From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f51.google.com (mail-pj1-f51.google.com [209.85.216.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B612F20F06E for ; Tue, 25 Feb 2025 21:14:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740518094; cv=none; b=W7G7KqoOYyr+sH5No2DiTRRYzY40sed8rgyL+gzJC/tuOtFphx5VSxybUOd/MnNh9G4vh4NGqxtA1TSvO41BtEBRz/AWTJAUHA8/ZE+XodOY1ggnjy7vFsQA+8hkhJ7s05cRlCuXBvmIInATOUnizP553FY+RJ51uDnn3jUcjQQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740518094; c=relaxed/simple; bh=n11yKJ/XUOHHHtUtLdxxZo6YMyQawd2VxE9bfT3uHmU=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=Uu6+vjFLR+aczvrO60DFXp/u7UcPy7nYT7nqaHTuyNjFWpKD4QvYveLQMgVWp5PbipxBj8HywpqcLoXyeiX2faTVEQN47uSDzzFsIEPLAaWTzkhOhJ5kSuXZVixeAoTRxTImhOnICj8/2yeJoxDA0AW/0sx+CieqXogPFjHdwZE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com; spf=fail smtp.mailfrom=purestorage.com; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b=B5xgEVTN; arc=none smtp.client-ip=209.85.216.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=purestorage.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="B5xgEVTN" Received: by mail-pj1-f51.google.com with SMTP id 98e67ed59e1d1-2fbf706c9cbso1520866a91.3 for ; Tue, 25 Feb 2025 13:14:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1740518092; x=1741122892; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=4OXvxLiWlJtD6MNQmCGa7+Dtk3fvzc2JcxyyAEw+Cl0=; b=B5xgEVTN7WRHAXcLvpvUOLdHK8FjR8jK1cOMR4jhi6w4InzhF0bTGisqqu47zkuLrj kk111Ol+pWexjX7Q1k1I7vqYNqlIfhMYcrItsJJkweToppo0RKSNv44G7FqJiH/Btf28 BEVg3p+xsUKDRIdEA5Itnm6YRDaZAu9DiSS3rSdZoQ4ir80+Hp+jdVsoj++1B9aiRZE0 IdWQ/2B5RQWHH2+oh4vRNJkttweP5hXNAAYyr53IFS3hzz6KWnaAub0hLaZ/k3n5U1TY bBqJVY/KiZKr6FnNX+owF0jeCbqViEMwzMU8bqKiZxV15GKvZLU9DW5uSrT587/TWJyp kPgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740518092; x=1741122892; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4OXvxLiWlJtD6MNQmCGa7+Dtk3fvzc2JcxyyAEw+Cl0=; b=FIwuNpmxFYyd5w/zWHvocEuoim+PoAtlF6cr0aMTVjDPiLKj633jHBf+bc5z5FvedF Lj8cdPDW78y07MS+4kHV7GBtJGy4W8o+Is+QVB4wUmKsHGIWXz9ueK4TRLHASeUH9aio eFMxVSa86H67UPNEPhcQCgt5OkCN0WwukpctgtyQootW9DuU2cUHniTrB1Y2MOJU/+rL XFx+epUbepBctxUhOaJk8dmbxUFI9Je3bGqtg3gFsKrmp1Lh1jSPw85bL1WQX8G39ICY abTERAXLTSeyYErVaLmWlLBpJBIpfU096+MFdfecQuwJkEaDO/1PuYDYx+mhgCblxy7O kcvA== X-Forwarded-Encrypted: i=1; AJvYcCXL+mBinKmXADS3A3A8Rooxro0mvX/ywOGBrwXwlZnlzVOW5Pa7sRbuNJYYgtlLAwRCmsm/Hfb8fA==@vger.kernel.org X-Gm-Message-State: AOJu0Yz7svBF7LOvKXDKiI+3XrTmSz959xH6DcfcdtRKh7et7oYBGfhJ Hv4gLuVnK3Iu2khUGvUrUqFZ2Ug0crOI9OBGammiLxZw44RmP7gz6bwNlt9tJ+8nZuaRB8QpBA2 vI+cqdzX1gcn0bXfscgumpxSghyXooTf2qvf0IA== X-Gm-Gg: ASbGncug9B95ERZWQQri0DToMyFV6bWr9POzxaZfUM5NManZsXWHjVJ2gF0qlN2EiLY mExZEeVYgJqx7LebS6GhJEwkIdOlZ7XNAm+cD0E8UXTqP47J3b6ndX4xSjQLe8Jyy9ZtHMBartE Ml8tTLPg== X-Google-Smtp-Source: AGHT+IE50MjoGcSCMnJzKG2scJXjCJKX4X7FbnEkntQnInGIq3YY2rA8EuIx8/svX3TY/zMcYPIc9lLwCO7OivRbzwQ= X-Received: by 2002:a17:90b:3b8e:b0:2ee:d372:91bd with SMTP id 98e67ed59e1d1-2fce77a6618mr11923594a91.2.1740518091913; Tue, 25 Feb 2025 13:14:51 -0800 (PST) Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250224213116.3509093-1-kbusch@meta.com> <20250224213116.3509093-10-kbusch@meta.com> In-Reply-To: <20250224213116.3509093-10-kbusch@meta.com> From: Caleb Sander Mateos Date: Tue, 25 Feb 2025 13:14:40 -0800 X-Gm-Features: AWEUYZmlDAOCvhcNkpfhcW755PQ6MyJDFj18xWwb2Ynp2yNFCT9B59GtWKB7q24 Message-ID: Subject: Re: [PATCHv5 09/11] ublk: zc register/unregister bvec To: Keith Busch Cc: ming.lei@redhat.com, asml.silence@gmail.com, axboe@kernel.dk, linux-block@vger.kernel.org, io-uring@vger.kernel.org, bernd@bsbernd.com, Keith Busch Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, Feb 24, 2025 at 1:31=E2=80=AFPM Keith Busch wrote= : > > From: Keith Busch > > Provide new operations for the user to request mapping an active request > to an io uring instance's buf_table. The user has to provide the index > it wants to install the buffer. > > A reference count is taken on the request to ensure it can't be > completed while it is active in a ring's buf_table. > > Signed-off-by: Keith Busch > --- > drivers/block/ublk_drv.c | 117 +++++++++++++++++++++++----------- > include/uapi/linux/ublk_cmd.h | 4 ++ > 2 files changed, 85 insertions(+), 36 deletions(-) > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c > index 529085181f355..a719d873e3882 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -51,6 +51,9 @@ > /* private ioctl command mirror */ > #define UBLK_CMD_DEL_DEV_ASYNC _IOC_NR(UBLK_U_CMD_DEL_DEV_ASYNC) > > +#define UBLK_IO_REGISTER_IO_BUF _IOC_NR(UBLK_U_IO_REGISTE= R_IO_BUF) > +#define UBLK_IO_UNREGISTER_IO_BUF _IOC_NR(UBLK_U_IO_UNREGISTER_IO_B= UF) > + > /* All UBLK_F_* have to be included into UBLK_F_ALL */ > #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \ > | UBLK_F_URING_CMD_COMP_IN_TASK \ > @@ -201,7 +204,7 @@ static inline struct ublksrv_io_desc *ublk_get_iod(st= ruct ublk_queue *ubq, > int tag); > static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub) > { > - return ub->dev_info.flags & UBLK_F_USER_COPY; > + return ub->dev_info.flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZE= RO_COPY); > } > > static inline bool ublk_dev_is_zoned(const struct ublk_device *ub) > @@ -581,7 +584,7 @@ static void ublk_apply_params(struct ublk_device *ub) > > static inline bool ublk_support_user_copy(const struct ublk_queue *ubq) > { > - return ubq->flags & UBLK_F_USER_COPY; > + return ubq->flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY)= ; > } > > static inline bool ublk_need_req_ref(const struct ublk_queue *ubq) > @@ -1747,6 +1750,77 @@ static inline void ublk_prep_cancel(struct io_urin= g_cmd *cmd, > io_uring_cmd_mark_cancelable(cmd, issue_flags); > } > > +static inline struct request *__ublk_check_and_get_req(struct ublk_devic= e *ub, > + struct ublk_queue *ubq, int tag, size_t offset) > +{ > + struct request *req; > + > + if (!ublk_need_req_ref(ubq)) > + return NULL; > + > + req =3D blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag); > + if (!req) > + return NULL; > + > + if (!ublk_get_req_ref(ubq, req)) > + return NULL; > + > + if (unlikely(!blk_mq_request_started(req) || req->tag !=3D tag)) > + goto fail_put; > + > + if (!ublk_rq_has_data(req)) > + goto fail_put; > + > + if (offset > blk_rq_bytes(req)) > + goto fail_put; > + > + return req; > +fail_put: > + ublk_put_req_ref(ubq, req); > + return NULL; > +} > + > +static void ublk_io_release(void *priv) > +{ > + struct request *rq =3D priv; > + struct ublk_queue *ubq =3D rq->mq_hctx->driver_data; > + > + ublk_put_req_ref(ubq, rq); > +} > + > +static int ublk_register_io_buf(struct io_uring_cmd *cmd, > + struct ublk_queue *ubq, unsigned int tag, > + const struct ublksrv_io_cmd *ub_cmd, > + unsigned int issue_flags) > +{ > + struct ublk_device *ub =3D cmd->file->private_data; > + int index =3D (int)ub_cmd->addr, ret; > + struct request *req; > + > + req =3D __ublk_check_and_get_req(ub, ubq, tag, 0); > + if (!req) > + return -EINVAL; > + > + ret =3D io_buffer_register_bvec(cmd, req, ublk_io_release, index, > + issue_flags); > + if (ret) { > + ublk_put_req_ref(ubq, req); > + return ret; > + } > + > + return 0; > +} > + > +static int ublk_unregister_io_buf(struct io_uring_cmd *cmd, > + const struct ublksrv_io_cmd *ub_cmd, > + unsigned int issue_flags) > +{ > + int index =3D (int)ub_cmd->addr; > + > + io_buffer_unregister_bvec(cmd, index, issue_flags); > + return 0; > +} > + > static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, > unsigned int issue_flags, > const struct ublksrv_io_cmd *ub_cmd) > @@ -1798,6 +1872,10 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd= *cmd, > > ret =3D -EINVAL; > switch (_IOC_NR(cmd_op)) { > + case UBLK_IO_REGISTER_IO_BUF: > + return ublk_register_io_buf(cmd, ubq, tag, ub_cmd, issue_= flags); > + case UBLK_IO_UNREGISTER_IO_BUF: > + return ublk_unregister_io_buf(cmd, ub_cmd, issue_flags); In the other cases, completion happens asynchronously by returning -EIOCBQUEUED and calling io_uring_cmd_done() when the command finishes. It looks like that's necessary because ublk_ch_uring_cmd_cb() ignores the return value from __ublk_ch_uring_cmd()/ublk_ch_uring_cmd_local(). (In the non-task-work case, ublk_ch_uring_cmd() does propagate the return value.) Maybe ublk_ch_uring_cmd_cb() should check the return value and call io_uring_cmd_done() if it's not -EIOCBQUEUED. Best, Caleb > case UBLK_IO_FETCH_REQ: > /* UBLK_IO_FETCH_REQ is only allowed before queue is setu= p */ > if (ublk_queue_ready(ubq)) { > @@ -1872,36 +1950,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd= *cmd, > return -EIOCBQUEUED; > } > > -static inline struct request *__ublk_check_and_get_req(struct ublk_devic= e *ub, > - struct ublk_queue *ubq, int tag, size_t offset) > -{ > - struct request *req; > - > - if (!ublk_need_req_ref(ubq)) > - return NULL; > - > - req =3D blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag); > - if (!req) > - return NULL; > - > - if (!ublk_get_req_ref(ubq, req)) > - return NULL; > - > - if (unlikely(!blk_mq_request_started(req) || req->tag !=3D tag)) > - goto fail_put; > - > - if (!ublk_rq_has_data(req)) > - goto fail_put; > - > - if (offset > blk_rq_bytes(req)) > - goto fail_put; > - > - return req; > -fail_put: > - ublk_put_req_ref(ubq, req); > - return NULL; > -} > - > static inline int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, > unsigned int issue_flags) > { > @@ -2527,9 +2575,6 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *c= md) > goto out_free_dev_number; > } > > - /* We are not ready to support zero copy */ > - ub->dev_info.flags &=3D ~UBLK_F_SUPPORT_ZERO_COPY; > - > ub->dev_info.nr_hw_queues =3D min_t(unsigned int, > ub->dev_info.nr_hw_queues, nr_cpu_ids); > ublk_align_max_io_size(ub); > @@ -2860,7 +2905,7 @@ static int ublk_ctrl_get_features(struct io_uring_c= md *cmd) > { > const struct ublksrv_ctrl_cmd *header =3D io_uring_sqe_cmd(cmd->s= qe); > void __user *argp =3D (void __user *)(unsigned long)header->addr; > - u64 features =3D UBLK_F_ALL & ~UBLK_F_SUPPORT_ZERO_COPY; > + u64 features =3D UBLK_F_ALL; > > if (header->len !=3D UBLK_FEATURES_LEN || !header->addr) > return -EINVAL; > diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.= h > index a8bc98bb69fce..74246c926b55f 100644 > --- a/include/uapi/linux/ublk_cmd.h > +++ b/include/uapi/linux/ublk_cmd.h > @@ -94,6 +94,10 @@ > _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) > #define UBLK_U_IO_NEED_GET_DATA \ > _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) > +#define UBLK_U_IO_REGISTER_IO_BUF \ > + _IOWR('u', 0x23, struct ublksrv_io_cmd) > +#define UBLK_U_IO_UNREGISTER_IO_BUF \ > + _IOWR('u', 0x24, struct ublksrv_io_cmd) > > /* only ABORT means that no re-fetch */ > #define UBLK_IO_RES_OK 0 > -- > 2.43.5 >