[23/27] block: add BIO_HOLD_PAGES flag

Message ID	20181130165646.27341-24-axboe@kernel.dk (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-block-owner@kernel.org> From: Jens Axboe <axboe@kernel.dk> To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org Cc: hch@lst.de, Jens Axboe <axboe@kernel.dk> Subject: [PATCH 23/27] block: add BIO_HOLD_PAGES flag Date: Fri, 30 Nov 2018 09:56:42 -0700 Message-Id: <20181130165646.27341-24-axboe@kernel.dk> In-Reply-To: <20181130165646.27341-1-axboe@kernel.dk> References: <20181130165646.27341-1-axboe@kernel.dk> Sender: linux-block-owner@vger.kernel.org Precedence: bulk
Series	[01/27] aio: fix failure to put the file pointer \| expand [01/27] aio: fix failure to put the file pointer [02/27] aio: clear IOCB_HIPRI [03/27] fs: add an iopoll method to struct file_operations [04/27] block: wire up block device iopoll method [05/27] block: ensure that async polled IO is marked REQ_NOWAIT [06/27] iomap: wire up the iopoll method [07/27] iomap: ensure that async polled IO is marked REQ_NOWAIT [08/27] aio: use assigned completion handler [09/27] aio: separate out ring reservation from req allocation [10/27] aio: don't zero entire aio_kiocb aio_get_req() [11/27] aio: only use blk plugs for > 2 depth submissions [12/27] aio: use iocb_put() instead of open coding it [13/27] aio: split out iocb copy from io_submit_one() [14/27] aio: abstract out io_event filler helper [15/27] aio: add io_setup2() system call [16/27] aio: add support for having user mapped iocbs [17/27] aio: support for IO polling [18/27] aio: add submission side request cache [19/27] fs: add fget_many() and fput_many() [20/27] aio: use fget/fput_many() for file references [21/27] aio: split iocb init from allocation [22/27] aio: batch aio_kiocb allocation [23/27] block: add BIO_HOLD_PAGES flag [24/27] block: implement bio helper to add iter kvec pages to bio [25/27] fs: add support for mapping an ITER_KVEC for O_DIRECT [26/27] iov_iter: add import_kvec() [27/27] aio: add support for pre-mapped user IO buffers

Message ID

20181130165646.27341-24-axboe@kernel.dk (mailing list archive)

State

New, archived

Headers

From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-aio@kvack.org
Cc: hch@lst.de, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 23/27] block: add BIO_HOLD_PAGES flag
Date: Fri, 30 Nov 2018 09:56:42 -0700
Message-Id: <20181130165646.27341-24-axboe@kernel.dk>
In-Reply-To: <20181130165646.27341-1-axboe@kernel.dk>
References: <20181130165646.27341-1-axboe@kernel.dk>
Sender: linux-block-owner@vger.kernel.org
Precedence: bulk

Series

[01/27] aio: fix failure to put the file pointer | expand

Commit Message

Jens Axboe Nov. 30, 2018, 4:56 p.m. UTC

For user mapped IO, we do get_user_pages() upfront, and then do a
put_page() on each page at end_io time to release the page reference. In
preparation for having permanently mapped pages, add a BIO_HOLD_PAGES
flag that tells us not to release the pages, the caller will do that.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/bio.c               | 6 ++++--
 include/linux/blk_types.h | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 03895cc0d74a..ab174bce5436 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1635,7 +1635,8 @@  static void bio_dirty_fn(struct work_struct *work)
 		next = bio->bi_private;
 
 		bio_set_pages_dirty(bio);
-		bio_release_pages(bio);
+		if (!bio_flagged(bio, BIO_HOLD_PAGES))
+			bio_release_pages(bio);
 		bio_put(bio);
 	}
 }
@@ -1651,7 +1652,8 @@  void bio_check_pages_dirty(struct bio *bio)
 			goto defer;
 	}
 
-	bio_release_pages(bio);
+	if (!bio_flagged(bio, BIO_HOLD_PAGES))
+		bio_release_pages(bio);
 	bio_put(bio);
 	return;
 defer:
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c0ba1a038ff3..78aaf7442688 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -227,6 +227,7 @@  struct bio {
 #define BIO_TRACE_COMPLETION 10	/* bio_endio() should trace the final completion
 				 * of this bio. */
 #define BIO_QUEUE_ENTERED 11	/* can use blk_queue_enter_live() */
+#define BIO_HOLD_PAGES	12	/* don't put O_DIRECT pages */
 
 /* See BVEC_POOL_OFFSET below before adding new flags */

[23/27] block: add BIO_HOLD_PAGES flag

Commit Message

Patch