Merge tag 'block-6.19-20251211' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull block fixes from Jens Axboe:

 - Always initialize DMA state, fixing a potentially nasty issue on the
   block side

 - btrfs zoned write fix with cached zone reports

 - Fix corruption issues in bcache with chained bio's, and further make
   it clear that the chained IO handler is simply a marker, it's not
   code meant to be executed

 - Kill old code dealing with synchronous IO polling in the block layer,
   that has been dead for a long time. Only async polling is supported
   these days

 - Fix a lockdep issue in tag_set management, moving it to RCU

 - Fix an issue with ublks bio_vec iteration

 - Don't unconditionally enforce blocking issue of ublk control
   commands, allow some of them with non-blocking issue as they
   do not block

* tag 'block-6.19-20251211' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  blk-mq-dma: always initialize dma state
  blk-mq: delete task running check in blk_hctx_poll()
  block: fix cached zone reports on devices with native zone append
  block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock
  ublk: don't mutate struct bio_vec in iteration
  block: prohibit calls to bio_chain_endio
  bcache: fix improper use of bi_end_io
  ublk: allow non-blocking ctrl cmds in IO_URING_F_NONBLOCK issue

Author: torvalds

block/bio.c

@@ -321,9 +321,13 @@ static struct bio *__bio_chain_endio(struct bio *bio)
 	return parent;
 }
 
+/*
+ * This function should only be used as a flag and must never be called.
+ * If execution reaches here, it indicates a serious programming error.
+ */
 static void bio_chain_endio(struct bio *bio)
 {
-	bio_endio(__bio_chain_endio(bio));
+	BUG();
 }
 
 /**

block/blk-mq-dma.c

@@ -199,6 +199,7 @@ static bool blk_dma_map_iter_start(struct request *req, struct device *dma_dev,
 	if (blk_can_dma_map_iova(req, dma_dev) &&
 	    dma_iova_try_alloc(dma_dev, state, vec.paddr, total_len))
 		return blk_rq_dma_map_iova(req, dma_dev, state, iter, &vec);
+	memset(state, 0, sizeof(*state));
 	return blk_dma_map_direct(req, dma_dev, iter, &vec);
 }
 

block/blk-mq.c

@@ -336,12 +336,12 @@ void blk_mq_quiesce_tagset(struct blk_mq_tag_set *set)
 {
 	struct request_queue *q;
 
-	mutex_lock(&set->tag_list_lock);
-	list_for_each_entry(q, &set->tag_list, tag_set_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(q, &set->tag_list, tag_set_list) {
 		if (!blk_queue_skip_tagset_quiesce(q))
 			blk_mq_quiesce_queue_nowait(q);
 	}
-	mutex_unlock(&set->tag_list_lock);
+	rcu_read_unlock();
 
 	blk_mq_wait_quiesce_done(set);
 }
@@ -351,12 +351,12 @@ void blk_mq_unquiesce_tagset(struct blk_mq_tag_set *set)
 {
 	struct request_queue *q;
 
-	mutex_lock(&set->tag_list_lock);
-	list_for_each_entry(q, &set->tag_list, tag_set_list) {
+	rcu_read_lock();
+	list_for_each_entry_rcu(q, &set->tag_list, tag_set_list) {
 		if (!blk_queue_skip_tagset_quiesce(q))
 			blk_mq_unquiesce_queue(q);
 	}
-	mutex_unlock(&set->tag_list_lock);
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(blk_mq_unquiesce_tagset);
 
@@ -4311,15 +4311,14 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q)
 	struct blk_mq_tag_set *set = q->tag_set;
 
 	mutex_lock(&set->tag_list_lock);
-	list_del(&q->tag_set_list);
+	list_del_rcu(&q->tag_set_list);
 	if (list_is_singular(&set->tag_list)) {
 		/* just transitioned to unshared */
 		set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
 		/* update existing queue */
 		blk_mq_update_tag_set_shared(set, false);
 	}
 	mutex_unlock(&set->tag_list_lock);
-	INIT_LIST_HEAD(&q->tag_set_list);
 }
 
 static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
@@ -4338,7 +4337,7 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
 	}
 	if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
 		queue_set_hctx_shared(q, true);
-	list_add_tail(&q->tag_set_list, &set->tag_list);
+	list_add_tail_rcu(&q->tag_set_list, &set->tag_list);
 
 	mutex_unlock(&set->tag_list_lock);
 }
@@ -5193,27 +5192,19 @@ EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
 static int blk_hctx_poll(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 			 struct io_comp_batch *iob, unsigned int flags)
 {
-	long state = get_current_state();
 	int ret;
 
 	do {
 		ret = q->mq_ops->poll(hctx, iob);
-		if (ret > 0) {
-			__set_current_state(TASK_RUNNING);
+		if (ret > 0)
 			return ret;
-		}
-
-		if (signal_pending_state(state, current))
-			__set_current_state(TASK_RUNNING);
-		if (task_is_running(current))
+		if (task_sigpending(current))
 			return 1;
-
 		if (ret < 0 || (flags & BLK_POLL_ONESHOT))
 			break;
 		cpu_relax();
 	} while (!need_resched());
 
-	__set_current_state(TASK_RUNNING);
 	return 0;
 }
 

block/blk-zoned.c

@@ -2100,7 +2100,7 @@ static int blk_revalidate_seq_zone(struct blk_zone *zone, unsigned int idx,
 	 * we have a zone write plug for such zone if the device has a zone
 	 * write plug hash table.
 	 */
-	if (!queue_emulates_zone_append(disk->queue) || !disk->zone_wplugs_hash)
+	if (!disk->zone_wplugs_hash)
 		return 0;
 
 	wp_offset = disk_zone_wplug_sync_wp_offset(disk, zone);

drivers/block/ublk_drv.c

@@ -926,6 +926,7 @@ static size_t ublk_copy_user_pages(const struct request *req,
 	size_t done = 0;
 
 	rq_for_each_segment(bv, req, iter) {
+		unsigned len;
 		void *bv_buf;
 		size_t copied;
 
@@ -934,18 +935,17 @@ static size_t ublk_copy_user_pages(const struct request *req,
 			continue;
 		}
 
-		bv.bv_offset += offset;
-		bv.bv_len -= offset;
-		bv_buf = bvec_kmap_local(&bv);
+		len = bv.bv_len - offset;
+		bv_buf = kmap_local_page(bv.bv_page) + bv.bv_offset + offset;
 		if (dir == ITER_DEST)
-			copied = copy_to_iter(bv_buf, bv.bv_len, uiter);
+			copied = copy_to_iter(bv_buf, len, uiter);
 		else
-			copied = copy_from_iter(bv_buf, bv.bv_len, uiter);
+			copied = copy_from_iter(bv_buf, len, uiter);
 
 		kunmap_local(bv_buf);
 
 		done += copied;
-		if (copied < bv.bv_len)
+		if (copied < len)
 			break;
 
 		offset = 0;
@@ -3673,6 +3673,19 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub,
 	return ret;
 }
 
+static bool ublk_ctrl_uring_cmd_may_sleep(u32 cmd_op)
+{
+	switch (_IOC_NR(cmd_op)) {
+	case UBLK_CMD_GET_QUEUE_AFFINITY:
+	case UBLK_CMD_GET_DEV_INFO:
+	case UBLK_CMD_GET_DEV_INFO2:
+	case _IOC_NR(UBLK_U_CMD_GET_FEATURES):
+		return false;
+	default:
+		return true;
+	}
+}
+
 static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 		unsigned int issue_flags)
 {
@@ -3681,7 +3694,8 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 	u32 cmd_op = cmd->cmd_op;
 	int ret = -EINVAL;
 
-	if (issue_flags & IO_URING_F_NONBLOCK)
+	if (ublk_ctrl_uring_cmd_may_sleep(cmd_op) &&
+	    issue_flags & IO_URING_F_NONBLOCK)
 		return -EAGAIN;
 
 	ublk_ctrl_cmd_dump(cmd);

drivers/md/bcache/request.c

@@ -1104,7 +1104,7 @@ static void detached_dev_end_io(struct bio *bio)
 	}
 
 	kfree(ddip);
-	bio->bi_end_io(bio);
+	bio_endio(bio);
 }
 
 static void detached_dev_do_request(struct bcache_device *d, struct bio *bio,
@@ -1121,7 +1121,7 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio,
 	ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO);
 	if (!ddip) {
 		bio->bi_status = BLK_STS_RESOURCE;
-		bio->bi_end_io(bio);
+		bio_endio(bio);
 		return;
 	}
 
@@ -1136,7 +1136,7 @@ static void detached_dev_do_request(struct bcache_device *d, struct bio *bio,
 
 	if ((bio_op(bio) == REQ_OP_DISCARD) &&
 	    !bdev_max_discard_sectors(dc->bdev))
-		bio->bi_end_io(bio);
+		detached_dev_end_io(bio);
 	else
 		submit_bio_noacct(bio);
 }