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: v2.6.38.8~119 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c63356c3ed12f1242ec7fb4b14a6a28b0e0c72a2;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 2f2ccf6862519..a0aabd904a512 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 4e874c5fa6059..ae15a4ddaa9b0 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 a2e29099ee0c1..413e4ef60356e 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -1790,7 +1790,7 @@ 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 aefadc6a16072..464ee7ba95b7e 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 0920e7cfde5ac..59277ba8d2903 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1233,6 +1233,8 @@ 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); @@ -1259,15 +1261,16 @@ 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 c0d5f6945c1eb..035bc67051ce5 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 */