writeback: merge try_to_writeback_inodes_sb_nr() into caller

Since commit 925a6efb ("Btrfs: stop using
try_to_writeback_inodes_sb_nr to flush delalloc") this function hasn't
been used outside so stop exporting it.

In addition we merge it into try_to_writeback_inodes_sb() which is the
only caller.  Also change return type of try_to_writeback_inodes_sb to
void as the only user ext4 doesn't care.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/fs-writeback.c

@@ -2376,37 +2376,19 @@ void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
 EXPORT_SYMBOL(writeback_inodes_sb);
 
 /**
- * try_to_writeback_inodes_sb_nr - try to start writeback if none underway
+ * try_to_writeback_inodes_sb - try to start writeback if none underway
  * @sb: the superblock
- * @nr: the number of pages to write
- * @reason: the reason of writeback
+ * @reason: reason why some writeback work was initiated
  *
- * Invoke writeback_inodes_sb_nr if no writeback is currently underway.
- * Returns 1 if writeback was started, 0 if not.
+ * Invoke __writeback_inodes_sb_nr if no writeback is currently underway.
  */
-bool try_to_writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr,
-				   enum wb_reason reason)
+void try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
 {
 	if (!down_read_trylock(&sb->s_umount))
-		return false;
+		return;
 
-	__writeback_inodes_sb_nr(sb, nr, reason, true);
+	__writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason, true);
 	up_read(&sb->s_umount);
-	return true;
-}
-EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr);
-
-/**
- * try_to_writeback_inodes_sb - try to start writeback if none underway
- * @sb: the superblock
- * @reason: reason why some writeback work was initiated
- *
- * Implement by try_to_writeback_inodes_sb_nr()
- * Returns 1 if writeback was started, 0 if not.
- */
-bool try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
-{
-	return try_to_writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason);
 }
 EXPORT_SYMBOL(try_to_writeback_inodes_sb);
 

include/linux/writeback.h

@@ -163,9 +163,7 @@ struct bdi_writeback;
 void writeback_inodes_sb(struct super_block *, enum wb_reason reason);
 void writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
 							enum wb_reason reason);
-bool try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason);
-bool try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
-				   enum wb_reason reason);
+void try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason);
 void sync_inodes_sb(struct super_block *);
 void wakeup_flusher_threads(enum wb_reason reason);
 void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi,