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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992 Linus Torvalds |
4 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
7b51e703 | 5 | * Copyright (C) 2016 - 2020 Christoph Hellwig |
1da177e4 LT |
6 | */ |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/mm.h> | |
1da177e4 LT |
10 | #include <linux/slab.h> |
11 | #include <linux/kmod.h> | |
12 | #include <linux/major.h> | |
7db9cfd3 | 13 | #include <linux/device_cgroup.h> |
1da177e4 | 14 | #include <linux/blkdev.h> |
fe45e630 | 15 | #include <linux/blk-integrity.h> |
66114cad | 16 | #include <linux/backing-dev.h> |
1da177e4 LT |
17 | #include <linux/module.h> |
18 | #include <linux/blkpg.h> | |
b502bd11 | 19 | #include <linux/magic.h> |
1da177e4 | 20 | #include <linux/buffer_head.h> |
ff01bb48 | 21 | #include <linux/swap.h> |
811d736f | 22 | #include <linux/writeback.h> |
1da177e4 | 23 | #include <linux/mount.h> |
9030d16e | 24 | #include <linux/pseudo_fs.h> |
1da177e4 LT |
25 | #include <linux/uio.h> |
26 | #include <linux/namei.h> | |
15e3d2c5 | 27 | #include <linux/part_stat.h> |
7c0f6ba6 | 28 | #include <linux/uaccess.h> |
2d985f8c | 29 | #include <linux/stat.h> |
0dca4462 CH |
30 | #include "../fs/internal.h" |
31 | #include "blk.h" | |
1da177e4 | 32 | |
ed5cc702 JK |
33 | /* Should we allow writing to mounted block devices? */ |
34 | static bool bdev_allow_write_mounted = IS_ENABLED(CONFIG_BLK_DEV_WRITE_MOUNTED); | |
35 | ||
1da177e4 LT |
36 | struct bdev_inode { |
37 | struct block_device bdev; | |
38 | struct inode vfs_inode; | |
39 | }; | |
40 | ||
41 | static inline struct bdev_inode *BDEV_I(struct inode *inode) | |
42 | { | |
43 | return container_of(inode, struct bdev_inode, vfs_inode); | |
44 | } | |
45 | ||
ff5053f6 | 46 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
47 | { |
48 | return &BDEV_I(inode)->bdev; | |
49 | } | |
1da177e4 LT |
50 | EXPORT_SYMBOL(I_BDEV); |
51 | ||
f3a60882 CB |
52 | struct block_device *file_bdev(struct file *bdev_file) |
53 | { | |
7c09a4ed | 54 | return I_BDEV(bdev_file->f_mapping->host); |
f3a60882 CB |
55 | } |
56 | EXPORT_SYMBOL(file_bdev); | |
57 | ||
dbd3ca50 | 58 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 59 | { |
dbd3ca50 VG |
60 | struct inode *inode = bdev->bd_inode; |
61 | int ret; | |
62 | ||
564f00f6 CH |
63 | spin_lock(&inode->i_lock); |
64 | while (inode->i_state & I_DIRTY) { | |
65 | spin_unlock(&inode->i_lock); | |
dbd3ca50 | 66 | ret = write_inode_now(inode, true); |
5bf83e9a CH |
67 | if (ret) |
68 | pr_warn_ratelimited( | |
69 | "VFS: Dirty inode writeback failed for block device %pg (err=%d).\n", | |
70 | bdev, ret); | |
564f00f6 CH |
71 | spin_lock(&inode->i_lock); |
72 | } | |
73 | spin_unlock(&inode->i_lock); | |
74 | } | |
75 | ||
f9a14399 | 76 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 77 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 78 | { |
ff01bb48 AV |
79 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
80 | ||
7716506a | 81 | if (mapping_empty(mapping)) |
f9a14399 | 82 | return; |
ff01bb48 | 83 | |
f9a14399 | 84 | invalidate_bh_lrus(); |
ff01bb48 | 85 | truncate_inode_pages(mapping, 0); |
3373a346 | 86 | } |
ff01bb48 AV |
87 | |
88 | /* Invalidate clean unused buffers and pagecache. */ | |
89 | void invalidate_bdev(struct block_device *bdev) | |
90 | { | |
91 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
92 | ||
a5f6a6a9 AR |
93 | if (mapping->nrpages) { |
94 | invalidate_bh_lrus(); | |
95 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
96 | invalidate_mapping_pages(mapping, 0, -1); | |
97 | } | |
ff01bb48 AV |
98 | } |
99 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 100 | |
384d87ef JK |
101 | /* |
102 | * Drop all buffers & page cache for given bdev range. This function bails | |
103 | * with error if bdev has other exclusive owner (such as filesystem). | |
104 | */ | |
05bdb996 | 105 | int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode, |
384d87ef JK |
106 | loff_t lstart, loff_t lend) |
107 | { | |
384d87ef JK |
108 | /* |
109 | * If we don't hold exclusive handle for the device, upgrade to it | |
110 | * while we discard the buffer cache to avoid discarding buffers | |
111 | * under live filesystem. | |
112 | */ | |
05bdb996 | 113 | if (!(mode & BLK_OPEN_EXCL)) { |
0718afd4 | 114 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range, NULL); |
384d87ef | 115 | if (err) |
56887cff | 116 | goto invalidate; |
384d87ef | 117 | } |
37c3fc9a | 118 | |
384d87ef | 119 | truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); |
05bdb996 | 120 | if (!(mode & BLK_OPEN_EXCL)) |
37c3fc9a | 121 | bd_abort_claiming(bdev, truncate_bdev_range); |
384d87ef | 122 | return 0; |
56887cff JK |
123 | |
124 | invalidate: | |
125 | /* | |
126 | * Someone else has handle exclusively open. Try invalidating instead. | |
127 | * The 'end' argument is inclusive so the rounding is safe. | |
128 | */ | |
129 | return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, | |
130 | lstart >> PAGE_SHIFT, | |
131 | lend >> PAGE_SHIFT); | |
384d87ef | 132 | } |
384d87ef | 133 | |
04906b2f JK |
134 | static void set_init_blocksize(struct block_device *bdev) |
135 | { | |
8dc932d3 MM |
136 | unsigned int bsize = bdev_logical_block_size(bdev); |
137 | loff_t size = i_size_read(bdev->bd_inode); | |
138 | ||
139 | while (bsize < PAGE_SIZE) { | |
140 | if (size & bsize) | |
141 | break; | |
142 | bsize <<= 1; | |
143 | } | |
144 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
04906b2f JK |
145 | } |
146 | ||
ead083ae | 147 | int set_blocksize(struct file *file, int size) |
1da177e4 | 148 | { |
ead083ae AV |
149 | struct inode *inode = file->f_mapping->host; |
150 | struct block_device *bdev = I_BDEV(inode); | |
151 | ||
1da177e4 | 152 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ |
1368c4f2 | 153 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
154 | return -EINVAL; |
155 | ||
156 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 157 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
158 | return -EINVAL; |
159 | ||
d18a8679 AV |
160 | if (!file->private_data) |
161 | return -EINVAL; | |
162 | ||
1da177e4 | 163 | /* Don't change the size if it is same as current */ |
ead083ae | 164 | if (inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 165 | sync_blockdev(bdev); |
ead083ae | 166 | inode->i_blkbits = blksize_bits(size); |
1da177e4 LT |
167 | kill_bdev(bdev); |
168 | } | |
169 | return 0; | |
170 | } | |
171 | ||
172 | EXPORT_SYMBOL(set_blocksize); | |
173 | ||
174 | int sb_set_blocksize(struct super_block *sb, int size) | |
175 | { | |
ead083ae | 176 | if (set_blocksize(sb->s_bdev_file, size)) |
1da177e4 LT |
177 | return 0; |
178 | /* If we get here, we know size is power of two | |
179 | * and it's value is between 512 and PAGE_SIZE */ | |
180 | sb->s_blocksize = size; | |
38885bd4 | 181 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
182 | return sb->s_blocksize; |
183 | } | |
184 | ||
185 | EXPORT_SYMBOL(sb_set_blocksize); | |
186 | ||
187 | int sb_min_blocksize(struct super_block *sb, int size) | |
188 | { | |
e1defc4f | 189 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
190 | if (size < minsize) |
191 | size = minsize; | |
192 | return sb_set_blocksize(sb, size); | |
193 | } | |
194 | ||
195 | EXPORT_SYMBOL(sb_min_blocksize); | |
196 | ||
70164eb6 | 197 | int sync_blockdev_nowait(struct block_device *bdev) |
5cee5815 JK |
198 | { |
199 | if (!bdev) | |
200 | return 0; | |
70164eb6 | 201 | return filemap_flush(bdev->bd_inode->i_mapping); |
5cee5815 | 202 | } |
70164eb6 | 203 | EXPORT_SYMBOL_GPL(sync_blockdev_nowait); |
5cee5815 | 204 | |
585d3bc0 NP |
205 | /* |
206 | * Write out and wait upon all the dirty data associated with a block | |
207 | * device via its mapping. Does not take the superblock lock. | |
208 | */ | |
209 | int sync_blockdev(struct block_device *bdev) | |
210 | { | |
70164eb6 CH |
211 | if (!bdev) |
212 | return 0; | |
213 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
585d3bc0 NP |
214 | } |
215 | EXPORT_SYMBOL(sync_blockdev); | |
216 | ||
97d6fb1b YM |
217 | int sync_blockdev_range(struct block_device *bdev, loff_t lstart, loff_t lend) |
218 | { | |
219 | return filemap_write_and_wait_range(bdev->bd_inode->i_mapping, | |
220 | lstart, lend); | |
221 | } | |
222 | EXPORT_SYMBOL(sync_blockdev_range); | |
223 | ||
585d3bc0 | 224 | /** |
982c3b30 | 225 | * bdev_freeze - lock a filesystem and force it into a consistent state |
585d3bc0 NP |
226 | * @bdev: blockdevice to lock |
227 | * | |
585d3bc0 NP |
228 | * If a superblock is found on this device, we take the s_umount semaphore |
229 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
230 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
231 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
982c3b30 CB |
232 | * freeze requests arrive simultaneously. It counts up in bdev_freeze() and |
233 | * count down in bdev_thaw(). When it becomes 0, thaw_bdev() will unfreeze | |
585d3bc0 | 234 | * actually. |
982c3b30 CB |
235 | * |
236 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 237 | */ |
982c3b30 | 238 | int bdev_freeze(struct block_device *bdev) |
585d3bc0 | 239 | { |
585d3bc0 NP |
240 | int error = 0; |
241 | ||
242 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd | 243 | |
49ef8832 CB |
244 | if (atomic_inc_return(&bdev->bd_fsfreeze_count) > 1) { |
245 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
246 | return 0; | |
585d3bc0 | 247 | } |
040f04bd | 248 | |
49ef8832 CB |
249 | mutex_lock(&bdev->bd_holder_lock); |
250 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->freeze) { | |
251 | error = bdev->bd_holder_ops->freeze(bdev); | |
252 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
253 | } else { | |
254 | mutex_unlock(&bdev->bd_holder_lock); | |
255 | error = sync_blockdev(bdev); | |
585d3bc0 | 256 | } |
040f04bd | 257 | |
49ef8832 CB |
258 | if (error) |
259 | atomic_dec(&bdev->bd_fsfreeze_count); | |
260 | ||
585d3bc0 | 261 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 262 | return error; |
585d3bc0 | 263 | } |
982c3b30 | 264 | EXPORT_SYMBOL(bdev_freeze); |
585d3bc0 NP |
265 | |
266 | /** | |
982c3b30 | 267 | * bdev_thaw - unlock filesystem |
585d3bc0 | 268 | * @bdev: blockdevice to unlock |
585d3bc0 | 269 | * |
982c3b30 CB |
270 | * Unlocks the filesystem and marks it writeable again after bdev_freeze(). |
271 | * | |
272 | * Return: On success zero is returned, negative error code on failure. | |
585d3bc0 | 273 | */ |
982c3b30 | 274 | int bdev_thaw(struct block_device *bdev) |
585d3bc0 | 275 | { |
49ef8832 | 276 | int error = -EINVAL, nr_freeze; |
585d3bc0 NP |
277 | |
278 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
49ef8832 CB |
279 | |
280 | /* | |
281 | * If this returns < 0 it means that @bd_fsfreeze_count was | |
282 | * already 0 and no decrement was performed. | |
283 | */ | |
284 | nr_freeze = atomic_dec_if_positive(&bdev->bd_fsfreeze_count); | |
285 | if (nr_freeze < 0) | |
18e9e510 | 286 | goto out; |
4504230a CH |
287 | |
288 | error = 0; | |
49ef8832 | 289 | if (nr_freeze > 0) |
18e9e510 | 290 | goto out; |
4504230a | 291 | |
49ef8832 CB |
292 | mutex_lock(&bdev->bd_holder_lock); |
293 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->thaw) { | |
294 | error = bdev->bd_holder_ops->thaw(bdev); | |
295 | lockdep_assert_not_held(&bdev->bd_holder_lock); | |
296 | } else { | |
297 | mutex_unlock(&bdev->bd_holder_lock); | |
298 | } | |
4504230a | 299 | |
997198ba | 300 | if (error) |
49ef8832 | 301 | atomic_inc(&bdev->bd_fsfreeze_count); |
18e9e510 | 302 | out: |
585d3bc0 | 303 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 304 | return error; |
585d3bc0 | 305 | } |
982c3b30 | 306 | EXPORT_SYMBOL(bdev_thaw); |
585d3bc0 | 307 | |
1da177e4 LT |
308 | /* |
309 | * pseudo-fs | |
310 | */ | |
311 | ||
74e6464a | 312 | static __cacheline_aligned_in_smp DEFINE_MUTEX(bdev_lock); |
68279f9c | 313 | static struct kmem_cache *bdev_cachep __ro_after_init; |
1da177e4 LT |
314 | |
315 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
316 | { | |
fd60b288 | 317 | struct bdev_inode *ei = alloc_inode_sb(sb, bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 318 | |
1da177e4 LT |
319 | if (!ei) |
320 | return NULL; | |
2d2f6f1b | 321 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
1da177e4 LT |
322 | return &ei->vfs_inode; |
323 | } | |
324 | ||
41149cb0 | 325 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 326 | { |
15e3d2c5 CH |
327 | struct block_device *bdev = I_BDEV(inode); |
328 | ||
329 | free_percpu(bdev->bd_stats); | |
231926db | 330 | kfree(bdev->bd_meta_info); |
15e3d2c5 | 331 | |
889c05cc CH |
332 | if (!bdev_is_partition(bdev)) { |
333 | if (bdev->bd_disk && bdev->bd_disk->bdi) | |
334 | bdi_put(bdev->bd_disk->bdi); | |
340e8457 | 335 | kfree(bdev->bd_disk); |
889c05cc | 336 | } |
9451aa0a CH |
337 | |
338 | if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) | |
339 | blk_free_ext_minor(MINOR(bdev->bd_dev)); | |
340 | ||
41149cb0 | 341 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
342 | } |
343 | ||
e6cb5382 | 344 | static void init_once(void *data) |
1da177e4 | 345 | { |
e6cb5382 | 346 | struct bdev_inode *ei = data; |
1da177e4 | 347 | |
a35afb83 | 348 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
349 | } |
350 | ||
b57922d9 | 351 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 | 352 | { |
91b0abe3 | 353 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 354 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 355 | clear_inode(inode); |
1da177e4 LT |
356 | } |
357 | ||
ee9b6d61 | 358 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
359 | .statfs = simple_statfs, |
360 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 361 | .free_inode = bdev_free_inode, |
1da177e4 | 362 | .drop_inode = generic_delete_inode, |
b57922d9 | 363 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
364 | }; |
365 | ||
9030d16e | 366 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 367 | { |
9030d16e DH |
368 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
369 | if (!ctx) | |
370 | return -ENOMEM; | |
371 | fc->s_iflags |= SB_I_CGROUPWB; | |
372 | ctx->ops = &bdev_sops; | |
373 | return 0; | |
1da177e4 LT |
374 | } |
375 | ||
376 | static struct file_system_type bd_type = { | |
377 | .name = "bdev", | |
9030d16e | 378 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
379 | .kill_sb = kill_anon_super, |
380 | }; | |
381 | ||
68279f9c | 382 | struct super_block *blockdev_superblock __ro_after_init; |
f3a60882 | 383 | struct vfsmount *blockdev_mnt __ro_after_init; |
a212b105 | 384 | EXPORT_SYMBOL_GPL(blockdev_superblock); |
1da177e4 LT |
385 | |
386 | void __init bdev_cache_init(void) | |
387 | { | |
388 | int err; | |
c2acf7b9 | 389 | |
1da177e4 | 390 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 391 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
82c6515d | 392 | SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 393 | init_once); |
1da177e4 LT |
394 | err = register_filesystem(&bd_type); |
395 | if (err) | |
396 | panic("Cannot register bdev pseudo-fs"); | |
f3a60882 CB |
397 | blockdev_mnt = kern_mount(&bd_type); |
398 | if (IS_ERR(blockdev_mnt)) | |
1da177e4 | 399 | panic("Cannot create bdev pseudo-fs"); |
f3a60882 | 400 | blockdev_superblock = blockdev_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
401 | } |
402 | ||
22ae8ce8 | 403 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
404 | { |
405 | struct block_device *bdev; | |
406 | struct inode *inode; | |
407 | ||
22ae8ce8 | 408 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
409 | if (!inode) |
410 | return NULL; | |
22ae8ce8 CH |
411 | inode->i_mode = S_IFBLK; |
412 | inode->i_rdev = 0; | |
413 | inode->i_data.a_ops = &def_blk_aops; | |
414 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
415 | ||
416 | bdev = I_BDEV(inode); | |
e6cb5382 | 417 | mutex_init(&bdev->bd_fsfreeze_mutex); |
22ae8ce8 | 418 | spin_lock_init(&bdev->bd_size_lock); |
0718afd4 | 419 | mutex_init(&bdev->bd_holder_lock); |
22ae8ce8 | 420 | bdev->bd_partno = partno; |
22ae8ce8 | 421 | bdev->bd_inode = inode; |
17220ca5 | 422 | bdev->bd_queue = disk->queue; |
38c8e3df ML |
423 | if (partno) |
424 | bdev->bd_has_submit_bio = disk->part0->bd_has_submit_bio; | |
425 | else | |
426 | bdev->bd_has_submit_bio = false; | |
15e3d2c5 CH |
427 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
428 | if (!bdev->bd_stats) { | |
429 | iput(inode); | |
430 | return NULL; | |
431 | } | |
06cc978d | 432 | bdev->bd_disk = disk; |
22ae8ce8 CH |
433 | return bdev; |
434 | } | |
1da177e4 | 435 | |
83794367 DLM |
436 | void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) |
437 | { | |
438 | spin_lock(&bdev->bd_size_lock); | |
439 | i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); | |
440 | bdev->bd_nr_sectors = sectors; | |
441 | spin_unlock(&bdev->bd_size_lock); | |
442 | } | |
443 | ||
22ae8ce8 CH |
444 | void bdev_add(struct block_device *bdev, dev_t dev) |
445 | { | |
1898efcd CH |
446 | if (bdev_stable_writes(bdev)) |
447 | mapping_set_stable_writes(bdev->bd_inode->i_mapping); | |
22ae8ce8 CH |
448 | bdev->bd_dev = dev; |
449 | bdev->bd_inode->i_rdev = dev; | |
450 | bdev->bd_inode->i_ino = dev; | |
451 | insert_inode_hash(bdev->bd_inode); | |
452 | } | |
1da177e4 | 453 | |
1da177e4 LT |
454 | long nr_blockdev_pages(void) |
455 | { | |
1008fe6d | 456 | struct inode *inode; |
1da177e4 | 457 | long ret = 0; |
1008fe6d CH |
458 | |
459 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
460 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
461 | ret += inode->i_mapping->nrpages; | |
462 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
463 | ||
1da177e4 LT |
464 | return ret; |
465 | } | |
466 | ||
1a3cbbc5 TH |
467 | /** |
468 | * bd_may_claim - test whether a block device can be claimed | |
469 | * @bdev: block device of interest | |
1a3cbbc5 | 470 | * @holder: holder trying to claim @bdev |
0718afd4 | 471 | * @hops: holder ops |
1a3cbbc5 | 472 | * |
25985edc | 473 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 | 474 | * |
1a3cbbc5 TH |
475 | * RETURNS: |
476 | * %true if @bdev can be claimed, %false otherwise. | |
477 | */ | |
0718afd4 CH |
478 | static bool bd_may_claim(struct block_device *bdev, void *holder, |
479 | const struct blk_holder_ops *hops) | |
ae5f855e CH |
480 | { |
481 | struct block_device *whole = bdev_whole(bdev); | |
482 | ||
74e6464a CH |
483 | lockdep_assert_held(&bdev_lock); |
484 | ||
ae5f855e CH |
485 | if (bdev->bd_holder) { |
486 | /* | |
487 | * The same holder can always re-claim. | |
488 | */ | |
0718afd4 CH |
489 | if (bdev->bd_holder == holder) { |
490 | if (WARN_ON_ONCE(bdev->bd_holder_ops != hops)) | |
491 | return false; | |
ae5f855e | 492 | return true; |
0718afd4 | 493 | } |
ae5f855e CH |
494 | return false; |
495 | } | |
496 | ||
497 | /* | |
498 | * If the whole devices holder is set to bd_may_claim, a partition on | |
499 | * the device is claimed, but not the whole device. | |
500 | */ | |
501 | if (whole != bdev && | |
502 | whole->bd_holder && whole->bd_holder != bd_may_claim) | |
503 | return false; | |
504 | return true; | |
1a3cbbc5 TH |
505 | } |
506 | ||
6b4517a7 | 507 | /** |
58e46ed9 | 508 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 509 | * @bdev: block device of interest |
6b4517a7 | 510 | * @holder: holder trying to claim @bdev |
0718afd4 | 511 | * @hops: holder ops. |
6b4517a7 | 512 | * |
58e46ed9 CH |
513 | * Claim @bdev. This function fails if @bdev is already claimed by another |
514 | * holder and waits if another claiming is in progress. return, the caller | |
515 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
516 | * |
517 | * RETURNS: | |
518 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
519 | */ | |
0718afd4 CH |
520 | int bd_prepare_to_claim(struct block_device *bdev, void *holder, |
521 | const struct blk_holder_ops *hops) | |
6b4517a7 | 522 | { |
37c3fc9a CH |
523 | struct block_device *whole = bdev_whole(bdev); |
524 | ||
525 | if (WARN_ON_ONCE(!holder)) | |
526 | return -EINVAL; | |
6b4517a7 | 527 | retry: |
74e6464a | 528 | mutex_lock(&bdev_lock); |
6b4517a7 | 529 | /* if someone else claimed, fail */ |
0718afd4 | 530 | if (!bd_may_claim(bdev, holder, hops)) { |
74e6464a | 531 | mutex_unlock(&bdev_lock); |
6b4517a7 | 532 | return -EBUSY; |
58e46ed9 | 533 | } |
6b4517a7 | 534 | |
e75aa858 TH |
535 | /* if claiming is already in progress, wait for it to finish */ |
536 | if (whole->bd_claiming) { | |
6b4517a7 TH |
537 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
538 | DEFINE_WAIT(wait); | |
539 | ||
540 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
74e6464a | 541 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
542 | schedule(); |
543 | finish_wait(wq, &wait); | |
6b4517a7 TH |
544 | goto retry; |
545 | } | |
546 | ||
547 | /* yay, all mine */ | |
58e46ed9 | 548 | whole->bd_claiming = holder; |
74e6464a | 549 | mutex_unlock(&bdev_lock); |
6b4517a7 TH |
550 | return 0; |
551 | } | |
ecbe6bc0 | 552 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 553 | |
89e524c0 JK |
554 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
555 | { | |
556 | lockdep_assert_held(&bdev_lock); | |
557 | /* tell others that we're done */ | |
558 | BUG_ON(whole->bd_claiming != holder); | |
559 | whole->bd_claiming = NULL; | |
560 | wake_up_bit(&whole->bd_claiming, 0); | |
561 | } | |
562 | ||
563 | /** | |
564 | * bd_finish_claiming - finish claiming of a block device | |
565 | * @bdev: block device of interest | |
89e524c0 | 566 | * @holder: holder that has claimed @bdev |
017fb83e | 567 | * @hops: block device holder operations |
89e524c0 JK |
568 | * |
569 | * Finish exclusive open of a block device. Mark the device as exlusively | |
570 | * open by the holder and wake up all waiters for exclusive open to finish. | |
571 | */ | |
0718afd4 CH |
572 | static void bd_finish_claiming(struct block_device *bdev, void *holder, |
573 | const struct blk_holder_ops *hops) | |
89e524c0 | 574 | { |
37c3fc9a CH |
575 | struct block_device *whole = bdev_whole(bdev); |
576 | ||
74e6464a | 577 | mutex_lock(&bdev_lock); |
0718afd4 | 578 | BUG_ON(!bd_may_claim(bdev, holder, hops)); |
89e524c0 JK |
579 | /* |
580 | * Note that for a whole device bd_holders will be incremented twice, | |
581 | * and bd_holder will be set to bd_may_claim before being set to holder | |
582 | */ | |
583 | whole->bd_holders++; | |
584 | whole->bd_holder = bd_may_claim; | |
585 | bdev->bd_holders++; | |
0718afd4 | 586 | mutex_lock(&bdev->bd_holder_lock); |
89e524c0 | 587 | bdev->bd_holder = holder; |
0718afd4 CH |
588 | bdev->bd_holder_ops = hops; |
589 | mutex_unlock(&bdev->bd_holder_lock); | |
89e524c0 | 590 | bd_clear_claiming(whole, holder); |
74e6464a | 591 | mutex_unlock(&bdev_lock); |
89e524c0 | 592 | } |
89e524c0 JK |
593 | |
594 | /** | |
595 | * bd_abort_claiming - abort claiming of a block device | |
596 | * @bdev: block device of interest | |
89e524c0 JK |
597 | * @holder: holder that has claimed @bdev |
598 | * | |
599 | * Abort claiming of a block device when the exclusive open failed. This can be | |
600 | * also used when exclusive open is not actually desired and we just needed | |
601 | * to block other exclusive openers for a while. | |
602 | */ | |
37c3fc9a | 603 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 604 | { |
74e6464a | 605 | mutex_lock(&bdev_lock); |
37c3fc9a | 606 | bd_clear_claiming(bdev_whole(bdev), holder); |
74e6464a | 607 | mutex_unlock(&bdev_lock); |
89e524c0 JK |
608 | } |
609 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 610 | |
2736e8ee | 611 | static void bd_end_claim(struct block_device *bdev, void *holder) |
0783b1a7 CH |
612 | { |
613 | struct block_device *whole = bdev_whole(bdev); | |
614 | bool unblock = false; | |
615 | ||
616 | /* | |
617 | * Release a claim on the device. The holder fields are protected with | |
618 | * bdev_lock. open_mutex is used to synchronize disk_holder unlinking. | |
619 | */ | |
74e6464a | 620 | mutex_lock(&bdev_lock); |
2736e8ee | 621 | WARN_ON_ONCE(bdev->bd_holder != holder); |
0783b1a7 CH |
622 | WARN_ON_ONCE(--bdev->bd_holders < 0); |
623 | WARN_ON_ONCE(--whole->bd_holders < 0); | |
624 | if (!bdev->bd_holders) { | |
0718afd4 | 625 | mutex_lock(&bdev->bd_holder_lock); |
0783b1a7 | 626 | bdev->bd_holder = NULL; |
0718afd4 CH |
627 | bdev->bd_holder_ops = NULL; |
628 | mutex_unlock(&bdev->bd_holder_lock); | |
0783b1a7 CH |
629 | if (bdev->bd_write_holder) |
630 | unblock = true; | |
631 | } | |
632 | if (!whole->bd_holders) | |
633 | whole->bd_holder = NULL; | |
74e6464a | 634 | mutex_unlock(&bdev_lock); |
0783b1a7 CH |
635 | |
636 | /* | |
637 | * If this was the last claim, remove holder link and unblock evpoll if | |
638 | * it was a write holder. | |
639 | */ | |
640 | if (unblock) { | |
641 | disk_unblock_events(bdev->bd_disk); | |
642 | bdev->bd_write_holder = false; | |
643 | } | |
644 | } | |
645 | ||
c8276b95 CH |
646 | static void blkdev_flush_mapping(struct block_device *bdev) |
647 | { | |
648 | WARN_ON_ONCE(bdev->bd_holders); | |
649 | sync_blockdev(bdev); | |
650 | kill_bdev(bdev); | |
651 | bdev_write_inode(bdev); | |
652 | } | |
37be4124 | 653 | |
752863bd CH |
654 | static void blkdev_put_whole(struct block_device *bdev) |
655 | { | |
656 | if (atomic_dec_and_test(&bdev->bd_openers)) | |
657 | blkdev_flush_mapping(bdev); | |
658 | if (bdev->bd_disk->fops->release) | |
659 | bdev->bd_disk->fops->release(bdev->bd_disk); | |
660 | } | |
661 | ||
05bdb996 | 662 | static int blkdev_get_whole(struct block_device *bdev, blk_mode_t mode) |
a1548b67 | 663 | { |
142fe8f4 | 664 | struct gendisk *disk = bdev->bd_disk; |
af22fef3 | 665 | int ret; |
a1548b67 | 666 | |
362529d9 | 667 | if (disk->fops->open) { |
d32e2bf8 | 668 | ret = disk->fops->open(disk, mode); |
362529d9 CH |
669 | if (ret) { |
670 | /* avoid ghost partitions on a removed medium */ | |
671 | if (ret == -ENOMEDIUM && | |
672 | test_bit(GD_NEED_PART_SCAN, &disk->state)) | |
0384264e | 673 | bdev_disk_changed(disk, true); |
362529d9 CH |
674 | return ret; |
675 | } | |
d981cb5b | 676 | } |
a1548b67 | 677 | |
9acf381f | 678 | if (!atomic_read(&bdev->bd_openers)) |
362529d9 | 679 | set_init_blocksize(bdev); |
9acf381f | 680 | atomic_inc(&bdev->bd_openers); |
752863bd CH |
681 | if (test_bit(GD_NEED_PART_SCAN, &disk->state)) { |
682 | /* | |
683 | * Only return scanning errors if we are called from contexts | |
684 | * that explicitly want them, e.g. the BLKRRPART ioctl. | |
685 | */ | |
686 | ret = bdev_disk_changed(disk, false); | |
687 | if (ret && (mode & BLK_OPEN_STRICT_SCAN)) { | |
688 | blkdev_put_whole(bdev); | |
689 | return ret; | |
690 | } | |
691 | } | |
483546c1 | 692 | return 0; |
362529d9 | 693 | } |
a1548b67 | 694 | |
05bdb996 | 695 | static int blkdev_get_part(struct block_device *part, blk_mode_t mode) |
1da177e4 | 696 | { |
362529d9 | 697 | struct gendisk *disk = part->bd_disk; |
362529d9 | 698 | int ret; |
5b642d8b | 699 | |
9d3b8813 | 700 | ret = blkdev_get_whole(bdev_whole(part), mode); |
a8698707 | 701 | if (ret) |
9d3b8813 | 702 | return ret; |
7e69723f | 703 | |
362529d9 CH |
704 | ret = -ENXIO; |
705 | if (!bdev_nr_sectors(part)) | |
706 | goto out_blkdev_put; | |
7e69723f | 707 | |
9d1c9287 CH |
708 | if (!atomic_read(&part->bd_openers)) { |
709 | disk->open_partitions++; | |
710 | set_init_blocksize(part); | |
711 | } | |
9acf381f | 712 | atomic_inc(&part->bd_openers); |
1da177e4 | 713 | return 0; |
5a023cdb | 714 | |
362529d9 | 715 | out_blkdev_put: |
ae220766 | 716 | blkdev_put_whole(bdev_whole(part)); |
362529d9 | 717 | return ret; |
1da177e4 | 718 | } |
5b56b6ed | 719 | |
a56aefca CB |
720 | int bdev_permission(dev_t dev, blk_mode_t mode, void *holder) |
721 | { | |
722 | int ret; | |
723 | ||
724 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, | |
725 | MAJOR(dev), MINOR(dev), | |
726 | ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | | |
727 | ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
728 | if (ret) | |
729 | return ret; | |
730 | ||
731 | /* Blocking writes requires exclusive opener */ | |
732 | if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) | |
733 | return -EINVAL; | |
734 | ||
ab838b3f CB |
735 | /* |
736 | * We're using error pointers to indicate to ->release() when we | |
737 | * failed to open that block device. Also this doesn't make sense. | |
738 | */ | |
739 | if (WARN_ON_ONCE(IS_ERR(holder))) | |
740 | return -EINVAL; | |
741 | ||
a56aefca CB |
742 | return 0; |
743 | } | |
744 | ||
ae220766 | 745 | static void blkdev_put_part(struct block_device *part) |
c8276b95 CH |
746 | { |
747 | struct block_device *whole = bdev_whole(part); | |
03e26279 | 748 | |
9d1c9287 CH |
749 | if (atomic_dec_and_test(&part->bd_openers)) { |
750 | blkdev_flush_mapping(part); | |
751 | whole->bd_disk->open_partitions--; | |
752 | } | |
ae220766 | 753 | blkdev_put_whole(whole); |
1da177e4 LT |
754 | } |
755 | ||
22ae8ce8 CH |
756 | struct block_device *blkdev_get_no_open(dev_t dev) |
757 | { | |
758 | struct block_device *bdev; | |
9d3b8813 | 759 | struct inode *inode; |
22ae8ce8 | 760 | |
9d3b8813 | 761 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b | 762 | if (!inode && IS_ENABLED(CONFIG_BLOCK_LEGACY_AUTOLOAD)) { |
22ae8ce8 | 763 | blk_request_module(dev); |
9d3b8813 | 764 | inode = ilookup(blockdev_superblock, dev); |
fbdee71b CH |
765 | if (inode) |
766 | pr_warn_ratelimited( | |
451f0b6f | 767 | "block device autoloading is deprecated and will be removed.\n"); |
22ae8ce8 | 768 | } |
fbdee71b CH |
769 | if (!inode) |
770 | return NULL; | |
22ae8ce8 | 771 | |
9d3b8813 CH |
772 | /* switch from the inode reference to a device mode one: */ |
773 | bdev = &BDEV_I(inode)->bdev; | |
774 | if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) | |
775 | bdev = NULL; | |
776 | iput(inode); | |
22ae8ce8 | 777 | return bdev; |
22ae8ce8 CH |
778 | } |
779 | ||
780 | void blkdev_put_no_open(struct block_device *bdev) | |
781 | { | |
9d3b8813 | 782 | put_device(&bdev->bd_device); |
22ae8ce8 | 783 | } |
ed5cc702 JK |
784 | |
785 | static bool bdev_writes_blocked(struct block_device *bdev) | |
786 | { | |
3ff56e28 | 787 | return bdev->bd_writers < 0; |
ed5cc702 JK |
788 | } |
789 | ||
790 | static void bdev_block_writes(struct block_device *bdev) | |
791 | { | |
3ff56e28 | 792 | bdev->bd_writers--; |
ed5cc702 JK |
793 | } |
794 | ||
795 | static void bdev_unblock_writes(struct block_device *bdev) | |
796 | { | |
3ff56e28 | 797 | bdev->bd_writers++; |
ed5cc702 JK |
798 | } |
799 | ||
800 | static bool bdev_may_open(struct block_device *bdev, blk_mode_t mode) | |
801 | { | |
802 | if (bdev_allow_write_mounted) | |
803 | return true; | |
804 | /* Writes blocked? */ | |
805 | if (mode & BLK_OPEN_WRITE && bdev_writes_blocked(bdev)) | |
806 | return false; | |
807 | if (mode & BLK_OPEN_RESTRICT_WRITES && bdev->bd_writers > 0) | |
808 | return false; | |
809 | return true; | |
810 | } | |
811 | ||
812 | static void bdev_claim_write_access(struct block_device *bdev, blk_mode_t mode) | |
813 | { | |
814 | if (bdev_allow_write_mounted) | |
815 | return; | |
816 | ||
817 | /* Claim exclusive or shared write access. */ | |
818 | if (mode & BLK_OPEN_RESTRICT_WRITES) | |
819 | bdev_block_writes(bdev); | |
820 | else if (mode & BLK_OPEN_WRITE) | |
821 | bdev->bd_writers++; | |
822 | } | |
823 | ||
22650a99 CB |
824 | static inline bool bdev_unclaimed(const struct file *bdev_file) |
825 | { | |
826 | return bdev_file->private_data == BDEV_I(bdev_file->f_mapping->host); | |
827 | } | |
828 | ||
ab838b3f | 829 | static void bdev_yield_write_access(struct file *bdev_file) |
ed5cc702 | 830 | { |
321de651 CB |
831 | struct block_device *bdev; |
832 | ||
ed5cc702 JK |
833 | if (bdev_allow_write_mounted) |
834 | return; | |
835 | ||
22650a99 CB |
836 | if (bdev_unclaimed(bdev_file)) |
837 | return; | |
838 | ||
321de651 | 839 | bdev = file_bdev(bdev_file); |
ddd65e19 CB |
840 | |
841 | if (bdev_file->f_mode & FMODE_WRITE_RESTRICTED) | |
842 | bdev_unblock_writes(bdev); | |
843 | else if (bdev_file->f_mode & FMODE_WRITE) | |
844 | bdev->bd_writers--; | |
ed5cc702 JK |
845 | } |
846 | ||
d4d77629 | 847 | /** |
a56aefca CB |
848 | * bdev_open - open a block device |
849 | * @bdev: block device to open | |
05bdb996 | 850 | * @mode: open mode (BLK_OPEN_*) |
d4d77629 | 851 | * @holder: exclusive holder identifier |
0718afd4 | 852 | * @hops: holder operations |
a56aefca | 853 | * @bdev_file: file for the block device |
d4d77629 | 854 | * |
a56aefca CB |
855 | * Open the block device. If @holder is not %NULL, the block device is opened |
856 | * with exclusive access. Exclusive opens may nest for the same @holder. | |
d4d77629 TH |
857 | * |
858 | * CONTEXT: | |
859 | * Might sleep. | |
860 | * | |
861 | * RETURNS: | |
a56aefca | 862 | * zero on success, -errno on failure. |
d4d77629 | 863 | */ |
a56aefca CB |
864 | int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder, |
865 | const struct blk_holder_ops *hops, struct file *bdev_file) | |
1da177e4 | 866 | { |
cd34758c | 867 | bool unblock_events = true; |
a56aefca | 868 | struct gendisk *disk = bdev->bd_disk; |
5b56b6ed | 869 | int ret; |
e525fd89 | 870 | |
2736e8ee | 871 | if (holder) { |
05bdb996 | 872 | mode |= BLK_OPEN_EXCL; |
0718afd4 | 873 | ret = bd_prepare_to_claim(bdev, holder, hops); |
5b56b6ed | 874 | if (ret) |
ab838b3f | 875 | return ret; |
2736e8ee | 876 | } else { |
ab838b3f CB |
877 | if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) |
878 | return -EIO; | |
5b56b6ed CH |
879 | } |
880 | ||
881 | disk_block_events(disk); | |
882 | ||
a8698707 | 883 | mutex_lock(&disk->open_mutex); |
362529d9 | 884 | ret = -ENXIO; |
50b4aecf | 885 | if (!disk_live(disk)) |
362529d9 | 886 | goto abort_claiming; |
efcf5932 ML |
887 | if (!try_module_get(disk->fops->owner)) |
888 | goto abort_claiming; | |
ed5cc702 JK |
889 | ret = -EBUSY; |
890 | if (!bdev_may_open(bdev, mode)) | |
9617cd6f | 891 | goto put_module; |
362529d9 CH |
892 | if (bdev_is_partition(bdev)) |
893 | ret = blkdev_get_part(bdev, mode); | |
894 | else | |
895 | ret = blkdev_get_whole(bdev, mode); | |
22ae8ce8 | 896 | if (ret) |
efcf5932 | 897 | goto put_module; |
ed5cc702 | 898 | bdev_claim_write_access(bdev, mode); |
2736e8ee | 899 | if (holder) { |
0718afd4 | 900 | bd_finish_claiming(bdev, holder, hops); |
5b56b6ed CH |
901 | |
902 | /* | |
903 | * Block event polling for write claims if requested. Any write | |
904 | * holder makes the write_holder state stick until all are | |
905 | * released. This is good enough and tracking individual | |
906 | * writeable reference is too fragile given the way @mode is | |
907 | * used in blkdev_get/put(). | |
908 | */ | |
05bdb996 | 909 | if ((mode & BLK_OPEN_WRITE) && !bdev->bd_write_holder && |
1545e0b4 | 910 | (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) { |
5b56b6ed CH |
911 | bdev->bd_write_holder = true; |
912 | unblock_events = false; | |
913 | } | |
914 | } | |
a8698707 | 915 | mutex_unlock(&disk->open_mutex); |
5b56b6ed CH |
916 | |
917 | if (unblock_events) | |
918 | disk_unblock_events(disk); | |
a56aefca CB |
919 | |
920 | bdev_file->f_flags |= O_LARGEFILE; | |
210a03c9 | 921 | bdev_file->f_mode |= FMODE_CAN_ODIRECT; |
a56aefca CB |
922 | if (bdev_nowait(bdev)) |
923 | bdev_file->f_mode |= FMODE_NOWAIT; | |
ddd65e19 CB |
924 | if (mode & BLK_OPEN_RESTRICT_WRITES) |
925 | bdev_file->f_mode |= FMODE_WRITE_RESTRICTED; | |
7c09a4ed | 926 | bdev_file->f_mapping = bdev->bd_inode->i_mapping; |
a56aefca | 927 | bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping); |
ab838b3f | 928 | bdev_file->private_data = holder; |
a56aefca CB |
929 | |
930 | return 0; | |
efcf5932 ML |
931 | put_module: |
932 | module_put(disk->fops->owner); | |
22ae8ce8 | 933 | abort_claiming: |
2736e8ee | 934 | if (holder) |
37c3fc9a | 935 | bd_abort_claiming(bdev, holder); |
a8698707 | 936 | mutex_unlock(&disk->open_mutex); |
22ae8ce8 | 937 | disk_unblock_events(disk); |
a56aefca | 938 | return ret; |
37be4124 | 939 | } |
e719b4d1 | 940 | |
f3a60882 CB |
941 | /* |
942 | * If BLK_OPEN_WRITE_IOCTL is set then this is a historical quirk | |
943 | * associated with the floppy driver where it has allowed ioctls if the | |
944 | * file was opened for writing, but does not allow reads or writes. | |
945 | * Make sure that this quirk is reflected in @f_flags. | |
946 | * | |
947 | * It can also happen if a block device is opened as O_RDWR | O_WRONLY. | |
948 | */ | |
949 | static unsigned blk_to_file_flags(blk_mode_t mode) | |
950 | { | |
951 | unsigned int flags = 0; | |
952 | ||
953 | if ((mode & (BLK_OPEN_READ | BLK_OPEN_WRITE)) == | |
954 | (BLK_OPEN_READ | BLK_OPEN_WRITE)) | |
955 | flags |= O_RDWR; | |
956 | else if (mode & BLK_OPEN_WRITE_IOCTL) | |
957 | flags |= O_RDWR | O_WRONLY; | |
958 | else if (mode & BLK_OPEN_WRITE) | |
959 | flags |= O_WRONLY; | |
960 | else if (mode & BLK_OPEN_READ) | |
961 | flags |= O_RDONLY; /* homeopathic, because O_RDONLY is 0 */ | |
962 | else | |
963 | WARN_ON_ONCE(true); | |
964 | ||
965 | if (mode & BLK_OPEN_NDELAY) | |
966 | flags |= O_NDELAY; | |
967 | ||
968 | return flags; | |
969 | } | |
970 | ||
971 | struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, | |
972 | const struct blk_holder_ops *hops) | |
973 | { | |
974 | struct file *bdev_file; | |
a56aefca | 975 | struct block_device *bdev; |
f3a60882 | 976 | unsigned int flags; |
a56aefca | 977 | int ret; |
f3a60882 | 978 | |
a56aefca CB |
979 | ret = bdev_permission(dev, mode, holder); |
980 | if (ret) | |
981 | return ERR_PTR(ret); | |
982 | ||
983 | bdev = blkdev_get_no_open(dev); | |
984 | if (!bdev) | |
985 | return ERR_PTR(-ENXIO); | |
f3a60882 CB |
986 | |
987 | flags = blk_to_file_flags(mode); | |
a56aefca | 988 | bdev_file = alloc_file_pseudo_noaccount(bdev->bd_inode, |
f3a60882 CB |
989 | blockdev_mnt, "", flags | O_LARGEFILE, &def_blk_fops); |
990 | if (IS_ERR(bdev_file)) { | |
a56aefca | 991 | blkdev_put_no_open(bdev); |
f3a60882 CB |
992 | return bdev_file; |
993 | } | |
a56aefca | 994 | ihold(bdev->bd_inode); |
f3a60882 | 995 | |
a56aefca CB |
996 | ret = bdev_open(bdev, mode, holder, hops, bdev_file); |
997 | if (ret) { | |
ab838b3f CB |
998 | /* We failed to open the block device. Let ->release() know. */ |
999 | bdev_file->private_data = ERR_PTR(ret); | |
a56aefca CB |
1000 | fput(bdev_file); |
1001 | return ERR_PTR(ret); | |
1002 | } | |
f3a60882 CB |
1003 | return bdev_file; |
1004 | } | |
1005 | EXPORT_SYMBOL(bdev_file_open_by_dev); | |
1006 | ||
1007 | struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, | |
1008 | void *holder, | |
1009 | const struct blk_holder_ops *hops) | |
1010 | { | |
7c09a4ed | 1011 | struct file *file; |
f3a60882 CB |
1012 | dev_t dev; |
1013 | int error; | |
1014 | ||
1015 | error = lookup_bdev(path, &dev); | |
1016 | if (error) | |
1017 | return ERR_PTR(error); | |
1018 | ||
7c09a4ed CB |
1019 | file = bdev_file_open_by_dev(dev, mode, holder, hops); |
1020 | if (!IS_ERR(file) && (mode & BLK_OPEN_WRITE)) { | |
1021 | if (bdev_read_only(file_bdev(file))) { | |
1022 | fput(file); | |
1023 | file = ERR_PTR(-EACCES); | |
f3a60882 CB |
1024 | } |
1025 | } | |
1026 | ||
7c09a4ed | 1027 | return file; |
f3a60882 CB |
1028 | } |
1029 | EXPORT_SYMBOL(bdev_file_open_by_path); | |
1030 | ||
22650a99 CB |
1031 | static inline void bd_yield_claim(struct file *bdev_file) |
1032 | { | |
1033 | struct block_device *bdev = file_bdev(bdev_file); | |
1034 | void *holder = bdev_file->private_data; | |
1035 | ||
1036 | lockdep_assert_held(&bdev->bd_disk->open_mutex); | |
1037 | ||
1038 | if (WARN_ON_ONCE(IS_ERR_OR_NULL(holder))) | |
1039 | return; | |
1040 | ||
1041 | if (!bdev_unclaimed(bdev_file)) | |
1042 | bd_end_claim(bdev, holder); | |
1043 | } | |
1044 | ||
7c09a4ed | 1045 | void bdev_release(struct file *bdev_file) |
2e7b651d | 1046 | { |
7c09a4ed | 1047 | struct block_device *bdev = file_bdev(bdev_file); |
ab838b3f | 1048 | void *holder = bdev_file->private_data; |
2e7b651d PZ |
1049 | struct gendisk *disk = bdev->bd_disk; |
1050 | ||
ab838b3f CB |
1051 | /* We failed to open that block device. */ |
1052 | if (IS_ERR(holder)) | |
1053 | goto put_no_open; | |
1054 | ||
b849dd84 DA |
1055 | /* |
1056 | * Sync early if it looks like we're the last one. If someone else | |
1057 | * opens the block device between now and the decrement of bd_openers | |
1058 | * then we did a sync that we didn't need to, but that's not the end | |
1059 | * of the world and we want to avoid long (could be several minute) | |
1060 | * syncs while holding the mutex. | |
1061 | */ | |
9acf381f | 1062 | if (atomic_read(&bdev->bd_openers) == 1) |
b849dd84 DA |
1063 | sync_blockdev(bdev); |
1064 | ||
a8698707 | 1065 | mutex_lock(&disk->open_mutex); |
ab838b3f | 1066 | bdev_yield_write_access(bdev_file); |
ed5cc702 | 1067 | |
ab838b3f | 1068 | if (holder) |
22650a99 | 1069 | bd_yield_claim(bdev_file); |
77ea887e | 1070 | |
85ef06d1 TH |
1071 | /* |
1072 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1073 | * event. This is to ensure detection of media removal commanded | |
1074 | * from userland - e.g. eject(1). | |
1075 | */ | |
5b56b6ed | 1076 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 | 1077 | |
c8276b95 | 1078 | if (bdev_is_partition(bdev)) |
ae220766 | 1079 | blkdev_put_part(bdev); |
c8276b95 | 1080 | else |
ae220766 | 1081 | blkdev_put_whole(bdev); |
a8698707 CH |
1082 | mutex_unlock(&disk->open_mutex); |
1083 | ||
efcf5932 | 1084 | module_put(disk->fops->owner); |
ab838b3f | 1085 | put_no_open: |
22ae8ce8 | 1086 | blkdev_put_no_open(bdev); |
e719b4d1 | 1087 | } |
e719b4d1 | 1088 | |
22650a99 CB |
1089 | /** |
1090 | * bdev_fput - yield claim to the block device and put the file | |
1091 | * @bdev_file: open block device | |
1092 | * | |
1093 | * Yield claim on the block device and put the file. Ensure that the | |
1094 | * block device can be reclaimed before the file is closed which is a | |
1095 | * deferred operation. | |
1096 | */ | |
1097 | void bdev_fput(struct file *bdev_file) | |
1098 | { | |
1099 | if (WARN_ON_ONCE(bdev_file->f_op != &def_blk_fops)) | |
1100 | return; | |
1101 | ||
1102 | if (bdev_file->private_data) { | |
1103 | struct block_device *bdev = file_bdev(bdev_file); | |
1104 | struct gendisk *disk = bdev->bd_disk; | |
1105 | ||
1106 | mutex_lock(&disk->open_mutex); | |
1107 | bdev_yield_write_access(bdev_file); | |
1108 | bd_yield_claim(bdev_file); | |
1109 | /* | |
1110 | * Tell release we already gave up our hold on the | |
1111 | * device and if write restrictions are available that | |
1112 | * we already gave up write access to the device. | |
1113 | */ | |
1114 | bdev_file->private_data = BDEV_I(bdev_file->f_mapping->host); | |
1115 | mutex_unlock(&disk->open_mutex); | |
1116 | } | |
1117 | ||
1118 | fput(bdev_file); | |
1119 | } | |
1120 | EXPORT_SYMBOL(bdev_fput); | |
1121 | ||
1da177e4 | 1122 | /** |
0ba4566c MWO |
1123 | * lookup_bdev() - Look up a struct block_device by name. |
1124 | * @pathname: Name of the block device in the filesystem. | |
1125 | * @dev: Pointer to the block device's dev_t, if found. | |
1da177e4 | 1126 | * |
057178cf | 1127 | * Lookup the block device's dev_t at @pathname in the current |
0ba4566c | 1128 | * namespace if possible and return it in @dev. |
057178cf | 1129 | * |
0ba4566c MWO |
1130 | * Context: May sleep. |
1131 | * Return: 0 if succeeded, negative errno otherwise. | |
1da177e4 | 1132 | */ |
4e7b5671 | 1133 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 1134 | { |
1da177e4 | 1135 | struct inode *inode; |
421748ec | 1136 | struct path path; |
1da177e4 LT |
1137 | int error; |
1138 | ||
421748ec | 1139 | if (!pathname || !*pathname) |
4e7b5671 | 1140 | return -EINVAL; |
1da177e4 | 1141 | |
421748ec | 1142 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 1143 | if (error) |
4e7b5671 | 1144 | return error; |
1da177e4 | 1145 | |
bb668734 | 1146 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1147 | error = -ENOTBLK; |
1148 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 1149 | goto out_path_put; |
1da177e4 | 1150 | error = -EACCES; |
a2982cc9 | 1151 | if (!may_open_dev(&path)) |
4e7b5671 CH |
1152 | goto out_path_put; |
1153 | ||
1154 | *dev = inode->i_rdev; | |
1155 | error = 0; | |
1156 | out_path_put: | |
421748ec | 1157 | path_put(&path); |
4e7b5671 | 1158 | return error; |
1da177e4 | 1159 | } |
d5686b44 | 1160 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1161 | |
560e20e4 CH |
1162 | /** |
1163 | * bdev_mark_dead - mark a block device as dead | |
1164 | * @bdev: block device to operate on | |
1165 | * @surprise: indicate a surprise removal | |
1166 | * | |
1167 | * Tell the file system that this devices or media is dead. If @surprise is set | |
1168 | * to %true the device or media is already gone, if not we are preparing for an | |
1169 | * orderly removal. | |
1170 | * | |
d8530de5 CH |
1171 | * This calls into the file system, which then typicall syncs out all dirty data |
1172 | * and writes back inodes and then invalidates any cached data in the inodes on | |
1173 | * the file system. In addition we also invalidate the block device mapping. | |
560e20e4 CH |
1174 | */ |
1175 | void bdev_mark_dead(struct block_device *bdev, bool surprise) | |
b71e8a4c | 1176 | { |
d8530de5 CH |
1177 | mutex_lock(&bdev->bd_holder_lock); |
1178 | if (bdev->bd_holder_ops && bdev->bd_holder_ops->mark_dead) | |
1179 | bdev->bd_holder_ops->mark_dead(bdev, surprise); | |
fd146410 JK |
1180 | else { |
1181 | mutex_unlock(&bdev->bd_holder_lock); | |
d8530de5 | 1182 | sync_blockdev(bdev); |
fd146410 | 1183 | } |
b71e8a4c | 1184 | |
f98393a6 | 1185 | invalidate_bdev(bdev); |
b71e8a4c | 1186 | } |
560e20e4 | 1187 | /* |
6e57236e CH |
1188 | * New drivers should not use this directly. There are some drivers however |
1189 | * that needs this for historical reasons. For example, the DASD driver has | |
1190 | * historically had a shutdown to offline mode that doesn't actually remove the | |
1191 | * gendisk that otherwise looks a lot like a safe device removal. | |
560e20e4 CH |
1192 | */ |
1193 | EXPORT_SYMBOL_GPL(bdev_mark_dead); | |
5c0d6b60 | 1194 | |
1e03a36b | 1195 | void sync_bdevs(bool wait) |
5c0d6b60 JK |
1196 | { |
1197 | struct inode *inode, *old_inode = NULL; | |
1198 | ||
74278da9 | 1199 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1200 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1201 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1202 | struct block_device *bdev; |
5c0d6b60 JK |
1203 | |
1204 | spin_lock(&inode->i_lock); | |
1205 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1206 | mapping->nrpages == 0) { | |
1207 | spin_unlock(&inode->i_lock); | |
1208 | continue; | |
1209 | } | |
1210 | __iget(inode); | |
1211 | spin_unlock(&inode->i_lock); | |
74278da9 | 1212 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1213 | /* |
1214 | * We hold a reference to 'inode' so it couldn't have been | |
1215 | * removed from s_inodes list while we dropped the | |
74278da9 | 1216 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1217 | * be holding the last reference and we cannot iput it under |
74278da9 | 1218 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1219 | * later. |
1220 | */ | |
1221 | iput(old_inode); | |
1222 | old_inode = inode; | |
af309226 | 1223 | bdev = I_BDEV(inode); |
5c0d6b60 | 1224 | |
a8698707 | 1225 | mutex_lock(&bdev->bd_disk->open_mutex); |
9acf381f | 1226 | if (!atomic_read(&bdev->bd_openers)) { |
1e03a36b CH |
1227 | ; /* skip */ |
1228 | } else if (wait) { | |
1229 | /* | |
1230 | * We keep the error status of individual mapping so | |
1231 | * that applications can catch the writeback error using | |
1232 | * fsync(2). See filemap_fdatawait_keep_errors() for | |
1233 | * details. | |
1234 | */ | |
1235 | filemap_fdatawait_keep_errors(inode->i_mapping); | |
1236 | } else { | |
1237 | filemap_fdatawrite(inode->i_mapping); | |
1238 | } | |
a8698707 | 1239 | mutex_unlock(&bdev->bd_disk->open_mutex); |
5c0d6b60 | 1240 | |
74278da9 | 1241 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1242 | } |
74278da9 | 1243 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1244 | iput(old_inode); |
1245 | } | |
2d985f8c EB |
1246 | |
1247 | /* | |
1248 | * Handle STATX_DIOALIGN for block devices. | |
1249 | * | |
1250 | * Note that the inode passed to this is the inode of a block device node file, | |
1251 | * not the block device's internal inode. Therefore it is *not* valid to use | |
1252 | * I_BDEV() here; the block device has to be looked up by i_rdev instead. | |
1253 | */ | |
1254 | void bdev_statx_dioalign(struct inode *inode, struct kstat *stat) | |
1255 | { | |
1256 | struct block_device *bdev; | |
1257 | ||
1258 | bdev = blkdev_get_no_open(inode->i_rdev); | |
1259 | if (!bdev) | |
1260 | return; | |
1261 | ||
1262 | stat->dio_mem_align = bdev_dma_alignment(bdev) + 1; | |
1263 | stat->dio_offset_align = bdev_logical_block_size(bdev); | |
1264 | stat->result_mask |= STATX_DIOALIGN; | |
1265 | ||
1266 | blkdev_put_no_open(bdev); | |
1267 | } | |
ed5cc702 JK |
1268 | |
1269 | static int __init setup_bdev_allow_write_mounted(char *str) | |
1270 | { | |
1271 | if (kstrtobool(str, &bdev_allow_write_mounted)) | |
1272 | pr_warn("Invalid option string for bdev_allow_write_mounted:" | |
1273 | " '%s'\n", str); | |
1274 | return 1; | |
1275 | } | |
1276 | __setup("bdev_allow_write_mounted=", setup_bdev_allow_write_mounted); |