[PATCH 6/9] xfs: map buffers in xfs_buf_alloc_folios

[Dave Chinner <david@fromorbit.com>]

From: Christoph Hellwig <hch@lst.de>

With the concept of unmapped buffer gone, there is no reason to not
vmap the buffer pages directly in xfs_buf_alloc_folios.

[dchinner: port to folio-enabled buffers.]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 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