From patchwork Sat Jun 27 07:55:32 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julia Lawall X-Patchwork-Id: 29226 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by bilbo.ozlabs.org (Postfix) with ESMTPS id 10F4BB70AD for ; Sat, 27 Jun 2009 18:15:19 +1000 (EST) Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1MKT2G-0004pI-HX; Sat, 27 Jun 2009 08:13:20 +0000 Received: from mgw1.diku.dk ([130.225.96.91]) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MKT1x-0002Wy-BH for linux-mtd@lists.infradead.org; Sat, 27 Jun 2009 08:13:16 +0000 Received: from localhost (localhost [127.0.0.1]) by mgw1.diku.dk (Postfix) with ESMTP id E8CCB52C47D; Sat, 27 Jun 2009 09:55:34 +0200 (CEST) X-Virus-Scanned: amavisd-new at diku.dk Received: from mgw1.diku.dk ([127.0.0.1]) by localhost (mgw1.diku.dk [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id rIeOV5Xz46FN; Sat, 27 Jun 2009 09:55:32 +0200 (CEST) Received: from nhugin.diku.dk (nhugin.diku.dk [130.225.96.140]) by mgw1.diku.dk (Postfix) with ESMTP id 62EC452C324; Sat, 27 Jun 2009 09:55:32 +0200 (CEST) Received: from ask.diku.dk (ask.diku.dk [130.225.96.225]) by nhugin.diku.dk (Postfix) with ESMTP id 0EC916DF823; Sat, 27 Jun 2009 09:55:31 +0200 (CEST) Received: by ask.diku.dk (Postfix, from userid 3767) id 4CB4715474D; Sat, 27 Jun 2009 09:55:32 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by ask.diku.dk (Postfix) with ESMTP id 4A4A715411A; Sat, 27 Jun 2009 09:55:32 +0200 (CEST) Date: Sat, 27 Jun 2009 09:55:32 +0200 (CEST) From: Julia Lawall To: dwmw2@infradead.org, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] drivers/mtd: use BLOCK_NIL Message-ID: MIME-Version: 1.0 X-Spam-Score: 0.0 (/) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Julia Lawall 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. // @r exists@ identifier f,C; @@ f(...) { ... return C; } @s@ identifier r.C; expression E; @@ #define C E @@ identifier r.f,r.C,I; expression s.E; @@ f(...) { <... ( I | - E + C ) ...> } // Signed-off-by: Julia Lawall --- drivers/mtd/inftlcore.c | 11 ++++++----- drivers/mtd/nftlcore.c | 16 ++++++++-------- 2 files changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/mtd/inftlcore.c b/drivers/mtd/inftlcore.c index 73f0522..d8cf29c 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 e3f8495..fb86cac 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,