Root/fs/ocfs2/localalloc.c

1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * localalloc.c
5 *
6 * Node local data allocation
7 *
8 * Copyright (C) 2002, 2004 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation; either
13 * version 2 of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public
21 * License along with this program; if not, write to the
22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 * Boston, MA 021110-1307, USA.
24 */
25
26#include <linux/fs.h>
27#include <linux/types.h>
28#include <linux/slab.h>
29#include <linux/highmem.h>
30#include <linux/bitops.h>
31
32#include <cluster/masklog.h>
33
34#include "ocfs2.h"
35
36#include "alloc.h"
37#include "blockcheck.h"
38#include "dlmglue.h"
39#include "inode.h"
40#include "journal.h"
41#include "localalloc.h"
42#include "suballoc.h"
43#include "super.h"
44#include "sysfile.h"
45#include "ocfs2_trace.h"
46
47#include "buffer_head_io.h"
48
49#define OCFS2_LOCAL_ALLOC(dinode) (&((dinode)->id2.i_lab))
50
51static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc);
52
53static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
54                         struct ocfs2_dinode *alloc,
55                         u32 *numbits,
56                         struct ocfs2_alloc_reservation *resv);
57
58static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc);
59
60static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
61                    handle_t *handle,
62                    struct ocfs2_dinode *alloc,
63                    struct inode *main_bm_inode,
64                    struct buffer_head *main_bm_bh);
65
66static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
67                        struct ocfs2_alloc_context **ac,
68                        struct inode **bitmap_inode,
69                        struct buffer_head **bitmap_bh);
70
71static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
72                    handle_t *handle,
73                    struct ocfs2_alloc_context *ac);
74
75static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
76                      struct inode *local_alloc_inode);
77
78/*
79 * ocfs2_la_default_mb() - determine a default size, in megabytes of
80 * the local alloc.
81 *
82 * Generally, we'd like to pick as large a local alloc as
83 * possible. Performance on large workloads tends to scale
84 * proportionally to la size. In addition to that, the reservations
85 * code functions more efficiently as it can reserve more windows for
86 * write.
87 *
88 * Some things work against us when trying to choose a large local alloc:
89 *
90 * - We need to ensure our sizing is picked to leave enough space in
91 * group descriptors for other allocations (such as block groups,
92 * etc). Picking default sizes which are a multiple of 4 could help
93 * - block groups are allocated in 2mb and 4mb chunks.
94 *
95 * - Likewise, we don't want to starve other nodes of bits on small
96 * file systems. This can easily be taken care of by limiting our
97 * default to a reasonable size (256M) on larger cluster sizes.
98 *
99 * - Some file systems can't support very large sizes - 4k and 8k in
100 * particular are limited to less than 128 and 256 megabytes respectively.
101 *
102 * The following reference table shows group descriptor and local
103 * alloc maximums at various cluster sizes (4k blocksize)
104 *
105 * csize: 4K group: 126M la: 121M
106 * csize: 8K group: 252M la: 243M
107 * csize: 16K group: 504M la: 486M
108 * csize: 32K group: 1008M la: 972M
109 * csize: 64K group: 2016M la: 1944M
110 * csize: 128K group: 4032M la: 3888M
111 * csize: 256K group: 8064M la: 7776M
112 * csize: 512K group: 16128M la: 15552M
113 * csize: 1024K group: 32256M la: 31104M
114 */
115#define OCFS2_LA_MAX_DEFAULT_MB 256
116#define OCFS2_LA_OLD_DEFAULT 8
117unsigned int ocfs2_la_default_mb(struct ocfs2_super *osb)
118{
119    unsigned int la_mb;
120    unsigned int gd_mb;
121    unsigned int la_max_mb;
122    unsigned int megs_per_slot;
123    struct super_block *sb = osb->sb;
124
125    gd_mb = ocfs2_clusters_to_megabytes(osb->sb,
126        8 * ocfs2_group_bitmap_size(sb, 0, osb->s_feature_incompat));
127
128    /*
129     * This takes care of files systems with very small group
130     * descriptors - 512 byte blocksize at cluster sizes lower
131     * than 16K and also 1k blocksize with 4k cluster size.
132     */
133    if ((sb->s_blocksize == 512 && osb->s_clustersize <= 8192)
134        || (sb->s_blocksize == 1024 && osb->s_clustersize == 4096))
135        return OCFS2_LA_OLD_DEFAULT;
136
137    /*
138     * Leave enough room for some block groups and make the final
139     * value we work from a multiple of 4.
140     */
141    gd_mb -= 16;
142    gd_mb &= 0xFFFFFFFB;
143
144    la_mb = gd_mb;
145
146    /*
147     * Keep window sizes down to a reasonable default
148     */
149    if (la_mb > OCFS2_LA_MAX_DEFAULT_MB) {
150        /*
151         * Some clustersize / blocksize combinations will have
152         * given us a larger than OCFS2_LA_MAX_DEFAULT_MB
153         * default size, but get poor distribution when
154         * limited to exactly 256 megabytes.
155         *
156         * As an example, 16K clustersize at 4K blocksize
157         * gives us a cluster group size of 504M. Paring the
158         * local alloc size down to 256 however, would give us
159         * only one window and around 200MB left in the
160         * cluster group. Instead, find the first size below
161         * 256 which would give us an even distribution.
162         *
163         * Larger cluster group sizes actually work out pretty
164         * well when pared to 256, so we don't have to do this
165         * for any group that fits more than two
166         * OCFS2_LA_MAX_DEFAULT_MB windows.
167         */
168        if (gd_mb > (2 * OCFS2_LA_MAX_DEFAULT_MB))
169            la_mb = 256;
170        else {
171            unsigned int gd_mult = gd_mb;
172
173            while (gd_mult > 256)
174                gd_mult = gd_mult >> 1;
175
176            la_mb = gd_mult;
177        }
178    }
179
180    megs_per_slot = osb->osb_clusters_at_boot / osb->max_slots;
181    megs_per_slot = ocfs2_clusters_to_megabytes(osb->sb, megs_per_slot);
182    /* Too many nodes, too few disk clusters. */
183    if (megs_per_slot < la_mb)
184        la_mb = megs_per_slot;
185
186    /* We can't store more bits than we can in a block. */
187    la_max_mb = ocfs2_clusters_to_megabytes(osb->sb,
188                        ocfs2_local_alloc_size(sb) * 8);
189    if (la_mb > la_max_mb)
190        la_mb = la_max_mb;
191
192    return la_mb;
193}
194
195void ocfs2_la_set_sizes(struct ocfs2_super *osb, int requested_mb)
196{
197    struct super_block *sb = osb->sb;
198    unsigned int la_default_mb = ocfs2_la_default_mb(osb);
199    unsigned int la_max_mb;
200
201    la_max_mb = ocfs2_clusters_to_megabytes(sb,
202                        ocfs2_local_alloc_size(sb) * 8);
203
204    trace_ocfs2_la_set_sizes(requested_mb, la_max_mb, la_default_mb);
205
206    if (requested_mb == -1) {
207        /* No user request - use defaults */
208        osb->local_alloc_default_bits =
209            ocfs2_megabytes_to_clusters(sb, la_default_mb);
210    } else if (requested_mb > la_max_mb) {
211        /* Request is too big, we give the maximum available */
212        osb->local_alloc_default_bits =
213            ocfs2_megabytes_to_clusters(sb, la_max_mb);
214    } else {
215        osb->local_alloc_default_bits =
216            ocfs2_megabytes_to_clusters(sb, requested_mb);
217    }
218
219    osb->local_alloc_bits = osb->local_alloc_default_bits;
220}
221
222static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb)
223{
224    return (osb->local_alloc_state == OCFS2_LA_THROTTLED ||
225        osb->local_alloc_state == OCFS2_LA_ENABLED);
226}
227
228void ocfs2_local_alloc_seen_free_bits(struct ocfs2_super *osb,
229                      unsigned int num_clusters)
230{
231    spin_lock(&osb->osb_lock);
232    if (osb->local_alloc_state == OCFS2_LA_DISABLED ||
233        osb->local_alloc_state == OCFS2_LA_THROTTLED)
234        if (num_clusters >= osb->local_alloc_default_bits) {
235            cancel_delayed_work(&osb->la_enable_wq);
236            osb->local_alloc_state = OCFS2_LA_ENABLED;
237        }
238    spin_unlock(&osb->osb_lock);
239}
240
241void ocfs2_la_enable_worker(struct work_struct *work)
242{
243    struct ocfs2_super *osb =
244        container_of(work, struct ocfs2_super,
245                 la_enable_wq.work);
246    spin_lock(&osb->osb_lock);
247    osb->local_alloc_state = OCFS2_LA_ENABLED;
248    spin_unlock(&osb->osb_lock);
249}
250
251/*
252 * Tell us whether a given allocation should use the local alloc
253 * file. Otherwise, it has to go to the main bitmap.
254 *
255 * This function does semi-dirty reads of local alloc size and state!
256 * This is ok however, as the values are re-checked once under mutex.
257 */
258int ocfs2_alloc_should_use_local(struct ocfs2_super *osb, u64 bits)
259{
260    int ret = 0;
261    int la_bits;
262
263    spin_lock(&osb->osb_lock);
264    la_bits = osb->local_alloc_bits;
265
266    if (!ocfs2_la_state_enabled(osb))
267        goto bail;
268
269    /* la_bits should be at least twice the size (in clusters) of
270     * a new block group. We want to be sure block group
271     * allocations go through the local alloc, so allow an
272     * allocation to take up to half the bitmap. */
273    if (bits > (la_bits / 2))
274        goto bail;
275
276    ret = 1;
277bail:
278    trace_ocfs2_alloc_should_use_local(
279         (unsigned long long)bits, osb->local_alloc_state, la_bits, ret);
280    spin_unlock(&osb->osb_lock);
281    return ret;
282}
283
284int ocfs2_load_local_alloc(struct ocfs2_super *osb)
285{
286    int status = 0;
287    struct ocfs2_dinode *alloc = NULL;
288    struct buffer_head *alloc_bh = NULL;
289    u32 num_used;
290    struct inode *inode = NULL;
291    struct ocfs2_local_alloc *la;
292
293    if (osb->local_alloc_bits == 0)
294        goto bail;
295
296    if (osb->local_alloc_bits >= osb->bitmap_cpg) {
297        mlog(ML_NOTICE, "Requested local alloc window %d is larger "
298             "than max possible %u. Using defaults.\n",
299             osb->local_alloc_bits, (osb->bitmap_cpg - 1));
300        osb->local_alloc_bits =
301            ocfs2_megabytes_to_clusters(osb->sb,
302                            ocfs2_la_default_mb(osb));
303    }
304
305    /* read the alloc off disk */
306    inode = ocfs2_get_system_file_inode(osb, LOCAL_ALLOC_SYSTEM_INODE,
307                        osb->slot_num);
308    if (!inode) {
309        status = -EINVAL;
310        mlog_errno(status);
311        goto bail;
312    }
313
314    status = ocfs2_read_inode_block_full(inode, &alloc_bh,
315                         OCFS2_BH_IGNORE_CACHE);
316    if (status < 0) {
317        mlog_errno(status);
318        goto bail;
319    }
320
321    alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
322    la = OCFS2_LOCAL_ALLOC(alloc);
323
324    if (!(le32_to_cpu(alloc->i_flags) &
325        (OCFS2_LOCAL_ALLOC_FL|OCFS2_BITMAP_FL))) {
326        mlog(ML_ERROR, "Invalid local alloc inode, %llu\n",
327             (unsigned long long)OCFS2_I(inode)->ip_blkno);
328        status = -EINVAL;
329        goto bail;
330    }
331
332    if ((la->la_size == 0) ||
333        (le16_to_cpu(la->la_size) > ocfs2_local_alloc_size(inode->i_sb))) {
334        mlog(ML_ERROR, "Local alloc size is invalid (la_size = %u)\n",
335             le16_to_cpu(la->la_size));
336        status = -EINVAL;
337        goto bail;
338    }
339
340    /* do a little verification. */
341    num_used = ocfs2_local_alloc_count_bits(alloc);
342
343    /* hopefully the local alloc has always been recovered before
344     * we load it. */
345    if (num_used
346        || alloc->id1.bitmap1.i_used
347        || alloc->id1.bitmap1.i_total
348        || la->la_bm_off)
349        mlog(ML_ERROR, "Local alloc hasn't been recovered!\n"
350             "found = %u, set = %u, taken = %u, off = %u\n",
351             num_used, le32_to_cpu(alloc->id1.bitmap1.i_used),
352             le32_to_cpu(alloc->id1.bitmap1.i_total),
353             OCFS2_LOCAL_ALLOC(alloc)->la_bm_off);
354
355    osb->local_alloc_bh = alloc_bh;
356    osb->local_alloc_state = OCFS2_LA_ENABLED;
357
358bail:
359    if (status < 0)
360        brelse(alloc_bh);
361    if (inode)
362        iput(inode);
363
364    trace_ocfs2_load_local_alloc(osb->local_alloc_bits);
365
366    if (status)
367        mlog_errno(status);
368    return status;
369}
370
371/*
372 * return any unused bits to the bitmap and write out a clean
373 * local_alloc.
374 *
375 * local_alloc_bh is optional. If not passed, we will simply use the
376 * one off osb. If you do pass it however, be warned that it *will* be
377 * returned brelse'd and NULL'd out.*/
378void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
379{
380    int status;
381    handle_t *handle;
382    struct inode *local_alloc_inode = NULL;
383    struct buffer_head *bh = NULL;
384    struct buffer_head *main_bm_bh = NULL;
385    struct inode *main_bm_inode = NULL;
386    struct ocfs2_dinode *alloc_copy = NULL;
387    struct ocfs2_dinode *alloc = NULL;
388
389    cancel_delayed_work(&osb->la_enable_wq);
390    flush_workqueue(ocfs2_wq);
391
392    if (osb->local_alloc_state == OCFS2_LA_UNUSED)
393        goto out;
394
395    local_alloc_inode =
396        ocfs2_get_system_file_inode(osb,
397                        LOCAL_ALLOC_SYSTEM_INODE,
398                        osb->slot_num);
399    if (!local_alloc_inode) {
400        status = -ENOENT;
401        mlog_errno(status);
402        goto out;
403    }
404
405    osb->local_alloc_state = OCFS2_LA_DISABLED;
406
407    ocfs2_resmap_uninit(&osb->osb_la_resmap);
408
409    main_bm_inode = ocfs2_get_system_file_inode(osb,
410                            GLOBAL_BITMAP_SYSTEM_INODE,
411                            OCFS2_INVALID_SLOT);
412    if (!main_bm_inode) {
413        status = -EINVAL;
414        mlog_errno(status);
415        goto out;
416    }
417
418    mutex_lock(&main_bm_inode->i_mutex);
419
420    status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
421    if (status < 0) {
422        mlog_errno(status);
423        goto out_mutex;
424    }
425
426    /* WINDOW_MOVE_CREDITS is a bit heavy... */
427    handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
428    if (IS_ERR(handle)) {
429        mlog_errno(PTR_ERR(handle));
430        handle = NULL;
431        goto out_unlock;
432    }
433
434    bh = osb->local_alloc_bh;
435    alloc = (struct ocfs2_dinode *) bh->b_data;
436
437    alloc_copy = kmalloc(bh->b_size, GFP_NOFS);
438    if (!alloc_copy) {
439        status = -ENOMEM;
440        goto out_commit;
441    }
442    memcpy(alloc_copy, alloc, bh->b_size);
443
444    status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode),
445                     bh, OCFS2_JOURNAL_ACCESS_WRITE);
446    if (status < 0) {
447        mlog_errno(status);
448        goto out_commit;
449    }
450
451    ocfs2_clear_local_alloc(alloc);
452    ocfs2_journal_dirty(handle, bh);
453
454    brelse(bh);
455    osb->local_alloc_bh = NULL;
456    osb->local_alloc_state = OCFS2_LA_UNUSED;
457
458    status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
459                      main_bm_inode, main_bm_bh);
460    if (status < 0)
461        mlog_errno(status);
462
463out_commit:
464    ocfs2_commit_trans(osb, handle);
465
466out_unlock:
467    brelse(main_bm_bh);
468
469    ocfs2_inode_unlock(main_bm_inode, 1);
470
471out_mutex:
472    mutex_unlock(&main_bm_inode->i_mutex);
473    iput(main_bm_inode);
474
475out:
476    if (local_alloc_inode)
477        iput(local_alloc_inode);
478
479    if (alloc_copy)
480        kfree(alloc_copy);
481}
482
483/*
484 * We want to free the bitmap bits outside of any recovery context as
485 * we'll need a cluster lock to do so, but we must clear the local
486 * alloc before giving up the recovered nodes journal. To solve this,
487 * we kmalloc a copy of the local alloc before it's change for the
488 * caller to process with ocfs2_complete_local_alloc_recovery
489 */
490int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb,
491                     int slot_num,
492                     struct ocfs2_dinode **alloc_copy)
493{
494    int status = 0;
495    struct buffer_head *alloc_bh = NULL;
496    struct inode *inode = NULL;
497    struct ocfs2_dinode *alloc;
498
499    trace_ocfs2_begin_local_alloc_recovery(slot_num);
500
501    *alloc_copy = NULL;
502
503    inode = ocfs2_get_system_file_inode(osb,
504                        LOCAL_ALLOC_SYSTEM_INODE,
505                        slot_num);
506    if (!inode) {
507        status = -EINVAL;
508        mlog_errno(status);
509        goto bail;
510    }
511
512    mutex_lock(&inode->i_mutex);
513
514    status = ocfs2_read_inode_block_full(inode, &alloc_bh,
515                         OCFS2_BH_IGNORE_CACHE);
516    if (status < 0) {
517        mlog_errno(status);
518        goto bail;
519    }
520
521    *alloc_copy = kmalloc(alloc_bh->b_size, GFP_KERNEL);
522    if (!(*alloc_copy)) {
523        status = -ENOMEM;
524        goto bail;
525    }
526    memcpy((*alloc_copy), alloc_bh->b_data, alloc_bh->b_size);
527
528    alloc = (struct ocfs2_dinode *) alloc_bh->b_data;
529    ocfs2_clear_local_alloc(alloc);
530
531    ocfs2_compute_meta_ecc(osb->sb, alloc_bh->b_data, &alloc->i_check);
532    status = ocfs2_write_block(osb, alloc_bh, INODE_CACHE(inode));
533    if (status < 0)
534        mlog_errno(status);
535
536bail:
537    if ((status < 0) && (*alloc_copy)) {
538        kfree(*alloc_copy);
539        *alloc_copy = NULL;
540    }
541
542    brelse(alloc_bh);
543
544    if (inode) {
545        mutex_unlock(&inode->i_mutex);
546        iput(inode);
547    }
548
549    if (status)
550        mlog_errno(status);
551    return status;
552}
553
554/*
555 * Step 2: By now, we've completed the journal recovery, we've stamped
556 * a clean local alloc on disk and dropped the node out of the
557 * recovery map. Dlm locks will no longer stall, so lets clear out the
558 * main bitmap.
559 */
560int ocfs2_complete_local_alloc_recovery(struct ocfs2_super *osb,
561                    struct ocfs2_dinode *alloc)
562{
563    int status;
564    handle_t *handle;
565    struct buffer_head *main_bm_bh = NULL;
566    struct inode *main_bm_inode;
567
568    main_bm_inode = ocfs2_get_system_file_inode(osb,
569                            GLOBAL_BITMAP_SYSTEM_INODE,
570                            OCFS2_INVALID_SLOT);
571    if (!main_bm_inode) {
572        status = -EINVAL;
573        mlog_errno(status);
574        goto out;
575    }
576
577    mutex_lock(&main_bm_inode->i_mutex);
578
579    status = ocfs2_inode_lock(main_bm_inode, &main_bm_bh, 1);
580    if (status < 0) {
581        mlog_errno(status);
582        goto out_mutex;
583    }
584
585    handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
586    if (IS_ERR(handle)) {
587        status = PTR_ERR(handle);
588        handle = NULL;
589        mlog_errno(status);
590        goto out_unlock;
591    }
592
593    /* we want the bitmap change to be recorded on disk asap */
594    handle->h_sync = 1;
595
596    status = ocfs2_sync_local_to_main(osb, handle, alloc,
597                      main_bm_inode, main_bm_bh);
598    if (status < 0)
599        mlog_errno(status);
600
601    ocfs2_commit_trans(osb, handle);
602
603out_unlock:
604    ocfs2_inode_unlock(main_bm_inode, 1);
605
606out_mutex:
607    mutex_unlock(&main_bm_inode->i_mutex);
608
609    brelse(main_bm_bh);
610
611    iput(main_bm_inode);
612
613out:
614    if (!status)
615        ocfs2_init_steal_slots(osb);
616    if (status)
617        mlog_errno(status);
618    return status;
619}
620
621/*
622 * make sure we've got at least bits_wanted contiguous bits in the
623 * local alloc. You lose them when you drop i_mutex.
624 *
625 * We will add ourselves to the transaction passed in, but may start
626 * our own in order to shift windows.
627 */
628int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
629                   u32 bits_wanted,
630                   struct ocfs2_alloc_context *ac)
631{
632    int status;
633    struct ocfs2_dinode *alloc;
634    struct inode *local_alloc_inode;
635    unsigned int free_bits;
636
637    BUG_ON(!ac);
638
639    local_alloc_inode =
640        ocfs2_get_system_file_inode(osb,
641                        LOCAL_ALLOC_SYSTEM_INODE,
642                        osb->slot_num);
643    if (!local_alloc_inode) {
644        status = -ENOENT;
645        mlog_errno(status);
646        goto bail;
647    }
648
649    mutex_lock(&local_alloc_inode->i_mutex);
650
651    /*
652     * We must double check state and allocator bits because
653     * another process may have changed them while holding i_mutex.
654     */
655    spin_lock(&osb->osb_lock);
656    if (!ocfs2_la_state_enabled(osb) ||
657        (bits_wanted > osb->local_alloc_bits)) {
658        spin_unlock(&osb->osb_lock);
659        status = -ENOSPC;
660        goto bail;
661    }
662    spin_unlock(&osb->osb_lock);
663
664    alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
665
666#ifdef CONFIG_OCFS2_DEBUG_FS
667    if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
668        ocfs2_local_alloc_count_bits(alloc)) {
669        ocfs2_error(osb->sb, "local alloc inode %llu says it has "
670                "%u free bits, but a count shows %u",
671                (unsigned long long)le64_to_cpu(alloc->i_blkno),
672                le32_to_cpu(alloc->id1.bitmap1.i_used),
673                ocfs2_local_alloc_count_bits(alloc));
674        status = -EIO;
675        goto bail;
676    }
677#endif
678
679    free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
680        le32_to_cpu(alloc->id1.bitmap1.i_used);
681    if (bits_wanted > free_bits) {
682        /* uhoh, window change time. */
683        status =
684            ocfs2_local_alloc_slide_window(osb, local_alloc_inode);
685        if (status < 0) {
686            if (status != -ENOSPC)
687                mlog_errno(status);
688            goto bail;
689        }
690
691        /*
692         * Under certain conditions, the window slide code
693         * might have reduced the number of bits available or
694         * disabled the the local alloc entirely. Re-check
695         * here and return -ENOSPC if necessary.
696         */
697        status = -ENOSPC;
698        if (!ocfs2_la_state_enabled(osb))
699            goto bail;
700
701        free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
702            le32_to_cpu(alloc->id1.bitmap1.i_used);
703        if (bits_wanted > free_bits)
704            goto bail;
705    }
706
707    ac->ac_inode = local_alloc_inode;
708    /* We should never use localalloc from another slot */
709    ac->ac_alloc_slot = osb->slot_num;
710    ac->ac_which = OCFS2_AC_USE_LOCAL;
711    get_bh(osb->local_alloc_bh);
712    ac->ac_bh = osb->local_alloc_bh;
713    status = 0;
714bail:
715    if (status < 0 && local_alloc_inode) {
716        mutex_unlock(&local_alloc_inode->i_mutex);
717        iput(local_alloc_inode);
718    }
719
720    trace_ocfs2_reserve_local_alloc_bits(
721        (unsigned long long)ac->ac_max_block,
722        bits_wanted, osb->slot_num, status);
723
724    if (status)
725        mlog_errno(status);
726    return status;
727}
728
729int ocfs2_claim_local_alloc_bits(struct ocfs2_super *osb,
730                 handle_t *handle,
731                 struct ocfs2_alloc_context *ac,
732                 u32 bits_wanted,
733                 u32 *bit_off,
734                 u32 *num_bits)
735{
736    int status, start;
737    struct inode *local_alloc_inode;
738    void *bitmap;
739    struct ocfs2_dinode *alloc;
740    struct ocfs2_local_alloc *la;
741
742    BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL);
743
744    local_alloc_inode = ac->ac_inode;
745    alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
746    la = OCFS2_LOCAL_ALLOC(alloc);
747
748    start = ocfs2_local_alloc_find_clear_bits(osb, alloc, &bits_wanted,
749                          ac->ac_resv);
750    if (start == -1) {
751        /* TODO: Shouldn't we just BUG here? */
752        status = -ENOSPC;
753        mlog_errno(status);
754        goto bail;
755    }
756
757    bitmap = la->la_bitmap;
758    *bit_off = le32_to_cpu(la->la_bm_off) + start;
759    *num_bits = bits_wanted;
760
761    status = ocfs2_journal_access_di(handle,
762                     INODE_CACHE(local_alloc_inode),
763                     osb->local_alloc_bh,
764                     OCFS2_JOURNAL_ACCESS_WRITE);
765    if (status < 0) {
766        mlog_errno(status);
767        goto bail;
768    }
769
770    ocfs2_resmap_claimed_bits(&osb->osb_la_resmap, ac->ac_resv, start,
771                  bits_wanted);
772
773    while(bits_wanted--)
774        ocfs2_set_bit(start++, bitmap);
775
776    le32_add_cpu(&alloc->id1.bitmap1.i_used, *num_bits);
777    ocfs2_journal_dirty(handle, osb->local_alloc_bh);
778
779bail:
780    if (status)
781        mlog_errno(status);
782    return status;
783}
784
785static u32 ocfs2_local_alloc_count_bits(struct ocfs2_dinode *alloc)
786{
787    int i;
788    u8 *buffer;
789    u32 count = 0;
790    struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
791
792    buffer = la->la_bitmap;
793    for (i = 0; i < le16_to_cpu(la->la_size); i++)
794        count += hweight8(buffer[i]);
795
796    trace_ocfs2_local_alloc_count_bits(count);
797    return count;
798}
799
800static int ocfs2_local_alloc_find_clear_bits(struct ocfs2_super *osb,
801                     struct ocfs2_dinode *alloc,
802                     u32 *numbits,
803                     struct ocfs2_alloc_reservation *resv)
804{
805    int numfound, bitoff, left, startoff, lastzero;
806    int local_resv = 0;
807    struct ocfs2_alloc_reservation r;
808    void *bitmap = NULL;
809    struct ocfs2_reservation_map *resmap = &osb->osb_la_resmap;
810
811    if (!alloc->id1.bitmap1.i_total) {
812        bitoff = -1;
813        goto bail;
814    }
815
816    if (!resv) {
817        local_resv = 1;
818        ocfs2_resv_init_once(&r);
819        ocfs2_resv_set_type(&r, OCFS2_RESV_FLAG_TMP);
820        resv = &r;
821    }
822
823    numfound = *numbits;
824    if (ocfs2_resmap_resv_bits(resmap, resv, &bitoff, &numfound) == 0) {
825        if (numfound < *numbits)
826            *numbits = numfound;
827        goto bail;
828    }
829
830    /*
831     * Code error. While reservations are enabled, local
832     * allocation should _always_ go through them.
833     */
834    BUG_ON(osb->osb_resv_level != 0);
835
836    /*
837     * Reservations are disabled. Handle this the old way.
838     */
839
840    bitmap = OCFS2_LOCAL_ALLOC(alloc)->la_bitmap;
841
842    numfound = bitoff = startoff = 0;
843    lastzero = -1;
844    left = le32_to_cpu(alloc->id1.bitmap1.i_total);
845    while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
846        if (bitoff == left) {
847            /* mlog(0, "bitoff (%d) == left", bitoff); */
848            break;
849        }
850        /* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
851           "numfound = %d\n", bitoff, startoff, numfound);*/
852
853        /* Ok, we found a zero bit... is it contig. or do we
854         * start over?*/
855        if (bitoff == startoff) {
856            /* we found a zero */
857            numfound++;
858            startoff++;
859        } else {
860            /* got a zero after some ones */
861            numfound = 1;
862            startoff = bitoff+1;
863        }
864        /* we got everything we needed */
865        if (numfound == *numbits) {
866            /* mlog(0, "Found it all!\n"); */
867            break;
868        }
869    }
870
871    trace_ocfs2_local_alloc_find_clear_bits_search_bitmap(bitoff, numfound);
872
873    if (numfound == *numbits)
874        bitoff = startoff - numfound;
875    else
876        bitoff = -1;
877
878bail:
879    if (local_resv)
880        ocfs2_resv_discard(resmap, resv);
881
882    trace_ocfs2_local_alloc_find_clear_bits(*numbits,
883        le32_to_cpu(alloc->id1.bitmap1.i_total),
884        bitoff, numfound);
885
886    return bitoff;
887}
888
889static void ocfs2_clear_local_alloc(struct ocfs2_dinode *alloc)
890{
891    struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
892    int i;
893
894    alloc->id1.bitmap1.i_total = 0;
895    alloc->id1.bitmap1.i_used = 0;
896    la->la_bm_off = 0;
897    for(i = 0; i < le16_to_cpu(la->la_size); i++)
898        la->la_bitmap[i] = 0;
899}
900
901#if 0
902/* turn this on and uncomment below to aid debugging window shifts. */
903static void ocfs2_verify_zero_bits(unsigned long *bitmap,
904                   unsigned int start,
905                   unsigned int count)
906{
907    unsigned int tmp = count;
908    while(tmp--) {
909        if (ocfs2_test_bit(start + tmp, bitmap)) {
910            printk("ocfs2_verify_zero_bits: start = %u, count = "
911                   "%u\n", start, count);
912            printk("ocfs2_verify_zero_bits: bit %u is set!",
913                   start + tmp);
914            BUG();
915        }
916    }
917}
918#endif
919
920/*
921 * sync the local alloc to main bitmap.
922 *
923 * assumes you've already locked the main bitmap -- the bitmap inode
924 * passed is used for caching.
925 */
926static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
927                    handle_t *handle,
928                    struct ocfs2_dinode *alloc,
929                    struct inode *main_bm_inode,
930                    struct buffer_head *main_bm_bh)
931{
932    int status = 0;
933    int bit_off, left, count, start;
934    u64 la_start_blk;
935    u64 blkno;
936    void *bitmap;
937    struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
938
939    trace_ocfs2_sync_local_to_main(
940         le32_to_cpu(alloc->id1.bitmap1.i_total),
941         le32_to_cpu(alloc->id1.bitmap1.i_used));
942
943    if (!alloc->id1.bitmap1.i_total) {
944        goto bail;
945    }
946
947    if (le32_to_cpu(alloc->id1.bitmap1.i_used) ==
948        le32_to_cpu(alloc->id1.bitmap1.i_total)) {
949        goto bail;
950    }
951
952    la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
953                        le32_to_cpu(la->la_bm_off));
954    bitmap = la->la_bitmap;
955    start = count = bit_off = 0;
956    left = le32_to_cpu(alloc->id1.bitmap1.i_total);
957
958    while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
959           != -1) {
960        if ((bit_off < left) && (bit_off == start)) {
961            count++;
962            start++;
963            continue;
964        }
965        if (count) {
966            blkno = la_start_blk +
967                ocfs2_clusters_to_blocks(osb->sb,
968                             start - count);
969
970            trace_ocfs2_sync_local_to_main_free(
971                 count, start - count,
972                 (unsigned long long)la_start_blk,
973                 (unsigned long long)blkno);
974
975            status = ocfs2_release_clusters(handle,
976                            main_bm_inode,
977                            main_bm_bh, blkno,
978                            count);
979            if (status < 0) {
980                mlog_errno(status);
981                goto bail;
982            }
983        }
984        if (bit_off >= left)
985            break;
986        count = 1;
987        start = bit_off + 1;
988    }
989
990bail:
991    if (status)
992        mlog_errno(status);
993    return status;
994}
995
996enum ocfs2_la_event {
997    OCFS2_LA_EVENT_SLIDE, /* Normal window slide. */
998    OCFS2_LA_EVENT_FRAGMENTED, /* The global bitmap has
999                     * enough bits theoretically
1000                     * free, but a contiguous
1001                     * allocation could not be
1002                     * found. */
1003    OCFS2_LA_EVENT_ENOSPC, /* Global bitmap doesn't have
1004                     * enough bits free to satisfy
1005                     * our request. */
1006};
1007#define OCFS2_LA_ENABLE_INTERVAL (30 * HZ)
1008/*
1009 * Given an event, calculate the size of our next local alloc window.
1010 *
1011 * This should always be called under i_mutex of the local alloc inode
1012 * so that local alloc disabling doesn't race with processes trying to
1013 * use the allocator.
1014 *
1015 * Returns the state which the local alloc was left in. This value can
1016 * be ignored by some paths.
1017 */
1018static int ocfs2_recalc_la_window(struct ocfs2_super *osb,
1019                  enum ocfs2_la_event event)
1020{
1021    unsigned int bits;
1022    int state;
1023
1024    spin_lock(&osb->osb_lock);
1025    if (osb->local_alloc_state == OCFS2_LA_DISABLED) {
1026        WARN_ON_ONCE(osb->local_alloc_state == OCFS2_LA_DISABLED);
1027        goto out_unlock;
1028    }
1029
1030    /*
1031     * ENOSPC and fragmentation are treated similarly for now.
1032     */
1033    if (event == OCFS2_LA_EVENT_ENOSPC ||
1034        event == OCFS2_LA_EVENT_FRAGMENTED) {
1035        /*
1036         * We ran out of contiguous space in the primary
1037         * bitmap. Drastically reduce the number of bits used
1038         * by local alloc until we have to disable it.
1039         */
1040        bits = osb->local_alloc_bits >> 1;
1041        if (bits > ocfs2_megabytes_to_clusters(osb->sb, 1)) {
1042            /*
1043             * By setting state to THROTTLED, we'll keep
1044             * the number of local alloc bits used down
1045             * until an event occurs which would give us
1046             * reason to assume the bitmap situation might
1047             * have changed.
1048             */
1049            osb->local_alloc_state = OCFS2_LA_THROTTLED;
1050            osb->local_alloc_bits = bits;
1051        } else {
1052            osb->local_alloc_state = OCFS2_LA_DISABLED;
1053        }
1054        queue_delayed_work(ocfs2_wq, &osb->la_enable_wq,
1055                   OCFS2_LA_ENABLE_INTERVAL);
1056        goto out_unlock;
1057    }
1058
1059    /*
1060     * Don't increase the size of the local alloc window until we
1061     * know we might be able to fulfill the request. Otherwise, we
1062     * risk bouncing around the global bitmap during periods of
1063     * low space.
1064     */
1065    if (osb->local_alloc_state != OCFS2_LA_THROTTLED)
1066        osb->local_alloc_bits = osb->local_alloc_default_bits;
1067
1068out_unlock:
1069    state = osb->local_alloc_state;
1070    spin_unlock(&osb->osb_lock);
1071
1072    return state;
1073}
1074
1075static int ocfs2_local_alloc_reserve_for_window(struct ocfs2_super *osb,
1076                        struct ocfs2_alloc_context **ac,
1077                        struct inode **bitmap_inode,
1078                        struct buffer_head **bitmap_bh)
1079{
1080    int status;
1081
1082    *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
1083    if (!(*ac)) {
1084        status = -ENOMEM;
1085        mlog_errno(status);
1086        goto bail;
1087    }
1088
1089retry_enospc:
1090    (*ac)->ac_bits_wanted = osb->local_alloc_default_bits;
1091    status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
1092    if (status == -ENOSPC) {
1093        if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_ENOSPC) ==
1094            OCFS2_LA_DISABLED)
1095            goto bail;
1096
1097        ocfs2_free_ac_resource(*ac);
1098        memset(*ac, 0, sizeof(struct ocfs2_alloc_context));
1099        goto retry_enospc;
1100    }
1101    if (status < 0) {
1102        mlog_errno(status);
1103        goto bail;
1104    }
1105
1106    *bitmap_inode = (*ac)->ac_inode;
1107    igrab(*bitmap_inode);
1108    *bitmap_bh = (*ac)->ac_bh;
1109    get_bh(*bitmap_bh);
1110    status = 0;
1111bail:
1112    if ((status < 0) && *ac) {
1113        ocfs2_free_alloc_context(*ac);
1114        *ac = NULL;
1115    }
1116
1117    if (status)
1118        mlog_errno(status);
1119    return status;
1120}
1121
1122/*
1123 * pass it the bitmap lock in lock_bh if you have it.
1124 */
1125static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb,
1126                    handle_t *handle,
1127                    struct ocfs2_alloc_context *ac)
1128{
1129    int status = 0;
1130    u32 cluster_off, cluster_count;
1131    struct ocfs2_dinode *alloc = NULL;
1132    struct ocfs2_local_alloc *la;
1133
1134    alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1135    la = OCFS2_LOCAL_ALLOC(alloc);
1136
1137    trace_ocfs2_local_alloc_new_window(
1138        le32_to_cpu(alloc->id1.bitmap1.i_total),
1139        osb->local_alloc_bits);
1140
1141    /* Instruct the allocation code to try the most recently used
1142     * cluster group. We'll re-record the group used this pass
1143     * below. */
1144    ac->ac_last_group = osb->la_last_gd;
1145
1146    /* we used the generic suballoc reserve function, but we set
1147     * everything up nicely, so there's no reason why we can't use
1148     * the more specific cluster api to claim bits. */
1149    status = ocfs2_claim_clusters(handle, ac, osb->local_alloc_bits,
1150                      &cluster_off, &cluster_count);
1151    if (status == -ENOSPC) {
1152retry_enospc:
1153        /*
1154         * Note: We could also try syncing the journal here to
1155         * allow use of any free bits which the current
1156         * transaction can't give us access to. --Mark
1157         */
1158        if (ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_FRAGMENTED) ==
1159            OCFS2_LA_DISABLED)
1160            goto bail;
1161
1162        ac->ac_bits_wanted = osb->local_alloc_default_bits;
1163        status = ocfs2_claim_clusters(handle, ac,
1164                          osb->local_alloc_bits,
1165                          &cluster_off,
1166                          &cluster_count);
1167        if (status == -ENOSPC)
1168            goto retry_enospc;
1169        /*
1170         * We only shrunk the *minimum* number of in our
1171         * request - it's entirely possible that the allocator
1172         * might give us more than we asked for.
1173         */
1174        if (status == 0) {
1175            spin_lock(&osb->osb_lock);
1176            osb->local_alloc_bits = cluster_count;
1177            spin_unlock(&osb->osb_lock);
1178        }
1179    }
1180    if (status < 0) {
1181        if (status != -ENOSPC)
1182            mlog_errno(status);
1183        goto bail;
1184    }
1185
1186    osb->la_last_gd = ac->ac_last_group;
1187
1188    la->la_bm_off = cpu_to_le32(cluster_off);
1189    alloc->id1.bitmap1.i_total = cpu_to_le32(cluster_count);
1190    /* just in case... In the future when we find space ourselves,
1191     * we don't have to get all contiguous -- but we'll have to
1192     * set all previously used bits in bitmap and update
1193     * la_bits_set before setting the bits in the main bitmap. */
1194    alloc->id1.bitmap1.i_used = 0;
1195    memset(OCFS2_LOCAL_ALLOC(alloc)->la_bitmap, 0,
1196           le16_to_cpu(la->la_size));
1197
1198    ocfs2_resmap_restart(&osb->osb_la_resmap, cluster_count,
1199                 OCFS2_LOCAL_ALLOC(alloc)->la_bitmap);
1200
1201    trace_ocfs2_local_alloc_new_window_result(
1202        OCFS2_LOCAL_ALLOC(alloc)->la_bm_off,
1203        le32_to_cpu(alloc->id1.bitmap1.i_total));
1204
1205bail:
1206    if (status)
1207        mlog_errno(status);
1208    return status;
1209}
1210
1211/* Note that we do *NOT* lock the local alloc inode here as
1212 * it's been locked already for us. */
1213static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb,
1214                      struct inode *local_alloc_inode)
1215{
1216    int status = 0;
1217    struct buffer_head *main_bm_bh = NULL;
1218    struct inode *main_bm_inode = NULL;
1219    handle_t *handle = NULL;
1220    struct ocfs2_dinode *alloc;
1221    struct ocfs2_dinode *alloc_copy = NULL;
1222    struct ocfs2_alloc_context *ac = NULL;
1223
1224    ocfs2_recalc_la_window(osb, OCFS2_LA_EVENT_SLIDE);
1225
1226    /* This will lock the main bitmap for us. */
1227    status = ocfs2_local_alloc_reserve_for_window(osb,
1228                              &ac,
1229                              &main_bm_inode,
1230                              &main_bm_bh);
1231    if (status < 0) {
1232        if (status != -ENOSPC)
1233            mlog_errno(status);
1234        goto bail;
1235    }
1236
1237    handle = ocfs2_start_trans(osb, OCFS2_WINDOW_MOVE_CREDITS);
1238    if (IS_ERR(handle)) {
1239        status = PTR_ERR(handle);
1240        handle = NULL;
1241        mlog_errno(status);
1242        goto bail;
1243    }
1244
1245    alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
1246
1247    /* We want to clear the local alloc before doing anything
1248     * else, so that if we error later during this operation,
1249     * local alloc shutdown won't try to double free main bitmap
1250     * bits. Make a copy so the sync function knows which bits to
1251     * free. */
1252    alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS);
1253    if (!alloc_copy) {
1254        status = -ENOMEM;
1255        mlog_errno(status);
1256        goto bail;
1257    }
1258    memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size);
1259
1260    status = ocfs2_journal_access_di(handle,
1261                     INODE_CACHE(local_alloc_inode),
1262                     osb->local_alloc_bh,
1263                     OCFS2_JOURNAL_ACCESS_WRITE);
1264    if (status < 0) {
1265        mlog_errno(status);
1266        goto bail;
1267    }
1268
1269    ocfs2_clear_local_alloc(alloc);
1270    ocfs2_journal_dirty(handle, osb->local_alloc_bh);
1271
1272    status = ocfs2_sync_local_to_main(osb, handle, alloc_copy,
1273                      main_bm_inode, main_bm_bh);
1274    if (status < 0) {
1275        mlog_errno(status);
1276        goto bail;
1277    }
1278
1279    status = ocfs2_local_alloc_new_window(osb, handle, ac);
1280    if (status < 0) {
1281        if (status != -ENOSPC)
1282            mlog_errno(status);
1283        goto bail;
1284    }
1285
1286    atomic_inc(&osb->alloc_stats.moves);
1287
1288bail:
1289    if (handle)
1290        ocfs2_commit_trans(osb, handle);
1291
1292    brelse(main_bm_bh);
1293
1294    if (main_bm_inode)
1295        iput(main_bm_inode);
1296
1297    if (alloc_copy)
1298        kfree(alloc_copy);
1299
1300    if (ac)
1301        ocfs2_free_alloc_context(ac);
1302
1303    if (status)
1304        mlog_errno(status);
1305    return status;
1306}
1307
1308

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