mtd: Use BLOCK_NIL consistently in NFTL/INFTL

Use BLOCK_NIL consistently rather than sometimes 0xffff and sometimes
BLOCK_NIL.

The semantic patch that finds this issue is below
(http://www.emn.fr/x-info/coccinelle/).  On the other hand, the changes
were made by hand, in part because drivers/mtd/inftlcore.c contains dead
code that causes spatch to ignore a relevant function.  Specifically, the
function INFTL_findwriteunit contains a do-while loop, but always takes a
return that leaves the loop on the first iteration.

// <smpl>
@r exists@
identifier f,C;
@@

f(...) { ... return C; }

@s@
identifier r.C;
expression E;
@@

@@
identifier r.f,r.C,I;
expression s.E;
@@

f(...) {
 <...
(
  I
|
- E
+ C
)
 ...>
}

// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/mtd/inftlcore.c b/drivers/mtd/inftlcore.c
index 73f05227dc8c..d8cf29c01cc4 100644
--- a/drivers/mtd/inftlcore.c
+++ b/drivers/mtd/inftlcore.c
@@ -226,7 +226,7 @@ static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
 	if (!desperate && inftl->numfreeEUNs < 2) {
 		DEBUG(MTD_DEBUG_LEVEL1, "INFTL: there are too few free "
 			"EUNs (%d)\n", inftl->numfreeEUNs);
-		return 0xffff;
+		return BLOCK_NIL;
 	}
 
 	/* Scan for a free block */
@@ -281,7 +281,8 @@ static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned
 	silly = MAX_LOOPS;
 	while (thisEUN < inftl->nb_blocks) {
 		for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
-			if ((BlockMap[block] != 0xffff) || BlockDeleted[block])
+			if ((BlockMap[block] != BLOCK_NIL) ||
+			    BlockDeleted[block])
 				continue;
 
 			if (inftl_read_oob(mtd, (thisEUN * inftl->EraseSize)
@@ -525,7 +526,7 @@ static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
 			if (!silly--) {
 				printk(KERN_WARNING "INFTL: infinite loop in "
 					"Virtual Unit Chain 0x%x\n", thisVUC);
-				return 0xffff;
+				return BLOCK_NIL;
 			}
 
 			/* Skip to next block in chain */
@@ -549,7 +550,7 @@ hitused:
 			 * waiting to be picked up. We're going to have to fold
 			 * a chain to make room.
 			 */
-			thisEUN = INFTL_makefreeblock(inftl, 0xffff);
+			thisEUN = INFTL_makefreeblock(inftl, BLOCK_NIL);
 
 			/*
 			 * Hopefully we free something, lets try again.
@@ -631,7 +632,7 @@ hitused:
 
 	printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
 		"Unit Chain 0x%x\n", thisVUC);
-	return 0xffff;
+	return BLOCK_NIL;
 }
 
 /*