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748de673 AF |
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 | ||
e8505970 AF |
22 | /** |
23 | * get_ext_path - Find an extent path for designated logical block number. | |
24 | * | |
25 | * @inode: an inode which is searched | |
26 | * @lblock: logical block number to find an extent path | |
27 | * @path: pointer to an extent path pointer (for output) | |
28 | * | |
29 | * ext4_ext_find_extent wrapper. Return 0 on success, or a negative error value | |
30 | * on failure. | |
31 | */ | |
32 | static inline int | |
33 | get_ext_path(struct inode *inode, ext4_lblk_t lblock, | |
34 | struct ext4_ext_path **path) | |
35 | { | |
36 | int ret = 0; | |
37 | ||
38 | *path = ext4_ext_find_extent(inode, lblock, *path); | |
39 | if (IS_ERR(*path)) { | |
40 | ret = PTR_ERR(*path); | |
41 | *path = NULL; | |
42 | } | |
43 | return ret; | |
44 | } | |
748de673 AF |
45 | |
46 | /** | |
47 | * copy_extent_status - Copy the extent's initialization status | |
48 | * | |
49 | * @src: an extent for getting initialize status | |
50 | * @dest: an extent to be set the status | |
51 | */ | |
52 | static void | |
53 | copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest) | |
54 | { | |
55 | if (ext4_ext_is_uninitialized(src)) | |
56 | ext4_ext_mark_uninitialized(dest); | |
57 | else | |
58 | dest->ee_len = cpu_to_le16(ext4_ext_get_actual_len(dest)); | |
59 | } | |
60 | ||
61 | /** | |
62 | * mext_next_extent - Search for the next extent and set it to "extent" | |
63 | * | |
64 | * @inode: inode which is searched | |
65 | * @path: this will obtain data for the next extent | |
66 | * @extent: pointer to the next extent we have just gotten | |
67 | * | |
68 | * Search the next extent in the array of ext4_ext_path structure (@path) | |
69 | * and set it to ext4_extent structure (@extent). In addition, the member of | |
70 | * @path (->p_ext) also points the next extent. Return 0 on success, 1 if | |
71 | * ext4_ext_path structure refers to the last extent, or a negative error | |
72 | * value on failure. | |
73 | */ | |
74 | static int | |
75 | mext_next_extent(struct inode *inode, struct ext4_ext_path *path, | |
76 | struct ext4_extent **extent) | |
77 | { | |
78 | int ppos, leaf_ppos = path->p_depth; | |
79 | ||
80 | ppos = leaf_ppos; | |
81 | if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) { | |
82 | /* leaf block */ | |
83 | *extent = ++path[ppos].p_ext; | |
84 | return 0; | |
85 | } | |
86 | ||
87 | while (--ppos >= 0) { | |
88 | if (EXT_LAST_INDEX(path[ppos].p_hdr) > | |
89 | path[ppos].p_idx) { | |
90 | int cur_ppos = ppos; | |
91 | ||
92 | /* index block */ | |
93 | path[ppos].p_idx++; | |
94 | path[ppos].p_block = idx_pblock(path[ppos].p_idx); | |
95 | if (path[ppos+1].p_bh) | |
96 | brelse(path[ppos+1].p_bh); | |
97 | path[ppos+1].p_bh = | |
98 | sb_bread(inode->i_sb, path[ppos].p_block); | |
99 | if (!path[ppos+1].p_bh) | |
100 | return -EIO; | |
101 | path[ppos+1].p_hdr = | |
102 | ext_block_hdr(path[ppos+1].p_bh); | |
103 | ||
104 | /* Halfway index block */ | |
105 | while (++cur_ppos < leaf_ppos) { | |
106 | path[cur_ppos].p_idx = | |
107 | EXT_FIRST_INDEX(path[cur_ppos].p_hdr); | |
108 | path[cur_ppos].p_block = | |
109 | idx_pblock(path[cur_ppos].p_idx); | |
110 | if (path[cur_ppos+1].p_bh) | |
111 | brelse(path[cur_ppos+1].p_bh); | |
112 | path[cur_ppos+1].p_bh = sb_bread(inode->i_sb, | |
113 | path[cur_ppos].p_block); | |
114 | if (!path[cur_ppos+1].p_bh) | |
115 | return -EIO; | |
116 | path[cur_ppos+1].p_hdr = | |
117 | ext_block_hdr(path[cur_ppos+1].p_bh); | |
118 | } | |
119 | ||
120 | /* leaf block */ | |
121 | path[leaf_ppos].p_ext = *extent = | |
122 | EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr); | |
123 | return 0; | |
124 | } | |
125 | } | |
126 | /* We found the last extent */ | |
127 | return 1; | |
128 | } | |
129 | ||
130 | /** | |
131 | * mext_double_down_read - Acquire two inodes' read semaphore | |
132 | * | |
133 | * @orig_inode: original inode structure | |
134 | * @donor_inode: donor inode structure | |
135 | * Acquire read semaphore of the two inodes (orig and donor) by i_ino order. | |
136 | */ | |
137 | static void | |
138 | mext_double_down_read(struct inode *orig_inode, struct inode *donor_inode) | |
139 | { | |
140 | struct inode *first = orig_inode, *second = donor_inode; | |
141 | ||
142 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
143 | ||
144 | /* | |
145 | * Use the inode number to provide the stable locking order instead | |
146 | * of its address, because the C language doesn't guarantee you can | |
147 | * compare pointers that don't come from the same array. | |
148 | */ | |
149 | if (donor_inode->i_ino < orig_inode->i_ino) { | |
150 | first = donor_inode; | |
151 | second = orig_inode; | |
152 | } | |
153 | ||
154 | down_read(&EXT4_I(first)->i_data_sem); | |
155 | down_read(&EXT4_I(second)->i_data_sem); | |
156 | } | |
157 | ||
158 | /** | |
159 | * mext_double_down_write - Acquire two inodes' write semaphore | |
160 | * | |
161 | * @orig_inode: original inode structure | |
162 | * @donor_inode: donor inode structure | |
163 | * Acquire write semaphore of the two inodes (orig and donor) by i_ino order. | |
164 | */ | |
165 | static void | |
166 | mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode) | |
167 | { | |
168 | struct inode *first = orig_inode, *second = donor_inode; | |
169 | ||
170 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
171 | ||
172 | /* | |
173 | * Use the inode number to provide the stable locking order instead | |
174 | * of its address, because the C language doesn't guarantee you can | |
175 | * compare pointers that don't come from the same array. | |
176 | */ | |
177 | if (donor_inode->i_ino < orig_inode->i_ino) { | |
178 | first = donor_inode; | |
179 | second = orig_inode; | |
180 | } | |
181 | ||
182 | down_write(&EXT4_I(first)->i_data_sem); | |
183 | down_write(&EXT4_I(second)->i_data_sem); | |
184 | } | |
185 | ||
186 | /** | |
187 | * mext_double_up_read - Release two inodes' read semaphore | |
188 | * | |
189 | * @orig_inode: original inode structure to be released its lock first | |
190 | * @donor_inode: donor inode structure to be released its lock second | |
191 | * Release read semaphore of two inodes (orig and donor). | |
192 | */ | |
193 | static void | |
194 | mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode) | |
195 | { | |
196 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
197 | ||
198 | up_read(&EXT4_I(orig_inode)->i_data_sem); | |
199 | up_read(&EXT4_I(donor_inode)->i_data_sem); | |
200 | } | |
201 | ||
202 | /** | |
203 | * mext_double_up_write - Release two inodes' write semaphore | |
204 | * | |
205 | * @orig_inode: original inode structure to be released its lock first | |
206 | * @donor_inode: donor inode structure to be released its lock second | |
207 | * Release write semaphore of two inodes (orig and donor). | |
208 | */ | |
209 | static void | |
210 | mext_double_up_write(struct inode *orig_inode, struct inode *donor_inode) | |
211 | { | |
212 | BUG_ON(orig_inode == NULL || donor_inode == NULL); | |
213 | ||
214 | up_write(&EXT4_I(orig_inode)->i_data_sem); | |
215 | up_write(&EXT4_I(donor_inode)->i_data_sem); | |
216 | } | |
217 | ||
218 | /** | |
219 | * mext_insert_across_blocks - Insert extents across leaf block | |
220 | * | |
221 | * @handle: journal handle | |
222 | * @orig_inode: original inode | |
223 | * @o_start: first original extent to be changed | |
224 | * @o_end: last original extent to be changed | |
225 | * @start_ext: first new extent to be inserted | |
226 | * @new_ext: middle of new extent to be inserted | |
227 | * @end_ext: last new extent to be inserted | |
228 | * | |
229 | * Allocate a new leaf block and insert extents into it. Return 0 on success, | |
230 | * or a negative error value on failure. | |
231 | */ | |
232 | static int | |
233 | mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode, | |
234 | struct ext4_extent *o_start, struct ext4_extent *o_end, | |
235 | struct ext4_extent *start_ext, struct ext4_extent *new_ext, | |
236 | struct ext4_extent *end_ext) | |
237 | { | |
238 | struct ext4_ext_path *orig_path = NULL; | |
239 | ext4_lblk_t eblock = 0; | |
240 | int new_flag = 0; | |
241 | int end_flag = 0; | |
242 | int err = 0; | |
243 | ||
244 | if (start_ext->ee_len && new_ext->ee_len && end_ext->ee_len) { | |
245 | if (o_start == o_end) { | |
246 | ||
247 | /* start_ext new_ext end_ext | |
248 | * donor |---------|-----------|--------| | |
249 | * orig |------------------------------| | |
250 | */ | |
251 | end_flag = 1; | |
252 | } else { | |
253 | ||
254 | /* start_ext new_ext end_ext | |
255 | * donor |---------|----------|---------| | |
256 | * orig |---------------|--------------| | |
257 | */ | |
258 | o_end->ee_block = end_ext->ee_block; | |
259 | o_end->ee_len = end_ext->ee_len; | |
260 | ext4_ext_store_pblock(o_end, ext_pblock(end_ext)); | |
261 | } | |
262 | ||
263 | o_start->ee_len = start_ext->ee_len; | |
264 | new_flag = 1; | |
265 | ||
266 | } else if (start_ext->ee_len && new_ext->ee_len && | |
267 | !end_ext->ee_len && o_start == o_end) { | |
268 | ||
269 | /* start_ext new_ext | |
270 | * donor |--------------|---------------| | |
271 | * orig |------------------------------| | |
272 | */ | |
273 | o_start->ee_len = start_ext->ee_len; | |
274 | new_flag = 1; | |
275 | ||
276 | } else if (!start_ext->ee_len && new_ext->ee_len && | |
277 | end_ext->ee_len && o_start == o_end) { | |
278 | ||
279 | /* new_ext end_ext | |
280 | * donor |--------------|---------------| | |
281 | * orig |------------------------------| | |
282 | */ | |
283 | o_end->ee_block = end_ext->ee_block; | |
284 | o_end->ee_len = end_ext->ee_len; | |
285 | ext4_ext_store_pblock(o_end, ext_pblock(end_ext)); | |
286 | ||
287 | /* | |
288 | * Set 0 to the extent block if new_ext was | |
289 | * the first block. | |
290 | */ | |
291 | if (new_ext->ee_block) | |
292 | eblock = le32_to_cpu(new_ext->ee_block); | |
293 | ||
294 | new_flag = 1; | |
295 | } else { | |
296 | ext4_debug("ext4 move extent: Unexpected insert case\n"); | |
297 | return -EIO; | |
298 | } | |
299 | ||
300 | if (new_flag) { | |
e8505970 | 301 | err = get_ext_path(orig_inode, eblock, &orig_path); |
748de673 AF |
302 | if (orig_path == NULL) |
303 | goto out; | |
304 | ||
305 | if (ext4_ext_insert_extent(handle, orig_inode, | |
306 | orig_path, new_ext)) | |
307 | goto out; | |
308 | } | |
309 | ||
310 | if (end_flag) { | |
e8505970 AF |
311 | err = get_ext_path(orig_inode, |
312 | le32_to_cpu(end_ext->ee_block) - 1, &orig_path); | |
748de673 AF |
313 | if (orig_path == NULL) |
314 | goto out; | |
315 | ||
316 | if (ext4_ext_insert_extent(handle, orig_inode, | |
317 | orig_path, end_ext)) | |
318 | goto out; | |
319 | } | |
320 | out: | |
321 | if (orig_path) { | |
322 | ext4_ext_drop_refs(orig_path); | |
323 | kfree(orig_path); | |
324 | } | |
325 | ||
326 | return err; | |
327 | ||
328 | } | |
329 | ||
330 | /** | |
331 | * mext_insert_inside_block - Insert new extent to the extent block | |
332 | * | |
333 | * @o_start: first original extent to be moved | |
334 | * @o_end: last original extent to be moved | |
335 | * @start_ext: first new extent to be inserted | |
336 | * @new_ext: middle of new extent to be inserted | |
337 | * @end_ext: last new extent to be inserted | |
338 | * @eh: extent header of target leaf block | |
339 | * @range_to_move: used to decide how to insert extent | |
340 | * | |
341 | * Insert extents into the leaf block. The extent (@o_start) is overwritten | |
342 | * by inserted extents. | |
343 | */ | |
344 | static void | |
345 | mext_insert_inside_block(struct ext4_extent *o_start, | |
346 | struct ext4_extent *o_end, | |
347 | struct ext4_extent *start_ext, | |
348 | struct ext4_extent *new_ext, | |
349 | struct ext4_extent *end_ext, | |
350 | struct ext4_extent_header *eh, | |
351 | int range_to_move) | |
352 | { | |
353 | int i = 0; | |
354 | unsigned long len; | |
355 | ||
356 | /* Move the existing extents */ | |
357 | if (range_to_move && o_end < EXT_LAST_EXTENT(eh)) { | |
358 | len = (unsigned long)(EXT_LAST_EXTENT(eh) + 1) - | |
359 | (unsigned long)(o_end + 1); | |
360 | memmove(o_end + 1 + range_to_move, o_end + 1, len); | |
361 | } | |
362 | ||
363 | /* Insert start entry */ | |
364 | if (start_ext->ee_len) | |
365 | o_start[i++].ee_len = start_ext->ee_len; | |
366 | ||
367 | /* Insert new entry */ | |
368 | if (new_ext->ee_len) { | |
369 | o_start[i] = *new_ext; | |
370 | ext4_ext_store_pblock(&o_start[i++], ext_pblock(new_ext)); | |
371 | } | |
372 | ||
373 | /* Insert end entry */ | |
374 | if (end_ext->ee_len) | |
375 | o_start[i] = *end_ext; | |
376 | ||
377 | /* Increment the total entries counter on the extent block */ | |
378 | le16_add_cpu(&eh->eh_entries, range_to_move); | |
379 | } | |
380 | ||
381 | /** | |
382 | * mext_insert_extents - Insert new extent | |
383 | * | |
384 | * @handle: journal handle | |
385 | * @orig_inode: original inode | |
386 | * @orig_path: path indicates first extent to be changed | |
387 | * @o_start: first original extent to be changed | |
388 | * @o_end: last original extent to be changed | |
389 | * @start_ext: first new extent to be inserted | |
390 | * @new_ext: middle of new extent to be inserted | |
391 | * @end_ext: last new extent to be inserted | |
392 | * | |
393 | * Call the function to insert extents. If we cannot add more extents into | |
394 | * the leaf block, we call mext_insert_across_blocks() to create a | |
395 | * new leaf block. Otherwise call mext_insert_inside_block(). Return 0 | |
396 | * on success, or a negative error value on failure. | |
397 | */ | |
398 | static int | |
399 | mext_insert_extents(handle_t *handle, struct inode *orig_inode, | |
400 | struct ext4_ext_path *orig_path, | |
401 | struct ext4_extent *o_start, | |
402 | struct ext4_extent *o_end, | |
403 | struct ext4_extent *start_ext, | |
404 | struct ext4_extent *new_ext, | |
405 | struct ext4_extent *end_ext) | |
406 | { | |
407 | struct ext4_extent_header *eh; | |
408 | unsigned long need_slots, slots_range; | |
409 | int range_to_move, depth, ret; | |
410 | ||
411 | /* | |
412 | * The extents need to be inserted | |
413 | * start_extent + new_extent + end_extent. | |
414 | */ | |
415 | need_slots = (start_ext->ee_len ? 1 : 0) + (end_ext->ee_len ? 1 : 0) + | |
416 | (new_ext->ee_len ? 1 : 0); | |
417 | ||
418 | /* The number of slots between start and end */ | |
419 | slots_range = ((unsigned long)(o_end + 1) - (unsigned long)o_start + 1) | |
420 | / sizeof(struct ext4_extent); | |
421 | ||
422 | /* Range to move the end of extent */ | |
423 | range_to_move = need_slots - slots_range; | |
424 | depth = orig_path->p_depth; | |
425 | orig_path += depth; | |
426 | eh = orig_path->p_hdr; | |
427 | ||
428 | if (depth) { | |
429 | /* Register to journal */ | |
430 | ret = ext4_journal_get_write_access(handle, orig_path->p_bh); | |
431 | if (ret) | |
432 | return ret; | |
433 | } | |
434 | ||
435 | /* Expansion */ | |
436 | if (range_to_move > 0 && | |
437 | (range_to_move > le16_to_cpu(eh->eh_max) | |
438 | - le16_to_cpu(eh->eh_entries))) { | |
439 | ||
440 | ret = mext_insert_across_blocks(handle, orig_inode, o_start, | |
441 | o_end, start_ext, new_ext, end_ext); | |
442 | if (ret < 0) | |
443 | return ret; | |
444 | } else | |
445 | mext_insert_inside_block(o_start, o_end, start_ext, new_ext, | |
446 | end_ext, eh, range_to_move); | |
447 | ||
448 | if (depth) { | |
449 | ret = ext4_handle_dirty_metadata(handle, orig_inode, | |
450 | orig_path->p_bh); | |
451 | if (ret) | |
452 | return ret; | |
453 | } else { | |
454 | ret = ext4_mark_inode_dirty(handle, orig_inode); | |
455 | if (ret < 0) | |
456 | return ret; | |
457 | } | |
458 | ||
459 | return 0; | |
460 | } | |
461 | ||
462 | /** | |
463 | * mext_leaf_block - Move one leaf extent block into the inode. | |
464 | * | |
465 | * @handle: journal handle | |
466 | * @orig_inode: original inode | |
467 | * @orig_path: path indicates first extent to be changed | |
468 | * @dext: donor extent | |
469 | * @from: start offset on the target file | |
470 | * | |
471 | * In order to insert extents into the leaf block, we must divide the extent | |
472 | * in the leaf block into three extents. The one is located to be inserted | |
473 | * extents, and the others are located around it. | |
474 | * | |
475 | * Therefore, this function creates structures to save extents of the leaf | |
476 | * block, and inserts extents by calling mext_insert_extents() with | |
477 | * created extents. Return 0 on success, or a negative error value on failure. | |
478 | */ | |
479 | static int | |
480 | mext_leaf_block(handle_t *handle, struct inode *orig_inode, | |
481 | struct ext4_ext_path *orig_path, struct ext4_extent *dext, | |
482 | ext4_lblk_t *from) | |
483 | { | |
484 | struct ext4_extent *oext, *o_start, *o_end, *prev_ext; | |
485 | struct ext4_extent new_ext, start_ext, end_ext; | |
486 | ext4_lblk_t new_ext_end; | |
487 | ext4_fsblk_t new_phys_end; | |
488 | int oext_alen, new_ext_alen, end_ext_alen; | |
489 | int depth = ext_depth(orig_inode); | |
490 | int ret; | |
491 | ||
492 | o_start = o_end = oext = orig_path[depth].p_ext; | |
493 | oext_alen = ext4_ext_get_actual_len(oext); | |
494 | start_ext.ee_len = end_ext.ee_len = 0; | |
495 | ||
496 | new_ext.ee_block = cpu_to_le32(*from); | |
497 | ext4_ext_store_pblock(&new_ext, ext_pblock(dext)); | |
498 | new_ext.ee_len = dext->ee_len; | |
499 | new_ext_alen = ext4_ext_get_actual_len(&new_ext); | |
500 | new_ext_end = le32_to_cpu(new_ext.ee_block) + new_ext_alen - 1; | |
501 | new_phys_end = ext_pblock(&new_ext) + new_ext_alen - 1; | |
502 | ||
503 | /* | |
504 | * Case: original extent is first | |
505 | * oext |--------| | |
506 | * new_ext |--| | |
507 | * start_ext |--| | |
508 | */ | |
509 | if (le32_to_cpu(oext->ee_block) < le32_to_cpu(new_ext.ee_block) && | |
510 | le32_to_cpu(new_ext.ee_block) < | |
511 | le32_to_cpu(oext->ee_block) + oext_alen) { | |
512 | start_ext.ee_len = cpu_to_le16(le32_to_cpu(new_ext.ee_block) - | |
513 | le32_to_cpu(oext->ee_block)); | |
514 | copy_extent_status(oext, &start_ext); | |
515 | } else if (oext > EXT_FIRST_EXTENT(orig_path[depth].p_hdr)) { | |
516 | prev_ext = oext - 1; | |
517 | /* | |
518 | * We can merge new_ext into previous extent, | |
519 | * if these are contiguous and same extent type. | |
520 | */ | |
521 | if (ext4_can_extents_be_merged(orig_inode, prev_ext, | |
522 | &new_ext)) { | |
523 | o_start = prev_ext; | |
524 | start_ext.ee_len = cpu_to_le16( | |
525 | ext4_ext_get_actual_len(prev_ext) + | |
526 | new_ext_alen); | |
527 | copy_extent_status(prev_ext, &start_ext); | |
528 | new_ext.ee_len = 0; | |
529 | } | |
530 | } | |
531 | ||
532 | /* | |
533 | * Case: new_ext_end must be less than oext | |
534 | * oext |-----------| | |
535 | * new_ext |-------| | |
536 | */ | |
537 | BUG_ON(le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end); | |
538 | ||
539 | /* | |
540 | * Case: new_ext is smaller than original extent | |
541 | * oext |---------------| | |
542 | * new_ext |-----------| | |
543 | * end_ext |---| | |
544 | */ | |
545 | if (le32_to_cpu(oext->ee_block) <= new_ext_end && | |
546 | new_ext_end < le32_to_cpu(oext->ee_block) + oext_alen - 1) { | |
547 | end_ext.ee_len = | |
548 | cpu_to_le16(le32_to_cpu(oext->ee_block) + | |
549 | oext_alen - 1 - new_ext_end); | |
550 | copy_extent_status(oext, &end_ext); | |
551 | end_ext_alen = ext4_ext_get_actual_len(&end_ext); | |
552 | ext4_ext_store_pblock(&end_ext, | |
553 | (ext_pblock(o_end) + oext_alen - end_ext_alen)); | |
554 | end_ext.ee_block = | |
555 | cpu_to_le32(le32_to_cpu(o_end->ee_block) + | |
556 | oext_alen - end_ext_alen); | |
557 | } | |
558 | ||
559 | ret = mext_insert_extents(handle, orig_inode, orig_path, o_start, | |
560 | o_end, &start_ext, &new_ext, &end_ext); | |
561 | return ret; | |
562 | } | |
563 | ||
564 | /** | |
565 | * mext_calc_swap_extents - Calculate extents for extent swapping. | |
566 | * | |
567 | * @tmp_dext: the extent that will belong to the original inode | |
568 | * @tmp_oext: the extent that will belong to the donor inode | |
569 | * @orig_off: block offset of original inode | |
570 | * @donor_off: block offset of donor inode | |
571 | * @max_count: the maximun length of extents | |
572 | */ | |
573 | static void | |
574 | mext_calc_swap_extents(struct ext4_extent *tmp_dext, | |
575 | struct ext4_extent *tmp_oext, | |
576 | ext4_lblk_t orig_off, ext4_lblk_t donor_off, | |
577 | ext4_lblk_t max_count) | |
578 | { | |
579 | ext4_lblk_t diff, orig_diff; | |
580 | struct ext4_extent dext_old, oext_old; | |
581 | ||
582 | dext_old = *tmp_dext; | |
583 | oext_old = *tmp_oext; | |
584 | ||
585 | /* When tmp_dext is too large, pick up the target range. */ | |
586 | diff = donor_off - le32_to_cpu(tmp_dext->ee_block); | |
587 | ||
588 | ext4_ext_store_pblock(tmp_dext, ext_pblock(tmp_dext) + diff); | |
589 | tmp_dext->ee_block = | |
590 | cpu_to_le32(le32_to_cpu(tmp_dext->ee_block) + diff); | |
591 | tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_dext->ee_len) - diff); | |
592 | ||
593 | if (max_count < ext4_ext_get_actual_len(tmp_dext)) | |
594 | tmp_dext->ee_len = cpu_to_le16(max_count); | |
595 | ||
596 | orig_diff = orig_off - le32_to_cpu(tmp_oext->ee_block); | |
597 | ext4_ext_store_pblock(tmp_oext, ext_pblock(tmp_oext) + orig_diff); | |
598 | ||
599 | /* Adjust extent length if donor extent is larger than orig */ | |
600 | if (ext4_ext_get_actual_len(tmp_dext) > | |
601 | ext4_ext_get_actual_len(tmp_oext) - orig_diff) | |
602 | tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_oext->ee_len) - | |
603 | orig_diff); | |
604 | ||
605 | tmp_oext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(tmp_dext)); | |
606 | ||
607 | copy_extent_status(&oext_old, tmp_dext); | |
608 | copy_extent_status(&dext_old, tmp_oext); | |
609 | } | |
610 | ||
611 | /** | |
612 | * mext_replace_branches - Replace original extents with new extents | |
613 | * | |
614 | * @handle: journal handle | |
615 | * @orig_inode: original inode | |
616 | * @donor_inode: donor inode | |
617 | * @from: block offset of orig_inode | |
618 | * @count: block count to be replaced | |
619 | * | |
620 | * Replace original inode extents and donor inode extents page by page. | |
621 | * We implement this replacement in the following three steps: | |
622 | * 1. Save the block information of original and donor inodes into | |
623 | * dummy extents. | |
624 | * 2. Change the block information of original inode to point at the | |
625 | * donor inode blocks. | |
626 | * 3. Change the block information of donor inode to point at the saved | |
627 | * original inode blocks in the dummy extents. | |
628 | * | |
629 | * Return 0 on success, or a negative error value on failure. | |
630 | */ | |
631 | static int | |
632 | mext_replace_branches(handle_t *handle, struct inode *orig_inode, | |
633 | struct inode *donor_inode, ext4_lblk_t from, | |
634 | ext4_lblk_t count) | |
635 | { | |
636 | struct ext4_ext_path *orig_path = NULL; | |
637 | struct ext4_ext_path *donor_path = NULL; | |
638 | struct ext4_extent *oext, *dext; | |
639 | struct ext4_extent tmp_dext, tmp_oext; | |
640 | ext4_lblk_t orig_off = from, donor_off = from; | |
641 | int err = 0; | |
642 | int depth; | |
643 | int replaced_count = 0; | |
644 | int dext_alen; | |
645 | ||
646 | mext_double_down_write(orig_inode, donor_inode); | |
647 | ||
648 | /* Get the original extent for the block "orig_off" */ | |
e8505970 | 649 | err = get_ext_path(orig_inode, orig_off, &orig_path); |
748de673 AF |
650 | if (orig_path == NULL) |
651 | goto out; | |
652 | ||
653 | /* Get the donor extent for the head */ | |
e8505970 | 654 | err = get_ext_path(donor_inode, donor_off, &donor_path); |
748de673 AF |
655 | if (donor_path == NULL) |
656 | goto out; | |
657 | depth = ext_depth(orig_inode); | |
658 | oext = orig_path[depth].p_ext; | |
659 | tmp_oext = *oext; | |
660 | ||
661 | depth = ext_depth(donor_inode); | |
662 | dext = donor_path[depth].p_ext; | |
663 | tmp_dext = *dext; | |
664 | ||
665 | mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, | |
666 | donor_off, count); | |
667 | ||
668 | /* Loop for the donor extents */ | |
669 | while (1) { | |
670 | /* The extent for donor must be found. */ | |
671 | BUG_ON(!dext || donor_off != le32_to_cpu(tmp_dext.ee_block)); | |
672 | ||
673 | /* Set donor extent to orig extent */ | |
674 | err = mext_leaf_block(handle, orig_inode, | |
675 | orig_path, &tmp_dext, &orig_off); | |
676 | if (err < 0) | |
677 | goto out; | |
678 | ||
679 | /* Set orig extent to donor extent */ | |
680 | err = mext_leaf_block(handle, donor_inode, | |
681 | donor_path, &tmp_oext, &donor_off); | |
682 | if (err < 0) | |
683 | goto out; | |
684 | ||
685 | dext_alen = ext4_ext_get_actual_len(&tmp_dext); | |
686 | replaced_count += dext_alen; | |
687 | donor_off += dext_alen; | |
688 | orig_off += dext_alen; | |
689 | ||
690 | /* Already moved the expected blocks */ | |
691 | if (replaced_count >= count) | |
692 | break; | |
693 | ||
694 | if (orig_path) | |
695 | ext4_ext_drop_refs(orig_path); | |
e8505970 | 696 | err = get_ext_path(orig_inode, orig_off, &orig_path); |
748de673 AF |
697 | if (orig_path == NULL) |
698 | goto out; | |
699 | depth = ext_depth(orig_inode); | |
700 | oext = orig_path[depth].p_ext; | |
701 | if (le32_to_cpu(oext->ee_block) + | |
702 | ext4_ext_get_actual_len(oext) <= orig_off) { | |
703 | err = 0; | |
704 | goto out; | |
705 | } | |
706 | tmp_oext = *oext; | |
707 | ||
708 | if (donor_path) | |
709 | ext4_ext_drop_refs(donor_path); | |
e8505970 | 710 | err = get_ext_path(donor_inode, donor_off, &donor_path); |
748de673 AF |
711 | if (donor_path == NULL) |
712 | goto out; | |
713 | depth = ext_depth(donor_inode); | |
714 | dext = donor_path[depth].p_ext; | |
715 | if (le32_to_cpu(dext->ee_block) + | |
716 | ext4_ext_get_actual_len(dext) <= donor_off) { | |
717 | err = 0; | |
718 | goto out; | |
719 | } | |
720 | tmp_dext = *dext; | |
721 | ||
722 | mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off, | |
723 | donor_off, | |
724 | count - replaced_count); | |
725 | } | |
726 | ||
727 | out: | |
728 | if (orig_path) { | |
729 | ext4_ext_drop_refs(orig_path); | |
730 | kfree(orig_path); | |
731 | } | |
732 | if (donor_path) { | |
733 | ext4_ext_drop_refs(donor_path); | |
734 | kfree(donor_path); | |
735 | } | |
736 | ||
737 | mext_double_up_write(orig_inode, donor_inode); | |
738 | return err; | |
739 | } | |
740 | ||
741 | /** | |
742 | * move_extent_per_page - Move extent data per page | |
743 | * | |
744 | * @o_filp: file structure of original file | |
745 | * @donor_inode: donor inode | |
746 | * @orig_page_offset: page index on original file | |
747 | * @data_offset_in_page: block index where data swapping starts | |
748 | * @block_len_in_page: the number of blocks to be swapped | |
749 | * @uninit: orig extent is uninitialized or not | |
750 | * | |
751 | * Save the data in original inode blocks and replace original inode extents | |
752 | * with donor inode extents by calling mext_replace_branches(). | |
753 | * Finally, write out the saved data in new original inode blocks. Return 0 | |
754 | * on success, or a negative error value on failure. | |
755 | */ | |
756 | static int | |
44fc48f7 | 757 | move_extent_per_page(struct file *o_filp, struct inode *donor_inode, |
748de673 AF |
758 | pgoff_t orig_page_offset, int data_offset_in_page, |
759 | int block_len_in_page, int uninit) | |
760 | { | |
761 | struct inode *orig_inode = o_filp->f_dentry->d_inode; | |
762 | struct address_space *mapping = orig_inode->i_mapping; | |
763 | struct buffer_head *bh; | |
764 | struct page *page = NULL; | |
765 | const struct address_space_operations *a_ops = mapping->a_ops; | |
766 | handle_t *handle; | |
767 | ext4_lblk_t orig_blk_offset; | |
768 | long long offs = orig_page_offset << PAGE_CACHE_SHIFT; | |
769 | unsigned long blocksize = orig_inode->i_sb->s_blocksize; | |
770 | unsigned int w_flags = 0; | |
771 | unsigned int tmp_data_len, data_len; | |
772 | void *fsdata; | |
773 | int ret, i, jblocks; | |
774 | int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; | |
775 | ||
776 | /* | |
777 | * It needs twice the amount of ordinary journal buffers because | |
778 | * inode and donor_inode may change each different metadata blocks. | |
779 | */ | |
780 | jblocks = ext4_writepage_trans_blocks(orig_inode) * 2; | |
781 | handle = ext4_journal_start(orig_inode, jblocks); | |
782 | if (IS_ERR(handle)) { | |
783 | ret = PTR_ERR(handle); | |
784 | return ret; | |
785 | } | |
786 | ||
787 | if (segment_eq(get_fs(), KERNEL_DS)) | |
788 | w_flags |= AOP_FLAG_UNINTERRUPTIBLE; | |
789 | ||
790 | orig_blk_offset = orig_page_offset * blocks_per_page + | |
791 | data_offset_in_page; | |
792 | ||
793 | /* | |
794 | * If orig extent is uninitialized one, | |
795 | * it's not necessary force the page into memory | |
796 | * and then force it to be written out again. | |
797 | * Just swap data blocks between orig and donor. | |
798 | */ | |
799 | if (uninit) { | |
800 | ret = mext_replace_branches(handle, orig_inode, | |
801 | donor_inode, orig_blk_offset, | |
802 | block_len_in_page); | |
803 | ||
804 | /* Clear the inode cache not to refer to the old data */ | |
805 | ext4_ext_invalidate_cache(orig_inode); | |
806 | ext4_ext_invalidate_cache(donor_inode); | |
807 | goto out2; | |
808 | } | |
809 | ||
810 | offs = (long long)orig_blk_offset << orig_inode->i_blkbits; | |
811 | ||
812 | /* Calculate data_len */ | |
813 | if ((orig_blk_offset + block_len_in_page - 1) == | |
814 | ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) { | |
815 | /* Replace the last block */ | |
816 | tmp_data_len = orig_inode->i_size & (blocksize - 1); | |
817 | /* | |
818 | * If data_len equal zero, it shows data_len is multiples of | |
819 | * blocksize. So we set appropriate value. | |
820 | */ | |
821 | if (tmp_data_len == 0) | |
822 | tmp_data_len = blocksize; | |
823 | ||
824 | data_len = tmp_data_len + | |
825 | ((block_len_in_page - 1) << orig_inode->i_blkbits); | |
826 | } else { | |
827 | data_len = block_len_in_page << orig_inode->i_blkbits; | |
828 | } | |
829 | ||
830 | ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags, | |
831 | &page, &fsdata); | |
832 | if (unlikely(ret < 0)) | |
833 | goto out; | |
834 | ||
835 | if (!PageUptodate(page)) { | |
836 | mapping->a_ops->readpage(o_filp, page); | |
837 | lock_page(page); | |
838 | } | |
839 | ||
840 | /* | |
841 | * try_to_release_page() doesn't call releasepage in writeback mode. | |
842 | * We should care about the order of writing to the same file | |
843 | * by multiple move extent processes. | |
844 | * It needs to call wait_on_page_writeback() to wait for the | |
845 | * writeback of the page. | |
846 | */ | |
847 | if (PageWriteback(page)) | |
848 | wait_on_page_writeback(page); | |
849 | ||
850 | /* Release old bh and drop refs */ | |
851 | try_to_release_page(page, 0); | |
852 | ||
853 | ret = mext_replace_branches(handle, orig_inode, donor_inode, | |
854 | orig_blk_offset, block_len_in_page); | |
855 | if (ret < 0) | |
856 | goto out; | |
857 | ||
858 | /* Clear the inode cache not to refer to the old data */ | |
859 | ext4_ext_invalidate_cache(orig_inode); | |
860 | ext4_ext_invalidate_cache(donor_inode); | |
861 | ||
862 | if (!page_has_buffers(page)) | |
863 | create_empty_buffers(page, 1 << orig_inode->i_blkbits, 0); | |
864 | ||
865 | bh = page_buffers(page); | |
866 | for (i = 0; i < data_offset_in_page; i++) | |
867 | bh = bh->b_this_page; | |
868 | ||
869 | for (i = 0; i < block_len_in_page; i++) { | |
870 | ret = ext4_get_block(orig_inode, | |
871 | (sector_t)(orig_blk_offset + i), bh, 0); | |
872 | if (ret < 0) | |
873 | goto out; | |
874 | ||
875 | if (bh->b_this_page != NULL) | |
876 | bh = bh->b_this_page; | |
877 | } | |
878 | ||
879 | ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len, | |
880 | page, fsdata); | |
881 | page = NULL; | |
882 | ||
883 | out: | |
884 | if (unlikely(page)) { | |
885 | if (PageLocked(page)) | |
886 | unlock_page(page); | |
887 | page_cache_release(page); | |
91cc219a | 888 | ext4_journal_stop(handle); |
748de673 AF |
889 | } |
890 | out2: | |
891 | ext4_journal_stop(handle); | |
892 | ||
893 | return ret < 0 ? ret : 0; | |
894 | } | |
895 | ||
896 | /** | |
897 | * mext_check_argumants - Check whether move extent can be done | |
898 | * | |
899 | * @orig_inode: original inode | |
900 | * @donor_inode: donor inode | |
901 | * @orig_start: logical start offset in block for orig | |
902 | * @donor_start: logical start offset in block for donor | |
903 | * @len: the number of blocks to be moved | |
904 | * @moved_len: moved block length | |
905 | * | |
906 | * Check the arguments of ext4_move_extents() whether the files can be | |
907 | * exchanged with each other. | |
908 | * Return 0 on success, or a negative error value on failure. | |
909 | */ | |
910 | static int | |
911 | mext_check_arguments(struct inode *orig_inode, | |
912 | struct inode *donor_inode, __u64 orig_start, | |
913 | __u64 donor_start, __u64 *len, __u64 moved_len) | |
914 | { | |
70d5d3dc AF |
915 | ext4_lblk_t orig_blocks, donor_blocks; |
916 | unsigned int blkbits = orig_inode->i_blkbits; | |
917 | unsigned int blocksize = 1 << blkbits; | |
918 | ||
748de673 AF |
919 | /* Regular file check */ |
920 | if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { | |
921 | ext4_debug("ext4 move extent: The argument files should be " | |
922 | "regular file [ino:orig %lu, donor %lu]\n", | |
923 | orig_inode->i_ino, donor_inode->i_ino); | |
924 | return -EINVAL; | |
925 | } | |
926 | ||
927 | /* Ext4 move extent does not support swapfile */ | |
928 | if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) { | |
929 | ext4_debug("ext4 move extent: The argument files should " | |
930 | "not be swapfile [ino:orig %lu, donor %lu]\n", | |
931 | orig_inode->i_ino, donor_inode->i_ino); | |
932 | return -EINVAL; | |
933 | } | |
934 | ||
935 | /* Files should be in the same ext4 FS */ | |
936 | if (orig_inode->i_sb != donor_inode->i_sb) { | |
937 | ext4_debug("ext4 move extent: The argument files " | |
938 | "should be in same FS [ino:orig %lu, donor %lu]\n", | |
939 | orig_inode->i_ino, donor_inode->i_ino); | |
940 | return -EINVAL; | |
941 | } | |
942 | ||
943 | /* orig and donor should be different file */ | |
944 | if (orig_inode->i_ino == donor_inode->i_ino) { | |
945 | ext4_debug("ext4 move extent: The argument files should not " | |
946 | "be same file [ino:orig %lu, donor %lu]\n", | |
947 | orig_inode->i_ino, donor_inode->i_ino); | |
948 | return -EINVAL; | |
949 | } | |
950 | ||
951 | /* Ext4 move extent supports only extent based file */ | |
952 | if (!(EXT4_I(orig_inode)->i_flags & EXT4_EXTENTS_FL)) { | |
953 | ext4_debug("ext4 move extent: orig file is not extents " | |
954 | "based file [ino:orig %lu]\n", orig_inode->i_ino); | |
955 | return -EOPNOTSUPP; | |
956 | } else if (!(EXT4_I(donor_inode)->i_flags & EXT4_EXTENTS_FL)) { | |
957 | ext4_debug("ext4 move extent: donor file is not extents " | |
958 | "based file [ino:donor %lu]\n", donor_inode->i_ino); | |
959 | return -EOPNOTSUPP; | |
960 | } | |
961 | ||
962 | if ((!orig_inode->i_size) || (!donor_inode->i_size)) { | |
963 | ext4_debug("ext4 move extent: File size is 0 byte\n"); | |
964 | return -EINVAL; | |
965 | } | |
966 | ||
967 | /* Start offset should be same */ | |
968 | if (orig_start != donor_start) { | |
969 | ext4_debug("ext4 move extent: orig and donor's start " | |
970 | "offset are not same [ino:orig %lu, donor %lu]\n", | |
971 | orig_inode->i_ino, donor_inode->i_ino); | |
972 | return -EINVAL; | |
973 | } | |
974 | ||
975 | if (moved_len) { | |
976 | ext4_debug("ext4 move extent: moved_len should be 0 " | |
977 | "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino, | |
978 | donor_inode->i_ino); | |
979 | return -EINVAL; | |
980 | } | |
981 | ||
982 | if ((orig_start > MAX_DEFRAG_SIZE) || | |
983 | (donor_start > MAX_DEFRAG_SIZE) || | |
984 | (*len > MAX_DEFRAG_SIZE) || | |
985 | (orig_start + *len > MAX_DEFRAG_SIZE)) { | |
986 | ext4_debug("ext4 move extent: Can't handle over [%lu] blocks " | |
987 | "[ino:orig %lu, donor %lu]\n", MAX_DEFRAG_SIZE, | |
988 | orig_inode->i_ino, donor_inode->i_ino); | |
989 | return -EINVAL; | |
990 | } | |
991 | ||
992 | if (orig_inode->i_size > donor_inode->i_size) { | |
70d5d3dc AF |
993 | donor_blocks = (donor_inode->i_size + blocksize - 1) >> blkbits; |
994 | /* TODO: eliminate this artificial restriction */ | |
995 | if (orig_start >= donor_blocks) { | |
748de673 | 996 | ext4_debug("ext4 move extent: orig start offset " |
70d5d3dc AF |
997 | "[%llu] should be less than donor file blocks " |
998 | "[%u] [ino:orig %lu, donor %lu]\n", | |
999 | orig_start, donor_blocks, | |
748de673 AF |
1000 | orig_inode->i_ino, donor_inode->i_ino); |
1001 | return -EINVAL; | |
1002 | } | |
1003 | ||
70d5d3dc AF |
1004 | /* TODO: eliminate this artificial restriction */ |
1005 | if (orig_start + *len > donor_blocks) { | |
748de673 | 1006 | ext4_debug("ext4 move extent: End offset [%llu] should " |
70d5d3dc AF |
1007 | "be less than donor file blocks [%u]." |
1008 | "So adjust length from %llu to %llu " | |
748de673 | 1009 | "[ino:orig %lu, donor %lu]\n", |
70d5d3dc AF |
1010 | orig_start + *len, donor_blocks, |
1011 | *len, donor_blocks - orig_start, | |
748de673 | 1012 | orig_inode->i_ino, donor_inode->i_ino); |
70d5d3dc | 1013 | *len = donor_blocks - orig_start; |
748de673 AF |
1014 | } |
1015 | } else { | |
70d5d3dc AF |
1016 | orig_blocks = (orig_inode->i_size + blocksize - 1) >> blkbits; |
1017 | if (orig_start >= orig_blocks) { | |
748de673 | 1018 | ext4_debug("ext4 move extent: start offset [%llu] " |
70d5d3dc AF |
1019 | "should be less than original file blocks " |
1020 | "[%u] [ino:orig %lu, donor %lu]\n", | |
1021 | orig_start, orig_blocks, | |
748de673 AF |
1022 | orig_inode->i_ino, donor_inode->i_ino); |
1023 | return -EINVAL; | |
1024 | } | |
1025 | ||
70d5d3dc | 1026 | if (orig_start + *len > orig_blocks) { |
748de673 | 1027 | ext4_debug("ext4 move extent: Adjust length " |
70d5d3dc AF |
1028 | "from %llu to %llu. Because it should be " |
1029 | "less than original file blocks " | |
748de673 | 1030 | "[ino:orig %lu, donor %lu]\n", |
70d5d3dc | 1031 | *len, orig_blocks - orig_start, |
748de673 | 1032 | orig_inode->i_ino, donor_inode->i_ino); |
70d5d3dc | 1033 | *len = orig_blocks - orig_start; |
748de673 AF |
1034 | } |
1035 | } | |
1036 | ||
1037 | if (!*len) { | |
1038 | ext4_debug("ext4 move extent: len shoudld not be 0 " | |
1039 | "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino, | |
1040 | donor_inode->i_ino); | |
1041 | return -EINVAL; | |
1042 | } | |
1043 | ||
1044 | return 0; | |
1045 | } | |
1046 | ||
1047 | /** | |
1048 | * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2 | |
1049 | * | |
1050 | * @inode1: the inode structure | |
1051 | * @inode2: the inode structure | |
1052 | * | |
1053 | * Lock two inodes' i_mutex by i_ino order. This function is moved from | |
1054 | * fs/inode.c. | |
1055 | */ | |
1056 | static void | |
1057 | mext_inode_double_lock(struct inode *inode1, struct inode *inode2) | |
1058 | { | |
1059 | if (inode1 == NULL || inode2 == NULL || inode1 == inode2) { | |
1060 | if (inode1) | |
1061 | mutex_lock(&inode1->i_mutex); | |
1062 | else if (inode2) | |
1063 | mutex_lock(&inode2->i_mutex); | |
1064 | return; | |
1065 | } | |
1066 | ||
1067 | if (inode1->i_ino < inode2->i_ino) { | |
1068 | mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); | |
1069 | mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); | |
1070 | } else { | |
1071 | mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT); | |
1072 | mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD); | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2 | |
1078 | * | |
1079 | * @inode1: the inode that is released first | |
1080 | * @inode2: the inode that is released second | |
1081 | * | |
1082 | * This function is moved from fs/inode.c. | |
1083 | */ | |
1084 | ||
1085 | static void | |
1086 | mext_inode_double_unlock(struct inode *inode1, struct inode *inode2) | |
1087 | { | |
1088 | if (inode1) | |
1089 | mutex_unlock(&inode1->i_mutex); | |
1090 | ||
1091 | if (inode2 && inode2 != inode1) | |
1092 | mutex_unlock(&inode2->i_mutex); | |
1093 | } | |
1094 | ||
1095 | /** | |
1096 | * ext4_move_extents - Exchange the specified range of a file | |
1097 | * | |
1098 | * @o_filp: file structure of the original file | |
1099 | * @d_filp: file structure of the donor file | |
1100 | * @orig_start: start offset in block for orig | |
1101 | * @donor_start: start offset in block for donor | |
1102 | * @len: the number of blocks to be moved | |
1103 | * @moved_len: moved block length | |
1104 | * | |
1105 | * This function returns 0 and moved block length is set in moved_len | |
1106 | * if succeed, otherwise returns error value. | |
1107 | * | |
1108 | * Note: ext4_move_extents() proceeds the following order. | |
1109 | * 1:ext4_move_extents() calculates the last block number of moving extent | |
1110 | * function by the start block number (orig_start) and the number of blocks | |
1111 | * to be moved (len) specified as arguments. | |
1112 | * If the {orig, donor}_start points a hole, the extent's start offset | |
1113 | * pointed by ext_cur (current extent), holecheck_path, orig_path are set | |
1114 | * after hole behind. | |
1115 | * 2:Continue step 3 to step 5, until the holecheck_path points to last_extent | |
1116 | * or the ext_cur exceeds the block_end which is last logical block number. | |
1117 | * 3:To get the length of continues area, call mext_next_extent() | |
1118 | * specified with the ext_cur (initial value is holecheck_path) re-cursive, | |
1119 | * until find un-continuous extent, the start logical block number exceeds | |
1120 | * the block_end or the extent points to the last extent. | |
1121 | * 4:Exchange the original inode data with donor inode data | |
1122 | * from orig_page_offset to seq_end_page. | |
1123 | * The start indexes of data are specified as arguments. | |
1124 | * That of the original inode is orig_page_offset, | |
1125 | * and the donor inode is also orig_page_offset | |
1126 | * (To easily handle blocksize != pagesize case, the offset for the | |
1127 | * donor inode is block unit). | |
1128 | * 5:Update holecheck_path and orig_path to points a next proceeding extent, | |
1129 | * then returns to step 2. | |
1130 | * 6:Release holecheck_path, orig_path and set the len to moved_len | |
1131 | * which shows the number of moved blocks. | |
1132 | * The moved_len is useful for the command to calculate the file offset | |
1133 | * for starting next move extent ioctl. | |
1134 | * 7:Return 0 on success, or a negative error value on failure. | |
1135 | */ | |
1136 | int | |
1137 | ext4_move_extents(struct file *o_filp, struct file *d_filp, | |
1138 | __u64 orig_start, __u64 donor_start, __u64 len, | |
1139 | __u64 *moved_len) | |
1140 | { | |
1141 | struct inode *orig_inode = o_filp->f_dentry->d_inode; | |
1142 | struct inode *donor_inode = d_filp->f_dentry->d_inode; | |
1143 | struct ext4_ext_path *orig_path = NULL, *holecheck_path = NULL; | |
1144 | struct ext4_extent *ext_prev, *ext_cur, *ext_dummy; | |
1145 | ext4_lblk_t block_start = orig_start; | |
1146 | ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0; | |
1147 | ext4_lblk_t rest_blocks; | |
1148 | pgoff_t orig_page_offset = 0, seq_end_page; | |
1149 | int ret, depth, last_extent = 0; | |
1150 | int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; | |
1151 | int data_offset_in_page; | |
1152 | int block_len_in_page; | |
1153 | int uninit; | |
1154 | ||
1155 | /* protect orig and donor against a truncate */ | |
1156 | mext_inode_double_lock(orig_inode, donor_inode); | |
1157 | ||
1158 | mext_double_down_read(orig_inode, donor_inode); | |
1159 | /* Check the filesystem environment whether move_extent can be done */ | |
1160 | ret = mext_check_arguments(orig_inode, donor_inode, orig_start, | |
1161 | donor_start, &len, *moved_len); | |
1162 | mext_double_up_read(orig_inode, donor_inode); | |
1163 | if (ret) | |
1164 | goto out2; | |
1165 | ||
1166 | file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits; | |
1167 | block_end = block_start + len - 1; | |
1168 | if (file_end < block_end) | |
1169 | len -= block_end - file_end; | |
1170 | ||
e8505970 | 1171 | ret = get_ext_path(orig_inode, block_start, &orig_path); |
748de673 AF |
1172 | if (orig_path == NULL) |
1173 | goto out2; | |
1174 | ||
1175 | /* Get path structure to check the hole */ | |
e8505970 | 1176 | ret = get_ext_path(orig_inode, block_start, &holecheck_path); |
748de673 AF |
1177 | if (holecheck_path == NULL) |
1178 | goto out; | |
1179 | ||
1180 | depth = ext_depth(orig_inode); | |
1181 | ext_cur = holecheck_path[depth].p_ext; | |
1182 | if (ext_cur == NULL) { | |
1183 | ret = -EINVAL; | |
1184 | goto out; | |
1185 | } | |
1186 | ||
1187 | /* | |
1188 | * Get proper extent whose ee_block is beyond block_start | |
1189 | * if block_start was within the hole. | |
1190 | */ | |
1191 | if (le32_to_cpu(ext_cur->ee_block) + | |
1192 | ext4_ext_get_actual_len(ext_cur) - 1 < block_start) { | |
1193 | last_extent = mext_next_extent(orig_inode, | |
1194 | holecheck_path, &ext_cur); | |
1195 | if (last_extent < 0) { | |
1196 | ret = last_extent; | |
1197 | goto out; | |
1198 | } | |
1199 | last_extent = mext_next_extent(orig_inode, orig_path, | |
1200 | &ext_dummy); | |
1201 | if (last_extent < 0) { | |
1202 | ret = last_extent; | |
1203 | goto out; | |
1204 | } | |
1205 | } | |
1206 | seq_start = block_start; | |
1207 | ||
1208 | /* No blocks within the specified range. */ | |
1209 | if (le32_to_cpu(ext_cur->ee_block) > block_end) { | |
1210 | ext4_debug("ext4 move extent: The specified range of file " | |
1211 | "may be the hole\n"); | |
1212 | ret = -EINVAL; | |
1213 | goto out; | |
1214 | } | |
1215 | ||
1216 | /* Adjust start blocks */ | |
1217 | add_blocks = min(le32_to_cpu(ext_cur->ee_block) + | |
1218 | ext4_ext_get_actual_len(ext_cur), block_end + 1) - | |
1219 | max(le32_to_cpu(ext_cur->ee_block), block_start); | |
1220 | ||
1221 | while (!last_extent && le32_to_cpu(ext_cur->ee_block) <= block_end) { | |
1222 | seq_blocks += add_blocks; | |
1223 | ||
1224 | /* Adjust tail blocks */ | |
1225 | if (seq_start + seq_blocks - 1 > block_end) | |
1226 | seq_blocks = block_end - seq_start + 1; | |
1227 | ||
1228 | ext_prev = ext_cur; | |
1229 | last_extent = mext_next_extent(orig_inode, holecheck_path, | |
1230 | &ext_cur); | |
1231 | if (last_extent < 0) { | |
1232 | ret = last_extent; | |
1233 | break; | |
1234 | } | |
1235 | add_blocks = ext4_ext_get_actual_len(ext_cur); | |
1236 | ||
1237 | /* | |
1238 | * Extend the length of contiguous block (seq_blocks) | |
1239 | * if extents are contiguous. | |
1240 | */ | |
1241 | if (ext4_can_extents_be_merged(orig_inode, | |
1242 | ext_prev, ext_cur) && | |
1243 | block_end >= le32_to_cpu(ext_cur->ee_block) && | |
1244 | !last_extent) | |
1245 | continue; | |
1246 | ||
1247 | /* Is original extent is uninitialized */ | |
1248 | uninit = ext4_ext_is_uninitialized(ext_prev); | |
1249 | ||
1250 | data_offset_in_page = seq_start % blocks_per_page; | |
1251 | ||
1252 | /* | |
1253 | * Calculate data blocks count that should be swapped | |
1254 | * at the first page. | |
1255 | */ | |
1256 | if (data_offset_in_page + seq_blocks > blocks_per_page) { | |
1257 | /* Swapped blocks are across pages */ | |
1258 | block_len_in_page = | |
1259 | blocks_per_page - data_offset_in_page; | |
1260 | } else { | |
1261 | /* Swapped blocks are in a page */ | |
1262 | block_len_in_page = seq_blocks; | |
1263 | } | |
1264 | ||
1265 | orig_page_offset = seq_start >> | |
1266 | (PAGE_CACHE_SHIFT - orig_inode->i_blkbits); | |
1267 | seq_end_page = (seq_start + seq_blocks - 1) >> | |
1268 | (PAGE_CACHE_SHIFT - orig_inode->i_blkbits); | |
1269 | seq_start = le32_to_cpu(ext_cur->ee_block); | |
1270 | rest_blocks = seq_blocks; | |
1271 | ||
1272 | /* Discard preallocations of two inodes */ | |
1273 | down_write(&EXT4_I(orig_inode)->i_data_sem); | |
1274 | ext4_discard_preallocations(orig_inode); | |
1275 | up_write(&EXT4_I(orig_inode)->i_data_sem); | |
1276 | ||
1277 | down_write(&EXT4_I(donor_inode)->i_data_sem); | |
1278 | ext4_discard_preallocations(donor_inode); | |
1279 | up_write(&EXT4_I(donor_inode)->i_data_sem); | |
1280 | ||
1281 | while (orig_page_offset <= seq_end_page) { | |
1282 | ||
1283 | /* Swap original branches with new branches */ | |
44fc48f7 | 1284 | ret = move_extent_per_page(o_filp, donor_inode, |
748de673 AF |
1285 | orig_page_offset, |
1286 | data_offset_in_page, | |
1287 | block_len_in_page, uninit); | |
1288 | if (ret < 0) | |
1289 | goto out; | |
1290 | orig_page_offset++; | |
1291 | /* Count how many blocks we have exchanged */ | |
1292 | *moved_len += block_len_in_page; | |
1293 | BUG_ON(*moved_len > len); | |
1294 | ||
1295 | data_offset_in_page = 0; | |
1296 | rest_blocks -= block_len_in_page; | |
1297 | if (rest_blocks > blocks_per_page) | |
1298 | block_len_in_page = blocks_per_page; | |
1299 | else | |
1300 | block_len_in_page = rest_blocks; | |
1301 | } | |
1302 | ||
1303 | /* Decrease buffer counter */ | |
1304 | if (holecheck_path) | |
1305 | ext4_ext_drop_refs(holecheck_path); | |
e8505970 | 1306 | ret = get_ext_path(orig_inode, seq_start, &holecheck_path); |
748de673 AF |
1307 | if (holecheck_path == NULL) |
1308 | break; | |
1309 | depth = holecheck_path->p_depth; | |
1310 | ||
1311 | /* Decrease buffer counter */ | |
1312 | if (orig_path) | |
1313 | ext4_ext_drop_refs(orig_path); | |
e8505970 | 1314 | ret = get_ext_path(orig_inode, seq_start, &orig_path); |
748de673 AF |
1315 | if (orig_path == NULL) |
1316 | break; | |
1317 | ||
1318 | ext_cur = holecheck_path[depth].p_ext; | |
1319 | add_blocks = ext4_ext_get_actual_len(ext_cur); | |
1320 | seq_blocks = 0; | |
1321 | ||
1322 | } | |
1323 | out: | |
1324 | if (orig_path) { | |
1325 | ext4_ext_drop_refs(orig_path); | |
1326 | kfree(orig_path); | |
1327 | } | |
1328 | if (holecheck_path) { | |
1329 | ext4_ext_drop_refs(holecheck_path); | |
1330 | kfree(holecheck_path); | |
1331 | } | |
1332 | out2: | |
1333 | mext_inode_double_unlock(orig_inode, donor_inode); | |
1334 | ||
1335 | if (ret) | |
1336 | return ret; | |
1337 | ||
748de673 AF |
1338 | return 0; |
1339 | } |