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1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This copyrighted material is made available to anyone wishing to use, | |
6 | * modify, copy, or redistribute it subject to the terms and conditions | |
7 | * of the GNU General Public License v.2. | |
8 | */ | |
9 | ||
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/buffer_head.h> | |
15 | #include <linux/pagemap.h> | |
16 | #include <asm/semaphore.h> | |
17 | ||
18 | #include "gfs2.h" | |
19 | #include "bmap.h" | |
20 | #include "glock.h" | |
21 | #include "inode.h" | |
22 | #include "jdata.h" | |
23 | #include "log.h" | |
24 | #include "meta_io.h" | |
25 | #include "ops_address.h" | |
26 | #include "page.h" | |
27 | #include "quota.h" | |
28 | #include "trans.h" | |
29 | ||
30 | /** | |
31 | * get_block - Fills in a buffer head with details about a block | |
32 | * @inode: The inode | |
33 | * @lblock: The block number to look up | |
34 | * @bh_result: The buffer head to return the result in | |
35 | * @create: Non-zero if we may add block to the file | |
36 | * | |
37 | * Returns: errno | |
38 | */ | |
39 | ||
40 | static int get_block(struct inode *inode, sector_t lblock, | |
41 | struct buffer_head *bh_result, int create) | |
42 | { | |
43 | struct gfs2_inode *ip = get_v2ip(inode); | |
44 | int new = create; | |
45 | uint64_t dblock; | |
46 | int error; | |
47 | ||
48 | error = gfs2_block_map(ip, lblock, &new, &dblock, NULL); | |
49 | if (error) | |
50 | return error; | |
51 | ||
52 | if (!dblock) | |
53 | return 0; | |
54 | ||
55 | map_bh(bh_result, inode->i_sb, dblock); | |
56 | if (new) | |
57 | set_buffer_new(bh_result); | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | /** | |
63 | * get_block_noalloc - Fills in a buffer head with details about a block | |
64 | * @inode: The inode | |
65 | * @lblock: The block number to look up | |
66 | * @bh_result: The buffer head to return the result in | |
67 | * @create: Non-zero if we may add block to the file | |
68 | * | |
69 | * Returns: errno | |
70 | */ | |
71 | ||
72 | static int get_block_noalloc(struct inode *inode, sector_t lblock, | |
73 | struct buffer_head *bh_result, int create) | |
74 | { | |
75 | struct gfs2_inode *ip = get_v2ip(inode); | |
76 | int new = 0; | |
77 | uint64_t dblock; | |
78 | int error; | |
79 | ||
80 | error = gfs2_block_map(ip, lblock, &new, &dblock, NULL); | |
81 | if (error) | |
82 | return error; | |
83 | ||
84 | if (dblock) | |
85 | map_bh(bh_result, inode->i_sb, dblock); | |
86 | else if (gfs2_assert_withdraw(ip->i_sbd, !create)) | |
87 | error = -EIO; | |
88 | ||
89 | return error; | |
90 | } | |
91 | ||
92 | static int get_blocks(struct inode *inode, sector_t lblock, | |
93 | unsigned long max_blocks, struct buffer_head *bh_result, | |
94 | int create) | |
95 | { | |
96 | struct gfs2_inode *ip = get_v2ip(inode); | |
97 | int new = create; | |
98 | uint64_t dblock; | |
99 | uint32_t extlen; | |
100 | int error; | |
101 | ||
102 | error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen); | |
103 | if (error) | |
104 | return error; | |
105 | ||
106 | if (!dblock) | |
107 | return 0; | |
108 | ||
109 | map_bh(bh_result, inode->i_sb, dblock); | |
110 | if (new) | |
111 | set_buffer_new(bh_result); | |
112 | ||
113 | if (extlen > max_blocks) | |
114 | extlen = max_blocks; | |
115 | bh_result->b_size = extlen << inode->i_blkbits; | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | static int get_blocks_noalloc(struct inode *inode, sector_t lblock, | |
121 | unsigned long max_blocks, | |
122 | struct buffer_head *bh_result, int create) | |
123 | { | |
124 | struct gfs2_inode *ip = get_v2ip(inode); | |
125 | int new = 0; | |
126 | uint64_t dblock; | |
127 | uint32_t extlen; | |
128 | int error; | |
129 | ||
130 | error = gfs2_block_map(ip, lblock, &new, &dblock, &extlen); | |
131 | if (error) | |
132 | return error; | |
133 | ||
134 | if (dblock) { | |
135 | map_bh(bh_result, inode->i_sb, dblock); | |
136 | if (extlen > max_blocks) | |
137 | extlen = max_blocks; | |
138 | bh_result->b_size = extlen << inode->i_blkbits; | |
139 | } else if (gfs2_assert_withdraw(ip->i_sbd, !create)) | |
140 | error = -EIO; | |
141 | ||
142 | return error; | |
143 | } | |
144 | ||
145 | /** | |
146 | * gfs2_writepage - Write complete page | |
147 | * @page: Page to write | |
148 | * | |
149 | * Returns: errno | |
150 | * | |
151 | * Use Linux VFS block_write_full_page() to write one page, | |
152 | * using GFS2's get_block_noalloc to find which blocks to write. | |
153 | */ | |
154 | ||
155 | static int gfs2_writepage(struct page *page, struct writeback_control *wbc) | |
156 | { | |
157 | struct gfs2_inode *ip = get_v2ip(page->mapping->host); | |
158 | struct gfs2_sbd *sdp = ip->i_sbd; | |
159 | int error; | |
160 | ||
161 | atomic_inc(&sdp->sd_ops_address); | |
162 | ||
163 | if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(ip->i_gl))) { | |
164 | unlock_page(page); | |
165 | return -EIO; | |
166 | } | |
167 | if (get_transaction) { | |
168 | redirty_page_for_writepage(wbc, page); | |
169 | unlock_page(page); | |
170 | return 0; | |
171 | } | |
172 | ||
173 | error = block_write_full_page(page, get_block_noalloc, wbc); | |
174 | ||
175 | gfs2_meta_cache_flush(ip); | |
176 | ||
177 | return error; | |
178 | } | |
179 | ||
180 | /** | |
181 | * stuffed_readpage - Fill in a Linux page with stuffed file data | |
182 | * @ip: the inode | |
183 | * @page: the page | |
184 | * | |
185 | * Returns: errno | |
186 | */ | |
187 | ||
188 | static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) | |
189 | { | |
190 | struct buffer_head *dibh; | |
191 | void *kaddr; | |
192 | int error; | |
193 | ||
194 | error = gfs2_meta_inode_buffer(ip, &dibh); | |
195 | if (error) | |
196 | return error; | |
197 | ||
198 | kaddr = kmap(page); | |
199 | memcpy((char *)kaddr, | |
200 | dibh->b_data + sizeof(struct gfs2_dinode), | |
201 | ip->i_di.di_size); | |
202 | memset((char *)kaddr + ip->i_di.di_size, | |
203 | 0, | |
204 | PAGE_CACHE_SIZE - ip->i_di.di_size); | |
205 | kunmap(page); | |
206 | ||
207 | brelse(dibh); | |
208 | ||
209 | SetPageUptodate(page); | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | static int zero_readpage(struct page *page) | |
215 | { | |
216 | void *kaddr; | |
217 | ||
218 | kaddr = kmap(page); | |
219 | memset(kaddr, 0, PAGE_CACHE_SIZE); | |
220 | kunmap(page); | |
221 | ||
222 | SetPageUptodate(page); | |
223 | unlock_page(page); | |
224 | ||
225 | return 0; | |
226 | } | |
227 | ||
228 | /** | |
229 | * jdata_readpage - readpage that goes through gfs2_jdata_read_mem() | |
230 | * @ip: | |
231 | * @page: The page to read | |
232 | * | |
233 | * Returns: errno | |
234 | */ | |
235 | ||
236 | static int jdata_readpage(struct gfs2_inode *ip, struct page *page) | |
237 | { | |
238 | void *kaddr; | |
239 | int ret; | |
240 | ||
241 | kaddr = kmap(page); | |
242 | ||
243 | ret = gfs2_jdata_read_mem(ip, kaddr, | |
244 | (uint64_t)page->index << PAGE_CACHE_SHIFT, | |
245 | PAGE_CACHE_SIZE); | |
246 | if (ret >= 0) { | |
247 | if (ret < PAGE_CACHE_SIZE) | |
248 | memset(kaddr + ret, 0, PAGE_CACHE_SIZE - ret); | |
249 | SetPageUptodate(page); | |
250 | ret = 0; | |
251 | } | |
252 | ||
253 | kunmap(page); | |
254 | ||
255 | unlock_page(page); | |
256 | ||
257 | return ret; | |
258 | } | |
259 | ||
260 | /** | |
261 | * gfs2_readpage - readpage with locking | |
262 | * @file: The file to read a page for | |
263 | * @page: The page to read | |
264 | * | |
265 | * Returns: errno | |
266 | */ | |
267 | ||
268 | static int gfs2_readpage(struct file *file, struct page *page) | |
269 | { | |
270 | struct gfs2_inode *ip = get_v2ip(page->mapping->host); | |
271 | struct gfs2_sbd *sdp = ip->i_sbd; | |
272 | int error; | |
273 | ||
274 | atomic_inc(&sdp->sd_ops_address); | |
275 | ||
276 | if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) { | |
277 | unlock_page(page); | |
278 | return -EOPNOTSUPP; | |
279 | } | |
280 | ||
281 | if (!gfs2_is_jdata(ip)) { | |
282 | if (gfs2_is_stuffed(ip)) { | |
283 | if (!page->index) { | |
284 | error = stuffed_readpage(ip, page); | |
285 | unlock_page(page); | |
286 | } else | |
287 | error = zero_readpage(page); | |
288 | } else | |
289 | error = block_read_full_page(page, get_block); | |
290 | } else | |
291 | error = jdata_readpage(ip, page); | |
292 | ||
293 | if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) | |
294 | error = -EIO; | |
295 | ||
296 | return error; | |
297 | } | |
298 | ||
299 | /** | |
300 | * gfs2_prepare_write - Prepare to write a page to a file | |
301 | * @file: The file to write to | |
302 | * @page: The page which is to be prepared for writing | |
303 | * @from: From (byte range within page) | |
304 | * @to: To (byte range within page) | |
305 | * | |
306 | * Returns: errno | |
307 | */ | |
308 | ||
309 | static int gfs2_prepare_write(struct file *file, struct page *page, | |
310 | unsigned from, unsigned to) | |
311 | { | |
312 | struct gfs2_inode *ip = get_v2ip(page->mapping->host); | |
313 | struct gfs2_sbd *sdp = ip->i_sbd; | |
314 | int error = 0; | |
315 | ||
316 | atomic_inc(&sdp->sd_ops_address); | |
317 | ||
318 | if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) | |
319 | return -EOPNOTSUPP; | |
320 | ||
321 | if (gfs2_is_stuffed(ip)) { | |
322 | uint64_t file_size; | |
323 | file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to; | |
324 | ||
325 | if (file_size > sdp->sd_sb.sb_bsize - | |
326 | sizeof(struct gfs2_dinode)) { | |
327 | error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, | |
328 | page); | |
329 | if (!error) | |
330 | error = block_prepare_write(page, from, to, | |
331 | get_block); | |
332 | } else if (!PageUptodate(page)) | |
333 | error = stuffed_readpage(ip, page); | |
334 | } else | |
335 | error = block_prepare_write(page, from, to, get_block); | |
336 | ||
337 | return error; | |
338 | } | |
339 | ||
340 | /** | |
341 | * gfs2_commit_write - Commit write to a file | |
342 | * @file: The file to write to | |
343 | * @page: The page containing the data | |
344 | * @from: From (byte range within page) | |
345 | * @to: To (byte range within page) | |
346 | * | |
347 | * Returns: errno | |
348 | */ | |
349 | ||
350 | static int gfs2_commit_write(struct file *file, struct page *page, | |
351 | unsigned from, unsigned to) | |
352 | { | |
353 | struct inode *inode = page->mapping->host; | |
354 | struct gfs2_inode *ip = get_v2ip(inode); | |
355 | struct gfs2_sbd *sdp = ip->i_sbd; | |
356 | int error; | |
357 | ||
358 | atomic_inc(&sdp->sd_ops_address); | |
359 | ||
360 | if (gfs2_is_stuffed(ip)) { | |
361 | struct buffer_head *dibh; | |
362 | uint64_t file_size; | |
363 | void *kaddr; | |
364 | ||
365 | file_size = ((uint64_t)page->index << PAGE_CACHE_SHIFT) + to; | |
366 | ||
367 | error = gfs2_meta_inode_buffer(ip, &dibh); | |
368 | if (error) | |
369 | goto fail; | |
370 | ||
d4e9c4c3 | 371 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
b3b94faa DT |
372 | |
373 | kaddr = kmap(page); | |
374 | memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, | |
375 | (char *)kaddr + from, | |
376 | to - from); | |
377 | kunmap(page); | |
378 | ||
379 | brelse(dibh); | |
380 | ||
381 | SetPageUptodate(page); | |
382 | ||
383 | if (inode->i_size < file_size) | |
384 | i_size_write(inode, file_size); | |
385 | } else { | |
386 | if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED) | |
387 | gfs2_page_add_databufs(sdp, page, from, to); | |
388 | error = generic_commit_write(file, page, from, to); | |
389 | if (error) | |
390 | goto fail; | |
391 | } | |
392 | ||
393 | return 0; | |
394 | ||
395 | fail: | |
396 | ClearPageUptodate(page); | |
397 | ||
398 | return error; | |
399 | } | |
400 | ||
401 | /** | |
402 | * gfs2_bmap - Block map function | |
403 | * @mapping: Address space info | |
404 | * @lblock: The block to map | |
405 | * | |
406 | * Returns: The disk address for the block or 0 on hole or error | |
407 | */ | |
408 | ||
409 | static sector_t gfs2_bmap(struct address_space *mapping, sector_t lblock) | |
410 | { | |
411 | struct gfs2_inode *ip = get_v2ip(mapping->host); | |
412 | struct gfs2_holder i_gh; | |
413 | sector_t dblock = 0; | |
414 | int error; | |
415 | ||
416 | atomic_inc(&ip->i_sbd->sd_ops_address); | |
417 | ||
418 | error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); | |
419 | if (error) | |
420 | return 0; | |
421 | ||
422 | if (!gfs2_is_stuffed(ip)) | |
423 | dblock = generic_block_bmap(mapping, lblock, get_block); | |
424 | ||
425 | gfs2_glock_dq_uninit(&i_gh); | |
426 | ||
427 | return dblock; | |
428 | } | |
429 | ||
430 | static void discard_buffer(struct gfs2_sbd *sdp, struct buffer_head *bh) | |
431 | { | |
432 | struct gfs2_databuf *db; | |
433 | ||
434 | gfs2_log_lock(sdp); | |
435 | db = get_v2db(bh); | |
436 | if (db) { | |
437 | db->db_bh = NULL; | |
438 | set_v2db(bh, NULL); | |
439 | gfs2_log_unlock(sdp); | |
440 | brelse(bh); | |
441 | } else | |
442 | gfs2_log_unlock(sdp); | |
443 | ||
444 | lock_buffer(bh); | |
445 | clear_buffer_dirty(bh); | |
446 | bh->b_bdev = NULL; | |
447 | clear_buffer_mapped(bh); | |
448 | clear_buffer_req(bh); | |
449 | clear_buffer_new(bh); | |
450 | clear_buffer_delay(bh); | |
451 | unlock_buffer(bh); | |
452 | } | |
453 | ||
454 | static int gfs2_invalidatepage(struct page *page, unsigned long offset) | |
455 | { | |
456 | struct gfs2_sbd *sdp = get_v2sdp(page->mapping->host->i_sb); | |
457 | struct buffer_head *head, *bh, *next; | |
458 | unsigned int curr_off = 0; | |
459 | int ret = 1; | |
460 | ||
461 | BUG_ON(!PageLocked(page)); | |
462 | if (!page_has_buffers(page)) | |
463 | return 1; | |
464 | ||
465 | bh = head = page_buffers(page); | |
466 | do { | |
467 | unsigned int next_off = curr_off + bh->b_size; | |
468 | next = bh->b_this_page; | |
469 | ||
470 | if (offset <= curr_off) | |
471 | discard_buffer(sdp, bh); | |
472 | ||
473 | curr_off = next_off; | |
474 | bh = next; | |
475 | } while (bh != head); | |
476 | ||
477 | if (!offset) | |
478 | ret = try_to_release_page(page, 0); | |
479 | ||
480 | return ret; | |
481 | } | |
482 | ||
483 | static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, | |
484 | loff_t offset, unsigned long nr_segs) | |
485 | { | |
486 | struct file *file = iocb->ki_filp; | |
487 | struct inode *inode = file->f_mapping->host; | |
488 | struct gfs2_inode *ip = get_v2ip(inode); | |
489 | struct gfs2_sbd *sdp = ip->i_sbd; | |
490 | get_blocks_t *gb = get_blocks; | |
491 | ||
492 | atomic_inc(&sdp->sd_ops_address); | |
493 | ||
494 | if (gfs2_assert_warn(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)) || | |
495 | gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip))) | |
496 | return -EINVAL; | |
497 | ||
498 | if (rw == WRITE && !get_transaction) | |
499 | gb = get_blocks_noalloc; | |
500 | ||
501 | return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, | |
502 | offset, nr_segs, gb, NULL); | |
503 | } | |
504 | ||
505 | struct address_space_operations gfs2_file_aops = { | |
506 | .writepage = gfs2_writepage, | |
507 | .readpage = gfs2_readpage, | |
508 | .sync_page = block_sync_page, | |
509 | .prepare_write = gfs2_prepare_write, | |
510 | .commit_write = gfs2_commit_write, | |
511 | .bmap = gfs2_bmap, | |
512 | .invalidatepage = gfs2_invalidatepage, | |
513 | .direct_IO = gfs2_direct_IO, | |
514 | }; | |
515 |