public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH 9/13] fs/xfs: Remove redundant test
@ 2008-12-21 15:40 Julia Lawall
  2008-12-21 16:01 ` Eric Sandeen
  0 siblings, 1 reply; 6+ messages in thread
From: Julia Lawall @ 2008-12-21 15:40 UTC (permalink / raw)
  To: xfs-masters, xfs, linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

In fs/cifs/cifssmb.c, pLockData is tested for being NULL at the beginning
of the function, and not reassigned subsequently.

In fs/xfs/xfs_trans_buf.c, bp is tested for being NULL just a few lines
above.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@

if (x@p1 == NULL || ...) { ... when forall
   return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
x@p2 == NULL
|
x@p2 != NULL
)

// another path to the test that is not through p1?
@s exists@
local idexpression r.x;
position r.p1,r.p2;
@@

... when != x@p1
(
x@p2 == NULL
|
x@p2 != NULL
)

@fix depends on !s@
position r.p1,r.p2;
expression x,E;
statement S1,S2;
@@

(
- if ((x@p2 != NULL) || ...)
  S1
|
- if ((x@p2 == NULL) && ...) S1
|
- BUG_ON(x@p2 == NULL);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 fs/xfs/xfs_trans_buf.c              |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 8ee2f8c..22afe29 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);

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 9/13] fs/xfs: Remove redundant test
  2008-12-21 15:40 [PATCH 9/13] fs/xfs: Remove redundant test Julia Lawall
@ 2008-12-21 16:01 ` Eric Sandeen
  2008-12-21 16:36   ` Julia Lawall
  2008-12-21 16:38   ` Julia Lawall
  0 siblings, 2 replies; 6+ messages in thread
From: Eric Sandeen @ 2008-12-21 16:01 UTC (permalink / raw)
  To: Julia Lawall; +Cc: xfs-masters, xfs, linux-kernel, kernel-janitors

Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> In fs/cifs/cifssmb.c, pLockData is tested for being NULL at the beginning
> of the function, and not reassigned subsequently.
> 
> In fs/xfs/xfs_trans_buf.c, bp is tested for being NULL just a few lines
> above.
> 
> A simplified version of the semantic patch that makes this change is as
> follows: (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> expression E;
> position p1,p2;
> @@
> 
> if (x@p1 == NULL || ...) { ... when forall
>    return ...; }
> ... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
> (
> x@p2 == NULL
> |
> x@p2 != NULL
> )
> 
> // another path to the test that is not through p1?
> @s exists@
> local idexpression r.x;
> position r.p1,r.p2;
> @@
> 
> ... when != x@p1
> (
> x@p2 == NULL
> |
> x@p2 != NULL
> )
> 
> @fix depends on !s@
> position r.p1,r.p2;
> expression x,E;
> statement S1,S2;
> @@
> 
> (
> - if ((x@p2 != NULL) || ...)
>   S1
> |
> - if ((x@p2 == NULL) && ...) S1
> |
> - BUG_ON(x@p2 == NULL);
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Looks fine to me, though a similar test under the #ifdef DEBUG can
probably also be removed.

-Eric

> ---
>  fs/xfs/xfs_trans_buf.c              |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
> index 8ee2f8c..22afe29 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);
> 
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 9/13] fs/xfs: Remove redundant test
  2008-12-21 16:01 ` Eric Sandeen
@ 2008-12-21 16:36   ` Julia Lawall
  2008-12-21 16:38   ` Julia Lawall
  1 sibling, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2008-12-21 16:36 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: xfs-masters, xfs, linux-kernel, kernel-janitors

> Looks fine to me, though a similar test under the #ifdef DEBUG can
> probably also be removed.

Indeed.  I will send an updated patch.

julia

> -Eric
> 
> > ---
> >  fs/xfs/xfs_trans_buf.c              |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
> > index 8ee2f8c..22afe29 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);
> > 
> > _______________________________________________
> > xfs mailing list
> > xfs@oss.sgi.com
> > http://oss.sgi.com/mailman/listinfo/xfs
> > 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 9/13] fs/xfs: Remove redundant test
  2008-12-21 16:01 ` Eric Sandeen
  2008-12-21 16:36   ` Julia Lawall
@ 2008-12-21 16:38   ` Julia Lawall
  2008-12-21 16:45     ` Julia Lawall
  2008-12-21 16:47     ` Eric Sandeen
  1 sibling, 2 replies; 6+ messages in thread
From: Julia Lawall @ 2008-12-21 16:38 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: xfs-masters, xfs, linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

In fs/xfs/xfs_trans_buf.c, bp is tested for being NULL just a few lines
above.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@

if (x@p1 == NULL || ...) { ... when forall
   return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
x@p2 == NULL
|
x@p2 != NULL
)

// another path to the test that is not through p1?
@s exists@
local idexpression r.x;
position r.p1,r.p2;
@@

... when != x@p1
(
x@p2 == NULL
|
x@p2 != NULL
)

@fix depends on !s@
position r.p1,r.p2;
expression x,E;
statement S1,S2;
@@

(
- if ((x@p2 != NULL) || ...)
  S1
|
- if ((x@p2 == NULL) && ...) S1
|
- BUG_ON(x@p2 == NULL);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 var/julia/linuxcopy/fs/xfs/xfs_trans_buf.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/var/linuxes/linux-next/fs/xfs/xfs_trans_buf.c b/var/julia/linuxcopy/fs/xfs/xfs_trans_buf.c
index 8ee2f8c..218829e 100644
--- a/var/linuxes/linux-next/fs/xfs/xfs_trans_buf.c
+++ b/var/julia/linuxcopy/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);

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 9/13] fs/xfs: Remove redundant test
  2008-12-21 16:38   ` Julia Lawall
@ 2008-12-21 16:45     ` Julia Lawall
  2008-12-21 16:47     ` Eric Sandeen
  1 sibling, 0 replies; 6+ messages in thread
From: Julia Lawall @ 2008-12-21 16:45 UTC (permalink / raw)
  To: Eric Sandeen; +Cc: xfs-masters, xfs, linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

In fs/xfs/xfs_trans_buf.c, bp is tested for being NULL just a few lines
above.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@

if (x@p1 == NULL || ...) { ... when forall
   return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
x@p2 == NULL
|
x@p2 != NULL
)

// another path to the test that is not through p1?
@s exists@
local idexpression r.x;
position r.p1,r.p2;
@@

... when != x@p1
(
x@p2 == NULL
|
x@p2 != NULL
)

@fix depends on !s@
position r.p1,r.p2;
expression x,E;
statement S1,S2;
@@

(
- if ((x@p2 != NULL) || ...)
  S1
|
- if ((x@p2 == NULL) && ...) S1
|
- BUG_ON(x@p2 == NULL);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 fs/xfs/xfs_trans_buf.c |    4 ++--
 1 file 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);

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 9/13] fs/xfs: Remove redundant test
  2008-12-21 16:38   ` Julia Lawall
  2008-12-21 16:45     ` Julia Lawall
@ 2008-12-21 16:47     ` Eric Sandeen
  1 sibling, 0 replies; 6+ messages in thread
From: Eric Sandeen @ 2008-12-21 16:47 UTC (permalink / raw)
  To: Julia Lawall; +Cc: xfs-masters, xfs, linux-kernel, kernel-janitors

Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> In fs/xfs/xfs_trans_buf.c, bp is tested for being NULL just a few lines
> above.
> 
> A simplified version of the semantic patch that makes this change is as
> follows: (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> expression E;
> position p1,p2;
> @@
> 
> if (x@p1 == NULL || ...) { ... when forall
>    return ...; }
> ... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
> (
> x@p2 == NULL
> |
> x@p2 != NULL
> )
> 
> // another path to the test that is not through p1?
> @s exists@
> local idexpression r.x;
> position r.p1,r.p2;
> @@
> 
> ... when != x@p1
> (
> x@p2 == NULL
> |
> x@p2 != NULL
> )
> 
> @fix depends on !s@
> position r.p1,r.p2;
> expression x,E;
> statement S1,S2;
> @@
> 
> (
> - if ((x@p2 != NULL) || ...)
>   S1
> |
> - if ((x@p2 == NULL) && ...) S1
> |
> - BUG_ON(x@p2 == NULL);
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Looks good to me, thanks.

Reviewed-by: Eric Sandeen <sandeen@sandeen.net>

> ---
>  var/julia/linuxcopy/fs/xfs/xfs_trans_buf.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/var/linuxes/linux-next/fs/xfs/xfs_trans_buf.c b/var/julia/linuxcopy/fs/xfs/xfs_trans_buf.c
> index 8ee2f8c..218829e 100644
> --- a/var/linuxes/linux-next/fs/xfs/xfs_trans_buf.c
> +++ b/var/julia/linuxcopy/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);
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2008-12-21 16:47 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-12-21 15:40 [PATCH 9/13] fs/xfs: Remove redundant test Julia Lawall
2008-12-21 16:01 ` Eric Sandeen
2008-12-21 16:36   ` Julia Lawall
2008-12-21 16:38   ` Julia Lawall
2008-12-21 16:45     ` Julia Lawall
2008-12-21 16:47     ` Eric Sandeen

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox