Commit 5b3ff237 authored by jiayingz@google.com (Jiaying Zhang)'s avatar jiayingz@google.com (Jiaying Zhang) Committed by Theodore Ts'o
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ext4: move aio completion after unwritten extent conversion 

This patch is to be applied upon Christoph's "direct-io: move aio_complete
into ->end_io" patch. It adds iocb and result fields to struct ext4_io_end_t,
so that we can call aio_complete from  ext4_end_io_nolock() after the extent
conversion has finished.

I have verified with Christoph's aio-dio test that used to fail after a few
runs on an original kernel but now succeeds on the patched kernel.

See http://thread.gmane.org/gmane.comp.file-systems.ext4/19659

 for details.

Signed-off-by: default avatarJiaying Zhang <jiayingz@google.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 552ef802

fs/ext4/ext4.h

+3 −1
Original line number Diff line number Diff line
@@ -170,13 +170,15 @@ struct mpage_da_data { 
};

#define	EXT4_IO_UNWRITTEN	0x1

typedef struct ext4_io_end {

	struct list_head	list;		/* per-file finished AIO list */

	struct list_head	list;		/* per-file finished IO list */

	struct inode		*inode;		/* file being written to */

	unsigned int		flag;		/* unwritten or not */

	struct page		*page;		/* page struct for buffer write */

	loff_t			offset;		/* offset in the file */

	ssize_t			size;		/* size of the extent */

	struct work_struct	work;		/* data work queue */

	struct kiocb		*iocb;		/* iocb struct for AIO */

	int			result;		/* error value for AIO */

} ext4_io_end_t;



/*

fs/ext4/inode.c

+12 −5
Original line number Diff line number Diff line
@@ -3668,6 +3668,8 @@ static int ext4_end_io_nolock(ext4_io_end_t *io) 
		return ret;

	}



	if (io->iocb)

		aio_complete(io->iocb, io->result, 0);

	/* clear the DIO AIO unwritten flag */

	io->flag = 0;

	return ret;
@@ -3767,6 +3769,8 @@ static ext4_io_end_t *ext4_init_io_end (struct inode *inode, gfp_t flags) 
		io->offset = 0;

		io->size = 0;

		io->page = NULL;

		io->iocb = NULL;

		io->result = 0;

		INIT_WORK(&io->work, ext4_end_io_work);

		INIT_LIST_HEAD(&io->list);

	}
@@ -3796,12 +3800,18 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, 
	if (io_end->flag != EXT4_IO_UNWRITTEN){

		ext4_free_io_end(io_end);

		iocb->private = NULL;

		goto out;

out:

		if (is_async)

			aio_complete(iocb, ret, 0);

		return;

	}



	io_end->offset = offset;

	io_end->size = size;

	io_end->flag = EXT4_IO_UNWRITTEN;

	if (is_async) {

		io_end->iocb = iocb;

		io_end->result = ret;

	}

	wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;



	/* queue the work to convert unwritten extents to written */
@@ -3813,9 +3823,6 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, 
	list_add_tail(&io_end->list, &ei->i_completed_io_list);

	spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);

	iocb->private = NULL;

out:

	if (is_async)

		aio_complete(iocb, ret, 0);

}



static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate)

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