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> |
| 66 | #include <linux/loop.h> |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 67 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | #include <linux/suspend.h> |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 69 | #include <linux/freezer.h> |
Arnd Bergmann | 2a48fc0 | 2010-06-02 14:28:52 +0200 | [diff] [blame] | 70 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | #include <linux/completion.h> |
| 73 | #include <linux/highmem.h> |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 74 | #include <linux/kthread.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 75 | #include <linux/splice.h> |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 76 | #include <linux/sysfs.h> |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 77 | #include <linux/miscdevice.h> |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 78 | #include <linux/falloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | #include <asm/uaccess.h> |
| 81 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 82 | static DEFINE_IDR(loop_index_idr); |
| 83 | static DEFINE_MUTEX(loop_index_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 85 | static int max_part; |
| 86 | static int part_shift; |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | /* |
| 89 | * Transfer functions |
| 90 | */ |
| 91 | static int transfer_none(struct loop_device *lo, int cmd, |
| 92 | struct page *raw_page, unsigned raw_off, |
| 93 | struct page *loop_page, unsigned loop_off, |
| 94 | int size, sector_t real_block) |
| 95 | { |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 96 | char *raw_buf = kmap_atomic(raw_page) + raw_off; |
| 97 | char *loop_buf = kmap_atomic(loop_page) + loop_off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | |
| 99 | if (cmd == READ) |
| 100 | memcpy(loop_buf, raw_buf, size); |
| 101 | else |
| 102 | memcpy(raw_buf, loop_buf, size); |
| 103 | |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 104 | kunmap_atomic(loop_buf); |
| 105 | kunmap_atomic(raw_buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | cond_resched(); |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static int transfer_xor(struct loop_device *lo, int cmd, |
| 111 | struct page *raw_page, unsigned raw_off, |
| 112 | struct page *loop_page, unsigned loop_off, |
| 113 | int size, sector_t real_block) |
| 114 | { |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 115 | char *raw_buf = kmap_atomic(raw_page) + raw_off; |
| 116 | char *loop_buf = kmap_atomic(loop_page) + loop_off; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | char *in, *out, *key; |
| 118 | int i, keysize; |
| 119 | |
| 120 | if (cmd == READ) { |
| 121 | in = raw_buf; |
| 122 | out = loop_buf; |
| 123 | } else { |
| 124 | in = loop_buf; |
| 125 | out = raw_buf; |
| 126 | } |
| 127 | |
| 128 | key = lo->lo_encrypt_key; |
| 129 | keysize = lo->lo_encrypt_key_size; |
| 130 | for (i = 0; i < size; i++) |
| 131 | *out++ = *in++ ^ key[(i & 511) % keysize]; |
| 132 | |
Cong Wang | cfd8005 | 2011-11-25 23:14:18 +0800 | [diff] [blame] | 133 | kunmap_atomic(loop_buf); |
| 134 | kunmap_atomic(raw_buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | cond_resched(); |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | static int xor_init(struct loop_device *lo, const struct loop_info64 *info) |
| 140 | { |
| 141 | if (unlikely(info->lo_encrypt_key_size <= 0)) |
| 142 | return -EINVAL; |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | static struct loop_func_table none_funcs = { |
| 147 | .number = LO_CRYPT_NONE, |
| 148 | .transfer = transfer_none, |
| 149 | }; |
| 150 | |
| 151 | static struct loop_func_table xor_funcs = { |
| 152 | .number = LO_CRYPT_XOR, |
| 153 | .transfer = transfer_xor, |
| 154 | .init = xor_init |
| 155 | }; |
| 156 | |
| 157 | /* xfer_funcs[0] is special - its release function is never called */ |
| 158 | static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = { |
| 159 | &none_funcs, |
| 160 | &xor_funcs |
| 161 | }; |
| 162 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 163 | 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] | 164 | { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 165 | loff_t size, loopsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | |
| 167 | /* Compute loopsize in bytes */ |
| 168 | size = i_size_read(file->f_mapping->host); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | loopsize = size - offset; |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 170 | /* offset is beyond i_size, wierd but possible */ |
| 171 | if (loopsize < 0) |
| 172 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 174 | if (sizelimit > 0 && sizelimit < loopsize) |
| 175 | loopsize = sizelimit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | /* |
| 177 | * Unfortunately, if we want to do I/O on the device, |
| 178 | * the number of 512-byte sectors has to fit into a sector_t. |
| 179 | */ |
| 180 | return loopsize >> 9; |
| 181 | } |
| 182 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 183 | 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] | 184 | { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 185 | return get_size(lo->lo_offset, lo->lo_sizelimit, file); |
| 186 | } |
| 187 | |
| 188 | static int |
| 189 | figure_loop_size(struct loop_device *lo, loff_t offset, loff_t sizelimit) |
| 190 | { |
| 191 | loff_t size = get_size(offset, sizelimit, lo->lo_backing_file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | sector_t x = (sector_t)size; |
| 193 | |
| 194 | if (unlikely((loff_t)x != size)) |
| 195 | return -EFBIG; |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 196 | if (lo->lo_offset != offset) |
| 197 | lo->lo_offset = offset; |
| 198 | if (lo->lo_sizelimit != sizelimit) |
| 199 | lo->lo_sizelimit = sizelimit; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 200 | set_capacity(lo->lo_disk, x); |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 201 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | } |
| 203 | |
| 204 | static inline int |
| 205 | lo_do_transfer(struct loop_device *lo, int cmd, |
| 206 | struct page *rpage, unsigned roffs, |
| 207 | struct page *lpage, unsigned loffs, |
| 208 | int size, sector_t rblock) |
| 209 | { |
| 210 | if (unlikely(!lo->transfer)) |
| 211 | return 0; |
| 212 | |
| 213 | return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock); |
| 214 | } |
| 215 | |
| 216 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | * __do_lo_send_write - helper for writing data to a loop device |
| 218 | * |
| 219 | * This helper just factors out common code between do_lo_send_direct_write() |
| 220 | * and do_lo_send_write(). |
| 221 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 222 | static int __do_lo_send_write(struct file *file, |
Al Viro | 98ae6cc | 2006-10-10 22:45:07 +0100 | [diff] [blame] | 223 | u8 *buf, const int len, loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | { |
| 225 | ssize_t bw; |
| 226 | mm_segment_t old_fs = get_fs(); |
| 227 | |
| 228 | set_fs(get_ds()); |
| 229 | bw = file->f_op->write(file, buf, len, &pos); |
| 230 | set_fs(old_fs); |
| 231 | if (likely(bw == len)) |
| 232 | return 0; |
| 233 | printk(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n", |
| 234 | (unsigned long long)pos, len); |
| 235 | if (bw >= 0) |
| 236 | bw = -EIO; |
| 237 | return bw; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * do_lo_send_direct_write - helper for writing data to a loop device |
| 242 | * |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 243 | * This is the fast, non-transforming version that does not need double |
| 244 | * buffering. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | */ |
| 246 | static int do_lo_send_direct_write(struct loop_device *lo, |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 247 | struct bio_vec *bvec, loff_t pos, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | { |
| 249 | ssize_t bw = __do_lo_send_write(lo->lo_backing_file, |
Al Viro | 98ae6cc | 2006-10-10 22:45:07 +0100 | [diff] [blame] | 250 | kmap(bvec->bv_page) + bvec->bv_offset, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | bvec->bv_len, pos); |
| 252 | kunmap(bvec->bv_page); |
| 253 | cond_resched(); |
| 254 | return bw; |
| 255 | } |
| 256 | |
| 257 | /** |
| 258 | * do_lo_send_write - helper for writing data to a loop device |
| 259 | * |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 260 | * This is the slow, transforming version that needs to double buffer the |
| 261 | * data as it cannot do the transformations in place without having direct |
| 262 | * access to the destination pages of the backing file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | */ |
| 264 | static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 265 | loff_t pos, struct page *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | { |
| 267 | int ret = lo_do_transfer(lo, WRITE, page, 0, bvec->bv_page, |
| 268 | bvec->bv_offset, bvec->bv_len, pos >> 9); |
| 269 | if (likely(!ret)) |
| 270 | return __do_lo_send_write(lo->lo_backing_file, |
Al Viro | 98ae6cc | 2006-10-10 22:45:07 +0100 | [diff] [blame] | 271 | page_address(page), bvec->bv_len, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | pos); |
| 273 | printk(KERN_ERR "loop: Transfer error at byte offset %llu, " |
| 274 | "length %i.\n", (unsigned long long)pos, bvec->bv_len); |
| 275 | if (ret > 0) |
| 276 | ret = -EIO; |
| 277 | return ret; |
| 278 | } |
| 279 | |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 280 | static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | { |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 282 | int (*do_lo_send)(struct loop_device *, struct bio_vec *, loff_t, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | struct page *page); |
| 284 | struct bio_vec *bvec; |
| 285 | struct page *page = NULL; |
| 286 | int i, ret = 0; |
| 287 | |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 288 | if (lo->transfer != transfer_none) { |
| 289 | page = alloc_page(GFP_NOIO | __GFP_HIGHMEM); |
| 290 | if (unlikely(!page)) |
| 291 | goto fail; |
| 292 | kmap(page); |
| 293 | do_lo_send = do_lo_send_write; |
| 294 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | do_lo_send = do_lo_send_direct_write; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | } |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | bio_for_each_segment(bvec, bio, i) { |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 299 | ret = do_lo_send(lo, bvec, pos, page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | if (ret < 0) |
| 301 | break; |
| 302 | pos += bvec->bv_len; |
| 303 | } |
| 304 | if (page) { |
| 305 | kunmap(page); |
| 306 | __free_page(page); |
| 307 | } |
| 308 | out: |
| 309 | return ret; |
| 310 | fail: |
| 311 | printk(KERN_ERR "loop: Failed to allocate temporary page for write.\n"); |
| 312 | ret = -ENOMEM; |
| 313 | goto out; |
| 314 | } |
| 315 | |
| 316 | struct lo_read_data { |
| 317 | struct loop_device *lo; |
| 318 | struct page *page; |
| 319 | unsigned offset; |
| 320 | int bsize; |
| 321 | }; |
| 322 | |
| 323 | static int |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 324 | lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
| 325 | struct splice_desc *sd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | { |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 327 | struct lo_read_data *p = sd->u.data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | struct loop_device *lo = p->lo; |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 329 | struct page *page = buf->page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | sector_t IV; |
Jens Axboe | 3603b8e | 2010-12-20 09:15:19 +0100 | [diff] [blame] | 331 | int size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 333 | IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9)) + |
| 334 | (buf->offset >> 9); |
| 335 | size = sd->len; |
| 336 | if (size > p->bsize) |
| 337 | size = p->bsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 339 | if (lo_do_transfer(lo, READ, page, buf->offset, p->page, p->offset, size, IV)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | printk(KERN_ERR "loop: transfer error block %ld\n", |
| 341 | page->index); |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 342 | size = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | } |
| 344 | |
| 345 | flush_dcache_page(p->page); |
| 346 | |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 347 | if (size > 0) |
| 348 | p->offset += size; |
| 349 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | return size; |
| 351 | } |
| 352 | |
| 353 | static int |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 354 | lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) |
| 355 | { |
| 356 | return __splice_from_pipe(pipe, sd, lo_splice_actor); |
| 357 | } |
| 358 | |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 359 | static ssize_t |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | do_lo_receive(struct loop_device *lo, |
| 361 | struct bio_vec *bvec, int bsize, loff_t pos) |
| 362 | { |
| 363 | struct lo_read_data cookie; |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 364 | struct splice_desc sd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | struct file *file; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 366 | ssize_t retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
| 368 | cookie.lo = lo; |
| 369 | cookie.page = bvec->bv_page; |
| 370 | cookie.offset = bvec->bv_offset; |
| 371 | cookie.bsize = bsize; |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 372 | |
| 373 | sd.len = 0; |
| 374 | sd.total_len = bvec->bv_len; |
| 375 | sd.flags = 0; |
| 376 | sd.pos = pos; |
| 377 | sd.u.data = &cookie; |
| 378 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | file = lo->lo_backing_file; |
Jens Axboe | fd58214 | 2007-06-12 21:20:37 +0200 | [diff] [blame] | 380 | retval = splice_direct_to_actor(file, &sd, lo_direct_splice_actor); |
| 381 | |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 382 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | } |
| 384 | |
| 385 | static int |
| 386 | lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos) |
| 387 | { |
| 388 | struct bio_vec *bvec; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 389 | ssize_t s; |
| 390 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | |
| 392 | bio_for_each_segment(bvec, bio, i) { |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 393 | s = do_lo_receive(lo, bvec, bsize, pos); |
| 394 | if (s < 0) |
| 395 | return s; |
| 396 | |
| 397 | if (s != bvec->bv_len) { |
| 398 | zero_fill_bio(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | break; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 400 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | pos += bvec->bv_len; |
| 402 | } |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 403 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | } |
| 405 | |
| 406 | static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) |
| 407 | { |
| 408 | loff_t pos; |
| 409 | int ret; |
| 410 | |
| 411 | pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 412 | |
| 413 | if (bio_rw(bio) == WRITE) { |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 414 | struct file *file = lo->lo_backing_file; |
| 415 | |
Tejun Heo | 6259f28 | 2010-09-03 11:56:17 +0200 | [diff] [blame] | 416 | if (bio->bi_rw & REQ_FLUSH) { |
Christoph Hellwig | 8018ab0 | 2010-03-22 17:32:25 +0100 | [diff] [blame] | 417 | ret = vfs_fsync(file, 0); |
Tejun Heo | 6259f28 | 2010-09-03 11:56:17 +0200 | [diff] [blame] | 418 | if (unlikely(ret && ret != -EINVAL)) { |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 419 | ret = -EIO; |
| 420 | goto out; |
| 421 | } |
| 422 | } |
| 423 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 424 | /* |
| 425 | * We use punch hole to reclaim the free space used by the |
Dave Young | ae95757 | 2011-11-25 09:41:25 +0100 | [diff] [blame] | 426 | * image a.k.a. discard. However we do not support discard if |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 427 | * encryption is enabled, because it may give an attacker |
| 428 | * useful information. |
| 429 | */ |
| 430 | if (bio->bi_rw & REQ_DISCARD) { |
| 431 | struct file *file = lo->lo_backing_file; |
| 432 | int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; |
| 433 | |
| 434 | if ((!file->f_op->fallocate) || |
| 435 | lo->lo_encrypt_key_size) { |
| 436 | ret = -EOPNOTSUPP; |
| 437 | goto out; |
| 438 | } |
| 439 | ret = file->f_op->fallocate(file, mode, pos, |
| 440 | bio->bi_size); |
| 441 | if (unlikely(ret && ret != -EINVAL && |
| 442 | ret != -EOPNOTSUPP)) |
| 443 | ret = -EIO; |
| 444 | goto out; |
| 445 | } |
| 446 | |
Al Viro | 511de73 | 2007-10-08 12:10:13 -0400 | [diff] [blame] | 447 | ret = lo_send(lo, bio, pos); |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 448 | |
Tejun Heo | 6259f28 | 2010-09-03 11:56:17 +0200 | [diff] [blame] | 449 | if ((bio->bi_rw & REQ_FUA) && !ret) { |
Christoph Hellwig | 8018ab0 | 2010-03-22 17:32:25 +0100 | [diff] [blame] | 450 | ret = vfs_fsync(file, 0); |
Tejun Heo | 6259f28 | 2010-09-03 11:56:17 +0200 | [diff] [blame] | 451 | if (unlikely(ret && ret != -EINVAL)) |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 452 | ret = -EIO; |
| 453 | } |
| 454 | } else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | ret = lo_receive(lo, bio, lo->lo_blocksize, pos); |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 456 | |
| 457 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | return ret; |
| 459 | } |
| 460 | |
| 461 | /* |
| 462 | * Add bio to back of pending list |
| 463 | */ |
| 464 | static void loop_add_bio(struct loop_device *lo, struct bio *bio) |
| 465 | { |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 466 | bio_list_add(&lo->lo_bio_list, bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | } |
| 468 | |
| 469 | /* |
| 470 | * Grab first pending buffer |
| 471 | */ |
| 472 | static struct bio *loop_get_bio(struct loop_device *lo) |
| 473 | { |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 474 | return bio_list_pop(&lo->lo_bio_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | } |
| 476 | |
Christoph Hellwig | 5a7bbad | 2011-09-12 12:12:01 +0200 | [diff] [blame] | 477 | static void loop_make_request(struct request_queue *q, struct bio *old_bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | { |
| 479 | struct loop_device *lo = q->queuedata; |
| 480 | int rw = bio_rw(old_bio); |
| 481 | |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 482 | if (rw == READA) |
| 483 | rw = READ; |
| 484 | |
| 485 | BUG_ON(!lo || (rw != READ && rw != WRITE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | |
| 487 | spin_lock_irq(&lo->lo_lock); |
| 488 | if (lo->lo_state != Lo_bound) |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 489 | goto out; |
| 490 | if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY))) |
| 491 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | loop_add_bio(lo, old_bio); |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 493 | wake_up(&lo->lo_event); |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 494 | spin_unlock_irq(&lo->lo_lock); |
Christoph Hellwig | 5a7bbad | 2011-09-12 12:12:01 +0200 | [diff] [blame] | 495 | return; |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 496 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | out: |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 498 | spin_unlock_irq(&lo->lo_lock); |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 499 | bio_io_error(old_bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | } |
| 501 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | struct switch_request { |
| 503 | struct file *file; |
| 504 | struct completion wait; |
| 505 | }; |
| 506 | |
| 507 | static void do_loop_switch(struct loop_device *, struct switch_request *); |
| 508 | |
| 509 | static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) |
| 510 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | if (unlikely(!bio->bi_bdev)) { |
| 512 | do_loop_switch(lo, bio->bi_private); |
| 513 | bio_put(bio); |
| 514 | } else { |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 515 | int ret = do_bio_filebacked(lo, bio); |
NeilBrown | 6712ecf | 2007-09-27 12:47:43 +0200 | [diff] [blame] | 516 | bio_endio(bio, ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | } |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | * worker thread that handles reads/writes to file backed loop devices, |
| 522 | * to avoid blocking in our make_request_fn. it also does loop decrypting |
| 523 | * on reads for block backed loop, as that is too heavy to do from |
| 524 | * b_end_io context where irqs may be disabled. |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 525 | * |
| 526 | * Loop explanation: loop_clr_fd() sets lo_state to Lo_rundown before |
| 527 | * calling kthread_stop(). Therefore once kthread_should_stop() is |
| 528 | * true, make_request will not place any more requests. Therefore |
| 529 | * once kthread_should_stop() is true and lo_bio is NULL, we are |
| 530 | * done with the loop. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | */ |
| 532 | static int loop_thread(void *data) |
| 533 | { |
| 534 | struct loop_device *lo = data; |
| 535 | struct bio *bio; |
| 536 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | set_user_nice(current, -20); |
| 538 | |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 539 | while (!kthread_should_stop() || !bio_list_empty(&lo->lo_bio_list)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 541 | wait_event_interruptible(lo->lo_event, |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 542 | !bio_list_empty(&lo->lo_bio_list) || |
| 543 | kthread_should_stop()); |
Linus Torvalds | 09c0dc6 | 2006-06-26 11:55:42 -0700 | [diff] [blame] | 544 | |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 545 | if (bio_list_empty(&lo->lo_bio_list)) |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 546 | continue; |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 547 | spin_lock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | bio = loop_get_bio(lo); |
Nick Piggin | 35a82d1 | 2005-06-23 00:09:06 -0700 | [diff] [blame] | 549 | spin_unlock_irq(&lo->lo_lock); |
| 550 | |
| 551 | BUG_ON(!bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | loop_handle_bio(lo, bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | } |
| 554 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | return 0; |
| 556 | } |
| 557 | |
| 558 | /* |
| 559 | * loop_switch performs the hard work of switching a backing store. |
| 560 | * First it needs to flush existing IO, it does this by sending a magic |
| 561 | * BIO down the pipe. The completion of this BIO does the actual switch. |
| 562 | */ |
| 563 | static int loop_switch(struct loop_device *lo, struct file *file) |
| 564 | { |
| 565 | struct switch_request w; |
Jens Axboe | a24eab1 | 2008-01-11 10:14:40 +0100 | [diff] [blame] | 566 | struct bio *bio = bio_alloc(GFP_KERNEL, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | if (!bio) |
| 568 | return -ENOMEM; |
| 569 | init_completion(&w.wait); |
| 570 | w.file = file; |
| 571 | bio->bi_private = &w; |
| 572 | bio->bi_bdev = NULL; |
| 573 | loop_make_request(lo->lo_queue, bio); |
| 574 | wait_for_completion(&w.wait); |
| 575 | return 0; |
| 576 | } |
| 577 | |
| 578 | /* |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 579 | * Helper to flush the IOs in loop, but keeping loop thread running |
| 580 | */ |
| 581 | static int loop_flush(struct loop_device *lo) |
| 582 | { |
| 583 | /* loop not yet configured, no running thread, nothing to flush */ |
| 584 | if (!lo->lo_thread) |
| 585 | return 0; |
| 586 | |
| 587 | return loop_switch(lo, NULL); |
| 588 | } |
| 589 | |
| 590 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | * Do the actual switch; called from the BIO completion routine |
| 592 | */ |
| 593 | static void do_loop_switch(struct loop_device *lo, struct switch_request *p) |
| 594 | { |
| 595 | struct file *file = p->file; |
| 596 | struct file *old_file = lo->lo_backing_file; |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 597 | struct address_space *mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 599 | /* if no new file, only flush of queued bios requested */ |
| 600 | if (!file) |
| 601 | goto out; |
| 602 | |
| 603 | mapping = file->f_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); |
| 605 | lo->lo_backing_file = file; |
Theodore Ts'o | ba52de1 | 2006-09-27 01:50:49 -0700 | [diff] [blame] | 606 | lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? |
| 607 | mapping->host->i_bdev->bd_block_size : PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
| 609 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 610 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | complete(&p->wait); |
| 612 | } |
| 613 | |
| 614 | |
| 615 | /* |
| 616 | * loop_change_fd switched the backing store of a loopback device to |
| 617 | * a new file. This is useful for operating system installers to free up |
| 618 | * the original file and in High Availability environments to switch to |
| 619 | * an alternative location for the content in case of server meltdown. |
| 620 | * This can only work if the loop device is used read-only, and if the |
| 621 | * new backing store is the same size and type as the old backing store. |
| 622 | */ |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 623 | static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, |
| 624 | unsigned int arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | { |
| 626 | struct file *file, *old_file; |
| 627 | struct inode *inode; |
| 628 | int error; |
| 629 | |
| 630 | error = -ENXIO; |
| 631 | if (lo->lo_state != Lo_bound) |
| 632 | goto out; |
| 633 | |
| 634 | /* the loop device has to be read-only */ |
| 635 | error = -EINVAL; |
| 636 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) |
| 637 | goto out; |
| 638 | |
| 639 | error = -EBADF; |
| 640 | file = fget(arg); |
| 641 | if (!file) |
| 642 | goto out; |
| 643 | |
| 644 | inode = file->f_mapping->host; |
| 645 | old_file = lo->lo_backing_file; |
| 646 | |
| 647 | error = -EINVAL; |
| 648 | |
| 649 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
| 650 | goto out_putf; |
| 651 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | /* size of the new backing store needs to be the same */ |
| 653 | if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) |
| 654 | goto out_putf; |
| 655 | |
| 656 | /* and ... switch */ |
| 657 | error = loop_switch(lo, file); |
| 658 | if (error) |
| 659 | goto out_putf; |
| 660 | |
| 661 | fput(old_file); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 662 | if (lo->lo_flags & LO_FLAGS_PARTSCAN) |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 663 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | return 0; |
| 665 | |
| 666 | out_putf: |
| 667 | fput(file); |
| 668 | out: |
| 669 | return error; |
| 670 | } |
| 671 | |
| 672 | static inline int is_loop_device(struct file *file) |
| 673 | { |
| 674 | struct inode *i = file->f_mapping->host; |
| 675 | |
| 676 | return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; |
| 677 | } |
| 678 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 679 | /* loop sysfs attributes */ |
| 680 | |
| 681 | static ssize_t loop_attr_show(struct device *dev, char *page, |
| 682 | ssize_t (*callback)(struct loop_device *, char *)) |
| 683 | { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 684 | struct gendisk *disk = dev_to_disk(dev); |
| 685 | struct loop_device *lo = disk->private_data; |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 686 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 687 | return callback(lo, page); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 688 | } |
| 689 | |
| 690 | #define LOOP_ATTR_RO(_name) \ |
| 691 | static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ |
| 692 | static ssize_t loop_attr_do_show_##_name(struct device *d, \ |
| 693 | struct device_attribute *attr, char *b) \ |
| 694 | { \ |
| 695 | return loop_attr_show(d, b, loop_attr_##_name##_show); \ |
| 696 | } \ |
| 697 | static struct device_attribute loop_attr_##_name = \ |
| 698 | __ATTR(_name, S_IRUGO, loop_attr_do_show_##_name, NULL); |
| 699 | |
| 700 | static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) |
| 701 | { |
| 702 | ssize_t ret; |
| 703 | char *p = NULL; |
| 704 | |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 705 | spin_lock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 706 | if (lo->lo_backing_file) |
| 707 | p = d_path(&lo->lo_backing_file->f_path, buf, PAGE_SIZE - 1); |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 708 | spin_unlock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 709 | |
| 710 | if (IS_ERR_OR_NULL(p)) |
| 711 | ret = PTR_ERR(p); |
| 712 | else { |
| 713 | ret = strlen(p); |
| 714 | memmove(buf, p, ret); |
| 715 | buf[ret++] = '\n'; |
| 716 | buf[ret] = 0; |
| 717 | } |
| 718 | |
| 719 | return ret; |
| 720 | } |
| 721 | |
| 722 | static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) |
| 723 | { |
| 724 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset); |
| 725 | } |
| 726 | |
| 727 | static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) |
| 728 | { |
| 729 | return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); |
| 730 | } |
| 731 | |
| 732 | static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) |
| 733 | { |
| 734 | int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); |
| 735 | |
| 736 | return sprintf(buf, "%s\n", autoclear ? "1" : "0"); |
| 737 | } |
| 738 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 739 | static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) |
| 740 | { |
| 741 | int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); |
| 742 | |
| 743 | return sprintf(buf, "%s\n", partscan ? "1" : "0"); |
| 744 | } |
| 745 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 746 | LOOP_ATTR_RO(backing_file); |
| 747 | LOOP_ATTR_RO(offset); |
| 748 | LOOP_ATTR_RO(sizelimit); |
| 749 | LOOP_ATTR_RO(autoclear); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 750 | LOOP_ATTR_RO(partscan); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 751 | |
| 752 | static struct attribute *loop_attrs[] = { |
| 753 | &loop_attr_backing_file.attr, |
| 754 | &loop_attr_offset.attr, |
| 755 | &loop_attr_sizelimit.attr, |
| 756 | &loop_attr_autoclear.attr, |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 757 | &loop_attr_partscan.attr, |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 758 | NULL, |
| 759 | }; |
| 760 | |
| 761 | static struct attribute_group loop_attribute_group = { |
| 762 | .name = "loop", |
| 763 | .attrs= loop_attrs, |
| 764 | }; |
| 765 | |
| 766 | static int loop_sysfs_init(struct loop_device *lo) |
| 767 | { |
| 768 | return sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 769 | &loop_attribute_group); |
| 770 | } |
| 771 | |
| 772 | static void loop_sysfs_exit(struct loop_device *lo) |
| 773 | { |
| 774 | sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 775 | &loop_attribute_group); |
| 776 | } |
| 777 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 778 | static void loop_config_discard(struct loop_device *lo) |
| 779 | { |
| 780 | struct file *file = lo->lo_backing_file; |
| 781 | struct inode *inode = file->f_mapping->host; |
| 782 | struct request_queue *q = lo->lo_queue; |
| 783 | |
| 784 | /* |
| 785 | * We use punch hole to reclaim the free space used by the |
| 786 | * image a.k.a. discard. However we do support discard if |
| 787 | * encryption is enabled, because it may give an attacker |
| 788 | * useful information. |
| 789 | */ |
| 790 | if ((!file->f_op->fallocate) || |
| 791 | lo->lo_encrypt_key_size) { |
| 792 | q->limits.discard_granularity = 0; |
| 793 | q->limits.discard_alignment = 0; |
| 794 | q->limits.max_discard_sectors = 0; |
| 795 | q->limits.discard_zeroes_data = 0; |
| 796 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q); |
| 797 | return; |
| 798 | } |
| 799 | |
| 800 | q->limits.discard_granularity = inode->i_sb->s_blocksize; |
Lukas Czerner | dfaf3c0 | 2011-12-02 14:47:03 +0100 | [diff] [blame] | 801 | q->limits.discard_alignment = 0; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 802 | q->limits.max_discard_sectors = UINT_MAX >> 9; |
| 803 | q->limits.discard_zeroes_data = 1; |
| 804 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); |
| 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; |
| 813 | unsigned lo_blocksize; |
| 814 | int lo_flags = 0; |
| 815 | int error; |
| 816 | loff_t size; |
| 817 | |
| 818 | /* This is safe, since we have a reference from open(). */ |
| 819 | __module_get(THIS_MODULE); |
| 820 | |
| 821 | error = -EBADF; |
| 822 | file = fget(arg); |
| 823 | if (!file) |
| 824 | goto out; |
| 825 | |
| 826 | error = -EBUSY; |
| 827 | if (lo->lo_state != Lo_unbound) |
| 828 | goto out_putf; |
| 829 | |
| 830 | /* Avoid recursion */ |
| 831 | f = file; |
| 832 | while (is_loop_device(f)) { |
| 833 | struct loop_device *l; |
| 834 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 835 | if (f->f_mapping->host->i_bdev == bdev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | goto out_putf; |
| 837 | |
| 838 | l = f->f_mapping->host->i_bdev->bd_disk->private_data; |
| 839 | if (l->lo_state == Lo_unbound) { |
| 840 | error = -EINVAL; |
| 841 | goto out_putf; |
| 842 | } |
| 843 | f = l->lo_backing_file; |
| 844 | } |
| 845 | |
| 846 | mapping = file->f_mapping; |
| 847 | inode = mapping->host; |
| 848 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | error = -EINVAL; |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 850 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | goto out_putf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 853 | if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || |
| 854 | !file->f_op->write) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | lo_flags |= LO_FLAGS_READ_ONLY; |
| 856 | |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 857 | lo_blocksize = S_ISBLK(inode->i_mode) ? |
| 858 | inode->i_bdev->bd_block_size : PAGE_SIZE; |
| 859 | |
| 860 | error = -EFBIG; |
| 861 | size = get_loop_size(lo, file); |
| 862 | if ((loff_t)(sector_t)size != size) |
| 863 | goto out_putf; |
| 864 | |
| 865 | error = 0; |
| 866 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0); |
| 868 | |
| 869 | lo->lo_blocksize = lo_blocksize; |
| 870 | lo->lo_device = bdev; |
| 871 | lo->lo_flags = lo_flags; |
| 872 | lo->lo_backing_file = file; |
Constantine Sapuntzakis | eefe85e | 2006-06-23 02:06:08 -0700 | [diff] [blame] | 873 | lo->transfer = transfer_none; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | lo->ioctl = NULL; |
| 875 | lo->lo_sizelimit = 0; |
| 876 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
| 877 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 878 | |
Akinobu Mita | e686307 | 2009-04-17 08:41:21 +0200 | [diff] [blame] | 879 | bio_list_init(&lo->lo_bio_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | |
| 881 | /* |
| 882 | * set queue make_request_fn, and add limits based on lower level |
| 883 | * device |
| 884 | */ |
| 885 | blk_queue_make_request(lo->lo_queue, loop_make_request); |
| 886 | lo->lo_queue->queuedata = lo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 888 | if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) |
Tejun Heo | 4913efe | 2010-09-03 11:56:16 +0200 | [diff] [blame] | 889 | blk_queue_flush(lo->lo_queue, REQ_FLUSH); |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 890 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 891 | set_capacity(lo->lo_disk, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 892 | bd_set_size(bdev, size << 9); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 893 | loop_sysfs_init(lo); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 894 | /* let user-space know about the new size */ |
| 895 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | |
| 897 | set_blocksize(bdev, lo_blocksize); |
| 898 | |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 899 | lo->lo_thread = kthread_create(loop_thread, lo, "loop%d", |
| 900 | lo->lo_number); |
| 901 | if (IS_ERR(lo->lo_thread)) { |
| 902 | error = PTR_ERR(lo->lo_thread); |
Serge E. Hallyn | a7422bf | 2006-09-29 02:01:18 -0700 | [diff] [blame] | 903 | goto out_clr; |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 904 | } |
| 905 | lo->lo_state = Lo_bound; |
| 906 | wake_up_process(lo->lo_thread); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 907 | if (part_shift) |
| 908 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
| 909 | if (lo->lo_flags & LO_FLAGS_PARTSCAN) |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 910 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | return 0; |
| 912 | |
Serge E. Hallyn | a7422bf | 2006-09-29 02:01:18 -0700 | [diff] [blame] | 913 | out_clr: |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 914 | loop_sysfs_exit(lo); |
Serge E. Hallyn | a7422bf | 2006-09-29 02:01:18 -0700 | [diff] [blame] | 915 | lo->lo_thread = NULL; |
| 916 | lo->lo_device = NULL; |
| 917 | lo->lo_backing_file = NULL; |
| 918 | lo->lo_flags = 0; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 919 | set_capacity(lo->lo_disk, 0); |
Peter Zijlstra | f98393a | 2007-05-06 14:49:54 -0700 | [diff] [blame] | 920 | invalidate_bdev(bdev); |
Serge E. Hallyn | a7422bf | 2006-09-29 02:01:18 -0700 | [diff] [blame] | 921 | bd_set_size(bdev, 0); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 922 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
Serge E. Hallyn | a7422bf | 2006-09-29 02:01:18 -0700 | [diff] [blame] | 923 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask); |
| 924 | lo->lo_state = Lo_unbound; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | out_putf: |
| 926 | fput(file); |
| 927 | out: |
| 928 | /* This is safe: open() is still holding a reference. */ |
| 929 | module_put(THIS_MODULE); |
| 930 | return error; |
| 931 | } |
| 932 | |
| 933 | static int |
| 934 | loop_release_xfer(struct loop_device *lo) |
| 935 | { |
| 936 | int err = 0; |
| 937 | struct loop_func_table *xfer = lo->lo_encryption; |
| 938 | |
| 939 | if (xfer) { |
| 940 | if (xfer->release) |
| 941 | err = xfer->release(lo); |
| 942 | lo->transfer = NULL; |
| 943 | lo->lo_encryption = NULL; |
| 944 | module_put(xfer->owner); |
| 945 | } |
| 946 | return err; |
| 947 | } |
| 948 | |
| 949 | static int |
| 950 | loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, |
| 951 | const struct loop_info64 *i) |
| 952 | { |
| 953 | int err = 0; |
| 954 | |
| 955 | if (xfer) { |
| 956 | struct module *owner = xfer->owner; |
| 957 | |
| 958 | if (!try_module_get(owner)) |
| 959 | return -EINVAL; |
| 960 | if (xfer->init) |
| 961 | err = xfer->init(lo, i); |
| 962 | if (err) |
| 963 | module_put(owner); |
| 964 | else |
| 965 | lo->lo_encryption = xfer; |
| 966 | } |
| 967 | return err; |
| 968 | } |
| 969 | |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 970 | static int loop_clr_fd(struct loop_device *lo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | { |
| 972 | struct file *filp = lo->lo_backing_file; |
Al Viro | b4e3ca1 | 2005-10-21 03:22:34 -0400 | [diff] [blame] | 973 | gfp_t gfp = lo->old_gfp_mask; |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 974 | struct block_device *bdev = lo->lo_device; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 975 | |
| 976 | if (lo->lo_state != Lo_bound) |
| 977 | return -ENXIO; |
| 978 | |
| 979 | if (lo->lo_refcnt > 1) /* we needed one fd for the ioctl */ |
| 980 | return -EBUSY; |
| 981 | |
| 982 | if (filp == NULL) |
| 983 | return -EINVAL; |
| 984 | |
| 985 | spin_lock_irq(&lo->lo_lock); |
| 986 | lo->lo_state = Lo_rundown; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | spin_unlock_irq(&lo->lo_lock); |
| 988 | |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 989 | kthread_stop(lo->lo_thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 990 | |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 991 | spin_lock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | lo->lo_backing_file = NULL; |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 993 | spin_unlock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | |
| 995 | loop_release_xfer(lo); |
| 996 | lo->transfer = NULL; |
| 997 | lo->ioctl = NULL; |
| 998 | lo->lo_device = NULL; |
| 999 | lo->lo_encryption = NULL; |
| 1000 | lo->lo_offset = 0; |
| 1001 | lo->lo_sizelimit = 0; |
| 1002 | lo->lo_encrypt_key_size = 0; |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 1003 | lo->lo_thread = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); |
| 1005 | memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); |
| 1006 | memset(lo->lo_file_name, 0, LO_NAME_SIZE); |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1007 | if (bdev) |
| 1008 | invalidate_bdev(bdev); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1009 | set_capacity(lo->lo_disk, 0); |
Milan Broz | 51a0bb0 | 2010-10-27 19:51:30 -0600 | [diff] [blame] | 1010 | loop_sysfs_exit(lo); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1011 | if (bdev) { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1012 | bd_set_size(bdev, 0); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1013 | /* let user-space know about this change */ |
| 1014 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
| 1015 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | mapping_set_gfp_mask(filp->f_mapping, gfp); |
| 1017 | lo->lo_state = Lo_unbound; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | /* This is safe: open() is still holding a reference. */ |
| 1019 | module_put(THIS_MODULE); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1020 | if (lo->lo_flags & LO_FLAGS_PARTSCAN && bdev) |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1021 | ioctl_by_bdev(bdev, BLKRRPART, 0); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1022 | lo->lo_flags = 0; |
| 1023 | if (!part_shift) |
| 1024 | lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1025 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1026 | /* |
| 1027 | * Need not hold lo_ctl_mutex to fput backing file. |
| 1028 | * Calling fput holding lo_ctl_mutex triggers a circular |
| 1029 | * lock dependency possibility warning as fput can take |
| 1030 | * bd_mutex which is usually taken before lo_ctl_mutex. |
| 1031 | */ |
| 1032 | fput(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1033 | return 0; |
| 1034 | } |
| 1035 | |
| 1036 | static int |
| 1037 | loop_set_status(struct loop_device *lo, const struct loop_info64 *info) |
| 1038 | { |
| 1039 | int err; |
| 1040 | struct loop_func_table *xfer; |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1041 | uid_t uid = current_uid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1042 | |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1043 | if (lo->lo_encrypt_key_size && |
| 1044 | lo->lo_key_owner != uid && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1045 | !capable(CAP_SYS_ADMIN)) |
| 1046 | return -EPERM; |
| 1047 | if (lo->lo_state != Lo_bound) |
| 1048 | return -ENXIO; |
| 1049 | if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) |
| 1050 | return -EINVAL; |
| 1051 | |
| 1052 | err = loop_release_xfer(lo); |
| 1053 | if (err) |
| 1054 | return err; |
| 1055 | |
| 1056 | if (info->lo_encrypt_type) { |
| 1057 | unsigned int type = info->lo_encrypt_type; |
| 1058 | |
| 1059 | if (type >= MAX_LO_CRYPT) |
| 1060 | return -EINVAL; |
| 1061 | xfer = xfer_funcs[type]; |
| 1062 | if (xfer == NULL) |
| 1063 | return -EINVAL; |
| 1064 | } else |
| 1065 | xfer = NULL; |
| 1066 | |
| 1067 | err = loop_init_xfer(lo, xfer, info); |
| 1068 | if (err) |
| 1069 | return err; |
| 1070 | |
| 1071 | if (lo->lo_offset != info->lo_offset || |
| 1072 | lo->lo_sizelimit != info->lo_sizelimit) { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1073 | if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | return -EFBIG; |
| 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 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1092 | if ((info->lo_flags & LO_FLAGS_PARTSCAN) && |
| 1093 | !(lo->lo_flags & LO_FLAGS_PARTSCAN)) { |
| 1094 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
| 1095 | lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; |
| 1096 | ioctl_by_bdev(lo->lo_device, BLKRRPART, 0); |
| 1097 | } |
| 1098 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1099 | lo->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1100 | lo->lo_init[0] = info->lo_init[0]; |
| 1101 | lo->lo_init[1] = info->lo_init[1]; |
| 1102 | if (info->lo_encrypt_key_size) { |
| 1103 | memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, |
| 1104 | info->lo_encrypt_key_size); |
David Howells | b0fafa8 | 2008-11-14 10:38:41 +1100 | [diff] [blame] | 1105 | lo->lo_key_owner = uid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | } |
| 1107 | |
| 1108 | return 0; |
| 1109 | } |
| 1110 | |
| 1111 | static int |
| 1112 | loop_get_status(struct loop_device *lo, struct loop_info64 *info) |
| 1113 | { |
| 1114 | struct file *file = lo->lo_backing_file; |
| 1115 | struct kstat stat; |
| 1116 | int error; |
| 1117 | |
| 1118 | if (lo->lo_state != Lo_bound) |
| 1119 | return -ENXIO; |
Josef Sipek | 6c648be | 2006-12-08 02:36:55 -0800 | [diff] [blame] | 1120 | error = vfs_getattr(file->f_path.mnt, file->f_path.dentry, &stat); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1121 | if (error) |
| 1122 | return error; |
| 1123 | memset(info, 0, sizeof(*info)); |
| 1124 | info->lo_number = lo->lo_number; |
| 1125 | info->lo_device = huge_encode_dev(stat.dev); |
| 1126 | info->lo_inode = stat.ino; |
| 1127 | info->lo_rdevice = huge_encode_dev(lo->lo_device ? stat.rdev : stat.dev); |
| 1128 | info->lo_offset = lo->lo_offset; |
| 1129 | info->lo_sizelimit = lo->lo_sizelimit; |
| 1130 | info->lo_flags = lo->lo_flags; |
| 1131 | memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); |
| 1132 | memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); |
| 1133 | info->lo_encrypt_type = |
| 1134 | lo->lo_encryption ? lo->lo_encryption->number : 0; |
| 1135 | if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { |
| 1136 | info->lo_encrypt_key_size = lo->lo_encrypt_key_size; |
| 1137 | memcpy(info->lo_encrypt_key, lo->lo_encrypt_key, |
| 1138 | lo->lo_encrypt_key_size); |
| 1139 | } |
| 1140 | return 0; |
| 1141 | } |
| 1142 | |
| 1143 | static void |
| 1144 | loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) |
| 1145 | { |
| 1146 | memset(info64, 0, sizeof(*info64)); |
| 1147 | info64->lo_number = info->lo_number; |
| 1148 | info64->lo_device = info->lo_device; |
| 1149 | info64->lo_inode = info->lo_inode; |
| 1150 | info64->lo_rdevice = info->lo_rdevice; |
| 1151 | info64->lo_offset = info->lo_offset; |
| 1152 | info64->lo_sizelimit = 0; |
| 1153 | info64->lo_encrypt_type = info->lo_encrypt_type; |
| 1154 | info64->lo_encrypt_key_size = info->lo_encrypt_key_size; |
| 1155 | info64->lo_flags = info->lo_flags; |
| 1156 | info64->lo_init[0] = info->lo_init[0]; |
| 1157 | info64->lo_init[1] = info->lo_init[1]; |
| 1158 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1159 | memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE); |
| 1160 | else |
| 1161 | memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); |
| 1162 | memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE); |
| 1163 | } |
| 1164 | |
| 1165 | static int |
| 1166 | loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) |
| 1167 | { |
| 1168 | memset(info, 0, sizeof(*info)); |
| 1169 | info->lo_number = info64->lo_number; |
| 1170 | info->lo_device = info64->lo_device; |
| 1171 | info->lo_inode = info64->lo_inode; |
| 1172 | info->lo_rdevice = info64->lo_rdevice; |
| 1173 | info->lo_offset = info64->lo_offset; |
| 1174 | info->lo_encrypt_type = info64->lo_encrypt_type; |
| 1175 | info->lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1176 | info->lo_flags = info64->lo_flags; |
| 1177 | info->lo_init[0] = info64->lo_init[0]; |
| 1178 | info->lo_init[1] = info64->lo_init[1]; |
| 1179 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1180 | memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1181 | else |
| 1182 | memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1183 | memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1184 | |
| 1185 | /* error in case values were truncated */ |
| 1186 | if (info->lo_device != info64->lo_device || |
| 1187 | info->lo_rdevice != info64->lo_rdevice || |
| 1188 | info->lo_inode != info64->lo_inode || |
| 1189 | info->lo_offset != info64->lo_offset) |
| 1190 | return -EOVERFLOW; |
| 1191 | |
| 1192 | return 0; |
| 1193 | } |
| 1194 | |
| 1195 | static int |
| 1196 | loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) |
| 1197 | { |
| 1198 | struct loop_info info; |
| 1199 | struct loop_info64 info64; |
| 1200 | |
| 1201 | if (copy_from_user(&info, arg, sizeof (struct loop_info))) |
| 1202 | return -EFAULT; |
| 1203 | loop_info64_from_old(&info, &info64); |
| 1204 | return loop_set_status(lo, &info64); |
| 1205 | } |
| 1206 | |
| 1207 | static int |
| 1208 | loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) |
| 1209 | { |
| 1210 | struct loop_info64 info64; |
| 1211 | |
| 1212 | if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) |
| 1213 | return -EFAULT; |
| 1214 | return loop_set_status(lo, &info64); |
| 1215 | } |
| 1216 | |
| 1217 | static int |
| 1218 | loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { |
| 1219 | struct loop_info info; |
| 1220 | struct loop_info64 info64; |
| 1221 | int err = 0; |
| 1222 | |
| 1223 | if (!arg) |
| 1224 | err = -EINVAL; |
| 1225 | if (!err) |
| 1226 | err = loop_get_status(lo, &info64); |
| 1227 | if (!err) |
| 1228 | err = loop_info64_to_old(&info64, &info); |
| 1229 | if (!err && copy_to_user(arg, &info, sizeof(info))) |
| 1230 | err = -EFAULT; |
| 1231 | |
| 1232 | return err; |
| 1233 | } |
| 1234 | |
| 1235 | static int |
| 1236 | loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { |
| 1237 | struct loop_info64 info64; |
| 1238 | int err = 0; |
| 1239 | |
| 1240 | if (!arg) |
| 1241 | err = -EINVAL; |
| 1242 | if (!err) |
| 1243 | err = loop_get_status(lo, &info64); |
| 1244 | if (!err && copy_to_user(arg, &info64, sizeof(info64))) |
| 1245 | err = -EFAULT; |
| 1246 | |
| 1247 | return err; |
| 1248 | } |
| 1249 | |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1250 | static int loop_set_capacity(struct loop_device *lo, struct block_device *bdev) |
| 1251 | { |
| 1252 | int err; |
| 1253 | sector_t sec; |
| 1254 | loff_t sz; |
| 1255 | |
| 1256 | err = -ENXIO; |
| 1257 | if (unlikely(lo->lo_state != Lo_bound)) |
| 1258 | goto out; |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1259 | err = figure_loop_size(lo, lo->lo_offset, lo->lo_sizelimit); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1260 | if (unlikely(err)) |
| 1261 | goto out; |
| 1262 | sec = get_capacity(lo->lo_disk); |
| 1263 | /* the width of sector_t may be narrow for bit-shift */ |
| 1264 | sz = sec; |
| 1265 | sz <<= 9; |
| 1266 | mutex_lock(&bdev->bd_mutex); |
| 1267 | bd_set_size(bdev, sz); |
David Zeuthen | c3473c6 | 2010-05-03 14:08:59 +0200 | [diff] [blame] | 1268 | /* let user-space know about the new size */ |
| 1269 | kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1270 | mutex_unlock(&bdev->bd_mutex); |
| 1271 | |
| 1272 | out: |
| 1273 | return err; |
| 1274 | } |
| 1275 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1276 | static int lo_ioctl(struct block_device *bdev, fmode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1277 | unsigned int cmd, unsigned long arg) |
| 1278 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1279 | struct loop_device *lo = bdev->bd_disk->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | int err; |
| 1281 | |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1282 | mutex_lock_nested(&lo->lo_ctl_mutex, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | switch (cmd) { |
| 1284 | case LOOP_SET_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1285 | err = loop_set_fd(lo, mode, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | break; |
| 1287 | case LOOP_CHANGE_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1288 | err = loop_change_fd(lo, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | break; |
| 1290 | case LOOP_CLR_FD: |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1291 | /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 1292 | err = loop_clr_fd(lo); |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1293 | if (!err) |
| 1294 | goto out_unlocked; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | break; |
| 1296 | case LOOP_SET_STATUS: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1297 | err = -EPERM; |
| 1298 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1299 | err = loop_set_status_old(lo, |
| 1300 | (struct loop_info __user *)arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | break; |
| 1302 | case LOOP_GET_STATUS: |
| 1303 | err = loop_get_status_old(lo, (struct loop_info __user *) arg); |
| 1304 | break; |
| 1305 | case LOOP_SET_STATUS64: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1306 | err = -EPERM; |
| 1307 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1308 | err = loop_set_status64(lo, |
| 1309 | (struct loop_info64 __user *) arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | break; |
| 1311 | case LOOP_GET_STATUS64: |
| 1312 | err = loop_get_status64(lo, (struct loop_info64 __user *) arg); |
| 1313 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1314 | case LOOP_SET_CAPACITY: |
| 1315 | err = -EPERM; |
| 1316 | if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) |
| 1317 | err = loop_set_capacity(lo, bdev); |
| 1318 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | default: |
| 1320 | err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; |
| 1321 | } |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1322 | mutex_unlock(&lo->lo_ctl_mutex); |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1323 | |
| 1324 | out_unlocked: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | return err; |
| 1326 | } |
| 1327 | |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1328 | #ifdef CONFIG_COMPAT |
| 1329 | struct compat_loop_info { |
| 1330 | compat_int_t lo_number; /* ioctl r/o */ |
| 1331 | compat_dev_t lo_device; /* ioctl r/o */ |
| 1332 | compat_ulong_t lo_inode; /* ioctl r/o */ |
| 1333 | compat_dev_t lo_rdevice; /* ioctl r/o */ |
| 1334 | compat_int_t lo_offset; |
| 1335 | compat_int_t lo_encrypt_type; |
| 1336 | compat_int_t lo_encrypt_key_size; /* ioctl w/o */ |
| 1337 | compat_int_t lo_flags; /* ioctl r/o */ |
| 1338 | char lo_name[LO_NAME_SIZE]; |
| 1339 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ |
| 1340 | compat_ulong_t lo_init[2]; |
| 1341 | char reserved[4]; |
| 1342 | }; |
| 1343 | |
| 1344 | /* |
| 1345 | * Transfer 32-bit compatibility structure in userspace to 64-bit loop info |
| 1346 | * - noinlined to reduce stack space usage in main part of driver |
| 1347 | */ |
| 1348 | static noinline int |
Al Viro | ba674cf | 2006-10-10 22:48:27 +0100 | [diff] [blame] | 1349 | loop_info64_from_compat(const struct compat_loop_info __user *arg, |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1350 | struct loop_info64 *info64) |
| 1351 | { |
| 1352 | struct compat_loop_info info; |
| 1353 | |
| 1354 | if (copy_from_user(&info, arg, sizeof(info))) |
| 1355 | return -EFAULT; |
| 1356 | |
| 1357 | memset(info64, 0, sizeof(*info64)); |
| 1358 | info64->lo_number = info.lo_number; |
| 1359 | info64->lo_device = info.lo_device; |
| 1360 | info64->lo_inode = info.lo_inode; |
| 1361 | info64->lo_rdevice = info.lo_rdevice; |
| 1362 | info64->lo_offset = info.lo_offset; |
| 1363 | info64->lo_sizelimit = 0; |
| 1364 | info64->lo_encrypt_type = info.lo_encrypt_type; |
| 1365 | info64->lo_encrypt_key_size = info.lo_encrypt_key_size; |
| 1366 | info64->lo_flags = info.lo_flags; |
| 1367 | info64->lo_init[0] = info.lo_init[0]; |
| 1368 | info64->lo_init[1] = info.lo_init[1]; |
| 1369 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1370 | memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE); |
| 1371 | else |
| 1372 | memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); |
| 1373 | memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE); |
| 1374 | return 0; |
| 1375 | } |
| 1376 | |
| 1377 | /* |
| 1378 | * Transfer 64-bit loop info to 32-bit compatibility structure in userspace |
| 1379 | * - noinlined to reduce stack space usage in main part of driver |
| 1380 | */ |
| 1381 | static noinline int |
| 1382 | loop_info64_to_compat(const struct loop_info64 *info64, |
| 1383 | struct compat_loop_info __user *arg) |
| 1384 | { |
| 1385 | struct compat_loop_info info; |
| 1386 | |
| 1387 | memset(&info, 0, sizeof(info)); |
| 1388 | info.lo_number = info64->lo_number; |
| 1389 | info.lo_device = info64->lo_device; |
| 1390 | info.lo_inode = info64->lo_inode; |
| 1391 | info.lo_rdevice = info64->lo_rdevice; |
| 1392 | info.lo_offset = info64->lo_offset; |
| 1393 | info.lo_encrypt_type = info64->lo_encrypt_type; |
| 1394 | info.lo_encrypt_key_size = info64->lo_encrypt_key_size; |
| 1395 | info.lo_flags = info64->lo_flags; |
| 1396 | info.lo_init[0] = info64->lo_init[0]; |
| 1397 | info.lo_init[1] = info64->lo_init[1]; |
| 1398 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) |
| 1399 | memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE); |
| 1400 | else |
| 1401 | memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); |
| 1402 | memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); |
| 1403 | |
| 1404 | /* error in case values were truncated */ |
| 1405 | if (info.lo_device != info64->lo_device || |
| 1406 | info.lo_rdevice != info64->lo_rdevice || |
| 1407 | info.lo_inode != info64->lo_inode || |
| 1408 | info.lo_offset != info64->lo_offset || |
| 1409 | info.lo_init[0] != info64->lo_init[0] || |
| 1410 | info.lo_init[1] != info64->lo_init[1]) |
| 1411 | return -EOVERFLOW; |
| 1412 | |
| 1413 | if (copy_to_user(arg, &info, sizeof(info))) |
| 1414 | return -EFAULT; |
| 1415 | return 0; |
| 1416 | } |
| 1417 | |
| 1418 | static int |
| 1419 | loop_set_status_compat(struct loop_device *lo, |
| 1420 | const struct compat_loop_info __user *arg) |
| 1421 | { |
| 1422 | struct loop_info64 info64; |
| 1423 | int ret; |
| 1424 | |
| 1425 | ret = loop_info64_from_compat(arg, &info64); |
| 1426 | if (ret < 0) |
| 1427 | return ret; |
| 1428 | return loop_set_status(lo, &info64); |
| 1429 | } |
| 1430 | |
| 1431 | static int |
| 1432 | loop_get_status_compat(struct loop_device *lo, |
| 1433 | struct compat_loop_info __user *arg) |
| 1434 | { |
| 1435 | struct loop_info64 info64; |
| 1436 | int err = 0; |
| 1437 | |
| 1438 | if (!arg) |
| 1439 | err = -EINVAL; |
| 1440 | if (!err) |
| 1441 | err = loop_get_status(lo, &info64); |
| 1442 | if (!err) |
| 1443 | err = loop_info64_to_compat(&info64, arg); |
| 1444 | return err; |
| 1445 | } |
| 1446 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1447 | static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, |
| 1448 | unsigned int cmd, unsigned long arg) |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1449 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1450 | struct loop_device *lo = bdev->bd_disk->private_data; |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1451 | int err; |
| 1452 | |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1453 | switch(cmd) { |
| 1454 | case LOOP_SET_STATUS: |
| 1455 | mutex_lock(&lo->lo_ctl_mutex); |
| 1456 | err = loop_set_status_compat( |
| 1457 | lo, (const struct compat_loop_info __user *) arg); |
| 1458 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1459 | break; |
| 1460 | case LOOP_GET_STATUS: |
| 1461 | mutex_lock(&lo->lo_ctl_mutex); |
| 1462 | err = loop_get_status_compat( |
| 1463 | lo, (struct compat_loop_info __user *) arg); |
| 1464 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1465 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1466 | case LOOP_SET_CAPACITY: |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1467 | case LOOP_CLR_FD: |
| 1468 | case LOOP_GET_STATUS64: |
| 1469 | case LOOP_SET_STATUS64: |
| 1470 | arg = (unsigned long) compat_ptr(arg); |
| 1471 | case LOOP_SET_FD: |
| 1472 | case LOOP_CHANGE_FD: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1473 | err = lo_ioctl(bdev, mode, cmd, arg); |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1474 | break; |
| 1475 | default: |
| 1476 | err = -ENOIOCTLCMD; |
| 1477 | break; |
| 1478 | } |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1479 | return err; |
| 1480 | } |
| 1481 | #endif |
| 1482 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1483 | static int lo_open(struct block_device *bdev, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1485 | struct loop_device *lo; |
| 1486 | int err = 0; |
| 1487 | |
| 1488 | mutex_lock(&loop_index_mutex); |
| 1489 | lo = bdev->bd_disk->private_data; |
| 1490 | if (!lo) { |
| 1491 | err = -ENXIO; |
| 1492 | goto out; |
| 1493 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1495 | mutex_lock(&lo->lo_ctl_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1496 | lo->lo_refcnt++; |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1497 | mutex_unlock(&lo->lo_ctl_mutex); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1498 | out: |
| 1499 | mutex_unlock(&loop_index_mutex); |
| 1500 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1501 | } |
| 1502 | |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1503 | static int lo_release(struct gendisk *disk, fmode_t mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1504 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1505 | struct loop_device *lo = disk->private_data; |
Alexander Beregalov | ffcd7dc | 2009-04-07 13:48:21 +0200 | [diff] [blame] | 1506 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1508 | mutex_lock(&lo->lo_ctl_mutex); |
David Woodhouse | 96c5865 | 2008-02-06 01:36:27 -0800 | [diff] [blame] | 1509 | |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1510 | if (--lo->lo_refcnt) |
| 1511 | goto out; |
| 1512 | |
| 1513 | if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { |
| 1514 | /* |
| 1515 | * In autoclear mode, stop the loop thread |
| 1516 | * and remove configuration after last close. |
| 1517 | */ |
Ayan George | 4c823cc | 2011-09-21 10:02:13 +0200 | [diff] [blame] | 1518 | err = loop_clr_fd(lo); |
Alexander Beregalov | ffcd7dc | 2009-04-07 13:48:21 +0200 | [diff] [blame] | 1519 | if (!err) |
| 1520 | goto out_unlocked; |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1521 | } else { |
| 1522 | /* |
| 1523 | * Otherwise keep thread (if running) and config, |
| 1524 | * but flush possible ongoing bios in thread. |
| 1525 | */ |
| 1526 | loop_flush(lo); |
| 1527 | } |
David Woodhouse | 96c5865 | 2008-02-06 01:36:27 -0800 | [diff] [blame] | 1528 | |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1529 | out: |
Ingo Molnar | f85221d | 2006-03-23 03:00:38 -0800 | [diff] [blame] | 1530 | mutex_unlock(&lo->lo_ctl_mutex); |
Alexander Beregalov | ffcd7dc | 2009-04-07 13:48:21 +0200 | [diff] [blame] | 1531 | out_unlocked: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | return 0; |
| 1533 | } |
| 1534 | |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1535 | static const struct block_device_operations lo_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1536 | .owner = THIS_MODULE, |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1537 | .open = lo_open, |
| 1538 | .release = lo_release, |
| 1539 | .ioctl = lo_ioctl, |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1540 | #ifdef CONFIG_COMPAT |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1541 | .compat_ioctl = lo_compat_ioctl, |
David Howells | 863d5b8 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1542 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | }; |
| 1544 | |
| 1545 | /* |
| 1546 | * And now the modules code and kernel interface. |
| 1547 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1548 | static int max_loop; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1549 | module_param(max_loop, int, S_IRUGO); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1550 | MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1551 | module_param(max_part, int, S_IRUGO); |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1552 | MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1553 | MODULE_LICENSE("GPL"); |
| 1554 | MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); |
| 1555 | |
| 1556 | int loop_register_transfer(struct loop_func_table *funcs) |
| 1557 | { |
| 1558 | unsigned int n = funcs->number; |
| 1559 | |
| 1560 | if (n >= MAX_LO_CRYPT || xfer_funcs[n]) |
| 1561 | return -EINVAL; |
| 1562 | xfer_funcs[n] = funcs; |
| 1563 | return 0; |
| 1564 | } |
| 1565 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1566 | static int unregister_transfer_cb(int id, void *ptr, void *data) |
| 1567 | { |
| 1568 | struct loop_device *lo = ptr; |
| 1569 | struct loop_func_table *xfer = data; |
| 1570 | |
| 1571 | mutex_lock(&lo->lo_ctl_mutex); |
| 1572 | if (lo->lo_encryption == xfer) |
| 1573 | loop_release_xfer(lo); |
| 1574 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1575 | return 0; |
| 1576 | } |
| 1577 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1578 | int loop_unregister_transfer(int number) |
| 1579 | { |
| 1580 | unsigned int n = number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1581 | struct loop_func_table *xfer; |
| 1582 | |
| 1583 | if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL) |
| 1584 | return -EINVAL; |
| 1585 | |
| 1586 | xfer_funcs[n] = NULL; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1587 | idr_for_each(&loop_index_idr, &unregister_transfer_cb, xfer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1588 | return 0; |
| 1589 | } |
| 1590 | |
| 1591 | EXPORT_SYMBOL(loop_register_transfer); |
| 1592 | EXPORT_SYMBOL(loop_unregister_transfer); |
| 1593 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1594 | static int loop_add(struct loop_device **l, int i) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1595 | { |
| 1596 | struct loop_device *lo; |
| 1597 | struct gendisk *disk; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1598 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1599 | |
| 1600 | lo = kzalloc(sizeof(*lo), GFP_KERNEL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1601 | if (!lo) { |
| 1602 | err = -ENOMEM; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1603 | goto out; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1604 | } |
| 1605 | |
| 1606 | err = idr_pre_get(&loop_index_idr, GFP_KERNEL); |
| 1607 | if (err < 0) |
| 1608 | goto out_free_dev; |
| 1609 | |
| 1610 | if (i >= 0) { |
| 1611 | int m; |
| 1612 | |
| 1613 | /* create specific i in the index */ |
| 1614 | err = idr_get_new_above(&loop_index_idr, lo, i, &m); |
| 1615 | if (err >= 0 && i != m) { |
| 1616 | idr_remove(&loop_index_idr, m); |
| 1617 | err = -EEXIST; |
| 1618 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1619 | } else if (i == -1) { |
| 1620 | int m; |
| 1621 | |
| 1622 | /* get next free nr */ |
| 1623 | err = idr_get_new(&loop_index_idr, lo, &m); |
| 1624 | if (err >= 0) |
| 1625 | i = m; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1626 | } else { |
| 1627 | err = -EINVAL; |
| 1628 | } |
| 1629 | if (err < 0) |
| 1630 | goto out_free_dev; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1631 | |
| 1632 | lo->lo_queue = blk_alloc_queue(GFP_KERNEL); |
| 1633 | if (!lo->lo_queue) |
| 1634 | goto out_free_dev; |
| 1635 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1636 | disk = lo->lo_disk = alloc_disk(1 << part_shift); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1637 | if (!disk) |
| 1638 | goto out_free_queue; |
| 1639 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1640 | /* |
| 1641 | * Disable partition scanning by default. The in-kernel partition |
| 1642 | * scanning can be requested individually per-device during its |
| 1643 | * setup. Userspace can always add and remove partitions from all |
| 1644 | * devices. The needed partition minors are allocated from the |
| 1645 | * extended minor space, the main loop device numbers will continue |
| 1646 | * to match the loop minors, regardless of the number of partitions |
| 1647 | * used. |
| 1648 | * |
| 1649 | * If max_part is given, partition scanning is globally enabled for |
| 1650 | * all loop devices. The minors for the main loop devices will be |
| 1651 | * multiples of max_part. |
| 1652 | * |
| 1653 | * Note: Global-for-all-devices, set-only-at-init, read-only module |
| 1654 | * parameteters like 'max_loop' and 'max_part' make things needlessly |
| 1655 | * complicated, are too static, inflexible and may surprise |
| 1656 | * userspace tools. Parameters like this in general should be avoided. |
| 1657 | */ |
| 1658 | if (!part_shift) |
| 1659 | disk->flags |= GENHD_FL_NO_PART_SCAN; |
| 1660 | disk->flags |= GENHD_FL_EXT_DEVT; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1661 | mutex_init(&lo->lo_ctl_mutex); |
| 1662 | lo->lo_number = i; |
| 1663 | lo->lo_thread = NULL; |
| 1664 | init_waitqueue_head(&lo->lo_event); |
| 1665 | spin_lock_init(&lo->lo_lock); |
| 1666 | disk->major = LOOP_MAJOR; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1667 | disk->first_minor = i << part_shift; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1668 | disk->fops = &lo_fops; |
| 1669 | disk->private_data = lo; |
| 1670 | disk->queue = lo->lo_queue; |
| 1671 | sprintf(disk->disk_name, "loop%d", i); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1672 | add_disk(disk); |
| 1673 | *l = lo; |
| 1674 | return lo->lo_number; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1675 | |
| 1676 | out_free_queue: |
| 1677 | blk_cleanup_queue(lo->lo_queue); |
| 1678 | out_free_dev: |
| 1679 | kfree(lo); |
| 1680 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1681 | return err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1682 | } |
| 1683 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1684 | static void loop_remove(struct loop_device *lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1685 | { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1686 | del_gendisk(lo->lo_disk); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1687 | blk_cleanup_queue(lo->lo_queue); |
| 1688 | put_disk(lo->lo_disk); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1689 | kfree(lo); |
| 1690 | } |
| 1691 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1692 | static int find_free_cb(int id, void *ptr, void *data) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1693 | { |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1694 | struct loop_device *lo = ptr; |
| 1695 | struct loop_device **l = data; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1696 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1697 | if (lo->lo_state == Lo_unbound) { |
| 1698 | *l = lo; |
| 1699 | return 1; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1700 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1701 | return 0; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1702 | } |
| 1703 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1704 | static int loop_lookup(struct loop_device **l, int i) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1705 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1706 | struct loop_device *lo; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1707 | int ret = -ENODEV; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1708 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1709 | if (i < 0) { |
| 1710 | int err; |
| 1711 | |
| 1712 | err = idr_for_each(&loop_index_idr, &find_free_cb, &lo); |
| 1713 | if (err == 1) { |
| 1714 | *l = lo; |
| 1715 | ret = lo->lo_number; |
| 1716 | } |
| 1717 | goto out; |
| 1718 | } |
| 1719 | |
| 1720 | /* lookup and return a specific i */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1721 | lo = idr_find(&loop_index_idr, i); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1722 | if (lo) { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1723 | *l = lo; |
| 1724 | ret = lo->lo_number; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1725 | } |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1726 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1727 | return ret; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1728 | } |
| 1729 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1730 | static struct kobject *loop_probe(dev_t dev, int *part, void *data) |
| 1731 | { |
Al Viro | 705962c | 2007-05-13 05:52:32 -0400 | [diff] [blame] | 1732 | struct loop_device *lo; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 1733 | struct kobject *kobj; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1734 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1735 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1736 | mutex_lock(&loop_index_mutex); |
| 1737 | err = loop_lookup(&lo, MINOR(dev) >> part_shift); |
| 1738 | if (err < 0) |
| 1739 | err = loop_add(&lo, MINOR(dev) >> part_shift); |
| 1740 | if (err < 0) |
| 1741 | kobj = ERR_PTR(err); |
| 1742 | else |
| 1743 | kobj = get_disk(lo->lo_disk); |
| 1744 | mutex_unlock(&loop_index_mutex); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1745 | |
| 1746 | *part = 0; |
Al Viro | 07002e9 | 2007-05-12 16:23:15 -0400 | [diff] [blame] | 1747 | return kobj; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1748 | } |
| 1749 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1750 | static long loop_control_ioctl(struct file *file, unsigned int cmd, |
| 1751 | unsigned long parm) |
| 1752 | { |
| 1753 | struct loop_device *lo; |
| 1754 | int ret = -ENOSYS; |
| 1755 | |
| 1756 | mutex_lock(&loop_index_mutex); |
| 1757 | switch (cmd) { |
| 1758 | case LOOP_CTL_ADD: |
| 1759 | ret = loop_lookup(&lo, parm); |
| 1760 | if (ret >= 0) { |
| 1761 | ret = -EEXIST; |
| 1762 | break; |
| 1763 | } |
| 1764 | ret = loop_add(&lo, parm); |
| 1765 | break; |
| 1766 | case LOOP_CTL_REMOVE: |
| 1767 | ret = loop_lookup(&lo, parm); |
| 1768 | if (ret < 0) |
| 1769 | break; |
| 1770 | mutex_lock(&lo->lo_ctl_mutex); |
| 1771 | if (lo->lo_state != Lo_unbound) { |
| 1772 | ret = -EBUSY; |
| 1773 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1774 | break; |
| 1775 | } |
| 1776 | if (lo->lo_refcnt > 0) { |
| 1777 | ret = -EBUSY; |
| 1778 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1779 | break; |
| 1780 | } |
| 1781 | lo->lo_disk->private_data = NULL; |
| 1782 | mutex_unlock(&lo->lo_ctl_mutex); |
| 1783 | idr_remove(&loop_index_idr, lo->lo_number); |
| 1784 | loop_remove(lo); |
| 1785 | break; |
| 1786 | case LOOP_CTL_GET_FREE: |
| 1787 | ret = loop_lookup(&lo, -1); |
| 1788 | if (ret >= 0) |
| 1789 | break; |
| 1790 | ret = loop_add(&lo, -1); |
| 1791 | } |
| 1792 | mutex_unlock(&loop_index_mutex); |
| 1793 | |
| 1794 | return ret; |
| 1795 | } |
| 1796 | |
| 1797 | static const struct file_operations loop_ctl_fops = { |
| 1798 | .open = nonseekable_open, |
| 1799 | .unlocked_ioctl = loop_control_ioctl, |
| 1800 | .compat_ioctl = loop_control_ioctl, |
| 1801 | .owner = THIS_MODULE, |
| 1802 | .llseek = noop_llseek, |
| 1803 | }; |
| 1804 | |
| 1805 | static struct miscdevice loop_misc = { |
| 1806 | .minor = LOOP_CTRL_MINOR, |
| 1807 | .name = "loop-control", |
| 1808 | .fops = &loop_ctl_fops, |
| 1809 | }; |
| 1810 | |
| 1811 | MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); |
| 1812 | MODULE_ALIAS("devname:loop-control"); |
| 1813 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1814 | static int __init loop_init(void) |
| 1815 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1816 | int i, nr; |
| 1817 | unsigned long range; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1818 | struct loop_device *lo; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1819 | int err; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1820 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1821 | err = misc_register(&loop_misc); |
| 1822 | if (err < 0) |
| 1823 | return err; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1824 | |
| 1825 | part_shift = 0; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1826 | if (max_part > 0) { |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1827 | part_shift = fls(max_part); |
| 1828 | |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 1829 | /* |
| 1830 | * Adjust max_part according to part_shift as it is exported |
| 1831 | * to user space so that user can decide correct minor number |
| 1832 | * if [s]he want to create more devices. |
| 1833 | * |
| 1834 | * Note that -1 is required because partition 0 is reserved |
| 1835 | * for the whole disk. |
| 1836 | */ |
| 1837 | max_part = (1UL << part_shift) - 1; |
| 1838 | } |
| 1839 | |
Namhyung Kim | 78f4bb3 | 2011-05-24 16:48:54 +0200 | [diff] [blame] | 1840 | if ((1UL << part_shift) > DISK_MAX_PARTS) |
| 1841 | return -EINVAL; |
| 1842 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1843 | if (max_loop > 1UL << (MINORBITS - part_shift)) |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1844 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1845 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1846 | /* |
| 1847 | * If max_loop is specified, create that many devices upfront. |
| 1848 | * This also becomes a hard limit. If max_loop is not specified, |
| 1849 | * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module |
| 1850 | * init time. Loop devices can be requested on-demand with the |
| 1851 | * /dev/loop-control interface, or be instantiated by accessing |
| 1852 | * a 'dead' device node. |
| 1853 | */ |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1854 | if (max_loop) { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1855 | nr = max_loop; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 1856 | range = max_loop << part_shift; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1857 | } else { |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1858 | nr = CONFIG_BLK_DEV_LOOP_MIN_COUNT; |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 1859 | range = 1UL << MINORBITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1860 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1861 | |
| 1862 | if (register_blkdev(LOOP_MAJOR, "loop")) |
| 1863 | return -EIO; |
| 1864 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1865 | blk_register_region(MKDEV(LOOP_MAJOR, 0), range, |
| 1866 | THIS_MODULE, loop_probe, NULL, NULL); |
| 1867 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1868 | /* pre-create number of devices given by config or max_loop */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1869 | mutex_lock(&loop_index_mutex); |
| 1870 | for (i = 0; i < nr; i++) |
| 1871 | loop_add(&lo, i); |
| 1872 | mutex_unlock(&loop_index_mutex); |
| 1873 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1874 | printk(KERN_INFO "loop: module loaded\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1875 | return 0; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1876 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1877 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1878 | static int loop_exit_cb(int id, void *ptr, void *data) |
| 1879 | { |
| 1880 | struct loop_device *lo = ptr; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1881 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1882 | loop_remove(lo); |
| 1883 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1884 | } |
| 1885 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1886 | static void __exit loop_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1887 | { |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1888 | unsigned long range; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1889 | |
Namhyung Kim | a1c15c5 | 2011-05-24 16:48:55 +0200 | [diff] [blame] | 1890 | range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1891 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1892 | idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); |
| 1893 | idr_remove_all(&loop_index_idr); |
| 1894 | idr_destroy(&loop_index_idr); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1895 | |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1896 | blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); |
Akinobu Mita | 00d5940 | 2007-07-17 04:03:46 -0700 | [diff] [blame] | 1897 | unregister_blkdev(LOOP_MAJOR, "loop"); |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1898 | |
| 1899 | misc_deregister(&loop_misc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1900 | } |
| 1901 | |
| 1902 | module_init(loop_init); |
| 1903 | module_exit(loop_exit); |
| 1904 | |
| 1905 | #ifndef MODULE |
| 1906 | static int __init max_loop_setup(char *str) |
| 1907 | { |
| 1908 | max_loop = simple_strtol(str, NULL, 0); |
| 1909 | return 1; |
| 1910 | } |
| 1911 | |
| 1912 | __setup("max_loop=", max_loop_setup); |
| 1913 | #endif |