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Message-ID: <745e2a68-ed19-dc3d-803a-a7d1d47903dd@redhat.com>
Date:   Mon, 22 May 2023 10:20:56 +0800
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Subject: Re: [PATCH 02/13] filemap: update ki_pos in generic_perform_write
Content-Language: en-US
To:     Christoph Hellwig <hch@lst.de>,
        Matthew Wilcox <willy@infradead.org>
Cc:     Jens Axboe <axboe@kernel.dk>, Ilya Dryomov <idryomov@gmail.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        Theodore Ts'o <tytso@mit.edu>,
        Jaegeuk Kim <jaegeuk@kernel.org>, Chao Yu <chao@kernel.org>,
        Miklos Szeredi <miklos@szeredi.hu>,
        Andreas Gruenbacher <agruenba@redhat.com>,
        "Darrick J. Wong" <djwong@kernel.org>,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna@kernel.org>,
        Damien Le Moal <dlemoal@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-block@vger.kernel.org, ceph-devel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
        "open list:F2FS FILE SYSTEM" <linux-f2fs-devel@lists.sourceforge.net>,
        cluster-devel@redhat.com, linux-xfs@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-mm@kvack.org
References: <20230519093521.133226-1-hch@lst.de>
 <20230519093521.133226-3-hch@lst.de>
From:   Xiubo Li <xiubli@redhat.com>
In-Reply-To: <20230519093521.133226-3-hch@lst.de>
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On 5/19/23 17:35, Christoph Hellwig wrote:
> All callers of generic_perform_write need to updated ki_pos, move it into
> common code.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   fs/ceph/file.c | 2 --
>   fs/ext4/file.c | 9 +++------
>   fs/f2fs/file.c | 1 -
>   fs/nfs/file.c  | 1 -
>   mm/filemap.c   | 8 ++++----
>   5 files changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index f4d8bf7dec88a8..feeb9882ef635a 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1894,8 +1894,6 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
>   		 * can not run at the same time
>   		 */
>   		written = generic_perform_write(iocb, from);
> -		if (likely(written >= 0))
> -			iocb->ki_pos = pos + written;
>   		ceph_end_io_write(inode);
>   	}
>   
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index d101b3b0c7dad8..50824831d31def 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -291,12 +291,9 @@ static ssize_t ext4_buffered_write_iter(struct kiocb *iocb,
>   
>   out:
>   	inode_unlock(inode);
> -	if (likely(ret > 0)) {
> -		iocb->ki_pos += ret;
> -		ret = generic_write_sync(iocb, ret);
> -	}
> -
> -	return ret;
> +	if (unlikely(ret <= 0))
> +		return ret;
> +	return generic_write_sync(iocb, ret);
>   }
>   
>   static ssize_t ext4_handle_inode_extension(struct inode *inode, loff_t offset,
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 5ac53d2627d20d..9e3855e43a7a63 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -4522,7 +4522,6 @@ static ssize_t f2fs_buffered_write_iter(struct kiocb *iocb,
>   	current->backing_dev_info = NULL;
>   
>   	if (ret > 0) {
> -		iocb->ki_pos += ret;
>   		f2fs_update_iostat(F2FS_I_SB(inode), inode,
>   						APP_BUFFERED_IO, ret);
>   	}
> diff --git a/fs/nfs/file.c b/fs/nfs/file.c
> index f0edf5a36237d1..3cc87ae8473356 100644
> --- a/fs/nfs/file.c
> +++ b/fs/nfs/file.c
> @@ -658,7 +658,6 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
>   		goto out;
>   
>   	written = result;
> -	iocb->ki_pos += written;
>   	nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
>   
>   	if (mntflags & NFS_MOUNT_WRITE_EAGER) {
> diff --git a/mm/filemap.c b/mm/filemap.c
> index b4c9bd368b7e58..4d0ec2fa1c7070 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3957,7 +3957,10 @@ ssize_t generic_perform_write(struct kiocb *iocb, struct iov_iter *i)
>   		balance_dirty_pages_ratelimited(mapping);
>   	} while (iov_iter_count(i));
>   
> -	return written ? written : status;
> +	if (!written)
> +		return status;
> +	iocb->ki_pos += written;
> +	return written;
>   }
>   EXPORT_SYMBOL(generic_perform_write);
>   
> @@ -4036,7 +4039,6 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>   		endbyte = pos + status - 1;
>   		err = filemap_write_and_wait_range(mapping, pos, endbyte);
>   		if (err == 0) {
> -			iocb->ki_pos = endbyte + 1;
>   			written += status;
>   			invalidate_mapping_pages(mapping,
>   						 pos >> PAGE_SHIFT,
> @@ -4049,8 +4051,6 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>   		}
>   	} else {
>   		written = generic_perform_write(iocb, from);
> -		if (likely(written > 0))
> -			iocb->ki_pos += written;
>   	}
>   out:
>   	current->backing_dev_info = NULL;

LGTM.

Reviewed-by: Xiubo Li <xiubli@redhat.com>

Thanks

- Xiubo