xfs: kill XBF_UNMAPPED

Unmapped buffer access is a pain, so kill it. The switch to large
folios means we rarely pay a vmap penalty for large buffers,
so this functionality is largely unnecessary now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

1 files changed, 4 insertions, 54 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index a831e8c755cb..b5ec7d83210f 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -145,7 +145,7 @@ _xfs_buf_alloc(
 	 * We don't want certain flags to appear in b_flags unless they are
 	 * specifically set by later operations on the buffer.
 	 */
-	flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
+	flags &= ~(XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
 
 	/*
 	 * A new buffer is held and locked by the owner.  This ensures that the
@@ -289,9 +289,7 @@ xfs_buf_alloc_kmem(
  *
  * The third type of buffer is the multi-page buffer. These are always made
  * up of single pages so that they can be fed to vmap_ram() to return a
- * contiguous memory region we can access the data through, or mark it as
- * XBF_UNMAPPED and access the data directly through individual page_address()
- * calls.
+ * contiguous memory region we can access the data through.
  */
 static int
 xfs_buf_alloc_backing_mem(
@@ -413,8 +411,6 @@ _xfs_buf_map_pages(
 	if (bp->b_page_count == 1) {
 		/* A single page buffer is always mappable */
 		bp->b_addr = page_address(bp->b_pages[0]);
-	} else if (flags & XBF_UNMAPPED) {
-		bp->b_addr = NULL;
 	} else {
 		int retried = 0;
 		unsigned nofs_flag;
@@ -1345,7 +1341,7 @@ __xfs_buf_ioend(
 	trace_xfs_buf_iodone(bp, _RET_IP_);
 
 	if (bp->b_flags & XBF_READ) {
-		if (!bp->b_error && bp->b_addr && is_vmalloc_addr(bp->b_addr))
+		if (!bp->b_error && is_vmalloc_addr(bp->b_addr))
 			invalidate_kernel_vmap_range(bp->b_addr,
 					xfs_buf_vmap_len(bp));
 		if (!bp->b_error && bp->b_ops)
@@ -1526,7 +1522,7 @@ xfs_buf_submit_bio(
 			__bio_add_page(bio, bp->b_pages[p], PAGE_SIZE, 0);
 		bio->bi_iter.bi_size = size; /* limit to the actual size used */
 
-		if (bp->b_addr && is_vmalloc_addr(bp->b_addr))
+		if (is_vmalloc_addr(bp->b_addr))
 			flush_kernel_vmap_range(bp->b_addr,
 					xfs_buf_vmap_len(bp));
 	}
@@ -1657,52 +1653,6 @@ xfs_buf_submit(
 	xfs_buf_submit_bio(bp);
 }
 
-void *
-xfs_buf_offset(
-	struct xfs_buf		*bp,
-	size_t			offset)
-{
-	struct page		*page;
-
-	if (bp->b_addr)
-		return bp->b_addr + offset;
-
-	page = bp->b_pages[offset >> PAGE_SHIFT];
-	return page_address(page) + (offset & (PAGE_SIZE-1));
-}
-
-void
-xfs_buf_zero(
-	struct xfs_buf		*bp,
-	size_t			boff,
-	size_t			bsize)
-{
-	size_t			bend;
-
-	if (bp->b_addr) {
-		memset(bp->b_addr + boff, 0, bsize);
-		return;
-	}
-
-	bend = boff + bsize;
-	while (boff < bend) {
-		struct page	*page;
-		int		page_index, page_offset, csize;
-
-		page_index = boff >> PAGE_SHIFT;
-		page_offset = boff & ~PAGE_MASK;
-		page = bp->b_pages[page_index];
-		csize = min_t(size_t, PAGE_SIZE - page_offset,
-				      BBTOB(bp->b_length) - boff);
-
-		ASSERT((csize + page_offset) <= PAGE_SIZE);
-
-		memset(page_address(page) + page_offset, 0, csize);
-
-		boff += csize;
-	}
-}
-
 /*
  * Log a message about and stale a buffer that a caller has decided is corrupt.
  *