Root/fs/ocfs2/move_extents.c

1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * move_extents.c
5 *
6 * Copyright (C) 2011 Oracle. All rights reserved.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public
10 * License version 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 */
17#include <linux/fs.h>
18#include <linux/types.h>
19#include <linux/mount.h>
20#include <linux/swap.h>
21
22#include <cluster/masklog.h>
23
24#include "ocfs2.h"
25#include "ocfs2_ioctl.h"
26
27#include "alloc.h"
28#include "aops.h"
29#include "dlmglue.h"
30#include "extent_map.h"
31#include "inode.h"
32#include "journal.h"
33#include "suballoc.h"
34#include "uptodate.h"
35#include "super.h"
36#include "dir.h"
37#include "buffer_head_io.h"
38#include "sysfile.h"
39#include "suballoc.h"
40#include "refcounttree.h"
41#include "move_extents.h"
42
43struct ocfs2_move_extents_context {
44    struct inode *inode;
45    struct file *file;
46    int auto_defrag;
47    int partial;
48    int credits;
49    u32 new_phys_cpos;
50    u32 clusters_moved;
51    u64 refcount_loc;
52    struct ocfs2_move_extents *range;
53    struct ocfs2_extent_tree et;
54    struct ocfs2_alloc_context *meta_ac;
55    struct ocfs2_alloc_context *data_ac;
56    struct ocfs2_cached_dealloc_ctxt dealloc;
57};
58
59static int __ocfs2_move_extent(handle_t *handle,
60                   struct ocfs2_move_extents_context *context,
61                   u32 cpos, u32 len, u32 p_cpos, u32 new_p_cpos,
62                   int ext_flags)
63{
64    int ret = 0, index;
65    struct inode *inode = context->inode;
66    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
67    struct ocfs2_extent_rec *rec, replace_rec;
68    struct ocfs2_path *path = NULL;
69    struct ocfs2_extent_list *el;
70    u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);
71    u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);
72
73    ret = ocfs2_duplicate_clusters_by_page(handle, context->file, cpos,
74                           p_cpos, new_p_cpos, len);
75    if (ret) {
76        mlog_errno(ret);
77        goto out;
78    }
79
80    memset(&replace_rec, 0, sizeof(replace_rec));
81    replace_rec.e_cpos = cpu_to_le32(cpos);
82    replace_rec.e_leaf_clusters = cpu_to_le16(len);
83    replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(inode->i_sb,
84                                   new_p_cpos));
85
86    path = ocfs2_new_path_from_et(&context->et);
87    if (!path) {
88        ret = -ENOMEM;
89        mlog_errno(ret);
90        goto out;
91    }
92
93    ret = ocfs2_find_path(INODE_CACHE(inode), path, cpos);
94    if (ret) {
95        mlog_errno(ret);
96        goto out;
97    }
98
99    el = path_leaf_el(path);
100
101    index = ocfs2_search_extent_list(el, cpos);
102    if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
103        ocfs2_error(inode->i_sb,
104                "Inode %llu has an extent at cpos %u which can no "
105                "longer be found.\n",
106                (unsigned long long)ino, cpos);
107        ret = -EROFS;
108        goto out;
109    }
110
111    rec = &el->l_recs[index];
112
113    BUG_ON(ext_flags != rec->e_flags);
114    /*
115     * after moving/defraging to new location, the extent is not going
116     * to be refcounted anymore.
117     */
118    replace_rec.e_flags = ext_flags & ~OCFS2_EXT_REFCOUNTED;
119
120    ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
121                      context->et.et_root_bh,
122                      OCFS2_JOURNAL_ACCESS_WRITE);
123    if (ret) {
124        mlog_errno(ret);
125        goto out;
126    }
127
128    ret = ocfs2_split_extent(handle, &context->et, path, index,
129                 &replace_rec, context->meta_ac,
130                 &context->dealloc);
131    if (ret) {
132        mlog_errno(ret);
133        goto out;
134    }
135
136    ocfs2_journal_dirty(handle, context->et.et_root_bh);
137
138    context->new_phys_cpos = new_p_cpos;
139
140    /*
141     * need I to append truncate log for old clusters?
142     */
143    if (old_blkno) {
144        if (ext_flags & OCFS2_EXT_REFCOUNTED)
145            ret = ocfs2_decrease_refcount(inode, handle,
146                    ocfs2_blocks_to_clusters(osb->sb,
147                                 old_blkno),
148                    len, context->meta_ac,
149                    &context->dealloc, 1);
150        else
151            ret = ocfs2_truncate_log_append(osb, handle,
152                            old_blkno, len);
153    }
154
155out:
156    return ret;
157}
158
159/*
160 * lock allocators, and reserving appropriate number of bits for
161 * meta blocks and data clusters.
162 *
163 * in some cases, we don't need to reserve clusters, just let data_ac
164 * be NULL.
165 */
166static int ocfs2_lock_allocators_move_extents(struct inode *inode,
167                    struct ocfs2_extent_tree *et,
168                    u32 clusters_to_move,
169                    u32 extents_to_split,
170                    struct ocfs2_alloc_context **meta_ac,
171                    struct ocfs2_alloc_context **data_ac,
172                    int extra_blocks,
173                    int *credits)
174{
175    int ret, num_free_extents;
176    unsigned int max_recs_needed = 2 * extents_to_split + clusters_to_move;
177    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
178
179    num_free_extents = ocfs2_num_free_extents(osb, et);
180    if (num_free_extents < 0) {
181        ret = num_free_extents;
182        mlog_errno(ret);
183        goto out;
184    }
185
186    if (!num_free_extents ||
187        (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
188        extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);
189
190    ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, meta_ac);
191    if (ret) {
192        mlog_errno(ret);
193        goto out;
194    }
195
196    if (data_ac) {
197        ret = ocfs2_reserve_clusters(osb, clusters_to_move, data_ac);
198        if (ret) {
199            mlog_errno(ret);
200            goto out;
201        }
202    }
203
204    *credits += ocfs2_calc_extend_credits(osb->sb, et->et_root_el,
205                          clusters_to_move + 2);
206
207    mlog(0, "reserve metadata_blocks: %d, data_clusters: %u, credits: %d\n",
208         extra_blocks, clusters_to_move, *credits);
209out:
210    if (ret) {
211        if (*meta_ac) {
212            ocfs2_free_alloc_context(*meta_ac);
213            *meta_ac = NULL;
214        }
215    }
216
217    return ret;
218}
219
220/*
221 * Using one journal handle to guarantee the data consistency in case
222 * crash happens anywhere.
223 *
224 * XXX: defrag can end up with finishing partial extent as requested,
225 * due to not enough contiguous clusters can be found in allocator.
226 */
227static int ocfs2_defrag_extent(struct ocfs2_move_extents_context *context,
228                   u32 cpos, u32 phys_cpos, u32 *len, int ext_flags)
229{
230    int ret, credits = 0, extra_blocks = 0, partial = context->partial;
231    handle_t *handle;
232    struct inode *inode = context->inode;
233    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
234    struct inode *tl_inode = osb->osb_tl_inode;
235    struct ocfs2_refcount_tree *ref_tree = NULL;
236    u32 new_phys_cpos, new_len;
237    u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
238
239    if ((ext_flags & OCFS2_EXT_REFCOUNTED) && *len) {
240
241        BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
242             OCFS2_HAS_REFCOUNT_FL));
243
244        BUG_ON(!context->refcount_loc);
245
246        ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,
247                           &ref_tree, NULL);
248        if (ret) {
249            mlog_errno(ret);
250            return ret;
251        }
252
253        ret = ocfs2_prepare_refcount_change_for_del(inode,
254                            context->refcount_loc,
255                            phys_blkno,
256                            *len,
257                            &credits,
258                            &extra_blocks);
259        if (ret) {
260            mlog_errno(ret);
261            goto out;
262        }
263    }
264
265    ret = ocfs2_lock_allocators_move_extents(inode, &context->et, *len, 1,
266                         &context->meta_ac,
267                         &context->data_ac,
268                         extra_blocks, &credits);
269    if (ret) {
270        mlog_errno(ret);
271        goto out;
272    }
273
274    /*
275     * should be using allocation reservation strategy there?
276     *
277     * if (context->data_ac)
278     * context->data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
279     */
280
281    mutex_lock(&tl_inode->i_mutex);
282
283    if (ocfs2_truncate_log_needs_flush(osb)) {
284        ret = __ocfs2_flush_truncate_log(osb);
285        if (ret < 0) {
286            mlog_errno(ret);
287            goto out_unlock_mutex;
288        }
289    }
290
291    handle = ocfs2_start_trans(osb, credits);
292    if (IS_ERR(handle)) {
293        ret = PTR_ERR(handle);
294        mlog_errno(ret);
295        goto out_unlock_mutex;
296    }
297
298    ret = __ocfs2_claim_clusters(handle, context->data_ac, 1, *len,
299                     &new_phys_cpos, &new_len);
300    if (ret) {
301        mlog_errno(ret);
302        goto out_commit;
303    }
304
305    /*
306     * allowing partial extent moving is kind of 'pros and cons', it makes
307     * whole defragmentation less likely to fail, on the contrary, the bad
308     * thing is it may make the fs even more fragmented after moving, let
309     * userspace make a good decision here.
310     */
311    if (new_len != *len) {
312        mlog(0, "len_claimed: %u, len: %u\n", new_len, *len);
313        if (!partial) {
314            context->range->me_flags &= ~OCFS2_MOVE_EXT_FL_COMPLETE;
315            ret = -ENOSPC;
316            goto out_commit;
317        }
318    }
319
320    mlog(0, "cpos: %u, phys_cpos: %u, new_phys_cpos: %u\n", cpos,
321         phys_cpos, new_phys_cpos);
322
323    ret = __ocfs2_move_extent(handle, context, cpos, new_len, phys_cpos,
324                  new_phys_cpos, ext_flags);
325    if (ret)
326        mlog_errno(ret);
327
328    if (partial && (new_len != *len))
329        *len = new_len;
330
331    /*
332     * Here we should write the new page out first if we are
333     * in write-back mode.
334     */
335    ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, *len);
336    if (ret)
337        mlog_errno(ret);
338
339out_commit:
340    ocfs2_commit_trans(osb, handle);
341
342out_unlock_mutex:
343    mutex_unlock(&tl_inode->i_mutex);
344
345    if (context->data_ac) {
346        ocfs2_free_alloc_context(context->data_ac);
347        context->data_ac = NULL;
348    }
349
350    if (context->meta_ac) {
351        ocfs2_free_alloc_context(context->meta_ac);
352        context->meta_ac = NULL;
353    }
354
355out:
356    if (ref_tree)
357        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
358
359    return ret;
360}
361
362/*
363 * find the victim alloc group, where #blkno fits.
364 */
365static int ocfs2_find_victim_alloc_group(struct inode *inode,
366                     u64 vict_blkno,
367                     int type, int slot,
368                     int *vict_bit,
369                     struct buffer_head **ret_bh)
370{
371    int ret, i, bits_per_unit = 0;
372    u64 blkno;
373    char namebuf[40];
374
375    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
376    struct buffer_head *ac_bh = NULL, *gd_bh = NULL;
377    struct ocfs2_chain_list *cl;
378    struct ocfs2_chain_rec *rec;
379    struct ocfs2_dinode *ac_dinode;
380    struct ocfs2_group_desc *bg;
381
382    ocfs2_sprintf_system_inode_name(namebuf, sizeof(namebuf), type, slot);
383    ret = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
384                     strlen(namebuf), &blkno);
385    if (ret) {
386        ret = -ENOENT;
387        goto out;
388    }
389
390    ret = ocfs2_read_blocks_sync(osb, blkno, 1, &ac_bh);
391    if (ret) {
392        mlog_errno(ret);
393        goto out;
394    }
395
396    ac_dinode = (struct ocfs2_dinode *)ac_bh->b_data;
397    cl = &(ac_dinode->id2.i_chain);
398    rec = &(cl->cl_recs[0]);
399
400    if (type == GLOBAL_BITMAP_SYSTEM_INODE)
401        bits_per_unit = osb->s_clustersize_bits -
402                    inode->i_sb->s_blocksize_bits;
403    /*
404     * 'vict_blkno' was out of the valid range.
405     */
406    if ((vict_blkno < le64_to_cpu(rec->c_blkno)) ||
407        (vict_blkno >= (le32_to_cpu(ac_dinode->id1.bitmap1.i_total) <<
408                bits_per_unit))) {
409        ret = -EINVAL;
410        goto out;
411    }
412
413    for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i++) {
414
415        rec = &(cl->cl_recs[i]);
416        if (!rec)
417            continue;
418
419        bg = NULL;
420
421        do {
422            if (!bg)
423                blkno = le64_to_cpu(rec->c_blkno);
424            else
425                blkno = le64_to_cpu(bg->bg_next_group);
426
427            if (gd_bh) {
428                brelse(gd_bh);
429                gd_bh = NULL;
430            }
431
432            ret = ocfs2_read_blocks_sync(osb, blkno, 1, &gd_bh);
433            if (ret) {
434                mlog_errno(ret);
435                goto out;
436            }
437
438            bg = (struct ocfs2_group_desc *)gd_bh->b_data;
439
440            if (vict_blkno < (le64_to_cpu(bg->bg_blkno) +
441                        le16_to_cpu(bg->bg_bits))) {
442
443                *ret_bh = gd_bh;
444                *vict_bit = (vict_blkno - blkno) >>
445                            bits_per_unit;
446                mlog(0, "find the victim group: #%llu, "
447                     "total_bits: %u, vict_bit: %u\n",
448                     blkno, le16_to_cpu(bg->bg_bits),
449                     *vict_bit);
450                goto out;
451            }
452
453        } while (le64_to_cpu(bg->bg_next_group));
454    }
455
456    ret = -EINVAL;
457out:
458    brelse(ac_bh);
459
460    /*
461     * caller has to release the gd_bh properly.
462     */
463    return ret;
464}
465
466/*
467 * XXX: helper to validate and adjust moving goal.
468 */
469static int ocfs2_validate_and_adjust_move_goal(struct inode *inode,
470                           struct ocfs2_move_extents *range)
471{
472    int ret, goal_bit = 0;
473
474    struct buffer_head *gd_bh = NULL;
475    struct ocfs2_group_desc *bg = NULL;
476    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
477    int c_to_b = 1 << (osb->s_clustersize_bits -
478                    inode->i_sb->s_blocksize_bits);
479
480    /*
481     * make goal become cluster aligned.
482     */
483    range->me_goal = ocfs2_block_to_cluster_start(inode->i_sb,
484                              range->me_goal);
485    /*
486     * moving goal is not allowd to start with a group desc blok(#0 blk)
487     * let's compromise to the latter cluster.
488     */
489    if (range->me_goal == le64_to_cpu(bg->bg_blkno))
490        range->me_goal += c_to_b;
491
492    /*
493     * validate goal sits within global_bitmap, and return the victim
494     * group desc
495     */
496    ret = ocfs2_find_victim_alloc_group(inode, range->me_goal,
497                        GLOBAL_BITMAP_SYSTEM_INODE,
498                        OCFS2_INVALID_SLOT,
499                        &goal_bit, &gd_bh);
500    if (ret)
501        goto out;
502
503    bg = (struct ocfs2_group_desc *)gd_bh->b_data;
504
505    /*
506     * movement is not gonna cross two groups.
507     */
508    if ((le16_to_cpu(bg->bg_bits) - goal_bit) * osb->s_clustersize <
509                                range->me_len) {
510        ret = -EINVAL;
511        goto out;
512    }
513    /*
514     * more exact validations/adjustments will be performed later during
515     * moving operation for each extent range.
516     */
517    mlog(0, "extents get ready to be moved to #%llu block\n",
518         range->me_goal);
519
520out:
521    brelse(gd_bh);
522
523    return ret;
524}
525
526static void ocfs2_probe_alloc_group(struct inode *inode, struct buffer_head *bh,
527                    int *goal_bit, u32 move_len, u32 max_hop,
528                    u32 *phys_cpos)
529{
530    int i, used, last_free_bits = 0, base_bit = *goal_bit;
531    struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
532    u32 base_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
533                         le64_to_cpu(gd->bg_blkno));
534
535    for (i = base_bit; i < le16_to_cpu(gd->bg_bits); i++) {
536
537        used = ocfs2_test_bit(i, (unsigned long *)gd->bg_bitmap);
538        if (used) {
539            /*
540             * we even tried searching the free chunk by jumping
541             * a 'max_hop' distance, but still failed.
542             */
543            if ((i - base_bit) > max_hop) {
544                *phys_cpos = 0;
545                break;
546            }
547
548            if (last_free_bits)
549                last_free_bits = 0;
550
551            continue;
552        } else
553            last_free_bits++;
554
555        if (last_free_bits == move_len) {
556            *goal_bit = i;
557            *phys_cpos = base_cpos + i;
558            break;
559        }
560    }
561
562    mlog(0, "found phys_cpos: %u to fit the wanted moving.\n", *phys_cpos);
563}
564
565static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
566                       handle_t *handle,
567                       struct buffer_head *di_bh,
568                       u32 num_bits,
569                       u16 chain)
570{
571    int ret;
572    u32 tmp_used;
573    struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
574    struct ocfs2_chain_list *cl =
575                (struct ocfs2_chain_list *) &di->id2.i_chain;
576
577    ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
578                      OCFS2_JOURNAL_ACCESS_WRITE);
579    if (ret < 0) {
580        mlog_errno(ret);
581        goto out;
582    }
583
584    tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
585    di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
586    le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
587    ocfs2_journal_dirty(handle, di_bh);
588
589out:
590    return ret;
591}
592
593static inline int ocfs2_block_group_set_bits(handle_t *handle,
594                         struct inode *alloc_inode,
595                         struct ocfs2_group_desc *bg,
596                         struct buffer_head *group_bh,
597                         unsigned int bit_off,
598                         unsigned int num_bits)
599{
600    int status;
601    void *bitmap = bg->bg_bitmap;
602    int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
603
604    /* All callers get the descriptor via
605     * ocfs2_read_group_descriptor(). Any corruption is a code bug. */
606    BUG_ON(!OCFS2_IS_VALID_GROUP_DESC(bg));
607    BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
608
609    mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
610         num_bits);
611
612    if (ocfs2_is_cluster_bitmap(alloc_inode))
613        journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
614
615    status = ocfs2_journal_access_gd(handle,
616                     INODE_CACHE(alloc_inode),
617                     group_bh,
618                     journal_type);
619    if (status < 0) {
620        mlog_errno(status);
621        goto bail;
622    }
623
624    le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
625    if (le16_to_cpu(bg->bg_free_bits_count) > le16_to_cpu(bg->bg_bits)) {
626        ocfs2_error(alloc_inode->i_sb, "Group descriptor # %llu has bit"
627                " count %u but claims %u are freed. num_bits %d",
628                (unsigned long long)le64_to_cpu(bg->bg_blkno),
629                le16_to_cpu(bg->bg_bits),
630                le16_to_cpu(bg->bg_free_bits_count), num_bits);
631        return -EROFS;
632    }
633    while (num_bits--)
634        ocfs2_set_bit(bit_off++, bitmap);
635
636    ocfs2_journal_dirty(handle, group_bh);
637
638bail:
639    return status;
640}
641
642static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
643                 u32 cpos, u32 phys_cpos, u32 *new_phys_cpos,
644                 u32 len, int ext_flags)
645{
646    int ret, credits = 0, extra_blocks = 0, goal_bit = 0;
647    handle_t *handle;
648    struct inode *inode = context->inode;
649    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
650    struct inode *tl_inode = osb->osb_tl_inode;
651    struct inode *gb_inode = NULL;
652    struct buffer_head *gb_bh = NULL;
653    struct buffer_head *gd_bh = NULL;
654    struct ocfs2_group_desc *gd;
655    struct ocfs2_refcount_tree *ref_tree = NULL;
656    u32 move_max_hop = ocfs2_blocks_to_clusters(inode->i_sb,
657                            context->range->me_threshold);
658    u64 phys_blkno, new_phys_blkno;
659
660    phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
661
662    if ((ext_flags & OCFS2_EXT_REFCOUNTED) && len) {
663
664        BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
665             OCFS2_HAS_REFCOUNT_FL));
666
667        BUG_ON(!context->refcount_loc);
668
669        ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,
670                           &ref_tree, NULL);
671        if (ret) {
672            mlog_errno(ret);
673            return ret;
674        }
675
676        ret = ocfs2_prepare_refcount_change_for_del(inode,
677                            context->refcount_loc,
678                            phys_blkno,
679                            len,
680                            &credits,
681                            &extra_blocks);
682        if (ret) {
683            mlog_errno(ret);
684            goto out;
685        }
686    }
687
688    ret = ocfs2_lock_allocators_move_extents(inode, &context->et, len, 1,
689                         &context->meta_ac,
690                         NULL, extra_blocks, &credits);
691    if (ret) {
692        mlog_errno(ret);
693        goto out;
694    }
695
696    /*
697     * need to count 2 extra credits for global_bitmap inode and
698     * group descriptor.
699     */
700    credits += OCFS2_INODE_UPDATE_CREDITS + 1;
701
702    /*
703     * ocfs2_move_extent() didn't reserve any clusters in lock_allocators()
704     * logic, while we still need to lock the global_bitmap.
705     */
706    gb_inode = ocfs2_get_system_file_inode(osb, GLOBAL_BITMAP_SYSTEM_INODE,
707                           OCFS2_INVALID_SLOT);
708    if (!gb_inode) {
709        mlog(ML_ERROR, "unable to get global_bitmap inode\n");
710        ret = -EIO;
711        goto out;
712    }
713
714    mutex_lock(&gb_inode->i_mutex);
715
716    ret = ocfs2_inode_lock(gb_inode, &gb_bh, 1);
717    if (ret) {
718        mlog_errno(ret);
719        goto out_unlock_gb_mutex;
720    }
721
722    mutex_lock(&tl_inode->i_mutex);
723
724    handle = ocfs2_start_trans(osb, credits);
725    if (IS_ERR(handle)) {
726        ret = PTR_ERR(handle);
727        mlog_errno(ret);
728        goto out_unlock_tl_inode;
729    }
730
731    new_phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *new_phys_cpos);
732    ret = ocfs2_find_victim_alloc_group(inode, new_phys_blkno,
733                        GLOBAL_BITMAP_SYSTEM_INODE,
734                        OCFS2_INVALID_SLOT,
735                        &goal_bit, &gd_bh);
736    if (ret) {
737        mlog_errno(ret);
738        goto out_commit;
739    }
740
741    /*
742     * probe the victim cluster group to find a proper
743     * region to fit wanted movement, it even will perfrom
744     * a best-effort attempt by compromising to a threshold
745     * around the goal.
746     */
747    ocfs2_probe_alloc_group(inode, gd_bh, &goal_bit, len, move_max_hop,
748                new_phys_cpos);
749    if (!new_phys_cpos) {
750        ret = -ENOSPC;
751        goto out_commit;
752    }
753
754    ret = __ocfs2_move_extent(handle, context, cpos, len, phys_cpos,
755                  *new_phys_cpos, ext_flags);
756    if (ret) {
757        mlog_errno(ret);
758        goto out_commit;
759    }
760
761    gd = (struct ocfs2_group_desc *)gd_bh->b_data;
762    ret = ocfs2_alloc_dinode_update_counts(gb_inode, handle, gb_bh, len,
763                           le16_to_cpu(gd->bg_chain));
764    if (ret) {
765        mlog_errno(ret);
766        goto out_commit;
767    }
768
769    ret = ocfs2_block_group_set_bits(handle, gb_inode, gd, gd_bh,
770                     goal_bit, len);
771    if (ret)
772        mlog_errno(ret);
773
774    /*
775     * Here we should write the new page out first if we are
776     * in write-back mode.
777     */
778    ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, len);
779    if (ret)
780        mlog_errno(ret);
781
782out_commit:
783    ocfs2_commit_trans(osb, handle);
784    brelse(gd_bh);
785
786out_unlock_tl_inode:
787    mutex_unlock(&tl_inode->i_mutex);
788
789    ocfs2_inode_unlock(gb_inode, 1);
790out_unlock_gb_mutex:
791    mutex_unlock(&gb_inode->i_mutex);
792    brelse(gb_bh);
793    iput(gb_inode);
794
795out:
796    if (context->meta_ac) {
797        ocfs2_free_alloc_context(context->meta_ac);
798        context->meta_ac = NULL;
799    }
800
801    if (ref_tree)
802        ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
803
804    return ret;
805}
806
807/*
808 * Helper to calculate the defraging length in one run according to threshold.
809 */
810static void ocfs2_calc_extent_defrag_len(u32 *alloc_size, u32 *len_defraged,
811                     u32 threshold, int *skip)
812{
813    if ((*alloc_size + *len_defraged) < threshold) {
814        /*
815         * proceed defragmentation until we meet the thresh
816         */
817        *len_defraged += *alloc_size;
818    } else if (*len_defraged == 0) {
819        /*
820         * XXX: skip a large extent.
821         */
822        *skip = 1;
823    } else {
824        /*
825         * split this extent to coalesce with former pieces as
826         * to reach the threshold.
827         *
828         * we're done here with one cycle of defragmentation
829         * in a size of 'thresh', resetting 'len_defraged'
830         * forces a new defragmentation.
831         */
832        *alloc_size = threshold - *len_defraged;
833        *len_defraged = 0;
834    }
835}
836
837static int __ocfs2_move_extents_range(struct buffer_head *di_bh,
838                struct ocfs2_move_extents_context *context)
839{
840    int ret = 0, flags, do_defrag, skip = 0;
841    u32 cpos, phys_cpos, move_start, len_to_move, alloc_size;
842    u32 len_defraged = 0, defrag_thresh = 0, new_phys_cpos = 0;
843
844    struct inode *inode = context->inode;
845    struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
846    struct ocfs2_move_extents *range = context->range;
847    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
848
849    if ((inode->i_size == 0) || (range->me_len == 0))
850        return 0;
851
852    if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
853        return 0;
854
855    context->refcount_loc = le64_to_cpu(di->i_refcount_loc);
856
857    ocfs2_init_dinode_extent_tree(&context->et, INODE_CACHE(inode), di_bh);
858    ocfs2_init_dealloc_ctxt(&context->dealloc);
859
860    /*
861     * TO-DO XXX:
862     *
863     * - xattr extents.
864     */
865
866    do_defrag = context->auto_defrag;
867
868    /*
869     * extents moving happens in unit of clusters, for the sake
870     * of simplicity, we may ignore two clusters where 'byte_start'
871     * and 'byte_start + len' were within.
872     */
873    move_start = ocfs2_clusters_for_bytes(osb->sb, range->me_start);
874    len_to_move = (range->me_start + range->me_len) >>
875                        osb->s_clustersize_bits;
876    if (len_to_move >= move_start)
877        len_to_move -= move_start;
878    else
879        len_to_move = 0;
880
881    if (do_defrag) {
882        defrag_thresh = range->me_threshold >> osb->s_clustersize_bits;
883        if (defrag_thresh <= 1)
884            goto done;
885    } else
886        new_phys_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
887                             range->me_goal);
888
889    mlog(0, "Inode: %llu, start: %llu, len: %llu, cstart: %u, clen: %u, "
890         "thresh: %u\n",
891         (unsigned long long)OCFS2_I(inode)->ip_blkno,
892         (unsigned long long)range->me_start,
893         (unsigned long long)range->me_len,
894         move_start, len_to_move, defrag_thresh);
895
896    cpos = move_start;
897    while (len_to_move) {
898        ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &alloc_size,
899                     &flags);
900        if (ret) {
901            mlog_errno(ret);
902            goto out;
903        }
904
905        if (alloc_size > len_to_move)
906            alloc_size = len_to_move;
907
908        /*
909         * XXX: how to deal with a hole:
910         *
911         * - skip the hole of course
912         * - force a new defragmentation
913         */
914        if (!phys_cpos) {
915            if (do_defrag)
916                len_defraged = 0;
917
918            goto next;
919        }
920
921        if (do_defrag) {
922            ocfs2_calc_extent_defrag_len(&alloc_size, &len_defraged,
923                             defrag_thresh, &skip);
924            /*
925             * skip large extents
926             */
927            if (skip) {
928                skip = 0;
929                goto next;
930            }
931
932            mlog(0, "#Defrag: cpos: %u, phys_cpos: %u, "
933                 "alloc_size: %u, len_defraged: %u\n",
934                 cpos, phys_cpos, alloc_size, len_defraged);
935
936            ret = ocfs2_defrag_extent(context, cpos, phys_cpos,
937                          &alloc_size, flags);
938        } else {
939            ret = ocfs2_move_extent(context, cpos, phys_cpos,
940                        &new_phys_cpos, alloc_size,
941                        flags);
942
943            new_phys_cpos += alloc_size;
944        }
945
946        if (ret < 0) {
947            mlog_errno(ret);
948            goto out;
949        }
950
951        context->clusters_moved += alloc_size;
952next:
953        cpos += alloc_size;
954        len_to_move -= alloc_size;
955    }
956
957done:
958    range->me_flags |= OCFS2_MOVE_EXT_FL_COMPLETE;
959
960out:
961    range->me_moved_len = ocfs2_clusters_to_bytes(osb->sb,
962                              context->clusters_moved);
963    range->me_new_offset = ocfs2_clusters_to_bytes(osb->sb,
964                               context->new_phys_cpos);
965
966    ocfs2_schedule_truncate_log_flush(osb, 1);
967    ocfs2_run_deallocs(osb, &context->dealloc);
968
969    return ret;
970}
971
972static int ocfs2_move_extents(struct ocfs2_move_extents_context *context)
973{
974    int status;
975    handle_t *handle;
976    struct inode *inode = context->inode;
977    struct ocfs2_dinode *di;
978    struct buffer_head *di_bh = NULL;
979    struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
980
981    if (!inode)
982        return -ENOENT;
983
984    if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
985        return -EROFS;
986
987    mutex_lock(&inode->i_mutex);
988
989    /*
990     * This prevents concurrent writes from other nodes
991     */
992    status = ocfs2_rw_lock(inode, 1);
993    if (status) {
994        mlog_errno(status);
995        goto out;
996    }
997
998    status = ocfs2_inode_lock(inode, &di_bh, 1);
999    if (status) {
1000        mlog_errno(status);
1001        goto out_rw_unlock;
1002    }
1003
1004    /*
1005     * rememer ip_xattr_sem also needs to be held if necessary
1006     */
1007    down_write(&OCFS2_I(inode)->ip_alloc_sem);
1008
1009    status = __ocfs2_move_extents_range(di_bh, context);
1010
1011    up_write(&OCFS2_I(inode)->ip_alloc_sem);
1012    if (status) {
1013        mlog_errno(status);
1014        goto out_inode_unlock;
1015    }
1016
1017    /*
1018     * We update ctime for these changes
1019     */
1020    handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
1021    if (IS_ERR(handle)) {
1022        status = PTR_ERR(handle);
1023        mlog_errno(status);
1024        goto out_inode_unlock;
1025    }
1026
1027    status = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
1028                     OCFS2_JOURNAL_ACCESS_WRITE);
1029    if (status) {
1030        mlog_errno(status);
1031        goto out_commit;
1032    }
1033
1034    di = (struct ocfs2_dinode *)di_bh->b_data;
1035    inode->i_ctime = CURRENT_TIME;
1036    di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
1037    di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
1038
1039    ocfs2_journal_dirty(handle, di_bh);
1040
1041out_commit:
1042    ocfs2_commit_trans(osb, handle);
1043
1044out_inode_unlock:
1045    brelse(di_bh);
1046    ocfs2_inode_unlock(inode, 1);
1047out_rw_unlock:
1048    ocfs2_rw_unlock(inode, 1);
1049out:
1050    mutex_unlock(&inode->i_mutex);
1051
1052    return status;
1053}
1054
1055int ocfs2_ioctl_move_extents(struct file *filp, void __user *argp)
1056{
1057    int status;
1058
1059    struct inode *inode = filp->f_path.dentry->d_inode;
1060    struct ocfs2_move_extents range;
1061    struct ocfs2_move_extents_context *context = NULL;
1062
1063    status = mnt_want_write(filp->f_path.mnt);
1064    if (status)
1065        return status;
1066
1067    if ((!S_ISREG(inode->i_mode)) || !(filp->f_mode & FMODE_WRITE))
1068        goto out;
1069
1070    if (inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
1071        status = -EPERM;
1072        goto out;
1073    }
1074
1075    context = kzalloc(sizeof(struct ocfs2_move_extents_context), GFP_NOFS);
1076    if (!context) {
1077        status = -ENOMEM;
1078        mlog_errno(status);
1079        goto out;
1080    }
1081
1082    context->inode = inode;
1083    context->file = filp;
1084
1085    if (argp) {
1086        if (copy_from_user(&range, (struct ocfs2_move_extents *)argp,
1087                   sizeof(range))) {
1088            status = -EFAULT;
1089            goto out;
1090        }
1091    } else {
1092        status = -EINVAL;
1093        goto out;
1094    }
1095
1096    if (range.me_start > i_size_read(inode))
1097        goto out;
1098
1099    if (range.me_start + range.me_len > i_size_read(inode))
1100            range.me_len = i_size_read(inode) - range.me_start;
1101
1102    context->range = &range;
1103
1104    if (range.me_flags & OCFS2_MOVE_EXT_FL_AUTO_DEFRAG) {
1105        context->auto_defrag = 1;
1106        /*
1107         * ok, the default theshold for the defragmentation
1108         * is 1M, since our maximum clustersize was 1M also.
1109         * any thought?
1110         */
1111        if (!range.me_threshold)
1112            range.me_threshold = 1024 * 1024;
1113
1114        if (range.me_threshold > i_size_read(inode))
1115            range.me_threshold = i_size_read(inode);
1116
1117        if (range.me_flags & OCFS2_MOVE_EXT_FL_PART_DEFRAG)
1118            context->partial = 1;
1119    } else {
1120        /*
1121         * first best-effort attempt to validate and adjust the goal
1122         * (physical address in block), while it can't guarantee later
1123         * operation can succeed all the time since global_bitmap may
1124         * change a bit over time.
1125         */
1126
1127        status = ocfs2_validate_and_adjust_move_goal(inode, &range);
1128        if (status)
1129            goto out;
1130    }
1131
1132    status = ocfs2_move_extents(context);
1133    if (status)
1134        mlog_errno(status);
1135out:
1136    /*
1137     * movement/defragmentation may end up being partially completed,
1138     * that's the reason why we need to return userspace the finished
1139     * length and new_offset even if failure happens somewhere.
1140     */
1141    if (argp) {
1142        if (copy_to_user((struct ocfs2_move_extents *)argp, &range,
1143                sizeof(range)))
1144            status = -EFAULT;
1145    }
1146
1147    kfree(context);
1148
1149    mnt_drop_write(filp->f_path.mnt);
1150
1151    return status;
1152}
1153

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