[PATCH] UBIFS: use an IS_ERR test rather than a NULL test

From: Artem Bityutskiy
Date: Tue Sep 30 2008 - 03:44:02 EST


From: Julien Brunel <brunel@xxxxxxx>

In case of error, the function kthread_create returns an ERR pointer,
but never returns a NULL pointer. So a NULL test that comes before an
IS_ERR test should be deleted.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@match_bad_null_test@
expression x, E;
statement S1,S2;
@@
x = kthread_create(...)
... when != x = E
* if (x == NULL)
S1 else S2
// </smpl>

Signed-off-by: Julien Brunel <brunel@xxxxxxx>
Signed-off-by: Julia Lawall <julia@xxxxxxx>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
---
fs/ubifs/super.c | 4 ----
1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 667c72d..d87b0cf 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1032,8 +1032,6 @@ static int mount_ubifs(struct ubifs_info *c)

/* Create background thread */
c->bgt = kthread_create(ubifs_bg_thread, c, c->bgt_name);
- if (!c->bgt)
- c->bgt = ERR_PTR(-EINVAL);
if (IS_ERR(c->bgt)) {
err = PTR_ERR(c->bgt);
c->bgt = NULL;
@@ -1347,8 +1345,6 @@ static int ubifs_remount_rw(struct ubifs_info *c)

/* Create background thread */
c->bgt = kthread_create(ubifs_bg_thread, c, c->bgt_name);
- if (!c->bgt)
- c->bgt = ERR_PTR(-EINVAL);
if (IS_ERR(c->bgt)) {
err = PTR_ERR(c->bgt);
c->bgt = NULL;
--
1.5.4.1

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