[PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Danil Kipnis]

Kbuild test robot reports a smatch warning:
drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting

To get rid of the warning, move the while_each_path() macro to a newline.
Rename the macro to end_each_path() to avoid the "while should follow close
brace '}'" checkpatch error.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")

Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Reported-by: kbuild test robot <lkp@intel.com>
---
 v1->v2 Add fixes line
 drivers/infiniband/ulp/rtrs/rtrs-clt.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 468fdd0d8713..0fa3a229d90e 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -734,7 +734,7 @@ struct path_it {
 			  (it)->i < (it)->clt->paths_num;		\
 	     (it)->i++)
 
-#define while_each_path(it)						\
+#define end_each_path(it)						\
 	path_it_deinit(it);						\
 	rcu_read_unlock();						\
 	}
@@ -1193,7 +1193,8 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
 		/* Success path */
 		rtrs_clt_inc_failover_cnt(alive_sess->stats);
 		break;
-	} while_each_path(&it);
+	}
+	end_each_path(&it);
 
 	return err;
 }
@@ -2887,7 +2888,8 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		}
 		/* Success path */
 		break;
-	} while_each_path(&it);
+	}
+	end_each_path(&it);
 
 	return err;
 }
-- 
2.25.1

Re: [PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Bart Van Assche]

On 2020-05-19 04:29, Danil Kipnis wrote:
> Kbuild test robot reports a smatch warning:
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting
> 
> To get rid of the warning, move the while_each_path() macro to a newline.
> Rename the macro to end_each_path() to avoid the "while should follow close
> brace '}'" checkpatch error.
> 
> Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
> 
> Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> Reported-by: kbuild test robot <lkp@intel.com>
> ---
>  v1->v2 Add fixes line
>  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> index 468fdd0d8713..0fa3a229d90e 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> @@ -734,7 +734,7 @@ struct path_it {
>  			  (it)->i < (it)->clt->paths_num;		\
>  	     (it)->i++)
>  
> -#define while_each_path(it)						\
> +#define end_each_path(it)						\
>  	path_it_deinit(it);						\
>  	rcu_read_unlock();						\
>  	}
> @@ -1193,7 +1193,8 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
>  		/* Success path */
>  		rtrs_clt_inc_failover_cnt(alive_sess->stats);
>  		break;
> -	} while_each_path(&it);
> +	}
> +	end_each_path(&it);
>  
>  	return err;
>  }
> @@ -2887,7 +2888,8 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
>  		}
>  		/* Success path */
>  		break;
> -	} while_each_path(&it);
> +	}
> +	end_each_path(&it);
>  
>  	return err;
>  }

I don't like the do_each_path() and end_each_path() macros because these do not
follow the pattern that is used elsewhere in the kernel to use a single macro
to iterate over a custom container. Has it been considered to combine these two
macros into a single macro, e.g. something like the following (untested) patch?


Subject: [PATCH] Combine while_each_path() and do_each_path() into
 for_each_path()

---
 drivers/infiniband/ulp/rtrs/rtrs-clt.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 468fdd0d8713..8dfa56dc32bc 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -727,18 +727,13 @@ struct path_it {
 	struct rtrs_clt_sess *(*next_path)(struct path_it *it);
 };

-#define do_each_path(path, clt, it) {					\
-	path_it_init(it, clt);						\
-	rcu_read_lock();						\
-	for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&		\
-			  (it)->i < (it)->clt->paths_num;		\
+#define for_each_path(path, clt, it)					\
+	for (path_it_init((it), (clt)), rcu_read_lock(), (it)->i = 0;	\
+	     (((path) = ((it)->next_path)(it)) &&			\
+	      (it)->i < (it)->clt->paths_num) ||			\
+		     (path_it_deinit(it), rcu_read_unlock(), 0);	\
 	     (it)->i++)

-#define while_each_path(it)						\
-	path_it_deinit(it);						\
-	rcu_read_unlock();						\
-	}
-
 /**
  * list_next_or_null_rr_rcu - get next list element in round-robin fashion.
  * @head:	the head for the list.
@@ -1177,7 +1172,7 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
 	int err = -ECONNABORTED;
 	struct path_it it;

-	do_each_path(alive_sess, clt, &it) {
+	for_each_path(alive_sess, clt, &it) {
 		if (unlikely(READ_ONCE(alive_sess->state) !=
 			     RTRS_CLT_CONNECTED))
 			continue;
@@ -1193,7 +1188,7 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
 		/* Success path */
 		rtrs_clt_inc_failover_cnt(alive_sess->stats);
 		break;
-	} while_each_path(&it);
+	}

 	return err;
 }
@@ -2862,7 +2857,7 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		dma_dir = DMA_TO_DEVICE;
 	}

-	do_each_path(sess, clt, &it) {
+	for_each_path(sess, clt, &it) {
 		if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED))
 			continue;

@@ -2887,7 +2882,7 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		}
 		/* Success path */
 		break;
-	} while_each_path(&it);
+	}

 	return err;
 }

Re: [PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Jason Gunthorpe]

On Tue, May 19, 2020 at 07:29:15AM -0700, Bart Van Assche wrote:
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> index 468fdd0d8713..8dfa56dc32bc 100644
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> @@ -727,18 +727,13 @@ struct path_it {
>  	struct rtrs_clt_sess *(*next_path)(struct path_it *it);
>  };
> 
> -#define do_each_path(path, clt, it) {					\
> -	path_it_init(it, clt);						\
> -	rcu_read_lock();						\
> -	for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&		\
> -			  (it)->i < (it)->clt->paths_num;		\
> +#define for_each_path(path, clt, it)					\
> +	for (path_it_init((it), (clt)), rcu_read_lock(), (it)->i = 0;	\
> +	     (((path) = ((it)->next_path)(it)) &&			\
> +	      (it)->i < (it)->clt->paths_num) ||			\
> +		     (path_it_deinit(it), rcu_read_unlock(), 0);	\
>  	     (it)->i++)

That is nicer, even better to write it with some inlines..

Jason

Re: [PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Danil Kipnis]

On Wed, May 20, 2020 at 1:38 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
>
> On Tue, May 19, 2020 at 07:29:15AM -0700, Bart Van Assche wrote:
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > index 468fdd0d8713..8dfa56dc32bc 100644
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > @@ -727,18 +727,13 @@ struct path_it {
> >       struct rtrs_clt_sess *(*next_path)(struct path_it *it);
> >  };
> >
> > -#define do_each_path(path, clt, it) {                                        \
> > -     path_it_init(it, clt);                                          \
> > -     rcu_read_lock();                                                \
> > -     for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&           \
> > -                       (it)->i < (it)->clt->paths_num;               \
> > +#define for_each_path(path, clt, it)                                 \
> > +     for (path_it_init((it), (clt)), rcu_read_lock(), (it)->i = 0;   \
> > +          (((path) = ((it)->next_path)(it)) &&                       \
> > +           (it)->i < (it)->clt->paths_num) ||                        \
> > +                  (path_it_deinit(it), rcu_read_unlock(), 0);        \
> >            (it)->i++)
>
> That is nicer, even better to write it with some inlines..

You mean pass a callback to an inline function that would iterate?
>
> Jason

Re: [PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Jason Gunthorpe]

On Wed, May 20, 2020 at 12:04:28PM +0200, Danil Kipnis wrote:
> On Wed, May 20, 2020 at 1:38 AM Jason Gunthorpe <jgg@ziepe.ca> wrote:
> >
> > On Tue, May 19, 2020 at 07:29:15AM -0700, Bart Van Assche wrote:
> > > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > > index 468fdd0d8713..8dfa56dc32bc 100644
> > > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > > @@ -727,18 +727,13 @@ struct path_it {
> > >       struct rtrs_clt_sess *(*next_path)(struct path_it *it);
> > >  };
> > >
> > > -#define do_each_path(path, clt, it) {                                        \
> > > -     path_it_init(it, clt);                                          \
> > > -     rcu_read_lock();                                                \
> > > -     for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&           \
> > > -                       (it)->i < (it)->clt->paths_num;               \
> > > +#define for_each_path(path, clt, it)                                 \
> > > +     for (path_it_init((it), (clt)), rcu_read_lock(), (it)->i = 0;   \
> > > +          (((path) = ((it)->next_path)(it)) &&                       \
> > > +           (it)->i < (it)->clt->paths_num) ||                        \
> > > +                  (path_it_deinit(it), rcu_read_unlock(), 0);        \
> > >            (it)->i++)
> >
> > That is nicer, even better to write it with some inlines..
> 
> You mean pass a callback to an inline function that would iterate?

no, just wrap some of that logic embedded in the for statement in some
inlines, not sure

Jason

[PATCH] RDMA/rtrs: get rid of the do_next_path while_next_path macros

[Danil Kipnis]

The macros do_each_path/while_each_path lead to a smatch warning:
drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting

Also checkpatch complains:
ERROR: Macros with multiple statements should be enclosed in a do - while loop

The macros are used only in two places: for a normal IO path and for the
failover path triggered after errors.

Get rid of the macros and just use a for loop iterating over the list
of paths in both places. It is easier to read and also less lines of code.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
---
 drivers/infiniband/ulp/rtrs/rtrs-clt.c | 29 ++++++++++++--------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
index 468fdd0d8713..45ea5aa5f406 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
@@ -727,18 +727,6 @@ struct path_it {
 	struct rtrs_clt_sess *(*next_path)(struct path_it *it);
 };
 
-#define do_each_path(path, clt, it) {					\
-	path_it_init(it, clt);						\
-	rcu_read_lock();						\
-	for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&		\
-			  (it)->i < (it)->clt->paths_num;		\
-	     (it)->i++)
-
-#define while_each_path(it)						\
-	path_it_deinit(it);						\
-	rcu_read_unlock();						\
-	}
-
 /**
  * list_next_or_null_rr_rcu - get next list element in round-robin fashion.
  * @head:	the head for the list.
@@ -1177,7 +1165,10 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
 	int err = -ECONNABORTED;
 	struct path_it it;
 
-	do_each_path(alive_sess, clt, &it) {
+	rcu_read_lock();
+	for (path_it_init(&it, clt);
+	     (alive_sess = it.next_path(&it)) && it.i < it.clt->paths_num;
+	     it.i++) {
 		if (unlikely(READ_ONCE(alive_sess->state) !=
 			     RTRS_CLT_CONNECTED))
 			continue;
@@ -1193,7 +1184,9 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
 		/* Success path */
 		rtrs_clt_inc_failover_cnt(alive_sess->stats);
 		break;
-	} while_each_path(&it);
+	}
+	path_it_deinit(&it);
+	rcu_read_unlock();
 
 	return err;
 }
@@ -2862,7 +2855,9 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		dma_dir = DMA_TO_DEVICE;
 	}
 
-	do_each_path(sess, clt, &it) {
+	rcu_read_lock();
+	for (path_it_init(&it, clt);
+	     (sess = it.next_path(&it)) && it.i < it.clt->paths_num; it.i++) {
 		if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED))
 			continue;
 
@@ -2887,7 +2882,9 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
 		}
 		/* Success path */
 		break;
-	} while_each_path(&it);
+	}
+	path_it_deinit(&it);
+	rcu_read_unlock();
 
 	return err;
 }
-- 
2.25.1

Re: [PATCH] RDMA/rtrs: get rid of the do_next_path while_next_path macros

[Jason Gunthorpe]

On Fri, May 22, 2020 at 07:39:24AM +0200, Danil Kipnis wrote:
> The macros do_each_path/while_each_path lead to a smatch warning:
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
> drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting
> 
> Also checkpatch complains:
> ERROR: Macros with multiple statements should be enclosed in a do - while loop
> 
> The macros are used only in two places: for a normal IO path and for the
> failover path triggered after errors.
> 
> Get rid of the macros and just use a for loop iterating over the list
> of paths in both places. It is easier to read and also less lines of code.
> 
> Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
> Reported-by: kbuild test robot <lkp@intel.com>
> Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 29 ++++++++++++--------------
>  1 file changed, 13 insertions(+), 16 deletions(-)

Applied to for-next, thanks

Jason

Re: [PATCH v2] rtrs-clt: silence kbuild test inconsistent intenting smatch warning

[Danil Kipnis]

Hi Bart,

On Tue, May 19, 2020 at 4:29 PM Bart Van Assche <bvanassche@acm.org> wrote:
>
> On 2020-05-19 04:29, Danil Kipnis wrote:
> > Kbuild test robot reports a smatch warning:
> > drivers/infiniband/ulp/rtrs/rtrs-clt.c:1196 rtrs_clt_failover_req() warn: inconsistent indenting
> > drivers/infiniband/ulp/rtrs/rtrs-clt.c:2890 rtrs_clt_request() warn: inconsistent indenting
> >
> > To get rid of the warning, move the while_each_path() macro to a newline.
> > Rename the macro to end_each_path() to avoid the "while should follow close
> > brace '}'" checkpatch error.
> >
> > Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
> >
> > Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
> > Reported-by: kbuild test robot <lkp@intel.com>
> > ---
> >  v1->v2 Add fixes line
> >  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > index 468fdd0d8713..0fa3a229d90e 100644
> > --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> > @@ -734,7 +734,7 @@ struct path_it {
> >                         (it)->i < (it)->clt->paths_num;               \
> >            (it)->i++)
> >
> > -#define while_each_path(it)                                          \
> > +#define end_each_path(it)                                            \
> >       path_it_deinit(it);                                             \
> >       rcu_read_unlock();                                              \
> >       }
> > @@ -1193,7 +1193,8 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
> >               /* Success path */
> >               rtrs_clt_inc_failover_cnt(alive_sess->stats);
> >               break;
> > -     } while_each_path(&it);
> > +     }
> > +     end_each_path(&it);
> >
> >       return err;
> >  }
> > @@ -2887,7 +2888,8 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
> >               }
> >               /* Success path */
> >               break;
> > -     } while_each_path(&it);
> > +     }
> > +     end_each_path(&it);
> >
> >       return err;
> >  }
>
> I don't like the do_each_path() and end_each_path() macros because these do not
> follow the pattern that is used elsewhere in the kernel to use a single macro
> to iterate over a custom container. Has it been considered to combine these two
> macros into a single macro, e.g. something like the following (untested) patch?
>
>
> Subject: [PATCH] Combine while_each_path() and do_each_path() into
>  for_each_path()
>
> ---
>  drivers/infiniband/ulp/rtrs/rtrs-clt.c | 23 +++++++++--------------
>  1 file changed, 9 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> index 468fdd0d8713..8dfa56dc32bc 100644
> --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c
> @@ -727,18 +727,13 @@ struct path_it {
>         struct rtrs_clt_sess *(*next_path)(struct path_it *it);
>  };
>
> -#define do_each_path(path, clt, it) {                                  \
> -       path_it_init(it, clt);                                          \
> -       rcu_read_lock();                                                \
> -       for ((it)->i = 0; ((path) = ((it)->next_path)(it)) &&           \
> -                         (it)->i < (it)->clt->paths_num;               \
> +#define for_each_path(path, clt, it)                                   \
> +       for (path_it_init((it), (clt)), rcu_read_lock(), (it)->i = 0;   \
> +            (((path) = ((it)->next_path)(it)) &&                       \
> +             (it)->i < (it)->clt->paths_num) ||                        \
> +                    (path_it_deinit(it), rcu_read_unlock(), 0);        \
>              (it)->i++)
>
> -#define while_each_path(it)                                            \
> -       path_it_deinit(it);                                             \
> -       rcu_read_unlock();                                              \
> -       }
> -
>  /**
>   * list_next_or_null_rr_rcu - get next list element in round-robin fashion.
>   * @head:      the head for the list.
> @@ -1177,7 +1172,7 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
>         int err = -ECONNABORTED;
>         struct path_it it;
>
> -       do_each_path(alive_sess, clt, &it) {
> +       for_each_path(alive_sess, clt, &it) {
>                 if (unlikely(READ_ONCE(alive_sess->state) !=
>                              RTRS_CLT_CONNECTED))
>                         continue;
> @@ -1193,7 +1188,7 @@ static int rtrs_clt_failover_req(struct rtrs_clt *clt,
>                 /* Success path */
>                 rtrs_clt_inc_failover_cnt(alive_sess->stats);
>                 break;
> -       } while_each_path(&it);
> +       }
>
>         return err;
>  }
> @@ -2862,7 +2857,7 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
>                 dma_dir = DMA_TO_DEVICE;
>         }
>
> -       do_each_path(sess, clt, &it) {
> +       for_each_path(sess, clt, &it) {
>                 if (unlikely(READ_ONCE(sess->state) != RTRS_CLT_CONNECTED))
>                         continue;
>
> @@ -2887,7 +2882,7 @@ int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
>                 }
>                 /* Success path */
>                 break;
> -       } while_each_path(&it);
> +       }
>
>         return err;
>  }

This does look better. Will run it through tests.