Commit 8147c4c4 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

jbd2: use a folio in jbd2_journal_write_metadata_buffer() 

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@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 07811230

fs/jbd2/journal.c

+16 −19
Original line number Diff line number Diff line
@@ -341,7 +341,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
	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 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
	 */

	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 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
	 * 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 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
		}



		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 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, 
	 * 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;