On Thu 13-07-23 04:55:11, Matthew Wilcox (Oracle) wrote:
> 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.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/jbd2/journal.c | 35 ++++++++++++++++-------------------
> 1 file changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index fbce16fedaa4..1b5a45ab62b0 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -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;
> --
> 2.39.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
