fs/xfs: Correct redundant test
authorJulia Lawall <julia@diku.dk>
Mon, 27 Jul 2009 16:15:25 +0000 (18:15 +0200)
committerFelix Blyakher <felixb@sgi.com>
Fri, 31 Jul 2009 05:00:47 +0000 (00:00 -0500)
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>
Acked-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
fs/xfs/xfs_trans_buf.c

index 8ee2f8c8b0a61863c9686a7bbae9b4794616615f..218829e6a152dce6698dbb8a9a8466fda694d92d 100644 (file)
@@ -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);