[PATCH 1/2] remove WRITE_ODIRECT_PLUG

[PATCH 1/2] remove WRITE_ODIRECT_PLUG

[Christoph Hellwig]

Instead of keeping a global flag around for one special case user use the
REQ_SYNC flag locally and explain what we're doing in a comment.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6/fs/direct-io.c
===================================================================
--- linux-2.6.orig/fs/direct-io.c	2010-06-23 11:48:32.000000000 +0200
+++ linux-2.6/fs/direct-io.c	2010-06-23 11:48:41.088253790 +0200
@@ -1152,8 +1152,12 @@ __blockdev_direct_IO_newtrunc(int rw, st
 	loff_t end = offset;
 	struct dio *dio;
 
+	/*
+	 * We do not want to enable the noidle logic for O_DIRECT I/O, but
+	 * otherwise treat the I/O as synchronous.
+	 */
 	if (rw & WRITE)
-		rw = WRITE_ODIRECT_PLUG;
+		rw |= REQ_SYNC;
 
 	if (bdev)
 		bdev_blkbits = blksize_bits(bdev_logical_block_size(bdev));
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h	2010-06-23 11:48:33.000000000 +0200
+++ linux-2.6/include/linux/fs.h	2010-06-23 11:48:51.460005641 +0200
@@ -132,7 +132,6 @@ struct inodes_stat_t {
  * WRITE_SYNC		Like WRITE_SYNC_PLUG, but also unplugs the device
  *			immediately after submission. The write equivalent
  *			of READ_SYNC.
- * WRITE_ODIRECT_PLUG	Special case write for O_DIRECT only.
  * SWRITE_SYNC
  * SWRITE_SYNC_PLUG	Like WRITE_SYNC/WRITE_SYNC_PLUG, but locks the buffer.
  *			See SWRITE.
@@ -156,7 +155,6 @@ struct inodes_stat_t {
 #define READ_META		(READ | REQ_META)
 #define WRITE_SYNC_PLUG		(WRITE | REQ_SYNC | REQ_NOIDLE)
 #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
-#define WRITE_ODIRECT_PLUG	(WRITE | REQ_SYNC)
 #define WRITE_META		(WRITE | REQ_META)
 #define WRITE_BARRIER		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
 				 REQ_HARDBARRIER)

Re: [PATCH 1/2] remove WRITE_ODIRECT_PLUG

[Christoph Hellwig]

ping?

On Wed, Jun 23, 2010 at 12:32:36PM +0200, Christoph Hellwig wrote:
> 
> Instead of keeping a global flag around for one special case user use the
> REQ_SYNC flag locally and explain what we're doing in a comment.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Index: linux-2.6/fs/direct-io.c
> ===================================================================
> --- linux-2.6.orig/fs/direct-io.c	2010-06-23 11:48:32.000000000 +0200
> +++ linux-2.6/fs/direct-io.c	2010-06-23 11:48:41.088253790 +0200
> @@ -1152,8 +1152,12 @@ __blockdev_direct_IO_newtrunc(int rw, st
>  	loff_t end = offset;
>  	struct dio *dio;
>  
> +	/*
> +	 * We do not want to enable the noidle logic for O_DIRECT I/O, but
> +	 * otherwise treat the I/O as synchronous.
> +	 */
>  	if (rw & WRITE)
> -		rw = WRITE_ODIRECT_PLUG;
> +		rw |= REQ_SYNC;
>  
>  	if (bdev)
>  		bdev_blkbits = blksize_bits(bdev_logical_block_size(bdev));
> Index: linux-2.6/include/linux/fs.h
> ===================================================================
> --- linux-2.6.orig/include/linux/fs.h	2010-06-23 11:48:33.000000000 +0200
> +++ linux-2.6/include/linux/fs.h	2010-06-23 11:48:51.460005641 +0200
> @@ -132,7 +132,6 @@ struct inodes_stat_t {
>   * WRITE_SYNC		Like WRITE_SYNC_PLUG, but also unplugs the device
>   *			immediately after submission. The write equivalent
>   *			of READ_SYNC.
> - * WRITE_ODIRECT_PLUG	Special case write for O_DIRECT only.
>   * SWRITE_SYNC
>   * SWRITE_SYNC_PLUG	Like WRITE_SYNC/WRITE_SYNC_PLUG, but locks the buffer.
>   *			See SWRITE.
> @@ -156,7 +155,6 @@ struct inodes_stat_t {
>  #define READ_META		(READ | REQ_META)
>  #define WRITE_SYNC_PLUG		(WRITE | REQ_SYNC | REQ_NOIDLE)
>  #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
> -#define WRITE_ODIRECT_PLUG	(WRITE | REQ_SYNC)
>  #define WRITE_META		(WRITE | REQ_META)
>  #define WRITE_BARRIER		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
>  				 REQ_HARDBARRIER)
---end quoted text---