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1 | /* |
2 | * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd. | |
3 | * Written by Takashi Sato <t-sato@yk.jp.nec.com> | |
4 | * Akira Fujita <a-fujita@rs.jp.nec.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of version 2.1 of the GNU Lesser General Public License | |
8 | * as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | */ | |
15 | ||
16 | #include <linux/fs.h> | |
17 | #include <linux/quotaops.h> | |
18 | #include "ext4_jbd2.h" | |
19 | #include "ext4_extents.h" | |
20 | #include "ext4.h" | |
21 | ||
22 | #define get_ext_path(path, inode, block, ret) \ | |
23 | do { \ | |
24 | path = ext4_ext_find_extent(inode, block, path); \ | |
25 | if (IS_ERR(path)) { \ | |
26 | ret = PTR_ERR(path); \ | |
27 | path = NULL; \ | |
28 | } \ | |
29 | } while (0) | |
30 | ||
31 | /** | |
32 | * copy_extent_status - Copy the extent's initialization status | |
33 | * | |
34 | * @src: an extent for getting initialize status | |
35 | * @dest: an extent to be set the status | |
36 | */ | |
37 | static void | |
38 | copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest) | |
39 | { | |
40 | if (ext4_ext_is_uninitialized(src)) | |
41 | ext4_ext_mark_uninitialized(dest); | |
42 | else | |
43 | dest->ee_len = cpu_to_le16(ext4_ext_get_actual_len(dest)); | |
44 | } | |
45 | ||
46 | /** | |
47 | * mext_next_extent - Search for the next extent and set it to "extent" | |
48 | * | |
49 | * @inode: inode which is searched | |
50 | * @path: this will obtain data for the next extent | |
51 | * @extent: pointer to the next extent we have just gotten | |
52 | * | |
53 | * Search the next extent in the array of ext4_ext_path structure (@path) | |
54 | * and set it to ext4_extent structure (@extent). In addition, the member of | |
55 | * @path (->p_ext) also points the next extent. Return 0 on success, 1 if | |
56 | * ext4_ext_path structure refers to the last extent, or a negative error | |
57 | * value on failure. | |
58 | */ | |
59 | static int | |
60 | mext_next_extent(struct inode *inode, struct ext4_ext_path *path, | |
61 | struct ext4_extent **extent) | |
62 | { | |
63 | int ppos, leaf_ppos = path->p_depth; | |
64 | ||
65 | ppos = leaf_ppos; | |
66 | if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) { | |
67 | /* leaf block */ | |
68 | *extent = ++path[ppos].p_ext; | |
69 | return 0; | |
70 | } | |
71 | ||
72 | while (--ppos >= 0) { | |
73 | if (EXT_LAST_INDEX(path[ppos].p_hdr) > | |
74 | path[ppos].p_idx) { | |
75 | int cur_ppos = ppos; | |
76 | ||
77 | /* index block */ | |
78 | path[ppos].p_idx++; | |
79 | path[ppos].p_block = idx_pblock(path[ppos].p_idx); | |
80 | if (path[ppos+1].p_bh) | |
81 | brelse(path[ppos+1].p_bh); | |
82 | path[ppos+1].p_bh = | |
83 | sb_bread(inode->i_sb, path[ppos].p_block); | |
84 | if (!path[ppos+1].p_bh) | |
85 | return -EIO; | |
86 | path[ppos+1].p_hdr = | |
87 | ext_block_hdr(path[ppos+1].p_bh); | |
88 | ||
89 | /* Halfway index block */ | |
90 | while (++cur_ppos < leaf_ppos) { | |
91 | path[cur_ppos].p_idx = | |
92 | EXT_FIRST_INDEX(path[cur_ppos].p_hdr); | |
93 | path[cur_ppos].p_block = | |
94 | idx_pblock(path[cur_ppos].p_idx); | |
95 | if (path[cur_ppos+1].p_bh) | |
96 | brelse(path[cur_ppos+1].p_bh); | |
97 | path[cur_ppos+1].p_bh = sb_bread(inode->i_sb, | |
98 | path[cur_ppos].p_block); | |
99 | if (!path[cur_ppos+1].p_bh) | |
100 | return -EIO; | |
101 | path[cur_ppos+1].p_hdr = | |
102 | ext_block_hdr(path[cur_ppos+1].p_bh); | |
103 | } | |
104 | ||
105 | /* leaf block */ | |
106 | path[leaf_ppos].p_ext = *extent = | |
107 | EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr); | |
108 | return 0; | |
109 | } | |
110 | } | |
111 | /* We found the last extent */ | |
112 | return 1; | |
113 | } | |
114 | ||
115 | /** | |
116 | * mext_double_down_read - Acquire two inodes' read semaphore | |
117 | * | |
118 | * @orig_inode: original inode structure | |
119 | * @donor_inode: donor inode structure | |
120 | * Acquire read semaphore of the two inodes (orig and donor) by i_ino order. | |
121 | */ | |
122 | static void | |
123 | mext_double_down_read(struct inode *orig_inode, struct inode *donor_inode) | |
124 | { | |
125 | struct inode *first = orig_inode, *second = donor_inode; | |
126 | ||
127 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
128 | ||
129 | /* | |
130 | * Use the inode number to provide the stable locking order instead | |
131 | * of its address, because the C language doesn't guarantee you can | |
132 | * compare pointers that don't come from the same array. | |
133 | */ | |
134 | if (donor_inode->i_ino < orig_inode->i_ino) { | |
135 | first = donor_inode; | |
136 | second = orig_inode; | |
137 | } | |
138 | ||
139 | down_read(&EXT4_I(first)->i_data_sem); | |
140 | down_read(&EXT4_I(second)->i_data_sem); | |
141 | } | |
142 | ||
143 | /** | |
144 | * mext_double_down_write - Acquire two inodes' write semaphore | |
145 | * | |
146 | * @orig_inode: original inode structure | |
147 | * @donor_inode: donor inode structure | |
148 | * Acquire write semaphore of the two inodes (orig and donor) by i_ino order. | |
149 | */ | |
150 | static void | |
151 | mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode) | |
152 | { | |
153 | struct inode *first = orig_inode, *second = donor_inode; | |
154 | ||
155 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
156 | ||
157 | /* | |
158 | * Use the inode number to provide the stable locking order instead | |
159 | * of its address, because the C language doesn't guarantee you can | |
160 | * compare pointers that don't come from the same array. | |
161 | */ | |
162 | if (donor_inode->i_ino < orig_inode->i_ino) { | |
163 | first = donor_inode; | |
164 | second = orig_inode; | |
165 | } | |
166 | ||
167 | down_write(&EXT4_I(first)->i_data_sem); | |
168 | down_write(&EXT4_I(second)->i_data_sem); | |
169 | } | |
170 | ||
171 | /** | |
172 | * mext_double_up_read - Release two inodes' read semaphore | |
173 | * | |
174 | * @orig_inode: original inode structure to be released its lock first | |
175 | * @donor_inode: donor inode structure to be released its lock second | |
176 | * Release read semaphore of two inodes (orig and donor). | |
177 | */ | |
178 | static void | |
179 | mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode) | |
180 | { | |
181 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
182 | ||
183 | up_read(&EXT4_I(orig_inode)->i_data_sem); | |
184 | up_read(&EXT4_I(donor_inode)->i_data_sem); | |
185 | } | |
186 | ||
187 | /** | |
188 | * mext_double_up_write - Release two inodes' write semaphore | |
189 | * | |
190 | * @orig_inode: original inode structure to be released its lock first | |
191 | * @donor_inode: donor inode structure to be released its lock second | |
192 | * Release write semaphore of two inodes (orig and donor). | |
193 | */ | |
194 | static void | |
195 | mext_double_up_write(struct inode *orig_inode, struct inode *donor_inode) | |
196 | { | |
197 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
198 | ||
199 | up_write(&EXT4_I(orig_inode)->i_data_sem); | |
200 | up_write(&EXT4_I(donor_inode)->i_data_sem); | |
201 | } | |
202 | ||
203 | /** | |
204 | * mext_insert_across_blocks - Insert extents across leaf block | |
205 | * | |
206 | * @handle: journal handle | |
207 | * @orig_inode: original inode | |
208 | * @o_start: first original extent to be changed | |
209 | * @o_end: last original extent to be changed | |
210 | * @start_ext: first new extent to be inserted | |
211 | * @new_ext: middle of new extent to be inserted | |
212 | * @end_ext: last new extent to be inserted | |
213 | * | |
214 | * Allocate a new leaf block and insert extents into it. Return 0 on success, | |
215 | * or a negative error value on failure. | |
216 | */ | |
217 | static int | |
218 | mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, | |
219 | struct ext4_extent *o_start, struct ext4_extent *o_end, | |
220 | struct ext4_extent *start_ext, struct ext4_extent *new_ext, | |
221 | struct ext4_extent *end_ext) | |
222 | { | |
223 | struct ext4_ext_path *orig_path = NULL; | |
224 | ext4_lblk_t eblock = 0; | |
225 | int new_flag = 0; | |
226 | int end_flag = 0; | |
227 | int err = 0; | |
228 | ||
229 | if (start_ext->ee_len && new_ext->ee_len && end_ext->ee_len) { | |
230 | if (o_start == o_end) { | |
231 | ||
232 | /* start_ext new_ext end_ext | |
233 | * donor |---------|-----------|--------| | |
234 | * orig |------------------------------| | |
235 | */ | |
236 | end_flag = 1; | |
237 | } else { | |
238 | ||
239 | /* start_ext new_ext end_ext | |
240 | * donor |---------|----------|---------| | |
241 | * orig |---------------|--------------| | |
242 | */ | |
243 | o_end->ee_block = end_ext->ee_block; | |
244 | o_end->ee_len = end_ext->ee_len; | |
245 | ext4_ext_store_pblock(o_end, ext_pblock(end_ext)); | |
246 | } | |
247 | ||
248 | o_start->ee_len = start_ext->ee_len; | |
249 | new_flag = 1; | |
250 | ||
251 | } else if (start_ext->ee_len && new_ext->ee_len && | |
252 | !end_ext->ee_len && o_start == o_end) { | |
253 | ||
254 | /* start_ext new_ext | |
255 | * donor |--------------|---------------| | |
256 | * orig |------------------------------| | |
257 | */ | |
258 | o_start->ee_len = start_ext->ee_len; | |
259 | new_flag = 1; | |
260 | ||
261 | } else if (!start_ext->ee_len && new_ext->ee_len && | |
262 | end_ext->ee_len && o_start == o_end) { | |
263 | ||
264 | /* new_ext end_ext | |
265 | * donor |--------------|---------------| | |
266 | * orig |------------------------------| | |
267 | */ | |
268 | o_end->ee_block = end_ext->ee_block; | |
269 | o_end->ee_len = end_ext->ee_len; | |
270 | ext4_ext_store_pblock(o_end, ext_pblock(end_ext)); | |
271 | ||
272 | /* | |
273 | * Set 0 to the extent block if new_ext was | |
274 | * the first block. | |
275 | */ | |
276 | if (new_ext->ee_block) | |
277 | eblock = le32_to_cpu(new_ext->ee_block); | |
278 | ||
279 | new_flag = 1; | |
280 | } else { | |
281 | ext4_debug("ext4 move extent: Unexpected insert case\n"); | |
282 | return -EIO; | |
283 | } | |
284 | ||
285 | if (new_flag) { | |
286 | get_ext_path(orig_path, orig_inode, eblock, err); | |
287 | if (orig_path == NULL) | |
288 | goto out; | |
289 | ||
290 | if (ext4_ext_insert_extent(handle, orig_inode, | |
291 | orig_path, new_ext)) | |
292 | goto out; | |
293 | } | |
294 | ||
295 | if (end_flag) { | |
296 | get_ext_path(orig_path, orig_inode, | |
297 | le32_to_cpu(end_ext->ee_block) - 1, err); | |
298 | if (orig_path == NULL) | |
299 | goto out; | |
300 | ||
301 | if (ext4_ext_insert_extent(handle, orig_inode, | |
302 | orig_path, end_ext)) | |
303 | goto out; | |
304 | } | |
305 | out: | |
306 | if (orig_path) { | |
307 | ext4_ext_drop_refs(orig_path); | |
308 | kfree(orig_path); | |
309 | } | |
310 | ||
311 | return err; | |
312 | ||
313 | } | |
314 | ||
315 | /** | |
316 | * mext_insert_inside_block - Insert new extent to the extent block | |
317 | * | |
318 | * @o_start: first original extent to be moved | |
319 | * @o_end: last original extent to be moved | |
320 | * @start_ext: first new extent to be inserted | |
321 | * @new_ext: middle of new extent to be inserted | |
322 | * @end_ext: last new extent to be inserted | |
323 | * @eh: extent header of target leaf block | |
324 | * @range_to_move: used to decide how to insert extent | |
325 | * | |
326 | * Insert extents into the leaf block. The extent (@o_start) is overwritten | |
327 | * by inserted extents. | |
328 | */ | |
329 | static void | |
330 | mext_insert_inside_block(struct ext4_extent *o_start, | |
331 | struct ext4_extent *o_end, | |
332 | struct ext4_extent *start_ext, | |
333 | struct ext4_extent *new_ext, | |
334 | struct ext4_extent *end_ext, | |
335 | struct ext4_extent_header *eh, | |
336 | int range_to_move) | |
337 | { | |
338 | int i = 0; | |
339 | unsigned long len; | |
340 | ||
341 | /* Move the existing extents */ | |
342 | if (range_to_move && o_end < EXT_LAST_EXTENT(eh)) { | |
343 | len = (unsigned long)(EXT_LAST_EXTENT(eh) + 1) - | |
344 | (unsigned long)(o_end + 1); | |
345 | memmove(o_end + 1 + range_to_move, o_end + 1, len); | |
346 | } | |
347 | ||
348 | /* Insert start entry */ | |
349 | if (start_ext->ee_len) | |
350 | o_start[i++].ee_len = start_ext->ee_len; | |
351 | ||
352 | /* Insert new entry */ | |
353 | if (new_ext->ee_len) { | |
354 | o_start[i] = *new_ext; | |
355 | ext4_ext_store_pblock(&o_start[i++], ext_pblock(new_ext)); | |
356 | } | |
357 | ||
358 | /* Insert end entry */ | |
359 | if (end_ext->ee_len) | |
360 | o_start[i] = *end_ext; | |
361 | ||
362 | /* Increment the total entries counter on the extent block */ | |
363 | le16_add_cpu(&eh->eh_entries, range_to_move); | |
364 | } | |
365 | ||
366 | /** | |
367 | * mext_insert_extents - Insert new extent | |
368 | * | |
369 | * @handle: journal handle | |
370 | * @orig_inode: original inode | |
371 | * @orig_path: path indicates first extent to be changed | |
372 | * @o_start: first original extent to be changed | |
373 | * @o_end: last original extent to be changed | |
374 | * @start_ext: first new extent to be inserted | |
375 | * @new_ext: middle of new extent to be inserted | |
376 | * @end_ext: last new extent to be inserted | |
377 | * | |
378 | * Call the function to insert extents. If we cannot add more extents into | |
379 | * the leaf block, we call mext_insert_across_blocks() to create a | |
380 | * new leaf block. Otherwise call mext_insert_inside_block(). Return 0 | |
381 | * on success, or a negative error value on failure. | |
382 | */ | |
383 | static int | |
384 | mext_insert_extents(handle_t *handle, struct inode *orig_inode, | |
385 | struct ext4_ext_path *orig_path, | |
386 | struct ext4_extent *o_start, | |
387 | struct ext4_extent *o_end, | |
388 | struct ext4_extent *start_ext, | |
389 | struct ext4_extent *new_ext, | |
390 | struct ext4_extent *end_ext) | |
391 | { | |
392 | struct ext4_extent_header *eh; | |
393 | unsigned long need_slots, slots_range; | |
394 | int range_to_move, depth, ret; | |
395 | ||
396 | /* | |
397 | * The extents need to be inserted | |
398 | * start_extent + new_extent + end_extent. | |
399 | */ | |
400 | need_slots = (start_ext->ee_len ? 1 : 0) + (end_ext->ee_len ? 1 : 0) + | |
401 | (new_ext->ee_len ? 1 : 0); | |
402 | ||
403 | /* The number of slots between start and end */ | |
404 | slots_range = ((unsigned long)(o_end + 1) - (unsigned long)o_start + 1) | |
405 | / sizeof(struct ext4_extent); | |
406 | ||
407 | /* Range to move the end of extent */ | |
408 | range_to_move = need_slots - slots_range; | |
409 | depth = orig_path->p_depth; | |
410 | orig_path += depth; | |
411 | eh = orig_path->p_hdr; | |
412 | ||
413 | if (depth) { | |
414 | /* Register to journal */ | |
415 | ret = ext4_journal_get_write_access(handle, orig_path->p_bh); | |
416 | if (ret) | |
417 | return ret; | |
418 | } | |
419 | ||
420 | /* Expansion */ | |
421 | if (range_to_move > 0 && | |
422 | (range_to_move > le16_to_cpu(eh->eh_max) | |
423 | - le16_to_cpu(eh->eh_entries))) { | |
424 | ||
425 | ret = mext_insert_across_blocks(handle, orig_inode, o_start, | |
426 | o_end, start_ext, new_ext, end_ext); | |
427 | if (ret < 0) | |
428 | return ret; | |
429 | } else | |
430 | mext_insert_inside_block(o_start, o_end, start_ext, new_ext, | |
431 | end_ext, eh, range_to_move); | |
432 | ||
433 | if (depth) { | |
434 | ret = ext4_handle_dirty_metadata(handle, orig_inode, | |
435 | orig_path->p_bh); | |
436 | if (ret) | |
437 | return ret; | |
438 | } else { | |
439 | ret = ext4_mark_inode_dirty(handle, orig_inode); | |
440 | if (ret < 0) | |
441 | return ret; | |
442 | } | |
443 | ||
444 | return 0; | |
445 | } | |
446 | ||
447 | /** | |
448 | * mext_leaf_block - Move one leaf extent block into the inode. | |
449 | * | |
450 | * @handle: journal handle | |
451 | * @orig_inode: original inode | |
452 | * @orig_path: path indicates first extent to be changed | |
453 | * @dext: donor extent | |
454 | * @from: start offset on the target file | |
455 | * | |
456 | * In order to insert extents into the leaf block, we must divide the extent | |
457 | * in the leaf block into three extents. The one is located to be inserted | |
458 | * extents, and the others are located around it. | |
459 | * | |
460 | * Therefore, this function creates structures to save extents of the leaf | |
461 | * block, and inserts extents by calling mext_insert_extents() with | |
462 | * created extents. Return 0 on success, or a negative error value on failure. | |
463 | */ | |
464 | static int | |
465 | mext_leaf_block(handle_t *handle, struct inode *orig_inode, | |
466 | struct ext4_ext_path *orig_path, struct ext4_extent *dext, | |
467 | ext4_lblk_t *from) | |
468 | { | |
469 | struct ext4_extent *oext, *o_start, *o_end, *prev_ext; | |
470 | struct ext4_extent new_ext, start_ext, end_ext; | |
471 | ext4_lblk_t new_ext_end; | |
472 | ext4_fsblk_t new_phys_end; | |
473 | int oext_alen, new_ext_alen, end_ext_alen; | |
474 | int depth = ext_depth(orig_inode); | |
475 | int ret; | |
476 | ||
477 | o_start = o_end = oext = orig_path[depth].p_ext; | |
478 | oext_alen = ext4_ext_get_actual_len(oext); | |
479 | start_ext.ee_len = end_ext.ee_len = 0; | |
480 | ||
481 | new_ext.ee_block = cpu_to_le32(*from); | |
482 | ext4_ext_store_pblock(&new_ext, ext_pblock(dext)); | |
483 | new_ext.ee_len = dext->ee_len; | |
484 | new_ext_alen = ext4_ext_get_actual_len(&new_ext); | |
485 | new_ext_end = le32_to_cpu(new_ext.ee_block) + new_ext_alen - 1; | |
486 | new_phys_end = ext_pblock(&new_ext) + new_ext_alen - 1; | |
487 | ||
488 | /* | |
489 | * Case: original extent is first | |
490 | * oext |--------| | |
491 | * new_ext |--| | |
492 | * start_ext |--| | |
493 | */ | |
494 | if (le32_to_cpu(oext->ee_block) < le32_to_cpu(new_ext.ee_block) && | |
495 | le32_to_cpu(new_ext.ee_block) < | |
496 | le32_to_cpu(oext->ee_block) + oext_alen) { | |
497 | start_ext.ee_len = cpu_to_le16(le32_to_cpu(new_ext.ee_block) - | |
498 | le32_to_cpu(oext->ee_block)); | |
499 | copy_extent_status(oext, &start_ext); | |
500 | } else if (oext > EXT_FIRST_EXTENT(orig_path[depth].p_hdr)) { | |
501 | prev_ext = oext - 1; | |
502 | /* | |
503 | * We can merge new_ext into previous extent, | |
504 | * if these are contiguous and same extent type. | |
505 | */ | |
506 | if (ext4_can_extents_be_merged(orig_inode, prev_ext, | |
507 | &new_ext)) { | |
508 | o_start = prev_ext; | |
509 | start_ext.ee_len = cpu_to_le16( | |
510 | ext4_ext_get_actual_len(prev_ext) + | |
511 | new_ext_alen); | |
512 | copy_extent_status(prev_ext, &start_ext); | |
513 | new_ext.ee_len = 0; | |
514 | } | |
515 | } | |
516 | ||
517 | /* | |
518 | * Case: new_ext_end must be less than oext | |
519 | * oext |-----------| | |
520 | * new_ext |-------| | |
521 | */ | |
522 | BUG_ON(le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end); | |
523 | ||
524 | /* | |
525 | * Case: new_ext is smaller than original extent | |
526 | * oext |---------------| | |
527 | * new_ext |-----------| | |
528 | * end_ext |---| | |
529 | */ | |
530 | if (le32_to_cpu(oext->ee_block) <= new_ext_end && | |
531 | new_ext_end < le32_to_cpu(oext->ee_block) + oext_alen - 1) { | |
532 | end_ext.ee_len = | |
533 | cpu_to_le16(le32_to_cpu(oext->ee_block) + | |
534 | oext_alen - 1 - new_ext_end); | |
535 | copy_extent_status(oext, &end_ext); | |
536 | end_ext_alen = ext4_ext_get_actual_len(&end_ext); | |
537 | ext4_ext_store_pblock(&end_ext, | |
538 | (ext_pblock(o_end) + oext_alen - end_ext_alen)); | |
539 | end_ext.ee_block = | |
540 | cpu_to_le32(le32_to_cpu(o_end->ee_block) + | |
541 | oext_alen - end_ext_alen); | |
542 | } | |
543 | ||
544 | ret = mext_insert_extents(handle, orig_inode, orig_path, o_start, | |
545 | o_end, &start_ext, &new_ext, &end_ext); | |
546 | return ret; | |
547 | } | |
548 | ||
549 | /** | |
550 | * mext_calc_swap_extents - Calculate extents for extent swapping. | |
551 | * | |
552 | * @tmp_dext: the extent that will belong to the original inode | |
553 | * @tmp_oext: the extent that will belong to the donor inode | |
554 | * @orig_off: block offset of original inode | |
555 | * @donor_off: block offset of donor inode | |
556 | * @max_count: the maximun length of extents | |
557 | */ | |
558 | static void | |
559 | mext_calc_swap_extents(struct ext4_extent *tmp_dext, | |
560 | struct ext4_extent *tmp_oext, | |
561 | ext4_lblk_t orig_off, ext4_lblk_t donor_off, | |
562 | ext4_lblk_t max_count) | |
563 | { | |
564 | ext4_lblk_t diff, orig_diff; | |
565 | struct ext4_extent dext_old, oext_old; | |
566 | ||
567 | dext_old = *tmp_dext; | |
568 | oext_old = *tmp_oext; | |
569 | ||
570 | /* When tmp_dext is too large, pick up the target range. */ | |
571 | diff = donor_off - le32_to_cpu(tmp_dext->ee_block); | |
572 | ||
573 | ext4_ext_store_pblock(tmp_dext, ext_pblock(tmp_dext) + diff); | |
574 | tmp_dext->ee_block = | |
575 | cpu_to_le32(le32_to_cpu(tmp_dext->ee_block) + diff); | |
576 | tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_dext->ee_len) - diff); | |
577 | ||
578 | if (max_count < ext4_ext_get_actual_len(tmp_dext)) | |
579 | tmp_dext->ee_len = cpu_to_le16(max_count); | |
580 | ||
581 | orig_diff = orig_off - le32_to_cpu(tmp_oext->ee_block); | |
582 | ext4_ext_store_pblock(tmp_oext, ext_pblock(tmp_oext) + orig_diff); | |
583 | ||
584 | /* Adjust extent length if donor extent is larger than orig */ | |
585 | if (ext4_ext_get_actual_len(tmp_dext) > | |
586 | ext4_ext_get_actual_len(tmp_oext) - orig_diff) | |
587 | tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_oext->ee_len) - | |
588 | orig_diff); | |
589 | ||
590 | tmp_oext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(tmp_dext)); | |
591 | ||
592 | copy_extent_status(&oext_old, tmp_dext); | |
593 | copy_extent_status(&dext_old, tmp_oext); | |
594 | } | |
595 | ||
596 | /** | |
597 | * mext_replace_branches - Replace original extents with new extents | |
598 | * | |
599 | * @handle: journal handle | |
600 | * @orig_inode: original inode | |
601 | * @donor_inode: donor inode | |
602 | * @from: block offset of orig_inode | |
603 | * @count: block count to be replaced | |
604 | * | |
605 | * Replace original inode extents and donor inode extents page by page. | |
606 | * We implement this replacement in the following three steps: | |
607 | * 1. Save the block information of original and donor inodes into | |
608 | * dummy extents. | |
609 | * 2. Change the block information of original inode to point at the | |
610 | * donor inode blocks. | |
611 | * 3. Change the block information of donor inode to point at the saved | |
612 | * original inode blocks in the dummy extents. | |
613 | * | |
614 | * Return 0 on success, or a negative error value on failure. | |
615 | */ | |
616 | static int | |
617 | mext_replace_branches(handle_t *handle, struct inode *orig_inode, | |
618 | struct inode *donor_inode, ext4_lblk_t from, | |
619 | ext4_lblk_t count) | |
620 | { | |
621 | struct ext4_ext_path *orig_path = NULL; | |
622 | struct ext4_ext_path *donor_path = NULL; | |
623 | struct ext4_extent *oext, *dext; | |
624 | struct ext4_extent tmp_dext, tmp_oext; | |
625 | ext4_lblk_t orig_off = from, donor_off = from; | |
626 | int err = 0; | |
627 | int depth; | |
628 | int replaced_count = 0; | |
629 | int dext_alen; | |
630 | ||
631 | mext_double_down_write(orig_inode, donor_inode); | |
632 | ||
633 | /* Get the original extent for the block "orig_off" */ | |
634 | get_ext_path(orig_path, orig_inode, orig_off, err); | |
635 | if (orig_path == NULL) | |
636 | goto out; | |
637 | ||
638 | /* Get the donor extent for the head */ | |
639 | get_ext_path(donor_path, donor_inode, donor_off, err); | |
640 | if (donor_path == NULL) | |
641 | goto out; | |
642 | depth = ext_depth(orig_inode); | |
643 | oext = orig_path[depth].p_ext; | |
644 | tmp_oext = *oext; | |
645 | ||
646 | depth = ext_depth(donor_inode); | |
647 | dext = donor_path[depth].p_ext; | |
648 | tmp_dext = *dext; | |
649 | ||
650 | mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, | |
651 | donor_off, count); | |
652 | ||
653 | /* Loop for the donor extents */ | |
654 | while (1) { | |
655 | /* The extent for donor must be found. */ | |
656 | BUG_ON(!dext || donor_off != le32_to_cpu(tmp_dext.ee_block)); | |
657 | ||
658 | /* Set donor extent to orig extent */ | |
659 | err = mext_leaf_block(handle, orig_inode, | |
660 | orig_path, &tmp_dext, &orig_off); | |
661 | if (err < 0) | |
662 | goto out; | |
663 | ||
664 | /* Set orig extent to donor extent */ | |
665 | err = mext_leaf_block(handle, donor_inode, | |
666 | donor_path, &tmp_oext, &donor_off); | |
667 | if (err < 0) | |
668 | goto out; | |
669 | ||
670 | dext_alen = ext4_ext_get_actual_len(&tmp_dext); | |
671 | replaced_count += dext_alen; | |
672 | donor_off += dext_alen; | |
673 | orig_off += dext_alen; | |
674 | ||
675 | /* Already moved the expected blocks */ | |
676 | if (replaced_count >= count) | |
677 | break; | |
678 | ||
679 | if (orig_path) | |
680 | ext4_ext_drop_refs(orig_path); | |
681 | get_ext_path(orig_path, orig_inode, orig_off, err); | |
682 | if (orig_path == NULL) | |
683 | goto out; | |
684 | depth = ext_depth(orig_inode); | |
685 | oext = orig_path[depth].p_ext; | |
686 | if (le32_to_cpu(oext->ee_block) + | |
687 | ext4_ext_get_actual_len(oext) <= orig_off) { | |
688 | err = 0; | |
689 | goto out; | |
690 | } | |
691 | tmp_oext = *oext; | |
692 | ||
693 | if (donor_path) | |
694 | ext4_ext_drop_refs(donor_path); | |
695 | get_ext_path(donor_path, donor_inode, | |
696 | donor_off, err); | |
697 | if (donor_path == NULL) | |
698 | goto out; | |
699 | depth = ext_depth(donor_inode); | |
700 | dext = donor_path[depth].p_ext; | |
701 | if (le32_to_cpu(dext->ee_block) + | |
702 | ext4_ext_get_actual_len(dext) <= donor_off) { | |
703 | err = 0; | |
704 | goto out; | |
705 | } | |
706 | tmp_dext = *dext; | |
707 | ||
708 | mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, | |
709 | donor_off, | |
710 | count - replaced_count); | |
711 | } | |
712 | ||
713 | out: | |
714 | if (orig_path) { | |
715 | ext4_ext_drop_refs(orig_path); | |
716 | kfree(orig_path); | |
717 | } | |
718 | if (donor_path) { | |
719 | ext4_ext_drop_refs(donor_path); | |
720 | kfree(donor_path); | |
721 | } | |
722 | ||
723 | mext_double_up_write(orig_inode, donor_inode); | |
724 | return err; | |
725 | } | |
726 | ||
727 | /** | |
728 | * move_extent_per_page - Move extent data per page | |
729 | * | |
730 | * @o_filp: file structure of original file | |
731 | * @donor_inode: donor inode | |
732 | * @orig_page_offset: page index on original file | |
733 | * @data_offset_in_page: block index where data swapping starts | |
734 | * @block_len_in_page: the number of blocks to be swapped | |
735 | * @uninit: orig extent is uninitialized or not | |
736 | * | |
737 | * Save the data in original inode blocks and replace original inode extents | |
738 | * with donor inode extents by calling mext_replace_branches(). | |
739 | * Finally, write out the saved data in new original inode blocks. Return 0 | |
740 | * on success, or a negative error value on failure. | |
741 | */ | |
742 | static int | |
743 | move_extent_par_page(struct file *o_filp, struct inode *donor_inode, | |
744 | pgoff_t orig_page_offset, int data_offset_in_page, | |
745 | int block_len_in_page, int uninit) | |
746 | { | |
747 | struct inode *orig_inode = o_filp->f_dentry->d_inode; | |
748 | struct address_space *mapping = orig_inode->i_mapping; | |
749 | struct buffer_head *bh; | |
750 | struct page *page = NULL; | |
751 | const struct address_space_operations *a_ops = mapping->a_ops; | |
752 | handle_t *handle; | |
753 | ext4_lblk_t orig_blk_offset; | |
754 | long long offs = orig_page_offset << PAGE_CACHE_SHIFT; | |
755 | unsigned long blocksize = orig_inode->i_sb->s_blocksize; | |
756 | unsigned int w_flags = 0; | |
757 | unsigned int tmp_data_len, data_len; | |
758 | void *fsdata; | |
759 | int ret, i, jblocks; | |
760 | int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; | |
761 | ||
762 | /* | |
763 | * It needs twice the amount of ordinary journal buffers because | |
764 | * inode and donor_inode may change each different metadata blocks. | |
765 | */ | |
766 | jblocks = ext4_writepage_trans_blocks(orig_inode) * 2; | |
767 | handle = ext4_journal_start(orig_inode, jblocks); | |
768 | if (IS_ERR(handle)) { | |
769 | ret = PTR_ERR(handle); | |
770 | return ret; | |
771 | } | |
772 | ||
773 | if (segment_eq(get_fs(), KERNEL_DS)) | |
774 | w_flags |= AOP_FLAG_UNINTERRUPTIBLE; | |
775 | ||
776 | orig_blk_offset = orig_page_offset * blocks_per_page + | |
777 | data_offset_in_page; | |
778 | ||
779 | /* | |
780 | * If orig extent is uninitialized one, | |
781 | * it's not necessary force the page into memory | |
782 | * and then force it to be written out again. | |
783 | * Just swap data blocks between orig and donor. | |
784 | */ | |
785 | if (uninit) { | |
786 | ret = mext_replace_branches(handle, orig_inode, | |
787 | donor_inode, orig_blk_offset, | |
788 | block_len_in_page); | |
789 | ||
790 | /* Clear the inode cache not to refer to the old data */ | |
791 | ext4_ext_invalidate_cache(orig_inode); | |
792 | ext4_ext_invalidate_cache(donor_inode); | |
793 | goto out2; | |
794 | } | |
795 | ||
796 | offs = (long long)orig_blk_offset << orig_inode->i_blkbits; | |
797 | ||
798 | /* Calculate data_len */ | |
799 | if ((orig_blk_offset + block_len_in_page - 1) == | |
800 | ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) { | |
801 | /* Replace the last block */ | |
802 | tmp_data_len = orig_inode->i_size & (blocksize - 1); | |
803 | /* | |
804 | * If data_len equal zero, it shows data_len is multiples of | |
805 | * blocksize. So we set appropriate value. | |
806 | */ | |
807 | if (tmp_data_len == 0) | |
808 | tmp_data_len = blocksize; | |
809 | ||
810 | data_len = tmp_data_len + | |
811 | ((block_len_in_page - 1) << orig_inode->i_blkbits); | |
812 | } else { | |
813 | data_len = block_len_in_page << orig_inode->i_blkbits; | |
814 | } | |
815 | ||
816 | ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags, | |
817 | &page, &fsdata); | |
818 | if (unlikely(ret < 0)) | |
819 | goto out; | |
820 | ||
821 | if (!PageUptodate(page)) { | |
822 | mapping->a_ops->readpage(o_filp, page); | |
823 | lock_page(page); | |
824 | } | |
825 | ||
826 | /* | |
827 | * try_to_release_page() doesn't call releasepage in writeback mode. | |
828 | * We should care about the order of writing to the same file | |
829 | * by multiple move extent processes. | |
830 | * It needs to call wait_on_page_writeback() to wait for the | |
831 | * writeback of the page. | |
832 | */ | |
833 | if (PageWriteback(page)) | |
834 | wait_on_page_writeback(page); | |
835 | ||
836 | /* Release old bh and drop refs */ | |
837 | try_to_release_page(page, 0); | |
838 | ||
839 | ret = mext_replace_branches(handle, orig_inode, donor_inode, | |
840 | orig_blk_offset, block_len_in_page); | |
841 | if (ret < 0) | |
842 | goto out; | |
843 | ||
844 | /* Clear the inode cache not to refer to the old data */ | |
845 | ext4_ext_invalidate_cache(orig_inode); | |
846 | ext4_ext_invalidate_cache(donor_inode); | |
847 | ||
848 | if (!page_has_buffers(page)) | |
849 | create_empty_buffers(page, 1 << orig_inode->i_blkbits, 0); | |
850 | ||
851 | bh = page_buffers(page); | |
852 | for (i = 0; i < data_offset_in_page; i++) | |
853 | bh = bh->b_this_page; | |
854 | ||
855 | for (i = 0; i < block_len_in_page; i++) { | |
856 | ret = ext4_get_block(orig_inode, | |
857 | (sector_t)(orig_blk_offset + i), bh, 0); | |
858 | if (ret < 0) | |
859 | goto out; | |
860 | ||
861 | if (bh->b_this_page != NULL) | |
862 | bh = bh->b_this_page; | |
863 | } | |
864 | ||
865 | ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len, | |
866 | page, fsdata); | |
867 | page = NULL; | |
868 | ||
869 | out: | |
870 | if (unlikely(page)) { | |
871 | if (PageLocked(page)) | |
872 | unlock_page(page); | |
873 | page_cache_release(page); | |
874 | } | |
875 | out2: | |
876 | ext4_journal_stop(handle); | |
877 | ||
878 | return ret < 0 ? ret : 0; | |
879 | } | |
880 | ||
881 | /** | |
882 | * mext_check_argumants - Check whether move extent can be done | |
883 | * | |
884 | * @orig_inode: original inode | |
885 | * @donor_inode: donor inode | |
886 | * @orig_start: logical start offset in block for orig | |
887 | * @donor_start: logical start offset in block for donor | |
888 | * @len: the number of blocks to be moved | |
889 | * @moved_len: moved block length | |
890 | * | |
891 | * Check the arguments of ext4_move_extents() whether the files can be | |
892 | * exchanged with each other. | |
893 | * Return 0 on success, or a negative error value on failure. | |
894 | */ | |
895 | static int | |
896 | mext_check_arguments(struct inode *orig_inode, | |
897 | struct inode *donor_inode, __u64 orig_start, | |
898 | __u64 donor_start, __u64 *len, __u64 moved_len) | |
899 | { | |
900 | /* Regular file check */ | |
901 | if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { | |
902 | ext4_debug("ext4 move extent: The argument files should be " | |
903 | "regular file [ino:orig %lu, donor %lu]\n", | |
904 | orig_inode->i_ino, donor_inode->i_ino); | |
905 | return -EINVAL; | |
906 | } | |
907 | ||
908 | /* Ext4 move extent does not support swapfile */ | |
909 | if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) { | |
910 | ext4_debug("ext4 move extent: The argument files should " | |
911 | "not be swapfile [ino:orig %lu, donor %lu]\n", | |
912 | orig_inode->i_ino, donor_inode->i_ino); | |
913 | return -EINVAL; | |
914 | } | |
915 | ||
916 | /* Files should be in the same ext4 FS */ | |
917 | if (orig_inode->i_sb != donor_inode->i_sb) { | |
918 | ext4_debug("ext4 move extent: The argument files " | |
919 | "should be in same FS [ino:orig %lu, donor %lu]\n", | |
920 | orig_inode->i_ino, donor_inode->i_ino); | |
921 | return -EINVAL; | |
922 | } | |
923 | ||
924 | /* orig and donor should be different file */ | |
925 | if (orig_inode->i_ino == donor_inode->i_ino) { | |
926 | ext4_debug("ext4 move extent: The argument files should not " | |
927 | "be same file [ino:orig %lu, donor %lu]\n", | |
928 | orig_inode->i_ino, donor_inode->i_ino); | |
929 | return -EINVAL; | |
930 | } | |
931 | ||
932 | /* Ext4 move extent supports only extent based file */ | |
933 | if (!(EXT4_I(orig_inode)->i_flags & EXT4_EXTENTS_FL)) { | |
934 | ext4_debug("ext4 move extent: orig file is not extents " | |
935 | "based file [ino:orig %lu]\n", orig_inode->i_ino); | |
936 | return -EOPNOTSUPP; | |
937 | } else if (!(EXT4_I(donor_inode)->i_flags & EXT4_EXTENTS_FL)) { | |
938 | ext4_debug("ext4 move extent: donor file is not extents " | |
939 | "based file [ino:donor %lu]\n", donor_inode->i_ino); | |
940 | return -EOPNOTSUPP; | |
941 | } | |
942 | ||
943 | if ((!orig_inode->i_size) || (!donor_inode->i_size)) { | |
944 | ext4_debug("ext4 move extent: File size is 0 byte\n"); | |
945 | return -EINVAL; | |
946 | } | |
947 | ||
948 | /* Start offset should be same */ | |
949 | if (orig_start != donor_start) { | |
950 | ext4_debug("ext4 move extent: orig and donor's start " | |
951 | "offset are not same [ino:orig %lu, donor %lu]\n", | |
952 | orig_inode->i_ino, donor_inode->i_ino); | |
953 | return -EINVAL; | |
954 | } | |
955 | ||
956 | if (moved_len) { | |
957 | ext4_debug("ext4 move extent: moved_len should be 0 " | |
958 | "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino, | |
959 | donor_inode->i_ino); | |
960 | return -EINVAL; | |
961 | } | |
962 | ||
963 | if ((orig_start > MAX_DEFRAG_SIZE) || | |
964 | (donor_start > MAX_DEFRAG_SIZE) || | |
965 | (*len > MAX_DEFRAG_SIZE) || | |
966 | (orig_start + *len > MAX_DEFRAG_SIZE)) { | |
967 | ext4_debug("ext4 move extent: Can't handle over [%lu] blocks " | |
968 | "[ino:orig %lu, donor %lu]\n", MAX_DEFRAG_SIZE, | |
969 | orig_inode->i_ino, donor_inode->i_ino); | |
970 | return -EINVAL; | |
971 | } | |
972 | ||
973 | if (orig_inode->i_size > donor_inode->i_size) { | |
974 | if (orig_start >= donor_inode->i_size) { | |
975 | ext4_debug("ext4 move extent: orig start offset " | |
976 | "[%llu] should be less than donor file size " | |
977 | "[%lld] [ino:orig %lu, donor_inode %lu]\n", | |
978 | orig_start, donor_inode->i_size, | |
979 | orig_inode->i_ino, donor_inode->i_ino); | |
980 | return -EINVAL; | |
981 | } | |
982 | ||
983 | if (orig_start + *len > donor_inode->i_size) { | |
984 | ext4_debug("ext4 move extent: End offset [%llu] should " | |
985 | "be less than donor file size [%lld]." | |
986 | "So adjust length from %llu to %lld " | |
987 | "[ino:orig %lu, donor %lu]\n", | |
988 | orig_start + *len, donor_inode->i_size, | |
989 | *len, donor_inode->i_size - orig_start, | |
990 | orig_inode->i_ino, donor_inode->i_ino); | |
991 | *len = donor_inode->i_size - orig_start; | |
992 | } | |
993 | } else { | |
994 | if (orig_start >= orig_inode->i_size) { | |
995 | ext4_debug("ext4 move extent: start offset [%llu] " | |
996 | "should be less than original file size " | |
997 | "[%lld] [inode:orig %lu, donor %lu]\n", | |
998 | orig_start, orig_inode->i_size, | |
999 | orig_inode->i_ino, donor_inode->i_ino); | |
1000 | return -EINVAL; | |
1001 | } | |
1002 | ||
1003 | if (orig_start + *len > orig_inode->i_size) { | |
1004 | ext4_debug("ext4 move extent: Adjust length " | |
1005 | "from %llu to %lld. Because it should be " | |
1006 | "less than original file size " | |
1007 | "[ino:orig %lu, donor %lu]\n", | |
1008 | *len, orig_inode->i_size - orig_start, | |
1009 | orig_inode->i_ino, donor_inode->i_ino); | |
1010 | *len = orig_inode->i_size - orig_start; | |
1011 | } | |
1012 | } | |
1013 | ||
1014 | if (!*len) { | |
1015 | ext4_debug("ext4 move extent: len shoudld not be 0 " | |
1016 | "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino, | |
1017 | donor_inode->i_ino); | |
1018 | return -EINVAL; | |
1019 | } | |
1020 | ||
1021 | return 0; | |
1022 | } | |
1023 | ||
1024 | /** | |
1025 | * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2 | |
1026 | * | |
1027 | * @inode1: the inode structure | |
1028 | * @inode2: the inode structure | |
1029 | * | |
1030 | * Lock two inodes' i_mutex by i_ino order. This function is moved from | |
1031 | * fs/inode.c. | |
1032 | */ | |
1033 | static void | |
1034 | mext_inode_double_lock(struct inode *inode1, struct inode *inode2) | |
1035 | { | |
1036 | if (inode1 == NULL || inode2 == NULL || inode1 == inode2) { | |
1037 | if (inode1) | |
1038 | mutex_lock(&inode1->i_mutex); | |
1039 | else if (inode2) | |
1040 | mutex_lock(&inode2->i_mutex); | |
1041 | return; | |
1042 | } | |
1043 | ||
1044 | if (inode1->i_ino < inode2->i_ino) { | |
1045 | mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); | |
1046 | mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); | |
1047 | } else { | |
1048 | mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT); | |
1049 | mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD); | |
1050 | } | |
1051 | } | |
1052 | ||
1053 | /** | |
1054 | * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2 | |
1055 | * | |
1056 | * @inode1: the inode that is released first | |
1057 | * @inode2: the inode that is released second | |
1058 | * | |
1059 | * This function is moved from fs/inode.c. | |
1060 | */ | |
1061 | ||
1062 | static void | |
1063 | mext_inode_double_unlock(struct inode *inode1, struct inode *inode2) | |
1064 | { | |
1065 | if (inode1) | |
1066 | mutex_unlock(&inode1->i_mutex); | |
1067 | ||
1068 | if (inode2 && inode2 != inode1) | |
1069 | mutex_unlock(&inode2->i_mutex); | |
1070 | } | |
1071 | ||
1072 | /** | |
1073 | * ext4_move_extents - Exchange the specified range of a file | |
1074 | * | |
1075 | * @o_filp: file structure of the original file | |
1076 | * @d_filp: file structure of the donor file | |
1077 | * @orig_start: start offset in block for orig | |
1078 | * @donor_start: start offset in block for donor | |
1079 | * @len: the number of blocks to be moved | |
1080 | * @moved_len: moved block length | |
1081 | * | |
1082 | * This function returns 0 and moved block length is set in moved_len | |
1083 | * if succeed, otherwise returns error value. | |
1084 | * | |
1085 | * Note: ext4_move_extents() proceeds the following order. | |
1086 | * 1:ext4_move_extents() calculates the last block number of moving extent | |
1087 | * function by the start block number (orig_start) and the number of blocks | |
1088 | * to be moved (len) specified as arguments. | |
1089 | * If the {orig, donor}_start points a hole, the extent's start offset | |
1090 | * pointed by ext_cur (current extent), holecheck_path, orig_path are set | |
1091 | * after hole behind. | |
1092 | * 2:Continue step 3 to step 5, until the holecheck_path points to last_extent | |
1093 | * or the ext_cur exceeds the block_end which is last logical block number. | |
1094 | * 3:To get the length of continues area, call mext_next_extent() | |
1095 | * specified with the ext_cur (initial value is holecheck_path) re-cursive, | |
1096 | * until find un-continuous extent, the start logical block number exceeds | |
1097 | * the block_end or the extent points to the last extent. | |
1098 | * 4:Exchange the original inode data with donor inode data | |
1099 | * from orig_page_offset to seq_end_page. | |
1100 | * The start indexes of data are specified as arguments. | |
1101 | * That of the original inode is orig_page_offset, | |
1102 | * and the donor inode is also orig_page_offset | |
1103 | * (To easily handle blocksize != pagesize case, the offset for the | |
1104 | * donor inode is block unit). | |
1105 | * 5:Update holecheck_path and orig_path to points a next proceeding extent, | |
1106 | * then returns to step 2. | |
1107 | * 6:Release holecheck_path, orig_path and set the len to moved_len | |
1108 | * which shows the number of moved blocks. | |
1109 | * The moved_len is useful for the command to calculate the file offset | |
1110 | * for starting next move extent ioctl. | |
1111 | * 7:Return 0 on success, or a negative error value on failure. | |
1112 | */ | |
1113 | int | |
1114 | ext4_move_extents(struct file *o_filp, struct file *d_filp, | |
1115 | __u64 orig_start, __u64 donor_start, __u64 len, | |
1116 | __u64 *moved_len) | |
1117 | { | |
1118 | struct inode *orig_inode = o_filp->f_dentry->d_inode; | |
1119 | struct inode *donor_inode = d_filp->f_dentry->d_inode; | |
1120 | struct ext4_ext_path *orig_path = NULL, *holecheck_path = NULL; | |
1121 | struct ext4_extent *ext_prev, *ext_cur, *ext_dummy; | |
1122 | ext4_lblk_t block_start = orig_start; | |
1123 | ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0; | |
1124 | ext4_lblk_t rest_blocks; | |
1125 | pgoff_t orig_page_offset = 0, seq_end_page; | |
1126 | int ret, depth, last_extent = 0; | |
1127 | int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; | |
1128 | int data_offset_in_page; | |
1129 | int block_len_in_page; | |
1130 | int uninit; | |
1131 | ||
1132 | /* protect orig and donor against a truncate */ | |
1133 | mext_inode_double_lock(orig_inode, donor_inode); | |
1134 | ||
1135 | mext_double_down_read(orig_inode, donor_inode); | |
1136 | /* Check the filesystem environment whether move_extent can be done */ | |
1137 | ret = mext_check_arguments(orig_inode, donor_inode, orig_start, | |
1138 | donor_start, &len, *moved_len); | |
1139 | mext_double_up_read(orig_inode, donor_inode); | |
1140 | if (ret) | |
1141 | goto out2; | |
1142 | ||
1143 | file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits; | |
1144 | block_end = block_start + len - 1; | |
1145 | if (file_end < block_end) | |
1146 | len -= block_end - file_end; | |
1147 | ||
1148 | get_ext_path(orig_path, orig_inode, block_start, ret); | |
1149 | if (orig_path == NULL) | |
1150 | goto out2; | |
1151 | ||
1152 | /* Get path structure to check the hole */ | |
1153 | get_ext_path(holecheck_path, orig_inode, block_start, ret); | |
1154 | if (holecheck_path == NULL) | |
1155 | goto out; | |
1156 | ||
1157 | depth = ext_depth(orig_inode); | |
1158 | ext_cur = holecheck_path[depth].p_ext; | |
1159 | if (ext_cur == NULL) { | |
1160 | ret = -EINVAL; | |
1161 | goto out; | |
1162 | } | |
1163 | ||
1164 | /* | |
1165 | * Get proper extent whose ee_block is beyond block_start | |
1166 | * if block_start was within the hole. | |
1167 | */ | |
1168 | if (le32_to_cpu(ext_cur->ee_block) + | |
1169 | ext4_ext_get_actual_len(ext_cur) - 1 < block_start) { | |
1170 | last_extent = mext_next_extent(orig_inode, | |
1171 | holecheck_path, &ext_cur); | |
1172 | if (last_extent < 0) { | |
1173 | ret = last_extent; | |
1174 | goto out; | |
1175 | } | |
1176 | last_extent = mext_next_extent(orig_inode, orig_path, | |
1177 | &ext_dummy); | |
1178 | if (last_extent < 0) { | |
1179 | ret = last_extent; | |
1180 | goto out; | |
1181 | } | |
1182 | } | |
1183 | seq_start = block_start; | |
1184 | ||
1185 | /* No blocks within the specified range. */ | |
1186 | if (le32_to_cpu(ext_cur->ee_block) > block_end) { | |
1187 | ext4_debug("ext4 move extent: The specified range of file " | |
1188 | "may be the hole\n"); | |
1189 | ret = -EINVAL; | |
1190 | goto out; | |
1191 | } | |
1192 | ||
1193 | /* Adjust start blocks */ | |
1194 | add_blocks = min(le32_to_cpu(ext_cur->ee_block) + | |
1195 | ext4_ext_get_actual_len(ext_cur), block_end + 1) - | |
1196 | max(le32_to_cpu(ext_cur->ee_block), block_start); | |
1197 | ||
1198 | while (!last_extent && le32_to_cpu(ext_cur->ee_block) <= block_end) { | |
1199 | seq_blocks += add_blocks; | |
1200 | ||
1201 | /* Adjust tail blocks */ | |
1202 | if (seq_start + seq_blocks - 1 > block_end) | |
1203 | seq_blocks = block_end - seq_start + 1; | |
1204 | ||
1205 | ext_prev = ext_cur; | |
1206 | last_extent = mext_next_extent(orig_inode, holecheck_path, | |
1207 | &ext_cur); | |
1208 | if (last_extent < 0) { | |
1209 | ret = last_extent; | |
1210 | break; | |
1211 | } | |
1212 | add_blocks = ext4_ext_get_actual_len(ext_cur); | |
1213 | ||
1214 | /* | |
1215 | * Extend the length of contiguous block (seq_blocks) | |
1216 | * if extents are contiguous. | |
1217 | */ | |
1218 | if (ext4_can_extents_be_merged(orig_inode, | |
1219 | ext_prev, ext_cur) && | |
1220 | block_end >= le32_to_cpu(ext_cur->ee_block) && | |
1221 | !last_extent) | |
1222 | continue; | |
1223 | ||
1224 | /* Is original extent is uninitialized */ | |
1225 | uninit = ext4_ext_is_uninitialized(ext_prev); | |
1226 | ||
1227 | data_offset_in_page = seq_start % blocks_per_page; | |
1228 | ||
1229 | /* | |
1230 | * Calculate data blocks count that should be swapped | |
1231 | * at the first page. | |
1232 | */ | |
1233 | if (data_offset_in_page + seq_blocks > blocks_per_page) { | |
1234 | /* Swapped blocks are across pages */ | |
1235 | block_len_in_page = | |
1236 | blocks_per_page - data_offset_in_page; | |
1237 | } else { | |
1238 | /* Swapped blocks are in a page */ | |
1239 | block_len_in_page = seq_blocks; | |
1240 | } | |
1241 | ||
1242 | orig_page_offset = seq_start >> | |
1243 | (PAGE_CACHE_SHIFT - orig_inode->i_blkbits); | |
1244 | seq_end_page = (seq_start + seq_blocks - 1) >> | |
1245 | (PAGE_CACHE_SHIFT - orig_inode->i_blkbits); | |
1246 | seq_start = le32_to_cpu(ext_cur->ee_block); | |
1247 | rest_blocks = seq_blocks; | |
1248 | ||
1249 | /* Discard preallocations of two inodes */ | |
1250 | down_write(&EXT4_I(orig_inode)->i_data_sem); | |
1251 | ext4_discard_preallocations(orig_inode); | |
1252 | up_write(&EXT4_I(orig_inode)->i_data_sem); | |
1253 | ||
1254 | down_write(&EXT4_I(donor_inode)->i_data_sem); | |
1255 | ext4_discard_preallocations(donor_inode); | |
1256 | up_write(&EXT4_I(donor_inode)->i_data_sem); | |
1257 | ||
1258 | while (orig_page_offset <= seq_end_page) { | |
1259 | ||
1260 | /* Swap original branches with new branches */ | |
1261 | ret = move_extent_par_page(o_filp, donor_inode, | |
1262 | orig_page_offset, | |
1263 | data_offset_in_page, | |
1264 | block_len_in_page, uninit); | |
1265 | if (ret < 0) | |
1266 | goto out; | |
1267 | orig_page_offset++; | |
1268 | /* Count how many blocks we have exchanged */ | |
1269 | *moved_len += block_len_in_page; | |
1270 | BUG_ON(*moved_len > len); | |
1271 | ||
1272 | data_offset_in_page = 0; | |
1273 | rest_blocks -= block_len_in_page; | |
1274 | if (rest_blocks > blocks_per_page) | |
1275 | block_len_in_page = blocks_per_page; | |
1276 | else | |
1277 | block_len_in_page = rest_blocks; | |
1278 | } | |
1279 | ||
1280 | /* Decrease buffer counter */ | |
1281 | if (holecheck_path) | |
1282 | ext4_ext_drop_refs(holecheck_path); | |
1283 | get_ext_path(holecheck_path, orig_inode, | |
1284 | seq_start, ret); | |
1285 | if (holecheck_path == NULL) | |
1286 | break; | |
1287 | depth = holecheck_path->p_depth; | |
1288 | ||
1289 | /* Decrease buffer counter */ | |
1290 | if (orig_path) | |
1291 | ext4_ext_drop_refs(orig_path); | |
1292 | get_ext_path(orig_path, orig_inode, seq_start, ret); | |
1293 | if (orig_path == NULL) | |
1294 | break; | |
1295 | ||
1296 | ext_cur = holecheck_path[depth].p_ext; | |
1297 | add_blocks = ext4_ext_get_actual_len(ext_cur); | |
1298 | seq_blocks = 0; | |
1299 | ||
1300 | } | |
1301 | out: | |
1302 | if (orig_path) { | |
1303 | ext4_ext_drop_refs(orig_path); | |
1304 | kfree(orig_path); | |
1305 | } | |
1306 | if (holecheck_path) { | |
1307 | ext4_ext_drop_refs(holecheck_path); | |
1308 | kfree(holecheck_path); | |
1309 | } | |
1310 | out2: | |
1311 | mext_inode_double_unlock(orig_inode, donor_inode); | |
1312 | ||
1313 | if (ret) | |
1314 | return ret; | |
1315 | ||
1316 | /* All of the specified blocks must be exchanged in succeed */ | |
1317 | BUG_ON(*moved_len != len); | |
1318 | ||
1319 | return 0; | |
1320 | } |