We'll need to get rid of the BLKDEV_IFL_BARRIER flag, and to facilitate
that and to make the interface less confusing pass all flags explicitly.

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

Index: linux-2.6/fs/ext4/mballoc.c
===================================================================
--- linux-2.6.orig/fs/ext4/mballoc.c	2010-08-17 15:56:00.337259833 +0200
+++ linux-2.6/fs/ext4/mballoc.c	2010-08-17 15:59:09.490005395 +0200
@@ -2588,7 +2588,10 @@ static void release_blocks_on_commit(jou
 			trace_ext4_discard_blocks(sb,
 					(unsigned long long)discard_block,
 					entry->count);
-			ret = sb_issue_discard(sb, discard_block, entry->count);
+			ret = sb_issue_discard(sb, discard_block, entry->count,
+						GFP_NOFS,
+						BLKDEV_IFL_WAIT |
+						BLKDEV_IFL_BARRIER);
 			if (ret == EOPNOTSUPP) {
 				ext4_warning(sb,
 					"discard not supported, disabling");
Index: linux-2.6/fs/fat/fatent.c
===================================================================
--- linux-2.6.orig/fs/fat/fatent.c	2010-08-17 15:56:00.351254455 +0200
+++ linux-2.6/fs/fat/fatent.c	2010-08-17 15:58:54.980023211 +0200
@@ -577,7 +577,9 @@ int fat_free_clusters(struct inode *inod
 
 				sb_issue_discard(sb,
 					fat_clus_to_blknr(sbi, first_cl),
-					nr_clus * sbi->sec_per_clus);
+					nr_clus * sbi->sec_per_clus,
+					GFP_NOFS,
+					BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
 
 				first_cl = cluster;
 			}
Index: linux-2.6/include/linux/blkdev.h
===================================================================
--- linux-2.6.orig/include/linux/blkdev.h	2010-08-17 15:55:24.299003653 +0200
+++ linux-2.6/include/linux/blkdev.h	2010-08-17 15:58:49.351006024 +0200
@@ -877,13 +877,12 @@ extern int blkdev_issue_discard(struct b
 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 			sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
-static inline int sb_issue_discard(struct super_block *sb,
-				   sector_t block, sector_t nr_blocks)
+static inline int sb_issue_discard(struct super_block *sb, sector_t block,
+		sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
 {
-	block <<= (sb->s_blocksize_bits - 9);
-	nr_blocks <<= (sb->s_blocksize_bits - 9);
-	return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_NOFS,
-				   BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
+	return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
+				    nr_blocks << (sb->s_blocksize_bits - 9),
+				    gfp_mask, flags);
 }
 
 extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);