Merge tag 'block-5.12-2021-04-02' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Remove comment that never came to fruition in 22 years of development
   (Christoph)

 - Remove unused request flag (Christoph)

 - Fix for null_blk fake timeout handling (Damien)

 - Fix for IOCB_NOWAIT being ignored for O_DIRECT on raw bdevs (Pavel)

 - Error propagation fix for multiple split bios (Yufen)

* tag 'block-5.12-2021-04-02' of git://git.kernel.dk/linux-block:
  block: remove the unused RQF_ALLOCED flag
  block: update a few comments in uapi/linux/blkpg.h
  block: don't ignore REQ_NOWAIT for direct IO
  null_blk: fix command timeout completion handling
  block: only update parent bi_status when bio fail

block/bio.c

@@ -277,7 +277,7 @@ static struct bio *__bio_chain_endio(struct bio *bio)
 {
 	struct bio *parent = bio->bi_private;
 
-	if (!parent->bi_status)
+	if (bio->bi_status && !parent->bi_status)
 		parent->bi_status = bio->bi_status;
 	bio_put(bio);
 	return parent;

block/blk-mq-debugfs.c

@@ -302,7 +302,6 @@ static const char *const rqf_name[] = {
 	RQF_NAME(QUIET),
 	RQF_NAME(ELVPRIV),
 	RQF_NAME(IO_STAT),
-	RQF_NAME(ALLOCED),
 	RQF_NAME(PM),
 	RQF_NAME(HASHED),
 	RQF_NAME(STATS),

drivers/block/null_blk/main.c

@@ -1369,10 +1369,13 @@ static blk_status_t null_handle_cmd(struct nullb_cmd *cmd, sector_t sector,
 	}
 
 	if (dev->zoned)
-		cmd->error = null_process_zoned_cmd(cmd, op,
-						    sector, nr_sectors);
+		sts = null_process_zoned_cmd(cmd, op, sector, nr_sectors);
 	else
-		cmd->error = null_process_cmd(cmd, op, sector, nr_sectors);
+		sts = null_process_cmd(cmd, op, sector, nr_sectors);
+
+	/* Do not overwrite errors (e.g. timeout errors) */
+	if (cmd->error == BLK_STS_OK)
+		cmd->error = sts;
 
 out:
 	nullb_complete_cmd(cmd);
@@ -1451,7 +1454,19 @@ static bool should_requeue_request(struct request *rq)
 
 static enum blk_eh_timer_return null_timeout_rq(struct request *rq, bool res)
 {
+	struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
+
 	pr_info("rq %p timed out\n", rq);
+
+	/*
+	 * If the device is marked as blocking (i.e. memory backed or zoned
+	 * device), the submission path may be blocked waiting for resources
+	 * and cause real timeouts. For these real timeouts, the submission
+	 * path will complete the request using blk_mq_complete_request().
+	 * Only fake timeouts need to execute blk_mq_complete_request() here.
+	 */
+	cmd->error = BLK_STS_TIMEOUT;
+	if (cmd->fake_timeout)
 		blk_mq_complete_request(rq);
 	return BLK_EH_DONE;
 }
@@ -1473,6 +1488,7 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
 	cmd->rq = bd->rq;
 	cmd->error = BLK_STS_OK;
 	cmd->nq = nq;
+	cmd->fake_timeout = should_timeout_request(bd->rq);
 
 	blk_mq_start_request(bd->rq);
 
@@ -1489,7 +1505,7 @@ static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
 			return BLK_STS_OK;
 		}
 	}
-	if (should_timeout_request(bd->rq))
+	if (cmd->fake_timeout)
 		return BLK_STS_OK;
 
 	return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq));

drivers/block/null_blk/null_blk.h

@@ -22,6 +22,7 @@ struct nullb_cmd {
 	blk_status_t error;
 	struct nullb_queue *nq;
 	struct hrtimer timer;
+	bool fake_timeout;
 };
 
 struct nullb_queue {

fs/block_dev.c

@@ -275,6 +275,8 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 		bio.bi_opf = dio_bio_write_op(iocb);
 		task_io_account_write(ret);
 	}
+	if (iocb->ki_flags & IOCB_NOWAIT)
+		bio.bi_opf |= REQ_NOWAIT;
 	if (iocb->ki_flags & IOCB_HIPRI)
 		bio_set_polled(&bio, iocb);
 
@@ -428,6 +430,8 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 			bio->bi_opf = dio_bio_write_op(iocb);
 			task_io_account_write(bio->bi_iter.bi_size);
 		}
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			bio->bi_opf |= REQ_NOWAIT;
 
 		dio->size += bio->bi_iter.bi_size;
 		pos += bio->bi_iter.bi_size;

include/linux/blkdev.h

@@ -85,8 +85,6 @@ typedef __u32 __bitwise req_flags_t;
 #define RQF_ELVPRIV		((__force req_flags_t)(1 << 12))
 /* account into disk and partition IO statistics */
 #define RQF_IO_STAT		((__force req_flags_t)(1 << 13))
-/* request came from our alloc pool */
-#define RQF_ALLOCED		((__force req_flags_t)(1 << 14))
 /* runtime pm request */
 #define RQF_PM			((__force req_flags_t)(1 << 15))
 /* on IO scheduler merge hash */

include/uapi/linux/blkpg.h

@@ -2,29 +2,6 @@
 #ifndef _UAPI__LINUX_BLKPG_H
 #define _UAPI__LINUX_BLKPG_H
 
-/*
- * Partition table and disk geometry handling
- *
- * A single ioctl with lots of subfunctions:
- *
- * Device number stuff:
- *    get_whole_disk()		(given the device number of a partition,
- *                               find the device number of the encompassing disk)
- *    get_all_partitions()	(given the device number of a disk, return the
- *				 device numbers of all its known partitions)
- *
- * Partition stuff:
- *    add_partition()
- *    delete_partition()
- *    test_partition_in_use()	(also for test_disk_in_use)
- *
- * Geometry stuff:
- *    get_geometry()
- *    set_geometry()
- *    get_bios_drivedata()
- *
- * For today, only the partition stuff - aeb, 990515
- */
 #include <linux/compiler.h>
 #include <linux/ioctl.h>
 
@@ -52,9 +29,8 @@ struct blkpg_partition {
 	long long start;		/* starting offset in bytes */
 	long long length;		/* length in bytes */
 	int pno;			/* partition number */
-	char devname[BLKPG_DEVNAMELTH];	/* partition name, like sda5 or c0d1p2,
-					   to be used in kernel messages */
-	char volname[BLKPG_VOLNAMELTH];	/* volume label */
+	char devname[BLKPG_DEVNAMELTH];	/* unused / ignored */
+	char volname[BLKPG_VOLNAMELTH];	/* unused / ignore */
 };
 
 #endif /* _UAPI__LINUX_BLKPG_H */