Merge branch 'writeback-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull writeback fixes from Fengguang Wu:
 "Three trivial writeback fixes"

* 'writeback-for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  CPU hotplug, writeback: Don't call writeback_set_ratelimit() too often during hotplug
  writeback: correct comment for move_expired_inodes()
  backing-dev: use kstrto* in preference to simple_strtoul

diff --combined fs/fs-writeback.c
index 401b6c6,fd255c0..51ea267
--- 1/fs/fs-writeback.c
--- 2/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@@ -63,7 -63,6 +63,7 @@@ int writeback_in_progress(struct backin
  {
        return test_bit(BDI_writeback_running, &bdi->state);
  }
 +EXPORT_SYMBOL(writeback_in_progress);
  
  static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
  {
@@@ -249,7 -248,7 +249,7 @@@ static bool inode_dirtied_after(struct 
  }
  
  /*
-  * Move expired (dirtied after work->older_than_this) dirty inodes from
+  * Move expired (dirtied before work->older_than_this) dirty inodes from
   * @delaying_queue to @dispatch_queue.
   */
  static int move_expired_inodes(struct list_head *delaying_queue,
@@@ -439,7 -438,8 +439,7 @@@ static void requeue_inode(struct inode 
   * setting I_SYNC flag and calling inode_sync_complete() to clear it.
   */
  static int
 -__writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
 -                       struct writeback_control *wbc)
 +__writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
  {
        struct address_space *mapping = inode->i_mapping;
        long nr_to_write = wbc->nr_to_write;
@@@ -526,7 -526,7 +526,7 @@@ writeback_single_inode(struct inode *in
        inode->i_state |= I_SYNC;
        spin_unlock(&inode->i_lock);
  
 -      ret = __writeback_single_inode(inode, wb, wbc);
 +      ret = __writeback_single_inode(inode, wbc);
  
        spin_lock(&wb->list_lock);
        spin_lock(&inode->i_lock);
@@@ -577,6 -577,10 +577,6 @@@ static long writeback_chunk_size(struc
  /*
   * Write a portion of b_io inodes which belong to @sb.
   *
 - * If @only_this_sb is true, then find and write all such
 - * inodes. Otherwise write only ones which go sequentially
 - * in reverse order.
 - *
   * Return the number of pages and/or inodes written.
   */
  static long writeback_sb_inodes(struct super_block *sb,
@@@ -669,7 -673,7 +669,7 @@@
                 * We use I_SYNC to pin the inode in memory. While it is set
                 * evict_inode() will wait so the inode cannot be freed.
                 */
 -              __writeback_single_inode(inode, wb, &wbc);
 +              __writeback_single_inode(inode, &wbc);
  
                work->nr_pages -= write_chunk - wbc.nr_to_write;
                wrote += write_chunk - wbc.nr_to_write;