Merge branch 'ext3-latency-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'ext3-latency-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext3: Add replace-on-rename hueristics for data=writeback mode
  ext3: Add replace-on-truncate hueristics for data=writeback mode
  ext3: Use WRITE_SYNC for commits which are caused by fsync()
  block_write_full_page: Use synchronous writes for WBC_SYNC_ALL writebacks

fs/buffer.c

@@ -1595,6 +1595,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	struct buffer_head *bh, *head;
 	const unsigned blocksize = 1 << inode->i_blkbits;
 	int nr_underway = 0;
+	int write_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
 
 	BUG_ON(!PageLocked(page));
 
@@ -1686,7 +1687,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	do {
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
-			submit_bh(WRITE, bh);
+			submit_bh(write_op, bh);
 			nr_underway++;
 		}
 		bh = next;
@@ -1740,7 +1741,7 @@ recover:
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
 			clear_buffer_dirty(bh);
-			submit_bh(WRITE, bh);
+			submit_bh(write_op, bh);
 			nr_underway++;
 		}
 		bh = next;

fs/ext3/file.c

@@ -33,6 +33,10 @@
  */
 static int ext3_release_file (struct inode * inode, struct file * filp)
 {
+	if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) {
+		filemap_flush(inode->i_mapping);
+		EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE;
+	}
 	/* if we are the last writer on the inode, drop the block reservation */
 	if ((filp->f_mode & FMODE_WRITE) &&
 			(atomic_read(&inode->i_writecount) == 1))

fs/ext3/inode.c

@@ -2363,6 +2363,9 @@ void ext3_truncate(struct inode *inode)
 	if (!ext3_can_truncate(inode))
 		return;
 
+	if (inode->i_size == 0 && ext3_should_writeback_data(inode))
+		ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE;
+
 	/*
 	 * We have to lock the EOF page here, because lock_page() nests
 	 * outside journal_start().

fs/ext3/namei.c

@@ -2274,7 +2274,7 @@ static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
 	struct inode * old_inode, * new_inode;
 	struct buffer_head * old_bh, * new_bh, * dir_bh;
 	struct ext3_dir_entry_2 * old_de, * new_de;
-	int retval;
+	int retval, flush_file = 0;
 
 	old_bh = new_bh = dir_bh = NULL;
 
@@ -2410,6 +2410,8 @@ static int ext3_rename (struct inode * old_dir, struct dentry *old_dentry,
 		ext3_mark_inode_dirty(handle, new_inode);
 		if (!new_inode->i_nlink)
 			ext3_orphan_add(handle, new_inode);
+		if (ext3_should_writeback_data(new_inode))
+			flush_file = 1;
 	}
 	retval = 0;
 
@@ -2418,6 +2420,8 @@ end_rename:
 	brelse (old_bh);
 	brelse (new_bh);
 	ext3_journal_stop(handle);
+	if (retval == 0 && flush_file)
+		filemap_flush(old_inode->i_mapping);
 	return retval;
 }
 

fs/jbd/commit.c

@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/bio.h>
 
 /*
  * Default IO end handler for temporary BJ_IO buffer_heads.
@@ -171,14 +172,15 @@ static int journal_write_commit_record(journal_t *journal,
 	return (ret == -EIO);
 }
 
-static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
+static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
+				   int write_op)
 {
 	int i;
 
 	for (i = 0; i < bufs; i++) {
 		wbuf[i]->b_end_io = end_buffer_write_sync;
 		/* We use-up our safety reference in submit_bh() */
-		submit_bh(WRITE, wbuf[i]);
+		submit_bh(write_op, wbuf[i]);
 	}
 }
 
@@ -186,7 +188,8 @@ static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
  *  Submit all the data buffers to disk
  */
 static int journal_submit_data_buffers(journal_t *journal,
-				transaction_t *commit_transaction)
+				       transaction_t *commit_transaction,
+				       int write_op)
 {
 	struct journal_head *jh;
 	struct buffer_head *bh;
@@ -225,7 +228,7 @@ write_out_data:
 				BUFFER_TRACE(bh, "needs blocking lock");
 				spin_unlock(&journal->j_list_lock);
 				/* Write out all data to prevent deadlocks */
-				journal_do_submit_data(wbuf, bufs);
+				journal_do_submit_data(wbuf, bufs, write_op);
 				bufs = 0;
 				lock_buffer(bh);
 				spin_lock(&journal->j_list_lock);
@@ -256,7 +259,7 @@ write_out_data:
 			jbd_unlock_bh_state(bh);
 			if (bufs == journal->j_wbufsize) {
 				spin_unlock(&journal->j_list_lock);
-				journal_do_submit_data(wbuf, bufs);
+				journal_do_submit_data(wbuf, bufs, write_op);
 				bufs = 0;
 				goto write_out_data;
 			}
@@ -286,7 +289,7 @@ write_out_data:
 		}
 	}
 	spin_unlock(&journal->j_list_lock);
-	journal_do_submit_data(wbuf, bufs);
+	journal_do_submit_data(wbuf, bufs, write_op);
 
 	return err;
 }
@@ -315,6 +318,7 @@ void journal_commit_transaction(journal_t *journal)
 	int first_tag = 0;
 	int tag_flag;
 	int i;
+	int write_op = WRITE;
 
 	/*
 	 * First job: lock down the current transaction and wait for
@@ -347,6 +351,8 @@ void journal_commit_transaction(journal_t *journal)
 	spin_lock(&journal->j_state_lock);
 	commit_transaction->t_state = T_LOCKED;
 
+	if (commit_transaction->t_synchronous_commit)
+		write_op = WRITE_SYNC;
 	spin_lock(&commit_transaction->t_handle_lock);
 	while (commit_transaction->t_updates) {
 		DEFINE_WAIT(wait);
@@ -431,7 +437,8 @@ void journal_commit_transaction(journal_t *journal)
 	 * Now start flushing things to disk, in the order they appear
 	 * on the transaction lists.  Data blocks go first.
 	 */
-	err = journal_submit_data_buffers(journal, commit_transaction);
+	err = journal_submit_data_buffers(journal, commit_transaction,
+					  write_op);
 
 	/*
 	 * Wait for all previously submitted IO to complete.
@@ -660,7 +667,7 @@ start_journal_io:
 				clear_buffer_dirty(bh);
 				set_buffer_uptodate(bh);
 				bh->b_end_io = journal_end_buffer_io_sync;
-				submit_bh(WRITE, bh);
+				submit_bh(write_op, bh);
 			}
 			cond_resched();
 

fs/jbd/transaction.c

@@ -1440,6 +1440,8 @@ int journal_stop(handle_t *handle)
 		}
 	}
 
+	if (handle->h_sync)
+		transaction->t_synchronous_commit = 1;
 	current->journal_info = NULL;
 	spin_lock(&journal->j_state_lock);
 	spin_lock(&transaction->t_handle_lock);

include/linux/ext3_fs.h

@@ -208,6 +208,7 @@ static inline __u32 ext3_mask_flags(umode_t mode, __u32 flags)
 #define EXT3_STATE_JDATA		0x00000001 /* journaled data exists */
 #define EXT3_STATE_NEW			0x00000002 /* inode is newly created */
 #define EXT3_STATE_XATTR		0x00000004 /* has in-inode xattrs */
+#define EXT3_STATE_FLUSH_ON_CLOSE	0x00000008
 
 /* Used to pass group descriptor data when online resize is done */
 struct ext3_new_group_input {

include/linux/jbd.h

@@ -552,6 +552,11 @@ struct transaction_s
 	 */
 	int t_handle_count;
 
+	/*
+	 * This transaction is being forced and some process is
+	 * waiting for it to finish.
+	 */
+	int t_synchronous_commit:1;
 };
 
 /**