jbd2: remove unused 'JBD2_CHECKPOINT_IO_ERROR' and 'j_atomic_flags'

Since 'JBD2_CHECKPOINT_IO_ERROR' and j_atomic_flags' are not useful
anymore after fs dev's errseq is imported into jbd2, just remove them.
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231213013224.2100050-4-chengzhihao1@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/jbd2/checkpoint.c

@@ -556,7 +556,6 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
 	struct transaction_chp_stats_s *stats;
 	transaction_t *transaction;
 	journal_t *journal;
-	struct buffer_head *bh = jh2bh(jh);
 
 	JBUFFER_TRACE(jh, "entry");
 
@@ -569,16 +568,6 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
 
 	JBUFFER_TRACE(jh, "removing from transaction");
 
-	/*
-	 * If we have failed to write the buffer out to disk, the filesystem
-	 * may become inconsistent. We cannot abort the journal here since
-	 * we hold j_list_lock and we have to be careful about races with
-	 * jbd2_journal_destroy(). So mark the writeback IO error in the
-	 * journal here and we abort the journal later from a better context.
-	 */
-	if (buffer_write_io_error(bh))
-		set_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags);
-
 	__buffer_unlink(jh);
 	jh->b_cp_transaction = NULL;
 	percpu_counter_dec(&journal->j_checkpoint_jh_count);

include/linux/jbd2.h

@@ -755,11 +755,6 @@ struct journal_s
 	 */
 	unsigned long		j_flags;
 
-	/**
-	 * @j_atomic_flags: Atomic journaling state flags.
-	 */
-	unsigned long		j_atomic_flags;
-
 	/**
 	 * @j_errno:
 	 *
@@ -1406,12 +1401,6 @@ JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit,	FAST_COMMIT)
 #define JBD2_JOURNAL_FLUSH_VALID	(JBD2_JOURNAL_FLUSH_DISCARD | \
 					JBD2_JOURNAL_FLUSH_ZEROOUT)
 
-/*
- * Journal atomic flag definitions
- */
-#define JBD2_CHECKPOINT_IO_ERROR	0x001	/* Detect io error while writing
-						 * buffer back to disk */
-
 /*
  * Function declarations for the journaling transaction and buffer
  * management