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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/block_dev.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
6 | */ | |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/mm.h> | |
10 | #include <linux/fcntl.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/kmod.h> | |
13 | #include <linux/major.h> | |
7db9cfd3 | 14 | #include <linux/device_cgroup.h> |
1da177e4 LT |
15 | #include <linux/highmem.h> |
16 | #include <linux/blkdev.h> | |
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> |
585d3bc0 | 22 | #include <linux/pagevec.h> |
811d736f | 23 | #include <linux/writeback.h> |
1da177e4 LT |
24 | #include <linux/mpage.h> |
25 | #include <linux/mount.h> | |
26 | #include <linux/uio.h> | |
27 | #include <linux/namei.h> | |
1368c4f2 | 28 | #include <linux/log2.h> |
ff01bb48 | 29 | #include <linux/cleancache.h> |
a27bb332 | 30 | #include <linux/aio.h> |
1da177e4 | 31 | #include <asm/uaccess.h> |
07f3f05c | 32 | #include "internal.h" |
1da177e4 LT |
33 | |
34 | struct bdev_inode { | |
35 | struct block_device bdev; | |
36 | struct inode vfs_inode; | |
37 | }; | |
38 | ||
4c54ac62 AB |
39 | static const struct address_space_operations def_blk_aops; |
40 | ||
1da177e4 LT |
41 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
42 | { | |
43 | return container_of(inode, struct bdev_inode, vfs_inode); | |
44 | } | |
45 | ||
46 | inline struct block_device *I_BDEV(struct inode *inode) | |
47 | { | |
48 | return &BDEV_I(inode)->bdev; | |
49 | } | |
1da177e4 LT |
50 | EXPORT_SYMBOL(I_BDEV); |
51 | ||
564f00f6 CH |
52 | static void bdev_write_inode(struct inode *inode) |
53 | { | |
54 | spin_lock(&inode->i_lock); | |
55 | while (inode->i_state & I_DIRTY) { | |
56 | spin_unlock(&inode->i_lock); | |
57 | WARN_ON_ONCE(write_inode_now(inode, true)); | |
58 | spin_lock(&inode->i_lock); | |
59 | } | |
60 | spin_unlock(&inode->i_lock); | |
61 | } | |
62 | ||
a5491e0c | 63 | /* |
018a17bd TH |
64 | * Move the inode from its current bdi to a new bdi. Make sure the inode |
65 | * is clean before moving so that it doesn't linger on the old bdi. | |
a5491e0c DC |
66 | */ |
67 | static void bdev_inode_switch_bdi(struct inode *inode, | |
68 | struct backing_dev_info *dst) | |
69 | { | |
564f00f6 CH |
70 | spin_lock(&inode->i_lock); |
71 | WARN_ON_ONCE(inode->i_state & I_DIRTY); | |
72 | inode->i_data.backing_dev_info = dst; | |
73 | spin_unlock(&inode->i_lock); | |
a5491e0c DC |
74 | } |
75 | ||
f9a14399 | 76 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
ff01bb48 | 77 | void kill_bdev(struct block_device *bdev) |
1da177e4 | 78 | { |
ff01bb48 AV |
79 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
80 | ||
91b0abe3 | 81 | if (mapping->nrpages == 0 && mapping->nrshadows == 0) |
f9a14399 | 82 | return; |
ff01bb48 | 83 | |
f9a14399 | 84 | invalidate_bh_lrus(); |
ff01bb48 | 85 | truncate_inode_pages(mapping, 0); |
1da177e4 | 86 | } |
ff01bb48 AV |
87 | EXPORT_SYMBOL(kill_bdev); |
88 | ||
89 | /* Invalidate clean unused buffers and pagecache. */ | |
90 | void invalidate_bdev(struct block_device *bdev) | |
91 | { | |
92 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
93 | ||
94 | if (mapping->nrpages == 0) | |
95 | return; | |
96 | ||
97 | invalidate_bh_lrus(); | |
98 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
99 | invalidate_mapping_pages(mapping, 0, -1); | |
100 | /* 99% of the time, we don't need to flush the cleancache on the bdev. | |
101 | * But, for the strange corners, lets be cautious | |
102 | */ | |
3167760f | 103 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
104 | } |
105 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 LT |
106 | |
107 | int set_blocksize(struct block_device *bdev, int size) | |
108 | { | |
109 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 110 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
111 | return -EINVAL; |
112 | ||
113 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 114 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
115 | return -EINVAL; |
116 | ||
117 | /* Don't change the size if it is same as current */ | |
118 | if (bdev->bd_block_size != size) { | |
119 | sync_blockdev(bdev); | |
120 | bdev->bd_block_size = size; | |
121 | bdev->bd_inode->i_blkbits = blksize_bits(size); | |
122 | kill_bdev(bdev); | |
123 | } | |
124 | return 0; | |
125 | } | |
126 | ||
127 | EXPORT_SYMBOL(set_blocksize); | |
128 | ||
129 | int sb_set_blocksize(struct super_block *sb, int size) | |
130 | { | |
1da177e4 LT |
131 | if (set_blocksize(sb->s_bdev, size)) |
132 | return 0; | |
133 | /* If we get here, we know size is power of two | |
134 | * and it's value is between 512 and PAGE_SIZE */ | |
135 | sb->s_blocksize = size; | |
38885bd4 | 136 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
137 | return sb->s_blocksize; |
138 | } | |
139 | ||
140 | EXPORT_SYMBOL(sb_set_blocksize); | |
141 | ||
142 | int sb_min_blocksize(struct super_block *sb, int size) | |
143 | { | |
e1defc4f | 144 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
145 | if (size < minsize) |
146 | size = minsize; | |
147 | return sb_set_blocksize(sb, size); | |
148 | } | |
149 | ||
150 | EXPORT_SYMBOL(sb_min_blocksize); | |
151 | ||
152 | static int | |
153 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
154 | struct buffer_head *bh, int create) | |
155 | { | |
1da177e4 LT |
156 | bh->b_bdev = I_BDEV(inode); |
157 | bh->b_blocknr = iblock; | |
158 | set_buffer_mapped(bh); | |
159 | return 0; | |
160 | } | |
161 | ||
b2e895db | 162 | static ssize_t |
d8d3d94b AV |
163 | blkdev_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, |
164 | loff_t offset) | |
b2e895db AM |
165 | { |
166 | struct file *file = iocb->ki_filp; | |
167 | struct inode *inode = file->f_mapping->host; | |
168 | ||
31b14039 AV |
169 | return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iter, |
170 | offset, blkdev_get_block, | |
d8d3d94b | 171 | NULL, NULL, 0); |
b2e895db AM |
172 | } |
173 | ||
5cee5815 JK |
174 | int __sync_blockdev(struct block_device *bdev, int wait) |
175 | { | |
176 | if (!bdev) | |
177 | return 0; | |
178 | if (!wait) | |
179 | return filemap_flush(bdev->bd_inode->i_mapping); | |
180 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
181 | } | |
182 | ||
585d3bc0 NP |
183 | /* |
184 | * Write out and wait upon all the dirty data associated with a block | |
185 | * device via its mapping. Does not take the superblock lock. | |
186 | */ | |
187 | int sync_blockdev(struct block_device *bdev) | |
188 | { | |
5cee5815 | 189 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
190 | } |
191 | EXPORT_SYMBOL(sync_blockdev); | |
192 | ||
193 | /* | |
194 | * Write out and wait upon all dirty data associated with this | |
195 | * device. Filesystem data as well as the underlying block | |
196 | * device. Takes the superblock lock. | |
197 | */ | |
198 | int fsync_bdev(struct block_device *bdev) | |
199 | { | |
200 | struct super_block *sb = get_super(bdev); | |
201 | if (sb) { | |
60b0680f | 202 | int res = sync_filesystem(sb); |
585d3bc0 NP |
203 | drop_super(sb); |
204 | return res; | |
205 | } | |
206 | return sync_blockdev(bdev); | |
207 | } | |
47e4491b | 208 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
209 | |
210 | /** | |
211 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
212 | * @bdev: blockdevice to lock | |
213 | * | |
585d3bc0 NP |
214 | * If a superblock is found on this device, we take the s_umount semaphore |
215 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
216 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
217 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
218 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
219 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
220 | * actually. | |
221 | */ | |
222 | struct super_block *freeze_bdev(struct block_device *bdev) | |
223 | { | |
224 | struct super_block *sb; | |
225 | int error = 0; | |
226 | ||
227 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a CH |
228 | if (++bdev->bd_fsfreeze_count > 1) { |
229 | /* | |
230 | * We don't even need to grab a reference - the first call | |
231 | * to freeze_bdev grab an active reference and only the last | |
232 | * thaw_bdev drops it. | |
233 | */ | |
585d3bc0 | 234 | sb = get_super(bdev); |
4504230a CH |
235 | drop_super(sb); |
236 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
237 | return sb; | |
238 | } | |
239 | ||
240 | sb = get_active_super(bdev); | |
241 | if (!sb) | |
242 | goto out; | |
48b6bca6 BM |
243 | if (sb->s_op->freeze_super) |
244 | error = sb->s_op->freeze_super(sb); | |
245 | else | |
246 | error = freeze_super(sb); | |
18e9e510 JB |
247 | if (error) { |
248 | deactivate_super(sb); | |
249 | bdev->bd_fsfreeze_count--; | |
585d3bc0 | 250 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
18e9e510 | 251 | return ERR_PTR(error); |
585d3bc0 | 252 | } |
18e9e510 | 253 | deactivate_super(sb); |
4504230a | 254 | out: |
585d3bc0 NP |
255 | sync_blockdev(bdev); |
256 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
4fadd7bb | 257 | return sb; /* thaw_bdev releases s->s_umount */ |
585d3bc0 NP |
258 | } |
259 | EXPORT_SYMBOL(freeze_bdev); | |
260 | ||
261 | /** | |
262 | * thaw_bdev -- unlock filesystem | |
263 | * @bdev: blockdevice to unlock | |
264 | * @sb: associated superblock | |
265 | * | |
266 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
267 | */ | |
268 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) | |
269 | { | |
4504230a | 270 | int error = -EINVAL; |
585d3bc0 NP |
271 | |
272 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 273 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 274 | goto out; |
4504230a CH |
275 | |
276 | error = 0; | |
277 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 278 | goto out; |
4504230a CH |
279 | |
280 | if (!sb) | |
18e9e510 | 281 | goto out; |
4504230a | 282 | |
48b6bca6 BM |
283 | if (sb->s_op->thaw_super) |
284 | error = sb->s_op->thaw_super(sb); | |
285 | else | |
286 | error = thaw_super(sb); | |
18e9e510 JB |
287 | if (error) { |
288 | bdev->bd_fsfreeze_count++; | |
289 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
290 | return error; | |
291 | } | |
292 | out: | |
585d3bc0 NP |
293 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
294 | return 0; | |
295 | } | |
296 | EXPORT_SYMBOL(thaw_bdev); | |
297 | ||
1da177e4 LT |
298 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
299 | { | |
300 | return block_write_full_page(page, blkdev_get_block, wbc); | |
301 | } | |
302 | ||
303 | static int blkdev_readpage(struct file * file, struct page * page) | |
304 | { | |
305 | return block_read_full_page(page, blkdev_get_block); | |
306 | } | |
307 | ||
447f05bb AM |
308 | static int blkdev_readpages(struct file *file, struct address_space *mapping, |
309 | struct list_head *pages, unsigned nr_pages) | |
310 | { | |
311 | return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block); | |
312 | } | |
313 | ||
6272b5a5 NP |
314 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
315 | loff_t pos, unsigned len, unsigned flags, | |
316 | struct page **pagep, void **fsdata) | |
1da177e4 | 317 | { |
155130a4 CH |
318 | return block_write_begin(mapping, pos, len, flags, pagep, |
319 | blkdev_get_block); | |
1da177e4 LT |
320 | } |
321 | ||
6272b5a5 NP |
322 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
323 | loff_t pos, unsigned len, unsigned copied, | |
324 | struct page *page, void *fsdata) | |
1da177e4 | 325 | { |
6272b5a5 NP |
326 | int ret; |
327 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
328 | ||
329 | unlock_page(page); | |
330 | page_cache_release(page); | |
331 | ||
332 | return ret; | |
1da177e4 LT |
333 | } |
334 | ||
335 | /* | |
336 | * private llseek: | |
496ad9aa | 337 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
338 | * so we compute the size by hand (just as in block_read/write above) |
339 | */ | |
965c8e59 | 340 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
341 | { |
342 | struct inode *bd_inode = file->f_mapping->host; | |
1da177e4 LT |
343 | loff_t retval; |
344 | ||
1b1dcc1b | 345 | mutex_lock(&bd_inode->i_mutex); |
5d48f3a2 | 346 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
1b1dcc1b | 347 | mutex_unlock(&bd_inode->i_mutex); |
1da177e4 LT |
348 | return retval; |
349 | } | |
350 | ||
02c24a82 | 351 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 352 | { |
b8af67e2 AB |
353 | struct inode *bd_inode = filp->f_mapping->host; |
354 | struct block_device *bdev = I_BDEV(bd_inode); | |
ab0a9735 | 355 | int error; |
da5aa861 RW |
356 | |
357 | error = filemap_write_and_wait_range(filp->f_mapping, start, end); | |
358 | if (error) | |
359 | return error; | |
ab0a9735 | 360 | |
b8af67e2 AB |
361 | /* |
362 | * There is no need to serialise calls to blkdev_issue_flush with | |
363 | * i_mutex and doing so causes performance issues with concurrent | |
364 | * O_SYNC writers to a block device. | |
365 | */ | |
dd3932ed | 366 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
ab0a9735 CH |
367 | if (error == -EOPNOTSUPP) |
368 | error = 0; | |
b8af67e2 | 369 | |
ab0a9735 | 370 | return error; |
1da177e4 | 371 | } |
b1dd3b28 | 372 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 373 | |
47a191fd MW |
374 | /** |
375 | * bdev_read_page() - Start reading a page from a block device | |
376 | * @bdev: The device to read the page from | |
377 | * @sector: The offset on the device to read the page to (need not be aligned) | |
378 | * @page: The page to read | |
379 | * | |
380 | * On entry, the page should be locked. It will be unlocked when the page | |
381 | * has been read. If the block driver implements rw_page synchronously, | |
382 | * that will be true on exit from this function, but it need not be. | |
383 | * | |
384 | * Errors returned by this function are usually "soft", eg out of memory, or | |
385 | * queue full; callers should try a different route to read this page rather | |
386 | * than propagate an error back up the stack. | |
387 | * | |
388 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
389 | */ | |
390 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
391 | struct page *page) | |
392 | { | |
393 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
394 | if (!ops->rw_page) | |
395 | return -EOPNOTSUPP; | |
396 | return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(bdev_read_page); | |
399 | ||
400 | /** | |
401 | * bdev_write_page() - Start writing a page to a block device | |
402 | * @bdev: The device to write the page to | |
403 | * @sector: The offset on the device to write the page to (need not be aligned) | |
404 | * @page: The page to write | |
405 | * @wbc: The writeback_control for the write | |
406 | * | |
407 | * On entry, the page should be locked and not currently under writeback. | |
408 | * On exit, if the write started successfully, the page will be unlocked and | |
409 | * under writeback. If the write failed already (eg the driver failed to | |
410 | * queue the page to the device), the page will still be locked. If the | |
411 | * caller is a ->writepage implementation, it will need to unlock the page. | |
412 | * | |
413 | * Errors returned by this function are usually "soft", eg out of memory, or | |
414 | * queue full; callers should try a different route to write this page rather | |
415 | * than propagate an error back up the stack. | |
416 | * | |
417 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
418 | */ | |
419 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
420 | struct page *page, struct writeback_control *wbc) | |
421 | { | |
422 | int result; | |
423 | int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE; | |
424 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
425 | if (!ops->rw_page) | |
426 | return -EOPNOTSUPP; | |
427 | set_page_writeback(page); | |
428 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); | |
429 | if (result) | |
430 | end_page_writeback(page); | |
431 | else | |
432 | unlock_page(page); | |
433 | return result; | |
434 | } | |
435 | EXPORT_SYMBOL_GPL(bdev_write_page); | |
436 | ||
1da177e4 LT |
437 | /* |
438 | * pseudo-fs | |
439 | */ | |
440 | ||
441 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 442 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
443 | |
444 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
445 | { | |
e94b1766 | 446 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
447 | if (!ei) |
448 | return NULL; | |
449 | return &ei->vfs_inode; | |
450 | } | |
451 | ||
fa0d7e3d | 452 | static void bdev_i_callback(struct rcu_head *head) |
1da177e4 | 453 | { |
fa0d7e3d | 454 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
455 | struct bdev_inode *bdi = BDEV_I(inode); |
456 | ||
1da177e4 LT |
457 | kmem_cache_free(bdev_cachep, bdi); |
458 | } | |
459 | ||
fa0d7e3d NP |
460 | static void bdev_destroy_inode(struct inode *inode) |
461 | { | |
462 | call_rcu(&inode->i_rcu, bdev_i_callback); | |
463 | } | |
464 | ||
51cc5068 | 465 | static void init_once(void *foo) |
1da177e4 LT |
466 | { |
467 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
468 | struct block_device *bdev = &ei->bdev; | |
469 | ||
a35afb83 CL |
470 | memset(bdev, 0, sizeof(*bdev)); |
471 | mutex_init(&bdev->bd_mutex); | |
a35afb83 CL |
472 | INIT_LIST_HEAD(&bdev->bd_inodes); |
473 | INIT_LIST_HEAD(&bdev->bd_list); | |
49731baa TH |
474 | #ifdef CONFIG_SYSFS |
475 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
476 | #endif | |
a35afb83 | 477 | inode_init_once(&ei->vfs_inode); |
fcccf502 TS |
478 | /* Initialize mutex for freeze. */ |
479 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
1da177e4 LT |
480 | } |
481 | ||
482 | static inline void __bd_forget(struct inode *inode) | |
483 | { | |
484 | list_del_init(&inode->i_devices); | |
485 | inode->i_bdev = NULL; | |
486 | inode->i_mapping = &inode->i_data; | |
487 | } | |
488 | ||
b57922d9 | 489 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
490 | { |
491 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
492 | struct list_head *p; | |
91b0abe3 | 493 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 494 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 495 | clear_inode(inode); |
1da177e4 LT |
496 | spin_lock(&bdev_lock); |
497 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { | |
498 | __bd_forget(list_entry(p, struct inode, i_devices)); | |
499 | } | |
500 | list_del_init(&bdev->bd_list); | |
501 | spin_unlock(&bdev_lock); | |
502 | } | |
503 | ||
ee9b6d61 | 504 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
505 | .statfs = simple_statfs, |
506 | .alloc_inode = bdev_alloc_inode, | |
507 | .destroy_inode = bdev_destroy_inode, | |
508 | .drop_inode = generic_delete_inode, | |
b57922d9 | 509 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
510 | }; |
511 | ||
51139ada AV |
512 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
513 | int flags, const char *dev_name, void *data) | |
1da177e4 | 514 | { |
b502bd11 | 515 | return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC); |
1da177e4 LT |
516 | } |
517 | ||
518 | static struct file_system_type bd_type = { | |
519 | .name = "bdev", | |
51139ada | 520 | .mount = bd_mount, |
1da177e4 LT |
521 | .kill_sb = kill_anon_super, |
522 | }; | |
523 | ||
f47ec3f2 | 524 | static struct super_block *blockdev_superblock __read_mostly; |
1da177e4 LT |
525 | |
526 | void __init bdev_cache_init(void) | |
527 | { | |
528 | int err; | |
ace8577a | 529 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 530 | |
1da177e4 | 531 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 PJ |
532 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
533 | SLAB_MEM_SPREAD|SLAB_PANIC), | |
20c2df83 | 534 | init_once); |
1da177e4 LT |
535 | err = register_filesystem(&bd_type); |
536 | if (err) | |
537 | panic("Cannot register bdev pseudo-fs"); | |
538 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
539 | if (IS_ERR(bd_mnt)) |
540 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 541 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
542 | } |
543 | ||
544 | /* | |
545 | * Most likely _very_ bad one - but then it's hardly critical for small | |
546 | * /dev and can be fixed when somebody will need really large one. | |
547 | * Keep in mind that it will be fed through icache hash function too. | |
548 | */ | |
549 | static inline unsigned long hash(dev_t dev) | |
550 | { | |
551 | return MAJOR(dev)+MINOR(dev); | |
552 | } | |
553 | ||
554 | static int bdev_test(struct inode *inode, void *data) | |
555 | { | |
556 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
557 | } | |
558 | ||
559 | static int bdev_set(struct inode *inode, void *data) | |
560 | { | |
561 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
562 | return 0; | |
563 | } | |
564 | ||
565 | static LIST_HEAD(all_bdevs); | |
566 | ||
567 | struct block_device *bdget(dev_t dev) | |
568 | { | |
569 | struct block_device *bdev; | |
570 | struct inode *inode; | |
571 | ||
c2acf7b9 | 572 | inode = iget5_locked(blockdev_superblock, hash(dev), |
1da177e4 LT |
573 | bdev_test, bdev_set, &dev); |
574 | ||
575 | if (!inode) | |
576 | return NULL; | |
577 | ||
578 | bdev = &BDEV_I(inode)->bdev; | |
579 | ||
580 | if (inode->i_state & I_NEW) { | |
581 | bdev->bd_contains = NULL; | |
782b94cd | 582 | bdev->bd_super = NULL; |
1da177e4 LT |
583 | bdev->bd_inode = inode; |
584 | bdev->bd_block_size = (1 << inode->i_blkbits); | |
585 | bdev->bd_part_count = 0; | |
586 | bdev->bd_invalidated = 0; | |
587 | inode->i_mode = S_IFBLK; | |
588 | inode->i_rdev = dev; | |
589 | inode->i_bdev = bdev; | |
590 | inode->i_data.a_ops = &def_blk_aops; | |
591 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
592 | inode->i_data.backing_dev_info = &default_backing_dev_info; | |
593 | spin_lock(&bdev_lock); | |
594 | list_add(&bdev->bd_list, &all_bdevs); | |
595 | spin_unlock(&bdev_lock); | |
596 | unlock_new_inode(inode); | |
597 | } | |
598 | return bdev; | |
599 | } | |
600 | ||
601 | EXPORT_SYMBOL(bdget); | |
602 | ||
dddac6a7 AJ |
603 | /** |
604 | * bdgrab -- Grab a reference to an already referenced block device | |
605 | * @bdev: Block device to grab a reference to. | |
606 | */ | |
607 | struct block_device *bdgrab(struct block_device *bdev) | |
608 | { | |
7de9c6ee | 609 | ihold(bdev->bd_inode); |
dddac6a7 AJ |
610 | return bdev; |
611 | } | |
c1681bf8 | 612 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 613 | |
1da177e4 LT |
614 | long nr_blockdev_pages(void) |
615 | { | |
203a2935 | 616 | struct block_device *bdev; |
1da177e4 LT |
617 | long ret = 0; |
618 | spin_lock(&bdev_lock); | |
203a2935 | 619 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4 LT |
620 | ret += bdev->bd_inode->i_mapping->nrpages; |
621 | } | |
622 | spin_unlock(&bdev_lock); | |
623 | return ret; | |
624 | } | |
625 | ||
626 | void bdput(struct block_device *bdev) | |
627 | { | |
628 | iput(bdev->bd_inode); | |
629 | } | |
630 | ||
631 | EXPORT_SYMBOL(bdput); | |
632 | ||
633 | static struct block_device *bd_acquire(struct inode *inode) | |
634 | { | |
635 | struct block_device *bdev; | |
09d967c6 | 636 | |
1da177e4 LT |
637 | spin_lock(&bdev_lock); |
638 | bdev = inode->i_bdev; | |
09d967c6 | 639 | if (bdev) { |
7de9c6ee | 640 | ihold(bdev->bd_inode); |
1da177e4 LT |
641 | spin_unlock(&bdev_lock); |
642 | return bdev; | |
643 | } | |
644 | spin_unlock(&bdev_lock); | |
09d967c6 | 645 | |
1da177e4 LT |
646 | bdev = bdget(inode->i_rdev); |
647 | if (bdev) { | |
648 | spin_lock(&bdev_lock); | |
09d967c6 OH |
649 | if (!inode->i_bdev) { |
650 | /* | |
7de9c6ee | 651 | * We take an additional reference to bd_inode, |
09d967c6 OH |
652 | * and it's released in clear_inode() of inode. |
653 | * So, we can access it via ->i_mapping always | |
654 | * without igrab(). | |
655 | */ | |
7de9c6ee | 656 | ihold(bdev->bd_inode); |
09d967c6 OH |
657 | inode->i_bdev = bdev; |
658 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
659 | list_add(&inode->i_devices, &bdev->bd_inodes); | |
660 | } | |
1da177e4 LT |
661 | spin_unlock(&bdev_lock); |
662 | } | |
663 | return bdev; | |
664 | } | |
665 | ||
a8855990 | 666 | int sb_is_blkdev_sb(struct super_block *sb) |
f47ec3f2 AV |
667 | { |
668 | return sb == blockdev_superblock; | |
669 | } | |
670 | ||
1da177e4 LT |
671 | /* Call when you free inode */ |
672 | ||
673 | void bd_forget(struct inode *inode) | |
674 | { | |
09d967c6 OH |
675 | struct block_device *bdev = NULL; |
676 | ||
1da177e4 | 677 | spin_lock(&bdev_lock); |
b4ea2eaa YH |
678 | if (!sb_is_blkdev_sb(inode->i_sb)) |
679 | bdev = inode->i_bdev; | |
680 | __bd_forget(inode); | |
1da177e4 | 681 | spin_unlock(&bdev_lock); |
09d967c6 OH |
682 | |
683 | if (bdev) | |
684 | iput(bdev->bd_inode); | |
1da177e4 LT |
685 | } |
686 | ||
1a3cbbc5 TH |
687 | /** |
688 | * bd_may_claim - test whether a block device can be claimed | |
689 | * @bdev: block device of interest | |
690 | * @whole: whole block device containing @bdev, may equal @bdev | |
691 | * @holder: holder trying to claim @bdev | |
692 | * | |
25985edc | 693 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
694 | * |
695 | * CONTEXT: | |
696 | * spin_lock(&bdev_lock). | |
697 | * | |
698 | * RETURNS: | |
699 | * %true if @bdev can be claimed, %false otherwise. | |
700 | */ | |
701 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
702 | void *holder) | |
1da177e4 | 703 | { |
1da177e4 | 704 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 705 | return true; /* already a holder */ |
1da177e4 | 706 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 707 | return false; /* held by someone else */ |
1da177e4 | 708 | else if (bdev->bd_contains == bdev) |
1a3cbbc5 | 709 | return true; /* is a whole device which isn't held */ |
1da177e4 | 710 | |
e525fd89 | 711 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
712 | return true; /* is a partition of a device that is being partitioned */ |
713 | else if (whole->bd_holder != NULL) | |
714 | return false; /* is a partition of a held device */ | |
1da177e4 | 715 | else |
1a3cbbc5 TH |
716 | return true; /* is a partition of an un-held device */ |
717 | } | |
718 | ||
6b4517a7 TH |
719 | /** |
720 | * bd_prepare_to_claim - prepare to claim a block device | |
721 | * @bdev: block device of interest | |
722 | * @whole: the whole device containing @bdev, may equal @bdev | |
723 | * @holder: holder trying to claim @bdev | |
724 | * | |
725 | * Prepare to claim @bdev. This function fails if @bdev is already | |
726 | * claimed by another holder and waits if another claiming is in | |
727 | * progress. This function doesn't actually claim. On successful | |
728 | * return, the caller has ownership of bd_claiming and bd_holder[s]. | |
729 | * | |
730 | * CONTEXT: | |
731 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab | |
732 | * it multiple times. | |
733 | * | |
734 | * RETURNS: | |
735 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
736 | */ | |
737 | static int bd_prepare_to_claim(struct block_device *bdev, | |
738 | struct block_device *whole, void *holder) | |
739 | { | |
740 | retry: | |
741 | /* if someone else claimed, fail */ | |
742 | if (!bd_may_claim(bdev, whole, holder)) | |
743 | return -EBUSY; | |
744 | ||
e75aa858 TH |
745 | /* if claiming is already in progress, wait for it to finish */ |
746 | if (whole->bd_claiming) { | |
6b4517a7 TH |
747 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
748 | DEFINE_WAIT(wait); | |
749 | ||
750 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
751 | spin_unlock(&bdev_lock); | |
752 | schedule(); | |
753 | finish_wait(wq, &wait); | |
754 | spin_lock(&bdev_lock); | |
755 | goto retry; | |
756 | } | |
757 | ||
758 | /* yay, all mine */ | |
759 | return 0; | |
760 | } | |
761 | ||
762 | /** | |
763 | * bd_start_claiming - start claiming a block device | |
764 | * @bdev: block device of interest | |
765 | * @holder: holder trying to claim @bdev | |
766 | * | |
767 | * @bdev is about to be opened exclusively. Check @bdev can be opened | |
768 | * exclusively and mark that an exclusive open is in progress. Each | |
769 | * successful call to this function must be matched with a call to | |
b0018361 NP |
770 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
771 | * fail). | |
772 | * | |
773 | * This function is used to gain exclusive access to the block device | |
774 | * without actually causing other exclusive open attempts to fail. It | |
775 | * should be used when the open sequence itself requires exclusive | |
776 | * access but may subsequently fail. | |
6b4517a7 TH |
777 | * |
778 | * CONTEXT: | |
779 | * Might sleep. | |
780 | * | |
781 | * RETURNS: | |
782 | * Pointer to the block device containing @bdev on success, ERR_PTR() | |
783 | * value on failure. | |
784 | */ | |
785 | static struct block_device *bd_start_claiming(struct block_device *bdev, | |
786 | void *holder) | |
787 | { | |
788 | struct gendisk *disk; | |
789 | struct block_device *whole; | |
790 | int partno, err; | |
791 | ||
792 | might_sleep(); | |
793 | ||
794 | /* | |
795 | * @bdev might not have been initialized properly yet, look up | |
796 | * and grab the outer block device the hard way. | |
797 | */ | |
798 | disk = get_gendisk(bdev->bd_dev, &partno); | |
799 | if (!disk) | |
800 | return ERR_PTR(-ENXIO); | |
801 | ||
d4c208b8 TH |
802 | /* |
803 | * Normally, @bdev should equal what's returned from bdget_disk() | |
804 | * if partno is 0; however, some drivers (floppy) use multiple | |
805 | * bdev's for the same physical device and @bdev may be one of the | |
806 | * aliases. Keep @bdev if partno is 0. This means claimer | |
807 | * tracking is broken for those devices but it has always been that | |
808 | * way. | |
809 | */ | |
810 | if (partno) | |
811 | whole = bdget_disk(disk, 0); | |
812 | else | |
813 | whole = bdgrab(bdev); | |
814 | ||
cf342570 | 815 | module_put(disk->fops->owner); |
6b4517a7 TH |
816 | put_disk(disk); |
817 | if (!whole) | |
818 | return ERR_PTR(-ENOMEM); | |
819 | ||
820 | /* prepare to claim, if successful, mark claiming in progress */ | |
821 | spin_lock(&bdev_lock); | |
822 | ||
823 | err = bd_prepare_to_claim(bdev, whole, holder); | |
824 | if (err == 0) { | |
825 | whole->bd_claiming = holder; | |
826 | spin_unlock(&bdev_lock); | |
827 | return whole; | |
828 | } else { | |
829 | spin_unlock(&bdev_lock); | |
830 | bdput(whole); | |
831 | return ERR_PTR(err); | |
832 | } | |
833 | } | |
834 | ||
641dc636 | 835 | #ifdef CONFIG_SYSFS |
49731baa TH |
836 | struct bd_holder_disk { |
837 | struct list_head list; | |
838 | struct gendisk *disk; | |
839 | int refcnt; | |
840 | }; | |
841 | ||
842 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
843 | struct gendisk *disk) | |
844 | { | |
845 | struct bd_holder_disk *holder; | |
846 | ||
847 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
848 | if (holder->disk == disk) | |
849 | return holder; | |
850 | return NULL; | |
851 | } | |
852 | ||
4d7dd8fd | 853 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 854 | { |
4d7dd8fd | 855 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
856 | } |
857 | ||
858 | static void del_symlink(struct kobject *from, struct kobject *to) | |
859 | { | |
641dc636 JN |
860 | sysfs_remove_link(from, kobject_name(to)); |
861 | } | |
862 | ||
df6c0cd9 | 863 | /** |
e09b457b TH |
864 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
865 | * @bdev: the claimed slave bdev | |
866 | * @disk: the holding disk | |
df6c0cd9 | 867 | * |
49731baa TH |
868 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
869 | * | |
e09b457b | 870 | * This functions creates the following sysfs symlinks. |
641dc636 | 871 | * |
e09b457b TH |
872 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
873 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 874 | * |
e09b457b TH |
875 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
876 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 877 | * |
e09b457b TH |
878 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
879 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 880 | * |
e09b457b TH |
881 | * The caller must have claimed @bdev before calling this function and |
882 | * ensure that both @bdev and @disk are valid during the creation and | |
883 | * lifetime of these symlinks. | |
641dc636 | 884 | * |
e09b457b TH |
885 | * CONTEXT: |
886 | * Might sleep. | |
641dc636 | 887 | * |
e09b457b TH |
888 | * RETURNS: |
889 | * 0 on success, -errno on failure. | |
641dc636 | 890 | */ |
e09b457b | 891 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 892 | { |
49731baa | 893 | struct bd_holder_disk *holder; |
e09b457b | 894 | int ret = 0; |
641dc636 | 895 | |
2e7b651d | 896 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 897 | |
49731baa | 898 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 899 | |
e09b457b TH |
900 | /* FIXME: remove the following once add_disk() handles errors */ |
901 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) | |
902 | goto out_unlock; | |
4e91672c | 903 | |
49731baa TH |
904 | holder = bd_find_holder_disk(bdev, disk); |
905 | if (holder) { | |
906 | holder->refcnt++; | |
e09b457b | 907 | goto out_unlock; |
49731baa | 908 | } |
641dc636 | 909 | |
49731baa TH |
910 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
911 | if (!holder) { | |
912 | ret = -ENOMEM; | |
e09b457b TH |
913 | goto out_unlock; |
914 | } | |
641dc636 | 915 | |
49731baa TH |
916 | INIT_LIST_HEAD(&holder->list); |
917 | holder->disk = disk; | |
918 | holder->refcnt = 1; | |
919 | ||
920 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
921 | if (ret) | |
922 | goto out_free; | |
923 | ||
924 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); | |
925 | if (ret) | |
926 | goto out_del; | |
e7407d16 TH |
927 | /* |
928 | * bdev could be deleted beneath us which would implicitly destroy | |
929 | * the holder directory. Hold on to it. | |
930 | */ | |
931 | kobject_get(bdev->bd_part->holder_dir); | |
49731baa TH |
932 | |
933 | list_add(&holder->list, &bdev->bd_holder_disks); | |
934 | goto out_unlock; | |
935 | ||
936 | out_del: | |
937 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
938 | out_free: | |
939 | kfree(holder); | |
e09b457b | 940 | out_unlock: |
b4cf1b72 | 941 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 942 | return ret; |
641dc636 | 943 | } |
e09b457b | 944 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 945 | |
49731baa TH |
946 | /** |
947 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
948 | * @bdev: the calimed slave bdev | |
949 | * @disk: the holding disk | |
950 | * | |
951 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
952 | * | |
953 | * CONTEXT: | |
954 | * Might sleep. | |
955 | */ | |
956 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 957 | { |
49731baa | 958 | struct bd_holder_disk *holder; |
641dc636 | 959 | |
49731baa | 960 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 961 | |
49731baa TH |
962 | holder = bd_find_holder_disk(bdev, disk); |
963 | ||
964 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
965 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
966 | del_symlink(bdev->bd_part->holder_dir, | |
967 | &disk_to_dev(disk)->kobj); | |
e7407d16 | 968 | kobject_put(bdev->bd_part->holder_dir); |
49731baa TH |
969 | list_del_init(&holder->list); |
970 | kfree(holder); | |
971 | } | |
972 | ||
973 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 974 | } |
49731baa | 975 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 976 | #endif |
1da177e4 | 977 | |
56ade44b AP |
978 | /** |
979 | * flush_disk - invalidates all buffer-cache entries on a disk | |
980 | * | |
981 | * @bdev: struct block device to be flushed | |
e6eb5ce1 | 982 | * @kill_dirty: flag to guide handling of dirty inodes |
56ade44b AP |
983 | * |
984 | * Invalidates all buffer-cache entries on a disk. It should be called | |
985 | * when a disk has been changed -- either by a media change or online | |
986 | * resize. | |
987 | */ | |
93b270f7 | 988 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
56ade44b | 989 | { |
93b270f7 | 990 | if (__invalidate_device(bdev, kill_dirty)) { |
56ade44b AP |
991 | char name[BDEVNAME_SIZE] = ""; |
992 | ||
993 | if (bdev->bd_disk) | |
994 | disk_name(bdev->bd_disk, 0, name); | |
995 | printk(KERN_WARNING "VFS: busy inodes on changed media or " | |
996 | "resized disk %s\n", name); | |
997 | } | |
998 | ||
999 | if (!bdev->bd_disk) | |
1000 | return; | |
d27769ec | 1001 | if (disk_part_scan_enabled(bdev->bd_disk)) |
56ade44b AP |
1002 | bdev->bd_invalidated = 1; |
1003 | } | |
1004 | ||
c3279d14 | 1005 | /** |
57d1b536 | 1006 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d14 AP |
1007 | * @disk: struct gendisk to check |
1008 | * @bdev: struct bdev to adjust. | |
1009 | * | |
1010 | * This routine checks to see if the bdev size does not match the disk size | |
1011 | * and adjusts it if it differs. | |
1012 | */ | |
1013 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) | |
1014 | { | |
1015 | loff_t disk_size, bdev_size; | |
1016 | ||
1017 | disk_size = (loff_t)get_capacity(disk) << 9; | |
1018 | bdev_size = i_size_read(bdev->bd_inode); | |
1019 | if (disk_size != bdev_size) { | |
1020 | char name[BDEVNAME_SIZE]; | |
1021 | ||
1022 | disk_name(disk, 0, name); | |
1023 | printk(KERN_INFO | |
1024 | "%s: detected capacity change from %lld to %lld\n", | |
1025 | name, bdev_size, disk_size); | |
1026 | i_size_write(bdev->bd_inode, disk_size); | |
93b270f7 | 1027 | flush_disk(bdev, false); |
c3279d14 AP |
1028 | } |
1029 | } | |
1030 | EXPORT_SYMBOL(check_disk_size_change); | |
1031 | ||
0c002c2f | 1032 | /** |
57d1b536 | 1033 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f AP |
1034 | * @disk: struct gendisk to be revalidated |
1035 | * | |
1036 | * This routine is a wrapper for lower-level driver's revalidate_disk | |
1037 | * call-backs. It is used to do common pre and post operations needed | |
1038 | * for all revalidate_disk operations. | |
1039 | */ | |
1040 | int revalidate_disk(struct gendisk *disk) | |
1041 | { | |
c3279d14 | 1042 | struct block_device *bdev; |
0c002c2f AP |
1043 | int ret = 0; |
1044 | ||
1045 | if (disk->fops->revalidate_disk) | |
1046 | ret = disk->fops->revalidate_disk(disk); | |
1047 | ||
c3279d14 AP |
1048 | bdev = bdget_disk(disk, 0); |
1049 | if (!bdev) | |
1050 | return ret; | |
1051 | ||
1052 | mutex_lock(&bdev->bd_mutex); | |
1053 | check_disk_size_change(disk, bdev); | |
7630b661 | 1054 | bdev->bd_invalidated = 0; |
c3279d14 AP |
1055 | mutex_unlock(&bdev->bd_mutex); |
1056 | bdput(bdev); | |
0c002c2f AP |
1057 | return ret; |
1058 | } | |
1059 | EXPORT_SYMBOL(revalidate_disk); | |
1060 | ||
1da177e4 LT |
1061 | /* |
1062 | * This routine checks whether a removable media has been changed, | |
1063 | * and invalidates all buffer-cache-entries in that case. This | |
1064 | * is a relatively slow routine, so we have to try to minimize using | |
1065 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1066 | * is the best way of combining speed and utility, I think. | |
1067 | * People changing diskettes in the middle of an operation deserve | |
1068 | * to lose :-) | |
1069 | */ | |
1070 | int check_disk_change(struct block_device *bdev) | |
1071 | { | |
1072 | struct gendisk *disk = bdev->bd_disk; | |
83d5cde4 | 1073 | const struct block_device_operations *bdops = disk->fops; |
77ea887e | 1074 | unsigned int events; |
1da177e4 | 1075 | |
77ea887e TH |
1076 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
1077 | DISK_EVENT_EJECT_REQUEST); | |
1078 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) | |
1da177e4 LT |
1079 | return 0; |
1080 | ||
93b270f7 | 1081 | flush_disk(bdev, true); |
1da177e4 LT |
1082 | if (bdops->revalidate_disk) |
1083 | bdops->revalidate_disk(bdev->bd_disk); | |
1da177e4 LT |
1084 | return 1; |
1085 | } | |
1086 | ||
1087 | EXPORT_SYMBOL(check_disk_change); | |
1088 | ||
1089 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1090 | { | |
e1defc4f | 1091 | unsigned bsize = bdev_logical_block_size(bdev); |
1da177e4 | 1092 | |
d646a02a GC |
1093 | mutex_lock(&bdev->bd_inode->i_mutex); |
1094 | i_size_write(bdev->bd_inode, size); | |
1095 | mutex_unlock(&bdev->bd_inode->i_mutex); | |
1da177e4 LT |
1096 | while (bsize < PAGE_CACHE_SIZE) { |
1097 | if (size & bsize) | |
1098 | break; | |
1099 | bsize <<= 1; | |
1100 | } | |
1101 | bdev->bd_block_size = bsize; | |
1102 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
1103 | } | |
1104 | EXPORT_SYMBOL(bd_set_size); | |
1105 | ||
4385bab1 | 1106 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1107 | |
6d740cd5 PZ |
1108 | /* |
1109 | * bd_mutex locking: | |
1110 | * | |
1111 | * mutex_lock(part->bd_mutex) | |
1112 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1113 | */ | |
1114 | ||
572c4892 | 1115 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
1da177e4 | 1116 | { |
1da177e4 | 1117 | struct gendisk *disk; |
523e1d39 | 1118 | struct module *owner; |
7db9cfd3 | 1119 | int ret; |
cf771cb5 | 1120 | int partno; |
fe6e9c1f AV |
1121 | int perm = 0; |
1122 | ||
572c4892 | 1123 | if (mode & FMODE_READ) |
fe6e9c1f | 1124 | perm |= MAY_READ; |
572c4892 | 1125 | if (mode & FMODE_WRITE) |
fe6e9c1f AV |
1126 | perm |= MAY_WRITE; |
1127 | /* | |
1128 | * hooks: /n/, see "layering violations". | |
1129 | */ | |
b7300b78 CW |
1130 | if (!for_part) { |
1131 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); | |
1132 | if (ret != 0) { | |
1133 | bdput(bdev); | |
1134 | return ret; | |
1135 | } | |
82666020 | 1136 | } |
7db9cfd3 | 1137 | |
d3374825 | 1138 | restart: |
0762b8bd | 1139 | |
89f97496 | 1140 | ret = -ENXIO; |
cf771cb5 | 1141 | disk = get_gendisk(bdev->bd_dev, &partno); |
0762b8bd | 1142 | if (!disk) |
6e9624b8 | 1143 | goto out; |
523e1d39 | 1144 | owner = disk->fops->owner; |
1da177e4 | 1145 | |
69e02c59 | 1146 | disk_block_events(disk); |
6796bf54 | 1147 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 LT |
1148 | if (!bdev->bd_openers) { |
1149 | bdev->bd_disk = disk; | |
87192a2a | 1150 | bdev->bd_queue = disk->queue; |
1da177e4 | 1151 | bdev->bd_contains = bdev; |
cf771cb5 | 1152 | if (!partno) { |
1da177e4 | 1153 | struct backing_dev_info *bdi; |
89f97496 TH |
1154 | |
1155 | ret = -ENXIO; | |
1156 | bdev->bd_part = disk_get_part(disk, partno); | |
1157 | if (!bdev->bd_part) | |
1158 | goto out_clear; | |
1159 | ||
1196f8b8 | 1160 | ret = 0; |
1da177e4 | 1161 | if (disk->fops->open) { |
572c4892 | 1162 | ret = disk->fops->open(bdev, mode); |
d3374825 N |
1163 | if (ret == -ERESTARTSYS) { |
1164 | /* Lost a race with 'disk' being | |
1165 | * deleted, try again. | |
1166 | * See md.c | |
1167 | */ | |
1168 | disk_put_part(bdev->bd_part); | |
1169 | bdev->bd_part = NULL; | |
d3374825 | 1170 | bdev->bd_disk = NULL; |
87192a2a | 1171 | bdev->bd_queue = NULL; |
d3374825 | 1172 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1173 | disk_unblock_events(disk); |
69e02c59 | 1174 | put_disk(disk); |
523e1d39 | 1175 | module_put(owner); |
d3374825 N |
1176 | goto restart; |
1177 | } | |
1da177e4 | 1178 | } |
7e69723f | 1179 | |
de33127d | 1180 | if (!ret) { |
7e69723f TH |
1181 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
1182 | bdi = blk_get_backing_dev_info(bdev); | |
7e69723f TH |
1183 | bdev_inode_switch_bdi(bdev->bd_inode, bdi); |
1184 | } | |
1185 | ||
1196f8b8 TH |
1186 | /* |
1187 | * If the device is invalidated, rescan partition | |
1188 | * if open succeeded or failed with -ENOMEDIUM. | |
1189 | * The latter is necessary to prevent ghost | |
1190 | * partitions on a removed medium. | |
1191 | */ | |
fe316bf2 JN |
1192 | if (bdev->bd_invalidated) { |
1193 | if (!ret) | |
1194 | rescan_partitions(disk, bdev); | |
1195 | else if (ret == -ENOMEDIUM) | |
1196 | invalidate_partitions(disk, bdev); | |
1197 | } | |
1196f8b8 TH |
1198 | if (ret) |
1199 | goto out_clear; | |
1da177e4 | 1200 | } else { |
1da177e4 LT |
1201 | struct block_device *whole; |
1202 | whole = bdget_disk(disk, 0); | |
1203 | ret = -ENOMEM; | |
1204 | if (!whole) | |
0762b8bd | 1205 | goto out_clear; |
37be4124 | 1206 | BUG_ON(for_part); |
572c4892 | 1207 | ret = __blkdev_get(whole, mode, 1); |
1da177e4 | 1208 | if (ret) |
0762b8bd | 1209 | goto out_clear; |
1da177e4 | 1210 | bdev->bd_contains = whole; |
a5491e0c DC |
1211 | bdev_inode_switch_bdi(bdev->bd_inode, |
1212 | whole->bd_inode->i_data.backing_dev_info); | |
89f97496 | 1213 | bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0 | 1214 | if (!(disk->flags & GENHD_FL_UP) || |
89f97496 | 1215 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4 | 1216 | ret = -ENXIO; |
0762b8bd | 1217 | goto out_clear; |
1da177e4 | 1218 | } |
89f97496 | 1219 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
1da177e4 LT |
1220 | } |
1221 | } else { | |
1da177e4 | 1222 | if (bdev->bd_contains == bdev) { |
1196f8b8 TH |
1223 | ret = 0; |
1224 | if (bdev->bd_disk->fops->open) | |
572c4892 | 1225 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1226 | /* the same as first opener case, read comment there */ |
fe316bf2 JN |
1227 | if (bdev->bd_invalidated) { |
1228 | if (!ret) | |
1229 | rescan_partitions(bdev->bd_disk, bdev); | |
1230 | else if (ret == -ENOMEDIUM) | |
1231 | invalidate_partitions(bdev->bd_disk, bdev); | |
1232 | } | |
1196f8b8 TH |
1233 | if (ret) |
1234 | goto out_unlock_bdev; | |
1da177e4 | 1235 | } |
69e02c59 | 1236 | /* only one opener holds refs to the module and disk */ |
69e02c59 | 1237 | put_disk(disk); |
523e1d39 | 1238 | module_put(owner); |
1da177e4 LT |
1239 | } |
1240 | bdev->bd_openers++; | |
37be4124 N |
1241 | if (for_part) |
1242 | bdev->bd_part_count++; | |
c039e313 | 1243 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1244 | disk_unblock_events(disk); |
1da177e4 LT |
1245 | return 0; |
1246 | ||
0762b8bd | 1247 | out_clear: |
89f97496 | 1248 | disk_put_part(bdev->bd_part); |
1da177e4 | 1249 | bdev->bd_disk = NULL; |
0762b8bd | 1250 | bdev->bd_part = NULL; |
87192a2a | 1251 | bdev->bd_queue = NULL; |
a5491e0c | 1252 | bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
1da177e4 | 1253 | if (bdev != bdev->bd_contains) |
572c4892 | 1254 | __blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4 | 1255 | bdev->bd_contains = NULL; |
0762b8bd | 1256 | out_unlock_bdev: |
c039e313 | 1257 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1258 | disk_unblock_events(disk); |
0762b8bd | 1259 | put_disk(disk); |
523e1d39 | 1260 | module_put(owner); |
4345caba | 1261 | out: |
0762b8bd TH |
1262 | bdput(bdev); |
1263 | ||
1da177e4 LT |
1264 | return ret; |
1265 | } | |
1266 | ||
d4d77629 TH |
1267 | /** |
1268 | * blkdev_get - open a block device | |
1269 | * @bdev: block_device to open | |
1270 | * @mode: FMODE_* mask | |
1271 | * @holder: exclusive holder identifier | |
1272 | * | |
1273 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is | |
1274 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL | |
1275 | * @holder is invalid. Exclusive opens may nest for the same @holder. | |
1276 | * | |
1277 | * On success, the reference count of @bdev is unchanged. On failure, | |
1278 | * @bdev is put. | |
1279 | * | |
1280 | * CONTEXT: | |
1281 | * Might sleep. | |
1282 | * | |
1283 | * RETURNS: | |
1284 | * 0 on success, -errno on failure. | |
1285 | */ | |
e525fd89 | 1286 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4 | 1287 | { |
e525fd89 TH |
1288 | struct block_device *whole = NULL; |
1289 | int res; | |
1290 | ||
1291 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); | |
1292 | ||
1293 | if ((mode & FMODE_EXCL) && holder) { | |
1294 | whole = bd_start_claiming(bdev, holder); | |
1295 | if (IS_ERR(whole)) { | |
1296 | bdput(bdev); | |
1297 | return PTR_ERR(whole); | |
1298 | } | |
1299 | } | |
1300 | ||
1301 | res = __blkdev_get(bdev, mode, 0); | |
1302 | ||
1303 | if (whole) { | |
d4dc210f TH |
1304 | struct gendisk *disk = whole->bd_disk; |
1305 | ||
6a027eff | 1306 | /* finish claiming */ |
77ea887e | 1307 | mutex_lock(&bdev->bd_mutex); |
6a027eff TH |
1308 | spin_lock(&bdev_lock); |
1309 | ||
77ea887e | 1310 | if (!res) { |
6a027eff TH |
1311 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
1312 | /* | |
1313 | * Note that for a whole device bd_holders | |
1314 | * will be incremented twice, and bd_holder | |
1315 | * will be set to bd_may_claim before being | |
1316 | * set to holder | |
1317 | */ | |
1318 | whole->bd_holders++; | |
1319 | whole->bd_holder = bd_may_claim; | |
1320 | bdev->bd_holders++; | |
1321 | bdev->bd_holder = holder; | |
1322 | } | |
1323 | ||
1324 | /* tell others that we're done */ | |
1325 | BUG_ON(whole->bd_claiming != holder); | |
1326 | whole->bd_claiming = NULL; | |
1327 | wake_up_bit(&whole->bd_claiming, 0); | |
1328 | ||
1329 | spin_unlock(&bdev_lock); | |
77ea887e TH |
1330 | |
1331 | /* | |
d4dc210f TH |
1332 | * Block event polling for write claims if requested. Any |
1333 | * write holder makes the write_holder state stick until | |
1334 | * all are released. This is good enough and tracking | |
1335 | * individual writeable reference is too fragile given the | |
1336 | * way @mode is used in blkdev_get/put(). | |
77ea887e | 1337 | */ |
4c49ff3f TH |
1338 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && |
1339 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
77ea887e | 1340 | bdev->bd_write_holder = true; |
d4dc210f | 1341 | disk_block_events(disk); |
77ea887e TH |
1342 | } |
1343 | ||
1344 | mutex_unlock(&bdev->bd_mutex); | |
6a027eff | 1345 | bdput(whole); |
e525fd89 TH |
1346 | } |
1347 | ||
1348 | return res; | |
37be4124 | 1349 | } |
1da177e4 LT |
1350 | EXPORT_SYMBOL(blkdev_get); |
1351 | ||
d4d77629 TH |
1352 | /** |
1353 | * blkdev_get_by_path - open a block device by name | |
1354 | * @path: path to the block device to open | |
1355 | * @mode: FMODE_* mask | |
1356 | * @holder: exclusive holder identifier | |
1357 | * | |
1358 | * Open the blockdevice described by the device file at @path. @mode | |
1359 | * and @holder are identical to blkdev_get(). | |
1360 | * | |
1361 | * On success, the returned block_device has reference count of one. | |
1362 | * | |
1363 | * CONTEXT: | |
1364 | * Might sleep. | |
1365 | * | |
1366 | * RETURNS: | |
1367 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1368 | */ | |
1369 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1370 | void *holder) | |
1371 | { | |
1372 | struct block_device *bdev; | |
1373 | int err; | |
1374 | ||
1375 | bdev = lookup_bdev(path); | |
1376 | if (IS_ERR(bdev)) | |
1377 | return bdev; | |
1378 | ||
1379 | err = blkdev_get(bdev, mode, holder); | |
1380 | if (err) | |
1381 | return ERR_PTR(err); | |
1382 | ||
e51900f7 CE |
1383 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
1384 | blkdev_put(bdev, mode); | |
1385 | return ERR_PTR(-EACCES); | |
1386 | } | |
1387 | ||
d4d77629 TH |
1388 | return bdev; |
1389 | } | |
1390 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1391 | ||
1392 | /** | |
1393 | * blkdev_get_by_dev - open a block device by device number | |
1394 | * @dev: device number of block device to open | |
1395 | * @mode: FMODE_* mask | |
1396 | * @holder: exclusive holder identifier | |
1397 | * | |
1398 | * Open the blockdevice described by device number @dev. @mode and | |
1399 | * @holder are identical to blkdev_get(). | |
1400 | * | |
1401 | * Use it ONLY if you really do not have anything better - i.e. when | |
1402 | * you are behind a truly sucky interface and all you are given is a | |
1403 | * device number. _Never_ to be used for internal purposes. If you | |
1404 | * ever need it - reconsider your API. | |
1405 | * | |
1406 | * On success, the returned block_device has reference count of one. | |
1407 | * | |
1408 | * CONTEXT: | |
1409 | * Might sleep. | |
1410 | * | |
1411 | * RETURNS: | |
1412 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1413 | */ | |
1414 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) | |
1415 | { | |
1416 | struct block_device *bdev; | |
1417 | int err; | |
1418 | ||
1419 | bdev = bdget(dev); | |
1420 | if (!bdev) | |
1421 | return ERR_PTR(-ENOMEM); | |
1422 | ||
1423 | err = blkdev_get(bdev, mode, holder); | |
1424 | if (err) | |
1425 | return ERR_PTR(err); | |
1426 | ||
1427 | return bdev; | |
1428 | } | |
1429 | EXPORT_SYMBOL(blkdev_get_by_dev); | |
1430 | ||
1da177e4 LT |
1431 | static int blkdev_open(struct inode * inode, struct file * filp) |
1432 | { | |
1433 | struct block_device *bdev; | |
1da177e4 LT |
1434 | |
1435 | /* | |
1436 | * Preserve backwards compatibility and allow large file access | |
1437 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1438 | * binary needs it. We might want to drop this workaround | |
1439 | * during an unstable branch. | |
1440 | */ | |
1441 | filp->f_flags |= O_LARGEFILE; | |
1442 | ||
572c4892 AV |
1443 | if (filp->f_flags & O_NDELAY) |
1444 | filp->f_mode |= FMODE_NDELAY; | |
1445 | if (filp->f_flags & O_EXCL) | |
1446 | filp->f_mode |= FMODE_EXCL; | |
1447 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1448 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1449 | ||
1da177e4 | 1450 | bdev = bd_acquire(inode); |
6a2aae06 PE |
1451 | if (bdev == NULL) |
1452 | return -ENOMEM; | |
1da177e4 | 1453 | |
572c4892 AV |
1454 | filp->f_mapping = bdev->bd_inode->i_mapping; |
1455 | ||
e525fd89 | 1456 | return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4 LT |
1457 | } |
1458 | ||
4385bab1 | 1459 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1460 | { |
2e7b651d | 1461 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1462 | struct block_device *victim = NULL; |
2e7b651d | 1463 | |
6796bf54 | 1464 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1465 | if (for_part) |
1466 | bdev->bd_part_count--; | |
1467 | ||
2e7b651d | 1468 | if (!--bdev->bd_openers) { |
6a027eff | 1469 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1470 | sync_blockdev(bdev); |
1471 | kill_bdev(bdev); | |
564f00f6 CH |
1472 | /* |
1473 | * ->release can cause the queue to disappear, so flush all | |
1474 | * dirty data before. | |
94007751 | 1475 | */ |
564f00f6 | 1476 | bdev_write_inode(bdev->bd_inode); |
94007751 N |
1477 | bdev_inode_switch_bdi(bdev->bd_inode, |
1478 | &default_backing_dev_info); | |
2e7b651d PZ |
1479 | } |
1480 | if (bdev->bd_contains == bdev) { | |
1481 | if (disk->fops->release) | |
db2a144b | 1482 | disk->fops->release(disk, mode); |
2e7b651d PZ |
1483 | } |
1484 | if (!bdev->bd_openers) { | |
1485 | struct module *owner = disk->fops->owner; | |
1486 | ||
0762b8bd TH |
1487 | disk_put_part(bdev->bd_part); |
1488 | bdev->bd_part = NULL; | |
2e7b651d | 1489 | bdev->bd_disk = NULL; |
37be4124 N |
1490 | if (bdev != bdev->bd_contains) |
1491 | victim = bdev->bd_contains; | |
2e7b651d | 1492 | bdev->bd_contains = NULL; |
523e1d39 TH |
1493 | |
1494 | put_disk(disk); | |
1495 | module_put(owner); | |
2e7b651d | 1496 | } |
2e7b651d PZ |
1497 | mutex_unlock(&bdev->bd_mutex); |
1498 | bdput(bdev); | |
37be4124 | 1499 | if (victim) |
9a1c3542 | 1500 | __blkdev_put(victim, mode, 1); |
2e7b651d PZ |
1501 | } |
1502 | ||
4385bab1 | 1503 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1504 | { |
85ef06d1 TH |
1505 | mutex_lock(&bdev->bd_mutex); |
1506 | ||
e525fd89 | 1507 | if (mode & FMODE_EXCL) { |
6a027eff TH |
1508 | bool bdev_free; |
1509 | ||
1510 | /* | |
1511 | * Release a claim on the device. The holder fields | |
1512 | * are protected with bdev_lock. bd_mutex is to | |
1513 | * synchronize disk_holder unlinking. | |
1514 | */ | |
6a027eff TH |
1515 | spin_lock(&bdev_lock); |
1516 | ||
1517 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
1518 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); | |
1519 | ||
1520 | /* bd_contains might point to self, check in a separate step */ | |
1521 | if ((bdev_free = !bdev->bd_holders)) | |
1522 | bdev->bd_holder = NULL; | |
1523 | if (!bdev->bd_contains->bd_holders) | |
1524 | bdev->bd_contains->bd_holder = NULL; | |
1525 | ||
1526 | spin_unlock(&bdev_lock); | |
1527 | ||
77ea887e TH |
1528 | /* |
1529 | * If this was the last claim, remove holder link and | |
1530 | * unblock evpoll if it was a write holder. | |
1531 | */ | |
85ef06d1 TH |
1532 | if (bdev_free && bdev->bd_write_holder) { |
1533 | disk_unblock_events(bdev->bd_disk); | |
1534 | bdev->bd_write_holder = false; | |
77ea887e | 1535 | } |
6936217c | 1536 | } |
77ea887e | 1537 | |
85ef06d1 TH |
1538 | /* |
1539 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1540 | * event. This is to ensure detection of media removal commanded | |
1541 | * from userland - e.g. eject(1). | |
1542 | */ | |
1543 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); | |
1544 | ||
1545 | mutex_unlock(&bdev->bd_mutex); | |
1546 | ||
4385bab1 | 1547 | __blkdev_put(bdev, mode, 0); |
37be4124 | 1548 | } |
2e7b651d PZ |
1549 | EXPORT_SYMBOL(blkdev_put); |
1550 | ||
1da177e4 LT |
1551 | static int blkdev_close(struct inode * inode, struct file * filp) |
1552 | { | |
1553 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); | |
4385bab1 AV |
1554 | blkdev_put(bdev, filp->f_mode); |
1555 | return 0; | |
1da177e4 LT |
1556 | } |
1557 | ||
bb93e3a5 | 1558 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1559 | { |
56b26add AV |
1560 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
1561 | fmode_t mode = file->f_mode; | |
fd4ce1ac CH |
1562 | |
1563 | /* | |
1564 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1565 | * to updated it before every ioctl. | |
1566 | */ | |
56b26add | 1567 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1568 | mode |= FMODE_NDELAY; |
1569 | else | |
1570 | mode &= ~FMODE_NDELAY; | |
1571 | ||
56b26add | 1572 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1573 | } |
1574 | ||
eef99380 CH |
1575 | /* |
1576 | * Write data to the block device. Only intended for the block device itself | |
1577 | * and the raw driver which basically is a fake block device. | |
1578 | * | |
1579 | * Does not take i_mutex for the write and thus is not for general purpose | |
1580 | * use. | |
1581 | */ | |
1456c0a8 | 1582 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
eef99380 CH |
1583 | { |
1584 | struct file *file = iocb->ki_filp; | |
53362a05 | 1585 | struct blk_plug plug; |
eef99380 CH |
1586 | ssize_t ret; |
1587 | ||
53362a05 | 1588 | blk_start_plug(&plug); |
1456c0a8 | 1589 | ret = __generic_file_write_iter(iocb, from); |
02afc27f | 1590 | if (ret > 0) { |
eef99380 | 1591 | ssize_t err; |
1456c0a8 | 1592 | err = generic_write_sync(file, iocb->ki_pos - ret, ret); |
45d4f855 | 1593 | if (err < 0) |
eef99380 CH |
1594 | ret = err; |
1595 | } | |
53362a05 | 1596 | blk_finish_plug(&plug); |
eef99380 CH |
1597 | return ret; |
1598 | } | |
1456c0a8 | 1599 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
eef99380 | 1600 | |
b2de525f | 1601 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
684c9aae LT |
1602 | { |
1603 | struct file *file = iocb->ki_filp; | |
1604 | struct inode *bd_inode = file->f_mapping->host; | |
1605 | loff_t size = i_size_read(bd_inode); | |
a886038b | 1606 | loff_t pos = iocb->ki_pos; |
684c9aae LT |
1607 | |
1608 | if (pos >= size) | |
1609 | return 0; | |
1610 | ||
1611 | size -= pos; | |
a886038b AV |
1612 | iov_iter_truncate(to, size); |
1613 | return generic_file_read_iter(iocb, to); | |
684c9aae | 1614 | } |
b2de525f | 1615 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
684c9aae | 1616 | |
87d8fe1e TT |
1617 | /* |
1618 | * Try to release a page associated with block device when the system | |
1619 | * is under memory pressure. | |
1620 | */ | |
1621 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1622 | { | |
1623 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1624 | ||
1625 | if (super && super->s_op->bdev_try_to_free_page) | |
1626 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1627 | ||
1628 | return try_to_free_buffers(page); | |
1629 | } | |
1630 | ||
4c54ac62 | 1631 | static const struct address_space_operations def_blk_aops = { |
1da177e4 | 1632 | .readpage = blkdev_readpage, |
447f05bb | 1633 | .readpages = blkdev_readpages, |
1da177e4 | 1634 | .writepage = blkdev_writepage, |
6272b5a5 NP |
1635 | .write_begin = blkdev_write_begin, |
1636 | .write_end = blkdev_write_end, | |
1da177e4 | 1637 | .writepages = generic_writepages, |
87d8fe1e | 1638 | .releasepage = blkdev_releasepage, |
1da177e4 | 1639 | .direct_IO = blkdev_direct_IO, |
b4597226 | 1640 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1641 | }; |
1642 | ||
4b6f5d20 | 1643 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1644 | .open = blkdev_open, |
1645 | .release = blkdev_close, | |
1646 | .llseek = block_llseek, | |
a886038b | 1647 | .read = new_sync_read, |
1456c0a8 | 1648 | .write = new_sync_write, |
a886038b | 1649 | .read_iter = blkdev_read_iter, |
1456c0a8 | 1650 | .write_iter = blkdev_write_iter, |
1e8b3332 | 1651 | .mmap = generic_file_mmap, |
b1dd3b28 | 1652 | .fsync = blkdev_fsync, |
bb93e3a5 | 1653 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1654 | #ifdef CONFIG_COMPAT |
1655 | .compat_ioctl = compat_blkdev_ioctl, | |
1656 | #endif | |
1e8b3332 | 1657 | .splice_read = generic_file_splice_read, |
8d020765 | 1658 | .splice_write = iter_file_splice_write, |
1da177e4 LT |
1659 | }; |
1660 | ||
1661 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) | |
1662 | { | |
1663 | int res; | |
1664 | mm_segment_t old_fs = get_fs(); | |
1665 | set_fs(KERNEL_DS); | |
56b26add | 1666 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
1da177e4 LT |
1667 | set_fs(old_fs); |
1668 | return res; | |
1669 | } | |
1670 | ||
1671 | EXPORT_SYMBOL(ioctl_by_bdev); | |
1672 | ||
1673 | /** | |
1674 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 1675 | * @pathname: special file representing the block device |
1da177e4 | 1676 | * |
57d1b536 | 1677 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
1678 | * namespace if possible and return it. Return ERR_PTR(error) |
1679 | * otherwise. | |
1680 | */ | |
421748ec | 1681 | struct block_device *lookup_bdev(const char *pathname) |
1da177e4 LT |
1682 | { |
1683 | struct block_device *bdev; | |
1684 | struct inode *inode; | |
421748ec | 1685 | struct path path; |
1da177e4 LT |
1686 | int error; |
1687 | ||
421748ec | 1688 | if (!pathname || !*pathname) |
1da177e4 LT |
1689 | return ERR_PTR(-EINVAL); |
1690 | ||
421748ec | 1691 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
1692 | if (error) |
1693 | return ERR_PTR(error); | |
1694 | ||
421748ec | 1695 | inode = path.dentry->d_inode; |
1da177e4 LT |
1696 | error = -ENOTBLK; |
1697 | if (!S_ISBLK(inode->i_mode)) | |
1698 | goto fail; | |
1699 | error = -EACCES; | |
421748ec | 1700 | if (path.mnt->mnt_flags & MNT_NODEV) |
1da177e4 LT |
1701 | goto fail; |
1702 | error = -ENOMEM; | |
1703 | bdev = bd_acquire(inode); | |
1704 | if (!bdev) | |
1705 | goto fail; | |
1706 | out: | |
421748ec | 1707 | path_put(&path); |
1da177e4 LT |
1708 | return bdev; |
1709 | fail: | |
1710 | bdev = ERR_PTR(error); | |
1711 | goto out; | |
1712 | } | |
d5686b44 | 1713 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1714 | |
93b270f7 | 1715 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
1716 | { |
1717 | struct super_block *sb = get_super(bdev); | |
1718 | int res = 0; | |
1719 | ||
1720 | if (sb) { | |
1721 | /* | |
1722 | * no need to lock the super, get_super holds the | |
1723 | * read mutex so the filesystem cannot go away | |
1724 | * under us (->put_super runs with the write lock | |
1725 | * hold). | |
1726 | */ | |
1727 | shrink_dcache_sb(sb); | |
93b270f7 | 1728 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
1729 | drop_super(sb); |
1730 | } | |
f98393a6 | 1731 | invalidate_bdev(bdev); |
b71e8a4c DH |
1732 | return res; |
1733 | } | |
1734 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
1735 | |
1736 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
1737 | { | |
1738 | struct inode *inode, *old_inode = NULL; | |
1739 | ||
1740 | spin_lock(&inode_sb_list_lock); | |
1741 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { | |
1742 | struct address_space *mapping = inode->i_mapping; | |
1743 | ||
1744 | spin_lock(&inode->i_lock); | |
1745 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1746 | mapping->nrpages == 0) { | |
1747 | spin_unlock(&inode->i_lock); | |
1748 | continue; | |
1749 | } | |
1750 | __iget(inode); | |
1751 | spin_unlock(&inode->i_lock); | |
1752 | spin_unlock(&inode_sb_list_lock); | |
1753 | /* | |
1754 | * We hold a reference to 'inode' so it couldn't have been | |
1755 | * removed from s_inodes list while we dropped the | |
1756 | * inode_sb_list_lock. We cannot iput the inode now as we can | |
1757 | * be holding the last reference and we cannot iput it under | |
1758 | * inode_sb_list_lock. So we keep the reference and iput it | |
1759 | * later. | |
1760 | */ | |
1761 | iput(old_inode); | |
1762 | old_inode = inode; | |
1763 | ||
1764 | func(I_BDEV(inode), arg); | |
1765 | ||
1766 | spin_lock(&inode_sb_list_lock); | |
1767 | } | |
1768 | spin_unlock(&inode_sb_list_lock); | |
1769 | iput(old_inode); | |
1770 | } |