Commit | Line | Data |
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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> | |
ff01bb48 | 27 | #include <linux/cleancache.h> |
15e3d2c5 | 28 | #include <linux/part_stat.h> |
7c0f6ba6 | 29 | #include <linux/uaccess.h> |
0dca4462 CH |
30 | #include "../fs/internal.h" |
31 | #include "blk.h" | |
1da177e4 LT |
32 | |
33 | struct bdev_inode { | |
34 | struct block_device bdev; | |
35 | struct inode vfs_inode; | |
36 | }; | |
37 | ||
38 | static inline struct bdev_inode *BDEV_I(struct inode *inode) | |
39 | { | |
40 | return container_of(inode, struct bdev_inode, vfs_inode); | |
41 | } | |
42 | ||
ff5053f6 | 43 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
44 | { |
45 | return &BDEV_I(inode)->bdev; | |
46 | } | |
1da177e4 LT |
47 | EXPORT_SYMBOL(I_BDEV); |
48 | ||
dbd3ca50 | 49 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 50 | { |
dbd3ca50 VG |
51 | struct inode *inode = bdev->bd_inode; |
52 | int ret; | |
53 | ||
564f00f6 CH |
54 | spin_lock(&inode->i_lock); |
55 | while (inode->i_state & I_DIRTY) { | |
56 | spin_unlock(&inode->i_lock); | |
dbd3ca50 VG |
57 | ret = write_inode_now(inode, true); |
58 | if (ret) { | |
59 | char name[BDEVNAME_SIZE]; | |
60 | pr_warn_ratelimited("VFS: Dirty inode writeback failed " | |
61 | "for block device %s (err=%d).\n", | |
62 | bdevname(bdev, name), ret); | |
63 | } | |
564f00f6 CH |
64 | spin_lock(&inode->i_lock); |
65 | } | |
66 | spin_unlock(&inode->i_lock); | |
67 | } | |
68 | ||
f9a14399 | 69 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 70 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 71 | { |
ff01bb48 AV |
72 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
73 | ||
7716506a | 74 | if (mapping_empty(mapping)) |
f9a14399 | 75 | return; |
ff01bb48 | 76 | |
f9a14399 | 77 | invalidate_bh_lrus(); |
ff01bb48 | 78 | truncate_inode_pages(mapping, 0); |
3373a346 | 79 | } |
ff01bb48 AV |
80 | |
81 | /* Invalidate clean unused buffers and pagecache. */ | |
82 | void invalidate_bdev(struct block_device *bdev) | |
83 | { | |
84 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
85 | ||
a5f6a6a9 AR |
86 | if (mapping->nrpages) { |
87 | invalidate_bh_lrus(); | |
88 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
89 | invalidate_mapping_pages(mapping, 0, -1); | |
90 | } | |
ff01bb48 AV |
91 | /* 99% of the time, we don't need to flush the cleancache on the bdev. |
92 | * But, for the strange corners, lets be cautious | |
93 | */ | |
3167760f | 94 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
95 | } |
96 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 97 | |
384d87ef JK |
98 | /* |
99 | * Drop all buffers & page cache for given bdev range. This function bails | |
100 | * with error if bdev has other exclusive owner (such as filesystem). | |
101 | */ | |
102 | int truncate_bdev_range(struct block_device *bdev, fmode_t mode, | |
103 | loff_t lstart, loff_t lend) | |
104 | { | |
384d87ef JK |
105 | /* |
106 | * If we don't hold exclusive handle for the device, upgrade to it | |
107 | * while we discard the buffer cache to avoid discarding buffers | |
108 | * under live filesystem. | |
109 | */ | |
110 | if (!(mode & FMODE_EXCL)) { | |
37c3fc9a | 111 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range); |
384d87ef | 112 | if (err) |
56887cff | 113 | goto invalidate; |
384d87ef | 114 | } |
37c3fc9a | 115 | |
384d87ef | 116 | truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); |
37c3fc9a CH |
117 | if (!(mode & FMODE_EXCL)) |
118 | bd_abort_claiming(bdev, truncate_bdev_range); | |
384d87ef | 119 | return 0; |
56887cff JK |
120 | |
121 | invalidate: | |
122 | /* | |
123 | * Someone else has handle exclusively open. Try invalidating instead. | |
124 | * The 'end' argument is inclusive so the rounding is safe. | |
125 | */ | |
126 | return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, | |
127 | lstart >> PAGE_SHIFT, | |
128 | lend >> PAGE_SHIFT); | |
384d87ef | 129 | } |
384d87ef | 130 | |
04906b2f JK |
131 | static void set_init_blocksize(struct block_device *bdev) |
132 | { | |
8dc932d3 MM |
133 | unsigned int bsize = bdev_logical_block_size(bdev); |
134 | loff_t size = i_size_read(bdev->bd_inode); | |
135 | ||
136 | while (bsize < PAGE_SIZE) { | |
137 | if (size & bsize) | |
138 | break; | |
139 | bsize <<= 1; | |
140 | } | |
141 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
04906b2f JK |
142 | } |
143 | ||
1da177e4 LT |
144 | int set_blocksize(struct block_device *bdev, int size) |
145 | { | |
146 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 147 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
148 | return -EINVAL; |
149 | ||
150 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 151 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
152 | return -EINVAL; |
153 | ||
154 | /* Don't change the size if it is same as current */ | |
6b7b181b | 155 | if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 156 | sync_blockdev(bdev); |
1da177e4 LT |
157 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
158 | kill_bdev(bdev); | |
159 | } | |
160 | return 0; | |
161 | } | |
162 | ||
163 | EXPORT_SYMBOL(set_blocksize); | |
164 | ||
165 | int sb_set_blocksize(struct super_block *sb, int size) | |
166 | { | |
1da177e4 LT |
167 | if (set_blocksize(sb->s_bdev, size)) |
168 | return 0; | |
169 | /* If we get here, we know size is power of two | |
170 | * and it's value is between 512 and PAGE_SIZE */ | |
171 | sb->s_blocksize = size; | |
38885bd4 | 172 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
173 | return sb->s_blocksize; |
174 | } | |
175 | ||
176 | EXPORT_SYMBOL(sb_set_blocksize); | |
177 | ||
178 | int sb_min_blocksize(struct super_block *sb, int size) | |
179 | { | |
e1defc4f | 180 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
181 | if (size < minsize) |
182 | size = minsize; | |
183 | return sb_set_blocksize(sb, size); | |
184 | } | |
185 | ||
186 | EXPORT_SYMBOL(sb_min_blocksize); | |
187 | ||
5cee5815 JK |
188 | int __sync_blockdev(struct block_device *bdev, int wait) |
189 | { | |
190 | if (!bdev) | |
191 | return 0; | |
192 | if (!wait) | |
193 | return filemap_flush(bdev->bd_inode->i_mapping); | |
194 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
195 | } | |
196 | ||
585d3bc0 NP |
197 | /* |
198 | * Write out and wait upon all the dirty data associated with a block | |
199 | * device via its mapping. Does not take the superblock lock. | |
200 | */ | |
201 | int sync_blockdev(struct block_device *bdev) | |
202 | { | |
5cee5815 | 203 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
204 | } |
205 | EXPORT_SYMBOL(sync_blockdev); | |
206 | ||
207 | /* | |
208 | * Write out and wait upon all dirty data associated with this | |
209 | * device. Filesystem data as well as the underlying block | |
210 | * device. Takes the superblock lock. | |
211 | */ | |
212 | int fsync_bdev(struct block_device *bdev) | |
213 | { | |
214 | struct super_block *sb = get_super(bdev); | |
215 | if (sb) { | |
60b0680f | 216 | int res = sync_filesystem(sb); |
585d3bc0 NP |
217 | drop_super(sb); |
218 | return res; | |
219 | } | |
220 | return sync_blockdev(bdev); | |
221 | } | |
47e4491b | 222 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
223 | |
224 | /** | |
225 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
226 | * @bdev: blockdevice to lock | |
227 | * | |
585d3bc0 NP |
228 | * If a superblock is found on this device, we take the s_umount semaphore |
229 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
230 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
231 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
232 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
233 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
234 | * actually. | |
235 | */ | |
040f04bd | 236 | int freeze_bdev(struct block_device *bdev) |
585d3bc0 NP |
237 | { |
238 | struct super_block *sb; | |
239 | int error = 0; | |
240 | ||
241 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd CH |
242 | if (++bdev->bd_fsfreeze_count > 1) |
243 | goto done; | |
4504230a CH |
244 | |
245 | sb = get_active_super(bdev); | |
246 | if (!sb) | |
040f04bd | 247 | goto sync; |
48b6bca6 BM |
248 | if (sb->s_op->freeze_super) |
249 | error = sb->s_op->freeze_super(sb); | |
250 | else | |
251 | error = freeze_super(sb); | |
040f04bd CH |
252 | deactivate_super(sb); |
253 | ||
18e9e510 | 254 | if (error) { |
18e9e510 | 255 | bdev->bd_fsfreeze_count--; |
040f04bd | 256 | goto done; |
585d3bc0 | 257 | } |
040f04bd CH |
258 | bdev->bd_fsfreeze_sb = sb; |
259 | ||
260 | sync: | |
585d3bc0 | 261 | sync_blockdev(bdev); |
040f04bd | 262 | done: |
585d3bc0 | 263 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 264 | return error; |
585d3bc0 NP |
265 | } |
266 | EXPORT_SYMBOL(freeze_bdev); | |
267 | ||
268 | /** | |
269 | * thaw_bdev -- unlock filesystem | |
270 | * @bdev: blockdevice to unlock | |
585d3bc0 NP |
271 | * |
272 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
273 | */ | |
040f04bd | 274 | int thaw_bdev(struct block_device *bdev) |
585d3bc0 | 275 | { |
040f04bd | 276 | struct super_block *sb; |
4504230a | 277 | int error = -EINVAL; |
585d3bc0 NP |
278 | |
279 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 280 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 281 | goto out; |
4504230a CH |
282 | |
283 | error = 0; | |
284 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 285 | goto out; |
4504230a | 286 | |
040f04bd | 287 | sb = bdev->bd_fsfreeze_sb; |
4504230a | 288 | if (!sb) |
18e9e510 | 289 | goto out; |
4504230a | 290 | |
48b6bca6 BM |
291 | if (sb->s_op->thaw_super) |
292 | error = sb->s_op->thaw_super(sb); | |
293 | else | |
294 | error = thaw_super(sb); | |
997198ba | 295 | if (error) |
18e9e510 | 296 | bdev->bd_fsfreeze_count++; |
04a6a536 ST |
297 | else |
298 | bdev->bd_fsfreeze_sb = NULL; | |
18e9e510 | 299 | out: |
585d3bc0 | 300 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 301 | return error; |
585d3bc0 NP |
302 | } |
303 | EXPORT_SYMBOL(thaw_bdev); | |
304 | ||
47a191fd MW |
305 | /** |
306 | * bdev_read_page() - Start reading a page from a block device | |
307 | * @bdev: The device to read the page from | |
308 | * @sector: The offset on the device to read the page to (need not be aligned) | |
309 | * @page: The page to read | |
310 | * | |
311 | * On entry, the page should be locked. It will be unlocked when the page | |
312 | * has been read. If the block driver implements rw_page synchronously, | |
313 | * that will be true on exit from this function, but it need not be. | |
314 | * | |
315 | * Errors returned by this function are usually "soft", eg out of memory, or | |
316 | * queue full; callers should try a different route to read this page rather | |
317 | * than propagate an error back up the stack. | |
318 | * | |
319 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
320 | */ | |
321 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
322 | struct page *page) | |
323 | { | |
324 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
2e6edc95 DW |
325 | int result = -EOPNOTSUPP; |
326 | ||
f68eb1e7 | 327 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
2e6edc95 DW |
328 | return result; |
329 | ||
025a3865 | 330 | result = blk_queue_enter(bdev_get_queue(bdev), 0); |
2e6edc95 DW |
331 | if (result) |
332 | return result; | |
3f289dcb TH |
333 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
334 | REQ_OP_READ); | |
025a3865 | 335 | blk_queue_exit(bdev_get_queue(bdev)); |
2e6edc95 | 336 | return result; |
47a191fd | 337 | } |
47a191fd MW |
338 | |
339 | /** | |
340 | * bdev_write_page() - Start writing a page to a block device | |
341 | * @bdev: The device to write the page to | |
342 | * @sector: The offset on the device to write the page to (need not be aligned) | |
343 | * @page: The page to write | |
344 | * @wbc: The writeback_control for the write | |
345 | * | |
346 | * On entry, the page should be locked and not currently under writeback. | |
347 | * On exit, if the write started successfully, the page will be unlocked and | |
348 | * under writeback. If the write failed already (eg the driver failed to | |
349 | * queue the page to the device), the page will still be locked. If the | |
350 | * caller is a ->writepage implementation, it will need to unlock the page. | |
351 | * | |
352 | * Errors returned by this function are usually "soft", eg out of memory, or | |
353 | * queue full; callers should try a different route to write this page rather | |
354 | * than propagate an error back up the stack. | |
355 | * | |
356 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
357 | */ | |
358 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
359 | struct page *page, struct writeback_control *wbc) | |
360 | { | |
361 | int result; | |
47a191fd | 362 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
2e6edc95 | 363 | |
f68eb1e7 | 364 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd | 365 | return -EOPNOTSUPP; |
025a3865 | 366 | result = blk_queue_enter(bdev_get_queue(bdev), 0); |
2e6edc95 DW |
367 | if (result) |
368 | return result; | |
369 | ||
47a191fd | 370 | set_page_writeback(page); |
3f289dcb TH |
371 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
372 | REQ_OP_WRITE); | |
f892760a | 373 | if (result) { |
47a191fd | 374 | end_page_writeback(page); |
f892760a MW |
375 | } else { |
376 | clean_page_buffers(page); | |
47a191fd | 377 | unlock_page(page); |
f892760a | 378 | } |
025a3865 | 379 | blk_queue_exit(bdev_get_queue(bdev)); |
47a191fd MW |
380 | return result; |
381 | } | |
47a191fd | 382 | |
1da177e4 LT |
383 | /* |
384 | * pseudo-fs | |
385 | */ | |
386 | ||
387 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 388 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
389 | |
390 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
391 | { | |
e94b1766 | 392 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 393 | |
1da177e4 LT |
394 | if (!ei) |
395 | return NULL; | |
2d2f6f1b | 396 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
1da177e4 LT |
397 | return &ei->vfs_inode; |
398 | } | |
399 | ||
41149cb0 | 400 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 401 | { |
15e3d2c5 CH |
402 | struct block_device *bdev = I_BDEV(inode); |
403 | ||
404 | free_percpu(bdev->bd_stats); | |
231926db | 405 | kfree(bdev->bd_meta_info); |
15e3d2c5 | 406 | |
889c05cc CH |
407 | if (!bdev_is_partition(bdev)) { |
408 | if (bdev->bd_disk && bdev->bd_disk->bdi) | |
409 | bdi_put(bdev->bd_disk->bdi); | |
340e8457 | 410 | kfree(bdev->bd_disk); |
889c05cc | 411 | } |
9451aa0a CH |
412 | |
413 | if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) | |
414 | blk_free_ext_minor(MINOR(bdev->bd_dev)); | |
415 | ||
41149cb0 | 416 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
417 | } |
418 | ||
e6cb5382 | 419 | static void init_once(void *data) |
1da177e4 | 420 | { |
e6cb5382 | 421 | struct bdev_inode *ei = data; |
1da177e4 | 422 | |
a35afb83 | 423 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
424 | } |
425 | ||
b57922d9 | 426 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 | 427 | { |
91b0abe3 | 428 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 429 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 430 | clear_inode(inode); |
1da177e4 LT |
431 | } |
432 | ||
ee9b6d61 | 433 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
434 | .statfs = simple_statfs, |
435 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 436 | .free_inode = bdev_free_inode, |
1da177e4 | 437 | .drop_inode = generic_delete_inode, |
b57922d9 | 438 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
439 | }; |
440 | ||
9030d16e | 441 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 442 | { |
9030d16e DH |
443 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
444 | if (!ctx) | |
445 | return -ENOMEM; | |
446 | fc->s_iflags |= SB_I_CGROUPWB; | |
447 | ctx->ops = &bdev_sops; | |
448 | return 0; | |
1da177e4 LT |
449 | } |
450 | ||
451 | static struct file_system_type bd_type = { | |
452 | .name = "bdev", | |
9030d16e | 453 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
454 | .kill_sb = kill_anon_super, |
455 | }; | |
456 | ||
a212b105 TH |
457 | struct super_block *blockdev_superblock __read_mostly; |
458 | EXPORT_SYMBOL_GPL(blockdev_superblock); | |
1da177e4 LT |
459 | |
460 | void __init bdev_cache_init(void) | |
461 | { | |
462 | int err; | |
ace8577a | 463 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 464 | |
1da177e4 | 465 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 466 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 467 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 468 | init_once); |
1da177e4 LT |
469 | err = register_filesystem(&bd_type); |
470 | if (err) | |
471 | panic("Cannot register bdev pseudo-fs"); | |
472 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
473 | if (IS_ERR(bd_mnt)) |
474 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 475 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
476 | } |
477 | ||
22ae8ce8 | 478 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
479 | { |
480 | struct block_device *bdev; | |
481 | struct inode *inode; | |
482 | ||
22ae8ce8 | 483 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
484 | if (!inode) |
485 | return NULL; | |
22ae8ce8 CH |
486 | inode->i_mode = S_IFBLK; |
487 | inode->i_rdev = 0; | |
488 | inode->i_data.a_ops = &def_blk_aops; | |
489 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
490 | ||
491 | bdev = I_BDEV(inode); | |
e6cb5382 | 492 | mutex_init(&bdev->bd_fsfreeze_mutex); |
22ae8ce8 | 493 | spin_lock_init(&bdev->bd_size_lock); |
22ae8ce8 | 494 | bdev->bd_partno = partno; |
22ae8ce8 | 495 | bdev->bd_inode = inode; |
17220ca5 | 496 | bdev->bd_queue = disk->queue; |
15e3d2c5 CH |
497 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
498 | if (!bdev->bd_stats) { | |
499 | iput(inode); | |
500 | return NULL; | |
501 | } | |
06cc978d | 502 | bdev->bd_disk = disk; |
22ae8ce8 CH |
503 | return bdev; |
504 | } | |
1da177e4 | 505 | |
22ae8ce8 CH |
506 | void bdev_add(struct block_device *bdev, dev_t dev) |
507 | { | |
508 | bdev->bd_dev = dev; | |
509 | bdev->bd_inode->i_rdev = dev; | |
510 | bdev->bd_inode->i_ino = dev; | |
511 | insert_inode_hash(bdev->bd_inode); | |
512 | } | |
1da177e4 | 513 | |
1da177e4 LT |
514 | long nr_blockdev_pages(void) |
515 | { | |
1008fe6d | 516 | struct inode *inode; |
1da177e4 | 517 | long ret = 0; |
1008fe6d CH |
518 | |
519 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
520 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
521 | ret += inode->i_mapping->nrpages; | |
522 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
523 | ||
1da177e4 LT |
524 | return ret; |
525 | } | |
526 | ||
1a3cbbc5 TH |
527 | /** |
528 | * bd_may_claim - test whether a block device can be claimed | |
529 | * @bdev: block device of interest | |
530 | * @whole: whole block device containing @bdev, may equal @bdev | |
531 | * @holder: holder trying to claim @bdev | |
532 | * | |
25985edc | 533 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
534 | * |
535 | * CONTEXT: | |
536 | * spin_lock(&bdev_lock). | |
537 | * | |
538 | * RETURNS: | |
539 | * %true if @bdev can be claimed, %false otherwise. | |
540 | */ | |
541 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
542 | void *holder) | |
1da177e4 | 543 | { |
1da177e4 | 544 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 545 | return true; /* already a holder */ |
1da177e4 | 546 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 547 | return false; /* held by someone else */ |
bcc7f5b4 | 548 | else if (whole == bdev) |
1a3cbbc5 | 549 | return true; /* is a whole device which isn't held */ |
1da177e4 | 550 | |
e525fd89 | 551 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
552 | return true; /* is a partition of a device that is being partitioned */ |
553 | else if (whole->bd_holder != NULL) | |
554 | return false; /* is a partition of a held device */ | |
1da177e4 | 555 | else |
1a3cbbc5 TH |
556 | return true; /* is a partition of an un-held device */ |
557 | } | |
558 | ||
6b4517a7 | 559 | /** |
58e46ed9 | 560 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 561 | * @bdev: block device of interest |
6b4517a7 TH |
562 | * @holder: holder trying to claim @bdev |
563 | * | |
58e46ed9 CH |
564 | * Claim @bdev. This function fails if @bdev is already claimed by another |
565 | * holder and waits if another claiming is in progress. return, the caller | |
566 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
567 | * |
568 | * RETURNS: | |
569 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
570 | */ | |
37c3fc9a | 571 | int bd_prepare_to_claim(struct block_device *bdev, void *holder) |
6b4517a7 | 572 | { |
37c3fc9a CH |
573 | struct block_device *whole = bdev_whole(bdev); |
574 | ||
575 | if (WARN_ON_ONCE(!holder)) | |
576 | return -EINVAL; | |
6b4517a7 | 577 | retry: |
58e46ed9 | 578 | spin_lock(&bdev_lock); |
6b4517a7 | 579 | /* if someone else claimed, fail */ |
58e46ed9 CH |
580 | if (!bd_may_claim(bdev, whole, holder)) { |
581 | spin_unlock(&bdev_lock); | |
6b4517a7 | 582 | return -EBUSY; |
58e46ed9 | 583 | } |
6b4517a7 | 584 | |
e75aa858 TH |
585 | /* if claiming is already in progress, wait for it to finish */ |
586 | if (whole->bd_claiming) { | |
6b4517a7 TH |
587 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
588 | DEFINE_WAIT(wait); | |
589 | ||
590 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
591 | spin_unlock(&bdev_lock); | |
592 | schedule(); | |
593 | finish_wait(wq, &wait); | |
6b4517a7 TH |
594 | goto retry; |
595 | } | |
596 | ||
597 | /* yay, all mine */ | |
58e46ed9 CH |
598 | whole->bd_claiming = holder; |
599 | spin_unlock(&bdev_lock); | |
6b4517a7 TH |
600 | return 0; |
601 | } | |
ecbe6bc0 | 602 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 603 | |
89e524c0 JK |
604 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
605 | { | |
606 | lockdep_assert_held(&bdev_lock); | |
607 | /* tell others that we're done */ | |
608 | BUG_ON(whole->bd_claiming != holder); | |
609 | whole->bd_claiming = NULL; | |
610 | wake_up_bit(&whole->bd_claiming, 0); | |
611 | } | |
612 | ||
613 | /** | |
614 | * bd_finish_claiming - finish claiming of a block device | |
615 | * @bdev: block device of interest | |
89e524c0 JK |
616 | * @holder: holder that has claimed @bdev |
617 | * | |
618 | * Finish exclusive open of a block device. Mark the device as exlusively | |
619 | * open by the holder and wake up all waiters for exclusive open to finish. | |
620 | */ | |
37c3fc9a | 621 | static void bd_finish_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 622 | { |
37c3fc9a CH |
623 | struct block_device *whole = bdev_whole(bdev); |
624 | ||
89e524c0 JK |
625 | spin_lock(&bdev_lock); |
626 | BUG_ON(!bd_may_claim(bdev, whole, holder)); | |
627 | /* | |
628 | * Note that for a whole device bd_holders will be incremented twice, | |
629 | * and bd_holder will be set to bd_may_claim before being set to holder | |
630 | */ | |
631 | whole->bd_holders++; | |
632 | whole->bd_holder = bd_may_claim; | |
633 | bdev->bd_holders++; | |
634 | bdev->bd_holder = holder; | |
635 | bd_clear_claiming(whole, holder); | |
636 | spin_unlock(&bdev_lock); | |
637 | } | |
89e524c0 JK |
638 | |
639 | /** | |
640 | * bd_abort_claiming - abort claiming of a block device | |
641 | * @bdev: block device of interest | |
89e524c0 JK |
642 | * @holder: holder that has claimed @bdev |
643 | * | |
644 | * Abort claiming of a block device when the exclusive open failed. This can be | |
645 | * also used when exclusive open is not actually desired and we just needed | |
646 | * to block other exclusive openers for a while. | |
647 | */ | |
37c3fc9a | 648 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 JK |
649 | { |
650 | spin_lock(&bdev_lock); | |
37c3fc9a | 651 | bd_clear_claiming(bdev_whole(bdev), holder); |
89e524c0 JK |
652 | spin_unlock(&bdev_lock); |
653 | } | |
654 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 655 | |
c8276b95 CH |
656 | static void blkdev_flush_mapping(struct block_device *bdev) |
657 | { | |
658 | WARN_ON_ONCE(bdev->bd_holders); | |
659 | sync_blockdev(bdev); | |
660 | kill_bdev(bdev); | |
661 | bdev_write_inode(bdev); | |
662 | } | |
37be4124 | 663 | |
362529d9 | 664 | static int blkdev_get_whole(struct block_device *bdev, fmode_t mode) |
a1548b67 | 665 | { |
142fe8f4 | 666 | struct gendisk *disk = bdev->bd_disk; |
d173b65a | 667 | int ret = 0; |
a1548b67 | 668 | |
362529d9 CH |
669 | if (disk->fops->open) { |
670 | ret = disk->fops->open(bdev, mode); | |
671 | if (ret) { | |
672 | /* avoid ghost partitions on a removed medium */ | |
673 | if (ret == -ENOMEDIUM && | |
674 | test_bit(GD_NEED_PART_SCAN, &disk->state)) | |
0384264e | 675 | bdev_disk_changed(disk, true); |
362529d9 CH |
676 | return ret; |
677 | } | |
d981cb5b | 678 | } |
a1548b67 | 679 | |
a11d7fc2 | 680 | if (!bdev->bd_openers) |
362529d9 | 681 | set_init_blocksize(bdev); |
362529d9 | 682 | if (test_bit(GD_NEED_PART_SCAN, &disk->state)) |
0384264e | 683 | bdev_disk_changed(disk, false); |
362529d9 CH |
684 | bdev->bd_openers++; |
685 | return 0;; | |
686 | } | |
a1548b67 | 687 | |
c8276b95 CH |
688 | static void blkdev_put_whole(struct block_device *bdev, fmode_t mode) |
689 | { | |
690 | if (!--bdev->bd_openers) | |
691 | blkdev_flush_mapping(bdev); | |
692 | if (bdev->bd_disk->fops->release) | |
693 | bdev->bd_disk->fops->release(bdev->bd_disk, mode); | |
a1548b67 CH |
694 | } |
695 | ||
362529d9 | 696 | static int blkdev_get_part(struct block_device *part, fmode_t mode) |
1da177e4 | 697 | { |
362529d9 | 698 | struct gendisk *disk = part->bd_disk; |
362529d9 | 699 | int ret; |
5b642d8b | 700 | |
362529d9 CH |
701 | if (part->bd_openers) |
702 | goto done; | |
6c60ff04 | 703 | |
9d3b8813 | 704 | ret = blkdev_get_whole(bdev_whole(part), mode); |
a8698707 | 705 | if (ret) |
9d3b8813 | 706 | return ret; |
7e69723f | 707 | |
362529d9 CH |
708 | ret = -ENXIO; |
709 | if (!bdev_nr_sectors(part)) | |
710 | goto out_blkdev_put; | |
7e69723f | 711 | |
ab4b5705 | 712 | disk->open_partitions++; |
362529d9 | 713 | set_init_blocksize(part); |
362529d9 CH |
714 | done: |
715 | part->bd_openers++; | |
1da177e4 | 716 | return 0; |
5a023cdb | 717 | |
362529d9 | 718 | out_blkdev_put: |
9d3b8813 | 719 | blkdev_put_whole(bdev_whole(part), mode); |
362529d9 | 720 | return ret; |
1da177e4 | 721 | } |
5b56b6ed | 722 | |
c8276b95 CH |
723 | static void blkdev_put_part(struct block_device *part, fmode_t mode) |
724 | { | |
725 | struct block_device *whole = bdev_whole(part); | |
03e26279 | 726 | |
c8276b95 CH |
727 | if (--part->bd_openers) |
728 | return; | |
729 | blkdev_flush_mapping(part); | |
ab4b5705 | 730 | whole->bd_disk->open_partitions--; |
c8276b95 | 731 | blkdev_put_whole(whole, mode); |
1da177e4 LT |
732 | } |
733 | ||
22ae8ce8 CH |
734 | struct block_device *blkdev_get_no_open(dev_t dev) |
735 | { | |
736 | struct block_device *bdev; | |
9d3b8813 | 737 | struct inode *inode; |
22ae8ce8 | 738 | |
9d3b8813 CH |
739 | inode = ilookup(blockdev_superblock, dev); |
740 | if (!inode) { | |
22ae8ce8 | 741 | blk_request_module(dev); |
9d3b8813 CH |
742 | inode = ilookup(blockdev_superblock, dev); |
743 | if (!inode) | |
6c60ff04 | 744 | return NULL; |
22ae8ce8 CH |
745 | } |
746 | ||
9d3b8813 CH |
747 | /* switch from the inode reference to a device mode one: */ |
748 | bdev = &BDEV_I(inode)->bdev; | |
749 | if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) | |
750 | bdev = NULL; | |
751 | iput(inode); | |
752 | ||
753 | if (!bdev) | |
754 | return NULL; | |
755 | if ((bdev->bd_disk->flags & GENHD_FL_HIDDEN) || | |
756 | !try_module_get(bdev->bd_disk->fops->owner)) { | |
757 | put_device(&bdev->bd_device); | |
758 | return NULL; | |
759 | } | |
760 | ||
22ae8ce8 | 761 | return bdev; |
22ae8ce8 CH |
762 | } |
763 | ||
764 | void blkdev_put_no_open(struct block_device *bdev) | |
765 | { | |
766 | module_put(bdev->bd_disk->fops->owner); | |
9d3b8813 | 767 | put_device(&bdev->bd_device); |
22ae8ce8 CH |
768 | } |
769 | ||
d4d77629 | 770 | /** |
4e7b5671 CH |
771 | * blkdev_get_by_dev - open a block device by device number |
772 | * @dev: device number of block device to open | |
d4d77629 TH |
773 | * @mode: FMODE_* mask |
774 | * @holder: exclusive holder identifier | |
775 | * | |
4e7b5671 CH |
776 | * Open the block device described by device number @dev. If @mode includes |
777 | * %FMODE_EXCL, the block device is opened with exclusive access. Specifying | |
778 | * %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may nest for | |
779 | * the same @holder. | |
d4d77629 | 780 | * |
4e7b5671 CH |
781 | * Use this interface ONLY if you really do not have anything better - i.e. when |
782 | * you are behind a truly sucky interface and all you are given is a device | |
783 | * number. Everything else should use blkdev_get_by_path(). | |
d4d77629 TH |
784 | * |
785 | * CONTEXT: | |
786 | * Might sleep. | |
787 | * | |
788 | * RETURNS: | |
4e7b5671 | 789 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 | 790 | */ |
4e7b5671 | 791 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) |
1da177e4 | 792 | { |
5b56b6ed | 793 | bool unblock_events = true; |
4e7b5671 | 794 | struct block_device *bdev; |
5b56b6ed | 795 | struct gendisk *disk; |
5b56b6ed | 796 | int ret; |
e525fd89 | 797 | |
7918f0f6 | 798 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, |
4e7b5671 | 799 | MAJOR(dev), MINOR(dev), |
7918f0f6 CH |
800 | ((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) | |
801 | ((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
e5c7fb40 | 802 | if (ret) |
4e7b5671 CH |
803 | return ERR_PTR(ret); |
804 | ||
22ae8ce8 CH |
805 | bdev = blkdev_get_no_open(dev); |
806 | if (!bdev) | |
807 | return ERR_PTR(-ENXIO); | |
808 | disk = bdev->bd_disk; | |
e5c7fb40 | 809 | |
5b56b6ed | 810 | if (mode & FMODE_EXCL) { |
37c3fc9a | 811 | ret = bd_prepare_to_claim(bdev, holder); |
5b56b6ed | 812 | if (ret) |
37c3fc9a | 813 | goto put_blkdev; |
5b56b6ed CH |
814 | } |
815 | ||
816 | disk_block_events(disk); | |
817 | ||
a8698707 | 818 | mutex_lock(&disk->open_mutex); |
362529d9 | 819 | ret = -ENXIO; |
50b4aecf | 820 | if (!disk_live(disk)) |
362529d9 CH |
821 | goto abort_claiming; |
822 | if (bdev_is_partition(bdev)) | |
823 | ret = blkdev_get_part(bdev, mode); | |
824 | else | |
825 | ret = blkdev_get_whole(bdev, mode); | |
22ae8ce8 CH |
826 | if (ret) |
827 | goto abort_claiming; | |
828 | if (mode & FMODE_EXCL) { | |
37c3fc9a | 829 | bd_finish_claiming(bdev, holder); |
5b56b6ed CH |
830 | |
831 | /* | |
832 | * Block event polling for write claims if requested. Any write | |
833 | * holder makes the write_holder state stick until all are | |
834 | * released. This is good enough and tracking individual | |
835 | * writeable reference is too fragile given the way @mode is | |
836 | * used in blkdev_get/put(). | |
837 | */ | |
838 | if ((mode & FMODE_WRITE) && !bdev->bd_write_holder && | |
839 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
840 | bdev->bd_write_holder = true; | |
841 | unblock_events = false; | |
842 | } | |
843 | } | |
a8698707 | 844 | mutex_unlock(&disk->open_mutex); |
5b56b6ed CH |
845 | |
846 | if (unblock_events) | |
847 | disk_unblock_events(disk); | |
22ae8ce8 | 848 | return bdev; |
5b56b6ed | 849 | |
22ae8ce8 CH |
850 | abort_claiming: |
851 | if (mode & FMODE_EXCL) | |
37c3fc9a | 852 | bd_abort_claiming(bdev, holder); |
a8698707 | 853 | mutex_unlock(&disk->open_mutex); |
22ae8ce8 | 854 | disk_unblock_events(disk); |
22ae8ce8 CH |
855 | put_blkdev: |
856 | blkdev_put_no_open(bdev); | |
22ae8ce8 | 857 | return ERR_PTR(ret); |
37be4124 | 858 | } |
4e7b5671 | 859 | EXPORT_SYMBOL(blkdev_get_by_dev); |
1da177e4 | 860 | |
d4d77629 TH |
861 | /** |
862 | * blkdev_get_by_path - open a block device by name | |
863 | * @path: path to the block device to open | |
864 | * @mode: FMODE_* mask | |
865 | * @holder: exclusive holder identifier | |
866 | * | |
4e7b5671 CH |
867 | * Open the block device described by the device file at @path. If @mode |
868 | * includes %FMODE_EXCL, the block device is opened with exclusive access. | |
869 | * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may | |
870 | * nest for the same @holder. | |
d4d77629 TH |
871 | * |
872 | * CONTEXT: | |
873 | * Might sleep. | |
874 | * | |
875 | * RETURNS: | |
4e7b5671 | 876 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 TH |
877 | */ |
878 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
879 | void *holder) | |
880 | { | |
881 | struct block_device *bdev; | |
4e7b5671 CH |
882 | dev_t dev; |
883 | int error; | |
d4d77629 | 884 | |
4e7b5671 CH |
885 | error = lookup_bdev(path, &dev); |
886 | if (error) | |
887 | return ERR_PTR(error); | |
d4d77629 | 888 | |
4e7b5671 CH |
889 | bdev = blkdev_get_by_dev(dev, mode, holder); |
890 | if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { | |
e51900f7 CE |
891 | blkdev_put(bdev, mode); |
892 | return ERR_PTR(-EACCES); | |
893 | } | |
894 | ||
d4d77629 TH |
895 | return bdev; |
896 | } | |
897 | EXPORT_SYMBOL(blkdev_get_by_path); | |
898 | ||
4385bab1 | 899 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
2e7b651d | 900 | { |
2e7b651d PZ |
901 | struct gendisk *disk = bdev->bd_disk; |
902 | ||
b849dd84 DA |
903 | /* |
904 | * Sync early if it looks like we're the last one. If someone else | |
905 | * opens the block device between now and the decrement of bd_openers | |
906 | * then we did a sync that we didn't need to, but that's not the end | |
907 | * of the world and we want to avoid long (could be several minute) | |
908 | * syncs while holding the mutex. | |
909 | */ | |
910 | if (bdev->bd_openers == 1) | |
911 | sync_blockdev(bdev); | |
912 | ||
a8698707 | 913 | mutex_lock(&disk->open_mutex); |
e525fd89 | 914 | if (mode & FMODE_EXCL) { |
a954ea81 | 915 | struct block_device *whole = bdev_whole(bdev); |
6a027eff TH |
916 | bool bdev_free; |
917 | ||
918 | /* | |
919 | * Release a claim on the device. The holder fields | |
a8698707 | 920 | * are protected with bdev_lock. open_mutex is to |
6a027eff TH |
921 | * synchronize disk_holder unlinking. |
922 | */ | |
6a027eff TH |
923 | spin_lock(&bdev_lock); |
924 | ||
925 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
a954ea81 | 926 | WARN_ON_ONCE(--whole->bd_holders < 0); |
6a027eff | 927 | |
6a027eff TH |
928 | if ((bdev_free = !bdev->bd_holders)) |
929 | bdev->bd_holder = NULL; | |
a954ea81 CH |
930 | if (!whole->bd_holders) |
931 | whole->bd_holder = NULL; | |
6a027eff TH |
932 | |
933 | spin_unlock(&bdev_lock); | |
934 | ||
77ea887e TH |
935 | /* |
936 | * If this was the last claim, remove holder link and | |
937 | * unblock evpoll if it was a write holder. | |
938 | */ | |
85ef06d1 | 939 | if (bdev_free && bdev->bd_write_holder) { |
5b56b6ed | 940 | disk_unblock_events(disk); |
85ef06d1 | 941 | bdev->bd_write_holder = false; |
77ea887e | 942 | } |
6936217c | 943 | } |
77ea887e | 944 | |
85ef06d1 TH |
945 | /* |
946 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
947 | * event. This is to ensure detection of media removal commanded | |
948 | * from userland - e.g. eject(1). | |
949 | */ | |
5b56b6ed | 950 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 | 951 | |
c8276b95 CH |
952 | if (bdev_is_partition(bdev)) |
953 | blkdev_put_part(bdev, mode); | |
954 | else | |
955 | blkdev_put_whole(bdev, mode); | |
a8698707 CH |
956 | mutex_unlock(&disk->open_mutex); |
957 | ||
22ae8ce8 | 958 | blkdev_put_no_open(bdev); |
37be4124 | 959 | } |
2e7b651d PZ |
960 | EXPORT_SYMBOL(blkdev_put); |
961 | ||
1da177e4 LT |
962 | /** |
963 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 964 | * @pathname: special file representing the block device |
875b2376 | 965 | * @dev: return value of the block device's dev_t |
1da177e4 | 966 | * |
57d1b536 | 967 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
968 | * namespace if possible and return it. Return ERR_PTR(error) |
969 | * otherwise. | |
970 | */ | |
4e7b5671 | 971 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 972 | { |
1da177e4 | 973 | struct inode *inode; |
421748ec | 974 | struct path path; |
1da177e4 LT |
975 | int error; |
976 | ||
421748ec | 977 | if (!pathname || !*pathname) |
4e7b5671 | 978 | return -EINVAL; |
1da177e4 | 979 | |
421748ec | 980 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 981 | if (error) |
4e7b5671 | 982 | return error; |
1da177e4 | 983 | |
bb668734 | 984 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
985 | error = -ENOTBLK; |
986 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 987 | goto out_path_put; |
1da177e4 | 988 | error = -EACCES; |
a2982cc9 | 989 | if (!may_open_dev(&path)) |
4e7b5671 CH |
990 | goto out_path_put; |
991 | ||
992 | *dev = inode->i_rdev; | |
993 | error = 0; | |
994 | out_path_put: | |
421748ec | 995 | path_put(&path); |
4e7b5671 | 996 | return error; |
1da177e4 | 997 | } |
d5686b44 | 998 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 999 | |
93b270f7 | 1000 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
1001 | { |
1002 | struct super_block *sb = get_super(bdev); | |
1003 | int res = 0; | |
1004 | ||
1005 | if (sb) { | |
1006 | /* | |
1007 | * no need to lock the super, get_super holds the | |
1008 | * read mutex so the filesystem cannot go away | |
1009 | * under us (->put_super runs with the write lock | |
1010 | * hold). | |
1011 | */ | |
1012 | shrink_dcache_sb(sb); | |
93b270f7 | 1013 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
1014 | drop_super(sb); |
1015 | } | |
f98393a6 | 1016 | invalidate_bdev(bdev); |
b71e8a4c DH |
1017 | return res; |
1018 | } | |
1019 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
1020 | |
1021 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
1022 | { | |
1023 | struct inode *inode, *old_inode = NULL; | |
1024 | ||
74278da9 | 1025 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1026 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1027 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1028 | struct block_device *bdev; |
5c0d6b60 JK |
1029 | |
1030 | spin_lock(&inode->i_lock); | |
1031 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1032 | mapping->nrpages == 0) { | |
1033 | spin_unlock(&inode->i_lock); | |
1034 | continue; | |
1035 | } | |
1036 | __iget(inode); | |
1037 | spin_unlock(&inode->i_lock); | |
74278da9 | 1038 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1039 | /* |
1040 | * We hold a reference to 'inode' so it couldn't have been | |
1041 | * removed from s_inodes list while we dropped the | |
74278da9 | 1042 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1043 | * be holding the last reference and we cannot iput it under |
74278da9 | 1044 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1045 | * later. |
1046 | */ | |
1047 | iput(old_inode); | |
1048 | old_inode = inode; | |
af309226 | 1049 | bdev = I_BDEV(inode); |
5c0d6b60 | 1050 | |
a8698707 | 1051 | mutex_lock(&bdev->bd_disk->open_mutex); |
af309226 RV |
1052 | if (bdev->bd_openers) |
1053 | func(bdev, arg); | |
a8698707 | 1054 | mutex_unlock(&bdev->bd_disk->open_mutex); |
5c0d6b60 | 1055 | |
74278da9 | 1056 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1057 | } |
74278da9 | 1058 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1059 | iput(old_inode); |
1060 | } |