jbd2: remove unneeded done_copy_out variable in jbd2_journal_write_metadata_buffer

It's more intuitive to use jh_in->b_frozen_data directly instead of
done_copy_out variable. Simply remove unneeded done_copy_out variable
and use b_frozen_data instead.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240801013815.2393869-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Author: Kemeng Shi

fs/jbd2/journal.c

@@ -318,7 +318,6 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 				  struct buffer_head **bh_out,
 				  sector_t blocknr)
 {
-	int done_copy_out = 0;
 	int do_escape = 0;
 	char *mapped_data;
 	struct buffer_head *new_bh;
@@ -349,25 +348,22 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 	 * we use that version of the data for the commit.
 	 */
 	if (jh_in->b_frozen_data) {
-		done_copy_out = 1;
 		new_folio = virt_to_folio(jh_in->b_frozen_data);
 		new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
 		mapped_data = jh_in->b_frozen_data;
 	} else {
 		new_folio = bh_in->b_folio;
 		new_offset = offset_in_folio(new_folio, bh_in->b_data);
 		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
-	 * offset.  If a copy-out happens afterwards, it will have the correct
-	 * data in the buffer.
-	 */
-	if (!done_copy_out)
+		/*
+		 * Fire data frozen trigger if data already wasn't frozen. Do
+		 * this before checking for escaping, as the trigger may modify
+		 * the magic offset.  If a copy-out happens afterwards, it will
+		 * have the correct data in the buffer.
+		 */
 		jbd2_buffer_frozen_trigger(jh_in, mapped_data,
 					   jh_in->b_triggers);
+	}
 
 	/*
 	 * Check for escaping
@@ -380,7 +376,7 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 	/*
 	 * Do we need to do a data copy?
 	 */
-	if (do_escape && !done_copy_out) {
+	if (do_escape && !jh_in->b_frozen_data) {
 		char *tmp;
 
 		spin_unlock(&jh_in->b_state_lock);
@@ -408,7 +404,6 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 copy_done:
 		new_folio = virt_to_folio(jh_in->b_frozen_data);
 		new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data);
-		done_copy_out = 1;
 	}
 
 	/*