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>

2 files changed, 14 insertions, 13 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;
 }
 
 /*
diff --git a/drivers/mtd/nftlcore.c b/drivers/mtd/nftlcore.c
index e3f8495a94c2..fb86cacd5bdb 100644
--- a/drivers/mtd/nftlcore.c
+++ b/drivers/mtd/nftlcore.c
@@ -208,7 +208,7 @@ static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate )
         /* Normally, we force a fold to happen before we run out of free blocks completely */
         if (!desperate && nftl->numfreeEUNs < 2) {
                 DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n");
-                return 0xffff;
+                return BLOCK_NIL;
         }
 
         /* Scan for a free block */
@@ -230,11 +230,11 @@ static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate )
                         printk("Argh! No free blocks found! LastFreeEUN = %d, "
                                "FirstEUN = %d\n", nftl->LastFreeEUN,
                                le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN));
-                        return 0xffff;
+                        return BLOCK_NIL;
                 }
         } while (pot != nftl->LastFreeEUN);
 
-        return 0xffff;
+        return BLOCK_NIL;
 }
 
 static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
@@ -431,7 +431,7 @@ static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned p
 
         /* add the header so that it is now a valid chain */
         oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
-        oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = 0xffff;
+        oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL;
 
         nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8,
                        8, &retlen, (char *)&oob.u);
@@ -515,7 +515,7 @@ static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock)
         if (ChainLength < 2) {
                 printk(KERN_WARNING "No Virtual Unit Chains available for folding. "
                        "Failing request\n");
-                return 0xffff;
+                return BLOCK_NIL;
         }
 
         return NFTL_foldchain (nftl, LongestChain, pendingblock);
@@ -578,7 +578,7 @@ static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block)
                                 printk(KERN_WARNING
                                        "Infinite loop in Virtual Unit Chain 0x%x\n",
                                        thisVUC);
-                                return 0xffff;
+                                return BLOCK_NIL;
                         }
 
                         /* Skip to next block in chain */
@@ -601,7 +601,7 @@ static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block)
                         //u16 startEUN = nftl->EUNtable[thisVUC];
 
                         //printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC);
-                        writeEUN = NFTL_makefreeblock(nftl, 0xffff);
+                        writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL);
 
                         if (writeEUN == BLOCK_NIL) {
                                 /* OK, we accept that the above comment is
@@ -673,7 +673,7 @@ static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block)
 
         printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n",
                thisVUC);
-        return 0xffff;
+        return BLOCK_NIL;
 }
 
 static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,