From: Jens Axboe <axboe@kernel.dk> To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, Jens Axboe <axboe@kernel.dk> Subject: [PATCH 03/18] block: add bio_set_polled() helper Date: Tue, 29 Jan 2019 12:26:47 -0700 [thread overview] Message-ID: <20190129192702.3605-4-axboe@kernel.dk> (raw) In-Reply-To: <20190129192702.3605-1-axboe@kernel.dk> For the upcoming async polled IO, we can't sleep allocating requests. If we do, then we introduce a deadlock where the submitter already has async polled IO in-flight, but can't wait for them to complete since polled requests must be active found and reaped. Utilize the helper in the blockdev DIRECT_IO code. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> --- fs/block_dev.c | 4 ++-- include/linux/bio.h | 14 ++++++++++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index f18d076a2596..392e2bfb636f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -247,7 +247,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, task_io_account_write(ret); } if (iocb->ki_flags & IOCB_HIPRI) - bio.bi_opf |= REQ_HIPRI; + bio_set_polled(&bio, iocb); qc = submit_bio(&bio); for (;;) { @@ -415,7 +415,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); if (!nr_pages) { if (iocb->ki_flags & IOCB_HIPRI) - bio->bi_opf |= REQ_HIPRI; + bio_set_polled(bio, iocb); qc = submit_bio(bio); WRITE_ONCE(iocb->ki_cookie, qc); diff --git a/include/linux/bio.h b/include/linux/bio.h index 7380b094dcca..f6f0a2b3cbc8 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -823,5 +823,19 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page, #endif /* CONFIG_BLK_DEV_INTEGRITY */ +/* + * Mark a bio as polled. Note that for async polled IO, the caller must + * expect -EWOULDBLOCK if we cannot allocate a request (or other resources). + * We cannot block waiting for requests on polled IO, as those completions + * must be found by the caller. This is different than IRQ driven IO, where + * it's safe to wait for IO to complete. + */ +static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) +{ + bio->bi_opf |= REQ_HIPRI; + if (!is_sync_kiocb(kiocb)) + bio->bi_opf |= REQ_NOWAIT; +} + #endif /* CONFIG_BLOCK */ #endif /* __LINUX_BIO_H */ -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Jens Axboe <axboe@kernel.dk> To: linux-aio@kvack.org, linux-block@vger.kernel.org, linux-api@vger.kernel.org Cc: hch@lst.de, jmoyer@redhat.com, avi@scylladb.com, jannh@google.com, Jens Axboe <axboe@kernel.dk> Subject: [PATCH 03/18] block: add bio_set_polled() helper Date: Tue, 29 Jan 2019 12:26:47 -0700 [thread overview] Message-ID: <20190129192702.3605-4-axboe@kernel.dk> (raw) In-Reply-To: <20190129192702.3605-1-axboe@kernel.dk> For the upcoming async polled IO, we can't sleep allocating requests. If we do, then we introduce a deadlock where the submitter already has async polled IO in-flight, but can't wait for them to complete since polled requests must be active found and reaped. Utilize the helper in the blockdev DIRECT_IO code. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> --- fs/block_dev.c | 4 ++-- include/linux/bio.h | 14 ++++++++++++++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index f18d076a2596..392e2bfb636f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -247,7 +247,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, task_io_account_write(ret); } if (iocb->ki_flags & IOCB_HIPRI) - bio.bi_opf |= REQ_HIPRI; + bio_set_polled(&bio, iocb); qc = submit_bio(&bio); for (;;) { @@ -415,7 +415,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); if (!nr_pages) { if (iocb->ki_flags & IOCB_HIPRI) - bio->bi_opf |= REQ_HIPRI; + bio_set_polled(bio, iocb); qc = submit_bio(bio); WRITE_ONCE(iocb->ki_cookie, qc); diff --git a/include/linux/bio.h b/include/linux/bio.h index 7380b094dcca..f6f0a2b3cbc8 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -823,5 +823,19 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page, #endif /* CONFIG_BLK_DEV_INTEGRITY */ +/* + * Mark a bio as polled. Note that for async polled IO, the caller must + * expect -EWOULDBLOCK if we cannot allocate a request (or other resources). + * We cannot block waiting for requests on polled IO, as those completions + * must be found by the caller. This is different than IRQ driven IO, where + * it's safe to wait for IO to complete. + */ +static inline void bio_set_polled(struct bio *bio, struct kiocb *kiocb) +{ + bio->bi_opf |= REQ_HIPRI; + if (!is_sync_kiocb(kiocb)) + bio->bi_opf |= REQ_NOWAIT; +} + #endif /* CONFIG_BLOCK */ #endif /* __LINUX_BIO_H */ -- 2.17.1 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: <a href=mailto:"aart@kvack.org">aart@kvack.org</a>
next prev parent reply other threads:[~2019-01-29 19:27 UTC|newest] Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-01-29 19:26 [PATCHSET v9] io_uring IO interface Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 01/18] fs: add an iopoll method to struct file_operations Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 02/18] block: wire up block device iopoll method Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` Jens Axboe [this message] 2019-01-29 19:26 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-01-29 19:26 ` [PATCH 04/18] iomap: wire up the iopoll method Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 05/18] Add io_uring IO interface Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 06/18] io_uring: add fsync support Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 07/18] io_uring: support for IO polling Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 20:47 ` Jann Horn 2019-01-29 20:47 ` Jann Horn 2019-01-29 20:56 ` Jens Axboe 2019-01-29 20:56 ` Jens Axboe 2019-01-29 21:10 ` Jann Horn 2019-01-29 21:10 ` Jann Horn 2019-01-29 21:33 ` Jens Axboe 2019-01-29 21:33 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 08/18] fs: add fget_many() and fput_many() Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 09/18] io_uring: use fget/fput_many() for file references Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 23:31 ` Jann Horn 2019-01-29 23:31 ` Jann Horn 2019-01-29 23:44 ` Jens Axboe 2019-01-29 23:44 ` Jens Axboe 2019-01-30 15:33 ` Jens Axboe 2019-01-30 15:33 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 10/18] io_uring: batch io_kiocb allocation Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 11/18] block: implement bio helper to add iter bvec pages to bio Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 12/18] io_uring: add support for pre-mapped user IO buffers Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 22:44 ` Jann Horn 2019-01-29 22:44 ` Jann Horn 2019-01-29 22:56 ` Jens Axboe 2019-01-29 22:56 ` Jens Axboe 2019-01-29 23:03 ` Jann Horn 2019-01-29 23:03 ` Jann Horn 2019-01-29 23:06 ` Jens Axboe 2019-01-29 23:06 ` Jens Axboe 2019-01-29 23:08 ` Jann Horn 2019-01-29 23:08 ` Jann Horn 2019-01-29 23:14 ` Jens Axboe 2019-01-29 23:14 ` Jens Axboe 2019-01-29 23:42 ` Jann Horn 2019-01-29 23:42 ` Jann Horn 2019-01-29 23:51 ` Jens Axboe 2019-01-29 23:51 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 13/18] io_uring: add file set registration Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-30 1:29 ` Jann Horn 2019-01-30 1:29 ` Jann Horn 2019-01-30 15:35 ` Jens Axboe 2019-01-30 15:35 ` Jens Axboe 2019-02-04 2:56 ` Al Viro 2019-02-04 2:56 ` Al Viro 2019-02-05 2:19 ` Jens Axboe 2019-02-05 2:19 ` Jens Axboe 2019-02-05 17:57 ` Jens Axboe 2019-02-05 17:57 ` Jens Axboe 2019-02-05 19:08 ` Jens Axboe 2019-02-05 19:08 ` Jens Axboe 2019-02-06 0:27 ` Jens Axboe 2019-02-06 0:27 ` Jens Axboe 2019-02-06 1:01 ` Al Viro 2019-02-06 1:01 ` Al Viro 2019-02-06 17:56 ` Jens Axboe 2019-02-06 17:56 ` Jens Axboe 2019-02-07 4:05 ` Al Viro 2019-02-07 4:05 ` Al Viro 2019-02-07 16:14 ` Jens Axboe 2019-02-07 16:30 ` Al Viro 2019-02-07 16:30 ` Al Viro 2019-02-07 16:35 ` Jens Axboe 2019-02-07 16:35 ` Jens Axboe 2019-02-07 16:51 ` Al Viro 2019-02-07 16:51 ` Al Viro 2019-02-06 0:56 ` Al Viro 2019-02-06 0:56 ` Al Viro 2019-02-06 13:41 ` Jens Axboe 2019-02-06 13:41 ` Jens Axboe 2019-02-07 4:00 ` Al Viro 2019-02-07 4:00 ` Al Viro 2019-02-07 9:22 ` Miklos Szeredi 2019-02-07 9:22 ` Miklos Szeredi 2019-02-07 13:31 ` Al Viro 2019-02-07 13:31 ` Al Viro 2019-02-07 14:20 ` Miklos Szeredi 2019-02-07 14:20 ` Miklos Szeredi 2019-02-07 15:20 ` Al Viro 2019-02-07 15:20 ` Al Viro 2019-02-07 15:27 ` Miklos Szeredi 2019-02-07 15:27 ` Miklos Szeredi 2019-02-07 16:26 ` Al Viro 2019-02-07 16:26 ` Al Viro 2019-02-07 19:08 ` Miklos Szeredi 2019-02-07 19:08 ` Miklos Szeredi 2019-02-07 18:45 ` Jens Axboe 2019-02-07 18:45 ` Jens Axboe 2019-02-07 18:58 ` Jens Axboe 2019-02-07 18:58 ` Jens Axboe 2019-02-11 15:55 ` Jonathan Corbet 2019-02-11 15:55 ` Jonathan Corbet 2019-02-11 17:35 ` Al Viro 2019-02-11 17:35 ` Al Viro 2019-02-11 20:33 ` Jonathan Corbet 2019-02-11 20:33 ` Jonathan Corbet 2019-01-29 19:26 ` [PATCH 14/18] io_uring: add submission polling Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:26 ` [PATCH 15/18] io_uring: add io_kiocb ref count Jens Axboe 2019-01-29 19:26 ` Jens Axboe 2019-01-29 19:27 ` [PATCH 16/18] io_uring: add support for IORING_OP_POLL Jens Axboe 2019-01-29 19:27 ` Jens Axboe 2019-01-29 19:27 ` [PATCH 17/18] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe 2019-01-29 19:27 ` Jens Axboe 2019-01-29 19:27 ` [PATCH 18/18] io_uring: add io_uring_event cache hit information Jens Axboe 2019-01-29 19:27 ` Jens Axboe -- strict thread matches above, loose matches on Subject: below -- 2019-02-07 19:55 [PATCHSET v12] io_uring IO interface Jens Axboe 2019-02-07 19:55 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-02-07 19:55 ` Jens Axboe 2019-02-01 15:23 [PATCHSET v11] io_uring IO interface Jens Axboe 2019-02-01 15:23 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-02-01 15:23 ` Jens Axboe 2019-01-30 21:55 [PATCHSET v10] io_uring IO interface Jens Axboe 2019-01-30 21:55 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-01-30 21:55 ` Jens Axboe 2019-01-28 21:35 [PATCHSET v8] io_uring IO interface Jens Axboe 2019-01-28 21:35 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-01-28 21:35 ` Jens Axboe 2019-01-23 15:35 [PATCHSET v7] io_uring IO interface Jens Axboe 2019-01-23 15:35 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe 2019-01-28 14:26 ` Christoph Hellwig
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