diff options
| -rw-r--r-- | drivers/block/loop.c | 69 | ||||
| -rw-r--r-- | include/linux/loop.h | 5 |
2 files changed, 26 insertions, 48 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index c774121684d..e87b88731ad 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -72,6 +72,7 @@ #include <linux/completion.h> #include <linux/highmem.h> #include <linux/gfp.h> +#include <linux/kthread.h> #include <asm/uaccess.h> @@ -522,15 +523,12 @@ static int loop_make_request(request_queue_t *q, struct bio *old_bio) goto out; if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY))) goto out; - lo->lo_pending++; loop_add_bio(lo, old_bio); + wake_up(&lo->lo_event); spin_unlock_irq(&lo->lo_lock); - complete(&lo->lo_bh_done); return 0; out: - if (lo->lo_pending == 0) - complete(&lo->lo_bh_done); spin_unlock_irq(&lo->lo_lock); bio_io_error(old_bio, old_bio->bi_size); return 0; @@ -570,14 +568,18 @@ static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) * to avoid blocking in our make_request_fn. it also does loop decrypting * on reads for block backed loop, as that is too heavy to do from * b_end_io context where irqs may be disabled. + * + * Loop explanation: loop_clr_fd() sets lo_state to Lo_rundown before + * calling kthread_stop(). Therefore once kthread_should_stop() is + * true, make_request will not place any more requests. Therefore + * once kthread_should_stop() is true and lo_bio is NULL, we are + * done with the loop. */ static int loop_thread(void *data) { struct loop_device *lo = data; struct bio *bio; - daemonize("loop%d", lo->lo_number); - /* * loop can be used in an encrypted device, * hence, it mustn't be stopped at all @@ -587,47 +589,21 @@ static int loop_thread(void *data) set_user_nice(current, -20); - lo->lo_state = Lo_bound; - lo->lo_pending = 1; - - /* - * complete it, we are running - */ - complete(&lo->lo_done); + while (!kthread_should_stop() || lo->lo_bio) { - for (;;) { - int pending; + wait_event_interruptible(lo->lo_event, + lo->lo_bio || kthread_should_stop()); - if (wait_for_completion_interruptible(&lo->lo_bh_done)) + if (!lo->lo_bio) continue; - spin_lock_irq(&lo->lo_lock); - - /* - * could be completed because of tear-down, not pending work - */ - if (unlikely(!lo->lo_pending)) { - spin_unlock_irq(&lo->lo_lock); - break; - } - bio = loop_get_bio(lo); - lo->lo_pending--; - pending = lo->lo_pending; spin_unlock_irq(&lo->lo_lock); BUG_ON(!bio); loop_handle_bio(lo, bio); - - /* - * upped both for pending work and tear-down, lo_pending - * will hit zero then - */ - if (unlikely(!pending)) - break; } - complete(&lo->lo_done); return 0; } @@ -840,10 +816,15 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, set_blocksize(bdev, lo_blocksize); - error = kernel_thread(loop_thread, lo, CLONE_KERNEL); - if (error < 0) + lo->lo_thread = kthread_create(loop_thread, lo, "loop%d", + lo->lo_number); + if (IS_ERR(lo->lo_thread)) { + error = PTR_ERR(lo->lo_thread); + lo->lo_thread = NULL; goto out_putf; - wait_for_completion(&lo->lo_done); + } + lo->lo_state = Lo_bound; + wake_up_process(lo->lo_thread); return 0; out_putf: @@ -907,12 +888,9 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) spin_lock_irq(&lo->lo_lock); lo->lo_state = Lo_rundown; - lo->lo_pending--; - if (!lo->lo_pending) - complete(&lo->lo_bh_done); spin_unlock_irq(&lo->lo_lock); - wait_for_completion(&lo->lo_done); + kthread_stop(lo->lo_thread); lo->lo_backing_file = NULL; @@ -925,6 +903,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) lo->lo_sizelimit = 0; lo->lo_encrypt_key_size = 0; lo->lo_flags = 0; + lo->lo_thread = NULL; memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); memset(lo->lo_file_name, 0, LO_NAME_SIZE); @@ -1287,9 +1266,9 @@ static int __init loop_init(void) if (!lo->lo_queue) goto out_mem4; mutex_init(&lo->lo_ctl_mutex); - init_completion(&lo->lo_done); - init_completion(&lo->lo_bh_done); lo->lo_number = i; + lo->lo_thread = NULL; + init_waitqueue_head(&lo->lo_event); spin_lock_init(&lo->lo_lock); disk->major = LOOP_MAJOR; disk->first_minor = i; diff --git a/include/linux/loop.h b/include/linux/loop.h index e76c7611d6c..191a595055f 100644 --- a/include/linux/loop.h +++ b/include/linux/loop.h @@ -59,10 +59,9 @@ struct loop_device { struct bio *lo_bio; struct bio *lo_biotail; int lo_state; - struct completion lo_done; - struct completion lo_bh_done; struct mutex lo_ctl_mutex; - int lo_pending; + struct task_struct *lo_thread; + wait_queue_head_t lo_event; request_queue_t *lo_queue; }; |