Christoph Hellwig | f21e6e1 | 2022-04-19 08:33:01 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
Christoph Hellwig | f21e6e1 | 2022-04-19 08:33:01 +0200 | [diff] [blame] | 3 | * Copyright 1993 by Theodore Ts'o. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | #include <linux/module.h> |
| 6 | #include <linux/moduleparam.h> |
| 7 | #include <linux/sched.h> |
| 8 | #include <linux/fs.h> |
Matthew Wilcox (Oracle) | 4ee60ec | 2021-05-06 18:02:27 -0700 | [diff] [blame] | 9 | #include <linux/pagemap.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/file.h> |
| 11 | #include <linux/stat.h> |
| 12 | #include <linux/errno.h> |
| 13 | #include <linux/major.h> |
| 14 | #include <linux/wait.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/blkpg.h> |
| 16 | #include <linux/init.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/swap.h> |
| 18 | #include <linux/slab.h> |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 19 | #include <linux/compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/suspend.h> |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 21 | #include <linux/freezer.h> |
Arnd Bergmann | 2a48fc0 | 2010-06-02 14:28:52 +0200 | [diff] [blame] | 22 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/writeback.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/completion.h> |
| 25 | #include <linux/highmem.h> |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 26 | #include <linux/splice.h> |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 27 | #include <linux/sysfs.h> |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 28 | #include <linux/miscdevice.h> |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 29 | #include <linux/falloc.h> |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 30 | #include <linux/uio.h> |
Adam Manzanares | d9a08a9 | 2018-05-22 10:52:19 -0700 | [diff] [blame] | 31 | #include <linux/ioprio.h> |
Dennis Zhou | db6638d | 2018-12-05 12:10:35 -0500 | [diff] [blame] | 32 | #include <linux/blk-cgroup.h> |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 33 | #include <linux/sched/mm.h> |
Ming Lei | 06582bc | 2022-01-26 11:58:30 +0800 | [diff] [blame] | 34 | #include <linux/statfs.h> |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 35 | #include <linux/uaccess.h> |
Christoph Hellwig | 754d967 | 2022-04-19 08:33:00 +0200 | [diff] [blame] | 36 | #include <linux/blk-mq.h> |
| 37 | #include <linux/spinlock.h> |
| 38 | #include <uapi/linux/loop.h> |
| 39 | |
| 40 | /* Possible states of device */ |
| 41 | enum { |
| 42 | Lo_unbound, |
| 43 | Lo_bound, |
| 44 | Lo_rundown, |
| 45 | Lo_deleting, |
| 46 | }; |
| 47 | |
| 48 | struct loop_func_table; |
| 49 | |
| 50 | struct loop_device { |
| 51 | int lo_number; |
| 52 | loff_t lo_offset; |
| 53 | loff_t lo_sizelimit; |
| 54 | int lo_flags; |
| 55 | char lo_file_name[LO_NAME_SIZE]; |
| 56 | |
| 57 | struct file * lo_backing_file; |
| 58 | struct block_device *lo_device; |
| 59 | |
| 60 | gfp_t old_gfp_mask; |
| 61 | |
| 62 | spinlock_t lo_lock; |
| 63 | int lo_state; |
| 64 | spinlock_t lo_work_lock; |
| 65 | struct workqueue_struct *workqueue; |
| 66 | struct work_struct rootcg_work; |
| 67 | struct list_head rootcg_cmd_list; |
| 68 | struct list_head idle_worker_list; |
| 69 | struct rb_root worker_tree; |
| 70 | struct timer_list timer; |
| 71 | bool use_dio; |
| 72 | bool sysfs_inited; |
| 73 | |
| 74 | struct request_queue *lo_queue; |
| 75 | struct blk_mq_tag_set tag_set; |
| 76 | struct gendisk *lo_disk; |
| 77 | struct mutex lo_mutex; |
| 78 | bool idr_visible; |
| 79 | }; |
| 80 | |
| 81 | struct loop_cmd { |
| 82 | struct list_head list_entry; |
| 83 | bool use_aio; /* use AIO interface to handle I/O */ |
| 84 | atomic_t ref; /* only for aio */ |
| 85 | long ret; |
| 86 | struct kiocb iocb; |
| 87 | struct bio_vec *bvec; |
| 88 | struct cgroup_subsys_state *blkcg_css; |
| 89 | struct cgroup_subsys_state *memcg_css; |
| 90 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 92 | #define LOOP_IDLE_WORKER_TIMEOUT (60 * HZ) |
Bart Van Assche | e152a05 | 2023-01-30 13:13:47 -0800 | [diff] [blame] | 93 | #define LOOP_DEFAULT_HW_Q_DEPTH 128 |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 94 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 95 | static DEFINE_IDR(loop_index_idr); |
Tetsuo Handa | 310ca16 | 2018-11-08 14:01:02 +0100 | [diff] [blame] | 96 | static DEFINE_MUTEX(loop_ctl_mutex); |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 97 | static DEFINE_MUTEX(loop_validate_mutex); |
| 98 | |
| 99 | /** |
| 100 | * loop_global_lock_killable() - take locks for safe loop_validate_file() test |
| 101 | * |
| 102 | * @lo: struct loop_device |
| 103 | * @global: true if @lo is about to bind another "struct loop_device", false otherwise |
| 104 | * |
| 105 | * Returns 0 on success, -EINTR otherwise. |
| 106 | * |
| 107 | * Since loop_validate_file() traverses on other "struct loop_device" if |
| 108 | * is_loop_device() is true, we need a global lock for serializing concurrent |
| 109 | * loop_configure()/loop_change_fd()/__loop_clr_fd() calls. |
| 110 | */ |
| 111 | static int loop_global_lock_killable(struct loop_device *lo, bool global) |
| 112 | { |
| 113 | int err; |
| 114 | |
| 115 | if (global) { |
| 116 | err = mutex_lock_killable(&loop_validate_mutex); |
| 117 | if (err) |
| 118 | return err; |
| 119 | } |
| 120 | err = mutex_lock_killable(&lo->lo_mutex); |
| 121 | if (err && global) |
| 122 | mutex_unlock(&loop_validate_mutex); |
| 123 | return err; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * loop_global_unlock() - release locks taken by loop_global_lock_killable() |
| 128 | * |
| 129 | * @lo: struct loop_device |
| 130 | * @global: true if @lo was about to bind another "struct loop_device", false otherwise |
| 131 | */ |
| 132 | static void loop_global_unlock(struct loop_device *lo, bool global) |
| 133 | { |
| 134 | mutex_unlock(&lo->lo_mutex); |
| 135 | if (global) |
| 136 | mutex_unlock(&loop_validate_mutex); |
| 137 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 139 | static int max_part; |
| 140 | static int part_shift; |
| 141 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 142 | 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] | 143 | { |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 144 | loff_t loopsize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
| 146 | /* Compute loopsize in bytes */ |
Guo Chao | b7a1da6 | 2013-02-21 15:16:50 -0800 | [diff] [blame] | 147 | loopsize = i_size_read(file->f_mapping->host); |
| 148 | if (offset > 0) |
| 149 | loopsize -= offset; |
| 150 | /* offset is beyond i_size, weird but possible */ |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 151 | if (loopsize < 0) |
| 152 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 154 | if (sizelimit > 0 && sizelimit < loopsize) |
| 155 | loopsize = sizelimit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | /* |
| 157 | * Unfortunately, if we want to do I/O on the device, |
| 158 | * the number of 512-byte sectors has to fit into a sector_t. |
| 159 | */ |
| 160 | return loopsize >> 9; |
| 161 | } |
| 162 | |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 163 | 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] | 164 | { |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 165 | return get_size(lo->lo_offset, lo->lo_sizelimit, file); |
| 166 | } |
| 167 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 168 | static void __loop_update_dio(struct loop_device *lo, bool dio) |
| 169 | { |
| 170 | struct file *file = lo->lo_backing_file; |
| 171 | struct address_space *mapping = file->f_mapping; |
| 172 | struct inode *inode = mapping->host; |
| 173 | unsigned short sb_bsize = 0; |
| 174 | unsigned dio_align = 0; |
| 175 | bool use_dio; |
| 176 | |
| 177 | if (inode->i_sb->s_bdev) { |
| 178 | sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); |
| 179 | dio_align = sb_bsize - 1; |
| 180 | } |
| 181 | |
| 182 | /* |
| 183 | * We support direct I/O only if lo_offset is aligned with the |
| 184 | * logical I/O size of backing device, and the logical block |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 185 | * size of loop is bigger than the backing device's. |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 186 | * |
| 187 | * TODO: the above condition may be loosed in the future, and |
| 188 | * direct I/O may be switched runtime at that time because most |
Masahiro Yamada | 89d790a | 2017-02-27 14:29:01 -0800 | [diff] [blame] | 189 | * of requests in sane applications should be PAGE_SIZE aligned |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 190 | */ |
| 191 | if (dio) { |
| 192 | if (queue_logical_block_size(lo->lo_queue) >= sb_bsize && |
NeilBrown | a2ad63d | 2022-05-09 18:20:49 -0700 | [diff] [blame] | 193 | !(lo->lo_offset & dio_align) && |
| 194 | (file->f_mode & FMODE_CAN_ODIRECT)) |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 195 | use_dio = true; |
| 196 | else |
| 197 | use_dio = false; |
| 198 | } else { |
| 199 | use_dio = false; |
| 200 | } |
| 201 | |
| 202 | if (lo->use_dio == use_dio) |
| 203 | return; |
| 204 | |
| 205 | /* flush dirty pages before changing direct IO */ |
| 206 | vfs_fsync(file, 0); |
| 207 | |
| 208 | /* |
| 209 | * The flag of LO_FLAGS_DIRECT_IO is handled similarly with |
| 210 | * LO_FLAGS_READ_ONLY, both are set from kernel, and losetup |
| 211 | * will get updated by ioctl(LOOP_GET_STATUS) |
| 212 | */ |
Martijn Coenen | 0fbcf579 | 2020-03-10 14:06:54 +0100 | [diff] [blame] | 213 | if (lo->lo_state == Lo_bound) |
| 214 | blk_mq_freeze_queue(lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 215 | lo->use_dio = use_dio; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 216 | if (use_dio) { |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 217 | blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 218 | lo->lo_flags |= LO_FLAGS_DIRECT_IO; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 219 | } else { |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 220 | blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 221 | lo->lo_flags &= ~LO_FLAGS_DIRECT_IO; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 222 | } |
Martijn Coenen | 0fbcf579 | 2020-03-10 14:06:54 +0100 | [diff] [blame] | 223 | if (lo->lo_state == Lo_bound) |
| 224 | blk_mq_unfreeze_queue(lo->lo_queue); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 225 | } |
| 226 | |
Martijn Coenen | 5795b6f | 2020-05-13 15:38:37 +0200 | [diff] [blame] | 227 | /** |
| 228 | * loop_set_size() - sets device size and notifies userspace |
| 229 | * @lo: struct loop_device to set the size for |
| 230 | * @size: new size of the loop device |
| 231 | * |
| 232 | * Callers must validate that the size passed into this function fits into |
| 233 | * a sector_t, eg using loop_validate_size() |
| 234 | */ |
| 235 | static void loop_set_size(struct loop_device *lo, loff_t size) |
| 236 | { |
Christoph Hellwig | 449f4ec | 2020-11-16 15:56:56 +0100 | [diff] [blame] | 237 | if (!set_capacity_and_notify(lo->lo_disk, size)) |
Christoph Hellwig | 3b4f85d | 2020-11-16 15:56:53 +0100 | [diff] [blame] | 238 | kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | } |
| 240 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 241 | static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 243 | struct iov_iter i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | ssize_t bw; |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 245 | |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 246 | iov_iter_bvec(&i, ITER_SOURCE, bvec, 1, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 248 | file_start_write(file); |
Christoph Hellwig | abbb6589 | 2017-05-27 11:16:52 +0300 | [diff] [blame] | 249 | bw = vfs_iter_write(file, &i, ppos, 0); |
Al Viro | 03d95eb | 2013-03-20 13:04:20 -0400 | [diff] [blame] | 250 | file_end_write(file); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 251 | |
| 252 | if (likely(bw == bvec->bv_len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | return 0; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 254 | |
| 255 | printk_ratelimited(KERN_ERR |
| 256 | "loop: Write error at byte offset %llu, length %i.\n", |
| 257 | (unsigned long long)*ppos, bvec->bv_len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | if (bw >= 0) |
| 259 | bw = -EIO; |
| 260 | return bw; |
| 261 | } |
| 262 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 263 | static int lo_write_simple(struct loop_device *lo, struct request *rq, |
| 264 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | { |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 266 | struct bio_vec bvec; |
| 267 | struct req_iterator iter; |
| 268 | int ret = 0; |
| 269 | |
| 270 | rq_for_each_segment(bvec, rq, iter) { |
| 271 | ret = lo_write_bvec(lo->lo_backing_file, &bvec, &pos); |
| 272 | if (ret < 0) |
| 273 | break; |
| 274 | cond_resched(); |
| 275 | } |
| 276 | |
| 277 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 278 | } |
| 279 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 280 | static int lo_read_simple(struct loop_device *lo, struct request *rq, |
| 281 | loff_t pos) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | { |
Kent Overstreet | 7988613 | 2013-11-23 17:19:00 -0800 | [diff] [blame] | 283 | struct bio_vec bvec; |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 284 | struct req_iterator iter; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 285 | struct iov_iter i; |
| 286 | ssize_t len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 288 | rq_for_each_segment(bvec, rq, iter) { |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 289 | iov_iter_bvec(&i, ITER_DEST, &bvec, 1, bvec.bv_len); |
Christoph Hellwig | 18e9710 | 2017-05-27 11:16:51 +0300 | [diff] [blame] | 290 | len = vfs_iter_read(lo->lo_backing_file, &i, &pos, 0); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 291 | if (len < 0) |
| 292 | return len; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 293 | |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 294 | flush_dcache_page(bvec.bv_page); |
| 295 | |
| 296 | if (len != bvec.bv_len) { |
Ming Lei | 3011201 | 2014-12-31 13:22:58 +0000 | [diff] [blame] | 297 | struct bio *bio; |
| 298 | |
| 299 | __rq_for_each_bio(bio, rq) |
| 300 | zero_fill_bio(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | break; |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 302 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 303 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | } |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 305 | |
Dave Young | 306df07 | 2012-02-08 22:07:19 +0100 | [diff] [blame] | 306 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | } |
| 308 | |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 309 | static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos, |
| 310 | int mode) |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 311 | { |
| 312 | /* |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 313 | * We use fallocate to manipulate the space mappings used by the image |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 314 | * a.k.a. discard/zerorange. |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 315 | */ |
| 316 | struct file *file = lo->lo_backing_file; |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 317 | int ret; |
| 318 | |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 319 | mode |= FALLOC_FL_KEEP_SIZE; |
| 320 | |
Christoph Hellwig | 7020057 | 2022-04-15 06:52:55 +0200 | [diff] [blame] | 321 | if (!bdev_max_discard_sectors(lo->lo_device)) |
| 322 | return -EOPNOTSUPP; |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 323 | |
| 324 | ret = file->f_op->fallocate(file, mode, pos, blk_rq_bytes(rq)); |
| 325 | if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP)) |
Christoph Hellwig | 7020057 | 2022-04-15 06:52:55 +0200 | [diff] [blame] | 326 | return -EIO; |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 327 | return ret; |
| 328 | } |
| 329 | |
| 330 | static int lo_req_flush(struct loop_device *lo, struct request *rq) |
| 331 | { |
Chaitanya Kulkarni | 9c64e38 | 2022-02-15 13:33:09 -0800 | [diff] [blame] | 332 | int ret = vfs_fsync(lo->lo_backing_file, 0); |
Ming Lei | cf655d9 | 2014-12-31 13:22:59 +0000 | [diff] [blame] | 333 | if (unlikely(ret && ret != -EINVAL)) |
| 334 | ret = -EIO; |
| 335 | |
| 336 | return ret; |
| 337 | } |
| 338 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 339 | static void lo_complete_rq(struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 340 | { |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 341 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 342 | blk_status_t ret = BLK_STS_OK; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 343 | |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 344 | if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || |
| 345 | req_op(rq) != REQ_OP_READ) { |
| 346 | if (cmd->ret < 0) |
Evan Green | 8cd5508 | 2020-04-03 16:43:03 +0200 | [diff] [blame] | 347 | ret = errno_to_blk_status(cmd->ret); |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 348 | goto end_io; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 349 | } |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 350 | |
Jens Axboe | f9de14b | 2018-04-13 16:25:57 -0600 | [diff] [blame] | 351 | /* |
| 352 | * Short READ - if we got some data, advance our request and |
| 353 | * retry it. If we got no data, end the rest with EIO. |
| 354 | */ |
| 355 | if (cmd->ret) { |
| 356 | blk_update_request(rq, BLK_STS_OK, cmd->ret); |
| 357 | cmd->ret = 0; |
| 358 | blk_mq_requeue_request(rq, true); |
| 359 | } else { |
| 360 | if (cmd->use_aio) { |
| 361 | struct bio *bio = rq->bio; |
| 362 | |
| 363 | while (bio) { |
| 364 | zero_fill_bio(bio); |
| 365 | bio = bio->bi_next; |
| 366 | } |
| 367 | } |
| 368 | ret = BLK_STS_IOERR; |
| 369 | end_io: |
| 370 | blk_mq_end_request(rq, ret); |
| 371 | } |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 372 | } |
| 373 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 374 | static void lo_rw_aio_do_completion(struct loop_cmd *cmd) |
| 375 | { |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 376 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
| 377 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 378 | if (!atomic_dec_and_test(&cmd->ref)) |
| 379 | return; |
| 380 | kfree(cmd->bvec); |
| 381 | cmd->bvec = NULL; |
Christoph Hellwig | 15f73f5 | 2020-06-11 08:44:47 +0200 | [diff] [blame] | 382 | if (likely(!blk_should_fake_timeout(rq->q))) |
| 383 | blk_mq_complete_request(rq); |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 384 | } |
| 385 | |
Jens Axboe | 6b19b76 | 2021-10-21 09:22:35 -0600 | [diff] [blame] | 386 | static void lo_rw_aio_complete(struct kiocb *iocb, long ret) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 387 | { |
| 388 | struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 389 | |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 390 | cmd->ret = ret; |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 391 | lo_rw_aio_do_completion(cmd); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 392 | } |
| 393 | |
| 394 | static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 395 | loff_t pos, int rw) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 396 | { |
| 397 | struct iov_iter iter; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 398 | struct req_iterator rq_iter; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 399 | struct bio_vec *bvec; |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 400 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 401 | struct bio *bio = rq->bio; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 402 | struct file *file = lo->lo_backing_file; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 403 | struct bio_vec tmp; |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 404 | unsigned int offset; |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 405 | int nr_bvec = 0; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 406 | int ret; |
| 407 | |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 408 | rq_for_each_bvec(tmp, rq, rq_iter) |
| 409 | nr_bvec++; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 410 | |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 411 | if (rq->bio != rq->biotail) { |
| 412 | |
| 413 | bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), |
Kees Cook | 6da2ec5 | 2018-06-12 13:55:00 -0700 | [diff] [blame] | 414 | GFP_NOIO); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 415 | if (!bvec) |
| 416 | return -EIO; |
| 417 | cmd->bvec = bvec; |
| 418 | |
| 419 | /* |
| 420 | * The bios of the request may be started from the middle of |
| 421 | * the 'bvec' because of bio splitting, so we can't directly |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 422 | * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 423 | * API will take care of all details for us. |
| 424 | */ |
Ming Lei | 86af595 | 2019-02-15 19:13:17 +0800 | [diff] [blame] | 425 | rq_for_each_bvec(tmp, rq, rq_iter) { |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 426 | *bvec = tmp; |
| 427 | bvec++; |
| 428 | } |
| 429 | bvec = cmd->bvec; |
| 430 | offset = 0; |
| 431 | } else { |
| 432 | /* |
| 433 | * Same here, this bio may be started from the middle of the |
| 434 | * 'bvec' because of bio splitting, so offset from the bvec |
| 435 | * must be passed to iov iterator |
| 436 | */ |
| 437 | offset = bio->bi_iter.bi_bvec_done; |
| 438 | bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 439 | } |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 440 | atomic_set(&cmd->ref, 2); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 441 | |
Christoph Hellwig | b620743 | 2019-06-26 15:49:28 +0200 | [diff] [blame] | 442 | iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq)); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 443 | iter.iov_offset = offset; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 444 | |
| 445 | cmd->iocb.ki_pos = pos; |
| 446 | cmd->iocb.ki_filp = file; |
| 447 | cmd->iocb.ki_complete = lo_rw_aio_complete; |
| 448 | cmd->iocb.ki_flags = IOCB_DIRECT; |
Adam Manzanares | d9a08a9 | 2018-05-22 10:52:19 -0700 | [diff] [blame] | 449 | cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 450 | |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 451 | if (rw == ITER_SOURCE) |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 452 | ret = call_write_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 453 | else |
Miklos Szeredi | bb7462b | 2017-02-20 16:51:23 +0100 | [diff] [blame] | 454 | ret = call_read_iter(file, &cmd->iocb, &iter); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 455 | |
Shaohua Li | 92d7733 | 2017-09-01 11:15:17 -0700 | [diff] [blame] | 456 | lo_rw_aio_do_completion(cmd); |
| 457 | |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 458 | if (ret != -EIOCBQUEUED) |
Jens Axboe | 6b19b76 | 2021-10-21 09:22:35 -0600 | [diff] [blame] | 459 | lo_rw_aio_complete(&cmd->iocb, ret); |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 460 | return 0; |
| 461 | } |
| 462 | |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 463 | static int do_req_filebacked(struct loop_device *lo, struct request *rq) |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 464 | { |
| 465 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 466 | loff_t pos = ((loff_t) blk_rq_pos(rq) << 9) + lo->lo_offset; |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 467 | |
| 468 | /* |
| 469 | * lo_write_simple and lo_read_simple should have been covered |
| 470 | * by io submit style function like lo_rw_aio(), one blocker |
| 471 | * is that lo_read_simple() need to call flush_dcache_page after |
| 472 | * the page is written from kernel, and it isn't easy to handle |
| 473 | * this in io submit style function which submits all segments |
| 474 | * of the req at one time. And direct read IO doesn't need to |
| 475 | * run flush_dcache_page(). |
| 476 | */ |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 477 | switch (req_op(rq)) { |
| 478 | case REQ_OP_FLUSH: |
| 479 | return lo_req_flush(lo, rq); |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 480 | case REQ_OP_WRITE_ZEROES: |
Darrick J. Wong | efcfec57 | 2019-10-30 20:29:48 -0700 | [diff] [blame] | 481 | /* |
| 482 | * If the caller doesn't want deallocation, call zeroout to |
| 483 | * write zeroes the range. Otherwise, punch them out. |
| 484 | */ |
| 485 | return lo_fallocate(lo, rq, pos, |
| 486 | (rq->cmd_flags & REQ_NOUNMAP) ? |
| 487 | FALLOC_FL_ZERO_RANGE : |
| 488 | FALLOC_FL_PUNCH_HOLE); |
| 489 | case REQ_OP_DISCARD: |
| 490 | return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 491 | case REQ_OP_WRITE: |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 492 | if (cmd->use_aio) |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 493 | return lo_rw_aio(lo, cmd, pos, ITER_SOURCE); |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 494 | else |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 495 | return lo_write_simple(lo, rq, pos); |
| 496 | case REQ_OP_READ: |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 497 | if (cmd->use_aio) |
Al Viro | de4eda9 | 2022-09-15 20:25:47 -0400 | [diff] [blame] | 498 | return lo_rw_aio(lo, cmd, pos, ITER_DEST); |
Christoph Hellwig | c1c87c2 | 2016-08-04 16:10:01 +0200 | [diff] [blame] | 499 | else |
| 500 | return lo_read_simple(lo, rq, pos); |
| 501 | default: |
| 502 | WARN_ON_ONCE(1); |
| 503 | return -EIO; |
Christoph Hellwig | aa4d861 | 2015-04-07 18:23:29 +0200 | [diff] [blame] | 504 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | } |
| 506 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 507 | static inline void loop_update_dio(struct loop_device *lo) |
| 508 | { |
Ira Weiny | efbe3c2 | 2020-04-30 07:41:33 -0700 | [diff] [blame] | 509 | __loop_update_dio(lo, (lo->lo_backing_file->f_flags & O_DIRECT) | |
| 510 | lo->use_dio); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 511 | } |
| 512 | |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 513 | static void loop_reread_partitions(struct loop_device *lo) |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 514 | { |
| 515 | int rc; |
| 516 | |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 517 | mutex_lock(&lo->lo_disk->open_mutex); |
| 518 | rc = bdev_disk_changed(lo->lo_disk, false); |
| 519 | mutex_unlock(&lo->lo_disk->open_mutex); |
Ming Lei | 06f0e9e | 2015-05-06 12:26:24 +0800 | [diff] [blame] | 520 | if (rc) |
| 521 | pr_warn("%s: partition scan of loop%d (%s) failed (rc=%d)\n", |
| 522 | __func__, lo->lo_number, lo->lo_file_name, rc); |
| 523 | } |
| 524 | |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 525 | static inline int is_loop_device(struct file *file) |
| 526 | { |
| 527 | struct inode *i = file->f_mapping->host; |
| 528 | |
Al Viro | 6f24784 | 2021-01-31 19:23:55 -0500 | [diff] [blame] | 529 | return i && S_ISBLK(i->i_mode) && imajor(i) == LOOP_MAJOR; |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 530 | } |
| 531 | |
| 532 | static int loop_validate_file(struct file *file, struct block_device *bdev) |
| 533 | { |
| 534 | struct inode *inode = file->f_mapping->host; |
| 535 | struct file *f = file; |
| 536 | |
| 537 | /* Avoid recursion */ |
| 538 | while (is_loop_device(f)) { |
| 539 | struct loop_device *l; |
| 540 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 541 | lockdep_assert_held(&loop_validate_mutex); |
Christoph Hellwig | 4e7b567 | 2020-11-23 13:38:40 +0100 | [diff] [blame] | 542 | if (f->f_mapping->host->i_rdev == bdev->bd_dev) |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 543 | return -EBADF; |
| 544 | |
Christoph Hellwig | 4e7b567 | 2020-11-23 13:38:40 +0100 | [diff] [blame] | 545 | l = I_BDEV(f->f_mapping->host)->bd_disk->private_data; |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 546 | if (l->lo_state != Lo_bound) |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 547 | return -EINVAL; |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 548 | /* Order wrt setting lo->lo_backing_file in loop_configure(). */ |
| 549 | rmb(); |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 550 | f = l->lo_backing_file; |
| 551 | } |
| 552 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) |
| 553 | return -EINVAL; |
| 554 | return 0; |
| 555 | } |
| 556 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | /* |
| 558 | * loop_change_fd switched the backing store of a loopback device to |
| 559 | * a new file. This is useful for operating system installers to free up |
| 560 | * the original file and in High Availability environments to switch to |
| 561 | * an alternative location for the content in case of server meltdown. |
| 562 | * This can only work if the loop device is used read-only, and if the |
| 563 | * new backing store is the same size and type as the old backing store. |
| 564 | */ |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 565 | static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, |
| 566 | unsigned int arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | { |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 568 | struct file *file = fget(arg); |
| 569 | struct file *old_file; |
| 570 | int error; |
| 571 | bool partscan; |
| 572 | bool is_loop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 574 | if (!file) |
| 575 | return -EBADF; |
Christoph Hellwig | 498ef5c | 2022-03-30 07:29:14 +0200 | [diff] [blame] | 576 | |
| 577 | /* suppress uevents while reconfiguring the device */ |
| 578 | dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 1); |
| 579 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 580 | is_loop = is_loop_device(file); |
| 581 | error = loop_global_lock_killable(lo, is_loop); |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 582 | if (error) |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 583 | goto out_putf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | error = -ENXIO; |
| 585 | if (lo->lo_state != Lo_bound) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 586 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | |
| 588 | /* the loop device has to be read-only */ |
| 589 | error = -EINVAL; |
| 590 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 591 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 593 | error = loop_validate_file(file, bdev); |
| 594 | if (error) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 595 | goto out_err; |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 596 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | old_file = lo->lo_backing_file; |
| 598 | |
| 599 | error = -EINVAL; |
| 600 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | /* size of the new backing store needs to be the same */ |
| 602 | if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 603 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | |
| 605 | /* and ... switch */ |
Matteo Croce | 9f65c48 | 2021-07-13 01:05:30 +0200 | [diff] [blame] | 606 | disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE); |
Omar Sandoval | 43cade80 | 2017-08-24 00:03:44 -0700 | [diff] [blame] | 607 | blk_mq_freeze_queue(lo->lo_queue); |
| 608 | mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); |
| 609 | lo->lo_backing_file = file; |
| 610 | lo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); |
| 611 | mapping_set_gfp_mask(file->f_mapping, |
| 612 | lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 613 | loop_update_dio(lo); |
| 614 | blk_mq_unfreeze_queue(lo->lo_queue); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 615 | partscan = lo->lo_flags & LO_FLAGS_PARTSCAN; |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 616 | loop_global_unlock(lo, is_loop); |
| 617 | |
| 618 | /* |
| 619 | * Flush loop_validate_file() before fput(), for l->lo_backing_file |
| 620 | * might be pointing at old_file which might be the last reference. |
| 621 | */ |
| 622 | if (!is_loop) { |
| 623 | mutex_lock(&loop_validate_mutex); |
| 624 | mutex_unlock(&loop_validate_mutex); |
| 625 | } |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 626 | /* |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 627 | * We must drop file reference outside of lo_mutex as dropping |
Christoph Hellwig | a869870 | 2021-05-25 08:12:56 +0200 | [diff] [blame] | 628 | * the file ref can take open_mutex which creates circular locking |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 629 | * dependency. |
| 630 | */ |
| 631 | fput(old_file); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 632 | if (partscan) |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 633 | loop_reread_partitions(lo); |
Christoph Hellwig | 498ef5c | 2022-03-30 07:29:14 +0200 | [diff] [blame] | 634 | |
| 635 | error = 0; |
| 636 | done: |
| 637 | /* enable and uncork uevent now that we are done */ |
| 638 | dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); |
| 639 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | |
Jan Kara | 1dded9a | 2018-11-08 14:01:15 +0100 | [diff] [blame] | 641 | out_err: |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 642 | loop_global_unlock(lo, is_loop); |
| 643 | out_putf: |
| 644 | fput(file); |
Christoph Hellwig | 498ef5c | 2022-03-30 07:29:14 +0200 | [diff] [blame] | 645 | goto done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | } |
| 647 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 648 | /* loop sysfs attributes */ |
| 649 | |
| 650 | static ssize_t loop_attr_show(struct device *dev, char *page, |
| 651 | ssize_t (*callback)(struct loop_device *, char *)) |
| 652 | { |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 653 | struct gendisk *disk = dev_to_disk(dev); |
| 654 | struct loop_device *lo = disk->private_data; |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 655 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 656 | return callback(lo, page); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 657 | } |
| 658 | |
| 659 | #define LOOP_ATTR_RO(_name) \ |
| 660 | static ssize_t loop_attr_##_name##_show(struct loop_device *, char *); \ |
| 661 | static ssize_t loop_attr_do_show_##_name(struct device *d, \ |
| 662 | struct device_attribute *attr, char *b) \ |
| 663 | { \ |
| 664 | return loop_attr_show(d, b, loop_attr_##_name##_show); \ |
| 665 | } \ |
| 666 | static struct device_attribute loop_attr_##_name = \ |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 667 | __ATTR(_name, 0444, loop_attr_do_show_##_name, NULL); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 668 | |
| 669 | static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf) |
| 670 | { |
| 671 | ssize_t ret; |
| 672 | char *p = NULL; |
| 673 | |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 674 | spin_lock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 675 | if (lo->lo_backing_file) |
Miklos Szeredi | 9bf39ab | 2015-06-19 10:29:13 +0200 | [diff] [blame] | 676 | p = file_path(lo->lo_backing_file, buf, PAGE_SIZE - 1); |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 677 | spin_unlock_irq(&lo->lo_lock); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 678 | |
| 679 | if (IS_ERR_OR_NULL(p)) |
| 680 | ret = PTR_ERR(p); |
| 681 | else { |
| 682 | ret = strlen(p); |
| 683 | memmove(buf, p, ret); |
| 684 | buf[ret++] = '\n'; |
| 685 | buf[ret] = 0; |
| 686 | } |
| 687 | |
| 688 | return ret; |
| 689 | } |
| 690 | |
| 691 | static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf) |
| 692 | { |
Chaitanya Kulkarni | b27824d | 2022-02-15 13:33:07 -0800 | [diff] [blame] | 693 | return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_offset); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 694 | } |
| 695 | |
| 696 | static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf) |
| 697 | { |
Chaitanya Kulkarni | b27824d | 2022-02-15 13:33:07 -0800 | [diff] [blame] | 698 | return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 699 | } |
| 700 | |
| 701 | static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf) |
| 702 | { |
| 703 | int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR); |
| 704 | |
Chaitanya Kulkarni | b27824d | 2022-02-15 13:33:07 -0800 | [diff] [blame] | 705 | return sysfs_emit(buf, "%s\n", autoclear ? "1" : "0"); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 706 | } |
| 707 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 708 | static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf) |
| 709 | { |
| 710 | int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN); |
| 711 | |
Chaitanya Kulkarni | b27824d | 2022-02-15 13:33:07 -0800 | [diff] [blame] | 712 | return sysfs_emit(buf, "%s\n", partscan ? "1" : "0"); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 713 | } |
| 714 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 715 | static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf) |
| 716 | { |
| 717 | int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO); |
| 718 | |
Chaitanya Kulkarni | b27824d | 2022-02-15 13:33:07 -0800 | [diff] [blame] | 719 | return sysfs_emit(buf, "%s\n", dio ? "1" : "0"); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 720 | } |
| 721 | |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 722 | LOOP_ATTR_RO(backing_file); |
| 723 | LOOP_ATTR_RO(offset); |
| 724 | LOOP_ATTR_RO(sizelimit); |
| 725 | LOOP_ATTR_RO(autoclear); |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 726 | LOOP_ATTR_RO(partscan); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 727 | LOOP_ATTR_RO(dio); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 728 | |
| 729 | static struct attribute *loop_attrs[] = { |
| 730 | &loop_attr_backing_file.attr, |
| 731 | &loop_attr_offset.attr, |
| 732 | &loop_attr_sizelimit.attr, |
| 733 | &loop_attr_autoclear.attr, |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 734 | &loop_attr_partscan.attr, |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 735 | &loop_attr_dio.attr, |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 736 | NULL, |
| 737 | }; |
| 738 | |
| 739 | static struct attribute_group loop_attribute_group = { |
| 740 | .name = "loop", |
| 741 | .attrs= loop_attrs, |
| 742 | }; |
| 743 | |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 744 | static void loop_sysfs_init(struct loop_device *lo) |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 745 | { |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 746 | lo->sysfs_inited = !sysfs_create_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 747 | &loop_attribute_group); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 748 | } |
| 749 | |
| 750 | static void loop_sysfs_exit(struct loop_device *lo) |
| 751 | { |
Tetsuo Handa | d3349b6 | 2018-05-04 10:58:09 -0600 | [diff] [blame] | 752 | if (lo->sysfs_inited) |
| 753 | sysfs_remove_group(&disk_to_dev(lo->lo_disk)->kobj, |
| 754 | &loop_attribute_group); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 755 | } |
| 756 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 757 | static void loop_config_discard(struct loop_device *lo) |
| 758 | { |
| 759 | struct file *file = lo->lo_backing_file; |
| 760 | struct inode *inode = file->f_mapping->host; |
| 761 | struct request_queue *q = lo->lo_queue; |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 762 | u32 granularity, max_discard_sectors; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 763 | |
| 764 | /* |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 765 | * If the backing device is a block device, mirror its zeroing |
| 766 | * capability. Set the discard sectors to the block device's zeroing |
| 767 | * capabilities because loop discards result in blkdev_issue_zeroout(), |
| 768 | * not blkdev_issue_discard(). This maintains consistent behavior with |
| 769 | * file-backed loop devices: discarded regions read back as zero. |
| 770 | */ |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 771 | if (S_ISBLK(inode->i_mode)) { |
Christoph Hellwig | 4e7b567 | 2020-11-23 13:38:40 +0100 | [diff] [blame] | 772 | struct request_queue *backingq = bdev_get_queue(I_BDEV(inode)); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 773 | |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 774 | max_discard_sectors = backingq->limits.max_write_zeroes_sectors; |
Christoph Hellwig | 7b47ef5 | 2022-04-15 06:52:56 +0200 | [diff] [blame] | 775 | granularity = bdev_discard_granularity(I_BDEV(inode)) ?: |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 776 | queue_physical_block_size(backingq); |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 777 | |
| 778 | /* |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 779 | * We use punch hole to reclaim the free space used by the |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 780 | * image a.k.a. discard. |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 781 | */ |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 782 | } else if (!file->f_op->fallocate) { |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 783 | max_discard_sectors = 0; |
| 784 | granularity = 0; |
Evan Green | c52abf5 | 2020-04-03 16:43:04 +0200 | [diff] [blame] | 785 | |
| 786 | } else { |
Ming Lei | 06582bc | 2022-01-26 11:58:30 +0800 | [diff] [blame] | 787 | struct kstatfs sbuf; |
| 788 | |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 789 | max_discard_sectors = UINT_MAX >> 9; |
Ming Lei | 06582bc | 2022-01-26 11:58:30 +0800 | [diff] [blame] | 790 | if (!vfs_statfs(&file->f_path, &sbuf)) |
| 791 | granularity = sbuf.f_bsize; |
| 792 | else |
| 793 | max_discard_sectors = 0; |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 794 | } |
| 795 | |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 796 | if (max_discard_sectors) { |
| 797 | q->limits.discard_granularity = granularity; |
| 798 | blk_queue_max_discard_sectors(q, max_discard_sectors); |
| 799 | blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 800 | } else { |
| 801 | q->limits.discard_granularity = 0; |
| 802 | blk_queue_max_discard_sectors(q, 0); |
| 803 | blk_queue_max_write_zeroes_sectors(q, 0); |
Ming Lei | bcb21c8 | 2020-08-17 18:01:30 +0800 | [diff] [blame] | 804 | } |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 805 | } |
| 806 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 807 | struct loop_worker { |
| 808 | struct rb_node rb_node; |
| 809 | struct work_struct work; |
| 810 | struct list_head cmd_list; |
| 811 | struct list_head idle_list; |
| 812 | struct loop_device *lo; |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 813 | struct cgroup_subsys_state *blkcg_css; |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 814 | unsigned long last_ran_at; |
| 815 | }; |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 816 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 817 | static void loop_workfn(struct work_struct *work); |
NeilBrown | b2ee7d4 | 2017-06-16 15:02:09 +1000 | [diff] [blame] | 818 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 819 | #ifdef CONFIG_BLK_CGROUP |
| 820 | static inline int queue_on_root_worker(struct cgroup_subsys_state *css) |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 821 | { |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 822 | return !css || css == blkcg_root_css; |
| 823 | } |
| 824 | #else |
| 825 | static inline int queue_on_root_worker(struct cgroup_subsys_state *css) |
| 826 | { |
| 827 | return !css; |
| 828 | } |
| 829 | #endif |
| 830 | |
| 831 | static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd) |
| 832 | { |
Colin Ian King | 413ec80 | 2022-01-13 00:14:32 +0000 | [diff] [blame] | 833 | struct rb_node **node, *parent = NULL; |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 834 | struct loop_worker *cur_worker, *worker = NULL; |
| 835 | struct work_struct *work; |
| 836 | struct list_head *cmd_list; |
| 837 | |
| 838 | spin_lock_irq(&lo->lo_work_lock); |
| 839 | |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 840 | if (queue_on_root_worker(cmd->blkcg_css)) |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 841 | goto queue_work; |
| 842 | |
| 843 | node = &lo->worker_tree.rb_node; |
| 844 | |
| 845 | while (*node) { |
| 846 | parent = *node; |
| 847 | cur_worker = container_of(*node, struct loop_worker, rb_node); |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 848 | if (cur_worker->blkcg_css == cmd->blkcg_css) { |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 849 | worker = cur_worker; |
| 850 | break; |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 851 | } else if ((long)cur_worker->blkcg_css < (long)cmd->blkcg_css) { |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 852 | node = &(*node)->rb_left; |
| 853 | } else { |
| 854 | node = &(*node)->rb_right; |
| 855 | } |
| 856 | } |
| 857 | if (worker) |
| 858 | goto queue_work; |
| 859 | |
| 860 | worker = kzalloc(sizeof(struct loop_worker), GFP_NOWAIT | __GFP_NOWARN); |
| 861 | /* |
| 862 | * In the event we cannot allocate a worker, just queue on the |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 863 | * rootcg worker and issue the I/O as the rootcg |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 864 | */ |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 865 | if (!worker) { |
| 866 | cmd->blkcg_css = NULL; |
| 867 | if (cmd->memcg_css) |
| 868 | css_put(cmd->memcg_css); |
| 869 | cmd->memcg_css = NULL; |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 870 | goto queue_work; |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 871 | } |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 872 | |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 873 | worker->blkcg_css = cmd->blkcg_css; |
| 874 | css_get(worker->blkcg_css); |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 875 | INIT_WORK(&worker->work, loop_workfn); |
| 876 | INIT_LIST_HEAD(&worker->cmd_list); |
| 877 | INIT_LIST_HEAD(&worker->idle_list); |
| 878 | worker->lo = lo; |
| 879 | rb_link_node(&worker->rb_node, parent, node); |
| 880 | rb_insert_color(&worker->rb_node, &lo->worker_tree); |
| 881 | queue_work: |
| 882 | if (worker) { |
| 883 | /* |
| 884 | * We need to remove from the idle list here while |
| 885 | * holding the lock so that the idle timer doesn't |
| 886 | * free the worker |
| 887 | */ |
| 888 | if (!list_empty(&worker->idle_list)) |
| 889 | list_del_init(&worker->idle_list); |
| 890 | work = &worker->work; |
| 891 | cmd_list = &worker->cmd_list; |
| 892 | } else { |
| 893 | work = &lo->rootcg_work; |
| 894 | cmd_list = &lo->rootcg_cmd_list; |
| 895 | } |
| 896 | list_add_tail(&cmd->list_entry, cmd_list); |
| 897 | queue_work(lo->workqueue, work); |
| 898 | spin_unlock_irq(&lo->lo_work_lock); |
Ming Lei | e03a3d7 | 2015-08-17 10:31:48 +0800 | [diff] [blame] | 899 | } |
| 900 | |
Christoph Hellwig | 2cf429b | 2022-03-30 07:29:08 +0200 | [diff] [blame] | 901 | static void loop_set_timer(struct loop_device *lo) |
| 902 | { |
| 903 | timer_reduce(&lo->timer, jiffies + LOOP_IDLE_WORKER_TIMEOUT); |
| 904 | } |
| 905 | |
| 906 | static void loop_free_idle_workers(struct loop_device *lo, bool delete_all) |
| 907 | { |
| 908 | struct loop_worker *pos, *worker; |
| 909 | |
| 910 | spin_lock_irq(&lo->lo_work_lock); |
| 911 | list_for_each_entry_safe(worker, pos, &lo->idle_worker_list, |
| 912 | idle_list) { |
| 913 | if (!delete_all && |
| 914 | time_is_after_jiffies(worker->last_ran_at + |
| 915 | LOOP_IDLE_WORKER_TIMEOUT)) |
| 916 | break; |
| 917 | list_del(&worker->idle_list); |
| 918 | rb_erase(&worker->rb_node, &lo->worker_tree); |
| 919 | css_put(worker->blkcg_css); |
| 920 | kfree(worker); |
| 921 | } |
| 922 | if (!list_empty(&lo->idle_worker_list)) |
| 923 | loop_set_timer(lo); |
| 924 | spin_unlock_irq(&lo->lo_work_lock); |
| 925 | } |
| 926 | |
| 927 | static void loop_free_idle_workers_timer(struct timer_list *timer) |
| 928 | { |
| 929 | struct loop_device *lo = container_of(timer, struct loop_device, timer); |
| 930 | |
| 931 | return loop_free_idle_workers(lo, false); |
| 932 | } |
| 933 | |
Holger Hoffstätte | 56a85fd | 2019-02-12 15:54:24 -0700 | [diff] [blame] | 934 | static void loop_update_rotational(struct loop_device *lo) |
| 935 | { |
| 936 | struct file *file = lo->lo_backing_file; |
| 937 | struct inode *file_inode = file->f_mapping->host; |
| 938 | struct block_device *file_bdev = file_inode->i_sb->s_bdev; |
| 939 | struct request_queue *q = lo->lo_queue; |
| 940 | bool nonrot = true; |
| 941 | |
| 942 | /* not all filesystems (e.g. tmpfs) have a sb->s_bdev */ |
| 943 | if (file_bdev) |
Christoph Hellwig | 10f0d2a5 | 2022-04-15 06:52:42 +0200 | [diff] [blame] | 944 | nonrot = bdev_nonrot(file_bdev); |
Holger Hoffstätte | 56a85fd | 2019-02-12 15:54:24 -0700 | [diff] [blame] | 945 | |
| 946 | if (nonrot) |
| 947 | blk_queue_flag_set(QUEUE_FLAG_NONROT, q); |
| 948 | else |
| 949 | blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); |
| 950 | } |
| 951 | |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 952 | /** |
| 953 | * loop_set_status_from_info - configure device from loop_info |
| 954 | * @lo: struct loop_device to configure |
| 955 | * @info: struct loop_info64 to configure the device with |
| 956 | * |
| 957 | * Configures the loop device parameters according to the passed |
| 958 | * in loop_info64 configuration. |
| 959 | */ |
| 960 | static int |
| 961 | loop_set_status_from_info(struct loop_device *lo, |
| 962 | const struct loop_info64 *info) |
| 963 | { |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 964 | if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) |
| 965 | return -EINVAL; |
| 966 | |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 967 | switch (info->lo_encrypt_type) { |
| 968 | case LO_CRYPT_NONE: |
| 969 | break; |
| 970 | case LO_CRYPT_XOR: |
| 971 | pr_warn("support for the xor transformation has been removed.\n"); |
| 972 | return -EINVAL; |
| 973 | case LO_CRYPT_CRYPTOAPI: |
| 974 | pr_warn("support for cryptoloop has been removed. Use dm-crypt instead.\n"); |
| 975 | return -EINVAL; |
| 976 | default: |
| 977 | return -EINVAL; |
| 978 | } |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 979 | |
Zhong Jinghua | 9f6ad5d | 2023-02-21 17:50:27 +0800 | [diff] [blame] | 980 | /* Avoid assigning overflow values */ |
| 981 | if (info->lo_offset > LLONG_MAX || info->lo_sizelimit > LLONG_MAX) |
| 982 | return -EOVERFLOW; |
| 983 | |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 984 | lo->lo_offset = info->lo_offset; |
| 985 | lo->lo_sizelimit = info->lo_sizelimit; |
Siddh Raman Pant | c490a0b | 2022-08-23 21:38:10 +0530 | [diff] [blame] | 986 | |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 987 | memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 988 | lo->lo_file_name[LO_NAME_SIZE-1] = 0; |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 989 | lo->lo_flags = info->lo_flags; |
Martijn Coenen | 62ab466 | 2020-05-13 15:38:42 +0200 | [diff] [blame] | 990 | return 0; |
| 991 | } |
| 992 | |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 993 | static int loop_configure(struct loop_device *lo, blk_mode_t mode, |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 994 | struct block_device *bdev, |
| 995 | const struct loop_config *config) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | { |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 997 | struct file *file = fget(config->fd); |
| 998 | struct inode *inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | struct address_space *mapping; |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 1000 | int error; |
| 1001 | loff_t size; |
| 1002 | bool partscan; |
| 1003 | unsigned short bsize; |
| 1004 | bool is_loop; |
| 1005 | |
| 1006 | if (!file) |
| 1007 | return -EBADF; |
| 1008 | is_loop = is_loop_device(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1009 | |
| 1010 | /* This is safe, since we have a reference from open(). */ |
| 1011 | __module_get(THIS_MODULE); |
| 1012 | |
Jan Kara | 33ec3e53 | 2019-05-16 16:01:27 +0200 | [diff] [blame] | 1013 | /* |
| 1014 | * If we don't hold exclusive handle for the device, upgrade to it |
| 1015 | * here to avoid changing device under exclusive owner. |
| 1016 | */ |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1017 | if (!(mode & BLK_OPEN_EXCL)) { |
Christoph Hellwig | 0718afd | 2023-06-01 11:44:52 +0200 | [diff] [blame] | 1018 | error = bd_prepare_to_claim(bdev, loop_configure, NULL); |
Christoph Hellwig | ecbe6bc | 2020-07-16 16:33:09 +0200 | [diff] [blame] | 1019 | if (error) |
Jan Kara | 33ec3e53 | 2019-05-16 16:01:27 +0200 | [diff] [blame] | 1020 | goto out_putf; |
| 1021 | } |
| 1022 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 1023 | error = loop_global_lock_killable(lo, is_loop); |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1024 | if (error) |
Jan Kara | 33ec3e53 | 2019-05-16 16:01:27 +0200 | [diff] [blame] | 1025 | goto out_bdev; |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1026 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | error = -EBUSY; |
| 1028 | if (lo->lo_state != Lo_unbound) |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1029 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | |
Theodore Ts'o | d2ac838 | 2018-05-07 11:37:58 -0400 | [diff] [blame] | 1031 | error = loop_validate_file(file, bdev); |
| 1032 | if (error) |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1033 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | |
| 1035 | mapping = file->f_mapping; |
| 1036 | inode = mapping->host; |
| 1037 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1038 | if ((config->info.lo_flags & ~LOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { |
| 1039 | error = -EINVAL; |
| 1040 | goto out_unlock; |
| 1041 | } |
| 1042 | |
| 1043 | if (config->block_size) { |
Xie Yongji | af3c570 | 2021-10-26 22:40:14 +0800 | [diff] [blame] | 1044 | error = blk_validate_block_size(config->block_size); |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1045 | if (error) |
| 1046 | goto out_unlock; |
| 1047 | } |
| 1048 | |
| 1049 | error = loop_set_status_from_info(lo, &config->info); |
| 1050 | if (error) |
| 1051 | goto out_unlock; |
| 1052 | |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1053 | if (!(file->f_mode & FMODE_WRITE) || !(mode & BLK_OPEN_WRITE) || |
Al Viro | 283e7e5 | 2015-04-03 15:21:59 -0400 | [diff] [blame] | 1054 | !file->f_op->write_iter) |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1055 | lo->lo_flags |= LO_FLAGS_READ_ONLY; |
Martijn Coenen | 083a6a5 | 2020-05-13 15:38:36 +0200 | [diff] [blame] | 1056 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1057 | if (!lo->workqueue) { |
Christoph Hellwig | d292dc8 | 2022-03-30 07:29:17 +0200 | [diff] [blame] | 1058 | lo->workqueue = alloc_workqueue("loop%d", |
| 1059 | WQ_UNBOUND | WQ_FREEZABLE, |
| 1060 | 0, lo->lo_number); |
| 1061 | if (!lo->workqueue) { |
| 1062 | error = -ENOMEM; |
| 1063 | goto out_unlock; |
| 1064 | } |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1065 | } |
Christoph Hellwig | 456be14 | 2011-10-17 12:57:20 +0200 | [diff] [blame] | 1066 | |
Alyssa Ross | bb430b6 | 2023-03-20 13:54:30 +0100 | [diff] [blame] | 1067 | /* suppress uevents while reconfiguring the device */ |
| 1068 | dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 1); |
| 1069 | |
Matteo Croce | 9f65c48 | 2021-07-13 01:05:30 +0200 | [diff] [blame] | 1070 | disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE); |
Christoph Hellwig | 7a2f0ce | 2020-11-03 11:00:16 +0100 | [diff] [blame] | 1071 | set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1072 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1073 | lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | lo->lo_device = bdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | lo->lo_backing_file = file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
| 1077 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); |
| 1078 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1079 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) |
Jens Axboe | 21d0727 | 2016-03-30 10:09:35 -0600 | [diff] [blame] | 1080 | blk_queue_write_cache(lo->lo_queue, true, false); |
Nikanth Karthikesan | 68db196 | 2009-03-24 12:29:54 +0100 | [diff] [blame] | 1081 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1082 | if (config->block_size) |
| 1083 | bsize = config->block_size; |
Linus Torvalds | 96ed320 | 2020-06-02 19:45:12 -0700 | [diff] [blame] | 1084 | else if ((lo->lo_backing_file->f_flags & O_DIRECT) && inode->i_sb->s_bdev) |
Martijn Coenen | 8556011 | 2019-09-04 21:49:01 +0200 | [diff] [blame] | 1085 | /* In case of direct I/O, match underlying block size */ |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1086 | bsize = bdev_logical_block_size(inode->i_sb->s_bdev); |
| 1087 | else |
| 1088 | bsize = 512; |
Martijn Coenen | 8556011 | 2019-09-04 21:49:01 +0200 | [diff] [blame] | 1089 | |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1090 | blk_queue_logical_block_size(lo->lo_queue, bsize); |
| 1091 | blk_queue_physical_block_size(lo->lo_queue, bsize); |
| 1092 | blk_queue_io_min(lo->lo_queue, bsize); |
Martijn Coenen | 8556011 | 2019-09-04 21:49:01 +0200 | [diff] [blame] | 1093 | |
Kristian Klausen | 2b9ac22 | 2021-06-18 13:51:57 +0200 | [diff] [blame] | 1094 | loop_config_discard(lo); |
Holger Hoffstätte | 56a85fd | 2019-02-12 15:54:24 -0700 | [diff] [blame] | 1095 | loop_update_rotational(lo); |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 1096 | loop_update_dio(lo); |
Milan Broz | ee86273 | 2010-08-23 15:16:00 +0200 | [diff] [blame] | 1097 | loop_sysfs_init(lo); |
Martijn Coenen | 79e5dc5 | 2020-08-25 09:18:29 +0200 | [diff] [blame] | 1098 | |
| 1099 | size = get_loop_size(lo, file); |
Martijn Coenen | 5795b6f | 2020-05-13 15:38:37 +0200 | [diff] [blame] | 1100 | loop_set_size(lo, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 1102 | /* Order wrt reading lo_state in loop_validate_file(). */ |
| 1103 | wmb(); |
| 1104 | |
Serge E. Hallyn | 6c99791 | 2006-09-29 01:59:11 -0700 | [diff] [blame] | 1105 | lo->lo_state = Lo_bound; |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 1106 | if (part_shift) |
| 1107 | lo->lo_flags |= LO_FLAGS_PARTSCAN; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1108 | partscan = lo->lo_flags & LO_FLAGS_PARTSCAN; |
Lennart Poettering | fe6a8fc | 2020-08-10 19:16:32 +0200 | [diff] [blame] | 1109 | if (partscan) |
Christoph Hellwig | b9684a7 | 2022-05-27 07:58:06 +0200 | [diff] [blame] | 1110 | clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); |
Anatol Pomozov | c1681bf | 2013-04-01 09:47:56 -0700 | [diff] [blame] | 1111 | |
Alyssa Ross | bb430b6 | 2023-03-20 13:54:30 +0100 | [diff] [blame] | 1112 | /* enable and uncork uevent now that we are done */ |
| 1113 | dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 0); |
| 1114 | |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 1115 | loop_global_unlock(lo, is_loop); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1116 | if (partscan) |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 1117 | loop_reread_partitions(lo); |
Alyssa Ross | bb430b6 | 2023-03-20 13:54:30 +0100 | [diff] [blame] | 1118 | |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1119 | if (!(mode & BLK_OPEN_EXCL)) |
Christoph Hellwig | 37c3fc9 | 2020-11-25 21:20:08 +0100 | [diff] [blame] | 1120 | bd_abort_claiming(bdev, loop_configure); |
Christoph Hellwig | 498ef5c | 2022-03-30 07:29:14 +0200 | [diff] [blame] | 1121 | |
Alyssa Ross | bb430b6 | 2023-03-20 13:54:30 +0100 | [diff] [blame] | 1122 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1124 | out_unlock: |
Tetsuo Handa | 3ce6e1f | 2021-07-06 23:40:34 +0900 | [diff] [blame] | 1125 | loop_global_unlock(lo, is_loop); |
Jan Kara | 33ec3e53 | 2019-05-16 16:01:27 +0200 | [diff] [blame] | 1126 | out_bdev: |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1127 | if (!(mode & BLK_OPEN_EXCL)) |
Christoph Hellwig | 37c3fc9 | 2020-11-25 21:20:08 +0100 | [diff] [blame] | 1128 | bd_abort_claiming(bdev, loop_configure); |
Jan Kara | 757ecf4 | 2018-11-08 14:01:10 +0100 | [diff] [blame] | 1129 | out_putf: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | fput(file); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1131 | /* This is safe: open() is still holding a reference. */ |
| 1132 | module_put(THIS_MODULE); |
Alyssa Ross | bb430b6 | 2023-03-20 13:54:30 +0100 | [diff] [blame] | 1133 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | } |
| 1135 | |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1136 | static void __loop_clr_fd(struct loop_device *lo, bool release) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | { |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1138 | struct file *filp; |
Al Viro | b4e3ca1 | 2005-10-21 03:22:34 -0400 | [diff] [blame] | 1139 | gfp_t gfp = lo->old_gfp_mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1140 | |
Mauricio Faria de Oliveira | 4ceddce | 2021-02-22 12:41:23 -0300 | [diff] [blame] | 1141 | if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags)) |
| 1142 | blk_queue_write_cache(lo->lo_queue, false, false); |
| 1143 | |
Christoph Hellwig | 1fe0b1a | 2022-03-30 07:29:12 +0200 | [diff] [blame] | 1144 | /* |
| 1145 | * Freeze the request queue when unbinding on a live file descriptor and |
| 1146 | * thus an open device. When called from ->release we are guaranteed |
| 1147 | * that there is no I/O in progress already. |
| 1148 | */ |
| 1149 | if (!release) |
| 1150 | blk_mq_freeze_queue(lo->lo_queue); |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1151 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | spin_lock_irq(&lo->lo_lock); |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1153 | filp = lo->lo_backing_file; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1154 | lo->lo_backing_file = NULL; |
Kay Sievers | 05eb0f2 | 2011-07-31 22:21:35 +0200 | [diff] [blame] | 1155 | spin_unlock_irq(&lo->lo_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | lo->lo_device = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | lo->lo_offset = 0; |
| 1159 | lo->lo_sizelimit = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1160 | memset(lo->lo_file_name, 0, LO_NAME_SIZE); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1161 | blk_queue_logical_block_size(lo->lo_queue, 512); |
Omar Sandoval | bf09375 | 2017-09-05 14:24:47 -0700 | [diff] [blame] | 1162 | blk_queue_physical_block_size(lo->lo_queue, 512); |
| 1163 | blk_queue_io_min(lo->lo_queue, 512); |
Xie Yongji | e515be8f3 | 2021-09-22 20:37:09 +0800 | [diff] [blame] | 1164 | invalidate_disk(lo->lo_disk); |
Milan Broz | 51a0bb0 | 2010-10-27 19:51:30 -0600 | [diff] [blame] | 1165 | loop_sysfs_exit(lo); |
Xie Yongji | 19f553d | 2021-09-22 20:37:10 +0800 | [diff] [blame] | 1166 | /* let user-space know about this change */ |
| 1167 | kobject_uevent(&disk_to_dev(lo->lo_disk)->kobj, KOBJ_CHANGE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1168 | mapping_set_gfp_mask(filp->f_mapping, gfp); |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1169 | /* This is safe: open() is still holding a reference. */ |
| 1170 | module_put(THIS_MODULE); |
Christoph Hellwig | 1fe0b1a | 2022-03-30 07:29:12 +0200 | [diff] [blame] | 1171 | if (!release) |
| 1172 | blk_mq_unfreeze_queue(lo->lo_queue); |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1173 | |
Matteo Croce | 9f65c48 | 2021-07-13 01:05:30 +0200 | [diff] [blame] | 1174 | disk_force_media_change(lo->lo_disk, DISK_EVENT_MEDIA_CHANGE); |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1175 | |
| 1176 | if (lo->lo_flags & LO_FLAGS_PARTSCAN) { |
| 1177 | int err; |
| 1178 | |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1179 | /* |
| 1180 | * open_mutex has been held already in release path, so don't |
| 1181 | * acquire it if this function is called in such case. |
| 1182 | * |
| 1183 | * If the reread partition isn't from release path, lo_refcnt |
| 1184 | * must be at least one and it can only become zero when the |
| 1185 | * current holder is released. |
| 1186 | */ |
| 1187 | if (!release) |
| 1188 | mutex_lock(&lo->lo_disk->open_mutex); |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 1189 | err = bdev_disk_changed(lo->lo_disk, false); |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1190 | if (!release) |
| 1191 | mutex_unlock(&lo->lo_disk->open_mutex); |
Dongli Zhang | 40853d6 | 2019-02-22 22:10:19 +0800 | [diff] [blame] | 1192 | if (err) |
| 1193 | pr_warn("%s: partition scan of loop%d failed (rc=%d)\n", |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1194 | __func__, lo->lo_number, err); |
Jan Kara | d57f337 | 2018-11-08 14:01:12 +0100 | [diff] [blame] | 1195 | /* Device is gone, no point in returning error */ |
Jan Kara | d57f337 | 2018-11-08 14:01:12 +0100 | [diff] [blame] | 1196 | } |
Dongli Zhang | 758a58d | 2019-02-22 22:10:20 +0800 | [diff] [blame] | 1197 | |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1198 | /* |
| 1199 | * lo->lo_state is set to Lo_unbound here after above partscan has |
| 1200 | * finished. There cannot be anybody else entering __loop_clr_fd() as |
| 1201 | * Lo_rundown state protects us from all the other places trying to |
| 1202 | * change the 'lo' device. |
| 1203 | */ |
Dongli Zhang | 758a58d | 2019-02-22 22:10:20 +0800 | [diff] [blame] | 1204 | lo->lo_flags = 0; |
| 1205 | if (!part_shift) |
Christoph Hellwig | b9684a7 | 2022-05-27 07:58:06 +0200 | [diff] [blame] | 1206 | set_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1207 | mutex_lock(&lo->lo_mutex); |
Dongli Zhang | 758a58d | 2019-02-22 22:10:20 +0800 | [diff] [blame] | 1208 | lo->lo_state = Lo_unbound; |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1209 | mutex_unlock(&lo->lo_mutex); |
Dongli Zhang | 758a58d | 2019-02-22 22:10:20 +0800 | [diff] [blame] | 1210 | |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1211 | /* |
| 1212 | * Need not hold lo_mutex to fput backing file. Calling fput holding |
| 1213 | * lo_mutex triggers a circular lock dependency possibility warning as |
| 1214 | * fput can take open_mutex which is usually taken before lo_mutex. |
| 1215 | */ |
| 1216 | fput(filp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | } |
| 1218 | |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1219 | static int loop_clr_fd(struct loop_device *lo) |
| 1220 | { |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1221 | int err; |
| 1222 | |
Tetsuo Handa | 158eaeb | 2022-03-30 07:29:15 +0200 | [diff] [blame] | 1223 | /* |
| 1224 | * Since lo_ioctl() is called without locks held, it is possible that |
| 1225 | * loop_configure()/loop_change_fd() and loop_clr_fd() run in parallel. |
| 1226 | * |
| 1227 | * Therefore, use global lock when setting Lo_rundown state in order to |
| 1228 | * make sure that loop_validate_file() will fail if the "struct file" |
| 1229 | * which loop_configure()/loop_change_fd() found via fget() was this |
| 1230 | * loop device. |
| 1231 | */ |
| 1232 | err = loop_global_lock_killable(lo, true); |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1233 | if (err) |
| 1234 | return err; |
| 1235 | if (lo->lo_state != Lo_bound) { |
Tetsuo Handa | 158eaeb | 2022-03-30 07:29:15 +0200 | [diff] [blame] | 1236 | loop_global_unlock(lo, true); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1237 | return -ENXIO; |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1238 | } |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1239 | /* |
| 1240 | * If we've explicitly asked to tear down the loop device, |
| 1241 | * and it has an elevated reference count, set it for auto-teardown when |
| 1242 | * the last reference goes away. This stops $!~#$@ udev from |
| 1243 | * preventing teardown because it decided that it needs to run blkid on |
| 1244 | * the loopback device whenever they appear. xfstests is notorious for |
| 1245 | * failing tests because blkid via udev races with a losetup |
| 1246 | * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d |
| 1247 | * command to fail with EBUSY. |
| 1248 | */ |
Christoph Hellwig | a0e286b | 2022-03-30 07:29:16 +0200 | [diff] [blame] | 1249 | if (disk_openers(lo->lo_disk) > 1) { |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1250 | lo->lo_flags |= LO_FLAGS_AUTOCLEAR; |
Tetsuo Handa | 158eaeb | 2022-03-30 07:29:15 +0200 | [diff] [blame] | 1251 | loop_global_unlock(lo, true); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1252 | return 0; |
| 1253 | } |
| 1254 | lo->lo_state = Lo_rundown; |
Tetsuo Handa | 158eaeb | 2022-03-30 07:29:15 +0200 | [diff] [blame] | 1255 | loop_global_unlock(lo, true); |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1256 | |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1257 | __loop_clr_fd(lo, false); |
Tetsuo Handa | 6050fa4 | 2021-11-24 19:47:40 +0900 | [diff] [blame] | 1258 | return 0; |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1259 | } |
| 1260 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1261 | static int |
| 1262 | loop_set_status(struct loop_device *lo, const struct loop_info64 *info) |
| 1263 | { |
| 1264 | int err; |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1265 | int prev_lo_flags; |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1266 | bool partscan = false; |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1267 | bool size_changed = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1269 | err = mutex_lock_killable(&lo->lo_mutex); |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1270 | if (err) |
| 1271 | return err; |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1272 | if (lo->lo_state != Lo_bound) { |
| 1273 | err = -ENXIO; |
| 1274 | goto out_unlock; |
| 1275 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1277 | if (lo->lo_offset != info->lo_offset || |
| 1278 | lo->lo_sizelimit != info->lo_sizelimit) { |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1279 | size_changed = true; |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1280 | sync_blockdev(lo->lo_device); |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1281 | invalidate_bdev(lo->lo_device); |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1282 | } |
| 1283 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1284 | /* I/O need to be drained during transfer transition */ |
| 1285 | blk_mq_freeze_queue(lo->lo_queue); |
| 1286 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1287 | prev_lo_flags = lo->lo_flags; |
| 1288 | |
Martijn Coenen | 0c3796c | 2020-05-13 15:38:41 +0200 | [diff] [blame] | 1289 | err = loop_set_status_from_info(lo, info); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1290 | if (err) |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1291 | goto out_unfreeze; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1293 | /* Mask out flags that can't be set using LOOP_SET_STATUS. */ |
Martijn Coenen | 6ac92fb | 2020-06-04 22:25:20 +0200 | [diff] [blame] | 1294 | lo->lo_flags &= LOOP_SET_STATUS_SETTABLE_FLAGS; |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1295 | /* For those flags, use the previous values instead */ |
| 1296 | lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_SETTABLE_FLAGS; |
| 1297 | /* For flags that can't be cleared, use previous values too */ |
| 1298 | lo->lo_flags |= prev_lo_flags & ~LOOP_SET_STATUS_CLEARABLE_FLAGS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1299 | |
Martijn Coenen | b0bd158 | 2020-05-13 15:38:39 +0200 | [diff] [blame] | 1300 | if (size_changed) { |
| 1301 | loff_t new_size = get_size(lo->lo_offset, lo->lo_sizelimit, |
| 1302 | lo->lo_backing_file); |
| 1303 | loop_set_size(lo, new_size); |
Arnd Bergmann | b040ad9 | 2017-06-09 12:19:18 +0200 | [diff] [blame] | 1304 | } |
Guo Chao | 541c742 | 2013-02-21 15:16:46 -0800 | [diff] [blame] | 1305 | |
Lukas Czerner | dfaa2ef | 2011-08-19 14:50:46 +0200 | [diff] [blame] | 1306 | loop_config_discard(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | |
Ming Lei | 2e5ab5f3 | 2015-08-17 10:31:49 +0800 | [diff] [blame] | 1308 | /* update dio if lo_offset or transfer is changed */ |
| 1309 | __loop_update_dio(lo, lo->use_dio); |
| 1310 | |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1311 | out_unfreeze: |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1312 | blk_mq_unfreeze_queue(lo->lo_queue); |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1313 | |
Martijn Coenen | faf1d25 | 2020-05-13 15:38:44 +0200 | [diff] [blame] | 1314 | if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) && |
| 1315 | !(prev_lo_flags & LO_FLAGS_PARTSCAN)) { |
Christoph Hellwig | b9684a7 | 2022-05-27 07:58:06 +0200 | [diff] [blame] | 1316 | clear_bit(GD_SUPPRESS_PART_SCAN, &lo->lo_disk->state); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1317 | partscan = true; |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1318 | } |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1319 | out_unlock: |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1320 | mutex_unlock(&lo->lo_mutex); |
Jan Kara | 85b0a54 | 2018-11-08 14:01:13 +0100 | [diff] [blame] | 1321 | if (partscan) |
Christoph Hellwig | 0384264 | 2021-06-24 14:32:40 +0200 | [diff] [blame] | 1322 | loop_reread_partitions(lo); |
Omar Sandoval | e02898b4 | 2017-03-01 10:42:38 -0800 | [diff] [blame] | 1323 | |
Ming Lei | ecdd095 | 2017-02-11 11:40:45 +0800 | [diff] [blame] | 1324 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | } |
| 1326 | |
| 1327 | static int |
| 1328 | loop_get_status(struct loop_device *lo, struct loop_info64 *info) |
| 1329 | { |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1330 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | struct kstat stat; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1332 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1333 | |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1334 | ret = mutex_lock_killable(&lo->lo_mutex); |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1335 | if (ret) |
| 1336 | return ret; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1337 | if (lo->lo_state != Lo_bound) { |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1338 | mutex_unlock(&lo->lo_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | return -ENXIO; |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1340 | } |
| 1341 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1342 | memset(info, 0, sizeof(*info)); |
| 1343 | info->lo_number = lo->lo_number; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | info->lo_offset = lo->lo_offset; |
| 1345 | info->lo_sizelimit = lo->lo_sizelimit; |
| 1346 | info->lo_flags = lo->lo_flags; |
| 1347 | memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1348 | |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1349 | /* Drop lo_mutex while we call into the filesystem. */ |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1350 | path = lo->lo_backing_file->f_path; |
| 1351 | path_get(&path); |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1352 | mutex_unlock(&lo->lo_mutex); |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1353 | ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT); |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1354 | if (!ret) { |
| 1355 | info->lo_device = huge_encode_dev(stat.dev); |
| 1356 | info->lo_inode = stat.ino; |
| 1357 | info->lo_rdevice = huge_encode_dev(stat.rdev); |
| 1358 | } |
Tetsuo Handa | b1ab5fa | 2018-11-08 14:01:01 +0100 | [diff] [blame] | 1359 | path_put(&path); |
Omar Sandoval | 2d1d4c1 | 2018-03-26 21:39:11 -0700 | [diff] [blame] | 1360 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1361 | } |
| 1362 | |
| 1363 | static void |
| 1364 | loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) |
| 1365 | { |
| 1366 | memset(info64, 0, sizeof(*info64)); |
| 1367 | info64->lo_number = info->lo_number; |
| 1368 | info64->lo_device = info->lo_device; |
| 1369 | info64->lo_inode = info->lo_inode; |
| 1370 | info64->lo_rdevice = info->lo_rdevice; |
| 1371 | info64->lo_offset = info->lo_offset; |
| 1372 | info64->lo_sizelimit = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | info64->lo_flags = info->lo_flags; |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1374 | memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | } |
| 1376 | |
| 1377 | static int |
| 1378 | loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) |
| 1379 | { |
| 1380 | memset(info, 0, sizeof(*info)); |
| 1381 | info->lo_number = info64->lo_number; |
| 1382 | info->lo_device = info64->lo_device; |
| 1383 | info->lo_inode = info64->lo_inode; |
| 1384 | info->lo_rdevice = info64->lo_rdevice; |
| 1385 | info->lo_offset = info64->lo_offset; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1386 | info->lo_flags = info64->lo_flags; |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1387 | memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | |
| 1389 | /* error in case values were truncated */ |
| 1390 | if (info->lo_device != info64->lo_device || |
| 1391 | info->lo_rdevice != info64->lo_rdevice || |
| 1392 | info->lo_inode != info64->lo_inode || |
| 1393 | info->lo_offset != info64->lo_offset) |
| 1394 | return -EOVERFLOW; |
| 1395 | |
| 1396 | return 0; |
| 1397 | } |
| 1398 | |
| 1399 | static int |
| 1400 | loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) |
| 1401 | { |
| 1402 | struct loop_info info; |
| 1403 | struct loop_info64 info64; |
| 1404 | |
| 1405 | if (copy_from_user(&info, arg, sizeof (struct loop_info))) |
| 1406 | return -EFAULT; |
| 1407 | loop_info64_from_old(&info, &info64); |
| 1408 | return loop_set_status(lo, &info64); |
| 1409 | } |
| 1410 | |
| 1411 | static int |
| 1412 | loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) |
| 1413 | { |
| 1414 | struct loop_info64 info64; |
| 1415 | |
| 1416 | if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) |
| 1417 | return -EFAULT; |
| 1418 | return loop_set_status(lo, &info64); |
| 1419 | } |
| 1420 | |
| 1421 | static int |
| 1422 | loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { |
| 1423 | struct loop_info info; |
| 1424 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1425 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1427 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1428 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1429 | err = loop_get_status(lo, &info64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | if (!err) |
| 1431 | err = loop_info64_to_old(&info64, &info); |
| 1432 | if (!err && copy_to_user(arg, &info, sizeof(info))) |
| 1433 | err = -EFAULT; |
| 1434 | |
| 1435 | return err; |
| 1436 | } |
| 1437 | |
| 1438 | static int |
| 1439 | loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { |
| 1440 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1441 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1442 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1443 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1444 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1445 | err = loop_get_status(lo, &info64); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | if (!err && copy_to_user(arg, &info64, sizeof(info64))) |
| 1447 | err = -EFAULT; |
| 1448 | |
| 1449 | return err; |
| 1450 | } |
| 1451 | |
Hannes Reinecke | 51001b7 | 2017-06-08 13:46:44 +0200 | [diff] [blame] | 1452 | static int loop_set_capacity(struct loop_device *lo) |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1453 | { |
Martijn Coenen | 0a6ed1b | 2020-05-13 15:38:40 +0200 | [diff] [blame] | 1454 | loff_t size; |
| 1455 | |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1456 | if (unlikely(lo->lo_state != Lo_bound)) |
Guo Chao | 7b0576a | 2013-02-21 15:16:47 -0800 | [diff] [blame] | 1457 | return -ENXIO; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1458 | |
Martijn Coenen | 0a6ed1b | 2020-05-13 15:38:40 +0200 | [diff] [blame] | 1459 | size = get_loop_size(lo, lo->lo_backing_file); |
| 1460 | loop_set_size(lo, size); |
Martijn Coenen | 083a6a5 | 2020-05-13 15:38:36 +0200 | [diff] [blame] | 1461 | |
| 1462 | return 0; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1463 | } |
| 1464 | |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1465 | static int loop_set_dio(struct loop_device *lo, unsigned long arg) |
| 1466 | { |
| 1467 | int error = -ENXIO; |
| 1468 | if (lo->lo_state != Lo_bound) |
| 1469 | goto out; |
| 1470 | |
| 1471 | __loop_update_dio(lo, !!arg); |
| 1472 | if (lo->use_dio == !!arg) |
| 1473 | return 0; |
| 1474 | error = -EINVAL; |
| 1475 | out: |
| 1476 | return error; |
| 1477 | } |
| 1478 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1479 | static int loop_set_block_size(struct loop_device *lo, unsigned long arg) |
| 1480 | { |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1481 | int err = 0; |
| 1482 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1483 | if (lo->lo_state != Lo_bound) |
| 1484 | return -ENXIO; |
| 1485 | |
Xie Yongji | af3c570 | 2021-10-26 22:40:14 +0800 | [diff] [blame] | 1486 | err = blk_validate_block_size(arg); |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1487 | if (err) |
| 1488 | return err; |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1489 | |
Martijn Coenen | 7e81f99 | 2020-03-10 14:12:30 +0100 | [diff] [blame] | 1490 | if (lo->lo_queue->limits.logical_block_size == arg) |
| 1491 | return 0; |
| 1492 | |
| 1493 | sync_blockdev(lo->lo_device); |
Zheng Bin | f4bd34b | 2020-06-18 12:21:37 +0800 | [diff] [blame] | 1494 | invalidate_bdev(lo->lo_device); |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1495 | |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1496 | blk_mq_freeze_queue(lo->lo_queue); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1497 | blk_queue_logical_block_size(lo->lo_queue, arg); |
Omar Sandoval | bf09375 | 2017-09-05 14:24:47 -0700 | [diff] [blame] | 1498 | blk_queue_physical_block_size(lo->lo_queue, arg); |
| 1499 | blk_queue_io_min(lo->lo_queue, arg); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1500 | loop_update_dio(lo); |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1501 | blk_mq_unfreeze_queue(lo->lo_queue); |
| 1502 | |
Jaegeuk Kim | 5db470e | 2019-01-09 19:17:14 -0800 | [diff] [blame] | 1503 | return err; |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1504 | } |
| 1505 | |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1506 | static int lo_simple_ioctl(struct loop_device *lo, unsigned int cmd, |
| 1507 | unsigned long arg) |
| 1508 | { |
| 1509 | int err; |
| 1510 | |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1511 | err = mutex_lock_killable(&lo->lo_mutex); |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1512 | if (err) |
| 1513 | return err; |
| 1514 | switch (cmd) { |
| 1515 | case LOOP_SET_CAPACITY: |
| 1516 | err = loop_set_capacity(lo); |
| 1517 | break; |
| 1518 | case LOOP_SET_DIRECT_IO: |
| 1519 | err = loop_set_dio(lo, arg); |
| 1520 | break; |
| 1521 | case LOOP_SET_BLOCK_SIZE: |
| 1522 | err = loop_set_block_size(lo, arg); |
| 1523 | break; |
| 1524 | default: |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1525 | err = -EINVAL; |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1526 | } |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1527 | mutex_unlock(&lo->lo_mutex); |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1528 | return err; |
| 1529 | } |
| 1530 | |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1531 | static int lo_ioctl(struct block_device *bdev, blk_mode_t mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1532 | unsigned int cmd, unsigned long arg) |
| 1533 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1534 | struct loop_device *lo = bdev->bd_disk->private_data; |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1535 | void __user *argp = (void __user *) arg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1536 | int err; |
| 1537 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1538 | switch (cmd) { |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1539 | case LOOP_SET_FD: { |
| 1540 | /* |
| 1541 | * Legacy case - pass in a zeroed out struct loop_config with |
| 1542 | * only the file descriptor set , which corresponds with the |
| 1543 | * default parameters we'd have used otherwise. |
| 1544 | */ |
| 1545 | struct loop_config config; |
| 1546 | |
| 1547 | memset(&config, 0, sizeof(config)); |
| 1548 | config.fd = arg; |
| 1549 | |
| 1550 | return loop_configure(lo, mode, bdev, &config); |
| 1551 | } |
| 1552 | case LOOP_CONFIGURE: { |
| 1553 | struct loop_config config; |
| 1554 | |
| 1555 | if (copy_from_user(&config, argp, sizeof(config))) |
| 1556 | return -EFAULT; |
| 1557 | |
| 1558 | return loop_configure(lo, mode, bdev, &config); |
| 1559 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1560 | case LOOP_CHANGE_FD: |
Jan Kara | c371077 | 2018-11-08 14:01:11 +0100 | [diff] [blame] | 1561 | return loop_change_fd(lo, bdev, arg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | case LOOP_CLR_FD: |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1563 | return loop_clr_fd(lo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | case LOOP_SET_STATUS: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1565 | err = -EPERM; |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1566 | if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN)) |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1567 | err = loop_set_status_old(lo, argp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1568 | break; |
| 1569 | case LOOP_GET_STATUS: |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1570 | return loop_get_status_old(lo, argp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1571 | case LOOP_SET_STATUS64: |
Dmitry Monakhov | 7035b5d | 2011-11-16 09:21:49 +0100 | [diff] [blame] | 1572 | err = -EPERM; |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1573 | if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN)) |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1574 | err = loop_set_status64(lo, argp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | break; |
| 1576 | case LOOP_GET_STATUS64: |
Martijn Coenen | 571fae6 | 2020-05-13 15:38:43 +0200 | [diff] [blame] | 1577 | return loop_get_status64(lo, argp); |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1578 | case LOOP_SET_CAPACITY: |
Ming Lei | ab1cb27 | 2015-08-17 10:31:50 +0800 | [diff] [blame] | 1579 | case LOOP_SET_DIRECT_IO: |
Omar Sandoval | 89e4fde | 2017-08-24 00:03:43 -0700 | [diff] [blame] | 1580 | case LOOP_SET_BLOCK_SIZE: |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1581 | if (!(mode & BLK_OPEN_WRITE) && !capable(CAP_SYS_ADMIN)) |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1582 | return -EPERM; |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1583 | fallthrough; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | default: |
Jan Kara | a131654 | 2018-11-08 14:01:05 +0100 | [diff] [blame] | 1585 | err = lo_simple_ioctl(lo, cmd, arg); |
| 1586 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1587 | } |
Nikanth Karthikesan | f028f3b | 2009-03-24 12:33:41 +0100 | [diff] [blame] | 1588 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1589 | return err; |
| 1590 | } |
| 1591 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1592 | #ifdef CONFIG_COMPAT |
| 1593 | struct compat_loop_info { |
| 1594 | compat_int_t lo_number; /* ioctl r/o */ |
| 1595 | compat_dev_t lo_device; /* ioctl r/o */ |
| 1596 | compat_ulong_t lo_inode; /* ioctl r/o */ |
| 1597 | compat_dev_t lo_rdevice; /* ioctl r/o */ |
| 1598 | compat_int_t lo_offset; |
Carlos Llamas | f941c51 | 2022-03-29 20:18:15 +0000 | [diff] [blame] | 1599 | compat_int_t lo_encrypt_type; /* obsolete, ignored */ |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1600 | compat_int_t lo_encrypt_key_size; /* ioctl w/o */ |
| 1601 | compat_int_t lo_flags; /* ioctl r/o */ |
| 1602 | char lo_name[LO_NAME_SIZE]; |
| 1603 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ |
| 1604 | compat_ulong_t lo_init[2]; |
| 1605 | char reserved[4]; |
| 1606 | }; |
| 1607 | |
| 1608 | /* |
| 1609 | * Transfer 32-bit compatibility structure in userspace to 64-bit loop info |
| 1610 | * - noinlined to reduce stack space usage in main part of driver |
| 1611 | */ |
| 1612 | static noinline int |
Al Viro | ba674cf | 2006-10-10 22:48:27 +0100 | [diff] [blame] | 1613 | loop_info64_from_compat(const struct compat_loop_info __user *arg, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1614 | struct loop_info64 *info64) |
| 1615 | { |
| 1616 | struct compat_loop_info info; |
| 1617 | |
| 1618 | if (copy_from_user(&info, arg, sizeof(info))) |
| 1619 | return -EFAULT; |
| 1620 | |
| 1621 | memset(info64, 0, sizeof(*info64)); |
| 1622 | info64->lo_number = info.lo_number; |
| 1623 | info64->lo_device = info.lo_device; |
| 1624 | info64->lo_inode = info.lo_inode; |
| 1625 | info64->lo_rdevice = info.lo_rdevice; |
| 1626 | info64->lo_offset = info.lo_offset; |
| 1627 | info64->lo_sizelimit = 0; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1628 | info64->lo_flags = info.lo_flags; |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1629 | memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1630 | return 0; |
| 1631 | } |
| 1632 | |
| 1633 | /* |
| 1634 | * Transfer 64-bit loop info to 32-bit compatibility structure in userspace |
| 1635 | * - noinlined to reduce stack space usage in main part of driver |
| 1636 | */ |
| 1637 | static noinline int |
| 1638 | loop_info64_to_compat(const struct loop_info64 *info64, |
| 1639 | struct compat_loop_info __user *arg) |
| 1640 | { |
| 1641 | struct compat_loop_info info; |
| 1642 | |
| 1643 | memset(&info, 0, sizeof(info)); |
| 1644 | info.lo_number = info64->lo_number; |
| 1645 | info.lo_device = info64->lo_device; |
| 1646 | info.lo_inode = info64->lo_inode; |
| 1647 | info.lo_rdevice = info64->lo_rdevice; |
| 1648 | info.lo_offset = info64->lo_offset; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1649 | info.lo_flags = info64->lo_flags; |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1650 | memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1651 | |
| 1652 | /* error in case values were truncated */ |
| 1653 | if (info.lo_device != info64->lo_device || |
| 1654 | info.lo_rdevice != info64->lo_rdevice || |
| 1655 | info.lo_inode != info64->lo_inode || |
Christoph Hellwig | 47e9624 | 2021-10-19 09:56:39 +0200 | [diff] [blame] | 1656 | info.lo_offset != info64->lo_offset) |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1657 | return -EOVERFLOW; |
| 1658 | |
| 1659 | if (copy_to_user(arg, &info, sizeof(info))) |
| 1660 | return -EFAULT; |
| 1661 | return 0; |
| 1662 | } |
| 1663 | |
| 1664 | static int |
| 1665 | loop_set_status_compat(struct loop_device *lo, |
| 1666 | const struct compat_loop_info __user *arg) |
| 1667 | { |
| 1668 | struct loop_info64 info64; |
| 1669 | int ret; |
| 1670 | |
| 1671 | ret = loop_info64_from_compat(arg, &info64); |
| 1672 | if (ret < 0) |
| 1673 | return ret; |
| 1674 | return loop_set_status(lo, &info64); |
| 1675 | } |
| 1676 | |
| 1677 | static int |
| 1678 | loop_get_status_compat(struct loop_device *lo, |
| 1679 | struct compat_loop_info __user *arg) |
| 1680 | { |
| 1681 | struct loop_info64 info64; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1682 | int err; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1683 | |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1684 | if (!arg) |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1685 | return -EINVAL; |
Omar Sandoval | bdac616db | 2018-04-06 09:57:03 -0700 | [diff] [blame] | 1686 | err = loop_get_status(lo, &info64); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1687 | if (!err) |
| 1688 | err = loop_info64_to_compat(&info64, arg); |
| 1689 | return err; |
| 1690 | } |
| 1691 | |
Christoph Hellwig | 05bdb99 | 2023-06-08 13:02:55 +0200 | [diff] [blame] | 1692 | static int lo_compat_ioctl(struct block_device *bdev, blk_mode_t mode, |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1693 | unsigned int cmd, unsigned long arg) |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1694 | { |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1695 | struct loop_device *lo = bdev->bd_disk->private_data; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1696 | int err; |
| 1697 | |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1698 | switch(cmd) { |
| 1699 | case LOOP_SET_STATUS: |
Jan Kara | 550df5fd | 2018-11-08 14:01:09 +0100 | [diff] [blame] | 1700 | err = loop_set_status_compat(lo, |
| 1701 | (const struct compat_loop_info __user *)arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1702 | break; |
| 1703 | case LOOP_GET_STATUS: |
Jan Kara | 4a5ce9b | 2018-11-08 14:01:08 +0100 | [diff] [blame] | 1704 | err = loop_get_status_compat(lo, |
| 1705 | (struct compat_loop_info __user *)arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1706 | break; |
J. R. Okajima | 53d6660 | 2009-03-31 15:23:43 -0700 | [diff] [blame] | 1707 | case LOOP_SET_CAPACITY: |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1708 | case LOOP_CLR_FD: |
| 1709 | case LOOP_GET_STATUS64: |
| 1710 | case LOOP_SET_STATUS64: |
Martijn Coenen | 3448914 | 2020-05-13 15:38:45 +0200 | [diff] [blame] | 1711 | case LOOP_CONFIGURE: |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1712 | arg = (unsigned long) compat_ptr(arg); |
Gustavo A. R. Silva | df561f66 | 2020-08-23 17:36:59 -0500 | [diff] [blame] | 1713 | fallthrough; |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1714 | case LOOP_SET_FD: |
| 1715 | case LOOP_CHANGE_FD: |
Evan Green | 9fea4b3 | 2018-07-02 16:03:46 -0700 | [diff] [blame] | 1716 | case LOOP_SET_BLOCK_SIZE: |
Alessio Balsini | fdbe4ee | 2019-08-07 01:48:28 +0100 | [diff] [blame] | 1717 | case LOOP_SET_DIRECT_IO: |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1718 | err = lo_ioctl(bdev, mode, cmd, arg); |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1719 | break; |
| 1720 | default: |
| 1721 | err = -ENOIOCTLCMD; |
| 1722 | break; |
| 1723 | } |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1724 | return err; |
| 1725 | } |
| 1726 | #endif |
| 1727 | |
Christoph Hellwig | ae22076 | 2023-06-08 13:02:37 +0200 | [diff] [blame] | 1728 | static void lo_release(struct gendisk *disk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1729 | { |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1730 | struct loop_device *lo = disk->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1731 | |
Christoph Hellwig | a0e286b | 2022-03-30 07:29:16 +0200 | [diff] [blame] | 1732 | if (disk_openers(disk) > 0) |
| 1733 | return; |
Ming Lei | f893366 | 2015-05-06 12:26:23 +0800 | [diff] [blame] | 1734 | |
Christoph Hellwig | a0e286b | 2022-03-30 07:29:16 +0200 | [diff] [blame] | 1735 | mutex_lock(&lo->lo_mutex); |
| 1736 | if (lo->lo_state == Lo_bound && (lo->lo_flags & LO_FLAGS_AUTOCLEAR)) { |
Jan Kara | a2505b7 | 2018-11-08 14:01:06 +0100 | [diff] [blame] | 1737 | lo->lo_state = Lo_rundown; |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1738 | mutex_unlock(&lo->lo_mutex); |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1739 | /* |
| 1740 | * In autoclear mode, stop the loop thread |
| 1741 | * and remove configuration after last close. |
| 1742 | */ |
Tetsuo Handa | bf23747 | 2022-02-11 16:15:54 +0900 | [diff] [blame] | 1743 | __loop_clr_fd(lo, true); |
Jan Kara | 7ccd079 | 2018-11-08 14:01:07 +0100 | [diff] [blame] | 1744 | return; |
Milan Broz | 14f2793 | 2008-12-12 14:48:27 +0100 | [diff] [blame] | 1745 | } |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 1746 | mutex_unlock(&lo->lo_mutex); |
Linus Torvalds | ae66501 | 2018-01-05 16:26:00 -0800 | [diff] [blame] | 1747 | } |
| 1748 | |
Christoph Hellwig | d2c7f56 | 2022-03-30 07:29:13 +0200 | [diff] [blame] | 1749 | static void lo_free_disk(struct gendisk *disk) |
| 1750 | { |
| 1751 | struct loop_device *lo = disk->private_data; |
| 1752 | |
Christoph Hellwig | d292dc8 | 2022-03-30 07:29:17 +0200 | [diff] [blame] | 1753 | if (lo->workqueue) |
| 1754 | destroy_workqueue(lo->workqueue); |
| 1755 | loop_free_idle_workers(lo, true); |
Steven Rostedt (Google) | 292a089 | 2022-12-20 13:45:19 -0500 | [diff] [blame] | 1756 | timer_shutdown_sync(&lo->timer); |
Christoph Hellwig | d2c7f56 | 2022-03-30 07:29:13 +0200 | [diff] [blame] | 1757 | mutex_destroy(&lo->lo_mutex); |
| 1758 | kfree(lo); |
| 1759 | } |
| 1760 | |
Alexey Dobriyan | 83d5cde | 2009-09-21 17:01:13 -0700 | [diff] [blame] | 1761 | static const struct block_device_operations lo_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1762 | .owner = THIS_MODULE, |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1763 | .release = lo_release, |
| 1764 | .ioctl = lo_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1765 | #ifdef CONFIG_COMPAT |
Al Viro | bb21488 | 2008-03-02 09:29:48 -0500 | [diff] [blame] | 1766 | .compat_ioctl = lo_compat_ioctl, |
David Howells | 863d5b82 | 2006-08-29 19:06:14 +0100 | [diff] [blame] | 1767 | #endif |
Christoph Hellwig | d2c7f56 | 2022-03-30 07:29:13 +0200 | [diff] [blame] | 1768 | .free_disk = lo_free_disk, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1769 | }; |
| 1770 | |
| 1771 | /* |
| 1772 | * And now the modules code and kernel interface. |
| 1773 | */ |
Isaac J. Manjarres | 85c5019 | 2022-12-08 13:29:01 -0800 | [diff] [blame] | 1774 | |
| 1775 | /* |
| 1776 | * If max_loop is specified, create that many devices upfront. |
| 1777 | * This also becomes a hard limit. If max_loop is not specified, |
| 1778 | * create CONFIG_BLK_DEV_LOOP_MIN_COUNT loop devices at module |
| 1779 | * init time. Loop devices can be requested on-demand with the |
| 1780 | * /dev/loop-control interface, or be instantiated by accessing |
| 1781 | * a 'dead' device node. |
| 1782 | */ |
| 1783 | static int max_loop = CONFIG_BLK_DEV_LOOP_MIN_COUNT; |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 1784 | module_param(max_loop, int, 0444); |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 1785 | MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); |
Joe Perches | 5657a81 | 2018-05-24 13:38:59 -0600 | [diff] [blame] | 1786 | module_param(max_part, int, 0444); |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 1787 | MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); |
Chaitanya Kulkarni | ef44c50 | 2022-02-15 13:33:10 -0800 | [diff] [blame] | 1788 | |
| 1789 | static int hw_queue_depth = LOOP_DEFAULT_HW_Q_DEPTH; |
| 1790 | |
| 1791 | static int loop_set_hw_queue_depth(const char *s, const struct kernel_param *p) |
| 1792 | { |
Bart Van Assche | e152a05 | 2023-01-30 13:13:47 -0800 | [diff] [blame] | 1793 | int qd, ret; |
Chaitanya Kulkarni | ef44c50 | 2022-02-15 13:33:10 -0800 | [diff] [blame] | 1794 | |
Bart Van Assche | e152a05 | 2023-01-30 13:13:47 -0800 | [diff] [blame] | 1795 | ret = kstrtoint(s, 0, &qd); |
| 1796 | if (ret < 0) |
| 1797 | return ret; |
| 1798 | if (qd < 1) |
| 1799 | return -EINVAL; |
| 1800 | hw_queue_depth = qd; |
| 1801 | return 0; |
Chaitanya Kulkarni | ef44c50 | 2022-02-15 13:33:10 -0800 | [diff] [blame] | 1802 | } |
| 1803 | |
| 1804 | static const struct kernel_param_ops loop_hw_qdepth_param_ops = { |
| 1805 | .set = loop_set_hw_queue_depth, |
| 1806 | .get = param_get_int, |
| 1807 | }; |
| 1808 | |
| 1809 | device_param_cb(hw_queue_depth, &loop_hw_qdepth_param_ops, &hw_queue_depth, 0444); |
Bart Van Assche | e152a05 | 2023-01-30 13:13:47 -0800 | [diff] [blame] | 1810 | MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: " __stringify(LOOP_DEFAULT_HW_Q_DEPTH)); |
Chaitanya Kulkarni | ef44c50 | 2022-02-15 13:33:10 -0800 | [diff] [blame] | 1811 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1812 | MODULE_LICENSE("GPL"); |
| 1813 | MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); |
| 1814 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1815 | static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1816 | const struct blk_mq_queue_data *bd) |
| 1817 | { |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 1818 | struct request *rq = bd->rq; |
| 1819 | struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq); |
| 1820 | struct loop_device *lo = rq->q->queuedata; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1821 | |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 1822 | blk_mq_start_request(rq); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1823 | |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 1824 | if (lo->lo_state != Lo_bound) |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1825 | return BLK_STS_IOERR; |
Ming Lei | f4aa4c7 | 2015-05-05 19:49:54 +0800 | [diff] [blame] | 1826 | |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 1827 | switch (req_op(rq)) { |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 1828 | case REQ_OP_FLUSH: |
| 1829 | case REQ_OP_DISCARD: |
Christoph Hellwig | 19372e2 | 2017-04-05 19:21:15 +0200 | [diff] [blame] | 1830 | case REQ_OP_WRITE_ZEROES: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1831 | cmd->use_aio = false; |
Christoph Hellwig | f0225ca | 2016-08-04 16:10:00 +0200 | [diff] [blame] | 1832 | break; |
| 1833 | default: |
| 1834 | cmd->use_aio = lo->use_dio; |
| 1835 | break; |
| 1836 | } |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1837 | |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 1838 | /* always use the first bio's css */ |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1839 | cmd->blkcg_css = NULL; |
| 1840 | cmd->memcg_css = NULL; |
Shaohua Li | 0b508bc | 2017-09-26 11:02:12 -0700 | [diff] [blame] | 1841 | #ifdef CONFIG_BLK_CGROUP |
Christoph Hellwig | bbb1ebe | 2022-04-20 06:27:17 +0200 | [diff] [blame] | 1842 | if (rq->bio) { |
| 1843 | cmd->blkcg_css = bio_blkcg_css(rq->bio); |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1844 | #ifdef CONFIG_MEMCG |
Christoph Hellwig | bbb1ebe | 2022-04-20 06:27:17 +0200 | [diff] [blame] | 1845 | if (cmd->blkcg_css) { |
| 1846 | cmd->memcg_css = |
| 1847 | cgroup_get_e_css(cmd->blkcg_css->cgroup, |
| 1848 | &memory_cgrp_subsys); |
| 1849 | } |
Shaohua Li | d4478e9 | 2017-09-25 13:07:22 -0600 | [diff] [blame] | 1850 | #endif |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1851 | } |
| 1852 | #endif |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1853 | loop_queue_work(lo, cmd); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1854 | |
Christoph Hellwig | fc17b65 | 2017-06-03 09:38:05 +0200 | [diff] [blame] | 1855 | return BLK_STS_OK; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1856 | } |
| 1857 | |
| 1858 | static void loop_handle_cmd(struct loop_cmd *cmd) |
| 1859 | { |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1860 | struct cgroup_subsys_state *cmd_blkcg_css = cmd->blkcg_css; |
| 1861 | struct cgroup_subsys_state *cmd_memcg_css = cmd->memcg_css; |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 1862 | struct request *rq = blk_mq_rq_from_pdu(cmd); |
| 1863 | const bool write = op_is_write(req_op(rq)); |
| 1864 | struct loop_device *lo = rq->q->queuedata; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1865 | int ret = 0; |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1866 | struct mem_cgroup *old_memcg = NULL; |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1867 | const bool use_aio = cmd->use_aio; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1868 | |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1869 | if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { |
| 1870 | ret = -EIO; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1871 | goto failed; |
Christoph Hellwig | f4829a9 | 2015-09-27 21:01:50 +0200 | [diff] [blame] | 1872 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1873 | |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1874 | if (cmd_blkcg_css) |
| 1875 | kthread_associate_blkcg(cmd_blkcg_css); |
| 1876 | if (cmd_memcg_css) |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1877 | old_memcg = set_active_memcg( |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1878 | mem_cgroup_from_css(cmd_memcg_css)); |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1879 | |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1880 | /* |
| 1881 | * do_req_filebacked() may call blk_mq_complete_request() synchronously |
| 1882 | * or asynchronously if using aio. Hence, do not touch 'cmd' after |
| 1883 | * do_req_filebacked() has returned unless we are sure that 'cmd' has |
| 1884 | * not yet been completed. |
| 1885 | */ |
Jens Axboe | 1894e916 | 2018-04-13 16:24:29 -0600 | [diff] [blame] | 1886 | ret = do_req_filebacked(lo, rq); |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1887 | |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1888 | if (cmd_blkcg_css) |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1889 | kthread_associate_blkcg(NULL); |
| 1890 | |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1891 | if (cmd_memcg_css) { |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1892 | set_active_memcg(old_memcg); |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1893 | css_put(cmd_memcg_css); |
Dan Schatzberg | c74d40e | 2021-06-28 19:38:21 -0700 | [diff] [blame] | 1894 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1895 | failed: |
Ming Lei | bc07c10 | 2015-08-17 10:31:51 +0800 | [diff] [blame] | 1896 | /* complete non-aio request */ |
Bart Van Assche | 9b0cb77 | 2023-03-14 11:21:54 -0700 | [diff] [blame] | 1897 | if (!use_aio || ret) { |
Evan Green | 8cd5508 | 2020-04-03 16:43:03 +0200 | [diff] [blame] | 1898 | if (ret == -EOPNOTSUPP) |
| 1899 | cmd->ret = ret; |
| 1900 | else |
| 1901 | cmd->ret = ret ? -EIO : 0; |
Christoph Hellwig | 15f73f5 | 2020-06-11 08:44:47 +0200 | [diff] [blame] | 1902 | if (likely(!blk_should_fake_timeout(rq->q))) |
| 1903 | blk_mq_complete_request(rq); |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 1904 | } |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1905 | } |
| 1906 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1907 | static void loop_process_work(struct loop_worker *worker, |
| 1908 | struct list_head *cmd_list, struct loop_device *lo) |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1909 | { |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1910 | int orig_flags = current->flags; |
| 1911 | struct loop_cmd *cmd; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1912 | |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 1913 | current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; |
| 1914 | spin_lock_irq(&lo->lo_work_lock); |
| 1915 | while (!list_empty(cmd_list)) { |
| 1916 | cmd = container_of( |
| 1917 | cmd_list->next, struct loop_cmd, list_entry); |
| 1918 | list_del(cmd_list->next); |
| 1919 | spin_unlock_irq(&lo->lo_work_lock); |
| 1920 | |
| 1921 | loop_handle_cmd(cmd); |
| 1922 | cond_resched(); |
| 1923 | |
| 1924 | spin_lock_irq(&lo->lo_work_lock); |
| 1925 | } |
| 1926 | |
| 1927 | /* |
| 1928 | * We only add to the idle list if there are no pending cmds |
| 1929 | * *and* the worker will not run again which ensures that it |
| 1930 | * is safe to free any worker on the idle list |
| 1931 | */ |
| 1932 | if (worker && !work_pending(&worker->work)) { |
| 1933 | worker->last_ran_at = jiffies; |
| 1934 | list_add_tail(&worker->idle_list, &lo->idle_worker_list); |
| 1935 | loop_set_timer(lo); |
| 1936 | } |
| 1937 | spin_unlock_irq(&lo->lo_work_lock); |
| 1938 | current->flags = orig_flags; |
| 1939 | } |
| 1940 | |
| 1941 | static void loop_workfn(struct work_struct *work) |
| 1942 | { |
| 1943 | struct loop_worker *worker = |
| 1944 | container_of(work, struct loop_worker, work); |
| 1945 | loop_process_work(worker, &worker->cmd_list, worker->lo); |
| 1946 | } |
| 1947 | |
| 1948 | static void loop_rootcg_workfn(struct work_struct *work) |
| 1949 | { |
| 1950 | struct loop_device *lo = |
| 1951 | container_of(work, struct loop_device, rootcg_work); |
| 1952 | loop_process_work(NULL, &lo->rootcg_cmd_list, lo); |
| 1953 | } |
| 1954 | |
Eric Biggers | f363b08 | 2017-03-30 13:39:16 -0700 | [diff] [blame] | 1955 | static const struct blk_mq_ops loop_mq_ops = { |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1956 | .queue_rq = loop_queue_rq, |
Christoph Hellwig | fe2cb29 | 2017-04-20 16:03:02 +0200 | [diff] [blame] | 1957 | .complete = lo_complete_rq, |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1958 | }; |
| 1959 | |
Christoph Hellwig | d6da83d | 2021-06-23 16:59:02 +0200 | [diff] [blame] | 1960 | static int loop_add(int i) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1961 | { |
| 1962 | struct loop_device *lo; |
| 1963 | struct gendisk *disk; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1964 | int err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1965 | |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 1966 | err = -ENOMEM; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1967 | lo = kzalloc(sizeof(*lo), GFP_KERNEL); |
Silva Paulo | 68d740d | 2012-07-14 15:39:58 -0700 | [diff] [blame] | 1968 | if (!lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1969 | goto out; |
Christoph Hellwig | b15ed54 | 2022-03-30 07:29:09 +0200 | [diff] [blame] | 1970 | lo->worker_tree = RB_ROOT; |
| 1971 | INIT_LIST_HEAD(&lo->idle_worker_list); |
| 1972 | timer_setup(&lo->timer, loop_free_idle_workers_timer, TIMER_DEFERRABLE); |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 1973 | lo->lo_state = Lo_unbound; |
| 1974 | |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 1975 | err = mutex_lock_killable(&loop_ctl_mutex); |
| 1976 | if (err) |
| 1977 | goto out_free_dev; |
| 1978 | |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1979 | /* allocate id, if @id >= 0, we're requesting that specific id */ |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1980 | if (i >= 0) { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1981 | err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL); |
| 1982 | if (err == -ENOSPC) |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1983 | err = -EEXIST; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1984 | } else { |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1985 | err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1986 | } |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 1987 | mutex_unlock(&loop_ctl_mutex); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 1988 | if (err < 0) |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 1989 | goto out_free_dev; |
Tejun Heo | c718aa6 | 2013-02-27 17:03:58 -0800 | [diff] [blame] | 1990 | i = err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 1991 | |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1992 | lo->tag_set.ops = &loop_mq_ops; |
| 1993 | lo->tag_set.nr_hw_queues = 1; |
Chaitanya Kulkarni | ef44c50 | 2022-02-15 13:33:10 -0800 | [diff] [blame] | 1994 | lo->tag_set.queue_depth = hw_queue_depth; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1995 | lo->tag_set.numa_node = NUMA_NO_NODE; |
| 1996 | lo->tag_set.cmd_size = sizeof(struct loop_cmd); |
Bart Van Assche | 2112f5c | 2021-08-05 10:42:00 -0700 | [diff] [blame] | 1997 | lo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING | |
| 1998 | BLK_MQ_F_NO_SCHED_BY_DEFAULT; |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 1999 | lo->tag_set.driver_data = lo; |
| 2000 | |
| 2001 | err = blk_mq_alloc_tag_set(&lo->tag_set); |
| 2002 | if (err) |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 2003 | goto out_free_idr; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2004 | |
Christoph Hellwig | 1c99502 | 2021-06-02 09:53:33 +0300 | [diff] [blame] | 2005 | disk = lo->lo_disk = blk_mq_alloc_disk(&lo->tag_set, lo); |
| 2006 | if (IS_ERR(disk)) { |
| 2007 | err = PTR_ERR(disk); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2008 | goto out_cleanup_tags; |
| 2009 | } |
Christoph Hellwig | 1c99502 | 2021-06-02 09:53:33 +0300 | [diff] [blame] | 2010 | lo->lo_queue = lo->lo_disk->queue; |
Mikulas Patocka | ef7e7c8 | 2013-10-15 14:14:38 -0600 | [diff] [blame] | 2011 | |
Shaohua Li | 54bb0ad | 2017-08-31 22:09:45 -0700 | [diff] [blame] | 2012 | blk_queue_max_hw_sectors(lo->lo_queue, BLK_DEF_MAX_SECTORS); |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 2013 | |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2014 | /* |
Shaohua Li | 40326d8 | 2017-08-31 22:09:46 -0700 | [diff] [blame] | 2015 | * By default, we do buffer IO, so it doesn't make sense to enable |
| 2016 | * merge because the I/O submitted to backing file is handled page by |
| 2017 | * page. For directio mode, merge does help to dispatch bigger request |
| 2018 | * to underlayer disk. We will enable merge once directio is enabled. |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2019 | */ |
Bart Van Assche | 8b904b5 | 2018-03-07 17:10:10 -0800 | [diff] [blame] | 2020 | blk_queue_flag_set(QUEUE_FLAG_NOMERGES, lo->lo_queue); |
Ming Lei | 5b5e20f | 2015-08-17 10:31:47 +0800 | [diff] [blame] | 2021 | |
Kay Sievers | e03c8dd | 2011-08-23 20:12:04 +0200 | [diff] [blame] | 2022 | /* |
| 2023 | * Disable partition scanning by default. The in-kernel partition |
| 2024 | * scanning can be requested individually per-device during its |
| 2025 | * setup. Userspace can always add and remove partitions from all |
| 2026 | * devices. The needed partition minors are allocated from the |
| 2027 | * extended minor space, the main loop device numbers will continue |
| 2028 | * to match the loop minors, regardless of the number of partitions |
| 2029 | * used. |
| 2030 | * |
| 2031 | * If max_part is given, partition scanning is globally enabled for |
| 2032 | * all loop devices. The minors for the main loop devices will be |
| 2033 | * multiples of max_part. |
| 2034 | * |
| 2035 | * Note: Global-for-all-devices, set-only-at-init, read-only module |
| 2036 | * parameteters like 'max_loop' and 'max_part' make things needlessly |
| 2037 | * complicated, are too static, inflexible and may surprise |
| 2038 | * userspace tools. Parameters like this in general should be avoided. |
| 2039 | */ |
| 2040 | if (!part_shift) |
Christoph Hellwig | b9684a7 | 2022-05-27 07:58:06 +0200 | [diff] [blame] | 2041 | set_bit(GD_SUPPRESS_PART_SCAN, &disk->state); |
Pavel Tatashin | 6cc8e74 | 2021-01-26 09:46:30 -0500 | [diff] [blame] | 2042 | mutex_init(&lo->lo_mutex); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2043 | lo->lo_number = i; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2044 | spin_lock_init(&lo->lo_lock); |
Dan Schatzberg | 87579e9 | 2021-06-28 19:38:15 -0700 | [diff] [blame] | 2045 | spin_lock_init(&lo->lo_work_lock); |
Christoph Hellwig | d292dc8 | 2022-03-30 07:29:17 +0200 | [diff] [blame] | 2046 | INIT_WORK(&lo->rootcg_work, loop_rootcg_workfn); |
| 2047 | INIT_LIST_HEAD(&lo->rootcg_cmd_list); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2048 | disk->major = LOOP_MAJOR; |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2049 | disk->first_minor = i << part_shift; |
Christoph Hellwig | 1c99502 | 2021-06-02 09:53:33 +0300 | [diff] [blame] | 2050 | disk->minors = 1 << part_shift; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2051 | disk->fops = &lo_fops; |
| 2052 | disk->private_data = lo; |
| 2053 | disk->queue = lo->lo_queue; |
Matteo Croce | 9f65c48 | 2021-07-13 01:05:30 +0200 | [diff] [blame] | 2054 | disk->events = DISK_EVENT_MEDIA_CHANGE; |
| 2055 | disk->event_flags = DISK_EVENT_FLAG_UEVENT; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2056 | sprintf(disk->disk_name, "loop%d", i); |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2057 | /* Make this loop device reachable from pathname. */ |
Luis Chamberlain | 905705f | 2021-09-27 14:59:57 -0700 | [diff] [blame] | 2058 | err = add_disk(disk); |
| 2059 | if (err) |
| 2060 | goto out_cleanup_disk; |
| 2061 | |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2062 | /* Show this loop device. */ |
| 2063 | mutex_lock(&loop_ctl_mutex); |
| 2064 | lo->idr_visible = true; |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 2065 | mutex_unlock(&loop_ctl_mutex); |
Luis Chamberlain | 905705f | 2021-09-27 14:59:57 -0700 | [diff] [blame] | 2066 | |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 2067 | return i; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2068 | |
Luis Chamberlain | 905705f | 2021-09-27 14:59:57 -0700 | [diff] [blame] | 2069 | out_cleanup_disk: |
Christoph Hellwig | 8b9ab62 | 2022-06-19 08:05:52 +0200 | [diff] [blame] | 2070 | put_disk(disk); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2071 | out_cleanup_tags: |
| 2072 | blk_mq_free_tag_set(&lo->tag_set); |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 2073 | out_free_idr: |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2074 | mutex_lock(&loop_ctl_mutex); |
Mikulas Patocka | 3ec981e | 2013-10-14 12:12:24 -0400 | [diff] [blame] | 2075 | idr_remove(&loop_index_idr, i); |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 2076 | mutex_unlock(&loop_ctl_mutex); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2077 | out_free_dev: |
| 2078 | kfree(lo); |
| 2079 | out: |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2080 | return err; |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2081 | } |
| 2082 | |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2083 | static void loop_remove(struct loop_device *lo) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2084 | { |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2085 | /* Make this loop device unreachable from pathname. */ |
NeilBrown | 6cd18e7 | 2015-04-27 14:12:22 +1000 | [diff] [blame] | 2086 | del_gendisk(lo->lo_disk); |
Ming Lei | b5dd2f6 | 2014-12-31 13:22:57 +0000 | [diff] [blame] | 2087 | blk_mq_free_tag_set(&lo->tag_set); |
Christoph Hellwig | ce8d786 | 2022-03-15 13:27:07 +0100 | [diff] [blame] | 2088 | |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2089 | mutex_lock(&loop_ctl_mutex); |
| 2090 | idr_remove(&loop_index_idr, lo->lo_number); |
| 2091 | mutex_unlock(&loop_ctl_mutex); |
Christoph Hellwig | d2c7f56 | 2022-03-30 07:29:13 +0200 | [diff] [blame] | 2092 | |
| 2093 | put_disk(lo->lo_disk); |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2094 | } |
| 2095 | |
Christoph Hellwig | 8410d38 | 2020-10-29 15:58:33 +0100 | [diff] [blame] | 2096 | static void loop_probe(dev_t dev) |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2097 | { |
Christoph Hellwig | 8410d38 | 2020-10-29 15:58:33 +0100 | [diff] [blame] | 2098 | int idx = MINOR(dev) >> part_shift; |
Christoph Hellwig | 8410d38 | 2020-10-29 15:58:33 +0100 | [diff] [blame] | 2099 | |
| 2100 | if (max_loop && idx >= max_loop) |
| 2101 | return; |
Christoph Hellwig | 4157fe0 | 2021-06-23 16:59:03 +0200 | [diff] [blame] | 2102 | loop_add(idx); |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2103 | } |
| 2104 | |
| 2105 | static int loop_control_remove(int idx) |
| 2106 | { |
| 2107 | struct loop_device *lo; |
| 2108 | int ret; |
Christoph Hellwig | e5d66a10 | 2021-06-23 16:59:06 +0200 | [diff] [blame] | 2109 | |
| 2110 | if (idx < 0) { |
Tetsuo Handa | e3f9387 | 2021-11-29 19:00:43 +0900 | [diff] [blame] | 2111 | pr_warn_once("deleting an unspecified loop device is not supported.\n"); |
Christoph Hellwig | e5d66a10 | 2021-06-23 16:59:06 +0200 | [diff] [blame] | 2112 | return -EINVAL; |
| 2113 | } |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2114 | |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2115 | /* Hide this loop device for serialization. */ |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2116 | ret = mutex_lock_killable(&loop_ctl_mutex); |
| 2117 | if (ret) |
| 2118 | return ret; |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2119 | lo = idr_find(&loop_index_idr, idx); |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2120 | if (!lo || !lo->idr_visible) |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2121 | ret = -ENODEV; |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2122 | else |
| 2123 | lo->idr_visible = false; |
| 2124 | mutex_unlock(&loop_ctl_mutex); |
| 2125 | if (ret) |
| 2126 | return ret; |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2127 | |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2128 | /* Check whether this loop device can be removed. */ |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2129 | ret = mutex_lock_killable(&lo->lo_mutex); |
| 2130 | if (ret) |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2131 | goto mark_visible; |
Christoph Hellwig | a0e286b | 2022-03-30 07:29:16 +0200 | [diff] [blame] | 2132 | if (lo->lo_state != Lo_unbound || disk_openers(lo->lo_disk) > 0) { |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2133 | mutex_unlock(&lo->lo_mutex); |
| 2134 | ret = -EBUSY; |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2135 | goto mark_visible; |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2136 | } |
Christoph Hellwig | a0e286b | 2022-03-30 07:29:16 +0200 | [diff] [blame] | 2137 | /* Mark this loop device as no more bound, but not quite unbound yet */ |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2138 | lo->lo_state = Lo_deleting; |
| 2139 | mutex_unlock(&lo->lo_mutex); |
| 2140 | |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2141 | loop_remove(lo); |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2142 | return 0; |
| 2143 | |
| 2144 | mark_visible: |
| 2145 | /* Show this loop device again. */ |
| 2146 | mutex_lock(&loop_ctl_mutex); |
| 2147 | lo->idr_visible = true; |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2148 | mutex_unlock(&loop_ctl_mutex); |
| 2149 | return ret; |
| 2150 | } |
| 2151 | |
| 2152 | static int loop_control_get_free(int idx) |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2153 | { |
| 2154 | struct loop_device *lo; |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2155 | int id, ret; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2156 | |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2157 | ret = mutex_lock_killable(&loop_ctl_mutex); |
| 2158 | if (ret) |
| 2159 | return ret; |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2160 | idr_for_each_entry(&loop_index_idr, lo, id) { |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2161 | /* Hitting a race results in creating a new loop device which is harmless. */ |
| 2162 | if (lo->idr_visible && data_race(lo->lo_state) == Lo_unbound) |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2163 | goto found; |
| 2164 | } |
Jan Kara | 0a42e99 | 2018-11-08 14:01:04 +0100 | [diff] [blame] | 2165 | mutex_unlock(&loop_ctl_mutex); |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 2166 | return loop_add(-1); |
Christoph Hellwig | b984808 | 2021-06-23 16:59:07 +0200 | [diff] [blame] | 2167 | found: |
| 2168 | mutex_unlock(&loop_ctl_mutex); |
| 2169 | return id; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2170 | } |
| 2171 | |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2172 | static long loop_control_ioctl(struct file *file, unsigned int cmd, |
| 2173 | unsigned long parm) |
| 2174 | { |
| 2175 | switch (cmd) { |
| 2176 | case LOOP_CTL_ADD: |
Christoph Hellwig | 18d1f20 | 2021-06-23 16:59:05 +0200 | [diff] [blame] | 2177 | return loop_add(parm); |
Christoph Hellwig | f9d1076 | 2021-06-23 16:59:04 +0200 | [diff] [blame] | 2178 | case LOOP_CTL_REMOVE: |
| 2179 | return loop_control_remove(parm); |
| 2180 | case LOOP_CTL_GET_FREE: |
| 2181 | return loop_control_get_free(parm); |
| 2182 | default: |
| 2183 | return -ENOSYS; |
| 2184 | } |
| 2185 | } |
| 2186 | |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2187 | static const struct file_operations loop_ctl_fops = { |
| 2188 | .open = nonseekable_open, |
| 2189 | .unlocked_ioctl = loop_control_ioctl, |
| 2190 | .compat_ioctl = loop_control_ioctl, |
| 2191 | .owner = THIS_MODULE, |
| 2192 | .llseek = noop_llseek, |
| 2193 | }; |
| 2194 | |
| 2195 | static struct miscdevice loop_misc = { |
| 2196 | .minor = LOOP_CTRL_MINOR, |
| 2197 | .name = "loop-control", |
| 2198 | .fops = &loop_ctl_fops, |
| 2199 | }; |
| 2200 | |
| 2201 | MODULE_ALIAS_MISCDEV(LOOP_CTRL_MINOR); |
| 2202 | MODULE_ALIAS("devname:loop-control"); |
| 2203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2204 | static int __init loop_init(void) |
| 2205 | { |
Isaac J. Manjarres | 85c5019 | 2022-12-08 13:29:01 -0800 | [diff] [blame] | 2206 | int i; |
Kay Sievers | 770fe30 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2207 | int err; |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2208 | |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2209 | part_shift = 0; |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 2210 | if (max_part > 0) { |
Laurent Vivier | 476a481 | 2008-03-26 12:11:53 +0100 | [diff] [blame] | 2211 | part_shift = fls(max_part); |
| 2212 | |
Namhyung Kim | ac04fee | 2011-05-27 07:59:25 +0200 | [diff] [blame] | 2213 | /* |
| 2214 | * Adjust max_part according to part_shift as it is exported |
| 2215 | * to user space so that user can decide correct minor number |
| 2216 | * if [s]he want to create more devices. |
| 2217 | * |
| 2218 | * Note that -1 is required because partition 0 is reserved |
| 2219 | * for the whole disk. |
| 2220 | */ |
| 2221 | max_part = (1UL << part_shift) - 1; |
| 2222 | } |
| 2223 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2224 | if ((1UL << part_shift) > DISK_MAX_PARTS) { |
| 2225 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2226 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2227 | } |
Namhyung Kim | 78f4bb3 | 2011-05-24 16:48:54 +0200 | [diff] [blame] | 2228 | |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2229 | if (max_loop > 1UL << (MINORBITS - part_shift)) { |
| 2230 | err = -EINVAL; |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2231 | goto err_out; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2232 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2233 | |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2234 | err = misc_register(&loop_misc); |
| 2235 | if (err < 0) |
| 2236 | goto err_out; |
| 2237 | |
| 2238 | |
Christoph Hellwig | 8410d38 | 2020-10-29 15:58:33 +0100 | [diff] [blame] | 2239 | if (__register_blkdev(LOOP_MAJOR, "loop", loop_probe)) { |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2240 | err = -EIO; |
| 2241 | goto misc_out; |
| 2242 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2243 | |
Kay Sievers | d134b00 | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2244 | /* pre-create number of devices given by config or max_loop */ |
Isaac J. Manjarres | 85c5019 | 2022-12-08 13:29:01 -0800 | [diff] [blame] | 2245 | for (i = 0; i < max_loop; i++) |
Christoph Hellwig | d6da83d | 2021-06-23 16:59:02 +0200 | [diff] [blame] | 2246 | loop_add(i); |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2247 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2248 | printk(KERN_INFO "loop: module loaded\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2249 | return 0; |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2250 | |
| 2251 | misc_out: |
| 2252 | misc_deregister(&loop_misc); |
Anton Volkov | a8c1d06 | 2017-08-07 15:37:50 +0300 | [diff] [blame] | 2253 | err_out: |
Guo Chao | b1a6650 | 2013-02-21 15:16:49 -0800 | [diff] [blame] | 2254 | return err; |
Kay Sievers | 34dd82a | 2011-07-31 22:08:04 +0200 | [diff] [blame] | 2255 | } |
Ken Chen | a47653f | 2007-06-08 13:46:44 -0700 | [diff] [blame] | 2256 | |
Ken Chen | 7328508 | 2007-05-08 00:28:20 -0700 | [diff] [blame] | 2257 | static void __exit loop_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2258 | { |
Christoph Hellwig | 8e60947 | 2021-06-23 16:59:08 +0200 | [diff] [blame] | 2259 | struct loop_device *lo; |
| 2260 | int id; |
| 2261 | |
Christoph Hellwig | 8b52d8b | 2021-06-23 16:59:00 +0200 | [diff] [blame] | 2262 | unregister_blkdev(LOOP_MAJOR, "loop"); |
| 2263 | misc_deregister(&loop_misc); |
Luis Chamberlain | 200f933 | 2020-06-19 20:47:27 +0000 | [diff] [blame] | 2264 | |
Tetsuo Handa | 1c500ad | 2021-09-02 09:07:35 +0900 | [diff] [blame] | 2265 | /* |
| 2266 | * There is no need to use loop_ctl_mutex here, for nobody else can |
| 2267 | * access loop_index_idr when this module is unloading (unless forced |
| 2268 | * module unloading is requested). If this is not a clean unloading, |
| 2269 | * we have no means to avoid kernel crash. |
| 2270 | */ |
Christoph Hellwig | 8e60947 | 2021-06-23 16:59:08 +0200 | [diff] [blame] | 2271 | idr_for_each_entry(&loop_index_idr, lo, id) |
| 2272 | loop_remove(lo); |
Christoph Hellwig | bd5c39e | 2021-06-23 16:59:01 +0200 | [diff] [blame] | 2273 | |
| 2274 | idr_destroy(&loop_index_idr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2275 | } |
| 2276 | |
| 2277 | module_init(loop_init); |
| 2278 | module_exit(loop_exit); |
| 2279 | |
| 2280 | #ifndef MODULE |
| 2281 | static int __init max_loop_setup(char *str) |
| 2282 | { |
| 2283 | max_loop = simple_strtol(str, NULL, 0); |
| 2284 | return 1; |
| 2285 | } |
| 2286 | |
| 2287 | __setup("max_loop=", max_loop_setup); |
| 2288 | #endif |