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> | |
1da177e4 LT |
14 | #include <linux/smp_lock.h> |
15 | #include <linux/highmem.h> | |
16 | #include <linux/blkdev.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/blkpg.h> | |
19 | #include <linux/buffer_head.h> | |
811d736f | 20 | #include <linux/writeback.h> |
1da177e4 LT |
21 | #include <linux/mpage.h> |
22 | #include <linux/mount.h> | |
23 | #include <linux/uio.h> | |
24 | #include <linux/namei.h> | |
1368c4f2 | 25 | #include <linux/log2.h> |
1da177e4 | 26 | #include <asm/uaccess.h> |
07f3f05c | 27 | #include "internal.h" |
1da177e4 LT |
28 | |
29 | struct bdev_inode { | |
30 | struct block_device bdev; | |
31 | struct inode vfs_inode; | |
32 | }; | |
33 | ||
34 | static inline struct bdev_inode *BDEV_I(struct inode *inode) | |
35 | { | |
36 | return container_of(inode, struct bdev_inode, vfs_inode); | |
37 | } | |
38 | ||
39 | inline struct block_device *I_BDEV(struct inode *inode) | |
40 | { | |
41 | return &BDEV_I(inode)->bdev; | |
42 | } | |
43 | ||
44 | EXPORT_SYMBOL(I_BDEV); | |
45 | ||
46 | static sector_t max_block(struct block_device *bdev) | |
47 | { | |
48 | sector_t retval = ~((sector_t)0); | |
49 | loff_t sz = i_size_read(bdev->bd_inode); | |
50 | ||
51 | if (sz) { | |
52 | unsigned int size = block_size(bdev); | |
53 | unsigned int sizebits = blksize_bits(size); | |
54 | retval = (sz >> sizebits); | |
55 | } | |
56 | return retval; | |
57 | } | |
58 | ||
f9a14399 | 59 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
1da177e4 LT |
60 | static void kill_bdev(struct block_device *bdev) |
61 | { | |
f9a14399 PZ |
62 | if (bdev->bd_inode->i_mapping->nrpages == 0) |
63 | return; | |
64 | invalidate_bh_lrus(); | |
1da177e4 LT |
65 | truncate_inode_pages(bdev->bd_inode->i_mapping, 0); |
66 | } | |
67 | ||
68 | int set_blocksize(struct block_device *bdev, int size) | |
69 | { | |
70 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 71 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
72 | return -EINVAL; |
73 | ||
74 | /* Size cannot be smaller than the size supported by the device */ | |
75 | if (size < bdev_hardsect_size(bdev)) | |
76 | return -EINVAL; | |
77 | ||
78 | /* Don't change the size if it is same as current */ | |
79 | if (bdev->bd_block_size != size) { | |
80 | sync_blockdev(bdev); | |
81 | bdev->bd_block_size = size; | |
82 | bdev->bd_inode->i_blkbits = blksize_bits(size); | |
83 | kill_bdev(bdev); | |
84 | } | |
85 | return 0; | |
86 | } | |
87 | ||
88 | EXPORT_SYMBOL(set_blocksize); | |
89 | ||
90 | int sb_set_blocksize(struct super_block *sb, int size) | |
91 | { | |
1da177e4 LT |
92 | if (set_blocksize(sb->s_bdev, size)) |
93 | return 0; | |
94 | /* If we get here, we know size is power of two | |
95 | * and it's value is between 512 and PAGE_SIZE */ | |
96 | sb->s_blocksize = size; | |
38885bd4 | 97 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
98 | return sb->s_blocksize; |
99 | } | |
100 | ||
101 | EXPORT_SYMBOL(sb_set_blocksize); | |
102 | ||
103 | int sb_min_blocksize(struct super_block *sb, int size) | |
104 | { | |
105 | int minsize = bdev_hardsect_size(sb->s_bdev); | |
106 | if (size < minsize) | |
107 | size = minsize; | |
108 | return sb_set_blocksize(sb, size); | |
109 | } | |
110 | ||
111 | EXPORT_SYMBOL(sb_min_blocksize); | |
112 | ||
113 | static int | |
114 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
115 | struct buffer_head *bh, int create) | |
116 | { | |
117 | if (iblock >= max_block(I_BDEV(inode))) { | |
118 | if (create) | |
119 | return -EIO; | |
120 | ||
121 | /* | |
122 | * for reads, we're just trying to fill a partial page. | |
123 | * return a hole, they will have to call get_block again | |
124 | * before they can fill it, and they will get -EIO at that | |
125 | * time | |
126 | */ | |
127 | return 0; | |
128 | } | |
129 | bh->b_bdev = I_BDEV(inode); | |
130 | bh->b_blocknr = iblock; | |
131 | set_buffer_mapped(bh); | |
132 | return 0; | |
133 | } | |
134 | ||
b2e895db AM |
135 | static int |
136 | blkdev_get_blocks(struct inode *inode, sector_t iblock, | |
137 | struct buffer_head *bh, int create) | |
138 | { | |
139 | sector_t end_block = max_block(I_BDEV(inode)); | |
140 | unsigned long max_blocks = bh->b_size >> inode->i_blkbits; | |
141 | ||
142 | if ((iblock + max_blocks) > end_block) { | |
143 | max_blocks = end_block - iblock; | |
144 | if ((long)max_blocks <= 0) { | |
145 | if (create) | |
146 | return -EIO; /* write fully beyond EOF */ | |
147 | /* | |
148 | * It is a read which is fully beyond EOF. We return | |
149 | * a !buffer_mapped buffer | |
150 | */ | |
151 | max_blocks = 0; | |
152 | } | |
153 | } | |
154 | ||
155 | bh->b_bdev = I_BDEV(inode); | |
156 | bh->b_blocknr = iblock; | |
157 | bh->b_size = max_blocks << inode->i_blkbits; | |
158 | if (max_blocks) | |
159 | set_buffer_mapped(bh); | |
160 | return 0; | |
161 | } | |
162 | ||
163 | static ssize_t | |
164 | blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, | |
165 | loff_t offset, unsigned long nr_segs) | |
166 | { | |
167 | struct file *file = iocb->ki_filp; | |
168 | struct inode *inode = file->f_mapping->host; | |
169 | ||
170 | return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode), | |
171 | iov, offset, nr_segs, blkdev_get_blocks, NULL); | |
172 | } | |
173 | ||
174 | #if 0 | |
6712ecf8 | 175 | static void blk_end_aio(struct bio *bio, int error) |
1da177e4 | 176 | { |
e61c9018 CK |
177 | struct kiocb *iocb = bio->bi_private; |
178 | atomic_t *bio_count = &iocb->ki_bio_count; | |
179 | ||
180 | if (bio_data_dir(bio) == READ) | |
181 | bio_check_pages_dirty(bio); | |
182 | else { | |
183 | bio_release_pages(bio); | |
184 | bio_put(bio); | |
185 | } | |
186 | ||
187 | /* iocb->ki_nbytes stores error code from LLDD */ | |
188 | if (error) | |
189 | iocb->ki_nbytes = -EIO; | |
190 | ||
191 | if (atomic_dec_and_test(bio_count)) { | |
790816dd | 192 | if ((long)iocb->ki_nbytes < 0) |
e61c9018 CK |
193 | aio_complete(iocb, iocb->ki_nbytes, 0); |
194 | else | |
195 | aio_complete(iocb, iocb->ki_left, 0); | |
1da177e4 LT |
196 | } |
197 | ||
1da177e4 LT |
198 | return 0; |
199 | } | |
200 | ||
e61c9018 CK |
201 | #define VEC_SIZE 16 |
202 | struct pvec { | |
203 | unsigned short nr; | |
204 | unsigned short idx; | |
205 | struct page *page[VEC_SIZE]; | |
206 | }; | |
207 | ||
208 | #define PAGES_SPANNED(addr, len) \ | |
209 | (DIV_ROUND_UP((addr) + (len), PAGE_SIZE) - (addr) / PAGE_SIZE); | |
210 | ||
211 | /* | |
212 | * get page pointer for user addr, we internally cache struct page array for | |
213 | * (addr, count) range in pvec to avoid frequent call to get_user_pages. If | |
214 | * internal page list is exhausted, a batch count of up to VEC_SIZE is used | |
215 | * to get next set of page struct. | |
216 | */ | |
217 | static struct page *blk_get_page(unsigned long addr, size_t count, int rw, | |
218 | struct pvec *pvec) | |
219 | { | |
220 | int ret, nr_pages; | |
221 | if (pvec->idx == pvec->nr) { | |
222 | nr_pages = PAGES_SPANNED(addr, count); | |
223 | nr_pages = min(nr_pages, VEC_SIZE); | |
224 | down_read(¤t->mm->mmap_sem); | |
225 | ret = get_user_pages(current, current->mm, addr, nr_pages, | |
226 | rw == READ, 0, pvec->page, NULL); | |
227 | up_read(¤t->mm->mmap_sem); | |
228 | if (ret < 0) | |
229 | return ERR_PTR(ret); | |
230 | pvec->nr = ret; | |
231 | pvec->idx = 0; | |
232 | } | |
233 | return pvec->page[pvec->idx++]; | |
234 | } | |
235 | ||
cda9205d CK |
236 | /* return a page back to pvec array */ |
237 | static void blk_unget_page(struct page *page, struct pvec *pvec) | |
238 | { | |
239 | pvec->page[--pvec->idx] = page; | |
240 | } | |
241 | ||
1da177e4 LT |
242 | static ssize_t |
243 | blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, | |
e61c9018 | 244 | loff_t pos, unsigned long nr_segs) |
1da177e4 | 245 | { |
e61c9018 CK |
246 | struct inode *inode = iocb->ki_filp->f_mapping->host; |
247 | unsigned blkbits = blksize_bits(bdev_hardsect_size(I_BDEV(inode))); | |
248 | unsigned blocksize_mask = (1 << blkbits) - 1; | |
249 | unsigned long seg = 0; /* iov segment iterator */ | |
250 | unsigned long nvec; /* number of bio vec needed */ | |
251 | unsigned long cur_off; /* offset into current page */ | |
252 | unsigned long cur_len; /* I/O len of current page, up to PAGE_SIZE */ | |
253 | ||
254 | unsigned long addr; /* user iovec address */ | |
255 | size_t count; /* user iovec len */ | |
256 | size_t nbytes = iocb->ki_nbytes = iocb->ki_left; /* total xfer size */ | |
257 | loff_t size; /* size of block device */ | |
258 | struct bio *bio; | |
259 | atomic_t *bio_count = &iocb->ki_bio_count; | |
260 | struct page *page; | |
261 | struct pvec pvec; | |
262 | ||
263 | pvec.nr = 0; | |
264 | pvec.idx = 0; | |
265 | ||
266 | if (pos & blocksize_mask) | |
267 | return -EINVAL; | |
268 | ||
269 | size = i_size_read(inode); | |
270 | if (pos + nbytes > size) { | |
271 | nbytes = size - pos; | |
272 | iocb->ki_left = nbytes; | |
273 | } | |
274 | ||
275 | /* | |
276 | * check first non-zero iov alignment, the remaining | |
277 | * iov alignment is checked inside bio loop below. | |
278 | */ | |
279 | do { | |
280 | addr = (unsigned long) iov[seg].iov_base; | |
281 | count = min(iov[seg].iov_len, nbytes); | |
282 | if (addr & blocksize_mask || count & blocksize_mask) | |
283 | return -EINVAL; | |
284 | } while (!count && ++seg < nr_segs); | |
285 | atomic_set(bio_count, 1); | |
286 | ||
287 | while (nbytes) { | |
288 | /* roughly estimate number of bio vec needed */ | |
289 | nvec = (nbytes + PAGE_SIZE - 1) / PAGE_SIZE; | |
290 | nvec = max(nvec, nr_segs - seg); | |
291 | nvec = min(nvec, (unsigned long) BIO_MAX_PAGES); | |
292 | ||
293 | /* bio_alloc should not fail with GFP_KERNEL flag */ | |
294 | bio = bio_alloc(GFP_KERNEL, nvec); | |
295 | bio->bi_bdev = I_BDEV(inode); | |
296 | bio->bi_end_io = blk_end_aio; | |
297 | bio->bi_private = iocb; | |
298 | bio->bi_sector = pos >> blkbits; | |
299 | same_bio: | |
300 | cur_off = addr & ~PAGE_MASK; | |
301 | cur_len = PAGE_SIZE - cur_off; | |
302 | if (count < cur_len) | |
303 | cur_len = count; | |
304 | ||
305 | page = blk_get_page(addr, count, rw, &pvec); | |
306 | if (unlikely(IS_ERR(page))) | |
307 | goto backout; | |
308 | ||
309 | if (bio_add_page(bio, page, cur_len, cur_off)) { | |
310 | pos += cur_len; | |
311 | addr += cur_len; | |
312 | count -= cur_len; | |
313 | nbytes -= cur_len; | |
314 | ||
315 | if (count) | |
316 | goto same_bio; | |
317 | while (++seg < nr_segs) { | |
318 | addr = (unsigned long) iov[seg].iov_base; | |
319 | count = iov[seg].iov_len; | |
320 | if (!count) | |
321 | continue; | |
322 | if (unlikely(addr & blocksize_mask || | |
323 | count & blocksize_mask)) { | |
324 | page = ERR_PTR(-EINVAL); | |
325 | goto backout; | |
326 | } | |
327 | count = min(count, nbytes); | |
328 | goto same_bio; | |
329 | } | |
cda9205d CK |
330 | } else { |
331 | blk_unget_page(page, &pvec); | |
e61c9018 CK |
332 | } |
333 | ||
334 | /* bio is ready, submit it */ | |
335 | if (rw == READ) | |
336 | bio_set_pages_dirty(bio); | |
337 | atomic_inc(bio_count); | |
338 | submit_bio(rw, bio); | |
339 | } | |
340 | ||
341 | completion: | |
342 | iocb->ki_left -= nbytes; | |
343 | nbytes = iocb->ki_left; | |
344 | iocb->ki_pos += nbytes; | |
345 | ||
346 | blk_run_address_space(inode->i_mapping); | |
347 | if (atomic_dec_and_test(bio_count)) | |
348 | aio_complete(iocb, nbytes, 0); | |
349 | ||
350 | return -EIOCBQUEUED; | |
351 | ||
352 | backout: | |
353 | /* | |
354 | * back out nbytes count constructed so far for this bio, | |
355 | * we will throw away current bio. | |
356 | */ | |
357 | nbytes += bio->bi_size; | |
358 | bio_release_pages(bio); | |
359 | bio_put(bio); | |
1da177e4 | 360 | |
e61c9018 CK |
361 | /* |
362 | * if no bio was submmitted, return the error code. | |
363 | * otherwise, proceed with pending I/O completion. | |
364 | */ | |
365 | if (atomic_read(bio_count) == 1) | |
366 | return PTR_ERR(page); | |
367 | goto completion; | |
1da177e4 | 368 | } |
b2e895db | 369 | #endif |
1da177e4 LT |
370 | |
371 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) | |
372 | { | |
373 | return block_write_full_page(page, blkdev_get_block, wbc); | |
374 | } | |
375 | ||
376 | static int blkdev_readpage(struct file * file, struct page * page) | |
377 | { | |
378 | return block_read_full_page(page, blkdev_get_block); | |
379 | } | |
380 | ||
6272b5a5 NP |
381 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
382 | loff_t pos, unsigned len, unsigned flags, | |
383 | struct page **pagep, void **fsdata) | |
1da177e4 | 384 | { |
6272b5a5 NP |
385 | *pagep = NULL; |
386 | return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, | |
387 | blkdev_get_block); | |
1da177e4 LT |
388 | } |
389 | ||
6272b5a5 NP |
390 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
391 | loff_t pos, unsigned len, unsigned copied, | |
392 | struct page *page, void *fsdata) | |
1da177e4 | 393 | { |
6272b5a5 NP |
394 | int ret; |
395 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
396 | ||
397 | unlock_page(page); | |
398 | page_cache_release(page); | |
399 | ||
400 | return ret; | |
1da177e4 LT |
401 | } |
402 | ||
403 | /* | |
404 | * private llseek: | |
0f7fc9e4 | 405 | * for a block special file file->f_path.dentry->d_inode->i_size is zero |
1da177e4 LT |
406 | * so we compute the size by hand (just as in block_read/write above) |
407 | */ | |
408 | static loff_t block_llseek(struct file *file, loff_t offset, int origin) | |
409 | { | |
410 | struct inode *bd_inode = file->f_mapping->host; | |
411 | loff_t size; | |
412 | loff_t retval; | |
413 | ||
1b1dcc1b | 414 | mutex_lock(&bd_inode->i_mutex); |
1da177e4 LT |
415 | size = i_size_read(bd_inode); |
416 | ||
417 | switch (origin) { | |
418 | case 2: | |
419 | offset += size; | |
420 | break; | |
421 | case 1: | |
422 | offset += file->f_pos; | |
423 | } | |
424 | retval = -EINVAL; | |
425 | if (offset >= 0 && offset <= size) { | |
426 | if (offset != file->f_pos) { | |
427 | file->f_pos = offset; | |
428 | } | |
429 | retval = offset; | |
430 | } | |
1b1dcc1b | 431 | mutex_unlock(&bd_inode->i_mutex); |
1da177e4 LT |
432 | return retval; |
433 | } | |
434 | ||
435 | /* | |
436 | * Filp is never NULL; the only case when ->fsync() is called with | |
437 | * NULL first argument is nfsd_sync_dir() and that's not a directory. | |
438 | */ | |
439 | ||
440 | static int block_fsync(struct file *filp, struct dentry *dentry, int datasync) | |
441 | { | |
442 | return sync_blockdev(I_BDEV(filp->f_mapping->host)); | |
443 | } | |
444 | ||
445 | /* | |
446 | * pseudo-fs | |
447 | */ | |
448 | ||
449 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 450 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
451 | |
452 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
453 | { | |
e94b1766 | 454 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
455 | if (!ei) |
456 | return NULL; | |
457 | return &ei->vfs_inode; | |
458 | } | |
459 | ||
460 | static void bdev_destroy_inode(struct inode *inode) | |
461 | { | |
462 | struct bdev_inode *bdi = BDEV_I(inode); | |
463 | ||
464 | bdi->bdev.bd_inode_backing_dev_info = NULL; | |
465 | kmem_cache_free(bdev_cachep, bdi); | |
466 | } | |
467 | ||
4ba9b9d0 | 468 | static void init_once(struct kmem_cache * cachep, void *foo) |
1da177e4 LT |
469 | { |
470 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
471 | struct block_device *bdev = &ei->bdev; | |
472 | ||
a35afb83 CL |
473 | memset(bdev, 0, sizeof(*bdev)); |
474 | mutex_init(&bdev->bd_mutex); | |
475 | sema_init(&bdev->bd_mount_sem, 1); | |
476 | INIT_LIST_HEAD(&bdev->bd_inodes); | |
477 | INIT_LIST_HEAD(&bdev->bd_list); | |
641dc636 | 478 | #ifdef CONFIG_SYSFS |
a35afb83 | 479 | INIT_LIST_HEAD(&bdev->bd_holder_list); |
641dc636 | 480 | #endif |
a35afb83 | 481 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
482 | } |
483 | ||
484 | static inline void __bd_forget(struct inode *inode) | |
485 | { | |
486 | list_del_init(&inode->i_devices); | |
487 | inode->i_bdev = NULL; | |
488 | inode->i_mapping = &inode->i_data; | |
489 | } | |
490 | ||
491 | static void bdev_clear_inode(struct inode *inode) | |
492 | { | |
493 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
494 | struct list_head *p; | |
495 | spin_lock(&bdev_lock); | |
496 | while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { | |
497 | __bd_forget(list_entry(p, struct inode, i_devices)); | |
498 | } | |
499 | list_del_init(&bdev->bd_list); | |
500 | spin_unlock(&bdev_lock); | |
501 | } | |
502 | ||
ee9b6d61 | 503 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
504 | .statfs = simple_statfs, |
505 | .alloc_inode = bdev_alloc_inode, | |
506 | .destroy_inode = bdev_destroy_inode, | |
507 | .drop_inode = generic_delete_inode, | |
508 | .clear_inode = bdev_clear_inode, | |
509 | }; | |
510 | ||
454e2398 DH |
511 | static int bd_get_sb(struct file_system_type *fs_type, |
512 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 513 | { |
454e2398 | 514 | return get_sb_pseudo(fs_type, "bdev:", &bdev_sops, 0x62646576, mnt); |
1da177e4 LT |
515 | } |
516 | ||
517 | static struct file_system_type bd_type = { | |
518 | .name = "bdev", | |
519 | .get_sb = bd_get_sb, | |
520 | .kill_sb = kill_anon_super, | |
521 | }; | |
522 | ||
fa3536cc | 523 | static struct vfsmount *bd_mnt __read_mostly; |
1da177e4 LT |
524 | struct super_block *blockdev_superblock; |
525 | ||
526 | void __init bdev_cache_init(void) | |
527 | { | |
528 | int err; | |
529 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), | |
fffb60f9 PJ |
530 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
531 | SLAB_MEM_SPREAD|SLAB_PANIC), | |
20c2df83 | 532 | init_once); |
1da177e4 LT |
533 | err = register_filesystem(&bd_type); |
534 | if (err) | |
535 | panic("Cannot register bdev pseudo-fs"); | |
536 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
537 | if (IS_ERR(bd_mnt)) |
538 | panic("Cannot create bdev pseudo-fs"); | |
539 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ | |
540 | } | |
541 | ||
542 | /* | |
543 | * Most likely _very_ bad one - but then it's hardly critical for small | |
544 | * /dev and can be fixed when somebody will need really large one. | |
545 | * Keep in mind that it will be fed through icache hash function too. | |
546 | */ | |
547 | static inline unsigned long hash(dev_t dev) | |
548 | { | |
549 | return MAJOR(dev)+MINOR(dev); | |
550 | } | |
551 | ||
552 | static int bdev_test(struct inode *inode, void *data) | |
553 | { | |
554 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
555 | } | |
556 | ||
557 | static int bdev_set(struct inode *inode, void *data) | |
558 | { | |
559 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
560 | return 0; | |
561 | } | |
562 | ||
563 | static LIST_HEAD(all_bdevs); | |
564 | ||
565 | struct block_device *bdget(dev_t dev) | |
566 | { | |
567 | struct block_device *bdev; | |
568 | struct inode *inode; | |
569 | ||
570 | inode = iget5_locked(bd_mnt->mnt_sb, hash(dev), | |
571 | bdev_test, bdev_set, &dev); | |
572 | ||
573 | if (!inode) | |
574 | return NULL; | |
575 | ||
576 | bdev = &BDEV_I(inode)->bdev; | |
577 | ||
578 | if (inode->i_state & I_NEW) { | |
579 | bdev->bd_contains = NULL; | |
580 | bdev->bd_inode = inode; | |
581 | bdev->bd_block_size = (1 << inode->i_blkbits); | |
582 | bdev->bd_part_count = 0; | |
583 | bdev->bd_invalidated = 0; | |
584 | inode->i_mode = S_IFBLK; | |
585 | inode->i_rdev = dev; | |
586 | inode->i_bdev = bdev; | |
587 | inode->i_data.a_ops = &def_blk_aops; | |
588 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
589 | inode->i_data.backing_dev_info = &default_backing_dev_info; | |
590 | spin_lock(&bdev_lock); | |
591 | list_add(&bdev->bd_list, &all_bdevs); | |
592 | spin_unlock(&bdev_lock); | |
593 | unlock_new_inode(inode); | |
594 | } | |
595 | return bdev; | |
596 | } | |
597 | ||
598 | EXPORT_SYMBOL(bdget); | |
599 | ||
600 | long nr_blockdev_pages(void) | |
601 | { | |
203a2935 | 602 | struct block_device *bdev; |
1da177e4 LT |
603 | long ret = 0; |
604 | spin_lock(&bdev_lock); | |
203a2935 | 605 | list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4 LT |
606 | ret += bdev->bd_inode->i_mapping->nrpages; |
607 | } | |
608 | spin_unlock(&bdev_lock); | |
609 | return ret; | |
610 | } | |
611 | ||
612 | void bdput(struct block_device *bdev) | |
613 | { | |
614 | iput(bdev->bd_inode); | |
615 | } | |
616 | ||
617 | EXPORT_SYMBOL(bdput); | |
618 | ||
619 | static struct block_device *bd_acquire(struct inode *inode) | |
620 | { | |
621 | struct block_device *bdev; | |
09d967c6 | 622 | |
1da177e4 LT |
623 | spin_lock(&bdev_lock); |
624 | bdev = inode->i_bdev; | |
09d967c6 OH |
625 | if (bdev) { |
626 | atomic_inc(&bdev->bd_inode->i_count); | |
1da177e4 LT |
627 | spin_unlock(&bdev_lock); |
628 | return bdev; | |
629 | } | |
630 | spin_unlock(&bdev_lock); | |
09d967c6 | 631 | |
1da177e4 LT |
632 | bdev = bdget(inode->i_rdev); |
633 | if (bdev) { | |
634 | spin_lock(&bdev_lock); | |
09d967c6 OH |
635 | if (!inode->i_bdev) { |
636 | /* | |
637 | * We take an additional bd_inode->i_count for inode, | |
638 | * and it's released in clear_inode() of inode. | |
639 | * So, we can access it via ->i_mapping always | |
640 | * without igrab(). | |
641 | */ | |
642 | atomic_inc(&bdev->bd_inode->i_count); | |
643 | inode->i_bdev = bdev; | |
644 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
645 | list_add(&inode->i_devices, &bdev->bd_inodes); | |
646 | } | |
1da177e4 LT |
647 | spin_unlock(&bdev_lock); |
648 | } | |
649 | return bdev; | |
650 | } | |
651 | ||
652 | /* Call when you free inode */ | |
653 | ||
654 | void bd_forget(struct inode *inode) | |
655 | { | |
09d967c6 OH |
656 | struct block_device *bdev = NULL; |
657 | ||
1da177e4 | 658 | spin_lock(&bdev_lock); |
09d967c6 OH |
659 | if (inode->i_bdev) { |
660 | if (inode->i_sb != blockdev_superblock) | |
661 | bdev = inode->i_bdev; | |
1da177e4 | 662 | __bd_forget(inode); |
09d967c6 | 663 | } |
1da177e4 | 664 | spin_unlock(&bdev_lock); |
09d967c6 OH |
665 | |
666 | if (bdev) | |
667 | iput(bdev->bd_inode); | |
1da177e4 LT |
668 | } |
669 | ||
670 | int bd_claim(struct block_device *bdev, void *holder) | |
671 | { | |
672 | int res; | |
673 | spin_lock(&bdev_lock); | |
674 | ||
675 | /* first decide result */ | |
676 | if (bdev->bd_holder == holder) | |
677 | res = 0; /* already a holder */ | |
678 | else if (bdev->bd_holder != NULL) | |
679 | res = -EBUSY; /* held by someone else */ | |
680 | else if (bdev->bd_contains == bdev) | |
681 | res = 0; /* is a whole device which isn't held */ | |
682 | ||
683 | else if (bdev->bd_contains->bd_holder == bd_claim) | |
684 | res = 0; /* is a partition of a device that is being partitioned */ | |
685 | else if (bdev->bd_contains->bd_holder != NULL) | |
686 | res = -EBUSY; /* is a partition of a held device */ | |
687 | else | |
688 | res = 0; /* is a partition of an un-held device */ | |
689 | ||
690 | /* now impose change */ | |
691 | if (res==0) { | |
692 | /* note that for a whole device bd_holders | |
693 | * will be incremented twice, and bd_holder will | |
694 | * be set to bd_claim before being set to holder | |
695 | */ | |
696 | bdev->bd_contains->bd_holders ++; | |
697 | bdev->bd_contains->bd_holder = bd_claim; | |
698 | bdev->bd_holders++; | |
699 | bdev->bd_holder = holder; | |
700 | } | |
701 | spin_unlock(&bdev_lock); | |
702 | return res; | |
703 | } | |
704 | ||
705 | EXPORT_SYMBOL(bd_claim); | |
706 | ||
707 | void bd_release(struct block_device *bdev) | |
708 | { | |
709 | spin_lock(&bdev_lock); | |
710 | if (!--bdev->bd_contains->bd_holders) | |
711 | bdev->bd_contains->bd_holder = NULL; | |
712 | if (!--bdev->bd_holders) | |
713 | bdev->bd_holder = NULL; | |
714 | spin_unlock(&bdev_lock); | |
715 | } | |
716 | ||
717 | EXPORT_SYMBOL(bd_release); | |
718 | ||
641dc636 JN |
719 | #ifdef CONFIG_SYSFS |
720 | /* | |
721 | * Functions for bd_claim_by_kobject / bd_release_from_kobject | |
722 | * | |
723 | * If a kobject is passed to bd_claim_by_kobject() | |
724 | * and the kobject has a parent directory, | |
725 | * following symlinks are created: | |
726 | * o from the kobject to the claimed bdev | |
727 | * o from "holders" directory of the bdev to the parent of the kobject | |
728 | * bd_release_from_kobject() removes these symlinks. | |
729 | * | |
730 | * Example: | |
731 | * If /dev/dm-0 maps to /dev/sda, kobject corresponding to | |
732 | * /sys/block/dm-0/slaves is passed to bd_claim_by_kobject(), then: | |
733 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda | |
734 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
735 | */ | |
736 | ||
737 | static struct kobject *bdev_get_kobj(struct block_device *bdev) | |
738 | { | |
739 | if (bdev->bd_contains != bdev) | |
edfaa7c3 | 740 | return kobject_get(&bdev->bd_part->dev.kobj); |
641dc636 | 741 | else |
edfaa7c3 | 742 | return kobject_get(&bdev->bd_disk->dev.kobj); |
641dc636 JN |
743 | } |
744 | ||
745 | static struct kobject *bdev_get_holder(struct block_device *bdev) | |
746 | { | |
747 | if (bdev->bd_contains != bdev) | |
748 | return kobject_get(bdev->bd_part->holder_dir); | |
749 | else | |
750 | return kobject_get(bdev->bd_disk->holder_dir); | |
751 | } | |
752 | ||
4d7dd8fd | 753 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 JN |
754 | { |
755 | if (!from || !to) | |
4d7dd8fd AM |
756 | return 0; |
757 | return sysfs_create_link(from, to, kobject_name(to)); | |
641dc636 JN |
758 | } |
759 | ||
760 | static void del_symlink(struct kobject *from, struct kobject *to) | |
761 | { | |
762 | if (!from || !to) | |
763 | return; | |
764 | sysfs_remove_link(from, kobject_name(to)); | |
765 | } | |
766 | ||
767 | /* | |
768 | * 'struct bd_holder' contains pointers to kobjects symlinked by | |
769 | * bd_claim_by_kobject. | |
770 | * It's connected to bd_holder_list which is protected by bdev->bd_sem. | |
771 | */ | |
772 | struct bd_holder { | |
773 | struct list_head list; /* chain of holders of the bdev */ | |
774 | int count; /* references from the holder */ | |
775 | struct kobject *sdir; /* holder object, e.g. "/block/dm-0/slaves" */ | |
776 | struct kobject *hdev; /* e.g. "/block/dm-0" */ | |
777 | struct kobject *hdir; /* e.g. "/block/sda/holders" */ | |
778 | struct kobject *sdev; /* e.g. "/block/sda" */ | |
779 | }; | |
780 | ||
781 | /* | |
782 | * Get references of related kobjects at once. | |
783 | * Returns 1 on success. 0 on failure. | |
784 | * | |
785 | * Should call bd_holder_release_dirs() after successful use. | |
786 | */ | |
787 | static int bd_holder_grab_dirs(struct block_device *bdev, | |
788 | struct bd_holder *bo) | |
789 | { | |
790 | if (!bdev || !bo) | |
791 | return 0; | |
792 | ||
793 | bo->sdir = kobject_get(bo->sdir); | |
794 | if (!bo->sdir) | |
795 | return 0; | |
796 | ||
797 | bo->hdev = kobject_get(bo->sdir->parent); | |
798 | if (!bo->hdev) | |
799 | goto fail_put_sdir; | |
800 | ||
801 | bo->sdev = bdev_get_kobj(bdev); | |
802 | if (!bo->sdev) | |
803 | goto fail_put_hdev; | |
804 | ||
805 | bo->hdir = bdev_get_holder(bdev); | |
806 | if (!bo->hdir) | |
807 | goto fail_put_sdev; | |
808 | ||
809 | return 1; | |
810 | ||
811 | fail_put_sdev: | |
812 | kobject_put(bo->sdev); | |
813 | fail_put_hdev: | |
814 | kobject_put(bo->hdev); | |
815 | fail_put_sdir: | |
816 | kobject_put(bo->sdir); | |
817 | ||
818 | return 0; | |
819 | } | |
820 | ||
821 | /* Put references of related kobjects at once. */ | |
822 | static void bd_holder_release_dirs(struct bd_holder *bo) | |
823 | { | |
824 | kobject_put(bo->hdir); | |
825 | kobject_put(bo->sdev); | |
826 | kobject_put(bo->hdev); | |
827 | kobject_put(bo->sdir); | |
828 | } | |
829 | ||
830 | static struct bd_holder *alloc_bd_holder(struct kobject *kobj) | |
831 | { | |
832 | struct bd_holder *bo; | |
833 | ||
834 | bo = kzalloc(sizeof(*bo), GFP_KERNEL); | |
835 | if (!bo) | |
836 | return NULL; | |
837 | ||
838 | bo->count = 1; | |
839 | bo->sdir = kobj; | |
840 | ||
841 | return bo; | |
842 | } | |
843 | ||
844 | static void free_bd_holder(struct bd_holder *bo) | |
845 | { | |
846 | kfree(bo); | |
847 | } | |
848 | ||
df6c0cd9 JN |
849 | /** |
850 | * find_bd_holder - find matching struct bd_holder from the block device | |
851 | * | |
852 | * @bdev: struct block device to be searched | |
853 | * @bo: target struct bd_holder | |
854 | * | |
855 | * Returns matching entry with @bo in @bdev->bd_holder_list. | |
856 | * If found, increment the reference count and return the pointer. | |
857 | * If not found, returns NULL. | |
858 | */ | |
36a561d6 AM |
859 | static struct bd_holder *find_bd_holder(struct block_device *bdev, |
860 | struct bd_holder *bo) | |
df6c0cd9 JN |
861 | { |
862 | struct bd_holder *tmp; | |
863 | ||
864 | list_for_each_entry(tmp, &bdev->bd_holder_list, list) | |
865 | if (tmp->sdir == bo->sdir) { | |
866 | tmp->count++; | |
867 | return tmp; | |
868 | } | |
869 | ||
870 | return NULL; | |
871 | } | |
872 | ||
641dc636 JN |
873 | /** |
874 | * add_bd_holder - create sysfs symlinks for bd_claim() relationship | |
875 | * | |
876 | * @bdev: block device to be bd_claimed | |
877 | * @bo: preallocated and initialized by alloc_bd_holder() | |
878 | * | |
df6c0cd9 | 879 | * Add @bo to @bdev->bd_holder_list, create symlinks. |
641dc636 | 880 | * |
df6c0cd9 JN |
881 | * Returns 0 if symlinks are created. |
882 | * Returns -ve if something fails. | |
641dc636 JN |
883 | */ |
884 | static int add_bd_holder(struct block_device *bdev, struct bd_holder *bo) | |
885 | { | |
4e91672c | 886 | int err; |
641dc636 JN |
887 | |
888 | if (!bo) | |
4d7dd8fd | 889 | return -EINVAL; |
641dc636 | 890 | |
641dc636 | 891 | if (!bd_holder_grab_dirs(bdev, bo)) |
4d7dd8fd | 892 | return -EBUSY; |
641dc636 | 893 | |
4e91672c JW |
894 | err = add_symlink(bo->sdir, bo->sdev); |
895 | if (err) | |
896 | return err; | |
897 | ||
898 | err = add_symlink(bo->hdir, bo->hdev); | |
899 | if (err) { | |
900 | del_symlink(bo->sdir, bo->sdev); | |
901 | return err; | |
4d7dd8fd | 902 | } |
4e91672c JW |
903 | |
904 | list_add_tail(&bo->list, &bdev->bd_holder_list); | |
905 | return 0; | |
641dc636 JN |
906 | } |
907 | ||
908 | /** | |
909 | * del_bd_holder - delete sysfs symlinks for bd_claim() relationship | |
910 | * | |
911 | * @bdev: block device to be bd_claimed | |
912 | * @kobj: holder's kobject | |
913 | * | |
914 | * If there is matching entry with @kobj in @bdev->bd_holder_list | |
915 | * and no other bd_claim() from the same kobject, | |
916 | * remove the struct bd_holder from the list, delete symlinks for it. | |
917 | * | |
918 | * Returns a pointer to the struct bd_holder when it's removed from the list | |
919 | * and ready to be freed. | |
920 | * Returns NULL if matching claim isn't found or there is other bd_claim() | |
921 | * by the same kobject. | |
922 | */ | |
923 | static struct bd_holder *del_bd_holder(struct block_device *bdev, | |
924 | struct kobject *kobj) | |
925 | { | |
926 | struct bd_holder *bo; | |
927 | ||
928 | list_for_each_entry(bo, &bdev->bd_holder_list, list) { | |
929 | if (bo->sdir == kobj) { | |
930 | bo->count--; | |
931 | BUG_ON(bo->count < 0); | |
932 | if (!bo->count) { | |
933 | list_del(&bo->list); | |
934 | del_symlink(bo->sdir, bo->sdev); | |
935 | del_symlink(bo->hdir, bo->hdev); | |
936 | bd_holder_release_dirs(bo); | |
937 | return bo; | |
938 | } | |
939 | break; | |
940 | } | |
941 | } | |
942 | ||
943 | return NULL; | |
944 | } | |
945 | ||
946 | /** | |
947 | * bd_claim_by_kobject - bd_claim() with additional kobject signature | |
948 | * | |
949 | * @bdev: block device to be claimed | |
950 | * @holder: holder's signature | |
951 | * @kobj: holder's kobject | |
952 | * | |
953 | * Do bd_claim() and if it succeeds, create sysfs symlinks between | |
954 | * the bdev and the holder's kobject. | |
955 | * Use bd_release_from_kobject() when relesing the claimed bdev. | |
956 | * | |
957 | * Returns 0 on success. (same as bd_claim()) | |
958 | * Returns errno on failure. | |
959 | */ | |
960 | static int bd_claim_by_kobject(struct block_device *bdev, void *holder, | |
961 | struct kobject *kobj) | |
962 | { | |
4e91672c | 963 | int err; |
df6c0cd9 | 964 | struct bd_holder *bo, *found; |
641dc636 JN |
965 | |
966 | if (!kobj) | |
967 | return -EINVAL; | |
968 | ||
969 | bo = alloc_bd_holder(kobj); | |
970 | if (!bo) | |
971 | return -ENOMEM; | |
972 | ||
2e7b651d | 973 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 974 | |
4e91672c JW |
975 | err = bd_claim(bdev, holder); |
976 | if (err) | |
4210df28 | 977 | goto fail; |
4e91672c JW |
978 | |
979 | found = find_bd_holder(bdev, bo); | |
980 | if (found) | |
4210df28 | 981 | goto fail; |
4e91672c JW |
982 | |
983 | err = add_bd_holder(bdev, bo); | |
984 | if (err) | |
985 | bd_release(bdev); | |
4210df28 AM |
986 | else |
987 | bo = NULL; | |
988 | fail: | |
b4cf1b72 | 989 | mutex_unlock(&bdev->bd_mutex); |
4210df28 | 990 | free_bd_holder(bo); |
4e91672c | 991 | return err; |
641dc636 JN |
992 | } |
993 | ||
994 | /** | |
995 | * bd_release_from_kobject - bd_release() with additional kobject signature | |
996 | * | |
997 | * @bdev: block device to be released | |
998 | * @kobj: holder's kobject | |
999 | * | |
1000 | * Do bd_release() and remove sysfs symlinks created by bd_claim_by_kobject(). | |
1001 | */ | |
1002 | static void bd_release_from_kobject(struct block_device *bdev, | |
1003 | struct kobject *kobj) | |
1004 | { | |
641dc636 JN |
1005 | if (!kobj) |
1006 | return; | |
1007 | ||
2e7b651d | 1008 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 1009 | bd_release(bdev); |
4210df28 | 1010 | free_bd_holder(del_bd_holder(bdev, kobj)); |
b4cf1b72 | 1011 | mutex_unlock(&bdev->bd_mutex); |
641dc636 JN |
1012 | } |
1013 | ||
1014 | /** | |
1015 | * bd_claim_by_disk - wrapper function for bd_claim_by_kobject() | |
1016 | * | |
1017 | * @bdev: block device to be claimed | |
1018 | * @holder: holder's signature | |
1019 | * @disk: holder's gendisk | |
1020 | * | |
1021 | * Call bd_claim_by_kobject() with getting @disk->slave_dir. | |
1022 | */ | |
1023 | int bd_claim_by_disk(struct block_device *bdev, void *holder, | |
1024 | struct gendisk *disk) | |
1025 | { | |
1026 | return bd_claim_by_kobject(bdev, holder, kobject_get(disk->slave_dir)); | |
1027 | } | |
1028 | EXPORT_SYMBOL_GPL(bd_claim_by_disk); | |
1029 | ||
1030 | /** | |
1031 | * bd_release_from_disk - wrapper function for bd_release_from_kobject() | |
1032 | * | |
1033 | * @bdev: block device to be claimed | |
1034 | * @disk: holder's gendisk | |
1035 | * | |
1036 | * Call bd_release_from_kobject() and put @disk->slave_dir. | |
1037 | */ | |
1038 | void bd_release_from_disk(struct block_device *bdev, struct gendisk *disk) | |
1039 | { | |
1040 | bd_release_from_kobject(bdev, disk->slave_dir); | |
1041 | kobject_put(disk->slave_dir); | |
1042 | } | |
1043 | EXPORT_SYMBOL_GPL(bd_release_from_disk); | |
1044 | #endif | |
1045 | ||
1da177e4 LT |
1046 | /* |
1047 | * Tries to open block device by device number. Use it ONLY if you | |
1048 | * really do not have anything better - i.e. when you are behind a | |
1049 | * truly sucky interface and all you are given is a device number. _Never_ | |
1050 | * to be used for internal purposes. If you ever need it - reconsider | |
1051 | * your API. | |
1052 | */ | |
1053 | struct block_device *open_by_devnum(dev_t dev, unsigned mode) | |
1054 | { | |
1055 | struct block_device *bdev = bdget(dev); | |
1056 | int err = -ENOMEM; | |
1057 | int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY; | |
1058 | if (bdev) | |
1059 | err = blkdev_get(bdev, mode, flags); | |
1060 | return err ? ERR_PTR(err) : bdev; | |
1061 | } | |
1062 | ||
1063 | EXPORT_SYMBOL(open_by_devnum); | |
1064 | ||
1065 | /* | |
1066 | * This routine checks whether a removable media has been changed, | |
1067 | * and invalidates all buffer-cache-entries in that case. This | |
1068 | * is a relatively slow routine, so we have to try to minimize using | |
1069 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1070 | * is the best way of combining speed and utility, I think. | |
1071 | * People changing diskettes in the middle of an operation deserve | |
1072 | * to lose :-) | |
1073 | */ | |
1074 | int check_disk_change(struct block_device *bdev) | |
1075 | { | |
1076 | struct gendisk *disk = bdev->bd_disk; | |
1077 | struct block_device_operations * bdops = disk->fops; | |
1078 | ||
1079 | if (!bdops->media_changed) | |
1080 | return 0; | |
1081 | if (!bdops->media_changed(bdev->bd_disk)) | |
1082 | return 0; | |
1083 | ||
2ef41634 | 1084 | if (__invalidate_device(bdev)) |
1da177e4 LT |
1085 | printk("VFS: busy inodes on changed media.\n"); |
1086 | ||
1087 | if (bdops->revalidate_disk) | |
1088 | bdops->revalidate_disk(bdev->bd_disk); | |
1089 | if (bdev->bd_disk->minors > 1) | |
1090 | bdev->bd_invalidated = 1; | |
1091 | return 1; | |
1092 | } | |
1093 | ||
1094 | EXPORT_SYMBOL(check_disk_change); | |
1095 | ||
1096 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1097 | { | |
1098 | unsigned bsize = bdev_hardsect_size(bdev); | |
1099 | ||
1100 | bdev->bd_inode->i_size = size; | |
1101 | while (bsize < PAGE_CACHE_SIZE) { | |
1102 | if (size & bsize) | |
1103 | break; | |
1104 | bsize <<= 1; | |
1105 | } | |
1106 | bdev->bd_block_size = bsize; | |
1107 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
1108 | } | |
1109 | EXPORT_SYMBOL(bd_set_size); | |
1110 | ||
37be4124 N |
1111 | static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags, |
1112 | int for_part); | |
c48f70c3 | 1113 | static int __blkdev_put(struct block_device *bdev, int for_part); |
37be4124 | 1114 | |
6d740cd5 PZ |
1115 | /* |
1116 | * bd_mutex locking: | |
1117 | * | |
1118 | * mutex_lock(part->bd_mutex) | |
1119 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1120 | */ | |
1121 | ||
37be4124 | 1122 | static int do_open(struct block_device *bdev, struct file *file, int for_part) |
1da177e4 LT |
1123 | { |
1124 | struct module *owner = NULL; | |
1125 | struct gendisk *disk; | |
1126 | int ret = -ENXIO; | |
1127 | int part; | |
1128 | ||
1129 | file->f_mapping = bdev->bd_inode->i_mapping; | |
1130 | lock_kernel(); | |
1131 | disk = get_gendisk(bdev->bd_dev, &part); | |
1132 | if (!disk) { | |
1133 | unlock_kernel(); | |
1134 | bdput(bdev); | |
1135 | return ret; | |
1136 | } | |
1137 | owner = disk->fops->owner; | |
1138 | ||
6796bf54 | 1139 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 LT |
1140 | if (!bdev->bd_openers) { |
1141 | bdev->bd_disk = disk; | |
1142 | bdev->bd_contains = bdev; | |
1143 | if (!part) { | |
1144 | struct backing_dev_info *bdi; | |
1145 | if (disk->fops->open) { | |
1146 | ret = disk->fops->open(bdev->bd_inode, file); | |
1147 | if (ret) | |
1148 | goto out_first; | |
1149 | } | |
1150 | if (!bdev->bd_openers) { | |
1151 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); | |
1152 | bdi = blk_get_backing_dev_info(bdev); | |
1153 | if (bdi == NULL) | |
1154 | bdi = &default_backing_dev_info; | |
1155 | bdev->bd_inode->i_data.backing_dev_info = bdi; | |
1156 | } | |
1157 | if (bdev->bd_invalidated) | |
1158 | rescan_partitions(disk, bdev); | |
1159 | } else { | |
1160 | struct hd_struct *p; | |
1161 | struct block_device *whole; | |
1162 | whole = bdget_disk(disk, 0); | |
1163 | ret = -ENOMEM; | |
1164 | if (!whole) | |
1165 | goto out_first; | |
37be4124 N |
1166 | BUG_ON(for_part); |
1167 | ret = __blkdev_get(whole, file->f_mode, file->f_flags, 1); | |
1da177e4 LT |
1168 | if (ret) |
1169 | goto out_first; | |
1170 | bdev->bd_contains = whole; | |
1da177e4 LT |
1171 | p = disk->part[part - 1]; |
1172 | bdev->bd_inode->i_data.backing_dev_info = | |
1173 | whole->bd_inode->i_data.backing_dev_info; | |
1174 | if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) { | |
1da177e4 LT |
1175 | ret = -ENXIO; |
1176 | goto out_first; | |
1177 | } | |
edfaa7c3 | 1178 | kobject_get(&p->dev.kobj); |
1da177e4 LT |
1179 | bdev->bd_part = p; |
1180 | bd_set_size(bdev, (loff_t) p->nr_sects << 9); | |
1da177e4 LT |
1181 | } |
1182 | } else { | |
1183 | put_disk(disk); | |
1184 | module_put(owner); | |
1185 | if (bdev->bd_contains == bdev) { | |
1186 | if (bdev->bd_disk->fops->open) { | |
1187 | ret = bdev->bd_disk->fops->open(bdev->bd_inode, file); | |
1188 | if (ret) | |
1189 | goto out; | |
1190 | } | |
1191 | if (bdev->bd_invalidated) | |
1192 | rescan_partitions(bdev->bd_disk, bdev); | |
1da177e4 LT |
1193 | } |
1194 | } | |
1195 | bdev->bd_openers++; | |
37be4124 N |
1196 | if (for_part) |
1197 | bdev->bd_part_count++; | |
c039e313 | 1198 | mutex_unlock(&bdev->bd_mutex); |
1da177e4 LT |
1199 | unlock_kernel(); |
1200 | return 0; | |
1201 | ||
1202 | out_first: | |
1203 | bdev->bd_disk = NULL; | |
1204 | bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info; | |
1205 | if (bdev != bdev->bd_contains) | |
c48f70c3 | 1206 | __blkdev_put(bdev->bd_contains, 1); |
1da177e4 LT |
1207 | bdev->bd_contains = NULL; |
1208 | put_disk(disk); | |
1209 | module_put(owner); | |
1210 | out: | |
c039e313 | 1211 | mutex_unlock(&bdev->bd_mutex); |
1da177e4 LT |
1212 | unlock_kernel(); |
1213 | if (ret) | |
1214 | bdput(bdev); | |
1215 | return ret; | |
1216 | } | |
1217 | ||
37be4124 N |
1218 | static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags, |
1219 | int for_part) | |
1da177e4 LT |
1220 | { |
1221 | /* | |
1222 | * This crockload is due to bad choice of ->open() type. | |
1223 | * It will go away. | |
1224 | * For now, block device ->open() routine must _not_ | |
1225 | * examine anything in 'inode' argument except ->i_rdev. | |
1226 | */ | |
1227 | struct file fake_file = {}; | |
1228 | struct dentry fake_dentry = {}; | |
1229 | fake_file.f_mode = mode; | |
1230 | fake_file.f_flags = flags; | |
0f7fc9e4 | 1231 | fake_file.f_path.dentry = &fake_dentry; |
1da177e4 LT |
1232 | fake_dentry.d_inode = bdev->bd_inode; |
1233 | ||
37be4124 | 1234 | return do_open(bdev, &fake_file, for_part); |
1da177e4 LT |
1235 | } |
1236 | ||
37be4124 N |
1237 | int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags) |
1238 | { | |
1239 | return __blkdev_get(bdev, mode, flags, 0); | |
1240 | } | |
1da177e4 LT |
1241 | EXPORT_SYMBOL(blkdev_get); |
1242 | ||
1243 | static int blkdev_open(struct inode * inode, struct file * filp) | |
1244 | { | |
1245 | struct block_device *bdev; | |
1246 | int res; | |
1247 | ||
1248 | /* | |
1249 | * Preserve backwards compatibility and allow large file access | |
1250 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1251 | * binary needs it. We might want to drop this workaround | |
1252 | * during an unstable branch. | |
1253 | */ | |
1254 | filp->f_flags |= O_LARGEFILE; | |
1255 | ||
1256 | bdev = bd_acquire(inode); | |
6a2aae06 PE |
1257 | if (bdev == NULL) |
1258 | return -ENOMEM; | |
1da177e4 | 1259 | |
37be4124 | 1260 | res = do_open(bdev, filp, 0); |
1da177e4 LT |
1261 | if (res) |
1262 | return res; | |
1263 | ||
1264 | if (!(filp->f_flags & O_EXCL) ) | |
1265 | return 0; | |
1266 | ||
1267 | if (!(res = bd_claim(bdev, filp))) | |
1268 | return 0; | |
1269 | ||
1270 | blkdev_put(bdev); | |
1271 | return res; | |
1272 | } | |
1273 | ||
37be4124 | 1274 | static int __blkdev_put(struct block_device *bdev, int for_part) |
2e7b651d PZ |
1275 | { |
1276 | int ret = 0; | |
1277 | struct inode *bd_inode = bdev->bd_inode; | |
1278 | struct gendisk *disk = bdev->bd_disk; | |
37be4124 | 1279 | struct block_device *victim = NULL; |
2e7b651d | 1280 | |
6796bf54 | 1281 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
2e7b651d | 1282 | lock_kernel(); |
37be4124 N |
1283 | if (for_part) |
1284 | bdev->bd_part_count--; | |
1285 | ||
2e7b651d PZ |
1286 | if (!--bdev->bd_openers) { |
1287 | sync_blockdev(bdev); | |
1288 | kill_bdev(bdev); | |
1289 | } | |
1290 | if (bdev->bd_contains == bdev) { | |
1291 | if (disk->fops->release) | |
1292 | ret = disk->fops->release(bd_inode, NULL); | |
2e7b651d PZ |
1293 | } |
1294 | if (!bdev->bd_openers) { | |
1295 | struct module *owner = disk->fops->owner; | |
1296 | ||
1297 | put_disk(disk); | |
1298 | module_put(owner); | |
1299 | ||
1300 | if (bdev->bd_contains != bdev) { | |
edfaa7c3 | 1301 | kobject_put(&bdev->bd_part->dev.kobj); |
2e7b651d PZ |
1302 | bdev->bd_part = NULL; |
1303 | } | |
1304 | bdev->bd_disk = NULL; | |
1305 | bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info; | |
37be4124 N |
1306 | if (bdev != bdev->bd_contains) |
1307 | victim = bdev->bd_contains; | |
2e7b651d PZ |
1308 | bdev->bd_contains = NULL; |
1309 | } | |
1310 | unlock_kernel(); | |
1311 | mutex_unlock(&bdev->bd_mutex); | |
1312 | bdput(bdev); | |
37be4124 N |
1313 | if (victim) |
1314 | __blkdev_put(victim, 1); | |
2e7b651d PZ |
1315 | return ret; |
1316 | } | |
1317 | ||
37be4124 N |
1318 | int blkdev_put(struct block_device *bdev) |
1319 | { | |
1320 | return __blkdev_put(bdev, 0); | |
1321 | } | |
2e7b651d PZ |
1322 | EXPORT_SYMBOL(blkdev_put); |
1323 | ||
1da177e4 LT |
1324 | static int blkdev_close(struct inode * inode, struct file * filp) |
1325 | { | |
1326 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); | |
1327 | if (bdev->bd_holder == filp) | |
1328 | bd_release(bdev); | |
1329 | return blkdev_put(bdev); | |
1330 | } | |
1331 | ||
bb93e3a5 | 1332 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 LT |
1333 | { |
1334 | return blkdev_ioctl(file->f_mapping->host, file, cmd, arg); | |
1335 | } | |
1336 | ||
f5e54d6e | 1337 | const struct address_space_operations def_blk_aops = { |
1da177e4 LT |
1338 | .readpage = blkdev_readpage, |
1339 | .writepage = blkdev_writepage, | |
1340 | .sync_page = block_sync_page, | |
6272b5a5 NP |
1341 | .write_begin = blkdev_write_begin, |
1342 | .write_end = blkdev_write_end, | |
1da177e4 LT |
1343 | .writepages = generic_writepages, |
1344 | .direct_IO = blkdev_direct_IO, | |
1345 | }; | |
1346 | ||
4b6f5d20 | 1347 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1348 | .open = blkdev_open, |
1349 | .release = blkdev_close, | |
1350 | .llseek = block_llseek, | |
543ade1f BP |
1351 | .read = do_sync_read, |
1352 | .write = do_sync_write, | |
1da177e4 | 1353 | .aio_read = generic_file_aio_read, |
027445c3 | 1354 | .aio_write = generic_file_aio_write_nolock, |
1da177e4 LT |
1355 | .mmap = generic_file_mmap, |
1356 | .fsync = block_fsync, | |
bb93e3a5 | 1357 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1358 | #ifdef CONFIG_COMPAT |
1359 | .compat_ioctl = compat_blkdev_ioctl, | |
1360 | #endif | |
7f9c51f0 JA |
1361 | .splice_read = generic_file_splice_read, |
1362 | .splice_write = generic_file_splice_write, | |
1da177e4 LT |
1363 | }; |
1364 | ||
1365 | int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) | |
1366 | { | |
1367 | int res; | |
1368 | mm_segment_t old_fs = get_fs(); | |
1369 | set_fs(KERNEL_DS); | |
1370 | res = blkdev_ioctl(bdev->bd_inode, NULL, cmd, arg); | |
1371 | set_fs(old_fs); | |
1372 | return res; | |
1373 | } | |
1374 | ||
1375 | EXPORT_SYMBOL(ioctl_by_bdev); | |
1376 | ||
1377 | /** | |
1378 | * lookup_bdev - lookup a struct block_device by name | |
1379 | * | |
1380 | * @path: special file representing the block device | |
1381 | * | |
1382 | * Get a reference to the blockdevice at @path in the current | |
1383 | * namespace if possible and return it. Return ERR_PTR(error) | |
1384 | * otherwise. | |
1385 | */ | |
1386 | struct block_device *lookup_bdev(const char *path) | |
1387 | { | |
1388 | struct block_device *bdev; | |
1389 | struct inode *inode; | |
1390 | struct nameidata nd; | |
1391 | int error; | |
1392 | ||
1393 | if (!path || !*path) | |
1394 | return ERR_PTR(-EINVAL); | |
1395 | ||
1396 | error = path_lookup(path, LOOKUP_FOLLOW, &nd); | |
1397 | if (error) | |
1398 | return ERR_PTR(error); | |
1399 | ||
1400 | inode = nd.dentry->d_inode; | |
1401 | error = -ENOTBLK; | |
1402 | if (!S_ISBLK(inode->i_mode)) | |
1403 | goto fail; | |
1404 | error = -EACCES; | |
1405 | if (nd.mnt->mnt_flags & MNT_NODEV) | |
1406 | goto fail; | |
1407 | error = -ENOMEM; | |
1408 | bdev = bd_acquire(inode); | |
1409 | if (!bdev) | |
1410 | goto fail; | |
1411 | out: | |
1412 | path_release(&nd); | |
1413 | return bdev; | |
1414 | fail: | |
1415 | bdev = ERR_PTR(error); | |
1416 | goto out; | |
1417 | } | |
1418 | ||
1419 | /** | |
1420 | * open_bdev_excl - open a block device by name and set it up for use | |
1421 | * | |
1422 | * @path: special file representing the block device | |
1423 | * @flags: %MS_RDONLY for opening read-only | |
1424 | * @holder: owner for exclusion | |
1425 | * | |
1426 | * Open the blockdevice described by the special file at @path, claim it | |
1427 | * for the @holder. | |
1428 | */ | |
1429 | struct block_device *open_bdev_excl(const char *path, int flags, void *holder) | |
1430 | { | |
1431 | struct block_device *bdev; | |
1432 | mode_t mode = FMODE_READ; | |
1433 | int error = 0; | |
1434 | ||
1435 | bdev = lookup_bdev(path); | |
1436 | if (IS_ERR(bdev)) | |
1437 | return bdev; | |
1438 | ||
1439 | if (!(flags & MS_RDONLY)) | |
1440 | mode |= FMODE_WRITE; | |
1441 | error = blkdev_get(bdev, mode, 0); | |
1442 | if (error) | |
1443 | return ERR_PTR(error); | |
1444 | error = -EACCES; | |
1445 | if (!(flags & MS_RDONLY) && bdev_read_only(bdev)) | |
1446 | goto blkdev_put; | |
1447 | error = bd_claim(bdev, holder); | |
1448 | if (error) | |
1449 | goto blkdev_put; | |
1450 | ||
1451 | return bdev; | |
1452 | ||
1453 | blkdev_put: | |
1454 | blkdev_put(bdev); | |
1455 | return ERR_PTR(error); | |
1456 | } | |
1457 | ||
1458 | EXPORT_SYMBOL(open_bdev_excl); | |
1459 | ||
1460 | /** | |
1461 | * close_bdev_excl - release a blockdevice openen by open_bdev_excl() | |
1462 | * | |
1463 | * @bdev: blockdevice to close | |
1464 | * | |
1465 | * This is the counterpart to open_bdev_excl(). | |
1466 | */ | |
1467 | void close_bdev_excl(struct block_device *bdev) | |
1468 | { | |
1469 | bd_release(bdev); | |
1470 | blkdev_put(bdev); | |
1471 | } | |
1472 | ||
1473 | EXPORT_SYMBOL(close_bdev_excl); | |
b71e8a4c DH |
1474 | |
1475 | int __invalidate_device(struct block_device *bdev) | |
1476 | { | |
1477 | struct super_block *sb = get_super(bdev); | |
1478 | int res = 0; | |
1479 | ||
1480 | if (sb) { | |
1481 | /* | |
1482 | * no need to lock the super, get_super holds the | |
1483 | * read mutex so the filesystem cannot go away | |
1484 | * under us (->put_super runs with the write lock | |
1485 | * hold). | |
1486 | */ | |
1487 | shrink_dcache_sb(sb); | |
1488 | res = invalidate_inodes(sb); | |
1489 | drop_super(sb); | |
1490 | } | |
f98393a6 | 1491 | invalidate_bdev(bdev); |
b71e8a4c DH |
1492 | return res; |
1493 | } | |
1494 | EXPORT_SYMBOL(__invalidate_device); |