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;
 }
 
 /*