From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boaz Harrosh Subject: Re: [PATCH v2 09/14] block: Add an explicit bio flag for bios that own their bvec Date: Thu, 24 May 2012 19:57:34 +0300 Message-ID: <4FBE687E.1030605@panasas.com> References: <1337817771-25038-1-git-send-email-koverstreet@google.com> <1337817771-25038-10-git-send-email-koverstreet@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1337817771-25038-10-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kent Overstreet Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, neilb-l3A5Bk7waGM@public.gmane.org, drbd-dev-cunTk1MwBs8qoQakbn7OcQ@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mpatocka-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, sage-BnTBU8nroG7k1uMJSBkQmQ@public.gmane.org, yehuda-L5o5AL9CYN0tUFlbccrkMA@public.gmane.org List-Id: dm-devel.ids On 05/24/2012 03:02 AM, Kent Overstreet wrote: > This is for the new bio splitting code. When we split a bio, if the > split occured on a bvec boundry we reuse the bvec for the new bio. But > that means bio_free() can't free it, hence the explicit flag. > How do you insure that the original bio which owns the bvec is not freed before the split-out bio. Perhaps calling code needs to make sure by taking an extra ref on the original bio, or something. If so a big fat comment at bio_split is do. And I understand you did not like my suggestion of negating the meaning of the flag, so the default is zero? Please say why? Thanks Boaz > Signed-off-by: Kent Overstreet > Change-Id: I040f6b501088e882a9f013d6b6e730ff04e9c1da > --- > fs/bio.c | 3 ++- > include/linux/bio.h | 5 ----- > include/linux/blk_types.h | 1 + > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/fs/bio.c b/fs/bio.c > index fc4a168..24b1d1c 100644 > --- a/fs/bio.c > +++ b/fs/bio.c > @@ -241,7 +241,7 @@ void bio_free(struct bio *bio, struct bio_set *bs) > return; > } > > - if (bio_has_allocated_vec(bio)) > + if (bio_flagged(bio, BIO_HAS_VEC)) > bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); > > if (bio_integrity(bio)) > @@ -312,6 +312,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) > goto err_free; > > nr_iovecs = bvec_nr_vecs(idx); > + bio->bi_flags |= 1 << BIO_HAS_VEC; > } > out_set: > bio->bi_flags |= idx << BIO_POOL_OFFSET; > diff --git a/include/linux/bio.h b/include/linux/bio.h > index 35f7c4d..8dd8cae 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -84,11 +84,6 @@ static inline void *bio_data(struct bio *bio) > return NULL; > } > > -static inline int bio_has_allocated_vec(struct bio *bio) > -{ > - return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs; > -} > - > /* > * will die > */ > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index b6ddbf1..ab2252d 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -101,6 +101,7 @@ struct bio { > #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ > #define BIO_QUIET 10 /* Make BIO Quiet */ > #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ > +#define BIO_HAS_VEC 12 /* bio_free() should free bvec */ > #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) > > /* From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra.linbit.com (zimbra.linbit.com [212.69.161.123]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id EEC991019A78 for ; Fri, 25 May 2012 09:03:39 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by zimbra.linbit.com (Postfix) with ESMTP id E4D8D1B4262 for ; Fri, 25 May 2012 09:03:39 +0200 (CEST) Received: from zimbra.linbit.com ([127.0.0.1]) by localhost (zimbra.linbit.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ztM1LKIopkKt for ; Fri, 25 May 2012 09:03:39 +0200 (CEST) Received: from soda.linbit (tuerlsteher.linbit.com [86.59.100.100]) by zimbra.linbit.com (Postfix) with ESMTP id C7E251B4206 for ; Fri, 25 May 2012 09:03:39 +0200 (CEST) Resent-Message-ID: <20120525070339.GA12726@soda.linbit> Received: from natasha.panasas.com (natasha.panasas.com [67.152.220.90]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 869A81017A2C for ; Thu, 24 May 2012 19:19:05 +0200 (CEST) Message-ID: <4FBE687E.1030605@panasas.com> Date: Thu, 24 May 2012 19:57:34 +0300 From: Boaz Harrosh MIME-Version: 1.0 To: Kent Overstreet References: <1337817771-25038-1-git-send-email-koverstreet@google.com> <1337817771-25038-10-git-send-email-koverstreet@google.com> In-Reply-To: <1337817771-25038-10-git-send-email-koverstreet@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: axboe@kernel.dk, dm-devel@redhat.com, neilb@suse.de, linux-kernel@vger.kernel.org, tj@kernel.org, linux-bcache@vger.kernel.org, mpatocka@redhat.com, vgoyal@redhat.com, yehuda@hq.newdream.net, linux-fsdevel@vger.kernel.org, sage@newdream.net, agk@redhat.com, drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] [PATCH v2 09/14] block: Add an explicit bio flag for bios that own their bvec List-Id: Coordination of development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 05/24/2012 03:02 AM, Kent Overstreet wrote: > This is for the new bio splitting code. When we split a bio, if the > split occured on a bvec boundry we reuse the bvec for the new bio. But > that means bio_free() can't free it, hence the explicit flag. > How do you insure that the original bio which owns the bvec is not freed before the split-out bio. Perhaps calling code needs to make sure by taking an extra ref on the original bio, or something. If so a big fat comment at bio_split is do. And I understand you did not like my suggestion of negating the meaning of the flag, so the default is zero? Please say why? Thanks Boaz > Signed-off-by: Kent Overstreet > Change-Id: I040f6b501088e882a9f013d6b6e730ff04e9c1da > --- > fs/bio.c | 3 ++- > include/linux/bio.h | 5 ----- > include/linux/blk_types.h | 1 + > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/fs/bio.c b/fs/bio.c > index fc4a168..24b1d1c 100644 > --- a/fs/bio.c > +++ b/fs/bio.c > @@ -241,7 +241,7 @@ void bio_free(struct bio *bio, struct bio_set *bs) > return; > } > > - if (bio_has_allocated_vec(bio)) > + if (bio_flagged(bio, BIO_HAS_VEC)) > bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); > > if (bio_integrity(bio)) > @@ -312,6 +312,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) > goto err_free; > > nr_iovecs = bvec_nr_vecs(idx); > + bio->bi_flags |= 1 << BIO_HAS_VEC; > } > out_set: > bio->bi_flags |= idx << BIO_POOL_OFFSET; > diff --git a/include/linux/bio.h b/include/linux/bio.h > index 35f7c4d..8dd8cae 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -84,11 +84,6 @@ static inline void *bio_data(struct bio *bio) > return NULL; > } > > -static inline int bio_has_allocated_vec(struct bio *bio) > -{ > - return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs; > -} > - > /* > * will die > */ > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index b6ddbf1..ab2252d 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -101,6 +101,7 @@ struct bio { > #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ > #define BIO_QUIET 10 /* Make BIO Quiet */ > #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ > +#define BIO_HAS_VEC 12 /* bio_free() should free bvec */ > #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) > > /* From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boaz Harrosh Subject: Re: [PATCH v2 09/14] block: Add an explicit bio flag for bios that own their bvec Date: Thu, 24 May 2012 19:57:34 +0300 Message-ID: <4FBE687E.1030605@panasas.com> References: <1337817771-25038-1-git-send-email-koverstreet@google.com> <1337817771-25038-10-git-send-email-koverstreet@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , , , , , , , , , , , To: Kent Overstreet Return-path: In-Reply-To: <1337817771-25038-10-git-send-email-koverstreet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On 05/24/2012 03:02 AM, Kent Overstreet wrote: > This is for the new bio splitting code. When we split a bio, if the > split occured on a bvec boundry we reuse the bvec for the new bio. But > that means bio_free() can't free it, hence the explicit flag. > How do you insure that the original bio which owns the bvec is not freed before the split-out bio. Perhaps calling code needs to make sure by taking an extra ref on the original bio, or something. If so a big fat comment at bio_split is do. And I understand you did not like my suggestion of negating the meaning of the flag, so the default is zero? Please say why? Thanks Boaz > Signed-off-by: Kent Overstreet > Change-Id: I040f6b501088e882a9f013d6b6e730ff04e9c1da > --- > fs/bio.c | 3 ++- > include/linux/bio.h | 5 ----- > include/linux/blk_types.h | 1 + > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/fs/bio.c b/fs/bio.c > index fc4a168..24b1d1c 100644 > --- a/fs/bio.c > +++ b/fs/bio.c > @@ -241,7 +241,7 @@ void bio_free(struct bio *bio, struct bio_set *bs) > return; > } > > - if (bio_has_allocated_vec(bio)) > + if (bio_flagged(bio, BIO_HAS_VEC)) > bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); > > if (bio_integrity(bio)) > @@ -312,6 +312,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) > goto err_free; > > nr_iovecs = bvec_nr_vecs(idx); > + bio->bi_flags |= 1 << BIO_HAS_VEC; > } > out_set: > bio->bi_flags |= idx << BIO_POOL_OFFSET; > diff --git a/include/linux/bio.h b/include/linux/bio.h > index 35f7c4d..8dd8cae 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -84,11 +84,6 @@ static inline void *bio_data(struct bio *bio) > return NULL; > } > > -static inline int bio_has_allocated_vec(struct bio *bio) > -{ > - return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs; > -} > - > /* > * will die > */ > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index b6ddbf1..ab2252d 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -101,6 +101,7 @@ struct bio { > #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ > #define BIO_QUIET 10 /* Make BIO Quiet */ > #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ > +#define BIO_HAS_VEC 12 /* bio_free() should free bvec */ > #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) > > /* From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964842Ab2EXQ6G (ORCPT ); Thu, 24 May 2012 12:58:06 -0400 Received: from natasha.panasas.com ([67.152.220.90]:50073 "EHLO natasha.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933723Ab2EXQ6D (ORCPT ); Thu, 24 May 2012 12:58:03 -0400 Message-ID: <4FBE687E.1030605@panasas.com> Date: Thu, 24 May 2012 19:57:34 +0300 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111113 Thunderbird/8.0 MIME-Version: 1.0 To: Kent Overstreet CC: , , , , , , , , , , , , Subject: Re: [PATCH v2 09/14] block: Add an explicit bio flag for bios that own their bvec References: <1337817771-25038-1-git-send-email-koverstreet@google.com> <1337817771-25038-10-git-send-email-koverstreet@google.com> In-Reply-To: <1337817771-25038-10-git-send-email-koverstreet@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/24/2012 03:02 AM, Kent Overstreet wrote: > This is for the new bio splitting code. When we split a bio, if the > split occured on a bvec boundry we reuse the bvec for the new bio. But > that means bio_free() can't free it, hence the explicit flag. > How do you insure that the original bio which owns the bvec is not freed before the split-out bio. Perhaps calling code needs to make sure by taking an extra ref on the original bio, or something. If so a big fat comment at bio_split is do. And I understand you did not like my suggestion of negating the meaning of the flag, so the default is zero? Please say why? Thanks Boaz > Signed-off-by: Kent Overstreet > Change-Id: I040f6b501088e882a9f013d6b6e730ff04e9c1da > --- > fs/bio.c | 3 ++- > include/linux/bio.h | 5 ----- > include/linux/blk_types.h | 1 + > 3 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/fs/bio.c b/fs/bio.c > index fc4a168..24b1d1c 100644 > --- a/fs/bio.c > +++ b/fs/bio.c > @@ -241,7 +241,7 @@ void bio_free(struct bio *bio, struct bio_set *bs) > return; > } > > - if (bio_has_allocated_vec(bio)) > + if (bio_flagged(bio, BIO_HAS_VEC)) > bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); > > if (bio_integrity(bio)) > @@ -312,6 +312,7 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) > goto err_free; > > nr_iovecs = bvec_nr_vecs(idx); > + bio->bi_flags |= 1 << BIO_HAS_VEC; > } > out_set: > bio->bi_flags |= idx << BIO_POOL_OFFSET; > diff --git a/include/linux/bio.h b/include/linux/bio.h > index 35f7c4d..8dd8cae 100644 > --- a/include/linux/bio.h > +++ b/include/linux/bio.h > @@ -84,11 +84,6 @@ static inline void *bio_data(struct bio *bio) > return NULL; > } > > -static inline int bio_has_allocated_vec(struct bio *bio) > -{ > - return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs; > -} > - > /* > * will die > */ > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index b6ddbf1..ab2252d 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -101,6 +101,7 @@ struct bio { > #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ > #define BIO_QUIET 10 /* Make BIO Quiet */ > #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ > +#define BIO_HAS_VEC 12 /* bio_free() should free bvec */ > #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) > > /*