Root/fs/ocfs2/slot_map.c

1/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * slot_map.c
5 *
6 *
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/types.h>
27#include <linux/slab.h>
28#include <linux/highmem.h>
29
30#include <cluster/masklog.h>
31
32#include "ocfs2.h"
33
34#include "dlmglue.h"
35#include "extent_map.h"
36#include "heartbeat.h"
37#include "inode.h"
38#include "slot_map.h"
39#include "super.h"
40#include "sysfile.h"
41#include "ocfs2_trace.h"
42
43#include "buffer_head_io.h"
44
45
46struct ocfs2_slot {
47    int sl_valid;
48    unsigned int sl_node_num;
49};
50
51struct ocfs2_slot_info {
52    int si_extended;
53    int si_slots_per_block;
54    struct inode *si_inode;
55    unsigned int si_blocks;
56    struct buffer_head **si_bh;
57    unsigned int si_num_slots;
58    struct ocfs2_slot *si_slots;
59};
60
61
62static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
63                    unsigned int node_num);
64
65static void ocfs2_invalidate_slot(struct ocfs2_slot_info *si,
66                  int slot_num)
67{
68    BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
69    si->si_slots[slot_num].sl_valid = 0;
70}
71
72static void ocfs2_set_slot(struct ocfs2_slot_info *si,
73               int slot_num, unsigned int node_num)
74{
75    BUG_ON((slot_num < 0) || (slot_num >= si->si_num_slots));
76
77    si->si_slots[slot_num].sl_valid = 1;
78    si->si_slots[slot_num].sl_node_num = node_num;
79}
80
81/* This version is for the extended slot map */
82static void ocfs2_update_slot_info_extended(struct ocfs2_slot_info *si)
83{
84    int b, i, slotno;
85    struct ocfs2_slot_map_extended *se;
86
87    slotno = 0;
88    for (b = 0; b < si->si_blocks; b++) {
89        se = (struct ocfs2_slot_map_extended *)si->si_bh[b]->b_data;
90        for (i = 0;
91             (i < si->si_slots_per_block) &&
92             (slotno < si->si_num_slots);
93             i++, slotno++) {
94            if (se->se_slots[i].es_valid)
95                ocfs2_set_slot(si, slotno,
96                           le32_to_cpu(se->se_slots[i].es_node_num));
97            else
98                ocfs2_invalidate_slot(si, slotno);
99        }
100    }
101}
102
103/*
104 * Post the slot information on disk into our slot_info struct.
105 * Must be protected by osb_lock.
106 */
107static void ocfs2_update_slot_info_old(struct ocfs2_slot_info *si)
108{
109    int i;
110    struct ocfs2_slot_map *sm;
111
112    sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
113
114    for (i = 0; i < si->si_num_slots; i++) {
115        if (le16_to_cpu(sm->sm_slots[i]) == (u16)OCFS2_INVALID_SLOT)
116            ocfs2_invalidate_slot(si, i);
117        else
118            ocfs2_set_slot(si, i, le16_to_cpu(sm->sm_slots[i]));
119    }
120}
121
122static void ocfs2_update_slot_info(struct ocfs2_slot_info *si)
123{
124    /*
125     * The slot data will have been refreshed when ocfs2_super_lock
126     * was taken.
127     */
128    if (si->si_extended)
129        ocfs2_update_slot_info_extended(si);
130    else
131        ocfs2_update_slot_info_old(si);
132}
133
134int ocfs2_refresh_slot_info(struct ocfs2_super *osb)
135{
136    int ret;
137    struct ocfs2_slot_info *si = osb->slot_info;
138
139    if (si == NULL)
140        return 0;
141
142    BUG_ON(si->si_blocks == 0);
143    BUG_ON(si->si_bh == NULL);
144
145    trace_ocfs2_refresh_slot_info(si->si_blocks);
146
147    /*
148     * We pass -1 as blocknr because we expect all of si->si_bh to
149     * be !NULL. Thus, ocfs2_read_blocks() will ignore blocknr. If
150     * this is not true, the read of -1 (UINT64_MAX) will fail.
151     */
152    ret = ocfs2_read_blocks(INODE_CACHE(si->si_inode), -1, si->si_blocks,
153                si->si_bh, OCFS2_BH_IGNORE_CACHE, NULL);
154    if (ret == 0) {
155        spin_lock(&osb->osb_lock);
156        ocfs2_update_slot_info(si);
157        spin_unlock(&osb->osb_lock);
158    }
159
160    return ret;
161}
162
163/* post the our slot info stuff into it's destination bh and write it
164 * out. */
165static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si,
166                        int slot_num,
167                        struct buffer_head **bh)
168{
169    int blkind = slot_num / si->si_slots_per_block;
170    int slotno = slot_num % si->si_slots_per_block;
171    struct ocfs2_slot_map_extended *se;
172
173    BUG_ON(blkind >= si->si_blocks);
174
175    se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data;
176    se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid;
177    if (si->si_slots[slot_num].sl_valid)
178        se->se_slots[slotno].es_node_num =
179            cpu_to_le32(si->si_slots[slot_num].sl_node_num);
180    *bh = si->si_bh[blkind];
181}
182
183static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si,
184                       int slot_num,
185                       struct buffer_head **bh)
186{
187    int i;
188    struct ocfs2_slot_map *sm;
189
190    sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data;
191    for (i = 0; i < si->si_num_slots; i++) {
192        if (si->si_slots[i].sl_valid)
193            sm->sm_slots[i] =
194                cpu_to_le16(si->si_slots[i].sl_node_num);
195        else
196            sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT);
197    }
198    *bh = si->si_bh[0];
199}
200
201static int ocfs2_update_disk_slot(struct ocfs2_super *osb,
202                  struct ocfs2_slot_info *si,
203                  int slot_num)
204{
205    int status;
206    struct buffer_head *bh;
207
208    spin_lock(&osb->osb_lock);
209    if (si->si_extended)
210        ocfs2_update_disk_slot_extended(si, slot_num, &bh);
211    else
212        ocfs2_update_disk_slot_old(si, slot_num, &bh);
213    spin_unlock(&osb->osb_lock);
214
215    status = ocfs2_write_block(osb, bh, INODE_CACHE(si->si_inode));
216    if (status < 0)
217        mlog_errno(status);
218
219    return status;
220}
221
222/*
223 * Calculate how many bytes are needed by the slot map. Returns
224 * an error if the slot map file is too small.
225 */
226static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb,
227                    struct inode *inode,
228                    unsigned long long *bytes)
229{
230    unsigned long long bytes_needed;
231
232    if (ocfs2_uses_extended_slot_map(osb)) {
233        bytes_needed = osb->max_slots *
234            sizeof(struct ocfs2_extended_slot);
235    } else {
236        bytes_needed = osb->max_slots * sizeof(__le16);
237    }
238    if (bytes_needed > i_size_read(inode)) {
239        mlog(ML_ERROR,
240             "Slot map file is too small! (size %llu, needed %llu)\n",
241             i_size_read(inode), bytes_needed);
242        return -ENOSPC;
243    }
244
245    *bytes = bytes_needed;
246    return 0;
247}
248
249/* try to find global node in the slot info. Returns -ENOENT
250 * if nothing is found. */
251static int __ocfs2_node_num_to_slot(struct ocfs2_slot_info *si,
252                    unsigned int node_num)
253{
254    int i, ret = -ENOENT;
255
256    for(i = 0; i < si->si_num_slots; i++) {
257        if (si->si_slots[i].sl_valid &&
258            (node_num == si->si_slots[i].sl_node_num)) {
259            ret = i;
260            break;
261        }
262    }
263
264    return ret;
265}
266
267static int __ocfs2_find_empty_slot(struct ocfs2_slot_info *si,
268                   int preferred)
269{
270    int i, ret = -ENOSPC;
271
272    if ((preferred >= 0) && (preferred < si->si_num_slots)) {
273        if (!si->si_slots[preferred].sl_valid) {
274            ret = preferred;
275            goto out;
276        }
277    }
278
279    for(i = 0; i < si->si_num_slots; i++) {
280        if (!si->si_slots[i].sl_valid) {
281            ret = i;
282            break;
283        }
284    }
285out:
286    return ret;
287}
288
289int ocfs2_node_num_to_slot(struct ocfs2_super *osb, unsigned int node_num)
290{
291    int slot;
292    struct ocfs2_slot_info *si = osb->slot_info;
293
294    spin_lock(&osb->osb_lock);
295    slot = __ocfs2_node_num_to_slot(si, node_num);
296    spin_unlock(&osb->osb_lock);
297
298    return slot;
299}
300
301int ocfs2_slot_to_node_num_locked(struct ocfs2_super *osb, int slot_num,
302                  unsigned int *node_num)
303{
304    struct ocfs2_slot_info *si = osb->slot_info;
305
306    assert_spin_locked(&osb->osb_lock);
307
308    BUG_ON(slot_num < 0);
309    BUG_ON(slot_num > osb->max_slots);
310
311    if (!si->si_slots[slot_num].sl_valid)
312        return -ENOENT;
313
314    *node_num = si->si_slots[slot_num].sl_node_num;
315    return 0;
316}
317
318static void __ocfs2_free_slot_info(struct ocfs2_slot_info *si)
319{
320    unsigned int i;
321
322    if (si == NULL)
323        return;
324
325    if (si->si_inode)
326        iput(si->si_inode);
327    if (si->si_bh) {
328        for (i = 0; i < si->si_blocks; i++) {
329            if (si->si_bh[i]) {
330                brelse(si->si_bh[i]);
331                si->si_bh[i] = NULL;
332            }
333        }
334        kfree(si->si_bh);
335    }
336
337    kfree(si);
338}
339
340int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num)
341{
342    struct ocfs2_slot_info *si = osb->slot_info;
343
344    if (si == NULL)
345        return 0;
346
347    spin_lock(&osb->osb_lock);
348    ocfs2_invalidate_slot(si, slot_num);
349    spin_unlock(&osb->osb_lock);
350
351    return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num);
352}
353
354static int ocfs2_map_slot_buffers(struct ocfs2_super *osb,
355                  struct ocfs2_slot_info *si)
356{
357    int status = 0;
358    u64 blkno;
359    unsigned long long blocks, bytes = 0;
360    unsigned int i;
361    struct buffer_head *bh;
362
363    status = ocfs2_slot_map_physical_size(osb, si->si_inode, &bytes);
364    if (status)
365        goto bail;
366
367    blocks = ocfs2_blocks_for_bytes(si->si_inode->i_sb, bytes);
368    BUG_ON(blocks > UINT_MAX);
369    si->si_blocks = blocks;
370    if (!si->si_blocks)
371        goto bail;
372
373    if (si->si_extended)
374        si->si_slots_per_block =
375            (osb->sb->s_blocksize /
376             sizeof(struct ocfs2_extended_slot));
377    else
378        si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16);
379
380    /* The size checks above should ensure this */
381    BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks);
382
383    trace_ocfs2_map_slot_buffers(bytes, si->si_blocks);
384
385    si->si_bh = kzalloc(sizeof(struct buffer_head *) * si->si_blocks,
386                GFP_KERNEL);
387    if (!si->si_bh) {
388        status = -ENOMEM;
389        mlog_errno(status);
390        goto bail;
391    }
392
393    for (i = 0; i < si->si_blocks; i++) {
394        status = ocfs2_extent_map_get_blocks(si->si_inode, i,
395                             &blkno, NULL, NULL);
396        if (status < 0) {
397            mlog_errno(status);
398            goto bail;
399        }
400
401        trace_ocfs2_map_slot_buffers_block((unsigned long long)blkno, i);
402
403        bh = NULL; /* Acquire a fresh bh */
404        status = ocfs2_read_blocks(INODE_CACHE(si->si_inode), blkno,
405                       1, &bh, OCFS2_BH_IGNORE_CACHE, NULL);
406        if (status < 0) {
407            mlog_errno(status);
408            goto bail;
409        }
410
411        si->si_bh[i] = bh;
412    }
413
414bail:
415    return status;
416}
417
418int ocfs2_init_slot_info(struct ocfs2_super *osb)
419{
420    int status;
421    struct inode *inode = NULL;
422    struct ocfs2_slot_info *si;
423
424    si = kzalloc(sizeof(struct ocfs2_slot_info) +
425             (sizeof(struct ocfs2_slot) * osb->max_slots),
426             GFP_KERNEL);
427    if (!si) {
428        status = -ENOMEM;
429        mlog_errno(status);
430        goto bail;
431    }
432
433    si->si_extended = ocfs2_uses_extended_slot_map(osb);
434    si->si_num_slots = osb->max_slots;
435    si->si_slots = (struct ocfs2_slot *)((char *)si +
436                         sizeof(struct ocfs2_slot_info));
437
438    inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
439                        OCFS2_INVALID_SLOT);
440    if (!inode) {
441        status = -EINVAL;
442        mlog_errno(status);
443        goto bail;
444    }
445
446    si->si_inode = inode;
447    status = ocfs2_map_slot_buffers(osb, si);
448    if (status < 0) {
449        mlog_errno(status);
450        goto bail;
451    }
452
453    osb->slot_info = (struct ocfs2_slot_info *)si;
454bail:
455    if (status < 0 && si)
456        __ocfs2_free_slot_info(si);
457
458    return status;
459}
460
461void ocfs2_free_slot_info(struct ocfs2_super *osb)
462{
463    struct ocfs2_slot_info *si = osb->slot_info;
464
465    osb->slot_info = NULL;
466    __ocfs2_free_slot_info(si);
467}
468
469int ocfs2_find_slot(struct ocfs2_super *osb)
470{
471    int status;
472    int slot;
473    struct ocfs2_slot_info *si;
474
475    si = osb->slot_info;
476
477    spin_lock(&osb->osb_lock);
478    ocfs2_update_slot_info(si);
479
480    /* search for ourselves first and take the slot if it already
481     * exists. Perhaps we need to mark this in a variable for our
482     * own journal recovery? Possibly not, though we certainly
483     * need to warn to the user */
484    slot = __ocfs2_node_num_to_slot(si, osb->node_num);
485    if (slot < 0) {
486        /* if no slot yet, then just take 1st available
487         * one. */
488        slot = __ocfs2_find_empty_slot(si, osb->preferred_slot);
489        if (slot < 0) {
490            spin_unlock(&osb->osb_lock);
491            mlog(ML_ERROR, "no free slots available!\n");
492            status = -EINVAL;
493            goto bail;
494        }
495    } else
496        mlog(ML_NOTICE, "slot %d is already allocated to this node!\n",
497             slot);
498
499    ocfs2_set_slot(si, slot, osb->node_num);
500    osb->slot_num = slot;
501    spin_unlock(&osb->osb_lock);
502
503    trace_ocfs2_find_slot(osb->slot_num);
504
505    status = ocfs2_update_disk_slot(osb, si, osb->slot_num);
506    if (status < 0)
507        mlog_errno(status);
508
509bail:
510    return status;
511}
512
513void ocfs2_put_slot(struct ocfs2_super *osb)
514{
515    int status, slot_num;
516    struct ocfs2_slot_info *si = osb->slot_info;
517
518    if (!si)
519        return;
520
521    spin_lock(&osb->osb_lock);
522    ocfs2_update_slot_info(si);
523
524    slot_num = osb->slot_num;
525    ocfs2_invalidate_slot(si, osb->slot_num);
526    osb->slot_num = OCFS2_INVALID_SLOT;
527    spin_unlock(&osb->osb_lock);
528
529    status = ocfs2_update_disk_slot(osb, si, slot_num);
530    if (status < 0) {
531        mlog_errno(status);
532        goto bail;
533    }
534
535bail:
536    ocfs2_free_slot_info(osb);
537}
538
539

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