11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/drivers/block/loop.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Written by Theodore Ts'o, 3/29/93 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Copyright 1993 by Theodore Ts'o. Redistribution of this file is 71da177e4SLinus Torvalds * permitted under the GNU General Public License. 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 101da177e4SLinus Torvalds * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 131da177e4SLinus Torvalds * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 141da177e4SLinus Torvalds * 151da177e4SLinus Torvalds * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 161da177e4SLinus Torvalds * 171da177e4SLinus Torvalds * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998 181da177e4SLinus Torvalds * 191da177e4SLinus Torvalds * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 201da177e4SLinus Torvalds * 211da177e4SLinus Torvalds * Loadable modules and other fixes by AK, 1998 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds * Make real block number available to downstream transfer functions, enables 241da177e4SLinus Torvalds * CBC (and relatives) mode encryption requiring unique IVs per data block. 251da177e4SLinus Torvalds * Reed H. Petty, rhp@draper.net 261da177e4SLinus Torvalds * 271da177e4SLinus Torvalds * Maximum number of loop devices now dynamic via max_loop module parameter. 281da177e4SLinus Torvalds * Russell Kroll <rkroll@exploits.org> 19990701 291da177e4SLinus Torvalds * 301da177e4SLinus Torvalds * Maximum number of loop devices when compiled-in now selectable by passing 311da177e4SLinus Torvalds * max_loop=<1-255> to the kernel on boot. 3296de0e25SJan Engelhardt * Erik I. Bolsø, <eriki@himolde.no>, Oct 31, 1999 331da177e4SLinus Torvalds * 341da177e4SLinus Torvalds * Completely rewrite request handling to be make_request_fn style and 351da177e4SLinus Torvalds * non blocking, pushing work to a helper thread. Lots of fixes from 361da177e4SLinus Torvalds * Al Viro too. 371da177e4SLinus Torvalds * Jens Axboe <axboe@suse.de>, Nov 2000 381da177e4SLinus Torvalds * 391da177e4SLinus Torvalds * Support up to 256 loop devices 401da177e4SLinus Torvalds * Heinz Mauelshagen <mge@sistina.com>, Feb 2002 411da177e4SLinus Torvalds * 421da177e4SLinus Torvalds * Support for falling back on the write file operation when the address space 434e02ed4bSNick Piggin * operations write_begin is not available on the backing filesystem. 441da177e4SLinus Torvalds * Anton Altaparmakov, 16 Feb 2005 451da177e4SLinus Torvalds * 461da177e4SLinus Torvalds * Still To Fix: 471da177e4SLinus Torvalds * - Advisory locking is ignored here. 481da177e4SLinus Torvalds * - Should use an own CAP_* category instead of CAP_SYS_ADMIN 491da177e4SLinus Torvalds * 501da177e4SLinus Torvalds */ 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds #include <linux/module.h> 531da177e4SLinus Torvalds #include <linux/moduleparam.h> 541da177e4SLinus Torvalds #include <linux/sched.h> 551da177e4SLinus Torvalds #include <linux/fs.h> 561da177e4SLinus Torvalds #include <linux/file.h> 571da177e4SLinus Torvalds #include <linux/stat.h> 581da177e4SLinus Torvalds #include <linux/errno.h> 591da177e4SLinus Torvalds #include <linux/major.h> 601da177e4SLinus Torvalds #include <linux/wait.h> 611da177e4SLinus Torvalds #include <linux/blkdev.h> 621da177e4SLinus Torvalds #include <linux/blkpg.h> 631da177e4SLinus Torvalds #include <linux/init.h> 641da177e4SLinus Torvalds #include <linux/swap.h> 651da177e4SLinus Torvalds #include <linux/slab.h> 66863d5b82SDavid Howells #include <linux/compat.h> 671da177e4SLinus Torvalds #include <linux/suspend.h> 6883144186SRafael J. Wysocki #include <linux/freezer.h> 692a48fc0aSArnd Bergmann #include <linux/mutex.h> 701da177e4SLinus Torvalds #include <linux/writeback.h> 711da177e4SLinus Torvalds #include <linux/completion.h> 721da177e4SLinus Torvalds #include <linux/highmem.h> 736c997918SSerge E. Hallyn #include <linux/kthread.h> 74d6b29d7cSJens Axboe #include <linux/splice.h> 75ee862730SMilan Broz #include <linux/sysfs.h> 76770fe30aSKay Sievers #include <linux/miscdevice.h> 77dfaa2ef6SLukas Czerner #include <linux/falloc.h> 78b5dd2f60SMing Lei #include <linux/blk-mq.h> 7983a87611SAl Viro #include "loop.h" 801da177e4SLinus Torvalds 811da177e4SLinus Torvalds #include <asm/uaccess.h> 821da177e4SLinus Torvalds 8334dd82afSKay Sievers static DEFINE_IDR(loop_index_idr); 8434dd82afSKay Sievers static DEFINE_MUTEX(loop_index_mutex); 851da177e4SLinus Torvalds 86476a4813SLaurent Vivier static int max_part; 87476a4813SLaurent Vivier static int part_shift; 88476a4813SLaurent Vivier 89b5dd2f60SMing Lei static struct workqueue_struct *loop_wq; 90b5dd2f60SMing Lei 911da177e4SLinus Torvalds /* 921da177e4SLinus Torvalds * Transfer functions 931da177e4SLinus Torvalds */ 941da177e4SLinus Torvalds static int transfer_none(struct loop_device *lo, int cmd, 951da177e4SLinus Torvalds struct page *raw_page, unsigned raw_off, 961da177e4SLinus Torvalds struct page *loop_page, unsigned loop_off, 971da177e4SLinus Torvalds int size, sector_t real_block) 981da177e4SLinus Torvalds { 99cfd8005cSCong Wang char *raw_buf = kmap_atomic(raw_page) + raw_off; 100cfd8005cSCong Wang char *loop_buf = kmap_atomic(loop_page) + loop_off; 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds if (cmd == READ) 1031da177e4SLinus Torvalds memcpy(loop_buf, raw_buf, size); 1041da177e4SLinus Torvalds else 1051da177e4SLinus Torvalds memcpy(raw_buf, loop_buf, size); 1061da177e4SLinus Torvalds 107cfd8005cSCong Wang kunmap_atomic(loop_buf); 108cfd8005cSCong Wang kunmap_atomic(raw_buf); 1091da177e4SLinus Torvalds cond_resched(); 1101da177e4SLinus Torvalds return 0; 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds 1131da177e4SLinus Torvalds static int transfer_xor(struct loop_device *lo, int cmd, 1141da177e4SLinus Torvalds struct page *raw_page, unsigned raw_off, 1151da177e4SLinus Torvalds struct page *loop_page, unsigned loop_off, 1161da177e4SLinus Torvalds int size, sector_t real_block) 1171da177e4SLinus Torvalds { 118cfd8005cSCong Wang char *raw_buf = kmap_atomic(raw_page) + raw_off; 119cfd8005cSCong Wang char *loop_buf = kmap_atomic(loop_page) + loop_off; 1201da177e4SLinus Torvalds char *in, *out, *key; 1211da177e4SLinus Torvalds int i, keysize; 1221da177e4SLinus Torvalds 1231da177e4SLinus Torvalds if (cmd == READ) { 1241da177e4SLinus Torvalds in = raw_buf; 1251da177e4SLinus Torvalds out = loop_buf; 1261da177e4SLinus Torvalds } else { 1271da177e4SLinus Torvalds in = loop_buf; 1281da177e4SLinus Torvalds out = raw_buf; 1291da177e4SLinus Torvalds } 1301da177e4SLinus Torvalds 1311da177e4SLinus Torvalds key = lo->lo_encrypt_key; 1321da177e4SLinus Torvalds keysize = lo->lo_encrypt_key_size; 1331da177e4SLinus Torvalds for (i = 0; i < size; i++) 1341da177e4SLinus Torvalds *out++ = *in++ ^ key[(i & 511) % keysize]; 1351da177e4SLinus Torvalds 136cfd8005cSCong Wang kunmap_atomic(loop_buf); 137cfd8005cSCong Wang kunmap_atomic(raw_buf); 1381da177e4SLinus Torvalds cond_resched(); 1391da177e4SLinus Torvalds return 0; 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds static int xor_init(struct loop_device *lo, const struct loop_info64 *info) 1431da177e4SLinus Torvalds { 1441da177e4SLinus Torvalds if (unlikely(info->lo_encrypt_key_size <= 0)) 1451da177e4SLinus Torvalds return -EINVAL; 1461da177e4SLinus Torvalds return 0; 1471da177e4SLinus Torvalds } 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds static struct loop_func_table none_funcs = { 1501da177e4SLinus Torvalds .number = LO_CRYPT_NONE, 1511da177e4SLinus Torvalds .transfer = transfer_none, 1521da177e4SLinus Torvalds }; 1531da177e4SLinus Torvalds 1541da177e4SLinus Torvalds static struct loop_func_table xor_funcs = { 1551da177e4SLinus Torvalds .number = LO_CRYPT_XOR, 1561da177e4SLinus Torvalds .transfer = transfer_xor, 1571da177e4SLinus Torvalds .init = xor_init 1581da177e4SLinus Torvalds }; 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds /* xfer_funcs[0] is special - its release function is never called */ 1611da177e4SLinus Torvalds static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = { 1621da177e4SLinus Torvalds &none_funcs, 1631da177e4SLinus Torvalds &xor_funcs 1641da177e4SLinus Torvalds }; 1651da177e4SLinus Torvalds 1667035b5dfSDmitry Monakhov static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file) 1671da177e4SLinus Torvalds { 168b7a1da69SGuo Chao loff_t loopsize; 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds /* Compute loopsize in bytes */ 171b7a1da69SGuo Chao loopsize = i_size_read(file->f_mapping->host); 172b7a1da69SGuo Chao if (offset > 0) 173b7a1da69SGuo Chao loopsize -= offset; 174b7a1da69SGuo Chao /* offset is beyond i_size, weird but possible */ 1757035b5dfSDmitry Monakhov if (loopsize < 0) 1767035b5dfSDmitry Monakhov return 0; 1771da177e4SLinus Torvalds 1787035b5dfSDmitry Monakhov if (sizelimit > 0 && sizelimit < loopsize) 1797035b5dfSDmitry Monakhov loopsize = sizelimit; 1801da177e4SLinus Torvalds /* 1811da177e4SLinus Torvalds * Unfortunately, if we want to do I/O on the device, 1821da177e4SLinus Torvalds * the number of 512-byte sectors has to fit into a sector_t. 1831da177e4SLinus Torvalds */ 1841da177e4SLinus Torvalds return loopsize >> 9; 1851da177e4SLinus Torvalds } 1861da177e4SLinus Torvalds 1877035b5dfSDmitry Monakhov static loff_t get_loop_size(struct loop_device *lo, struct file *file) 1881da177e4SLinus Torvalds { 1897035b5dfSDmitry Monakhov return get_size(lo->lo_offset, lo->lo_sizelimit, file); 1907035b5dfSDmitry Monakhov } 1917035b5dfSDmitry Monakhov 1927035b5dfSDmitry Monakhov static int 1937035b5dfSDmitry Monakhov figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) 1947035b5dfSDmitry Monakhov { 1957035b5dfSDmitry Monakhov loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); 1961da177e4SLinus Torvalds sector_t x = (sector_t)size; 1977b0576a3SGuo Chao struct block_device *bdev = lo->lo_device; 1981da177e4SLinus Torvalds 1991da177e4SLinus Torvalds if (unlikely((loff_t)x != size)) 2001da177e4SLinus Torvalds return -EFBIG; 2017035b5dfSDmitry Monakhov if (lo->lo_offset != offset) 2027035b5dfSDmitry Monakhov lo->lo_offset = offset; 2037035b5dfSDmitry Monakhov if (lo->lo_sizelimit != sizelimit) 2047035b5dfSDmitry Monakhov lo->lo_sizelimit = sizelimit; 20573285082SKen Chen set_capacity(lo->lo_disk, x); 2067b0576a3SGuo Chao bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9); 2077b0576a3SGuo Chao /* let user-space know about the new size */ 2087b0576a3SGuo Chao kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); 2091da177e4SLinus Torvalds return 0; 2101da177e4SLinus Torvalds } 2111da177e4SLinus Torvalds 2121da177e4SLinus Torvalds static inline int 2131da177e4SLinus Torvalds lo_do_transfer(struct loop_device *lo, int cmd, 2141da177e4SLinus Torvalds struct page *rpage, unsigned roffs, 2151da177e4SLinus Torvalds struct page *lpage, unsigned loffs, 2161da177e4SLinus Torvalds int size, sector_t rblock) 2171da177e4SLinus Torvalds { 2181da177e4SLinus Torvalds if (unlikely(!lo->transfer)) 2191da177e4SLinus Torvalds return 0; 2201da177e4SLinus Torvalds 2211da177e4SLinus Torvalds return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock); 2221da177e4SLinus Torvalds } 2231da177e4SLinus Torvalds 2241da177e4SLinus Torvalds /** 2251da177e4SLinus Torvalds * __do_lo_send_write - helper for writing data to a loop device 2261da177e4SLinus Torvalds * 2271da177e4SLinus Torvalds * This helper just factors out common code between do_lo_send_direct_write() 2281da177e4SLinus Torvalds * and do_lo_send_write(). 2291da177e4SLinus Torvalds */ 230858119e1SArjan van de Ven static int __do_lo_send_write(struct file *file, 23198ae6ccdSAl Viro u8 *buf, const int len, loff_t pos) 2321da177e4SLinus Torvalds { 2331da177e4SLinus Torvalds ssize_t bw; 2341da177e4SLinus Torvalds mm_segment_t old_fs = get_fs(); 2351da177e4SLinus Torvalds 23603d95eb2SAl Viro file_start_write(file); 2371da177e4SLinus Torvalds set_fs(get_ds()); 2381da177e4SLinus Torvalds bw = file->f_op->write(file, buf, len, &pos); 2391da177e4SLinus Torvalds set_fs(old_fs); 24003d95eb2SAl Viro file_end_write(file); 2411da177e4SLinus Torvalds if (likely(bw == len)) 2421da177e4SLinus Torvalds return 0; 24344bd70c3SMike Galbraith printk_ratelimited(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n", 2441da177e4SLinus Torvalds (unsigned long long)pos, len); 2451da177e4SLinus Torvalds if (bw >= 0) 2461da177e4SLinus Torvalds bw = -EIO; 2471da177e4SLinus Torvalds return bw; 2481da177e4SLinus Torvalds } 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvalds /** 2511da177e4SLinus Torvalds * do_lo_send_direct_write - helper for writing data to a loop device 2521da177e4SLinus Torvalds * 253456be148SChristoph Hellwig * This is the fast, non-transforming version that does not need double 254456be148SChristoph Hellwig * buffering. 2551da177e4SLinus Torvalds */ 2561da177e4SLinus Torvalds static int do_lo_send_direct_write(struct loop_device *lo, 257511de73fSAl Viro struct bio_vec *bvec, loff_t pos, struct page *page) 2581da177e4SLinus Torvalds { 2591da177e4SLinus Torvalds ssize_t bw = __do_lo_send_write(lo->lo_backing_file, 26098ae6ccdSAl Viro kmap(bvec->bv_page) + bvec->bv_offset, 2611da177e4SLinus Torvalds bvec->bv_len, pos); 2621da177e4SLinus Torvalds kunmap(bvec->bv_page); 2631da177e4SLinus Torvalds cond_resched(); 2641da177e4SLinus Torvalds return bw; 2651da177e4SLinus Torvalds } 2661da177e4SLinus Torvalds 2671da177e4SLinus Torvalds /** 2681da177e4SLinus Torvalds * do_lo_send_write - helper for writing data to a loop device 2691da177e4SLinus Torvalds * 270456be148SChristoph Hellwig * This is the slow, transforming version that needs to double buffer the 271456be148SChristoph Hellwig * data as it cannot do the transformations in place without having direct 272456be148SChristoph Hellwig * access to the destination pages of the backing file. 2731da177e4SLinus Torvalds */ 2741da177e4SLinus Torvalds static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, 275511de73fSAl Viro loff_t pos, struct page *page) 2761da177e4SLinus Torvalds { 2771da177e4SLinus Torvalds int ret = lo_do_transfer(lo, WRITE, page, 0, bvec->bv_page, 2781da177e4SLinus Torvalds bvec->bv_offset, bvec->bv_len, pos >> 9); 2791da177e4SLinus Torvalds if (likely(!ret)) 2801da177e4SLinus Torvalds return __do_lo_send_write(lo->lo_backing_file, 28198ae6ccdSAl Viro page_address(page), bvec->bv_len, 2821da177e4SLinus Torvalds pos); 28344bd70c3SMike Galbraith printk_ratelimited(KERN_ERR "loop: Transfer error at byte offset %llu, " 2841da177e4SLinus Torvalds "length %i.\n", (unsigned long long)pos, bvec->bv_len); 2851da177e4SLinus Torvalds if (ret > 0) 2861da177e4SLinus Torvalds ret = -EIO; 2871da177e4SLinus Torvalds return ret; 2881da177e4SLinus Torvalds } 2891da177e4SLinus Torvalds 290511de73fSAl Viro static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) 2911da177e4SLinus Torvalds { 292511de73fSAl Viro int (*do_lo_send)(struct loop_device *, struct bio_vec *, loff_t, 2931da177e4SLinus Torvalds struct page *page); 2947988613bSKent Overstreet struct bio_vec bvec; 2957988613bSKent Overstreet struct bvec_iter iter; 2961da177e4SLinus Torvalds struct page *page = NULL; 2977988613bSKent Overstreet int ret = 0; 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds if (lo->transfer != transfer_none) { 3001da177e4SLinus Torvalds page = alloc_page(GFP_NOIO | __GFP_HIGHMEM); 3011da177e4SLinus Torvalds if (unlikely(!page)) 3021da177e4SLinus Torvalds goto fail; 3031da177e4SLinus Torvalds kmap(page); 3041da177e4SLinus Torvalds do_lo_send = do_lo_send_write; 305456be148SChristoph Hellwig } else { 306456be148SChristoph Hellwig do_lo_send = do_lo_send_direct_write; 3071da177e4SLinus Torvalds } 308456be148SChristoph Hellwig 3097988613bSKent Overstreet bio_for_each_segment(bvec, bio, iter) { 3107988613bSKent Overstreet ret = do_lo_send(lo, &bvec, pos, page); 3111da177e4SLinus Torvalds if (ret < 0) 3121da177e4SLinus Torvalds break; 3137988613bSKent Overstreet pos += bvec.bv_len; 3141da177e4SLinus Torvalds } 3151da177e4SLinus Torvalds if (page) { 3161da177e4SLinus Torvalds kunmap(page); 3171da177e4SLinus Torvalds __free_page(page); 3181da177e4SLinus Torvalds } 3191da177e4SLinus Torvalds out: 3201da177e4SLinus Torvalds return ret; 3211da177e4SLinus Torvalds fail: 32244bd70c3SMike Galbraith printk_ratelimited(KERN_ERR "loop: Failed to allocate temporary page for write.\n"); 3231da177e4SLinus Torvalds ret = -ENOMEM; 3241da177e4SLinus Torvalds goto out; 3251da177e4SLinus Torvalds } 3261da177e4SLinus Torvalds 3271da177e4SLinus Torvalds struct lo_read_data { 3281da177e4SLinus Torvalds struct loop_device *lo; 3291da177e4SLinus Torvalds struct page *page; 3301da177e4SLinus Torvalds unsigned offset; 3311da177e4SLinus Torvalds int bsize; 3321da177e4SLinus Torvalds }; 3331da177e4SLinus Torvalds 3341da177e4SLinus Torvalds static int 335fd582140SJens Axboe lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 336fd582140SJens Axboe struct splice_desc *sd) 3371da177e4SLinus Torvalds { 338fd582140SJens Axboe struct lo_read_data *p = sd->u.data; 3391da177e4SLinus Torvalds struct loop_device *lo = p->lo; 340fd582140SJens Axboe struct page *page = buf->page; 3411da177e4SLinus Torvalds sector_t IV; 3423603b8eaSJens Axboe int size; 3431da177e4SLinus Torvalds 344fd582140SJens Axboe IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9)) + 345fd582140SJens Axboe (buf->offset >> 9); 346fd582140SJens Axboe size = sd->len; 347fd582140SJens Axboe if (size > p->bsize) 348fd582140SJens Axboe size = p->bsize; 3491da177e4SLinus Torvalds 350fd582140SJens Axboe if (lo_do_transfer(lo, READ, page, buf->offset, p->page, p->offset, size, IV)) { 35144bd70c3SMike Galbraith printk_ratelimited(KERN_ERR "loop: transfer error block %ld\n", 3521da177e4SLinus Torvalds page->index); 353fd582140SJens Axboe size = -EINVAL; 3541da177e4SLinus Torvalds } 3551da177e4SLinus Torvalds 3561da177e4SLinus Torvalds flush_dcache_page(p->page); 3571da177e4SLinus Torvalds 358fd582140SJens Axboe if (size > 0) 3591da177e4SLinus Torvalds p->offset += size; 360fd582140SJens Axboe 3611da177e4SLinus Torvalds return size; 3621da177e4SLinus Torvalds } 3631da177e4SLinus Torvalds 3641da177e4SLinus Torvalds static int 365fd582140SJens Axboe lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) 366fd582140SJens Axboe { 367fd582140SJens Axboe return __splice_from_pipe(pipe, sd, lo_splice_actor); 368fd582140SJens Axboe } 369fd582140SJens Axboe 370306df071SDave Young static ssize_t 3711da177e4SLinus Torvalds do_lo_receive(struct loop_device *lo, 3721da177e4SLinus Torvalds struct bio_vec *bvec, int bsize, loff_t pos) 3731da177e4SLinus Torvalds { 3741da177e4SLinus Torvalds struct lo_read_data cookie; 375fd582140SJens Axboe struct splice_desc sd; 3761da177e4SLinus Torvalds struct file *file; 377306df071SDave Young ssize_t retval; 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds cookie.lo = lo; 3801da177e4SLinus Torvalds cookie.page = bvec->bv_page; 3811da177e4SLinus Torvalds cookie.offset = bvec->bv_offset; 3821da177e4SLinus Torvalds cookie.bsize = bsize; 383fd582140SJens Axboe 384fd582140SJens Axboe sd.len = 0; 385fd582140SJens Axboe sd.total_len = bvec->bv_len; 386fd582140SJens Axboe sd.flags = 0; 387fd582140SJens Axboe sd.pos = pos; 388fd582140SJens Axboe sd.u.data = &cookie; 389fd582140SJens Axboe 3901da177e4SLinus Torvalds file = lo->lo_backing_file; 391fd582140SJens Axboe retval = splice_direct_to_actor(file, &sd, lo_direct_splice_actor); 392fd582140SJens Axboe 393fd582140SJens Axboe return retval; 3941da177e4SLinus Torvalds } 3951da177e4SLinus Torvalds 3961da177e4SLinus Torvalds static int 3971da177e4SLinus Torvalds lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos) 3981da177e4SLinus Torvalds { 3997988613bSKent Overstreet struct bio_vec bvec; 4007988613bSKent Overstreet struct bvec_iter iter; 401306df071SDave Young ssize_t s; 4021da177e4SLinus Torvalds 4037988613bSKent Overstreet bio_for_each_segment(bvec, bio, iter) { 4047988613bSKent Overstreet s = do_lo_receive(lo, &bvec, bsize, pos); 405306df071SDave Young if (s < 0) 406306df071SDave Young return s; 407306df071SDave Young 4087988613bSKent Overstreet if (s != bvec.bv_len) { 409306df071SDave Young zero_fill_bio(bio); 4101da177e4SLinus Torvalds break; 411306df071SDave Young } 4127988613bSKent Overstreet pos += bvec.bv_len; 4131da177e4SLinus Torvalds } 414306df071SDave Young return 0; 4151da177e4SLinus Torvalds } 4161da177e4SLinus Torvalds 4171da177e4SLinus Torvalds static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) 4181da177e4SLinus Torvalds { 4191da177e4SLinus Torvalds loff_t pos; 4201da177e4SLinus Torvalds int ret; 4211da177e4SLinus Torvalds 4224f024f37SKent Overstreet pos = ((loff_t) bio->bi_iter.bi_sector << 9) + lo->lo_offset; 42368db1961SNikanth Karthikesan 42468db1961SNikanth Karthikesan if (bio_rw(bio) == WRITE) { 42568db1961SNikanth Karthikesan struct file *file = lo->lo_backing_file; 42668db1961SNikanth Karthikesan 4276259f284STejun Heo if (bio->bi_rw & REQ_FLUSH) { 4288018ab05SChristoph Hellwig ret = vfs_fsync(file, 0); 4296259f284STejun Heo if (unlikely(ret && ret != -EINVAL)) { 43068db1961SNikanth Karthikesan ret = -EIO; 43168db1961SNikanth Karthikesan goto out; 43268db1961SNikanth Karthikesan } 43368db1961SNikanth Karthikesan } 43468db1961SNikanth Karthikesan 435dfaa2ef6SLukas Czerner /* 436dfaa2ef6SLukas Czerner * We use punch hole to reclaim the free space used by the 437ae95757aSDave Young * image a.k.a. discard. However we do not support discard if 438dfaa2ef6SLukas Czerner * encryption is enabled, because it may give an attacker 439dfaa2ef6SLukas Czerner * useful information. 440dfaa2ef6SLukas Czerner */ 441dfaa2ef6SLukas Czerner if (bio->bi_rw & REQ_DISCARD) { 442dfaa2ef6SLukas Czerner struct file *file = lo->lo_backing_file; 443dfaa2ef6SLukas Czerner int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; 444dfaa2ef6SLukas Czerner 445dfaa2ef6SLukas Czerner if ((!file->f_op->fallocate) || 446dfaa2ef6SLukas Czerner lo->lo_encrypt_key_size) { 447dfaa2ef6SLukas Czerner ret = -EOPNOTSUPP; 448dfaa2ef6SLukas Czerner goto out; 449dfaa2ef6SLukas Czerner } 450dfaa2ef6SLukas Czerner ret = file->f_op->fallocate(file, mode, pos, 4514f024f37SKent Overstreet bio->bi_iter.bi_size); 452dfaa2ef6SLukas Czerner if (unlikely(ret && ret != -EINVAL && 453dfaa2ef6SLukas Czerner ret != -EOPNOTSUPP)) 454dfaa2ef6SLukas Czerner ret = -EIO; 455dfaa2ef6SLukas Czerner goto out; 456dfaa2ef6SLukas Czerner } 457dfaa2ef6SLukas Czerner 458511de73fSAl Viro ret = lo_send(lo, bio, pos); 45968db1961SNikanth Karthikesan 4606259f284STejun Heo if ((bio->bi_rw & REQ_FUA) && !ret) { 4618018ab05SChristoph Hellwig ret = vfs_fsync(file, 0); 4626259f284STejun Heo if (unlikely(ret && ret != -EINVAL)) 46368db1961SNikanth Karthikesan ret = -EIO; 46468db1961SNikanth Karthikesan } 46568db1961SNikanth Karthikesan } else 4661da177e4SLinus Torvalds ret = lo_receive(lo, bio, lo->lo_blocksize, pos); 46768db1961SNikanth Karthikesan 46868db1961SNikanth Karthikesan out: 4691da177e4SLinus Torvalds return ret; 4701da177e4SLinus Torvalds } 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvalds struct switch_request { 4731da177e4SLinus Torvalds struct file *file; 4741da177e4SLinus Torvalds struct completion wait; 4751da177e4SLinus Torvalds }; 4761da177e4SLinus Torvalds 477b5dd2f60SMing Lei static inline int loop_handle_bio(struct loop_device *lo, struct bio *bio) 4781da177e4SLinus Torvalds { 479b5dd2f60SMing Lei return do_bio_filebacked(lo, bio); 48014f27939SMilan Broz } 48114f27939SMilan Broz 48214f27939SMilan Broz /* 4831da177e4SLinus Torvalds * Do the actual switch; called from the BIO completion routine 4841da177e4SLinus Torvalds */ 4851da177e4SLinus Torvalds static void do_loop_switch(struct loop_device *lo, struct switch_request *p) 4861da177e4SLinus Torvalds { 4871da177e4SLinus Torvalds struct file *file = p->file; 4881da177e4SLinus Torvalds struct file *old_file = lo->lo_backing_file; 48914f27939SMilan Broz struct address_space *mapping; 4901da177e4SLinus Torvalds 49114f27939SMilan Broz /* if no new file, only flush of queued bios requested */ 49214f27939SMilan Broz if (!file) 493b5dd2f60SMing Lei return; 49414f27939SMilan Broz 49514f27939SMilan Broz mapping = file->f_mapping; 4961da177e4SLinus Torvalds mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); 4971da177e4SLinus Torvalds lo->lo_backing_file = file; 498ba52de12STheodore Ts'o lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? 499ba52de12STheodore Ts'o mapping->host->i_bdev->bd_block_size : PAGE_SIZE; 5001da177e4SLinus Torvalds lo->old_gfp_mask = mapping_gfp_mask(mapping); 5011da177e4SLinus Torvalds mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); 5021da177e4SLinus Torvalds } 5031da177e4SLinus Torvalds 504b5dd2f60SMing Lei /* 505b5dd2f60SMing Lei * loop_switch performs the hard work of switching a backing store. 506b5dd2f60SMing Lei * First it needs to flush existing IO, it does this by sending a magic 507b5dd2f60SMing Lei * BIO down the pipe. The completion of this BIO does the actual switch. 508b5dd2f60SMing Lei */ 509b5dd2f60SMing Lei static int loop_switch(struct loop_device *lo, struct file *file) 510b5dd2f60SMing Lei { 511b5dd2f60SMing Lei struct switch_request w; 512b5dd2f60SMing Lei 513b5dd2f60SMing Lei w.file = file; 514b5dd2f60SMing Lei 515b5dd2f60SMing Lei /* freeze queue and wait for completion of scheduled requests */ 516b5dd2f60SMing Lei blk_mq_freeze_queue(lo->lo_queue); 517b5dd2f60SMing Lei 518b5dd2f60SMing Lei /* do the switch action */ 519b5dd2f60SMing Lei do_loop_switch(lo, &w); 520b5dd2f60SMing Lei 521b5dd2f60SMing Lei /* unfreeze */ 522b5dd2f60SMing Lei blk_mq_unfreeze_queue(lo->lo_queue); 523b5dd2f60SMing Lei 524b5dd2f60SMing Lei return 0; 525b5dd2f60SMing Lei } 526b5dd2f60SMing Lei 527b5dd2f60SMing Lei /* 528b5dd2f60SMing Lei * Helper to flush the IOs in loop, but keeping loop thread running 529b5dd2f60SMing Lei */ 530b5dd2f60SMing Lei static int loop_flush(struct loop_device *lo) 531b5dd2f60SMing Lei { 532b5dd2f60SMing Lei return loop_switch(lo, NULL); 533b5dd2f60SMing Lei } 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds /* 5361da177e4SLinus Torvalds * loop_change_fd switched the backing store of a loopback device to 5371da177e4SLinus Torvalds * a new file. This is useful for operating system installers to free up 5381da177e4SLinus Torvalds * the original file and in High Availability environments to switch to 5391da177e4SLinus Torvalds * an alternative location for the content in case of server meltdown. 5401da177e4SLinus Torvalds * This can only work if the loop device is used read-only, and if the 5411da177e4SLinus Torvalds * new backing store is the same size and type as the old backing store. 5421da177e4SLinus Torvalds */ 543bb214884SAl Viro static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, 544bb214884SAl Viro unsigned int arg) 5451da177e4SLinus Torvalds { 5461da177e4SLinus Torvalds struct file *file, *old_file; 5471da177e4SLinus Torvalds struct inode *inode; 5481da177e4SLinus Torvalds int error; 5491da177e4SLinus Torvalds 5501da177e4SLinus Torvalds error = -ENXIO; 5511da177e4SLinus Torvalds if (lo->lo_state != Lo_bound) 5521da177e4SLinus Torvalds goto out; 5531da177e4SLinus Torvalds 5541da177e4SLinus Torvalds /* the loop device has to be read-only */ 5551da177e4SLinus Torvalds error = -EINVAL; 5561da177e4SLinus Torvalds if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) 5571da177e4SLinus Torvalds goto out; 5581da177e4SLinus Torvalds 5591da177e4SLinus Torvalds error = -EBADF; 5601da177e4SLinus Torvalds file = fget(arg); 5611da177e4SLinus Torvalds if (!file) 5621da177e4SLinus Torvalds goto out; 5631da177e4SLinus Torvalds 5641da177e4SLinus Torvalds inode = file->f_mapping->host; 5651da177e4SLinus Torvalds old_file = lo->lo_backing_file; 5661da177e4SLinus Torvalds 5671da177e4SLinus Torvalds error = -EINVAL; 5681da177e4SLinus Torvalds 5691da177e4SLinus Torvalds if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) 5701da177e4SLinus Torvalds goto out_putf; 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds /* size of the new backing store needs to be the same */ 5731da177e4SLinus Torvalds if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) 5741da177e4SLinus Torvalds goto out_putf; 5751da177e4SLinus Torvalds 5761da177e4SLinus Torvalds /* and ... switch */ 5771da177e4SLinus Torvalds error = loop_switch(lo, file); 5781da177e4SLinus Torvalds if (error) 5791da177e4SLinus Torvalds goto out_putf; 5801da177e4SLinus Torvalds 5811da177e4SLinus Torvalds fput(old_file); 582e03c8dd1SKay Sievers if (lo->lo_flags & LO_FLAGS_PARTSCAN) 583476a4813SLaurent Vivier ioctl_by_bdev(bdev, BLKRRPART, 0); 5841da177e4SLinus Torvalds return 0; 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds out_putf: 5871da177e4SLinus Torvalds fput(file); 5881da177e4SLinus Torvalds out: 5891da177e4SLinus Torvalds return error; 5901da177e4SLinus Torvalds } 5911da177e4SLinus Torvalds 5921da177e4SLinus Torvalds static inline int is_loop_device(struct file *file) 5931da177e4SLinus Torvalds { 5941da177e4SLinus Torvalds struct inode *i = file->f_mapping->host; 5951da177e4SLinus Torvalds 5961da177e4SLinus Torvalds return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; 5971da177e4SLinus Torvalds } 5981da177e4SLinus Torvalds 599ee862730SMilan Broz /* loop sysfs attributes */ 600ee862730SMilan Broz 601ee862730SMilan Broz static ssize_t loop_attr_show(struct device *dev, char *page, 602ee862730SMilan Broz ssize_t (*callback)(struct loop_device *, char *)) 603ee862730SMilan Broz { 60434dd82afSKay Sievers struct gendisk *disk = dev_to_disk(dev); 60534dd82afSKay Sievers struct loop_device *lo = disk->private_data; 606ee862730SMilan Broz 60734dd82afSKay Sievers return callback(lo, page); 608ee862730SMilan Broz } 609ee862730SMilan Broz 610ee862730SMilan Broz #define LOOP_ATTR_RO(_name) \ 611ee862730SMilan Broz static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ 612ee862730SMilan Broz static ssize_t loop_attr_do_show_##_name(struct device *d, \ 613ee862730SMilan Broz struct device_attribute *attr, char *b) \ 614ee862730SMilan Broz { \ 615ee862730SMilan Broz return loop_attr_show(d, b, loop_attr_##_name##_show); \ 616ee862730SMilan Broz } \ 617ee862730SMilan Broz static struct device_attribute loop_attr_##_name = \ 618ee862730SMilan Broz __ATTR(_name, S_IRUGO, loop_attr_do_show_##_name, NULL); 619ee862730SMilan Broz 620ee862730SMilan Broz static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) 621ee862730SMilan Broz { 622ee862730SMilan Broz ssize_t ret; 623ee862730SMilan Broz char *p = NULL; 624ee862730SMilan Broz 62505eb0f25SKay Sievers spin_lock_irq(&lo->lo_lock); 626ee862730SMilan Broz if (lo->lo_backing_file) 627ee862730SMilan Broz p = d_path(&lo->lo_backing_file->f_path, buf, PAGE_SIZE - 1); 62805eb0f25SKay Sievers spin_unlock_irq(&lo->lo_lock); 629ee862730SMilan Broz 630ee862730SMilan Broz if (IS_ERR_OR_NULL(p)) 631ee862730SMilan Broz ret = PTR_ERR(p); 632ee862730SMilan Broz else { 633ee862730SMilan Broz ret = strlen(p); 634ee862730SMilan Broz memmove(buf, p, ret); 635ee862730SMilan Broz buf[ret++] = '\n'; 636ee862730SMilan Broz buf[ret] = 0; 637ee862730SMilan Broz } 638ee862730SMilan Broz 639ee862730SMilan Broz return ret; 640ee862730SMilan Broz } 641ee862730SMilan Broz 642ee862730SMilan Broz static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) 643ee862730SMilan Broz { 644ee862730SMilan Broz return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); 645ee862730SMilan Broz } 646ee862730SMilan Broz 647ee862730SMilan Broz static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) 648ee862730SMilan Broz { 649ee862730SMilan Broz return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); 650ee862730SMilan Broz } 651ee862730SMilan Broz 652ee862730SMilan Broz static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) 653ee862730SMilan Broz { 654ee862730SMilan Broz int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); 655ee862730SMilan Broz 656ee862730SMilan Broz return sprintf(buf, "%s\n", autoclear ? "1" : "0"); 657ee862730SMilan Broz } 658ee862730SMilan Broz 659e03c8dd1SKay Sievers static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) 660e03c8dd1SKay Sievers { 661e03c8dd1SKay Sievers int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); 662e03c8dd1SKay Sievers 663e03c8dd1SKay Sievers return sprintf(buf, "%s\n", partscan ? "1" : "0"); 664e03c8dd1SKay Sievers } 665e03c8dd1SKay Sievers 666ee862730SMilan Broz LOOP_ATTR_RO(backing_file); 667ee862730SMilan Broz LOOP_ATTR_RO(offset); 668ee862730SMilan Broz LOOP_ATTR_RO(sizelimit); 669ee862730SMilan Broz LOOP_ATTR_RO(autoclear); 670e03c8dd1SKay Sievers LOOP_ATTR_RO(partscan); 671ee862730SMilan Broz 672ee862730SMilan Broz static struct attribute *loop_attrs[] = { 673ee862730SMilan Broz &loop_attr_backing_file.attr, 674ee862730SMilan Broz &loop_attr_offset.attr, 675ee862730SMilan Broz &loop_attr_sizelimit.attr, 676ee862730SMilan Broz &loop_attr_autoclear.attr, 677e03c8dd1SKay Sievers &loop_attr_partscan.attr, 678ee862730SMilan Broz NULL, 679ee862730SMilan Broz }; 680ee862730SMilan Broz 681ee862730SMilan Broz static struct attribute_group loop_attribute_group = { 682ee862730SMilan Broz .name = "loop", 683ee862730SMilan Broz .attrs= loop_attrs, 684ee862730SMilan Broz }; 685ee862730SMilan Broz 686ee862730SMilan Broz static int loop_sysfs_init(struct loop_device *lo) 687ee862730SMilan Broz { 688ee862730SMilan Broz return sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, 689ee862730SMilan Broz &loop_attribute_group); 690ee862730SMilan Broz } 691ee862730SMilan Broz 692ee862730SMilan Broz static void loop_sysfs_exit(struct loop_device *lo) 693ee862730SMilan Broz { 694ee862730SMilan Broz sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, 695ee862730SMilan Broz &loop_attribute_group); 696ee862730SMilan Broz } 697ee862730SMilan Broz 698dfaa2ef6SLukas Czerner static void loop_config_discard(struct loop_device *lo) 699dfaa2ef6SLukas Czerner { 700dfaa2ef6SLukas Czerner struct file *file = lo->lo_backing_file; 701dfaa2ef6SLukas Czerner struct inode *inode = file->f_mapping->host; 702dfaa2ef6SLukas Czerner struct request_queue *q = lo->lo_queue; 703dfaa2ef6SLukas Czerner 704dfaa2ef6SLukas Czerner /* 705dfaa2ef6SLukas Czerner * We use punch hole to reclaim the free space used by the 70612a64d2fSOlaf Hering * image a.k.a. discard. However we do not support discard if 707dfaa2ef6SLukas Czerner * encryption is enabled, because it may give an attacker 708dfaa2ef6SLukas Czerner * useful information. 709dfaa2ef6SLukas Czerner */ 710dfaa2ef6SLukas Czerner if ((!file->f_op->fallocate) || 711dfaa2ef6SLukas Czerner lo->lo_encrypt_key_size) { 712dfaa2ef6SLukas Czerner q->limits.discard_granularity = 0; 713dfaa2ef6SLukas Czerner q->limits.discard_alignment = 0; 714dfaa2ef6SLukas Czerner q->limits.max_discard_sectors = 0; 715dfaa2ef6SLukas Czerner q->limits.discard_zeroes_data = 0; 716dfaa2ef6SLukas Czerner queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); 717dfaa2ef6SLukas Czerner return; 718dfaa2ef6SLukas Czerner } 719dfaa2ef6SLukas Czerner 720dfaa2ef6SLukas Czerner q->limits.discard_granularity = inode->i_sb->s_blocksize; 721dfaf3c03SLukas Czerner q->limits.discard_alignment = 0; 722dfaa2ef6SLukas Czerner q->limits.max_discard_sectors = UINT_MAX >> 9; 723dfaa2ef6SLukas Czerner q->limits.discard_zeroes_data = 1; 724dfaa2ef6SLukas Czerner queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); 725dfaa2ef6SLukas Czerner } 726dfaa2ef6SLukas Czerner 727bb214884SAl Viro static int loop_set_fd(struct loop_device *lo, fmode_t mode, 7281da177e4SLinus Torvalds struct block_device *bdev, unsigned int arg) 7291da177e4SLinus Torvalds { 7301da177e4SLinus Torvalds struct file *file, *f; 7311da177e4SLinus Torvalds struct inode *inode; 7321da177e4SLinus Torvalds struct address_space *mapping; 7331da177e4SLinus Torvalds unsigned lo_blocksize; 7341da177e4SLinus Torvalds int lo_flags = 0; 7351da177e4SLinus Torvalds int error; 7361da177e4SLinus Torvalds loff_t size; 7371da177e4SLinus Torvalds 7381da177e4SLinus Torvalds /* This is safe, since we have a reference from open(). */ 7391da177e4SLinus Torvalds __module_get(THIS_MODULE); 7401da177e4SLinus Torvalds 7411da177e4SLinus Torvalds error = -EBADF; 7421da177e4SLinus Torvalds file = fget(arg); 7431da177e4SLinus Torvalds if (!file) 7441da177e4SLinus Torvalds goto out; 7451da177e4SLinus Torvalds 7461da177e4SLinus Torvalds error = -EBUSY; 7471da177e4SLinus Torvalds if (lo->lo_state != Lo_unbound) 7481da177e4SLinus Torvalds goto out_putf; 7491da177e4SLinus Torvalds 7501da177e4SLinus Torvalds /* Avoid recursion */ 7511da177e4SLinus Torvalds f = file; 7521da177e4SLinus Torvalds while (is_loop_device(f)) { 7531da177e4SLinus Torvalds struct loop_device *l; 7541da177e4SLinus Torvalds 755bb214884SAl Viro if (f->f_mapping->host->i_bdev == bdev) 7561da177e4SLinus Torvalds goto out_putf; 7571da177e4SLinus Torvalds 7581da177e4SLinus Torvalds l = f->f_mapping->host->i_bdev->bd_disk->private_data; 7591da177e4SLinus Torvalds if (l->lo_state == Lo_unbound) { 7601da177e4SLinus Torvalds error = -EINVAL; 7611da177e4SLinus Torvalds goto out_putf; 7621da177e4SLinus Torvalds } 7631da177e4SLinus Torvalds f = l->lo_backing_file; 7641da177e4SLinus Torvalds } 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds mapping = file->f_mapping; 7671da177e4SLinus Torvalds inode = mapping->host; 7681da177e4SLinus Torvalds 7691da177e4SLinus Torvalds error = -EINVAL; 770456be148SChristoph Hellwig if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) 771456be148SChristoph Hellwig goto out_putf; 7726818173bSMiklos Szeredi 773456be148SChristoph Hellwig if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || 774456be148SChristoph Hellwig !file->f_op->write) 7751da177e4SLinus Torvalds lo_flags |= LO_FLAGS_READ_ONLY; 7761da177e4SLinus Torvalds 777ba52de12STheodore Ts'o lo_blocksize = S_ISBLK(inode->i_mode) ? 778ba52de12STheodore Ts'o inode->i_bdev->bd_block_size : PAGE_SIZE; 779ba52de12STheodore Ts'o 7801da177e4SLinus Torvalds error = -EFBIG; 781456be148SChristoph Hellwig size = get_loop_size(lo, file); 782456be148SChristoph Hellwig if ((loff_t)(sector_t)size != size) 7831da177e4SLinus Torvalds goto out_putf; 7841da177e4SLinus Torvalds 785456be148SChristoph Hellwig error = 0; 7861da177e4SLinus Torvalds 7871da177e4SLinus Torvalds set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0); 7881da177e4SLinus Torvalds 7891da177e4SLinus Torvalds lo->lo_blocksize = lo_blocksize; 7901da177e4SLinus Torvalds lo->lo_device = bdev; 7911da177e4SLinus Torvalds lo->lo_flags = lo_flags; 7921da177e4SLinus Torvalds lo->lo_backing_file = file; 793eefe85eeSConstantine Sapuntzakis lo->transfer = transfer_none; 7941da177e4SLinus Torvalds lo->ioctl = NULL; 7951da177e4SLinus Torvalds lo->lo_sizelimit = 0; 7961da177e4SLinus Torvalds lo->old_gfp_mask = mapping_gfp_mask(mapping); 7971da177e4SLinus Torvalds mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); 7981da177e4SLinus Torvalds 79968db1961SNikanth Karthikesan if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) 8004913efe4STejun Heo blk_queue_flush(lo->lo_queue, REQ_FLUSH); 80168db1961SNikanth Karthikesan 80273285082SKen Chen set_capacity(lo->lo_disk, size); 8031da177e4SLinus Torvalds bd_set_size(bdev, size << 9); 804ee862730SMilan Broz loop_sysfs_init(lo); 805c3473c63SDavid Zeuthen /* let user-space know about the new size */ 806c3473c63SDavid Zeuthen kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds set_blocksize(bdev, lo_blocksize); 8091da177e4SLinus Torvalds 8106c997918SSerge E. Hallyn lo->lo_state = Lo_bound; 811e03c8dd1SKay Sievers if (part_shift) 812e03c8dd1SKay Sievers lo->lo_flags |= LO_FLAGS_PARTSCAN; 813e03c8dd1SKay Sievers if (lo->lo_flags & LO_FLAGS_PARTSCAN) 814476a4813SLaurent Vivier ioctl_by_bdev(bdev, BLKRRPART, 0); 815c1681bf8SAnatol Pomozov 816c1681bf8SAnatol Pomozov /* Grab the block_device to prevent its destruction after we 817c1681bf8SAnatol Pomozov * put /dev/loopXX inode. Later in loop_clr_fd() we bdput(bdev). 818c1681bf8SAnatol Pomozov */ 819c1681bf8SAnatol Pomozov bdgrab(bdev); 8201da177e4SLinus Torvalds return 0; 8211da177e4SLinus Torvalds 8221da177e4SLinus Torvalds out_putf: 8231da177e4SLinus Torvalds fput(file); 8241da177e4SLinus Torvalds out: 8251da177e4SLinus Torvalds /* This is safe: open() is still holding a reference. */ 8261da177e4SLinus Torvalds module_put(THIS_MODULE); 8271da177e4SLinus Torvalds return error; 8281da177e4SLinus Torvalds } 8291da177e4SLinus Torvalds 8301da177e4SLinus Torvalds static int 8311da177e4SLinus Torvalds loop_release_xfer(struct loop_device *lo) 8321da177e4SLinus Torvalds { 8331da177e4SLinus Torvalds int err = 0; 8341da177e4SLinus Torvalds struct loop_func_table *xfer = lo->lo_encryption; 8351da177e4SLinus Torvalds 8361da177e4SLinus Torvalds if (xfer) { 8371da177e4SLinus Torvalds if (xfer->release) 8381da177e4SLinus Torvalds err = xfer->release(lo); 8391da177e4SLinus Torvalds lo->transfer = NULL; 8401da177e4SLinus Torvalds lo->lo_encryption = NULL; 8411da177e4SLinus Torvalds module_put(xfer->owner); 8421da177e4SLinus Torvalds } 8431da177e4SLinus Torvalds return err; 8441da177e4SLinus Torvalds } 8451da177e4SLinus Torvalds 8461da177e4SLinus Torvalds static int 8471da177e4SLinus Torvalds loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, 8481da177e4SLinus Torvalds const struct loop_info64 *i) 8491da177e4SLinus Torvalds { 8501da177e4SLinus Torvalds int err = 0; 8511da177e4SLinus Torvalds 8521da177e4SLinus Torvalds if (xfer) { 8531da177e4SLinus Torvalds struct module *owner = xfer->owner; 8541da177e4SLinus Torvalds 8551da177e4SLinus Torvalds if (!try_module_get(owner)) 8561da177e4SLinus Torvalds return -EINVAL; 8571da177e4SLinus Torvalds if (xfer->init) 8581da177e4SLinus Torvalds err = xfer->init(lo, i); 8591da177e4SLinus Torvalds if (err) 8601da177e4SLinus Torvalds module_put(owner); 8611da177e4SLinus Torvalds else 8621da177e4SLinus Torvalds lo->lo_encryption = xfer; 8631da177e4SLinus Torvalds } 8641da177e4SLinus Torvalds return err; 8651da177e4SLinus Torvalds } 8661da177e4SLinus Torvalds 8674c823cc3SAyan George static int loop_clr_fd(struct loop_device *lo) 8681da177e4SLinus Torvalds { 8691da177e4SLinus Torvalds struct file *filp = lo->lo_backing_file; 870b4e3ca1aSAl Viro gfp_t gfp = lo->old_gfp_mask; 8714c823cc3SAyan George struct block_device *bdev = lo->lo_device; 8721da177e4SLinus Torvalds 8731da177e4SLinus Torvalds if (lo->lo_state != Lo_bound) 8741da177e4SLinus Torvalds return -ENXIO; 8751da177e4SLinus Torvalds 876a1ecac3bSDave Chinner /* 877a1ecac3bSDave Chinner * If we've explicitly asked to tear down the loop device, 878a1ecac3bSDave Chinner * and it has an elevated reference count, set it for auto-teardown when 879a1ecac3bSDave Chinner * the last reference goes away. This stops $!~#$@ udev from 880a1ecac3bSDave Chinner * preventing teardown because it decided that it needs to run blkid on 881a1ecac3bSDave Chinner * the loopback device whenever they appear. xfstests is notorious for 882a1ecac3bSDave Chinner * failing tests because blkid via udev races with a losetup 883a1ecac3bSDave Chinner * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d 884a1ecac3bSDave Chinner * command to fail with EBUSY. 885a1ecac3bSDave Chinner */ 886a1ecac3bSDave Chinner if (lo->lo_refcnt > 1) { 887a1ecac3bSDave Chinner lo->lo_flags |= LO_FLAGS_AUTOCLEAR; 888a1ecac3bSDave Chinner mutex_unlock(&lo->lo_ctl_mutex); 889a1ecac3bSDave Chinner return 0; 890a1ecac3bSDave Chinner } 8911da177e4SLinus Torvalds 8921da177e4SLinus Torvalds if (filp == NULL) 8931da177e4SLinus Torvalds return -EINVAL; 8941da177e4SLinus Torvalds 8951da177e4SLinus Torvalds spin_lock_irq(&lo->lo_lock); 8961da177e4SLinus Torvalds lo->lo_state = Lo_rundown; 8971da177e4SLinus Torvalds lo->lo_backing_file = NULL; 89805eb0f25SKay Sievers spin_unlock_irq(&lo->lo_lock); 8991da177e4SLinus Torvalds 9001da177e4SLinus Torvalds loop_release_xfer(lo); 9011da177e4SLinus Torvalds lo->transfer = NULL; 9021da177e4SLinus Torvalds lo->ioctl = NULL; 9031da177e4SLinus Torvalds lo->lo_device = NULL; 9041da177e4SLinus Torvalds lo->lo_encryption = NULL; 9051da177e4SLinus Torvalds lo->lo_offset = 0; 9061da177e4SLinus Torvalds lo->lo_sizelimit = 0; 9071da177e4SLinus Torvalds lo->lo_encrypt_key_size = 0; 9081da177e4SLinus Torvalds memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); 9091da177e4SLinus Torvalds memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); 9101da177e4SLinus Torvalds memset(lo->lo_file_name, 0, LO_NAME_SIZE); 911c1681bf8SAnatol Pomozov if (bdev) { 912c1681bf8SAnatol Pomozov bdput(bdev); 913f98393a6SPeter Zijlstra invalidate_bdev(bdev); 914c1681bf8SAnatol Pomozov } 91573285082SKen Chen set_capacity(lo->lo_disk, 0); 91651a0bb0cSMilan Broz loop_sysfs_exit(lo); 917c3473c63SDavid Zeuthen if (bdev) { 9181da177e4SLinus Torvalds bd_set_size(bdev, 0); 919c3473c63SDavid Zeuthen /* let user-space know about this change */ 920c3473c63SDavid Zeuthen kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); 921c3473c63SDavid Zeuthen } 9221da177e4SLinus Torvalds mapping_set_gfp_mask(filp->f_mapping, gfp); 9231da177e4SLinus Torvalds lo->lo_state = Lo_unbound; 9241da177e4SLinus Torvalds /* This is safe: open() is still holding a reference. */ 9251da177e4SLinus Torvalds module_put(THIS_MODULE); 926c2fccc1cSJens Axboe if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev) 927c2fccc1cSJens Axboe ioctl_by_bdev(bdev, BLKRRPART, 0); 928e03c8dd1SKay Sievers lo->lo_flags = 0; 929e03c8dd1SKay Sievers if (!part_shift) 930e03c8dd1SKay Sievers lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; 931f028f3b2SNikanth Karthikesan mutex_unlock(&lo->lo_ctl_mutex); 932f028f3b2SNikanth Karthikesan /* 933f028f3b2SNikanth Karthikesan * Need not hold lo_ctl_mutex to fput backing file. 934f028f3b2SNikanth Karthikesan * Calling fput holding lo_ctl_mutex triggers a circular 935f028f3b2SNikanth Karthikesan * lock dependency possibility warning as fput can take 936f028f3b2SNikanth Karthikesan * bd_mutex which is usually taken before lo_ctl_mutex. 937f028f3b2SNikanth Karthikesan */ 938f028f3b2SNikanth Karthikesan fput(filp); 9391da177e4SLinus Torvalds return 0; 9401da177e4SLinus Torvalds } 9411da177e4SLinus Torvalds 9421da177e4SLinus Torvalds static int 9431da177e4SLinus Torvalds loop_set_status(struct loop_device *lo, const struct loop_info64 *info) 9441da177e4SLinus Torvalds { 9451da177e4SLinus Torvalds int err; 9461da177e4SLinus Torvalds struct loop_func_table *xfer; 947e4849737SEric W. Biederman kuid_t uid = current_uid(); 9481da177e4SLinus Torvalds 949b0fafa81SDavid Howells if (lo->lo_encrypt_key_size && 950e4849737SEric W. Biederman !uid_eq(lo->lo_key_owner, uid) && 9511da177e4SLinus Torvalds !capable(CAP_SYS_ADMIN)) 9521da177e4SLinus Torvalds return -EPERM; 9531da177e4SLinus Torvalds if (lo->lo_state != Lo_bound) 9541da177e4SLinus Torvalds return -ENXIO; 9551da177e4SLinus Torvalds if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) 9561da177e4SLinus Torvalds return -EINVAL; 9571da177e4SLinus Torvalds 9581da177e4SLinus Torvalds err = loop_release_xfer(lo); 9591da177e4SLinus Torvalds if (err) 9601da177e4SLinus Torvalds return err; 9611da177e4SLinus Torvalds 9621da177e4SLinus Torvalds if (info->lo_encrypt_type) { 9631da177e4SLinus Torvalds unsigned int type = info->lo_encrypt_type; 9641da177e4SLinus Torvalds 9651da177e4SLinus Torvalds if (type >= MAX_LO_CRYPT) 9661da177e4SLinus Torvalds return -EINVAL; 9671da177e4SLinus Torvalds xfer = xfer_funcs[type]; 9681da177e4SLinus Torvalds if (xfer == NULL) 9691da177e4SLinus Torvalds return -EINVAL; 9701da177e4SLinus Torvalds } else 9711da177e4SLinus Torvalds xfer = NULL; 9721da177e4SLinus Torvalds 9731da177e4SLinus Torvalds err = loop_init_xfer(lo, xfer, info); 9741da177e4SLinus Torvalds if (err) 9751da177e4SLinus Torvalds return err; 9761da177e4SLinus Torvalds 9771da177e4SLinus Torvalds if (lo->lo_offset != info->lo_offset || 9787b0576a3SGuo Chao lo->lo_sizelimit != info->lo_sizelimit) 9797035b5dfSDmitry Monakhov if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) 9801da177e4SLinus Torvalds return -EFBIG; 981541c742aSGuo Chao 982dfaa2ef6SLukas Czerner loop_config_discard(lo); 9831da177e4SLinus Torvalds 9841da177e4SLinus Torvalds memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); 9851da177e4SLinus Torvalds memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); 9861da177e4SLinus Torvalds lo->lo_file_name[LO_NAME_SIZE-1] = 0; 9871da177e4SLinus Torvalds lo->lo_crypt_name[LO_NAME_SIZE-1] = 0; 9881da177e4SLinus Torvalds 9891da177e4SLinus Torvalds if (!xfer) 9901da177e4SLinus Torvalds xfer = &none_funcs; 9911da177e4SLinus Torvalds lo->transfer = xfer->transfer; 9921da177e4SLinus Torvalds lo->ioctl = xfer->ioctl; 9931da177e4SLinus Torvalds 99496c58655SDavid Woodhouse if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) != 99596c58655SDavid Woodhouse (info->lo_flags & LO_FLAGS_AUTOCLEAR)) 99696c58655SDavid Woodhouse lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; 99796c58655SDavid Woodhouse 998e03c8dd1SKay Sievers if ((info->lo_flags & LO_FLAGS_PARTSCAN) && 999e03c8dd1SKay Sievers !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { 1000e03c8dd1SKay Sievers lo->lo_flags |= LO_FLAGS_PARTSCAN; 1001e03c8dd1SKay Sievers lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; 1002e03c8dd1SKay Sievers ioctl_by_bdev(lo->lo_device, BLKRRPART, 0); 1003e03c8dd1SKay Sievers } 1004e03c8dd1SKay Sievers 10051da177e4SLinus Torvalds lo->lo_encrypt_key_size = info->lo_encrypt_key_size; 10061da177e4SLinus Torvalds lo->lo_init[0] = info->lo_init[0]; 10071da177e4SLinus Torvalds lo->lo_init[1] = info->lo_init[1]; 10081da177e4SLinus Torvalds if (info->lo_encrypt_key_size) { 10091da177e4SLinus Torvalds memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, 10101da177e4SLinus Torvalds info->lo_encrypt_key_size); 1011b0fafa81SDavid Howells lo->lo_key_owner = uid; 10121da177e4SLinus Torvalds } 10131da177e4SLinus Torvalds 10141da177e4SLinus Torvalds return 0; 10151da177e4SLinus Torvalds } 10161da177e4SLinus Torvalds 10171da177e4SLinus Torvalds static int 10181da177e4SLinus Torvalds loop_get_status(struct loop_device *lo, struct loop_info64 *info) 10191da177e4SLinus Torvalds { 10201da177e4SLinus Torvalds struct file *file = lo->lo_backing_file; 10211da177e4SLinus Torvalds struct kstat stat; 10221da177e4SLinus Torvalds int error; 10231da177e4SLinus Torvalds 10241da177e4SLinus Torvalds if (lo->lo_state != Lo_bound) 10251da177e4SLinus Torvalds return -ENXIO; 10263dadecceSAl Viro error = vfs_getattr(&file->f_path, &stat); 10271da177e4SLinus Torvalds if (error) 10281da177e4SLinus Torvalds return error; 10291da177e4SLinus Torvalds memset(info, 0, sizeof(*info)); 10301da177e4SLinus Torvalds info->lo_number = lo->lo_number; 10311da177e4SLinus Torvalds info->lo_device = huge_encode_dev(stat.dev); 10321da177e4SLinus Torvalds info->lo_inode = stat.ino; 10331da177e4SLinus Torvalds info->lo_rdevice = huge_encode_dev(lo->lo_device ? stat.rdev : stat.dev); 10341da177e4SLinus Torvalds info->lo_offset = lo->lo_offset; 10351da177e4SLinus Torvalds info->lo_sizelimit = lo->lo_sizelimit; 10361da177e4SLinus Torvalds info->lo_flags = lo->lo_flags; 10371da177e4SLinus Torvalds memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); 10381da177e4SLinus Torvalds memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); 10391da177e4SLinus Torvalds info->lo_encrypt_type = 10401da177e4SLinus Torvalds lo->lo_encryption ? lo->lo_encryption->number : 0; 10411da177e4SLinus Torvalds if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { 10421da177e4SLinus Torvalds info->lo_encrypt_key_size = lo->lo_encrypt_key_size; 10431da177e4SLinus Torvalds memcpy(info->lo_encrypt_key, lo->lo_encrypt_key, 10441da177e4SLinus Torvalds lo->lo_encrypt_key_size); 10451da177e4SLinus Torvalds } 10461da177e4SLinus Torvalds return 0; 10471da177e4SLinus Torvalds } 10481da177e4SLinus Torvalds 10491da177e4SLinus Torvalds static void 10501da177e4SLinus Torvalds loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) 10511da177e4SLinus Torvalds { 10521da177e4SLinus Torvalds memset(info64, 0, sizeof(*info64)); 10531da177e4SLinus Torvalds info64->lo_number = info->lo_number; 10541da177e4SLinus Torvalds info64->lo_device = info->lo_device; 10551da177e4SLinus Torvalds info64->lo_inode = info->lo_inode; 10561da177e4SLinus Torvalds info64->lo_rdevice = info->lo_rdevice; 10571da177e4SLinus Torvalds info64->lo_offset = info->lo_offset; 10581da177e4SLinus Torvalds info64->lo_sizelimit = 0; 10591da177e4SLinus Torvalds info64->lo_encrypt_type = info->lo_encrypt_type; 10601da177e4SLinus Torvalds info64->lo_encrypt_key_size = info->lo_encrypt_key_size; 10611da177e4SLinus Torvalds info64->lo_flags = info->lo_flags; 10621da177e4SLinus Torvalds info64->lo_init[0] = info->lo_init[0]; 10631da177e4SLinus Torvalds info64->lo_init[1] = info->lo_init[1]; 10641da177e4SLinus Torvalds if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) 10651da177e4SLinus Torvalds memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE); 10661da177e4SLinus Torvalds else 10671da177e4SLinus Torvalds memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); 10681da177e4SLinus Torvalds memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE); 10691da177e4SLinus Torvalds } 10701da177e4SLinus Torvalds 10711da177e4SLinus Torvalds static int 10721da177e4SLinus Torvalds loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) 10731da177e4SLinus Torvalds { 10741da177e4SLinus Torvalds memset(info, 0, sizeof(*info)); 10751da177e4SLinus Torvalds info->lo_number = info64->lo_number; 10761da177e4SLinus Torvalds info->lo_device = info64->lo_device; 10771da177e4SLinus Torvalds info->lo_inode = info64->lo_inode; 10781da177e4SLinus Torvalds info->lo_rdevice = info64->lo_rdevice; 10791da177e4SLinus Torvalds info->lo_offset = info64->lo_offset; 10801da177e4SLinus Torvalds info->lo_encrypt_type = info64->lo_encrypt_type; 10811da177e4SLinus Torvalds info->lo_encrypt_key_size = info64->lo_encrypt_key_size; 10821da177e4SLinus Torvalds info->lo_flags = info64->lo_flags; 10831da177e4SLinus Torvalds info->lo_init[0] = info64->lo_init[0]; 10841da177e4SLinus Torvalds info->lo_init[1] = info64->lo_init[1]; 10851da177e4SLinus Torvalds if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) 10861da177e4SLinus Torvalds memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE); 10871da177e4SLinus Torvalds else 10881da177e4SLinus Torvalds memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); 10891da177e4SLinus Torvalds memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); 10901da177e4SLinus Torvalds 10911da177e4SLinus Torvalds /* error in case values were truncated */ 10921da177e4SLinus Torvalds if (info->lo_device != info64->lo_device || 10931da177e4SLinus Torvalds info->lo_rdevice != info64->lo_rdevice || 10941da177e4SLinus Torvalds info->lo_inode != info64->lo_inode || 10951da177e4SLinus Torvalds info->lo_offset != info64->lo_offset) 10961da177e4SLinus Torvalds return -EOVERFLOW; 10971da177e4SLinus Torvalds 10981da177e4SLinus Torvalds return 0; 10991da177e4SLinus Torvalds } 11001da177e4SLinus Torvalds 11011da177e4SLinus Torvalds static int 11021da177e4SLinus Torvalds loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) 11031da177e4SLinus Torvalds { 11041da177e4SLinus Torvalds struct loop_info info; 11051da177e4SLinus Torvalds struct loop_info64 info64; 11061da177e4SLinus Torvalds 11071da177e4SLinus Torvalds if (copy_from_user(&info, arg, sizeof (struct loop_info))) 11081da177e4SLinus Torvalds return -EFAULT; 11091da177e4SLinus Torvalds loop_info64_from_old(&info, &info64); 11101da177e4SLinus Torvalds return loop_set_status(lo, &info64); 11111da177e4SLinus Torvalds } 11121da177e4SLinus Torvalds 11131da177e4SLinus Torvalds static int 11141da177e4SLinus Torvalds loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) 11151da177e4SLinus Torvalds { 11161da177e4SLinus Torvalds struct loop_info64 info64; 11171da177e4SLinus Torvalds 11181da177e4SLinus Torvalds if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) 11191da177e4SLinus Torvalds return -EFAULT; 11201da177e4SLinus Torvalds return loop_set_status(lo, &info64); 11211da177e4SLinus Torvalds } 11221da177e4SLinus Torvalds 11231da177e4SLinus Torvalds static int 11241da177e4SLinus Torvalds loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { 11251da177e4SLinus Torvalds struct loop_info info; 11261da177e4SLinus Torvalds struct loop_info64 info64; 11271da177e4SLinus Torvalds int err = 0; 11281da177e4SLinus Torvalds 11291da177e4SLinus Torvalds if (!arg) 11301da177e4SLinus Torvalds err = -EINVAL; 11311da177e4SLinus Torvalds if (!err) 11321da177e4SLinus Torvalds err = loop_get_status(lo, &info64); 11331da177e4SLinus Torvalds if (!err) 11341da177e4SLinus Torvalds err = loop_info64_to_old(&info64, &info); 11351da177e4SLinus Torvalds if (!err && copy_to_user(arg, &info, sizeof(info))) 11361da177e4SLinus Torvalds err = -EFAULT; 11371da177e4SLinus Torvalds 11381da177e4SLinus Torvalds return err; 11391da177e4SLinus Torvalds } 11401da177e4SLinus Torvalds 11411da177e4SLinus Torvalds static int 11421da177e4SLinus Torvalds loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { 11431da177e4SLinus Torvalds struct loop_info64 info64; 11441da177e4SLinus Torvalds int err = 0; 11451da177e4SLinus Torvalds 11461da177e4SLinus Torvalds if (!arg) 11471da177e4SLinus Torvalds err = -EINVAL; 11481da177e4SLinus Torvalds if (!err) 11491da177e4SLinus Torvalds err = loop_get_status(lo, &info64); 11501da177e4SLinus Torvalds if (!err && copy_to_user(arg, &info64, sizeof(info64))) 11511da177e4SLinus Torvalds err = -EFAULT; 11521da177e4SLinus Torvalds 11531da177e4SLinus Torvalds return err; 11541da177e4SLinus Torvalds } 11551da177e4SLinus Torvalds 115653d66608SJ. R. Okajima static int loop_set_capacity(struct loop_device *lo, struct block_device *bdev) 115753d66608SJ. R. Okajima { 115853d66608SJ. R. Okajima if (unlikely(lo->lo_state != Lo_bound)) 11597b0576a3SGuo Chao return -ENXIO; 116053d66608SJ. R. Okajima 11617b0576a3SGuo Chao return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit); 116253d66608SJ. R. Okajima } 116353d66608SJ. R. Okajima 1164bb214884SAl Viro static int lo_ioctl(struct block_device *bdev, fmode_t mode, 11651da177e4SLinus Torvalds unsigned int cmd, unsigned long arg) 11661da177e4SLinus Torvalds { 1167bb214884SAl Viro struct loop_device *lo = bdev->bd_disk->private_data; 11681da177e4SLinus Torvalds int err; 11691da177e4SLinus Torvalds 1170f028f3b2SNikanth Karthikesan mutex_lock_nested(&lo->lo_ctl_mutex, 1); 11711da177e4SLinus Torvalds switch (cmd) { 11721da177e4SLinus Torvalds case LOOP_SET_FD: 1173bb214884SAl Viro err = loop_set_fd(lo, mode, bdev, arg); 11741da177e4SLinus Torvalds break; 11751da177e4SLinus Torvalds case LOOP_CHANGE_FD: 1176bb214884SAl Viro err = loop_change_fd(lo, bdev, arg); 11771da177e4SLinus Torvalds break; 11781da177e4SLinus Torvalds case LOOP_CLR_FD: 1179f028f3b2SNikanth Karthikesan /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ 11804c823cc3SAyan George err = loop_clr_fd(lo); 1181f028f3b2SNikanth Karthikesan if (!err) 1182f028f3b2SNikanth Karthikesan goto out_unlocked; 11831da177e4SLinus Torvalds break; 11841da177e4SLinus Torvalds case LOOP_SET_STATUS: 11857035b5dfSDmitry Monakhov err = -EPERM; 11867035b5dfSDmitry Monakhov if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) 11877035b5dfSDmitry Monakhov err = loop_set_status_old(lo, 11887035b5dfSDmitry Monakhov (struct loop_info __user *)arg); 11891da177e4SLinus Torvalds break; 11901da177e4SLinus Torvalds case LOOP_GET_STATUS: 11911da177e4SLinus Torvalds err = loop_get_status_old(lo, (struct loop_info __user *) arg); 11921da177e4SLinus Torvalds break; 11931da177e4SLinus Torvalds case LOOP_SET_STATUS64: 11947035b5dfSDmitry Monakhov err = -EPERM; 11957035b5dfSDmitry Monakhov if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) 11967035b5dfSDmitry Monakhov err = loop_set_status64(lo, 11977035b5dfSDmitry Monakhov (struct loop_info64 __user *) arg); 11981da177e4SLinus Torvalds break; 11991da177e4SLinus Torvalds case LOOP_GET_STATUS64: 12001da177e4SLinus Torvalds err = loop_get_status64(lo, (struct loop_info64 __user *) arg); 12011da177e4SLinus Torvalds break; 120253d66608SJ. R. Okajima case LOOP_SET_CAPACITY: 120353d66608SJ. R. Okajima err = -EPERM; 120453d66608SJ. R. Okajima if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) 120553d66608SJ. R. Okajima err = loop_set_capacity(lo, bdev); 120653d66608SJ. R. Okajima break; 12071da177e4SLinus Torvalds default: 12081da177e4SLinus Torvalds err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; 12091da177e4SLinus Torvalds } 1210f85221ddSIngo Molnar mutex_unlock(&lo->lo_ctl_mutex); 1211f028f3b2SNikanth Karthikesan 1212f028f3b2SNikanth Karthikesan out_unlocked: 12131da177e4SLinus Torvalds return err; 12141da177e4SLinus Torvalds } 12151da177e4SLinus Torvalds 1216863d5b82SDavid Howells #ifdef CONFIG_COMPAT 1217863d5b82SDavid Howells struct compat_loop_info { 1218863d5b82SDavid Howells compat_int_t lo_number; /* ioctl r/o */ 1219863d5b82SDavid Howells compat_dev_t lo_device; /* ioctl r/o */ 1220863d5b82SDavid Howells compat_ulong_t lo_inode; /* ioctl r/o */ 1221863d5b82SDavid Howells compat_dev_t lo_rdevice; /* ioctl r/o */ 1222863d5b82SDavid Howells compat_int_t lo_offset; 1223863d5b82SDavid Howells compat_int_t lo_encrypt_type; 1224863d5b82SDavid Howells compat_int_t lo_encrypt_key_size; /* ioctl w/o */ 1225863d5b82SDavid Howells compat_int_t lo_flags; /* ioctl r/o */ 1226863d5b82SDavid Howells char lo_name[LO_NAME_SIZE]; 1227863d5b82SDavid Howells unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ 1228863d5b82SDavid Howells compat_ulong_t lo_init[2]; 1229863d5b82SDavid Howells char reserved[4]; 1230863d5b82SDavid Howells }; 1231863d5b82SDavid Howells 1232863d5b82SDavid Howells /* 1233863d5b82SDavid Howells * Transfer 32-bit compatibility structure in userspace to 64-bit loop info 1234863d5b82SDavid Howells * - noinlined to reduce stack space usage in main part of driver 1235863d5b82SDavid Howells */ 1236863d5b82SDavid Howells static noinline int 1237ba674cfcSAl Viro loop_info64_from_compat(const struct compat_loop_info __user *arg, 1238863d5b82SDavid Howells struct loop_info64 *info64) 1239863d5b82SDavid Howells { 1240863d5b82SDavid Howells struct compat_loop_info info; 1241863d5b82SDavid Howells 1242863d5b82SDavid Howells if (copy_from_user(&info, arg, sizeof(info))) 1243863d5b82SDavid Howells return -EFAULT; 1244863d5b82SDavid Howells 1245863d5b82SDavid Howells memset(info64, 0, sizeof(*info64)); 1246863d5b82SDavid Howells info64->lo_number = info.lo_number; 1247863d5b82SDavid Howells info64->lo_device = info.lo_device; 1248863d5b82SDavid Howells info64->lo_inode = info.lo_inode; 1249863d5b82SDavid Howells info64->lo_rdevice = info.lo_rdevice; 1250863d5b82SDavid Howells info64->lo_offset = info.lo_offset; 1251863d5b82SDavid Howells info64->lo_sizelimit = 0; 1252863d5b82SDavid Howells info64->lo_encrypt_type = info.lo_encrypt_type; 1253863d5b82SDavid Howells info64->lo_encrypt_key_size = info.lo_encrypt_key_size; 1254863d5b82SDavid Howells info64->lo_flags = info.lo_flags; 1255863d5b82SDavid Howells info64->lo_init[0] = info.lo_init[0]; 1256863d5b82SDavid Howells info64->lo_init[1] = info.lo_init[1]; 1257863d5b82SDavid Howells if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) 1258863d5b82SDavid Howells memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE); 1259863d5b82SDavid Howells else 1260863d5b82SDavid Howells memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); 1261863d5b82SDavid Howells memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE); 1262863d5b82SDavid Howells return 0; 1263863d5b82SDavid Howells } 1264863d5b82SDavid Howells 1265863d5b82SDavid Howells /* 1266863d5b82SDavid Howells * Transfer 64-bit loop info to 32-bit compatibility structure in userspace 1267863d5b82SDavid Howells * - noinlined to reduce stack space usage in main part of driver 1268863d5b82SDavid Howells */ 1269863d5b82SDavid Howells static noinline int 1270863d5b82SDavid Howells loop_info64_to_compat(const struct loop_info64 *info64, 1271863d5b82SDavid Howells struct compat_loop_info __user *arg) 1272863d5b82SDavid Howells { 1273863d5b82SDavid Howells struct compat_loop_info info; 1274863d5b82SDavid Howells 1275863d5b82SDavid Howells memset(&info, 0, sizeof(info)); 1276863d5b82SDavid Howells info.lo_number = info64->lo_number; 1277863d5b82SDavid Howells info.lo_device = info64->lo_device; 1278863d5b82SDavid Howells info.lo_inode = info64->lo_inode; 1279863d5b82SDavid Howells info.lo_rdevice = info64->lo_rdevice; 1280863d5b82SDavid Howells info.lo_offset = info64->lo_offset; 1281863d5b82SDavid Howells info.lo_encrypt_type = info64->lo_encrypt_type; 1282863d5b82SDavid Howells info.lo_encrypt_key_size = info64->lo_encrypt_key_size; 1283863d5b82SDavid Howells info.lo_flags = info64->lo_flags; 1284863d5b82SDavid Howells info.lo_init[0] = info64->lo_init[0]; 1285863d5b82SDavid Howells info.lo_init[1] = info64->lo_init[1]; 1286863d5b82SDavid Howells if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) 1287863d5b82SDavid Howells memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE); 1288863d5b82SDavid Howells else 1289863d5b82SDavid Howells memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); 1290863d5b82SDavid Howells memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); 1291863d5b82SDavid Howells 1292863d5b82SDavid Howells /* error in case values were truncated */ 1293863d5b82SDavid Howells if (info.lo_device != info64->lo_device || 1294863d5b82SDavid Howells info.lo_rdevice != info64->lo_rdevice || 1295863d5b82SDavid Howells info.lo_inode != info64->lo_inode || 1296863d5b82SDavid Howells info.lo_offset != info64->lo_offset || 1297863d5b82SDavid Howells info.lo_init[0] != info64->lo_init[0] || 1298863d5b82SDavid Howells info.lo_init[1] != info64->lo_init[1]) 1299863d5b82SDavid Howells return -EOVERFLOW; 1300863d5b82SDavid Howells 1301863d5b82SDavid Howells if (copy_to_user(arg, &info, sizeof(info))) 1302863d5b82SDavid Howells return -EFAULT; 1303863d5b82SDavid Howells return 0; 1304863d5b82SDavid Howells } 1305863d5b82SDavid Howells 1306863d5b82SDavid Howells static int 1307863d5b82SDavid Howells loop_set_status_compat(struct loop_device *lo, 1308863d5b82SDavid Howells const struct compat_loop_info __user *arg) 1309863d5b82SDavid Howells { 1310863d5b82SDavid Howells struct loop_info64 info64; 1311863d5b82SDavid Howells int ret; 1312863d5b82SDavid Howells 1313863d5b82SDavid Howells ret = loop_info64_from_compat(arg, &info64); 1314863d5b82SDavid Howells if (ret < 0) 1315863d5b82SDavid Howells return ret; 1316863d5b82SDavid Howells return loop_set_status(lo, &info64); 1317863d5b82SDavid Howells } 1318863d5b82SDavid Howells 1319863d5b82SDavid Howells static int 1320863d5b82SDavid Howells loop_get_status_compat(struct loop_device *lo, 1321863d5b82SDavid Howells struct compat_loop_info __user *arg) 1322863d5b82SDavid Howells { 1323863d5b82SDavid Howells struct loop_info64 info64; 1324863d5b82SDavid Howells int err = 0; 1325863d5b82SDavid Howells 1326863d5b82SDavid Howells if (!arg) 1327863d5b82SDavid Howells err = -EINVAL; 1328863d5b82SDavid Howells if (!err) 1329863d5b82SDavid Howells err = loop_get_status(lo, &info64); 1330863d5b82SDavid Howells if (!err) 1331863d5b82SDavid Howells err = loop_info64_to_compat(&info64, arg); 1332863d5b82SDavid Howells return err; 1333863d5b82SDavid Howells } 1334863d5b82SDavid Howells 1335bb214884SAl Viro static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, 1336bb214884SAl Viro unsigned int cmd, unsigned long arg) 1337863d5b82SDavid Howells { 1338bb214884SAl Viro struct loop_device *lo = bdev->bd_disk->private_data; 1339863d5b82SDavid Howells int err; 1340863d5b82SDavid Howells 1341863d5b82SDavid Howells switch(cmd) { 1342863d5b82SDavid Howells case LOOP_SET_STATUS: 1343863d5b82SDavid Howells mutex_lock(&lo->lo_ctl_mutex); 1344863d5b82SDavid Howells err = loop_set_status_compat( 1345863d5b82SDavid Howells lo, (const struct compat_loop_info __user *) arg); 1346863d5b82SDavid Howells mutex_unlock(&lo->lo_ctl_mutex); 1347863d5b82SDavid Howells break; 1348863d5b82SDavid Howells case LOOP_GET_STATUS: 1349863d5b82SDavid Howells mutex_lock(&lo->lo_ctl_mutex); 1350863d5b82SDavid Howells err = loop_get_status_compat( 1351863d5b82SDavid Howells lo, (struct compat_loop_info __user *) arg); 1352863d5b82SDavid Howells mutex_unlock(&lo->lo_ctl_mutex); 1353863d5b82SDavid Howells break; 135453d66608SJ. R. Okajima case LOOP_SET_CAPACITY: 1355863d5b82SDavid Howells case LOOP_CLR_FD: 1356863d5b82SDavid Howells case LOOP_GET_STATUS64: 1357863d5b82SDavid Howells case LOOP_SET_STATUS64: 1358863d5b82SDavid Howells arg = (unsigned long) compat_ptr(arg); 1359863d5b82SDavid Howells case LOOP_SET_FD: 1360863d5b82SDavid Howells case LOOP_CHANGE_FD: 1361bb214884SAl Viro err = lo_ioctl(bdev, mode, cmd, arg); 1362863d5b82SDavid Howells break; 1363863d5b82SDavid Howells default: 1364863d5b82SDavid Howells err = -ENOIOCTLCMD; 1365863d5b82SDavid Howells break; 1366863d5b82SDavid Howells } 1367863d5b82SDavid Howells return err; 1368863d5b82SDavid Howells } 1369863d5b82SDavid Howells #endif 1370863d5b82SDavid Howells 1371bb214884SAl Viro static int lo_open(struct block_device *bdev, fmode_t mode) 13721da177e4SLinus Torvalds { 1373770fe30aSKay Sievers struct loop_device *lo; 1374770fe30aSKay Sievers int err = 0; 1375770fe30aSKay Sievers 1376770fe30aSKay Sievers mutex_lock(&loop_index_mutex); 1377770fe30aSKay Sievers lo = bdev->bd_disk->private_data; 1378770fe30aSKay Sievers if (!lo) { 1379770fe30aSKay Sievers err = -ENXIO; 1380770fe30aSKay Sievers goto out; 1381770fe30aSKay Sievers } 13821da177e4SLinus Torvalds 1383f85221ddSIngo Molnar mutex_lock(&lo->lo_ctl_mutex); 13841da177e4SLinus Torvalds lo->lo_refcnt++; 1385f85221ddSIngo Molnar mutex_unlock(&lo->lo_ctl_mutex); 1386770fe30aSKay Sievers out: 1387770fe30aSKay Sievers mutex_unlock(&loop_index_mutex); 1388770fe30aSKay Sievers return err; 13891da177e4SLinus Torvalds } 13901da177e4SLinus Torvalds 1391db2a144bSAl Viro static void lo_release(struct gendisk *disk, fmode_t mode) 13921da177e4SLinus Torvalds { 1393bb214884SAl Viro struct loop_device *lo = disk->private_data; 1394ffcd7dcaSAlexander Beregalov int err; 13951da177e4SLinus Torvalds 1396f85221ddSIngo Molnar mutex_lock(&lo->lo_ctl_mutex); 139796c58655SDavid Woodhouse 139814f27939SMilan Broz if (--lo->lo_refcnt) 139914f27939SMilan Broz goto out; 140014f27939SMilan Broz 140114f27939SMilan Broz if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { 140214f27939SMilan Broz /* 140314f27939SMilan Broz * In autoclear mode, stop the loop thread 140414f27939SMilan Broz * and remove configuration after last close. 140514f27939SMilan Broz */ 14064c823cc3SAyan George err = loop_clr_fd(lo); 1407ffcd7dcaSAlexander Beregalov if (!err) 1408db2a144bSAl Viro return; 140914f27939SMilan Broz } else { 141014f27939SMilan Broz /* 141114f27939SMilan Broz * Otherwise keep thread (if running) and config, 141214f27939SMilan Broz * but flush possible ongoing bios in thread. 141314f27939SMilan Broz */ 141414f27939SMilan Broz loop_flush(lo); 141514f27939SMilan Broz } 141696c58655SDavid Woodhouse 141714f27939SMilan Broz out: 1418f85221ddSIngo Molnar mutex_unlock(&lo->lo_ctl_mutex); 14191da177e4SLinus Torvalds } 14201da177e4SLinus Torvalds 142183d5cde4SAlexey Dobriyan static const struct block_device_operations lo_fops = { 14221da177e4SLinus Torvalds .owner = THIS_MODULE, 1423bb214884SAl Viro .open = lo_open, 1424bb214884SAl Viro .release = lo_release, 1425bb214884SAl Viro .ioctl = lo_ioctl, 1426863d5b82SDavid Howells #ifdef CONFIG_COMPAT 1427bb214884SAl Viro .compat_ioctl = lo_compat_ioctl, 1428863d5b82SDavid Howells #endif 14291da177e4SLinus Torvalds }; 14301da177e4SLinus Torvalds 14311da177e4SLinus Torvalds /* 14321da177e4SLinus Torvalds * And now the modules code and kernel interface. 14331da177e4SLinus Torvalds */ 143473285082SKen Chen static int max_loop; 1435ac04fee0SNamhyung Kim module_param(max_loop, int, S_IRUGO); 1436a47653fcSKen Chen MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); 1437ac04fee0SNamhyung Kim module_param(max_part, int, S_IRUGO); 1438476a4813SLaurent Vivier MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); 14391da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 14401da177e4SLinus Torvalds MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); 14411da177e4SLinus Torvalds 14421da177e4SLinus Torvalds int loop_register_transfer(struct loop_func_table *funcs) 14431da177e4SLinus Torvalds { 14441da177e4SLinus Torvalds unsigned int n = funcs->number; 14451da177e4SLinus Torvalds 14461da177e4SLinus Torvalds if (n >= MAX_LO_CRYPT || xfer_funcs[n]) 14471da177e4SLinus Torvalds return -EINVAL; 14481da177e4SLinus Torvalds xfer_funcs[n] = funcs; 14491da177e4SLinus Torvalds return 0; 14501da177e4SLinus Torvalds } 14511da177e4SLinus Torvalds 145234dd82afSKay Sievers static int unregister_transfer_cb(int id, void *ptr, void *data) 145334dd82afSKay Sievers { 145434dd82afSKay Sievers struct loop_device *lo = ptr; 145534dd82afSKay Sievers struct loop_func_table *xfer = data; 145634dd82afSKay Sievers 145734dd82afSKay Sievers mutex_lock(&lo->lo_ctl_mutex); 145834dd82afSKay Sievers if (lo->lo_encryption == xfer) 145934dd82afSKay Sievers loop_release_xfer(lo); 146034dd82afSKay Sievers mutex_unlock(&lo->lo_ctl_mutex); 146134dd82afSKay Sievers return 0; 146234dd82afSKay Sievers } 146334dd82afSKay Sievers 14641da177e4SLinus Torvalds int loop_unregister_transfer(int number) 14651da177e4SLinus Torvalds { 14661da177e4SLinus Torvalds unsigned int n = number; 14671da177e4SLinus Torvalds struct loop_func_table *xfer; 14681da177e4SLinus Torvalds 14691da177e4SLinus Torvalds if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL) 14701da177e4SLinus Torvalds return -EINVAL; 14711da177e4SLinus Torvalds 14721da177e4SLinus Torvalds xfer_funcs[n] = NULL; 147334dd82afSKay Sievers idr_for_each(&loop_index_idr, &unregister_transfer_cb, xfer); 14741da177e4SLinus Torvalds return 0; 14751da177e4SLinus Torvalds } 14761da177e4SLinus Torvalds 14771da177e4SLinus Torvalds EXPORT_SYMBOL(loop_register_transfer); 14781da177e4SLinus Torvalds EXPORT_SYMBOL(loop_unregister_transfer); 14791da177e4SLinus Torvalds 1480b5dd2f60SMing Lei static int loop_queue_rq(struct blk_mq_hw_ctx *hctx, 1481b5dd2f60SMing Lei const struct blk_mq_queue_data *bd) 1482b5dd2f60SMing Lei { 1483b5dd2f60SMing Lei struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); 1484b5dd2f60SMing Lei 1485b5dd2f60SMing Lei blk_mq_start_request(bd->rq); 1486b5dd2f60SMing Lei 1487b5dd2f60SMing Lei if (cmd->rq->cmd_flags & REQ_WRITE) { 1488b5dd2f60SMing Lei struct loop_device *lo = cmd->rq->q->queuedata; 1489b5dd2f60SMing Lei bool need_sched = true; 1490b5dd2f60SMing Lei 1491b5dd2f60SMing Lei spin_lock_irq(&lo->lo_lock); 1492b5dd2f60SMing Lei if (lo->write_started) 1493b5dd2f60SMing Lei need_sched = false; 1494b5dd2f60SMing Lei else 1495b5dd2f60SMing Lei lo->write_started = true; 1496b5dd2f60SMing Lei list_add_tail(&cmd->list, &lo->write_cmd_head); 1497b5dd2f60SMing Lei spin_unlock_irq(&lo->lo_lock); 1498b5dd2f60SMing Lei 1499b5dd2f60SMing Lei if (need_sched) 1500b5dd2f60SMing Lei queue_work(loop_wq, &lo->write_work); 1501b5dd2f60SMing Lei } else { 1502b5dd2f60SMing Lei queue_work(loop_wq, &cmd->read_work); 1503b5dd2f60SMing Lei } 1504b5dd2f60SMing Lei 1505b5dd2f60SMing Lei return BLK_MQ_RQ_QUEUE_OK; 1506b5dd2f60SMing Lei } 1507b5dd2f60SMing Lei 1508b5dd2f60SMing Lei static void loop_handle_cmd(struct loop_cmd *cmd) 1509b5dd2f60SMing Lei { 1510b5dd2f60SMing Lei const bool write = cmd->rq->cmd_flags & REQ_WRITE; 1511b5dd2f60SMing Lei struct loop_device *lo = cmd->rq->q->queuedata; 1512b5dd2f60SMing Lei int ret = -EIO; 1513b5dd2f60SMing Lei struct bio *bio; 1514b5dd2f60SMing Lei 1515b5dd2f60SMing Lei if (lo->lo_state != Lo_bound) 1516b5dd2f60SMing Lei goto failed; 1517b5dd2f60SMing Lei 1518b5dd2f60SMing Lei if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) 1519b5dd2f60SMing Lei goto failed; 1520b5dd2f60SMing Lei 1521b5dd2f60SMing Lei ret = 0; 1522b5dd2f60SMing Lei __rq_for_each_bio(bio, cmd->rq) 1523b5dd2f60SMing Lei ret |= loop_handle_bio(lo, bio); 1524b5dd2f60SMing Lei 1525b5dd2f60SMing Lei failed: 1526b5dd2f60SMing Lei if (ret) 1527b5dd2f60SMing Lei cmd->rq->errors = -EIO; 1528b5dd2f60SMing Lei blk_mq_complete_request(cmd->rq); 1529b5dd2f60SMing Lei } 1530b5dd2f60SMing Lei 1531b5dd2f60SMing Lei static void loop_queue_write_work(struct work_struct *work) 1532b5dd2f60SMing Lei { 1533b5dd2f60SMing Lei struct loop_device *lo = 1534b5dd2f60SMing Lei container_of(work, struct loop_device, write_work); 1535b5dd2f60SMing Lei LIST_HEAD(cmd_list); 1536b5dd2f60SMing Lei 1537b5dd2f60SMing Lei spin_lock_irq(&lo->lo_lock); 1538b5dd2f60SMing Lei repeat: 1539b5dd2f60SMing Lei list_splice_init(&lo->write_cmd_head, &cmd_list); 1540b5dd2f60SMing Lei spin_unlock_irq(&lo->lo_lock); 1541b5dd2f60SMing Lei 1542b5dd2f60SMing Lei while (!list_empty(&cmd_list)) { 1543b5dd2f60SMing Lei struct loop_cmd *cmd = list_first_entry(&cmd_list, 1544b5dd2f60SMing Lei struct loop_cmd, list); 1545b5dd2f60SMing Lei list_del_init(&cmd->list); 1546b5dd2f60SMing Lei loop_handle_cmd(cmd); 1547b5dd2f60SMing Lei } 1548b5dd2f60SMing Lei 1549b5dd2f60SMing Lei spin_lock_irq(&lo->lo_lock); 1550b5dd2f60SMing Lei if (!list_empty(&lo->write_cmd_head)) 1551b5dd2f60SMing Lei goto repeat; 1552b5dd2f60SMing Lei lo->write_started = false; 1553b5dd2f60SMing Lei spin_unlock_irq(&lo->lo_lock); 1554b5dd2f60SMing Lei } 1555b5dd2f60SMing Lei 1556b5dd2f60SMing Lei static void loop_queue_read_work(struct work_struct *work) 1557b5dd2f60SMing Lei { 1558b5dd2f60SMing Lei struct loop_cmd *cmd = 1559b5dd2f60SMing Lei container_of(work, struct loop_cmd, read_work); 1560b5dd2f60SMing Lei 1561b5dd2f60SMing Lei loop_handle_cmd(cmd); 1562b5dd2f60SMing Lei } 1563b5dd2f60SMing Lei 1564b5dd2f60SMing Lei static int loop_init_request(void *data, struct request *rq, 1565b5dd2f60SMing Lei unsigned int hctx_idx, unsigned int request_idx, 1566b5dd2f60SMing Lei unsigned int numa_node) 1567b5dd2f60SMing Lei { 1568b5dd2f60SMing Lei struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); 1569b5dd2f60SMing Lei 1570b5dd2f60SMing Lei cmd->rq = rq; 1571b5dd2f60SMing Lei INIT_WORK(&cmd->read_work, loop_queue_read_work); 1572b5dd2f60SMing Lei 1573b5dd2f60SMing Lei return 0; 1574b5dd2f60SMing Lei } 1575b5dd2f60SMing Lei 1576b5dd2f60SMing Lei static struct blk_mq_ops loop_mq_ops = { 1577b5dd2f60SMing Lei .queue_rq = loop_queue_rq, 1578b5dd2f60SMing Lei .map_queue = blk_mq_map_queue, 1579b5dd2f60SMing Lei .init_request = loop_init_request, 1580b5dd2f60SMing Lei }; 1581b5dd2f60SMing Lei 158234dd82afSKay Sievers static int loop_add(struct loop_device **l, int i) 15831da177e4SLinus Torvalds { 158473285082SKen Chen struct loop_device *lo; 158573285082SKen Chen struct gendisk *disk; 158634dd82afSKay Sievers int err; 15871da177e4SLinus Torvalds 158834dd82afSKay Sievers err = -ENOMEM; 158968d740d7SSilva Paulo lo = kzalloc(sizeof(*lo), GFP_KERNEL); 159068d740d7SSilva Paulo if (!lo) 159173285082SKen Chen goto out; 159234dd82afSKay Sievers 1593ef7e7c82SMikulas Patocka lo->lo_state = Lo_unbound; 1594ef7e7c82SMikulas Patocka 1595c718aa65STejun Heo /* allocate id, if @id >= 0, we're requesting that specific id */ 159634dd82afSKay Sievers if (i >= 0) { 1597c718aa65STejun Heo err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL); 1598c718aa65STejun Heo if (err == -ENOSPC) 159934dd82afSKay Sievers err = -EEXIST; 160034dd82afSKay Sievers } else { 1601c718aa65STejun Heo err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL); 160234dd82afSKay Sievers } 160334dd82afSKay Sievers if (err < 0) 160434dd82afSKay Sievers goto out_free_dev; 1605c718aa65STejun Heo i = err; 16061da177e4SLinus Torvalds 1607183cfb57SWei Yongjun err = -ENOMEM; 1608b5dd2f60SMing Lei lo->tag_set.ops = &loop_mq_ops; 1609b5dd2f60SMing Lei lo->tag_set.nr_hw_queues = 1; 1610b5dd2f60SMing Lei lo->tag_set.queue_depth = 128; 1611b5dd2f60SMing Lei lo->tag_set.numa_node = NUMA_NO_NODE; 1612b5dd2f60SMing Lei lo->tag_set.cmd_size = sizeof(struct loop_cmd); 1613b5dd2f60SMing Lei lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; 1614b5dd2f60SMing Lei lo->tag_set.driver_data = lo; 1615b5dd2f60SMing Lei 1616b5dd2f60SMing Lei err = blk_mq_alloc_tag_set(&lo->tag_set); 1617b5dd2f60SMing Lei if (err) 16183ec981e3SMikulas Patocka goto out_free_idr; 161973285082SKen Chen 1620b5dd2f60SMing Lei lo->lo_queue = blk_mq_init_queue(&lo->tag_set); 1621b5dd2f60SMing Lei if (IS_ERR_OR_NULL(lo->lo_queue)) { 1622b5dd2f60SMing Lei err = PTR_ERR(lo->lo_queue); 1623b5dd2f60SMing Lei goto out_cleanup_tags; 1624b5dd2f60SMing Lei } 1625ef7e7c82SMikulas Patocka lo->lo_queue->queuedata = lo; 1626ef7e7c82SMikulas Patocka 1627b5dd2f60SMing Lei INIT_LIST_HEAD(&lo->write_cmd_head); 1628b5dd2f60SMing Lei INIT_WORK(&lo->write_work, loop_queue_write_work); 1629b5dd2f60SMing Lei 1630476a4813SLaurent Vivier disk = lo->lo_disk = alloc_disk(1 << part_shift); 163173285082SKen Chen if (!disk) 163273285082SKen Chen goto out_free_queue; 163373285082SKen Chen 1634e03c8dd1SKay Sievers /* 1635e03c8dd1SKay Sievers * Disable partition scanning by default. The in-kernel partition 1636e03c8dd1SKay Sievers * scanning can be requested individually per-device during its 1637e03c8dd1SKay Sievers * setup. Userspace can always add and remove partitions from all 1638e03c8dd1SKay Sievers * devices. The needed partition minors are allocated from the 1639e03c8dd1SKay Sievers * extended minor space, the main loop device numbers will continue 1640e03c8dd1SKay Sievers * to match the loop minors, regardless of the number of partitions 1641e03c8dd1SKay Sievers * used. 1642e03c8dd1SKay Sievers * 1643e03c8dd1SKay Sievers * If max_part is given, partition scanning is globally enabled for 1644e03c8dd1SKay Sievers * all loop devices. The minors for the main loop devices will be 1645e03c8dd1SKay Sievers * multiples of max_part. 1646e03c8dd1SKay Sievers * 1647e03c8dd1SKay Sievers * Note: Global-for-all-devices, set-only-at-init, read-only module 1648e03c8dd1SKay Sievers * parameteters like 'max_loop' and 'max_part' make things needlessly 1649e03c8dd1SKay Sievers * complicated, are too static, inflexible and may surprise 1650e03c8dd1SKay Sievers * userspace tools. Parameters like this in general should be avoided. 1651e03c8dd1SKay Sievers */ 1652e03c8dd1SKay Sievers if (!part_shift) 1653e03c8dd1SKay Sievers disk->flags |= GENHD_FL_NO_PART_SCAN; 1654e03c8dd1SKay Sievers disk->flags |= GENHD_FL_EXT_DEVT; 1655f85221ddSIngo Molnar mutex_init(&lo->lo_ctl_mutex); 16561da177e4SLinus Torvalds lo->lo_number = i; 16571da177e4SLinus Torvalds spin_lock_init(&lo->lo_lock); 16581da177e4SLinus Torvalds disk->major = LOOP_MAJOR; 1659476a4813SLaurent Vivier disk->first_minor = i << part_shift; 16601da177e4SLinus Torvalds disk->fops = &lo_fops; 16611da177e4SLinus Torvalds disk->private_data = lo; 16621da177e4SLinus Torvalds disk->queue = lo->lo_queue; 166373285082SKen Chen sprintf(disk->disk_name, "loop%d", i); 166434dd82afSKay Sievers add_disk(disk); 166534dd82afSKay Sievers *l = lo; 166634dd82afSKay Sievers return lo->lo_number; 166773285082SKen Chen 166873285082SKen Chen out_free_queue: 166973285082SKen Chen blk_cleanup_queue(lo->lo_queue); 1670b5dd2f60SMing Lei out_cleanup_tags: 1671b5dd2f60SMing Lei blk_mq_free_tag_set(&lo->tag_set); 16723ec981e3SMikulas Patocka out_free_idr: 16733ec981e3SMikulas Patocka idr_remove(&loop_index_idr, i); 167473285082SKen Chen out_free_dev: 167573285082SKen Chen kfree(lo); 167673285082SKen Chen out: 167734dd82afSKay Sievers return err; 16781da177e4SLinus Torvalds } 16791da177e4SLinus Torvalds 168034dd82afSKay Sievers static void loop_remove(struct loop_device *lo) 168173285082SKen Chen { 168234dd82afSKay Sievers del_gendisk(lo->lo_disk); 168373285082SKen Chen blk_cleanup_queue(lo->lo_queue); 1684b5dd2f60SMing Lei blk_mq_free_tag_set(&lo->tag_set); 168573285082SKen Chen put_disk(lo->lo_disk); 168673285082SKen Chen kfree(lo); 168773285082SKen Chen } 168873285082SKen Chen 1689770fe30aSKay Sievers static int find_free_cb(int id, void *ptr, void *data) 1690770fe30aSKay Sievers { 1691770fe30aSKay Sievers struct loop_device *lo = ptr; 1692770fe30aSKay Sievers struct loop_device **l = data; 1693770fe30aSKay Sievers 1694770fe30aSKay Sievers if (lo->lo_state == Lo_unbound) { 1695770fe30aSKay Sievers *l = lo; 1696770fe30aSKay Sievers return 1; 1697770fe30aSKay Sievers } 1698770fe30aSKay Sievers return 0; 1699770fe30aSKay Sievers } 1700770fe30aSKay Sievers 170134dd82afSKay Sievers static int loop_lookup(struct loop_device **l, int i) 1702a47653fcSKen Chen { 1703a47653fcSKen Chen struct loop_device *lo; 170434dd82afSKay Sievers int ret = -ENODEV; 1705a47653fcSKen Chen 1706770fe30aSKay Sievers if (i < 0) { 1707770fe30aSKay Sievers int err; 1708770fe30aSKay Sievers 1709770fe30aSKay Sievers err = idr_for_each(&loop_index_idr, &find_free_cb, &lo); 1710770fe30aSKay Sievers if (err == 1) { 1711770fe30aSKay Sievers *l = lo; 1712770fe30aSKay Sievers ret = lo->lo_number; 1713770fe30aSKay Sievers } 1714770fe30aSKay Sievers goto out; 1715a47653fcSKen Chen } 1716a47653fcSKen Chen 1717770fe30aSKay Sievers /* lookup and return a specific i */ 171834dd82afSKay Sievers lo = idr_find(&loop_index_idr, i); 1719a47653fcSKen Chen if (lo) { 172034dd82afSKay Sievers *l = lo; 172134dd82afSKay Sievers ret = lo->lo_number; 1722a47653fcSKen Chen } 1723770fe30aSKay Sievers out: 172434dd82afSKay Sievers return ret; 1725a47653fcSKen Chen } 1726a47653fcSKen Chen 172773285082SKen Chen static struct kobject *loop_probe(dev_t dev, int *part, void *data) 172873285082SKen Chen { 1729705962ccSAl Viro struct loop_device *lo; 173007002e99SAl Viro struct kobject *kobj; 173134dd82afSKay Sievers int err; 173273285082SKen Chen 173334dd82afSKay Sievers mutex_lock(&loop_index_mutex); 173434dd82afSKay Sievers err = loop_lookup(&lo, MINOR(dev) >> part_shift); 173534dd82afSKay Sievers if (err < 0) 173634dd82afSKay Sievers err = loop_add(&lo, MINOR(dev) >> part_shift); 173734dd82afSKay Sievers if (err < 0) 1738a207f593SMikulas Patocka kobj = NULL; 173934dd82afSKay Sievers else 174034dd82afSKay Sievers kobj = get_disk(lo->lo_disk); 174134dd82afSKay Sievers mutex_unlock(&loop_index_mutex); 174273285082SKen Chen 174373285082SKen Chen *part = 0; 174407002e99SAl Viro return kobj; 174573285082SKen Chen } 174673285082SKen Chen 1747770fe30aSKay Sievers static long loop_control_ioctl(struct file *file, unsigned int cmd, 1748770fe30aSKay Sievers unsigned long parm) 1749770fe30aSKay Sievers { 1750770fe30aSKay Sievers struct loop_device *lo; 1751770fe30aSKay Sievers int ret = -ENOSYS; 1752770fe30aSKay Sievers 1753770fe30aSKay Sievers mutex_lock(&loop_index_mutex); 1754770fe30aSKay Sievers switch (cmd) { 1755770fe30aSKay Sievers case LOOP_CTL_ADD: 1756770fe30aSKay Sievers ret = loop_lookup(&lo, parm); 1757770fe30aSKay Sievers if (ret >= 0) { 1758770fe30aSKay Sievers ret = -EEXIST; 1759770fe30aSKay Sievers break; 1760770fe30aSKay Sievers } 1761770fe30aSKay Sievers ret = loop_add(&lo, parm); 1762770fe30aSKay Sievers break; 1763770fe30aSKay Sievers case LOOP_CTL_REMOVE: 1764770fe30aSKay Sievers ret = loop_lookup(&lo, parm); 1765770fe30aSKay Sievers if (ret < 0) 1766770fe30aSKay Sievers break; 1767770fe30aSKay Sievers mutex_lock(&lo->lo_ctl_mutex); 1768770fe30aSKay Sievers if (lo->lo_state != Lo_unbound) { 1769770fe30aSKay Sievers ret = -EBUSY; 1770770fe30aSKay Sievers mutex_unlock(&lo->lo_ctl_mutex); 1771770fe30aSKay Sievers break; 1772770fe30aSKay Sievers } 1773770fe30aSKay Sievers if (lo->lo_refcnt > 0) { 1774770fe30aSKay Sievers ret = -EBUSY; 1775770fe30aSKay Sievers mutex_unlock(&lo->lo_ctl_mutex); 1776770fe30aSKay Sievers break; 1777770fe30aSKay Sievers } 1778770fe30aSKay Sievers lo->lo_disk->private_data = NULL; 1779770fe30aSKay Sievers mutex_unlock(&lo->lo_ctl_mutex); 1780770fe30aSKay Sievers idr_remove(&loop_index_idr, lo->lo_number); 1781770fe30aSKay Sievers loop_remove(lo); 1782770fe30aSKay Sievers break; 1783770fe30aSKay Sievers case LOOP_CTL_GET_FREE: 1784770fe30aSKay Sievers ret = loop_lookup(&lo, -1); 1785770fe30aSKay Sievers if (ret >= 0) 1786770fe30aSKay Sievers break; 1787770fe30aSKay Sievers ret = loop_add(&lo, -1); 1788770fe30aSKay Sievers } 1789770fe30aSKay Sievers mutex_unlock(&loop_index_mutex); 1790770fe30aSKay Sievers 1791770fe30aSKay Sievers return ret; 1792770fe30aSKay Sievers } 1793770fe30aSKay Sievers 1794770fe30aSKay Sievers static const struct file_operations loop_ctl_fops = { 1795770fe30aSKay Sievers .open = nonseekable_open, 1796770fe30aSKay Sievers .unlocked_ioctl = loop_control_ioctl, 1797770fe30aSKay Sievers .compat_ioctl = loop_control_ioctl, 1798770fe30aSKay Sievers .owner = THIS_MODULE, 1799770fe30aSKay Sievers .llseek = noop_llseek, 1800770fe30aSKay Sievers }; 1801770fe30aSKay Sievers 1802770fe30aSKay Sievers static struct miscdevice loop_misc = { 1803770fe30aSKay Sievers .minor = LOOP_CTRL_MINOR, 1804770fe30aSKay Sievers .name = "loop-control", 1805770fe30aSKay Sievers .fops = &loop_ctl_fops, 1806770fe30aSKay Sievers }; 1807770fe30aSKay Sievers 1808770fe30aSKay Sievers MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); 1809770fe30aSKay Sievers MODULE_ALIAS("devname:loop-control"); 1810770fe30aSKay Sievers 181173285082SKen Chen static int __init loop_init(void) 181273285082SKen Chen { 1813a47653fcSKen Chen int i, nr; 1814a47653fcSKen Chen unsigned long range; 181534dd82afSKay Sievers struct loop_device *lo; 1816770fe30aSKay Sievers int err; 1817a47653fcSKen Chen 1818770fe30aSKay Sievers err = misc_register(&loop_misc); 1819770fe30aSKay Sievers if (err < 0) 1820770fe30aSKay Sievers return err; 1821476a4813SLaurent Vivier 1822476a4813SLaurent Vivier part_shift = 0; 1823ac04fee0SNamhyung Kim if (max_part > 0) { 1824476a4813SLaurent Vivier part_shift = fls(max_part); 1825476a4813SLaurent Vivier 1826ac04fee0SNamhyung Kim /* 1827ac04fee0SNamhyung Kim * Adjust max_part according to part_shift as it is exported 1828ac04fee0SNamhyung Kim * to user space so that user can decide correct minor number 1829ac04fee0SNamhyung Kim * if [s]he want to create more devices. 1830ac04fee0SNamhyung Kim * 1831ac04fee0SNamhyung Kim * Note that -1 is required because partition 0 is reserved 1832ac04fee0SNamhyung Kim * for the whole disk. 1833ac04fee0SNamhyung Kim */ 1834ac04fee0SNamhyung Kim max_part = (1UL << part_shift) - 1; 1835ac04fee0SNamhyung Kim } 1836ac04fee0SNamhyung Kim 1837b1a66504SGuo Chao if ((1UL << part_shift) > DISK_MAX_PARTS) { 1838b1a66504SGuo Chao err = -EINVAL; 1839b1a66504SGuo Chao goto misc_out; 1840b1a66504SGuo Chao } 184178f4bb36SNamhyung Kim 1842b1a66504SGuo Chao if (max_loop > 1UL << (MINORBITS - part_shift)) { 1843b1a66504SGuo Chao err = -EINVAL; 1844b1a66504SGuo Chao goto misc_out; 1845b1a66504SGuo Chao } 184673285082SKen Chen 1847d134b00bSKay Sievers /* 1848d134b00bSKay Sievers * If max_loop is specified, create that many devices upfront. 1849d134b00bSKay Sievers * This also becomes a hard limit. If max_loop is not specified, 1850d134b00bSKay Sievers * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module 1851d134b00bSKay Sievers * init time. Loop devices can be requested on-demand with the 1852d134b00bSKay Sievers * /dev/loop-control interface, or be instantiated by accessing 1853d134b00bSKay Sievers * a 'dead' device node. 1854d134b00bSKay Sievers */ 185573285082SKen Chen if (max_loop) { 1856a47653fcSKen Chen nr = max_loop; 1857a1c15c59SNamhyung Kim range = max_loop << part_shift; 1858a47653fcSKen Chen } else { 1859d134b00bSKay Sievers nr = CONFIG_BLK_DEV_LOOP_MIN_COUNT; 1860a1c15c59SNamhyung Kim range = 1UL << MINORBITS; 186173285082SKen Chen } 1862a47653fcSKen Chen 1863b1a66504SGuo Chao if (register_blkdev(LOOP_MAJOR, "loop")) { 1864b1a66504SGuo Chao err = -EIO; 1865b1a66504SGuo Chao goto misc_out; 1866b1a66504SGuo Chao } 1867a47653fcSKen Chen 1868b5dd2f60SMing Lei loop_wq = alloc_workqueue("kloopd", 1869b5dd2f60SMing Lei WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0); 1870b5dd2f60SMing Lei if (!loop_wq) { 1871b5dd2f60SMing Lei err = -ENOMEM; 1872b5dd2f60SMing Lei goto misc_out; 1873b5dd2f60SMing Lei } 1874b5dd2f60SMing Lei 1875a47653fcSKen Chen blk_register_region(MKDEV(LOOP_MAJOR, 0), range, 1876a47653fcSKen Chen THIS_MODULE, loop_probe, NULL, NULL); 1877a47653fcSKen Chen 1878d134b00bSKay Sievers /* pre-create number of devices given by config or max_loop */ 187934dd82afSKay Sievers mutex_lock(&loop_index_mutex); 188034dd82afSKay Sievers for (i = 0; i < nr; i++) 188134dd82afSKay Sievers loop_add(&lo, i); 188234dd82afSKay Sievers mutex_unlock(&loop_index_mutex); 188334dd82afSKay Sievers 188473285082SKen Chen printk(KERN_INFO "loop: module loaded\n"); 18851da177e4SLinus Torvalds return 0; 1886b1a66504SGuo Chao 1887b1a66504SGuo Chao misc_out: 1888b1a66504SGuo Chao misc_deregister(&loop_misc); 1889b1a66504SGuo Chao return err; 189034dd82afSKay Sievers } 1891a47653fcSKen Chen 189234dd82afSKay Sievers static int loop_exit_cb(int id, void *ptr, void *data) 189334dd82afSKay Sievers { 189434dd82afSKay Sievers struct loop_device *lo = ptr; 1895a47653fcSKen Chen 189634dd82afSKay Sievers loop_remove(lo); 189734dd82afSKay Sievers return 0; 18981da177e4SLinus Torvalds } 18991da177e4SLinus Torvalds 190073285082SKen Chen static void __exit loop_exit(void) 19011da177e4SLinus Torvalds { 1902a47653fcSKen Chen unsigned long range; 19031da177e4SLinus Torvalds 1904a1c15c59SNamhyung Kim range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; 1905a47653fcSKen Chen 190634dd82afSKay Sievers idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); 190734dd82afSKay Sievers idr_destroy(&loop_index_idr); 190873285082SKen Chen 1909a47653fcSKen Chen blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); 191000d59405SAkinobu Mita unregister_blkdev(LOOP_MAJOR, "loop"); 1911770fe30aSKay Sievers 1912b5dd2f60SMing Lei destroy_workqueue(loop_wq); 1913b5dd2f60SMing Lei 1914770fe30aSKay Sievers misc_deregister(&loop_misc); 19151da177e4SLinus Torvalds } 19161da177e4SLinus Torvalds 19171da177e4SLinus Torvalds module_init(loop_init); 19181da177e4SLinus Torvalds module_exit(loop_exit); 19191da177e4SLinus Torvalds 19201da177e4SLinus Torvalds #ifndef MODULE 19211da177e4SLinus Torvalds static int __init max_loop_setup(char *str) 19221da177e4SLinus Torvalds { 19231da177e4SLinus Torvalds max_loop = simple_strtol(str, NULL, 0); 19241da177e4SLinus Torvalds return 1; 19251da177e4SLinus Torvalds } 19261da177e4SLinus Torvalds 19271da177e4SLinus Torvalds __setup("max_loop=", max_loop_setup); 19281da177e4SLinus Torvalds #endif 1929