blob: b9ce24129070bff5cee547a333139d9a4645d2c7 [file] [log] [blame]
Alex Tomasa86c6182006-10-11 01:21:03 -07001/*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public Licens
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23/*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32#include <linux/module.h>
33#include <linux/fs.h>
34#include <linux/time.h>
35#include <linux/ext4_jbd2.h>
36#include <linux/jbd.h>
Alex Tomasa86c6182006-10-11 01:21:03 -070037#include <linux/highuid.h>
38#include <linux/pagemap.h>
39#include <linux/quotaops.h>
40#include <linux/string.h>
41#include <linux/slab.h>
42#include <linux/ext4_fs_extents.h>
43#include <asm/uaccess.h>
44
45
Randy Dunlapd0d856e2006-10-11 01:21:07 -070046/*
47 * ext_pblock:
48 * combine low and high parts of physical block number into ext4_fsblk_t
49 */
Avantika Mathur09b88252006-12-06 20:41:36 -080050static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070051{
52 ext4_fsblk_t block;
53
54 block = le32_to_cpu(ex->ee_start);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070055 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070056 return block;
57}
58
Randy Dunlapd0d856e2006-10-11 01:21:07 -070059/*
60 * idx_pblock:
61 * combine low and high parts of a leaf physical block number into ext4_fsblk_t
62 */
Avantika Mathur09b88252006-12-06 20:41:36 -080063static ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070064{
65 ext4_fsblk_t block;
66
67 block = le32_to_cpu(ix->ei_leaf);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070068 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070069 return block;
70}
71
Randy Dunlapd0d856e2006-10-11 01:21:07 -070072/*
73 * ext4_ext_store_pblock:
74 * stores a large physical block number into an extent struct,
75 * breaking it into parts
76 */
Avantika Mathur09b88252006-12-06 20:41:36 -080077static void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070078{
79 ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070080 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070081}
82
Randy Dunlapd0d856e2006-10-11 01:21:07 -070083/*
84 * ext4_idx_store_pblock:
85 * stores a large physical block number into an index struct,
86 * breaking it into parts
87 */
Avantika Mathur09b88252006-12-06 20:41:36 -080088static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070089{
90 ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070091 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070092}
93
Alex Tomasa86c6182006-10-11 01:21:03 -070094static int ext4_ext_check_header(const char *function, struct inode *inode,
95 struct ext4_extent_header *eh)
96{
97 const char *error_msg = NULL;
98
99 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
100 error_msg = "invalid magic";
101 goto corrupted;
102 }
103 if (unlikely(eh->eh_max == 0)) {
104 error_msg = "invalid eh_max";
105 goto corrupted;
106 }
107 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
108 error_msg = "invalid eh_entries";
109 goto corrupted;
110 }
111 return 0;
112
113corrupted:
114 ext4_error(inode->i_sb, function,
115 "bad header in inode #%lu: %s - magic %x, "
116 "entries %u, max %u, depth %u",
117 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
118 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
119 le16_to_cpu(eh->eh_depth));
120
121 return -EIO;
122}
123
124static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
125{
126 int err;
127
128 if (handle->h_buffer_credits > needed)
129 return handle;
130 if (!ext4_journal_extend(handle, needed))
131 return handle;
132 err = ext4_journal_restart(handle, needed);
133
134 return handle;
135}
136
137/*
138 * could return:
139 * - EROFS
140 * - ENOMEM
141 */
142static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
143 struct ext4_ext_path *path)
144{
145 if (path->p_bh) {
146 /* path points to block */
147 return ext4_journal_get_write_access(handle, path->p_bh);
148 }
149 /* path points to leaf/index in inode body */
150 /* we use in-core data, no need to protect them */
151 return 0;
152}
153
154/*
155 * could return:
156 * - EROFS
157 * - ENOMEM
158 * - EIO
159 */
160static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
161 struct ext4_ext_path *path)
162{
163 int err;
164 if (path->p_bh) {
165 /* path points to block */
166 err = ext4_journal_dirty_metadata(handle, path->p_bh);
167 } else {
168 /* path points to leaf/index in inode body */
169 err = ext4_mark_inode_dirty(handle, inode);
170 }
171 return err;
172}
173
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700174static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700175 struct ext4_ext_path *path,
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700176 ext4_fsblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700177{
178 struct ext4_inode_info *ei = EXT4_I(inode);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700179 ext4_fsblk_t bg_start;
180 ext4_grpblk_t colour;
Alex Tomasa86c6182006-10-11 01:21:03 -0700181 int depth;
182
183 if (path) {
184 struct ext4_extent *ex;
185 depth = path->p_depth;
186
187 /* try to predict block placement */
Avantika Mathur7e028972006-12-06 20:41:33 -0800188 ex = path[depth].p_ext;
189 if (ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700190 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700191
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700192 /* it looks like index is empty;
193 * try to find starting block from index itself */
Alex Tomasa86c6182006-10-11 01:21:03 -0700194 if (path[depth].p_bh)
195 return path[depth].p_bh->b_blocknr;
196 }
197
198 /* OK. use inode's group */
199 bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) +
200 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block);
201 colour = (current->pid % 16) *
202 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
203 return bg_start + colour + block;
204}
205
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700206static ext4_fsblk_t
Alex Tomasa86c6182006-10-11 01:21:03 -0700207ext4_ext_new_block(handle_t *handle, struct inode *inode,
208 struct ext4_ext_path *path,
209 struct ext4_extent *ex, int *err)
210{
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700211 ext4_fsblk_t goal, newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700212
213 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
214 newblock = ext4_new_block(handle, inode, goal, err);
215 return newblock;
216}
217
Avantika Mathur09b88252006-12-06 20:41:36 -0800218static int ext4_ext_space_block(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700219{
220 int size;
221
222 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
223 / sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100224#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700225 if (size > 6)
226 size = 6;
227#endif
228 return size;
229}
230
Avantika Mathur09b88252006-12-06 20:41:36 -0800231static int ext4_ext_space_block_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700232{
233 int size;
234
235 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
236 / sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100237#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700238 if (size > 5)
239 size = 5;
240#endif
241 return size;
242}
243
Avantika Mathur09b88252006-12-06 20:41:36 -0800244static int ext4_ext_space_root(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700245{
246 int size;
247
248 size = sizeof(EXT4_I(inode)->i_data);
249 size -= sizeof(struct ext4_extent_header);
250 size /= sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100251#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700252 if (size > 3)
253 size = 3;
254#endif
255 return size;
256}
257
Avantika Mathur09b88252006-12-06 20:41:36 -0800258static int ext4_ext_space_root_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700259{
260 int size;
261
262 size = sizeof(EXT4_I(inode)->i_data);
263 size -= sizeof(struct ext4_extent_header);
264 size /= sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100265#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700266 if (size > 4)
267 size = 4;
268#endif
269 return size;
270}
271
272#ifdef EXT_DEBUG
273static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
274{
275 int k, l = path->p_depth;
276
277 ext_debug("path:");
278 for (k = 0; k <= l; k++, path++) {
279 if (path->p_idx) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700280 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700281 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700282 } else if (path->p_ext) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700283 ext_debug(" %d:%d:%llu ",
Alex Tomasa86c6182006-10-11 01:21:03 -0700284 le32_to_cpu(path->p_ext->ee_block),
285 le16_to_cpu(path->p_ext->ee_len),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700286 ext_pblock(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700287 } else
288 ext_debug(" []");
289 }
290 ext_debug("\n");
291}
292
293static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
294{
295 int depth = ext_depth(inode);
296 struct ext4_extent_header *eh;
297 struct ext4_extent *ex;
298 int i;
299
300 if (!path)
301 return;
302
303 eh = path[depth].p_hdr;
304 ex = EXT_FIRST_EXTENT(eh);
305
306 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700307 ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700308 le16_to_cpu(ex->ee_len), ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -0700309 }
310 ext_debug("\n");
311}
312#else
313#define ext4_ext_show_path(inode,path)
314#define ext4_ext_show_leaf(inode,path)
315#endif
316
317static void ext4_ext_drop_refs(struct ext4_ext_path *path)
318{
319 int depth = path->p_depth;
320 int i;
321
322 for (i = 0; i <= depth; i++, path++)
323 if (path->p_bh) {
324 brelse(path->p_bh);
325 path->p_bh = NULL;
326 }
327}
328
329/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700330 * ext4_ext_binsearch_idx:
331 * binary search for the closest index of the given block
Alex Tomasa86c6182006-10-11 01:21:03 -0700332 */
333static void
334ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block)
335{
336 struct ext4_extent_header *eh = path->p_hdr;
337 struct ext4_extent_idx *r, *l, *m;
338
339 BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
340 BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
341 BUG_ON(le16_to_cpu(eh->eh_entries) <= 0);
342
343 ext_debug("binsearch for %d(idx): ", block);
344
345 l = EXT_FIRST_INDEX(eh) + 1;
346 r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1;
347 while (l <= r) {
348 m = l + (r - l) / 2;
349 if (block < le32_to_cpu(m->ei_block))
350 r = m - 1;
351 else
352 l = m + 1;
353 ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block,
354 m, m->ei_block, r, r->ei_block);
355 }
356
357 path->p_idx = l - 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700358 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
359 idx_block(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700360
361#ifdef CHECK_BINSEARCH
362 {
363 struct ext4_extent_idx *chix, *ix;
364 int k;
365
366 chix = ix = EXT_FIRST_INDEX(eh);
367 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
368 if (k != 0 &&
369 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
370 printk("k=%d, ix=0x%p, first=0x%p\n", k,
371 ix, EXT_FIRST_INDEX(eh));
372 printk("%u <= %u\n",
373 le32_to_cpu(ix->ei_block),
374 le32_to_cpu(ix[-1].ei_block));
375 }
376 BUG_ON(k && le32_to_cpu(ix->ei_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400377 <= le32_to_cpu(ix[-1].ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700378 if (block < le32_to_cpu(ix->ei_block))
379 break;
380 chix = ix;
381 }
382 BUG_ON(chix != path->p_idx);
383 }
384#endif
385
386}
387
388/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700389 * ext4_ext_binsearch:
390 * binary search for closest extent of the given block
Alex Tomasa86c6182006-10-11 01:21:03 -0700391 */
392static void
393ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
394{
395 struct ext4_extent_header *eh = path->p_hdr;
396 struct ext4_extent *r, *l, *m;
397
398 BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
399 BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
400
401 if (eh->eh_entries == 0) {
402 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700403 * this leaf is empty:
404 * we get such a leaf in split/add case
Alex Tomasa86c6182006-10-11 01:21:03 -0700405 */
406 return;
407 }
408
409 ext_debug("binsearch for %d: ", block);
410
411 l = EXT_FIRST_EXTENT(eh) + 1;
412 r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1;
413
414 while (l <= r) {
415 m = l + (r - l) / 2;
416 if (block < le32_to_cpu(m->ee_block))
417 r = m - 1;
418 else
419 l = m + 1;
420 ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block,
421 m, m->ee_block, r, r->ee_block);
422 }
423
424 path->p_ext = l - 1;
Mingming Cao2ae02102006-10-11 01:21:11 -0700425 ext_debug(" -> %d:%llu:%d ",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400426 le32_to_cpu(path->p_ext->ee_block),
427 ext_pblock(path->p_ext),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700428 le16_to_cpu(path->p_ext->ee_len));
Alex Tomasa86c6182006-10-11 01:21:03 -0700429
430#ifdef CHECK_BINSEARCH
431 {
432 struct ext4_extent *chex, *ex;
433 int k;
434
435 chex = ex = EXT_FIRST_EXTENT(eh);
436 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
437 BUG_ON(k && le32_to_cpu(ex->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400438 <= le32_to_cpu(ex[-1].ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700439 if (block < le32_to_cpu(ex->ee_block))
440 break;
441 chex = ex;
442 }
443 BUG_ON(chex != path->p_ext);
444 }
445#endif
446
447}
448
449int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
450{
451 struct ext4_extent_header *eh;
452
453 eh = ext_inode_hdr(inode);
454 eh->eh_depth = 0;
455 eh->eh_entries = 0;
456 eh->eh_magic = EXT4_EXT_MAGIC;
457 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
458 ext4_mark_inode_dirty(handle, inode);
459 ext4_ext_invalidate_cache(inode);
460 return 0;
461}
462
463struct ext4_ext_path *
464ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
465{
466 struct ext4_extent_header *eh;
467 struct buffer_head *bh;
468 short int depth, i, ppos = 0, alloc = 0;
469
470 eh = ext_inode_hdr(inode);
471 BUG_ON(eh == NULL);
472 if (ext4_ext_check_header(__FUNCTION__, inode, eh))
473 return ERR_PTR(-EIO);
474
475 i = depth = ext_depth(inode);
476
477 /* account possible depth increase */
478 if (!path) {
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800479 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
Alex Tomasa86c6182006-10-11 01:21:03 -0700480 GFP_NOFS);
481 if (!path)
482 return ERR_PTR(-ENOMEM);
483 alloc = 1;
484 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700485 path[0].p_hdr = eh;
486
487 /* walk through the tree */
488 while (i) {
489 ext_debug("depth %d: num %d, max %d\n",
490 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
491 ext4_ext_binsearch_idx(inode, path + ppos, block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700492 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -0700493 path[ppos].p_depth = i;
494 path[ppos].p_ext = NULL;
495
496 bh = sb_bread(inode->i_sb, path[ppos].p_block);
497 if (!bh)
498 goto err;
499
500 eh = ext_block_hdr(bh);
501 ppos++;
502 BUG_ON(ppos > depth);
503 path[ppos].p_bh = bh;
504 path[ppos].p_hdr = eh;
505 i--;
506
507 if (ext4_ext_check_header(__FUNCTION__, inode, eh))
508 goto err;
509 }
510
511 path[ppos].p_depth = i;
512 path[ppos].p_hdr = eh;
513 path[ppos].p_ext = NULL;
514 path[ppos].p_idx = NULL;
515
516 if (ext4_ext_check_header(__FUNCTION__, inode, eh))
517 goto err;
518
519 /* find extent */
520 ext4_ext_binsearch(inode, path + ppos, block);
521
522 ext4_ext_show_path(inode, path);
523
524 return path;
525
526err:
527 ext4_ext_drop_refs(path);
528 if (alloc)
529 kfree(path);
530 return ERR_PTR(-EIO);
531}
532
533/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700534 * ext4_ext_insert_index:
535 * insert new index [@logical;@ptr] into the block at @curp;
536 * check where to insert: before @curp or after @curp
Alex Tomasa86c6182006-10-11 01:21:03 -0700537 */
538static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
539 struct ext4_ext_path *curp,
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700540 int logical, ext4_fsblk_t ptr)
Alex Tomasa86c6182006-10-11 01:21:03 -0700541{
542 struct ext4_extent_idx *ix;
543 int len, err;
544
Avantika Mathur7e028972006-12-06 20:41:33 -0800545 err = ext4_ext_get_access(handle, inode, curp);
546 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700547 return err;
548
549 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
550 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
551 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
552 /* insert after */
553 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
554 len = (len - 1) * sizeof(struct ext4_extent_idx);
555 len = len < 0 ? 0 : len;
556 ext_debug("insert new index %d after: %d. "
557 "move %d from 0x%p to 0x%p\n",
558 logical, ptr, len,
559 (curp->p_idx + 1), (curp->p_idx + 2));
560 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
561 }
562 ix = curp->p_idx + 1;
563 } else {
564 /* insert before */
565 len = len * sizeof(struct ext4_extent_idx);
566 len = len < 0 ? 0 : len;
567 ext_debug("insert new index %d before: %d. "
568 "move %d from 0x%p to 0x%p\n",
569 logical, ptr, len,
570 curp->p_idx, (curp->p_idx + 1));
571 memmove(curp->p_idx + 1, curp->p_idx, len);
572 ix = curp->p_idx;
573 }
574
575 ix->ei_block = cpu_to_le32(logical);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700576 ext4_idx_store_pblock(ix, ptr);
Alex Tomasa86c6182006-10-11 01:21:03 -0700577 curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1);
578
579 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400580 > le16_to_cpu(curp->p_hdr->eh_max));
Alex Tomasa86c6182006-10-11 01:21:03 -0700581 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
582
583 err = ext4_ext_dirty(handle, inode, curp);
584 ext4_std_error(inode->i_sb, err);
585
586 return err;
587}
588
589/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700590 * ext4_ext_split:
591 * inserts new subtree into the path, using free index entry
592 * at depth @at:
593 * - allocates all needed blocks (new leaf and all intermediate index blocks)
594 * - makes decision where to split
595 * - moves remaining extents and index entries (right to the split point)
596 * into the newly allocated blocks
597 * - initializes subtree
Alex Tomasa86c6182006-10-11 01:21:03 -0700598 */
599static int ext4_ext_split(handle_t *handle, struct inode *inode,
600 struct ext4_ext_path *path,
601 struct ext4_extent *newext, int at)
602{
603 struct buffer_head *bh = NULL;
604 int depth = ext_depth(inode);
605 struct ext4_extent_header *neh;
606 struct ext4_extent_idx *fidx;
607 struct ext4_extent *ex;
608 int i = at, k, m, a;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700609 ext4_fsblk_t newblock, oldblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700610 __le32 border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700611 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
Alex Tomasa86c6182006-10-11 01:21:03 -0700612 int err = 0;
613
614 /* make decision: where to split? */
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700615 /* FIXME: now decision is simplest: at current extent */
Alex Tomasa86c6182006-10-11 01:21:03 -0700616
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700617 /* if current leaf will be split, then we should use
Alex Tomasa86c6182006-10-11 01:21:03 -0700618 * border from split point */
619 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));
620 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
621 border = path[depth].p_ext[1].ee_block;
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700622 ext_debug("leaf will be split."
Alex Tomasa86c6182006-10-11 01:21:03 -0700623 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400624 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700625 } else {
626 border = newext->ee_block;
627 ext_debug("leaf will be added."
628 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400629 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700630 }
631
632 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700633 * If error occurs, then we break processing
634 * and mark filesystem read-only. index won't
Alex Tomasa86c6182006-10-11 01:21:03 -0700635 * be inserted and tree will be in consistent
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700636 * state. Next mount will repair buffers too.
Alex Tomasa86c6182006-10-11 01:21:03 -0700637 */
638
639 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700640 * Get array to track all allocated blocks.
641 * We need this to handle errors and free blocks
642 * upon them.
Alex Tomasa86c6182006-10-11 01:21:03 -0700643 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800644 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -0700645 if (!ablocks)
646 return -ENOMEM;
Alex Tomasa86c6182006-10-11 01:21:03 -0700647
648 /* allocate all needed blocks */
649 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
650 for (a = 0; a < depth - at; a++) {
651 newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
652 if (newblock == 0)
653 goto cleanup;
654 ablocks[a] = newblock;
655 }
656
657 /* initialize new leaf */
658 newblock = ablocks[--a];
659 BUG_ON(newblock == 0);
660 bh = sb_getblk(inode->i_sb, newblock);
661 if (!bh) {
662 err = -EIO;
663 goto cleanup;
664 }
665 lock_buffer(bh);
666
Avantika Mathur7e028972006-12-06 20:41:33 -0800667 err = ext4_journal_get_create_access(handle, bh);
668 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700669 goto cleanup;
670
671 neh = ext_block_hdr(bh);
672 neh->eh_entries = 0;
673 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
674 neh->eh_magic = EXT4_EXT_MAGIC;
675 neh->eh_depth = 0;
676 ex = EXT_FIRST_EXTENT(neh);
677
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700678 /* move remainder of path[depth] to the new leaf */
Alex Tomasa86c6182006-10-11 01:21:03 -0700679 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);
680 /* start copy from next extent */
681 /* TODO: we could do it by single memmove */
682 m = 0;
683 path[depth].p_ext++;
684 while (path[depth].p_ext <=
685 EXT_MAX_EXTENT(path[depth].p_hdr)) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700686 ext_debug("move %d:%llu:%d in new leaf %llu\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400687 le32_to_cpu(path[depth].p_ext->ee_block),
688 ext_pblock(path[depth].p_ext),
689 le16_to_cpu(path[depth].p_ext->ee_len),
Alex Tomasa86c6182006-10-11 01:21:03 -0700690 newblock);
691 /*memmove(ex++, path[depth].p_ext++,
692 sizeof(struct ext4_extent));
693 neh->eh_entries++;*/
694 path[depth].p_ext++;
695 m++;
696 }
697 if (m) {
698 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
699 neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m);
700 }
701
702 set_buffer_uptodate(bh);
703 unlock_buffer(bh);
704
Avantika Mathur7e028972006-12-06 20:41:33 -0800705 err = ext4_journal_dirty_metadata(handle, bh);
706 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700707 goto cleanup;
708 brelse(bh);
709 bh = NULL;
710
711 /* correct old leaf */
712 if (m) {
Avantika Mathur7e028972006-12-06 20:41:33 -0800713 err = ext4_ext_get_access(handle, inode, path + depth);
714 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700715 goto cleanup;
716 path[depth].p_hdr->eh_entries =
717 cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m);
Avantika Mathur7e028972006-12-06 20:41:33 -0800718 err = ext4_ext_dirty(handle, inode, path + depth);
719 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700720 goto cleanup;
721
722 }
723
724 /* create intermediate indexes */
725 k = depth - at - 1;
726 BUG_ON(k < 0);
727 if (k)
728 ext_debug("create %d intermediate indices\n", k);
729 /* insert new index into current index block */
730 /* current depth stored in i var */
731 i = depth - 1;
732 while (k--) {
733 oldblock = newblock;
734 newblock = ablocks[--a];
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700735 bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700736 if (!bh) {
737 err = -EIO;
738 goto cleanup;
739 }
740 lock_buffer(bh);
741
Avantika Mathur7e028972006-12-06 20:41:33 -0800742 err = ext4_journal_get_create_access(handle, bh);
743 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700744 goto cleanup;
745
746 neh = ext_block_hdr(bh);
747 neh->eh_entries = cpu_to_le16(1);
748 neh->eh_magic = EXT4_EXT_MAGIC;
749 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
750 neh->eh_depth = cpu_to_le16(depth - i);
751 fidx = EXT_FIRST_INDEX(neh);
752 fidx->ei_block = border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700753 ext4_idx_store_pblock(fidx, oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700754
Mingming Cao2ae02102006-10-11 01:21:11 -0700755 ext_debug("int.index at %d (block %llu): %lu -> %llu\n", i,
Alex Tomasa86c6182006-10-11 01:21:03 -0700756 newblock, (unsigned long) le32_to_cpu(border),
757 oldblock);
758 /* copy indexes */
759 m = 0;
760 path[i].p_idx++;
761
762 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
763 EXT_MAX_INDEX(path[i].p_hdr));
764 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
765 EXT_LAST_INDEX(path[i].p_hdr));
766 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700767 ext_debug("%d: move %d:%d in new index %llu\n", i,
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400768 le32_to_cpu(path[i].p_idx->ei_block),
769 idx_pblock(path[i].p_idx),
770 newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700771 /*memmove(++fidx, path[i].p_idx++,
772 sizeof(struct ext4_extent_idx));
773 neh->eh_entries++;
774 BUG_ON(neh->eh_entries > neh->eh_max);*/
775 path[i].p_idx++;
776 m++;
777 }
778 if (m) {
779 memmove(++fidx, path[i].p_idx - m,
780 sizeof(struct ext4_extent_idx) * m);
781 neh->eh_entries =
782 cpu_to_le16(le16_to_cpu(neh->eh_entries) + m);
783 }
784 set_buffer_uptodate(bh);
785 unlock_buffer(bh);
786
Avantika Mathur7e028972006-12-06 20:41:33 -0800787 err = ext4_journal_dirty_metadata(handle, bh);
788 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700789 goto cleanup;
790 brelse(bh);
791 bh = NULL;
792
793 /* correct old index */
794 if (m) {
795 err = ext4_ext_get_access(handle, inode, path + i);
796 if (err)
797 goto cleanup;
798 path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m);
799 err = ext4_ext_dirty(handle, inode, path + i);
800 if (err)
801 goto cleanup;
802 }
803
804 i--;
805 }
806
807 /* insert new index */
Alex Tomasa86c6182006-10-11 01:21:03 -0700808 err = ext4_ext_insert_index(handle, inode, path + at,
809 le32_to_cpu(border), newblock);
810
811cleanup:
812 if (bh) {
813 if (buffer_locked(bh))
814 unlock_buffer(bh);
815 brelse(bh);
816 }
817
818 if (err) {
819 /* free all allocated blocks in error case */
820 for (i = 0; i < depth; i++) {
821 if (!ablocks[i])
822 continue;
823 ext4_free_blocks(handle, inode, ablocks[i], 1);
824 }
825 }
826 kfree(ablocks);
827
828 return err;
829}
830
831/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700832 * ext4_ext_grow_indepth:
833 * implements tree growing procedure:
834 * - allocates new block
835 * - moves top-level data (index block or leaf) into the new block
836 * - initializes new top-level, creating index that points to the
837 * just created block
Alex Tomasa86c6182006-10-11 01:21:03 -0700838 */
839static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
840 struct ext4_ext_path *path,
841 struct ext4_extent *newext)
842{
843 struct ext4_ext_path *curp = path;
844 struct ext4_extent_header *neh;
845 struct ext4_extent_idx *fidx;
846 struct buffer_head *bh;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700847 ext4_fsblk_t newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700848 int err = 0;
849
850 newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
851 if (newblock == 0)
852 return err;
853
854 bh = sb_getblk(inode->i_sb, newblock);
855 if (!bh) {
856 err = -EIO;
857 ext4_std_error(inode->i_sb, err);
858 return err;
859 }
860 lock_buffer(bh);
861
Avantika Mathur7e028972006-12-06 20:41:33 -0800862 err = ext4_journal_get_create_access(handle, bh);
863 if (err) {
Alex Tomasa86c6182006-10-11 01:21:03 -0700864 unlock_buffer(bh);
865 goto out;
866 }
867
868 /* move top-level index/leaf into new block */
869 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
870
871 /* set size of new block */
872 neh = ext_block_hdr(bh);
873 /* old root could have indexes or leaves
874 * so calculate e_max right way */
875 if (ext_depth(inode))
876 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
877 else
878 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
879 neh->eh_magic = EXT4_EXT_MAGIC;
880 set_buffer_uptodate(bh);
881 unlock_buffer(bh);
882
Avantika Mathur7e028972006-12-06 20:41:33 -0800883 err = ext4_journal_dirty_metadata(handle, bh);
884 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700885 goto out;
886
887 /* create index in new top-level index: num,max,pointer */
Avantika Mathur7e028972006-12-06 20:41:33 -0800888 err = ext4_ext_get_access(handle, inode, curp);
889 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700890 goto out;
891
892 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
893 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
894 curp->p_hdr->eh_entries = cpu_to_le16(1);
895 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
896 /* FIXME: it works, but actually path[0] can be index */
897 curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700898 ext4_idx_store_pblock(curp->p_idx, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700899
900 neh = ext_inode_hdr(inode);
901 fidx = EXT_FIRST_INDEX(neh);
Mingming Cao2ae02102006-10-11 01:21:11 -0700902 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -0700903 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700904 le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700905
906 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
907 err = ext4_ext_dirty(handle, inode, curp);
908out:
909 brelse(bh);
910
911 return err;
912}
913
914/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700915 * ext4_ext_create_new_leaf:
916 * finds empty index and adds new leaf.
917 * if no free index is found, then it requests in-depth growing.
Alex Tomasa86c6182006-10-11 01:21:03 -0700918 */
919static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
920 struct ext4_ext_path *path,
921 struct ext4_extent *newext)
922{
923 struct ext4_ext_path *curp;
924 int depth, i, err = 0;
925
926repeat:
927 i = depth = ext_depth(inode);
928
929 /* walk up to the tree and look for free index entry */
930 curp = path + depth;
931 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
932 i--;
933 curp--;
934 }
935
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700936 /* we use already allocated block for index block,
937 * so subsequent data blocks should be contiguous */
Alex Tomasa86c6182006-10-11 01:21:03 -0700938 if (EXT_HAS_FREE_INDEX(curp)) {
939 /* if we found index with free entry, then use that
940 * entry: create all needed subtree and add new leaf */
941 err = ext4_ext_split(handle, inode, path, newext, i);
942
943 /* refill path */
944 ext4_ext_drop_refs(path);
945 path = ext4_ext_find_extent(inode,
946 le32_to_cpu(newext->ee_block),
947 path);
948 if (IS_ERR(path))
949 err = PTR_ERR(path);
950 } else {
951 /* tree is full, time to grow in depth */
952 err = ext4_ext_grow_indepth(handle, inode, path, newext);
953 if (err)
954 goto out;
955
956 /* refill path */
957 ext4_ext_drop_refs(path);
958 path = ext4_ext_find_extent(inode,
959 le32_to_cpu(newext->ee_block),
960 path);
961 if (IS_ERR(path)) {
962 err = PTR_ERR(path);
963 goto out;
964 }
965
966 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700967 * only first (depth 0 -> 1) produces free space;
968 * in all other cases we have to split the grown tree
Alex Tomasa86c6182006-10-11 01:21:03 -0700969 */
970 depth = ext_depth(inode);
971 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700972 /* now we need to split */
Alex Tomasa86c6182006-10-11 01:21:03 -0700973 goto repeat;
974 }
975 }
976
977out:
978 return err;
979}
980
981/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700982 * ext4_ext_next_allocated_block:
983 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
984 * NOTE: it considers block number from index entry as
985 * allocated block. Thus, index entries have to be consistent
986 * with leaves.
Alex Tomasa86c6182006-10-11 01:21:03 -0700987 */
988static unsigned long
989ext4_ext_next_allocated_block(struct ext4_ext_path *path)
990{
991 int depth;
992
993 BUG_ON(path == NULL);
994 depth = path->p_depth;
995
996 if (depth == 0 && path->p_ext == NULL)
997 return EXT_MAX_BLOCK;
998
999 while (depth >= 0) {
1000 if (depth == path->p_depth) {
1001 /* leaf */
1002 if (path[depth].p_ext !=
1003 EXT_LAST_EXTENT(path[depth].p_hdr))
1004 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1005 } else {
1006 /* index */
1007 if (path[depth].p_idx !=
1008 EXT_LAST_INDEX(path[depth].p_hdr))
1009 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1010 }
1011 depth--;
1012 }
1013
1014 return EXT_MAX_BLOCK;
1015}
1016
1017/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001018 * ext4_ext_next_leaf_block:
Alex Tomasa86c6182006-10-11 01:21:03 -07001019 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1020 */
1021static unsigned ext4_ext_next_leaf_block(struct inode *inode,
Andrew Morton63f57932006-10-11 01:21:24 -07001022 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -07001023{
1024 int depth;
1025
1026 BUG_ON(path == NULL);
1027 depth = path->p_depth;
1028
1029 /* zero-tree has no leaf blocks at all */
1030 if (depth == 0)
1031 return EXT_MAX_BLOCK;
1032
1033 /* go to index block */
1034 depth--;
1035
1036 while (depth >= 0) {
1037 if (path[depth].p_idx !=
1038 EXT_LAST_INDEX(path[depth].p_hdr))
1039 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1040 depth--;
1041 }
1042
1043 return EXT_MAX_BLOCK;
1044}
1045
1046/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001047 * ext4_ext_correct_indexes:
1048 * if leaf gets modified and modified extent is first in the leaf,
1049 * then we have to correct all indexes above.
Alex Tomasa86c6182006-10-11 01:21:03 -07001050 * TODO: do we need to correct tree in all cases?
1051 */
1052int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1053 struct ext4_ext_path *path)
1054{
1055 struct ext4_extent_header *eh;
1056 int depth = ext_depth(inode);
1057 struct ext4_extent *ex;
1058 __le32 border;
1059 int k, err = 0;
1060
1061 eh = path[depth].p_hdr;
1062 ex = path[depth].p_ext;
1063 BUG_ON(ex == NULL);
1064 BUG_ON(eh == NULL);
1065
1066 if (depth == 0) {
1067 /* there is no tree at all */
1068 return 0;
1069 }
1070
1071 if (ex != EXT_FIRST_EXTENT(eh)) {
1072 /* we correct tree if first leaf got modified only */
1073 return 0;
1074 }
1075
1076 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001077 * TODO: we need correction if border is smaller than current one
Alex Tomasa86c6182006-10-11 01:21:03 -07001078 */
1079 k = depth - 1;
1080 border = path[depth].p_ext->ee_block;
Avantika Mathur7e028972006-12-06 20:41:33 -08001081 err = ext4_ext_get_access(handle, inode, path + k);
1082 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001083 return err;
1084 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001085 err = ext4_ext_dirty(handle, inode, path + k);
1086 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001087 return err;
1088
1089 while (k--) {
1090 /* change all left-side indexes */
1091 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1092 break;
Avantika Mathur7e028972006-12-06 20:41:33 -08001093 err = ext4_ext_get_access(handle, inode, path + k);
1094 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001095 break;
1096 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001097 err = ext4_ext_dirty(handle, inode, path + k);
1098 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001099 break;
1100 }
1101
1102 return err;
1103}
1104
Avantika Mathur09b88252006-12-06 20:41:36 -08001105static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001106ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1107 struct ext4_extent *ex2)
1108{
Andrew Morton63f57932006-10-11 01:21:24 -07001109 if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len) !=
1110 le32_to_cpu(ex2->ee_block))
Alex Tomasa86c6182006-10-11 01:21:03 -07001111 return 0;
1112
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001113 /*
1114 * To allow future support for preallocated extents to be added
1115 * as an RO_COMPAT feature, refuse to merge to extents if
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001116 * this can result in the top bit of ee_len being set.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001117 */
1118 if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN)
1119 return 0;
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01001120#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -07001121 if (le16_to_cpu(ex1->ee_len) >= 4)
1122 return 0;
1123#endif
1124
Andrew Morton63f57932006-10-11 01:21:24 -07001125 if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2))
Alex Tomasa86c6182006-10-11 01:21:03 -07001126 return 1;
1127 return 0;
1128}
1129
1130/*
Amit Arora25d14f92007-05-24 13:04:13 -04001131 * check if a portion of the "newext" extent overlaps with an
1132 * existing extent.
1133 *
1134 * If there is an overlap discovered, it updates the length of the newext
1135 * such that there will be no overlap, and then returns 1.
1136 * If there is no overlap found, it returns 0.
1137 */
1138unsigned int ext4_ext_check_overlap(struct inode *inode,
1139 struct ext4_extent *newext,
1140 struct ext4_ext_path *path)
1141{
1142 unsigned long b1, b2;
1143 unsigned int depth, len1;
1144 unsigned int ret = 0;
1145
1146 b1 = le32_to_cpu(newext->ee_block);
1147 len1 = le16_to_cpu(newext->ee_len);
1148 depth = ext_depth(inode);
1149 if (!path[depth].p_ext)
1150 goto out;
1151 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1152
1153 /*
1154 * get the next allocated block if the extent in the path
1155 * is before the requested block(s)
1156 */
1157 if (b2 < b1) {
1158 b2 = ext4_ext_next_allocated_block(path);
1159 if (b2 == EXT_MAX_BLOCK)
1160 goto out;
1161 }
1162
1163 /* check for wrap through zero */
1164 if (b1 + len1 < b1) {
1165 len1 = EXT_MAX_BLOCK - b1;
1166 newext->ee_len = cpu_to_le16(len1);
1167 ret = 1;
1168 }
1169
1170 /* check for overlap */
1171 if (b1 + len1 > b2) {
1172 newext->ee_len = cpu_to_le16(b2 - b1);
1173 ret = 1;
1174 }
1175out:
1176 return ret;
1177}
1178
1179/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001180 * ext4_ext_insert_extent:
1181 * tries to merge requsted extent into the existing extent or
1182 * inserts requested extent as new one into the tree,
1183 * creating new leaf in the no-space case.
Alex Tomasa86c6182006-10-11 01:21:03 -07001184 */
1185int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1186 struct ext4_ext_path *path,
1187 struct ext4_extent *newext)
1188{
1189 struct ext4_extent_header * eh;
1190 struct ext4_extent *ex, *fex;
1191 struct ext4_extent *nearex; /* nearest extent */
1192 struct ext4_ext_path *npath = NULL;
1193 int depth, len, err, next;
1194
1195 BUG_ON(newext->ee_len == 0);
1196 depth = ext_depth(inode);
1197 ex = path[depth].p_ext;
1198 BUG_ON(path[depth].p_hdr == NULL);
1199
1200 /* try to insert block into found extent and return */
1201 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
Mingming Cao2ae02102006-10-11 01:21:11 -07001202 ext_debug("append %d block to %d:%d (from %llu)\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07001203 le16_to_cpu(newext->ee_len),
1204 le32_to_cpu(ex->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001205 le16_to_cpu(ex->ee_len), ext_pblock(ex));
Avantika Mathur7e028972006-12-06 20:41:33 -08001206 err = ext4_ext_get_access(handle, inode, path + depth);
1207 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001208 return err;
1209 ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len)
1210 + le16_to_cpu(newext->ee_len));
1211 eh = path[depth].p_hdr;
1212 nearex = ex;
1213 goto merge;
1214 }
1215
1216repeat:
1217 depth = ext_depth(inode);
1218 eh = path[depth].p_hdr;
1219 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1220 goto has_space;
1221
1222 /* probably next leaf has space for us? */
1223 fex = EXT_LAST_EXTENT(eh);
1224 next = ext4_ext_next_leaf_block(inode, path);
1225 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
1226 && next != EXT_MAX_BLOCK) {
1227 ext_debug("next leaf block - %d\n", next);
1228 BUG_ON(npath != NULL);
1229 npath = ext4_ext_find_extent(inode, next, NULL);
1230 if (IS_ERR(npath))
1231 return PTR_ERR(npath);
1232 BUG_ON(npath->p_depth != path->p_depth);
1233 eh = npath[depth].p_hdr;
1234 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1235 ext_debug("next leaf isnt full(%d)\n",
1236 le16_to_cpu(eh->eh_entries));
1237 path = npath;
1238 goto repeat;
1239 }
1240 ext_debug("next leaf has no free space(%d,%d)\n",
1241 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1242 }
1243
1244 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001245 * There is no free space in the found leaf.
1246 * We're gonna add a new leaf in the tree.
Alex Tomasa86c6182006-10-11 01:21:03 -07001247 */
1248 err = ext4_ext_create_new_leaf(handle, inode, path, newext);
1249 if (err)
1250 goto cleanup;
1251 depth = ext_depth(inode);
1252 eh = path[depth].p_hdr;
1253
1254has_space:
1255 nearex = path[depth].p_ext;
1256
Avantika Mathur7e028972006-12-06 20:41:33 -08001257 err = ext4_ext_get_access(handle, inode, path + depth);
1258 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001259 goto cleanup;
1260
1261 if (!nearex) {
1262 /* there is no extent in this leaf, create first one */
Mingming Cao2ae02102006-10-11 01:21:11 -07001263 ext_debug("first extent in the leaf: %d:%llu:%d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001264 le32_to_cpu(newext->ee_block),
1265 ext_pblock(newext),
1266 le16_to_cpu(newext->ee_len));
Alex Tomasa86c6182006-10-11 01:21:03 -07001267 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1268 } else if (le32_to_cpu(newext->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001269 > le32_to_cpu(nearex->ee_block)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001270/* BUG_ON(newext->ee_block == nearex->ee_block); */
1271 if (nearex != EXT_LAST_EXTENT(eh)) {
1272 len = EXT_MAX_EXTENT(eh) - nearex;
1273 len = (len - 1) * sizeof(struct ext4_extent);
1274 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001275 ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001276 "move %d from 0x%p to 0x%p\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001277 le32_to_cpu(newext->ee_block),
1278 ext_pblock(newext),
1279 le16_to_cpu(newext->ee_len),
Alex Tomasa86c6182006-10-11 01:21:03 -07001280 nearex, len, nearex + 1, nearex + 2);
1281 memmove(nearex + 2, nearex + 1, len);
1282 }
1283 path[depth].p_ext = nearex + 1;
1284 } else {
1285 BUG_ON(newext->ee_block == nearex->ee_block);
1286 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1287 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001288 ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001289 "move %d from 0x%p to 0x%p\n",
1290 le32_to_cpu(newext->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001291 ext_pblock(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001292 le16_to_cpu(newext->ee_len),
1293 nearex, len, nearex + 1, nearex + 2);
1294 memmove(nearex + 1, nearex, len);
1295 path[depth].p_ext = nearex;
1296 }
1297
1298 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1);
1299 nearex = path[depth].p_ext;
1300 nearex->ee_block = newext->ee_block;
1301 nearex->ee_start = newext->ee_start;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001302 nearex->ee_start_hi = newext->ee_start_hi;
Alex Tomasa86c6182006-10-11 01:21:03 -07001303 nearex->ee_len = newext->ee_len;
Alex Tomasa86c6182006-10-11 01:21:03 -07001304
1305merge:
1306 /* try to merge extents to the right */
1307 while (nearex < EXT_LAST_EXTENT(eh)) {
1308 if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1))
1309 break;
1310 /* merge with next extent! */
1311 nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len)
1312 + le16_to_cpu(nearex[1].ee_len));
1313 if (nearex + 1 < EXT_LAST_EXTENT(eh)) {
1314 len = (EXT_LAST_EXTENT(eh) - nearex - 1)
1315 * sizeof(struct ext4_extent);
1316 memmove(nearex + 1, nearex + 2, len);
1317 }
1318 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
1319 BUG_ON(eh->eh_entries == 0);
1320 }
1321
1322 /* try to merge extents to the left */
1323
1324 /* time to correct all indexes above */
1325 err = ext4_ext_correct_indexes(handle, inode, path);
1326 if (err)
1327 goto cleanup;
1328
1329 err = ext4_ext_dirty(handle, inode, path + depth);
1330
1331cleanup:
1332 if (npath) {
1333 ext4_ext_drop_refs(npath);
1334 kfree(npath);
1335 }
1336 ext4_ext_tree_changed(inode);
1337 ext4_ext_invalidate_cache(inode);
1338 return err;
1339}
1340
1341int ext4_ext_walk_space(struct inode *inode, unsigned long block,
1342 unsigned long num, ext_prepare_callback func,
1343 void *cbdata)
1344{
1345 struct ext4_ext_path *path = NULL;
1346 struct ext4_ext_cache cbex;
1347 struct ext4_extent *ex;
1348 unsigned long next, start = 0, end = 0;
1349 unsigned long last = block + num;
1350 int depth, exists, err = 0;
1351
1352 BUG_ON(func == NULL);
1353 BUG_ON(inode == NULL);
1354
1355 while (block < last && block != EXT_MAX_BLOCK) {
1356 num = last - block;
1357 /* find extent for this block */
1358 path = ext4_ext_find_extent(inode, block, path);
1359 if (IS_ERR(path)) {
1360 err = PTR_ERR(path);
1361 path = NULL;
1362 break;
1363 }
1364
1365 depth = ext_depth(inode);
1366 BUG_ON(path[depth].p_hdr == NULL);
1367 ex = path[depth].p_ext;
1368 next = ext4_ext_next_allocated_block(path);
1369
1370 exists = 0;
1371 if (!ex) {
1372 /* there is no extent yet, so try to allocate
1373 * all requested space */
1374 start = block;
1375 end = block + num;
1376 } else if (le32_to_cpu(ex->ee_block) > block) {
1377 /* need to allocate space before found extent */
1378 start = block;
1379 end = le32_to_cpu(ex->ee_block);
1380 if (block + num < end)
1381 end = block + num;
1382 } else if (block >=
1383 le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) {
1384 /* need to allocate space after found extent */
1385 start = block;
1386 end = block + num;
1387 if (end >= next)
1388 end = next;
1389 } else if (block >= le32_to_cpu(ex->ee_block)) {
1390 /*
1391 * some part of requested space is covered
1392 * by found extent
1393 */
1394 start = block;
1395 end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len);
1396 if (block + num < end)
1397 end = block + num;
1398 exists = 1;
1399 } else {
1400 BUG();
1401 }
1402 BUG_ON(end <= start);
1403
1404 if (!exists) {
1405 cbex.ec_block = start;
1406 cbex.ec_len = end - start;
1407 cbex.ec_start = 0;
1408 cbex.ec_type = EXT4_EXT_CACHE_GAP;
1409 } else {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001410 cbex.ec_block = le32_to_cpu(ex->ee_block);
1411 cbex.ec_len = le16_to_cpu(ex->ee_len);
1412 cbex.ec_start = ext_pblock(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001413 cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
1414 }
1415
1416 BUG_ON(cbex.ec_len == 0);
1417 err = func(inode, path, &cbex, cbdata);
1418 ext4_ext_drop_refs(path);
1419
1420 if (err < 0)
1421 break;
1422 if (err == EXT_REPEAT)
1423 continue;
1424 else if (err == EXT_BREAK) {
1425 err = 0;
1426 break;
1427 }
1428
1429 if (ext_depth(inode) != depth) {
1430 /* depth was changed. we have to realloc path */
1431 kfree(path);
1432 path = NULL;
1433 }
1434
1435 block = cbex.ec_block + cbex.ec_len;
1436 }
1437
1438 if (path) {
1439 ext4_ext_drop_refs(path);
1440 kfree(path);
1441 }
1442
1443 return err;
1444}
1445
Avantika Mathur09b88252006-12-06 20:41:36 -08001446static void
Alex Tomasa86c6182006-10-11 01:21:03 -07001447ext4_ext_put_in_cache(struct inode *inode, __u32 block,
1448 __u32 len, __u32 start, int type)
1449{
1450 struct ext4_ext_cache *cex;
1451 BUG_ON(len == 0);
1452 cex = &EXT4_I(inode)->i_cached_extent;
1453 cex->ec_type = type;
1454 cex->ec_block = block;
1455 cex->ec_len = len;
1456 cex->ec_start = start;
1457}
1458
1459/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001460 * ext4_ext_put_gap_in_cache:
1461 * calculate boundaries of the gap that the requested block fits into
Alex Tomasa86c6182006-10-11 01:21:03 -07001462 * and cache this gap
1463 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001464static void
Alex Tomasa86c6182006-10-11 01:21:03 -07001465ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
1466 unsigned long block)
1467{
1468 int depth = ext_depth(inode);
1469 unsigned long lblock, len;
1470 struct ext4_extent *ex;
1471
1472 ex = path[depth].p_ext;
1473 if (ex == NULL) {
1474 /* there is no extent yet, so gap is [0;-] */
1475 lblock = 0;
1476 len = EXT_MAX_BLOCK;
1477 ext_debug("cache gap(whole file):");
1478 } else if (block < le32_to_cpu(ex->ee_block)) {
1479 lblock = block;
1480 len = le32_to_cpu(ex->ee_block) - block;
1481 ext_debug("cache gap(before): %lu [%lu:%lu]",
1482 (unsigned long) block,
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001483 (unsigned long) le32_to_cpu(ex->ee_block),
1484 (unsigned long) le16_to_cpu(ex->ee_len));
Alex Tomasa86c6182006-10-11 01:21:03 -07001485 } else if (block >= le32_to_cpu(ex->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001486 + le16_to_cpu(ex->ee_len)) {
1487 lblock = le32_to_cpu(ex->ee_block)
1488 + le16_to_cpu(ex->ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001489 len = ext4_ext_next_allocated_block(path);
1490 ext_debug("cache gap(after): [%lu:%lu] %lu",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001491 (unsigned long) le32_to_cpu(ex->ee_block),
1492 (unsigned long) le16_to_cpu(ex->ee_len),
Alex Tomasa86c6182006-10-11 01:21:03 -07001493 (unsigned long) block);
1494 BUG_ON(len == lblock);
1495 len = len - lblock;
1496 } else {
1497 lblock = len = 0;
1498 BUG();
1499 }
1500
1501 ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len);
1502 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
1503}
1504
Avantika Mathur09b88252006-12-06 20:41:36 -08001505static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001506ext4_ext_in_cache(struct inode *inode, unsigned long block,
1507 struct ext4_extent *ex)
1508{
1509 struct ext4_ext_cache *cex;
1510
1511 cex = &EXT4_I(inode)->i_cached_extent;
1512
1513 /* has cache valid data? */
1514 if (cex->ec_type == EXT4_EXT_CACHE_NO)
1515 return EXT4_EXT_CACHE_NO;
1516
1517 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
1518 cex->ec_type != EXT4_EXT_CACHE_EXTENT);
1519 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001520 ex->ee_block = cpu_to_le32(cex->ec_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001521 ext4_ext_store_pblock(ex, cex->ec_start);
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001522 ex->ee_len = cpu_to_le16(cex->ec_len);
Mingming Cao2ae02102006-10-11 01:21:11 -07001523 ext_debug("%lu cached by %lu:%lu:%llu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07001524 (unsigned long) block,
1525 (unsigned long) cex->ec_block,
1526 (unsigned long) cex->ec_len,
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001527 cex->ec_start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001528 return cex->ec_type;
1529 }
1530
1531 /* not in cache */
1532 return EXT4_EXT_CACHE_NO;
1533}
1534
1535/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001536 * ext4_ext_rm_idx:
1537 * removes index from the index block.
1538 * It's used in truncate case only, thus all requests are for
1539 * last index in the block only.
Alex Tomasa86c6182006-10-11 01:21:03 -07001540 */
1541int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
1542 struct ext4_ext_path *path)
1543{
1544 struct buffer_head *bh;
1545 int err;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001546 ext4_fsblk_t leaf;
Alex Tomasa86c6182006-10-11 01:21:03 -07001547
1548 /* free index block */
1549 path--;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001550 leaf = idx_pblock(path->p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -07001551 BUG_ON(path->p_hdr->eh_entries == 0);
Avantika Mathur7e028972006-12-06 20:41:33 -08001552 err = ext4_ext_get_access(handle, inode, path);
1553 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001554 return err;
1555 path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1);
Avantika Mathur7e028972006-12-06 20:41:33 -08001556 err = ext4_ext_dirty(handle, inode, path);
1557 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001558 return err;
Mingming Cao2ae02102006-10-11 01:21:11 -07001559 ext_debug("index is empty, remove it, free block %llu\n", leaf);
Alex Tomasa86c6182006-10-11 01:21:03 -07001560 bh = sb_find_get_block(inode->i_sb, leaf);
1561 ext4_forget(handle, 1, inode, bh, leaf);
1562 ext4_free_blocks(handle, inode, leaf, 1);
1563 return err;
1564}
1565
1566/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001567 * ext4_ext_calc_credits_for_insert:
1568 * This routine returns max. credits that the extent tree can consume.
Alex Tomasa86c6182006-10-11 01:21:03 -07001569 * It should be OK for low-performance paths like ->writepage()
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001570 * To allow many writing processes to fit into a single transaction,
1571 * the caller should calculate credits under truncate_mutex and
1572 * pass the actual path.
Alex Tomasa86c6182006-10-11 01:21:03 -07001573 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001574int ext4_ext_calc_credits_for_insert(struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001575 struct ext4_ext_path *path)
1576{
1577 int depth, needed;
1578
1579 if (path) {
1580 /* probably there is space in leaf? */
1581 depth = ext_depth(inode);
1582 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
1583 < le16_to_cpu(path[depth].p_hdr->eh_max))
1584 return 1;
1585 }
1586
1587 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001588 * given 32-bit logical block (4294967296 blocks), max. tree
Alex Tomasa86c6182006-10-11 01:21:03 -07001589 * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001590 * Let's also add one more level for imbalance.
Alex Tomasa86c6182006-10-11 01:21:03 -07001591 */
1592 depth = 5;
1593
1594 /* allocation of new data block(s) */
1595 needed = 2;
1596
1597 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001598 * tree can be full, so it would need to grow in depth:
Johann Lombardifeb18922006-12-06 20:40:46 -08001599 * we need one credit to modify old root, credits for
1600 * new root will be added in split accounting
Alex Tomasa86c6182006-10-11 01:21:03 -07001601 */
Johann Lombardifeb18922006-12-06 20:40:46 -08001602 needed += 1;
Alex Tomasa86c6182006-10-11 01:21:03 -07001603
1604 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001605 * Index split can happen, we would need:
Alex Tomasa86c6182006-10-11 01:21:03 -07001606 * allocate intermediate indexes (bitmap + group)
1607 * + change two blocks at each level, but root (already included)
1608 */
Johann Lombardifeb18922006-12-06 20:40:46 -08001609 needed += (depth * 2) + (depth * 2);
Alex Tomasa86c6182006-10-11 01:21:03 -07001610
1611 /* any allocation modifies superblock */
1612 needed += 1;
1613
1614 return needed;
1615}
1616
1617static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
1618 struct ext4_extent *ex,
1619 unsigned long from, unsigned long to)
1620{
1621 struct buffer_head *bh;
1622 int i;
1623
1624#ifdef EXTENTS_STATS
1625 {
1626 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1627 unsigned short ee_len = le16_to_cpu(ex->ee_len);
1628 spin_lock(&sbi->s_ext_stats_lock);
1629 sbi->s_ext_blocks += ee_len;
1630 sbi->s_ext_extents++;
1631 if (ee_len < sbi->s_ext_min)
1632 sbi->s_ext_min = ee_len;
1633 if (ee_len > sbi->s_ext_max)
1634 sbi->s_ext_max = ee_len;
1635 if (ext_depth(inode) > sbi->s_depth_max)
1636 sbi->s_depth_max = ext_depth(inode);
1637 spin_unlock(&sbi->s_ext_stats_lock);
1638 }
1639#endif
1640 if (from >= le32_to_cpu(ex->ee_block)
1641 && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
1642 /* tail removal */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001643 unsigned long num;
1644 ext4_fsblk_t start;
Alex Tomasa86c6182006-10-11 01:21:03 -07001645 num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001646 start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num;
Mingming Cao2ae02102006-10-11 01:21:11 -07001647 ext_debug("free last %lu blocks starting %llu\n", num, start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001648 for (i = 0; i < num; i++) {
1649 bh = sb_find_get_block(inode->i_sb, start + i);
1650 ext4_forget(handle, 0, inode, bh, start + i);
1651 }
1652 ext4_free_blocks(handle, inode, start, num);
1653 } else if (from == le32_to_cpu(ex->ee_block)
1654 && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
1655 printk("strange request: removal %lu-%lu from %u:%u\n",
1656 from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
1657 } else {
1658 printk("strange request: removal(2) %lu-%lu from %u:%u\n",
1659 from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
1660 }
1661 return 0;
1662}
1663
1664static int
1665ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
1666 struct ext4_ext_path *path, unsigned long start)
1667{
1668 int err = 0, correct_index = 0;
1669 int depth = ext_depth(inode), credits;
1670 struct ext4_extent_header *eh;
1671 unsigned a, b, block, num;
1672 unsigned long ex_ee_block;
1673 unsigned short ex_ee_len;
1674 struct ext4_extent *ex;
1675
1676 ext_debug("truncate since %lu in leaf\n", start);
1677 if (!path[depth].p_hdr)
1678 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
1679 eh = path[depth].p_hdr;
1680 BUG_ON(eh == NULL);
1681 BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
1682 BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
1683
1684 /* find where to start removing */
1685 ex = EXT_LAST_EXTENT(eh);
1686
1687 ex_ee_block = le32_to_cpu(ex->ee_block);
1688 ex_ee_len = le16_to_cpu(ex->ee_len);
1689
1690 while (ex >= EXT_FIRST_EXTENT(eh) &&
1691 ex_ee_block + ex_ee_len > start) {
1692 ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len);
1693 path[depth].p_ext = ex;
1694
1695 a = ex_ee_block > start ? ex_ee_block : start;
1696 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
1697 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
1698
1699 ext_debug(" border %u:%u\n", a, b);
1700
1701 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
1702 block = 0;
1703 num = 0;
1704 BUG();
1705 } else if (a != ex_ee_block) {
1706 /* remove tail of the extent */
1707 block = ex_ee_block;
1708 num = a - block;
1709 } else if (b != ex_ee_block + ex_ee_len - 1) {
1710 /* remove head of the extent */
1711 block = a;
1712 num = b - a;
1713 /* there is no "make a hole" API yet */
1714 BUG();
1715 } else {
1716 /* remove whole extent: excellent! */
1717 block = ex_ee_block;
1718 num = 0;
1719 BUG_ON(a != ex_ee_block);
1720 BUG_ON(b != ex_ee_block + ex_ee_len - 1);
1721 }
1722
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001723 /* at present, extent can't cross block group: */
Alex Tomasa86c6182006-10-11 01:21:03 -07001724 /* leaf + bitmap + group desc + sb + inode */
1725 credits = 5;
1726 if (ex == EXT_FIRST_EXTENT(eh)) {
1727 correct_index = 1;
1728 credits += (ext_depth(inode)) + 1;
1729 }
1730#ifdef CONFIG_QUOTA
1731 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
1732#endif
1733
1734 handle = ext4_ext_journal_restart(handle, credits);
1735 if (IS_ERR(handle)) {
1736 err = PTR_ERR(handle);
1737 goto out;
1738 }
1739
1740 err = ext4_ext_get_access(handle, inode, path + depth);
1741 if (err)
1742 goto out;
1743
1744 err = ext4_remove_blocks(handle, inode, ex, a, b);
1745 if (err)
1746 goto out;
1747
1748 if (num == 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001749 /* this extent is removed; mark slot entirely unused */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001750 ext4_ext_store_pblock(ex, 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07001751 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
1752 }
1753
1754 ex->ee_block = cpu_to_le32(block);
1755 ex->ee_len = cpu_to_le16(num);
1756
1757 err = ext4_ext_dirty(handle, inode, path + depth);
1758 if (err)
1759 goto out;
1760
Mingming Cao2ae02102006-10-11 01:21:11 -07001761 ext_debug("new extent: %u:%u:%llu\n", block, num,
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001762 ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07001763 ex--;
1764 ex_ee_block = le32_to_cpu(ex->ee_block);
1765 ex_ee_len = le16_to_cpu(ex->ee_len);
1766 }
1767
1768 if (correct_index && eh->eh_entries)
1769 err = ext4_ext_correct_indexes(handle, inode, path);
1770
1771 /* if this leaf is free, then we should
1772 * remove it from index block above */
1773 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
1774 err = ext4_ext_rm_idx(handle, inode, path + depth);
1775
1776out:
1777 return err;
1778}
1779
1780/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001781 * ext4_ext_more_to_rm:
1782 * returns 1 if current index has to be freed (even partial)
Alex Tomasa86c6182006-10-11 01:21:03 -07001783 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001784static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001785ext4_ext_more_to_rm(struct ext4_ext_path *path)
1786{
1787 BUG_ON(path->p_idx == NULL);
1788
1789 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
1790 return 0;
1791
1792 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001793 * if truncate on deeper level happened, it wasn't partial,
Alex Tomasa86c6182006-10-11 01:21:03 -07001794 * so we have to consider current index for truncation
1795 */
1796 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
1797 return 0;
1798 return 1;
1799}
1800
1801int ext4_ext_remove_space(struct inode *inode, unsigned long start)
1802{
1803 struct super_block *sb = inode->i_sb;
1804 int depth = ext_depth(inode);
1805 struct ext4_ext_path *path;
1806 handle_t *handle;
1807 int i = 0, err = 0;
1808
1809 ext_debug("truncate since %lu\n", start);
1810
1811 /* probably first extent we're gonna free will be last in block */
1812 handle = ext4_journal_start(inode, depth + 1);
1813 if (IS_ERR(handle))
1814 return PTR_ERR(handle);
1815
1816 ext4_ext_invalidate_cache(inode);
1817
1818 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001819 * We start scanning from right side, freeing all the blocks
1820 * after i_size and walking into the tree depth-wise.
Alex Tomasa86c6182006-10-11 01:21:03 -07001821 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -08001822 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL);
Alex Tomasa86c6182006-10-11 01:21:03 -07001823 if (path == NULL) {
1824 ext4_journal_stop(handle);
1825 return -ENOMEM;
1826 }
Alex Tomasa86c6182006-10-11 01:21:03 -07001827 path[0].p_hdr = ext_inode_hdr(inode);
1828 if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) {
1829 err = -EIO;
1830 goto out;
1831 }
1832 path[0].p_depth = depth;
1833
1834 while (i >= 0 && err == 0) {
1835 if (i == depth) {
1836 /* this is leaf block */
1837 err = ext4_ext_rm_leaf(handle, inode, path, start);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001838 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07001839 brelse(path[i].p_bh);
1840 path[i].p_bh = NULL;
1841 i--;
1842 continue;
1843 }
1844
1845 /* this is index block */
1846 if (!path[i].p_hdr) {
1847 ext_debug("initialize header\n");
1848 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
1849 if (ext4_ext_check_header(__FUNCTION__, inode,
1850 path[i].p_hdr)) {
1851 err = -EIO;
1852 goto out;
1853 }
1854 }
1855
1856 BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries)
1857 > le16_to_cpu(path[i].p_hdr->eh_max));
1858 BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC);
1859
1860 if (!path[i].p_idx) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001861 /* this level hasn't been touched yet */
Alex Tomasa86c6182006-10-11 01:21:03 -07001862 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
1863 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
1864 ext_debug("init index ptr: hdr 0x%p, num %d\n",
1865 path[i].p_hdr,
1866 le16_to_cpu(path[i].p_hdr->eh_entries));
1867 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001868 /* we were already here, see at next index */
Alex Tomasa86c6182006-10-11 01:21:03 -07001869 path[i].p_idx--;
1870 }
1871
1872 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
1873 i, EXT_FIRST_INDEX(path[i].p_hdr),
1874 path[i].p_idx);
1875 if (ext4_ext_more_to_rm(path + i)) {
1876 /* go to the next level */
Mingming Cao2ae02102006-10-11 01:21:11 -07001877 ext_debug("move to level %d (block %llu)\n",
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001878 i + 1, idx_pblock(path[i].p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -07001879 memset(path + i + 1, 0, sizeof(*path));
1880 path[i+1].p_bh =
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001881 sb_bread(sb, idx_pblock(path[i].p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -07001882 if (!path[i+1].p_bh) {
1883 /* should we reset i_size? */
1884 err = -EIO;
1885 break;
1886 }
1887
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001888 /* save actual number of indexes since this
1889 * number is changed at the next iteration */
Alex Tomasa86c6182006-10-11 01:21:03 -07001890 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
1891 i++;
1892 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001893 /* we finished processing this index, go up */
Alex Tomasa86c6182006-10-11 01:21:03 -07001894 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001895 /* index is empty, remove it;
Alex Tomasa86c6182006-10-11 01:21:03 -07001896 * handle must be already prepared by the
1897 * truncatei_leaf() */
1898 err = ext4_ext_rm_idx(handle, inode, path + i);
1899 }
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001900 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07001901 brelse(path[i].p_bh);
1902 path[i].p_bh = NULL;
1903 i--;
1904 ext_debug("return to level %d\n", i);
1905 }
1906 }
1907
1908 /* TODO: flexible tree reduction should be here */
1909 if (path->p_hdr->eh_entries == 0) {
1910 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001911 * truncate to zero freed all the tree,
1912 * so we need to correct eh_depth
Alex Tomasa86c6182006-10-11 01:21:03 -07001913 */
1914 err = ext4_ext_get_access(handle, inode, path);
1915 if (err == 0) {
1916 ext_inode_hdr(inode)->eh_depth = 0;
1917 ext_inode_hdr(inode)->eh_max =
1918 cpu_to_le16(ext4_ext_space_root(inode));
1919 err = ext4_ext_dirty(handle, inode, path);
1920 }
1921 }
1922out:
1923 ext4_ext_tree_changed(inode);
1924 ext4_ext_drop_refs(path);
1925 kfree(path);
1926 ext4_journal_stop(handle);
1927
1928 return err;
1929}
1930
1931/*
1932 * called at mount time
1933 */
1934void ext4_ext_init(struct super_block *sb)
1935{
1936 /*
1937 * possible initialization would be here
1938 */
1939
1940 if (test_opt(sb, EXTENTS)) {
1941 printk("EXT4-fs: file extents enabled");
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01001942#ifdef AGGRESSIVE_TEST
1943 printk(", aggressive tests");
Alex Tomasa86c6182006-10-11 01:21:03 -07001944#endif
1945#ifdef CHECK_BINSEARCH
1946 printk(", check binsearch");
1947#endif
1948#ifdef EXTENTS_STATS
1949 printk(", stats");
1950#endif
1951 printk("\n");
1952#ifdef EXTENTS_STATS
1953 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
1954 EXT4_SB(sb)->s_ext_min = 1 << 30;
1955 EXT4_SB(sb)->s_ext_max = 0;
1956#endif
1957 }
1958}
1959
1960/*
1961 * called at umount time
1962 */
1963void ext4_ext_release(struct super_block *sb)
1964{
1965 if (!test_opt(sb, EXTENTS))
1966 return;
1967
1968#ifdef EXTENTS_STATS
1969 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
1970 struct ext4_sb_info *sbi = EXT4_SB(sb);
1971 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
1972 sbi->s_ext_blocks, sbi->s_ext_extents,
1973 sbi->s_ext_blocks / sbi->s_ext_extents);
1974 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
1975 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
1976 }
1977#endif
1978}
1979
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001980int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1981 ext4_fsblk_t iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07001982 unsigned long max_blocks, struct buffer_head *bh_result,
1983 int create, int extend_disksize)
1984{
1985 struct ext4_ext_path *path = NULL;
1986 struct ext4_extent newex, *ex;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001987 ext4_fsblk_t goal, newblock;
1988 int err = 0, depth;
Alex Tomasa86c6182006-10-11 01:21:03 -07001989 unsigned long allocated = 0;
1990
1991 __clear_bit(BH_New, &bh_result->b_state);
1992 ext_debug("blocks %d/%lu requested for inode %u\n", (int) iblock,
1993 max_blocks, (unsigned) inode->i_ino);
1994 mutex_lock(&EXT4_I(inode)->truncate_mutex);
1995
1996 /* check in cache */
Avantika Mathur7e028972006-12-06 20:41:33 -08001997 goal = ext4_ext_in_cache(inode, iblock, &newex);
1998 if (goal) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001999 if (goal == EXT4_EXT_CACHE_GAP) {
2000 if (!create) {
2001 /* block isn't allocated yet and
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002002 * user doesn't want to allocate it */
Alex Tomasa86c6182006-10-11 01:21:03 -07002003 goto out2;
2004 }
2005 /* we should allocate requested block */
2006 } else if (goal == EXT4_EXT_CACHE_EXTENT) {
2007 /* block is already allocated */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002008 newblock = iblock
2009 - le32_to_cpu(newex.ee_block)
2010 + ext_pblock(&newex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002011 /* number of remaining blocks in the extent */
Alex Tomasa86c6182006-10-11 01:21:03 -07002012 allocated = le16_to_cpu(newex.ee_len) -
2013 (iblock - le32_to_cpu(newex.ee_block));
2014 goto out;
2015 } else {
2016 BUG();
2017 }
2018 }
2019
2020 /* find extent for this block */
2021 path = ext4_ext_find_extent(inode, iblock, NULL);
2022 if (IS_ERR(path)) {
2023 err = PTR_ERR(path);
2024 path = NULL;
2025 goto out2;
2026 }
2027
2028 depth = ext_depth(inode);
2029
2030 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002031 * consistent leaf must not be empty;
2032 * this situation is possible, though, _during_ tree modification;
Alex Tomasa86c6182006-10-11 01:21:03 -07002033 * this is why assert can't be put in ext4_ext_find_extent()
2034 */
2035 BUG_ON(path[depth].p_ext == NULL && depth != 0);
2036
Avantika Mathur7e028972006-12-06 20:41:33 -08002037 ex = path[depth].p_ext;
2038 if (ex) {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002039 unsigned long ee_block = le32_to_cpu(ex->ee_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002040 ext4_fsblk_t ee_start = ext_pblock(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002041 unsigned short ee_len = le16_to_cpu(ex->ee_len);
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002042
2043 /*
2044 * Allow future support for preallocated extents to be added
2045 * as an RO_COMPAT feature:
2046 * Uninitialized extents are treated as holes, except that
2047 * we avoid (fail) allocating new blocks during a write.
2048 */
2049 if (ee_len > EXT_MAX_LEN)
2050 goto out2;
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002051 /* if found extent covers block, simply return it */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002052 if (iblock >= ee_block && iblock < ee_block + ee_len) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002053 newblock = iblock - ee_block + ee_start;
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002054 /* number of remaining blocks in the extent */
Alex Tomasa86c6182006-10-11 01:21:03 -07002055 allocated = ee_len - (iblock - ee_block);
Mingming Cao2ae02102006-10-11 01:21:11 -07002056 ext_debug("%d fit into %lu:%d -> %llu\n", (int) iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07002057 ee_block, ee_len, newblock);
2058 ext4_ext_put_in_cache(inode, ee_block, ee_len,
2059 ee_start, EXT4_EXT_CACHE_EXTENT);
2060 goto out;
2061 }
2062 }
2063
2064 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002065 * requested block isn't allocated yet;
Alex Tomasa86c6182006-10-11 01:21:03 -07002066 * we couldn't try to create block if create flag is zero
2067 */
2068 if (!create) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002069 /* put just found gap into cache to speed up
2070 * subsequent requests */
Alex Tomasa86c6182006-10-11 01:21:03 -07002071 ext4_ext_put_gap_in_cache(inode, path, iblock);
2072 goto out2;
2073 }
2074 /*
Andrew Morton63f57932006-10-11 01:21:24 -07002075 * Okay, we need to do block allocation. Lazily initialize the block
2076 * allocation info here if necessary.
2077 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002078 if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
2079 ext4_init_block_alloc_info(inode);
2080
2081 /* allocate new block */
2082 goal = ext4_ext_find_goal(inode, path, iblock);
Amit Arora25d14f92007-05-24 13:04:13 -04002083
2084 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
2085 newex.ee_block = cpu_to_le32(iblock);
2086 newex.ee_len = cpu_to_le16(max_blocks);
2087 err = ext4_ext_check_overlap(inode, &newex, path);
2088 if (err)
2089 allocated = le16_to_cpu(newex.ee_len);
2090 else
2091 allocated = max_blocks;
Alex Tomasa86c6182006-10-11 01:21:03 -07002092 newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err);
2093 if (!newblock)
2094 goto out2;
Mingming Cao2ae02102006-10-11 01:21:11 -07002095 ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07002096 goal, newblock, allocated);
2097
2098 /* try to insert new extent into found leaf and return */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002099 ext4_ext_store_pblock(&newex, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -07002100 newex.ee_len = cpu_to_le16(allocated);
2101 err = ext4_ext_insert_extent(handle, inode, path, &newex);
Alex Tomas315054f2007-05-24 13:04:25 -04002102 if (err) {
2103 /* free data blocks we just allocated */
2104 ext4_free_blocks(handle, inode, ext_pblock(&newex),
2105 le16_to_cpu(newex.ee_len));
Alex Tomasa86c6182006-10-11 01:21:03 -07002106 goto out2;
Alex Tomas315054f2007-05-24 13:04:25 -04002107 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002108
2109 if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize)
2110 EXT4_I(inode)->i_disksize = inode->i_size;
2111
2112 /* previous routine could use block we allocated */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002113 newblock = ext_pblock(&newex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002114 __set_bit(BH_New, &bh_result->b_state);
2115
2116 ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
2117 EXT4_EXT_CACHE_EXTENT);
2118out:
2119 if (allocated > max_blocks)
2120 allocated = max_blocks;
2121 ext4_ext_show_leaf(inode, path);
2122 __set_bit(BH_Mapped, &bh_result->b_state);
2123 bh_result->b_bdev = inode->i_sb->s_bdev;
2124 bh_result->b_blocknr = newblock;
2125out2:
2126 if (path) {
2127 ext4_ext_drop_refs(path);
2128 kfree(path);
2129 }
2130 mutex_unlock(&EXT4_I(inode)->truncate_mutex);
2131
2132 return err ? err : allocated;
2133}
2134
2135void ext4_ext_truncate(struct inode * inode, struct page *page)
2136{
2137 struct address_space *mapping = inode->i_mapping;
2138 struct super_block *sb = inode->i_sb;
2139 unsigned long last_block;
2140 handle_t *handle;
2141 int err = 0;
2142
2143 /*
2144 * probably first extent we're gonna free will be last in block
2145 */
2146 err = ext4_writepage_trans_blocks(inode) + 3;
2147 handle = ext4_journal_start(inode, err);
2148 if (IS_ERR(handle)) {
2149 if (page) {
2150 clear_highpage(page);
2151 flush_dcache_page(page);
2152 unlock_page(page);
2153 page_cache_release(page);
2154 }
2155 return;
2156 }
2157
2158 if (page)
2159 ext4_block_truncate_page(handle, page, mapping, inode->i_size);
2160
2161 mutex_lock(&EXT4_I(inode)->truncate_mutex);
2162 ext4_ext_invalidate_cache(inode);
2163
2164 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002165 * TODO: optimization is possible here.
2166 * Probably we need not scan at all,
2167 * because page truncation is enough.
Alex Tomasa86c6182006-10-11 01:21:03 -07002168 */
2169 if (ext4_orphan_add(handle, inode))
2170 goto out_stop;
2171
2172 /* we have to know where to truncate from in crash case */
2173 EXT4_I(inode)->i_disksize = inode->i_size;
2174 ext4_mark_inode_dirty(handle, inode);
2175
2176 last_block = (inode->i_size + sb->s_blocksize - 1)
2177 >> EXT4_BLOCK_SIZE_BITS(sb);
2178 err = ext4_ext_remove_space(inode, last_block);
2179
2180 /* In a multi-transaction truncate, we only make the final
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002181 * transaction synchronous. */
Alex Tomasa86c6182006-10-11 01:21:03 -07002182 if (IS_SYNC(inode))
2183 handle->h_sync = 1;
2184
2185out_stop:
2186 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002187 * If this was a simple ftruncate() and the file will remain alive,
Alex Tomasa86c6182006-10-11 01:21:03 -07002188 * then we need to clear up the orphan record which we created above.
2189 * However, if this was a real unlink then we were called by
2190 * ext4_delete_inode(), and we allow that function to clean up the
2191 * orphan info for us.
2192 */
2193 if (inode->i_nlink)
2194 ext4_orphan_del(handle, inode);
2195
2196 mutex_unlock(&EXT4_I(inode)->truncate_mutex);
2197 ext4_journal_stop(handle);
2198}
2199
2200/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002201 * ext4_ext_writepage_trans_blocks:
2202 * calculate max number of blocks we could modify
Alex Tomasa86c6182006-10-11 01:21:03 -07002203 * in order to allocate new block for an inode
2204 */
2205int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
2206{
2207 int needed;
2208
2209 needed = ext4_ext_calc_credits_for_insert(inode, NULL);
2210
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002211 /* caller wants to allocate num blocks, but note it includes sb */
Alex Tomasa86c6182006-10-11 01:21:03 -07002212 needed = needed * num - (num - 1);
2213
2214#ifdef CONFIG_QUOTA
2215 needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
2216#endif
2217
2218 return needed;
2219}