From: Julia Lawall <julia@diku.dk>
To: felixb@sgi.com, xfs-masters@oss.sgi.com, xfs@oss.sgi.com,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH 10/12] fs/xfs: Correct redundant test
Date: Mon, 27 Jul 2009 18:15:25 +0200 (CEST) [thread overview]
Message-ID: <Pine.LNX.4.64.0907271815060.2682@ask.diku.dk> (raw)
From: Julia Lawall <julia@diku.dk>
bp was tested for NULL a few lines before, followed by a return, and there
is no intervening modification of its value.
A simplified version of the semantic match that finds this problem is as
follows: (http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@
if (x == NULL || ...) { ... when forall
return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
*x == NULL
|
*x != NULL
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
fs/xfs/xfs_trans_buf.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 8ee2f8c..218829e 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -307,7 +307,7 @@ xfs_trans_read_buf(
return (flags & XFS_BUF_TRYLOCK) ?
EAGAIN : XFS_ERROR(ENOMEM);
- if ((bp != NULL) && (XFS_BUF_GETERROR(bp) != 0)) {
+ if (XFS_BUF_GETERROR(bp) != 0) {
xfs_ioerror_alert("xfs_trans_read_buf", mp,
bp, blkno);
error = XFS_BUF_GETERROR(bp);
@@ -315,7 +315,7 @@ xfs_trans_read_buf(
return error;
}
#ifdef DEBUG
- if (xfs_do_error && (bp != NULL)) {
+ if (xfs_do_error) {
if (xfs_error_target == target) {
if (((xfs_req_num++) % xfs_error_mod) == 0) {
xfs_buf_relse(bp);
next reply other threads:[~2009-07-27 16:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-27 16:15 Julia Lawall [this message]
2009-07-27 16:37 ` Felix Blyakher
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