From: Kanchan Joshi <joshiiitr@gmail.com> To: "hch@infradead.org" <hch@infradead.org> Cc: Damien Le Moal <Damien.LeMoal@wdc.com>, Jens Axboe <axboe@kernel.dk>, Pavel Begunkov <asml.silence@gmail.com>, Kanchan Joshi <joshi.k@samsung.com>, "viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>, "bcrl@kvack.org" <bcrl@kvack.org>, Matthew Wilcox <willy@infradead.org>, "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-aio@kvack.org" <linux-aio@kvack.org>, "io-uring@vger.kernel.org" <io-uring@vger.kernel.org>, "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>, "linux-api@vger.kernel.org" <linux-api@vger.kernel.org>, SelvaKumar S <selvakuma.s1@samsung.com>, Nitesh Shetty <nj.shetty@samsung.com>, Javier Gonzalez <javier.gonz@samsung.com>, Johannes Thumshirn <Johannes.Thumshirn@wdc.com>, Naohiro Aota <Naohiro.Aota@wdc.com> Subject: Re: [PATCH v4 6/6] io_uring: add support for zone-append Date: Fri, 31 Jul 2020 20:37:35 +0530 Message-ID: <CA+1E3r+7ZChHK+ZH06LitijEbZ0=UhOtAzLpw4SWVY1ZN4HOSw@mail.gmail.com> (raw) In-Reply-To: <20200731130802.GA16665@infradead.org> On Fri, Jul 31, 2020 at 6:38 PM hch@infradead.org <hch@infradead.org> wrote: > > And FYI, this is what I'd do for a hacky aio-only prototype (untested): > > > diff --git a/fs/aio.c b/fs/aio.c > index 91e7cc4a9f179b..42b1934e38758b 100644 > --- a/fs/aio.c > +++ b/fs/aio.c > @@ -1438,7 +1438,10 @@ static void aio_complete_rw(struct kiocb *kiocb, long res, long res2) > } > > iocb->ki_res.res = res; > - iocb->ki_res.res2 = res2; > + if ((kiocb->ki_flags & IOCB_REPORT_OFFSET) && res > 0) > + iocb->ki_res.res2 = kiocb->ki_pos - res; > + else > + iocb->ki_res.res2 = res2; > iocb_put(iocb); > } > > @@ -1452,6 +1455,8 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb) > req->ki_flags = iocb_flags(req->ki_filp); > if (iocb->aio_flags & IOCB_FLAG_RESFD) > req->ki_flags |= IOCB_EVENTFD; > + if (iocb->aio_flags & IOCB_FLAG_REPORT_OFFSET) > + req->ki_flags |= IOCB_REPORT_OFFSET; > req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp)); > if (iocb->aio_flags & IOCB_FLAG_IOPRIO) { > /* > diff --git a/include/linux/fs.h b/include/linux/fs.h > index f5abba86107d86..522b0a3437d420 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -316,6 +316,7 @@ enum rw_hint { > #define IOCB_WRITE (1 << 6) > #define IOCB_NOWAIT (1 << 7) > #define IOCB_NOIO (1 << 9) > +#define IOCB_REPORT_OFFSET (1 << 10) > > struct kiocb { > struct file *ki_filp; > diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h > index 8387e0af0f768a..e4313d7aa3b7e7 100644 > --- a/include/uapi/linux/aio_abi.h > +++ b/include/uapi/linux/aio_abi.h > @@ -55,6 +55,7 @@ enum { > */ > #define IOCB_FLAG_RESFD (1 << 0) > #define IOCB_FLAG_IOPRIO (1 << 1) > +#define IOCB_FLAG_REPORT_OFFSET (1 << 2) > > /* read() from /dev/aio returns these structures. */ > struct io_event { Looks good, but it drops io_uring. How about two flags - 1. RWF_REPORT_OFFSET (only for aio) ----> aio fails the second one 2. RWF_REPORT_OFFSET_INDIRECT (for io_uring). ----> uring fails the first one Since these are RWF flags, they can be used by other sync/async transports also in future if need be. Either of these flags will set single IOCB_REPORT_OFFSET, which can be used by FS/Block etc (they don't have to worry how uring/aio sends it up). This is what I mean in code - diff --git a/fs/aio.c b/fs/aio.c index 91e7cc4a9f17..307dfbfb04f7 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1472,6 +1472,11 @@ static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb) ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags); if (unlikely(ret)) return ret; + /* support only direct offset */ + if (unlikely(iocb->aio_rw_flags & RWF_REPORT_OFFSET_INDIRECT)) + return -EOPNOTSUPP; + req->ki_flags &= ~IOCB_HIPRI; /* no one is going to poll for this I/O */ return 0; diff --git a/fs/io_uring.c b/fs/io_uring.c index 3e406bc1f855..5fa21644251f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2451,6 +2451,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, struct kiocb *kiocb = &req->rw.kiocb; unsigned ioprio; int ret; + rwf_t rw_flags; if (S_ISREG(file_inode(req->file)->i_mode)) req->flags |= REQ_F_ISREG; @@ -2462,9 +2463,13 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); kiocb->ki_flags = iocb_flags(kiocb->ki_filp); - ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); + rw_flags = READ_ONCE(sqe->rw_flags); + ret = kiocb_set_rw_flags(kiocb, rw_flags); if (unlikely(ret)) return ret; + /* support only indirect offset */ + if (unlikely(rw_flags & RWF_REPORT_OFFSET_DIRECT)) + return -EOPNOTSUPP; ioprio = READ_ONCE(sqe->ioprio); if (ioprio) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 8a00ba99284e..fe2f1f5c5d33 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3296,8 +3296,17 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) ki->ki_flags |= IOCB_DSYNC; if (flags & RWF_SYNC) ki->ki_flags |= (IOCB_DSYNC | IOCB_SYNC); - if (flags & RWF_APPEND) + if (flags & RWF_APPEND) { ki->ki_flags |= IOCB_APPEND; + /* + * 1. These flags do not make sense when used standalone + * 2. RWF_REPORT_OFFSET_DIRECT = report result directly (for aio) + * 3. RWF_REPORT_INDIRECT_OFFSER = use pointer (for io_uring) + * */ + if (flags & RWF_REPORT_OFFSET_DIRECT || + flags & RWF_REPORT_OFFSET_INDIRECT) + ki->ki_flags |= IOCB_REPORT_OFFSET;
next prev parent reply index Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <CGME20200724155244epcas5p2902f57e36e490ee8772da19aa9408cdc@epcas5p2.samsung.com> 2020-07-24 15:49 ` [PATCH v4 0/6] zone-append support in io-uring and aio Kanchan Joshi [not found] ` <CGME20200724155258epcas5p1a75b926950a18cd1e6c8e7a047e6c589@epcas5p1.samsung.com> 2020-07-24 15:49 ` [PATCH v4 1/6] fs: introduce FMODE_ZONE_APPEND and IOCB_ZONE_APPEND Kanchan Joshi 2020-07-24 16:34 ` Jens Axboe 2020-07-26 15:18 ` Christoph Hellwig 2020-07-28 1:49 ` Matthew Wilcox 2020-07-28 7:26 ` Christoph Hellwig [not found] ` <CGME20200724155324epcas5p18e1d3b4402d1e4a8eca87d0b56a3fa9b@epcas5p1.samsung.com> 2020-07-24 15:49 ` [PATCH v4 2/6] fs: change ki_complete interface to support 64bit ret2 Kanchan Joshi 2020-07-26 15:18 ` Christoph Hellwig [not found] ` <CGME20200724155329epcas5p345ba6bad0b8fe18056bb4bcd26c10019@epcas5p3.samsung.com> 2020-07-24 15:49 ` [PATCH v4 3/6] uio: return status with iov truncation Kanchan Joshi [not found] ` <CGME20200724155341epcas5p15bfc55927f2abb60f19784270fe8e377@epcas5p1.samsung.com> 2020-07-24 15:49 ` [PATCH v4 4/6] block: add zone append handling for direct I/O path Kanchan Joshi 2020-07-26 15:19 ` Christoph Hellwig [not found] ` <CGME20200724155346epcas5p2cfb383fe9904a45280c6145f4c13e1b4@epcas5p2.samsung.com> 2020-07-24 15:49 ` [PATCH v4 5/6] block: enable zone-append for iov_iter of bvec type Kanchan Joshi 2020-07-26 15:20 ` Christoph Hellwig [not found] ` <CGME20200724155350epcas5p3b8f1d59eda7f8fbb38c828f692d42fd6@epcas5p3.samsung.com> 2020-07-24 15:49 ` [PATCH v4 6/6] io_uring: add support for zone-append Kanchan Joshi 2020-07-24 16:29 ` Jens Axboe 2020-07-27 19:16 ` Kanchan Joshi 2020-07-27 20:34 ` Jens Axboe 2020-07-30 16:08 ` Pavel Begunkov 2020-07-30 16:13 ` Jens Axboe 2020-07-30 16:26 ` Pavel Begunkov 2020-07-30 17:16 ` Jens Axboe 2020-07-30 17:38 ` Pavel Begunkov 2020-07-30 17:51 ` Kanchan Joshi 2020-07-30 17:54 ` Jens Axboe 2020-07-30 18:25 ` Kanchan Joshi 2020-07-31 6:42 ` Damien Le Moal 2020-07-31 6:45 ` hch 2020-07-31 6:59 ` Damien Le Moal 2020-07-31 7:58 ` Kanchan Joshi 2020-07-31 8:14 ` Damien Le Moal 2020-07-31 9:14 ` hch 2020-07-31 9:34 ` Damien Le Moal 2020-07-31 9:41 ` hch 2020-07-31 10:16 ` Damien Le Moal 2020-07-31 12:51 ` hch 2020-07-31 13:08 ` hch 2020-07-31 15:07 ` Kanchan Joshi [this message] 2020-08-05 7:35 ` Damien Le Moal 2020-08-14 8:14 ` hch 2020-08-14 8:27 ` Damien Le Moal 2020-08-14 12:04 ` hch 2020-08-14 12:20 ` Damien Le Moal 2020-09-07 7:01 ` Kanchan Joshi 2020-09-08 15:18 ` hch 2020-09-24 17:19 ` Kanchan Joshi 2020-09-25 2:52 ` Damien Le Moal 2020-09-28 18:58 ` Kanchan Joshi 2020-09-29 1:24 ` Damien Le Moal 2020-09-29 18:49 ` Kanchan Joshi 2020-07-31 9:38 ` Kanchan Joshi 2020-07-31 7:08 ` Kanchan Joshi 2020-07-30 15:57 ` Pavel Begunkov
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