public inbox for [email protected]
 help / color / mirror / Atom feed
From: John Garry <[email protected]>
To: [email protected], [email protected], [email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected], [email protected],
	[email protected], [email protected]
Cc: [email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected], [email protected],
	John Garry <[email protected]>
Subject: [PATCH v7 6/9] block: Add fops atomic write support
Date: Sun,  2 Jun 2024 14:09:09 +0000	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

Support atomic writes by submitting a single BIO with the REQ_ATOMIC set.

It must be ensured that the atomic write adheres to its rules, like
naturally aligned offset, so call blkdev_dio_invalid() ->
blkdev_atomic_write_valid() [with renaming blkdev_dio_unaligned() to
blkdev_dio_invalid()] for this purpose. The BIO submission path currently
checks for atomic writes which are too large, so no need to check here.

In blkdev_direct_IO(), if the nr_pages exceeds BIO_MAX_VECS, then we cannot
produce a single BIO, so error in this case.

Finally set FMODE_CAN_ATOMIC_WRITE when the bdev can support atomic writes
and the associated file flag is for O_DIRECT.

Signed-off-by: John Garry <[email protected]>
---
 block/fops.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/block/fops.c b/block/fops.c
index 376265935714..9d6d86ebefb9 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -34,9 +34,12 @@ static blk_opf_t dio_bio_write_op(struct kiocb *iocb)
 	return opf;
 }
 
-static bool blkdev_dio_unaligned(struct block_device *bdev, loff_t pos,
-			      struct iov_iter *iter)
+static bool blkdev_dio_invalid(struct block_device *bdev, loff_t pos,
+				struct iov_iter *iter, bool is_atomic)
 {
+	if (is_atomic && !generic_atomic_write_valid(pos, iter))
+		return true;
+
 	return pos & (bdev_logical_block_size(bdev) - 1) ||
 		!bdev_iter_is_aligned(bdev, iter);
 }
@@ -72,6 +75,8 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
 	bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
 	bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint;
 	bio.bi_ioprio = iocb->ki_ioprio;
+	if (iocb->ki_flags & IOCB_ATOMIC)
+		bio.bi_opf |= REQ_ATOMIC;
 
 	ret = bio_iov_iter_get_pages(&bio, iter);
 	if (unlikely(ret))
@@ -343,6 +348,9 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 		task_io_account_write(bio->bi_iter.bi_size);
 	}
 
+	if (iocb->ki_flags & IOCB_ATOMIC)
+		bio->bi_opf |= REQ_ATOMIC;
+
 	if (iocb->ki_flags & IOCB_NOWAIT)
 		bio->bi_opf |= REQ_NOWAIT;
 
@@ -359,12 +367,13 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
+	bool is_atomic = iocb->ki_flags & IOCB_ATOMIC;
 	unsigned int nr_pages;
 
 	if (!iov_iter_count(iter))
 		return 0;
 
-	if (blkdev_dio_unaligned(bdev, iocb->ki_pos, iter))
+	if (blkdev_dio_invalid(bdev, iocb->ki_pos, iter, is_atomic))
 		return -EINVAL;
 
 	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
@@ -373,6 +382,8 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 			return __blkdev_direct_IO_simple(iocb, iter, bdev,
 							nr_pages);
 		return __blkdev_direct_IO_async(iocb, iter, bdev, nr_pages);
+	} else if (is_atomic) {
+		return -EINVAL;
 	}
 	return __blkdev_direct_IO(iocb, iter, bdev, bio_max_segs(nr_pages));
 }
@@ -612,6 +623,9 @@ static int blkdev_open(struct inode *inode, struct file *filp)
 	if (!bdev)
 		return -ENXIO;
 
+	if (bdev_can_atomic_write(bdev) && filp->f_flags & O_DIRECT)
+		filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
+
 	ret = bdev_open(bdev, mode, filp->private_data, NULL, filp);
 	if (ret)
 		blkdev_put_no_open(bdev);
-- 
2.31.1


  parent reply	other threads:[~2024-06-02 14:10 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-06-02 14:09 [PATCH v7 0/9] block atomic writes John Garry
2024-06-02 14:09 ` [PATCH v7 1/9] block: Pass blk_queue_get_max_sectors() a request pointer John Garry
2024-06-02 14:09 ` [PATCH v7 2/9] fs: Initial atomic write support John Garry
2024-06-05  8:30   ` Christoph Hellwig
2024-06-05 10:48     ` John Garry
2024-06-06  5:41       ` Christoph Hellwig
2024-06-06  6:38         ` John Garry
2024-06-02 14:09 ` [PATCH v7 3/9] fs: Add initial atomic write support info to statx John Garry
2024-06-02 14:09 ` [PATCH v7 4/9] block: Add core atomic write support John Garry
2024-06-03  9:26   ` Hannes Reinecke
2024-06-03 11:38     ` John Garry
2024-06-03 12:31       ` Hannes Reinecke
2024-06-03 13:29         ` John Garry
2024-06-05  8:32           ` Christoph Hellwig
2024-06-05 11:21             ` John Garry
2024-06-06  5:44               ` Christoph Hellwig
2024-06-05  8:31         ` Christoph Hellwig
2024-06-02 14:09 ` [PATCH v7 5/9] block: Add atomic write support for statx John Garry
2024-06-02 14:09 ` John Garry [this message]
2024-06-02 14:09 ` [PATCH v7 7/9] scsi: sd: Atomic write support John Garry
2024-06-02 14:09 ` [PATCH v7 8/9] scsi: scsi_debug: " John Garry
2024-06-02 14:09 ` [PATCH v7 9/9] nvme: " John Garry
2024-06-07  6:16 ` [PATCH v7 0/9] block atomic writes John Garry

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox