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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
39279cc3 CM |
19 | #include <linux/module.h> |
20 | #include <linux/buffer_head.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/highmem.h> | |
24 | #include <linux/time.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/string.h> | |
27 | #include <linux/smp_lock.h> | |
28 | #include <linux/backing-dev.h> | |
29 | #include <linux/mpage.h> | |
30 | #include <linux/swap.h> | |
31 | #include <linux/writeback.h> | |
32 | #include <linux/statfs.h> | |
33 | #include <linux/compat.h> | |
34 | #include "ctree.h" | |
35 | #include "disk-io.h" | |
36 | #include "transaction.h" | |
37 | #include "btrfs_inode.h" | |
38 | #include "ioctl.h" | |
39 | #include "print-tree.h" | |
40 | ||
41 | ||
42 | static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes, | |
43 | struct page **prepared_pages, | |
44 | const char __user * buf) | |
45 | { | |
46 | long page_fault = 0; | |
47 | int i; | |
48 | int offset = pos & (PAGE_CACHE_SIZE - 1); | |
49 | ||
50 | for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { | |
51 | size_t count = min_t(size_t, | |
52 | PAGE_CACHE_SIZE - offset, write_bytes); | |
53 | struct page *page = prepared_pages[i]; | |
54 | fault_in_pages_readable(buf, count); | |
55 | ||
56 | /* Copy data from userspace to the current page */ | |
57 | kmap(page); | |
58 | page_fault = __copy_from_user(page_address(page) + offset, | |
59 | buf, count); | |
60 | /* Flush processor's dcache for this page */ | |
61 | flush_dcache_page(page); | |
62 | kunmap(page); | |
63 | buf += count; | |
64 | write_bytes -= count; | |
65 | ||
66 | if (page_fault) | |
67 | break; | |
68 | } | |
69 | return page_fault ? -EFAULT : 0; | |
70 | } | |
71 | ||
72 | static void btrfs_drop_pages(struct page **pages, size_t num_pages) | |
73 | { | |
74 | size_t i; | |
75 | for (i = 0; i < num_pages; i++) { | |
76 | if (!pages[i]) | |
77 | break; | |
78 | unlock_page(pages[i]); | |
79 | mark_page_accessed(pages[i]); | |
80 | page_cache_release(pages[i]); | |
81 | } | |
82 | } | |
83 | ||
84 | static int dirty_and_release_pages(struct btrfs_trans_handle *trans, | |
85 | struct btrfs_root *root, | |
86 | struct file *file, | |
87 | struct page **pages, | |
88 | size_t num_pages, | |
89 | loff_t pos, | |
90 | size_t write_bytes) | |
91 | { | |
92 | int i; | |
93 | int offset; | |
94 | int err = 0; | |
95 | int ret; | |
96 | int this_write; | |
97 | struct inode *inode = file->f_path.dentry->d_inode; | |
98 | struct buffer_head *bh; | |
99 | struct btrfs_file_extent_item *ei; | |
100 | ||
101 | for (i = 0; i < num_pages; i++) { | |
102 | offset = pos & (PAGE_CACHE_SIZE -1); | |
84f54cfa | 103 | this_write = min((size_t)PAGE_CACHE_SIZE - offset, write_bytes); |
39279cc3 CM |
104 | /* FIXME, one block at a time */ |
105 | ||
106 | mutex_lock(&root->fs_info->fs_mutex); | |
107 | trans = btrfs_start_transaction(root, 1); | |
108 | btrfs_set_trans_block_group(trans, inode); | |
109 | ||
110 | bh = page_buffers(pages[i]); | |
111 | ||
112 | if (buffer_mapped(bh) && bh->b_blocknr == 0) { | |
113 | struct btrfs_key key; | |
114 | struct btrfs_path *path; | |
34088780 | 115 | char *ptr, *kaddr; |
39279cc3 CM |
116 | u32 datasize; |
117 | ||
118 | /* create an inline extent, and copy the data in */ | |
119 | path = btrfs_alloc_path(); | |
120 | BUG_ON(!path); | |
121 | key.objectid = inode->i_ino; | |
122 | key.offset = pages[i]->index << PAGE_CACHE_SHIFT; | |
123 | key.flags = 0; | |
124 | btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); | |
125 | BUG_ON(write_bytes >= PAGE_CACHE_SIZE); | |
126 | datasize = offset + | |
127 | btrfs_file_extent_calc_inline_size(write_bytes); | |
128 | ||
129 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
130 | datasize); | |
131 | BUG_ON(ret); | |
132 | ei = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), | |
133 | path->slots[0], struct btrfs_file_extent_item); | |
134 | btrfs_set_file_extent_generation(ei, trans->transid); | |
135 | btrfs_set_file_extent_type(ei, | |
136 | BTRFS_FILE_EXTENT_INLINE); | |
137 | ptr = btrfs_file_extent_inline_start(ei); | |
34088780 | 138 | kaddr = kmap_atomic(bh->b_page, KM_USER0); |
39279cc3 | 139 | btrfs_memcpy(root, path->nodes[0]->b_data, |
34088780 CM |
140 | ptr, kaddr + bh_offset(bh), |
141 | offset + write_bytes); | |
142 | kunmap_atomic(kaddr, KM_USER0); | |
39279cc3 CM |
143 | mark_buffer_dirty(path->nodes[0]); |
144 | btrfs_free_path(path); | |
145 | } else if (buffer_mapped(bh)) { | |
146 | /* csum the file data */ | |
147 | btrfs_csum_file_block(trans, root, inode->i_ino, | |
148 | pages[i]->index << PAGE_CACHE_SHIFT, | |
149 | kmap(pages[i]), PAGE_CACHE_SIZE); | |
150 | kunmap(pages[i]); | |
151 | } | |
152 | SetPageChecked(pages[i]); | |
153 | ret = btrfs_end_transaction(trans, root); | |
154 | BUG_ON(ret); | |
155 | mutex_unlock(&root->fs_info->fs_mutex); | |
156 | ||
157 | ret = btrfs_commit_write(file, pages[i], offset, | |
158 | offset + this_write); | |
159 | pos += this_write; | |
160 | if (ret) { | |
161 | err = ret; | |
162 | goto failed; | |
163 | } | |
164 | WARN_ON(this_write > write_bytes); | |
165 | write_bytes -= this_write; | |
166 | } | |
167 | failed: | |
168 | return err; | |
169 | } | |
170 | ||
171 | /* | |
172 | * this is very complex, but the basic idea is to drop all extents | |
173 | * in the range start - end. hint_block is filled in with a block number | |
174 | * that would be a good hint to the block allocator for this file. | |
175 | * | |
176 | * If an extent intersects the range but is not entirely inside the range | |
177 | * it is either truncated or split. Anything entirely inside the range | |
178 | * is deleted from the tree. | |
179 | */ | |
180 | int btrfs_drop_extents(struct btrfs_trans_handle *trans, | |
181 | struct btrfs_root *root, struct inode *inode, | |
182 | u64 start, u64 end, u64 *hint_block) | |
183 | { | |
184 | int ret; | |
185 | struct btrfs_key key; | |
186 | struct btrfs_leaf *leaf; | |
187 | int slot; | |
188 | struct btrfs_file_extent_item *extent; | |
189 | u64 extent_end = 0; | |
190 | int keep; | |
191 | struct btrfs_file_extent_item old; | |
192 | struct btrfs_path *path; | |
193 | u64 search_start = start; | |
194 | int bookend; | |
195 | int found_type; | |
196 | int found_extent; | |
197 | int found_inline; | |
198 | ||
199 | path = btrfs_alloc_path(); | |
200 | if (!path) | |
201 | return -ENOMEM; | |
202 | while(1) { | |
203 | btrfs_release_path(root, path); | |
204 | ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, | |
205 | search_start, -1); | |
206 | if (ret < 0) | |
207 | goto out; | |
208 | if (ret > 0) { | |
209 | if (path->slots[0] == 0) { | |
210 | ret = 0; | |
211 | goto out; | |
212 | } | |
213 | path->slots[0]--; | |
214 | } | |
215 | keep = 0; | |
216 | bookend = 0; | |
217 | found_extent = 0; | |
218 | found_inline = 0; | |
219 | extent = NULL; | |
220 | leaf = btrfs_buffer_leaf(path->nodes[0]); | |
221 | slot = path->slots[0]; | |
222 | btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key); | |
223 | if (key.offset >= end || key.objectid != inode->i_ino) { | |
224 | ret = 0; | |
225 | goto out; | |
226 | } | |
227 | if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) { | |
228 | ret = 0; | |
229 | goto out; | |
230 | } | |
231 | extent = btrfs_item_ptr(leaf, slot, | |
232 | struct btrfs_file_extent_item); | |
233 | found_type = btrfs_file_extent_type(extent); | |
234 | if (found_type == BTRFS_FILE_EXTENT_REG) { | |
235 | extent_end = key.offset + | |
236 | (btrfs_file_extent_num_blocks(extent) << | |
237 | inode->i_blkbits); | |
238 | found_extent = 1; | |
239 | } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { | |
240 | found_inline = 1; | |
241 | extent_end = key.offset + | |
242 | btrfs_file_extent_inline_len(leaf->items + slot); | |
243 | } | |
244 | ||
245 | /* we found nothing we can drop */ | |
246 | if (!found_extent && !found_inline) { | |
247 | ret = 0; | |
248 | goto out; | |
249 | } | |
250 | ||
251 | /* we found nothing inside the range */ | |
252 | if (search_start >= extent_end) { | |
253 | ret = 0; | |
254 | goto out; | |
255 | } | |
256 | ||
257 | /* FIXME, there's only one inline extent allowed right now */ | |
258 | if (found_inline) { | |
259 | u64 mask = root->blocksize - 1; | |
260 | search_start = (extent_end + mask) & ~mask; | |
261 | } else | |
262 | search_start = extent_end; | |
263 | ||
264 | if (end < extent_end && end >= key.offset) { | |
265 | if (found_extent) { | |
266 | u64 disk_blocknr = | |
267 | btrfs_file_extent_disk_blocknr(extent); | |
268 | u64 disk_num_blocks = | |
269 | btrfs_file_extent_disk_num_blocks(extent); | |
270 | memcpy(&old, extent, sizeof(old)); | |
271 | if (disk_blocknr != 0) { | |
272 | ret = btrfs_inc_extent_ref(trans, root, | |
273 | disk_blocknr, disk_num_blocks); | |
274 | BUG_ON(ret); | |
275 | } | |
276 | } | |
277 | WARN_ON(found_inline); | |
278 | bookend = 1; | |
279 | } | |
280 | ||
281 | /* truncate existing extent */ | |
282 | if (start > key.offset) { | |
283 | u64 new_num; | |
284 | u64 old_num; | |
285 | keep = 1; | |
286 | WARN_ON(start & (root->blocksize - 1)); | |
287 | if (found_extent) { | |
288 | new_num = (start - key.offset) >> | |
289 | inode->i_blkbits; | |
290 | old_num = btrfs_file_extent_num_blocks(extent); | |
291 | *hint_block = | |
292 | btrfs_file_extent_disk_blocknr(extent); | |
293 | if (btrfs_file_extent_disk_blocknr(extent)) { | |
294 | inode->i_blocks -= | |
295 | (old_num - new_num) << 3; | |
296 | } | |
297 | btrfs_set_file_extent_num_blocks(extent, | |
298 | new_num); | |
299 | mark_buffer_dirty(path->nodes[0]); | |
300 | } else { | |
301 | WARN_ON(1); | |
302 | } | |
303 | } | |
304 | /* delete the entire extent */ | |
305 | if (!keep) { | |
306 | u64 disk_blocknr = 0; | |
307 | u64 disk_num_blocks = 0; | |
308 | u64 extent_num_blocks = 0; | |
309 | if (found_extent) { | |
310 | disk_blocknr = | |
311 | btrfs_file_extent_disk_blocknr(extent); | |
312 | disk_num_blocks = | |
313 | btrfs_file_extent_disk_num_blocks(extent); | |
314 | extent_num_blocks = | |
315 | btrfs_file_extent_num_blocks(extent); | |
316 | *hint_block = | |
317 | btrfs_file_extent_disk_blocknr(extent); | |
318 | } | |
319 | ret = btrfs_del_item(trans, root, path); | |
320 | BUG_ON(ret); | |
321 | btrfs_release_path(root, path); | |
322 | extent = NULL; | |
323 | if (found_extent && disk_blocknr != 0) { | |
324 | inode->i_blocks -= extent_num_blocks << 3; | |
325 | ret = btrfs_free_extent(trans, root, | |
326 | disk_blocknr, | |
327 | disk_num_blocks, 0); | |
328 | } | |
329 | ||
330 | BUG_ON(ret); | |
331 | if (!bookend && search_start >= end) { | |
332 | ret = 0; | |
333 | goto out; | |
334 | } | |
335 | if (!bookend) | |
336 | continue; | |
337 | } | |
338 | /* create bookend, splitting the extent in two */ | |
339 | if (bookend && found_extent) { | |
340 | struct btrfs_key ins; | |
341 | ins.objectid = inode->i_ino; | |
342 | ins.offset = end; | |
343 | ins.flags = 0; | |
344 | btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY); | |
345 | ||
346 | btrfs_release_path(root, path); | |
347 | ret = btrfs_insert_empty_item(trans, root, path, &ins, | |
348 | sizeof(*extent)); | |
349 | BUG_ON(ret); | |
350 | extent = btrfs_item_ptr( | |
351 | btrfs_buffer_leaf(path->nodes[0]), | |
352 | path->slots[0], | |
353 | struct btrfs_file_extent_item); | |
354 | btrfs_set_file_extent_disk_blocknr(extent, | |
355 | btrfs_file_extent_disk_blocknr(&old)); | |
356 | btrfs_set_file_extent_disk_num_blocks(extent, | |
357 | btrfs_file_extent_disk_num_blocks(&old)); | |
358 | ||
359 | btrfs_set_file_extent_offset(extent, | |
360 | btrfs_file_extent_offset(&old) + | |
361 | ((end - key.offset) >> inode->i_blkbits)); | |
362 | WARN_ON(btrfs_file_extent_num_blocks(&old) < | |
363 | (extent_end - end) >> inode->i_blkbits); | |
364 | btrfs_set_file_extent_num_blocks(extent, | |
365 | (extent_end - end) >> inode->i_blkbits); | |
366 | ||
367 | btrfs_set_file_extent_type(extent, | |
368 | BTRFS_FILE_EXTENT_REG); | |
369 | btrfs_set_file_extent_generation(extent, | |
370 | btrfs_file_extent_generation(&old)); | |
371 | btrfs_mark_buffer_dirty(path->nodes[0]); | |
372 | if (btrfs_file_extent_disk_blocknr(&old) != 0) { | |
373 | inode->i_blocks += | |
374 | btrfs_file_extent_num_blocks(extent) << 3; | |
375 | } | |
376 | ret = 0; | |
377 | goto out; | |
378 | } | |
379 | } | |
380 | out: | |
381 | btrfs_free_path(path); | |
382 | return ret; | |
383 | } | |
384 | ||
385 | /* | |
386 | * this gets pages into the page cache and locks them down | |
387 | */ | |
388 | static int prepare_pages(struct btrfs_root *root, | |
389 | struct file *file, | |
390 | struct page **pages, | |
391 | size_t num_pages, | |
392 | loff_t pos, | |
393 | unsigned long first_index, | |
394 | unsigned long last_index, | |
395 | size_t write_bytes, | |
396 | u64 alloc_extent_start) | |
397 | { | |
398 | int i; | |
399 | unsigned long index = pos >> PAGE_CACHE_SHIFT; | |
400 | struct inode *inode = file->f_path.dentry->d_inode; | |
401 | int offset; | |
402 | int err = 0; | |
403 | int this_write; | |
404 | struct buffer_head *bh; | |
405 | struct buffer_head *head; | |
406 | loff_t isize = i_size_read(inode); | |
407 | ||
408 | memset(pages, 0, num_pages * sizeof(struct page *)); | |
409 | ||
410 | for (i = 0; i < num_pages; i++) { | |
411 | pages[i] = grab_cache_page(inode->i_mapping, index + i); | |
412 | if (!pages[i]) { | |
413 | err = -ENOMEM; | |
414 | goto failed_release; | |
415 | } | |
416 | cancel_dirty_page(pages[i], PAGE_CACHE_SIZE); | |
417 | wait_on_page_writeback(pages[i]); | |
418 | offset = pos & (PAGE_CACHE_SIZE -1); | |
84f54cfa | 419 | this_write = min((size_t)PAGE_CACHE_SIZE - offset, write_bytes); |
39279cc3 CM |
420 | if (!page_has_buffers(pages[i])) { |
421 | create_empty_buffers(pages[i], | |
422 | root->fs_info->sb->s_blocksize, | |
423 | (1 << BH_Uptodate)); | |
424 | } | |
425 | head = page_buffers(pages[i]); | |
426 | bh = head; | |
427 | do { | |
428 | err = btrfs_map_bh_to_logical(root, bh, | |
429 | alloc_extent_start); | |
430 | BUG_ON(err); | |
431 | if (err) | |
432 | goto failed_truncate; | |
433 | bh = bh->b_this_page; | |
434 | if (alloc_extent_start) | |
435 | alloc_extent_start++; | |
436 | } while (bh != head); | |
437 | pos += this_write; | |
438 | WARN_ON(this_write > write_bytes); | |
439 | write_bytes -= this_write; | |
440 | } | |
441 | return 0; | |
442 | ||
443 | failed_release: | |
444 | btrfs_drop_pages(pages, num_pages); | |
445 | return err; | |
446 | ||
447 | failed_truncate: | |
448 | btrfs_drop_pages(pages, num_pages); | |
449 | if (pos > isize) | |
450 | vmtruncate(inode, isize); | |
451 | return err; | |
452 | } | |
453 | ||
454 | static ssize_t btrfs_file_write(struct file *file, const char __user *buf, | |
455 | size_t count, loff_t *ppos) | |
456 | { | |
457 | loff_t pos; | |
458 | size_t num_written = 0; | |
459 | int err = 0; | |
460 | int ret = 0; | |
461 | struct inode *inode = file->f_path.dentry->d_inode; | |
462 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
463 | struct page *pages[8]; | |
464 | struct page *pinned[2]; | |
465 | unsigned long first_index; | |
466 | unsigned long last_index; | |
467 | u64 start_pos; | |
468 | u64 num_blocks; | |
469 | u64 alloc_extent_start; | |
470 | u64 hint_block; | |
471 | struct btrfs_trans_handle *trans; | |
472 | struct btrfs_key ins; | |
473 | pinned[0] = NULL; | |
474 | pinned[1] = NULL; | |
475 | if (file->f_flags & O_DIRECT) | |
476 | return -EINVAL; | |
477 | pos = *ppos; | |
478 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); | |
479 | current->backing_dev_info = inode->i_mapping->backing_dev_info; | |
480 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); | |
481 | if (err) | |
482 | goto out; | |
483 | if (count == 0) | |
484 | goto out; | |
485 | err = remove_suid(file->f_path.dentry); | |
486 | if (err) | |
487 | goto out; | |
488 | file_update_time(file); | |
489 | ||
490 | start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1); | |
491 | num_blocks = (count + pos - start_pos + root->blocksize - 1) >> | |
492 | inode->i_blkbits; | |
493 | ||
494 | mutex_lock(&inode->i_mutex); | |
495 | first_index = pos >> PAGE_CACHE_SHIFT; | |
496 | last_index = (pos + count) >> PAGE_CACHE_SHIFT; | |
497 | ||
498 | /* | |
499 | * there are lots of better ways to do this, but this code | |
500 | * makes sure the first and last page in the file range are | |
501 | * up to date and ready for cow | |
502 | */ | |
503 | if ((pos & (PAGE_CACHE_SIZE - 1))) { | |
504 | pinned[0] = grab_cache_page(inode->i_mapping, first_index); | |
505 | if (!PageUptodate(pinned[0])) { | |
506 | ret = mpage_readpage(pinned[0], btrfs_get_block); | |
507 | BUG_ON(ret); | |
508 | wait_on_page_locked(pinned[0]); | |
509 | } else { | |
510 | unlock_page(pinned[0]); | |
511 | } | |
512 | } | |
513 | if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { | |
514 | pinned[1] = grab_cache_page(inode->i_mapping, last_index); | |
515 | if (!PageUptodate(pinned[1])) { | |
516 | ret = mpage_readpage(pinned[1], btrfs_get_block); | |
517 | BUG_ON(ret); | |
518 | wait_on_page_locked(pinned[1]); | |
519 | } else { | |
520 | unlock_page(pinned[1]); | |
521 | } | |
522 | } | |
523 | ||
524 | mutex_lock(&root->fs_info->fs_mutex); | |
525 | trans = btrfs_start_transaction(root, 1); | |
526 | if (!trans) { | |
527 | err = -ENOMEM; | |
528 | mutex_unlock(&root->fs_info->fs_mutex); | |
529 | goto out_unlock; | |
530 | } | |
531 | btrfs_set_trans_block_group(trans, inode); | |
532 | /* FIXME blocksize != 4096 */ | |
533 | inode->i_blocks += num_blocks << 3; | |
534 | hint_block = 0; | |
535 | ||
536 | /* FIXME...EIEIO, ENOSPC and more */ | |
537 | ||
538 | /* step one, delete the existing extents in this range */ | |
539 | if (start_pos < inode->i_size) { | |
540 | /* FIXME blocksize != pagesize */ | |
541 | ret = btrfs_drop_extents(trans, root, inode, | |
542 | start_pos, | |
543 | (pos + count + root->blocksize -1) & | |
544 | ~((u64)root->blocksize - 1), | |
545 | &hint_block); | |
546 | BUG_ON(ret); | |
547 | } | |
548 | ||
549 | /* insert any holes we need to create */ | |
550 | if (inode->i_size < start_pos) { | |
551 | u64 last_pos_in_file; | |
552 | u64 hole_size; | |
553 | u64 mask = root->blocksize - 1; | |
554 | last_pos_in_file = (inode->i_size + mask) & ~mask; | |
555 | hole_size = (start_pos - last_pos_in_file + mask) & ~mask; | |
556 | hole_size >>= inode->i_blkbits; | |
557 | if (last_pos_in_file < start_pos) { | |
558 | ret = btrfs_insert_file_extent(trans, root, | |
559 | inode->i_ino, | |
560 | last_pos_in_file, | |
561 | 0, 0, hole_size); | |
562 | } | |
563 | BUG_ON(ret); | |
564 | } | |
565 | ||
566 | /* | |
567 | * either allocate an extent for the new bytes or setup the key | |
568 | * to show we are doing inline data in the extent | |
569 | */ | |
570 | if (inode->i_size >= PAGE_CACHE_SIZE || pos + count < inode->i_size || | |
571 | pos + count - start_pos > BTRFS_MAX_INLINE_DATA_SIZE(root)) { | |
572 | ret = btrfs_alloc_extent(trans, root, inode->i_ino, | |
573 | num_blocks, hint_block, (u64)-1, | |
574 | &ins, 1); | |
575 | BUG_ON(ret); | |
576 | ret = btrfs_insert_file_extent(trans, root, inode->i_ino, | |
577 | start_pos, ins.objectid, ins.offset, | |
578 | ins.offset); | |
579 | BUG_ON(ret); | |
580 | } else { | |
581 | ins.offset = 0; | |
582 | ins.objectid = 0; | |
583 | } | |
584 | BUG_ON(ret); | |
585 | alloc_extent_start = ins.objectid; | |
586 | ret = btrfs_end_transaction(trans, root); | |
587 | mutex_unlock(&root->fs_info->fs_mutex); | |
588 | ||
589 | while(count > 0) { | |
590 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); | |
84f54cfa CM |
591 | size_t write_bytes = min(count, |
592 | (size_t)PAGE_CACHE_SIZE - offset); | |
39279cc3 CM |
593 | size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
594 | PAGE_CACHE_SHIFT; | |
595 | ||
596 | memset(pages, 0, sizeof(pages)); | |
597 | ret = prepare_pages(root, file, pages, num_pages, | |
598 | pos, first_index, last_index, | |
599 | write_bytes, alloc_extent_start); | |
600 | BUG_ON(ret); | |
601 | ||
602 | /* FIXME blocks != pagesize */ | |
603 | if (alloc_extent_start) | |
604 | alloc_extent_start += num_pages; | |
605 | ret = btrfs_copy_from_user(pos, num_pages, | |
606 | write_bytes, pages, buf); | |
607 | BUG_ON(ret); | |
608 | ||
609 | ret = dirty_and_release_pages(NULL, root, file, pages, | |
610 | num_pages, pos, write_bytes); | |
611 | BUG_ON(ret); | |
612 | btrfs_drop_pages(pages, num_pages); | |
613 | ||
614 | buf += write_bytes; | |
615 | count -= write_bytes; | |
616 | pos += write_bytes; | |
617 | num_written += write_bytes; | |
618 | ||
619 | balance_dirty_pages_ratelimited(inode->i_mapping); | |
620 | btrfs_btree_balance_dirty(root); | |
621 | cond_resched(); | |
622 | } | |
623 | out_unlock: | |
624 | mutex_unlock(&inode->i_mutex); | |
625 | out: | |
626 | if (pinned[0]) | |
627 | page_cache_release(pinned[0]); | |
628 | if (pinned[1]) | |
629 | page_cache_release(pinned[1]); | |
630 | *ppos = pos; | |
631 | current->backing_dev_info = NULL; | |
632 | mark_inode_dirty(inode); | |
633 | return num_written ? num_written : err; | |
634 | } | |
635 | ||
636 | /* | |
637 | * FIXME, do this by stuffing the csum we want in the info hanging off | |
638 | * page->private. For now, verify file csums on read | |
639 | */ | |
640 | static int btrfs_read_actor(read_descriptor_t *desc, struct page *page, | |
641 | unsigned long offset, unsigned long size) | |
642 | { | |
643 | char *kaddr; | |
644 | unsigned long left, count = desc->count; | |
645 | struct inode *inode = page->mapping->host; | |
646 | ||
647 | if (size > count) | |
648 | size = count; | |
649 | ||
650 | if (!PageChecked(page)) { | |
651 | /* FIXME, do it per block */ | |
652 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
653 | int ret; | |
654 | struct buffer_head *bh; | |
655 | ||
656 | if (page_has_buffers(page)) { | |
657 | bh = page_buffers(page); | |
658 | if (!buffer_mapped(bh)) { | |
659 | SetPageChecked(page); | |
660 | goto checked; | |
661 | } | |
662 | } | |
663 | ||
664 | ret = btrfs_csum_verify_file_block(root, | |
665 | page->mapping->host->i_ino, | |
666 | page->index << PAGE_CACHE_SHIFT, | |
667 | kmap(page), PAGE_CACHE_SIZE); | |
668 | if (ret) { | |
669 | if (ret != -ENOENT) { | |
670 | printk("failed to verify ino %lu page %lu ret %d\n", | |
671 | page->mapping->host->i_ino, | |
672 | page->index, ret); | |
673 | memset(page_address(page), 1, PAGE_CACHE_SIZE); | |
674 | flush_dcache_page(page); | |
675 | } | |
676 | } | |
677 | SetPageChecked(page); | |
678 | kunmap(page); | |
679 | } | |
680 | checked: | |
681 | /* | |
682 | * Faults on the destination of a read are common, so do it before | |
683 | * taking the kmap. | |
684 | */ | |
685 | if (!fault_in_pages_writeable(desc->arg.buf, size)) { | |
686 | kaddr = kmap_atomic(page, KM_USER0); | |
687 | left = __copy_to_user_inatomic(desc->arg.buf, | |
688 | kaddr + offset, size); | |
689 | kunmap_atomic(kaddr, KM_USER0); | |
690 | if (left == 0) | |
691 | goto success; | |
692 | } | |
693 | ||
694 | /* Do it the slow way */ | |
695 | kaddr = kmap(page); | |
696 | left = __copy_to_user(desc->arg.buf, kaddr + offset, size); | |
697 | kunmap(page); | |
698 | ||
699 | if (left) { | |
700 | size -= left; | |
701 | desc->error = -EFAULT; | |
702 | } | |
703 | success: | |
704 | desc->count = count - size; | |
705 | desc->written += size; | |
706 | desc->arg.buf += size; | |
707 | return size; | |
708 | } | |
709 | ||
710 | /** | |
711 | * btrfs_file_aio_read - filesystem read routine, with a mod to csum verify | |
712 | * @iocb: kernel I/O control block | |
713 | * @iov: io vector request | |
714 | * @nr_segs: number of segments in the iovec | |
715 | * @pos: current file position | |
716 | */ | |
717 | static ssize_t btrfs_file_aio_read(struct kiocb *iocb, const struct iovec *iov, | |
718 | unsigned long nr_segs, loff_t pos) | |
719 | { | |
720 | struct file *filp = iocb->ki_filp; | |
721 | ssize_t retval; | |
722 | unsigned long seg; | |
723 | size_t count; | |
724 | loff_t *ppos = &iocb->ki_pos; | |
725 | ||
726 | count = 0; | |
727 | for (seg = 0; seg < nr_segs; seg++) { | |
728 | const struct iovec *iv = &iov[seg]; | |
729 | ||
730 | /* | |
731 | * If any segment has a negative length, or the cumulative | |
732 | * length ever wraps negative then return -EINVAL. | |
733 | */ | |
734 | count += iv->iov_len; | |
735 | if (unlikely((ssize_t)(count|iv->iov_len) < 0)) | |
736 | return -EINVAL; | |
737 | if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len)) | |
738 | continue; | |
739 | if (seg == 0) | |
740 | return -EFAULT; | |
741 | nr_segs = seg; | |
742 | count -= iv->iov_len; /* This segment is no good */ | |
743 | break; | |
744 | } | |
745 | retval = 0; | |
746 | if (count) { | |
747 | for (seg = 0; seg < nr_segs; seg++) { | |
748 | read_descriptor_t desc; | |
749 | ||
750 | desc.written = 0; | |
751 | desc.arg.buf = iov[seg].iov_base; | |
752 | desc.count = iov[seg].iov_len; | |
753 | if (desc.count == 0) | |
754 | continue; | |
755 | desc.error = 0; | |
756 | do_generic_file_read(filp, ppos, &desc, | |
757 | btrfs_read_actor); | |
758 | retval += desc.written; | |
759 | if (desc.error) { | |
760 | retval = retval ?: desc.error; | |
761 | break; | |
762 | } | |
763 | } | |
764 | } | |
765 | return retval; | |
766 | } | |
767 | ||
768 | static int btrfs_sync_file(struct file *file, | |
769 | struct dentry *dentry, int datasync) | |
770 | { | |
771 | struct inode *inode = dentry->d_inode; | |
772 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
773 | int ret; | |
774 | struct btrfs_trans_handle *trans; | |
775 | ||
776 | /* | |
777 | * FIXME, use inode generation number to check if we can skip the | |
778 | * commit | |
779 | */ | |
780 | mutex_lock(&root->fs_info->fs_mutex); | |
781 | trans = btrfs_start_transaction(root, 1); | |
782 | if (!trans) { | |
783 | ret = -ENOMEM; | |
784 | goto out; | |
785 | } | |
786 | ret = btrfs_commit_transaction(trans, root); | |
787 | mutex_unlock(&root->fs_info->fs_mutex); | |
788 | out: | |
789 | return ret > 0 ? EIO : ret; | |
790 | } | |
791 | ||
792 | struct file_operations btrfs_file_operations = { | |
793 | .llseek = generic_file_llseek, | |
794 | .read = do_sync_read, | |
795 | .aio_read = btrfs_file_aio_read, | |
796 | .write = btrfs_file_write, | |
797 | .mmap = generic_file_mmap, | |
798 | .open = generic_file_open, | |
799 | .ioctl = btrfs_ioctl, | |
800 | .fsync = btrfs_sync_file, | |
801 | #ifdef CONFIG_COMPAT | |
802 | .compat_ioctl = btrfs_compat_ioctl, | |
803 | #endif | |
804 | }; | |
805 |