v4.19.13 snapshot.
diff --git a/drivers/md/raid5-log.h b/drivers/md/raid5-log.h
new file mode 100644
index 0000000..bfb8114
--- /dev/null
+++ b/drivers/md/raid5-log.h
@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _RAID5_LOG_H
+#define _RAID5_LOG_H
+
+extern int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev);
+extern void r5l_exit_log(struct r5conf *conf);
+extern int r5l_write_stripe(struct r5l_log *log, struct stripe_head *head_sh);
+extern void r5l_write_stripe_run(struct r5l_log *log);
+extern void r5l_flush_stripe_to_raid(struct r5l_log *log);
+extern void r5l_stripe_write_finished(struct stripe_head *sh);
+extern int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio);
+extern void r5l_quiesce(struct r5l_log *log, int quiesce);
+extern bool r5l_log_disk_error(struct r5conf *conf);
+extern bool r5c_is_writeback(struct r5l_log *log);
+extern int
+r5c_try_caching_write(struct r5conf *conf, struct stripe_head *sh,
+ struct stripe_head_state *s, int disks);
+extern void
+r5c_finish_stripe_write_out(struct r5conf *conf, struct stripe_head *sh,
+ struct stripe_head_state *s);
+extern void r5c_release_extra_page(struct stripe_head *sh);
+extern void r5c_use_extra_page(struct stripe_head *sh);
+extern void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
+extern void r5c_handle_cached_data_endio(struct r5conf *conf,
+ struct stripe_head *sh, int disks);
+extern int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh);
+extern void r5c_make_stripe_write_out(struct stripe_head *sh);
+extern void r5c_flush_cache(struct r5conf *conf, int num);
+extern void r5c_check_stripe_cache_usage(struct r5conf *conf);
+extern void r5c_check_cached_full_stripe(struct r5conf *conf);
+extern struct md_sysfs_entry r5c_journal_mode;
+extern void r5c_update_on_rdev_error(struct mddev *mddev,
+ struct md_rdev *rdev);
+extern bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect);
+extern int r5l_start(struct r5l_log *log);
+
+extern struct dma_async_tx_descriptor *
+ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
+ struct dma_async_tx_descriptor *tx);
+extern int ppl_init_log(struct r5conf *conf);
+extern void ppl_exit_log(struct r5conf *conf);
+extern int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh);
+extern void ppl_write_stripe_run(struct r5conf *conf);
+extern void ppl_stripe_write_finished(struct stripe_head *sh);
+extern int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add);
+extern void ppl_quiesce(struct r5conf *conf, int quiesce);
+extern int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio);
+
+static inline bool raid5_has_log(struct r5conf *conf)
+{
+ return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
+}
+
+static inline bool raid5_has_ppl(struct r5conf *conf)
+{
+ return test_bit(MD_HAS_PPL, &conf->mddev->flags);
+}
+
+static inline int log_stripe(struct stripe_head *sh, struct stripe_head_state *s)
+{
+ struct r5conf *conf = sh->raid_conf;
+
+ if (conf->log) {
+ if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
+ /* writing out phase */
+ if (s->waiting_extra_page)
+ return 0;
+ return r5l_write_stripe(conf->log, sh);
+ } else if (test_bit(STRIPE_LOG_TRAPPED, &sh->state)) {
+ /* caching phase */
+ return r5c_cache_data(conf->log, sh);
+ }
+ } else if (raid5_has_ppl(conf)) {
+ return ppl_write_stripe(conf, sh);
+ }
+
+ return -EAGAIN;
+}
+
+static inline void log_stripe_write_finished(struct stripe_head *sh)
+{
+ struct r5conf *conf = sh->raid_conf;
+
+ if (conf->log)
+ r5l_stripe_write_finished(sh);
+ else if (raid5_has_ppl(conf))
+ ppl_stripe_write_finished(sh);
+}
+
+static inline void log_write_stripe_run(struct r5conf *conf)
+{
+ if (conf->log)
+ r5l_write_stripe_run(conf->log);
+ else if (raid5_has_ppl(conf))
+ ppl_write_stripe_run(conf);
+}
+
+static inline void log_flush_stripe_to_raid(struct r5conf *conf)
+{
+ if (conf->log)
+ r5l_flush_stripe_to_raid(conf->log);
+ else if (raid5_has_ppl(conf))
+ ppl_write_stripe_run(conf);
+}
+
+static inline int log_handle_flush_request(struct r5conf *conf, struct bio *bio)
+{
+ int ret = -ENODEV;
+
+ if (conf->log)
+ ret = r5l_handle_flush_request(conf->log, bio);
+ else if (raid5_has_ppl(conf))
+ ret = ppl_handle_flush_request(conf->log, bio);
+
+ return ret;
+}
+
+static inline void log_quiesce(struct r5conf *conf, int quiesce)
+{
+ if (conf->log)
+ r5l_quiesce(conf->log, quiesce);
+ else if (raid5_has_ppl(conf))
+ ppl_quiesce(conf, quiesce);
+}
+
+static inline void log_exit(struct r5conf *conf)
+{
+ if (conf->log)
+ r5l_exit_log(conf);
+ else if (raid5_has_ppl(conf))
+ ppl_exit_log(conf);
+}
+
+static inline int log_init(struct r5conf *conf, struct md_rdev *journal_dev,
+ bool ppl)
+{
+ if (journal_dev)
+ return r5l_init_log(conf, journal_dev);
+ else if (ppl)
+ return ppl_init_log(conf);
+
+ return 0;
+}
+
+static inline int log_modify(struct r5conf *conf, struct md_rdev *rdev, bool add)
+{
+ if (raid5_has_ppl(conf))
+ return ppl_modify_log(conf, rdev, add);
+
+ return 0;
+}
+
+#endif