mm/mmap.c b/mm/mmap.c
index 40248d84ad5f..1fc0e92be4ba 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1666,7 +1666,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
 
 	/* Can the mapping track the dirty pages? */
 	return vma->vm_file && vma->vm_file->f_mapping &&
-		mapping_cap_account_dirty(vma->vm_file->f_mapping);
+		mapping_can_writeback(vma->vm_file->f_mapping);
 }
 
 /*
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 0139f9622a92..358d6f28c627 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1882,7 +1882,7 @@ void balance_dirty_pages_ratelimited(struct address_space *mapping)
 	int ratelimit;
 	int *p;
 
-	if (!bdi_cap_account_dirty(bdi))
+	if (!(bdi->capabilities & BDI_CAP_WRITEBACK))
 		return;
 
 	if (inode_cgwb_enabled(inode))
@@ -2423,7 +2423,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 
 	trace_writeback_dirty_page(page, mapping);
 
-	if (mapping_cap_account_dirty(mapping)) {
+	if (mapping_can_writeback(mapping)) {
 		struct bdi_writeback *wb;
 
 		inode_attach_wb(inode, page);
@@ -2450,7 +2450,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 void account_page_cleaned(struct page *page, struct address_space *mapping,
 			  struct bdi_writeback *wb)
 {
-	if (mapping_cap_account_dirty(mapping)) {
+	if (mapping_can_writeback(mapping)) {
 		dec_lruvec_page_state(page, NR_FILE_DIRTY);
 		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 		dec_wb_stat(wb, WB_RECLAIMABLE);
@@ -2513,7 +2513,7 @@ void account_page_redirty(struct page *page)
 {
 	struct address_space *mapping = page->mapping;
 
-	if (mapping && mapping_cap_account_dirty(mapping)) {
+	if (mapping && mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
@@ -2625,7 +2625,7 @@ void __cancel_dirty_page(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
 
-	if (mapping_cap_account_dirty(mapping)) {
+	if (mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
@@ -2665,7 +2665,7 @@ int clear_page_dirty_for_io(struct page *page)
 
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 
-	if (mapping && mapping_cap_account_dirty(mapping)) {
+	if (mapping && mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};