]>
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> | |
b55d26bd | 27 | #include <linux/security.h> |
15e3d2c5 | 28 | #include <linux/part_stat.h> |
7c0f6ba6 | 29 | #include <linux/uaccess.h> |
2d985f8c | 30 | #include <linux/stat.h> |
0dca4462 CH |
31 | #include "../fs/internal.h" |
32 | #include "blk.h" | |
1da177e4 | 33 | |
ed5cc702 JK |
34 | /* Should we allow writing to mounted block devices? */ |
35 | static bool bdev_allow_write_mounted = IS_ENABLED(CONFIG_BLK_DEV_WRITE_MOUNTED); | |
36 | ||
1da177e4 LT |
37 | struct bdev_inode { |
38 | struct block_device bdev; | |
39 | struct inode vfs_inode; | |
40 | }; | |
41 | ||
42 | static inline struct bdev_inode *BDEV_I(struct inode *inode) | |
43 | { | |
44 | return container_of(inode, struct bdev_inode, vfs_inode); | |
45 | } | |
46 | ||
df65f166 AV |
47 | static inline struct inode *BD_INODE(struct block_device *bdev) |
48 | { | |
49 | return &container_of(bdev, struct bdev_inode, bdev)->vfs_inode; | |
50 | } | |
51 | ||
ff5053f6 | 52 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
53 | { |
54 | return &BDEV_I(inode)->bdev; | |
55 | } | |
1da177e4 LT |
56 | EXPORT_SYMBOL(I_BDEV); |
57 | ||
f3a60882 CB |
58 | struct block_device *file_bdev(struct file *bdev_file) |
59 | { | |
7c09a4ed | 60 | return I_BDEV(bdev_file->f_mapping->host); |
f3a60882 CB |
61 | } |
62 | EXPORT_SYMBOL(file_bdev); | |
63 | ||
dbd3ca50 | 64 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 65 | { |
df65f166 | 66 | struct inode *inode = BD_INODE(bdev); |
dbd3ca50 VG |
67 | int ret; |
68 | ||
564f00f6 CH |
69 | spin_lock(&inode->i_lock); |
70 | while (inode->i_state & I_DIRTY) { | |
71 | spin_unlock(&inode->i_lock); | |
dbd3ca50 | 72 | ret = write_inode_now(inode, true); |
5bf83e9a CH |
73 | if (ret) |
74 | pr_warn_ratelimited( | |
75 | "VFS: Dirty inode writeback failed for block device %pg (err=%d).\n", | |
76 | bdev, ret); | |
564f00f6 CH |
77 | spin_lock(&inode->i_lock); |
78 | } | |
79 | spin_unlock(&inode->i_lock); | |
80 | } | |
81 | ||
f9a14399 | 82 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 83 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 84 | { |
224941e8 | 85 | struct address_space *mapping = bdev->bd_mapping; |
ff01bb48 | 86 | |
7716506a | 87 | if (mapping_empty(mapping)) |
f9a14399 | 88 | return; |
ff01bb48 | 89 | |
f9a14399 | 90 | invalidate_bh_lrus(); |
ff01bb48 | 91 | truncate_inode_pages(mapping, 0); |
3373a346 | 92 | } |
ff01bb48 AV |
93 | |
94 | /* Invalidate clean unused buffers and pagecache. */ | |
95 | void invalidate_bdev(struct block_device *bdev) | |
96 | { | |
224941e8 | 97 | struct address_space *mapping = bdev->bd_mapping; |
ff01bb48 | 98 | |
a5f6a6a9 AR |
99 | if (mapping->nrpages) { |
100 | invalidate_bh_lrus(); | |
101 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
102 | invalidate_mapping_pages(mapping, 0, -1); | |
103 | } | |
ff01bb48 AV |
104 | } |
105 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 106 | |
384d87ef JK |
107 | /* |
108 | * Drop all buffers & page cache for given bdev range. This function bails | |
109 | * with error if bdev has other exclusive owner (such as filesystem). | |
110 | */ | |
05bdb996 | 111 | int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode, |
384d87ef JK |
112 | loff_t lstart, loff_t lend) |
113 | { | |
384d87ef JK |
114 | /* |
115 | * If we don't hold exclusive handle for the device, upgrade to it | |
116 | * while we discard the buffer cache to avoid discarding buffers | |
117 | * under live filesystem. | |
118 | */ | |
05bdb996 | 119 | if (!(mode & BLK_OPEN_EXCL)) { |
0718afd4 | 120 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL); |
384d87ef | 121 | if (err) |
56887cff | 122 | goto invalidate; |
384d87ef | 123 | } |
37c3fc9a | 124 | |
224941e8 | 125 | truncate_inode_pages_range(bdev->bd_mapping, lstart, lend); |
05bdb996 | 126 | if (!(mode & BLK_OPEN_EXCL)) |
37c3fc9a | 127 | bd_abort_claiming(bdev, truncate_bdev_range); |
384d87ef | 128 | return 0; |
56887cff JK |
129 | |
130 | invalidate: | |
131 | /* | |
132 | * Someone else has handle exclusively open. Try invalidating instead. | |
133 | * The 'end' argument is inclusive so the rounding is safe. | |
134 | */ | |
224941e8 | 135 | return invalidate_inode_pages2_range(bdev->bd_mapping, |
56887cff JK |
136 | lstart >> PAGE_SHIFT, |
137 | lend >> PAGE_SHIFT); | |
384d87ef | 138 | } |
384d87ef | 139 | |
04906b2f JK |
140 | static void set_init_blocksize(struct block_device *bdev) |
141 | { | |
8dc932d3 | 142 | unsigned int bsize = bdev_logical_block_size(bdev); |
df65f166 | 143 | loff_t size = i_size_read(BD_INODE(bdev)); |
8dc932d3 MM |
144 | |
145 | while (bsize < PAGE_SIZE) { | |
146 | if (size & bsize) | |
147 | break; | |
148 | bsize <<= 1; | |
149 | } | |
df65f166 | 150 | BD_INODE(bdev)->i_blkbits = blksize_bits(bsize); |
04906b2f JK |
151 | } |
152 | ||
ead083ae | 153 | int set_blocksize(struct file *file, int size) |
1da177e4 | 154 | { |
ead083ae AV |
155 | struct inode *inode = file->f_mapping->host; |
156 | struct block_device *bdev = I_BDEV(inode); | |
157 | ||
1da177e4 | 158 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ |
1368c4f2 | 159 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
160 | return -EINVAL; |
161 | ||
162 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 163 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
164 | return -EINVAL; |
165 | ||
d18a8679 AV |
166 | if (!file->private_data) |
167 | return -EINVAL; | |
168 | ||
1da177e4 | 169 | /* Don't change the size if it is same as current */ |
ead083ae | 170 | if (inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 171 | sync_blockdev(bdev); |
ead083ae | 172 | inode->i_blkbits = blksize_bits(size); |
1da177e4 LT |
173 | kill_bdev(bdev); |
174 | } | |
175 | return 0; | |
176 | } | |
177 | ||
178 | EXPORT_SYMBOL(set_blocksize); | |
179 | ||
180 | int sb_set_blocksize(struct super_block *sb, int size) | |
181 | { | |
ead083ae | 182 | if (set_blocksize(sb->s_bdev_file, size)) |
1da177e4 LT |
183 | return 0; |
184 | /* If we get here, we know size is power of two | |
185 | * and it's value is between 512 and PAGE_SIZE */ | |
186 | sb->s_blocksize = size; | |
38885bd4 | 187 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
188 | return sb->s_blocksize; |
189 | } | |
190 | ||
191 | EXPORT_SYMBOL(sb_set_blocksize); | |
192 | ||
193 | int sb_min_blocksize(struct super_block *sb, int size) | |
194 | { | |
e1defc4f | 195 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
196 | if (size < minsize) |
197 | size = minsize; | |
198 | return sb_set_blocksize(sb, size); | |
199 | } | |
200 | ||
201 | EXPORT_SYMBOL(sb_min_blocksize); | |
202 | ||
70164eb6 | 203 | int sync_blockdev_nowait(struct block_device *bdev) |
5cee5815 JK |
204 | { |
205 | if (!bdev) | |
206 | return 0; | |
224941e8 | 207 | return filemap_flush(bdev->bd_mapping); |
5cee5815 | 208 | } |
70164eb6 | 209 | EXPORT_SYMBOL_GPL(sync_blockdev_nowait); |
5cee5815 | 210 | |
585d3bc0 NP |
211 | /* |
212 | * Write out and wait upon all the dirty data associated with a block | |
213 | * device via its mapping. Does not take the superblock lock. | |
214 | */ | |
215 | int sync_blockdev(struct block_device *bdev) | |
216 | { | |
70164eb6 CH |
217 | if (!bdev) |
218 | return 0; | |
224941e8 | 219 | return filemap_write_and_wait(bdev->bd_mapping); |
585d3bc0 NP |
220 | } |
221 | EXPORT_SYMBOL(sync_blockdev); | |
222 | ||
97d6fb1b YM |
223 | int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend) |
224 | { | |
224941e8 | 225 | return filemap_write_and_wait_range(bdev->bd_mapping, |
97d6fb1b YM |
226 | lstart, lend); |
227 | } | |
228 | EXPORT_SYMBOL(sync_blockdev_range); | |
229 | ||
585d3bc0 | 230 | /** |
982c3b30 | 231 | * bdev_freeze - lock a filesystem and force it into a consistent state |
585d3bc0 NP |
232 | * @bdev: blockdevice to lock |
233 | * | |
585d3bc0 NP |
234 | * If a superblock is found on this device, we take the s_umount semaphore |
235 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
236 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
237 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
982c3b30 CB |
238 | * freeze requests arrive simultaneously. It counts up in bdev_freeze() and |
239 | * count down in bdev_thaw(). When it becomes 0, thaw_bdev() will unfreeze | |
585d3bc0 | 240 | * actually. |
982c3b30 CB |
241 | * |
242 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 243 | */ |
982c3b30 | 244 | int bdev_freeze(struct block_device *bdev) |
585d3bc0 | 245 | { |
585d3bc0 NP |
246 | int error = 0; |
247 | ||
248 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd | 249 | |
49ef8832 CB |
250 | if (atomic_inc_return(&bdev->bd_fsfreeze_count) > 1) { |
251 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
252 | return 0; | |
585d3bc0 | 253 | } |
040f04bd | 254 | |
49ef8832 CB |
255 | mutex_lock(&bdev->bd_holder_lock); |
256 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->freeze) { | |
257 | error = bdev->bd_holder_ops->freeze(bdev); | |
258 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
259 | } else { | |
260 | mutex_unlock(&bdev->bd_holder_lock); | |
261 | error = sync_blockdev(bdev); | |
585d3bc0 | 262 | } |
040f04bd | 263 | |
49ef8832 CB |
264 | if (error) |
265 | atomic_dec(&bdev->bd_fsfreeze_count); | |
266 | ||
585d3bc0 | 267 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 268 | return error; |
585d3bc0 | 269 | } |
982c3b30 | 270 | EXPORT_SYMBOL(bdev_freeze); |
585d3bc0 NP |
271 | |
272 | /** | |
982c3b30 | 273 | * bdev_thaw - unlock filesystem |
585d3bc0 | 274 | * @bdev: blockdevice to unlock |
585d3bc0 | 275 | * |
982c3b30 CB |
276 | * Unlocks the filesystem and marks it writeable again after bdev_freeze(). |
277 | * | |
278 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 279 | */ |
982c3b30 | 280 | int bdev_thaw(struct block_device *bdev) |
585d3bc0 | 281 | { |
49ef8832 | 282 | int error = -EINVAL, nr_freeze; |
585d3bc0 NP |
283 | |
284 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
49ef8832 CB |
285 | |
286 | /* | |
287 | * If this returns < 0 it means that @bd_fsfreeze_count was | |
288 | * already 0 and no decrement was performed. | |
289 | */ | |
290 | nr_freeze = atomic_dec_if_positive(&bdev->bd_fsfreeze_count); | |
291 | if (nr_freeze < 0) | |
18e9e510 | 292 | goto out; |
4504230a CH |
293 | |
294 | error = 0; | |
49ef8832 | 295 | if (nr_freeze > 0) |
18e9e510 | 296 | goto out; |
4504230a | 297 | |
49ef8832 CB |
298 | mutex_lock(&bdev->bd_holder_lock); |
299 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->thaw) { | |
300 | error = bdev->bd_holder_ops->thaw(bdev); | |
301 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
302 | } else { | |
303 | mutex_unlock(&bdev->bd_holder_lock); | |
304 | } | |
4504230a | 305 | |
997198ba | 306 | if (error) |
49ef8832 | 307 | atomic_inc(&bdev->bd_fsfreeze_count); |
18e9e510 | 308 | out: |
585d3bc0 | 309 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 310 | return error; |
585d3bc0 | 311 | } |
982c3b30 | 312 | EXPORT_SYMBOL(bdev_thaw); |
585d3bc0 | 313 | |
1da177e4 LT |
314 | /* |
315 | * pseudo-fs | |
316 | */ | |
317 | ||
74e6464a | 318 | static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); |
68279f9c | 319 | static struct kmem_cache *bdev_cachep __ro_after_init; |
1da177e4 LT |
320 | |
321 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
322 | { | |
fd60b288 | 323 | struct bdev_inode *ei = alloc_inode_sb(sb, bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 324 | |
1da177e4 LT |
325 | if (!ei) |
326 | return NULL; | |
2d2f6f1b | 327 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
b55d26bd DB |
328 | |
329 | if (security_bdev_alloc(&ei->bdev)) { | |
330 | kmem_cache_free(bdev_cachep, ei); | |
331 | return NULL; | |
332 | } | |
1da177e4 LT |
333 | return &ei->vfs_inode; |
334 | } | |
335 | ||
41149cb0 | 336 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 337 | { |
15e3d2c5 CH |
338 | struct block_device *bdev = I_BDEV(inode); |
339 | ||
340 | free_percpu(bdev->bd_stats); | |
231926db | 341 | kfree(bdev->bd_meta_info); |
b55d26bd | 342 | security_bdev_free(bdev); |
15e3d2c5 | 343 | |
889c05cc CH |
344 | if (!bdev_is_partition(bdev)) { |
345 | if (bdev->bd_disk && bdev->bd_disk->bdi) | |
346 | bdi_put(bdev->bd_disk->bdi); | |
340e8457 | 347 | kfree(bdev->bd_disk); |
889c05cc | 348 | } |
9451aa0a CH |
349 | |
350 | if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) | |
351 | blk_free_ext_minor(MINOR(bdev->bd_dev)); | |
352 | ||
41149cb0 | 353 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
354 | } |
355 | ||
e6cb5382 | 356 | static void init_once(void *data) |
1da177e4 | 357 | { |
e6cb5382 | 358 | struct bdev_inode *ei = data; |
1da177e4 | 359 | |
a35afb83 | 360 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
361 | } |
362 | ||
b57922d9 | 363 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 | 364 | { |
91b0abe3 | 365 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 366 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 367 | clear_inode(inode); |
1da177e4 LT |
368 | } |
369 | ||
ee9b6d61 | 370 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
371 | .statfs = simple_statfs, |
372 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 373 | .free_inode = bdev_free_inode, |
1da177e4 | 374 | .drop_inode = generic_delete_inode, |
b57922d9 | 375 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
376 | }; |
377 | ||
9030d16e | 378 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 379 | { |
9030d16e DH |
380 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
381 | if (!ctx) | |
382 | return -ENOMEM; | |
383 | fc->s_iflags |= SB_I_CGROUPWB; | |
384 | ctx->ops = &bdev_sops; | |
385 | return 0; | |
1da177e4 LT |
386 | } |
387 | ||
388 | static struct file_system_type bd_type = { | |
389 | .name = "bdev", | |
9030d16e | 390 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
391 | .kill_sb = kill_anon_super, |
392 | }; | |
393 | ||
68279f9c | 394 | struct super_block *blockdev_superblock __ro_after_init; |
d9c23321 | 395 | static struct vfsmount *blockdev_mnt __ro_after_init; |
a212b105 | 396 | EXPORT_SYMBOL_GPL(blockdev_superblock); |
1da177e4 LT |
397 | |
398 | void __init bdev_cache_init(void) | |
399 | { | |
400 | int err; | |
c2acf7b9 | 401 | |
1da177e4 | 402 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 403 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
82c6515d | 404 | SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 405 | init_once); |
1da177e4 LT |
406 | err = register_filesystem(&bd_type); |
407 | if (err) | |
408 | panic("Cannot register bdev pseudo-fs"); | |
f3a60882 CB |
409 | blockdev_mnt = kern_mount(&bd_type); |
410 | if (IS_ERR(blockdev_mnt)) | |
1da177e4 | 411 | panic("Cannot create bdev pseudo-fs"); |
f3a60882 | 412 | blockdev_superblock = blockdev_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
413 | } |
414 | ||
22ae8ce8 | 415 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
416 | { |
417 | struct block_device *bdev; | |
418 | struct inode *inode; | |
419 | ||
22ae8ce8 | 420 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
421 | if (!inode) |
422 | return NULL; | |
22ae8ce8 CH |
423 | inode->i_mode = S_IFBLK; |
424 | inode->i_rdev = 0; | |
425 | inode->i_data.a_ops = &def_blk_aops; | |
426 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
427 | ||
428 | bdev = I_BDEV(inode); | |
e6cb5382 | 429 | mutex_init(&bdev->bd_fsfreeze_mutex); |
22ae8ce8 | 430 | spin_lock_init(&bdev->bd_size_lock); |
0718afd4 | 431 | mutex_init(&bdev->bd_holder_lock); |
1116b9fa | 432 | atomic_set(&bdev->__bd_flags, partno); |
e33aef2c | 433 | bdev->bd_mapping = &inode->i_data; |
17220ca5 | 434 | bdev->bd_queue = disk->queue; |
ac2b6f9d AV |
435 | if (partno && bdev_test_flag(disk->part0, BD_HAS_SUBMIT_BIO)) |
436 | bdev_set_flag(bdev, BD_HAS_SUBMIT_BIO); | |
15e3d2c5 CH |
437 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
438 | if (!bdev->bd_stats) { | |
439 | iput(inode); | |
440 | return NULL; | |
441 | } | |
06cc978d | 442 | bdev->bd_disk = disk; |
22ae8ce8 CH |
443 | return bdev; |
444 | } | |
1da177e4 | 445 | |
83794367 DLM |
446 | void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) |
447 | { | |
448 | spin_lock(&bdev->bd_size_lock); | |
df65f166 | 449 | i_size_write(BD_INODE(bdev), (loff_t)sectors << SECTOR_SHIFT); |
83794367 DLM |
450 | bdev->bd_nr_sectors = sectors; |
451 | spin_unlock(&bdev->bd_size_lock); | |
452 | } | |
453 | ||
22ae8ce8 CH |
454 | void bdev_add(struct block_device *bdev, dev_t dev) |
455 | { | |
df65f166 | 456 | struct inode *inode = BD_INODE(bdev); |
1898efcd | 457 | if (bdev_stable_writes(bdev)) |
224941e8 | 458 | mapping_set_stable_writes(bdev->bd_mapping); |
22ae8ce8 | 459 | bdev->bd_dev = dev; |
df65f166 AV |
460 | inode->i_rdev = dev; |
461 | inode->i_ino = dev; | |
462 | insert_inode_hash(inode); | |
22ae8ce8 | 463 | } |
1da177e4 | 464 | |
2638c208 AV |
465 | void bdev_unhash(struct block_device *bdev) |
466 | { | |
df65f166 | 467 | remove_inode_hash(BD_INODE(bdev)); |
2638c208 AV |
468 | } |
469 | ||
470 | void bdev_drop(struct block_device *bdev) | |
471 | { | |
df65f166 | 472 | iput(BD_INODE(bdev)); |
22ae8ce8 | 473 | } |
1da177e4 | 474 | |
1da177e4 LT |
475 | long nr_blockdev_pages(void) |
476 | { | |
1008fe6d | 477 | struct inode *inode; |
1da177e4 | 478 | long ret = 0; |
1008fe6d CH |
479 | |
480 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
481 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
482 | ret += inode->i_mapping->nrpages; | |
483 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
484 | ||
1da177e4 LT |
485 | return ret; |
486 | } | |
487 | ||
1a3cbbc5 TH |
488 | /** |
489 | * bd_may_claim - test whether a block device can be claimed | |
490 | * @bdev: block device of interest | |
1a3cbbc5 | 491 | * @holder: holder trying to claim @bdev |
0718afd4 | 492 | * @hops: holder ops |
1a3cbbc5 | 493 | * |
25985edc | 494 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 | 495 | * |
1a3cbbc5 TH |
496 | * RETURNS: |
497 | * %true if @bdev can be claimed, %false otherwise. | |
498 | */ | |
0718afd4 CH |
499 | static bool bd_may_claim(struct block_device *bdev, void *holder, |
500 | const struct blk_holder_ops *hops) | |
ae5f855e CH |
501 | { |
502 | struct block_device *whole = bdev_whole(bdev); | |
503 | ||
74e6464a CH |
504 | lockdep_assert_held(&bdev_lock); |
505 | ||
ae5f855e CH |
506 | if (bdev->bd_holder) { |
507 | /* | |
508 | * The same holder can always re-claim. | |
509 | */ | |
0718afd4 CH |
510 | if (bdev->bd_holder == holder) { |
511 | if (WARN_ON_ONCE(bdev->bd_holder_ops != hops)) | |
512 | return false; | |
ae5f855e | 513 | return true; |
0718afd4 | 514 | } |
ae5f855e CH |
515 | return false; |
516 | } | |
517 | ||
518 | /* | |
519 | * If the whole devices holder is set to bd_may_claim, a partition on | |
520 | * the device is claimed, but not the whole device. | |
521 | */ | |
522 | if (whole != bdev && | |
523 | whole->bd_holder && whole->bd_holder != bd_may_claim) | |
524 | return false; | |
525 | return true; | |
1a3cbbc5 TH |
526 | } |
527 | ||
6b4517a7 | 528 | /** |
58e46ed9 | 529 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 530 | * @bdev: block device of interest |
6b4517a7 | 531 | * @holder: holder trying to claim @bdev |
0718afd4 | 532 | * @hops: holder ops. |
6b4517a7 | 533 | * |
58e46ed9 CH |
534 | * Claim @bdev. This function fails if @bdev is already claimed by another |
535 | * holder and waits if another claiming is in progress. return, the caller | |
536 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
537 | * |
538 | * RETURNS: | |
539 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
540 | */ | |
0718afd4 CH |
541 | int bd_prepare_to_claim(struct block_device *bdev, void *holder, |
542 | const struct blk_holder_ops *hops) | |
6b4517a7 | 543 | { |
37c3fc9a CH |
544 | struct block_device *whole = bdev_whole(bdev); |
545 | ||
546 | if (WARN_ON_ONCE(!holder)) | |
547 | return -EINVAL; | |
6b4517a7 | 548 | retry: |
74e6464a | 549 | mutex_lock(&bdev_lock); |
6b4517a7 | 550 | /* if someone else claimed, fail */ |
0718afd4 | 551 | if (!bd_may_claim(bdev, holder, hops)) { |
74e6464a | 552 | mutex_unlock(&bdev_lock); |
6b4517a7 | 553 | return -EBUSY; |
58e46ed9 | 554 | } |
6b4517a7 | 555 | |
e75aa858 TH |
556 | /* if claiming is already in progress, wait for it to finish */ |
557 | if (whole->bd_claiming) { | |
6b4517a7 TH |
558 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
559 | DEFINE_WAIT(wait); | |
560 | ||
561 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
74e6464a | 562 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
563 | schedule(); |
564 | finish_wait(wq, &wait); | |
6b4517a7 TH |
565 | goto retry; |
566 | } | |
567 | ||
568 | /* yay, all mine */ | |
58e46ed9 | 569 | whole->bd_claiming = holder; |
74e6464a | 570 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
571 | return 0; |
572 | } | |
ecbe6bc0 | 573 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 574 | |
89e524c0 JK |
575 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
576 | { | |
577 | lockdep_assert_held(&bdev_lock); | |
578 | /* tell others that we're done */ | |
579 | BUG_ON(whole->bd_claiming != holder); | |
580 | whole->bd_claiming = NULL; | |
581 | wake_up_bit(&whole->bd_claiming, 0); | |
582 | } | |
583 | ||
584 | /** | |
585 | * bd_finish_claiming - finish claiming of a block device | |
586 | * @bdev: block device of interest | |
89e524c0 | 587 | * @holder: holder that has claimed @bdev |
017fb83e | 588 | * @hops: block device holder operations |
89e524c0 JK |
589 | * |
590 | * Finish exclusive open of a block device. Mark the device as exlusively | |
591 | * open by the holder and wake up all waiters for exclusive open to finish. | |
592 | */ | |
0718afd4 CH |
593 | static void bd_finish_claiming(struct block_device *bdev, void *holder, |
594 | const struct blk_holder_ops *hops) | |
89e524c0 | 595 | { |
37c3fc9a CH |
596 | struct block_device *whole = bdev_whole(bdev); |
597 | ||
74e6464a | 598 | mutex_lock(&bdev_lock); |
0718afd4 | 599 | BUG_ON(!bd_may_claim(bdev, holder, hops)); |
89e524c0 JK |
600 | /* |
601 | * Note that for a whole device bd_holders will be incremented twice, | |
602 | * and bd_holder will be set to bd_may_claim before being set to holder | |
603 | */ | |
604 | whole->bd_holders++; | |
605 | whole->bd_holder = bd_may_claim; | |
606 | bdev->bd_holders++; | |
0718afd4 | 607 | mutex_lock(&bdev->bd_holder_lock); |
89e524c0 | 608 | bdev->bd_holder = holder; |
0718afd4 CH |
609 | bdev->bd_holder_ops = hops; |
610 | mutex_unlock(&bdev->bd_holder_lock); | |
89e524c0 | 611 | bd_clear_claiming(whole, holder); |
74e6464a | 612 | mutex_unlock(&bdev_lock); |
89e524c0 | 613 | } |
89e524c0 JK |
614 | |
615 | /** | |
616 | * bd_abort_claiming - abort claiming of a block device | |
617 | * @bdev: block device of interest | |
89e524c0 JK |
618 | * @holder: holder that has claimed @bdev |
619 | * | |
620 | * Abort claiming of a block device when the exclusive open failed. This can be | |
621 | * also used when exclusive open is not actually desired and we just needed | |
622 | * to block other exclusive openers for a while. | |
623 | */ | |
37c3fc9a | 624 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 625 | { |
74e6464a | 626 | mutex_lock(&bdev_lock); |
37c3fc9a | 627 | bd_clear_claiming(bdev_whole(bdev), holder); |
74e6464a | 628 | mutex_unlock(&bdev_lock); |
89e524c0 JK |
629 | } |
630 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 631 | |
2736e8ee | 632 | static void bd_end_claim(struct block_device *bdev, void *holder) |
0783b1a7 CH |
633 | { |
634 | struct block_device *whole = bdev_whole(bdev); | |
635 | bool unblock = false; | |
636 | ||
637 | /* | |
638 | * Release a claim on the device. The holder fields are protected with | |
639 | * bdev_lock. open_mutex is used to synchronize disk_holder unlinking. | |
640 | */ | |
74e6464a | 641 | mutex_lock(&bdev_lock); |
2736e8ee | 642 | WARN_ON_ONCE(bdev->bd_holder != holder); |
0783b1a7 CH |
643 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
644 | WARN_ON_ONCE(--whole->bd_holders < 0); | |
645 | if (!bdev->bd_holders) { | |
0718afd4 | 646 | mutex_lock(&bdev->bd_holder_lock); |
0783b1a7 | 647 | bdev->bd_holder = NULL; |
0718afd4 CH |
648 | bdev->bd_holder_ops = NULL; |
649 | mutex_unlock(&bdev->bd_holder_lock); | |
4c80105e | 650 | if (bdev_test_flag(bdev, BD_WRITE_HOLDER)) |
0783b1a7 CH |
651 | unblock = true; |
652 | } | |
653 | if (!whole->bd_holders) | |
654 | whole->bd_holder = NULL; | |
74e6464a | 655 | mutex_unlock(&bdev_lock); |
0783b1a7 CH |
656 | |
657 | /* | |
658 | * If this was the last claim, remove holder link and unblock evpoll if | |
659 | * it was a write holder. | |
660 | */ | |
661 | if (unblock) { | |
662 | disk_unblock_events(bdev->bd_disk); | |
4c80105e | 663 | bdev_clear_flag(bdev, BD_WRITE_HOLDER); |
0783b1a7 CH |
664 | } |
665 | } | |
666 | ||
c8276b95 CH |
667 | static void blkdev_flush_mapping(struct block_device *bdev) |
668 | { | |
669 | WARN_ON_ONCE(bdev->bd_holders); | |
670 | sync_blockdev(bdev); | |
671 | kill_bdev(bdev); | |
672 | bdev_write_inode(bdev); | |
673 | } | |
37be4124 | 674 | |
752863bd CH |
675 | static void blkdev_put_whole(struct block_device *bdev) |
676 | { | |
677 | if (atomic_dec_and_test(&bdev->bd_openers)) | |
678 | blkdev_flush_mapping(bdev); | |
679 | if (bdev->bd_disk->fops->release) | |
680 | bdev->bd_disk->fops->release(bdev->bd_disk); | |
681 | } | |
682 | ||
05bdb996 | 683 | static int blkdev_get_whole(struct block_device *bdev, blk_mode_t mode) |
a1548b67 | 684 | { |
142fe8f4 | 685 | struct gendisk *disk = bdev->bd_disk; |
af22fef3 | 686 | int ret; |
a1548b67 | 687 | |
362529d9 | 688 | if (disk->fops->open) { |
d32e2bf8 | 689 | ret = disk->fops->open(disk, mode); |
362529d9 CH |
690 | if (ret) { |
691 | /* avoid ghost partitions on a removed medium */ | |
692 | if (ret == -ENOMEDIUM && | |
693 | test_bit(GD_NEED_PART_SCAN, &disk->state)) | |
0384264e | 694 | bdev_disk_changed(disk, true); |
362529d9 CH |
695 | return ret; |
696 | } | |
d981cb5b | 697 | } |
a1548b67 | 698 | |
9acf381f | 699 | if (!atomic_read(&bdev->bd_openers)) |
362529d9 | 700 | set_init_blocksize(bdev); |
9acf381f | 701 | atomic_inc(&bdev->bd_openers); |
752863bd CH |
702 | if (test_bit(GD_NEED_PART_SCAN, &disk->state)) { |
703 | /* | |
704 | * Only return scanning errors if we are called from contexts | |
705 | * that explicitly want them, e.g. the BLKRRPART ioctl. | |
706 | */ | |
707 | ret = bdev_disk_changed(disk, false); | |
708 | if (ret && (mode & BLK_OPEN_STRICT_SCAN)) { | |
709 | blkdev_put_whole(bdev); | |
710 | return ret; | |
711 | } | |
712 | } | |
483546c1 | 713 | return 0; |
362529d9 | 714 | } |
a1548b67 | 715 | |
05bdb996 | 716 | static int blkdev_get_part(struct block_device *part, blk_mode_t mode) |
1da177e4 | 717 | { |
362529d9 | 718 | struct gendisk *disk = part->bd_disk; |
362529d9 | 719 | int ret; |
5b642d8b | 720 | |
9d3b8813 | 721 | ret = blkdev_get_whole(bdev_whole(part), mode); |
a8698707 | 722 | if (ret) |
9d3b8813 | 723 | return ret; |
7e69723f | 724 | |
362529d9 CH |
725 | ret = -ENXIO; |
726 | if (!bdev_nr_sectors(part)) | |
727 | goto out_blkdev_put; | |
7e69723f | 728 | |
9d1c9287 CH |
729 | if (!atomic_read(&part->bd_openers)) { |
730 | disk->open_partitions++; | |
731 | set_init_blocksize(part); | |
732 | } | |
9acf381f | 733 | atomic_inc(&part->bd_openers); |
1da177e4 | 734 | return 0; |
5a023cdb | 735 | |
362529d9 | 736 | out_blkdev_put: |
ae220766 | 737 | blkdev_put_whole(bdev_whole(part)); |
362529d9 | 738 | return ret; |
1da177e4 | 739 | } |
5b56b6ed | 740 | |
a56aefca CB |
741 | int bdev_permission(dev_t dev, blk_mode_t mode, void *holder) |
742 | { | |
743 | int ret; | |
744 | ||
745 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, | |
746 | MAJOR(dev), MINOR(dev), | |
747 | ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | | |
748 | ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
749 | if (ret) | |
750 | return ret; | |
751 | ||
752 | /* Blocking writes requires exclusive opener */ | |
753 | if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) | |
754 | return -EINVAL; | |
755 | ||
ab838b3f CB |
756 | /* |
757 | * We're using error pointers to indicate to ->release() when we | |
758 | * failed to open that block device. Also this doesn't make sense. | |
759 | */ | |
760 | if (WARN_ON_ONCE(IS_ERR(holder))) | |
761 | return -EINVAL; | |
762 | ||
a56aefca CB |
763 | return 0; |
764 | } | |
765 | ||
ae220766 | 766 | static void blkdev_put_part(struct block_device *part) |
c8276b95 CH |
767 | { |
768 | struct block_device *whole = bdev_whole(part); | |
03e26279 | 769 | |
9d1c9287 CH |
770 | if (atomic_dec_and_test(&part->bd_openers)) { |
771 | blkdev_flush_mapping(part); | |
772 | whole->bd_disk->open_partitions--; | |
773 | } | |
ae220766 | 774 | blkdev_put_whole(whole); |
1da177e4 LT |
775 | } |
776 | ||
22ae8ce8 CH |
777 | struct block_device *blkdev_get_no_open(dev_t dev) |
778 | { | |
779 | struct block_device *bdev; | |
9d3b8813 | 780 | struct inode *inode; |
22ae8ce8 | 781 | |
9d3b8813 | 782 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b | 783 | if (!inode && IS_ENABLED(CONFIG_BLOCK_LEGACY_AUTOLOAD)) { |
22ae8ce8 | 784 | blk_request_module(dev); |
9d3b8813 | 785 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b CH |
786 | if (inode) |
787 | pr_warn_ratelimited( | |
451f0b6f | 788 | "block device autoloading is deprecated and will be removed.\n"); |
22ae8ce8 | 789 | } |
fbdee71b CH |
790 | if (!inode) |
791 | return NULL; | |
22ae8ce8 | 792 | |
9d3b8813 CH |
793 | /* switch from the inode reference to a device mode one: */ |
794 | bdev = &BDEV_I(inode)->bdev; | |
795 | if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) | |
796 | bdev = NULL; | |
797 | iput(inode); | |
22ae8ce8 | 798 | return bdev; |
22ae8ce8 CH |
799 | } |
800 | ||
801 | void blkdev_put_no_open(struct block_device *bdev) | |
802 | { | |
9d3b8813 | 803 | put_device(&bdev->bd_device); |
22ae8ce8 | 804 | } |
ed5cc702 JK |
805 | |
806 | static bool bdev_writes_blocked(struct block_device *bdev) | |
807 | { | |
3ff56e28 | 808 | return bdev->bd_writers < 0; |
ed5cc702 JK |
809 | } |
810 | ||
811 | static void bdev_block_writes(struct block_device *bdev) | |
812 | { | |
3ff56e28 | 813 | bdev->bd_writers--; |
ed5cc702 JK |
814 | } |
815 | ||
816 | static void bdev_unblock_writes(struct block_device *bdev) | |
817 | { | |
3ff56e28 | 818 | bdev->bd_writers++; |
ed5cc702 JK |
819 | } |
820 | ||
821 | static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode) | |
822 | { | |
823 | if (bdev_allow_write_mounted) | |
824 | return true; | |
825 | /* Writes blocked? */ | |
826 | if (mode & BLK_OPEN_WRITE && bdev_writes_blocked(bdev)) | |
827 | return false; | |
828 | if (mode & BLK_OPEN_RESTRICT_WRITES && bdev->bd_writers > 0) | |
829 | return false; | |
830 | return true; | |
831 | } | |
832 | ||
833 | static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode) | |
834 | { | |
835 | if (bdev_allow_write_mounted) | |
836 | return; | |
837 | ||
838 | /* Claim exclusive or shared write access. */ | |
839 | if (mode & BLK_OPEN_RESTRICT_WRITES) | |
840 | bdev_block_writes(bdev); | |
841 | else if (mode & BLK_OPEN_WRITE) | |
842 | bdev->bd_writers++; | |
843 | } | |
844 | ||
22650a99 CB |
845 | static inline bool bdev_unclaimed(const struct file *bdev_file) |
846 | { | |
847 | return bdev_file->private_data == BDEV_I(bdev_file->f_mapping->host); | |
848 | } | |
849 | ||
ab838b3f | 850 | static void bdev_yield_write_access(struct file *bdev_file) |
ed5cc702 | 851 | { |
321de651 CB |
852 | struct block_device *bdev; |
853 | ||
ed5cc702 JK |
854 | if (bdev_allow_write_mounted) |
855 | return; | |
856 | ||
22650a99 CB |
857 | if (bdev_unclaimed(bdev_file)) |
858 | return; | |
859 | ||
321de651 | 860 | bdev = file_bdev(bdev_file); |
ddd65e19 CB |
861 | |
862 | if (bdev_file->f_mode & FMODE_WRITE_RESTRICTED) | |
863 | bdev_unblock_writes(bdev); | |
864 | else if (bdev_file->f_mode & FMODE_WRITE) | |
865 | bdev->bd_writers--; | |
ed5cc702 JK |
866 | } |
867 | ||
d4d77629 | 868 | /** |
a56aefca CB |
869 | * bdev_open - open a block device |
870 | * @bdev: block device to open | |
05bdb996 | 871 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 872 | * @holder: exclusive holder identifier |
0718afd4 | 873 | * @hops: holder operations |
a56aefca | 874 | * @bdev_file: file for the block device |
d4d77629 | 875 | * |
a56aefca CB |
876 | * Open the block device. If @holder is not %NULL, the block device is opened |
877 | * with exclusive access. Exclusive opens may nest for the same @holder. | |
d4d77629 TH |
878 | * |
879 | * CONTEXT: | |
880 | * Might sleep. | |
881 | * | |
882 | * RETURNS: | |
a56aefca | 883 | * zero on success, -errno on failure. |
d4d77629 | 884 | */ |
a56aefca CB |
885 | int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder, |
886 | const struct blk_holder_ops *hops, struct file *bdev_file) | |
1da177e4 | 887 | { |
cd34758c | 888 | bool unblock_events = true; |
a56aefca | 889 | struct gendisk *disk = bdev->bd_disk; |
5b56b6ed | 890 | int ret; |
e525fd89 | 891 | |
2736e8ee | 892 | if (holder) { |
05bdb996 | 893 | mode |= BLK_OPEN_EXCL; |
0718afd4 | 894 | ret = bd_prepare_to_claim(bdev, holder, hops); |
5b56b6ed | 895 | if (ret) |
ab838b3f | 896 | return ret; |
2736e8ee | 897 | } else { |
ab838b3f CB |
898 | if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) |
899 | return -EIO; | |
5b56b6ed CH |
900 | } |
901 | ||
902 | disk_block_events(disk); | |
903 | ||
a8698707 | 904 | mutex_lock(&disk->open_mutex); |
362529d9 | 905 | ret = -ENXIO; |
50b4aecf | 906 | if (!disk_live(disk)) |
362529d9 | 907 | goto abort_claiming; |
efcf5932 ML |
908 | if (!try_module_get(disk->fops->owner)) |
909 | goto abort_claiming; | |
ed5cc702 JK |
910 | ret = -EBUSY; |
911 | if (!bdev_may_open(bdev, mode)) | |
9617cd6f | 912 | goto put_module; |
362529d9 CH |
913 | if (bdev_is_partition(bdev)) |
914 | ret = blkdev_get_part(bdev, mode); | |
915 | else | |
916 | ret = blkdev_get_whole(bdev, mode); | |
22ae8ce8 | 917 | if (ret) |
efcf5932 | 918 | goto put_module; |
ed5cc702 | 919 | bdev_claim_write_access(bdev, mode); |
2736e8ee | 920 | if (holder) { |
0718afd4 | 921 | bd_finish_claiming(bdev, holder, hops); |
5b56b6ed CH |
922 | |
923 | /* | |
924 | * Block event polling for write claims if requested. Any write | |
925 | * holder makes the write_holder state stick until all are | |
926 | * released. This is good enough and tracking individual | |
927 | * writeable reference is too fragile given the way @mode is | |
928 | * used in blkdev_get/put(). | |
929 | */ | |
4c80105e AV |
930 | if ((mode & BLK_OPEN_WRITE) && |
931 | !bdev_test_flag(bdev, BD_WRITE_HOLDER) && | |
1545e0b4 | 932 | (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) { |
4c80105e | 933 | bdev_set_flag(bdev, BD_WRITE_HOLDER); |
5b56b6ed CH |
934 | unblock_events = false; |
935 | } | |
936 | } | |
a8698707 | 937 | mutex_unlock(&disk->open_mutex); |
5b56b6ed CH |
938 | |
939 | if (unblock_events) | |
940 | disk_unblock_events(disk); | |
a56aefca CB |
941 | |
942 | bdev_file->f_flags |= O_LARGEFILE; | |
210a03c9 | 943 | bdev_file->f_mode |= FMODE_CAN_ODIRECT; |
a56aefca CB |
944 | if (bdev_nowait(bdev)) |
945 | bdev_file->f_mode |= FMODE_NOWAIT; | |
ddd65e19 CB |
946 | if (mode & BLK_OPEN_RESTRICT_WRITES) |
947 | bdev_file->f_mode |= FMODE_WRITE_RESTRICTED; | |
224941e8 | 948 | bdev_file->f_mapping = bdev->bd_mapping; |
a56aefca | 949 | bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping); |
ab838b3f | 950 | bdev_file->private_data = holder; |
a56aefca CB |
951 | |
952 | return 0; | |
efcf5932 ML |
953 | put_module: |
954 | module_put(disk->fops->owner); | |
22ae8ce8 | 955 | abort_claiming: |
2736e8ee | 956 | if (holder) |
37c3fc9a | 957 | bd_abort_claiming(bdev, holder); |
a8698707 | 958 | mutex_unlock(&disk->open_mutex); |
22ae8ce8 | 959 | disk_unblock_events(disk); |
a56aefca | 960 | return ret; |
37be4124 | 961 | } |
e719b4d1 | 962 | |
f3a60882 CB |
963 | /* |
964 | * If BLK_OPEN_WRITE_IOCTL is set then this is a historical quirk | |
965 | * associated with the floppy driver where it has allowed ioctls if the | |
966 | * file was opened for writing, but does not allow reads or writes. | |
967 | * Make sure that this quirk is reflected in @f_flags. | |
968 | * | |
969 | * It can also happen if a block device is opened as O_RDWR | O_WRONLY. | |
970 | */ | |
971 | static unsigned blk_to_file_flags(blk_mode_t mode) | |
972 | { | |
973 | unsigned int flags = 0; | |
974 | ||
975 | if ((mode & (BLK_OPEN_READ | BLK_OPEN_WRITE)) == | |
976 | (BLK_OPEN_READ | BLK_OPEN_WRITE)) | |
977 | flags |= O_RDWR; | |
978 | else if (mode & BLK_OPEN_WRITE_IOCTL) | |
979 | flags |= O_RDWR | O_WRONLY; | |
980 | else if (mode & BLK_OPEN_WRITE) | |
981 | flags |= O_WRONLY; | |
982 | else if (mode & BLK_OPEN_READ) | |
983 | flags |= O_RDONLY; /* homeopathic, because O_RDONLY is 0 */ | |
984 | else | |
985 | WARN_ON_ONCE(true); | |
986 | ||
987 | if (mode & BLK_OPEN_NDELAY) | |
988 | flags |= O_NDELAY; | |
989 | ||
990 | return flags; | |
991 | } | |
992 | ||
993 | struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, | |
994 | const struct blk_holder_ops *hops) | |
995 | { | |
996 | struct file *bdev_file; | |
a56aefca | 997 | struct block_device *bdev; |
f3a60882 | 998 | unsigned int flags; |
a56aefca | 999 | int ret; |
f3a60882 | 1000 | |
a56aefca CB |
1001 | ret = bdev_permission(dev, mode, holder); |
1002 | if (ret) | |
1003 | return ERR_PTR(ret); | |
1004 | ||
1005 | bdev = blkdev_get_no_open(dev); | |
1006 | if (!bdev) | |
1007 | return ERR_PTR(-ENXIO); | |
f3a60882 CB |
1008 | |
1009 | flags = blk_to_file_flags(mode); | |
df65f166 | 1010 | bdev_file = alloc_file_pseudo_noaccount(BD_INODE(bdev), |
f3a60882 CB |
1011 | blockdev_mnt, "", flags | O_LARGEFILE, &def_blk_fops); |
1012 | if (IS_ERR(bdev_file)) { | |
a56aefca | 1013 | blkdev_put_no_open(bdev); |
f3a60882 CB |
1014 | return bdev_file; |
1015 | } | |
df65f166 | 1016 | ihold(BD_INODE(bdev)); |
f3a60882 | 1017 | |
a56aefca CB |
1018 | ret = bdev_open(bdev, mode, holder, hops, bdev_file); |
1019 | if (ret) { | |
ab838b3f CB |
1020 | /* We failed to open the block device. Let ->release() know. */ |
1021 | bdev_file->private_data = ERR_PTR(ret); | |
a56aefca CB |
1022 | fput(bdev_file); |
1023 | return ERR_PTR(ret); | |
1024 | } | |
f3a60882 CB |
1025 | return bdev_file; |
1026 | } | |
1027 | EXPORT_SYMBOL(bdev_file_open_by_dev); | |
1028 | ||
1029 | struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, | |
1030 | void *holder, | |
1031 | const struct blk_holder_ops *hops) | |
1032 | { | |
7c09a4ed | 1033 | struct file *file; |
f3a60882 CB |
1034 | dev_t dev; |
1035 | int error; | |
1036 | ||
1037 | error = lookup_bdev(path, &dev); | |
1038 | if (error) | |
1039 | return ERR_PTR(error); | |
1040 | ||
7c09a4ed CB |
1041 | file = bdev_file_open_by_dev(dev, mode, holder, hops); |
1042 | if (!IS_ERR(file) && (mode & BLK_OPEN_WRITE)) { | |
1043 | if (bdev_read_only(file_bdev(file))) { | |
1044 | fput(file); | |
1045 | file = ERR_PTR(-EACCES); | |
f3a60882 CB |
1046 | } |
1047 | } | |
1048 | ||
7c09a4ed | 1049 | return file; |
f3a60882 CB |
1050 | } |
1051 | EXPORT_SYMBOL(bdev_file_open_by_path); | |
1052 | ||
22650a99 CB |
1053 | static inline void bd_yield_claim(struct file *bdev_file) |
1054 | { | |
1055 | struct block_device *bdev = file_bdev(bdev_file); | |
1056 | void *holder = bdev_file->private_data; | |
1057 | ||
1058 | lockdep_assert_held(&bdev->bd_disk->open_mutex); | |
1059 | ||
1060 | if (WARN_ON_ONCE(IS_ERR_OR_NULL(holder))) | |
1061 | return; | |
1062 | ||
1063 | if (!bdev_unclaimed(bdev_file)) | |
1064 | bd_end_claim(bdev, holder); | |
1065 | } | |
1066 | ||
7c09a4ed | 1067 | void bdev_release(struct file *bdev_file) |
2e7b651d | 1068 | { |
7c09a4ed | 1069 | struct block_device *bdev = file_bdev(bdev_file); |
ab838b3f | 1070 | void *holder = bdev_file->private_data; |
2e7b651d PZ |
1071 | struct gendisk *disk = bdev->bd_disk; |
1072 | ||
ab838b3f CB |
1073 | /* We failed to open that block device. */ |
1074 | if (IS_ERR(holder)) | |
1075 | goto put_no_open; | |
1076 | ||
b849dd84 DA |
1077 | /* |
1078 | * Sync early if it looks like we're the last one. If someone else | |
1079 | * opens the block device between now and the decrement of bd_openers | |
1080 | * then we did a sync that we didn't need to, but that's not the end | |
1081 | * of the world and we want to avoid long (could be several minute) | |
1082 | * syncs while holding the mutex. | |
1083 | */ | |
9acf381f | 1084 | if (atomic_read(&bdev->bd_openers) == 1) |
b849dd84 DA |
1085 | sync_blockdev(bdev); |
1086 | ||
a8698707 | 1087 | mutex_lock(&disk->open_mutex); |
ab838b3f | 1088 | bdev_yield_write_access(bdev_file); |
ed5cc702 | 1089 | |
ab838b3f | 1090 | if (holder) |
22650a99 | 1091 | bd_yield_claim(bdev_file); |
77ea887e | 1092 | |
85ef06d1 TH |
1093 | /* |
1094 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1095 | * event. This is to ensure detection of media removal commanded | |
1096 | * from userland - e.g. eject(1). | |
1097 | */ | |
5b56b6ed | 1098 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 | 1099 | |
c8276b95 | 1100 | if (bdev_is_partition(bdev)) |
ae220766 | 1101 | blkdev_put_part(bdev); |
c8276b95 | 1102 | else |
ae220766 | 1103 | blkdev_put_whole(bdev); |
a8698707 CH |
1104 | mutex_unlock(&disk->open_mutex); |
1105 | ||
efcf5932 | 1106 | module_put(disk->fops->owner); |
ab838b3f | 1107 | put_no_open: |
22ae8ce8 | 1108 | blkdev_put_no_open(bdev); |
e719b4d1 | 1109 | } |
e719b4d1 | 1110 | |
22650a99 CB |
1111 | /** |
1112 | * bdev_fput - yield claim to the block device and put the file | |
1113 | * @bdev_file: open block device | |
1114 | * | |
1115 | * Yield claim on the block device and put the file. Ensure that the | |
1116 | * block device can be reclaimed before the file is closed which is a | |
1117 | * deferred operation. | |
1118 | */ | |
1119 | void bdev_fput(struct file *bdev_file) | |
1120 | { | |
1121 | if (WARN_ON_ONCE(bdev_file->f_op != &def_blk_fops)) | |
1122 | return; | |
1123 | ||
1124 | if (bdev_file->private_data) { | |
1125 | struct block_device *bdev = file_bdev(bdev_file); | |
1126 | struct gendisk *disk = bdev->bd_disk; | |
1127 | ||
1128 | mutex_lock(&disk->open_mutex); | |
1129 | bdev_yield_write_access(bdev_file); | |
1130 | bd_yield_claim(bdev_file); | |
1131 | /* | |
1132 | * Tell release we already gave up our hold on the | |
1133 | * device and if write restrictions are available that | |
1134 | * we already gave up write access to the device. | |
1135 | */ | |
1136 | bdev_file->private_data = BDEV_I(bdev_file->f_mapping->host); | |
1137 | mutex_unlock(&disk->open_mutex); | |
1138 | } | |
1139 | ||
1140 | fput(bdev_file); | |
1141 | } | |
1142 | EXPORT_SYMBOL(bdev_fput); | |
1143 | ||
1da177e4 | 1144 | /** |
0ba4566c MWO |
1145 | * lookup_bdev() - Look up a struct block_device by name. |
1146 | * @pathname: Name of the block device in the filesystem. | |
1147 | * @dev: Pointer to the block device's dev_t, if found. | |
1da177e4 | 1148 | * |
057178cf | 1149 | * Lookup the block device's dev_t at @pathname in the current |
0ba4566c | 1150 | * namespace if possible and return it in @dev. |
057178cf | 1151 | * |
0ba4566c MWO |
1152 | * Context: May sleep. |
1153 | * Return: 0 if succeeded, negative errno otherwise. | |
1da177e4 | 1154 | */ |
4e7b5671 | 1155 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 1156 | { |
1da177e4 | 1157 | struct inode *inode; |
421748ec | 1158 | struct path path; |
1da177e4 LT |
1159 | int error; |
1160 | ||
421748ec | 1161 | if (!pathname || !*pathname) |
4e7b5671 | 1162 | return -EINVAL; |
1da177e4 | 1163 | |
421748ec | 1164 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 1165 | if (error) |
4e7b5671 | 1166 | return error; |
1da177e4 | 1167 | |
bb668734 | 1168 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1169 | error = -ENOTBLK; |
1170 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 1171 | goto out_path_put; |
1da177e4 | 1172 | error = -EACCES; |
a2982cc9 | 1173 | if (!may_open_dev(&path)) |
4e7b5671 CH |
1174 | goto out_path_put; |
1175 | ||
1176 | *dev = inode->i_rdev; | |
1177 | error = 0; | |
1178 | out_path_put: | |
421748ec | 1179 | path_put(&path); |
4e7b5671 | 1180 | return error; |
1da177e4 | 1181 | } |
d5686b44 | 1182 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1183 | |
560e20e4 CH |
1184 | /** |
1185 | * bdev_mark_dead - mark a block device as dead | |
1186 | * @bdev: block device to operate on | |
1187 | * @surprise: indicate a surprise removal | |
1188 | * | |
1189 | * Tell the file system that this devices or media is dead. If @surprise is set | |
1190 | * to %true the device or media is already gone, if not we are preparing for an | |
1191 | * orderly removal. | |
1192 | * | |
d8530de5 CH |
1193 | * This calls into the file system, which then typicall syncs out all dirty data |
1194 | * and writes back inodes and then invalidates any cached data in the inodes on | |
1195 | * the file system. In addition we also invalidate the block device mapping. | |
560e20e4 CH |
1196 | */ |
1197 | void bdev_mark_dead(struct block_device *bdev, bool surprise) | |
b71e8a4c | 1198 | { |
d8530de5 CH |
1199 | mutex_lock(&bdev->bd_holder_lock); |
1200 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead) | |
1201 | bdev->bd_holder_ops->mark_dead(bdev, surprise); | |
fd146410 JK |
1202 | else { |
1203 | mutex_unlock(&bdev->bd_holder_lock); | |
d8530de5 | 1204 | sync_blockdev(bdev); |
fd146410 | 1205 | } |
b71e8a4c | 1206 | |
f98393a6 | 1207 | invalidate_bdev(bdev); |
b71e8a4c | 1208 | } |
560e20e4 | 1209 | /* |
6e57236e CH |
1210 | * New drivers should not use this directly. There are some drivers however |
1211 | * that needs this for historical reasons. For example, the DASD driver has | |
1212 | * historically had a shutdown to offline mode that doesn't actually remove the | |
1213 | * gendisk that otherwise looks a lot like a safe device removal. | |
560e20e4 CH |
1214 | */ |
1215 | EXPORT_SYMBOL_GPL(bdev_mark_dead); | |
5c0d6b60 | 1216 | |
1e03a36b | 1217 | void sync_bdevs(bool wait) |
5c0d6b60 JK |
1218 | { |
1219 | struct inode *inode, *old_inode = NULL; | |
1220 | ||
74278da9 | 1221 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1222 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1223 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1224 | struct block_device *bdev; |
5c0d6b60 JK |
1225 | |
1226 | spin_lock(&inode->i_lock); | |
1227 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1228 | mapping->nrpages == 0) { | |
1229 | spin_unlock(&inode->i_lock); | |
1230 | continue; | |
1231 | } | |
1232 | __iget(inode); | |
1233 | spin_unlock(&inode->i_lock); | |
74278da9 | 1234 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1235 | /* |
1236 | * We hold a reference to 'inode' so it couldn't have been | |
1237 | * removed from s_inodes list while we dropped the | |
74278da9 | 1238 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1239 | * be holding the last reference and we cannot iput it under |
74278da9 | 1240 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1241 | * later. |
1242 | */ | |
1243 | iput(old_inode); | |
1244 | old_inode = inode; | |
af309226 | 1245 | bdev = I_BDEV(inode); |
5c0d6b60 | 1246 | |
a8698707 | 1247 | mutex_lock(&bdev->bd_disk->open_mutex); |
9acf381f | 1248 | if (!atomic_read(&bdev->bd_openers)) { |
1e03a36b CH |
1249 | ; /* skip */ |
1250 | } else if (wait) { | |
1251 | /* | |
1252 | * We keep the error status of individual mapping so | |
1253 | * that applications can catch the writeback error using | |
1254 | * fsync(2). See filemap_fdatawait_keep_errors() for | |
1255 | * details. | |
1256 | */ | |
1257 | filemap_fdatawait_keep_errors(inode->i_mapping); | |
1258 | } else { | |
1259 | filemap_fdatawrite(inode->i_mapping); | |
1260 | } | |
a8698707 | 1261 | mutex_unlock(&bdev->bd_disk->open_mutex); |
5c0d6b60 | 1262 | |
74278da9 | 1263 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1264 | } |
74278da9 | 1265 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1266 | iput(old_inode); |
1267 | } | |
2d985f8c EB |
1268 | |
1269 | /* | |
9abcfbd2 | 1270 | * Handle STATX_{DIOALIGN, WRITE_ATOMIC} for block devices. |
2d985f8c | 1271 | */ |
3e781988 | 1272 | void bdev_statx(struct path *path, struct kstat *stat, |
9abcfbd2 | 1273 | u32 request_mask) |
2d985f8c | 1274 | { |
3e781988 | 1275 | struct inode *backing_inode; |
2d985f8c EB |
1276 | struct block_device *bdev; |
1277 | ||
9abcfbd2 PS |
1278 | if (!(request_mask & (STATX_DIOALIGN | STATX_WRITE_ATOMIC))) |
1279 | return; | |
1280 | ||
3e781988 LT |
1281 | backing_inode = d_backing_inode(path->dentry); |
1282 | ||
9abcfbd2 PS |
1283 | /* |
1284 | * Note that backing_inode is the inode of a block device node file, | |
1285 | * not the block device's internal inode. Therefore it is *not* valid | |
1286 | * to use I_BDEV() here; the block device has to be looked up by i_rdev | |
1287 | * instead. | |
1288 | */ | |
1289 | bdev = blkdev_get_no_open(backing_inode->i_rdev); | |
2d985f8c EB |
1290 | if (!bdev) |
1291 | return; | |
1292 | ||
9abcfbd2 PS |
1293 | if (request_mask & STATX_DIOALIGN) { |
1294 | stat->dio_mem_align = bdev_dma_alignment(bdev) + 1; | |
1295 | stat->dio_offset_align = bdev_logical_block_size(bdev); | |
1296 | stat->result_mask |= STATX_DIOALIGN; | |
1297 | } | |
1298 | ||
1299 | if (request_mask & STATX_WRITE_ATOMIC && bdev_can_atomic_write(bdev)) { | |
1300 | struct request_queue *bd_queue = bdev->bd_queue; | |
1301 | ||
1302 | generic_fill_statx_atomic_writes(stat, | |
1303 | queue_atomic_write_unit_min_bytes(bd_queue), | |
1304 | queue_atomic_write_unit_max_bytes(bd_queue)); | |
1305 | } | |
2d985f8c EB |
1306 | |
1307 | blkdev_put_no_open(bdev); | |
1308 | } | |
ed5cc702 | 1309 | |
186ddac2 YK |
1310 | bool disk_live(struct gendisk *disk) |
1311 | { | |
df65f166 | 1312 | return !inode_unhashed(BD_INODE(disk->part0)); |
186ddac2 YK |
1313 | } |
1314 | EXPORT_SYMBOL_GPL(disk_live); | |
1315 | ||
1316 | unsigned int block_size(struct block_device *bdev) | |
1317 | { | |
df65f166 | 1318 | return 1 << BD_INODE(bdev)->i_blkbits; |
186ddac2 YK |
1319 | } |
1320 | EXPORT_SYMBOL_GPL(block_size); | |
1321 | ||
ed5cc702 JK |
1322 | static int __init setup_bdev_allow_write_mounted(char *str) |
1323 | { | |
1324 | if (kstrtobool(str, &bdev_allow_write_mounted)) | |
1325 | pr_warn("Invalid option string for bdev_allow_write_mounted:" | |
1326 | " '%s'\n", str); | |
1327 | return 1; | |
1328 | } | |
1329 | __setup("bdev_allow_write_mounted=", setup_bdev_allow_write_mounted); |