1 files changed, 13 insertions, 65 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 0b06b2d26c9a..44df4fcef65c 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -110,33 +110,14 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
 /*
  * Flags in backing_dev_info::capability
  *
- * The first three flags control whether dirty pages will contribute to the
- * VM's accounting and whether writepages() should be called for dirty pages
- * (something that would not, for example, be appropriate for ramfs)
- *
- * WARNING: these flags are closely related and should not normally be
- * used separately.  The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these
- * three flags into a single convenience macro.
- *
- * BDI_CAP_NO_ACCT_DIRTY:  Dirty pages shouldn't contribute to accounting
- * BDI_CAP_NO_WRITEBACK:   Don't write pages back
- * BDI_CAP_NO_ACCT_WB:     Don't automatically account writeback pages
- * BDI_CAP_STRICTLIMIT:    Keep number of dirty pages below bdi threshold.
- *
- * BDI_CAP_CGROUP_WRITEBACK: Supports cgroup-aware writeback.
- * BDI_CAP_SYNCHRONOUS_IO: Device is so fast that asynchronous IO would be
- *			   inefficient.
+ * BDI_CAP_WRITEBACK:		Supports dirty page writeback, and dirty pages
+ *				should contribute to accounting
+ * BDI_CAP_WRITEBACK_ACCT:	Automatically account writeback pages
+ * BDI_CAP_STRICTLIMIT:		Keep number of dirty pages below bdi threshold
  */
-#define BDI_CAP_NO_ACCT_DIRTY	0x00000001
-#define BDI_CAP_NO_WRITEBACK	0x00000002
-#define BDI_CAP_NO_ACCT_WB	0x00000004
-#define BDI_CAP_STABLE_WRITES	0x00000008
-#define BDI_CAP_STRICTLIMIT	0x00000010
-#define BDI_CAP_CGROUP_WRITEBACK 0x00000020
-#define BDI_CAP_SYNCHRONOUS_IO	0x00000040
-
-#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
-	(BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
+#define BDI_CAP_WRITEBACK		(1 << 0)
+#define BDI_CAP_WRITEBACK_ACCT		(1 << 1)
+#define BDI_CAP_STRICTLIMIT		(1 << 2)
 
 extern struct backing_dev_info noop_backing_dev_info;
 
@@ -175,41 +156,9 @@ static inline int wb_congested(struct bdi_writeback *wb, int cong_bits)
 long congestion_wait(int sync, long timeout);
 long wait_iff_congested(int sync, long timeout);
 
-static inline bool bdi_cap_synchronous_io(struct backing_dev_info *bdi)
-{
-	return bdi->capabilities & BDI_CAP_SYNCHRONOUS_IO;
-}
-
-static inline bool bdi_cap_stable_pages_required(struct backing_dev_info *bdi)
-{
-	return bdi->capabilities & BDI_CAP_STABLE_WRITES;
-}
-
-static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi)
-{
-	return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK);
-}
-
-static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi)
-{
-	return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY);
-}
-
-static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi)
-{
-	/* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */
-	return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB |
-				      BDI_CAP_NO_WRITEBACK));
-}
-
-static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)
-{
-	return bdi_cap_writeback_dirty(inode_to_bdi(mapping->host));
-}
-
-static inline bool mapping_cap_account_dirty(struct address_space *mapping)
+static inline bool mapping_can_writeback(struct address_space *mapping)
 {
-	return bdi_cap_account_dirty(inode_to_bdi(mapping->host));
+	return inode_to_bdi(mapping->host)->capabilities & BDI_CAP_WRITEBACK;
 }
 
 static inline int bdi_sched_wait(void *word)
@@ -233,9 +182,9 @@ int inode_congested(struct inode *inode, int cong_bits);
  * inode_cgwb_enabled - test whether cgroup writeback is enabled on an inode
  * @inode: inode of interest
  *
- * cgroup writeback requires support from both the bdi and filesystem.
- * Also, both memcg and iocg have to be on the default hierarchy.  Test
- * whether all conditions are met.
+ * Cgroup writeback requires support from the filesystem.  Also, both memcg and
+ * iocg have to be on the default hierarchy.  Test whether all conditions are
+ * met.
  *
  * Note that the test result may change dynamically on the same inode
  * depending on how memcg and iocg are configured.
@@ -246,8 +195,7 @@ static inline bool inode_cgwb_enabled(struct inode *inode)
 
 	return cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
 		cgroup_subsys_on_dfl(io_cgrp_subsys) &&
-		bdi_cap_account_dirty(bdi) &&
-		(bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
+		(bdi->capabilities & BDI_CAP_WRITEBACK) &&
 		(inode->i_sb->s_iflags & SB_I_CGROUPWB);
 }