block: don't block events on excl write for non-optical devices
Disk event code automatically blocks events on excl write. This is
primarily to avoid issuing polling commands while burning is in
progress. This behavior doesn't fit other types of devices with
removeable media where polling commands don't have adverse side
effects and door locking usually doesn't exist.
This patch introduces new genhd flag which controls the auto-blocking
behavior and uses it to enable auto-blocking only on optical devices.
Note for stable: 2.6.38 and later only
Cc: stable@kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 2f2ccf6..a0aabd9 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -320,6 +320,7 @@
disk->first_minor = unit;
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;
}
}
diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c
index 4e874c5..ae15a4d 100644
--- a/drivers/cdrom/viocd.c
+++ b/drivers/cdrom/viocd.c
@@ -625,7 +625,8 @@
blk_queue_max_hw_sectors(q, 4096 / 512);
gendisk->queue = q;
gendisk->fops = &viocd_fops;
- gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE;
+ gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
+ GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
gendisk->events = DISK_EVENT_MEDIA_CHANGE;
set_capacity(gendisk, 0);
gendisk->private_data = d;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index fd1e117..6e5123b 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1781,7 +1781,7 @@
ide_cd_read_toc(drive, &sense);
g->fops = &idecd_ops;
- g->flags |= GENHD_FL_REMOVABLE;
+ g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
g->events = DISK_EVENT_MEDIA_CHANGE;
add_disk(g);
return 0;
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 95019c7..4778e27 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -636,7 +636,7 @@
disk->first_minor = minor;
sprintf(disk->disk_name, "sr%d", minor);
disk->fops = &sr_bdops;
- disk->flags = GENHD_FL_CD;
+ disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 257b00e..d7c2e0f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1237,6 +1237,8 @@
res = __blkdev_get(bdev, mode, 0);
if (whole) {
+ struct gendisk *disk = whole->bd_disk;
+
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
@@ -1263,15 +1265,16 @@
spin_unlock(&bdev_lock);
/*
- * Block event polling for write claims. Any write
- * holder makes the write_holder state stick until all
- * are released. This is good enough and tracking
- * individual writeable reference is too fragile given
- * the way @mode is used in blkdev_get/put().
+ * Block event polling for write claims if requested. Any
+ * write holder makes the write_holder state stick until
+ * all are released. This is good enough and tracking
+ * individual writeable reference is too fragile given the
+ * way @mode is used in blkdev_get/put().
*/
- if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+ if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&
+ !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
bdev->bd_write_holder = true;
- disk_block_events(bdev->bd_disk);
+ disk_block_events(disk);
}
mutex_unlock(&bdev->bd_mutex);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index d764a42..300d758 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -127,6 +127,7 @@
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY 128
+#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
enum {
DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */