[PATCH 003/102] xfs: defer AIO/DIO completions

[Dave Chinner]

From: Christoph Hellwig <hch at infradead.org>

Upstream commit: c859cdd1da008b3825555be3242908088a3de366

We really shouldn't complete AIO or DIO requests until we have finished
the unwritten extent conversion and size update.  This means fsync never
has to pick up any ioends as all work has been completed when signalling
I/O completion.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Dave Chinner <dchinner at redhat.com>
Signed-off-by: Alex Elder <aelder at sgi.com>
---
 fs/xfs/linux-2.6/xfs_aops.c |   21 ++++++++-------------
 fs/xfs/linux-2.6/xfs_aops.h |    1 +
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 05df3a8..68ac1ce 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -122,6 +122,10 @@ xfs_destroy_ioend(
 		bh->b_end_io(bh, !ioend->io_error);
 	}
 
+	if (ioend->io_iocb) {
+		if (ioend->io_isasync)
+			aio_complete(ioend->io_iocb, ioend->io_result, 0);
+	}
 	xfs_ioend_wake(ip);
 	mempool_free(ioend, xfs_ioend_pool);
 }
@@ -235,8 +239,6 @@ xfs_end_io(
 		/* ensure we don't spin on blocked ioends */
 		delay(1);
 	} else {
-		if (ioend->io_iocb)
-			aio_complete(ioend->io_iocb, ioend->io_result, 0);
 		xfs_destroy_ioend(ioend);
 	}
 }
@@ -273,6 +275,7 @@ xfs_alloc_ioend(
 	 * all the I/O from calling the completion routine too early.
 	 */
 	atomic_set(&ioend->io_remaining, 1);
+	ioend->io_isasync = 0;
 	ioend->io_error = 0;
 	ioend->io_list = NULL;
 	ioend->io_type = type;
@@ -1309,21 +1312,13 @@ xfs_end_io_direct_write(
 
 	ioend->io_offset = offset;
 	ioend->io_size = size;
+	ioend->io_iocb = iocb;
+	ioend->io_result = ret;
 	if (private && size > 0)
 		ioend->io_type = IO_UNWRITTEN;
 
 	if (is_async) {
-		/*
-		 * If we are converting an unwritten extent we need to delay
-		 * the AIO completion until after the unwrittent extent
-		 * conversion has completed, otherwise do it ASAP.
-		 */
-		if (ioend->io_type == IO_UNWRITTEN) {
-			ioend->io_iocb = iocb;
-			ioend->io_result = ret;
-		} else {
-			aio_complete(iocb, ret, 0);
-		}
+		ioend->io_isasync = 1;
 		xfs_finish_ioend(ioend);
 	} else {
 		xfs_finish_ioend_sync(ioend);
diff --git a/fs/xfs/linux-2.6/xfs_aops.h b/fs/xfs/linux-2.6/xfs_aops.h
index 71f721e..ce3dcb5 100644
--- a/fs/xfs/linux-2.6/xfs_aops.h
+++ b/fs/xfs/linux-2.6/xfs_aops.h
@@ -47,6 +47,7 @@ typedef struct xfs_ioend {
 	unsigned int		io_type;	/* delalloc / unwritten */
 	int			io_error;	/* I/O error code */
 	atomic_t		io_remaining;	/* hold count */
+	unsigned int		io_isasync : 1;	/* needs aio_complete */
 	struct inode		*io_inode;	/* file being written to */
 	struct buffer_head	*io_buffer_head;/* buffer linked list head */
 	struct buffer_head	*io_buffer_tail;/* buffer linked list tail */
-- 
1.7.10