xfs: remove SYNC_IOWAIT

We want to wait for all I/O to finish when we do data integrity syncs. So
there is no reason to keep SYNC_WAIT separate from SYNC_IOWAIT. This
causes a little change in behaviour for the ENOSPC flushing code which now
does a second submission and wait of buffered I/O, but that should finish
ASAP as we already did an asynchronous writeout earlier.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Josef 'Jeff' Sipek <[e-mail]>
Reviewed-by: Eric Sandeen <[e-mail]>

fs/xfs/linux-2.6/xfs_sync.c

···
 	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 
  out_wait:
-	if (flags & SYNC_IOWAIT)
+	if (flags & SYNC_WAIT)
 		xfs_ioend_wait(ip);
 	IRELE(ip);
 	return error;
···
 {
 	int			error;
 
-	ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT|SYNC_IOWAIT)) == 0);
+	ASSERT((flags & ~(SYNC_TRYLOCK|SYNC_WAIT)) == 0);
 
 	error = xfs_inode_ag_iterator(mp, xfs_sync_inode_data, flags,
 				      XFS_ICI_NO_TAG);
···
 	xfs_filestream_flush(mp);
 
 	/* push and block */
-	xfs_sync_data(mp, SYNC_WAIT|SYNC_IOWAIT);
+	xfs_sync_data(mp, SYNC_WAIT);
 	xfs_qm_sync(mp, SYNC_WAIT);
 
 	/* write superblock and hoover up shutdown errors */
···
 {
 	struct inode	*inode = arg;
 	xfs_sync_data(mp, SYNC_TRYLOCK);
-	xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_IOWAIT);
+	xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
 	iput(inode);
 }
 

fs/xfs/linux-2.6/xfs_sync.h

···
 
 #define SYNC_WAIT		0x0004	/* wait for i/o to complete */
 #define SYNC_BDFLUSH		0x0008	/* BDFLUSH is calling -- don't block */
-#define SYNC_IOWAIT		0x0010  /* wait for all I/O to complete */
 #define SYNC_TRYLOCK		0x0020  /* only try to lock inodes */
 
 int xfs_syncd_init(struct xfs_mount *mp);