[PATCH] fs, dlm: don't do pointless NULL check and use kzalloc

[PATCH] fs, dlm: don't do pointless NULL check and use kzalloc

[Jesper Juhl]

In fs/dlm/lock.c in the dlm_scan_waiters() function there are 2 small
issues:

1) There's no need to test the return value of the allocation and do a
memset if is succeedes. Just use kzalloc() to obtain zeroed memory.

2) Since kfree() handles NULL pointers gracefully, the test of
'warned' against NULL before the kfree() after the loop is completely
pointless. Remove it.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: David Teigland <teigland@redhat.com>
---
 fs/dlm/lock.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index f71d0b5..26d6d88 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -849,9 +849,7 @@ void dlm_scan_waiters(struct dlm_ls *ls)
 
 		if (!num_nodes) {
 			num_nodes = ls->ls_num_nodes;
-			warned = kmalloc(GFP_KERNEL, num_nodes * sizeof(int));
-			if (warned)
-				memset(warned, 0, num_nodes * sizeof(int));
+			warned = kzalloc(GFP_KERNEL, num_nodes * sizeof(int));
 		}
 		if (!warned)
 			continue;
@@ -863,9 +861,7 @@ void dlm_scan_waiters(struct dlm_ls *ls)
 			  dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
 	}
 	mutex_unlock(&ls->ls_waiters_mutex);
-
-	if (warned)
-		kfree(warned);
+	kfree(warned);
 
 	if (debug_expired)
 		log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
-- 
1.7.6



-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
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[PATCH v3] fs, dlm: don't do pointless NULL check, use kzalloc and fix order of arguments

[Jesper Juhl]

In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
issues:

1) There's no need to test the return value of the allocation and do a
memset if is succeedes. Just use kzalloc() to obtain zeroed memory.

2) Since kfree() handles NULL pointers gracefully, the test of
'warned' against NULL before the kfree() after the loop is completely
pointless. Remove it.

3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to
Dr. David Alan Gilbert for pointing this out.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 fs/dlm/lock.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index f71d0b5..84c52e6 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -849,9 +849,7 @@ void dlm_scan_waiters(struct dlm_ls *ls)
 
 		if (!num_nodes) {
 			num_nodes = ls->ls_num_nodes;
-			warned = kmalloc(GFP_KERNEL, num_nodes * sizeof(int));
-			if (warned)
-				memset(warned, 0, num_nodes * sizeof(int));
+			warned = kzalloc(num_nodes * sizeof(int), GFP_KERNEL);
 		}
 		if (!warned)
 			continue;
@@ -863,9 +861,7 @@ void dlm_scan_waiters(struct dlm_ls *ls)
 			  dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid);
 	}
 	mutex_unlock(&ls->ls_waiters_mutex);
-
-	if (warned)
-		kfree(warned);
+	kfree(warned);
 
 	if (debug_expired)
 		log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us",
-- 
1.7.6


-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

Re: [PATCH v3] fs, dlm: don't do pointless NULL check, use kzalloc and fix order of arguments

[David Teigland]

On Sun, Jul 10, 2011 at 10:54:31PM +0200, Jesper Juhl wrote:
> In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
> issues:
> 
> 1) There's no need to test the return value of the allocation and do a
> memset if is succeedes. Just use kzalloc() to obtain zeroed memory.
> 
> 2) Since kfree() handles NULL pointers gracefully, the test of
> 'warned' against NULL before the kfree() after the loop is completely
> pointless. Remove it.
> 
> 3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to
> Dr. David Alan Gilbert for pointing this out.
> 
> Signed-off-by: Jesper Juhl <jj@chaosbits.net>

Thanks, I pushed this and a patch for the other swapped kmalloc to the
next branch.
Dave

Re: [PATCH v3] fs, dlm: don't do pointless NULL check, use kzalloc and fix order of arguments

[Jesper Juhl]

On Mon, 11 Jul 2011, David Teigland wrote:

> On Sun, Jul 10, 2011 at 10:54:31PM +0200, Jesper Juhl wrote:
> > In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small
> > issues:
> > 
> > 1) There's no need to test the return value of the allocation and do a
> > memset if is succeedes. Just use kzalloc() to obtain zeroed memory.
> > 
> > 2) Since kfree() handles NULL pointers gracefully, the test of
> > 'warned' against NULL before the kfree() after the loop is completely
> > pointless. Remove it.
> > 
> > 3) The arguments to kmalloc() (now kzalloc()) were swapped. Thanks to
> > Dr. David Alan Gilbert for pointing this out.
> > 
> > Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> 
> Thanks, I pushed this and a patch for the other swapped kmalloc to the
> next branch.
> Dave
> 
Ok, thanks, then I won't bother updating my patch with that other kmalloc.

-- 
Jesper Juhl <jj@chaosbits.net>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
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