Re: [PATCH 05/30] xfs: mark dquot buffers in cache

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Tue, Jun 02, 2020 at 07:42:26AM +1000, Dave Chinner wrote:
> dquot buffers always have write IO callbacks, so by marking them
> directly we can avoid needing to attach ->b_iodone functions to
> them. This avoids an indirect call, and makes future modifications
> much simpler.
> 
> This is largely a rearrangement of the code at this point - no IO
> completion functionality changes at this point, just how the
> code is run is modified.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Seems fine to me,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
>  fs/xfs/xfs_buf.c       |  5 +++++
>  fs/xfs/xfs_buf.h       |  2 ++
>  fs/xfs/xfs_buf_item.c  | 10 ++++++++++
>  fs/xfs/xfs_buf_item.h  |  1 +
>  fs/xfs/xfs_dquot.c     |  1 +
>  fs/xfs/xfs_trans_buf.c |  1 +
>  6 files changed, 20 insertions(+)
> 
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index fcf650575be61..3bffde8640a52 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -1212,6 +1212,11 @@ xfs_buf_ioend(
>  		return;
>  	}
>  
> +	if (bp->b_flags & _XBF_DQUOTS) {
> +		xfs_buf_dquot_iodone(bp);
> +		return;
> +	}
> +
>  	if (bp->b_iodone) {
>  		(*(bp->b_iodone))(bp);
>  		return;
> diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
> index 2400cb90a04c6..c1d0843206dd6 100644
> --- a/fs/xfs/xfs_buf.h
> +++ b/fs/xfs/xfs_buf.h
> @@ -32,6 +32,7 @@
>  
>  /* buffer type flags for write callbacks */
>  #define _XBF_INODES	 (1 << 16)/* inode buffer */
> +#define _XBF_DQUOTS	 (1 << 17)/* dquot buffer */
>  
>  /* flags used only internally */
>  #define _XBF_PAGES	 (1 << 20)/* backed by refcounted pages */
> @@ -54,6 +55,7 @@ typedef unsigned int xfs_buf_flags_t;
>  	{ XBF_STALE,		"STALE" }, \
>  	{ XBF_WRITE_FAIL,	"WRITE_FAIL" }, \
>  	{ _XBF_INODES,		"INODES" }, \
> +	{ _XBF_DQUOTS,		"DQUOTS" }, \
>  	{ _XBF_PAGES,		"PAGES" }, \
>  	{ _XBF_KMEM,		"KMEM" }, \
>  	{ _XBF_DELWRI_Q,	"DELWRI_Q" }, \
> diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
> index 8659cf4282a64..a42cdf9ccc47d 100644
> --- a/fs/xfs/xfs_buf_item.c
> +++ b/fs/xfs/xfs_buf_item.c
> @@ -1210,6 +1210,16 @@ xfs_buf_inode_iodone(
>  	xfs_buf_ioend_finish(bp);
>  }
>  
> +/*
> + * Dquot buffer iodone callback function.
> + */
> +void
> +xfs_buf_dquot_iodone(
> +	struct xfs_buf		*bp)
> +{
> +	xfs_buf_run_callbacks(bp);
> +	xfs_buf_ioend_finish(bp);
> +}
>  
>  /*
>   * This is the iodone() function for buffers which have been
> diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
> index a342933ad9b8d..27d13d29b5bbb 100644
> --- a/fs/xfs/xfs_buf_item.h
> +++ b/fs/xfs/xfs_buf_item.h
> @@ -60,6 +60,7 @@ void	xfs_buf_attach_iodone(struct xfs_buf *,
>  void	xfs_buf_iodone_callbacks(struct xfs_buf *);
>  void	xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
>  void	xfs_buf_inode_iodone(struct xfs_buf *);
> +void	xfs_buf_dquot_iodone(struct xfs_buf *);
>  bool	xfs_buf_log_check_iovec(struct xfs_log_iovec *iovec);
>  
>  extern kmem_zone_t	*xfs_buf_item_zone;
> diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
> index d5b7f03e93c8d..2e2146fa0914c 100644
> --- a/fs/xfs/xfs_dquot.c
> +++ b/fs/xfs/xfs_dquot.c
> @@ -1179,6 +1179,7 @@ xfs_qm_dqflush(
>  	 * Attach an iodone routine so that we can remove this dquot from the
>  	 * AIL and release the flush lock once the dquot is synced to disk.
>  	 */
> +	bp->b_flags |= _XBF_DQUOTS;
>  	xfs_buf_attach_iodone(bp, xfs_qm_dqflush_done,
>  				  &dqp->q_logitem.qli_item);
>  
> diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
> index 552d0869aa0fe..93d62cb864c15 100644
> --- a/fs/xfs/xfs_trans_buf.c
> +++ b/fs/xfs/xfs_trans_buf.c
> @@ -788,5 +788,6 @@ xfs_trans_dquot_buf(
>  		break;
>  	}
>  
> +	bp->b_flags |= _XBF_DQUOTS;
>  	xfs_trans_buf_set_type(tp, bp, type);
>  }
> -- 
> 2.26.2.761.g0e0b3e54be
>