1 files changed, 85 insertions, 38 deletions

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index bfa1e907c472..f1c86d938502 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -23,7 +23,7 @@
 #include <linux/types.h>
 #include "md.h"
 #include "raid5.h"
-#include "bitmap.h"
+#include "md-bitmap.h"
 #include "raid5-log.h"
 
 /*
@@ -236,9 +236,10 @@ struct r5l_io_unit {
 	bool need_split_bio;
 	struct bio *split_bio;
 
-	unsigned int has_flush:1;      /* include flush request */
-	unsigned int has_fua:1;        /* include fua request */
-	unsigned int has_null_flush:1; /* include empty flush request */
+	unsigned int has_flush:1;		/* include flush request */
+	unsigned int has_fua:1;			/* include fua request */
+	unsigned int has_null_flush:1;		/* include null flush request */
+	unsigned int has_flush_payload:1;	/* include flush payload  */
 	/*
 	 * io isn't sent yet, flush/fua request can only be submitted till it's
 	 * the first IO in running_ios list
@@ -538,7 +539,7 @@ static void r5l_log_run_stripes(struct r5l_log *log)
 {
 	struct r5l_io_unit *io, *next;
 
-	assert_spin_locked(&log->io_list_lock);
+	lockdep_assert_held(&log->io_list_lock);
 
 	list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
 		/* don't change list order */
@@ -554,7 +555,7 @@ static void r5l_move_to_end_ios(struct r5l_log *log)
 {
 	struct r5l_io_unit *io, *next;
 
-	assert_spin_locked(&log->io_list_lock);
+	lockdep_assert_held(&log->io_list_lock);
 
 	list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
 		/* don't change list order */
@@ -571,6 +572,8 @@ static void r5l_log_endio(struct bio *bio)
 	struct r5l_io_unit *io_deferred;
 	struct r5l_log *log = io->log;
 	unsigned long flags;
+	bool has_null_flush;
+	bool has_flush_payload;
 
 	if (bio->bi_status)
 		md_error(log->rdev->mddev, log->rdev);
@@ -580,6 +583,16 @@ static void r5l_log_endio(struct bio *bio)
 
 	spin_lock_irqsave(&log->io_list_lock, flags);
 	__r5l_set_io_unit_state(io, IO_UNIT_IO_END);
+
+	/*
+	 * if the io doesn't not have null_flush or flush payload,
+	 * it is not safe to access it after releasing io_list_lock.
+	 * Therefore, it is necessary to check the condition with
+	 * the lock held.
+	 */
+	has_null_flush = io->has_null_flush;
+	has_flush_payload = io->has_flush_payload;
+
 	if (log->need_cache_flush && !list_empty(&io->stripe_list))
 		r5l_move_to_end_ios(log);
 	else
@@ -600,19 +613,23 @@ static void r5l_log_endio(struct bio *bio)
 	if (log->need_cache_flush)
 		md_wakeup_thread(log->rdev->mddev->thread);
 
-	if (io->has_null_flush) {
+	/* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
+	if (has_null_flush) {
 		struct bio *bi;
 
 		WARN_ON(bio_list_empty(&io->flush_barriers));
 		while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
 			bio_endio(bi);
-			atomic_dec(&io->pending_stripe);
+			if (atomic_dec_and_test(&io->pending_stripe)) {
+				__r5l_stripe_write_finished(io);
+				return;
+			}
 		}
 	}
-
-	/* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
-	if (atomic_read(&io->pending_stripe) == 0)
-		__r5l_stripe_write_finished(io);
+	/* decrease pending_stripe for flush payload */
+	if (has_flush_payload)
+		if (atomic_dec_and_test(&io->pending_stripe))
+			__r5l_stripe_write_finished(io);
 }
 
 static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
@@ -676,6 +693,8 @@ static void r5c_disable_writeback_async(struct work_struct *work)
 	struct r5l_log *log = container_of(work, struct r5l_log,
 					   disable_writeback_work);
 	struct mddev *mddev = log->rdev->mddev;
+	struct r5conf *conf = mddev->private;
+	int locked = 0;
 
 	if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
 		return;
@@ -684,11 +703,15 @@ static void r5c_disable_writeback_async(struct work_struct *work)
 
 	/* wait superblock change before suspend */
 	wait_event(mddev->sb_wait,
-		   !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
-
-	mddev_suspend(mddev);
-	log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
-	mddev_resume(mddev);
+		   conf->log == NULL ||
+		   (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) &&
+		    (locked = mddev_trylock(mddev))));
+	if (locked) {
+		mddev_suspend(mddev);
+		log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
+		mddev_resume(mddev);
+		mddev_unlock(mddev);
+	}
 }
 
 static void r5l_submit_current_io(struct r5l_log *log)
@@ -728,7 +751,7 @@ static struct bio *r5l_bio_alloc(struct r5l_log *log)
 	struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, log->bs);
 
 	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
-	bio->bi_bdev = log->rdev->bdev;
+	bio_set_dev(bio, log->rdev->bdev);
 	bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
 
 	return bio;
@@ -881,6 +904,11 @@ static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)
 	payload->size = cpu_to_le32(sizeof(__le64));
 	payload->flush_stripes[0] = cpu_to_le64(sect);
 	io->meta_offset += meta_size;
+	/* multiple flush payloads count as one pending_stripe */
+	if (!io->has_flush_payload) {
+		io->has_flush_payload = 1;
+		atomic_inc(&io->pending_stripe);
+	}
 	mutex_unlock(&log->io_mutex);
 }
 
@@ -1172,7 +1200,7 @@ static void r5l_run_no_mem_stripe(struct r5l_log *log)
 {
 	struct stripe_head *sh;
 
-	assert_spin_locked(&log->io_list_lock);
+	lockdep_assert_held(&log->io_list_lock);
 
 	if (!list_empty(&log->no_mem_stripes)) {
 		sh = list_first_entry(&log->no_mem_stripes,
@@ -1188,7 +1216,7 @@ static bool r5l_complete_finished_ios(struct r5l_log *log)
 	struct r5l_io_unit *io, *next;
 	bool found = false;
 
-	assert_spin_locked(&log->io_list_lock);
+	lockdep_assert_held(&log->io_list_lock);
 
 	list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
 		/* don't change list order */
@@ -1291,7 +1319,7 @@ void r5l_flush_stripe_to_raid(struct r5l_log *log)
 	if (!do_flush)
 		return;
 	bio_reset(&log->flush_bio);
-	log->flush_bio.bi_bdev = log->rdev->bdev;
+	bio_set_dev(&log->flush_bio, log->rdev->bdev);
 	log->flush_bio.bi_end_io = r5l_log_flush_endio;
 	log->flush_bio.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 	submit_bio(&log->flush_bio);
@@ -1360,7 +1388,7 @@ static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
 	 * raid5_release_stripe() while holding conf->device_lock
 	 */
 	BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
-	assert_spin_locked(&conf->device_lock);
+	lockdep_assert_held(&conf->device_lock);
 
 	list_del_init(&sh->lru);
 	atomic_inc(&sh->count);
@@ -1387,7 +1415,7 @@ void r5c_flush_cache(struct r5conf *conf, int num)
 	int count;
 	struct stripe_head *sh, *next;
 
-	assert_spin_locked(&conf->device_lock);
+	lockdep_assert_held(&conf->device_lock);
 	if (!conf->log)
 		return;
 
@@ -1561,21 +1589,21 @@ void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
 	md_wakeup_thread(log->reclaim_thread);
 }
 
-void r5l_quiesce(struct r5l_log *log, int state)
+void r5l_quiesce(struct r5l_log *log, int quiesce)
 {
 	struct mddev *mddev;
-	if (!log || state == 2)
+	if (!log)
 		return;
-	if (state == 0)
-		kthread_unpark(log->reclaim_thread->tsk);
-	else if (state == 1) {
+
+	if (quiesce) {
 		/* make sure r5l_write_super_and_discard_space exits */
 		mddev = log->rdev->mddev;
 		wake_up(&mddev->sb_wait);
 		kthread_park(log->reclaim_thread->tsk);
 		r5l_wake_reclaim(log, MaxSector);
 		r5l_do_reclaim(log);
-	}
+	} else
+		kthread_unpark(log->reclaim_thread->tsk);
 }
 
 bool r5l_log_disk_error(struct r5conf *conf)
@@ -1669,7 +1697,7 @@ static int r5l_recovery_fetch_ra_pool(struct r5l_log *log,
 				      sector_t offset)
 {
 	bio_reset(ctx->ra_bio);
-	ctx->ra_bio->bi_bdev = log->rdev->bdev;
+	bio_set_dev(ctx->ra_bio, log->rdev->bdev);
 	bio_set_op_attrs(ctx->ra_bio, REQ_OP_READ, 0);
 	ctx->ra_bio->bi_iter.bi_sector = log->rdev->data_offset + offset;
 
@@ -2507,11 +2535,18 @@ static void r5l_write_super(struct r5l_log *log, sector_t cp)
 
 static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 {
-	struct r5conf *conf = mddev->private;
+	struct r5conf *conf;
 	int ret;
 
-	if (!conf->log)
+	ret = mddev_lock(mddev);
+	if (ret)
+		return ret;
+
+	conf = mddev->private;
+	if (!conf || !conf->log) {
+		mddev_unlock(mddev);
 		return 0;
+	}
 
 	switch (conf->log->r5c_journal_mode) {
 	case R5C_JOURNAL_MODE_WRITE_THROUGH:
@@ -2529,6 +2564,7 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
 	default:
 		ret = 0;
 	}
+	mddev_unlock(mddev);
 	return ret;
 }
 
@@ -2540,23 +2576,32 @@ static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
  */
 int r5c_journal_mode_set(struct mddev *mddev, int mode)
 {
-	struct r5conf *conf = mddev->private;
-	struct r5l_log *log = conf->log;
-
-	if (!log)
-		return -ENODEV;
+	struct r5conf *conf;
+	int err;
 
 	if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
 	    mode > R5C_JOURNAL_MODE_WRITE_BACK)
 		return -EINVAL;
 
+	err = mddev_lock(mddev);
+	if (err)
+		return err;
+	conf = mddev->private;
+	if (!conf || !conf->log) {
+		mddev_unlock(mddev);
+		return -ENODEV;
+	}
+
 	if (raid5_calc_degraded(conf) > 0 &&
-	    mode == R5C_JOURNAL_MODE_WRITE_BACK)
+	    mode == R5C_JOURNAL_MODE_WRITE_BACK) {
+		mddev_unlock(mddev);
 		return -EINVAL;
+	}
 
 	mddev_suspend(mddev);
 	conf->log->r5c_journal_mode = mode;
 	mddev_resume(mddev);
+	mddev_unlock(mddev);
 
 	pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
 		 mdname(mddev), mode, r5c_journal_mode_str[mode]);
@@ -3126,6 +3171,8 @@ void r5l_exit_log(struct r5conf *conf)
 	conf->log = NULL;
 	synchronize_rcu();
 
+	/* Ensure disable_writeback_work wakes up and exits */
+	wake_up(&conf->mddev->sb_wait);
 	flush_work(&log->disable_writeback_work);
 	md_unregister_thread(&log->reclaim_thread);
 	mempool_destroy(log->meta_pool);