On Tue, Mar 19, 2024 at 09:45:57AM +1100, Dave Chinner wrote:
> From: Christoph Hellwig <hch@xxxxxx>
>
> With the concept of unmapped buffer gone, there is no reason to not
> vmap the buffer pages directly in xfs_buf_alloc_folios.
"..no reason to not map the buffer pages..."?
I say that mostly because the first dumb thought I had was "wait, we're
going to vm_map_ram everything now??" which of course is not true.
> [dchinner: port to folio-enabled buffers.]
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
With that changed,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/xfs_buf.c | 37 ++++++-------------------------------
> 1 file changed, 6 insertions(+), 31 deletions(-)
>
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index 2cd3671f3ce3..a77e2d8c8107 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -469,18 +469,7 @@ xfs_buf_alloc_folios(
> XFS_STATS_INC(bp->b_mount, xb_page_retries);
> memalloc_retry_wait(gfp_mask);
> }
> - return 0;
> -}
>
> -/*
> - * Map buffer into kernel address-space if necessary.
> - */
> -STATIC int
> -_xfs_buf_map_folios(
> - struct xfs_buf *bp,
> - xfs_buf_flags_t flags)
> -{
> - ASSERT(bp->b_flags & _XBF_FOLIOS);
> if (bp->b_folio_count == 1) {
> /* A single folio buffer is always mappable */
> bp->b_addr = folio_address(bp->b_folios[0]);
> @@ -513,8 +502,13 @@ _xfs_buf_map_folios(
> } while (retried++ <= 1);
> memalloc_nofs_restore(nofs_flag);
>
> - if (!bp->b_addr)
> + if (!bp->b_addr) {
> + xfs_warn_ratelimited(bp->b_mount,
> + "%s: failed to map %u folios", __func__,
> + bp->b_folio_count);
> + xfs_buf_free_folios(bp);
> return -ENOMEM;
> + }
> }
>
> return 0;
> @@ -816,18 +810,6 @@ xfs_buf_get_map(
> xfs_perag_put(pag);
> }
>
> - /* We do not hold a perag reference anymore. */
> - if (!bp->b_addr) {
> - error = _xfs_buf_map_folios(bp, flags);
> - if (unlikely(error)) {
> - xfs_warn_ratelimited(btp->bt_mount,
> - "%s: failed to map %u folios", __func__,
> - bp->b_folio_count);
> - xfs_buf_relse(bp);
> - return error;
> - }
> - }
> -
> /*
> * Clear b_error if this is a lookup from a caller that doesn't expect
> * valid data to be found in the buffer.
> @@ -1068,13 +1050,6 @@ xfs_buf_get_uncached(
> if (error)
> goto fail_free_buf;
>
> - error = _xfs_buf_map_folios(bp, 0);
> - if (unlikely(error)) {
> - xfs_warn(target->bt_mount,
> - "%s: failed to map folios", __func__);
> - goto fail_free_buf;
> - }
> -
> trace_xfs_buf_get_uncached(bp, _RET_IP_);
> *bpp = bp;
> return 0;
> --
> 2.43.0
>
>
