[XFS] Add back the pagebuf flag for scheduling on the data daemon. Moving

this into just a pagebuf_iodone parameter was broken as we don't have
sufficient state in all the places we need it to make the decision.

SGI Modid: 2.5.x-xfs:slinx:141626a

fs/xfs/linux/xfs_aops.c

@@ -78,6 +78,7 @@ xfs_unwritten_conv(
 				  XFS_BUF_OFFSET(bp), XFS_BUF_SIZE(bp));
 	XFS_BUF_SET_FSPRIVATE(bp, NULL);
 	XFS_BUF_CLR_IODONE_FUNC(bp);
+	XFS_BUF_UNDATAIO(bp);
 	xfs_biodone(bp);
 }
 
@@ -431,6 +432,7 @@ map_unwritten(
 	size = nblocks;		/* NB: using 64bit number here */
 	size <<= block_bits;	/* convert fsb's to byte range */
 
+	XFS_BUF_DATAIO(pb);
 	XFS_BUF_SET_SIZE(pb, size);
 	XFS_BUF_SET_OFFSET(pb, offset);
 	XFS_BUF_SET_FSPRIVATE(pb, LINVFS_GET_VP(inode)->v_fbhv);

fs/xfs/pagebuf/page_buf.c

@@ -1290,7 +1290,7 @@ bio_end_io_pagebuf(
 
 	if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
 		pb->pb_locked = 0;
-		pagebuf_iodone(pb, 0, 1);
+		pagebuf_iodone(pb, (pb->pb_flags & PBF_FS_DATAIOD), 1);
 	}
 
 	bio_put(bio);
@@ -1434,7 +1434,7 @@ pagebuf_iorequest(			/* start real I/O		*/
 
 	if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
 		pb->pb_locked = 0;
-		pagebuf_iodone(pb, 0, 0);
+		pagebuf_iodone(pb, (pb->pb_flags & PBF_FS_DATAIOD), 1);
 	}
 
 	return 0;

fs/xfs/pagebuf/page_buf.h

@@ -96,6 +96,7 @@ typedef enum page_buf_flags_e {		/* pb_flags values */
 	PBF_MAPPABLE = (1 << 9),/* use directly-addressable pages	   */
 	PBF_STALE = (1 << 10),	/* buffer has been staled, do not find it  */
 	PBF_FS_MANAGED = (1 << 11), /* filesystem controls freeing memory  */
+	PBF_FS_DATAIOD = (1 << 12), /* schedule IO completion on fs datad  */
 
 	/* flags used only as arguments to access routines */
 	PBF_LOCK = (1 << 13),	/* lock requested			   */

fs/xfs/xfs_buf.h

@@ -124,6 +124,9 @@ typedef struct page_buf_s xfs_buf_t;
 typedef struct pb_target xfs_buftarg_t;
 #define xfs_buftarg pb_target
 
+#define XFS_BUF_DATAIO(x)	((x)->pb_flags |= PBF_FS_DATAIOD)
+#define XFS_BUF_UNDATAIO(x)	((x)->pb_flags &= ~PBF_FS_DATAIOD)
+
 #define XFS_BUF_IODONE_FUNC(buf)	(buf)->pb_iodone
 #define XFS_BUF_SET_IODONE_FUNC(buf, func)	\
 			(buf)->pb_iodone = (func)
@@ -244,7 +247,7 @@ static inline void	xfs_buf_relse(page_buf_t *bp)
 
 
 #define xfs_biodone(pb)		    \
-	    pagebuf_iodone(pb, 0, 0)
+	    pagebuf_iodone(pb, (pb->pb_flags & PBF_FS_DATAIOD), 0)
 
 #define xfs_incore(buftarg,blkno,len,lockit) \
 	    pagebuf_find(buftarg, blkno ,len, lockit)