xfs: remove xfs_flush_space

The only thing we need to do now when we get an ENOSPC condition during delayed
allocation reservation is flush all the other inodes with delalloc blocks on
them and retry without EOF preallocation. Remove the unneeded mess that is
xfs_flush_space() and just call xfs_flush_inodes() directly from
xfs_iomap_write_delay().

Also, change the location of the retry label to avoid trying to do EOF
preallocation because we don't want to do that at ENOSPC. This enables us to
remove the BMAPI_SYNC flag as it is no longer used.

Signed-off-by: Dave Chinner <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>

fs/xfs/xfs_iomap.c

···
 }
 
 STATIC int
-xfs_flush_space(
-	xfs_inode_t	*ip,
-	int		*fsynced,
-	int		*ioflags)
-{
-	switch (*fsynced) {
-	case 0:
-		if (ip->i_delayed_blks) {
-			xfs_iunlock(ip, XFS_ILOCK_EXCL);
-			delay(1);
-			xfs_ilock(ip, XFS_ILOCK_EXCL);
-			*fsynced = 1;
-		} else {
-			*ioflags |= BMAPI_SYNC;
-			*fsynced = 2;
-		}
-		return 0;
-	case 1:
-		*fsynced = 2;
-		*ioflags |= BMAPI_SYNC;
-		return 0;
-	case 2:
-		xfs_iunlock(ip, XFS_ILOCK_EXCL);
-		xfs_flush_inodes(ip);
-		xfs_ilock(ip, XFS_ILOCK_EXCL);
-		*fsynced = 3;
-		return 0;
-	}
-	return 1;
-}
-
-STATIC int
 xfs_cmn_err_fsblock_zero(
 	xfs_inode_t	*ip,
 	xfs_bmbt_irec_t	*imap)
···
 }
 
 /*
- * If the caller is doing a write at the end of the file,
- * then extend the allocation out to the file system's write
- * iosize.  We clean up any extra space left over when the
- * file is closed in xfs_inactive().
- *
- * For sync writes, we are flushing delayed allocate space to
- * try to make additional space available for allocation near
- * the filesystem full boundary - preallocation hurts in that
- * situation, of course.
+ * If the caller is doing a write at the end of the file, then extend the
+ * allocation out to the file system's write iosize.  We clean up any extra
+ * space left over when the file is closed in xfs_inactive().
  */
 STATIC int
 xfs_iomap_eof_want_preallocate(
···
 	int		n, error, imaps;
 
 	*prealloc = 0;
-	if ((ioflag & BMAPI_SYNC) || (offset + count) <= ip->i_size)
+	if ((offset + count) <= ip->i_size)
 		return 0;
 
 	/*
···
 	xfs_extlen_t	extsz;
 	int		nimaps;
 	xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
-	int		prealloc, fsynced = 0;
+	int		prealloc, flushed = 0;
 	int		error;
 
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
···
 	extsz = xfs_get_extsz_hint(ip);
 	offset_fsb = XFS_B_TO_FSBT(mp, offset);
 
-retry:
 	error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
 				ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
 	if (error)
 		return error;
 
+retry:
 	if (prealloc) {
 		aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
 		ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
···
 
 	/*
 	 * If bmapi returned us nothing, and if we didn't get back EDQUOT,
-	 * then we must have run out of space - flush delalloc, and retry..
+	 * then we must have run out of space - flush all other inodes with
+	 * delalloc blocks and retry without EOF preallocation.
 	 */
 	if (nimaps == 0) {
 		xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
 					ip, offset, count);
-		if (xfs_flush_space(ip, &fsynced, &ioflag))
+		if (flushed)
 			return XFS_ERROR(ENOSPC);
 
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+		xfs_flush_inodes(ip);
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+		flushed = 1;
 		error = 0;
+		prealloc = 0;
 		goto retry;
 	}
 

fs/xfs/xfs_iomap.h

···
 	BMAPI_IGNSTATE = (1 << 4),	/* ignore unwritten state on read */
 	BMAPI_DIRECT = (1 << 5),	/* direct instead of buffered write */
 	BMAPI_MMAP = (1 << 6),		/* allocate for mmap write */
-	BMAPI_SYNC = (1 << 7),		/* sync write to flush delalloc space */
-	BMAPI_TRYLOCK = (1 << 8),	/* non-blocking request */
+	BMAPI_TRYLOCK = (1 << 7),	/* non-blocking request */
 } bmapi_flags_t;