The patch titled
Subject: jbd2: use a folio in jbd2_journal_write_metadata_buffer()
has been added to the -mm mm-unstable branch. Its filename is
jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: jbd2: use a folio in jbd2_journal_write_metadata_buffer()
Date: Thu, 13 Jul 2023 04:55:11 +0100
The primary goal here is removing the use of set_bh_page(). Take the
opportunity to switch from kmap_atomic() to kmap_local(). This simplifies
the function as the offset is already added to the pointer.
Link: https://lkml.kernel.org/r/20230713035512.4139457-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/jbd2/journal.c | 35 ++++++++++++++++-------------------
1 file changed, 16 insertions(+), 19 deletions(-)
--- a/fs/jbd2/journal.c~jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer
+++ a/fs/jbd2/journal.c
@@ -341,7 +341,7 @@ int jbd2_journal_write_metadata_buffer(t
int do_escape = 0;
char *mapped_data;
struct buffer_head *new_bh;
- struct page *new_page;
+ struct folio *new_folio;
unsigned int new_offset;
struct buffer_head *bh_in = jh2bh(jh_in);
journal_t *journal = transaction->t_journal;
@@ -370,14 +370,14 @@ repeat:
*/
if (jh_in->b_frozen_data) {
done_copy_out = 1;
- new_page = virt_to_page(jh_in->b_frozen_data);
- new_offset = offset_in_page(jh_in->b_frozen_data);
+ new_folio = virt_to_folio(jh_in->b_frozen_data);
+ new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
} else {
- new_page = jh2bh(jh_in)->b_page;
- new_offset = offset_in_page(jh2bh(jh_in)->b_data);
+ new_folio = jh2bh(jh_in)->b_folio;
+ new_offset = offset_in_folio(new_folio, jh2bh(jh_in)->b_data);
}
- mapped_data = kmap_atomic(new_page);
+ mapped_data = kmap_local_folio(new_folio, new_offset);
/*
* Fire data frozen trigger if data already wasn't frozen. Do this
* before checking for escaping, as the trigger may modify the magic
@@ -385,18 +385,17 @@ repeat:
* data in the buffer.
*/
if (!done_copy_out)
- jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset,
+ jbd2_buffer_frozen_trigger(jh_in, mapped_data,
jh_in->b_triggers);
/*
* Check for escaping
*/
- if (*((__be32 *)(mapped_data + new_offset)) ==
- cpu_to_be32(JBD2_MAGIC_NUMBER)) {
+ if (*((__be32 *)mapped_data) == cpu_to_be32(JBD2_MAGIC_NUMBER)) {
need_copy_out = 1;
do_escape = 1;
}
- kunmap_atomic(mapped_data);
+ kunmap_local(mapped_data);
/*
* Do we need to do a data copy?
@@ -417,12 +416,10 @@ repeat:
}
jh_in->b_frozen_data = tmp;
- mapped_data = kmap_atomic(new_page);
- memcpy(tmp, mapped_data + new_offset, bh_in->b_size);
- kunmap_atomic(mapped_data);
+ memcpy_from_folio(tmp, new_folio, new_offset, bh_in->b_size);
- new_page = virt_to_page(tmp);
- new_offset = offset_in_page(tmp);
+ new_folio = virt_to_folio(tmp);
+ new_offset = offset_in_folio(new_folio, tmp);
done_copy_out = 1;
/*
@@ -438,12 +435,12 @@ repeat:
* copying, we can finally do so.
*/
if (do_escape) {
- mapped_data = kmap_atomic(new_page);
- *((unsigned int *)(mapped_data + new_offset)) = 0;
- kunmap_atomic(mapped_data);
+ mapped_data = kmap_local_folio(new_folio, new_offset);
+ *((unsigned int *)mapped_data) = 0;
+ kunmap_local(mapped_data);
}
- set_bh_page(new_bh, new_page, new_offset);
+ folio_set_bh(new_bh, new_folio, new_offset);
new_bh->b_size = bh_in->b_size;
new_bh->b_bdev = journal->j_dev;
new_bh->b_blocknr = blocknr;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
rmap-pass-the-folio-to-__page_check_anon_rmap.patch
highmem-add-memcpy_to_folio-and-memcpy_from_folio.patch
affs-convert-affs_symlink_read_folio-to-use-the-folio.patch
affs-convert-data-read-and-write-to-use-folios.patch
migrate-use-folio_set_bh-instead-of-set_bh_page.patch
ntfs3-convert-ntfs_get_block_vbo-to-use-a-folio.patch
jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer.patch
buffer-remove-set_bh_page.patch
