From 58c1a35cd52268ae1524b3ff5eac9fa2414e6efc Mon Sep 17 00:00:00 2001 From: Ira Weiny <ira.weiny@intel.com> Date: Tue, 16 Feb 2021 18:48:23 -0800 Subject: btrfs: convert kmap to kmap_local_page, simple cases Use a simple coccinelle script to help convert the most common kmap()/kunmap() patterns to kmap_local_page()/kunmap_local(). Note that some kmaps which were caught by this script needed to be handled by hand because of the strict unmapping order of kunmap_local() so they are not included in this patch. But this script got us started. There's another temp variable added for the final length write to the first page so it does not interfere with cpage_out that is used for mapping other pages. The development of this patch was aided by the follow script: // <smpl> // SPDX-License-Identifier: GPL-2.0-only // Find kmap and replace with kmap_local_page then mark kunmap // // Confidence: Low // Copyright: (C) 2021 Intel Corporation // URL: http://coccinelle.lip6.fr/ @ catch_all @ expression e, e2; @@ ( -kmap(e) +kmap_local_page(e) ) ... ( -kunmap(...) +kunmap_local() ) // </smpl> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> --- fs/btrfs/lzo.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'fs/btrfs/lzo.c') diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 9084a950dc09..cd042c7567a4 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, struct workspace *workspace = list_entry(ws, struct workspace, list); int ret = 0; char *data_in; - char *cpage_out; + char *cpage_out, *sizes_ptr; int nr_pages = 0; struct page *in_page = NULL; struct page *out_page = NULL; @@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, } /* store the size of all chunks of compressed data */ - cpage_out = kmap(pages[0]); - write_compress_length(cpage_out, tot_out); - - kunmap(pages[0]); + sizes_ptr = kmap_local_page(pages[0]); + write_compress_length(sizes_ptr, tot_out); + kunmap_local(sizes_ptr); ret = 0; *total_out = tot_out; -- cgit v1.2.3