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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/fs.h> |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/highmem.h> | |
22 | #include <linux/time.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/string.h> | |
25 | #include <linux/smp_lock.h> | |
26 | #include <linux/backing-dev.h> | |
27 | #include <linux/mpage.h> | |
28 | #include <linux/swap.h> | |
29 | #include <linux/writeback.h> | |
30 | #include <linux/statfs.h> | |
31 | #include <linux/compat.h> | |
92fee66d | 32 | #include <linux/version.h> |
39279cc3 CM |
33 | #include "ctree.h" |
34 | #include "disk-io.h" | |
35 | #include "transaction.h" | |
36 | #include "btrfs_inode.h" | |
37 | #include "ioctl.h" | |
38 | #include "print-tree.h" | |
39 | ||
40 | ||
41 | static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes, | |
42 | struct page **prepared_pages, | |
43 | const char __user * buf) | |
44 | { | |
45 | long page_fault = 0; | |
46 | int i; | |
47 | int offset = pos & (PAGE_CACHE_SIZE - 1); | |
48 | ||
49 | for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) { | |
50 | size_t count = min_t(size_t, | |
51 | PAGE_CACHE_SIZE - offset, write_bytes); | |
52 | struct page *page = prepared_pages[i]; | |
53 | fault_in_pages_readable(buf, count); | |
54 | ||
55 | /* Copy data from userspace to the current page */ | |
56 | kmap(page); | |
57 | page_fault = __copy_from_user(page_address(page) + offset, | |
58 | buf, count); | |
59 | /* Flush processor's dcache for this page */ | |
60 | flush_dcache_page(page); | |
61 | kunmap(page); | |
62 | buf += count; | |
63 | write_bytes -= count; | |
64 | ||
65 | if (page_fault) | |
66 | break; | |
67 | } | |
68 | return page_fault ? -EFAULT : 0; | |
69 | } | |
70 | ||
71 | static void btrfs_drop_pages(struct page **pages, size_t num_pages) | |
72 | { | |
73 | size_t i; | |
74 | for (i = 0; i < num_pages; i++) { | |
75 | if (!pages[i]) | |
76 | break; | |
77 | unlock_page(pages[i]); | |
78 | mark_page_accessed(pages[i]); | |
79 | page_cache_release(pages[i]); | |
80 | } | |
81 | } | |
82 | ||
a52d9a80 CM |
83 | static int insert_inline_extent(struct btrfs_trans_handle *trans, |
84 | struct btrfs_root *root, struct inode *inode, | |
54aa1f4d | 85 | u64 offset, ssize_t size, |
a52d9a80 | 86 | struct page *page, size_t page_offset) |
54aa1f4d CM |
87 | { |
88 | struct btrfs_key key; | |
89 | struct btrfs_path *path; | |
5f39d397 CM |
90 | struct extent_buffer *leaf; |
91 | char *kaddr; | |
92 | unsigned long ptr; | |
54aa1f4d CM |
93 | struct btrfs_file_extent_item *ei; |
94 | u32 datasize; | |
95 | int err = 0; | |
96 | int ret; | |
97 | ||
98 | path = btrfs_alloc_path(); | |
99 | if (!path) | |
100 | return -ENOMEM; | |
101 | ||
54aa1f4d CM |
102 | btrfs_set_trans_block_group(trans, inode); |
103 | ||
104 | key.objectid = inode->i_ino; | |
105 | key.offset = offset; | |
54aa1f4d CM |
106 | btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); |
107 | BUG_ON(size >= PAGE_CACHE_SIZE); | |
108 | datasize = btrfs_file_extent_calc_inline_size(size); | |
109 | ||
110 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
111 | datasize); | |
112 | if (ret) { | |
113 | err = ret; | |
114 | goto fail; | |
115 | } | |
5f39d397 CM |
116 | leaf = path->nodes[0]; |
117 | ei = btrfs_item_ptr(leaf, path->slots[0], | |
118 | struct btrfs_file_extent_item); | |
119 | btrfs_set_file_extent_generation(leaf, ei, trans->transid); | |
120 | btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); | |
54aa1f4d CM |
121 | ptr = btrfs_file_extent_inline_start(ei); |
122 | ||
db94535d | 123 | kaddr = kmap_atomic(page, KM_USER1); |
5f39d397 | 124 | write_extent_buffer(leaf, kaddr + page_offset, ptr, size); |
db94535d | 125 | kunmap_atomic(kaddr, KM_USER1); |
5f39d397 | 126 | btrfs_mark_buffer_dirty(leaf); |
54aa1f4d CM |
127 | fail: |
128 | btrfs_free_path(path); | |
54aa1f4d CM |
129 | return err; |
130 | } | |
131 | ||
39279cc3 CM |
132 | static int dirty_and_release_pages(struct btrfs_trans_handle *trans, |
133 | struct btrfs_root *root, | |
134 | struct file *file, | |
135 | struct page **pages, | |
136 | size_t num_pages, | |
137 | loff_t pos, | |
138 | size_t write_bytes) | |
139 | { | |
39279cc3 | 140 | int err = 0; |
a52d9a80 | 141 | int i; |
39279cc3 | 142 | struct inode *inode = file->f_path.dentry->d_inode; |
a52d9a80 CM |
143 | struct extent_map *em; |
144 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; | |
db94535d CM |
145 | u64 hint_byte; |
146 | u64 num_bytes; | |
a52d9a80 CM |
147 | u64 start_pos; |
148 | u64 end_of_last_block; | |
149 | u64 end_pos = pos + write_bytes; | |
db94535d | 150 | u32 inline_size; |
a52d9a80 | 151 | loff_t isize = i_size_read(inode); |
39279cc3 | 152 | |
a52d9a80 CM |
153 | em = alloc_extent_map(GFP_NOFS); |
154 | if (!em) | |
155 | return -ENOMEM; | |
39279cc3 | 156 | |
a52d9a80 | 157 | em->bdev = inode->i_sb->s_bdev; |
39279cc3 | 158 | |
5f39d397 | 159 | start_pos = pos & ~((u64)root->sectorsize - 1); |
db94535d CM |
160 | num_bytes = (write_bytes + pos - start_pos + |
161 | root->sectorsize - 1) & ~((u64)root->sectorsize - 1); | |
39279cc3 | 162 | |
011410bd | 163 | down_read(&BTRFS_I(inode)->root->snap_sem); |
db94535d CM |
164 | end_of_last_block = start_pos + num_bytes - 1; |
165 | ||
b888db2b | 166 | lock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS); |
a52d9a80 CM |
167 | mutex_lock(&root->fs_info->fs_mutex); |
168 | trans = btrfs_start_transaction(root, 1); | |
169 | if (!trans) { | |
170 | err = -ENOMEM; | |
171 | goto out_unlock; | |
172 | } | |
173 | btrfs_set_trans_block_group(trans, inode); | |
db94535d CM |
174 | inode->i_blocks += num_bytes >> 9; |
175 | hint_byte = 0; | |
a52d9a80 CM |
176 | |
177 | if ((end_of_last_block & 4095) == 0) { | |
9433063b | 178 | printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block); |
a52d9a80 CM |
179 | } |
180 | set_extent_uptodate(em_tree, start_pos, end_of_last_block, GFP_NOFS); | |
181 | ||
182 | /* FIXME...EIEIO, ENOSPC and more */ | |
183 | ||
a52d9a80 CM |
184 | /* insert any holes we need to create */ |
185 | if (inode->i_size < start_pos) { | |
186 | u64 last_pos_in_file; | |
187 | u64 hole_size; | |
5f39d397 | 188 | u64 mask = root->sectorsize - 1; |
a52d9a80 CM |
189 | last_pos_in_file = (isize + mask) & ~mask; |
190 | hole_size = (start_pos - last_pos_in_file + mask) & ~mask; | |
2bf5a725 | 191 | |
a52d9a80 | 192 | if (last_pos_in_file < start_pos) { |
2bf5a725 CM |
193 | err = btrfs_drop_extents(trans, root, inode, |
194 | last_pos_in_file, | |
195 | last_pos_in_file + hole_size, | |
db94535d | 196 | &hint_byte); |
2bf5a725 CM |
197 | if (err) |
198 | goto failed; | |
199 | ||
a52d9a80 CM |
200 | err = btrfs_insert_file_extent(trans, root, |
201 | inode->i_ino, | |
202 | last_pos_in_file, | |
203 | 0, 0, hole_size); | |
204 | } | |
205 | if (err) | |
39279cc3 | 206 | goto failed; |
a52d9a80 CM |
207 | } |
208 | ||
209 | /* | |
210 | * either allocate an extent for the new bytes or setup the key | |
211 | * to show we are doing inline data in the extent | |
212 | */ | |
db94535d | 213 | inline_size = end_pos - start_pos; |
a52d9a80 | 214 | if (isize >= PAGE_CACHE_SIZE || pos + write_bytes < inode->i_size || |
db94535d CM |
215 | inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root) || |
216 | inline_size >= PAGE_CACHE_SIZE) { | |
b888db2b | 217 | u64 last_end; |
a52d9a80 CM |
218 | for (i = 0; i < num_pages; i++) { |
219 | struct page *p = pages[i]; | |
220 | SetPageUptodate(p); | |
b888db2b | 221 | set_page_dirty(p); |
39279cc3 | 222 | } |
b888db2b CM |
223 | last_end = pages[num_pages -1]->index << PAGE_CACHE_SHIFT; |
224 | last_end += PAGE_CACHE_SIZE - 1; | |
225 | set_extent_delalloc(em_tree, start_pos, end_of_last_block, | |
226 | GFP_NOFS); | |
a52d9a80 CM |
227 | } else { |
228 | struct page *p = pages[0]; | |
b888db2b | 229 | /* step one, delete the existing extents in this range */ |
2bf5a725 | 230 | err = btrfs_drop_extents(trans, root, inode, start_pos, |
5f39d397 | 231 | (pos + write_bytes + root->sectorsize -1) & |
db94535d | 232 | ~((u64)root->sectorsize - 1), &hint_byte); |
2bf5a725 CM |
233 | if (err) |
234 | goto failed; | |
b888db2b | 235 | |
a52d9a80 CM |
236 | err = insert_inline_extent(trans, root, inode, start_pos, |
237 | end_pos - start_pos, p, 0); | |
238 | BUG_ON(err); | |
239 | em->start = start_pos; | |
6af858b2 | 240 | em->end = end_pos - 1; |
a52d9a80 CM |
241 | em->block_start = EXTENT_MAP_INLINE; |
242 | em->block_end = EXTENT_MAP_INLINE; | |
243 | add_extent_mapping(em_tree, em); | |
244 | } | |
245 | if (end_pos > isize) { | |
246 | i_size_write(inode, end_pos); | |
247 | btrfs_update_inode(trans, root, inode); | |
39279cc3 CM |
248 | } |
249 | failed: | |
a52d9a80 CM |
250 | err = btrfs_end_transaction(trans, root); |
251 | out_unlock: | |
252 | mutex_unlock(&root->fs_info->fs_mutex); | |
b888db2b | 253 | unlock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS); |
a52d9a80 | 254 | free_extent_map(em); |
011410bd | 255 | up_read(&BTRFS_I(inode)->root->snap_sem); |
39279cc3 CM |
256 | return err; |
257 | } | |
258 | ||
a52d9a80 CM |
259 | int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end) |
260 | { | |
261 | struct extent_map *em; | |
262 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; | |
263 | ||
264 | while(1) { | |
265 | em = lookup_extent_mapping(em_tree, start, end); | |
266 | if (!em) | |
267 | break; | |
268 | remove_extent_mapping(em_tree, em); | |
269 | /* once for us */ | |
270 | free_extent_map(em); | |
271 | /* once for the tree*/ | |
272 | free_extent_map(em); | |
273 | } | |
274 | return 0; | |
275 | } | |
276 | ||
39279cc3 CM |
277 | /* |
278 | * this is very complex, but the basic idea is to drop all extents | |
279 | * in the range start - end. hint_block is filled in with a block number | |
280 | * that would be a good hint to the block allocator for this file. | |
281 | * | |
282 | * If an extent intersects the range but is not entirely inside the range | |
283 | * it is either truncated or split. Anything entirely inside the range | |
284 | * is deleted from the tree. | |
285 | */ | |
286 | int btrfs_drop_extents(struct btrfs_trans_handle *trans, | |
287 | struct btrfs_root *root, struct inode *inode, | |
db94535d | 288 | u64 start, u64 end, u64 *hint_byte) |
39279cc3 CM |
289 | { |
290 | int ret; | |
291 | struct btrfs_key key; | |
5f39d397 | 292 | struct extent_buffer *leaf; |
39279cc3 CM |
293 | int slot; |
294 | struct btrfs_file_extent_item *extent; | |
295 | u64 extent_end = 0; | |
296 | int keep; | |
297 | struct btrfs_file_extent_item old; | |
298 | struct btrfs_path *path; | |
299 | u64 search_start = start; | |
300 | int bookend; | |
301 | int found_type; | |
302 | int found_extent; | |
303 | int found_inline; | |
ccd467d6 | 304 | int recow; |
39279cc3 | 305 | |
a52d9a80 CM |
306 | btrfs_drop_extent_cache(inode, start, end - 1); |
307 | ||
39279cc3 CM |
308 | path = btrfs_alloc_path(); |
309 | if (!path) | |
310 | return -ENOMEM; | |
311 | while(1) { | |
ccd467d6 | 312 | recow = 0; |
39279cc3 CM |
313 | btrfs_release_path(root, path); |
314 | ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino, | |
315 | search_start, -1); | |
316 | if (ret < 0) | |
317 | goto out; | |
318 | if (ret > 0) { | |
319 | if (path->slots[0] == 0) { | |
320 | ret = 0; | |
321 | goto out; | |
322 | } | |
323 | path->slots[0]--; | |
324 | } | |
8c2383c3 | 325 | next_slot: |
39279cc3 CM |
326 | keep = 0; |
327 | bookend = 0; | |
328 | found_extent = 0; | |
329 | found_inline = 0; | |
330 | extent = NULL; | |
5f39d397 | 331 | leaf = path->nodes[0]; |
39279cc3 | 332 | slot = path->slots[0]; |
8c2383c3 | 333 | ret = 0; |
5f39d397 | 334 | btrfs_item_key_to_cpu(leaf, &key, slot); |
39279cc3 | 335 | if (key.offset >= end || key.objectid != inode->i_ino) { |
39279cc3 CM |
336 | goto out; |
337 | } | |
8c2383c3 | 338 | if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY) { |
39279cc3 CM |
339 | goto out; |
340 | } | |
ccd467d6 CM |
341 | if (recow) { |
342 | search_start = key.offset; | |
343 | continue; | |
344 | } | |
8c2383c3 CM |
345 | if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) { |
346 | extent = btrfs_item_ptr(leaf, slot, | |
347 | struct btrfs_file_extent_item); | |
5f39d397 | 348 | found_type = btrfs_file_extent_type(leaf, extent); |
8c2383c3 CM |
349 | if (found_type == BTRFS_FILE_EXTENT_REG) { |
350 | extent_end = key.offset + | |
db94535d | 351 | btrfs_file_extent_num_bytes(leaf, extent); |
8c2383c3 CM |
352 | found_extent = 1; |
353 | } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { | |
5f39d397 CM |
354 | struct btrfs_item *item; |
355 | item = btrfs_item_nr(leaf, slot); | |
8c2383c3 CM |
356 | found_inline = 1; |
357 | extent_end = key.offset + | |
5f39d397 | 358 | btrfs_file_extent_inline_len(leaf, item); |
8c2383c3 CM |
359 | } |
360 | } else { | |
361 | extent_end = search_start; | |
39279cc3 CM |
362 | } |
363 | ||
364 | /* we found nothing we can drop */ | |
8c2383c3 CM |
365 | if ((!found_extent && !found_inline) || |
366 | search_start >= extent_end) { | |
367 | int nextret; | |
368 | u32 nritems; | |
5f39d397 | 369 | nritems = btrfs_header_nritems(leaf); |
8c2383c3 CM |
370 | if (slot >= nritems - 1) { |
371 | nextret = btrfs_next_leaf(root, path); | |
372 | if (nextret) | |
373 | goto out; | |
ccd467d6 | 374 | recow = 1; |
8c2383c3 CM |
375 | } else { |
376 | path->slots[0]++; | |
377 | } | |
378 | goto next_slot; | |
39279cc3 CM |
379 | } |
380 | ||
381 | /* FIXME, there's only one inline extent allowed right now */ | |
382 | if (found_inline) { | |
5f39d397 | 383 | u64 mask = root->sectorsize - 1; |
39279cc3 CM |
384 | search_start = (extent_end + mask) & ~mask; |
385 | } else | |
386 | search_start = extent_end; | |
387 | ||
388 | if (end < extent_end && end >= key.offset) { | |
389 | if (found_extent) { | |
db94535d CM |
390 | u64 disk_bytenr = |
391 | btrfs_file_extent_disk_bytenr(leaf, extent); | |
392 | u64 disk_num_bytes = | |
393 | btrfs_file_extent_disk_num_bytes(leaf, | |
5f39d397 CM |
394 | extent); |
395 | read_extent_buffer(leaf, &old, | |
396 | (unsigned long)extent, | |
397 | sizeof(old)); | |
db94535d | 398 | if (disk_bytenr != 0) { |
39279cc3 | 399 | ret = btrfs_inc_extent_ref(trans, root, |
db94535d | 400 | disk_bytenr, disk_num_bytes); |
39279cc3 CM |
401 | BUG_ON(ret); |
402 | } | |
403 | } | |
404 | WARN_ON(found_inline); | |
405 | bookend = 1; | |
406 | } | |
39279cc3 CM |
407 | /* truncate existing extent */ |
408 | if (start > key.offset) { | |
409 | u64 new_num; | |
410 | u64 old_num; | |
411 | keep = 1; | |
5f39d397 | 412 | WARN_ON(start & (root->sectorsize - 1)); |
39279cc3 | 413 | if (found_extent) { |
db94535d CM |
414 | new_num = start - key.offset; |
415 | old_num = btrfs_file_extent_num_bytes(leaf, | |
416 | extent); | |
417 | *hint_byte = | |
418 | btrfs_file_extent_disk_bytenr(leaf, | |
419 | extent); | |
420 | if (btrfs_file_extent_disk_bytenr(leaf, | |
421 | extent)) { | |
39279cc3 | 422 | inode->i_blocks -= |
db94535d | 423 | (old_num - new_num) >> 9; |
39279cc3 | 424 | } |
db94535d CM |
425 | btrfs_set_file_extent_num_bytes(leaf, extent, |
426 | new_num); | |
5f39d397 | 427 | btrfs_mark_buffer_dirty(leaf); |
39279cc3 CM |
428 | } else { |
429 | WARN_ON(1); | |
430 | } | |
431 | } | |
432 | /* delete the entire extent */ | |
433 | if (!keep) { | |
db94535d CM |
434 | u64 disk_bytenr = 0; |
435 | u64 disk_num_bytes = 0; | |
436 | u64 extent_num_bytes = 0; | |
39279cc3 | 437 | if (found_extent) { |
db94535d CM |
438 | disk_bytenr = |
439 | btrfs_file_extent_disk_bytenr(leaf, | |
5f39d397 | 440 | extent); |
db94535d CM |
441 | disk_num_bytes = |
442 | btrfs_file_extent_disk_num_bytes(leaf, | |
5f39d397 | 443 | extent); |
db94535d CM |
444 | extent_num_bytes = |
445 | btrfs_file_extent_num_bytes(leaf, extent); | |
446 | *hint_byte = | |
447 | btrfs_file_extent_disk_bytenr(leaf, | |
448 | extent); | |
39279cc3 CM |
449 | } |
450 | ret = btrfs_del_item(trans, root, path); | |
54aa1f4d | 451 | /* TODO update progress marker and return */ |
39279cc3 CM |
452 | BUG_ON(ret); |
453 | btrfs_release_path(root, path); | |
454 | extent = NULL; | |
db94535d CM |
455 | if (found_extent && disk_bytenr != 0) { |
456 | inode->i_blocks -= extent_num_bytes >> 9; | |
39279cc3 | 457 | ret = btrfs_free_extent(trans, root, |
db94535d CM |
458 | disk_bytenr, |
459 | disk_num_bytes, 0); | |
39279cc3 CM |
460 | } |
461 | ||
462 | BUG_ON(ret); | |
463 | if (!bookend && search_start >= end) { | |
464 | ret = 0; | |
465 | goto out; | |
466 | } | |
467 | if (!bookend) | |
468 | continue; | |
469 | } | |
470 | /* create bookend, splitting the extent in two */ | |
471 | if (bookend && found_extent) { | |
472 | struct btrfs_key ins; | |
473 | ins.objectid = inode->i_ino; | |
474 | ins.offset = end; | |
39279cc3 | 475 | btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY); |
39279cc3 CM |
476 | btrfs_release_path(root, path); |
477 | ret = btrfs_insert_empty_item(trans, root, path, &ins, | |
478 | sizeof(*extent)); | |
8c2383c3 | 479 | |
5f39d397 | 480 | leaf = path->nodes[0]; |
8c2383c3 | 481 | if (ret) { |
5f39d397 CM |
482 | btrfs_print_leaf(root, leaf); |
483 | printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret , ins.objectid, ins.type, ins.offset, start, end, key.offset, extent_end, keep); | |
8c2383c3 | 484 | } |
39279cc3 | 485 | BUG_ON(ret); |
5f39d397 CM |
486 | extent = btrfs_item_ptr(leaf, path->slots[0], |
487 | struct btrfs_file_extent_item); | |
488 | write_extent_buffer(leaf, &old, | |
489 | (unsigned long)extent, sizeof(old)); | |
490 | ||
491 | btrfs_set_file_extent_offset(leaf, extent, | |
db94535d CM |
492 | le64_to_cpu(old.offset) + end - key.offset); |
493 | WARN_ON(le64_to_cpu(old.num_bytes) < | |
494 | (extent_end - end)); | |
495 | btrfs_set_file_extent_num_bytes(leaf, extent, | |
496 | extent_end - end); | |
5f39d397 | 497 | btrfs_set_file_extent_type(leaf, extent, |
39279cc3 | 498 | BTRFS_FILE_EXTENT_REG); |
db94535d | 499 | |
39279cc3 | 500 | btrfs_mark_buffer_dirty(path->nodes[0]); |
db94535d | 501 | if (le64_to_cpu(old.disk_bytenr) != 0) { |
39279cc3 | 502 | inode->i_blocks += |
db94535d CM |
503 | btrfs_file_extent_num_bytes(leaf, |
504 | extent) >> 9; | |
39279cc3 CM |
505 | } |
506 | ret = 0; | |
507 | goto out; | |
508 | } | |
509 | } | |
510 | out: | |
511 | btrfs_free_path(path); | |
512 | return ret; | |
513 | } | |
514 | ||
515 | /* | |
516 | * this gets pages into the page cache and locks them down | |
517 | */ | |
518 | static int prepare_pages(struct btrfs_root *root, | |
519 | struct file *file, | |
520 | struct page **pages, | |
521 | size_t num_pages, | |
522 | loff_t pos, | |
523 | unsigned long first_index, | |
524 | unsigned long last_index, | |
8c2383c3 | 525 | size_t write_bytes) |
39279cc3 CM |
526 | { |
527 | int i; | |
528 | unsigned long index = pos >> PAGE_CACHE_SHIFT; | |
529 | struct inode *inode = file->f_path.dentry->d_inode; | |
39279cc3 | 530 | int err = 0; |
8c2383c3 | 531 | u64 start_pos; |
8c2383c3 | 532 | |
5f39d397 | 533 | start_pos = pos & ~((u64)root->sectorsize - 1); |
39279cc3 CM |
534 | |
535 | memset(pages, 0, num_pages * sizeof(struct page *)); | |
536 | ||
537 | for (i = 0; i < num_pages; i++) { | |
538 | pages[i] = grab_cache_page(inode->i_mapping, index + i); | |
539 | if (!pages[i]) { | |
540 | err = -ENOMEM; | |
a52d9a80 | 541 | BUG_ON(1); |
39279cc3 | 542 | } |
ccd467d6 CM |
543 | cancel_dirty_page(pages[i], PAGE_CACHE_SIZE); |
544 | wait_on_page_writeback(pages[i]); | |
b3cfa35a | 545 | set_page_extent_mapped(pages[i]); |
b888db2b | 546 | WARN_ON(!PageLocked(pages[i])); |
39279cc3 CM |
547 | } |
548 | return 0; | |
39279cc3 CM |
549 | } |
550 | ||
551 | static ssize_t btrfs_file_write(struct file *file, const char __user *buf, | |
552 | size_t count, loff_t *ppos) | |
553 | { | |
554 | loff_t pos; | |
555 | size_t num_written = 0; | |
556 | int err = 0; | |
557 | int ret = 0; | |
558 | struct inode *inode = file->f_path.dentry->d_inode; | |
559 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
8c2383c3 CM |
560 | struct page **pages = NULL; |
561 | int nrptrs; | |
39279cc3 CM |
562 | struct page *pinned[2]; |
563 | unsigned long first_index; | |
564 | unsigned long last_index; | |
8c2383c3 CM |
565 | |
566 | nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, | |
567 | PAGE_CACHE_SIZE / (sizeof(struct page *))); | |
39279cc3 CM |
568 | pinned[0] = NULL; |
569 | pinned[1] = NULL; | |
570 | if (file->f_flags & O_DIRECT) | |
571 | return -EINVAL; | |
572 | pos = *ppos; | |
573 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); | |
574 | current->backing_dev_info = inode->i_mapping->backing_dev_info; | |
575 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); | |
576 | if (err) | |
577 | goto out; | |
578 | if (count == 0) | |
579 | goto out; | |
580 | err = remove_suid(file->f_path.dentry); | |
581 | if (err) | |
582 | goto out; | |
583 | file_update_time(file); | |
584 | ||
8c2383c3 | 585 | pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); |
39279cc3 CM |
586 | |
587 | mutex_lock(&inode->i_mutex); | |
588 | first_index = pos >> PAGE_CACHE_SHIFT; | |
589 | last_index = (pos + count) >> PAGE_CACHE_SHIFT; | |
590 | ||
591 | /* | |
592 | * there are lots of better ways to do this, but this code | |
593 | * makes sure the first and last page in the file range are | |
594 | * up to date and ready for cow | |
595 | */ | |
596 | if ((pos & (PAGE_CACHE_SIZE - 1))) { | |
597 | pinned[0] = grab_cache_page(inode->i_mapping, first_index); | |
598 | if (!PageUptodate(pinned[0])) { | |
9ebefb18 | 599 | ret = btrfs_readpage(NULL, pinned[0]); |
39279cc3 CM |
600 | BUG_ON(ret); |
601 | wait_on_page_locked(pinned[0]); | |
602 | } else { | |
603 | unlock_page(pinned[0]); | |
604 | } | |
605 | } | |
606 | if ((pos + count) & (PAGE_CACHE_SIZE - 1)) { | |
607 | pinned[1] = grab_cache_page(inode->i_mapping, last_index); | |
608 | if (!PageUptodate(pinned[1])) { | |
9ebefb18 | 609 | ret = btrfs_readpage(NULL, pinned[1]); |
39279cc3 CM |
610 | BUG_ON(ret); |
611 | wait_on_page_locked(pinned[1]); | |
612 | } else { | |
613 | unlock_page(pinned[1]); | |
614 | } | |
615 | } | |
616 | ||
39279cc3 CM |
617 | while(count > 0) { |
618 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); | |
11bd143f CM |
619 | size_t write_bytes = min(count, nrptrs * |
620 | (size_t)PAGE_CACHE_SIZE - | |
8c2383c3 | 621 | offset); |
39279cc3 CM |
622 | size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >> |
623 | PAGE_CACHE_SHIFT; | |
624 | ||
8c2383c3 | 625 | WARN_ON(num_pages > nrptrs); |
39279cc3 CM |
626 | memset(pages, 0, sizeof(pages)); |
627 | ret = prepare_pages(root, file, pages, num_pages, | |
628 | pos, first_index, last_index, | |
8c2383c3 | 629 | write_bytes); |
54aa1f4d CM |
630 | if (ret) |
631 | goto out; | |
39279cc3 | 632 | |
39279cc3 CM |
633 | ret = btrfs_copy_from_user(pos, num_pages, |
634 | write_bytes, pages, buf); | |
54aa1f4d CM |
635 | if (ret) { |
636 | btrfs_drop_pages(pages, num_pages); | |
637 | goto out; | |
638 | } | |
39279cc3 CM |
639 | |
640 | ret = dirty_and_release_pages(NULL, root, file, pages, | |
641 | num_pages, pos, write_bytes); | |
39279cc3 | 642 | btrfs_drop_pages(pages, num_pages); |
54aa1f4d CM |
643 | if (ret) |
644 | goto out; | |
39279cc3 CM |
645 | |
646 | buf += write_bytes; | |
647 | count -= write_bytes; | |
648 | pos += write_bytes; | |
649 | num_written += write_bytes; | |
650 | ||
8c2383c3 | 651 | balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages); |
d3c2fdcf | 652 | btrfs_btree_balance_dirty(root, 1); |
39279cc3 CM |
653 | cond_resched(); |
654 | } | |
39279cc3 CM |
655 | mutex_unlock(&inode->i_mutex); |
656 | out: | |
8c2383c3 | 657 | kfree(pages); |
39279cc3 CM |
658 | if (pinned[0]) |
659 | page_cache_release(pinned[0]); | |
660 | if (pinned[1]) | |
661 | page_cache_release(pinned[1]); | |
662 | *ppos = pos; | |
663 | current->backing_dev_info = NULL; | |
39279cc3 CM |
664 | return num_written ? num_written : err; |
665 | } | |
666 | ||
39279cc3 CM |
667 | static int btrfs_sync_file(struct file *file, |
668 | struct dentry *dentry, int datasync) | |
669 | { | |
670 | struct inode *inode = dentry->d_inode; | |
671 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
15ee9bc7 | 672 | int ret = 0; |
39279cc3 CM |
673 | struct btrfs_trans_handle *trans; |
674 | ||
675 | /* | |
15ee9bc7 JB |
676 | * check the transaction that last modified this inode |
677 | * and see if its already been committed | |
39279cc3 CM |
678 | */ |
679 | mutex_lock(&root->fs_info->fs_mutex); | |
15ee9bc7 JB |
680 | if (!BTRFS_I(inode)->last_trans) |
681 | goto out; | |
682 | mutex_lock(&root->fs_info->trans_mutex); | |
683 | if (BTRFS_I(inode)->last_trans <= | |
684 | root->fs_info->last_trans_committed) { | |
685 | BTRFS_I(inode)->last_trans = 0; | |
686 | mutex_unlock(&root->fs_info->trans_mutex); | |
687 | goto out; | |
688 | } | |
689 | mutex_unlock(&root->fs_info->trans_mutex); | |
690 | ||
691 | /* | |
a52d9a80 CM |
692 | * ok we haven't committed the transaction yet, lets do a commit |
693 | */ | |
39279cc3 CM |
694 | trans = btrfs_start_transaction(root, 1); |
695 | if (!trans) { | |
696 | ret = -ENOMEM; | |
697 | goto out; | |
698 | } | |
699 | ret = btrfs_commit_transaction(trans, root); | |
39279cc3 | 700 | out: |
15ee9bc7 | 701 | mutex_unlock(&root->fs_info->fs_mutex); |
39279cc3 CM |
702 | return ret > 0 ? EIO : ret; |
703 | } | |
704 | ||
9ebefb18 | 705 | static struct vm_operations_struct btrfs_file_vm_ops = { |
92fee66d CM |
706 | #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23) |
707 | .nopage = filemap_nopage, | |
708 | .populate = filemap_populate, | |
709 | #else | |
710 | .fault = filemap_fault, | |
711 | #endif | |
9ebefb18 CM |
712 | .page_mkwrite = btrfs_page_mkwrite, |
713 | }; | |
714 | ||
715 | static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) | |
716 | { | |
717 | vma->vm_ops = &btrfs_file_vm_ops; | |
718 | file_accessed(filp); | |
719 | return 0; | |
720 | } | |
721 | ||
39279cc3 CM |
722 | struct file_operations btrfs_file_operations = { |
723 | .llseek = generic_file_llseek, | |
724 | .read = do_sync_read, | |
9ebefb18 | 725 | .aio_read = generic_file_aio_read, |
39279cc3 | 726 | .write = btrfs_file_write, |
9ebefb18 | 727 | .mmap = btrfs_file_mmap, |
39279cc3 | 728 | .open = generic_file_open, |
39279cc3 | 729 | .fsync = btrfs_sync_file, |
34287aa3 | 730 | .unlocked_ioctl = btrfs_ioctl, |
39279cc3 | 731 | #ifdef CONFIG_COMPAT |
34287aa3 | 732 | .compat_ioctl = btrfs_ioctl, |
39279cc3 CM |
733 | #endif |
734 | }; | |
735 |