From: Tejun Heo Date: Thu, 21 Apr 2011 18:54:46 +0000 (+0200) Subject: block: don't block events on excl write for non-optical devices X-Git-Tag: v2.6.39.1~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9a18274e9444e3581a6ba7479ddad080d1be63c0;p=thirdparty%2Fkernel%2Fstable.git block: don't block events on excl write for non-optical devices commit d4dc210f69bcb0b4bef5a83b1c323817be89bad1 upstream. 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 Signed-off-by: Tejun Heo Reported-by: Kay Sievers Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c index 8690e31d99328..46b8136c31bbe 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; } } diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c index e427fbe459994..7878da89d29e2 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; set_capacity(gendisk, 0); gendisk->private_data = d; d->viocd_disk = gendisk; diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index a5ec5a7cb381b..95608228b981a 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -1773,7 +1773,8 @@ static int ide_cd_probe(ide_drive_t *drive) g->minors = 1; g->driverfs_dev = &drive->gendev; - g->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE; + g->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE | + GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE; if (ide_cdrom_setup(drive)) { put_device(&info->dev); goto failed; diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 95019c747cc17..4778e27071689 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 bf9c7a7203717..1f2b199783334 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1238,6 +1238,8 @@ 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); @@ -1264,15 +1266,16 @@ 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 d764a426e9fdb..300d7582006e4 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 */