commit: d4dc210f69bcb0b4bef5a83b1c323817be89bad1 From: Tejun Heo <[email protected]> Date: Thu, 21 Apr 2011 20:54:46 +0200 Subject: [PATCH] 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: [email protected] Signed-off-by: Tejun Heo <[email protected]> Reported-by: Kay Sievers <[email protected]> Signed-off-by: Jens Axboe <[email protected]> --- drivers/block/paride/pcd.c | 1 + drivers/cdrom/viocd.c | 3 ++- drivers/ide/ide-cd.c | 2 +- drivers/scsi/sr.c | 2 +- fs/block_dev.c | 17 ++++++++++------- include/linux/genhd.h | 1 + 6 files changed, 16 insertions(+), 10 deletions(-) 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 @@ static void pcd_init_units(void) 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 @@ static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id) 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 @@ static int ide_cd_probe(ide_drive_t *drive) 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 @@ static int sr_probe(struct device *dev) 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 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) 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 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) 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 @@ struct hd_struct { #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 */ _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
