Linux-api Archive on lore.kernel.org
 help / color / Atom feed
From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: linux-fsdevel@vger.kernel.org, jack@suse.com, hch@infradead.org,
	linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org,
	linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
	axboe@kernel.dk, linux-api@vger.kernel.org,
	adam.manzanares@wdc.com, viro@zeniv.linux.org.uk,
	Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: Re: [PATCH 09/10] xfs: nowait aio support
Date: Wed, 24 May 2017 09:49:58 -0700
Message-ID: <20170524164958.GU4519@birch.djwong.org> (raw)
In-Reply-To: <20170524164150.9492-10-rgoldwyn@suse.de>

On Wed, May 24, 2017 at 11:41:49AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> If IOCB_NOWAIT is set, bail if the i_rwsem is not lockable
> immediately.
> 
> IF IOMAP_NOWAIT is set, return EAGAIN in xfs_file_iomap_begin
> if it needs allocation either due to file extension, writing to a hole,
> or COW or waiting for other DIOs to finish.
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Looks good,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/xfs/xfs_file.c  | 19 ++++++++++++++-----
>  fs/xfs/xfs_iomap.c | 17 +++++++++++++++++
>  2 files changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 35703a801372..b307940e7d56 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -541,8 +541,11 @@ xfs_file_dio_aio_write(
>  		iolock = XFS_IOLOCK_SHARED;
>  	}
>  
> -	xfs_ilock(ip, iolock);
> -
> +	if (!xfs_ilock_nowait(ip, iolock)) {
> +		if (iocb->ki_flags & IOCB_NOWAIT)
> +			return -EAGAIN;
> +		xfs_ilock(ip, iolock);
> +	}
>  	ret = xfs_file_aio_write_checks(iocb, from, &iolock);
>  	if (ret)
>  		goto out;
> @@ -553,9 +556,15 @@ xfs_file_dio_aio_write(
>  	 * otherwise demote the lock if we had to take the exclusive lock
>  	 * for other reasons in xfs_file_aio_write_checks.
>  	 */
> -	if (unaligned_io)
> -		inode_dio_wait(inode);
> -	else if (iolock == XFS_IOLOCK_EXCL) {
> +	if (unaligned_io) {
> +		/* If we are going to wait for other DIO to finish, bail */
> +		if (iocb->ki_flags & IOCB_NOWAIT) {
> +			if (atomic_read(&inode->i_dio_count))
> +				return -EAGAIN;
> +		} else {
> +			inode_dio_wait(inode);
> +		}
> +	} else if (iolock == XFS_IOLOCK_EXCL) {
>  		xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
>  		iolock = XFS_IOLOCK_SHARED;
>  	}
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index 94e5bdf7304c..8b0e3c1e086d 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -1016,6 +1016,15 @@ xfs_file_iomap_begin(
>  
>  	if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
>  		if (flags & IOMAP_DIRECT) {
> +			/*
> +			 * A reflinked inode will result in CoW alloc.
> +			 * FIXME: It could still overwrite on unshared extents
> +			 * and not need allocation.
> +			 */
> +			if (flags & IOMAP_NOWAIT) {
> +				error = -EAGAIN;
> +				goto out_unlock;
> +			}
>  			/* may drop and re-acquire the ilock */
>  			error = xfs_reflink_allocate_cow(ip, &imap, &shared,
>  					&lockmode);
> @@ -1033,6 +1042,14 @@ xfs_file_iomap_begin(
>  
>  	if ((flags & IOMAP_WRITE) && imap_needs_alloc(inode, &imap, nimaps)) {
>  		/*
> +		 * If nowait is set bail since we are going to make
> +		 * allocations.
> +		 */
> +		if (flags & IOMAP_NOWAIT) {
> +			error = -EAGAIN;
> +			goto out_unlock;
> +		}
> +		/*
>  		 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
>  		 * pages to keep the chunks of work done where somewhat symmetric
>  		 * with the work writeback does. This is a completely arbitrary
> -- 
> 2.12.0
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-24 16:41 [PATCH 0/10 v9] No wait AIO Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 01/10] fs: Separate out kiocb flags setup based on RWF_* flags Goldwyn Rodrigues
2017-05-25  8:16   ` Jan Kara
2017-05-24 16:41 ` [PATCH 02/10] fs: Introduce filemap_range_has_page() Goldwyn Rodrigues
2017-05-25  8:25   ` Jan Kara
     [not found] ` <20170524164150.9492-1-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-24 16:41   ` [PATCH 03/10] fs: Use RWF_* flags for AIO operations Goldwyn Rodrigues
2017-05-25  8:27     ` Jan Kara
2017-05-24 16:41   ` [PATCH 05/10] fs: return if direct write will trigger writeback Goldwyn Rodrigues
2017-05-25  8:32     ` Jan Kara
2017-05-28  9:27   ` [PATCH 0/10 v9] No wait AIO Christoph Hellwig
2017-05-29  2:38     ` Goldwyn Rodrigues
2017-05-29  8:32       ` Christoph Hellwig
2017-05-24 16:41 ` [PATCH 04/10] fs: Introduce RWF_NOWAIT Goldwyn Rodrigues
2017-05-25  8:30   ` Jan Kara
2017-05-24 16:41 ` [PATCH 06/10] fs: Introduce IOMAP_NOWAIT Goldwyn Rodrigues
2017-05-25  8:33   ` Jan Kara
2017-05-24 16:41 ` [PATCH 07/10] fs: return on congested block device Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 08/10] ext4: nowait aio support Goldwyn Rodrigues
2017-05-24 16:41 ` [PATCH 09/10] xfs: " Goldwyn Rodrigues
2017-05-24 16:49   ` Darrick J. Wong [this message]
     [not found]   ` <20170524164150.9492-10-rgoldwyn-l3A5Bk7waGM@public.gmane.org>
2017-05-28  9:31     ` Christoph Hellwig
2017-05-29  2:38       ` Goldwyn Rodrigues
2017-05-29  8:21         ` Jan Kara
2017-05-29  8:33         ` Christoph Hellwig
     [not found]           ` <20170529083338.GC1899-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2017-05-30 16:13             ` Goldwyn Rodrigues
2017-05-31  8:51               ` Jan Kara
2017-05-24 16:41 ` [PATCH 10/10] btrfs: " Goldwyn Rodrigues
  -- strict thread matches above, loose matches on Subject: below --
2017-06-15 15:59 [PATCH 0/10 v12] No wait AIO Goldwyn Rodrigues
2017-06-15 16:00 ` [PATCH 09/10] xfs: nowait aio support Goldwyn Rodrigues
2017-06-06 11:19 [PATCH 0/10 v11] No wait AIO Goldwyn Rodrigues
2017-06-06 11:19 ` [PATCH 09/10] xfs: nowait aio support Goldwyn Rodrigues
2017-06-05  5:35 [PATCH 0/10 v10] No wait AIO Goldwyn Rodrigues
2017-06-05  5:35 ` [PATCH 09/10] xfs: nowait aio support Goldwyn Rodrigues
2017-05-11 19:17 [PATCH 0/10 v8] No wait AIO Goldwyn Rodrigues
2017-05-11 19:17 ` [PATCH 09/10] xfs: nowait aio support Goldwyn Rodrigues

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 \
    --in-reply-to=20170524164958.GU4519@birch.djwong.org \
    --to=darrick.wong@oracle.com \
    --cc=adam.manzanares@wdc.com \
    --cc=axboe@kernel.dk \
    --cc=hch@infradead.org \
    --cc=jack@suse.com \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=rgoldwyn@suse.com \
    --cc=rgoldwyn@suse.de \
    --cc=viro@zeniv.linux.org.uk \
    /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

Linux-api Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-api/0 linux-api/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-api linux-api/ https://lore.kernel.org/linux-api \
		linux-api@vger.kernel.org
	public-inbox-index linux-api

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-api


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git