Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992 Linus Torvalds |
4 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
7b51e703 | 5 | * Copyright (C) 2016 - 2020 Christoph Hellwig |
1da177e4 LT |
6 | */ |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/mm.h> | |
1da177e4 LT |
10 | #include <linux/slab.h> |
11 | #include <linux/kmod.h> | |
12 | #include <linux/major.h> | |
7db9cfd3 | 13 | #include <linux/device_cgroup.h> |
1da177e4 | 14 | #include <linux/blkdev.h> |
fe45e630 | 15 | #include <linux/blk-integrity.h> |
66114cad | 16 | #include <linux/backing-dev.h> |
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/blkpg.h> | |
b502bd11 | 19 | #include <linux/magic.h> |
1da177e4 | 20 | #include <linux/buffer_head.h> |
ff01bb48 | 21 | #include <linux/swap.h> |
811d736f | 22 | #include <linux/writeback.h> |
1da177e4 | 23 | #include <linux/mount.h> |
9030d16e | 24 | #include <linux/pseudo_fs.h> |
1da177e4 LT |
25 | #include <linux/uio.h> |
26 | #include <linux/namei.h> | |
15e3d2c5 | 27 | #include <linux/part_stat.h> |
7c0f6ba6 | 28 | #include <linux/uaccess.h> |
2d985f8c | 29 | #include <linux/stat.h> |
0dca4462 CH |
30 | #include "../fs/internal.h" |
31 | #include "blk.h" | |
1da177e4 | 32 | |
ed5cc702 JK |
33 | /* Should we allow writing to mounted block devices? */ |
34 | static bool bdev_allow_write_mounted = IS_ENABLED(CONFIG_BLK_DEV_WRITE_MOUNTED); | |
35 | ||
1da177e4 LT |
36 | struct bdev_inode { |
37 | struct block_device bdev; | |
38 | struct inode vfs_inode; | |
39 | }; | |
40 | ||
41 | static inline struct bdev_inode *BDEV_I(struct inode *inode) | |
42 | { | |
43 | return container_of(inode, struct bdev_inode, vfs_inode); | |
44 | } | |
45 | ||
ff5053f6 | 46 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
47 | { |
48 | return &BDEV_I(inode)->bdev; | |
49 | } | |
1da177e4 LT |
50 | EXPORT_SYMBOL(I_BDEV); |
51 | ||
dbd3ca50 | 52 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 53 | { |
dbd3ca50 VG |
54 | struct inode *inode = bdev->bd_inode; |
55 | int ret; | |
56 | ||
564f00f6 CH |
57 | spin_lock(&inode->i_lock); |
58 | while (inode->i_state & I_DIRTY) { | |
59 | spin_unlock(&inode->i_lock); | |
dbd3ca50 | 60 | ret = write_inode_now(inode, true); |
5bf83e9a CH |
61 | if (ret) |
62 | pr_warn_ratelimited( | |
63 | "VFS: Dirty inode writeback failed for block device %pg (err=%d).\n", | |
64 | bdev, ret); | |
564f00f6 CH |
65 | spin_lock(&inode->i_lock); |
66 | } | |
67 | spin_unlock(&inode->i_lock); | |
68 | } | |
69 | ||
f9a14399 | 70 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 71 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 72 | { |
ff01bb48 AV |
73 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
74 | ||
7716506a | 75 | if (mapping_empty(mapping)) |
f9a14399 | 76 | return; |
ff01bb48 | 77 | |
f9a14399 | 78 | invalidate_bh_lrus(); |
ff01bb48 | 79 | truncate_inode_pages(mapping, 0); |
3373a346 | 80 | } |
ff01bb48 AV |
81 | |
82 | /* Invalidate clean unused buffers and pagecache. */ | |
83 | void invalidate_bdev(struct block_device *bdev) | |
84 | { | |
85 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
86 | ||
a5f6a6a9 AR |
87 | if (mapping->nrpages) { |
88 | invalidate_bh_lrus(); | |
89 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
90 | invalidate_mapping_pages(mapping, 0, -1); | |
91 | } | |
ff01bb48 AV |
92 | } |
93 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 94 | |
384d87ef JK |
95 | /* |
96 | * Drop all buffers & page cache for given bdev range. This function bails | |
97 | * with error if bdev has other exclusive owner (such as filesystem). | |
98 | */ | |
05bdb996 | 99 | int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode, |
384d87ef JK |
100 | loff_t lstart, loff_t lend) |
101 | { | |
384d87ef JK |
102 | /* |
103 | * If we don't hold exclusive handle for the device, upgrade to it | |
104 | * while we discard the buffer cache to avoid discarding buffers | |
105 | * under live filesystem. | |
106 | */ | |
05bdb996 | 107 | if (!(mode & BLK_OPEN_EXCL)) { |
0718afd4 | 108 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL); |
384d87ef | 109 | if (err) |
56887cff | 110 | goto invalidate; |
384d87ef | 111 | } |
37c3fc9a | 112 | |
384d87ef | 113 | truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); |
05bdb996 | 114 | if (!(mode & BLK_OPEN_EXCL)) |
37c3fc9a | 115 | bd_abort_claiming(bdev, truncate_bdev_range); |
384d87ef | 116 | return 0; |
56887cff JK |
117 | |
118 | invalidate: | |
119 | /* | |
120 | * Someone else has handle exclusively open. Try invalidating instead. | |
121 | * The 'end' argument is inclusive so the rounding is safe. | |
122 | */ | |
123 | return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, | |
124 | lstart >> PAGE_SHIFT, | |
125 | lend >> PAGE_SHIFT); | |
384d87ef | 126 | } |
384d87ef | 127 | |
04906b2f JK |
128 | static void set_init_blocksize(struct block_device *bdev) |
129 | { | |
8dc932d3 MM |
130 | unsigned int bsize = bdev_logical_block_size(bdev); |
131 | loff_t size = i_size_read(bdev->bd_inode); | |
132 | ||
133 | while (bsize < PAGE_SIZE) { | |
134 | if (size & bsize) | |
135 | break; | |
136 | bsize <<= 1; | |
137 | } | |
138 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
04906b2f JK |
139 | } |
140 | ||
1da177e4 LT |
141 | int set_blocksize(struct block_device *bdev, int size) |
142 | { | |
143 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 144 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
145 | return -EINVAL; |
146 | ||
147 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 148 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
149 | return -EINVAL; |
150 | ||
151 | /* Don't change the size if it is same as current */ | |
6b7b181b | 152 | if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 153 | sync_blockdev(bdev); |
1da177e4 LT |
154 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
155 | kill_bdev(bdev); | |
156 | } | |
157 | return 0; | |
158 | } | |
159 | ||
160 | EXPORT_SYMBOL(set_blocksize); | |
161 | ||
162 | int sb_set_blocksize(struct super_block *sb, int size) | |
163 | { | |
1da177e4 LT |
164 | if (set_blocksize(sb->s_bdev, size)) |
165 | return 0; | |
166 | /* If we get here, we know size is power of two | |
167 | * and it's value is between 512 and PAGE_SIZE */ | |
168 | sb->s_blocksize = size; | |
38885bd4 | 169 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
170 | return sb->s_blocksize; |
171 | } | |
172 | ||
173 | EXPORT_SYMBOL(sb_set_blocksize); | |
174 | ||
175 | int sb_min_blocksize(struct super_block *sb, int size) | |
176 | { | |
e1defc4f | 177 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
178 | if (size < minsize) |
179 | size = minsize; | |
180 | return sb_set_blocksize(sb, size); | |
181 | } | |
182 | ||
183 | EXPORT_SYMBOL(sb_min_blocksize); | |
184 | ||
70164eb6 | 185 | int sync_blockdev_nowait(struct block_device *bdev) |
5cee5815 JK |
186 | { |
187 | if (!bdev) | |
188 | return 0; | |
70164eb6 | 189 | return filemap_flush(bdev->bd_inode->i_mapping); |
5cee5815 | 190 | } |
70164eb6 | 191 | EXPORT_SYMBOL_GPL(sync_blockdev_nowait); |
5cee5815 | 192 | |
585d3bc0 NP |
193 | /* |
194 | * Write out and wait upon all the dirty data associated with a block | |
195 | * device via its mapping. Does not take the superblock lock. | |
196 | */ | |
197 | int sync_blockdev(struct block_device *bdev) | |
198 | { | |
70164eb6 CH |
199 | if (!bdev) |
200 | return 0; | |
201 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
585d3bc0 NP |
202 | } |
203 | EXPORT_SYMBOL(sync_blockdev); | |
204 | ||
97d6fb1b YM |
205 | int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend) |
206 | { | |
207 | return filemap_write_and_wait_range(bdev->bd_inode->i_mapping, | |
208 | lstart, lend); | |
209 | } | |
210 | EXPORT_SYMBOL(sync_blockdev_range); | |
211 | ||
585d3bc0 | 212 | /** |
982c3b30 | 213 | * bdev_freeze - lock a filesystem and force it into a consistent state |
585d3bc0 NP |
214 | * @bdev: blockdevice to lock |
215 | * | |
585d3bc0 NP |
216 | * If a superblock is found on this device, we take the s_umount semaphore |
217 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
218 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
219 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
982c3b30 CB |
220 | * freeze requests arrive simultaneously. It counts up in bdev_freeze() and |
221 | * count down in bdev_thaw(). When it becomes 0, thaw_bdev() will unfreeze | |
585d3bc0 | 222 | * actually. |
982c3b30 CB |
223 | * |
224 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 225 | */ |
982c3b30 | 226 | int bdev_freeze(struct block_device *bdev) |
585d3bc0 | 227 | { |
585d3bc0 NP |
228 | int error = 0; |
229 | ||
230 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd | 231 | |
49ef8832 CB |
232 | if (atomic_inc_return(&bdev->bd_fsfreeze_count) > 1) { |
233 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
234 | return 0; | |
585d3bc0 | 235 | } |
040f04bd | 236 | |
49ef8832 CB |
237 | mutex_lock(&bdev->bd_holder_lock); |
238 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->freeze) { | |
239 | error = bdev->bd_holder_ops->freeze(bdev); | |
240 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
241 | } else { | |
242 | mutex_unlock(&bdev->bd_holder_lock); | |
243 | error = sync_blockdev(bdev); | |
585d3bc0 | 244 | } |
040f04bd | 245 | |
49ef8832 CB |
246 | if (error) |
247 | atomic_dec(&bdev->bd_fsfreeze_count); | |
248 | ||
585d3bc0 | 249 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 250 | return error; |
585d3bc0 | 251 | } |
982c3b30 | 252 | EXPORT_SYMBOL(bdev_freeze); |
585d3bc0 NP |
253 | |
254 | /** | |
982c3b30 | 255 | * bdev_thaw - unlock filesystem |
585d3bc0 | 256 | * @bdev: blockdevice to unlock |
585d3bc0 | 257 | * |
982c3b30 CB |
258 | * Unlocks the filesystem and marks it writeable again after bdev_freeze(). |
259 | * | |
260 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 261 | */ |
982c3b30 | 262 | int bdev_thaw(struct block_device *bdev) |
585d3bc0 | 263 | { |
49ef8832 | 264 | int error = -EINVAL, nr_freeze; |
585d3bc0 NP |
265 | |
266 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
49ef8832 CB |
267 | |
268 | /* | |
269 | * If this returns < 0 it means that @bd_fsfreeze_count was | |
270 | * already 0 and no decrement was performed. | |
271 | */ | |
272 | nr_freeze = atomic_dec_if_positive(&bdev->bd_fsfreeze_count); | |
273 | if (nr_freeze < 0) | |
18e9e510 | 274 | goto out; |
4504230a CH |
275 | |
276 | error = 0; | |
49ef8832 | 277 | if (nr_freeze > 0) |
18e9e510 | 278 | goto out; |
4504230a | 279 | |
49ef8832 CB |
280 | mutex_lock(&bdev->bd_holder_lock); |
281 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->thaw) { | |
282 | error = bdev->bd_holder_ops->thaw(bdev); | |
283 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
284 | } else { | |
285 | mutex_unlock(&bdev->bd_holder_lock); | |
286 | } | |
4504230a | 287 | |
997198ba | 288 | if (error) |
49ef8832 | 289 | atomic_inc(&bdev->bd_fsfreeze_count); |
18e9e510 | 290 | out: |
585d3bc0 | 291 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 292 | return error; |
585d3bc0 | 293 | } |
982c3b30 | 294 | EXPORT_SYMBOL(bdev_thaw); |
585d3bc0 | 295 | |
1da177e4 LT |
296 | /* |
297 | * pseudo-fs | |
298 | */ | |
299 | ||
74e6464a | 300 | static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); |
68279f9c | 301 | static struct kmem_cache *bdev_cachep __ro_after_init; |
1da177e4 LT |
302 | |
303 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
304 | { | |
fd60b288 | 305 | struct bdev_inode *ei = alloc_inode_sb(sb, bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 306 | |
1da177e4 LT |
307 | if (!ei) |
308 | return NULL; | |
2d2f6f1b | 309 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
1da177e4 LT |
310 | return &ei->vfs_inode; |
311 | } | |
312 | ||
41149cb0 | 313 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 314 | { |
15e3d2c5 CH |
315 | struct block_device *bdev = I_BDEV(inode); |
316 | ||
317 | free_percpu(bdev->bd_stats); | |
231926db | 318 | kfree(bdev->bd_meta_info); |
15e3d2c5 | 319 | |
889c05cc CH |
320 | if (!bdev_is_partition(bdev)) { |
321 | if (bdev->bd_disk && bdev->bd_disk->bdi) | |
322 | bdi_put(bdev->bd_disk->bdi); | |
340e8457 | 323 | kfree(bdev->bd_disk); |
889c05cc | 324 | } |
9451aa0a CH |
325 | |
326 | if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) | |
327 | blk_free_ext_minor(MINOR(bdev->bd_dev)); | |
328 | ||
41149cb0 | 329 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
330 | } |
331 | ||
e6cb5382 | 332 | static void init_once(void *data) |
1da177e4 | 333 | { |
e6cb5382 | 334 | struct bdev_inode *ei = data; |
1da177e4 | 335 | |
a35afb83 | 336 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
337 | } |
338 | ||
b57922d9 | 339 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 | 340 | { |
91b0abe3 | 341 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 342 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 343 | clear_inode(inode); |
1da177e4 LT |
344 | } |
345 | ||
ee9b6d61 | 346 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
347 | .statfs = simple_statfs, |
348 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 349 | .free_inode = bdev_free_inode, |
1da177e4 | 350 | .drop_inode = generic_delete_inode, |
b57922d9 | 351 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
352 | }; |
353 | ||
9030d16e | 354 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 355 | { |
9030d16e DH |
356 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
357 | if (!ctx) | |
358 | return -ENOMEM; | |
359 | fc->s_iflags |= SB_I_CGROUPWB; | |
360 | ctx->ops = &bdev_sops; | |
361 | return 0; | |
1da177e4 LT |
362 | } |
363 | ||
364 | static struct file_system_type bd_type = { | |
365 | .name = "bdev", | |
9030d16e | 366 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
367 | .kill_sb = kill_anon_super, |
368 | }; | |
369 | ||
68279f9c | 370 | struct super_block *blockdev_superblock __ro_after_init; |
a212b105 | 371 | EXPORT_SYMBOL_GPL(blockdev_superblock); |
1da177e4 LT |
372 | |
373 | void __init bdev_cache_init(void) | |
374 | { | |
375 | int err; | |
68279f9c | 376 | static struct vfsmount *bd_mnt __ro_after_init; |
c2acf7b9 | 377 | |
1da177e4 | 378 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 379 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 380 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 381 | init_once); |
1da177e4 LT |
382 | err = register_filesystem(&bd_type); |
383 | if (err) | |
384 | panic("Cannot register bdev pseudo-fs"); | |
385 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
386 | if (IS_ERR(bd_mnt)) |
387 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 388 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
389 | } |
390 | ||
22ae8ce8 | 391 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
392 | { |
393 | struct block_device *bdev; | |
394 | struct inode *inode; | |
395 | ||
22ae8ce8 | 396 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
397 | if (!inode) |
398 | return NULL; | |
22ae8ce8 CH |
399 | inode->i_mode = S_IFBLK; |
400 | inode->i_rdev = 0; | |
401 | inode->i_data.a_ops = &def_blk_aops; | |
402 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
403 | ||
404 | bdev = I_BDEV(inode); | |
e6cb5382 | 405 | mutex_init(&bdev->bd_fsfreeze_mutex); |
22ae8ce8 | 406 | spin_lock_init(&bdev->bd_size_lock); |
0718afd4 | 407 | mutex_init(&bdev->bd_holder_lock); |
22ae8ce8 | 408 | bdev->bd_partno = partno; |
22ae8ce8 | 409 | bdev->bd_inode = inode; |
17220ca5 | 410 | bdev->bd_queue = disk->queue; |
38c8e3df ML |
411 | if (partno) |
412 | bdev->bd_has_submit_bio = disk->part0->bd_has_submit_bio; | |
413 | else | |
414 | bdev->bd_has_submit_bio = false; | |
15e3d2c5 CH |
415 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
416 | if (!bdev->bd_stats) { | |
417 | iput(inode); | |
418 | return NULL; | |
419 | } | |
06cc978d | 420 | bdev->bd_disk = disk; |
22ae8ce8 CH |
421 | return bdev; |
422 | } | |
1da177e4 | 423 | |
83794367 DLM |
424 | void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) |
425 | { | |
426 | spin_lock(&bdev->bd_size_lock); | |
427 | i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); | |
428 | bdev->bd_nr_sectors = sectors; | |
429 | spin_unlock(&bdev->bd_size_lock); | |
430 | } | |
431 | ||
22ae8ce8 CH |
432 | void bdev_add(struct block_device *bdev, dev_t dev) |
433 | { | |
1898efcd CH |
434 | if (bdev_stable_writes(bdev)) |
435 | mapping_set_stable_writes(bdev->bd_inode->i_mapping); | |
22ae8ce8 CH |
436 | bdev->bd_dev = dev; |
437 | bdev->bd_inode->i_rdev = dev; | |
438 | bdev->bd_inode->i_ino = dev; | |
439 | insert_inode_hash(bdev->bd_inode); | |
440 | } | |
1da177e4 | 441 | |
1da177e4 LT |
442 | long nr_blockdev_pages(void) |
443 | { | |
1008fe6d | 444 | struct inode *inode; |
1da177e4 | 445 | long ret = 0; |
1008fe6d CH |
446 | |
447 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
448 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
449 | ret += inode->i_mapping->nrpages; | |
450 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
451 | ||
1da177e4 LT |
452 | return ret; |
453 | } | |
454 | ||
1a3cbbc5 TH |
455 | /** |
456 | * bd_may_claim - test whether a block device can be claimed | |
457 | * @bdev: block device of interest | |
1a3cbbc5 | 458 | * @holder: holder trying to claim @bdev |
0718afd4 | 459 | * @hops: holder ops |
1a3cbbc5 | 460 | * |
25985edc | 461 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 | 462 | * |
1a3cbbc5 TH |
463 | * RETURNS: |
464 | * %true if @bdev can be claimed, %false otherwise. | |
465 | */ | |
0718afd4 CH |
466 | static bool bd_may_claim(struct block_device *bdev, void *holder, |
467 | const struct blk_holder_ops *hops) | |
ae5f855e CH |
468 | { |
469 | struct block_device *whole = bdev_whole(bdev); | |
470 | ||
74e6464a CH |
471 | lockdep_assert_held(&bdev_lock); |
472 | ||
ae5f855e CH |
473 | if (bdev->bd_holder) { |
474 | /* | |
475 | * The same holder can always re-claim. | |
476 | */ | |
0718afd4 CH |
477 | if (bdev->bd_holder == holder) { |
478 | if (WARN_ON_ONCE(bdev->bd_holder_ops != hops)) | |
479 | return false; | |
ae5f855e | 480 | return true; |
0718afd4 | 481 | } |
ae5f855e CH |
482 | return false; |
483 | } | |
484 | ||
485 | /* | |
486 | * If the whole devices holder is set to bd_may_claim, a partition on | |
487 | * the device is claimed, but not the whole device. | |
488 | */ | |
489 | if (whole != bdev && | |
490 | whole->bd_holder && whole->bd_holder != bd_may_claim) | |
491 | return false; | |
492 | return true; | |
1a3cbbc5 TH |
493 | } |
494 | ||
6b4517a7 | 495 | /** |
58e46ed9 | 496 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 497 | * @bdev: block device of interest |
6b4517a7 | 498 | * @holder: holder trying to claim @bdev |
0718afd4 | 499 | * @hops: holder ops. |
6b4517a7 | 500 | * |
58e46ed9 CH |
501 | * Claim @bdev. This function fails if @bdev is already claimed by another |
502 | * holder and waits if another claiming is in progress. return, the caller | |
503 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
504 | * |
505 | * RETURNS: | |
506 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
507 | */ | |
0718afd4 CH |
508 | int bd_prepare_to_claim(struct block_device *bdev, void *holder, |
509 | const struct blk_holder_ops *hops) | |
6b4517a7 | 510 | { |
37c3fc9a CH |
511 | struct block_device *whole = bdev_whole(bdev); |
512 | ||
513 | if (WARN_ON_ONCE(!holder)) | |
514 | return -EINVAL; | |
6b4517a7 | 515 | retry: |
74e6464a | 516 | mutex_lock(&bdev_lock); |
6b4517a7 | 517 | /* if someone else claimed, fail */ |
0718afd4 | 518 | if (!bd_may_claim(bdev, holder, hops)) { |
74e6464a | 519 | mutex_unlock(&bdev_lock); |
6b4517a7 | 520 | return -EBUSY; |
58e46ed9 | 521 | } |
6b4517a7 | 522 | |
e75aa858 TH |
523 | /* if claiming is already in progress, wait for it to finish */ |
524 | if (whole->bd_claiming) { | |
6b4517a7 TH |
525 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
526 | DEFINE_WAIT(wait); | |
527 | ||
528 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
74e6464a | 529 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
530 | schedule(); |
531 | finish_wait(wq, &wait); | |
6b4517a7 TH |
532 | goto retry; |
533 | } | |
534 | ||
535 | /* yay, all mine */ | |
58e46ed9 | 536 | whole->bd_claiming = holder; |
74e6464a | 537 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
538 | return 0; |
539 | } | |
ecbe6bc0 | 540 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 541 | |
89e524c0 JK |
542 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
543 | { | |
544 | lockdep_assert_held(&bdev_lock); | |
545 | /* tell others that we're done */ | |
546 | BUG_ON(whole->bd_claiming != holder); | |
547 | whole->bd_claiming = NULL; | |
548 | wake_up_bit(&whole->bd_claiming, 0); | |
549 | } | |
550 | ||
551 | /** | |
552 | * bd_finish_claiming - finish claiming of a block device | |
553 | * @bdev: block device of interest | |
89e524c0 | 554 | * @holder: holder that has claimed @bdev |
017fb83e | 555 | * @hops: block device holder operations |
89e524c0 JK |
556 | * |
557 | * Finish exclusive open of a block device. Mark the device as exlusively | |
558 | * open by the holder and wake up all waiters for exclusive open to finish. | |
559 | */ | |
0718afd4 CH |
560 | static void bd_finish_claiming(struct block_device *bdev, void *holder, |
561 | const struct blk_holder_ops *hops) | |
89e524c0 | 562 | { |
37c3fc9a CH |
563 | struct block_device *whole = bdev_whole(bdev); |
564 | ||
74e6464a | 565 | mutex_lock(&bdev_lock); |
0718afd4 | 566 | BUG_ON(!bd_may_claim(bdev, holder, hops)); |
89e524c0 JK |
567 | /* |
568 | * Note that for a whole device bd_holders will be incremented twice, | |
569 | * and bd_holder will be set to bd_may_claim before being set to holder | |
570 | */ | |
571 | whole->bd_holders++; | |
572 | whole->bd_holder = bd_may_claim; | |
573 | bdev->bd_holders++; | |
0718afd4 | 574 | mutex_lock(&bdev->bd_holder_lock); |
89e524c0 | 575 | bdev->bd_holder = holder; |
0718afd4 CH |
576 | bdev->bd_holder_ops = hops; |
577 | mutex_unlock(&bdev->bd_holder_lock); | |
89e524c0 | 578 | bd_clear_claiming(whole, holder); |
74e6464a | 579 | mutex_unlock(&bdev_lock); |
89e524c0 | 580 | } |
89e524c0 JK |
581 | |
582 | /** | |
583 | * bd_abort_claiming - abort claiming of a block device | |
584 | * @bdev: block device of interest | |
89e524c0 JK |
585 | * @holder: holder that has claimed @bdev |
586 | * | |
587 | * Abort claiming of a block device when the exclusive open failed. This can be | |
588 | * also used when exclusive open is not actually desired and we just needed | |
589 | * to block other exclusive openers for a while. | |
590 | */ | |
37c3fc9a | 591 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 592 | { |
74e6464a | 593 | mutex_lock(&bdev_lock); |
37c3fc9a | 594 | bd_clear_claiming(bdev_whole(bdev), holder); |
74e6464a | 595 | mutex_unlock(&bdev_lock); |
89e524c0 JK |
596 | } |
597 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 598 | |
2736e8ee | 599 | static void bd_end_claim(struct block_device *bdev, void *holder) |
0783b1a7 CH |
600 | { |
601 | struct block_device *whole = bdev_whole(bdev); | |
602 | bool unblock = false; | |
603 | ||
604 | /* | |
605 | * Release a claim on the device. The holder fields are protected with | |
606 | * bdev_lock. open_mutex is used to synchronize disk_holder unlinking. | |
607 | */ | |
74e6464a | 608 | mutex_lock(&bdev_lock); |
2736e8ee | 609 | WARN_ON_ONCE(bdev->bd_holder != holder); |
0783b1a7 CH |
610 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
611 | WARN_ON_ONCE(--whole->bd_holders < 0); | |
612 | if (!bdev->bd_holders) { | |
0718afd4 | 613 | mutex_lock(&bdev->bd_holder_lock); |
0783b1a7 | 614 | bdev->bd_holder = NULL; |
0718afd4 CH |
615 | bdev->bd_holder_ops = NULL; |
616 | mutex_unlock(&bdev->bd_holder_lock); | |
0783b1a7 CH |
617 | if (bdev->bd_write_holder) |
618 | unblock = true; | |
619 | } | |
620 | if (!whole->bd_holders) | |
621 | whole->bd_holder = NULL; | |
74e6464a | 622 | mutex_unlock(&bdev_lock); |
0783b1a7 CH |
623 | |
624 | /* | |
625 | * If this was the last claim, remove holder link and unblock evpoll if | |
626 | * it was a write holder. | |
627 | */ | |
628 | if (unblock) { | |
629 | disk_unblock_events(bdev->bd_disk); | |
630 | bdev->bd_write_holder = false; | |
631 | } | |
632 | } | |
633 | ||
c8276b95 CH |
634 | static void blkdev_flush_mapping(struct block_device *bdev) |
635 | { | |
636 | WARN_ON_ONCE(bdev->bd_holders); | |
637 | sync_blockdev(bdev); | |
638 | kill_bdev(bdev); | |
639 | bdev_write_inode(bdev); | |
640 | } | |
37be4124 | 641 | |
05bdb996 | 642 | static int blkdev_get_whole(struct block_device *bdev, blk_mode_t mode) |
a1548b67 | 643 | { |
142fe8f4 | 644 | struct gendisk *disk = bdev->bd_disk; |
af22fef3 | 645 | int ret; |
a1548b67 | 646 | |
362529d9 | 647 | if (disk->fops->open) { |
d32e2bf8 | 648 | ret = disk->fops->open(disk, mode); |
362529d9 CH |
649 | if (ret) { |
650 | /* avoid ghost partitions on a removed medium */ | |
651 | if (ret == -ENOMEDIUM && | |
652 | test_bit(GD_NEED_PART_SCAN, &disk->state)) | |
0384264e | 653 | bdev_disk_changed(disk, true); |
362529d9 CH |
654 | return ret; |
655 | } | |
d981cb5b | 656 | } |
a1548b67 | 657 | |
9acf381f | 658 | if (!atomic_read(&bdev->bd_openers)) |
362529d9 | 659 | set_init_blocksize(bdev); |
362529d9 | 660 | if (test_bit(GD_NEED_PART_SCAN, &disk->state)) |
0384264e | 661 | bdev_disk_changed(disk, false); |
9acf381f | 662 | atomic_inc(&bdev->bd_openers); |
483546c1 | 663 | return 0; |
362529d9 | 664 | } |
a1548b67 | 665 | |
ae220766 | 666 | static void blkdev_put_whole(struct block_device *bdev) |
c8276b95 | 667 | { |
9acf381f | 668 | if (atomic_dec_and_test(&bdev->bd_openers)) |
c8276b95 CH |
669 | blkdev_flush_mapping(bdev); |
670 | if (bdev->bd_disk->fops->release) | |
ae220766 | 671 | bdev->bd_disk->fops->release(bdev->bd_disk); |
a1548b67 CH |
672 | } |
673 | ||
05bdb996 | 674 | static int blkdev_get_part(struct block_device *part, blk_mode_t mode) |
1da177e4 | 675 | { |
362529d9 | 676 | struct gendisk *disk = part->bd_disk; |
362529d9 | 677 | int ret; |
5b642d8b | 678 | |
9d3b8813 | 679 | ret = blkdev_get_whole(bdev_whole(part), mode); |
a8698707 | 680 | if (ret) |
9d3b8813 | 681 | return ret; |
7e69723f | 682 | |
362529d9 CH |
683 | ret = -ENXIO; |
684 | if (!bdev_nr_sectors(part)) | |
685 | goto out_blkdev_put; | |
7e69723f | 686 | |
9d1c9287 CH |
687 | if (!atomic_read(&part->bd_openers)) { |
688 | disk->open_partitions++; | |
689 | set_init_blocksize(part); | |
690 | } | |
9acf381f | 691 | atomic_inc(&part->bd_openers); |
1da177e4 | 692 | return 0; |
5a023cdb | 693 | |
362529d9 | 694 | out_blkdev_put: |
ae220766 | 695 | blkdev_put_whole(bdev_whole(part)); |
362529d9 | 696 | return ret; |
1da177e4 | 697 | } |
5b56b6ed | 698 | |
ae220766 | 699 | static void blkdev_put_part(struct block_device *part) |
c8276b95 CH |
700 | { |
701 | struct block_device *whole = bdev_whole(part); | |
03e26279 | 702 | |
9d1c9287 CH |
703 | if (atomic_dec_and_test(&part->bd_openers)) { |
704 | blkdev_flush_mapping(part); | |
705 | whole->bd_disk->open_partitions--; | |
706 | } | |
ae220766 | 707 | blkdev_put_whole(whole); |
1da177e4 LT |
708 | } |
709 | ||
22ae8ce8 CH |
710 | struct block_device *blkdev_get_no_open(dev_t dev) |
711 | { | |
712 | struct block_device *bdev; | |
9d3b8813 | 713 | struct inode *inode; |
22ae8ce8 | 714 | |
9d3b8813 | 715 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b | 716 | if (!inode && IS_ENABLED(CONFIG_BLOCK_LEGACY_AUTOLOAD)) { |
22ae8ce8 | 717 | blk_request_module(dev); |
9d3b8813 | 718 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b CH |
719 | if (inode) |
720 | pr_warn_ratelimited( | |
451f0b6f | 721 | "block device autoloading is deprecated and will be removed.\n"); |
22ae8ce8 | 722 | } |
fbdee71b CH |
723 | if (!inode) |
724 | return NULL; | |
22ae8ce8 | 725 | |
9d3b8813 CH |
726 | /* switch from the inode reference to a device mode one: */ |
727 | bdev = &BDEV_I(inode)->bdev; | |
728 | if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) | |
729 | bdev = NULL; | |
730 | iput(inode); | |
22ae8ce8 | 731 | return bdev; |
22ae8ce8 CH |
732 | } |
733 | ||
734 | void blkdev_put_no_open(struct block_device *bdev) | |
735 | { | |
9d3b8813 | 736 | put_device(&bdev->bd_device); |
22ae8ce8 | 737 | } |
ed5cc702 JK |
738 | |
739 | static bool bdev_writes_blocked(struct block_device *bdev) | |
740 | { | |
741 | return bdev->bd_writers == -1; | |
742 | } | |
743 | ||
744 | static void bdev_block_writes(struct block_device *bdev) | |
745 | { | |
746 | bdev->bd_writers = -1; | |
747 | } | |
748 | ||
749 | static void bdev_unblock_writes(struct block_device *bdev) | |
750 | { | |
751 | bdev->bd_writers = 0; | |
752 | } | |
753 | ||
754 | static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode) | |
755 | { | |
756 | if (bdev_allow_write_mounted) | |
757 | return true; | |
758 | /* Writes blocked? */ | |
759 | if (mode & BLK_OPEN_WRITE && bdev_writes_blocked(bdev)) | |
760 | return false; | |
761 | if (mode & BLK_OPEN_RESTRICT_WRITES && bdev->bd_writers > 0) | |
762 | return false; | |
763 | return true; | |
764 | } | |
765 | ||
766 | static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode) | |
767 | { | |
768 | if (bdev_allow_write_mounted) | |
769 | return; | |
770 | ||
771 | /* Claim exclusive or shared write access. */ | |
772 | if (mode & BLK_OPEN_RESTRICT_WRITES) | |
773 | bdev_block_writes(bdev); | |
774 | else if (mode & BLK_OPEN_WRITE) | |
775 | bdev->bd_writers++; | |
776 | } | |
777 | ||
778 | static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode) | |
779 | { | |
780 | if (bdev_allow_write_mounted) | |
781 | return; | |
782 | ||
783 | /* Yield exclusive or shared write access. */ | |
784 | if (mode & BLK_OPEN_RESTRICT_WRITES) | |
785 | bdev_unblock_writes(bdev); | |
786 | else if (mode & BLK_OPEN_WRITE) | |
787 | bdev->bd_writers--; | |
788 | } | |
789 | ||
d4d77629 | 790 | /** |
cd34758c | 791 | * bdev_open_by_dev - open a block device by device number |
4e7b5671 | 792 | * @dev: device number of block device to open |
05bdb996 | 793 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 794 | * @holder: exclusive holder identifier |
0718afd4 | 795 | * @hops: holder operations |
d4d77629 | 796 | * |
2736e8ee CH |
797 | * Open the block device described by device number @dev. If @holder is not |
798 | * %NULL, the block device is opened with exclusive access. Exclusive opens may | |
799 | * nest for the same @holder. | |
d4d77629 | 800 | * |
4e7b5671 CH |
801 | * Use this interface ONLY if you really do not have anything better - i.e. when |
802 | * you are behind a truly sucky interface and all you are given is a device | |
cd34758c | 803 | * number. Everything else should use bdev_open_by_path(). |
d4d77629 TH |
804 | * |
805 | * CONTEXT: | |
806 | * Might sleep. | |
807 | * | |
808 | * RETURNS: | |
cd34758c JK |
809 | * Handle with a reference to the block_device on success, ERR_PTR(-errno) on |
810 | * failure. | |
d4d77629 | 811 | */ |
cd34758c JK |
812 | struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, |
813 | const struct blk_holder_ops *hops) | |
1da177e4 | 814 | { |
cd34758c JK |
815 | struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle), |
816 | GFP_KERNEL); | |
4e7b5671 | 817 | struct block_device *bdev; |
cd34758c | 818 | bool unblock_events = true; |
5b56b6ed | 819 | struct gendisk *disk; |
5b56b6ed | 820 | int ret; |
e525fd89 | 821 | |
cd34758c JK |
822 | if (!handle) |
823 | return ERR_PTR(-ENOMEM); | |
824 | ||
7918f0f6 | 825 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, |
4e7b5671 | 826 | MAJOR(dev), MINOR(dev), |
05bdb996 CH |
827 | ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | |
828 | ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
e5c7fb40 | 829 | if (ret) |
cd34758c | 830 | goto free_handle; |
4e7b5671 | 831 | |
ed5cc702 | 832 | /* Blocking writes requires exclusive opener */ |
8ff363ad CJ |
833 | if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) { |
834 | ret = -EINVAL; | |
835 | goto free_handle; | |
836 | } | |
4e7b5671 | 837 | |
22ae8ce8 | 838 | bdev = blkdev_get_no_open(dev); |
cd34758c JK |
839 | if (!bdev) { |
840 | ret = -ENXIO; | |
841 | goto free_handle; | |
842 | } | |
22ae8ce8 | 843 | disk = bdev->bd_disk; |
e5c7fb40 | 844 | |
2736e8ee | 845 | if (holder) { |
05bdb996 | 846 | mode |= BLK_OPEN_EXCL; |
0718afd4 | 847 | ret = bd_prepare_to_claim(bdev, holder, hops); |
5b56b6ed | 848 | if (ret) |
37c3fc9a | 849 | goto put_blkdev; |
2736e8ee | 850 | } else { |
05bdb996 | 851 | if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) { |
2736e8ee CH |
852 | ret = -EIO; |
853 | goto put_blkdev; | |
854 | } | |
5b56b6ed CH |
855 | } |
856 | ||
857 | disk_block_events(disk); | |
858 | ||
a8698707 | 859 | mutex_lock(&disk->open_mutex); |
362529d9 | 860 | ret = -ENXIO; |
50b4aecf | 861 | if (!disk_live(disk)) |
362529d9 | 862 | goto abort_claiming; |
efcf5932 ML |
863 | if (!try_module_get(disk->fops->owner)) |
864 | goto abort_claiming; | |
ed5cc702 JK |
865 | ret = -EBUSY; |
866 | if (!bdev_may_open(bdev, mode)) | |
867 | goto abort_claiming; | |
362529d9 CH |
868 | if (bdev_is_partition(bdev)) |
869 | ret = blkdev_get_part(bdev, mode); | |
870 | else | |
871 | ret = blkdev_get_whole(bdev, mode); | |
22ae8ce8 | 872 | if (ret) |
efcf5932 | 873 | goto put_module; |
ed5cc702 | 874 | bdev_claim_write_access(bdev, mode); |
2736e8ee | 875 | if (holder) { |
0718afd4 | 876 | bd_finish_claiming(bdev, holder, hops); |
5b56b6ed CH |
877 | |
878 | /* | |
879 | * Block event polling for write claims if requested. Any write | |
880 | * holder makes the write_holder state stick until all are | |
881 | * released. This is good enough and tracking individual | |
882 | * writeable reference is too fragile given the way @mode is | |
883 | * used in blkdev_get/put(). | |
884 | */ | |
05bdb996 | 885 | if ((mode & BLK_OPEN_WRITE) && !bdev->bd_write_holder && |
1545e0b4 | 886 | (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) { |
5b56b6ed CH |
887 | bdev->bd_write_holder = true; |
888 | unblock_events = false; | |
889 | } | |
890 | } | |
a8698707 | 891 | mutex_unlock(&disk->open_mutex); |
5b56b6ed CH |
892 | |
893 | if (unblock_events) | |
894 | disk_unblock_events(disk); | |
cd34758c JK |
895 | handle->bdev = bdev; |
896 | handle->holder = holder; | |
897 | handle->mode = mode; | |
898 | return handle; | |
efcf5932 ML |
899 | put_module: |
900 | module_put(disk->fops->owner); | |
22ae8ce8 | 901 | abort_claiming: |
2736e8ee | 902 | if (holder) |
37c3fc9a | 903 | bd_abort_claiming(bdev, holder); |
a8698707 | 904 | mutex_unlock(&disk->open_mutex); |
22ae8ce8 | 905 | disk_unblock_events(disk); |
22ae8ce8 CH |
906 | put_blkdev: |
907 | blkdev_put_no_open(bdev); | |
cd34758c JK |
908 | free_handle: |
909 | kfree(handle); | |
22ae8ce8 | 910 | return ERR_PTR(ret); |
37be4124 | 911 | } |
e719b4d1 JK |
912 | EXPORT_SYMBOL(bdev_open_by_dev); |
913 | ||
d4d77629 | 914 | /** |
cd34758c | 915 | * bdev_open_by_path - open a block device by name |
d4d77629 | 916 | * @path: path to the block device to open |
05bdb996 | 917 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 918 | * @holder: exclusive holder identifier |
e89e001f | 919 | * @hops: holder operations |
d4d77629 | 920 | * |
2736e8ee CH |
921 | * Open the block device described by the device file at @path. If @holder is |
922 | * not %NULL, the block device is opened with exclusive access. Exclusive opens | |
923 | * may nest for the same @holder. | |
d4d77629 TH |
924 | * |
925 | * CONTEXT: | |
926 | * Might sleep. | |
927 | * | |
928 | * RETURNS: | |
cd34758c JK |
929 | * Handle with a reference to the block_device on success, ERR_PTR(-errno) on |
930 | * failure. | |
d4d77629 | 931 | */ |
e719b4d1 JK |
932 | struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode, |
933 | void *holder, const struct blk_holder_ops *hops) | |
934 | { | |
935 | struct bdev_handle *handle; | |
936 | dev_t dev; | |
937 | int error; | |
938 | ||
939 | error = lookup_bdev(path, &dev); | |
940 | if (error) | |
941 | return ERR_PTR(error); | |
942 | ||
943 | handle = bdev_open_by_dev(dev, mode, holder, hops); | |
944 | if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) && | |
945 | bdev_read_only(handle->bdev)) { | |
946 | bdev_release(handle); | |
947 | return ERR_PTR(-EACCES); | |
948 | } | |
949 | ||
950 | return handle; | |
951 | } | |
952 | EXPORT_SYMBOL(bdev_open_by_path); | |
953 | ||
cd34758c | 954 | void bdev_release(struct bdev_handle *handle) |
2e7b651d | 955 | { |
cd34758c | 956 | struct block_device *bdev = handle->bdev; |
2e7b651d PZ |
957 | struct gendisk *disk = bdev->bd_disk; |
958 | ||
b849dd84 DA |
959 | /* |
960 | * Sync early if it looks like we're the last one. If someone else | |
961 | * opens the block device between now and the decrement of bd_openers | |
962 | * then we did a sync that we didn't need to, but that's not the end | |
963 | * of the world and we want to avoid long (could be several minute) | |
964 | * syncs while holding the mutex. | |
965 | */ | |
9acf381f | 966 | if (atomic_read(&bdev->bd_openers) == 1) |
b849dd84 DA |
967 | sync_blockdev(bdev); |
968 | ||
a8698707 | 969 | mutex_lock(&disk->open_mutex); |
ed5cc702 JK |
970 | bdev_yield_write_access(bdev, handle->mode); |
971 | ||
cd34758c JK |
972 | if (handle->holder) |
973 | bd_end_claim(bdev, handle->holder); | |
77ea887e | 974 | |
85ef06d1 TH |
975 | /* |
976 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
977 | * event. This is to ensure detection of media removal commanded | |
978 | * from userland - e.g. eject(1). | |
979 | */ | |
5b56b6ed | 980 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 | 981 | |
c8276b95 | 982 | if (bdev_is_partition(bdev)) |
ae220766 | 983 | blkdev_put_part(bdev); |
c8276b95 | 984 | else |
ae220766 | 985 | blkdev_put_whole(bdev); |
a8698707 CH |
986 | mutex_unlock(&disk->open_mutex); |
987 | ||
efcf5932 | 988 | module_put(disk->fops->owner); |
22ae8ce8 | 989 | blkdev_put_no_open(bdev); |
e719b4d1 JK |
990 | kfree(handle); |
991 | } | |
992 | EXPORT_SYMBOL(bdev_release); | |
993 | ||
1da177e4 | 994 | /** |
0ba4566c MWO |
995 | * lookup_bdev() - Look up a struct block_device by name. |
996 | * @pathname: Name of the block device in the filesystem. | |
997 | * @dev: Pointer to the block device's dev_t, if found. | |
1da177e4 | 998 | * |
057178cf | 999 | * Lookup the block device's dev_t at @pathname in the current |
0ba4566c | 1000 | * namespace if possible and return it in @dev. |
057178cf | 1001 | * |
0ba4566c MWO |
1002 | * Context: May sleep. |
1003 | * Return: 0 if succeeded, negative errno otherwise. | |
1da177e4 | 1004 | */ |
4e7b5671 | 1005 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 1006 | { |
1da177e4 | 1007 | struct inode *inode; |
421748ec | 1008 | struct path path; |
1da177e4 LT |
1009 | int error; |
1010 | ||
421748ec | 1011 | if (!pathname || !*pathname) |
4e7b5671 | 1012 | return -EINVAL; |
1da177e4 | 1013 | |
421748ec | 1014 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 1015 | if (error) |
4e7b5671 | 1016 | return error; |
1da177e4 | 1017 | |
bb668734 | 1018 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1019 | error = -ENOTBLK; |
1020 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 1021 | goto out_path_put; |
1da177e4 | 1022 | error = -EACCES; |
a2982cc9 | 1023 | if (!may_open_dev(&path)) |
4e7b5671 CH |
1024 | goto out_path_put; |
1025 | ||
1026 | *dev = inode->i_rdev; | |
1027 | error = 0; | |
1028 | out_path_put: | |
421748ec | 1029 | path_put(&path); |
4e7b5671 | 1030 | return error; |
1da177e4 | 1031 | } |
d5686b44 | 1032 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1033 | |
560e20e4 CH |
1034 | /** |
1035 | * bdev_mark_dead - mark a block device as dead | |
1036 | * @bdev: block device to operate on | |
1037 | * @surprise: indicate a surprise removal | |
1038 | * | |
1039 | * Tell the file system that this devices or media is dead. If @surprise is set | |
1040 | * to %true the device or media is already gone, if not we are preparing for an | |
1041 | * orderly removal. | |
1042 | * | |
d8530de5 CH |
1043 | * This calls into the file system, which then typicall syncs out all dirty data |
1044 | * and writes back inodes and then invalidates any cached data in the inodes on | |
1045 | * the file system. In addition we also invalidate the block device mapping. | |
560e20e4 CH |
1046 | */ |
1047 | void bdev_mark_dead(struct block_device *bdev, bool surprise) | |
b71e8a4c | 1048 | { |
d8530de5 CH |
1049 | mutex_lock(&bdev->bd_holder_lock); |
1050 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead) | |
1051 | bdev->bd_holder_ops->mark_dead(bdev, surprise); | |
fd146410 JK |
1052 | else { |
1053 | mutex_unlock(&bdev->bd_holder_lock); | |
d8530de5 | 1054 | sync_blockdev(bdev); |
fd146410 | 1055 | } |
b71e8a4c | 1056 | |
f98393a6 | 1057 | invalidate_bdev(bdev); |
b71e8a4c | 1058 | } |
560e20e4 | 1059 | /* |
6e57236e CH |
1060 | * New drivers should not use this directly. There are some drivers however |
1061 | * that needs this for historical reasons. For example, the DASD driver has | |
1062 | * historically had a shutdown to offline mode that doesn't actually remove the | |
1063 | * gendisk that otherwise looks a lot like a safe device removal. | |
560e20e4 CH |
1064 | */ |
1065 | EXPORT_SYMBOL_GPL(bdev_mark_dead); | |
5c0d6b60 | 1066 | |
1e03a36b | 1067 | void sync_bdevs(bool wait) |
5c0d6b60 JK |
1068 | { |
1069 | struct inode *inode, *old_inode = NULL; | |
1070 | ||
74278da9 | 1071 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1072 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1073 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1074 | struct block_device *bdev; |
5c0d6b60 JK |
1075 | |
1076 | spin_lock(&inode->i_lock); | |
1077 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1078 | mapping->nrpages == 0) { | |
1079 | spin_unlock(&inode->i_lock); | |
1080 | continue; | |
1081 | } | |
1082 | __iget(inode); | |
1083 | spin_unlock(&inode->i_lock); | |
74278da9 | 1084 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1085 | /* |
1086 | * We hold a reference to 'inode' so it couldn't have been | |
1087 | * removed from s_inodes list while we dropped the | |
74278da9 | 1088 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1089 | * be holding the last reference and we cannot iput it under |
74278da9 | 1090 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1091 | * later. |
1092 | */ | |
1093 | iput(old_inode); | |
1094 | old_inode = inode; | |
af309226 | 1095 | bdev = I_BDEV(inode); |
5c0d6b60 | 1096 | |
a8698707 | 1097 | mutex_lock(&bdev->bd_disk->open_mutex); |
9acf381f | 1098 | if (!atomic_read(&bdev->bd_openers)) { |
1e03a36b CH |
1099 | ; /* skip */ |
1100 | } else if (wait) { | |
1101 | /* | |
1102 | * We keep the error status of individual mapping so | |
1103 | * that applications can catch the writeback error using | |
1104 | * fsync(2). See filemap_fdatawait_keep_errors() for | |
1105 | * details. | |
1106 | */ | |
1107 | filemap_fdatawait_keep_errors(inode->i_mapping); | |
1108 | } else { | |
1109 | filemap_fdatawrite(inode->i_mapping); | |
1110 | } | |
a8698707 | 1111 | mutex_unlock(&bdev->bd_disk->open_mutex); |
5c0d6b60 | 1112 | |
74278da9 | 1113 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1114 | } |
74278da9 | 1115 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1116 | iput(old_inode); |
1117 | } | |
2d985f8c EB |
1118 | |
1119 | /* | |
1120 | * Handle STATX_DIOALIGN for block devices. | |
1121 | * | |
1122 | * Note that the inode passed to this is the inode of a block device node file, | |
1123 | * not the block device's internal inode. Therefore it is *not* valid to use | |
1124 | * I_BDEV() here; the block device has to be looked up by i_rdev instead. | |
1125 | */ | |
1126 | void bdev_statx_dioalign(struct inode *inode, struct kstat *stat) | |
1127 | { | |
1128 | struct block_device *bdev; | |
1129 | ||
1130 | bdev = blkdev_get_no_open(inode->i_rdev); | |
1131 | if (!bdev) | |
1132 | return; | |
1133 | ||
1134 | stat->dio_mem_align = bdev_dma_alignment(bdev) + 1; | |
1135 | stat->dio_offset_align = bdev_logical_block_size(bdev); | |
1136 | stat->result_mask |= STATX_DIOALIGN; | |
1137 | ||
1138 | blkdev_put_no_open(bdev); | |
1139 | } | |
ed5cc702 JK |
1140 | |
1141 | static int __init setup_bdev_allow_write_mounted(char *str) | |
1142 | { | |
1143 | if (kstrtobool(str, &bdev_allow_write_mounted)) | |
1144 | pr_warn("Invalid option string for bdev_allow_write_mounted:" | |
1145 | " '%s'\n", str); | |
1146 | return 1; | |
1147 | } | |
1148 | __setup("bdev_allow_write_mounted=", setup_bdev_allow_write_mounted); |