block: move GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE to disk->event_flags

GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE is all about the event reporting
mechanism, so move it to the event_flags field.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211122130625.1136848-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/bdev.c

@@ -837,7 +837,7 @@ struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
 		 * used in blkdev_get/put().
 		 */
 		if ((mode & FMODE_WRITE) && !bdev->bd_write_holder &&
-		    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
+		    (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) {
 			bdev->bd_write_holder = true;
 			unblock_events = false;
 		}

drivers/block/paride/pcd.c

@@ -928,8 +928,8 @@ static int pcd_init_unit(struct pcd_unit *cd, bool autoprobe, int port,
 	disk->minors = 1;
 	strcpy(disk->disk_name, cd->name);	/* umm... */
 	disk->fops = &pcd_bdops;
-	disk->flags = GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
+	disk->event_flags = DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE;
 
 	if (!pi_init(cd->pi, autoprobe, port, mode, unit, protocol, delay,
 			pcd_buffer, PI_PCD, verbose, cd->name)) {

drivers/scsi/sr.c

@@ -684,9 +684,10 @@ static int sr_probe(struct device *dev)
 	disk->minors = 1;
 	sprintf(disk->disk_name, "sr%d", minor);
 	disk->fops = &sr_bdops;
-	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
+	disk->flags = GENHD_FL_CD;
 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
-	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
+	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT |
+				DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE;
 
 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 

include/linux/genhd.h

@@ -60,9 +60,6 @@ struct partition_meta_info {
  * (``BLOCK_EXT_MAJOR``).
  * This affects the maximum number of partitions.
  *
- * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
- * blocked whenever a writer holds an exclusive lock.
- *
  * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
  * Used for loop devices in their default settings and some MMC
  * devices.
@@ -80,7 +77,6 @@ struct partition_meta_info {
 #define GENHD_FL_CD				0x0008
 #define GENHD_FL_SUPPRESS_PARTITION_INFO	0x0020
 #define GENHD_FL_EXT_DEVT			0x0040
-#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100
 #define GENHD_FL_NO_PART_SCAN			0x0200
 #define GENHD_FL_HIDDEN				0x0400
 
@@ -94,6 +90,8 @@ enum {
 	DISK_EVENT_FLAG_POLL			= 1 << 0,
 	/* Forward events to udev */
 	DISK_EVENT_FLAG_UEVENT			= 1 << 1,
+	/* Block event polling when open for exclusive write */
+	DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE	= 1 << 2,
 };
 
 struct disk_events;