Commit | Line | Data |
---|---|---|
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> | |
66114cad | 17 | #include <linux/backing-dev.h> |
1da177e4 LT |
18 | #include <linux/module.h> |
19 | #include <linux/blkpg.h> | |
b502bd11 | 20 | #include <linux/magic.h> |
1da177e4 | 21 | #include <linux/buffer_head.h> |
ff01bb48 | 22 | #include <linux/swap.h> |
585d3bc0 | 23 | #include <linux/pagevec.h> |
811d736f | 24 | #include <linux/writeback.h> |
1da177e4 LT |
25 | #include <linux/mpage.h> |
26 | #include <linux/mount.h> | |
27 | #include <linux/uio.h> | |
28 | #include <linux/namei.h> | |
1368c4f2 | 29 | #include <linux/log2.h> |
ff01bb48 | 30 | #include <linux/cleancache.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 | ||
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 | ||
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 | ||
f9a14399 | 63 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
ff01bb48 | 64 | void kill_bdev(struct block_device *bdev) |
1da177e4 | 65 | { |
ff01bb48 AV |
66 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
67 | ||
91b0abe3 | 68 | if (mapping->nrpages == 0 && mapping->nrshadows == 0) |
f9a14399 | 69 | return; |
ff01bb48 | 70 | |
f9a14399 | 71 | invalidate_bh_lrus(); |
ff01bb48 | 72 | truncate_inode_pages(mapping, 0); |
1da177e4 | 73 | } |
ff01bb48 AV |
74 | EXPORT_SYMBOL(kill_bdev); |
75 | ||
76 | /* Invalidate clean unused buffers and pagecache. */ | |
77 | void invalidate_bdev(struct block_device *bdev) | |
78 | { | |
79 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
80 | ||
81 | if (mapping->nrpages == 0) | |
82 | return; | |
83 | ||
84 | invalidate_bh_lrus(); | |
85 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
86 | invalidate_mapping_pages(mapping, 0, -1); | |
87 | /* 99% of the time, we don't need to flush the cleancache on the bdev. | |
88 | * But, for the strange corners, lets be cautious | |
89 | */ | |
3167760f | 90 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
91 | } |
92 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 LT |
93 | |
94 | int set_blocksize(struct block_device *bdev, int size) | |
95 | { | |
96 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 97 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
98 | return -EINVAL; |
99 | ||
100 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 101 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
102 | return -EINVAL; |
103 | ||
104 | /* Don't change the size if it is same as current */ | |
105 | if (bdev->bd_block_size != size) { | |
106 | sync_blockdev(bdev); | |
107 | bdev->bd_block_size = size; | |
108 | bdev->bd_inode->i_blkbits = blksize_bits(size); | |
109 | kill_bdev(bdev); | |
110 | } | |
111 | return 0; | |
112 | } | |
113 | ||
114 | EXPORT_SYMBOL(set_blocksize); | |
115 | ||
116 | int sb_set_blocksize(struct super_block *sb, int size) | |
117 | { | |
1da177e4 LT |
118 | if (set_blocksize(sb->s_bdev, size)) |
119 | return 0; | |
120 | /* If we get here, we know size is power of two | |
121 | * and it's value is between 512 and PAGE_SIZE */ | |
122 | sb->s_blocksize = size; | |
38885bd4 | 123 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
124 | return sb->s_blocksize; |
125 | } | |
126 | ||
127 | EXPORT_SYMBOL(sb_set_blocksize); | |
128 | ||
129 | int sb_min_blocksize(struct super_block *sb, int size) | |
130 | { | |
e1defc4f | 131 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
132 | if (size < minsize) |
133 | size = minsize; | |
134 | return sb_set_blocksize(sb, size); | |
135 | } | |
136 | ||
137 | EXPORT_SYMBOL(sb_min_blocksize); | |
138 | ||
139 | static int | |
140 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
141 | struct buffer_head *bh, int create) | |
142 | { | |
1da177e4 LT |
143 | bh->b_bdev = I_BDEV(inode); |
144 | bh->b_blocknr = iblock; | |
145 | set_buffer_mapped(bh); | |
146 | return 0; | |
147 | } | |
148 | ||
b2e895db | 149 | static ssize_t |
22c6186e | 150 | blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, loff_t offset) |
b2e895db AM |
151 | { |
152 | struct file *file = iocb->ki_filp; | |
153 | struct inode *inode = file->f_mapping->host; | |
154 | ||
bbab37dd MW |
155 | if (IS_DAX(inode)) |
156 | return dax_do_io(iocb, inode, iter, offset, blkdev_get_block, | |
157 | NULL, DIO_SKIP_DIO_COUNT); | |
17f8c842 | 158 | return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, offset, |
fe0f07d0 JA |
159 | blkdev_get_block, NULL, NULL, |
160 | DIO_SKIP_DIO_COUNT); | |
b2e895db AM |
161 | } |
162 | ||
5cee5815 JK |
163 | int __sync_blockdev(struct block_device *bdev, int wait) |
164 | { | |
165 | if (!bdev) | |
166 | return 0; | |
167 | if (!wait) | |
168 | return filemap_flush(bdev->bd_inode->i_mapping); | |
169 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
170 | } | |
171 | ||
585d3bc0 NP |
172 | /* |
173 | * Write out and wait upon all the dirty data associated with a block | |
174 | * device via its mapping. Does not take the superblock lock. | |
175 | */ | |
176 | int sync_blockdev(struct block_device *bdev) | |
177 | { | |
5cee5815 | 178 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
179 | } |
180 | EXPORT_SYMBOL(sync_blockdev); | |
181 | ||
182 | /* | |
183 | * Write out and wait upon all dirty data associated with this | |
184 | * device. Filesystem data as well as the underlying block | |
185 | * device. Takes the superblock lock. | |
186 | */ | |
187 | int fsync_bdev(struct block_device *bdev) | |
188 | { | |
189 | struct super_block *sb = get_super(bdev); | |
190 | if (sb) { | |
60b0680f | 191 | int res = sync_filesystem(sb); |
585d3bc0 NP |
192 | drop_super(sb); |
193 | return res; | |
194 | } | |
195 | return sync_blockdev(bdev); | |
196 | } | |
47e4491b | 197 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
198 | |
199 | /** | |
200 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
201 | * @bdev: blockdevice to lock | |
202 | * | |
585d3bc0 NP |
203 | * If a superblock is found on this device, we take the s_umount semaphore |
204 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
205 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
206 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
207 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
208 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
209 | * actually. | |
210 | */ | |
211 | struct super_block *freeze_bdev(struct block_device *bdev) | |
212 | { | |
213 | struct super_block *sb; | |
214 | int error = 0; | |
215 | ||
216 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a CH |
217 | if (++bdev->bd_fsfreeze_count > 1) { |
218 | /* | |
219 | * We don't even need to grab a reference - the first call | |
220 | * to freeze_bdev grab an active reference and only the last | |
221 | * thaw_bdev drops it. | |
222 | */ | |
585d3bc0 | 223 | sb = get_super(bdev); |
4504230a CH |
224 | drop_super(sb); |
225 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
226 | return sb; | |
227 | } | |
228 | ||
229 | sb = get_active_super(bdev); | |
230 | if (!sb) | |
231 | goto out; | |
48b6bca6 BM |
232 | if (sb->s_op->freeze_super) |
233 | error = sb->s_op->freeze_super(sb); | |
234 | else | |
235 | error = freeze_super(sb); | |
18e9e510 JB |
236 | if (error) { |
237 | deactivate_super(sb); | |
238 | bdev->bd_fsfreeze_count--; | |
585d3bc0 | 239 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
18e9e510 | 240 | return ERR_PTR(error); |
585d3bc0 | 241 | } |
18e9e510 | 242 | deactivate_super(sb); |
4504230a | 243 | out: |
585d3bc0 NP |
244 | sync_blockdev(bdev); |
245 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
4fadd7bb | 246 | return sb; /* thaw_bdev releases s->s_umount */ |
585d3bc0 NP |
247 | } |
248 | EXPORT_SYMBOL(freeze_bdev); | |
249 | ||
250 | /** | |
251 | * thaw_bdev -- unlock filesystem | |
252 | * @bdev: blockdevice to unlock | |
253 | * @sb: associated superblock | |
254 | * | |
255 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
256 | */ | |
257 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) | |
258 | { | |
4504230a | 259 | int error = -EINVAL; |
585d3bc0 NP |
260 | |
261 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 262 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 263 | goto out; |
4504230a CH |
264 | |
265 | error = 0; | |
266 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 267 | goto out; |
4504230a CH |
268 | |
269 | if (!sb) | |
18e9e510 | 270 | goto out; |
4504230a | 271 | |
48b6bca6 BM |
272 | if (sb->s_op->thaw_super) |
273 | error = sb->s_op->thaw_super(sb); | |
274 | else | |
275 | error = thaw_super(sb); | |
18e9e510 JB |
276 | if (error) { |
277 | bdev->bd_fsfreeze_count++; | |
278 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
279 | return error; | |
280 | } | |
281 | out: | |
585d3bc0 NP |
282 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
283 | return 0; | |
284 | } | |
285 | EXPORT_SYMBOL(thaw_bdev); | |
286 | ||
1da177e4 LT |
287 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
288 | { | |
289 | return block_write_full_page(page, blkdev_get_block, wbc); | |
290 | } | |
291 | ||
292 | static int blkdev_readpage(struct file * file, struct page * page) | |
293 | { | |
294 | return block_read_full_page(page, blkdev_get_block); | |
295 | } | |
296 | ||
447f05bb AM |
297 | static int blkdev_readpages(struct file *file, struct address_space *mapping, |
298 | struct list_head *pages, unsigned nr_pages) | |
299 | { | |
300 | return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block); | |
301 | } | |
302 | ||
6272b5a5 NP |
303 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
304 | loff_t pos, unsigned len, unsigned flags, | |
305 | struct page **pagep, void **fsdata) | |
1da177e4 | 306 | { |
155130a4 CH |
307 | return block_write_begin(mapping, pos, len, flags, pagep, |
308 | blkdev_get_block); | |
1da177e4 LT |
309 | } |
310 | ||
6272b5a5 NP |
311 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
312 | loff_t pos, unsigned len, unsigned copied, | |
313 | struct page *page, void *fsdata) | |
1da177e4 | 314 | { |
6272b5a5 NP |
315 | int ret; |
316 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
317 | ||
318 | unlock_page(page); | |
319 | page_cache_release(page); | |
320 | ||
321 | return ret; | |
1da177e4 LT |
322 | } |
323 | ||
324 | /* | |
325 | * private llseek: | |
496ad9aa | 326 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
327 | * so we compute the size by hand (just as in block_read/write above) |
328 | */ | |
965c8e59 | 329 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
330 | { |
331 | struct inode *bd_inode = file->f_mapping->host; | |
1da177e4 LT |
332 | loff_t retval; |
333 | ||
1b1dcc1b | 334 | mutex_lock(&bd_inode->i_mutex); |
5d48f3a2 | 335 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
1b1dcc1b | 336 | mutex_unlock(&bd_inode->i_mutex); |
1da177e4 LT |
337 | return retval; |
338 | } | |
339 | ||
02c24a82 | 340 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 341 | { |
b8af67e2 AB |
342 | struct inode *bd_inode = filp->f_mapping->host; |
343 | struct block_device *bdev = I_BDEV(bd_inode); | |
ab0a9735 | 344 | int error; |
da5aa861 RW |
345 | |
346 | error = filemap_write_and_wait_range(filp->f_mapping, start, end); | |
347 | if (error) | |
348 | return error; | |
ab0a9735 | 349 | |
b8af67e2 AB |
350 | /* |
351 | * There is no need to serialise calls to blkdev_issue_flush with | |
352 | * i_mutex and doing so causes performance issues with concurrent | |
353 | * O_SYNC writers to a block device. | |
354 | */ | |
dd3932ed | 355 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
ab0a9735 CH |
356 | if (error == -EOPNOTSUPP) |
357 | error = 0; | |
b8af67e2 | 358 | |
ab0a9735 | 359 | return error; |
1da177e4 | 360 | } |
b1dd3b28 | 361 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 362 | |
47a191fd MW |
363 | /** |
364 | * bdev_read_page() - Start reading a page from a block device | |
365 | * @bdev: The device to read the page from | |
366 | * @sector: The offset on the device to read the page to (need not be aligned) | |
367 | * @page: The page to read | |
368 | * | |
369 | * On entry, the page should be locked. It will be unlocked when the page | |
370 | * has been read. If the block driver implements rw_page synchronously, | |
371 | * that will be true on exit from this function, but it need not be. | |
372 | * | |
373 | * Errors returned by this function are usually "soft", eg out of memory, or | |
374 | * queue full; callers should try a different route to read this page rather | |
375 | * than propagate an error back up the stack. | |
376 | * | |
377 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
378 | */ | |
379 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
380 | struct page *page) | |
381 | { | |
382 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
f68eb1e7 | 383 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd MW |
384 | return -EOPNOTSUPP; |
385 | return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(bdev_read_page); | |
388 | ||
389 | /** | |
390 | * bdev_write_page() - Start writing a page to a block device | |
391 | * @bdev: The device to write the page to | |
392 | * @sector: The offset on the device to write the page to (need not be aligned) | |
393 | * @page: The page to write | |
394 | * @wbc: The writeback_control for the write | |
395 | * | |
396 | * On entry, the page should be locked and not currently under writeback. | |
397 | * On exit, if the write started successfully, the page will be unlocked and | |
398 | * under writeback. If the write failed already (eg the driver failed to | |
399 | * queue the page to the device), the page will still be locked. If the | |
400 | * caller is a ->writepage implementation, it will need to unlock the page. | |
401 | * | |
402 | * Errors returned by this function are usually "soft", eg out of memory, or | |
403 | * queue full; callers should try a different route to write this page rather | |
404 | * than propagate an error back up the stack. | |
405 | * | |
406 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
407 | */ | |
408 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
409 | struct page *page, struct writeback_control *wbc) | |
410 | { | |
411 | int result; | |
412 | int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE; | |
413 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
f68eb1e7 | 414 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd MW |
415 | return -EOPNOTSUPP; |
416 | set_page_writeback(page); | |
417 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); | |
418 | if (result) | |
419 | end_page_writeback(page); | |
420 | else | |
421 | unlock_page(page); | |
422 | return result; | |
423 | } | |
424 | EXPORT_SYMBOL_GPL(bdev_write_page); | |
425 | ||
dd22f551 MW |
426 | /** |
427 | * bdev_direct_access() - Get the address for directly-accessibly memory | |
428 | * @bdev: The device containing the memory | |
429 | * @sector: The offset within the device | |
430 | * @addr: Where to put the address of the memory | |
431 | * @pfn: The Page Frame Number for the memory | |
432 | * @size: The number of bytes requested | |
433 | * | |
434 | * If a block device is made up of directly addressable memory, this function | |
435 | * will tell the caller the PFN and the address of the memory. The address | |
436 | * may be directly dereferenced within the kernel without the need to call | |
437 | * ioremap(), kmap() or similar. The PFN is suitable for inserting into | |
438 | * page tables. | |
439 | * | |
440 | * Return: negative errno if an error occurs, otherwise the number of bytes | |
441 | * accessible at this address. | |
442 | */ | |
443 | long bdev_direct_access(struct block_device *bdev, sector_t sector, | |
444 | void **addr, unsigned long *pfn, long size) | |
445 | { | |
446 | long avail; | |
447 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
448 | ||
43c3dd08 MW |
449 | /* |
450 | * The device driver is allowed to sleep, in order to make the | |
451 | * memory directly accessible. | |
452 | */ | |
453 | might_sleep(); | |
454 | ||
dd22f551 MW |
455 | if (size < 0) |
456 | return size; | |
457 | if (!ops->direct_access) | |
458 | return -EOPNOTSUPP; | |
459 | if ((sector + DIV_ROUND_UP(size, 512)) > | |
460 | part_nr_sects_read(bdev->bd_part)) | |
461 | return -ERANGE; | |
462 | sector += get_start_sect(bdev); | |
463 | if (sector % (PAGE_SIZE / 512)) | |
464 | return -EINVAL; | |
465 | avail = ops->direct_access(bdev, sector, addr, pfn, size); | |
466 | if (!avail) | |
467 | return -ERANGE; | |
468 | return min(avail, size); | |
469 | } | |
470 | EXPORT_SYMBOL_GPL(bdev_direct_access); | |
471 | ||
1da177e4 LT |
472 | /* |
473 | * pseudo-fs | |
474 | */ | |
475 | ||
476 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 477 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
478 | |
479 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
480 | { | |
e94b1766 | 481 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
482 | if (!ei) |
483 | return NULL; | |
484 | return &ei->vfs_inode; | |
485 | } | |
486 | ||
fa0d7e3d | 487 | static void bdev_i_callback(struct rcu_head *head) |
1da177e4 | 488 | { |
fa0d7e3d | 489 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
490 | struct bdev_inode *bdi = BDEV_I(inode); |
491 | ||
1da177e4 LT |
492 | kmem_cache_free(bdev_cachep, bdi); |
493 | } | |
494 | ||
fa0d7e3d NP |
495 | static void bdev_destroy_inode(struct inode *inode) |
496 | { | |
497 | call_rcu(&inode->i_rcu, bdev_i_callback); | |
498 | } | |
499 | ||
51cc5068 | 500 | static void init_once(void *foo) |
1da177e4 LT |
501 | { |
502 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
503 | struct block_device *bdev = &ei->bdev; | |
504 | ||
a35afb83 CL |
505 | memset(bdev, 0, sizeof(*bdev)); |
506 | mutex_init(&bdev->bd_mutex); | |
a35afb83 CL |
507 | INIT_LIST_HEAD(&bdev->bd_inodes); |
508 | INIT_LIST_HEAD(&bdev->bd_list); | |
49731baa TH |
509 | #ifdef CONFIG_SYSFS |
510 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
511 | #endif | |
a35afb83 | 512 | inode_init_once(&ei->vfs_inode); |
fcccf502 TS |
513 | /* Initialize mutex for freeze. */ |
514 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
1da177e4 LT |
515 | } |
516 | ||
517 | static inline void __bd_forget(struct inode *inode) | |
518 | { | |
519 | list_del_init(&inode->i_devices); | |
520 | inode->i_bdev = NULL; | |
521 | inode->i_mapping = &inode->i_data; | |
522 | } | |
523 | ||
b57922d9 | 524 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
525 | { |
526 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
527 | struct list_head *p; | |
91b0abe3 | 528 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 529 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 530 | clear_inode(inode); |
1da177e4 LT |
531 | spin_lock(&bdev_lock); |
532 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { | |
533 | __bd_forget(list_entry(p, struct inode, i_devices)); | |
534 | } | |
535 | list_del_init(&bdev->bd_list); | |
536 | spin_unlock(&bdev_lock); | |
537 | } | |
538 | ||
ee9b6d61 | 539 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
540 | .statfs = simple_statfs, |
541 | .alloc_inode = bdev_alloc_inode, | |
542 | .destroy_inode = bdev_destroy_inode, | |
543 | .drop_inode = generic_delete_inode, | |
b57922d9 | 544 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
545 | }; |
546 | ||
51139ada AV |
547 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
548 | int flags, const char *dev_name, void *data) | |
1da177e4 | 549 | { |
b502bd11 | 550 | return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC); |
1da177e4 LT |
551 | } |
552 | ||
553 | static struct file_system_type bd_type = { | |
554 | .name = "bdev", | |
51139ada | 555 | .mount = bd_mount, |
1da177e4 LT |
556 | .kill_sb = kill_anon_super, |
557 | }; | |
558 | ||
a212b105 TH |
559 | struct super_block *blockdev_superblock __read_mostly; |
560 | EXPORT_SYMBOL_GPL(blockdev_superblock); | |
1da177e4 LT |
561 | |
562 | void __init bdev_cache_init(void) | |
563 | { | |
564 | int err; | |
ace8577a | 565 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 566 | |
1da177e4 | 567 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 PJ |
568 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
569 | SLAB_MEM_SPREAD|SLAB_PANIC), | |
20c2df83 | 570 | init_once); |
1da177e4 LT |
571 | err = register_filesystem(&bd_type); |
572 | if (err) | |
573 | panic("Cannot register bdev pseudo-fs"); | |
574 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
575 | if (IS_ERR(bd_mnt)) |
576 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 577 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
578 | } |
579 | ||
580 | /* | |
581 | * Most likely _very_ bad one - but then it's hardly critical for small | |
582 | * /dev and can be fixed when somebody will need really large one. | |
583 | * Keep in mind that it will be fed through icache hash function too. | |
584 | */ | |
585 | static inline unsigned long hash(dev_t dev) | |
586 | { | |
587 | return MAJOR(dev)+MINOR(dev); | |
588 | } | |
589 | ||
590 | static int bdev_test(struct inode *inode, void *data) | |
591 | { | |
592 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
593 | } | |
594 | ||
595 | static int bdev_set(struct inode *inode, void *data) | |
596 | { | |
597 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
598 | return 0; | |
599 | } | |
600 | ||
601 | static LIST_HEAD(all_bdevs); | |
602 | ||
603 | struct block_device *bdget(dev_t dev) | |
604 | { | |
605 | struct block_device *bdev; | |
606 | struct inode *inode; | |
607 | ||
c2acf7b9 | 608 | inode = iget5_locked(blockdev_superblock, hash(dev), |
1da177e4 LT |
609 | bdev_test, bdev_set, &dev); |
610 | ||
611 | if (!inode) | |
612 | return NULL; | |
613 | ||
614 | bdev = &BDEV_I(inode)->bdev; | |
615 | ||
616 | if (inode->i_state & I_NEW) { | |
617 | bdev->bd_contains = NULL; | |
782b94cd | 618 | bdev->bd_super = NULL; |
1da177e4 LT |
619 | bdev->bd_inode = inode; |
620 | bdev->bd_block_size = (1 << inode->i_blkbits); | |
621 | bdev->bd_part_count = 0; | |
622 | bdev->bd_invalidated = 0; | |
623 | inode->i_mode = S_IFBLK; | |
624 | inode->i_rdev = dev; | |
625 | inode->i_bdev = bdev; | |
626 | inode->i_data.a_ops = &def_blk_aops; | |
627 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
1da177e4 LT |
628 | spin_lock(&bdev_lock); |
629 | list_add(&bdev->bd_list, &all_bdevs); | |
630 | spin_unlock(&bdev_lock); | |
631 | unlock_new_inode(inode); | |
632 | } | |
633 | return bdev; | |
634 | } | |
635 | ||
636 | EXPORT_SYMBOL(bdget); | |
637 | ||
dddac6a7 AJ |
638 | /** |
639 | * bdgrab -- Grab a reference to an already referenced block device | |
640 | * @bdev: Block device to grab a reference to. | |
641 | */ | |
642 | struct block_device *bdgrab(struct block_device *bdev) | |
643 | { | |
7de9c6ee | 644 | ihold(bdev->bd_inode); |
dddac6a7 AJ |
645 | return bdev; |
646 | } | |
c1681bf8 | 647 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 648 | |
1da177e4 LT |
649 | long nr_blockdev_pages(void) |
650 | { | |
203a2935 | 651 | struct block_device *bdev; |
1da177e4 LT |
652 | long ret = 0; |
653 | spin_lock(&bdev_lock); | |
203a2935 | 654 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4 LT |
655 | ret += bdev->bd_inode->i_mapping->nrpages; |
656 | } | |
657 | spin_unlock(&bdev_lock); | |
658 | return ret; | |
659 | } | |
660 | ||
661 | void bdput(struct block_device *bdev) | |
662 | { | |
663 | iput(bdev->bd_inode); | |
664 | } | |
665 | ||
666 | EXPORT_SYMBOL(bdput); | |
667 | ||
668 | static struct block_device *bd_acquire(struct inode *inode) | |
669 | { | |
670 | struct block_device *bdev; | |
09d967c6 | 671 | |
1da177e4 LT |
672 | spin_lock(&bdev_lock); |
673 | bdev = inode->i_bdev; | |
09d967c6 | 674 | if (bdev) { |
7de9c6ee | 675 | ihold(bdev->bd_inode); |
1da177e4 LT |
676 | spin_unlock(&bdev_lock); |
677 | return bdev; | |
678 | } | |
679 | spin_unlock(&bdev_lock); | |
09d967c6 | 680 | |
1da177e4 LT |
681 | bdev = bdget(inode->i_rdev); |
682 | if (bdev) { | |
683 | spin_lock(&bdev_lock); | |
09d967c6 OH |
684 | if (!inode->i_bdev) { |
685 | /* | |
7de9c6ee | 686 | * We take an additional reference to bd_inode, |
09d967c6 OH |
687 | * and it's released in clear_inode() of inode. |
688 | * So, we can access it via ->i_mapping always | |
689 | * without igrab(). | |
690 | */ | |
7de9c6ee | 691 | ihold(bdev->bd_inode); |
09d967c6 OH |
692 | inode->i_bdev = bdev; |
693 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
694 | list_add(&inode->i_devices, &bdev->bd_inodes); | |
695 | } | |
1da177e4 LT |
696 | spin_unlock(&bdev_lock); |
697 | } | |
698 | return bdev; | |
699 | } | |
700 | ||
701 | /* Call when you free inode */ | |
702 | ||
703 | void bd_forget(struct inode *inode) | |
704 | { | |
09d967c6 OH |
705 | struct block_device *bdev = NULL; |
706 | ||
1da177e4 | 707 | spin_lock(&bdev_lock); |
b4ea2eaa YH |
708 | if (!sb_is_blkdev_sb(inode->i_sb)) |
709 | bdev = inode->i_bdev; | |
710 | __bd_forget(inode); | |
1da177e4 | 711 | spin_unlock(&bdev_lock); |
09d967c6 OH |
712 | |
713 | if (bdev) | |
714 | iput(bdev->bd_inode); | |
1da177e4 LT |
715 | } |
716 | ||
1a3cbbc5 TH |
717 | /** |
718 | * bd_may_claim - test whether a block device can be claimed | |
719 | * @bdev: block device of interest | |
720 | * @whole: whole block device containing @bdev, may equal @bdev | |
721 | * @holder: holder trying to claim @bdev | |
722 | * | |
25985edc | 723 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
724 | * |
725 | * CONTEXT: | |
726 | * spin_lock(&bdev_lock). | |
727 | * | |
728 | * RETURNS: | |
729 | * %true if @bdev can be claimed, %false otherwise. | |
730 | */ | |
731 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
732 | void *holder) | |
1da177e4 | 733 | { |
1da177e4 | 734 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 735 | return true; /* already a holder */ |
1da177e4 | 736 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 737 | return false; /* held by someone else */ |
1da177e4 | 738 | else if (bdev->bd_contains == bdev) |
1a3cbbc5 | 739 | return true; /* is a whole device which isn't held */ |
1da177e4 | 740 | |
e525fd89 | 741 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
742 | return true; /* is a partition of a device that is being partitioned */ |
743 | else if (whole->bd_holder != NULL) | |
744 | return false; /* is a partition of a held device */ | |
1da177e4 | 745 | else |
1a3cbbc5 TH |
746 | return true; /* is a partition of an un-held device */ |
747 | } | |
748 | ||
6b4517a7 TH |
749 | /** |
750 | * bd_prepare_to_claim - prepare to claim a block device | |
751 | * @bdev: block device of interest | |
752 | * @whole: the whole device containing @bdev, may equal @bdev | |
753 | * @holder: holder trying to claim @bdev | |
754 | * | |
755 | * Prepare to claim @bdev. This function fails if @bdev is already | |
756 | * claimed by another holder and waits if another claiming is in | |
757 | * progress. This function doesn't actually claim. On successful | |
758 | * return, the caller has ownership of bd_claiming and bd_holder[s]. | |
759 | * | |
760 | * CONTEXT: | |
761 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab | |
762 | * it multiple times. | |
763 | * | |
764 | * RETURNS: | |
765 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
766 | */ | |
767 | static int bd_prepare_to_claim(struct block_device *bdev, | |
768 | struct block_device *whole, void *holder) | |
769 | { | |
770 | retry: | |
771 | /* if someone else claimed, fail */ | |
772 | if (!bd_may_claim(bdev, whole, holder)) | |
773 | return -EBUSY; | |
774 | ||
e75aa858 TH |
775 | /* if claiming is already in progress, wait for it to finish */ |
776 | if (whole->bd_claiming) { | |
6b4517a7 TH |
777 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
778 | DEFINE_WAIT(wait); | |
779 | ||
780 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
781 | spin_unlock(&bdev_lock); | |
782 | schedule(); | |
783 | finish_wait(wq, &wait); | |
784 | spin_lock(&bdev_lock); | |
785 | goto retry; | |
786 | } | |
787 | ||
788 | /* yay, all mine */ | |
789 | return 0; | |
790 | } | |
791 | ||
792 | /** | |
793 | * bd_start_claiming - start claiming a block device | |
794 | * @bdev: block device of interest | |
795 | * @holder: holder trying to claim @bdev | |
796 | * | |
797 | * @bdev is about to be opened exclusively. Check @bdev can be opened | |
798 | * exclusively and mark that an exclusive open is in progress. Each | |
799 | * successful call to this function must be matched with a call to | |
b0018361 NP |
800 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
801 | * fail). | |
802 | * | |
803 | * This function is used to gain exclusive access to the block device | |
804 | * without actually causing other exclusive open attempts to fail. It | |
805 | * should be used when the open sequence itself requires exclusive | |
806 | * access but may subsequently fail. | |
6b4517a7 TH |
807 | * |
808 | * CONTEXT: | |
809 | * Might sleep. | |
810 | * | |
811 | * RETURNS: | |
812 | * Pointer to the block device containing @bdev on success, ERR_PTR() | |
813 | * value on failure. | |
814 | */ | |
815 | static struct block_device *bd_start_claiming(struct block_device *bdev, | |
816 | void *holder) | |
817 | { | |
818 | struct gendisk *disk; | |
819 | struct block_device *whole; | |
820 | int partno, err; | |
821 | ||
822 | might_sleep(); | |
823 | ||
824 | /* | |
825 | * @bdev might not have been initialized properly yet, look up | |
826 | * and grab the outer block device the hard way. | |
827 | */ | |
828 | disk = get_gendisk(bdev->bd_dev, &partno); | |
829 | if (!disk) | |
830 | return ERR_PTR(-ENXIO); | |
831 | ||
d4c208b8 TH |
832 | /* |
833 | * Normally, @bdev should equal what's returned from bdget_disk() | |
834 | * if partno is 0; however, some drivers (floppy) use multiple | |
835 | * bdev's for the same physical device and @bdev may be one of the | |
836 | * aliases. Keep @bdev if partno is 0. This means claimer | |
837 | * tracking is broken for those devices but it has always been that | |
838 | * way. | |
839 | */ | |
840 | if (partno) | |
841 | whole = bdget_disk(disk, 0); | |
842 | else | |
843 | whole = bdgrab(bdev); | |
844 | ||
cf342570 | 845 | module_put(disk->fops->owner); |
6b4517a7 TH |
846 | put_disk(disk); |
847 | if (!whole) | |
848 | return ERR_PTR(-ENOMEM); | |
849 | ||
850 | /* prepare to claim, if successful, mark claiming in progress */ | |
851 | spin_lock(&bdev_lock); | |
852 | ||
853 | err = bd_prepare_to_claim(bdev, whole, holder); | |
854 | if (err == 0) { | |
855 | whole->bd_claiming = holder; | |
856 | spin_unlock(&bdev_lock); | |
857 | return whole; | |
858 | } else { | |
859 | spin_unlock(&bdev_lock); | |
860 | bdput(whole); | |
861 | return ERR_PTR(err); | |
862 | } | |
863 | } | |
864 | ||
641dc636 | 865 | #ifdef CONFIG_SYSFS |
49731baa TH |
866 | struct bd_holder_disk { |
867 | struct list_head list; | |
868 | struct gendisk *disk; | |
869 | int refcnt; | |
870 | }; | |
871 | ||
872 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
873 | struct gendisk *disk) | |
874 | { | |
875 | struct bd_holder_disk *holder; | |
876 | ||
877 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
878 | if (holder->disk == disk) | |
879 | return holder; | |
880 | return NULL; | |
881 | } | |
882 | ||
4d7dd8fd | 883 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 884 | { |
4d7dd8fd | 885 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
886 | } |
887 | ||
888 | static void del_symlink(struct kobject *from, struct kobject *to) | |
889 | { | |
641dc636 JN |
890 | sysfs_remove_link(from, kobject_name(to)); |
891 | } | |
892 | ||
df6c0cd9 | 893 | /** |
e09b457b TH |
894 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
895 | * @bdev: the claimed slave bdev | |
896 | * @disk: the holding disk | |
df6c0cd9 | 897 | * |
49731baa TH |
898 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
899 | * | |
e09b457b | 900 | * This functions creates the following sysfs symlinks. |
641dc636 | 901 | * |
e09b457b TH |
902 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
903 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 904 | * |
e09b457b TH |
905 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
906 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 907 | * |
e09b457b TH |
908 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
909 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 910 | * |
e09b457b TH |
911 | * The caller must have claimed @bdev before calling this function and |
912 | * ensure that both @bdev and @disk are valid during the creation and | |
913 | * lifetime of these symlinks. | |
641dc636 | 914 | * |
e09b457b TH |
915 | * CONTEXT: |
916 | * Might sleep. | |
641dc636 | 917 | * |
e09b457b TH |
918 | * RETURNS: |
919 | * 0 on success, -errno on failure. | |
641dc636 | 920 | */ |
e09b457b | 921 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 922 | { |
49731baa | 923 | struct bd_holder_disk *holder; |
e09b457b | 924 | int ret = 0; |
641dc636 | 925 | |
2e7b651d | 926 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 927 | |
49731baa | 928 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 929 | |
e09b457b TH |
930 | /* FIXME: remove the following once add_disk() handles errors */ |
931 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) | |
932 | goto out_unlock; | |
4e91672c | 933 | |
49731baa TH |
934 | holder = bd_find_holder_disk(bdev, disk); |
935 | if (holder) { | |
936 | holder->refcnt++; | |
e09b457b | 937 | goto out_unlock; |
49731baa | 938 | } |
641dc636 | 939 | |
49731baa TH |
940 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
941 | if (!holder) { | |
942 | ret = -ENOMEM; | |
e09b457b TH |
943 | goto out_unlock; |
944 | } | |
641dc636 | 945 | |
49731baa TH |
946 | INIT_LIST_HEAD(&holder->list); |
947 | holder->disk = disk; | |
948 | holder->refcnt = 1; | |
949 | ||
950 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
951 | if (ret) | |
952 | goto out_free; | |
953 | ||
954 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); | |
955 | if (ret) | |
956 | goto out_del; | |
e7407d16 TH |
957 | /* |
958 | * bdev could be deleted beneath us which would implicitly destroy | |
959 | * the holder directory. Hold on to it. | |
960 | */ | |
961 | kobject_get(bdev->bd_part->holder_dir); | |
49731baa TH |
962 | |
963 | list_add(&holder->list, &bdev->bd_holder_disks); | |
964 | goto out_unlock; | |
965 | ||
966 | out_del: | |
967 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
968 | out_free: | |
969 | kfree(holder); | |
e09b457b | 970 | out_unlock: |
b4cf1b72 | 971 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 972 | return ret; |
641dc636 | 973 | } |
e09b457b | 974 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 975 | |
49731baa TH |
976 | /** |
977 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
978 | * @bdev: the calimed slave bdev | |
979 | * @disk: the holding disk | |
980 | * | |
981 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
982 | * | |
983 | * CONTEXT: | |
984 | * Might sleep. | |
985 | */ | |
986 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 987 | { |
49731baa | 988 | struct bd_holder_disk *holder; |
641dc636 | 989 | |
49731baa | 990 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 991 | |
49731baa TH |
992 | holder = bd_find_holder_disk(bdev, disk); |
993 | ||
994 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
995 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
996 | del_symlink(bdev->bd_part->holder_dir, | |
997 | &disk_to_dev(disk)->kobj); | |
e7407d16 | 998 | kobject_put(bdev->bd_part->holder_dir); |
49731baa TH |
999 | list_del_init(&holder->list); |
1000 | kfree(holder); | |
1001 | } | |
1002 | ||
1003 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 1004 | } |
49731baa | 1005 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 1006 | #endif |
1da177e4 | 1007 | |
56ade44b AP |
1008 | /** |
1009 | * flush_disk - invalidates all buffer-cache entries on a disk | |
1010 | * | |
1011 | * @bdev: struct block device to be flushed | |
e6eb5ce1 | 1012 | * @kill_dirty: flag to guide handling of dirty inodes |
56ade44b AP |
1013 | * |
1014 | * Invalidates all buffer-cache entries on a disk. It should be called | |
1015 | * when a disk has been changed -- either by a media change or online | |
1016 | * resize. | |
1017 | */ | |
93b270f7 | 1018 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
56ade44b | 1019 | { |
93b270f7 | 1020 | if (__invalidate_device(bdev, kill_dirty)) { |
56ade44b AP |
1021 | char name[BDEVNAME_SIZE] = ""; |
1022 | ||
1023 | if (bdev->bd_disk) | |
1024 | disk_name(bdev->bd_disk, 0, name); | |
1025 | printk(KERN_WARNING "VFS: busy inodes on changed media or " | |
1026 | "resized disk %s\n", name); | |
1027 | } | |
1028 | ||
1029 | if (!bdev->bd_disk) | |
1030 | return; | |
d27769ec | 1031 | if (disk_part_scan_enabled(bdev->bd_disk)) |
56ade44b AP |
1032 | bdev->bd_invalidated = 1; |
1033 | } | |
1034 | ||
c3279d14 | 1035 | /** |
57d1b536 | 1036 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d14 AP |
1037 | * @disk: struct gendisk to check |
1038 | * @bdev: struct bdev to adjust. | |
1039 | * | |
1040 | * This routine checks to see if the bdev size does not match the disk size | |
1041 | * and adjusts it if it differs. | |
1042 | */ | |
1043 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) | |
1044 | { | |
1045 | loff_t disk_size, bdev_size; | |
1046 | ||
1047 | disk_size = (loff_t)get_capacity(disk) << 9; | |
1048 | bdev_size = i_size_read(bdev->bd_inode); | |
1049 | if (disk_size != bdev_size) { | |
1050 | char name[BDEVNAME_SIZE]; | |
1051 | ||
1052 | disk_name(disk, 0, name); | |
1053 | printk(KERN_INFO | |
1054 | "%s: detected capacity change from %lld to %lld\n", | |
1055 | name, bdev_size, disk_size); | |
1056 | i_size_write(bdev->bd_inode, disk_size); | |
93b270f7 | 1057 | flush_disk(bdev, false); |
c3279d14 AP |
1058 | } |
1059 | } | |
1060 | EXPORT_SYMBOL(check_disk_size_change); | |
1061 | ||
0c002c2f | 1062 | /** |
57d1b536 | 1063 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f AP |
1064 | * @disk: struct gendisk to be revalidated |
1065 | * | |
1066 | * This routine is a wrapper for lower-level driver's revalidate_disk | |
1067 | * call-backs. It is used to do common pre and post operations needed | |
1068 | * for all revalidate_disk operations. | |
1069 | */ | |
1070 | int revalidate_disk(struct gendisk *disk) | |
1071 | { | |
c3279d14 | 1072 | struct block_device *bdev; |
0c002c2f AP |
1073 | int ret = 0; |
1074 | ||
1075 | if (disk->fops->revalidate_disk) | |
1076 | ret = disk->fops->revalidate_disk(disk); | |
1077 | ||
c3279d14 AP |
1078 | bdev = bdget_disk(disk, 0); |
1079 | if (!bdev) | |
1080 | return ret; | |
1081 | ||
1082 | mutex_lock(&bdev->bd_mutex); | |
1083 | check_disk_size_change(disk, bdev); | |
7630b661 | 1084 | bdev->bd_invalidated = 0; |
c3279d14 AP |
1085 | mutex_unlock(&bdev->bd_mutex); |
1086 | bdput(bdev); | |
0c002c2f AP |
1087 | return ret; |
1088 | } | |
1089 | EXPORT_SYMBOL(revalidate_disk); | |
1090 | ||
1da177e4 LT |
1091 | /* |
1092 | * This routine checks whether a removable media has been changed, | |
1093 | * and invalidates all buffer-cache-entries in that case. This | |
1094 | * is a relatively slow routine, so we have to try to minimize using | |
1095 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1096 | * is the best way of combining speed and utility, I think. | |
1097 | * People changing diskettes in the middle of an operation deserve | |
1098 | * to lose :-) | |
1099 | */ | |
1100 | int check_disk_change(struct block_device *bdev) | |
1101 | { | |
1102 | struct gendisk *disk = bdev->bd_disk; | |
83d5cde4 | 1103 | const struct block_device_operations *bdops = disk->fops; |
77ea887e | 1104 | unsigned int events; |
1da177e4 | 1105 | |
77ea887e TH |
1106 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
1107 | DISK_EVENT_EJECT_REQUEST); | |
1108 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) | |
1da177e4 LT |
1109 | return 0; |
1110 | ||
93b270f7 | 1111 | flush_disk(bdev, true); |
1da177e4 LT |
1112 | if (bdops->revalidate_disk) |
1113 | bdops->revalidate_disk(bdev->bd_disk); | |
1da177e4 LT |
1114 | return 1; |
1115 | } | |
1116 | ||
1117 | EXPORT_SYMBOL(check_disk_change); | |
1118 | ||
1119 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1120 | { | |
e1defc4f | 1121 | unsigned bsize = bdev_logical_block_size(bdev); |
1da177e4 | 1122 | |
d646a02a GC |
1123 | mutex_lock(&bdev->bd_inode->i_mutex); |
1124 | i_size_write(bdev->bd_inode, size); | |
1125 | mutex_unlock(&bdev->bd_inode->i_mutex); | |
1da177e4 LT |
1126 | while (bsize < PAGE_CACHE_SIZE) { |
1127 | if (size & bsize) | |
1128 | break; | |
1129 | bsize <<= 1; | |
1130 | } | |
1131 | bdev->bd_block_size = bsize; | |
1132 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
1133 | } | |
1134 | EXPORT_SYMBOL(bd_set_size); | |
1135 | ||
4385bab1 | 1136 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1137 | |
6d740cd5 PZ |
1138 | /* |
1139 | * bd_mutex locking: | |
1140 | * | |
1141 | * mutex_lock(part->bd_mutex) | |
1142 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1143 | */ | |
1144 | ||
572c4892 | 1145 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
1da177e4 | 1146 | { |
1da177e4 | 1147 | struct gendisk *disk; |
523e1d39 | 1148 | struct module *owner; |
7db9cfd3 | 1149 | int ret; |
cf771cb5 | 1150 | int partno; |
fe6e9c1f AV |
1151 | int perm = 0; |
1152 | ||
572c4892 | 1153 | if (mode & FMODE_READ) |
fe6e9c1f | 1154 | perm |= MAY_READ; |
572c4892 | 1155 | if (mode & FMODE_WRITE) |
fe6e9c1f AV |
1156 | perm |= MAY_WRITE; |
1157 | /* | |
1158 | * hooks: /n/, see "layering violations". | |
1159 | */ | |
b7300b78 CW |
1160 | if (!for_part) { |
1161 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); | |
1162 | if (ret != 0) { | |
1163 | bdput(bdev); | |
1164 | return ret; | |
1165 | } | |
82666020 | 1166 | } |
7db9cfd3 | 1167 | |
d3374825 | 1168 | restart: |
0762b8bd | 1169 | |
89f97496 | 1170 | ret = -ENXIO; |
cf771cb5 | 1171 | disk = get_gendisk(bdev->bd_dev, &partno); |
0762b8bd | 1172 | if (!disk) |
6e9624b8 | 1173 | goto out; |
523e1d39 | 1174 | owner = disk->fops->owner; |
1da177e4 | 1175 | |
69e02c59 | 1176 | disk_block_events(disk); |
6796bf54 | 1177 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 LT |
1178 | if (!bdev->bd_openers) { |
1179 | bdev->bd_disk = disk; | |
87192a2a | 1180 | bdev->bd_queue = disk->queue; |
1da177e4 | 1181 | bdev->bd_contains = bdev; |
bbab37dd | 1182 | bdev->bd_inode->i_flags = disk->fops->direct_access ? S_DAX : 0; |
cf771cb5 | 1183 | if (!partno) { |
89f97496 TH |
1184 | ret = -ENXIO; |
1185 | bdev->bd_part = disk_get_part(disk, partno); | |
1186 | if (!bdev->bd_part) | |
1187 | goto out_clear; | |
1188 | ||
1196f8b8 | 1189 | ret = 0; |
1da177e4 | 1190 | if (disk->fops->open) { |
572c4892 | 1191 | ret = disk->fops->open(bdev, mode); |
d3374825 N |
1192 | if (ret == -ERESTARTSYS) { |
1193 | /* Lost a race with 'disk' being | |
1194 | * deleted, try again. | |
1195 | * See md.c | |
1196 | */ | |
1197 | disk_put_part(bdev->bd_part); | |
1198 | bdev->bd_part = NULL; | |
d3374825 | 1199 | bdev->bd_disk = NULL; |
87192a2a | 1200 | bdev->bd_queue = NULL; |
d3374825 | 1201 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1202 | disk_unblock_events(disk); |
69e02c59 | 1203 | put_disk(disk); |
523e1d39 | 1204 | module_put(owner); |
d3374825 N |
1205 | goto restart; |
1206 | } | |
1da177e4 | 1207 | } |
7e69723f | 1208 | |
b83ae6d4 | 1209 | if (!ret) |
7e69723f | 1210 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
7e69723f | 1211 | |
1196f8b8 TH |
1212 | /* |
1213 | * If the device is invalidated, rescan partition | |
1214 | * if open succeeded or failed with -ENOMEDIUM. | |
1215 | * The latter is necessary to prevent ghost | |
1216 | * partitions on a removed medium. | |
1217 | */ | |
fe316bf2 JN |
1218 | if (bdev->bd_invalidated) { |
1219 | if (!ret) | |
1220 | rescan_partitions(disk, bdev); | |
1221 | else if (ret == -ENOMEDIUM) | |
1222 | invalidate_partitions(disk, bdev); | |
1223 | } | |
1196f8b8 TH |
1224 | if (ret) |
1225 | goto out_clear; | |
1da177e4 | 1226 | } else { |
1da177e4 LT |
1227 | struct block_device *whole; |
1228 | whole = bdget_disk(disk, 0); | |
1229 | ret = -ENOMEM; | |
1230 | if (!whole) | |
0762b8bd | 1231 | goto out_clear; |
37be4124 | 1232 | BUG_ON(for_part); |
572c4892 | 1233 | ret = __blkdev_get(whole, mode, 1); |
1da177e4 | 1234 | if (ret) |
0762b8bd | 1235 | goto out_clear; |
1da177e4 | 1236 | bdev->bd_contains = whole; |
89f97496 | 1237 | bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0 | 1238 | if (!(disk->flags & GENHD_FL_UP) || |
89f97496 | 1239 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4 | 1240 | ret = -ENXIO; |
0762b8bd | 1241 | goto out_clear; |
1da177e4 | 1242 | } |
89f97496 | 1243 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
1da177e4 LT |
1244 | } |
1245 | } else { | |
1da177e4 | 1246 | if (bdev->bd_contains == bdev) { |
1196f8b8 TH |
1247 | ret = 0; |
1248 | if (bdev->bd_disk->fops->open) | |
572c4892 | 1249 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1250 | /* the same as first opener case, read comment there */ |
fe316bf2 JN |
1251 | if (bdev->bd_invalidated) { |
1252 | if (!ret) | |
1253 | rescan_partitions(bdev->bd_disk, bdev); | |
1254 | else if (ret == -ENOMEDIUM) | |
1255 | invalidate_partitions(bdev->bd_disk, bdev); | |
1256 | } | |
1196f8b8 TH |
1257 | if (ret) |
1258 | goto out_unlock_bdev; | |
1da177e4 | 1259 | } |
69e02c59 | 1260 | /* only one opener holds refs to the module and disk */ |
69e02c59 | 1261 | put_disk(disk); |
523e1d39 | 1262 | module_put(owner); |
1da177e4 LT |
1263 | } |
1264 | bdev->bd_openers++; | |
37be4124 N |
1265 | if (for_part) |
1266 | bdev->bd_part_count++; | |
c039e313 | 1267 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1268 | disk_unblock_events(disk); |
1da177e4 LT |
1269 | return 0; |
1270 | ||
0762b8bd | 1271 | out_clear: |
89f97496 | 1272 | disk_put_part(bdev->bd_part); |
1da177e4 | 1273 | bdev->bd_disk = NULL; |
0762b8bd | 1274 | bdev->bd_part = NULL; |
87192a2a | 1275 | bdev->bd_queue = NULL; |
1da177e4 | 1276 | if (bdev != bdev->bd_contains) |
572c4892 | 1277 | __blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4 | 1278 | bdev->bd_contains = NULL; |
0762b8bd | 1279 | out_unlock_bdev: |
c039e313 | 1280 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1281 | disk_unblock_events(disk); |
0762b8bd | 1282 | put_disk(disk); |
523e1d39 | 1283 | module_put(owner); |
4345caba | 1284 | out: |
0762b8bd TH |
1285 | bdput(bdev); |
1286 | ||
1da177e4 LT |
1287 | return ret; |
1288 | } | |
1289 | ||
d4d77629 TH |
1290 | /** |
1291 | * blkdev_get - open a block device | |
1292 | * @bdev: block_device to open | |
1293 | * @mode: FMODE_* mask | |
1294 | * @holder: exclusive holder identifier | |
1295 | * | |
1296 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is | |
1297 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL | |
1298 | * @holder is invalid. Exclusive opens may nest for the same @holder. | |
1299 | * | |
1300 | * On success, the reference count of @bdev is unchanged. On failure, | |
1301 | * @bdev is put. | |
1302 | * | |
1303 | * CONTEXT: | |
1304 | * Might sleep. | |
1305 | * | |
1306 | * RETURNS: | |
1307 | * 0 on success, -errno on failure. | |
1308 | */ | |
e525fd89 | 1309 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4 | 1310 | { |
e525fd89 TH |
1311 | struct block_device *whole = NULL; |
1312 | int res; | |
1313 | ||
1314 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); | |
1315 | ||
1316 | if ((mode & FMODE_EXCL) && holder) { | |
1317 | whole = bd_start_claiming(bdev, holder); | |
1318 | if (IS_ERR(whole)) { | |
1319 | bdput(bdev); | |
1320 | return PTR_ERR(whole); | |
1321 | } | |
1322 | } | |
1323 | ||
1324 | res = __blkdev_get(bdev, mode, 0); | |
1325 | ||
1326 | if (whole) { | |
d4dc210f TH |
1327 | struct gendisk *disk = whole->bd_disk; |
1328 | ||
6a027eff | 1329 | /* finish claiming */ |
77ea887e | 1330 | mutex_lock(&bdev->bd_mutex); |
6a027eff TH |
1331 | spin_lock(&bdev_lock); |
1332 | ||
77ea887e | 1333 | if (!res) { |
6a027eff TH |
1334 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
1335 | /* | |
1336 | * Note that for a whole device bd_holders | |
1337 | * will be incremented twice, and bd_holder | |
1338 | * will be set to bd_may_claim before being | |
1339 | * set to holder | |
1340 | */ | |
1341 | whole->bd_holders++; | |
1342 | whole->bd_holder = bd_may_claim; | |
1343 | bdev->bd_holders++; | |
1344 | bdev->bd_holder = holder; | |
1345 | } | |
1346 | ||
1347 | /* tell others that we're done */ | |
1348 | BUG_ON(whole->bd_claiming != holder); | |
1349 | whole->bd_claiming = NULL; | |
1350 | wake_up_bit(&whole->bd_claiming, 0); | |
1351 | ||
1352 | spin_unlock(&bdev_lock); | |
77ea887e TH |
1353 | |
1354 | /* | |
d4dc210f TH |
1355 | * Block event polling for write claims if requested. Any |
1356 | * write holder makes the write_holder state stick until | |
1357 | * all are released. This is good enough and tracking | |
1358 | * individual writeable reference is too fragile given the | |
1359 | * way @mode is used in blkdev_get/put(). | |
77ea887e | 1360 | */ |
4c49ff3f TH |
1361 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && |
1362 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
77ea887e | 1363 | bdev->bd_write_holder = true; |
d4dc210f | 1364 | disk_block_events(disk); |
77ea887e TH |
1365 | } |
1366 | ||
1367 | mutex_unlock(&bdev->bd_mutex); | |
6a027eff | 1368 | bdput(whole); |
e525fd89 TH |
1369 | } |
1370 | ||
1371 | return res; | |
37be4124 | 1372 | } |
1da177e4 LT |
1373 | EXPORT_SYMBOL(blkdev_get); |
1374 | ||
d4d77629 TH |
1375 | /** |
1376 | * blkdev_get_by_path - open a block device by name | |
1377 | * @path: path to the block device to open | |
1378 | * @mode: FMODE_* mask | |
1379 | * @holder: exclusive holder identifier | |
1380 | * | |
1381 | * Open the blockdevice described by the device file at @path. @mode | |
1382 | * and @holder are identical to blkdev_get(). | |
1383 | * | |
1384 | * On success, the returned block_device has reference count of one. | |
1385 | * | |
1386 | * CONTEXT: | |
1387 | * Might sleep. | |
1388 | * | |
1389 | * RETURNS: | |
1390 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1391 | */ | |
1392 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1393 | void *holder) | |
1394 | { | |
1395 | struct block_device *bdev; | |
1396 | int err; | |
1397 | ||
1398 | bdev = lookup_bdev(path); | |
1399 | if (IS_ERR(bdev)) | |
1400 | return bdev; | |
1401 | ||
1402 | err = blkdev_get(bdev, mode, holder); | |
1403 | if (err) | |
1404 | return ERR_PTR(err); | |
1405 | ||
e51900f7 CE |
1406 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
1407 | blkdev_put(bdev, mode); | |
1408 | return ERR_PTR(-EACCES); | |
1409 | } | |
1410 | ||
d4d77629 TH |
1411 | return bdev; |
1412 | } | |
1413 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1414 | ||
1415 | /** | |
1416 | * blkdev_get_by_dev - open a block device by device number | |
1417 | * @dev: device number of block device to open | |
1418 | * @mode: FMODE_* mask | |
1419 | * @holder: exclusive holder identifier | |
1420 | * | |
1421 | * Open the blockdevice described by device number @dev. @mode and | |
1422 | * @holder are identical to blkdev_get(). | |
1423 | * | |
1424 | * Use it ONLY if you really do not have anything better - i.e. when | |
1425 | * you are behind a truly sucky interface and all you are given is a | |
1426 | * device number. _Never_ to be used for internal purposes. If you | |
1427 | * ever need it - reconsider your API. | |
1428 | * | |
1429 | * On success, the returned block_device has reference count of one. | |
1430 | * | |
1431 | * CONTEXT: | |
1432 | * Might sleep. | |
1433 | * | |
1434 | * RETURNS: | |
1435 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1436 | */ | |
1437 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) | |
1438 | { | |
1439 | struct block_device *bdev; | |
1440 | int err; | |
1441 | ||
1442 | bdev = bdget(dev); | |
1443 | if (!bdev) | |
1444 | return ERR_PTR(-ENOMEM); | |
1445 | ||
1446 | err = blkdev_get(bdev, mode, holder); | |
1447 | if (err) | |
1448 | return ERR_PTR(err); | |
1449 | ||
1450 | return bdev; | |
1451 | } | |
1452 | EXPORT_SYMBOL(blkdev_get_by_dev); | |
1453 | ||
1da177e4 LT |
1454 | static int blkdev_open(struct inode * inode, struct file * filp) |
1455 | { | |
1456 | struct block_device *bdev; | |
1da177e4 LT |
1457 | |
1458 | /* | |
1459 | * Preserve backwards compatibility and allow large file access | |
1460 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1461 | * binary needs it. We might want to drop this workaround | |
1462 | * during an unstable branch. | |
1463 | */ | |
1464 | filp->f_flags |= O_LARGEFILE; | |
1465 | ||
572c4892 AV |
1466 | if (filp->f_flags & O_NDELAY) |
1467 | filp->f_mode |= FMODE_NDELAY; | |
1468 | if (filp->f_flags & O_EXCL) | |
1469 | filp->f_mode |= FMODE_EXCL; | |
1470 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1471 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1472 | ||
1da177e4 | 1473 | bdev = bd_acquire(inode); |
6a2aae06 PE |
1474 | if (bdev == NULL) |
1475 | return -ENOMEM; | |
1da177e4 | 1476 | |
572c4892 AV |
1477 | filp->f_mapping = bdev->bd_inode->i_mapping; |
1478 | ||
e525fd89 | 1479 | return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4 LT |
1480 | } |
1481 | ||
4385bab1 | 1482 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1483 | { |
2e7b651d | 1484 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1485 | struct block_device *victim = NULL; |
2e7b651d | 1486 | |
6796bf54 | 1487 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1488 | if (for_part) |
1489 | bdev->bd_part_count--; | |
1490 | ||
2e7b651d | 1491 | if (!--bdev->bd_openers) { |
6a027eff | 1492 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1493 | sync_blockdev(bdev); |
1494 | kill_bdev(bdev); | |
564f00f6 CH |
1495 | /* |
1496 | * ->release can cause the queue to disappear, so flush all | |
1497 | * dirty data before. | |
94007751 | 1498 | */ |
564f00f6 | 1499 | bdev_write_inode(bdev->bd_inode); |
2e7b651d PZ |
1500 | } |
1501 | if (bdev->bd_contains == bdev) { | |
1502 | if (disk->fops->release) | |
db2a144b | 1503 | disk->fops->release(disk, mode); |
2e7b651d PZ |
1504 | } |
1505 | if (!bdev->bd_openers) { | |
1506 | struct module *owner = disk->fops->owner; | |
1507 | ||
0762b8bd TH |
1508 | disk_put_part(bdev->bd_part); |
1509 | bdev->bd_part = NULL; | |
2e7b651d | 1510 | bdev->bd_disk = NULL; |
37be4124 N |
1511 | if (bdev != bdev->bd_contains) |
1512 | victim = bdev->bd_contains; | |
2e7b651d | 1513 | bdev->bd_contains = NULL; |
523e1d39 TH |
1514 | |
1515 | put_disk(disk); | |
1516 | module_put(owner); | |
2e7b651d | 1517 | } |
2e7b651d PZ |
1518 | mutex_unlock(&bdev->bd_mutex); |
1519 | bdput(bdev); | |
37be4124 | 1520 | if (victim) |
9a1c3542 | 1521 | __blkdev_put(victim, mode, 1); |
2e7b651d PZ |
1522 | } |
1523 | ||
4385bab1 | 1524 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1525 | { |
85ef06d1 TH |
1526 | mutex_lock(&bdev->bd_mutex); |
1527 | ||
e525fd89 | 1528 | if (mode & FMODE_EXCL) { |
6a027eff TH |
1529 | bool bdev_free; |
1530 | ||
1531 | /* | |
1532 | * Release a claim on the device. The holder fields | |
1533 | * are protected with bdev_lock. bd_mutex is to | |
1534 | * synchronize disk_holder unlinking. | |
1535 | */ | |
6a027eff TH |
1536 | spin_lock(&bdev_lock); |
1537 | ||
1538 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
1539 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); | |
1540 | ||
1541 | /* bd_contains might point to self, check in a separate step */ | |
1542 | if ((bdev_free = !bdev->bd_holders)) | |
1543 | bdev->bd_holder = NULL; | |
1544 | if (!bdev->bd_contains->bd_holders) | |
1545 | bdev->bd_contains->bd_holder = NULL; | |
1546 | ||
1547 | spin_unlock(&bdev_lock); | |
1548 | ||
77ea887e TH |
1549 | /* |
1550 | * If this was the last claim, remove holder link and | |
1551 | * unblock evpoll if it was a write holder. | |
1552 | */ | |
85ef06d1 TH |
1553 | if (bdev_free && bdev->bd_write_holder) { |
1554 | disk_unblock_events(bdev->bd_disk); | |
1555 | bdev->bd_write_holder = false; | |
77ea887e | 1556 | } |
6936217c | 1557 | } |
77ea887e | 1558 | |
85ef06d1 TH |
1559 | /* |
1560 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1561 | * event. This is to ensure detection of media removal commanded | |
1562 | * from userland - e.g. eject(1). | |
1563 | */ | |
1564 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); | |
1565 | ||
1566 | mutex_unlock(&bdev->bd_mutex); | |
1567 | ||
4385bab1 | 1568 | __blkdev_put(bdev, mode, 0); |
37be4124 | 1569 | } |
2e7b651d PZ |
1570 | EXPORT_SYMBOL(blkdev_put); |
1571 | ||
1da177e4 LT |
1572 | static int blkdev_close(struct inode * inode, struct file * filp) |
1573 | { | |
1574 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); | |
4385bab1 AV |
1575 | blkdev_put(bdev, filp->f_mode); |
1576 | return 0; | |
1da177e4 LT |
1577 | } |
1578 | ||
bb93e3a5 | 1579 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1580 | { |
56b26add AV |
1581 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
1582 | fmode_t mode = file->f_mode; | |
fd4ce1ac CH |
1583 | |
1584 | /* | |
1585 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1586 | * to updated it before every ioctl. | |
1587 | */ | |
56b26add | 1588 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1589 | mode |= FMODE_NDELAY; |
1590 | else | |
1591 | mode &= ~FMODE_NDELAY; | |
1592 | ||
56b26add | 1593 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1594 | } |
1595 | ||
eef99380 CH |
1596 | /* |
1597 | * Write data to the block device. Only intended for the block device itself | |
1598 | * and the raw driver which basically is a fake block device. | |
1599 | * | |
1600 | * Does not take i_mutex for the write and thus is not for general purpose | |
1601 | * use. | |
1602 | */ | |
1456c0a8 | 1603 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
eef99380 CH |
1604 | { |
1605 | struct file *file = iocb->ki_filp; | |
7ec7b94a AV |
1606 | struct inode *bd_inode = file->f_mapping->host; |
1607 | loff_t size = i_size_read(bd_inode); | |
53362a05 | 1608 | struct blk_plug plug; |
eef99380 | 1609 | ssize_t ret; |
5f380c7f | 1610 | |
7ec7b94a AV |
1611 | if (bdev_read_only(I_BDEV(bd_inode))) |
1612 | return -EPERM; | |
5f380c7f | 1613 | |
7ec7b94a | 1614 | if (!iov_iter_count(from)) |
5f380c7f AV |
1615 | return 0; |
1616 | ||
7ec7b94a AV |
1617 | if (iocb->ki_pos >= size) |
1618 | return -ENOSPC; | |
1619 | ||
1620 | iov_iter_truncate(from, size - iocb->ki_pos); | |
eef99380 | 1621 | |
53362a05 | 1622 | blk_start_plug(&plug); |
1456c0a8 | 1623 | ret = __generic_file_write_iter(iocb, from); |
02afc27f | 1624 | if (ret > 0) { |
eef99380 | 1625 | ssize_t err; |
1456c0a8 | 1626 | err = generic_write_sync(file, iocb->ki_pos - ret, ret); |
45d4f855 | 1627 | if (err < 0) |
eef99380 CH |
1628 | ret = err; |
1629 | } | |
53362a05 | 1630 | blk_finish_plug(&plug); |
eef99380 CH |
1631 | return ret; |
1632 | } | |
1456c0a8 | 1633 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
eef99380 | 1634 | |
b2de525f | 1635 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
684c9aae LT |
1636 | { |
1637 | struct file *file = iocb->ki_filp; | |
1638 | struct inode *bd_inode = file->f_mapping->host; | |
1639 | loff_t size = i_size_read(bd_inode); | |
a886038b | 1640 | loff_t pos = iocb->ki_pos; |
684c9aae LT |
1641 | |
1642 | if (pos >= size) | |
1643 | return 0; | |
1644 | ||
1645 | size -= pos; | |
a886038b AV |
1646 | iov_iter_truncate(to, size); |
1647 | return generic_file_read_iter(iocb, to); | |
684c9aae | 1648 | } |
b2de525f | 1649 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
684c9aae | 1650 | |
87d8fe1e TT |
1651 | /* |
1652 | * Try to release a page associated with block device when the system | |
1653 | * is under memory pressure. | |
1654 | */ | |
1655 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1656 | { | |
1657 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1658 | ||
1659 | if (super && super->s_op->bdev_try_to_free_page) | |
1660 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1661 | ||
1662 | return try_to_free_buffers(page); | |
1663 | } | |
1664 | ||
4c54ac62 | 1665 | static const struct address_space_operations def_blk_aops = { |
1da177e4 | 1666 | .readpage = blkdev_readpage, |
447f05bb | 1667 | .readpages = blkdev_readpages, |
1da177e4 | 1668 | .writepage = blkdev_writepage, |
6272b5a5 NP |
1669 | .write_begin = blkdev_write_begin, |
1670 | .write_end = blkdev_write_end, | |
1da177e4 | 1671 | .writepages = generic_writepages, |
87d8fe1e | 1672 | .releasepage = blkdev_releasepage, |
1da177e4 | 1673 | .direct_IO = blkdev_direct_IO, |
b4597226 | 1674 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1675 | }; |
1676 | ||
4b6f5d20 | 1677 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1678 | .open = blkdev_open, |
1679 | .release = blkdev_close, | |
1680 | .llseek = block_llseek, | |
a886038b | 1681 | .read_iter = blkdev_read_iter, |
1456c0a8 | 1682 | .write_iter = blkdev_write_iter, |
1e8b3332 | 1683 | .mmap = generic_file_mmap, |
b1dd3b28 | 1684 | .fsync = blkdev_fsync, |
bb93e3a5 | 1685 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1686 | #ifdef CONFIG_COMPAT |
1687 | .compat_ioctl = compat_blkdev_ioctl, | |
1688 | #endif | |
1e8b3332 | 1689 | .splice_read = generic_file_splice_read, |
8d020765 | 1690 | .splice_write = iter_file_splice_write, |
1da177e4 LT |
1691 | }; |
1692 | ||
1693 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) | |
1694 | { | |
1695 | int res; | |
1696 | mm_segment_t old_fs = get_fs(); | |
1697 | set_fs(KERNEL_DS); | |
56b26add | 1698 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
1da177e4 LT |
1699 | set_fs(old_fs); |
1700 | return res; | |
1701 | } | |
1702 | ||
1703 | EXPORT_SYMBOL(ioctl_by_bdev); | |
1704 | ||
1705 | /** | |
1706 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 1707 | * @pathname: special file representing the block device |
1da177e4 | 1708 | * |
57d1b536 | 1709 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
1710 | * namespace if possible and return it. Return ERR_PTR(error) |
1711 | * otherwise. | |
1712 | */ | |
421748ec | 1713 | struct block_device *lookup_bdev(const char *pathname) |
1da177e4 LT |
1714 | { |
1715 | struct block_device *bdev; | |
1716 | struct inode *inode; | |
421748ec | 1717 | struct path path; |
1da177e4 LT |
1718 | int error; |
1719 | ||
421748ec | 1720 | if (!pathname || !*pathname) |
1da177e4 LT |
1721 | return ERR_PTR(-EINVAL); |
1722 | ||
421748ec | 1723 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
1724 | if (error) |
1725 | return ERR_PTR(error); | |
1726 | ||
bb668734 | 1727 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1728 | error = -ENOTBLK; |
1729 | if (!S_ISBLK(inode->i_mode)) | |
1730 | goto fail; | |
1731 | error = -EACCES; | |
421748ec | 1732 | if (path.mnt->mnt_flags & MNT_NODEV) |
1da177e4 LT |
1733 | goto fail; |
1734 | error = -ENOMEM; | |
1735 | bdev = bd_acquire(inode); | |
1736 | if (!bdev) | |
1737 | goto fail; | |
1738 | out: | |
421748ec | 1739 | path_put(&path); |
1da177e4 LT |
1740 | return bdev; |
1741 | fail: | |
1742 | bdev = ERR_PTR(error); | |
1743 | goto out; | |
1744 | } | |
d5686b44 | 1745 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1746 | |
93b270f7 | 1747 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
1748 | { |
1749 | struct super_block *sb = get_super(bdev); | |
1750 | int res = 0; | |
1751 | ||
1752 | if (sb) { | |
1753 | /* | |
1754 | * no need to lock the super, get_super holds the | |
1755 | * read mutex so the filesystem cannot go away | |
1756 | * under us (->put_super runs with the write lock | |
1757 | * hold). | |
1758 | */ | |
1759 | shrink_dcache_sb(sb); | |
93b270f7 | 1760 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
1761 | drop_super(sb); |
1762 | } | |
f98393a6 | 1763 | invalidate_bdev(bdev); |
b71e8a4c DH |
1764 | return res; |
1765 | } | |
1766 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
1767 | |
1768 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
1769 | { | |
1770 | struct inode *inode, *old_inode = NULL; | |
1771 | ||
1772 | spin_lock(&inode_sb_list_lock); | |
1773 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { | |
1774 | struct address_space *mapping = inode->i_mapping; | |
1775 | ||
1776 | spin_lock(&inode->i_lock); | |
1777 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1778 | mapping->nrpages == 0) { | |
1779 | spin_unlock(&inode->i_lock); | |
1780 | continue; | |
1781 | } | |
1782 | __iget(inode); | |
1783 | spin_unlock(&inode->i_lock); | |
1784 | spin_unlock(&inode_sb_list_lock); | |
1785 | /* | |
1786 | * We hold a reference to 'inode' so it couldn't have been | |
1787 | * removed from s_inodes list while we dropped the | |
1788 | * inode_sb_list_lock. We cannot iput the inode now as we can | |
1789 | * be holding the last reference and we cannot iput it under | |
1790 | * inode_sb_list_lock. So we keep the reference and iput it | |
1791 | * later. | |
1792 | */ | |
1793 | iput(old_inode); | |
1794 | old_inode = inode; | |
1795 | ||
1796 | func(I_BDEV(inode), arg); | |
1797 | ||
1798 | spin_lock(&inode_sb_list_lock); | |
1799 | } | |
1800 | spin_unlock(&inode_sb_list_lock); | |
1801 | iput(old_inode); | |
1802 | } |