linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: ira.weiny@intel.com
To: David Sterba <dsterba@suse.cz>
Cc: Ira Weiny <ira.weiny@intel.com>, Chris Mason <clm@fb.com>,
	Josef Bacik <josef@toxicpanda.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
Date: Tue, 16 Feb 2021 18:48:23 -0800	[thread overview]
Message-ID: <20210217024826.3466046-2-ira.weiny@intel.com> (raw)
In-Reply-To: <20210217024826.3466046-1-ira.weiny@intel.com>

From: Ira Weiny <ira.weiny@intel.com>

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.

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>
---
 fs/btrfs/compression.c | 4 ++--
 fs/btrfs/inode.c       | 4 ++--
 fs/btrfs/lzo.c         | 9 ++++-----
 fs/btrfs/raid56.c      | 4 ++--
 4 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index a219dcdb749e..21833a2fe8c6 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1578,7 +1578,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
 	curr_sample_pos = 0;
 	while (index < index_end) {
 		page = find_get_page(inode->i_mapping, index);
-		in_data = kmap(page);
+		in_data = kmap_local_page(page);
 		/* Handle case where the start is not aligned to PAGE_SIZE */
 		i = start % PAGE_SIZE;
 		while (i < PAGE_SIZE - SAMPLING_READ_SIZE) {
@@ -1591,7 +1591,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
 			start += SAMPLING_INTERVAL;
 			curr_sample_pos += SAMPLING_READ_SIZE;
 		}
-		kunmap(page);
+		kunmap_local(in_data);
 		put_page(page);
 
 		index++;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 641f21a11722..66c6f1185de2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6845,7 +6845,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 				if (ret)
 					goto out;
 			} else {
-				map = kmap(page);
+				map = kmap_local_page(page);
 				read_extent_buffer(leaf, map + pg_offset, ptr,
 						   copy_size);
 				if (pg_offset + copy_size < PAGE_SIZE) {
@@ -6853,7 +6853,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 					       PAGE_SIZE - pg_offset -
 					       copy_size);
 				}
-				kunmap(page);
+				kunmap_local(map);
 			}
 			flush_dcache_page(page);
 		}
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;
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 7c3f6dc918c1..9759fb31b73e 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2391,13 +2391,13 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
 
 		/* Check scrubbing parity and repair it */
 		p = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
-		parity = kmap(p);
+		parity = kmap_local_page(p);
 		if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))
 			copy_page(parity, pointers[rbio->scrubp]);
 		else
 			/* Parity is right, needn't writeback */
 			bitmap_clear(rbio->dbitmap, pagenr, 1);
-		kunmap(p);
+		kunmap_local(parity);
 
 		for (stripe = 0; stripe < nr_data; stripe++)
 			kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
-- 
2.28.0.rc0.12.gb6a658bd00c9


  reply	other threads:[~2021-02-17  2:49 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-17  2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
2021-02-17  2:48 ` ira.weiny [this message]
2021-03-12 18:58   ` [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle David Sterba
2021-03-12 20:03     ` Ira Weiny
2021-03-16 11:04       ` David Sterba
2021-02-17  2:48 ` [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page() ira.weiny
2021-03-12 19:26   ` David Sterba
2021-02-17  2:48 ` [PATCH 3/4] fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio() ira.weiny
2021-02-17  2:48 ` [PATCH 4/4] fs/btrfs: Convert block context kmap's to kmap_local_page() ira.weiny
2021-03-11 21:30 ` [PATCH 0/4] btrfs: Convert more kmaps " Ira Weiny
2021-03-12 19:41 ` David Sterba
2021-03-12 20:05   ` Ira Weiny
2021-03-16 11:07     ` David Sterba
2021-03-16 16:56       ` Ira Weiny

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210217024826.3466046-2-ira.weiny@intel.com \
    --to=ira.weiny@intel.com \
    --cc=clm@fb.com \
    --cc=dsterba@suse.cz \
    --cc=josef@toxicpanda.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --subject='Re: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).