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 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 | 57 | ret = write_inode_now(inode, true); |
5bf83e9a CH |
58 | if (ret) |
59 | pr_warn_ratelimited( | |
60 | "VFS: Dirty inode writeback failed for block device %pg (err=%d).\n", | |
61 | bdev, ret); | |
564f00f6 CH |
62 | spin_lock(&inode->i_lock); |
63 | } | |
64 | spin_unlock(&inode->i_lock); | |
65 | } | |
66 | ||
f9a14399 | 67 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 68 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 69 | { |
ff01bb48 AV |
70 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
71 | ||
7716506a | 72 | if (mapping_empty(mapping)) |
f9a14399 | 73 | return; |
ff01bb48 | 74 | |
f9a14399 | 75 | invalidate_bh_lrus(); |
ff01bb48 | 76 | truncate_inode_pages(mapping, 0); |
3373a346 | 77 | } |
ff01bb48 AV |
78 | |
79 | /* Invalidate clean unused buffers and pagecache. */ | |
80 | void invalidate_bdev(struct block_device *bdev) | |
81 | { | |
82 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
83 | ||
a5f6a6a9 AR |
84 | if (mapping->nrpages) { |
85 | invalidate_bh_lrus(); | |
86 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
87 | invalidate_mapping_pages(mapping, 0, -1); | |
88 | } | |
ff01bb48 AV |
89 | } |
90 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 91 | |
384d87ef JK |
92 | /* |
93 | * Drop all buffers & page cache for given bdev range. This function bails | |
94 | * with error if bdev has other exclusive owner (such as filesystem). | |
95 | */ | |
05bdb996 | 96 | int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode, |
384d87ef JK |
97 | loff_t lstart, loff_t lend) |
98 | { | |
384d87ef JK |
99 | /* |
100 | * If we don't hold exclusive handle for the device, upgrade to it | |
101 | * while we discard the buffer cache to avoid discarding buffers | |
102 | * under live filesystem. | |
103 | */ | |
05bdb996 | 104 | if (!(mode & BLK_OPEN_EXCL)) { |
0718afd4 | 105 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL); |
384d87ef | 106 | if (err) |
56887cff | 107 | goto invalidate; |
384d87ef | 108 | } |
37c3fc9a | 109 | |
384d87ef | 110 | truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); |
05bdb996 | 111 | if (!(mode & BLK_OPEN_EXCL)) |
37c3fc9a | 112 | bd_abort_claiming(bdev, truncate_bdev_range); |
384d87ef | 113 | return 0; |
56887cff JK |
114 | |
115 | invalidate: | |
116 | /* | |
117 | * Someone else has handle exclusively open. Try invalidating instead. | |
118 | * The 'end' argument is inclusive so the rounding is safe. | |
119 | */ | |
120 | return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, | |
121 | lstart >> PAGE_SHIFT, | |
122 | lend >> PAGE_SHIFT); | |
384d87ef | 123 | } |
384d87ef | 124 | |
04906b2f JK |
125 | static void set_init_blocksize(struct block_device *bdev) |
126 | { | |
8dc932d3 MM |
127 | unsigned int bsize = bdev_logical_block_size(bdev); |
128 | loff_t size = i_size_read(bdev->bd_inode); | |
129 | ||
130 | while (bsize < PAGE_SIZE) { | |
131 | if (size & bsize) | |
132 | break; | |
133 | bsize <<= 1; | |
134 | } | |
135 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
04906b2f JK |
136 | } |
137 | ||
1da177e4 LT |
138 | int set_blocksize(struct block_device *bdev, int size) |
139 | { | |
140 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 141 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
142 | return -EINVAL; |
143 | ||
144 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 145 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
146 | return -EINVAL; |
147 | ||
148 | /* Don't change the size if it is same as current */ | |
6b7b181b | 149 | if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 150 | sync_blockdev(bdev); |
1da177e4 LT |
151 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
152 | kill_bdev(bdev); | |
153 | } | |
154 | return 0; | |
155 | } | |
156 | ||
157 | EXPORT_SYMBOL(set_blocksize); | |
158 | ||
159 | int sb_set_blocksize(struct super_block *sb, int size) | |
160 | { | |
1da177e4 LT |
161 | if (set_blocksize(sb->s_bdev, size)) |
162 | return 0; | |
163 | /* If we get here, we know size is power of two | |
164 | * and it's value is between 512 and PAGE_SIZE */ | |
165 | sb->s_blocksize = size; | |
38885bd4 | 166 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
167 | return sb->s_blocksize; |
168 | } | |
169 | ||
170 | EXPORT_SYMBOL(sb_set_blocksize); | |
171 | ||
172 | int sb_min_blocksize(struct super_block *sb, int size) | |
173 | { | |
e1defc4f | 174 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
175 | if (size < minsize) |
176 | size = minsize; | |
177 | return sb_set_blocksize(sb, size); | |
178 | } | |
179 | ||
180 | EXPORT_SYMBOL(sb_min_blocksize); | |
181 | ||
70164eb6 | 182 | int sync_blockdev_nowait(struct block_device *bdev) |
5cee5815 JK |
183 | { |
184 | if (!bdev) | |
185 | return 0; | |
70164eb6 | 186 | return filemap_flush(bdev->bd_inode->i_mapping); |
5cee5815 | 187 | } |
70164eb6 | 188 | EXPORT_SYMBOL_GPL(sync_blockdev_nowait); |
5cee5815 | 189 | |
585d3bc0 NP |
190 | /* |
191 | * Write out and wait upon all the dirty data associated with a block | |
192 | * device via its mapping. Does not take the superblock lock. | |
193 | */ | |
194 | int sync_blockdev(struct block_device *bdev) | |
195 | { | |
70164eb6 CH |
196 | if (!bdev) |
197 | return 0; | |
198 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
585d3bc0 NP |
199 | } |
200 | EXPORT_SYMBOL(sync_blockdev); | |
201 | ||
97d6fb1b YM |
202 | int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend) |
203 | { | |
204 | return filemap_write_and_wait_range(bdev->bd_inode->i_mapping, | |
205 | lstart, lend); | |
206 | } | |
207 | EXPORT_SYMBOL(sync_blockdev_range); | |
208 | ||
585d3bc0 | 209 | /** |
2e833c8c | 210 | * freeze_bdev - lock a filesystem and force it into a consistent state |
585d3bc0 NP |
211 | * @bdev: blockdevice to lock |
212 | * | |
585d3bc0 NP |
213 | * If a superblock is found on this device, we take the s_umount semaphore |
214 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
215 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
216 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
217 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
218 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
219 | * actually. | |
220 | */ | |
040f04bd | 221 | int freeze_bdev(struct block_device *bdev) |
585d3bc0 NP |
222 | { |
223 | struct super_block *sb; | |
224 | int error = 0; | |
225 | ||
226 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd CH |
227 | if (++bdev->bd_fsfreeze_count > 1) |
228 | goto done; | |
4504230a CH |
229 | |
230 | sb = get_active_super(bdev); | |
231 | if (!sb) | |
040f04bd | 232 | goto sync; |
48b6bca6 | 233 | if (sb->s_op->freeze_super) |
880b9577 | 234 | error = sb->s_op->freeze_super(sb, FREEZE_HOLDER_USERSPACE); |
48b6bca6 | 235 | else |
880b9577 | 236 | error = freeze_super(sb, FREEZE_HOLDER_USERSPACE); |
040f04bd CH |
237 | deactivate_super(sb); |
238 | ||
18e9e510 | 239 | if (error) { |
18e9e510 | 240 | bdev->bd_fsfreeze_count--; |
040f04bd | 241 | goto done; |
585d3bc0 | 242 | } |
040f04bd CH |
243 | bdev->bd_fsfreeze_sb = sb; |
244 | ||
245 | sync: | |
585d3bc0 | 246 | sync_blockdev(bdev); |
040f04bd | 247 | done: |
585d3bc0 | 248 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 249 | return error; |
585d3bc0 NP |
250 | } |
251 | EXPORT_SYMBOL(freeze_bdev); | |
252 | ||
253 | /** | |
2e833c8c | 254 | * thaw_bdev - unlock filesystem |
585d3bc0 | 255 | * @bdev: blockdevice to unlock |
585d3bc0 NP |
256 | * |
257 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
258 | */ | |
040f04bd | 259 | int thaw_bdev(struct block_device *bdev) |
585d3bc0 | 260 | { |
040f04bd | 261 | struct super_block *sb; |
4504230a | 262 | int error = -EINVAL; |
585d3bc0 NP |
263 | |
264 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 265 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 266 | goto out; |
4504230a CH |
267 | |
268 | error = 0; | |
269 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 270 | goto out; |
4504230a | 271 | |
040f04bd | 272 | sb = bdev->bd_fsfreeze_sb; |
4504230a | 273 | if (!sb) |
18e9e510 | 274 | goto out; |
4504230a | 275 | |
48b6bca6 | 276 | if (sb->s_op->thaw_super) |
880b9577 | 277 | error = sb->s_op->thaw_super(sb, FREEZE_HOLDER_USERSPACE); |
48b6bca6 | 278 | else |
880b9577 | 279 | error = thaw_super(sb, FREEZE_HOLDER_USERSPACE); |
997198ba | 280 | if (error) |
18e9e510 | 281 | bdev->bd_fsfreeze_count++; |
04a6a536 ST |
282 | else |
283 | bdev->bd_fsfreeze_sb = NULL; | |
18e9e510 | 284 | out: |
585d3bc0 | 285 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 286 | return error; |
585d3bc0 NP |
287 | } |
288 | EXPORT_SYMBOL(thaw_bdev); | |
289 | ||
1da177e4 LT |
290 | /* |
291 | * pseudo-fs | |
292 | */ | |
293 | ||
74e6464a | 294 | static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); |
68279f9c | 295 | static struct kmem_cache *bdev_cachep __ro_after_init; |
1da177e4 LT |
296 | |
297 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
298 | { | |
fd60b288 | 299 | struct bdev_inode *ei = alloc_inode_sb(sb, bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 300 | |
1da177e4 LT |
301 | if (!ei) |
302 | return NULL; | |
2d2f6f1b | 303 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
1da177e4 LT |
304 | return &ei->vfs_inode; |
305 | } | |
306 | ||
41149cb0 | 307 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 308 | { |
15e3d2c5 CH |
309 | struct block_device *bdev = I_BDEV(inode); |
310 | ||
311 | free_percpu(bdev->bd_stats); | |
231926db | 312 | kfree(bdev->bd_meta_info); |
15e3d2c5 | 313 | |
889c05cc CH |
314 | if (!bdev_is_partition(bdev)) { |
315 | if (bdev->bd_disk && bdev->bd_disk->bdi) | |
316 | bdi_put(bdev->bd_disk->bdi); | |
340e8457 | 317 | kfree(bdev->bd_disk); |
889c05cc | 318 | } |
9451aa0a CH |
319 | |
320 | if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) | |
321 | blk_free_ext_minor(MINOR(bdev->bd_dev)); | |
322 | ||
41149cb0 | 323 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
324 | } |
325 | ||
e6cb5382 | 326 | static void init_once(void *data) |
1da177e4 | 327 | { |
e6cb5382 | 328 | struct bdev_inode *ei = data; |
1da177e4 | 329 | |
a35afb83 | 330 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
331 | } |
332 | ||
b57922d9 | 333 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 | 334 | { |
91b0abe3 | 335 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 336 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 337 | clear_inode(inode); |
1da177e4 LT |
338 | } |
339 | ||
ee9b6d61 | 340 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
341 | .statfs = simple_statfs, |
342 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 343 | .free_inode = bdev_free_inode, |
1da177e4 | 344 | .drop_inode = generic_delete_inode, |
b57922d9 | 345 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
346 | }; |
347 | ||
9030d16e | 348 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 349 | { |
9030d16e DH |
350 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
351 | if (!ctx) | |
352 | return -ENOMEM; | |
353 | fc->s_iflags |= SB_I_CGROUPWB; | |
354 | ctx->ops = &bdev_sops; | |
355 | return 0; | |
1da177e4 LT |
356 | } |
357 | ||
358 | static struct file_system_type bd_type = { | |
359 | .name = "bdev", | |
9030d16e | 360 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
361 | .kill_sb = kill_anon_super, |
362 | }; | |
363 | ||
68279f9c | 364 | struct super_block *blockdev_superblock __ro_after_init; |
a212b105 | 365 | EXPORT_SYMBOL_GPL(blockdev_superblock); |
1da177e4 LT |
366 | |
367 | void __init bdev_cache_init(void) | |
368 | { | |
369 | int err; | |
68279f9c | 370 | static struct vfsmount *bd_mnt __ro_after_init; |
c2acf7b9 | 371 | |
1da177e4 | 372 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 373 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 374 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 375 | init_once); |
1da177e4 LT |
376 | err = register_filesystem(&bd_type); |
377 | if (err) | |
378 | panic("Cannot register bdev pseudo-fs"); | |
379 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
380 | if (IS_ERR(bd_mnt)) |
381 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 382 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
383 | } |
384 | ||
22ae8ce8 | 385 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
386 | { |
387 | struct block_device *bdev; | |
388 | struct inode *inode; | |
389 | ||
22ae8ce8 | 390 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
391 | if (!inode) |
392 | return NULL; | |
22ae8ce8 CH |
393 | inode->i_mode = S_IFBLK; |
394 | inode->i_rdev = 0; | |
395 | inode->i_data.a_ops = &def_blk_aops; | |
396 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
397 | ||
398 | bdev = I_BDEV(inode); | |
e6cb5382 | 399 | mutex_init(&bdev->bd_fsfreeze_mutex); |
22ae8ce8 | 400 | spin_lock_init(&bdev->bd_size_lock); |
0718afd4 | 401 | mutex_init(&bdev->bd_holder_lock); |
22ae8ce8 | 402 | bdev->bd_partno = partno; |
22ae8ce8 | 403 | bdev->bd_inode = inode; |
17220ca5 | 404 | bdev->bd_queue = disk->queue; |
38c8e3df ML |
405 | if (partno) |
406 | bdev->bd_has_submit_bio = disk->part0->bd_has_submit_bio; | |
407 | else | |
408 | bdev->bd_has_submit_bio = false; | |
15e3d2c5 CH |
409 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
410 | if (!bdev->bd_stats) { | |
411 | iput(inode); | |
412 | return NULL; | |
413 | } | |
06cc978d | 414 | bdev->bd_disk = disk; |
22ae8ce8 CH |
415 | return bdev; |
416 | } | |
1da177e4 | 417 | |
83794367 DLM |
418 | void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) |
419 | { | |
420 | spin_lock(&bdev->bd_size_lock); | |
421 | i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); | |
422 | bdev->bd_nr_sectors = sectors; | |
423 | spin_unlock(&bdev->bd_size_lock); | |
424 | } | |
425 | ||
22ae8ce8 CH |
426 | void bdev_add(struct block_device *bdev, dev_t dev) |
427 | { | |
428 | bdev->bd_dev = dev; | |
429 | bdev->bd_inode->i_rdev = dev; | |
430 | bdev->bd_inode->i_ino = dev; | |
431 | insert_inode_hash(bdev->bd_inode); | |
432 | } | |
1da177e4 | 433 | |
1da177e4 LT |
434 | long nr_blockdev_pages(void) |
435 | { | |
1008fe6d | 436 | struct inode *inode; |
1da177e4 | 437 | long ret = 0; |
1008fe6d CH |
438 | |
439 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
440 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
441 | ret += inode->i_mapping->nrpages; | |
442 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
443 | ||
1da177e4 LT |
444 | return ret; |
445 | } | |
446 | ||
1a3cbbc5 TH |
447 | /** |
448 | * bd_may_claim - test whether a block device can be claimed | |
449 | * @bdev: block device of interest | |
1a3cbbc5 | 450 | * @holder: holder trying to claim @bdev |
0718afd4 | 451 | * @hops: holder ops |
1a3cbbc5 | 452 | * |
25985edc | 453 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 | 454 | * |
1a3cbbc5 TH |
455 | * RETURNS: |
456 | * %true if @bdev can be claimed, %false otherwise. | |
457 | */ | |
0718afd4 CH |
458 | static bool bd_may_claim(struct block_device *bdev, void *holder, |
459 | const struct blk_holder_ops *hops) | |
ae5f855e CH |
460 | { |
461 | struct block_device *whole = bdev_whole(bdev); | |
462 | ||
74e6464a CH |
463 | lockdep_assert_held(&bdev_lock); |
464 | ||
ae5f855e CH |
465 | if (bdev->bd_holder) { |
466 | /* | |
467 | * The same holder can always re-claim. | |
468 | */ | |
0718afd4 CH |
469 | if (bdev->bd_holder == holder) { |
470 | if (WARN_ON_ONCE(bdev->bd_holder_ops != hops)) | |
471 | return false; | |
ae5f855e | 472 | return true; |
0718afd4 | 473 | } |
ae5f855e CH |
474 | return false; |
475 | } | |
476 | ||
477 | /* | |
478 | * If the whole devices holder is set to bd_may_claim, a partition on | |
479 | * the device is claimed, but not the whole device. | |
480 | */ | |
481 | if (whole != bdev && | |
482 | whole->bd_holder && whole->bd_holder != bd_may_claim) | |
483 | return false; | |
484 | return true; | |
1a3cbbc5 TH |
485 | } |
486 | ||
6b4517a7 | 487 | /** |
58e46ed9 | 488 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 489 | * @bdev: block device of interest |
6b4517a7 | 490 | * @holder: holder trying to claim @bdev |
0718afd4 | 491 | * @hops: holder ops. |
6b4517a7 | 492 | * |
58e46ed9 CH |
493 | * Claim @bdev. This function fails if @bdev is already claimed by another |
494 | * holder and waits if another claiming is in progress. return, the caller | |
495 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
496 | * |
497 | * RETURNS: | |
498 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
499 | */ | |
0718afd4 CH |
500 | int bd_prepare_to_claim(struct block_device *bdev, void *holder, |
501 | const struct blk_holder_ops *hops) | |
6b4517a7 | 502 | { |
37c3fc9a CH |
503 | struct block_device *whole = bdev_whole(bdev); |
504 | ||
505 | if (WARN_ON_ONCE(!holder)) | |
506 | return -EINVAL; | |
6b4517a7 | 507 | retry: |
74e6464a | 508 | mutex_lock(&bdev_lock); |
6b4517a7 | 509 | /* if someone else claimed, fail */ |
0718afd4 | 510 | if (!bd_may_claim(bdev, holder, hops)) { |
74e6464a | 511 | mutex_unlock(&bdev_lock); |
6b4517a7 | 512 | return -EBUSY; |
58e46ed9 | 513 | } |
6b4517a7 | 514 | |
e75aa858 TH |
515 | /* if claiming is already in progress, wait for it to finish */ |
516 | if (whole->bd_claiming) { | |
6b4517a7 TH |
517 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
518 | DEFINE_WAIT(wait); | |
519 | ||
520 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
74e6464a | 521 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
522 | schedule(); |
523 | finish_wait(wq, &wait); | |
6b4517a7 TH |
524 | goto retry; |
525 | } | |
526 | ||
527 | /* yay, all mine */ | |
58e46ed9 | 528 | whole->bd_claiming = holder; |
74e6464a | 529 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
530 | return 0; |
531 | } | |
ecbe6bc0 | 532 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 533 | |
89e524c0 JK |
534 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
535 | { | |
536 | lockdep_assert_held(&bdev_lock); | |
537 | /* tell others that we're done */ | |
538 | BUG_ON(whole->bd_claiming != holder); | |
539 | whole->bd_claiming = NULL; | |
540 | wake_up_bit(&whole->bd_claiming, 0); | |
541 | } | |
542 | ||
543 | /** | |
544 | * bd_finish_claiming - finish claiming of a block device | |
545 | * @bdev: block device of interest | |
89e524c0 | 546 | * @holder: holder that has claimed @bdev |
017fb83e | 547 | * @hops: block device holder operations |
89e524c0 JK |
548 | * |
549 | * Finish exclusive open of a block device. Mark the device as exlusively | |
550 | * open by the holder and wake up all waiters for exclusive open to finish. | |
551 | */ | |
0718afd4 CH |
552 | static void bd_finish_claiming(struct block_device *bdev, void *holder, |
553 | const struct blk_holder_ops *hops) | |
89e524c0 | 554 | { |
37c3fc9a CH |
555 | struct block_device *whole = bdev_whole(bdev); |
556 | ||
74e6464a | 557 | mutex_lock(&bdev_lock); |
0718afd4 | 558 | BUG_ON(!bd_may_claim(bdev, holder, hops)); |
89e524c0 JK |
559 | /* |
560 | * Note that for a whole device bd_holders will be incremented twice, | |
561 | * and bd_holder will be set to bd_may_claim before being set to holder | |
562 | */ | |
563 | whole->bd_holders++; | |
564 | whole->bd_holder = bd_may_claim; | |
565 | bdev->bd_holders++; | |
0718afd4 | 566 | mutex_lock(&bdev->bd_holder_lock); |
89e524c0 | 567 | bdev->bd_holder = holder; |
0718afd4 CH |
568 | bdev->bd_holder_ops = hops; |
569 | mutex_unlock(&bdev->bd_holder_lock); | |
89e524c0 | 570 | bd_clear_claiming(whole, holder); |
74e6464a | 571 | mutex_unlock(&bdev_lock); |
89e524c0 | 572 | } |
89e524c0 JK |
573 | |
574 | /** | |
575 | * bd_abort_claiming - abort claiming of a block device | |
576 | * @bdev: block device of interest | |
89e524c0 JK |
577 | * @holder: holder that has claimed @bdev |
578 | * | |
579 | * Abort claiming of a block device when the exclusive open failed. This can be | |
580 | * also used when exclusive open is not actually desired and we just needed | |
581 | * to block other exclusive openers for a while. | |
582 | */ | |
37c3fc9a | 583 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 584 | { |
74e6464a | 585 | mutex_lock(&bdev_lock); |
37c3fc9a | 586 | bd_clear_claiming(bdev_whole(bdev), holder); |
74e6464a | 587 | mutex_unlock(&bdev_lock); |
89e524c0 JK |
588 | } |
589 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 590 | |
2736e8ee | 591 | static void bd_end_claim(struct block_device *bdev, void *holder) |
0783b1a7 CH |
592 | { |
593 | struct block_device *whole = bdev_whole(bdev); | |
594 | bool unblock = false; | |
595 | ||
596 | /* | |
597 | * Release a claim on the device. The holder fields are protected with | |
598 | * bdev_lock. open_mutex is used to synchronize disk_holder unlinking. | |
599 | */ | |
74e6464a | 600 | mutex_lock(&bdev_lock); |
2736e8ee | 601 | WARN_ON_ONCE(bdev->bd_holder != holder); |
0783b1a7 CH |
602 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
603 | WARN_ON_ONCE(--whole->bd_holders < 0); | |
604 | if (!bdev->bd_holders) { | |
0718afd4 | 605 | mutex_lock(&bdev->bd_holder_lock); |
0783b1a7 | 606 | bdev->bd_holder = NULL; |
0718afd4 CH |
607 | bdev->bd_holder_ops = NULL; |
608 | mutex_unlock(&bdev->bd_holder_lock); | |
0783b1a7 CH |
609 | if (bdev->bd_write_holder) |
610 | unblock = true; | |
611 | } | |
612 | if (!whole->bd_holders) | |
613 | whole->bd_holder = NULL; | |
74e6464a | 614 | mutex_unlock(&bdev_lock); |
0783b1a7 CH |
615 | |
616 | /* | |
617 | * If this was the last claim, remove holder link and unblock evpoll if | |
618 | * it was a write holder. | |
619 | */ | |
620 | if (unblock) { | |
621 | disk_unblock_events(bdev->bd_disk); | |
622 | bdev->bd_write_holder = false; | |
623 | } | |
624 | } | |
625 | ||
c8276b95 CH |
626 | static void blkdev_flush_mapping(struct block_device *bdev) |
627 | { | |
628 | WARN_ON_ONCE(bdev->bd_holders); | |
629 | sync_blockdev(bdev); | |
630 | kill_bdev(bdev); | |
631 | bdev_write_inode(bdev); | |
632 | } | |
37be4124 | 633 | |
05bdb996 | 634 | static int blkdev_get_whole(struct block_device *bdev, blk_mode_t mode) |
a1548b67 | 635 | { |
142fe8f4 | 636 | struct gendisk *disk = bdev->bd_disk; |
af22fef3 | 637 | int ret; |
a1548b67 | 638 | |
362529d9 | 639 | if (disk->fops->open) { |
d32e2bf8 | 640 | ret = disk->fops->open(disk, mode); |
362529d9 CH |
641 | if (ret) { |
642 | /* avoid ghost partitions on a removed medium */ | |
643 | if (ret == -ENOMEDIUM && | |
644 | test_bit(GD_NEED_PART_SCAN, &disk->state)) | |
0384264e | 645 | bdev_disk_changed(disk, true); |
362529d9 CH |
646 | return ret; |
647 | } | |
d981cb5b | 648 | } |
a1548b67 | 649 | |
9acf381f | 650 | if (!atomic_read(&bdev->bd_openers)) |
362529d9 | 651 | set_init_blocksize(bdev); |
362529d9 | 652 | if (test_bit(GD_NEED_PART_SCAN, &disk->state)) |
0384264e | 653 | bdev_disk_changed(disk, false); |
9acf381f | 654 | atomic_inc(&bdev->bd_openers); |
483546c1 | 655 | return 0; |
362529d9 | 656 | } |
a1548b67 | 657 | |
ae220766 | 658 | static void blkdev_put_whole(struct block_device *bdev) |
c8276b95 | 659 | { |
9acf381f | 660 | if (atomic_dec_and_test(&bdev->bd_openers)) |
c8276b95 CH |
661 | blkdev_flush_mapping(bdev); |
662 | if (bdev->bd_disk->fops->release) | |
ae220766 | 663 | bdev->bd_disk->fops->release(bdev->bd_disk); |
a1548b67 CH |
664 | } |
665 | ||
05bdb996 | 666 | static int blkdev_get_part(struct block_device *part, blk_mode_t mode) |
1da177e4 | 667 | { |
362529d9 | 668 | struct gendisk *disk = part->bd_disk; |
362529d9 | 669 | int ret; |
5b642d8b | 670 | |
9d3b8813 | 671 | ret = blkdev_get_whole(bdev_whole(part), mode); |
a8698707 | 672 | if (ret) |
9d3b8813 | 673 | return ret; |
7e69723f | 674 | |
362529d9 CH |
675 | ret = -ENXIO; |
676 | if (!bdev_nr_sectors(part)) | |
677 | goto out_blkdev_put; | |
7e69723f | 678 | |
9d1c9287 CH |
679 | if (!atomic_read(&part->bd_openers)) { |
680 | disk->open_partitions++; | |
681 | set_init_blocksize(part); | |
682 | } | |
9acf381f | 683 | atomic_inc(&part->bd_openers); |
1da177e4 | 684 | return 0; |
5a023cdb | 685 | |
362529d9 | 686 | out_blkdev_put: |
ae220766 | 687 | blkdev_put_whole(bdev_whole(part)); |
362529d9 | 688 | return ret; |
1da177e4 | 689 | } |
5b56b6ed | 690 | |
ae220766 | 691 | static void blkdev_put_part(struct block_device *part) |
c8276b95 CH |
692 | { |
693 | struct block_device *whole = bdev_whole(part); | |
03e26279 | 694 | |
9d1c9287 CH |
695 | if (atomic_dec_and_test(&part->bd_openers)) { |
696 | blkdev_flush_mapping(part); | |
697 | whole->bd_disk->open_partitions--; | |
698 | } | |
ae220766 | 699 | blkdev_put_whole(whole); |
1da177e4 LT |
700 | } |
701 | ||
22ae8ce8 CH |
702 | struct block_device *blkdev_get_no_open(dev_t dev) |
703 | { | |
704 | struct block_device *bdev; | |
9d3b8813 | 705 | struct inode *inode; |
22ae8ce8 | 706 | |
9d3b8813 | 707 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b | 708 | if (!inode && IS_ENABLED(CONFIG_BLOCK_LEGACY_AUTOLOAD)) { |
22ae8ce8 | 709 | blk_request_module(dev); |
9d3b8813 | 710 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b CH |
711 | if (inode) |
712 | pr_warn_ratelimited( | |
451f0b6f | 713 | "block device autoloading is deprecated and will be removed.\n"); |
22ae8ce8 | 714 | } |
fbdee71b CH |
715 | if (!inode) |
716 | return NULL; | |
22ae8ce8 | 717 | |
9d3b8813 CH |
718 | /* switch from the inode reference to a device mode one: */ |
719 | bdev = &BDEV_I(inode)->bdev; | |
720 | if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) | |
721 | bdev = NULL; | |
722 | iput(inode); | |
22ae8ce8 | 723 | return bdev; |
22ae8ce8 CH |
724 | } |
725 | ||
726 | void blkdev_put_no_open(struct block_device *bdev) | |
727 | { | |
9d3b8813 | 728 | put_device(&bdev->bd_device); |
22ae8ce8 | 729 | } |
05bdb996 | 730 | |
d4d77629 | 731 | /** |
4e7b5671 CH |
732 | * blkdev_get_by_dev - open a block device by device number |
733 | * @dev: device number of block device to open | |
05bdb996 | 734 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 735 | * @holder: exclusive holder identifier |
0718afd4 | 736 | * @hops: holder operations |
d4d77629 | 737 | * |
2736e8ee CH |
738 | * Open the block device described by device number @dev. If @holder is not |
739 | * %NULL, the block device is opened with exclusive access. Exclusive opens may | |
740 | * nest for the same @holder. | |
d4d77629 | 741 | * |
4e7b5671 CH |
742 | * Use this interface ONLY if you really do not have anything better - i.e. when |
743 | * you are behind a truly sucky interface and all you are given is a device | |
744 | * number. Everything else should use blkdev_get_by_path(). | |
d4d77629 TH |
745 | * |
746 | * CONTEXT: | |
747 | * Might sleep. | |
748 | * | |
749 | * RETURNS: | |
4e7b5671 | 750 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 | 751 | */ |
05bdb996 | 752 | struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder, |
0718afd4 | 753 | const struct blk_holder_ops *hops) |
1da177e4 | 754 | { |
5b56b6ed | 755 | bool unblock_events = true; |
4e7b5671 | 756 | struct block_device *bdev; |
5b56b6ed | 757 | struct gendisk *disk; |
5b56b6ed | 758 | int ret; |
e525fd89 | 759 | |
7918f0f6 | 760 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, |
4e7b5671 | 761 | MAJOR(dev), MINOR(dev), |
05bdb996 CH |
762 | ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | |
763 | ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
e5c7fb40 | 764 | if (ret) |
4e7b5671 CH |
765 | return ERR_PTR(ret); |
766 | ||
22ae8ce8 CH |
767 | bdev = blkdev_get_no_open(dev); |
768 | if (!bdev) | |
769 | return ERR_PTR(-ENXIO); | |
770 | disk = bdev->bd_disk; | |
e5c7fb40 | 771 | |
2736e8ee | 772 | if (holder) { |
05bdb996 | 773 | mode |= BLK_OPEN_EXCL; |
0718afd4 | 774 | ret = bd_prepare_to_claim(bdev, holder, hops); |
5b56b6ed | 775 | if (ret) |
37c3fc9a | 776 | goto put_blkdev; |
2736e8ee | 777 | } else { |
05bdb996 | 778 | if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) { |
2736e8ee CH |
779 | ret = -EIO; |
780 | goto put_blkdev; | |
781 | } | |
5b56b6ed CH |
782 | } |
783 | ||
784 | disk_block_events(disk); | |
785 | ||
a8698707 | 786 | mutex_lock(&disk->open_mutex); |
362529d9 | 787 | ret = -ENXIO; |
50b4aecf | 788 | if (!disk_live(disk)) |
362529d9 | 789 | goto abort_claiming; |
efcf5932 ML |
790 | if (!try_module_get(disk->fops->owner)) |
791 | goto abort_claiming; | |
362529d9 CH |
792 | if (bdev_is_partition(bdev)) |
793 | ret = blkdev_get_part(bdev, mode); | |
794 | else | |
795 | ret = blkdev_get_whole(bdev, mode); | |
22ae8ce8 | 796 | if (ret) |
efcf5932 | 797 | goto put_module; |
2736e8ee | 798 | if (holder) { |
0718afd4 | 799 | bd_finish_claiming(bdev, holder, hops); |
5b56b6ed CH |
800 | |
801 | /* | |
802 | * Block event polling for write claims if requested. Any write | |
803 | * holder makes the write_holder state stick until all are | |
804 | * released. This is good enough and tracking individual | |
805 | * writeable reference is too fragile given the way @mode is | |
806 | * used in blkdev_get/put(). | |
807 | */ | |
05bdb996 | 808 | if ((mode & BLK_OPEN_WRITE) && !bdev->bd_write_holder && |
1545e0b4 | 809 | (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) { |
5b56b6ed CH |
810 | bdev->bd_write_holder = true; |
811 | unblock_events = false; | |
812 | } | |
813 | } | |
a8698707 | 814 | mutex_unlock(&disk->open_mutex); |
5b56b6ed CH |
815 | |
816 | if (unblock_events) | |
817 | disk_unblock_events(disk); | |
22ae8ce8 | 818 | return bdev; |
efcf5932 ML |
819 | put_module: |
820 | module_put(disk->fops->owner); | |
22ae8ce8 | 821 | abort_claiming: |
2736e8ee | 822 | if (holder) |
37c3fc9a | 823 | bd_abort_claiming(bdev, holder); |
a8698707 | 824 | mutex_unlock(&disk->open_mutex); |
22ae8ce8 | 825 | disk_unblock_events(disk); |
22ae8ce8 CH |
826 | put_blkdev: |
827 | blkdev_put_no_open(bdev); | |
22ae8ce8 | 828 | return ERR_PTR(ret); |
37be4124 | 829 | } |
4e7b5671 | 830 | EXPORT_SYMBOL(blkdev_get_by_dev); |
1da177e4 | 831 | |
e719b4d1 JK |
832 | struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, |
833 | const struct blk_holder_ops *hops) | |
834 | { | |
835 | struct bdev_handle *handle = kmalloc(sizeof(*handle), GFP_KERNEL); | |
836 | struct block_device *bdev; | |
837 | ||
838 | if (!handle) | |
839 | return ERR_PTR(-ENOMEM); | |
840 | bdev = blkdev_get_by_dev(dev, mode, holder, hops); | |
841 | if (IS_ERR(bdev)) { | |
842 | kfree(handle); | |
843 | return ERR_CAST(bdev); | |
844 | } | |
845 | handle->bdev = bdev; | |
846 | handle->holder = holder; | |
841dd789 JK |
847 | if (holder) |
848 | mode |= BLK_OPEN_EXCL; | |
849 | handle->mode = mode; | |
e719b4d1 JK |
850 | return handle; |
851 | } | |
852 | EXPORT_SYMBOL(bdev_open_by_dev); | |
853 | ||
d4d77629 TH |
854 | /** |
855 | * blkdev_get_by_path - open a block device by name | |
856 | * @path: path to the block device to open | |
05bdb996 | 857 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 858 | * @holder: exclusive holder identifier |
e89e001f | 859 | * @hops: holder operations |
d4d77629 | 860 | * |
2736e8ee CH |
861 | * Open the block device described by the device file at @path. If @holder is |
862 | * not %NULL, the block device is opened with exclusive access. Exclusive opens | |
863 | * may nest for the same @holder. | |
d4d77629 TH |
864 | * |
865 | * CONTEXT: | |
866 | * Might sleep. | |
867 | * | |
868 | * RETURNS: | |
4e7b5671 | 869 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 | 870 | */ |
05bdb996 | 871 | struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode, |
0718afd4 | 872 | void *holder, const struct blk_holder_ops *hops) |
d4d77629 TH |
873 | { |
874 | struct block_device *bdev; | |
4e7b5671 CH |
875 | dev_t dev; |
876 | int error; | |
d4d77629 | 877 | |
4e7b5671 CH |
878 | error = lookup_bdev(path, &dev); |
879 | if (error) | |
880 | return ERR_PTR(error); | |
d4d77629 | 881 | |
0718afd4 | 882 | bdev = blkdev_get_by_dev(dev, mode, holder, hops); |
05bdb996 | 883 | if (!IS_ERR(bdev) && (mode & BLK_OPEN_WRITE) && bdev_read_only(bdev)) { |
2736e8ee | 884 | blkdev_put(bdev, holder); |
e51900f7 CE |
885 | return ERR_PTR(-EACCES); |
886 | } | |
887 | ||
d4d77629 TH |
888 | return bdev; |
889 | } | |
890 | EXPORT_SYMBOL(blkdev_get_by_path); | |
891 | ||
e719b4d1 JK |
892 | struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode, |
893 | void *holder, const struct blk_holder_ops *hops) | |
894 | { | |
895 | struct bdev_handle *handle; | |
896 | dev_t dev; | |
897 | int error; | |
898 | ||
899 | error = lookup_bdev(path, &dev); | |
900 | if (error) | |
901 | return ERR_PTR(error); | |
902 | ||
903 | handle = bdev_open_by_dev(dev, mode, holder, hops); | |
904 | if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) && | |
905 | bdev_read_only(handle->bdev)) { | |
906 | bdev_release(handle); | |
907 | return ERR_PTR(-EACCES); | |
908 | } | |
909 | ||
910 | return handle; | |
911 | } | |
912 | EXPORT_SYMBOL(bdev_open_by_path); | |
913 | ||
2736e8ee | 914 | void blkdev_put(struct block_device *bdev, void *holder) |
2e7b651d | 915 | { |
2e7b651d PZ |
916 | struct gendisk *disk = bdev->bd_disk; |
917 | ||
b849dd84 DA |
918 | /* |
919 | * Sync early if it looks like we're the last one. If someone else | |
920 | * opens the block device between now and the decrement of bd_openers | |
921 | * then we did a sync that we didn't need to, but that's not the end | |
922 | * of the world and we want to avoid long (could be several minute) | |
923 | * syncs while holding the mutex. | |
924 | */ | |
9acf381f | 925 | if (atomic_read(&bdev->bd_openers) == 1) |
b849dd84 DA |
926 | sync_blockdev(bdev); |
927 | ||
a8698707 | 928 | mutex_lock(&disk->open_mutex); |
2736e8ee CH |
929 | if (holder) |
930 | bd_end_claim(bdev, holder); | |
77ea887e | 931 | |
85ef06d1 TH |
932 | /* |
933 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
934 | * event. This is to ensure detection of media removal commanded | |
935 | * from userland - e.g. eject(1). | |
936 | */ | |
5b56b6ed | 937 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 | 938 | |
c8276b95 | 939 | if (bdev_is_partition(bdev)) |
ae220766 | 940 | blkdev_put_part(bdev); |
c8276b95 | 941 | else |
ae220766 | 942 | blkdev_put_whole(bdev); |
a8698707 CH |
943 | mutex_unlock(&disk->open_mutex); |
944 | ||
efcf5932 | 945 | module_put(disk->fops->owner); |
22ae8ce8 | 946 | blkdev_put_no_open(bdev); |
37be4124 | 947 | } |
2e7b651d PZ |
948 | EXPORT_SYMBOL(blkdev_put); |
949 | ||
e719b4d1 JK |
950 | void bdev_release(struct bdev_handle *handle) |
951 | { | |
952 | blkdev_put(handle->bdev, handle->holder); | |
953 | kfree(handle); | |
954 | } | |
955 | EXPORT_SYMBOL(bdev_release); | |
956 | ||
1da177e4 | 957 | /** |
0ba4566c MWO |
958 | * lookup_bdev() - Look up a struct block_device by name. |
959 | * @pathname: Name of the block device in the filesystem. | |
960 | * @dev: Pointer to the block device's dev_t, if found. | |
1da177e4 | 961 | * |
057178cf | 962 | * Lookup the block device's dev_t at @pathname in the current |
0ba4566c | 963 | * namespace if possible and return it in @dev. |
057178cf | 964 | * |
0ba4566c MWO |
965 | * Context: May sleep. |
966 | * Return: 0 if succeeded, negative errno otherwise. | |
1da177e4 | 967 | */ |
4e7b5671 | 968 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 969 | { |
1da177e4 | 970 | struct inode *inode; |
421748ec | 971 | struct path path; |
1da177e4 LT |
972 | int error; |
973 | ||
421748ec | 974 | if (!pathname || !*pathname) |
4e7b5671 | 975 | return -EINVAL; |
1da177e4 | 976 | |
421748ec | 977 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 978 | if (error) |
4e7b5671 | 979 | return error; |
1da177e4 | 980 | |
bb668734 | 981 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
982 | error = -ENOTBLK; |
983 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 984 | goto out_path_put; |
1da177e4 | 985 | error = -EACCES; |
a2982cc9 | 986 | if (!may_open_dev(&path)) |
4e7b5671 CH |
987 | goto out_path_put; |
988 | ||
989 | *dev = inode->i_rdev; | |
990 | error = 0; | |
991 | out_path_put: | |
421748ec | 992 | path_put(&path); |
4e7b5671 | 993 | return error; |
1da177e4 | 994 | } |
d5686b44 | 995 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 996 | |
560e20e4 CH |
997 | /** |
998 | * bdev_mark_dead - mark a block device as dead | |
999 | * @bdev: block device to operate on | |
1000 | * @surprise: indicate a surprise removal | |
1001 | * | |
1002 | * Tell the file system that this devices or media is dead. If @surprise is set | |
1003 | * to %true the device or media is already gone, if not we are preparing for an | |
1004 | * orderly removal. | |
1005 | * | |
d8530de5 CH |
1006 | * This calls into the file system, which then typicall syncs out all dirty data |
1007 | * and writes back inodes and then invalidates any cached data in the inodes on | |
1008 | * the file system. In addition we also invalidate the block device mapping. | |
560e20e4 CH |
1009 | */ |
1010 | void bdev_mark_dead(struct block_device *bdev, bool surprise) | |
b71e8a4c | 1011 | { |
d8530de5 CH |
1012 | mutex_lock(&bdev->bd_holder_lock); |
1013 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead) | |
1014 | bdev->bd_holder_ops->mark_dead(bdev, surprise); | |
fd146410 JK |
1015 | else { |
1016 | mutex_unlock(&bdev->bd_holder_lock); | |
d8530de5 | 1017 | sync_blockdev(bdev); |
fd146410 | 1018 | } |
b71e8a4c | 1019 | |
f98393a6 | 1020 | invalidate_bdev(bdev); |
b71e8a4c | 1021 | } |
560e20e4 | 1022 | /* |
6e57236e CH |
1023 | * New drivers should not use this directly. There are some drivers however |
1024 | * that needs this for historical reasons. For example, the DASD driver has | |
1025 | * historically had a shutdown to offline mode that doesn't actually remove the | |
1026 | * gendisk that otherwise looks a lot like a safe device removal. | |
560e20e4 CH |
1027 | */ |
1028 | EXPORT_SYMBOL_GPL(bdev_mark_dead); | |
5c0d6b60 | 1029 | |
1e03a36b | 1030 | void sync_bdevs(bool wait) |
5c0d6b60 JK |
1031 | { |
1032 | struct inode *inode, *old_inode = NULL; | |
1033 | ||
74278da9 | 1034 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1035 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1036 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1037 | struct block_device *bdev; |
5c0d6b60 JK |
1038 | |
1039 | spin_lock(&inode->i_lock); | |
1040 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1041 | mapping->nrpages == 0) { | |
1042 | spin_unlock(&inode->i_lock); | |
1043 | continue; | |
1044 | } | |
1045 | __iget(inode); | |
1046 | spin_unlock(&inode->i_lock); | |
74278da9 | 1047 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1048 | /* |
1049 | * We hold a reference to 'inode' so it couldn't have been | |
1050 | * removed from s_inodes list while we dropped the | |
74278da9 | 1051 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1052 | * be holding the last reference and we cannot iput it under |
74278da9 | 1053 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1054 | * later. |
1055 | */ | |
1056 | iput(old_inode); | |
1057 | old_inode = inode; | |
af309226 | 1058 | bdev = I_BDEV(inode); |
5c0d6b60 | 1059 | |
a8698707 | 1060 | mutex_lock(&bdev->bd_disk->open_mutex); |
9acf381f | 1061 | if (!atomic_read(&bdev->bd_openers)) { |
1e03a36b CH |
1062 | ; /* skip */ |
1063 | } else if (wait) { | |
1064 | /* | |
1065 | * We keep the error status of individual mapping so | |
1066 | * that applications can catch the writeback error using | |
1067 | * fsync(2). See filemap_fdatawait_keep_errors() for | |
1068 | * details. | |
1069 | */ | |
1070 | filemap_fdatawait_keep_errors(inode->i_mapping); | |
1071 | } else { | |
1072 | filemap_fdatawrite(inode->i_mapping); | |
1073 | } | |
a8698707 | 1074 | mutex_unlock(&bdev->bd_disk->open_mutex); |
5c0d6b60 | 1075 | |
74278da9 | 1076 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1077 | } |
74278da9 | 1078 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1079 | iput(old_inode); |
1080 | } | |
2d985f8c EB |
1081 | |
1082 | /* | |
1083 | * Handle STATX_DIOALIGN for block devices. | |
1084 | * | |
1085 | * Note that the inode passed to this is the inode of a block device node file, | |
1086 | * not the block device's internal inode. Therefore it is *not* valid to use | |
1087 | * I_BDEV() here; the block device has to be looked up by i_rdev instead. | |
1088 | */ | |
1089 | void bdev_statx_dioalign(struct inode *inode, struct kstat *stat) | |
1090 | { | |
1091 | struct block_device *bdev; | |
1092 | ||
1093 | bdev = blkdev_get_no_open(inode->i_rdev); | |
1094 | if (!bdev) | |
1095 | return; | |
1096 | ||
1097 | stat->dio_mem_align = bdev_dma_alignment(bdev) + 1; | |
1098 | stat->dio_offset_align = bdev_logical_block_size(bdev); | |
1099 | stat->result_mask |= STATX_DIOALIGN; | |
1100 | ||
1101 | blkdev_put_no_open(bdev); | |
1102 | } |