1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
30 * Use is subject to license terms.
32 * Copyright (c) 2011 Whamcloud, Inc.
36 * This file is part of Lustre, http://www.lustre.org/
37 * Lustre is a trademark of Sun Microsystems, Inc.
41 * linux/drivers/block/loop.c
43 * Written by Theodore Ts'o, 3/29/93
45 * Copyright 1993 by Theodore Ts'o. Redistribution of this file is
46 * permitted under the GNU General Public License.
48 * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994
49 * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996
51 * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997
53 * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998
55 * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998
57 * Loadable modules and other fixes by AK, 1998
59 * Maximum number of loop devices now dynamic via max_loop module parameter.
60 * Russell Kroll <rkroll@exploits.org> 19990701
62 * Maximum number of loop devices when compiled-in now selectable by passing
63 * max_loop=<1-255> to the kernel on boot.
64 * Erik I. Bols?, <eriki@himolde.no>, Oct 31, 1999
66 * Completely rewrite request handling to be make_request_fn style and
67 * non blocking, pushing work to a helper thread. Lots of fixes from
69 * Jens Axboe <axboe@suse.de>, Nov 2000
71 * Support up to 256 loop devices
72 * Heinz Mauelshagen <mge@sistina.com>, Feb 2002
74 * Support for falling back on the write file operation when the address space
75 * operations prepare_write and/or commit_write are not available on the
77 * Anton Altaparmakov, 16 Feb 2005
80 * - Advisory locking is ignored here.
81 * - Should use an own CAP_* category instead of CAP_SYS_ADMIN
85 #ifndef AUTOCONF_INCLUDED
86 #include <linux/config.h>
88 #include <linux/module.h>
90 #include <linux/sched.h>
92 #include <linux/file.h>
93 #include <linux/stat.h>
94 #include <linux/errno.h>
95 #include <linux/major.h>
96 #include <linux/wait.h>
97 #include <linux/blkdev.h>
98 #include <linux/blkpg.h>
99 #include <linux/init.h>
100 #include <linux/smp_lock.h>
101 #include <linux/swap.h>
102 #include <linux/slab.h>
103 #include <linux/suspend.h>
104 #include <linux/writeback.h>
105 #include <linux/buffer_head.h> /* for invalidate_bdev() */
106 #include <linux/completion.h>
107 #include <linux/highmem.h>
108 #include <linux/gfp.h>
109 #include <linux/swap.h>
110 #include <linux/pagevec.h>
112 #include <asm/uaccess.h>
114 #include <lustre_lib.h>
115 #include <lustre_lite.h>
116 #include "llite_internal.h"
118 #define LLOOP_MAX_SEGMENTS PTLRPC_MAX_BRW_PAGES
120 /* Possible states of device */
127 struct lloop_device {
133 int (*ioctl)(struct lloop_device *, int cmd,
136 struct file *lo_backing_file;
137 struct block_device *lo_device;
138 unsigned lo_blocksize;
142 cfs_spinlock_t lo_lock;
144 struct bio *lo_biotail;
146 cfs_semaphore_t lo_sem;
147 cfs_semaphore_t lo_ctl_mutex;
148 cfs_atomic_t lo_pending;
149 cfs_waitq_t lo_bh_wait;
151 struct request_queue *lo_queue;
153 const struct lu_env *lo_env;
155 struct ll_dio_pages lo_pvec;
157 /* data to handle bio for lustre. */
158 struct lo_request_data {
159 struct page *lrd_pages[LLOOP_MAX_SEGMENTS];
160 loff_t lrd_offsets[LLOOP_MAX_SEGMENTS];
168 LO_FLAGS_READ_ONLY = 1,
171 static int lloop_major;
172 #define MAX_LOOP_DEFAULT 16
173 static int max_loop = MAX_LOOP_DEFAULT;
174 static struct lloop_device *loop_dev;
175 static struct gendisk **disks;
176 static cfs_semaphore_t lloop_mutex;
177 static void *ll_iocontrol_magic = NULL;
179 static loff_t get_loop_size(struct lloop_device *lo, struct file *file)
181 loff_t size, offset, loopsize;
183 /* Compute loopsize in bytes */
184 size = i_size_read(file->f_mapping->host);
185 offset = lo->lo_offset;
186 loopsize = size - offset;
187 if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize)
188 loopsize = lo->lo_sizelimit;
191 * Unfortunately, if we want to do I/O on the device,
192 * the number of 512-byte sectors has to fit into a sector_t.
194 return loopsize >> 9;
197 static int do_bio_lustrebacked(struct lloop_device *lo, struct bio *head)
199 const struct lu_env *env = lo->lo_env;
200 struct cl_io *io = &lo->lo_io;
201 struct inode *inode = lo->lo_backing_file->f_dentry->d_inode;
202 struct cl_object *obj = ll_i2info(inode)->lli_clob;
207 obd_count page_count = 0;
208 struct bio_vec *bvec;
212 struct ll_dio_pages *pvec = &lo->lo_pvec;
213 struct page **pages = pvec->ldp_pages;
214 loff_t *offsets = pvec->ldp_offsets;
216 truncate_inode_pages(inode->i_mapping, 0);
218 /* initialize the IO */
219 memset(io, 0, sizeof(*io));
221 ret = cl_io_init(env, io, CIT_MISC, obj);
223 return io->ci_result;
224 io->ci_lockreq = CILR_NEVER;
226 LASSERT(head != NULL);
228 for (bio = head; bio != NULL; bio = bio->bi_next) {
229 LASSERT(rw == bio->bi_rw);
231 offset = (pgoff_t)(bio->bi_sector << 9) + lo->lo_offset;
232 bio_for_each_segment(bvec, bio, i) {
233 BUG_ON(bvec->bv_offset != 0);
234 BUG_ON(bvec->bv_len != CFS_PAGE_SIZE);
236 pages[page_count] = bvec->bv_page;
237 offsets[page_count] = offset;
239 offset += bvec->bv_len;
241 LASSERT(page_count <= LLOOP_MAX_SEGMENTS);
244 ll_stats_ops_tally(ll_i2sbi(inode),
245 (rw == WRITE) ? LPROC_LL_BRW_WRITE : LPROC_LL_BRW_READ,
248 pvec->ldp_size = page_count << PAGE_CACHE_SHIFT;
249 pvec->ldp_nr = page_count;
251 /* FIXME: in ll_direct_rw_pages, it has to allocate many cl_page{}s to
252 * write those pages into OST. Even worse case is that more pages
253 * would be asked to write out to swap space, and then finally get here
255 * Unfortunately this is NOT easy to fix.
256 * Thoughts on solution:
257 * 0. Define a reserved pool for cl_pages, which could be a list of
258 * pre-allocated cl_pages from cl_page_kmem;
259 * 1. Define a new operation in cl_object_operations{}, says clo_depth,
260 * which measures how many layers for this lustre object. Generally
261 * speaking, the depth would be 2, one for llite, and one for lovsub.
262 * However, for SNS, there will be more since we need additional page
264 * 2. Reserve the # of (page_count * depth) cl_pages from the reserved
265 * pool. Afterwards, the clio would allocate the pages from reserved
266 * pool, this guarantees we neeedn't allocate the cl_pages from
267 * generic cl_page slab cache.
268 * Of course, if there is NOT enough pages in the pool, we might
269 * be asked to write less pages once, this purely depends on
270 * implementation. Anyway, we should be careful to avoid deadlocking.
272 LOCK_INODE_MUTEX(inode);
273 bytes = ll_direct_rw_pages(env, io, rw, inode, pvec);
274 UNLOCK_INODE_MUTEX(inode);
276 return (bytes == pvec->ldp_size) ? 0 : (int)bytes;
280 * Add bio to back of pending list
282 static void loop_add_bio(struct lloop_device *lo, struct bio *bio)
286 cfs_spin_lock_irqsave(&lo->lo_lock, flags);
287 if (lo->lo_biotail) {
288 lo->lo_biotail->bi_next = bio;
289 lo->lo_biotail = bio;
291 lo->lo_bio = lo->lo_biotail = bio;
292 cfs_spin_unlock_irqrestore(&lo->lo_lock, flags);
294 cfs_atomic_inc(&lo->lo_pending);
295 if (cfs_waitq_active(&lo->lo_bh_wait))
296 cfs_waitq_signal(&lo->lo_bh_wait);
300 * Grab first pending buffer
302 static unsigned int loop_get_bio(struct lloop_device *lo, struct bio **req)
306 unsigned int count = 0;
307 unsigned int page_count = 0;
310 cfs_spin_lock_irq(&lo->lo_lock);
312 if (unlikely(first == NULL)) {
313 cfs_spin_unlock_irq(&lo->lo_lock);
317 /* TODO: need to split the bio, too bad. */
318 LASSERT(first->bi_vcnt <= LLOOP_MAX_SEGMENTS);
322 while (*bio && (*bio)->bi_rw == rw) {
323 CDEBUG(D_INFO, "bio sector %llu size %u count %u vcnt%u \n",
324 (unsigned long long)(*bio)->bi_sector, (*bio)->bi_size,
325 page_count, (*bio)->bi_vcnt);
326 if (page_count + (*bio)->bi_vcnt > LLOOP_MAX_SEGMENTS)
330 page_count += (*bio)->bi_vcnt;
332 bio = &(*bio)->bi_next;
335 /* Some of bios can't be mergable. */
339 /* Hit the end of queue */
340 lo->lo_biotail = NULL;
344 cfs_spin_unlock_irq(&lo->lo_lock);
348 static int loop_make_request(struct request_queue *q, struct bio *old_bio)
350 struct lloop_device *lo = q->queuedata;
351 int rw = bio_rw(old_bio);
357 CDEBUG(D_INFO, "submit bio sector %llu size %u\n",
358 (unsigned long long)old_bio->bi_sector, old_bio->bi_size);
360 cfs_spin_lock_irq(&lo->lo_lock);
361 inactive = (lo->lo_state != LLOOP_BOUND);
362 cfs_spin_unlock_irq(&lo->lo_lock);
367 if (lo->lo_flags & LO_FLAGS_READ_ONLY)
369 } else if (rw == READA) {
371 } else if (rw != READ) {
372 CERROR("lloop: unknown command (%x)\n", rw);
375 loop_add_bio(lo, old_bio);
378 cfs_bio_io_error(old_bio, old_bio->bi_size);
382 #ifdef HAVE_REQUEST_QUEUE_UNPLUG_FN
384 * kick off io on the underlying address space
386 static void loop_unplug(struct request_queue *q)
388 struct lloop_device *lo = q->queuedata;
390 clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
391 blk_run_address_space(lo->lo_backing_file->f_mapping);
395 static inline void loop_handle_bio(struct lloop_device *lo, struct bio *bio)
398 ret = do_bio_lustrebacked(lo, bio);
400 struct bio *tmp = bio->bi_next;
402 cfs_bio_endio(bio, bio->bi_size, ret);
407 static inline int loop_active(struct lloop_device *lo)
409 return cfs_atomic_read(&lo->lo_pending) ||
410 (lo->lo_state == LLOOP_RUNDOWN);
414 * worker thread that handles reads/writes to file backed loop devices,
415 * to avoid blocking in our make_request_fn.
417 static int loop_thread(void *data)
419 struct lloop_device *lo = data;
422 unsigned long times = 0;
423 unsigned long total_count = 0;
429 daemonize("lloop%d", lo->lo_number);
431 set_user_nice(current, -20);
433 lo->lo_state = LLOOP_BOUND;
435 env = cl_env_get(&refcheck);
437 GOTO(out, ret = PTR_ERR(env));
440 memset(&lo->lo_pvec, 0, sizeof(lo->lo_pvec));
441 lo->lo_pvec.ldp_pages = lo->lo_requests[0].lrd_pages;
442 lo->lo_pvec.ldp_offsets = lo->lo_requests[0].lrd_offsets;
445 * up sem, we are running
450 cfs_wait_event(lo->lo_bh_wait, loop_active(lo));
451 if (!cfs_atomic_read(&lo->lo_pending)) {
453 cfs_spin_lock_irq(&lo->lo_lock);
454 exiting = (lo->lo_state == LLOOP_RUNDOWN);
455 cfs_spin_unlock_irq(&lo->lo_lock);
461 count = loop_get_bio(lo, &bio);
463 CWARN("lloop(minor: %d): missing bio\n", lo->lo_number);
467 total_count += count;
468 if (total_count < count) { /* overflow */
474 if ((times & 127) == 0) {
475 CDEBUG(D_INFO, "total: %lu, count: %lu, avg: %lu\n",
476 total_count, times, total_count / times);
479 LASSERT(bio != NULL);
480 LASSERT(count <= cfs_atomic_read(&lo->lo_pending));
481 loop_handle_bio(lo, bio);
482 cfs_atomic_sub(count, &lo->lo_pending);
484 cl_env_put(env, &refcheck);
491 static int loop_set_fd(struct lloop_device *lo, struct file *unused,
492 struct block_device *bdev, struct file *file)
495 struct address_space *mapping;
500 if (!cfs_try_module_get(THIS_MODULE))
504 if (lo->lo_state != LLOOP_UNBOUND)
507 mapping = file->f_mapping;
508 inode = mapping->host;
511 if (!S_ISREG(inode->i_mode) || inode->i_sb->s_magic != LL_SUPER_MAGIC)
514 if (!(file->f_mode & FMODE_WRITE))
515 lo_flags |= LO_FLAGS_READ_ONLY;
517 size = get_loop_size(lo, file);
519 if ((loff_t)(sector_t)size != size) {
524 /* remove all pages in cache so as dirty pages not to be existent. */
525 truncate_inode_pages(mapping, 0);
527 set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
529 lo->lo_blocksize = CFS_PAGE_SIZE;
530 lo->lo_device = bdev;
531 lo->lo_flags = lo_flags;
532 lo->lo_backing_file = file;
534 lo->lo_sizelimit = 0;
535 lo->old_gfp_mask = mapping_gfp_mask(mapping);
536 mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
538 lo->lo_bio = lo->lo_biotail = NULL;
541 * set queue make_request_fn, and add limits based on lower level
544 blk_queue_make_request(lo->lo_queue, loop_make_request);
545 lo->lo_queue->queuedata = lo;
546 #ifdef HAVE_REQUEST_QUEUE_UNPLUG_FN
547 lo->lo_queue->unplug_fn = loop_unplug;
550 /* queue parameters */
551 CLASSERT(CFS_PAGE_SIZE < (1 << (sizeof(unsigned short) * 8)));
552 blk_queue_logical_block_size(lo->lo_queue,
553 (unsigned short)CFS_PAGE_SIZE);
554 blk_queue_max_hw_sectors(lo->lo_queue,
555 LLOOP_MAX_SEGMENTS << (CFS_PAGE_SHIFT - 9));
556 blk_queue_max_segments(lo->lo_queue, LLOOP_MAX_SEGMENTS);
558 set_capacity(disks[lo->lo_number], size);
559 bd_set_size(bdev, size << 9);
561 set_blocksize(bdev, lo->lo_blocksize);
563 cfs_create_thread(loop_thread, lo, CLONE_KERNEL);
564 cfs_down(&lo->lo_sem);
568 /* This is safe: open() is still holding a reference. */
569 cfs_module_put(THIS_MODULE);
573 static int loop_clr_fd(struct lloop_device *lo, struct block_device *bdev,
576 struct file *filp = lo->lo_backing_file;
577 int gfp = lo->old_gfp_mask;
579 if (lo->lo_state != LLOOP_BOUND)
582 if (lo->lo_refcnt > count) /* we needed one fd for the ioctl */
588 cfs_spin_lock_irq(&lo->lo_lock);
589 lo->lo_state = LLOOP_RUNDOWN;
590 cfs_spin_unlock_irq(&lo->lo_lock);
591 cfs_waitq_signal(&lo->lo_bh_wait);
593 cfs_down(&lo->lo_sem);
594 lo->lo_backing_file = NULL;
596 lo->lo_device = NULL;
598 lo->lo_sizelimit = 0;
600 ll_invalidate_bdev(bdev, 0);
601 set_capacity(disks[lo->lo_number], 0);
602 bd_set_size(bdev, 0);
603 mapping_set_gfp_mask(filp->f_mapping, gfp);
604 lo->lo_state = LLOOP_UNBOUND;
606 /* This is safe: open() is still holding a reference. */
607 cfs_module_put(THIS_MODULE);
611 #ifdef HAVE_BLKDEV_PUT_2ARGS
612 static int lo_open(struct block_device *bdev, fmode_t mode)
614 struct lloop_device *lo = bdev->bd_disk->private_data;
616 static int lo_open(struct inode *inode, struct file *file)
618 struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
621 cfs_down(&lo->lo_ctl_mutex);
623 cfs_up(&lo->lo_ctl_mutex);
628 #ifdef HAVE_BLKDEV_PUT_2ARGS
629 static int lo_release(struct gendisk *disk, fmode_t mode)
631 struct lloop_device *lo = disk->private_data;
633 static int lo_release(struct inode *inode, struct file *file)
635 struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
638 cfs_down(&lo->lo_ctl_mutex);
640 cfs_up(&lo->lo_ctl_mutex);
645 /* lloop device node's ioctl function. */
646 #ifdef HAVE_BLKDEV_PUT_2ARGS
647 static int lo_ioctl(struct block_device *bdev, fmode_t mode,
648 unsigned int cmd, unsigned long arg)
650 struct lloop_device *lo = bdev->bd_disk->private_data;
651 struct inode *inode = lo->lo_backing_file->f_dentry->d_inode;
653 static int lo_ioctl(struct inode *inode, struct file *unused,
654 unsigned int cmd, unsigned long arg)
656 struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
657 struct block_device *bdev = inode->i_bdev;
661 cfs_down(&lloop_mutex);
663 case LL_IOC_LLOOP_DETACH: {
664 err = loop_clr_fd(lo, bdev, 2);
666 ll_blkdev_put(bdev, 0); /* grabbed in LLOOP_ATTACH */
670 case LL_IOC_LLOOP_INFO: {
673 if (lo->lo_state == LLOOP_BOUND)
674 fid = ll_i2info(inode)->lli_fid;
678 if (copy_to_user((struct lu_fid *)arg, &fid, sizeof(fid)))
687 cfs_up(&lloop_mutex);
692 static struct block_device_operations lo_fops = {
693 .owner = THIS_MODULE,
695 .release = lo_release,
699 /* dynamic iocontrol callback.
700 * This callback is registered in lloop_init and will be called by
703 * This is a llite regular file ioctl function. It takes the responsibility
704 * of attaching or detaching a file by a lloop's device numner.
706 static enum llioc_iter lloop_ioctl(struct inode *unused, struct file *file,
707 unsigned int cmd, unsigned long arg,
708 void *magic, int *rcp)
710 struct lloop_device *lo = NULL;
711 struct block_device *bdev = NULL;
715 if (magic != ll_iocontrol_magic)
719 GOTO(out1, err = -ENODEV);
721 CWARN("Enter llop_ioctl\n");
723 cfs_down(&lloop_mutex);
725 case LL_IOC_LLOOP_ATTACH: {
726 struct lloop_device *lo_free = NULL;
729 for (i = 0; i < max_loop; i++, lo = NULL) {
731 if (lo->lo_state == LLOOP_UNBOUND) {
736 if (lo->lo_backing_file->f_dentry->d_inode ==
737 file->f_dentry->d_inode)
741 GOTO(out, err = -EBUSY);
744 dev = MKDEV(lloop_major, lo->lo_number);
746 /* quit if the used pointer is writable */
747 if (put_user((long)old_encode_dev(dev), (long*)arg))
748 GOTO(out, err = -EFAULT);
750 bdev = blkdev_get_by_dev(dev, file->f_mode, NULL);
752 GOTO(out, err = PTR_ERR(bdev));
755 err = loop_set_fd(lo, NULL, bdev, file);
758 ll_blkdev_put(bdev, 0);
764 case LL_IOC_LLOOP_DETACH_BYDEV: {
767 dev = old_decode_dev(arg);
768 if (MAJOR(dev) != lloop_major)
769 GOTO(out, err = -EINVAL);
772 if (minor > max_loop - 1)
773 GOTO(out, err = -EINVAL);
775 lo = &loop_dev[minor];
776 if (lo->lo_state != LLOOP_BOUND)
777 GOTO(out, err = -EINVAL);
779 bdev = lo->lo_device;
780 err = loop_clr_fd(lo, bdev, 1);
782 ll_blkdev_put(bdev, 0); /* grabbed in LLOOP_ATTACH */
793 cfs_up(&lloop_mutex);
800 static int __init lloop_init(void)
803 unsigned int cmdlist[] = {
805 LL_IOC_LLOOP_DETACH_BYDEV,
808 if (max_loop < 1 || max_loop > 256) {
809 max_loop = MAX_LOOP_DEFAULT;
810 CWARN("lloop: invalid max_loop (must be between"
811 " 1 and 256), using default (%u)\n", max_loop);
814 lloop_major = register_blkdev(0, "lloop");
818 CDEBUG(D_CONFIG, "registered lloop major %d with %u minors\n",
819 lloop_major, max_loop);
821 ll_iocontrol_magic = ll_iocontrol_register(lloop_ioctl, 2, cmdlist);
822 if (ll_iocontrol_magic == NULL)
825 OBD_ALLOC_WAIT(loop_dev, max_loop * sizeof(*loop_dev));
829 OBD_ALLOC_WAIT(disks, max_loop * sizeof(*disks));
833 for (i = 0; i < max_loop; i++) {
834 disks[i] = alloc_disk(1);
839 cfs_init_mutex(&lloop_mutex);
841 for (i = 0; i < max_loop; i++) {
842 struct lloop_device *lo = &loop_dev[i];
843 struct gendisk *disk = disks[i];
845 lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
849 cfs_init_mutex(&lo->lo_ctl_mutex);
850 cfs_init_mutex_locked(&lo->lo_sem);
851 cfs_waitq_init(&lo->lo_bh_wait);
853 cfs_spin_lock_init(&lo->lo_lock);
854 disk->major = lloop_major;
855 disk->first_minor = i;
856 disk->fops = &lo_fops;
857 sprintf(disk->disk_name, "lloop%d", i);
858 disk->private_data = lo;
859 disk->queue = lo->lo_queue;
862 /* We cannot fail after we call this, so another loop!*/
863 for (i = 0; i < max_loop; i++)
869 blk_cleanup_queue(loop_dev[i].lo_queue);
874 OBD_FREE(disks, max_loop * sizeof(*disks));
876 OBD_FREE(loop_dev, max_loop * sizeof(*loop_dev));
878 unregister_blkdev(lloop_major, "lloop");
879 ll_iocontrol_unregister(ll_iocontrol_magic);
880 CERROR("lloop: ran out of memory\n");
884 static void lloop_exit(void)
888 ll_iocontrol_unregister(ll_iocontrol_magic);
889 for (i = 0; i < max_loop; i++) {
890 del_gendisk(disks[i]);
891 blk_cleanup_queue(loop_dev[i].lo_queue);
894 if (ll_unregister_blkdev(lloop_major, "lloop"))
895 CWARN("lloop: cannot unregister blkdev\n");
897 CDEBUG(D_CONFIG, "unregistered lloop major %d\n", lloop_major);
899 OBD_FREE(disks, max_loop * sizeof(*disks));
900 OBD_FREE(loop_dev, max_loop * sizeof(*loop_dev));
903 module_init(lloop_init);
904 module_exit(lloop_exit);
906 CFS_MODULE_PARM(max_loop, "i", int, 0444, "maximum of lloop_device");
907 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
908 MODULE_DESCRIPTION("Lustre virtual block device");
909 MODULE_LICENSE("GPL");