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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/block_dev.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
6 | */ | |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/mm.h> | |
10 | #include <linux/fcntl.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/kmod.h> | |
13 | #include <linux/major.h> | |
7db9cfd3 | 14 | #include <linux/device_cgroup.h> |
1da177e4 LT |
15 | #include <linux/highmem.h> |
16 | #include <linux/blkdev.h> | |
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> |
c94c2acf | 31 | #include <linux/dax.h> |
acc93d30 | 32 | #include <linux/badblocks.h> |
189ce2b9 | 33 | #include <linux/task_io_accounting_ops.h> |
25f4c414 | 34 | #include <linux/falloc.h> |
1da177e4 | 35 | #include <asm/uaccess.h> |
07f3f05c | 36 | #include "internal.h" |
1da177e4 LT |
37 | |
38 | struct bdev_inode { | |
39 | struct block_device bdev; | |
40 | struct inode vfs_inode; | |
41 | }; | |
42 | ||
4c54ac62 AB |
43 | static const struct address_space_operations def_blk_aops; |
44 | ||
1da177e4 LT |
45 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
46 | { | |
47 | return container_of(inode, struct bdev_inode, vfs_inode); | |
48 | } | |
49 | ||
ff5053f6 | 50 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
51 | { |
52 | return &BDEV_I(inode)->bdev; | |
53 | } | |
1da177e4 LT |
54 | EXPORT_SYMBOL(I_BDEV); |
55 | ||
2af3a815 TK |
56 | void __vfs_msg(struct super_block *sb, const char *prefix, const char *fmt, ...) |
57 | { | |
58 | struct va_format vaf; | |
59 | va_list args; | |
60 | ||
61 | va_start(args, fmt); | |
62 | vaf.fmt = fmt; | |
63 | vaf.va = &args; | |
64 | printk_ratelimited("%sVFS (%s): %pV\n", prefix, sb->s_id, &vaf); | |
65 | va_end(args); | |
66 | } | |
67 | ||
dbd3ca50 | 68 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 69 | { |
dbd3ca50 VG |
70 | struct inode *inode = bdev->bd_inode; |
71 | int ret; | |
72 | ||
564f00f6 CH |
73 | spin_lock(&inode->i_lock); |
74 | while (inode->i_state & I_DIRTY) { | |
75 | spin_unlock(&inode->i_lock); | |
dbd3ca50 VG |
76 | ret = write_inode_now(inode, true); |
77 | if (ret) { | |
78 | char name[BDEVNAME_SIZE]; | |
79 | pr_warn_ratelimited("VFS: Dirty inode writeback failed " | |
80 | "for block device %s (err=%d).\n", | |
81 | bdevname(bdev, name), ret); | |
82 | } | |
564f00f6 CH |
83 | spin_lock(&inode->i_lock); |
84 | } | |
85 | spin_unlock(&inode->i_lock); | |
86 | } | |
87 | ||
f9a14399 | 88 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
ff01bb48 | 89 | void kill_bdev(struct block_device *bdev) |
1da177e4 | 90 | { |
ff01bb48 AV |
91 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
92 | ||
f9fe48be | 93 | if (mapping->nrpages == 0 && mapping->nrexceptional == 0) |
f9a14399 | 94 | return; |
ff01bb48 | 95 | |
f9a14399 | 96 | invalidate_bh_lrus(); |
ff01bb48 | 97 | truncate_inode_pages(mapping, 0); |
1da177e4 | 98 | } |
ff01bb48 AV |
99 | EXPORT_SYMBOL(kill_bdev); |
100 | ||
101 | /* Invalidate clean unused buffers and pagecache. */ | |
102 | void invalidate_bdev(struct block_device *bdev) | |
103 | { | |
104 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
105 | ||
106 | if (mapping->nrpages == 0) | |
107 | return; | |
108 | ||
109 | invalidate_bh_lrus(); | |
110 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
111 | invalidate_mapping_pages(mapping, 0, -1); | |
112 | /* 99% of the time, we don't need to flush the cleancache on the bdev. | |
113 | * But, for the strange corners, lets be cautious | |
114 | */ | |
3167760f | 115 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
116 | } |
117 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 LT |
118 | |
119 | int set_blocksize(struct block_device *bdev, int size) | |
120 | { | |
121 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 122 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
123 | return -EINVAL; |
124 | ||
125 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 126 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
127 | return -EINVAL; |
128 | ||
129 | /* Don't change the size if it is same as current */ | |
130 | if (bdev->bd_block_size != size) { | |
131 | sync_blockdev(bdev); | |
132 | bdev->bd_block_size = size; | |
133 | bdev->bd_inode->i_blkbits = blksize_bits(size); | |
134 | kill_bdev(bdev); | |
135 | } | |
136 | return 0; | |
137 | } | |
138 | ||
139 | EXPORT_SYMBOL(set_blocksize); | |
140 | ||
141 | int sb_set_blocksize(struct super_block *sb, int size) | |
142 | { | |
1da177e4 LT |
143 | if (set_blocksize(sb->s_bdev, size)) |
144 | return 0; | |
145 | /* If we get here, we know size is power of two | |
146 | * and it's value is between 512 and PAGE_SIZE */ | |
147 | sb->s_blocksize = size; | |
38885bd4 | 148 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
149 | return sb->s_blocksize; |
150 | } | |
151 | ||
152 | EXPORT_SYMBOL(sb_set_blocksize); | |
153 | ||
154 | int sb_min_blocksize(struct super_block *sb, int size) | |
155 | { | |
e1defc4f | 156 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
157 | if (size < minsize) |
158 | size = minsize; | |
159 | return sb_set_blocksize(sb, size); | |
160 | } | |
161 | ||
162 | EXPORT_SYMBOL(sb_min_blocksize); | |
163 | ||
164 | static int | |
165 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
166 | struct buffer_head *bh, int create) | |
167 | { | |
1da177e4 LT |
168 | bh->b_bdev = I_BDEV(inode); |
169 | bh->b_blocknr = iblock; | |
170 | set_buffer_mapped(bh); | |
171 | return 0; | |
172 | } | |
173 | ||
4ebb16ca DW |
174 | static struct inode *bdev_file_inode(struct file *file) |
175 | { | |
176 | return file->f_mapping->host; | |
177 | } | |
178 | ||
189ce2b9 CH |
179 | #define DIO_INLINE_BIO_VECS 4 |
180 | ||
181 | static void blkdev_bio_end_io_simple(struct bio *bio) | |
182 | { | |
183 | struct task_struct *waiter = bio->bi_private; | |
184 | ||
185 | WRITE_ONCE(bio->bi_private, NULL); | |
186 | wake_up_process(waiter); | |
187 | } | |
188 | ||
189 | static ssize_t | |
190 | __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, | |
191 | int nr_pages) | |
192 | { | |
193 | struct file *file = iocb->ki_filp; | |
194 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
195 | unsigned blkbits = blksize_bits(bdev_logical_block_size(bdev)); | |
72ecad22 | 196 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs, *bvec; |
189ce2b9 CH |
197 | loff_t pos = iocb->ki_pos; |
198 | bool should_dirty = false; | |
199 | struct bio bio; | |
200 | ssize_t ret; | |
201 | blk_qc_t qc; | |
202 | int i; | |
203 | ||
204 | if ((pos | iov_iter_alignment(iter)) & ((1 << blkbits) - 1)) | |
205 | return -EINVAL; | |
206 | ||
72ecad22 JA |
207 | if (nr_pages <= DIO_INLINE_BIO_VECS) |
208 | vecs = inline_vecs; | |
209 | else { | |
210 | vecs = kmalloc(nr_pages * sizeof(struct bio_vec), GFP_KERNEL); | |
211 | if (!vecs) | |
212 | return -ENOMEM; | |
213 | } | |
214 | ||
189ce2b9 CH |
215 | bio_init(&bio); |
216 | bio.bi_max_vecs = nr_pages; | |
72ecad22 | 217 | bio.bi_io_vec = vecs; |
189ce2b9 CH |
218 | bio.bi_bdev = bdev; |
219 | bio.bi_iter.bi_sector = pos >> blkbits; | |
220 | bio.bi_private = current; | |
221 | bio.bi_end_io = blkdev_bio_end_io_simple; | |
222 | ||
223 | ret = bio_iov_iter_get_pages(&bio, iter); | |
224 | if (unlikely(ret)) | |
225 | return ret; | |
226 | ret = bio.bi_iter.bi_size; | |
227 | ||
228 | if (iov_iter_rw(iter) == READ) { | |
229 | bio_set_op_attrs(&bio, REQ_OP_READ, 0); | |
230 | if (iter_is_iovec(iter)) | |
231 | should_dirty = true; | |
232 | } else { | |
233 | bio_set_op_attrs(&bio, REQ_OP_WRITE, REQ_SYNC | REQ_IDLE); | |
234 | task_io_account_write(ret); | |
235 | } | |
236 | ||
237 | qc = submit_bio(&bio); | |
238 | for (;;) { | |
239 | set_current_state(TASK_UNINTERRUPTIBLE); | |
240 | if (!READ_ONCE(bio.bi_private)) | |
241 | break; | |
242 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
243 | !blk_mq_poll(bdev_get_queue(bdev), qc)) | |
244 | io_schedule(); | |
245 | } | |
246 | __set_current_state(TASK_RUNNING); | |
247 | ||
248 | bio_for_each_segment_all(bvec, &bio, i) { | |
249 | if (should_dirty && !PageCompound(bvec->bv_page)) | |
250 | set_page_dirty_lock(bvec->bv_page); | |
251 | put_page(bvec->bv_page); | |
252 | } | |
253 | ||
72ecad22 JA |
254 | if (vecs != inline_vecs) |
255 | kfree(vecs); | |
256 | ||
189ce2b9 CH |
257 | if (unlikely(bio.bi_error)) |
258 | return bio.bi_error; | |
259 | iocb->ki_pos += ret; | |
260 | return ret; | |
261 | } | |
262 | ||
b2e895db | 263 | static ssize_t |
c8b8e32d | 264 | blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
b2e895db AM |
265 | { |
266 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 267 | struct inode *inode = bdev_file_inode(file); |
189ce2b9 | 268 | int nr_pages; |
b2e895db | 269 | |
72ecad22 | 270 | nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1); |
189ce2b9 CH |
271 | if (!nr_pages) |
272 | return 0; | |
72ecad22 | 273 | if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) |
189ce2b9 | 274 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); |
c8b8e32d | 275 | return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, |
fe0f07d0 JA |
276 | blkdev_get_block, NULL, NULL, |
277 | DIO_SKIP_DIO_COUNT); | |
b2e895db AM |
278 | } |
279 | ||
5cee5815 JK |
280 | int __sync_blockdev(struct block_device *bdev, int wait) |
281 | { | |
282 | if (!bdev) | |
283 | return 0; | |
284 | if (!wait) | |
285 | return filemap_flush(bdev->bd_inode->i_mapping); | |
286 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
287 | } | |
288 | ||
585d3bc0 NP |
289 | /* |
290 | * Write out and wait upon all the dirty data associated with a block | |
291 | * device via its mapping. Does not take the superblock lock. | |
292 | */ | |
293 | int sync_blockdev(struct block_device *bdev) | |
294 | { | |
5cee5815 | 295 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
296 | } |
297 | EXPORT_SYMBOL(sync_blockdev); | |
298 | ||
299 | /* | |
300 | * Write out and wait upon all dirty data associated with this | |
301 | * device. Filesystem data as well as the underlying block | |
302 | * device. Takes the superblock lock. | |
303 | */ | |
304 | int fsync_bdev(struct block_device *bdev) | |
305 | { | |
306 | struct super_block *sb = get_super(bdev); | |
307 | if (sb) { | |
60b0680f | 308 | int res = sync_filesystem(sb); |
585d3bc0 NP |
309 | drop_super(sb); |
310 | return res; | |
311 | } | |
312 | return sync_blockdev(bdev); | |
313 | } | |
47e4491b | 314 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
315 | |
316 | /** | |
317 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
318 | * @bdev: blockdevice to lock | |
319 | * | |
585d3bc0 NP |
320 | * If a superblock is found on this device, we take the s_umount semaphore |
321 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
322 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
323 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
324 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
325 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
326 | * actually. | |
327 | */ | |
328 | struct super_block *freeze_bdev(struct block_device *bdev) | |
329 | { | |
330 | struct super_block *sb; | |
331 | int error = 0; | |
332 | ||
333 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a CH |
334 | if (++bdev->bd_fsfreeze_count > 1) { |
335 | /* | |
336 | * We don't even need to grab a reference - the first call | |
337 | * to freeze_bdev grab an active reference and only the last | |
338 | * thaw_bdev drops it. | |
339 | */ | |
585d3bc0 | 340 | sb = get_super(bdev); |
5bb53c0f AR |
341 | if (sb) |
342 | drop_super(sb); | |
4504230a CH |
343 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
344 | return sb; | |
345 | } | |
346 | ||
347 | sb = get_active_super(bdev); | |
348 | if (!sb) | |
349 | goto out; | |
48b6bca6 BM |
350 | if (sb->s_op->freeze_super) |
351 | error = sb->s_op->freeze_super(sb); | |
352 | else | |
353 | error = freeze_super(sb); | |
18e9e510 JB |
354 | if (error) { |
355 | deactivate_super(sb); | |
356 | bdev->bd_fsfreeze_count--; | |
585d3bc0 | 357 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
18e9e510 | 358 | return ERR_PTR(error); |
585d3bc0 | 359 | } |
18e9e510 | 360 | deactivate_super(sb); |
4504230a | 361 | out: |
585d3bc0 NP |
362 | sync_blockdev(bdev); |
363 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
4fadd7bb | 364 | return sb; /* thaw_bdev releases s->s_umount */ |
585d3bc0 NP |
365 | } |
366 | EXPORT_SYMBOL(freeze_bdev); | |
367 | ||
368 | /** | |
369 | * thaw_bdev -- unlock filesystem | |
370 | * @bdev: blockdevice to unlock | |
371 | * @sb: associated superblock | |
372 | * | |
373 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
374 | */ | |
375 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) | |
376 | { | |
4504230a | 377 | int error = -EINVAL; |
585d3bc0 NP |
378 | |
379 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 380 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 381 | goto out; |
4504230a CH |
382 | |
383 | error = 0; | |
384 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 385 | goto out; |
4504230a CH |
386 | |
387 | if (!sb) | |
18e9e510 | 388 | goto out; |
4504230a | 389 | |
48b6bca6 BM |
390 | if (sb->s_op->thaw_super) |
391 | error = sb->s_op->thaw_super(sb); | |
392 | else | |
393 | error = thaw_super(sb); | |
997198ba | 394 | if (error) |
18e9e510 | 395 | bdev->bd_fsfreeze_count++; |
18e9e510 | 396 | out: |
585d3bc0 | 397 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 398 | return error; |
585d3bc0 NP |
399 | } |
400 | EXPORT_SYMBOL(thaw_bdev); | |
401 | ||
1da177e4 LT |
402 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
403 | { | |
404 | return block_write_full_page(page, blkdev_get_block, wbc); | |
405 | } | |
406 | ||
407 | static int blkdev_readpage(struct file * file, struct page * page) | |
408 | { | |
409 | return block_read_full_page(page, blkdev_get_block); | |
410 | } | |
411 | ||
447f05bb AM |
412 | static int blkdev_readpages(struct file *file, struct address_space *mapping, |
413 | struct list_head *pages, unsigned nr_pages) | |
414 | { | |
415 | return mpage_readpages(mapping, pages, nr_pages, blkdev_get_block); | |
416 | } | |
417 | ||
6272b5a5 NP |
418 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
419 | loff_t pos, unsigned len, unsigned flags, | |
420 | struct page **pagep, void **fsdata) | |
1da177e4 | 421 | { |
155130a4 CH |
422 | return block_write_begin(mapping, pos, len, flags, pagep, |
423 | blkdev_get_block); | |
1da177e4 LT |
424 | } |
425 | ||
6272b5a5 NP |
426 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
427 | loff_t pos, unsigned len, unsigned copied, | |
428 | struct page *page, void *fsdata) | |
1da177e4 | 429 | { |
6272b5a5 NP |
430 | int ret; |
431 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
432 | ||
433 | unlock_page(page); | |
09cbfeaf | 434 | put_page(page); |
6272b5a5 NP |
435 | |
436 | return ret; | |
1da177e4 LT |
437 | } |
438 | ||
439 | /* | |
440 | * private llseek: | |
496ad9aa | 441 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
442 | * so we compute the size by hand (just as in block_read/write above) |
443 | */ | |
965c8e59 | 444 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 445 | { |
4ebb16ca | 446 | struct inode *bd_inode = bdev_file_inode(file); |
1da177e4 LT |
447 | loff_t retval; |
448 | ||
5955102c | 449 | inode_lock(bd_inode); |
5d48f3a2 | 450 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
5955102c | 451 | inode_unlock(bd_inode); |
1da177e4 LT |
452 | return retval; |
453 | } | |
454 | ||
02c24a82 | 455 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 456 | { |
4ebb16ca | 457 | struct inode *bd_inode = bdev_file_inode(filp); |
b8af67e2 | 458 | struct block_device *bdev = I_BDEV(bd_inode); |
ab0a9735 | 459 | int error; |
da5aa861 RW |
460 | |
461 | error = filemap_write_and_wait_range(filp->f_mapping, start, end); | |
462 | if (error) | |
463 | return error; | |
ab0a9735 | 464 | |
b8af67e2 AB |
465 | /* |
466 | * There is no need to serialise calls to blkdev_issue_flush with | |
467 | * i_mutex and doing so causes performance issues with concurrent | |
468 | * O_SYNC writers to a block device. | |
469 | */ | |
dd3932ed | 470 | error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
ab0a9735 CH |
471 | if (error == -EOPNOTSUPP) |
472 | error = 0; | |
b8af67e2 | 473 | |
ab0a9735 | 474 | return error; |
1da177e4 | 475 | } |
b1dd3b28 | 476 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 477 | |
47a191fd MW |
478 | /** |
479 | * bdev_read_page() - Start reading a page from a block device | |
480 | * @bdev: The device to read the page from | |
481 | * @sector: The offset on the device to read the page to (need not be aligned) | |
482 | * @page: The page to read | |
483 | * | |
484 | * On entry, the page should be locked. It will be unlocked when the page | |
485 | * has been read. If the block driver implements rw_page synchronously, | |
486 | * that will be true on exit from this function, but it need not be. | |
487 | * | |
488 | * Errors returned by this function are usually "soft", eg out of memory, or | |
489 | * queue full; callers should try a different route to read this page rather | |
490 | * than propagate an error back up the stack. | |
491 | * | |
492 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
493 | */ | |
494 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
495 | struct page *page) | |
496 | { | |
497 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
2e6edc95 DW |
498 | int result = -EOPNOTSUPP; |
499 | ||
f68eb1e7 | 500 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
2e6edc95 DW |
501 | return result; |
502 | ||
6f3b0e8b | 503 | result = blk_queue_enter(bdev->bd_queue, false); |
2e6edc95 DW |
504 | if (result) |
505 | return result; | |
c11f0c0b | 506 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, false); |
2e6edc95 DW |
507 | blk_queue_exit(bdev->bd_queue); |
508 | return result; | |
47a191fd MW |
509 | } |
510 | EXPORT_SYMBOL_GPL(bdev_read_page); | |
511 | ||
512 | /** | |
513 | * bdev_write_page() - Start writing a page to a block device | |
514 | * @bdev: The device to write the page to | |
515 | * @sector: The offset on the device to write the page to (need not be aligned) | |
516 | * @page: The page to write | |
517 | * @wbc: The writeback_control for the write | |
518 | * | |
519 | * On entry, the page should be locked and not currently under writeback. | |
520 | * On exit, if the write started successfully, the page will be unlocked and | |
521 | * under writeback. If the write failed already (eg the driver failed to | |
522 | * queue the page to the device), the page will still be locked. If the | |
523 | * caller is a ->writepage implementation, it will need to unlock the page. | |
524 | * | |
525 | * Errors returned by this function are usually "soft", eg out of memory, or | |
526 | * queue full; callers should try a different route to write this page rather | |
527 | * than propagate an error back up the stack. | |
528 | * | |
529 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
530 | */ | |
531 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
532 | struct page *page, struct writeback_control *wbc) | |
533 | { | |
534 | int result; | |
47a191fd | 535 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
2e6edc95 | 536 | |
f68eb1e7 | 537 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd | 538 | return -EOPNOTSUPP; |
6f3b0e8b | 539 | result = blk_queue_enter(bdev->bd_queue, false); |
2e6edc95 DW |
540 | if (result) |
541 | return result; | |
542 | ||
47a191fd | 543 | set_page_writeback(page); |
c11f0c0b | 544 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, true); |
47a191fd MW |
545 | if (result) |
546 | end_page_writeback(page); | |
547 | else | |
548 | unlock_page(page); | |
2e6edc95 | 549 | blk_queue_exit(bdev->bd_queue); |
47a191fd MW |
550 | return result; |
551 | } | |
552 | EXPORT_SYMBOL_GPL(bdev_write_page); | |
553 | ||
dd22f551 MW |
554 | /** |
555 | * bdev_direct_access() - Get the address for directly-accessibly memory | |
556 | * @bdev: The device containing the memory | |
b2e0d162 | 557 | * @dax: control and output parameters for ->direct_access |
dd22f551 MW |
558 | * |
559 | * If a block device is made up of directly addressable memory, this function | |
560 | * will tell the caller the PFN and the address of the memory. The address | |
561 | * may be directly dereferenced within the kernel without the need to call | |
562 | * ioremap(), kmap() or similar. The PFN is suitable for inserting into | |
563 | * page tables. | |
564 | * | |
565 | * Return: negative errno if an error occurs, otherwise the number of bytes | |
566 | * accessible at this address. | |
567 | */ | |
b2e0d162 | 568 | long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax) |
dd22f551 | 569 | { |
b2e0d162 DW |
570 | sector_t sector = dax->sector; |
571 | long avail, size = dax->size; | |
dd22f551 MW |
572 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
573 | ||
43c3dd08 MW |
574 | /* |
575 | * The device driver is allowed to sleep, in order to make the | |
576 | * memory directly accessible. | |
577 | */ | |
578 | might_sleep(); | |
579 | ||
dd22f551 MW |
580 | if (size < 0) |
581 | return size; | |
163d4baa | 582 | if (!blk_queue_dax(bdev_get_queue(bdev)) || !ops->direct_access) |
dd22f551 MW |
583 | return -EOPNOTSUPP; |
584 | if ((sector + DIV_ROUND_UP(size, 512)) > | |
585 | part_nr_sects_read(bdev->bd_part)) | |
586 | return -ERANGE; | |
587 | sector += get_start_sect(bdev); | |
588 | if (sector % (PAGE_SIZE / 512)) | |
589 | return -EINVAL; | |
0a70bd43 | 590 | avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size); |
dd22f551 MW |
591 | if (!avail) |
592 | return -ERANGE; | |
fe683ada DW |
593 | if (avail > 0 && avail & ~PAGE_MASK) |
594 | return -ENXIO; | |
dd22f551 MW |
595 | return min(avail, size); |
596 | } | |
597 | EXPORT_SYMBOL_GPL(bdev_direct_access); | |
598 | ||
2d96afc8 TK |
599 | /** |
600 | * bdev_dax_supported() - Check if the device supports dax for filesystem | |
601 | * @sb: The superblock of the device | |
602 | * @blocksize: The block size of the device | |
603 | * | |
604 | * This is a library function for filesystems to check if the block device | |
605 | * can be mounted with dax option. | |
606 | * | |
607 | * Return: negative errno if unsupported, 0 if supported. | |
608 | */ | |
609 | int bdev_dax_supported(struct super_block *sb, int blocksize) | |
610 | { | |
611 | struct blk_dax_ctl dax = { | |
612 | .sector = 0, | |
613 | .size = PAGE_SIZE, | |
614 | }; | |
615 | int err; | |
616 | ||
617 | if (blocksize != PAGE_SIZE) { | |
618 | vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); | |
619 | return -EINVAL; | |
620 | } | |
621 | ||
622 | err = bdev_direct_access(sb->s_bdev, &dax); | |
623 | if (err < 0) { | |
624 | switch (err) { | |
625 | case -EOPNOTSUPP: | |
626 | vfs_msg(sb, KERN_ERR, | |
627 | "error: device does not support dax"); | |
628 | break; | |
629 | case -EINVAL: | |
630 | vfs_msg(sb, KERN_ERR, | |
631 | "error: unaligned partition for dax"); | |
632 | break; | |
633 | default: | |
634 | vfs_msg(sb, KERN_ERR, | |
635 | "error: dax access failed (%d)", err); | |
636 | } | |
637 | return err; | |
638 | } | |
639 | ||
640 | return 0; | |
641 | } | |
642 | EXPORT_SYMBOL_GPL(bdev_dax_supported); | |
643 | ||
a8078b1f TK |
644 | /** |
645 | * bdev_dax_capable() - Return if the raw device is capable for dax | |
646 | * @bdev: The device for raw block device access | |
647 | */ | |
648 | bool bdev_dax_capable(struct block_device *bdev) | |
649 | { | |
a8078b1f TK |
650 | struct blk_dax_ctl dax = { |
651 | .size = PAGE_SIZE, | |
652 | }; | |
653 | ||
654 | if (!IS_ENABLED(CONFIG_FS_DAX)) | |
655 | return false; | |
656 | ||
657 | dax.sector = 0; | |
658 | if (bdev_direct_access(bdev, &dax) < 0) | |
659 | return false; | |
660 | ||
661 | dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512); | |
662 | if (bdev_direct_access(bdev, &dax) < 0) | |
663 | return false; | |
664 | ||
a8078b1f TK |
665 | return true; |
666 | } | |
667 | ||
1da177e4 LT |
668 | /* |
669 | * pseudo-fs | |
670 | */ | |
671 | ||
672 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 673 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
674 | |
675 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
676 | { | |
e94b1766 | 677 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
678 | if (!ei) |
679 | return NULL; | |
680 | return &ei->vfs_inode; | |
681 | } | |
682 | ||
fa0d7e3d | 683 | static void bdev_i_callback(struct rcu_head *head) |
1da177e4 | 684 | { |
fa0d7e3d | 685 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
686 | struct bdev_inode *bdi = BDEV_I(inode); |
687 | ||
1da177e4 LT |
688 | kmem_cache_free(bdev_cachep, bdi); |
689 | } | |
690 | ||
fa0d7e3d NP |
691 | static void bdev_destroy_inode(struct inode *inode) |
692 | { | |
693 | call_rcu(&inode->i_rcu, bdev_i_callback); | |
694 | } | |
695 | ||
51cc5068 | 696 | static void init_once(void *foo) |
1da177e4 LT |
697 | { |
698 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
699 | struct block_device *bdev = &ei->bdev; | |
700 | ||
a35afb83 CL |
701 | memset(bdev, 0, sizeof(*bdev)); |
702 | mutex_init(&bdev->bd_mutex); | |
a35afb83 | 703 | INIT_LIST_HEAD(&bdev->bd_list); |
49731baa TH |
704 | #ifdef CONFIG_SYSFS |
705 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
706 | #endif | |
a35afb83 | 707 | inode_init_once(&ei->vfs_inode); |
fcccf502 TS |
708 | /* Initialize mutex for freeze. */ |
709 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
1da177e4 LT |
710 | } |
711 | ||
b57922d9 | 712 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
713 | { |
714 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
91b0abe3 | 715 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 716 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 717 | clear_inode(inode); |
1da177e4 | 718 | spin_lock(&bdev_lock); |
1da177e4 LT |
719 | list_del_init(&bdev->bd_list); |
720 | spin_unlock(&bdev_lock); | |
721 | } | |
722 | ||
ee9b6d61 | 723 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
724 | .statfs = simple_statfs, |
725 | .alloc_inode = bdev_alloc_inode, | |
726 | .destroy_inode = bdev_destroy_inode, | |
727 | .drop_inode = generic_delete_inode, | |
b57922d9 | 728 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
729 | }; |
730 | ||
51139ada AV |
731 | static struct dentry *bd_mount(struct file_system_type *fs_type, |
732 | int flags, const char *dev_name, void *data) | |
1da177e4 | 733 | { |
3684aa70 SL |
734 | struct dentry *dent; |
735 | dent = mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC); | |
e9e5e3fa | 736 | if (!IS_ERR(dent)) |
3684aa70 SL |
737 | dent->d_sb->s_iflags |= SB_I_CGROUPWB; |
738 | return dent; | |
1da177e4 LT |
739 | } |
740 | ||
741 | static struct file_system_type bd_type = { | |
742 | .name = "bdev", | |
51139ada | 743 | .mount = bd_mount, |
1da177e4 LT |
744 | .kill_sb = kill_anon_super, |
745 | }; | |
746 | ||
a212b105 TH |
747 | struct super_block *blockdev_superblock __read_mostly; |
748 | EXPORT_SYMBOL_GPL(blockdev_superblock); | |
1da177e4 LT |
749 | |
750 | void __init bdev_cache_init(void) | |
751 | { | |
752 | int err; | |
ace8577a | 753 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 754 | |
1da177e4 | 755 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 756 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 757 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 758 | init_once); |
1da177e4 LT |
759 | err = register_filesystem(&bd_type); |
760 | if (err) | |
761 | panic("Cannot register bdev pseudo-fs"); | |
762 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
763 | if (IS_ERR(bd_mnt)) |
764 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 765 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
766 | } |
767 | ||
768 | /* | |
769 | * Most likely _very_ bad one - but then it's hardly critical for small | |
770 | * /dev and can be fixed when somebody will need really large one. | |
771 | * Keep in mind that it will be fed through icache hash function too. | |
772 | */ | |
773 | static inline unsigned long hash(dev_t dev) | |
774 | { | |
775 | return MAJOR(dev)+MINOR(dev); | |
776 | } | |
777 | ||
778 | static int bdev_test(struct inode *inode, void *data) | |
779 | { | |
780 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
781 | } | |
782 | ||
783 | static int bdev_set(struct inode *inode, void *data) | |
784 | { | |
785 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
786 | return 0; | |
787 | } | |
788 | ||
789 | static LIST_HEAD(all_bdevs); | |
790 | ||
791 | struct block_device *bdget(dev_t dev) | |
792 | { | |
793 | struct block_device *bdev; | |
794 | struct inode *inode; | |
795 | ||
c2acf7b9 | 796 | inode = iget5_locked(blockdev_superblock, hash(dev), |
1da177e4 LT |
797 | bdev_test, bdev_set, &dev); |
798 | ||
799 | if (!inode) | |
800 | return NULL; | |
801 | ||
802 | bdev = &BDEV_I(inode)->bdev; | |
803 | ||
804 | if (inode->i_state & I_NEW) { | |
805 | bdev->bd_contains = NULL; | |
782b94cd | 806 | bdev->bd_super = NULL; |
1da177e4 LT |
807 | bdev->bd_inode = inode; |
808 | bdev->bd_block_size = (1 << inode->i_blkbits); | |
809 | bdev->bd_part_count = 0; | |
810 | bdev->bd_invalidated = 0; | |
811 | inode->i_mode = S_IFBLK; | |
812 | inode->i_rdev = dev; | |
813 | inode->i_bdev = bdev; | |
814 | inode->i_data.a_ops = &def_blk_aops; | |
815 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
1da177e4 LT |
816 | spin_lock(&bdev_lock); |
817 | list_add(&bdev->bd_list, &all_bdevs); | |
818 | spin_unlock(&bdev_lock); | |
819 | unlock_new_inode(inode); | |
820 | } | |
821 | return bdev; | |
822 | } | |
823 | ||
824 | EXPORT_SYMBOL(bdget); | |
825 | ||
dddac6a7 AJ |
826 | /** |
827 | * bdgrab -- Grab a reference to an already referenced block device | |
828 | * @bdev: Block device to grab a reference to. | |
829 | */ | |
830 | struct block_device *bdgrab(struct block_device *bdev) | |
831 | { | |
7de9c6ee | 832 | ihold(bdev->bd_inode); |
dddac6a7 AJ |
833 | return bdev; |
834 | } | |
c1681bf8 | 835 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 836 | |
1da177e4 LT |
837 | long nr_blockdev_pages(void) |
838 | { | |
203a2935 | 839 | struct block_device *bdev; |
1da177e4 LT |
840 | long ret = 0; |
841 | spin_lock(&bdev_lock); | |
203a2935 | 842 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4 LT |
843 | ret += bdev->bd_inode->i_mapping->nrpages; |
844 | } | |
845 | spin_unlock(&bdev_lock); | |
846 | return ret; | |
847 | } | |
848 | ||
849 | void bdput(struct block_device *bdev) | |
850 | { | |
851 | iput(bdev->bd_inode); | |
852 | } | |
853 | ||
854 | EXPORT_SYMBOL(bdput); | |
855 | ||
856 | static struct block_device *bd_acquire(struct inode *inode) | |
857 | { | |
858 | struct block_device *bdev; | |
09d967c6 | 859 | |
1da177e4 LT |
860 | spin_lock(&bdev_lock); |
861 | bdev = inode->i_bdev; | |
09d967c6 | 862 | if (bdev) { |
ed8a9d2c | 863 | bdgrab(bdev); |
1da177e4 LT |
864 | spin_unlock(&bdev_lock); |
865 | return bdev; | |
866 | } | |
867 | spin_unlock(&bdev_lock); | |
09d967c6 | 868 | |
1da177e4 LT |
869 | bdev = bdget(inode->i_rdev); |
870 | if (bdev) { | |
871 | spin_lock(&bdev_lock); | |
09d967c6 OH |
872 | if (!inode->i_bdev) { |
873 | /* | |
7de9c6ee | 874 | * We take an additional reference to bd_inode, |
09d967c6 OH |
875 | * and it's released in clear_inode() of inode. |
876 | * So, we can access it via ->i_mapping always | |
877 | * without igrab(). | |
878 | */ | |
ed8a9d2c | 879 | bdgrab(bdev); |
09d967c6 OH |
880 | inode->i_bdev = bdev; |
881 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
09d967c6 | 882 | } |
1da177e4 LT |
883 | spin_unlock(&bdev_lock); |
884 | } | |
885 | return bdev; | |
886 | } | |
887 | ||
888 | /* Call when you free inode */ | |
889 | ||
890 | void bd_forget(struct inode *inode) | |
891 | { | |
09d967c6 OH |
892 | struct block_device *bdev = NULL; |
893 | ||
1da177e4 | 894 | spin_lock(&bdev_lock); |
b4ea2eaa YH |
895 | if (!sb_is_blkdev_sb(inode->i_sb)) |
896 | bdev = inode->i_bdev; | |
a4a4f943 AV |
897 | inode->i_bdev = NULL; |
898 | inode->i_mapping = &inode->i_data; | |
1da177e4 | 899 | spin_unlock(&bdev_lock); |
09d967c6 OH |
900 | |
901 | if (bdev) | |
ed8a9d2c | 902 | bdput(bdev); |
1da177e4 LT |
903 | } |
904 | ||
1a3cbbc5 TH |
905 | /** |
906 | * bd_may_claim - test whether a block device can be claimed | |
907 | * @bdev: block device of interest | |
908 | * @whole: whole block device containing @bdev, may equal @bdev | |
909 | * @holder: holder trying to claim @bdev | |
910 | * | |
25985edc | 911 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
912 | * |
913 | * CONTEXT: | |
914 | * spin_lock(&bdev_lock). | |
915 | * | |
916 | * RETURNS: | |
917 | * %true if @bdev can be claimed, %false otherwise. | |
918 | */ | |
919 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
920 | void *holder) | |
1da177e4 | 921 | { |
1da177e4 | 922 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 923 | return true; /* already a holder */ |
1da177e4 | 924 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 925 | return false; /* held by someone else */ |
1da177e4 | 926 | else if (bdev->bd_contains == bdev) |
1a3cbbc5 | 927 | return true; /* is a whole device which isn't held */ |
1da177e4 | 928 | |
e525fd89 | 929 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
930 | return true; /* is a partition of a device that is being partitioned */ |
931 | else if (whole->bd_holder != NULL) | |
932 | return false; /* is a partition of a held device */ | |
1da177e4 | 933 | else |
1a3cbbc5 TH |
934 | return true; /* is a partition of an un-held device */ |
935 | } | |
936 | ||
6b4517a7 TH |
937 | /** |
938 | * bd_prepare_to_claim - prepare to claim a block device | |
939 | * @bdev: block device of interest | |
940 | * @whole: the whole device containing @bdev, may equal @bdev | |
941 | * @holder: holder trying to claim @bdev | |
942 | * | |
943 | * Prepare to claim @bdev. This function fails if @bdev is already | |
944 | * claimed by another holder and waits if another claiming is in | |
945 | * progress. This function doesn't actually claim. On successful | |
946 | * return, the caller has ownership of bd_claiming and bd_holder[s]. | |
947 | * | |
948 | * CONTEXT: | |
949 | * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab | |
950 | * it multiple times. | |
951 | * | |
952 | * RETURNS: | |
953 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
954 | */ | |
955 | static int bd_prepare_to_claim(struct block_device *bdev, | |
956 | struct block_device *whole, void *holder) | |
957 | { | |
958 | retry: | |
959 | /* if someone else claimed, fail */ | |
960 | if (!bd_may_claim(bdev, whole, holder)) | |
961 | return -EBUSY; | |
962 | ||
e75aa858 TH |
963 | /* if claiming is already in progress, wait for it to finish */ |
964 | if (whole->bd_claiming) { | |
6b4517a7 TH |
965 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
966 | DEFINE_WAIT(wait); | |
967 | ||
968 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
969 | spin_unlock(&bdev_lock); | |
970 | schedule(); | |
971 | finish_wait(wq, &wait); | |
972 | spin_lock(&bdev_lock); | |
973 | goto retry; | |
974 | } | |
975 | ||
976 | /* yay, all mine */ | |
977 | return 0; | |
978 | } | |
979 | ||
980 | /** | |
981 | * bd_start_claiming - start claiming a block device | |
982 | * @bdev: block device of interest | |
983 | * @holder: holder trying to claim @bdev | |
984 | * | |
985 | * @bdev is about to be opened exclusively. Check @bdev can be opened | |
986 | * exclusively and mark that an exclusive open is in progress. Each | |
987 | * successful call to this function must be matched with a call to | |
b0018361 NP |
988 | * either bd_finish_claiming() or bd_abort_claiming() (which do not |
989 | * fail). | |
990 | * | |
991 | * This function is used to gain exclusive access to the block device | |
992 | * without actually causing other exclusive open attempts to fail. It | |
993 | * should be used when the open sequence itself requires exclusive | |
994 | * access but may subsequently fail. | |
6b4517a7 TH |
995 | * |
996 | * CONTEXT: | |
997 | * Might sleep. | |
998 | * | |
999 | * RETURNS: | |
1000 | * Pointer to the block device containing @bdev on success, ERR_PTR() | |
1001 | * value on failure. | |
1002 | */ | |
1003 | static struct block_device *bd_start_claiming(struct block_device *bdev, | |
1004 | void *holder) | |
1005 | { | |
1006 | struct gendisk *disk; | |
1007 | struct block_device *whole; | |
1008 | int partno, err; | |
1009 | ||
1010 | might_sleep(); | |
1011 | ||
1012 | /* | |
1013 | * @bdev might not have been initialized properly yet, look up | |
1014 | * and grab the outer block device the hard way. | |
1015 | */ | |
1016 | disk = get_gendisk(bdev->bd_dev, &partno); | |
1017 | if (!disk) | |
1018 | return ERR_PTR(-ENXIO); | |
1019 | ||
d4c208b8 TH |
1020 | /* |
1021 | * Normally, @bdev should equal what's returned from bdget_disk() | |
1022 | * if partno is 0; however, some drivers (floppy) use multiple | |
1023 | * bdev's for the same physical device and @bdev may be one of the | |
1024 | * aliases. Keep @bdev if partno is 0. This means claimer | |
1025 | * tracking is broken for those devices but it has always been that | |
1026 | * way. | |
1027 | */ | |
1028 | if (partno) | |
1029 | whole = bdget_disk(disk, 0); | |
1030 | else | |
1031 | whole = bdgrab(bdev); | |
1032 | ||
cf342570 | 1033 | module_put(disk->fops->owner); |
6b4517a7 TH |
1034 | put_disk(disk); |
1035 | if (!whole) | |
1036 | return ERR_PTR(-ENOMEM); | |
1037 | ||
1038 | /* prepare to claim, if successful, mark claiming in progress */ | |
1039 | spin_lock(&bdev_lock); | |
1040 | ||
1041 | err = bd_prepare_to_claim(bdev, whole, holder); | |
1042 | if (err == 0) { | |
1043 | whole->bd_claiming = holder; | |
1044 | spin_unlock(&bdev_lock); | |
1045 | return whole; | |
1046 | } else { | |
1047 | spin_unlock(&bdev_lock); | |
1048 | bdput(whole); | |
1049 | return ERR_PTR(err); | |
1050 | } | |
1051 | } | |
1052 | ||
641dc636 | 1053 | #ifdef CONFIG_SYSFS |
49731baa TH |
1054 | struct bd_holder_disk { |
1055 | struct list_head list; | |
1056 | struct gendisk *disk; | |
1057 | int refcnt; | |
1058 | }; | |
1059 | ||
1060 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
1061 | struct gendisk *disk) | |
1062 | { | |
1063 | struct bd_holder_disk *holder; | |
1064 | ||
1065 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
1066 | if (holder->disk == disk) | |
1067 | return holder; | |
1068 | return NULL; | |
1069 | } | |
1070 | ||
4d7dd8fd | 1071 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 1072 | { |
4d7dd8fd | 1073 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
1074 | } |
1075 | ||
1076 | static void del_symlink(struct kobject *from, struct kobject *to) | |
1077 | { | |
641dc636 JN |
1078 | sysfs_remove_link(from, kobject_name(to)); |
1079 | } | |
1080 | ||
df6c0cd9 | 1081 | /** |
e09b457b TH |
1082 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
1083 | * @bdev: the claimed slave bdev | |
1084 | * @disk: the holding disk | |
df6c0cd9 | 1085 | * |
49731baa TH |
1086 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
1087 | * | |
e09b457b | 1088 | * This functions creates the following sysfs symlinks. |
641dc636 | 1089 | * |
e09b457b TH |
1090 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
1091 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 1092 | * |
e09b457b TH |
1093 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
1094 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 1095 | * |
e09b457b TH |
1096 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
1097 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 1098 | * |
e09b457b TH |
1099 | * The caller must have claimed @bdev before calling this function and |
1100 | * ensure that both @bdev and @disk are valid during the creation and | |
1101 | * lifetime of these symlinks. | |
641dc636 | 1102 | * |
e09b457b TH |
1103 | * CONTEXT: |
1104 | * Might sleep. | |
641dc636 | 1105 | * |
e09b457b TH |
1106 | * RETURNS: |
1107 | * 0 on success, -errno on failure. | |
641dc636 | 1108 | */ |
e09b457b | 1109 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 1110 | { |
49731baa | 1111 | struct bd_holder_disk *holder; |
e09b457b | 1112 | int ret = 0; |
641dc636 | 1113 | |
2e7b651d | 1114 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 1115 | |
49731baa | 1116 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 1117 | |
e09b457b TH |
1118 | /* FIXME: remove the following once add_disk() handles errors */ |
1119 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) | |
1120 | goto out_unlock; | |
4e91672c | 1121 | |
49731baa TH |
1122 | holder = bd_find_holder_disk(bdev, disk); |
1123 | if (holder) { | |
1124 | holder->refcnt++; | |
e09b457b | 1125 | goto out_unlock; |
49731baa | 1126 | } |
641dc636 | 1127 | |
49731baa TH |
1128 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
1129 | if (!holder) { | |
1130 | ret = -ENOMEM; | |
e09b457b TH |
1131 | goto out_unlock; |
1132 | } | |
641dc636 | 1133 | |
49731baa TH |
1134 | INIT_LIST_HEAD(&holder->list); |
1135 | holder->disk = disk; | |
1136 | holder->refcnt = 1; | |
1137 | ||
1138 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1139 | if (ret) | |
1140 | goto out_free; | |
1141 | ||
1142 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); | |
1143 | if (ret) | |
1144 | goto out_del; | |
e7407d16 TH |
1145 | /* |
1146 | * bdev could be deleted beneath us which would implicitly destroy | |
1147 | * the holder directory. Hold on to it. | |
1148 | */ | |
1149 | kobject_get(bdev->bd_part->holder_dir); | |
49731baa TH |
1150 | |
1151 | list_add(&holder->list, &bdev->bd_holder_disks); | |
1152 | goto out_unlock; | |
1153 | ||
1154 | out_del: | |
1155 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1156 | out_free: | |
1157 | kfree(holder); | |
e09b457b | 1158 | out_unlock: |
b4cf1b72 | 1159 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 1160 | return ret; |
641dc636 | 1161 | } |
e09b457b | 1162 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 1163 | |
49731baa TH |
1164 | /** |
1165 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
1166 | * @bdev: the calimed slave bdev | |
1167 | * @disk: the holding disk | |
1168 | * | |
1169 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
1170 | * | |
1171 | * CONTEXT: | |
1172 | * Might sleep. | |
1173 | */ | |
1174 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 1175 | { |
49731baa | 1176 | struct bd_holder_disk *holder; |
641dc636 | 1177 | |
49731baa | 1178 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 1179 | |
49731baa TH |
1180 | holder = bd_find_holder_disk(bdev, disk); |
1181 | ||
1182 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
1183 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1184 | del_symlink(bdev->bd_part->holder_dir, | |
1185 | &disk_to_dev(disk)->kobj); | |
e7407d16 | 1186 | kobject_put(bdev->bd_part->holder_dir); |
49731baa TH |
1187 | list_del_init(&holder->list); |
1188 | kfree(holder); | |
1189 | } | |
1190 | ||
1191 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 1192 | } |
49731baa | 1193 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 1194 | #endif |
1da177e4 | 1195 | |
56ade44b AP |
1196 | /** |
1197 | * flush_disk - invalidates all buffer-cache entries on a disk | |
1198 | * | |
1199 | * @bdev: struct block device to be flushed | |
e6eb5ce1 | 1200 | * @kill_dirty: flag to guide handling of dirty inodes |
56ade44b AP |
1201 | * |
1202 | * Invalidates all buffer-cache entries on a disk. It should be called | |
1203 | * when a disk has been changed -- either by a media change or online | |
1204 | * resize. | |
1205 | */ | |
93b270f7 | 1206 | static void flush_disk(struct block_device *bdev, bool kill_dirty) |
56ade44b | 1207 | { |
93b270f7 | 1208 | if (__invalidate_device(bdev, kill_dirty)) { |
56ade44b | 1209 | printk(KERN_WARNING "VFS: busy inodes on changed media or " |
424081f3 DM |
1210 | "resized disk %s\n", |
1211 | bdev->bd_disk ? bdev->bd_disk->disk_name : ""); | |
56ade44b AP |
1212 | } |
1213 | ||
1214 | if (!bdev->bd_disk) | |
1215 | return; | |
d27769ec | 1216 | if (disk_part_scan_enabled(bdev->bd_disk)) |
56ade44b AP |
1217 | bdev->bd_invalidated = 1; |
1218 | } | |
1219 | ||
c3279d14 | 1220 | /** |
57d1b536 | 1221 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d14 AP |
1222 | * @disk: struct gendisk to check |
1223 | * @bdev: struct bdev to adjust. | |
1224 | * | |
1225 | * This routine checks to see if the bdev size does not match the disk size | |
1226 | * and adjusts it if it differs. | |
1227 | */ | |
1228 | void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) | |
1229 | { | |
1230 | loff_t disk_size, bdev_size; | |
1231 | ||
1232 | disk_size = (loff_t)get_capacity(disk) << 9; | |
1233 | bdev_size = i_size_read(bdev->bd_inode); | |
1234 | if (disk_size != bdev_size) { | |
c3279d14 AP |
1235 | printk(KERN_INFO |
1236 | "%s: detected capacity change from %lld to %lld\n", | |
424081f3 | 1237 | disk->disk_name, bdev_size, disk_size); |
c3279d14 | 1238 | i_size_write(bdev->bd_inode, disk_size); |
93b270f7 | 1239 | flush_disk(bdev, false); |
c3279d14 AP |
1240 | } |
1241 | } | |
1242 | EXPORT_SYMBOL(check_disk_size_change); | |
1243 | ||
0c002c2f | 1244 | /** |
57d1b536 | 1245 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f AP |
1246 | * @disk: struct gendisk to be revalidated |
1247 | * | |
1248 | * This routine is a wrapper for lower-level driver's revalidate_disk | |
1249 | * call-backs. It is used to do common pre and post operations needed | |
1250 | * for all revalidate_disk operations. | |
1251 | */ | |
1252 | int revalidate_disk(struct gendisk *disk) | |
1253 | { | |
c3279d14 | 1254 | struct block_device *bdev; |
0c002c2f AP |
1255 | int ret = 0; |
1256 | ||
1257 | if (disk->fops->revalidate_disk) | |
1258 | ret = disk->fops->revalidate_disk(disk); | |
25520d55 | 1259 | blk_integrity_revalidate(disk); |
c3279d14 AP |
1260 | bdev = bdget_disk(disk, 0); |
1261 | if (!bdev) | |
1262 | return ret; | |
1263 | ||
1264 | mutex_lock(&bdev->bd_mutex); | |
1265 | check_disk_size_change(disk, bdev); | |
7630b661 | 1266 | bdev->bd_invalidated = 0; |
c3279d14 AP |
1267 | mutex_unlock(&bdev->bd_mutex); |
1268 | bdput(bdev); | |
0c002c2f AP |
1269 | return ret; |
1270 | } | |
1271 | EXPORT_SYMBOL(revalidate_disk); | |
1272 | ||
1da177e4 LT |
1273 | /* |
1274 | * This routine checks whether a removable media has been changed, | |
1275 | * and invalidates all buffer-cache-entries in that case. This | |
1276 | * is a relatively slow routine, so we have to try to minimize using | |
1277 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1278 | * is the best way of combining speed and utility, I think. | |
1279 | * People changing diskettes in the middle of an operation deserve | |
1280 | * to lose :-) | |
1281 | */ | |
1282 | int check_disk_change(struct block_device *bdev) | |
1283 | { | |
1284 | struct gendisk *disk = bdev->bd_disk; | |
83d5cde4 | 1285 | const struct block_device_operations *bdops = disk->fops; |
77ea887e | 1286 | unsigned int events; |
1da177e4 | 1287 | |
77ea887e TH |
1288 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
1289 | DISK_EVENT_EJECT_REQUEST); | |
1290 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) | |
1da177e4 LT |
1291 | return 0; |
1292 | ||
93b270f7 | 1293 | flush_disk(bdev, true); |
1da177e4 LT |
1294 | if (bdops->revalidate_disk) |
1295 | bdops->revalidate_disk(bdev->bd_disk); | |
1da177e4 LT |
1296 | return 1; |
1297 | } | |
1298 | ||
1299 | EXPORT_SYMBOL(check_disk_change); | |
1300 | ||
1301 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1302 | { | |
e1defc4f | 1303 | unsigned bsize = bdev_logical_block_size(bdev); |
1da177e4 | 1304 | |
5955102c | 1305 | inode_lock(bdev->bd_inode); |
d646a02a | 1306 | i_size_write(bdev->bd_inode, size); |
5955102c | 1307 | inode_unlock(bdev->bd_inode); |
09cbfeaf | 1308 | while (bsize < PAGE_SIZE) { |
1da177e4 LT |
1309 | if (size & bsize) |
1310 | break; | |
1311 | bsize <<= 1; | |
1312 | } | |
1313 | bdev->bd_block_size = bsize; | |
1314 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
1315 | } | |
1316 | EXPORT_SYMBOL(bd_set_size); | |
1317 | ||
4385bab1 | 1318 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1319 | |
6d740cd5 PZ |
1320 | /* |
1321 | * bd_mutex locking: | |
1322 | * | |
1323 | * mutex_lock(part->bd_mutex) | |
1324 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1325 | */ | |
1326 | ||
572c4892 | 1327 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
1da177e4 | 1328 | { |
1da177e4 | 1329 | struct gendisk *disk; |
523e1d39 | 1330 | struct module *owner; |
7db9cfd3 | 1331 | int ret; |
cf771cb5 | 1332 | int partno; |
fe6e9c1f AV |
1333 | int perm = 0; |
1334 | ||
572c4892 | 1335 | if (mode & FMODE_READ) |
fe6e9c1f | 1336 | perm |= MAY_READ; |
572c4892 | 1337 | if (mode & FMODE_WRITE) |
fe6e9c1f AV |
1338 | perm |= MAY_WRITE; |
1339 | /* | |
1340 | * hooks: /n/, see "layering violations". | |
1341 | */ | |
b7300b78 CW |
1342 | if (!for_part) { |
1343 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); | |
1344 | if (ret != 0) { | |
1345 | bdput(bdev); | |
1346 | return ret; | |
1347 | } | |
82666020 | 1348 | } |
7db9cfd3 | 1349 | |
d3374825 | 1350 | restart: |
0762b8bd | 1351 | |
89f97496 | 1352 | ret = -ENXIO; |
cf771cb5 | 1353 | disk = get_gendisk(bdev->bd_dev, &partno); |
0762b8bd | 1354 | if (!disk) |
6e9624b8 | 1355 | goto out; |
523e1d39 | 1356 | owner = disk->fops->owner; |
1da177e4 | 1357 | |
69e02c59 | 1358 | disk_block_events(disk); |
6796bf54 | 1359 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 LT |
1360 | if (!bdev->bd_openers) { |
1361 | bdev->bd_disk = disk; | |
87192a2a | 1362 | bdev->bd_queue = disk->queue; |
1da177e4 | 1363 | bdev->bd_contains = bdev; |
03cdadb0 | 1364 | |
cf771cb5 | 1365 | if (!partno) { |
89f97496 TH |
1366 | ret = -ENXIO; |
1367 | bdev->bd_part = disk_get_part(disk, partno); | |
1368 | if (!bdev->bd_part) | |
1369 | goto out_clear; | |
1370 | ||
1196f8b8 | 1371 | ret = 0; |
1da177e4 | 1372 | if (disk->fops->open) { |
572c4892 | 1373 | ret = disk->fops->open(bdev, mode); |
d3374825 N |
1374 | if (ret == -ERESTARTSYS) { |
1375 | /* Lost a race with 'disk' being | |
1376 | * deleted, try again. | |
1377 | * See md.c | |
1378 | */ | |
1379 | disk_put_part(bdev->bd_part); | |
1380 | bdev->bd_part = NULL; | |
d3374825 | 1381 | bdev->bd_disk = NULL; |
87192a2a | 1382 | bdev->bd_queue = NULL; |
d3374825 | 1383 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1384 | disk_unblock_events(disk); |
69e02c59 | 1385 | put_disk(disk); |
523e1d39 | 1386 | module_put(owner); |
d3374825 N |
1387 | goto restart; |
1388 | } | |
1da177e4 | 1389 | } |
7e69723f | 1390 | |
22375701 | 1391 | if (!ret) |
7e69723f | 1392 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
7e69723f | 1393 | |
1196f8b8 TH |
1394 | /* |
1395 | * If the device is invalidated, rescan partition | |
1396 | * if open succeeded or failed with -ENOMEDIUM. | |
1397 | * The latter is necessary to prevent ghost | |
1398 | * partitions on a removed medium. | |
1399 | */ | |
fe316bf2 JN |
1400 | if (bdev->bd_invalidated) { |
1401 | if (!ret) | |
1402 | rescan_partitions(disk, bdev); | |
1403 | else if (ret == -ENOMEDIUM) | |
1404 | invalidate_partitions(disk, bdev); | |
1405 | } | |
5a023cdb | 1406 | |
1196f8b8 TH |
1407 | if (ret) |
1408 | goto out_clear; | |
1da177e4 | 1409 | } else { |
1da177e4 LT |
1410 | struct block_device *whole; |
1411 | whole = bdget_disk(disk, 0); | |
1412 | ret = -ENOMEM; | |
1413 | if (!whole) | |
0762b8bd | 1414 | goto out_clear; |
37be4124 | 1415 | BUG_ON(for_part); |
572c4892 | 1416 | ret = __blkdev_get(whole, mode, 1); |
1da177e4 | 1417 | if (ret) |
0762b8bd | 1418 | goto out_clear; |
1da177e4 | 1419 | bdev->bd_contains = whole; |
89f97496 | 1420 | bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0 | 1421 | if (!(disk->flags & GENHD_FL_UP) || |
89f97496 | 1422 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4 | 1423 | ret = -ENXIO; |
0762b8bd | 1424 | goto out_clear; |
1da177e4 | 1425 | } |
89f97496 | 1426 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
1da177e4 LT |
1427 | } |
1428 | } else { | |
1da177e4 | 1429 | if (bdev->bd_contains == bdev) { |
1196f8b8 TH |
1430 | ret = 0; |
1431 | if (bdev->bd_disk->fops->open) | |
572c4892 | 1432 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1433 | /* the same as first opener case, read comment there */ |
fe316bf2 JN |
1434 | if (bdev->bd_invalidated) { |
1435 | if (!ret) | |
1436 | rescan_partitions(bdev->bd_disk, bdev); | |
1437 | else if (ret == -ENOMEDIUM) | |
1438 | invalidate_partitions(bdev->bd_disk, bdev); | |
1439 | } | |
1196f8b8 TH |
1440 | if (ret) |
1441 | goto out_unlock_bdev; | |
1da177e4 | 1442 | } |
69e02c59 | 1443 | /* only one opener holds refs to the module and disk */ |
69e02c59 | 1444 | put_disk(disk); |
523e1d39 | 1445 | module_put(owner); |
1da177e4 LT |
1446 | } |
1447 | bdev->bd_openers++; | |
37be4124 N |
1448 | if (for_part) |
1449 | bdev->bd_part_count++; | |
c039e313 | 1450 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1451 | disk_unblock_events(disk); |
1da177e4 LT |
1452 | return 0; |
1453 | ||
0762b8bd | 1454 | out_clear: |
89f97496 | 1455 | disk_put_part(bdev->bd_part); |
1da177e4 | 1456 | bdev->bd_disk = NULL; |
0762b8bd | 1457 | bdev->bd_part = NULL; |
87192a2a | 1458 | bdev->bd_queue = NULL; |
1da177e4 | 1459 | if (bdev != bdev->bd_contains) |
572c4892 | 1460 | __blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4 | 1461 | bdev->bd_contains = NULL; |
0762b8bd | 1462 | out_unlock_bdev: |
c039e313 | 1463 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1464 | disk_unblock_events(disk); |
0762b8bd | 1465 | put_disk(disk); |
523e1d39 | 1466 | module_put(owner); |
4345caba | 1467 | out: |
0762b8bd TH |
1468 | bdput(bdev); |
1469 | ||
1da177e4 LT |
1470 | return ret; |
1471 | } | |
1472 | ||
d4d77629 TH |
1473 | /** |
1474 | * blkdev_get - open a block device | |
1475 | * @bdev: block_device to open | |
1476 | * @mode: FMODE_* mask | |
1477 | * @holder: exclusive holder identifier | |
1478 | * | |
1479 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is | |
1480 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL | |
1481 | * @holder is invalid. Exclusive opens may nest for the same @holder. | |
1482 | * | |
1483 | * On success, the reference count of @bdev is unchanged. On failure, | |
1484 | * @bdev is put. | |
1485 | * | |
1486 | * CONTEXT: | |
1487 | * Might sleep. | |
1488 | * | |
1489 | * RETURNS: | |
1490 | * 0 on success, -errno on failure. | |
1491 | */ | |
e525fd89 | 1492 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4 | 1493 | { |
e525fd89 TH |
1494 | struct block_device *whole = NULL; |
1495 | int res; | |
1496 | ||
1497 | WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); | |
1498 | ||
1499 | if ((mode & FMODE_EXCL) && holder) { | |
1500 | whole = bd_start_claiming(bdev, holder); | |
1501 | if (IS_ERR(whole)) { | |
1502 | bdput(bdev); | |
1503 | return PTR_ERR(whole); | |
1504 | } | |
1505 | } | |
1506 | ||
1507 | res = __blkdev_get(bdev, mode, 0); | |
1508 | ||
1509 | if (whole) { | |
d4dc210f TH |
1510 | struct gendisk *disk = whole->bd_disk; |
1511 | ||
6a027eff | 1512 | /* finish claiming */ |
77ea887e | 1513 | mutex_lock(&bdev->bd_mutex); |
6a027eff TH |
1514 | spin_lock(&bdev_lock); |
1515 | ||
77ea887e | 1516 | if (!res) { |
6a027eff TH |
1517 | BUG_ON(!bd_may_claim(bdev, whole, holder)); |
1518 | /* | |
1519 | * Note that for a whole device bd_holders | |
1520 | * will be incremented twice, and bd_holder | |
1521 | * will be set to bd_may_claim before being | |
1522 | * set to holder | |
1523 | */ | |
1524 | whole->bd_holders++; | |
1525 | whole->bd_holder = bd_may_claim; | |
1526 | bdev->bd_holders++; | |
1527 | bdev->bd_holder = holder; | |
1528 | } | |
1529 | ||
1530 | /* tell others that we're done */ | |
1531 | BUG_ON(whole->bd_claiming != holder); | |
1532 | whole->bd_claiming = NULL; | |
1533 | wake_up_bit(&whole->bd_claiming, 0); | |
1534 | ||
1535 | spin_unlock(&bdev_lock); | |
77ea887e TH |
1536 | |
1537 | /* | |
d4dc210f TH |
1538 | * Block event polling for write claims if requested. Any |
1539 | * write holder makes the write_holder state stick until | |
1540 | * all are released. This is good enough and tracking | |
1541 | * individual writeable reference is too fragile given the | |
1542 | * way @mode is used in blkdev_get/put(). | |
77ea887e | 1543 | */ |
4c49ff3f TH |
1544 | if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && |
1545 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
77ea887e | 1546 | bdev->bd_write_holder = true; |
d4dc210f | 1547 | disk_block_events(disk); |
77ea887e TH |
1548 | } |
1549 | ||
1550 | mutex_unlock(&bdev->bd_mutex); | |
6a027eff | 1551 | bdput(whole); |
e525fd89 TH |
1552 | } |
1553 | ||
1554 | return res; | |
37be4124 | 1555 | } |
1da177e4 LT |
1556 | EXPORT_SYMBOL(blkdev_get); |
1557 | ||
d4d77629 TH |
1558 | /** |
1559 | * blkdev_get_by_path - open a block device by name | |
1560 | * @path: path to the block device to open | |
1561 | * @mode: FMODE_* mask | |
1562 | * @holder: exclusive holder identifier | |
1563 | * | |
1564 | * Open the blockdevice described by the device file at @path. @mode | |
1565 | * and @holder are identical to blkdev_get(). | |
1566 | * | |
1567 | * On success, the returned block_device has reference count of one. | |
1568 | * | |
1569 | * CONTEXT: | |
1570 | * Might sleep. | |
1571 | * | |
1572 | * RETURNS: | |
1573 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1574 | */ | |
1575 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1576 | void *holder) | |
1577 | { | |
1578 | struct block_device *bdev; | |
1579 | int err; | |
1580 | ||
1581 | bdev = lookup_bdev(path); | |
1582 | if (IS_ERR(bdev)) | |
1583 | return bdev; | |
1584 | ||
1585 | err = blkdev_get(bdev, mode, holder); | |
1586 | if (err) | |
1587 | return ERR_PTR(err); | |
1588 | ||
e51900f7 CE |
1589 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
1590 | blkdev_put(bdev, mode); | |
1591 | return ERR_PTR(-EACCES); | |
1592 | } | |
1593 | ||
d4d77629 TH |
1594 | return bdev; |
1595 | } | |
1596 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1597 | ||
1598 | /** | |
1599 | * blkdev_get_by_dev - open a block device by device number | |
1600 | * @dev: device number of block device to open | |
1601 | * @mode: FMODE_* mask | |
1602 | * @holder: exclusive holder identifier | |
1603 | * | |
1604 | * Open the blockdevice described by device number @dev. @mode and | |
1605 | * @holder are identical to blkdev_get(). | |
1606 | * | |
1607 | * Use it ONLY if you really do not have anything better - i.e. when | |
1608 | * you are behind a truly sucky interface and all you are given is a | |
1609 | * device number. _Never_ to be used for internal purposes. If you | |
1610 | * ever need it - reconsider your API. | |
1611 | * | |
1612 | * On success, the returned block_device has reference count of one. | |
1613 | * | |
1614 | * CONTEXT: | |
1615 | * Might sleep. | |
1616 | * | |
1617 | * RETURNS: | |
1618 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1619 | */ | |
1620 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) | |
1621 | { | |
1622 | struct block_device *bdev; | |
1623 | int err; | |
1624 | ||
1625 | bdev = bdget(dev); | |
1626 | if (!bdev) | |
1627 | return ERR_PTR(-ENOMEM); | |
1628 | ||
1629 | err = blkdev_get(bdev, mode, holder); | |
1630 | if (err) | |
1631 | return ERR_PTR(err); | |
1632 | ||
1633 | return bdev; | |
1634 | } | |
1635 | EXPORT_SYMBOL(blkdev_get_by_dev); | |
1636 | ||
1da177e4 LT |
1637 | static int blkdev_open(struct inode * inode, struct file * filp) |
1638 | { | |
1639 | struct block_device *bdev; | |
1da177e4 LT |
1640 | |
1641 | /* | |
1642 | * Preserve backwards compatibility and allow large file access | |
1643 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1644 | * binary needs it. We might want to drop this workaround | |
1645 | * during an unstable branch. | |
1646 | */ | |
1647 | filp->f_flags |= O_LARGEFILE; | |
1648 | ||
572c4892 AV |
1649 | if (filp->f_flags & O_NDELAY) |
1650 | filp->f_mode |= FMODE_NDELAY; | |
1651 | if (filp->f_flags & O_EXCL) | |
1652 | filp->f_mode |= FMODE_EXCL; | |
1653 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1654 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1655 | ||
1da177e4 | 1656 | bdev = bd_acquire(inode); |
6a2aae06 PE |
1657 | if (bdev == NULL) |
1658 | return -ENOMEM; | |
1da177e4 | 1659 | |
572c4892 AV |
1660 | filp->f_mapping = bdev->bd_inode->i_mapping; |
1661 | ||
e525fd89 | 1662 | return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4 LT |
1663 | } |
1664 | ||
4385bab1 | 1665 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1666 | { |
2e7b651d | 1667 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1668 | struct block_device *victim = NULL; |
2e7b651d | 1669 | |
6796bf54 | 1670 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1671 | if (for_part) |
1672 | bdev->bd_part_count--; | |
1673 | ||
2e7b651d | 1674 | if (!--bdev->bd_openers) { |
6a027eff | 1675 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1676 | sync_blockdev(bdev); |
1677 | kill_bdev(bdev); | |
43d1c0eb ID |
1678 | |
1679 | bdev_write_inode(bdev); | |
564f00f6 | 1680 | /* |
43d1c0eb ID |
1681 | * Detaching bdev inode from its wb in __destroy_inode() |
1682 | * is too late: the queue which embeds its bdi (along with | |
1683 | * root wb) can be gone as soon as we put_disk() below. | |
94007751 | 1684 | */ |
43d1c0eb | 1685 | inode_detach_wb(bdev->bd_inode); |
2e7b651d PZ |
1686 | } |
1687 | if (bdev->bd_contains == bdev) { | |
1688 | if (disk->fops->release) | |
db2a144b | 1689 | disk->fops->release(disk, mode); |
2e7b651d PZ |
1690 | } |
1691 | if (!bdev->bd_openers) { | |
1692 | struct module *owner = disk->fops->owner; | |
1693 | ||
0762b8bd TH |
1694 | disk_put_part(bdev->bd_part); |
1695 | bdev->bd_part = NULL; | |
2e7b651d | 1696 | bdev->bd_disk = NULL; |
37be4124 N |
1697 | if (bdev != bdev->bd_contains) |
1698 | victim = bdev->bd_contains; | |
2e7b651d | 1699 | bdev->bd_contains = NULL; |
523e1d39 TH |
1700 | |
1701 | put_disk(disk); | |
1702 | module_put(owner); | |
2e7b651d | 1703 | } |
2e7b651d PZ |
1704 | mutex_unlock(&bdev->bd_mutex); |
1705 | bdput(bdev); | |
37be4124 | 1706 | if (victim) |
9a1c3542 | 1707 | __blkdev_put(victim, mode, 1); |
2e7b651d PZ |
1708 | } |
1709 | ||
4385bab1 | 1710 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1711 | { |
85ef06d1 TH |
1712 | mutex_lock(&bdev->bd_mutex); |
1713 | ||
e525fd89 | 1714 | if (mode & FMODE_EXCL) { |
6a027eff TH |
1715 | bool bdev_free; |
1716 | ||
1717 | /* | |
1718 | * Release a claim on the device. The holder fields | |
1719 | * are protected with bdev_lock. bd_mutex is to | |
1720 | * synchronize disk_holder unlinking. | |
1721 | */ | |
6a027eff TH |
1722 | spin_lock(&bdev_lock); |
1723 | ||
1724 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
1725 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); | |
1726 | ||
1727 | /* bd_contains might point to self, check in a separate step */ | |
1728 | if ((bdev_free = !bdev->bd_holders)) | |
1729 | bdev->bd_holder = NULL; | |
1730 | if (!bdev->bd_contains->bd_holders) | |
1731 | bdev->bd_contains->bd_holder = NULL; | |
1732 | ||
1733 | spin_unlock(&bdev_lock); | |
1734 | ||
77ea887e TH |
1735 | /* |
1736 | * If this was the last claim, remove holder link and | |
1737 | * unblock evpoll if it was a write holder. | |
1738 | */ | |
85ef06d1 TH |
1739 | if (bdev_free && bdev->bd_write_holder) { |
1740 | disk_unblock_events(bdev->bd_disk); | |
1741 | bdev->bd_write_holder = false; | |
77ea887e | 1742 | } |
6936217c | 1743 | } |
77ea887e | 1744 | |
85ef06d1 TH |
1745 | /* |
1746 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1747 | * event. This is to ensure detection of media removal commanded | |
1748 | * from userland - e.g. eject(1). | |
1749 | */ | |
1750 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); | |
1751 | ||
1752 | mutex_unlock(&bdev->bd_mutex); | |
1753 | ||
4385bab1 | 1754 | __blkdev_put(bdev, mode, 0); |
37be4124 | 1755 | } |
2e7b651d PZ |
1756 | EXPORT_SYMBOL(blkdev_put); |
1757 | ||
1da177e4 LT |
1758 | static int blkdev_close(struct inode * inode, struct file * filp) |
1759 | { | |
4ebb16ca | 1760 | struct block_device *bdev = I_BDEV(bdev_file_inode(filp)); |
4385bab1 AV |
1761 | blkdev_put(bdev, filp->f_mode); |
1762 | return 0; | |
1da177e4 LT |
1763 | } |
1764 | ||
bb93e3a5 | 1765 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1766 | { |
4ebb16ca | 1767 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); |
56b26add | 1768 | fmode_t mode = file->f_mode; |
fd4ce1ac CH |
1769 | |
1770 | /* | |
1771 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1772 | * to updated it before every ioctl. | |
1773 | */ | |
56b26add | 1774 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1775 | mode |= FMODE_NDELAY; |
1776 | else | |
1777 | mode &= ~FMODE_NDELAY; | |
1778 | ||
56b26add | 1779 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1780 | } |
1781 | ||
eef99380 CH |
1782 | /* |
1783 | * Write data to the block device. Only intended for the block device itself | |
1784 | * and the raw driver which basically is a fake block device. | |
1785 | * | |
1786 | * Does not take i_mutex for the write and thus is not for general purpose | |
1787 | * use. | |
1788 | */ | |
1456c0a8 | 1789 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
eef99380 CH |
1790 | { |
1791 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1792 | struct inode *bd_inode = bdev_file_inode(file); |
7ec7b94a | 1793 | loff_t size = i_size_read(bd_inode); |
53362a05 | 1794 | struct blk_plug plug; |
eef99380 | 1795 | ssize_t ret; |
5f380c7f | 1796 | |
7ec7b94a AV |
1797 | if (bdev_read_only(I_BDEV(bd_inode))) |
1798 | return -EPERM; | |
5f380c7f | 1799 | |
7ec7b94a | 1800 | if (!iov_iter_count(from)) |
5f380c7f AV |
1801 | return 0; |
1802 | ||
7ec7b94a AV |
1803 | if (iocb->ki_pos >= size) |
1804 | return -ENOSPC; | |
1805 | ||
1806 | iov_iter_truncate(from, size - iocb->ki_pos); | |
eef99380 | 1807 | |
53362a05 | 1808 | blk_start_plug(&plug); |
1456c0a8 | 1809 | ret = __generic_file_write_iter(iocb, from); |
e2592217 CH |
1810 | if (ret > 0) |
1811 | ret = generic_write_sync(iocb, ret); | |
53362a05 | 1812 | blk_finish_plug(&plug); |
eef99380 CH |
1813 | return ret; |
1814 | } | |
1456c0a8 | 1815 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
eef99380 | 1816 | |
b2de525f | 1817 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
684c9aae LT |
1818 | { |
1819 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1820 | struct inode *bd_inode = bdev_file_inode(file); |
684c9aae | 1821 | loff_t size = i_size_read(bd_inode); |
a886038b | 1822 | loff_t pos = iocb->ki_pos; |
684c9aae LT |
1823 | |
1824 | if (pos >= size) | |
1825 | return 0; | |
1826 | ||
1827 | size -= pos; | |
a886038b AV |
1828 | iov_iter_truncate(to, size); |
1829 | return generic_file_read_iter(iocb, to); | |
684c9aae | 1830 | } |
b2de525f | 1831 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
684c9aae | 1832 | |
87d8fe1e TT |
1833 | /* |
1834 | * Try to release a page associated with block device when the system | |
1835 | * is under memory pressure. | |
1836 | */ | |
1837 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1838 | { | |
1839 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1840 | ||
1841 | if (super && super->s_op->bdev_try_to_free_page) | |
1842 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1843 | ||
1844 | return try_to_free_buffers(page); | |
1845 | } | |
1846 | ||
7f6d5b52 RZ |
1847 | static int blkdev_writepages(struct address_space *mapping, |
1848 | struct writeback_control *wbc) | |
1849 | { | |
1850 | if (dax_mapping(mapping)) { | |
1851 | struct block_device *bdev = I_BDEV(mapping->host); | |
1852 | ||
1853 | return dax_writeback_mapping_range(mapping, bdev, wbc); | |
1854 | } | |
1855 | return generic_writepages(mapping, wbc); | |
1856 | } | |
1857 | ||
4c54ac62 | 1858 | static const struct address_space_operations def_blk_aops = { |
1da177e4 | 1859 | .readpage = blkdev_readpage, |
447f05bb | 1860 | .readpages = blkdev_readpages, |
1da177e4 | 1861 | .writepage = blkdev_writepage, |
6272b5a5 NP |
1862 | .write_begin = blkdev_write_begin, |
1863 | .write_end = blkdev_write_end, | |
7f6d5b52 | 1864 | .writepages = blkdev_writepages, |
87d8fe1e | 1865 | .releasepage = blkdev_releasepage, |
1da177e4 | 1866 | .direct_IO = blkdev_direct_IO, |
b4597226 | 1867 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1868 | }; |
1869 | ||
25f4c414 DW |
1870 | #define BLKDEV_FALLOC_FL_SUPPORTED \ |
1871 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
1872 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
1873 | ||
1874 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
1875 | loff_t len) | |
1876 | { | |
1877 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
1878 | struct request_queue *q = bdev_get_queue(bdev); | |
1879 | struct address_space *mapping; | |
1880 | loff_t end = start + len - 1; | |
1881 | loff_t isize; | |
1882 | int error; | |
1883 | ||
1884 | /* Fail if we don't recognize the flags. */ | |
1885 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
1886 | return -EOPNOTSUPP; | |
1887 | ||
1888 | /* Don't go off the end of the device. */ | |
1889 | isize = i_size_read(bdev->bd_inode); | |
1890 | if (start >= isize) | |
1891 | return -EINVAL; | |
1892 | if (end >= isize) { | |
1893 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
1894 | len = isize - start; | |
1895 | end = start + len - 1; | |
1896 | } else | |
1897 | return -EINVAL; | |
1898 | } | |
1899 | ||
1900 | /* | |
1901 | * Don't allow IO that isn't aligned to logical block size. | |
1902 | */ | |
1903 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
1904 | return -EINVAL; | |
1905 | ||
1906 | /* Invalidate the page cache, including dirty pages. */ | |
1907 | mapping = bdev->bd_inode->i_mapping; | |
1908 | truncate_inode_pages_range(mapping, start, end); | |
1909 | ||
1910 | switch (mode) { | |
1911 | case FALLOC_FL_ZERO_RANGE: | |
1912 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
1913 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, | |
1914 | GFP_KERNEL, false); | |
1915 | break; | |
1916 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
1917 | /* Only punch if the device can do zeroing discard. */ | |
1918 | if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data) | |
1919 | return -EOPNOTSUPP; | |
1920 | error = blkdev_issue_discard(bdev, start >> 9, len >> 9, | |
1921 | GFP_KERNEL, 0); | |
1922 | break; | |
1923 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
1924 | if (!blk_queue_discard(q)) | |
1925 | return -EOPNOTSUPP; | |
1926 | error = blkdev_issue_discard(bdev, start >> 9, len >> 9, | |
1927 | GFP_KERNEL, 0); | |
1928 | break; | |
1929 | default: | |
1930 | return -EOPNOTSUPP; | |
1931 | } | |
1932 | if (error) | |
1933 | return error; | |
1934 | ||
1935 | /* | |
1936 | * Invalidate again; if someone wandered in and dirtied a page, | |
1937 | * the caller will be given -EBUSY. The third argument is | |
1938 | * inclusive, so the rounding here is safe. | |
1939 | */ | |
1940 | return invalidate_inode_pages2_range(mapping, | |
1941 | start >> PAGE_SHIFT, | |
1942 | end >> PAGE_SHIFT); | |
1943 | } | |
1944 | ||
4b6f5d20 | 1945 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1946 | .open = blkdev_open, |
1947 | .release = blkdev_close, | |
1948 | .llseek = block_llseek, | |
a886038b | 1949 | .read_iter = blkdev_read_iter, |
1456c0a8 | 1950 | .write_iter = blkdev_write_iter, |
acc93d30 | 1951 | .mmap = generic_file_mmap, |
b1dd3b28 | 1952 | .fsync = blkdev_fsync, |
bb93e3a5 | 1953 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1954 | #ifdef CONFIG_COMPAT |
1955 | .compat_ioctl = compat_blkdev_ioctl, | |
1956 | #endif | |
1e8b3332 | 1957 | .splice_read = generic_file_splice_read, |
8d020765 | 1958 | .splice_write = iter_file_splice_write, |
25f4c414 | 1959 | .fallocate = blkdev_fallocate, |
1da177e4 LT |
1960 | }; |
1961 | ||
1962 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) | |
1963 | { | |
1964 | int res; | |
1965 | mm_segment_t old_fs = get_fs(); | |
1966 | set_fs(KERNEL_DS); | |
56b26add | 1967 | res = blkdev_ioctl(bdev, 0, cmd, arg); |
1da177e4 LT |
1968 | set_fs(old_fs); |
1969 | return res; | |
1970 | } | |
1971 | ||
1972 | EXPORT_SYMBOL(ioctl_by_bdev); | |
1973 | ||
1974 | /** | |
1975 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 1976 | * @pathname: special file representing the block device |
1da177e4 | 1977 | * |
57d1b536 | 1978 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
1979 | * namespace if possible and return it. Return ERR_PTR(error) |
1980 | * otherwise. | |
1981 | */ | |
421748ec | 1982 | struct block_device *lookup_bdev(const char *pathname) |
1da177e4 LT |
1983 | { |
1984 | struct block_device *bdev; | |
1985 | struct inode *inode; | |
421748ec | 1986 | struct path path; |
1da177e4 LT |
1987 | int error; |
1988 | ||
421748ec | 1989 | if (!pathname || !*pathname) |
1da177e4 LT |
1990 | return ERR_PTR(-EINVAL); |
1991 | ||
421748ec | 1992 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
1993 | if (error) |
1994 | return ERR_PTR(error); | |
1995 | ||
bb668734 | 1996 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1997 | error = -ENOTBLK; |
1998 | if (!S_ISBLK(inode->i_mode)) | |
1999 | goto fail; | |
2000 | error = -EACCES; | |
a2982cc9 | 2001 | if (!may_open_dev(&path)) |
1da177e4 LT |
2002 | goto fail; |
2003 | error = -ENOMEM; | |
2004 | bdev = bd_acquire(inode); | |
2005 | if (!bdev) | |
2006 | goto fail; | |
2007 | out: | |
421748ec | 2008 | path_put(&path); |
1da177e4 LT |
2009 | return bdev; |
2010 | fail: | |
2011 | bdev = ERR_PTR(error); | |
2012 | goto out; | |
2013 | } | |
d5686b44 | 2014 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 2015 | |
93b270f7 | 2016 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
2017 | { |
2018 | struct super_block *sb = get_super(bdev); | |
2019 | int res = 0; | |
2020 | ||
2021 | if (sb) { | |
2022 | /* | |
2023 | * no need to lock the super, get_super holds the | |
2024 | * read mutex so the filesystem cannot go away | |
2025 | * under us (->put_super runs with the write lock | |
2026 | * hold). | |
2027 | */ | |
2028 | shrink_dcache_sb(sb); | |
93b270f7 | 2029 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
2030 | drop_super(sb); |
2031 | } | |
f98393a6 | 2032 | invalidate_bdev(bdev); |
b71e8a4c DH |
2033 | return res; |
2034 | } | |
2035 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
2036 | |
2037 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
2038 | { | |
2039 | struct inode *inode, *old_inode = NULL; | |
2040 | ||
74278da9 | 2041 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2042 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
2043 | struct address_space *mapping = inode->i_mapping; | |
2044 | ||
2045 | spin_lock(&inode->i_lock); | |
2046 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
2047 | mapping->nrpages == 0) { | |
2048 | spin_unlock(&inode->i_lock); | |
2049 | continue; | |
2050 | } | |
2051 | __iget(inode); | |
2052 | spin_unlock(&inode->i_lock); | |
74278da9 | 2053 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2054 | /* |
2055 | * We hold a reference to 'inode' so it couldn't have been | |
2056 | * removed from s_inodes list while we dropped the | |
74278da9 | 2057 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 2058 | * be holding the last reference and we cannot iput it under |
74278da9 | 2059 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
2060 | * later. |
2061 | */ | |
2062 | iput(old_inode); | |
2063 | old_inode = inode; | |
2064 | ||
2065 | func(I_BDEV(inode), arg); | |
2066 | ||
74278da9 | 2067 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 2068 | } |
74278da9 | 2069 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2070 | iput(old_inode); |
2071 | } |