xfs: remove XFS_IO_INVALID

The invalid state isn't any different from a hole, so merge the two
states.  Use the more descriptive hole name, but keep it as the first
value of the enum to catch uninitialized fields.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_aops.c

@@ -917,7 +917,7 @@ xfs_vm_writepage(
 	struct writeback_control *wbc)
 {
 	struct xfs_writepage_ctx wpc = {
-		.io_type = XFS_IO_INVALID,
+		.io_type = XFS_IO_HOLE,
 	};
 	int			ret;
 
@@ -933,7 +933,7 @@ xfs_vm_writepages(
 	struct writeback_control *wbc)
 {
 	struct xfs_writepage_ctx wpc = {
-		.io_type = XFS_IO_INVALID,
+		.io_type = XFS_IO_HOLE,
 	};
 	int			ret;
 

fs/xfs/xfs_aops.h

@@ -12,21 +12,19 @@ extern struct bio_set xfs_ioend_bioset;
  * Types of I/O for bmap clustering and I/O completion tracking.
  */
 enum {
-	XFS_IO_INVALID,		/* initial state */
+	XFS_IO_HOLE,		/* covers region without any block allocation */
 	XFS_IO_DELALLOC,	/* covers delalloc region */
 	XFS_IO_UNWRITTEN,	/* covers allocated but uninitialized data */
 	XFS_IO_OVERWRITE,	/* covers already allocated extent */
 	XFS_IO_COW,		/* covers copy-on-write extent */
-	XFS_IO_HOLE,		/* covers region without any block allocation */
 };
 
 #define XFS_IO_TYPES \
-	{ XFS_IO_INVALID,		"invalid" }, \
-	{ XFS_IO_DELALLOC,		"delalloc" }, \
-	{ XFS_IO_UNWRITTEN,		"unwritten" }, \
-	{ XFS_IO_OVERWRITE,		"overwrite" }, \
-	{ XFS_IO_COW,			"CoW" }, \
-	{ XFS_IO_HOLE,			"hole" }
+	{ XFS_IO_HOLE,			"hole" },	\
+	{ XFS_IO_DELALLOC,		"delalloc" },	\
+	{ XFS_IO_UNWRITTEN,		"unwritten" },	\
+	{ XFS_IO_OVERWRITE,		"overwrite" },	\
+	{ XFS_IO_COW,			"CoW" }
 
 /*
  * Structure for buffered I/O completions.