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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-04-06 22:01:29 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-07 11:31:13 -0400
commit5442680fd23abc01f29af585cc1a2f793bd74565 (patch)
treeecc3231149c4f0d422443cab2f4df60ba3a3ca03
parent5eb563f5f299a2ed488d9eb52acede45ccb14c7b (diff)
nilfs2: persistent object allocator
This adds common functions to allocate or deallocate entries with bitmaps on a meta data file. This feature is used by the DAT and ifile. Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/nilfs2/alloc.c504
-rw-r--r--fs/nilfs2/alloc.h72
2 files changed, 576 insertions, 0 deletions
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
new file mode 100644
index 000000000000..d69e6ae59251
--- /dev/null
+++ b/fs/nilfs2/alloc.c
@@ -0,0 +1,504 @@
1/*
2 * alloc.c - NILFS dat/inode allocator
3 *
4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
23 */
24
25#include <linux/types.h>
26#include <linux/buffer_head.h>
27#include <linux/fs.h>
28#include <linux/bitops.h>
29#include "mdt.h"
30#include "alloc.h"
31
32
33static inline unsigned long
34nilfs_palloc_groups_per_desc_block(const struct inode *inode)
35{
36 return (1UL << inode->i_blkbits) /
37 sizeof(struct nilfs_palloc_group_desc);
38}
39
40static inline unsigned long
41nilfs_palloc_groups_count(const struct inode *inode)
42{
43 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
44}
45
46int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
47{
48 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
49
50 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
51 if (!mi->mi_bgl)
52 return -ENOMEM;
53
54 bgl_lock_init(mi->mi_bgl);
55
56 nilfs_mdt_set_entry_size(inode, entry_size, 0);
57
58 mi->mi_blocks_per_group =
59 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
60 mi->mi_entries_per_block) + 1;
61 /* Number of blocks in a group including entry blocks and
62 a bitmap block */
63 mi->mi_blocks_per_desc_block =
64 nilfs_palloc_groups_per_desc_block(inode) *
65 mi->mi_blocks_per_group + 1;
66 /* Number of blocks per descriptor including the
67 descriptor block */
68 return 0;
69}
70
71static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
72 unsigned long *offset)
73{
74 __u64 group = nr;
75
76 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
77 return group;
78}
79
80static unsigned long
81nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
82{
83 unsigned long desc_block =
84 group / nilfs_palloc_groups_per_desc_block(inode);
85 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
86}
87
88static unsigned long
89nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
90{
91 unsigned long desc_offset =
92 group % nilfs_palloc_groups_per_desc_block(inode);
93 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
94 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
95}
96
97static unsigned long
98nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,
99 const struct nilfs_palloc_group_desc *desc)
100{
101 unsigned long nfree;
102
103 spin_lock(nilfs_mdt_bgl_lock(inode, group));
104 nfree = le32_to_cpu(desc->pg_nfrees);
105 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
106 return nfree;
107}
108
109static void
110nilfs_palloc_group_desc_add_entries(struct inode *inode,
111 unsigned long group,
112 struct nilfs_palloc_group_desc *desc,
113 u32 n)
114{
115 spin_lock(nilfs_mdt_bgl_lock(inode, group));
116 le32_add_cpu(&desc->pg_nfrees, n);
117 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
118}
119
120static unsigned long
121nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
122{
123 unsigned long group, group_offset;
124
125 group = nilfs_palloc_group(inode, nr, &group_offset);
126
127 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
128 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
129}
130
131static void nilfs_palloc_desc_block_init(struct inode *inode,
132 struct buffer_head *bh, void *kaddr)
133{
134 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
135 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
136 __le32 nfrees;
137
138 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
139 while (n-- > 0) {
140 desc->pg_nfrees = nfrees;
141 desc++;
142 }
143}
144
145static int nilfs_palloc_get_desc_block(struct inode *inode,
146 unsigned long group,
147 int create, struct buffer_head **bhp)
148{
149 return nilfs_mdt_get_block(inode,
150 nilfs_palloc_desc_blkoff(inode, group),
151 create, nilfs_palloc_desc_block_init, bhp);
152}
153
154static int nilfs_palloc_get_bitmap_block(struct inode *inode,
155 unsigned long group,
156 int create, struct buffer_head **bhp)
157{
158 return nilfs_mdt_get_block(inode,
159 nilfs_palloc_bitmap_blkoff(inode, group),
160 create, NULL, bhp);
161}
162
163int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
164 int create, struct buffer_head **bhp)
165{
166 return nilfs_mdt_get_block(inode, nilfs_palloc_entry_blkoff(inode, nr),
167 create, NULL, bhp);
168}
169
170static struct nilfs_palloc_group_desc *
171nilfs_palloc_block_get_group_desc(const struct inode *inode,
172 unsigned long group,
173 const struct buffer_head *bh, void *kaddr)
174{
175 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
176 group % nilfs_palloc_groups_per_desc_block(inode);
177}
178
179static unsigned char *
180nilfs_palloc_block_get_bitmap(const struct inode *inode,
181 const struct buffer_head *bh, void *kaddr)
182{
183 return (unsigned char *)(kaddr + bh_offset(bh));
184}
185
186void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
187 const struct buffer_head *bh, void *kaddr)
188{
189 unsigned long entry_offset, group_offset;
190
191 nilfs_palloc_group(inode, nr, &group_offset);
192 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
193
194 return kaddr + bh_offset(bh) +
195 entry_offset * NILFS_MDT(inode)->mi_entry_size;
196}
197
198static int nilfs_palloc_find_available_slot(struct inode *inode,
199 unsigned long group,
200 unsigned long target,
201 unsigned char *bitmap,
202 int bsize) /* size in bits */
203{
204 int curr, pos, end, i;
205
206 if (target > 0) {
207 end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
208 if (end > bsize)
209 end = bsize;
210 pos = nilfs_find_next_zero_bit(bitmap, end, target);
211 if (pos < end &&
212 !nilfs_set_bit_atomic(
213 nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
214 return pos;
215 } else
216 end = 0;
217
218 for (i = 0, curr = end;
219 i < bsize;
220 i += BITS_PER_LONG, curr += BITS_PER_LONG) {
221 /* wrap around */
222 if (curr >= bsize)
223 curr = 0;
224 while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
225 != ~0UL) {
226 end = curr + BITS_PER_LONG;
227 if (end > bsize)
228 end = bsize;
229 pos = nilfs_find_next_zero_bit(bitmap, end, curr);
230 if ((pos < end) &&
231 !nilfs_set_bit_atomic(
232 nilfs_mdt_bgl_lock(inode, group), pos,
233 bitmap))
234 return pos;
235 }
236 }
237 return -ENOSPC;
238}
239
240static unsigned long
241nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
242 unsigned long curr, unsigned long max)
243{
244 return min_t(unsigned long,
245 nilfs_palloc_groups_per_desc_block(inode) -
246 curr % nilfs_palloc_groups_per_desc_block(inode),
247 max - curr + 1);
248}
249
250int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
251 struct nilfs_palloc_req *req)
252{
253 struct buffer_head *desc_bh, *bitmap_bh;
254 struct nilfs_palloc_group_desc *desc;
255 unsigned char *bitmap;
256 void *desc_kaddr, *bitmap_kaddr;
257 unsigned long group, maxgroup, ngroups;
258 unsigned long group_offset, maxgroup_offset;
259 unsigned long n, entries_per_group, groups_per_desc_block;
260 unsigned long i, j;
261 int pos, ret;
262
263 ngroups = nilfs_palloc_groups_count(inode);
264 maxgroup = ngroups - 1;
265 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
266 entries_per_group = nilfs_palloc_entries_per_group(inode);
267 groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
268
269 for (i = 0; i < ngroups; i += n) {
270 if (group >= ngroups) {
271 /* wrap around */
272 group = 0;
273 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
274 &maxgroup_offset) - 1;
275 }
276 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
277 if (ret < 0)
278 return ret;
279 desc_kaddr = kmap(desc_bh->b_page);
280 desc = nilfs_palloc_block_get_group_desc(
281 inode, group, desc_bh, desc_kaddr);
282 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
283 maxgroup);
284 for (j = 0; j < n; j++, desc++, group++) {
285 if (nilfs_palloc_group_desc_nfrees(inode, group, desc)
286 > 0) {
287 ret = nilfs_palloc_get_bitmap_block(
288 inode, group, 1, &bitmap_bh);
289 if (ret < 0)
290 goto out_desc;
291 bitmap_kaddr = kmap(bitmap_bh->b_page);
292 bitmap = nilfs_palloc_block_get_bitmap(
293 inode, bitmap_bh, bitmap_kaddr);
294 pos = nilfs_palloc_find_available_slot(
295 inode, group, group_offset, bitmap,
296 entries_per_group);
297 if (pos >= 0) {
298 /* found a free entry */
299 nilfs_palloc_group_desc_add_entries(
300 inode, group, desc, -1);
301 req->pr_entry_nr =
302 entries_per_group * group + pos;
303 kunmap(desc_bh->b_page);
304 kunmap(bitmap_bh->b_page);
305
306 req->pr_desc_bh = desc_bh;
307 req->pr_bitmap_bh = bitmap_bh;
308 return 0;
309 }
310 kunmap(bitmap_bh->b_page);
311 brelse(bitmap_bh);
312 }
313
314 group_offset = 0;
315 }
316
317 kunmap(desc_bh->b_page);
318 brelse(desc_bh);
319 }
320
321 /* no entries left */
322 return -ENOSPC;
323
324 out_desc:
325 kunmap(desc_bh->b_page);
326 brelse(desc_bh);
327 return ret;
328}
329
330void nilfs_palloc_commit_alloc_entry(struct inode *inode,
331 struct nilfs_palloc_req *req)
332{
333 nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
334 nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
335 nilfs_mdt_mark_dirty(inode);
336
337 brelse(req->pr_bitmap_bh);
338 brelse(req->pr_desc_bh);
339}
340
341void nilfs_palloc_commit_free_entry(struct inode *inode,
342 struct nilfs_palloc_req *req)
343{
344 struct nilfs_palloc_group_desc *desc;
345 unsigned long group, group_offset;
346 unsigned char *bitmap;
347 void *desc_kaddr, *bitmap_kaddr;
348
349 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
350 desc_kaddr = kmap(req->pr_desc_bh->b_page);
351 desc = nilfs_palloc_block_get_group_desc(inode, group,
352 req->pr_desc_bh, desc_kaddr);
353 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
354 bitmap = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh,
355 bitmap_kaddr);
356
357 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
358 group_offset, bitmap))
359 printk(KERN_WARNING "%s: entry number %llu already freed\n",
360 __func__, (unsigned long long)req->pr_entry_nr);
361
362 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
363
364 kunmap(req->pr_bitmap_bh->b_page);
365 kunmap(req->pr_desc_bh->b_page);
366
367 nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
368 nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
369 nilfs_mdt_mark_dirty(inode);
370
371 brelse(req->pr_bitmap_bh);
372 brelse(req->pr_desc_bh);
373}
374
375void nilfs_palloc_abort_alloc_entry(struct inode *inode,
376 struct nilfs_palloc_req *req)
377{
378 struct nilfs_palloc_group_desc *desc;
379 void *desc_kaddr, *bitmap_kaddr;
380 unsigned char *bitmap;
381 unsigned long group, group_offset;
382
383 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
384 desc_kaddr = kmap(req->pr_desc_bh->b_page);
385 desc = nilfs_palloc_block_get_group_desc(inode, group,
386 req->pr_desc_bh, desc_kaddr);
387 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
388 bitmap = nilfs_palloc_block_get_bitmap(inode, req->pr_bitmap_bh,
389 bitmap_kaddr);
390 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
391 group_offset, bitmap))
392 printk(KERN_WARNING "%s: entry numer %llu already freed\n",
393 __func__, (unsigned long long)req->pr_entry_nr);
394
395 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
396
397 kunmap(req->pr_bitmap_bh->b_page);
398 kunmap(req->pr_desc_bh->b_page);
399
400 brelse(req->pr_bitmap_bh);
401 brelse(req->pr_desc_bh);
402
403 req->pr_entry_nr = 0;
404 req->pr_bitmap_bh = NULL;
405 req->pr_desc_bh = NULL;
406}
407
408int nilfs_palloc_prepare_free_entry(struct inode *inode,
409 struct nilfs_palloc_req *req)
410{
411 struct buffer_head *desc_bh, *bitmap_bh;
412 unsigned long group, group_offset;
413 int ret;
414
415 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
416 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
417 if (ret < 0)
418 return ret;
419 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
420 if (ret < 0) {
421 brelse(desc_bh);
422 return ret;
423 }
424
425 req->pr_desc_bh = desc_bh;
426 req->pr_bitmap_bh = bitmap_bh;
427 return 0;
428}
429
430void nilfs_palloc_abort_free_entry(struct inode *inode,
431 struct nilfs_palloc_req *req)
432{
433 brelse(req->pr_bitmap_bh);
434 brelse(req->pr_desc_bh);
435
436 req->pr_entry_nr = 0;
437 req->pr_bitmap_bh = NULL;
438 req->pr_desc_bh = NULL;
439}
440
441static int
442nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
443{
444 __u64 first, last;
445
446 first = group * nilfs_palloc_entries_per_group(inode);
447 last = first + nilfs_palloc_entries_per_group(inode) - 1;
448 return (nr >= first) && (nr <= last);
449}
450
451int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
452{
453 struct buffer_head *desc_bh, *bitmap_bh;
454 struct nilfs_palloc_group_desc *desc;
455 unsigned char *bitmap;
456 void *desc_kaddr, *bitmap_kaddr;
457 unsigned long group, group_offset;
458 int i, j, n, ret;
459
460 for (i = 0; i < nitems; i += n) {
461 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
462 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
463 if (ret < 0)
464 return ret;
465 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
466 &bitmap_bh);
467 if (ret < 0) {
468 brelse(desc_bh);
469 return ret;
470 }
471 desc_kaddr = kmap(desc_bh->b_page);
472 desc = nilfs_palloc_block_get_group_desc(
473 inode, group, desc_bh, desc_kaddr);
474 bitmap_kaddr = kmap(bitmap_bh->b_page);
475 bitmap = nilfs_palloc_block_get_bitmap(
476 inode, bitmap_bh, bitmap_kaddr);
477 for (j = i, n = 0;
478 (j < nitems) && nilfs_palloc_group_is_in(inode, group,
479 entry_nrs[j]);
480 j++, n++) {
481 nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
482 if (!nilfs_clear_bit_atomic(
483 nilfs_mdt_bgl_lock(inode, group),
484 group_offset, bitmap)) {
485 printk(KERN_WARNING
486 "%s: entry number %llu already freed\n",
487 __func__,
488 (unsigned long long)entry_nrs[j]);
489 }
490 }
491 nilfs_palloc_group_desc_add_entries(inode, group, desc, n);
492
493 kunmap(bitmap_bh->b_page);
494 kunmap(desc_bh->b_page);
495
496 nilfs_mdt_mark_buffer_dirty(desc_bh);
497 nilfs_mdt_mark_buffer_dirty(bitmap_bh);
498 nilfs_mdt_mark_dirty(inode);
499
500 brelse(bitmap_bh);
501 brelse(desc_bh);
502 }
503 return 0;
504}
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
new file mode 100644
index 000000000000..4ace5475c2c7
--- /dev/null
+++ b/fs/nilfs2/alloc.h
@@ -0,0 +1,72 @@
1/*
2 * alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
3 *
4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
23 */
24
25#ifndef _NILFS_ALLOC_H
26#define _NILFS_ALLOC_H
27
28#include <linux/types.h>
29#include <linux/buffer_head.h>
30#include <linux/fs.h>
31
32static inline unsigned long
33nilfs_palloc_entries_per_group(const struct inode *inode)
34{
35 return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
36}
37
38int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
39int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
40 struct buffer_head **);
41void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
42 const struct buffer_head *, void *);
43
44/**
45 * nilfs_palloc_req - persistent alloctor request and reply
46 * @pr_entry_nr: entry number (vblocknr or inode number)
47 * @pr_desc_bh: buffer head of the buffer containing block group descriptors
48 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
49 * @pr_entry_bh: buffer head of the buffer containing translation entries
50 */
51struct nilfs_palloc_req {
52 __u64 pr_entry_nr;
53 struct buffer_head *pr_desc_bh;
54 struct buffer_head *pr_bitmap_bh;
55 struct buffer_head *pr_entry_bh;
56};
57
58int nilfs_palloc_prepare_alloc_entry(struct inode *,
59 struct nilfs_palloc_req *);
60void nilfs_palloc_commit_alloc_entry(struct inode *,
61 struct nilfs_palloc_req *);
62void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
63void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
64int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
65void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
66int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
67
68#define nilfs_set_bit_atomic ext2_set_bit_atomic
69#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
70#define nilfs_find_next_zero_bit ext2_find_next_zero_bit
71
72#endif /* _NILFS_ALLOC_H */