Commit 1d5ae5df authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

xfs: cleanup I/O-related buffer flags 



Remove the unused and misnamed _XBF_RUN_QUEUES flag, rename XBF_LOG_BUFFER
to the more fitting XBF_SYNCIO, and split XBF_ORDERED into XBF_FUA and
XBF_FLUSH to allow more fine grained control over the bio flags.  Also
cleanup processing of the flags in _xfs_buf_ioapply to make more sense,
and renumber the sparse flag number space to group flags by purpose.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarAlex Elder <aelder@sgi.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent c8da0faf

fs/xfs/linux-2.6/xfs_buf.c

+15 −20
Original line number Diff line number Diff line
@@ -592,10 +592,8 @@ _xfs_buf_read( 
	ASSERT(!(flags & (XBF_DELWRI|XBF_WRITE)));

	ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);



	bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | \

			XBF_READ_AHEAD | _XBF_RUN_QUEUES);

	bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | \

			XBF_READ_AHEAD | _XBF_RUN_QUEUES);

	bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_DELWRI | XBF_READ_AHEAD);

	bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD);



	status = xfs_buf_iorequest(bp);

	if (status || XFS_BUF_ISERROR(bp) || (flags & XBF_ASYNC))
@@ -1211,23 +1209,21 @@ _xfs_buf_ioapply( 
	total_nr_pages = bp->b_page_count;

	map_i = 0;



	if (bp->b_flags & XBF_ORDERED) {

		ASSERT(!(bp->b_flags & XBF_READ));

		rw = WRITE_FLUSH_FUA;

	} else if (bp->b_flags & XBF_LOG_BUFFER) {

		ASSERT(!(bp->b_flags & XBF_READ_AHEAD));

		bp->b_flags &= ~_XBF_RUN_QUEUES;

		rw = (bp->b_flags & XBF_WRITE) ? WRITE_SYNC : READ_SYNC;

	} else if (bp->b_flags & _XBF_RUN_QUEUES) {

		ASSERT(!(bp->b_flags & XBF_READ_AHEAD));

		bp->b_flags &= ~_XBF_RUN_QUEUES;

		rw = (bp->b_flags & XBF_WRITE) ? WRITE_META : READ_META;

	if (bp->b_flags & XBF_WRITE) {

		if (bp->b_flags & XBF_SYNCIO)

			rw = WRITE_SYNC;

		else

			rw = WRITE;

		if (bp->b_flags & XBF_FUA)

			rw |= REQ_FUA;

		if (bp->b_flags & XBF_FLUSH)

			rw |= REQ_FLUSH;

	} else if (bp->b_flags & XBF_READ_AHEAD) {

		rw = READA;

	} else {

		rw = (bp->b_flags & XBF_WRITE) ? WRITE :

		     (bp->b_flags & XBF_READ_AHEAD) ? READA : READ;

		rw = READ;

	}





next_chunk:

	atomic_inc(&bp->b_io_remaining);

	nr_pages = BIO_MAX_SECTORS >> (PAGE_SHIFT - BBSHIFT);
@@ -1689,8 +1685,7 @@ xfs_buf_delwri_split( 
				break;

			}



			bp->b_flags &= ~(XBF_DELWRI|_XBF_DELWRI_Q|

					 _XBF_RUN_QUEUES);

			bp->b_flags &= ~(XBF_DELWRI | _XBF_DELWRI_Q);

			bp->b_flags |= XBF_WRITE;

			list_move_tail(&bp->b_list, list);

			trace_xfs_buf_delwri_split(bp, _RET_IP_);

fs/xfs/linux-2.6/xfs_buf.h

+20 −20
Original line number Diff line number Diff line
@@ -46,43 +46,46 @@ typedef enum { 


#define XBF_READ	(1 << 0) /* buffer intended for reading from device */

#define XBF_WRITE	(1 << 1) /* buffer intended for writing to device */

#define XBF_MAPPED	(1 << 2) /* buffer mapped (b_addr valid) */

#define XBF_READ_AHEAD	(1 << 2) /* asynchronous read-ahead */

#define XBF_MAPPED	(1 << 3) /* buffer mapped (b_addr valid) */

#define XBF_ASYNC	(1 << 4) /* initiator will not wait for completion */

#define XBF_DONE	(1 << 5) /* all pages in the buffer uptodate */

#define XBF_DELWRI	(1 << 6) /* buffer has dirty pages */

#define XBF_STALE	(1 << 7) /* buffer has been staled, do not find it */

#define XBF_ORDERED	(1 << 11)/* use ordered writes */

#define XBF_READ_AHEAD	(1 << 12)/* asynchronous read-ahead */

#define XBF_LOG_BUFFER	(1 << 13)/* this is a buffer used for the log */



/* I/O hints for the BIO layer */

#define XBF_SYNCIO	(1 << 10)/* treat this buffer as synchronous I/O */

#define XBF_FUA		(1 << 11)/* force cache write through mode */

#define XBF_FLUSH	(1 << 12)/* flush the disk cache before a write */



/* flags used only as arguments to access routines */

#define XBF_LOCK	(1 << 14)/* lock requested */

#define XBF_TRYLOCK	(1 << 15)/* lock requested, but do not wait */

#define XBF_DONT_BLOCK	(1 << 16)/* do not block in current thread */

#define XBF_LOCK	(1 << 15)/* lock requested */

#define XBF_TRYLOCK	(1 << 16)/* lock requested, but do not wait */

#define XBF_DONT_BLOCK	(1 << 17)/* do not block in current thread */



/* flags used only internally */

#define _XBF_PAGES	(1 << 18)/* backed by refcounted pages */

#define	_XBF_RUN_QUEUES	(1 << 19)/* run block device task queue	*/

#define	_XBF_KMEM	(1 << 20)/* backed by heap memory */

#define _XBF_DELWRI_Q	(1 << 21)/* buffer on delwri queue */

#define _XBF_PAGES	(1 << 20)/* backed by refcounted pages */

#define _XBF_KMEM	(1 << 21)/* backed by heap memory */

#define _XBF_DELWRI_Q	(1 << 22)/* buffer on delwri queue */



typedef unsigned int xfs_buf_flags_t;



#define XFS_BUF_FLAGS \

	{ XBF_READ,		"READ" }, \

	{ XBF_WRITE,		"WRITE" }, \

	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \

	{ XBF_MAPPED,		"MAPPED" }, \

	{ XBF_ASYNC,		"ASYNC" }, \

	{ XBF_DONE,		"DONE" }, \

	{ XBF_DELWRI,		"DELWRI" }, \

	{ XBF_STALE,		"STALE" }, \

	{ XBF_ORDERED,		"ORDERED" }, \

	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \

	{ XBF_SYNCIO,		"SYNCIO" }, \

	{ XBF_FUA,		"FUA" }, \

	{ XBF_FLUSH,		"FLUSH" }, \

	{ XBF_LOCK,		"LOCK" },  	/* should never be set */\

	{ XBF_TRYLOCK,		"TRYLOCK" }, 	/* ditto */\

	{ XBF_DONT_BLOCK,	"DONT_BLOCK" },	/* ditto */\

	{ _XBF_PAGES,		"PAGES" }, \

	{ _XBF_RUN_QUEUES,	"RUN_QUEUES" }, \

	{ _XBF_KMEM,		"KMEM" }, \

	{ _XBF_DELWRI_Q,	"DELWRI_Q" }
@@ -230,8 +233,9 @@ extern void xfs_buf_terminate(void); 




#define XFS_BUF_BFLAGS(bp)	((bp)->b_flags)

#define XFS_BUF_ZEROFLAGS(bp)	((bp)->b_flags &= \

		~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED))

#define XFS_BUF_ZEROFLAGS(bp) \

	((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI| \

			    XBF_SYNCIO|XBF_FUA|XBF_FLUSH))



void xfs_buf_stale(struct xfs_buf *bp);

#define XFS_BUF_STALE(bp)	xfs_buf_stale(bp);
@@ -263,10 +267,6 @@ void xfs_buf_stale(struct xfs_buf *bp); 
#define XFS_BUF_UNASYNC(bp)	((bp)->b_flags &= ~XBF_ASYNC)

#define XFS_BUF_ISASYNC(bp)	((bp)->b_flags & XBF_ASYNC)



#define XFS_BUF_ORDERED(bp)	((bp)->b_flags |= XBF_ORDERED)

#define XFS_BUF_UNORDERED(bp)	((bp)->b_flags &= ~XBF_ORDERED)

#define XFS_BUF_ISORDERED(bp)	((bp)->b_flags & XBF_ORDERED)



#define XFS_BUF_HOLD(bp)	xfs_buf_hold(bp)

#define XFS_BUF_READ(bp)	((bp)->b_flags |= XBF_READ)

#define XFS_BUF_UNREAD(bp)	((bp)->b_flags &= ~XBF_READ)

fs/xfs/xfs_log.c

+4 −5
Original line number Diff line number Diff line
@@ -1268,7 +1268,6 @@ xlog_bdstrat( 
		return 0;

	}



	bp->b_flags |= _XBF_RUN_QUEUES;

	xfs_buf_iorequest(bp);

	return 0;

}
@@ -1369,7 +1368,7 @@ xlog_sync(xlog_t *log, 
	XFS_BUF_ZEROFLAGS(bp);

	XFS_BUF_BUSY(bp);

	XFS_BUF_ASYNC(bp);

	bp->b_flags |= XBF_LOG_BUFFER;

	bp->b_flags |= XBF_SYNCIO;



	if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) {

		/*
@@ -1380,7 +1379,7 @@ xlog_sync(xlog_t *log, 
		 */

		if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)

			xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);

		XFS_BUF_ORDERED(bp);

		bp->b_flags |= XBF_FUA | XBF_FLUSH;

	}



	ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
@@ -1413,9 +1412,9 @@ xlog_sync(xlog_t *log, 
		XFS_BUF_ZEROFLAGS(bp);

		XFS_BUF_BUSY(bp);

		XFS_BUF_ASYNC(bp);

		bp->b_flags |= XBF_LOG_BUFFER;

		bp->b_flags |= XBF_SYNCIO;

		if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)

			XFS_BUF_ORDERED(bp);

			bp->b_flags |= XBF_FUA | XBF_FLUSH;

		dptr = XFS_BUF_PTR(bp);

		/*

		 * Bump the cycle numbers at the start of each block