Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/drivers/block/loop.c |
| 3 | * |
| 4 | * Written by Theodore Ts'o, 3/29/93 |
| 5 | * |
| 6 | * Copyright 1993 by Theodore Ts'o. Redistribution of this file is |
| 7 | * permitted under the GNU General Public License. |
| 8 | * |
| 9 | * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 |
| 10 | * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 |
| 11 | * |
| 12 | * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 |
| 13 | * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 |
| 14 | * |
| 15 | * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 |
| 16 | * |
| 17 | * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998 |
| 18 | * |
| 19 | * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 |
| 20 | * |
| 21 | * Loadable modules and other fixes by AK, 1998 |
| 22 | * |
| 23 | * Make real block number available to downstream transfer functions, enables |
| 24 | * CBC (and relatives) mode encryption requiring unique IVs per data block. |
| 25 | * Reed H. Petty, rhp@draper.net |
| 26 | * |
| 27 | * Maximum number of loop devices now dynamic via max_loop module parameter. |
| 28 | * Russell Kroll <rkroll@exploits.org> 19990701 |
| 29 | * |
| 30 | * Maximum number of loop devices when compiled-in now selectable by passing |
| 31 | * max_loop=<1-255> to the kernel on boot. |
Jan Engelhardt | 96de0e2 | 2007-10-19 23:21:04 +0200 | [diff] [blame] | 32 | * Erik I. Bolsø, <eriki@himolde.no>, Oct 31, 1999 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | * |
| 34 | * Completely rewrite request handling to be make_request_fn style and |
| 35 | * non blocking, pushing work to a helper thread. Lots of fixes from |
| 36 | * Al Viro too. |
| 37 | * Jens Axboe <axboe@suse.de>, Nov 2000 |
| 38 | * |
| 39 | * Support up to 256 loop devices |
| 40 | * Heinz Mauelshagen <mge@sistina.com>, Feb 2002 |
| 41 | * |
| 42 | * Support for falling back on the write file operation when the address space |
Nick Piggin | 4e02ed4 | 2008-10-29 14:00:55 -0700 | [diff] [blame] | 43 | * operations write_begin is not available on the backing filesystem. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * Anton Altaparmakov, 16 Feb 2005 |
| 45 | * |
| 46 | * Still To Fix: |
| 47 | * - Advisory locking is ignored here. |
| 48 | * - Should use an own CAP_* category instead of CAP_SYS_ADMIN |
| 49 | * |
| 50 | */ |
| 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | #include <linux/module.h> |
| 53 | #include <linux/moduleparam.h> |
| 54 | #include <linux/sched.h> |
| 55 | #include <linux/fs.h> |
| 56 | #include <linux/file.h> |
| 57 | #include <linux/stat.h> |
| 58 | #include <linux/errno.h> |
| 59 | #include <linux/major.h> |
| 60 | #include <linux/wait.h> |
| 61 | #include <linux/blkdev.h> |
| 62 | #include <linux/blkpg.h> |
| 63 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | #include <linux/swap.h> |
| 65 | #include <linux/slab.h> |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 66 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | #include <linux/suspend.h> |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 68 | #include <linux/freezer.h> |
Arnd Bergmann | 2a48fc0 | 2010-06-02 14:28:52 +0200 | [diff] [blame] | 69 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #include <linux/completion.h> |
| 72 | #include <linux/highmem.h> |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 73 | #include <linux/kthread.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 74 | #include <linux/splice.h> |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 75 | #include <linux/sysfs.h> |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 76 | #include <linux/miscdevice.h> |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 77 | #include <linux/falloc.h> |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 78 | #include <linux/uio.h> |
Al Viro | 83a8761 | 2013-05-12 10:14:07 -0400 | [diff] [blame] | 79 | #include "loop.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 81 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 83 | static DEFINE_IDR(loop_index_idr); |
| 84 | static DEFINE_MUTEX(loop_index_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 86 | static int max_part; |
| 87 | static int part_shift; |
| 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | static int transfer_xor(struct loop_device *lo, int cmd, |
| 90 | struct page *raw_page, unsigned raw_off, |
| 91 | struct page *loop_page, unsigned loop_off, |
| 92 | int size, sector_t real_block) |
| 93 | { |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 94 | char *raw_buf = kmap_atomic(raw_page) + raw_off; |
| 95 | char *loop_buf = kmap_atomic(loop_page) + loop_off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | char *in, *out, *key; |
| 97 | int i, keysize; |
| 98 | |
| 99 | if (cmd == READ) { |
| 100 | in = raw_buf; |
| 101 | out = loop_buf; |
| 102 | } else { |
| 103 | in = loop_buf; |
| 104 | out = raw_buf; |
| 105 | } |
| 106 | |
| 107 | key = lo->lo_encrypt_key; |
| 108 | keysize = lo->lo_encrypt_key_size; |
| 109 | for (i = 0; i < size; i++) |
| 110 | *out++ = *in++ ^ key[(i & 511) % keysize]; |
| 111 | |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 112 | kunmap_atomic(loop_buf); |
| 113 | kunmap_atomic(raw_buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | cond_resched(); |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static int xor_init(struct loop_device *lo, const struct loop_info64 *info) |
| 119 | { |
| 120 | if (unlikely(info->lo_encrypt_key_size <= 0)) |
| 121 | return -EINVAL; |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | static struct loop_func_table none_funcs = { |
| 126 | .number = LO_CRYPT_NONE, |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 127 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
| 129 | static struct loop_func_table xor_funcs = { |
| 130 | .number = LO_CRYPT_XOR, |
| 131 | .transfer = transfer_xor, |
| 132 | .init = xor_init |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 133 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
| 135 | /* xfer_funcs[0] is special - its release function is never called */ |
| 136 | static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = { |
| 137 | &none_funcs, |
| 138 | &xor_funcs |
| 139 | }; |
| 140 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 141 | static loff_t get_size(loff_t offset, loff_t sizelimit, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | { |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 143 | loff_t loopsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | |
| 145 | /* Compute loopsize in bytes */ |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 146 | loopsize = i_size_read(file->f_mapping->host); |
| 147 | if (offset > 0) |
| 148 | loopsize -= offset; |
| 149 | /* offset is beyond i_size, weird but possible */ |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 150 | if (loopsize < 0) |
| 151 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 153 | if (sizelimit > 0 && sizelimit < loopsize) |
| 154 | loopsize = sizelimit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | /* |
| 156 | * Unfortunately, if we want to do I/O on the device, |
| 157 | * the number of 512-byte sectors has to fit into a sector_t. |
| 158 | */ |
| 159 | return loopsize >> 9; |
| 160 | } |
| 161 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 162 | static loff_t get_loop_size(struct loop_device *lo, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 164 | return get_size(lo->lo_offset, lo->lo_sizelimit, file); |
| 165 | } |
| 166 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 167 | static void __loop_update_dio(struct loop_device *lo, bool dio) |
| 168 | { |
| 169 | struct file *file = lo->lo_backing_file; |
| 170 | struct address_space *mapping = file->f_mapping; |
| 171 | struct inode *inode = mapping->host; |
| 172 | unsigned short sb_bsize = 0; |
| 173 | unsigned dio_align = 0; |
| 174 | bool use_dio; |
| 175 | |
| 176 | if (inode->i_sb->s_bdev) { |
| 177 | sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); |
| 178 | dio_align = sb_bsize - 1; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * We support direct I/O only if lo_offset is aligned with the |
| 183 | * logical I/O size of backing device, and the logical block |
| 184 | * size of loop is bigger than the backing device's and the loop |
| 185 | * needn't transform transfer. |
| 186 | * |
| 187 | * TODO: the above condition may be loosed in the future, and |
| 188 | * direct I/O may be switched runtime at that time because most |
Masahiro Yamada | 89d790a | 2017-02-27 14:29:01 -0800 | [diff] [blame] | 189 | * of requests in sane applications should be PAGE_SIZE aligned |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 190 | */ |
| 191 | if (dio) { |
| 192 | if (queue_logical_block_size(lo->lo_queue) >= sb_bsize && |
| 193 | !(lo->lo_offset & dio_align) && |
| 194 | mapping->a_ops->direct_IO && |
| 195 | !lo->transfer) |
| 196 | use_dio = true; |
| 197 | else |
| 198 | use_dio = false; |
| 199 | } else { |
| 200 | use_dio = false; |
| 201 | } |
| 202 | |
| 203 | if (lo->use_dio == use_dio) |
| 204 | return; |
| 205 | |
| 206 | /* flush dirty pages before changing direct IO */ |
| 207 | vfs_fsync(file, 0); |
| 208 | |
| 209 | /* |
| 210 | * The flag of LO_FLAGS_DIRECT_IO is handled similarly with |
| 211 | * LO_FLAGS_READ_ONLY, both are set from kernel, and losetup |
| 212 | * will get updated by ioctl(LOOP_GET_STATUS) |
| 213 | */ |
| 214 | blk_mq_freeze_queue(lo->lo_queue); |
| 215 | lo->use_dio = use_dio; |
| 216 | if (use_dio) |
| 217 | lo->lo_flags |= LO_FLAGS_DIRECT_IO; |
| 218 | else |
| 219 | lo->lo_flags &= ~LO_FLAGS_DIRECT_IO; |
| 220 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 221 | } |
| 222 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 223 | static int |
Omar Sandoval | 1e6ec9e | 2017-08-23 14:54:59 -0700 | [diff] [blame] | 224 | figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 225 | { |
| 226 | loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | sector_t x = (sector_t)size; |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 228 | struct block_device *bdev = lo->lo_device; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | |
| 230 | if (unlikely((loff_t)x != size)) |
| 231 | return -EFBIG; |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 232 | if (lo->lo_offset != offset) |
| 233 | lo->lo_offset = offset; |
| 234 | if (lo->lo_sizelimit != sizelimit) |
| 235 | lo->lo_sizelimit = sizelimit; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 236 | set_capacity(lo->lo_disk, x); |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 237 | bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9); |
| 238 | /* let user-space know about the new size */ |
| 239 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 240 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | } |
| 242 | |
| 243 | static inline int |
| 244 | lo_do_transfer(struct loop_device *lo, int cmd, |
| 245 | struct page *rpage, unsigned roffs, |
| 246 | struct page *lpage, unsigned loffs, |
| 247 | int size, sector_t rblock) |
| 248 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 249 | int ret; |
| 250 | |
| 251 | ret = lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock); |
| 252 | if (likely(!ret)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | return 0; |
| 254 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 255 | printk_ratelimited(KERN_ERR |
| 256 | "loop: Transfer error at byte offset %llu, length %i.\n", |
| 257 | (unsigned long long)rblock << 9, size); |
| 258 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | } |
| 260 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 261 | static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 263 | struct iov_iter i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | ssize_t bw; |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 265 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 266 | iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 268 | file_start_write(file); |
Christoph Hellwig | abbb6589 | 2017-05-27 11:16:52 +0300 | [diff] [blame] | 269 | bw = vfs_iter_write(file, &i, ppos, 0); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 270 | file_end_write(file); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 271 | |
| 272 | if (likely(bw == bvec->bv_len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | return 0; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 274 | |
| 275 | printk_ratelimited(KERN_ERR |
| 276 | "loop: Write error at byte offset %llu, length %i.\n", |
| 277 | (unsigned long long)*ppos, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | if (bw >= 0) |
| 279 | bw = -EIO; |
| 280 | return bw; |
| 281 | } |
| 282 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 283 | static int lo_write_simple(struct loop_device *lo, struct request *rq, |
| 284 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 286 | struct bio_vec bvec; |
| 287 | struct req_iterator iter; |
| 288 | int ret = 0; |
| 289 | |
| 290 | rq_for_each_segment(bvec, rq, iter) { |
| 291 | ret = lo_write_bvec(lo->lo_backing_file, &bvec, &pos); |
| 292 | if (ret < 0) |
| 293 | break; |
| 294 | cond_resched(); |
| 295 | } |
| 296 | |
| 297 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | } |
| 299 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 300 | /* |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 301 | * This is the slow, transforming version that needs to double buffer the |
| 302 | * data as it cannot do the transformations in place without having direct |
| 303 | * access to the destination pages of the backing file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | */ |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 305 | static int lo_write_transfer(struct loop_device *lo, struct request *rq, |
| 306 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 308 | struct bio_vec bvec, b; |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 309 | struct req_iterator iter; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 310 | struct page *page; |
Kent Overstreet | 7988613 | 2013-11-23 17:19:00 -0800 | [diff] [blame] | 311 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 313 | page = alloc_page(GFP_NOIO); |
| 314 | if (unlikely(!page)) |
| 315 | return -ENOMEM; |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 316 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 317 | rq_for_each_segment(bvec, rq, iter) { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 318 | ret = lo_do_transfer(lo, WRITE, page, 0, bvec.bv_page, |
| 319 | bvec.bv_offset, bvec.bv_len, pos >> 9); |
| 320 | if (unlikely(ret)) |
| 321 | break; |
| 322 | |
| 323 | b.bv_page = page; |
| 324 | b.bv_offset = 0; |
| 325 | b.bv_len = bvec.bv_len; |
| 326 | ret = lo_write_bvec(lo->lo_backing_file, &b, &pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | if (ret < 0) |
| 328 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 330 | |
| 331 | __free_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | } |
| 334 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 335 | static int lo_read_simple(struct loop_device *lo, struct request *rq, |
| 336 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | { |
Kent Overstreet | 7988613 | 2013-11-23 17:19:00 -0800 | [diff] [blame] | 338 | struct bio_vec bvec; |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 339 | struct req_iterator iter; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 340 | struct iov_iter i; |
| 341 | ssize_t len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 343 | rq_for_each_segment(bvec, rq, iter) { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 344 | iov_iter_bvec(&i, ITER_BVEC, &bvec, 1, bvec.bv_len); |
Christoph Hellwig | 18e9710 | 2017-05-27 11:16:51 +0300 | [diff] [blame] | 345 | len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 346 | if (len < 0) |
| 347 | return len; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 348 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 349 | flush_dcache_page(bvec.bv_page); |
| 350 | |
| 351 | if (len != bvec.bv_len) { |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 352 | struct bio *bio; |
| 353 | |
| 354 | __rq_for_each_bio(bio, rq) |
| 355 | zero_fill_bio(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | break; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 357 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 358 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 360 | |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 361 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | } |
| 363 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 364 | static int lo_read_transfer(struct loop_device *lo, struct request *rq, |
| 365 | loff_t pos) |
| 366 | { |
| 367 | struct bio_vec bvec, b; |
| 368 | struct req_iterator iter; |
| 369 | struct iov_iter i; |
| 370 | struct page *page; |
| 371 | ssize_t len; |
| 372 | int ret = 0; |
| 373 | |
| 374 | page = alloc_page(GFP_NOIO); |
| 375 | if (unlikely(!page)) |
| 376 | return -ENOMEM; |
| 377 | |
| 378 | rq_for_each_segment(bvec, rq, iter) { |
| 379 | loff_t offset = pos; |
| 380 | |
| 381 | b.bv_page = page; |
| 382 | b.bv_offset = 0; |
| 383 | b.bv_len = bvec.bv_len; |
| 384 | |
| 385 | iov_iter_bvec(&i, ITER_BVEC, &b, 1, b.bv_len); |
Christoph Hellwig | 18e9710 | 2017-05-27 11:16:51 +0300 | [diff] [blame] | 386 | len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 387 | if (len < 0) { |
| 388 | ret = len; |
| 389 | goto out_free_page; |
| 390 | } |
| 391 | |
| 392 | ret = lo_do_transfer(lo, READ, page, 0, bvec.bv_page, |
| 393 | bvec.bv_offset, len, offset >> 9); |
| 394 | if (ret) |
| 395 | goto out_free_page; |
| 396 | |
| 397 | flush_dcache_page(bvec.bv_page); |
| 398 | |
| 399 | if (len != bvec.bv_len) { |
| 400 | struct bio *bio; |
| 401 | |
| 402 | __rq_for_each_bio(bio, rq) |
| 403 | zero_fill_bio(bio); |
| 404 | break; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | ret = 0; |
| 409 | out_free_page: |
| 410 | __free_page(page); |
| 411 | return ret; |
| 412 | } |
| 413 | |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 414 | static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos) |
| 415 | { |
| 416 | /* |
| 417 | * We use punch hole to reclaim the free space used by the |
| 418 | * image a.k.a. discard. However we do not support discard if |
| 419 | * encryption is enabled, because it may give an attacker |
| 420 | * useful information. |
| 421 | */ |
| 422 | struct file *file = lo->lo_backing_file; |
| 423 | int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; |
| 424 | int ret; |
| 425 | |
| 426 | if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) { |
| 427 | ret = -EOPNOTSUPP; |
| 428 | goto out; |
| 429 | } |
| 430 | |
| 431 | ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); |
| 432 | if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) |
| 433 | ret = -EIO; |
| 434 | out: |
| 435 | return ret; |
| 436 | } |
| 437 | |
| 438 | static int lo_req_flush(struct loop_device *lo, struct request *rq) |
| 439 | { |
| 440 | struct file *file = lo->lo_backing_file; |
| 441 | int ret = vfs_fsync(file, 0); |
| 442 | if (unlikely(ret && ret != -EINVAL)) |
| 443 | ret = -EIO; |
| 444 | |
| 445 | return ret; |
| 446 | } |
| 447 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 448 | static void lo_complete_rq(struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 449 | { |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 450 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 451 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 452 | if (unlikely(req_op(cmd->rq) == REQ_OP_READ && cmd->use_aio && |
| 453 | cmd->ret >= 0 && cmd->ret < blk_rq_bytes(cmd->rq))) { |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 454 | struct bio *bio = cmd->rq->bio; |
| 455 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 456 | bio_advance(bio, cmd->ret); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 457 | zero_fill_bio(bio); |
| 458 | } |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 459 | |
Christoph Hellwig | 2a842ac | 2017-06-03 09:38:04 +0200 | [diff] [blame] | 460 | blk_mq_end_request(rq, cmd->ret < 0 ? BLK_STS_IOERR : BLK_STS_OK); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 461 | } |
| 462 | |
| 463 | static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2) |
| 464 | { |
| 465 | struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 466 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 467 | cmd->ret = ret; |
Christoph Hellwig | 08e0029 | 2017-04-20 16:03:09 +0200 | [diff] [blame] | 468 | blk_mq_complete_request(cmd->rq); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 469 | } |
| 470 | |
| 471 | static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, |
| 472 | loff_t pos, bool rw) |
| 473 | { |
| 474 | struct iov_iter iter; |
| 475 | struct bio_vec *bvec; |
| 476 | struct bio *bio = cmd->rq->bio; |
| 477 | struct file *file = lo->lo_backing_file; |
| 478 | int ret; |
| 479 | |
| 480 | /* nomerge for loop request queue */ |
| 481 | WARN_ON(cmd->rq->bio != cmd->rq->biotail); |
| 482 | |
| 483 | bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); |
| 484 | iov_iter_bvec(&iter, ITER_BVEC | rw, bvec, |
| 485 | bio_segments(bio), blk_rq_bytes(cmd->rq)); |
Ming Lei | a7297a6 | 2016-04-15 18:51:28 +0800 | [diff] [blame] | 486 | /* |
| 487 | * This bio may be started from the middle of the 'bvec' |
| 488 | * because of bio splitting, so offset from the bvec must |
| 489 | * be passed to iov iterator |
| 490 | */ |
| 491 | iter.iov_offset = bio->bi_iter.bi_bvec_done; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 492 | |
| 493 | cmd->iocb.ki_pos = pos; |
| 494 | cmd->iocb.ki_filp = file; |
| 495 | cmd->iocb.ki_complete = lo_rw_aio_complete; |
| 496 | cmd->iocb.ki_flags = IOCB_DIRECT; |
| 497 | |
| 498 | if (rw == WRITE) |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 499 | ret = call_write_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 500 | else |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 501 | ret = call_read_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 502 | |
| 503 | if (ret != -EIOCBQUEUED) |
| 504 | cmd->iocb.ki_complete(&cmd->iocb, ret, 0); |
| 505 | return 0; |
| 506 | } |
| 507 | |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 508 | static int do_req_filebacked(struct loop_device *lo, struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 509 | { |
| 510 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 511 | loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 512 | |
| 513 | /* |
| 514 | * lo_write_simple and lo_read_simple should have been covered |
| 515 | * by io submit style function like lo_rw_aio(), one blocker |
| 516 | * is that lo_read_simple() need to call flush_dcache_page after |
| 517 | * the page is written from kernel, and it isn't easy to handle |
| 518 | * this in io submit style function which submits all segments |
| 519 | * of the req at one time. And direct read IO doesn't need to |
| 520 | * run flush_dcache_page(). |
| 521 | */ |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 522 | switch (req_op(rq)) { |
| 523 | case REQ_OP_FLUSH: |
| 524 | return lo_req_flush(lo, rq); |
| 525 | case REQ_OP_DISCARD: |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 526 | case REQ_OP_WRITE_ZEROES: |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 527 | return lo_discard(lo, rq, pos); |
| 528 | case REQ_OP_WRITE: |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 529 | if (lo->transfer) |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 530 | return lo_write_transfer(lo, rq, pos); |
| 531 | else if (cmd->use_aio) |
| 532 | return lo_rw_aio(lo, cmd, pos, WRITE); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 533 | else |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 534 | return lo_write_simple(lo, rq, pos); |
| 535 | case REQ_OP_READ: |
| 536 | if (lo->transfer) |
| 537 | return lo_read_transfer(lo, rq, pos); |
| 538 | else if (cmd->use_aio) |
| 539 | return lo_rw_aio(lo, cmd, pos, READ); |
| 540 | else |
| 541 | return lo_read_simple(lo, rq, pos); |
| 542 | default: |
| 543 | WARN_ON_ONCE(1); |
| 544 | return -EIO; |
| 545 | break; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 546 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | } |
| 548 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 549 | static inline void loop_update_dio(struct loop_device *lo) |
| 550 | { |
| 551 | __loop_update_dio(lo, io_is_direct(lo->lo_backing_file) | |
| 552 | lo->use_dio); |
| 553 | } |
| 554 | |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 555 | static void loop_reread_partitions(struct loop_device *lo, |
| 556 | struct block_device *bdev) |
| 557 | { |
| 558 | int rc; |
| 559 | |
| 560 | /* |
| 561 | * bd_mutex has been held already in release path, so don't |
| 562 | * acquire it if this function is called in such case. |
| 563 | * |
| 564 | * If the reread partition isn't from release path, lo_refcnt |
| 565 | * must be at least one and it can only become zero when the |
| 566 | * current holder is released. |
| 567 | */ |
| 568 | if (!atomic_read(&lo->lo_refcnt)) |
| 569 | rc = __blkdev_reread_part(bdev); |
| 570 | else |
| 571 | rc = blkdev_reread_part(bdev); |
| 572 | if (rc) |
| 573 | pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n", |
| 574 | __func__, lo->lo_number, lo->lo_file_name, rc); |
| 575 | } |
| 576 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | /* |
| 578 | * loop_change_fd switched the backing store of a loopback device to |
| 579 | * a new file. This is useful for operating system installers to free up |
| 580 | * the original file and in High Availability environments to switch to |
| 581 | * an alternative location for the content in case of server meltdown. |
| 582 | * This can only work if the loop device is used read-only, and if the |
| 583 | * new backing store is the same size and type as the old backing store. |
| 584 | */ |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 585 | static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, |
| 586 | unsigned int arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | { |
| 588 | struct file *file, *old_file; |
| 589 | struct inode *inode; |
| 590 | int error; |
| 591 | |
| 592 | error = -ENXIO; |
| 593 | if (lo->lo_state != Lo_bound) |
| 594 | goto out; |
| 595 | |
| 596 | /* the loop device has to be read-only */ |
| 597 | error = -EINVAL; |
| 598 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) |
| 599 | goto out; |
| 600 | |
| 601 | error = -EBADF; |
| 602 | file = fget(arg); |
| 603 | if (!file) |
| 604 | goto out; |
| 605 | |
| 606 | inode = file->f_mapping->host; |
| 607 | old_file = lo->lo_backing_file; |
| 608 | |
| 609 | error = -EINVAL; |
| 610 | |
| 611 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
| 612 | goto out_putf; |
| 613 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | /* size of the new backing store needs to be the same */ |
| 615 | if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) |
| 616 | goto out_putf; |
| 617 | |
| 618 | /* and ... switch */ |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame^] | 619 | blk_mq_freeze_queue(lo->lo_queue); |
| 620 | mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); |
| 621 | lo->lo_backing_file = file; |
| 622 | lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); |
| 623 | mapping_set_gfp_mask(file->f_mapping, |
| 624 | lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 625 | loop_update_dio(lo); |
| 626 | blk_mq_unfreeze_queue(lo->lo_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | |
| 628 | fput(old_file); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 629 | if (lo->lo_flags & LO_FLAGS_PARTSCAN) |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 630 | loop_reread_partitions(lo, bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | return 0; |
| 632 | |
| 633 | out_putf: |
| 634 | fput(file); |
| 635 | out: |
| 636 | return error; |
| 637 | } |
| 638 | |
| 639 | static inline int is_loop_device(struct file *file) |
| 640 | { |
| 641 | struct inode *i = file->f_mapping->host; |
| 642 | |
| 643 | return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; |
| 644 | } |
| 645 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 646 | /* loop sysfs attributes */ |
| 647 | |
| 648 | static ssize_t loop_attr_show(struct device *dev, char *page, |
| 649 | ssize_t (*callback)(struct loop_device *, char *)) |
| 650 | { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 651 | struct gendisk *disk = dev_to_disk(dev); |
| 652 | struct loop_device *lo = disk->private_data; |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 653 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 654 | return callback(lo, page); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 655 | } |
| 656 | |
| 657 | #define LOOP_ATTR_RO(_name) \ |
| 658 | static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ |
| 659 | static ssize_t loop_attr_do_show_##_name(struct device *d, \ |
| 660 | struct device_attribute *attr, char *b) \ |
| 661 | { \ |
| 662 | return loop_attr_show(d, b, loop_attr_##_name##_show); \ |
| 663 | } \ |
| 664 | static struct device_attribute loop_attr_##_name = \ |
| 665 | __ATTR(_name, S_IRUGO, loop_attr_do_show_##_name, NULL); |
| 666 | |
| 667 | static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) |
| 668 | { |
| 669 | ssize_t ret; |
| 670 | char *p = NULL; |
| 671 | |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 672 | spin_lock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 673 | if (lo->lo_backing_file) |
Miklos Szeredi | 9bf39ab | 2015-06-19 10:29:13 +0200 | [diff] [blame] | 674 | p = file_path(lo->lo_backing_file, buf, PAGE_SIZE - 1); |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 675 | spin_unlock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 676 | |
| 677 | if (IS_ERR_OR_NULL(p)) |
| 678 | ret = PTR_ERR(p); |
| 679 | else { |
| 680 | ret = strlen(p); |
| 681 | memmove(buf, p, ret); |
| 682 | buf[ret++] = '\n'; |
| 683 | buf[ret] = 0; |
| 684 | } |
| 685 | |
| 686 | return ret; |
| 687 | } |
| 688 | |
| 689 | static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) |
| 690 | { |
| 691 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); |
| 692 | } |
| 693 | |
| 694 | static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) |
| 695 | { |
| 696 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); |
| 697 | } |
| 698 | |
| 699 | static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) |
| 700 | { |
| 701 | int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); |
| 702 | |
| 703 | return sprintf(buf, "%s\n", autoclear ? "1" : "0"); |
| 704 | } |
| 705 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 706 | static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) |
| 707 | { |
| 708 | int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); |
| 709 | |
| 710 | return sprintf(buf, "%s\n", partscan ? "1" : "0"); |
| 711 | } |
| 712 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 713 | static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf) |
| 714 | { |
| 715 | int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO); |
| 716 | |
| 717 | return sprintf(buf, "%s\n", dio ? "1" : "0"); |
| 718 | } |
| 719 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 720 | LOOP_ATTR_RO(backing_file); |
| 721 | LOOP_ATTR_RO(offset); |
| 722 | LOOP_ATTR_RO(sizelimit); |
| 723 | LOOP_ATTR_RO(autoclear); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 724 | LOOP_ATTR_RO(partscan); |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 725 | LOOP_ATTR_RO(dio); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 726 | |
| 727 | static struct attribute *loop_attrs[] = { |
| 728 | &loop_attr_backing_file.attr, |
| 729 | &loop_attr_offset.attr, |
| 730 | &loop_attr_sizelimit.attr, |
| 731 | &loop_attr_autoclear.attr, |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 732 | &loop_attr_partscan.attr, |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 733 | &loop_attr_dio.attr, |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 734 | NULL, |
| 735 | }; |
| 736 | |
| 737 | static struct attribute_group loop_attribute_group = { |
| 738 | .name = "loop", |
| 739 | .attrs= loop_attrs, |
| 740 | }; |
| 741 | |
| 742 | static int loop_sysfs_init(struct loop_device *lo) |
| 743 | { |
| 744 | return sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 745 | &loop_attribute_group); |
| 746 | } |
| 747 | |
| 748 | static void loop_sysfs_exit(struct loop_device *lo) |
| 749 | { |
| 750 | sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 751 | &loop_attribute_group); |
| 752 | } |
| 753 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 754 | static void loop_config_discard(struct loop_device *lo) |
| 755 | { |
| 756 | struct file *file = lo->lo_backing_file; |
| 757 | struct inode *inode = file->f_mapping->host; |
| 758 | struct request_queue *q = lo->lo_queue; |
| 759 | |
| 760 | /* |
| 761 | * We use punch hole to reclaim the free space used by the |
Olaf Hering | 12a64d2 | 2014-01-21 14:39:24 -0800 | [diff] [blame] | 762 | * image a.k.a. discard. However we do not support discard if |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 763 | * encryption is enabled, because it may give an attacker |
| 764 | * useful information. |
| 765 | */ |
| 766 | if ((!file->f_op->fallocate) || |
| 767 | lo->lo_encrypt_key_size) { |
| 768 | q->limits.discard_granularity = 0; |
| 769 | q->limits.discard_alignment = 0; |
Jens Axboe | 2bb4cd5 | 2015-07-14 08:15:12 -0600 | [diff] [blame] | 770 | blk_queue_max_discard_sectors(q, 0); |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 771 | blk_queue_max_write_zeroes_sectors(q, 0); |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 772 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); |
| 773 | return; |
| 774 | } |
| 775 | |
| 776 | q->limits.discard_granularity = inode->i_sb->s_blocksize; |
Lukas Czerner | dfaf3c0 | 2011-12-02 14:47:03 +0100 | [diff] [blame] | 777 | q->limits.discard_alignment = 0; |
Hannes Reinecke | f2c6df7 | 2017-06-08 13:46:45 +0200 | [diff] [blame] | 778 | |
Omar Sandoval | 1e6ec9e | 2017-08-23 14:54:59 -0700 | [diff] [blame] | 779 | blk_queue_max_discard_sectors(q, UINT_MAX >> 9); |
| 780 | blk_queue_max_write_zeroes_sectors(q, UINT_MAX >> 9); |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 781 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); |
| 782 | } |
| 783 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 784 | static void loop_unprepare_queue(struct loop_device *lo) |
| 785 | { |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 786 | kthread_flush_worker(&lo->worker); |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 787 | kthread_stop(lo->worker_task); |
| 788 | } |
| 789 | |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 790 | static int loop_kthread_worker_fn(void *worker_ptr) |
| 791 | { |
| 792 | current->flags |= PF_LESS_THROTTLE; |
| 793 | return kthread_worker_fn(worker_ptr); |
| 794 | } |
| 795 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 796 | static int loop_prepare_queue(struct loop_device *lo) |
| 797 | { |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 798 | kthread_init_worker(&lo->worker); |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 799 | lo->worker_task = kthread_run(loop_kthread_worker_fn, |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 800 | &lo->worker, "loop%d", lo->lo_number); |
| 801 | if (IS_ERR(lo->worker_task)) |
| 802 | return -ENOMEM; |
| 803 | set_user_nice(lo->worker_task, MIN_NICE); |
| 804 | return 0; |
| 805 | } |
| 806 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 807 | static int loop_set_fd(struct loop_device *lo, fmode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | struct block_device *bdev, unsigned int arg) |
| 809 | { |
| 810 | struct file *file, *f; |
| 811 | struct inode *inode; |
| 812 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | int lo_flags = 0; |
| 814 | int error; |
| 815 | loff_t size; |
| 816 | |
| 817 | /* This is safe, since we have a reference from open(). */ |
| 818 | __module_get(THIS_MODULE); |
| 819 | |
| 820 | error = -EBADF; |
| 821 | file = fget(arg); |
| 822 | if (!file) |
| 823 | goto out; |
| 824 | |
| 825 | error = -EBUSY; |
| 826 | if (lo->lo_state != Lo_unbound) |
| 827 | goto out_putf; |
| 828 | |
| 829 | /* Avoid recursion */ |
| 830 | f = file; |
| 831 | while (is_loop_device(f)) { |
| 832 | struct loop_device *l; |
| 833 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 834 | if (f->f_mapping->host->i_bdev == bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | goto out_putf; |
| 836 | |
| 837 | l = f->f_mapping->host->i_bdev->bd_disk->private_data; |
| 838 | if (l->lo_state == Lo_unbound) { |
| 839 | error = -EINVAL; |
| 840 | goto out_putf; |
| 841 | } |
| 842 | f = l->lo_backing_file; |
| 843 | } |
| 844 | |
| 845 | mapping = file->f_mapping; |
| 846 | inode = mapping->host; |
| 847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | error = -EINVAL; |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 849 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | goto out_putf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 852 | if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 853 | !file->f_op->write_iter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 854 | lo_flags |= LO_FLAGS_READ_ONLY; |
| 855 | |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 856 | error = -EFBIG; |
| 857 | size = get_loop_size(lo, file); |
| 858 | if ((loff_t)(sector_t)size != size) |
| 859 | goto out_putf; |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 860 | error = loop_prepare_queue(lo); |
| 861 | if (error) |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 862 | goto out_putf; |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 863 | |
| 864 | error = 0; |
| 865 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0); |
| 867 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 868 | lo->use_dio = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | lo->lo_device = bdev; |
| 870 | lo->lo_flags = lo_flags; |
| 871 | lo->lo_backing_file = file; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 872 | lo->transfer = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | lo->ioctl = NULL; |
| 874 | lo->lo_sizelimit = 0; |
| 875 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
| 876 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 877 | |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 878 | if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) |
Jens Axboe | 21d0727 | 2016-03-30 10:09:35 -0600 | [diff] [blame] | 879 | blk_queue_write_cache(lo->lo_queue, true, false); |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 880 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 881 | loop_update_dio(lo); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 882 | set_capacity(lo->lo_disk, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | bd_set_size(bdev, size << 9); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 884 | loop_sysfs_init(lo); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 885 | /* let user-space know about the new size */ |
| 886 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | |
Omar Sandoval | 8a0740c | 2017-08-24 00:03:41 -0700 | [diff] [blame] | 888 | set_blocksize(bdev, S_ISBLK(inode->i_mode) ? |
| 889 | block_size(inode->i_bdev) : PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 890 | |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 891 | lo->lo_state = Lo_bound; |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 892 | if (part_shift) |
| 893 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
| 894 | if (lo->lo_flags & LO_FLAGS_PARTSCAN) |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 895 | loop_reread_partitions(lo, bdev); |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 896 | |
| 897 | /* Grab the block_device to prevent its destruction after we |
| 898 | * put /dev/loopXX inode. Later in loop_clr_fd() we bdput(bdev). |
| 899 | */ |
| 900 | bdgrab(bdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 901 | return 0; |
| 902 | |
| 903 | out_putf: |
| 904 | fput(file); |
| 905 | out: |
| 906 | /* This is safe: open() is still holding a reference. */ |
| 907 | module_put(THIS_MODULE); |
| 908 | return error; |
| 909 | } |
| 910 | |
| 911 | static int |
| 912 | loop_release_xfer(struct loop_device *lo) |
| 913 | { |
| 914 | int err = 0; |
| 915 | struct loop_func_table *xfer = lo->lo_encryption; |
| 916 | |
| 917 | if (xfer) { |
| 918 | if (xfer->release) |
| 919 | err = xfer->release(lo); |
| 920 | lo->transfer = NULL; |
| 921 | lo->lo_encryption = NULL; |
| 922 | module_put(xfer->owner); |
| 923 | } |
| 924 | return err; |
| 925 | } |
| 926 | |
| 927 | static int |
| 928 | loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, |
| 929 | const struct loop_info64 *i) |
| 930 | { |
| 931 | int err = 0; |
| 932 | |
| 933 | if (xfer) { |
| 934 | struct module *owner = xfer->owner; |
| 935 | |
| 936 | if (!try_module_get(owner)) |
| 937 | return -EINVAL; |
| 938 | if (xfer->init) |
| 939 | err = xfer->init(lo, i); |
| 940 | if (err) |
| 941 | module_put(owner); |
| 942 | else |
| 943 | lo->lo_encryption = xfer; |
| 944 | } |
| 945 | return err; |
| 946 | } |
| 947 | |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 948 | static int loop_clr_fd(struct loop_device *lo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | { |
| 950 | struct file *filp = lo->lo_backing_file; |
Al Viro | b4e3ca1 | 2005-10-21 03:22:34 -0400 | [diff] [blame] | 951 | gfp_t gfp = lo->old_gfp_mask; |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 952 | struct block_device *bdev = lo->lo_device; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | |
| 954 | if (lo->lo_state != Lo_bound) |
| 955 | return -ENXIO; |
| 956 | |
Dave Chinner | a1ecac3 | 2012-09-28 10:42:23 +0200 | [diff] [blame] | 957 | /* |
| 958 | * If we've explicitly asked to tear down the loop device, |
| 959 | * and it has an elevated reference count, set it for auto-teardown when |
| 960 | * the last reference goes away. This stops $!~#$@ udev from |
| 961 | * preventing teardown because it decided that it needs to run blkid on |
| 962 | * the loopback device whenever they appear. xfstests is notorious for |
| 963 | * failing tests because blkid via udev races with a losetup |
| 964 | * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d |
| 965 | * command to fail with EBUSY. |
| 966 | */ |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 967 | if (atomic_read(&lo->lo_refcnt) > 1) { |
Dave Chinner | a1ecac3 | 2012-09-28 10:42:23 +0200 | [diff] [blame] | 968 | lo->lo_flags |= LO_FLAGS_AUTOCLEAR; |
| 969 | mutex_unlock(&lo->lo_ctl_mutex); |
| 970 | return 0; |
| 971 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 972 | |
| 973 | if (filp == NULL) |
| 974 | return -EINVAL; |
| 975 | |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 976 | /* freeze request queue during the transition */ |
| 977 | blk_mq_freeze_queue(lo->lo_queue); |
| 978 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | spin_lock_irq(&lo->lo_lock); |
| 980 | lo->lo_state = Lo_rundown; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | lo->lo_backing_file = NULL; |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 982 | spin_unlock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | |
| 984 | loop_release_xfer(lo); |
| 985 | lo->transfer = NULL; |
| 986 | lo->ioctl = NULL; |
| 987 | lo->lo_device = NULL; |
| 988 | lo->lo_encryption = NULL; |
| 989 | lo->lo_offset = 0; |
| 990 | lo->lo_sizelimit = 0; |
| 991 | lo->lo_encrypt_key_size = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); |
| 993 | memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); |
| 994 | memset(lo->lo_file_name, 0, LO_NAME_SIZE); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 995 | blk_queue_logical_block_size(lo->lo_queue, 512); |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 996 | if (bdev) { |
| 997 | bdput(bdev); |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 998 | invalidate_bdev(bdev); |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 999 | } |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1000 | set_capacity(lo->lo_disk, 0); |
Milan Broz | 51a0bb0 | 2010-10-27 19:51:30 -0600 | [diff] [blame] | 1001 | loop_sysfs_exit(lo); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1002 | if (bdev) { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1003 | bd_set_size(bdev, 0); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1004 | /* let user-space know about this change */ |
| 1005 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
| 1006 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1007 | mapping_set_gfp_mask(filp->f_mapping, gfp); |
| 1008 | lo->lo_state = Lo_unbound; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | /* This is safe: open() is still holding a reference. */ |
| 1010 | module_put(THIS_MODULE); |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1011 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 1012 | |
Jens Axboe | c2fccc1 | 2013-04-08 10:12:11 +0200 | [diff] [blame] | 1013 | if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev) |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 1014 | loop_reread_partitions(lo, bdev); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1015 | lo->lo_flags = 0; |
| 1016 | if (!part_shift) |
| 1017 | lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 1018 | loop_unprepare_queue(lo); |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1019 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1020 | /* |
| 1021 | * Need not hold lo_ctl_mutex to fput backing file. |
| 1022 | * Calling fput holding lo_ctl_mutex triggers a circular |
| 1023 | * lock dependency possibility warning as fput can take |
| 1024 | * bd_mutex which is usually taken before lo_ctl_mutex. |
| 1025 | */ |
| 1026 | fput(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | return 0; |
| 1028 | } |
| 1029 | |
| 1030 | static int |
| 1031 | loop_set_status(struct loop_device *lo, const struct loop_info64 *info) |
| 1032 | { |
| 1033 | int err; |
| 1034 | struct loop_func_table *xfer; |
Eric W. Biederman | e484973 | 2012-02-11 11:23:51 -0800 | [diff] [blame] | 1035 | kuid_t uid = current_uid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1037 | if (lo->lo_encrypt_key_size && |
Eric W. Biederman | e484973 | 2012-02-11 11:23:51 -0800 | [diff] [blame] | 1038 | !uid_eq(lo->lo_key_owner, uid) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | !capable(CAP_SYS_ADMIN)) |
| 1040 | return -EPERM; |
| 1041 | if (lo->lo_state != Lo_bound) |
| 1042 | return -ENXIO; |
| 1043 | if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) |
| 1044 | return -EINVAL; |
| 1045 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1046 | /* I/O need to be drained during transfer transition */ |
| 1047 | blk_mq_freeze_queue(lo->lo_queue); |
| 1048 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1049 | err = loop_release_xfer(lo); |
| 1050 | if (err) |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1051 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1052 | |
| 1053 | if (info->lo_encrypt_type) { |
| 1054 | unsigned int type = info->lo_encrypt_type; |
| 1055 | |
| 1056 | if (type >= MAX_LO_CRYPT) |
| 1057 | return -EINVAL; |
| 1058 | xfer = xfer_funcs[type]; |
| 1059 | if (xfer == NULL) |
| 1060 | return -EINVAL; |
| 1061 | } else |
| 1062 | xfer = NULL; |
| 1063 | |
| 1064 | err = loop_init_xfer(lo, xfer, info); |
| 1065 | if (err) |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1066 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1067 | |
| 1068 | if (lo->lo_offset != info->lo_offset || |
Omar Sandoval | 1e6ec9e | 2017-08-23 14:54:59 -0700 | [diff] [blame] | 1069 | lo->lo_sizelimit != info->lo_sizelimit) { |
| 1070 | if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) { |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1071 | err = -EFBIG; |
| 1072 | goto exit; |
| 1073 | } |
Arnd Bergmann | b040ad9 | 2017-06-09 12:19:18 +0200 | [diff] [blame] | 1074 | } |
Guo Chao | 541c742 | 2013-02-21 15:16:46 -0800 | [diff] [blame] | 1075 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 1076 | loop_config_discard(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1077 | |
| 1078 | memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); |
| 1079 | memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); |
| 1080 | lo->lo_file_name[LO_NAME_SIZE-1] = 0; |
| 1081 | lo->lo_crypt_name[LO_NAME_SIZE-1] = 0; |
| 1082 | |
| 1083 | if (!xfer) |
| 1084 | xfer = &none_funcs; |
| 1085 | lo->transfer = xfer->transfer; |
| 1086 | lo->ioctl = xfer->ioctl; |
| 1087 | |
David Woodhouse | 96c5865 | 2008-02-06 01:36:27 -0800 | [diff] [blame] | 1088 | if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) != |
| 1089 | (info->lo_flags & LO_FLAGS_AUTOCLEAR)) |
| 1090 | lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; |
| 1091 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1092 | lo->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1093 | lo->lo_init[0] = info->lo_init[0]; |
| 1094 | lo->lo_init[1] = info->lo_init[1]; |
| 1095 | if (info->lo_encrypt_key_size) { |
| 1096 | memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, |
| 1097 | info->lo_encrypt_key_size); |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1098 | lo->lo_key_owner = uid; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 1099 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | |
Ming Lei | 2e5ab5f | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 1101 | /* update dio if lo_offset or transfer is changed */ |
| 1102 | __loop_update_dio(lo, lo->use_dio); |
| 1103 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1104 | exit: |
| 1105 | blk_mq_unfreeze_queue(lo->lo_queue); |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1106 | |
| 1107 | if (!err && (info->lo_flags & LO_FLAGS_PARTSCAN) && |
| 1108 | !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { |
| 1109 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
| 1110 | lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; |
| 1111 | loop_reread_partitions(lo, lo->lo_device); |
| 1112 | } |
| 1113 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1114 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | } |
| 1116 | |
| 1117 | static int |
| 1118 | loop_get_status(struct loop_device *lo, struct loop_info64 *info) |
| 1119 | { |
| 1120 | struct file *file = lo->lo_backing_file; |
| 1121 | struct kstat stat; |
| 1122 | int error; |
| 1123 | |
| 1124 | if (lo->lo_state != Lo_bound) |
| 1125 | return -ENXIO; |
David Howells | a528d35 | 2017-01-31 16:46:22 +0000 | [diff] [blame] | 1126 | error = vfs_getattr(&file->f_path, &stat, |
| 1127 | STATX_INO, AT_STATX_SYNC_AS_STAT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | if (error) |
| 1129 | return error; |
| 1130 | memset(info, 0, sizeof(*info)); |
| 1131 | info->lo_number = lo->lo_number; |
| 1132 | info->lo_device = huge_encode_dev(stat.dev); |
| 1133 | info->lo_inode = stat.ino; |
| 1134 | info->lo_rdevice = huge_encode_dev(lo->lo_device ? stat.rdev : stat.dev); |
| 1135 | info->lo_offset = lo->lo_offset; |
| 1136 | info->lo_sizelimit = lo->lo_sizelimit; |
| 1137 | info->lo_flags = lo->lo_flags; |
| 1138 | memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); |
| 1139 | memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); |
| 1140 | info->lo_encrypt_type = |
| 1141 | lo->lo_encryption ? lo->lo_encryption->number : 0; |
| 1142 | if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { |
| 1143 | info->lo_encrypt_key_size = lo->lo_encrypt_key_size; |
| 1144 | memcpy(info->lo_encrypt_key, lo->lo_encrypt_key, |
| 1145 | lo->lo_encrypt_key_size); |
| 1146 | } |
| 1147 | return 0; |
| 1148 | } |
| 1149 | |
| 1150 | static void |
| 1151 | loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) |
| 1152 | { |
| 1153 | memset(info64, 0, sizeof(*info64)); |
| 1154 | info64->lo_number = info->lo_number; |
| 1155 | info64->lo_device = info->lo_device; |
| 1156 | info64->lo_inode = info->lo_inode; |
| 1157 | info64->lo_rdevice = info->lo_rdevice; |
| 1158 | info64->lo_offset = info->lo_offset; |
| 1159 | info64->lo_sizelimit = 0; |
| 1160 | info64->lo_encrypt_type = info->lo_encrypt_type; |
| 1161 | info64->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1162 | info64->lo_flags = info->lo_flags; |
| 1163 | info64->lo_init[0] = info->lo_init[0]; |
| 1164 | info64->lo_init[1] = info->lo_init[1]; |
| 1165 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1166 | memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE); |
| 1167 | else |
| 1168 | memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); |
| 1169 | memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE); |
| 1170 | } |
| 1171 | |
| 1172 | static int |
| 1173 | loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) |
| 1174 | { |
| 1175 | memset(info, 0, sizeof(*info)); |
| 1176 | info->lo_number = info64->lo_number; |
| 1177 | info->lo_device = info64->lo_device; |
| 1178 | info->lo_inode = info64->lo_inode; |
| 1179 | info->lo_rdevice = info64->lo_rdevice; |
| 1180 | info->lo_offset = info64->lo_offset; |
| 1181 | info->lo_encrypt_type = info64->lo_encrypt_type; |
| 1182 | info->lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1183 | info->lo_flags = info64->lo_flags; |
| 1184 | info->lo_init[0] = info64->lo_init[0]; |
| 1185 | info->lo_init[1] = info64->lo_init[1]; |
| 1186 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1187 | memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1188 | else |
| 1189 | memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1190 | memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1191 | |
| 1192 | /* error in case values were truncated */ |
| 1193 | if (info->lo_device != info64->lo_device || |
| 1194 | info->lo_rdevice != info64->lo_rdevice || |
| 1195 | info->lo_inode != info64->lo_inode || |
| 1196 | info->lo_offset != info64->lo_offset) |
| 1197 | return -EOVERFLOW; |
| 1198 | |
| 1199 | return 0; |
| 1200 | } |
| 1201 | |
| 1202 | static int |
| 1203 | loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) |
| 1204 | { |
| 1205 | struct loop_info info; |
| 1206 | struct loop_info64 info64; |
| 1207 | |
| 1208 | if (copy_from_user(&info, arg, sizeof (struct loop_info))) |
| 1209 | return -EFAULT; |
| 1210 | loop_info64_from_old(&info, &info64); |
| 1211 | return loop_set_status(lo, &info64); |
| 1212 | } |
| 1213 | |
| 1214 | static int |
| 1215 | loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) |
| 1216 | { |
| 1217 | struct loop_info64 info64; |
| 1218 | |
| 1219 | if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) |
| 1220 | return -EFAULT; |
| 1221 | return loop_set_status(lo, &info64); |
| 1222 | } |
| 1223 | |
| 1224 | static int |
| 1225 | loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { |
| 1226 | struct loop_info info; |
| 1227 | struct loop_info64 info64; |
| 1228 | int err = 0; |
| 1229 | |
| 1230 | if (!arg) |
| 1231 | err = -EINVAL; |
| 1232 | if (!err) |
| 1233 | err = loop_get_status(lo, &info64); |
| 1234 | if (!err) |
| 1235 | err = loop_info64_to_old(&info64, &info); |
| 1236 | if (!err && copy_to_user(arg, &info, sizeof(info))) |
| 1237 | err = -EFAULT; |
| 1238 | |
| 1239 | return err; |
| 1240 | } |
| 1241 | |
| 1242 | static int |
| 1243 | loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { |
| 1244 | struct loop_info64 info64; |
| 1245 | int err = 0; |
| 1246 | |
| 1247 | if (!arg) |
| 1248 | err = -EINVAL; |
| 1249 | if (!err) |
| 1250 | err = loop_get_status(lo, &info64); |
| 1251 | if (!err && copy_to_user(arg, &info64, sizeof(info64))) |
| 1252 | err = -EFAULT; |
| 1253 | |
| 1254 | return err; |
| 1255 | } |
| 1256 | |
Hannes Reinecke | 51001b7 | 2017-06-08 13:46:44 +0200 | [diff] [blame] | 1257 | static int loop_set_capacity(struct loop_device *lo) |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1258 | { |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1259 | if (unlikely(lo->lo_state != Lo_bound)) |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 1260 | return -ENXIO; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1261 | |
Omar Sandoval | 1e6ec9e | 2017-08-23 14:54:59 -0700 | [diff] [blame] | 1262 | return figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1263 | } |
| 1264 | |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1265 | static int loop_set_dio(struct loop_device *lo, unsigned long arg) |
| 1266 | { |
| 1267 | int error = -ENXIO; |
| 1268 | if (lo->lo_state != Lo_bound) |
| 1269 | goto out; |
| 1270 | |
| 1271 | __loop_update_dio(lo, !!arg); |
| 1272 | if (lo->use_dio == !!arg) |
| 1273 | return 0; |
| 1274 | error = -EINVAL; |
| 1275 | out: |
| 1276 | return error; |
| 1277 | } |
| 1278 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1279 | static int loop_set_block_size(struct loop_device *lo, unsigned long arg) |
| 1280 | { |
| 1281 | if (lo->lo_state != Lo_bound) |
| 1282 | return -ENXIO; |
| 1283 | |
| 1284 | if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg)) |
| 1285 | return -EINVAL; |
| 1286 | |
| 1287 | blk_mq_freeze_queue(lo->lo_queue); |
| 1288 | |
| 1289 | blk_queue_logical_block_size(lo->lo_queue, arg); |
| 1290 | loop_update_dio(lo); |
| 1291 | |
| 1292 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 1293 | |
| 1294 | return 0; |
| 1295 | } |
| 1296 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1297 | static int lo_ioctl(struct block_device *bdev, fmode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | unsigned int cmd, unsigned long arg) |
| 1299 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1300 | struct loop_device *lo = bdev->bd_disk->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | int err; |
| 1302 | |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1303 | mutex_lock_nested(&lo->lo_ctl_mutex, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | switch (cmd) { |
| 1305 | case LOOP_SET_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1306 | err = loop_set_fd(lo, mode, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | break; |
| 1308 | case LOOP_CHANGE_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1309 | err = loop_change_fd(lo, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | break; |
| 1311 | case LOOP_CLR_FD: |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1312 | /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 1313 | err = loop_clr_fd(lo); |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1314 | if (!err) |
| 1315 | goto out_unlocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | break; |
| 1317 | case LOOP_SET_STATUS: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1318 | err = -EPERM; |
| 1319 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1320 | err = loop_set_status_old(lo, |
| 1321 | (struct loop_info __user *)arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | break; |
| 1323 | case LOOP_GET_STATUS: |
| 1324 | err = loop_get_status_old(lo, (struct loop_info __user *) arg); |
| 1325 | break; |
| 1326 | case LOOP_SET_STATUS64: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1327 | err = -EPERM; |
| 1328 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1329 | err = loop_set_status64(lo, |
| 1330 | (struct loop_info64 __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | break; |
| 1332 | case LOOP_GET_STATUS64: |
| 1333 | err = loop_get_status64(lo, (struct loop_info64 __user *) arg); |
| 1334 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1335 | case LOOP_SET_CAPACITY: |
| 1336 | err = -EPERM; |
| 1337 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
Hannes Reinecke | 51001b7 | 2017-06-08 13:46:44 +0200 | [diff] [blame] | 1338 | err = loop_set_capacity(lo); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1339 | break; |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1340 | case LOOP_SET_DIRECT_IO: |
| 1341 | err = -EPERM; |
| 1342 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1343 | err = loop_set_dio(lo, arg); |
| 1344 | break; |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1345 | case LOOP_SET_BLOCK_SIZE: |
| 1346 | err = -EPERM; |
| 1347 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1348 | err = loop_set_block_size(lo, arg); |
| 1349 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1350 | default: |
| 1351 | err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; |
| 1352 | } |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1353 | mutex_unlock(&lo->lo_ctl_mutex); |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1354 | |
| 1355 | out_unlocked: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | return err; |
| 1357 | } |
| 1358 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1359 | #ifdef CONFIG_COMPAT |
| 1360 | struct compat_loop_info { |
| 1361 | compat_int_t lo_number; /* ioctl r/o */ |
| 1362 | compat_dev_t lo_device; /* ioctl r/o */ |
| 1363 | compat_ulong_t lo_inode; /* ioctl r/o */ |
| 1364 | compat_dev_t lo_rdevice; /* ioctl r/o */ |
| 1365 | compat_int_t lo_offset; |
| 1366 | compat_int_t lo_encrypt_type; |
| 1367 | compat_int_t lo_encrypt_key_size; /* ioctl w/o */ |
| 1368 | compat_int_t lo_flags; /* ioctl r/o */ |
| 1369 | char lo_name[LO_NAME_SIZE]; |
| 1370 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ |
| 1371 | compat_ulong_t lo_init[2]; |
| 1372 | char reserved[4]; |
| 1373 | }; |
| 1374 | |
| 1375 | /* |
| 1376 | * Transfer 32-bit compatibility structure in userspace to 64-bit loop info |
| 1377 | * - noinlined to reduce stack space usage in main part of driver |
| 1378 | */ |
| 1379 | static noinline int |
Al Viro | ba674cf | 2006-10-10 22:48:27 +0100 | [diff] [blame] | 1380 | loop_info64_from_compat(const struct compat_loop_info __user *arg, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1381 | struct loop_info64 *info64) |
| 1382 | { |
| 1383 | struct compat_loop_info info; |
| 1384 | |
| 1385 | if (copy_from_user(&info, arg, sizeof(info))) |
| 1386 | return -EFAULT; |
| 1387 | |
| 1388 | memset(info64, 0, sizeof(*info64)); |
| 1389 | info64->lo_number = info.lo_number; |
| 1390 | info64->lo_device = info.lo_device; |
| 1391 | info64->lo_inode = info.lo_inode; |
| 1392 | info64->lo_rdevice = info.lo_rdevice; |
| 1393 | info64->lo_offset = info.lo_offset; |
| 1394 | info64->lo_sizelimit = 0; |
| 1395 | info64->lo_encrypt_type = info.lo_encrypt_type; |
| 1396 | info64->lo_encrypt_key_size = info.lo_encrypt_key_size; |
| 1397 | info64->lo_flags = info.lo_flags; |
| 1398 | info64->lo_init[0] = info.lo_init[0]; |
| 1399 | info64->lo_init[1] = info.lo_init[1]; |
| 1400 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1401 | memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE); |
| 1402 | else |
| 1403 | memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); |
| 1404 | memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE); |
| 1405 | return 0; |
| 1406 | } |
| 1407 | |
| 1408 | /* |
| 1409 | * Transfer 64-bit loop info to 32-bit compatibility structure in userspace |
| 1410 | * - noinlined to reduce stack space usage in main part of driver |
| 1411 | */ |
| 1412 | static noinline int |
| 1413 | loop_info64_to_compat(const struct loop_info64 *info64, |
| 1414 | struct compat_loop_info __user *arg) |
| 1415 | { |
| 1416 | struct compat_loop_info info; |
| 1417 | |
| 1418 | memset(&info, 0, sizeof(info)); |
| 1419 | info.lo_number = info64->lo_number; |
| 1420 | info.lo_device = info64->lo_device; |
| 1421 | info.lo_inode = info64->lo_inode; |
| 1422 | info.lo_rdevice = info64->lo_rdevice; |
| 1423 | info.lo_offset = info64->lo_offset; |
| 1424 | info.lo_encrypt_type = info64->lo_encrypt_type; |
| 1425 | info.lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1426 | info.lo_flags = info64->lo_flags; |
| 1427 | info.lo_init[0] = info64->lo_init[0]; |
| 1428 | info.lo_init[1] = info64->lo_init[1]; |
| 1429 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1430 | memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1431 | else |
| 1432 | memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1433 | memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1434 | |
| 1435 | /* error in case values were truncated */ |
| 1436 | if (info.lo_device != info64->lo_device || |
| 1437 | info.lo_rdevice != info64->lo_rdevice || |
| 1438 | info.lo_inode != info64->lo_inode || |
| 1439 | info.lo_offset != info64->lo_offset || |
| 1440 | info.lo_init[0] != info64->lo_init[0] || |
| 1441 | info.lo_init[1] != info64->lo_init[1]) |
| 1442 | return -EOVERFLOW; |
| 1443 | |
| 1444 | if (copy_to_user(arg, &info, sizeof(info))) |
| 1445 | return -EFAULT; |
| 1446 | return 0; |
| 1447 | } |
| 1448 | |
| 1449 | static int |
| 1450 | loop_set_status_compat(struct loop_device *lo, |
| 1451 | const struct compat_loop_info __user *arg) |
| 1452 | { |
| 1453 | struct loop_info64 info64; |
| 1454 | int ret; |
| 1455 | |
| 1456 | ret = loop_info64_from_compat(arg, &info64); |
| 1457 | if (ret < 0) |
| 1458 | return ret; |
| 1459 | return loop_set_status(lo, &info64); |
| 1460 | } |
| 1461 | |
| 1462 | static int |
| 1463 | loop_get_status_compat(struct loop_device *lo, |
| 1464 | struct compat_loop_info __user *arg) |
| 1465 | { |
| 1466 | struct loop_info64 info64; |
| 1467 | int err = 0; |
| 1468 | |
| 1469 | if (!arg) |
| 1470 | err = -EINVAL; |
| 1471 | if (!err) |
| 1472 | err = loop_get_status(lo, &info64); |
| 1473 | if (!err) |
| 1474 | err = loop_info64_to_compat(&info64, arg); |
| 1475 | return err; |
| 1476 | } |
| 1477 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1478 | static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, |
| 1479 | unsigned int cmd, unsigned long arg) |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1480 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1481 | struct loop_device *lo = bdev->bd_disk->private_data; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1482 | int err; |
| 1483 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1484 | switch(cmd) { |
| 1485 | case LOOP_SET_STATUS: |
| 1486 | mutex_lock(&lo->lo_ctl_mutex); |
| 1487 | err = loop_set_status_compat( |
| 1488 | lo, (const struct compat_loop_info __user *) arg); |
| 1489 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1490 | break; |
| 1491 | case LOOP_GET_STATUS: |
| 1492 | mutex_lock(&lo->lo_ctl_mutex); |
| 1493 | err = loop_get_status_compat( |
| 1494 | lo, (struct compat_loop_info __user *) arg); |
| 1495 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1496 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1497 | case LOOP_SET_CAPACITY: |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1498 | case LOOP_CLR_FD: |
| 1499 | case LOOP_GET_STATUS64: |
| 1500 | case LOOP_SET_STATUS64: |
| 1501 | arg = (unsigned long) compat_ptr(arg); |
| 1502 | case LOOP_SET_FD: |
| 1503 | case LOOP_CHANGE_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1504 | err = lo_ioctl(bdev, mode, cmd, arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1505 | break; |
| 1506 | default: |
| 1507 | err = -ENOIOCTLCMD; |
| 1508 | break; |
| 1509 | } |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1510 | return err; |
| 1511 | } |
| 1512 | #endif |
| 1513 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1514 | static int lo_open(struct block_device *bdev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1516 | struct loop_device *lo; |
| 1517 | int err = 0; |
| 1518 | |
| 1519 | mutex_lock(&loop_index_mutex); |
| 1520 | lo = bdev->bd_disk->private_data; |
| 1521 | if (!lo) { |
| 1522 | err = -ENXIO; |
| 1523 | goto out; |
| 1524 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1525 | |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1526 | atomic_inc(&lo->lo_refcnt); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1527 | out: |
| 1528 | mutex_unlock(&loop_index_mutex); |
| 1529 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1530 | } |
| 1531 | |
Al Viro | db2a144 | 2013-05-05 21:52:57 -0400 | [diff] [blame] | 1532 | static void lo_release(struct gendisk *disk, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1534 | struct loop_device *lo = disk->private_data; |
Alexander Beregalov | ffcd7dc | 2009-04-07 13:48:21 +0200 | [diff] [blame] | 1535 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1536 | |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1537 | if (atomic_dec_return(&lo->lo_refcnt)) |
| 1538 | return; |
| 1539 | |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1540 | mutex_lock(&lo->lo_ctl_mutex); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1541 | if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { |
| 1542 | /* |
| 1543 | * In autoclear mode, stop the loop thread |
| 1544 | * and remove configuration after last close. |
| 1545 | */ |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 1546 | err = loop_clr_fd(lo); |
Alexander Beregalov | ffcd7dc | 2009-04-07 13:48:21 +0200 | [diff] [blame] | 1547 | if (!err) |
Al Viro | db2a144 | 2013-05-05 21:52:57 -0400 | [diff] [blame] | 1548 | return; |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame^] | 1549 | } else if (lo->lo_state == Lo_bound) { |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1550 | /* |
| 1551 | * Otherwise keep thread (if running) and config, |
| 1552 | * but flush possible ongoing bios in thread. |
| 1553 | */ |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame^] | 1554 | blk_mq_freeze_queue(lo->lo_queue); |
| 1555 | blk_mq_unfreeze_queue(lo->lo_queue); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1556 | } |
David Woodhouse | 96c5865 | 2008-02-06 01:36:27 -0800 | [diff] [blame] | 1557 | |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1558 | mutex_unlock(&lo->lo_ctl_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | } |
| 1560 | |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1561 | static const struct block_device_operations lo_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | .owner = THIS_MODULE, |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1563 | .open = lo_open, |
| 1564 | .release = lo_release, |
| 1565 | .ioctl = lo_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1566 | #ifdef CONFIG_COMPAT |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1567 | .compat_ioctl = lo_compat_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1568 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1569 | }; |
| 1570 | |
| 1571 | /* |
| 1572 | * And now the modules code and kernel interface. |
| 1573 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1574 | static int max_loop; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1575 | module_param(max_loop, int, S_IRUGO); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1576 | MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1577 | module_param(max_part, int, S_IRUGO); |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1578 | MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | MODULE_LICENSE("GPL"); |
| 1580 | MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); |
| 1581 | |
| 1582 | int loop_register_transfer(struct loop_func_table *funcs) |
| 1583 | { |
| 1584 | unsigned int n = funcs->number; |
| 1585 | |
| 1586 | if (n >= MAX_LO_CRYPT || xfer_funcs[n]) |
| 1587 | return -EINVAL; |
| 1588 | xfer_funcs[n] = funcs; |
| 1589 | return 0; |
| 1590 | } |
| 1591 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1592 | static int unregister_transfer_cb(int id, void *ptr, void *data) |
| 1593 | { |
| 1594 | struct loop_device *lo = ptr; |
| 1595 | struct loop_func_table *xfer = data; |
| 1596 | |
| 1597 | mutex_lock(&lo->lo_ctl_mutex); |
| 1598 | if (lo->lo_encryption == xfer) |
| 1599 | loop_release_xfer(lo); |
| 1600 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1601 | return 0; |
| 1602 | } |
| 1603 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | int loop_unregister_transfer(int number) |
| 1605 | { |
| 1606 | unsigned int n = number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1607 | struct loop_func_table *xfer; |
| 1608 | |
| 1609 | if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL) |
| 1610 | return -EINVAL; |
| 1611 | |
| 1612 | xfer_funcs[n] = NULL; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1613 | idr_for_each(&loop_index_idr, &unregister_transfer_cb, xfer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1614 | return 0; |
| 1615 | } |
| 1616 | |
| 1617 | EXPORT_SYMBOL(loop_register_transfer); |
| 1618 | EXPORT_SYMBOL(loop_unregister_transfer); |
| 1619 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1620 | static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1621 | const struct blk_mq_queue_data *bd) |
| 1622 | { |
| 1623 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 1624 | struct loop_device *lo = cmd->rq->q->queuedata; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1625 | |
| 1626 | blk_mq_start_request(bd->rq); |
| 1627 | |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 1628 | if (lo->lo_state != Lo_bound) |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1629 | return BLK_STS_IOERR; |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 1630 | |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 1631 | switch (req_op(cmd->rq)) { |
| 1632 | case REQ_OP_FLUSH: |
| 1633 | case REQ_OP_DISCARD: |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 1634 | case REQ_OP_WRITE_ZEROES: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1635 | cmd->use_aio = false; |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 1636 | break; |
| 1637 | default: |
| 1638 | cmd->use_aio = lo->use_dio; |
| 1639 | break; |
| 1640 | } |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1641 | |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 1642 | kthread_queue_work(&lo->worker, &cmd->work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1643 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1644 | return BLK_STS_OK; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1645 | } |
| 1646 | |
| 1647 | static void loop_handle_cmd(struct loop_cmd *cmd) |
| 1648 | { |
Mike Christie | a8ebb05 | 2016-06-05 14:31:45 -0500 | [diff] [blame] | 1649 | const bool write = op_is_write(req_op(cmd->rq)); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1650 | struct loop_device *lo = cmd->rq->q->queuedata; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1651 | int ret = 0; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1652 | |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1653 | if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { |
| 1654 | ret = -EIO; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1655 | goto failed; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1656 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1657 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 1658 | ret = do_req_filebacked(lo, cmd->rq); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1659 | failed: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1660 | /* complete non-aio request */ |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 1661 | if (!cmd->use_aio || ret) { |
| 1662 | cmd->ret = ret ? -EIO : 0; |
Christoph Hellwig | 08e0029 | 2017-04-20 16:03:09 +0200 | [diff] [blame] | 1663 | blk_mq_complete_request(cmd->rq); |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 1664 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1665 | } |
| 1666 | |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 1667 | static void loop_queue_work(struct kthread_work *work) |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1668 | { |
| 1669 | struct loop_cmd *cmd = |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 1670 | container_of(work, struct loop_cmd, work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1671 | |
| 1672 | loop_handle_cmd(cmd); |
| 1673 | } |
| 1674 | |
Christoph Hellwig | d6296d3 | 2017-05-01 10:19:08 -0600 | [diff] [blame] | 1675 | static int loop_init_request(struct blk_mq_tag_set *set, struct request *rq, |
| 1676 | unsigned int hctx_idx, unsigned int numa_node) |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1677 | { |
| 1678 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
| 1679 | |
| 1680 | cmd->rq = rq; |
Petr Mladek | 3989144 | 2016-10-11 13:55:20 -0700 | [diff] [blame] | 1681 | kthread_init_work(&cmd->work, loop_queue_work); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1682 | |
| 1683 | return 0; |
| 1684 | } |
| 1685 | |
Eric Biggers | f363b08 | 2017-03-30 13:39:16 -0700 | [diff] [blame] | 1686 | static const struct blk_mq_ops loop_mq_ops = { |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1687 | .queue_rq = loop_queue_rq, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1688 | .init_request = loop_init_request, |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 1689 | .complete = lo_complete_rq, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1690 | }; |
| 1691 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1692 | static int loop_add(struct loop_device **l, int i) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1693 | { |
| 1694 | struct loop_device *lo; |
| 1695 | struct gendisk *disk; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1696 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1697 | |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 1698 | err = -ENOMEM; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1699 | lo = kzalloc(sizeof(*lo), GFP_KERNEL); |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 1700 | if (!lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1701 | goto out; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1702 | |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 1703 | lo->lo_state = Lo_unbound; |
| 1704 | |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1705 | /* allocate id, if @id >= 0, we're requesting that specific id */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1706 | if (i >= 0) { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1707 | err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL); |
| 1708 | if (err == -ENOSPC) |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1709 | err = -EEXIST; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1710 | } else { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1711 | err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1712 | } |
| 1713 | if (err < 0) |
| 1714 | goto out_free_dev; |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1715 | i = err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1716 | |
Wei Yongjun | 183cfb5 | 2013-03-22 08:59:19 -0600 | [diff] [blame] | 1717 | err = -ENOMEM; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1718 | lo->tag_set.ops = &loop_mq_ops; |
| 1719 | lo->tag_set.nr_hw_queues = 1; |
| 1720 | lo->tag_set.queue_depth = 128; |
| 1721 | lo->tag_set.numa_node = NUMA_NO_NODE; |
| 1722 | lo->tag_set.cmd_size = sizeof(struct loop_cmd); |
| 1723 | lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; |
| 1724 | lo->tag_set.driver_data = lo; |
| 1725 | |
| 1726 | err = blk_mq_alloc_tag_set(&lo->tag_set); |
| 1727 | if (err) |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 1728 | goto out_free_idr; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1729 | |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1730 | lo->lo_queue = blk_mq_init_queue(&lo->tag_set); |
| 1731 | if (IS_ERR_OR_NULL(lo->lo_queue)) { |
| 1732 | err = PTR_ERR(lo->lo_queue); |
| 1733 | goto out_cleanup_tags; |
| 1734 | } |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 1735 | lo->lo_queue->queuedata = lo; |
| 1736 | |
Omar Sandoval | 6c6b6f2 | 2017-08-24 00:03:42 -0700 | [diff] [blame] | 1737 | blk_queue_physical_block_size(lo->lo_queue, PAGE_SIZE); |
| 1738 | |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 1739 | /* |
| 1740 | * It doesn't make sense to enable merge because the I/O |
| 1741 | * submitted to backing file is handled page by page. |
| 1742 | */ |
| 1743 | queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
| 1744 | |
Minfei Huang | 7a64973 | 2016-06-07 10:05:15 +0800 | [diff] [blame] | 1745 | err = -ENOMEM; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1746 | disk = lo->lo_disk = alloc_disk(1 << part_shift); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1747 | if (!disk) |
| 1748 | goto out_free_queue; |
| 1749 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1750 | /* |
| 1751 | * Disable partition scanning by default. The in-kernel partition |
| 1752 | * scanning can be requested individually per-device during its |
| 1753 | * setup. Userspace can always add and remove partitions from all |
| 1754 | * devices. The needed partition minors are allocated from the |
| 1755 | * extended minor space, the main loop device numbers will continue |
| 1756 | * to match the loop minors, regardless of the number of partitions |
| 1757 | * used. |
| 1758 | * |
| 1759 | * If max_part is given, partition scanning is globally enabled for |
| 1760 | * all loop devices. The minors for the main loop devices will be |
| 1761 | * multiples of max_part. |
| 1762 | * |
| 1763 | * Note: Global-for-all-devices, set-only-at-init, read-only module |
| 1764 | * parameteters like 'max_loop' and 'max_part' make things needlessly |
| 1765 | * complicated, are too static, inflexible and may surprise |
| 1766 | * userspace tools. Parameters like this in general should be avoided. |
| 1767 | */ |
| 1768 | if (!part_shift) |
| 1769 | disk->flags |= GENHD_FL_NO_PART_SCAN; |
| 1770 | disk->flags |= GENHD_FL_EXT_DEVT; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1771 | mutex_init(&lo->lo_ctl_mutex); |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1772 | atomic_set(&lo->lo_refcnt, 0); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1773 | lo->lo_number = i; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1774 | spin_lock_init(&lo->lo_lock); |
| 1775 | disk->major = LOOP_MAJOR; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1776 | disk->first_minor = i << part_shift; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1777 | disk->fops = &lo_fops; |
| 1778 | disk->private_data = lo; |
| 1779 | disk->queue = lo->lo_queue; |
| 1780 | sprintf(disk->disk_name, "loop%d", i); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1781 | add_disk(disk); |
| 1782 | *l = lo; |
| 1783 | return lo->lo_number; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1784 | |
| 1785 | out_free_queue: |
| 1786 | blk_cleanup_queue(lo->lo_queue); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1787 | out_cleanup_tags: |
| 1788 | blk_mq_free_tag_set(&lo->tag_set); |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 1789 | out_free_idr: |
| 1790 | idr_remove(&loop_index_idr, i); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1791 | out_free_dev: |
| 1792 | kfree(lo); |
| 1793 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1794 | return err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1795 | } |
| 1796 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1797 | static void loop_remove(struct loop_device *lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1798 | { |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1799 | blk_cleanup_queue(lo->lo_queue); |
NeilBrown | 6cd18e7 | 2015-04-27 14:12:22 +1000 | [diff] [blame] | 1800 | del_gendisk(lo->lo_disk); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1801 | blk_mq_free_tag_set(&lo->tag_set); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1802 | put_disk(lo->lo_disk); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1803 | kfree(lo); |
| 1804 | } |
| 1805 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1806 | static int find_free_cb(int id, void *ptr, void *data) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1807 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1808 | struct loop_device *lo = ptr; |
| 1809 | struct loop_device **l = data; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1810 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1811 | if (lo->lo_state == Lo_unbound) { |
| 1812 | *l = lo; |
| 1813 | return 1; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1814 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1815 | return 0; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1816 | } |
| 1817 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1818 | static int loop_lookup(struct loop_device **l, int i) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1819 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1820 | struct loop_device *lo; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1821 | int ret = -ENODEV; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1822 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1823 | if (i < 0) { |
| 1824 | int err; |
| 1825 | |
| 1826 | err = idr_for_each(&loop_index_idr, &find_free_cb, &lo); |
| 1827 | if (err == 1) { |
| 1828 | *l = lo; |
| 1829 | ret = lo->lo_number; |
| 1830 | } |
| 1831 | goto out; |
| 1832 | } |
| 1833 | |
| 1834 | /* lookup and return a specific i */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1835 | lo = idr_find(&loop_index_idr, i); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1836 | if (lo) { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1837 | *l = lo; |
| 1838 | ret = lo->lo_number; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1839 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1840 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1841 | return ret; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1842 | } |
| 1843 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1844 | static struct kobject *loop_probe(dev_t dev, int *part, void *data) |
| 1845 | { |
Al Viro | 705962c | 2007-05-13 05:52:32 -0400 | [diff] [blame] | 1846 | struct loop_device *lo; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 1847 | struct kobject *kobj; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1848 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1849 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1850 | mutex_lock(&loop_index_mutex); |
| 1851 | err = loop_lookup(&lo, MINOR(dev) >> part_shift); |
| 1852 | if (err < 0) |
| 1853 | err = loop_add(&lo, MINOR(dev) >> part_shift); |
| 1854 | if (err < 0) |
Mikulas Patocka | a207f59 | 2013-10-14 12:13:24 -0400 | [diff] [blame] | 1855 | kobj = NULL; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1856 | else |
| 1857 | kobj = get_disk(lo->lo_disk); |
| 1858 | mutex_unlock(&loop_index_mutex); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1859 | |
| 1860 | *part = 0; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 1861 | return kobj; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1862 | } |
| 1863 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1864 | static long loop_control_ioctl(struct file *file, unsigned int cmd, |
| 1865 | unsigned long parm) |
| 1866 | { |
| 1867 | struct loop_device *lo; |
| 1868 | int ret = -ENOSYS; |
| 1869 | |
| 1870 | mutex_lock(&loop_index_mutex); |
| 1871 | switch (cmd) { |
| 1872 | case LOOP_CTL_ADD: |
| 1873 | ret = loop_lookup(&lo, parm); |
| 1874 | if (ret >= 0) { |
| 1875 | ret = -EEXIST; |
| 1876 | break; |
| 1877 | } |
| 1878 | ret = loop_add(&lo, parm); |
| 1879 | break; |
| 1880 | case LOOP_CTL_REMOVE: |
| 1881 | ret = loop_lookup(&lo, parm); |
| 1882 | if (ret < 0) |
| 1883 | break; |
| 1884 | mutex_lock(&lo->lo_ctl_mutex); |
| 1885 | if (lo->lo_state != Lo_unbound) { |
| 1886 | ret = -EBUSY; |
| 1887 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1888 | break; |
| 1889 | } |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1890 | if (atomic_read(&lo->lo_refcnt) > 0) { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1891 | ret = -EBUSY; |
| 1892 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1893 | break; |
| 1894 | } |
| 1895 | lo->lo_disk->private_data = NULL; |
| 1896 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1897 | idr_remove(&loop_index_idr, lo->lo_number); |
| 1898 | loop_remove(lo); |
| 1899 | break; |
| 1900 | case LOOP_CTL_GET_FREE: |
| 1901 | ret = loop_lookup(&lo, -1); |
| 1902 | if (ret >= 0) |
| 1903 | break; |
| 1904 | ret = loop_add(&lo, -1); |
| 1905 | } |
| 1906 | mutex_unlock(&loop_index_mutex); |
| 1907 | |
| 1908 | return ret; |
| 1909 | } |
| 1910 | |
| 1911 | static const struct file_operations loop_ctl_fops = { |
| 1912 | .open = nonseekable_open, |
| 1913 | .unlocked_ioctl = loop_control_ioctl, |
| 1914 | .compat_ioctl = loop_control_ioctl, |
| 1915 | .owner = THIS_MODULE, |
| 1916 | .llseek = noop_llseek, |
| 1917 | }; |
| 1918 | |
| 1919 | static struct miscdevice loop_misc = { |
| 1920 | .minor = LOOP_CTRL_MINOR, |
| 1921 | .name = "loop-control", |
| 1922 | .fops = &loop_ctl_fops, |
| 1923 | }; |
| 1924 | |
| 1925 | MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); |
| 1926 | MODULE_ALIAS("devname:loop-control"); |
| 1927 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1928 | static int __init loop_init(void) |
| 1929 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1930 | int i, nr; |
| 1931 | unsigned long range; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1932 | struct loop_device *lo; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1933 | int err; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1934 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1935 | part_shift = 0; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1936 | if (max_part > 0) { |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1937 | part_shift = fls(max_part); |
| 1938 | |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1939 | /* |
| 1940 | * Adjust max_part according to part_shift as it is exported |
| 1941 | * to user space so that user can decide correct minor number |
| 1942 | * if [s]he want to create more devices. |
| 1943 | * |
| 1944 | * Note that -1 is required because partition 0 is reserved |
| 1945 | * for the whole disk. |
| 1946 | */ |
| 1947 | max_part = (1UL << part_shift) - 1; |
| 1948 | } |
| 1949 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1950 | if ((1UL << part_shift) > DISK_MAX_PARTS) { |
| 1951 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 1952 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1953 | } |
Namhyung Kim | 78f4bb3 | 2011-05-24 16:48:54 +0200 | [diff] [blame] | 1954 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1955 | if (max_loop > 1UL << (MINORBITS - part_shift)) { |
| 1956 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 1957 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1958 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1960 | /* |
| 1961 | * If max_loop is specified, create that many devices upfront. |
| 1962 | * This also becomes a hard limit. If max_loop is not specified, |
| 1963 | * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module |
| 1964 | * init time. Loop devices can be requested on-demand with the |
| 1965 | * /dev/loop-control interface, or be instantiated by accessing |
| 1966 | * a 'dead' device node. |
| 1967 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1968 | if (max_loop) { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1969 | nr = max_loop; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 1970 | range = max_loop << part_shift; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1971 | } else { |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1972 | nr = CONFIG_BLK_DEV_LOOP_MIN_COUNT; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 1973 | range = 1UL << MINORBITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1974 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1975 | |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 1976 | err = misc_register(&loop_misc); |
| 1977 | if (err < 0) |
| 1978 | goto err_out; |
| 1979 | |
| 1980 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1981 | if (register_blkdev(LOOP_MAJOR, "loop")) { |
| 1982 | err = -EIO; |
| 1983 | goto misc_out; |
| 1984 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1985 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1986 | blk_register_region(MKDEV(LOOP_MAJOR, 0), range, |
| 1987 | THIS_MODULE, loop_probe, NULL, NULL); |
| 1988 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1989 | /* pre-create number of devices given by config or max_loop */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1990 | mutex_lock(&loop_index_mutex); |
| 1991 | for (i = 0; i < nr; i++) |
| 1992 | loop_add(&lo, i); |
| 1993 | mutex_unlock(&loop_index_mutex); |
| 1994 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1995 | printk(KERN_INFO "loop: module loaded\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1996 | return 0; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 1997 | |
| 1998 | misc_out: |
| 1999 | misc_deregister(&loop_misc); |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2000 | err_out: |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2001 | return err; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2002 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2003 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2004 | static int loop_exit_cb(int id, void *ptr, void *data) |
| 2005 | { |
| 2006 | struct loop_device *lo = ptr; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2007 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2008 | loop_remove(lo); |
| 2009 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2010 | } |
| 2011 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2012 | static void __exit loop_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2013 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2014 | unsigned long range; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2015 | |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 2016 | range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2017 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2018 | idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2019 | idr_destroy(&loop_index_idr); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2020 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2021 | blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); |
Akinobu Mita | 00d5940 | 2007-07-17 04:03:46 -0700 | [diff] [blame] | 2022 | unregister_blkdev(LOOP_MAJOR, "loop"); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2023 | |
| 2024 | misc_deregister(&loop_misc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2025 | } |
| 2026 | |
| 2027 | module_init(loop_init); |
| 2028 | module_exit(loop_exit); |
| 2029 | |
| 2030 | #ifndef MODULE |
| 2031 | static int __init max_loop_setup(char *str) |
| 2032 | { |
| 2033 | max_loop = simple_strtol(str, NULL, 0); |
| 2034 | return 1; |
| 2035 | } |
| 2036 | |
| 2037 | __setup("max_loop=", max_loop_setup); |
| 2038 | #endif |