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: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan 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: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index fbce16fedaa4a8cd7535aa6915f6659475c2f82c..1b5a45ab62b0d1e21826d34e1b92bb79e0ba7d2b 100644 (file)
--- 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 @@ 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;