diff mbox series

[v9,7/8] xfs: Validate atomic writes

Message ID 20241016100325.3534494-8-john.g.garry@oracle.com (mailing list archive)
State New, archived
Headers show
Series block atomic writes for xfs | expand

Commit Message

John Garry Oct. 16, 2024, 10:03 a.m. UTC
Validate that an atomic write adheres to length/offset rules. Currently
we can only write a single FS block.

For an IOCB with IOCB_ATOMIC set to get as far as xfs_file_write_iter(),
FMODE_CAN_ATOMIC_WRITE will need to be set for the file; for this,
ATOMICWRITES flags would also need to be set for the inode.

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 fs/xfs/xfs_file.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Christoph Hellwig Oct. 16, 2024, 12:29 p.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Darrick J. Wong Oct. 16, 2024, 8:13 p.m. UTC | #2
On Wed, Oct 16, 2024 at 10:03:24AM +0000, John Garry wrote:
> Validate that an atomic write adheres to length/offset rules. Currently
> we can only write a single FS block.
> 
> For an IOCB with IOCB_ATOMIC set to get as far as xfs_file_write_iter(),
> FMODE_CAN_ATOMIC_WRITE will need to be set for the file; for this,
> ATOMICWRITES flags would also need to be set for the inode.
> 
> Signed-off-by: John Garry <john.g.garry@oracle.com>

This looks ok to me now,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/xfs/xfs_file.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index b19916b11fd5..1ccbc1eb75c9 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -852,6 +852,20 @@ xfs_file_write_iter(
>  	if (IS_DAX(inode))
>  		return xfs_file_dax_write(iocb, from);
>  
> +	if (iocb->ki_flags & IOCB_ATOMIC) {
> +		/*
> +		 * Currently only atomic writing of a single FS block is
> +		 * supported. It would be possible to atomic write smaller than
> +		 * a FS block, but there is no requirement to support this.
> +		 * Note that iomap also does not support this yet.
> +		 */
> +		if (ocount != ip->i_mount->m_sb.sb_blocksize)
> +			return -EINVAL;
> +		ret = generic_atomic_write_valid(iocb, from);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	if (iocb->ki_flags & IOCB_DIRECT) {
>  		/*
>  		 * Allow a directio write to fall back to a buffered
> -- 
> 2.31.1
> 
>
diff mbox series

Patch

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b19916b11fd5..1ccbc1eb75c9 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -852,6 +852,20 @@  xfs_file_write_iter(
 	if (IS_DAX(inode))
 		return xfs_file_dax_write(iocb, from);
 
+	if (iocb->ki_flags & IOCB_ATOMIC) {
+		/*
+		 * Currently only atomic writing of a single FS block is
+		 * supported. It would be possible to atomic write smaller than
+		 * a FS block, but there is no requirement to support this.
+		 * Note that iomap also does not support this yet.
+		 */
+		if (ocount != ip->i_mount->m_sb.sb_blocksize)
+			return -EINVAL;
+		ret = generic_atomic_write_valid(iocb, from);
+		if (ret)
+			return ret;
+	}
+
 	if (iocb->ki_flags & IOCB_DIRECT) {
 		/*
 		 * Allow a directio write to fall back to a buffered