Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0f1b1fd8 authored by Dave Chinner's avatar Dave Chinner Committed by Al Viro
Browse files

fs: pull inode->i_lock up out of writeback_single_inode 



First thing we do in writeback_single_inode() is take the i_lock and
the last thing we do is drop it. A caller already holds the i_lock,
so pull the i_lock out of writeback_single_inode() to reduce the
round trips on this lock during inode writeback.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 67a23c49

fs/fs-writeback.c

+11 −7
Original line number Diff line number Diff line
@@ -332,9 +332,9 @@ static void inode_wait_for_writeback(struct inode *inode) 
}



/*

 * Write out an inode's dirty pages.  Called under inode_wb_list_lock.  Either

 * the caller has an active reference on the inode or the inode has I_WILL_FREE

 * set.

 * Write out an inode's dirty pages.  Called under inode_wb_list_lock and

 * inode->i_lock.  Either the caller has an active reference on the inode or

 * the inode has I_WILL_FREE set.

 *

 * If `wait' is set, wait on the writeout.

 *
@@ -349,7 +349,9 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) 
	unsigned dirty;

	int ret;



	spin_lock(&inode->i_lock);

	assert_spin_locked(&inode_wb_list_lock);

	assert_spin_locked(&inode->i_lock);



	if (!atomic_read(&inode->i_count))

		WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING)));

	else
@@ -365,7 +367,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) 
		 * completed a full scan of b_io.

		 */

		if (wbc->sync_mode != WB_SYNC_ALL) {

			spin_unlock(&inode->i_lock);

			requeue_io(inode);

			return 0;

		}
@@ -456,7 +457,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) 
		}

	}

	inode_sync_complete(inode);

	spin_unlock(&inode->i_lock);

	return ret;

}
@@ -544,7 +544,6 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, 
		}



		__iget(inode);

		spin_unlock(&inode->i_lock);



		pages_skipped = wbc->pages_skipped;

		writeback_single_inode(inode, wbc);
@@ -555,6 +554,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, 
			 */

			redirty_tail(inode);

		}

		spin_unlock(&inode->i_lock);

		spin_unlock(&inode_wb_list_lock);

		iput(inode);

		cond_resched();
@@ -1309,7 +1309,9 @@ int write_inode_now(struct inode *inode, int sync) 


	might_sleep();

	spin_lock(&inode_wb_list_lock);

	spin_lock(&inode->i_lock);

	ret = writeback_single_inode(inode, &wbc);

	spin_unlock(&inode->i_lock);

	spin_unlock(&inode_wb_list_lock);

	if (sync)

		inode_sync_wait(inode);
@@ -1333,7 +1335,9 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc) 
	int ret;



	spin_lock(&inode_wb_list_lock);

	spin_lock(&inode->i_lock);

	ret = writeback_single_inode(inode, wbc);

	spin_unlock(&inode->i_lock);

	spin_unlock(&inode_wb_list_lock);

	return ret;

}