diff options
| -rw-r--r-- | drivers/block/loop.c | 21 | ||||
| -rw-r--r-- | drivers/block/loop.h | 2 |
2 files changed, 13 insertions, 10 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 1bee523aa349..b3e294e529ec 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -831,7 +831,7 @@ static int loop_clr_fd(struct loop_device *lo) * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d * command to fail with EBUSY. */ - if (lo->lo_refcnt > 1) { + if (atomic_read(&lo->lo_refcnt) > 1) { lo->lo_flags |= LO_FLAGS_AUTOCLEAR; mutex_unlock(&lo->lo_ctl_mutex); return 0; @@ -840,6 +840,9 @@ static int loop_clr_fd(struct loop_device *lo) if (filp == NULL) return -EINVAL; + /* freeze request queue during the transition */ + blk_mq_freeze_queue(lo->lo_queue); + spin_lock_irq(&lo->lo_lock); lo->lo_state = Lo_rundown; lo->lo_backing_file = NULL; @@ -871,6 +874,8 @@ static int loop_clr_fd(struct loop_device *lo) lo->lo_state = Lo_unbound; /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); + blk_mq_unfreeze_queue(lo->lo_queue); + if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev) ioctl_by_bdev(bdev, BLKRRPART, 0); lo->lo_flags = 0; @@ -1330,9 +1335,7 @@ static int lo_open(struct block_device *bdev, fmode_t mode) goto out; } - mutex_lock(&lo->lo_ctl_mutex); - lo->lo_refcnt++; - mutex_unlock(&lo->lo_ctl_mutex); + atomic_inc(&lo->lo_refcnt); out: mutex_unlock(&loop_index_mutex); return err; @@ -1343,11 +1346,10 @@ static void lo_release(struct gendisk *disk, fmode_t mode) struct loop_device *lo = disk->private_data; int err; - mutex_lock(&lo->lo_ctl_mutex); - - if (--lo->lo_refcnt) - goto out; + if (atomic_dec_return(&lo->lo_refcnt)) + return; + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { /* * In autoclear mode, stop the loop thread @@ -1601,6 +1603,7 @@ static int loop_add(struct loop_device **l, int i) disk->flags |= GENHD_FL_NO_PART_SCAN; disk->flags |= GENHD_FL_EXT_DEVT; mutex_init(&lo->lo_ctl_mutex); + atomic_set(&lo->lo_refcnt, 0); lo->lo_number = i; spin_lock_init(&lo->lo_lock); disk->major = LOOP_MAJOR; @@ -1718,7 +1721,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, mutex_unlock(&lo->lo_ctl_mutex); break; } - if (lo->lo_refcnt > 0) { + if (atomic_read(&lo->lo_refcnt) > 0) { ret = -EBUSY; mutex_unlock(&lo->lo_ctl_mutex); break; diff --git a/drivers/block/loop.h b/drivers/block/loop.h index 49564edf5581..25e8997ed246 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -28,7 +28,7 @@ struct loop_func_table; struct loop_device { int lo_number; - int lo_refcnt; + atomic_t lo_refcnt; loff_t lo_offset; loff_t lo_sizelimit; int lo_flags; |