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> | |
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 | ||
a5491e0c | 52 | /* |
f758eeab CH |
53 | * Move the inode from its current bdi to a new bdi. If the inode is dirty we |
54 | * need to move it onto the dirty list of @dst so that the inode is always on | |
55 | * the right list. | |
a5491e0c DC |
56 | */ |
57 | static void bdev_inode_switch_bdi(struct inode *inode, | |
58 | struct backing_dev_info *dst) | |
59 | { | |
f758eeab | 60 | struct backing_dev_info *old = inode->i_data.backing_dev_info; |
a5faeaf9 | 61 | bool wakeup_bdi = false; |
f758eeab CH |
62 | |
63 | if (unlikely(dst == old)) /* deadlock avoidance */ | |
64 | return; | |
65 | bdi_lock_two(&old->wb, &dst->wb); | |
250df6ed | 66 | spin_lock(&inode->i_lock); |
a5491e0c | 67 | inode->i_data.backing_dev_info = dst; |
a5faeaf9 JK |
68 | if (inode->i_state & I_DIRTY) { |
69 | if (bdi_cap_writeback_dirty(dst) && !wb_has_dirty_io(&dst->wb)) | |
70 | wakeup_bdi = true; | |
7ccf19a8 | 71 | list_move(&inode->i_wb_list, &dst->wb.b_dirty); |
a5faeaf9 | 72 | } |
250df6ed | 73 | spin_unlock(&inode->i_lock); |
f758eeab CH |
74 | spin_unlock(&old->wb.list_lock); |
75 | spin_unlock(&dst->wb.list_lock); | |
a5faeaf9 JK |
76 | |
77 | if (wakeup_bdi) | |
78 | bdi_wakeup_thread_delayed(dst); | |
a5491e0c DC |
79 | } |
80 | ||
f9a14399 | 81 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
ff01bb48 | 82 | void kill_bdev(struct block_device *bdev) |
1da177e4 | 83 | { |
ff01bb48 AV |
84 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
85 | ||
91b0abe3 | 86 | if (mapping->nrpages == 0 && mapping->nrshadows == 0) |
f9a14399 | 87 | return; |
ff01bb48 | 88 | |
f9a14399 | 89 | invalidate_bh_lrus(); |
ff01bb48 | 90 | truncate_inode_pages(mapping, 0); |
1da177e4 | 91 | } |
ff01bb48 AV |
92 | EXPORT_SYMBOL(kill_bdev); |
93 | ||
94 | /* Invalidate clean unused buffers and pagecache. */ | |
95 | void invalidate_bdev(struct block_device *bdev) | |
96 | { | |
97 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
98 | ||
99 | if (mapping->nrpages == 0) | |
100 | return; | |
101 | ||
102 | invalidate_bh_lrus(); | |
103 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
104 | invalidate_mapping_pages(mapping, 0, -1); | |
105 | /* 99% of the time, we don't need to flush the cleancache on the bdev. | |
106 | * But, for the strange corners, lets be cautious | |
107 | */ | |
3167760f | 108 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
109 | } |
110 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 LT |
111 | |
112 | int set_blocksize(struct block_device *bdev, int size) | |
113 | { | |
114 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 115 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
116 | return -EINVAL; |
117 | ||
118 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 119 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
120 | return -EINVAL; |
121 | ||
122 | /* Don't change the size if it is same as current */ | |
123 | if (bdev->bd_block_size != size) { | |
124 | sync_blockdev(bdev); | |
125 | bdev->bd_block_size = size; | |
126 | bdev->bd_inode->i_blkbits = blksize_bits(size); | |
127 | kill_bdev(bdev); | |
128 | } | |
129 | return 0; | |
130 | } | |
131 | ||
132 | EXPORT_SYMBOL(set_blocksize); | |
133 | ||
134 | int sb_set_blocksize(struct super_block *sb, int size) | |
135 | { | |
1da177e4 LT |
136 | if (set_blocksize(sb->s_bdev, size)) |
137 | return 0; | |
138 | /* If we get here, we know size is power of two | |
139 | * and it's value is between 512 and PAGE_SIZE */ | |
140 | sb->s_blocksize = size; | |
38885bd4 | 141 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
142 | return sb->s_blocksize; |
143 | } | |
144 | ||
145 | EXPORT_SYMBOL(sb_set_blocksize); | |
146 | ||
147 | int sb_min_blocksize(struct super_block *sb, int size) | |
148 | { | |
e1defc4f | 149 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
150 | if (size < minsize) |
151 | size = minsize; | |
152 | return sb_set_blocksize(sb, size); | |
153 | } | |
154 | ||
155 | EXPORT_SYMBOL(sb_min_blocksize); | |
156 | ||
157 | static int | |
158 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
159 | struct buffer_head *bh, int create) | |
160 | { | |
1da177e4 LT |
161 | bh->b_bdev = I_BDEV(inode); |
162 | bh->b_blocknr = iblock; | |
163 | set_buffer_mapped(bh); | |
164 | return 0; | |
165 | } | |
166 | ||
b2e895db AM |
167 | static ssize_t |
168 | blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, | |
169 | loff_t offset, unsigned long nr_segs) | |
170 | { | |
171 | struct file *file = iocb->ki_filp; | |
172 | struct inode *inode = file->f_mapping->host; | |
173 | ||
eafdc7d1 | 174 | return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iov, offset, |
bbec0270 | 175 | nr_segs, blkdev_get_block, NULL, NULL, 0); |
b2e895db AM |
176 | } |
177 | ||
5cee5815 JK |
178 | int __sync_blockdev(struct block_device *bdev, int wait) |
179 | { | |
180 | if (!bdev) | |
181 | return 0; | |
182 | if (!wait) | |
183 | return filemap_flush(bdev->bd_inode->i_mapping); | |
184 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
185 | } | |
186 | ||
585d3bc0 NP |
187 | /* |
188 | * Write out and wait upon all the dirty data associated with a block | |
189 | * device via its mapping. Does not take the superblock lock. | |
190 | */ | |
191 | int sync_blockdev(struct block_device *bdev) | |
192 | { | |
5cee5815 | 193 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
194 | } |
195 | EXPORT_SYMBOL(sync_blockdev); | |
196 | ||
197 | /* | |
198 | * Write out and wait upon all dirty data associated with this | |
199 | * device. Filesystem data as well as the underlying block | |
200 | * device. Takes the superblock lock. | |
201 | */ | |
202 | int fsync_bdev(struct block_device *bdev) | |
203 | { | |
204 | struct super_block *sb = get_super(bdev); | |
205 | if (sb) { | |
60b0680f | 206 | int res = sync_filesystem(sb); |
585d3bc0 NP |
207 | drop_super(sb); |
208 | return res; | |
209 | } | |
210 | return sync_blockdev(bdev); | |
211 | } | |
47e4491b | 212 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
213 | |
214 | /** | |
215 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
216 | * @bdev: blockdevice to lock | |
217 | * | |
585d3bc0 NP |
218 | * If a superblock is found on this device, we take the s_umount semaphore |
219 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
220 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
221 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
222 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
223 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
224 | * actually. | |
225 | */ | |
226 | struct super_block *freeze_bdev(struct block_device *bdev) | |
227 | { | |
228 | struct super_block *sb; | |
229 | int error = 0; | |
230 | ||
231 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a CH |
232 | if (++bdev->bd_fsfreeze_count > 1) { |
233 | /* | |
234 | * We don't even need to grab a reference - the first call | |
235 | * to freeze_bdev grab an active reference and only the last | |
236 | * thaw_bdev drops it. | |
237 | */ | |
585d3bc0 | 238 | sb = get_super(bdev); |
4504230a CH |
239 | drop_super(sb); |
240 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
241 | return sb; | |
242 | } | |
243 | ||
244 | sb = get_active_super(bdev); | |
245 | if (!sb) | |
246 | goto out; | |
18e9e510 JB |
247 | error = freeze_super(sb); |
248 | if (error) { | |
249 | deactivate_super(sb); | |
250 | bdev->bd_fsfreeze_count--; | |
585d3bc0 | 251 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
18e9e510 | 252 | return ERR_PTR(error); |
585d3bc0 | 253 | } |
18e9e510 | 254 | deactivate_super(sb); |
4504230a | 255 | out: |
585d3bc0 NP |
256 | sync_blockdev(bdev); |
257 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
4fadd7bb | 258 | return sb; /* thaw_bdev releases s->s_umount */ |
585d3bc0 NP |
259 | } |
260 | EXPORT_SYMBOL(freeze_bdev); | |
261 | ||
262 | /** | |
263 | * thaw_bdev -- unlock filesystem | |
264 | * @bdev: blockdevice to unlock | |
265 | * @sb: associated superblock | |
266 | * | |
267 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
268 | */ | |
269 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) | |
270 | { | |
4504230a | 271 | int error = -EINVAL; |
585d3bc0 NP |
272 | |
273 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 274 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 275 | goto out; |
4504230a CH |
276 | |
277 | error = 0; | |
278 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 279 | goto out; |
4504230a CH |
280 | |
281 | if (!sb) | |
18e9e510 | 282 | goto out; |
4504230a | 283 | |
18e9e510 JB |
284 | error = thaw_super(sb); |
285 | if (error) { | |
286 | bdev->bd_fsfreeze_count++; | |
287 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
288 | return error; | |
289 | } | |
290 | out: | |
585d3bc0 NP |
291 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
292 | return 0; | |
293 | } | |
294 | EXPORT_SYMBOL(thaw_bdev); | |
295 | ||
1da177e4 LT |
296 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
297 | { | |
298 | return block_write_full_page(page, blkdev_get_block, wbc); | |
299 | } | |
300 | ||
301 | static int blkdev_readpage(struct file * file, struct page * page) | |
302 | { | |
303 | return block_read_full_page(page, blkdev_get_block); | |
304 | } | |
305 | ||
6272b5a5 NP |
306 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
307 | loff_t pos, unsigned len, unsigned flags, | |
308 | struct page **pagep, void **fsdata) | |
1da177e4 | 309 | { |
155130a4 CH |
310 | return block_write_begin(mapping, pos, len, flags, pagep, |
311 | blkdev_get_block); | |
1da177e4 LT |
312 | } |
313 | ||
6272b5a5 NP |
314 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
315 | loff_t pos, unsigned len, unsigned copied, | |
316 | struct page *page, void *fsdata) | |
1da177e4 | 317 | { |
6272b5a5 NP |
318 | int ret; |
319 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
320 | ||
321 | unlock_page(page); | |
322 | page_cache_release(page); | |
323 | ||
324 | return ret; | |
1da177e4 LT |
325 | } |
326 | ||
327 | /* | |
328 | * private llseek: | |
496ad9aa | 329 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
330 | * so we compute the size by hand (just as in block_read/write above) |
331 | */ | |
965c8e59 | 332 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 LT |
333 | { |
334 | struct inode *bd_inode = file->f_mapping->host; | |
1da177e4 LT |
335 | loff_t retval; |
336 | ||
1b1dcc1b | 337 | mutex_lock(&bd_inode->i_mutex); |
5d48f3a2 | 338 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
1b1dcc1b | 339 | mutex_unlock(&bd_inode->i_mutex); |
1da177e4 LT |
340 | return retval; |
341 | } | |
342 | ||
02c24a82 | 343 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 344 | { |
b8af67e2 AB |
345 | struct inode *bd_inode = filp->f_mapping->host; |
346 | struct block_device *bdev = I_BDEV(bd_inode); | |
ab0a9735 | 347 | int error; |
da5aa861 RW |
348 | |
349 | error = filemap_write_and_wait_range(filp->f_mapping, start, end); | |
350 | if (error) | |
351 | return error; | |
ab0a9735 | 352 | |
b8af67e2 AB |
353 | /* |
354 | * There is no need to serialise calls to blkdev_issue_flush with | |
355 | * i_mutex and doing so causes performance issues with concurrent | |
356 | * O_SYNC writers to a block device. | |
357 | */ | |
dd3932ed | 358 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
ab0a9735 CH |
359 | if (error == -EOPNOTSUPP) |
360 | error = 0; | |
b8af67e2 | 361 | |
ab0a9735 | 362 | return error; |
1da177e4 | 363 | } |
b1dd3b28 | 364 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 365 | |
47a191fd MW |
366 | /** |
367 | * bdev_read_page() - Start reading a page from a block device | |
368 | * @bdev: The device to read the page from | |
369 | * @sector: The offset on the device to read the page to (need not be aligned) | |
370 | * @page: The page to read | |
371 | * | |
372 | * On entry, the page should be locked. It will be unlocked when the page | |
373 | * has been read. If the block driver implements rw_page synchronously, | |
374 | * that will be true on exit from this function, but it need not be. | |
375 | * | |
376 | * Errors returned by this function are usually "soft", eg out of memory, or | |
377 | * queue full; callers should try a different route to read this page rather | |
378 | * than propagate an error back up the stack. | |
379 | * | |
380 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
381 | */ | |
382 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
383 | struct page *page) | |
384 | { | |
385 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
386 | if (!ops->rw_page) | |
387 | return -EOPNOTSUPP; | |
388 | return ops->rw_page(bdev, sector + get_start_sect(bdev), page, READ); | |
389 | } | |
390 | EXPORT_SYMBOL_GPL(bdev_read_page); | |
391 | ||
392 | /** | |
393 | * bdev_write_page() - Start writing a page to a block device | |
394 | * @bdev: The device to write the page to | |
395 | * @sector: The offset on the device to write the page to (need not be aligned) | |
396 | * @page: The page to write | |
397 | * @wbc: The writeback_control for the write | |
398 | * | |
399 | * On entry, the page should be locked and not currently under writeback. | |
400 | * On exit, if the write started successfully, the page will be unlocked and | |
401 | * under writeback. If the write failed already (eg the driver failed to | |
402 | * queue the page to the device), the page will still be locked. If the | |
403 | * caller is a ->writepage implementation, it will need to unlock the page. | |
404 | * | |
405 | * Errors returned by this function are usually "soft", eg out of memory, or | |
406 | * queue full; callers should try a different route to write this page rather | |
407 | * than propagate an error back up the stack. | |
408 | * | |
409 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
410 | */ | |
411 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
412 | struct page *page, struct writeback_control *wbc) | |
413 | { | |
414 | int result; | |
415 | int rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE; | |
416 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
417 | if (!ops->rw_page) | |
418 | return -EOPNOTSUPP; | |
419 | set_page_writeback(page); | |
420 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, rw); | |
421 | if (result) | |
422 | end_page_writeback(page); | |
423 | else | |
424 | unlock_page(page); | |
425 | return result; | |
426 | } | |
427 | EXPORT_SYMBOL_GPL(bdev_write_page); | |
428 | ||
1da177e4 LT |
429 | /* |
430 | * pseudo-fs | |
431 | */ | |
432 | ||
433 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 434 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
435 | |
436 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
437 | { | |
e94b1766 | 438 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
439 | if (!ei) |
440 | return NULL; | |
441 | return &ei->vfs_inode; | |
442 | } | |
443 | ||
fa0d7e3d | 444 | static void bdev_i_callback(struct rcu_head *head) |
1da177e4 | 445 | { |
fa0d7e3d | 446 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
447 | struct bdev_inode *bdi = BDEV_I(inode); |
448 | ||
1da177e4 LT |
449 | kmem_cache_free(bdev_cachep, bdi); |
450 | } | |
451 | ||
fa0d7e3d NP |
452 | static void bdev_destroy_inode(struct inode *inode) |
453 | { | |
454 | call_rcu(&inode->i_rcu, bdev_i_callback); | |
455 | } | |
456 | ||
51cc5068 | 457 | static void init_once(void *foo) |
1da177e4 LT |
458 | { |
459 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
460 | struct block_device *bdev = &ei->bdev; | |
461 | ||
a35afb83 CL |
462 | memset(bdev, 0, sizeof(*bdev)); |
463 | mutex_init(&bdev->bd_mutex); | |
a35afb83 CL |
464 | INIT_LIST_HEAD(&bdev->bd_inodes); |
465 | INIT_LIST_HEAD(&bdev->bd_list); | |
49731baa TH |
466 | #ifdef CONFIG_SYSFS |
467 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
468 | #endif | |
a35afb83 | 469 | inode_init_once(&ei->vfs_inode); |
fcccf502 TS |
470 | /* Initialize mutex for freeze. */ |
471 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
1da177e4 LT |
472 | } |
473 | ||
474 | static inline void __bd_forget(struct inode *inode) | |
475 | { | |
476 | list_del_init(&inode->i_devices); | |
477 | inode->i_bdev = NULL; | |
478 | inode->i_mapping = &inode->i_data; | |
479 | } | |
480 | ||
b57922d9 | 481 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
482 | { |
483 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
484 | struct list_head *p; | |
91b0abe3 | 485 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 486 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 487 | clear_inode(inode); |
1da177e4 LT |
488 | spin_lock(&bdev_lock); |
489 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { | |
490 | __bd_forget(list_entry(p, struct inode, i_devices)); | |
491 | } | |
492 | list_del_init(&bdev->bd_list); | |
493 | spin_unlock(&bdev_lock); | |
494 | } | |
495 | ||
ee9b6d61 | 496 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
497 | .statfs = simple_statfs, |
498 | .alloc_inode = bdev_alloc_inode, | |
499 | .destroy_inode = bdev_destroy_inode, | |
500 | .drop_inode = generic_delete_inode, | |
b57922d9 | 501 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
502 | }; |
503 | ||
51139ada AV |
504 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
505 | int flags, const char *dev_name, void *data) | |
1da177e4 | 506 | { |
b502bd11 | 507 | return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC); |
1da177e4 LT |
508 | } |
509 | ||
510 | static struct file_system_type bd_type = { | |
511 | .name = "bdev", | |
51139ada | 512 | .mount = bd_mount, |
1da177e4 LT |
513 | .kill_sb = kill_anon_super, |
514 | }; | |
515 | ||
f47ec3f2 | 516 | static struct super_block *blockdev_superblock __read_mostly; |
1da177e4 LT |
517 | |
518 | void __init bdev_cache_init(void) | |
519 | { | |
520 | int err; | |
ace8577a | 521 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 522 | |
1da177e4 | 523 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 PJ |
524 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
525 | SLAB_MEM_SPREAD|SLAB_PANIC), | |
20c2df83 | 526 | init_once); |
1da177e4 LT |
527 | err = register_filesystem(&bd_type); |
528 | if (err) | |
529 | panic("Cannot register bdev pseudo-fs"); | |
530 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
531 | if (IS_ERR(bd_mnt)) |
532 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 533 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
534 | } |
535 | ||
536 | /* | |
537 | * Most likely _very_ bad one - but then it's hardly critical for small | |
538 | * /dev and can be fixed when somebody will need really large one. | |
539 | * Keep in mind that it will be fed through icache hash function too. | |
540 | */ | |
541 | static inline unsigned long hash(dev_t dev) | |
542 | { | |
543 | return MAJOR(dev)+MINOR(dev); | |
544 | } | |
545 | ||
546 | static int bdev_test(struct inode *inode, void *data) | |
547 | { | |
548 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
549 | } | |
550 | ||
551 | static int bdev_set(struct inode *inode, void *data) | |
552 | { | |
553 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
554 | return 0; | |
555 | } | |
556 | ||
557 | static LIST_HEAD(all_bdevs); | |
558 | ||
559 | struct block_device *bdget(dev_t dev) | |
560 | { | |
561 | struct block_device *bdev; | |
562 | struct inode *inode; | |
563 | ||
c2acf7b9 | 564 | inode = iget5_locked(blockdev_superblock, hash(dev), |
1da177e4 LT |
565 | bdev_test, bdev_set, &dev); |
566 | ||
567 | if (!inode) | |
568 | return NULL; | |
569 | ||
570 | bdev = &BDEV_I(inode)->bdev; | |
571 | ||
572 | if (inode->i_state & I_NEW) { | |
573 | bdev->bd_contains = NULL; | |
782b94cd | 574 | bdev->bd_super = NULL; |
1da177e4 LT |
575 | bdev->bd_inode = inode; |
576 | bdev->bd_block_size = (1 << inode->i_blkbits); | |
577 | bdev->bd_part_count = 0; | |
578 | bdev->bd_invalidated = 0; | |
579 | inode->i_mode = S_IFBLK; | |
580 | inode->i_rdev = dev; | |
581 | inode->i_bdev = bdev; | |
582 | inode->i_data.a_ops = &def_blk_aops; | |
583 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
584 | inode->i_data.backing_dev_info = &default_backing_dev_info; | |
585 | spin_lock(&bdev_lock); | |
586 | list_add(&bdev->bd_list, &all_bdevs); | |
587 | spin_unlock(&bdev_lock); | |
588 | unlock_new_inode(inode); | |
589 | } | |
590 | return bdev; | |
591 | } | |
592 | ||
593 | EXPORT_SYMBOL(bdget); | |
594 | ||
dddac6a7 AJ |
595 | /** |
596 | * bdgrab -- Grab a reference to an already referenced block device | |
597 | * @bdev: Block device to grab a reference to. | |
598 | */ | |
599 | struct block_device *bdgrab(struct block_device *bdev) | |
600 | { | |
7de9c6ee | 601 | ihold(bdev->bd_inode); |
dddac6a7 AJ |
602 | return bdev; |
603 | } | |
c1681bf8 | 604 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 605 | |
1da177e4 LT |
606 | long nr_blockdev_pages(void) |
607 | { | |
203a2935 | 608 | struct block_device *bdev; |
1da177e4 LT |
609 | long ret = 0; |
610 | spin_lock(&bdev_lock); | |
203a2935 | 611 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4 LT |
612 | ret += bdev->bd_inode->i_mapping->nrpages; |
613 | } | |
614 | spin_unlock(&bdev_lock); | |
615 | return ret; | |
616 | } | |
617 | ||
618 | void bdput(struct block_device *bdev) | |
619 | { | |
620 | iput(bdev->bd_inode); | |
621 | } | |
622 | ||
623 | EXPORT_SYMBOL(bdput); | |
624 | ||
625 | static struct block_device *bd_acquire(struct inode *inode) | |
626 | { | |
627 | struct block_device *bdev; | |
09d967c6 | 628 | |
1da177e4 LT |
629 | spin_lock(&bdev_lock); |
630 | bdev = inode->i_bdev; | |
09d967c6 | 631 | if (bdev) { |
7de9c6ee | 632 | ihold(bdev->bd_inode); |
1da177e4 LT |
633 | spin_unlock(&bdev_lock); |
634 | return bdev; | |
635 | } | |
636 | spin_unlock(&bdev_lock); | |
09d967c6 | 637 | |
1da177e4 LT |
638 | bdev = bdget(inode->i_rdev); |
639 | if (bdev) { | |
640 | spin_lock(&bdev_lock); | |
09d967c6 OH |
641 | if (!inode->i_bdev) { |
642 | /* | |
7de9c6ee | 643 | * We take an additional reference to bd_inode, |
09d967c6 OH |
644 | * and it's released in clear_inode() of inode. |
645 | * So, we can access it via ->i_mapping always | |
646 | * without igrab(). | |
647 | */ | |
7de9c6ee | 648 | ihold(bdev->bd_inode); |
09d967c6 OH |
649 | inode->i_bdev = bdev; |
650 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
651 | list_add(&inode->i_devices, &bdev->bd_inodes); | |
652 | } | |
1da177e4 LT |
653 | spin_unlock(&bdev_lock); |
654 | } | |
655 | return bdev; | |
656 | } | |
657 | ||
a8855990 | 658 | int sb_is_blkdev_sb(struct super_block *sb) |
f47ec3f2 AV |
659 | { |
660 | return sb == blockdev_superblock; | |
661 | } | |
662 | ||
1da177e4 LT |
663 | /* Call when you free inode */ |
664 | ||
665 | void bd_forget(struct inode *inode) | |
666 | { | |
09d967c6 OH |
667 | struct block_device *bdev = NULL; |
668 | ||
1da177e4 | 669 | spin_lock(&bdev_lock); |
b4ea2eaa YH |
670 | if (!sb_is_blkdev_sb(inode->i_sb)) |
671 | bdev = inode->i_bdev; | |
672 | __bd_forget(inode); | |
1da177e4 | 673 | spin_unlock(&bdev_lock); |
09d967c6 OH |
674 | |
675 | if (bdev) | |
676 | iput(bdev->bd_inode); | |
1da177e4 LT |
677 | } |
678 | ||
1a3cbbc5 TH |
679 | /** |
680 | * bd_may_claim - test whether a block device can be claimed | |
681 | * @bdev: block device of interest | |
682 | * @whole: whole block device containing @bdev, may equal @bdev | |
683 | * @holder: holder trying to claim @bdev | |
684 | * | |
25985edc | 685 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
686 | * |
687 | * CONTEXT: | |
688 | * spin_lock(&bdev_lock). | |
689 | * | |
690 | * RETURNS: | |
691 | * %true if @bdev can be claimed, %false otherwise. | |
692 | */ | |
693 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
694 | void *holder) | |
1da177e4 | 695 | { |
1da177e4 | 696 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 697 | return true; /* already a holder */ |
1da177e4 | 698 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 699 | return false; /* held by someone else */ |
1da177e4 | 700 | else if (bdev->bd_contains == bdev) |
1a3cbbc5 | 701 | return true; /* is a whole device which isn't held */ |
1da177e4 | 702 | |
e525fd89 | 703 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
704 | return true; /* is a partition of a device that is being partitioned */ |
705 | else if (whole->bd_holder != NULL) | |
706 | return false; /* is a partition of a held device */ | |
1da177e4 | 707 | else |
1a3cbbc5 TH |
708 | return true; /* is a partition of an un-held device */ |
709 | } | |
710 | ||
6b4517a7 TH |
711 | /** |
712 | * bd_prepare_to_claim - prepare to claim a block device | |
713 | * @bdev: block device of interest | |
714 | * @whole: the whole device containing @bdev, may equal @bdev | |
715 | * @holder: holder trying to claim @bdev | |
716 | * | |
717 | * Prepare to claim @bdev. This function fails if @bdev is already | |
718 | * claimed by another holder and waits if another claiming is in | |
719 | * progress. This function doesn't actually claim. On successful | |
720 | * return, the caller has ownership of bd_claiming and bd_holder[s]. | |
721 | * | |
722 | * CONTEXT: | |
723 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab | |
724 | * it multiple times. | |
725 | * | |
726 | * RETURNS: | |
727 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
728 | */ | |
729 | static int bd_prepare_to_claim(struct block_device *bdev, | |
730 | struct block_device *whole, void *holder) | |
731 | { | |
732 | retry: | |
733 | /* if someone else claimed, fail */ | |
734 | if (!bd_may_claim(bdev, whole, holder)) | |
735 | return -EBUSY; | |
736 | ||
e75aa858 TH |
737 | /* if claiming is already in progress, wait for it to finish */ |
738 | if (whole->bd_claiming) { | |
6b4517a7 TH |
739 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
740 | DEFINE_WAIT(wait); | |
741 | ||
742 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
743 | spin_unlock(&bdev_lock); | |
744 | schedule(); | |
745 | finish_wait(wq, &wait); | |
746 | spin_lock(&bdev_lock); | |
747 | goto retry; | |
748 | } | |
749 | ||
750 | /* yay, all mine */ | |
751 | return 0; | |
752 | } | |
753 | ||
754 | /** | |
755 | * bd_start_claiming - start claiming a block device | |
756 | * @bdev: block device of interest | |
757 | * @holder: holder trying to claim @bdev | |
758 | * | |
759 | * @bdev is about to be opened exclusively. Check @bdev can be opened | |
760 | * exclusively and mark that an exclusive open is in progress. Each | |
761 | * successful call to this function must be matched with a call to | |
b0018361 NP |
762 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
763 | * fail). | |
764 | * | |
765 | * This function is used to gain exclusive access to the block device | |
766 | * without actually causing other exclusive open attempts to fail. It | |
767 | * should be used when the open sequence itself requires exclusive | |
768 | * access but may subsequently fail. | |
6b4517a7 TH |
769 | * |
770 | * CONTEXT: | |
771 | * Might sleep. | |
772 | * | |
773 | * RETURNS: | |
774 | * Pointer to the block device containing @bdev on success, ERR_PTR() | |
775 | * value on failure. | |
776 | */ | |
777 | static struct block_device *bd_start_claiming(struct block_device *bdev, | |
778 | void *holder) | |
779 | { | |
780 | struct gendisk *disk; | |
781 | struct block_device *whole; | |
782 | int partno, err; | |
783 | ||
784 | might_sleep(); | |
785 | ||
786 | /* | |
787 | * @bdev might not have been initialized properly yet, look up | |
788 | * and grab the outer block device the hard way. | |
789 | */ | |
790 | disk = get_gendisk(bdev->bd_dev, &partno); | |
791 | if (!disk) | |
792 | return ERR_PTR(-ENXIO); | |
793 | ||
d4c208b8 TH |
794 | /* |
795 | * Normally, @bdev should equal what's returned from bdget_disk() | |
796 | * if partno is 0; however, some drivers (floppy) use multiple | |
797 | * bdev's for the same physical device and @bdev may be one of the | |
798 | * aliases. Keep @bdev if partno is 0. This means claimer | |
799 | * tracking is broken for those devices but it has always been that | |
800 | * way. | |
801 | */ | |
802 | if (partno) | |
803 | whole = bdget_disk(disk, 0); | |
804 | else | |
805 | whole = bdgrab(bdev); | |
806 | ||
cf342570 | 807 | module_put(disk->fops->owner); |
6b4517a7 TH |
808 | put_disk(disk); |
809 | if (!whole) | |
810 | return ERR_PTR(-ENOMEM); | |
811 | ||
812 | /* prepare to claim, if successful, mark claiming in progress */ | |
813 | spin_lock(&bdev_lock); | |
814 | ||
815 | err = bd_prepare_to_claim(bdev, whole, holder); | |
816 | if (err == 0) { | |
817 | whole->bd_claiming = holder; | |
818 | spin_unlock(&bdev_lock); | |
819 | return whole; | |
820 | } else { | |
821 | spin_unlock(&bdev_lock); | |
822 | bdput(whole); | |
823 | return ERR_PTR(err); | |
824 | } | |
825 | } | |
826 | ||
641dc636 | 827 | #ifdef CONFIG_SYSFS |
49731baa TH |
828 | struct bd_holder_disk { |
829 | struct list_head list; | |
830 | struct gendisk *disk; | |
831 | int refcnt; | |
832 | }; | |
833 | ||
834 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
835 | struct gendisk *disk) | |
836 | { | |
837 | struct bd_holder_disk *holder; | |
838 | ||
839 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
840 | if (holder->disk == disk) | |
841 | return holder; | |
842 | return NULL; | |
843 | } | |
844 | ||
4d7dd8fd | 845 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 846 | { |
4d7dd8fd | 847 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
848 | } |
849 | ||
850 | static void del_symlink(struct kobject *from, struct kobject *to) | |
851 | { | |
641dc636 JN |
852 | sysfs_remove_link(from, kobject_name(to)); |
853 | } | |
854 | ||
df6c0cd9 | 855 | /** |
e09b457b TH |
856 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
857 | * @bdev: the claimed slave bdev | |
858 | * @disk: the holding disk | |
df6c0cd9 | 859 | * |
49731baa TH |
860 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
861 | * | |
e09b457b | 862 | * This functions creates the following sysfs symlinks. |
641dc636 | 863 | * |
e09b457b TH |
864 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
865 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 866 | * |
e09b457b TH |
867 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
868 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 869 | * |
e09b457b TH |
870 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
871 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 872 | * |
e09b457b TH |
873 | * The caller must have claimed @bdev before calling this function and |
874 | * ensure that both @bdev and @disk are valid during the creation and | |
875 | * lifetime of these symlinks. | |
641dc636 | 876 | * |
e09b457b TH |
877 | * CONTEXT: |
878 | * Might sleep. | |
641dc636 | 879 | * |
e09b457b TH |
880 | * RETURNS: |
881 | * 0 on success, -errno on failure. | |
641dc636 | 882 | */ |
e09b457b | 883 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 884 | { |
49731baa | 885 | struct bd_holder_disk *holder; |
e09b457b | 886 | int ret = 0; |
641dc636 | 887 | |
2e7b651d | 888 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 889 | |
49731baa | 890 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 891 | |
e09b457b TH |
892 | /* FIXME: remove the following once add_disk() handles errors */ |
893 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) | |
894 | goto out_unlock; | |
4e91672c | 895 | |
49731baa TH |
896 | holder = bd_find_holder_disk(bdev, disk); |
897 | if (holder) { | |
898 | holder->refcnt++; | |
e09b457b | 899 | goto out_unlock; |
49731baa | 900 | } |
641dc636 | 901 | |
49731baa TH |
902 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
903 | if (!holder) { | |
904 | ret = -ENOMEM; | |
e09b457b TH |
905 | goto out_unlock; |
906 | } | |
641dc636 | 907 | |
49731baa TH |
908 | INIT_LIST_HEAD(&holder->list); |
909 | holder->disk = disk; | |
910 | holder->refcnt = 1; | |
911 | ||
912 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
913 | if (ret) | |
914 | goto out_free; | |
915 | ||
916 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); | |
917 | if (ret) | |
918 | goto out_del; | |
e7407d16 TH |
919 | /* |
920 | * bdev could be deleted beneath us which would implicitly destroy | |
921 | * the holder directory. Hold on to it. | |
922 | */ | |
923 | kobject_get(bdev->bd_part->holder_dir); | |
49731baa TH |
924 | |
925 | list_add(&holder->list, &bdev->bd_holder_disks); | |
926 | goto out_unlock; | |
927 | ||
928 | out_del: | |
929 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
930 | out_free: | |
931 | kfree(holder); | |
e09b457b | 932 | out_unlock: |
b4cf1b72 | 933 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 934 | return ret; |
641dc636 | 935 | } |
e09b457b | 936 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 937 | |
49731baa TH |
938 | /** |
939 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
940 | * @bdev: the calimed slave bdev | |
941 | * @disk: the holding disk | |
942 | * | |
943 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
944 | * | |
945 | * CONTEXT: | |
946 | * Might sleep. | |
947 | */ | |
948 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 949 | { |
49731baa | 950 | struct bd_holder_disk *holder; |
641dc636 | 951 | |
49731baa | 952 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 953 | |
49731baa TH |
954 | holder = bd_find_holder_disk(bdev, disk); |
955 | ||
956 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
957 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
958 | del_symlink(bdev->bd_part->holder_dir, | |
959 | &disk_to_dev(disk)->kobj); | |
e7407d16 | 960 | kobject_put(bdev->bd_part->holder_dir); |
49731baa TH |
961 | list_del_init(&holder->list); |
962 | kfree(holder); | |
963 | } | |
964 | ||
965 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 966 | } |
49731baa | 967 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 968 | #endif |
1da177e4 | 969 | |
56ade44b AP |
970 | /** |
971 | * flush_disk - invalidates all buffer-cache entries on a disk | |
972 | * | |
973 | * @bdev: struct block device to be flushed | |
e6eb5ce1 | 974 | * @kill_dirty: flag to guide handling of dirty inodes |
56ade44b AP |
975 | * |
976 | * Invalidates all buffer-cache entries on a disk. It should be called | |
977 | * when a disk has been changed -- either by a media change or online | |
978 | * resize. | |
979 | */ | |
93b270f7 | 980 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
56ade44b | 981 | { |
93b270f7 | 982 | if (__invalidate_device(bdev, kill_dirty)) { |
56ade44b AP |
983 | char name[BDEVNAME_SIZE] = ""; |
984 | ||
985 | if (bdev->bd_disk) | |
986 | disk_name(bdev->bd_disk, 0, name); | |
987 | printk(KERN_WARNING "VFS: busy inodes on changed media or " | |
988 | "resized disk %s\n", name); | |
989 | } | |
990 | ||
991 | if (!bdev->bd_disk) | |
992 | return; | |
d27769ec | 993 | if (disk_part_scan_enabled(bdev->bd_disk)) |
56ade44b AP |
994 | bdev->bd_invalidated = 1; |
995 | } | |
996 | ||
c3279d14 | 997 | /** |
57d1b536 | 998 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d14 AP |
999 | * @disk: struct gendisk to check |
1000 | * @bdev: struct bdev to adjust. | |
1001 | * | |
1002 | * This routine checks to see if the bdev size does not match the disk size | |
1003 | * and adjusts it if it differs. | |
1004 | */ | |
1005 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) | |
1006 | { | |
1007 | loff_t disk_size, bdev_size; | |
1008 | ||
1009 | disk_size = (loff_t)get_capacity(disk) << 9; | |
1010 | bdev_size = i_size_read(bdev->bd_inode); | |
1011 | if (disk_size != bdev_size) { | |
1012 | char name[BDEVNAME_SIZE]; | |
1013 | ||
1014 | disk_name(disk, 0, name); | |
1015 | printk(KERN_INFO | |
1016 | "%s: detected capacity change from %lld to %lld\n", | |
1017 | name, bdev_size, disk_size); | |
1018 | i_size_write(bdev->bd_inode, disk_size); | |
93b270f7 | 1019 | flush_disk(bdev, false); |
c3279d14 AP |
1020 | } |
1021 | } | |
1022 | EXPORT_SYMBOL(check_disk_size_change); | |
1023 | ||
0c002c2f | 1024 | /** |
57d1b536 | 1025 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f AP |
1026 | * @disk: struct gendisk to be revalidated |
1027 | * | |
1028 | * This routine is a wrapper for lower-level driver's revalidate_disk | |
1029 | * call-backs. It is used to do common pre and post operations needed | |
1030 | * for all revalidate_disk operations. | |
1031 | */ | |
1032 | int revalidate_disk(struct gendisk *disk) | |
1033 | { | |
c3279d14 | 1034 | struct block_device *bdev; |
0c002c2f AP |
1035 | int ret = 0; |
1036 | ||
1037 | if (disk->fops->revalidate_disk) | |
1038 | ret = disk->fops->revalidate_disk(disk); | |
1039 | ||
c3279d14 AP |
1040 | bdev = bdget_disk(disk, 0); |
1041 | if (!bdev) | |
1042 | return ret; | |
1043 | ||
1044 | mutex_lock(&bdev->bd_mutex); | |
1045 | check_disk_size_change(disk, bdev); | |
7630b661 | 1046 | bdev->bd_invalidated = 0; |
c3279d14 AP |
1047 | mutex_unlock(&bdev->bd_mutex); |
1048 | bdput(bdev); | |
0c002c2f AP |
1049 | return ret; |
1050 | } | |
1051 | EXPORT_SYMBOL(revalidate_disk); | |
1052 | ||
1da177e4 LT |
1053 | /* |
1054 | * This routine checks whether a removable media has been changed, | |
1055 | * and invalidates all buffer-cache-entries in that case. This | |
1056 | * is a relatively slow routine, so we have to try to minimize using | |
1057 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1058 | * is the best way of combining speed and utility, I think. | |
1059 | * People changing diskettes in the middle of an operation deserve | |
1060 | * to lose :-) | |
1061 | */ | |
1062 | int check_disk_change(struct block_device *bdev) | |
1063 | { | |
1064 | struct gendisk *disk = bdev->bd_disk; | |
83d5cde4 | 1065 | const struct block_device_operations *bdops = disk->fops; |
77ea887e | 1066 | unsigned int events; |
1da177e4 | 1067 | |
77ea887e TH |
1068 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
1069 | DISK_EVENT_EJECT_REQUEST); | |
1070 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) | |
1da177e4 LT |
1071 | return 0; |
1072 | ||
93b270f7 | 1073 | flush_disk(bdev, true); |
1da177e4 LT |
1074 | if (bdops->revalidate_disk) |
1075 | bdops->revalidate_disk(bdev->bd_disk); | |
1da177e4 LT |
1076 | return 1; |
1077 | } | |
1078 | ||
1079 | EXPORT_SYMBOL(check_disk_change); | |
1080 | ||
1081 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1082 | { | |
e1defc4f | 1083 | unsigned bsize = bdev_logical_block_size(bdev); |
1da177e4 | 1084 | |
d646a02a GC |
1085 | mutex_lock(&bdev->bd_inode->i_mutex); |
1086 | i_size_write(bdev->bd_inode, size); | |
1087 | mutex_unlock(&bdev->bd_inode->i_mutex); | |
1da177e4 LT |
1088 | while (bsize < PAGE_CACHE_SIZE) { |
1089 | if (size & bsize) | |
1090 | break; | |
1091 | bsize <<= 1; | |
1092 | } | |
1093 | bdev->bd_block_size = bsize; | |
1094 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
1095 | } | |
1096 | EXPORT_SYMBOL(bd_set_size); | |
1097 | ||
4385bab1 | 1098 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1099 | |
6d740cd5 PZ |
1100 | /* |
1101 | * bd_mutex locking: | |
1102 | * | |
1103 | * mutex_lock(part->bd_mutex) | |
1104 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1105 | */ | |
1106 | ||
572c4892 | 1107 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
1da177e4 | 1108 | { |
1da177e4 | 1109 | struct gendisk *disk; |
523e1d39 | 1110 | struct module *owner; |
7db9cfd3 | 1111 | int ret; |
cf771cb5 | 1112 | int partno; |
fe6e9c1f AV |
1113 | int perm = 0; |
1114 | ||
572c4892 | 1115 | if (mode & FMODE_READ) |
fe6e9c1f | 1116 | perm |= MAY_READ; |
572c4892 | 1117 | if (mode & FMODE_WRITE) |
fe6e9c1f AV |
1118 | perm |= MAY_WRITE; |
1119 | /* | |
1120 | * hooks: /n/, see "layering violations". | |
1121 | */ | |
b7300b78 CW |
1122 | if (!for_part) { |
1123 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); | |
1124 | if (ret != 0) { | |
1125 | bdput(bdev); | |
1126 | return ret; | |
1127 | } | |
82666020 | 1128 | } |
7db9cfd3 | 1129 | |
d3374825 | 1130 | restart: |
0762b8bd | 1131 | |
89f97496 | 1132 | ret = -ENXIO; |
cf771cb5 | 1133 | disk = get_gendisk(bdev->bd_dev, &partno); |
0762b8bd | 1134 | if (!disk) |
6e9624b8 | 1135 | goto out; |
523e1d39 | 1136 | owner = disk->fops->owner; |
1da177e4 | 1137 | |
69e02c59 | 1138 | disk_block_events(disk); |
6796bf54 | 1139 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 LT |
1140 | if (!bdev->bd_openers) { |
1141 | bdev->bd_disk = disk; | |
87192a2a | 1142 | bdev->bd_queue = disk->queue; |
1da177e4 | 1143 | bdev->bd_contains = bdev; |
cf771cb5 | 1144 | if (!partno) { |
1da177e4 | 1145 | struct backing_dev_info *bdi; |
89f97496 TH |
1146 | |
1147 | ret = -ENXIO; | |
1148 | bdev->bd_part = disk_get_part(disk, partno); | |
1149 | if (!bdev->bd_part) | |
1150 | goto out_clear; | |
1151 | ||
1196f8b8 | 1152 | ret = 0; |
1da177e4 | 1153 | if (disk->fops->open) { |
572c4892 | 1154 | ret = disk->fops->open(bdev, mode); |
d3374825 N |
1155 | if (ret == -ERESTARTSYS) { |
1156 | /* Lost a race with 'disk' being | |
1157 | * deleted, try again. | |
1158 | * See md.c | |
1159 | */ | |
1160 | disk_put_part(bdev->bd_part); | |
1161 | bdev->bd_part = NULL; | |
d3374825 | 1162 | bdev->bd_disk = NULL; |
87192a2a | 1163 | bdev->bd_queue = NULL; |
d3374825 | 1164 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1165 | disk_unblock_events(disk); |
69e02c59 | 1166 | put_disk(disk); |
523e1d39 | 1167 | module_put(owner); |
d3374825 N |
1168 | goto restart; |
1169 | } | |
1da177e4 | 1170 | } |
7e69723f | 1171 | |
de33127d | 1172 | if (!ret) { |
7e69723f TH |
1173 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
1174 | bdi = blk_get_backing_dev_info(bdev); | |
1175 | if (bdi == NULL) | |
1176 | bdi = &default_backing_dev_info; | |
1177 | bdev_inode_switch_bdi(bdev->bd_inode, bdi); | |
1178 | } | |
1179 | ||
1196f8b8 TH |
1180 | /* |
1181 | * If the device is invalidated, rescan partition | |
1182 | * if open succeeded or failed with -ENOMEDIUM. | |
1183 | * The latter is necessary to prevent ghost | |
1184 | * partitions on a removed medium. | |
1185 | */ | |
fe316bf2 JN |
1186 | if (bdev->bd_invalidated) { |
1187 | if (!ret) | |
1188 | rescan_partitions(disk, bdev); | |
1189 | else if (ret == -ENOMEDIUM) | |
1190 | invalidate_partitions(disk, bdev); | |
1191 | } | |
1196f8b8 TH |
1192 | if (ret) |
1193 | goto out_clear; | |
1da177e4 | 1194 | } else { |
1da177e4 LT |
1195 | struct block_device *whole; |
1196 | whole = bdget_disk(disk, 0); | |
1197 | ret = -ENOMEM; | |
1198 | if (!whole) | |
0762b8bd | 1199 | goto out_clear; |
37be4124 | 1200 | BUG_ON(for_part); |
572c4892 | 1201 | ret = __blkdev_get(whole, mode, 1); |
1da177e4 | 1202 | if (ret) |
0762b8bd | 1203 | goto out_clear; |
1da177e4 | 1204 | bdev->bd_contains = whole; |
a5491e0c DC |
1205 | bdev_inode_switch_bdi(bdev->bd_inode, |
1206 | whole->bd_inode->i_data.backing_dev_info); | |
89f97496 | 1207 | bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0 | 1208 | if (!(disk->flags & GENHD_FL_UP) || |
89f97496 | 1209 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4 | 1210 | ret = -ENXIO; |
0762b8bd | 1211 | goto out_clear; |
1da177e4 | 1212 | } |
89f97496 | 1213 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
1da177e4 LT |
1214 | } |
1215 | } else { | |
1da177e4 | 1216 | if (bdev->bd_contains == bdev) { |
1196f8b8 TH |
1217 | ret = 0; |
1218 | if (bdev->bd_disk->fops->open) | |
572c4892 | 1219 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1220 | /* the same as first opener case, read comment there */ |
fe316bf2 JN |
1221 | if (bdev->bd_invalidated) { |
1222 | if (!ret) | |
1223 | rescan_partitions(bdev->bd_disk, bdev); | |
1224 | else if (ret == -ENOMEDIUM) | |
1225 | invalidate_partitions(bdev->bd_disk, bdev); | |
1226 | } | |
1196f8b8 TH |
1227 | if (ret) |
1228 | goto out_unlock_bdev; | |
1da177e4 | 1229 | } |
69e02c59 | 1230 | /* only one opener holds refs to the module and disk */ |
69e02c59 | 1231 | put_disk(disk); |
523e1d39 | 1232 | module_put(owner); |
1da177e4 LT |
1233 | } |
1234 | bdev->bd_openers++; | |
37be4124 N |
1235 | if (for_part) |
1236 | bdev->bd_part_count++; | |
c039e313 | 1237 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1238 | disk_unblock_events(disk); |
1da177e4 LT |
1239 | return 0; |
1240 | ||
0762b8bd | 1241 | out_clear: |
89f97496 | 1242 | disk_put_part(bdev->bd_part); |
1da177e4 | 1243 | bdev->bd_disk = NULL; |
0762b8bd | 1244 | bdev->bd_part = NULL; |
87192a2a | 1245 | bdev->bd_queue = NULL; |
a5491e0c | 1246 | bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
1da177e4 | 1247 | if (bdev != bdev->bd_contains) |
572c4892 | 1248 | __blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4 | 1249 | bdev->bd_contains = NULL; |
0762b8bd | 1250 | out_unlock_bdev: |
c039e313 | 1251 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1252 | disk_unblock_events(disk); |
0762b8bd | 1253 | put_disk(disk); |
523e1d39 | 1254 | module_put(owner); |
4345caba | 1255 | out: |
0762b8bd TH |
1256 | bdput(bdev); |
1257 | ||
1da177e4 LT |
1258 | return ret; |
1259 | } | |
1260 | ||
d4d77629 TH |
1261 | /** |
1262 | * blkdev_get - open a block device | |
1263 | * @bdev: block_device to open | |
1264 | * @mode: FMODE_* mask | |
1265 | * @holder: exclusive holder identifier | |
1266 | * | |
1267 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is | |
1268 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL | |
1269 | * @holder is invalid. Exclusive opens may nest for the same @holder. | |
1270 | * | |
1271 | * On success, the reference count of @bdev is unchanged. On failure, | |
1272 | * @bdev is put. | |
1273 | * | |
1274 | * CONTEXT: | |
1275 | * Might sleep. | |
1276 | * | |
1277 | * RETURNS: | |
1278 | * 0 on success, -errno on failure. | |
1279 | */ | |
e525fd89 | 1280 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4 | 1281 | { |
e525fd89 TH |
1282 | struct block_device *whole = NULL; |
1283 | int res; | |
1284 | ||
1285 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); | |
1286 | ||
1287 | if ((mode & FMODE_EXCL) && holder) { | |
1288 | whole = bd_start_claiming(bdev, holder); | |
1289 | if (IS_ERR(whole)) { | |
1290 | bdput(bdev); | |
1291 | return PTR_ERR(whole); | |
1292 | } | |
1293 | } | |
1294 | ||
1295 | res = __blkdev_get(bdev, mode, 0); | |
1296 | ||
1297 | if (whole) { | |
d4dc210f TH |
1298 | struct gendisk *disk = whole->bd_disk; |
1299 | ||
6a027eff | 1300 | /* finish claiming */ |
77ea887e | 1301 | mutex_lock(&bdev->bd_mutex); |
6a027eff TH |
1302 | spin_lock(&bdev_lock); |
1303 | ||
77ea887e | 1304 | if (!res) { |
6a027eff TH |
1305 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
1306 | /* | |
1307 | * Note that for a whole device bd_holders | |
1308 | * will be incremented twice, and bd_holder | |
1309 | * will be set to bd_may_claim before being | |
1310 | * set to holder | |
1311 | */ | |
1312 | whole->bd_holders++; | |
1313 | whole->bd_holder = bd_may_claim; | |
1314 | bdev->bd_holders++; | |
1315 | bdev->bd_holder = holder; | |
1316 | } | |
1317 | ||
1318 | /* tell others that we're done */ | |
1319 | BUG_ON(whole->bd_claiming != holder); | |
1320 | whole->bd_claiming = NULL; | |
1321 | wake_up_bit(&whole->bd_claiming, 0); | |
1322 | ||
1323 | spin_unlock(&bdev_lock); | |
77ea887e TH |
1324 | |
1325 | /* | |
d4dc210f TH |
1326 | * Block event polling for write claims if requested. Any |
1327 | * write holder makes the write_holder state stick until | |
1328 | * all are released. This is good enough and tracking | |
1329 | * individual writeable reference is too fragile given the | |
1330 | * way @mode is used in blkdev_get/put(). | |
77ea887e | 1331 | */ |
4c49ff3f TH |
1332 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && |
1333 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
77ea887e | 1334 | bdev->bd_write_holder = true; |
d4dc210f | 1335 | disk_block_events(disk); |
77ea887e TH |
1336 | } |
1337 | ||
1338 | mutex_unlock(&bdev->bd_mutex); | |
6a027eff | 1339 | bdput(whole); |
e525fd89 TH |
1340 | } |
1341 | ||
1342 | return res; | |
37be4124 | 1343 | } |
1da177e4 LT |
1344 | EXPORT_SYMBOL(blkdev_get); |
1345 | ||
d4d77629 TH |
1346 | /** |
1347 | * blkdev_get_by_path - open a block device by name | |
1348 | * @path: path to the block device to open | |
1349 | * @mode: FMODE_* mask | |
1350 | * @holder: exclusive holder identifier | |
1351 | * | |
1352 | * Open the blockdevice described by the device file at @path. @mode | |
1353 | * and @holder are identical to blkdev_get(). | |
1354 | * | |
1355 | * On success, the returned block_device has reference count of one. | |
1356 | * | |
1357 | * CONTEXT: | |
1358 | * Might sleep. | |
1359 | * | |
1360 | * RETURNS: | |
1361 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1362 | */ | |
1363 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1364 | void *holder) | |
1365 | { | |
1366 | struct block_device *bdev; | |
1367 | int err; | |
1368 | ||
1369 | bdev = lookup_bdev(path); | |
1370 | if (IS_ERR(bdev)) | |
1371 | return bdev; | |
1372 | ||
1373 | err = blkdev_get(bdev, mode, holder); | |
1374 | if (err) | |
1375 | return ERR_PTR(err); | |
1376 | ||
e51900f7 CE |
1377 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
1378 | blkdev_put(bdev, mode); | |
1379 | return ERR_PTR(-EACCES); | |
1380 | } | |
1381 | ||
d4d77629 TH |
1382 | return bdev; |
1383 | } | |
1384 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1385 | ||
1386 | /** | |
1387 | * blkdev_get_by_dev - open a block device by device number | |
1388 | * @dev: device number of block device to open | |
1389 | * @mode: FMODE_* mask | |
1390 | * @holder: exclusive holder identifier | |
1391 | * | |
1392 | * Open the blockdevice described by device number @dev. @mode and | |
1393 | * @holder are identical to blkdev_get(). | |
1394 | * | |
1395 | * Use it ONLY if you really do not have anything better - i.e. when | |
1396 | * you are behind a truly sucky interface and all you are given is a | |
1397 | * device number. _Never_ to be used for internal purposes. If you | |
1398 | * ever need it - reconsider your API. | |
1399 | * | |
1400 | * On success, the returned block_device has reference count of one. | |
1401 | * | |
1402 | * CONTEXT: | |
1403 | * Might sleep. | |
1404 | * | |
1405 | * RETURNS: | |
1406 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1407 | */ | |
1408 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) | |
1409 | { | |
1410 | struct block_device *bdev; | |
1411 | int err; | |
1412 | ||
1413 | bdev = bdget(dev); | |
1414 | if (!bdev) | |
1415 | return ERR_PTR(-ENOMEM); | |
1416 | ||
1417 | err = blkdev_get(bdev, mode, holder); | |
1418 | if (err) | |
1419 | return ERR_PTR(err); | |
1420 | ||
1421 | return bdev; | |
1422 | } | |
1423 | EXPORT_SYMBOL(blkdev_get_by_dev); | |
1424 | ||
1da177e4 LT |
1425 | static int blkdev_open(struct inode * inode, struct file * filp) |
1426 | { | |
1427 | struct block_device *bdev; | |
1da177e4 LT |
1428 | |
1429 | /* | |
1430 | * Preserve backwards compatibility and allow large file access | |
1431 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1432 | * binary needs it. We might want to drop this workaround | |
1433 | * during an unstable branch. | |
1434 | */ | |
1435 | filp->f_flags |= O_LARGEFILE; | |
1436 | ||
572c4892 AV |
1437 | if (filp->f_flags & O_NDELAY) |
1438 | filp->f_mode |= FMODE_NDELAY; | |
1439 | if (filp->f_flags & O_EXCL) | |
1440 | filp->f_mode |= FMODE_EXCL; | |
1441 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1442 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1443 | ||
1da177e4 | 1444 | bdev = bd_acquire(inode); |
6a2aae06 PE |
1445 | if (bdev == NULL) |
1446 | return -ENOMEM; | |
1da177e4 | 1447 | |
572c4892 AV |
1448 | filp->f_mapping = bdev->bd_inode->i_mapping; |
1449 | ||
e525fd89 | 1450 | return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4 LT |
1451 | } |
1452 | ||
4385bab1 | 1453 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1454 | { |
2e7b651d | 1455 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1456 | struct block_device *victim = NULL; |
2e7b651d | 1457 | |
6796bf54 | 1458 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1459 | if (for_part) |
1460 | bdev->bd_part_count--; | |
1461 | ||
2e7b651d | 1462 | if (!--bdev->bd_openers) { |
6a027eff | 1463 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1464 | sync_blockdev(bdev); |
1465 | kill_bdev(bdev); | |
94007751 N |
1466 | /* ->release can cause the old bdi to disappear, |
1467 | * so must switch it out first | |
1468 | */ | |
1469 | bdev_inode_switch_bdi(bdev->bd_inode, | |
1470 | &default_backing_dev_info); | |
2e7b651d PZ |
1471 | } |
1472 | if (bdev->bd_contains == bdev) { | |
1473 | if (disk->fops->release) | |
db2a144b | 1474 | disk->fops->release(disk, mode); |
2e7b651d PZ |
1475 | } |
1476 | if (!bdev->bd_openers) { | |
1477 | struct module *owner = disk->fops->owner; | |
1478 | ||
0762b8bd TH |
1479 | disk_put_part(bdev->bd_part); |
1480 | bdev->bd_part = NULL; | |
2e7b651d | 1481 | bdev->bd_disk = NULL; |
37be4124 N |
1482 | if (bdev != bdev->bd_contains) |
1483 | victim = bdev->bd_contains; | |
2e7b651d | 1484 | bdev->bd_contains = NULL; |
523e1d39 TH |
1485 | |
1486 | put_disk(disk); | |
1487 | module_put(owner); | |
2e7b651d | 1488 | } |
2e7b651d PZ |
1489 | mutex_unlock(&bdev->bd_mutex); |
1490 | bdput(bdev); | |
37be4124 | 1491 | if (victim) |
9a1c3542 | 1492 | __blkdev_put(victim, mode, 1); |
2e7b651d PZ |
1493 | } |
1494 | ||
4385bab1 | 1495 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1496 | { |
85ef06d1 TH |
1497 | mutex_lock(&bdev->bd_mutex); |
1498 | ||
e525fd89 | 1499 | if (mode & FMODE_EXCL) { |
6a027eff TH |
1500 | bool bdev_free; |
1501 | ||
1502 | /* | |
1503 | * Release a claim on the device. The holder fields | |
1504 | * are protected with bdev_lock. bd_mutex is to | |
1505 | * synchronize disk_holder unlinking. | |
1506 | */ | |
6a027eff TH |
1507 | spin_lock(&bdev_lock); |
1508 | ||
1509 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
1510 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); | |
1511 | ||
1512 | /* bd_contains might point to self, check in a separate step */ | |
1513 | if ((bdev_free = !bdev->bd_holders)) | |
1514 | bdev->bd_holder = NULL; | |
1515 | if (!bdev->bd_contains->bd_holders) | |
1516 | bdev->bd_contains->bd_holder = NULL; | |
1517 | ||
1518 | spin_unlock(&bdev_lock); | |
1519 | ||
77ea887e TH |
1520 | /* |
1521 | * If this was the last claim, remove holder link and | |
1522 | * unblock evpoll if it was a write holder. | |
1523 | */ | |
85ef06d1 TH |
1524 | if (bdev_free && bdev->bd_write_holder) { |
1525 | disk_unblock_events(bdev->bd_disk); | |
1526 | bdev->bd_write_holder = false; | |
77ea887e | 1527 | } |
6936217c | 1528 | } |
77ea887e | 1529 | |
85ef06d1 TH |
1530 | /* |
1531 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1532 | * event. This is to ensure detection of media removal commanded | |
1533 | * from userland - e.g. eject(1). | |
1534 | */ | |
1535 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); | |
1536 | ||
1537 | mutex_unlock(&bdev->bd_mutex); | |
1538 | ||
4385bab1 | 1539 | __blkdev_put(bdev, mode, 0); |
37be4124 | 1540 | } |
2e7b651d PZ |
1541 | EXPORT_SYMBOL(blkdev_put); |
1542 | ||
1da177e4 LT |
1543 | static int blkdev_close(struct inode * inode, struct file * filp) |
1544 | { | |
1545 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); | |
4385bab1 AV |
1546 | blkdev_put(bdev, filp->f_mode); |
1547 | return 0; | |
1da177e4 LT |
1548 | } |
1549 | ||
bb93e3a5 | 1550 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1551 | { |
56b26add AV |
1552 | struct block_device *bdev = I_BDEV(file->f_mapping->host); |
1553 | fmode_t mode = file->f_mode; | |
fd4ce1ac CH |
1554 | |
1555 | /* | |
1556 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1557 | * to updated it before every ioctl. | |
1558 | */ | |
56b26add | 1559 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1560 | mode |= FMODE_NDELAY; |
1561 | else | |
1562 | mode &= ~FMODE_NDELAY; | |
1563 | ||
56b26add | 1564 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1565 | } |
1566 | ||
eef99380 CH |
1567 | /* |
1568 | * Write data to the block device. Only intended for the block device itself | |
1569 | * and the raw driver which basically is a fake block device. | |
1570 | * | |
1571 | * Does not take i_mutex for the write and thus is not for general purpose | |
1572 | * use. | |
1573 | */ | |
1574 | ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, | |
1575 | unsigned long nr_segs, loff_t pos) | |
1576 | { | |
1577 | struct file *file = iocb->ki_filp; | |
53362a05 | 1578 | struct blk_plug plug; |
eef99380 CH |
1579 | ssize_t ret; |
1580 | ||
1581 | BUG_ON(iocb->ki_pos != pos); | |
1582 | ||
53362a05 | 1583 | blk_start_plug(&plug); |
41fc56d5 | 1584 | ret = __generic_file_aio_write(iocb, iov, nr_segs); |
02afc27f | 1585 | if (ret > 0) { |
eef99380 CH |
1586 | ssize_t err; |
1587 | ||
1588 | err = generic_write_sync(file, pos, ret); | |
45d4f855 | 1589 | if (err < 0) |
eef99380 CH |
1590 | ret = err; |
1591 | } | |
53362a05 | 1592 | blk_finish_plug(&plug); |
eef99380 CH |
1593 | return ret; |
1594 | } | |
1595 | EXPORT_SYMBOL_GPL(blkdev_aio_write); | |
1596 | ||
684c9aae LT |
1597 | static ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov, |
1598 | unsigned long nr_segs, loff_t pos) | |
1599 | { | |
1600 | struct file *file = iocb->ki_filp; | |
1601 | struct inode *bd_inode = file->f_mapping->host; | |
1602 | loff_t size = i_size_read(bd_inode); | |
1603 | ||
1604 | if (pos >= size) | |
1605 | return 0; | |
1606 | ||
1607 | size -= pos; | |
73a7075e | 1608 | if (size < iocb->ki_nbytes) |
684c9aae LT |
1609 | nr_segs = iov_shorten((struct iovec *)iov, nr_segs, size); |
1610 | return generic_file_aio_read(iocb, iov, nr_segs, pos); | |
1611 | } | |
1612 | ||
87d8fe1e TT |
1613 | /* |
1614 | * Try to release a page associated with block device when the system | |
1615 | * is under memory pressure. | |
1616 | */ | |
1617 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1618 | { | |
1619 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1620 | ||
1621 | if (super && super->s_op->bdev_try_to_free_page) | |
1622 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1623 | ||
1624 | return try_to_free_buffers(page); | |
1625 | } | |
1626 | ||
4c54ac62 | 1627 | static const struct address_space_operations def_blk_aops = { |
1da177e4 LT |
1628 | .readpage = blkdev_readpage, |
1629 | .writepage = blkdev_writepage, | |
6272b5a5 NP |
1630 | .write_begin = blkdev_write_begin, |
1631 | .write_end = blkdev_write_end, | |
1da177e4 | 1632 | .writepages = generic_writepages, |
87d8fe1e | 1633 | .releasepage = blkdev_releasepage, |
1da177e4 | 1634 | .direct_IO = blkdev_direct_IO, |
b4597226 | 1635 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1636 | }; |
1637 | ||
4b6f5d20 | 1638 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1639 | .open = blkdev_open, |
1640 | .release = blkdev_close, | |
1641 | .llseek = block_llseek, | |
543ade1f BP |
1642 | .read = do_sync_read, |
1643 | .write = do_sync_write, | |
684c9aae | 1644 | .aio_read = blkdev_aio_read, |
eef99380 | 1645 | .aio_write = blkdev_aio_write, |
1e8b3332 | 1646 | .mmap = generic_file_mmap, |
b1dd3b28 | 1647 | .fsync = blkdev_fsync, |
bb93e3a5 | 1648 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1649 | #ifdef CONFIG_COMPAT |
1650 | .compat_ioctl = compat_blkdev_ioctl, | |
1651 | #endif | |
1e8b3332 LT |
1652 | .splice_read = generic_file_splice_read, |
1653 | .splice_write = generic_file_splice_write, | |
1da177e4 LT |
1654 | }; |
1655 | ||
1656 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) | |
1657 | { | |
1658 | int res; | |
1659 | mm_segment_t old_fs = get_fs(); | |
1660 | set_fs(KERNEL_DS); | |
56b26add | 1661 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
1da177e4 LT |
1662 | set_fs(old_fs); |
1663 | return res; | |
1664 | } | |
1665 | ||
1666 | EXPORT_SYMBOL(ioctl_by_bdev); | |
1667 | ||
1668 | /** | |
1669 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 1670 | * @pathname: special file representing the block device |
1da177e4 | 1671 | * |
57d1b536 | 1672 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
1673 | * namespace if possible and return it. Return ERR_PTR(error) |
1674 | * otherwise. | |
1675 | */ | |
421748ec | 1676 | struct block_device *lookup_bdev(const char *pathname) |
1da177e4 LT |
1677 | { |
1678 | struct block_device *bdev; | |
1679 | struct inode *inode; | |
421748ec | 1680 | struct path path; |
1da177e4 LT |
1681 | int error; |
1682 | ||
421748ec | 1683 | if (!pathname || !*pathname) |
1da177e4 LT |
1684 | return ERR_PTR(-EINVAL); |
1685 | ||
421748ec | 1686 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
1687 | if (error) |
1688 | return ERR_PTR(error); | |
1689 | ||
421748ec | 1690 | inode = path.dentry->d_inode; |
1da177e4 LT |
1691 | error = -ENOTBLK; |
1692 | if (!S_ISBLK(inode->i_mode)) | |
1693 | goto fail; | |
1694 | error = -EACCES; | |
421748ec | 1695 | if (path.mnt->mnt_flags & MNT_NODEV) |
1da177e4 LT |
1696 | goto fail; |
1697 | error = -ENOMEM; | |
1698 | bdev = bd_acquire(inode); | |
1699 | if (!bdev) | |
1700 | goto fail; | |
1701 | out: | |
421748ec | 1702 | path_put(&path); |
1da177e4 LT |
1703 | return bdev; |
1704 | fail: | |
1705 | bdev = ERR_PTR(error); | |
1706 | goto out; | |
1707 | } | |
d5686b44 | 1708 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1709 | |
93b270f7 | 1710 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
1711 | { |
1712 | struct super_block *sb = get_super(bdev); | |
1713 | int res = 0; | |
1714 | ||
1715 | if (sb) { | |
1716 | /* | |
1717 | * no need to lock the super, get_super holds the | |
1718 | * read mutex so the filesystem cannot go away | |
1719 | * under us (->put_super runs with the write lock | |
1720 | * hold). | |
1721 | */ | |
1722 | shrink_dcache_sb(sb); | |
93b270f7 | 1723 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
1724 | drop_super(sb); |
1725 | } | |
f98393a6 | 1726 | invalidate_bdev(bdev); |
b71e8a4c DH |
1727 | return res; |
1728 | } | |
1729 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
1730 | |
1731 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
1732 | { | |
1733 | struct inode *inode, *old_inode = NULL; | |
1734 | ||
1735 | spin_lock(&inode_sb_list_lock); | |
1736 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { | |
1737 | struct address_space *mapping = inode->i_mapping; | |
1738 | ||
1739 | spin_lock(&inode->i_lock); | |
1740 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1741 | mapping->nrpages == 0) { | |
1742 | spin_unlock(&inode->i_lock); | |
1743 | continue; | |
1744 | } | |
1745 | __iget(inode); | |
1746 | spin_unlock(&inode->i_lock); | |
1747 | spin_unlock(&inode_sb_list_lock); | |
1748 | /* | |
1749 | * We hold a reference to 'inode' so it couldn't have been | |
1750 | * removed from s_inodes list while we dropped the | |
1751 | * inode_sb_list_lock. We cannot iput the inode now as we can | |
1752 | * be holding the last reference and we cannot iput it under | |
1753 | * inode_sb_list_lock. So we keep the reference and iput it | |
1754 | * later. | |
1755 | */ | |
1756 | iput(old_inode); | |
1757 | old_inode = inode; | |
1758 | ||
1759 | func(I_BDEV(inode), arg); | |
1760 | ||
1761 | spin_lock(&inode_sb_list_lock); | |
1762 | } | |
1763 | spin_unlock(&inode_sb_list_lock); | |
1764 | iput(old_inode); | |
1765 | } |