Merge back cpufreq updates for v5.11.
[linux-2.6-microblaze.git] / fs / gfs2 / super.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
5  */
6
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9 #include <linux/bio.h>
10 #include <linux/sched/signal.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/statfs.h>
16 #include <linux/seq_file.h>
17 #include <linux/mount.h>
18 #include <linux/kthread.h>
19 #include <linux/delay.h>
20 #include <linux/gfs2_ondisk.h>
21 #include <linux/crc32.h>
22 #include <linux/time.h>
23 #include <linux/wait.h>
24 #include <linux/writeback.h>
25 #include <linux/backing-dev.h>
26 #include <linux/kernel.h>
27
28 #include "gfs2.h"
29 #include "incore.h"
30 #include "bmap.h"
31 #include "dir.h"
32 #include "glock.h"
33 #include "glops.h"
34 #include "inode.h"
35 #include "log.h"
36 #include "meta_io.h"
37 #include "quota.h"
38 #include "recovery.h"
39 #include "rgrp.h"
40 #include "super.h"
41 #include "trans.h"
42 #include "util.h"
43 #include "sys.h"
44 #include "xattr.h"
45 #include "lops.h"
46
47 enum dinode_demise {
48         SHOULD_DELETE_DINODE,
49         SHOULD_NOT_DELETE_DINODE,
50         SHOULD_DEFER_EVICTION,
51 };
52
53 /**
54  * gfs2_jindex_free - Clear all the journal index information
55  * @sdp: The GFS2 superblock
56  *
57  */
58
59 void gfs2_jindex_free(struct gfs2_sbd *sdp)
60 {
61         struct list_head list;
62         struct gfs2_jdesc *jd;
63
64         spin_lock(&sdp->sd_jindex_spin);
65         list_add(&list, &sdp->sd_jindex_list);
66         list_del_init(&sdp->sd_jindex_list);
67         sdp->sd_journals = 0;
68         spin_unlock(&sdp->sd_jindex_spin);
69
70         sdp->sd_jdesc = NULL;
71         while (!list_empty(&list)) {
72                 jd = list_first_entry(&list, struct gfs2_jdesc, jd_list);
73                 gfs2_free_journal_extents(jd);
74                 list_del(&jd->jd_list);
75                 iput(jd->jd_inode);
76                 jd->jd_inode = NULL;
77                 kfree(jd);
78         }
79 }
80
81 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
82 {
83         struct gfs2_jdesc *jd;
84         int found = 0;
85
86         list_for_each_entry(jd, head, jd_list) {
87                 if (jd->jd_jid == jid) {
88                         found = 1;
89                         break;
90                 }
91         }
92
93         if (!found)
94                 jd = NULL;
95
96         return jd;
97 }
98
99 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
100 {
101         struct gfs2_jdesc *jd;
102
103         spin_lock(&sdp->sd_jindex_spin);
104         jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
105         spin_unlock(&sdp->sd_jindex_spin);
106
107         return jd;
108 }
109
110 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
111 {
112         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
113         struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
114         u64 size = i_size_read(jd->jd_inode);
115
116         if (gfs2_check_internal_file_size(jd->jd_inode, 8 << 20, BIT(30)))
117                 return -EIO;
118
119         jd->jd_blocks = size >> sdp->sd_sb.sb_bsize_shift;
120
121         if (gfs2_write_alloc_required(ip, 0, size)) {
122                 gfs2_consist_inode(ip);
123                 return -EIO;
124         }
125
126         return 0;
127 }
128
129 static int init_threads(struct gfs2_sbd *sdp)
130 {
131         struct task_struct *p;
132         int error = 0;
133
134         p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
135         if (IS_ERR(p)) {
136                 error = PTR_ERR(p);
137                 fs_err(sdp, "can't start logd thread: %d\n", error);
138                 return error;
139         }
140         sdp->sd_logd_process = p;
141
142         p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
143         if (IS_ERR(p)) {
144                 error = PTR_ERR(p);
145                 fs_err(sdp, "can't start quotad thread: %d\n", error);
146                 goto fail;
147         }
148         sdp->sd_quotad_process = p;
149         return 0;
150
151 fail:
152         kthread_stop(sdp->sd_logd_process);
153         sdp->sd_logd_process = NULL;
154         return error;
155 }
156
157 /**
158  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
159  * @sdp: the filesystem
160  *
161  * Returns: errno
162  */
163
164 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
165 {
166         struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
167         struct gfs2_glock *j_gl = ip->i_gl;
168         struct gfs2_holder freeze_gh;
169         struct gfs2_log_header_host head;
170         int error;
171
172         error = init_threads(sdp);
173         if (error)
174                 return error;
175
176         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
177                                    LM_FLAG_NOEXP | GL_EXACT,
178                                    &freeze_gh);
179         if (error)
180                 goto fail_threads;
181
182         j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
183         if (gfs2_withdrawn(sdp)) {
184                 error = -EIO;
185                 goto fail;
186         }
187
188         error = gfs2_find_jhead(sdp->sd_jdesc, &head, false);
189         if (error || gfs2_withdrawn(sdp))
190                 goto fail;
191
192         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
193                 gfs2_consist(sdp);
194                 error = -EIO;
195                 goto fail;
196         }
197
198         /*  Initialize some head of the log stuff  */
199         sdp->sd_log_sequence = head.lh_sequence + 1;
200         gfs2_log_pointers_init(sdp, head.lh_blkno);
201
202         error = gfs2_quota_init(sdp);
203         if (error || gfs2_withdrawn(sdp))
204                 goto fail;
205
206         set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
207
208         gfs2_glock_dq_uninit(&freeze_gh);
209
210         return 0;
211
212 fail:
213         gfs2_glock_dq_uninit(&freeze_gh);
214 fail_threads:
215         if (sdp->sd_quotad_process)
216                 kthread_stop(sdp->sd_quotad_process);
217         sdp->sd_quotad_process = NULL;
218         if (sdp->sd_logd_process)
219                 kthread_stop(sdp->sd_logd_process);
220         sdp->sd_logd_process = NULL;
221         return error;
222 }
223
224 void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
225 {
226         const struct gfs2_statfs_change *str = buf;
227
228         sc->sc_total = be64_to_cpu(str->sc_total);
229         sc->sc_free = be64_to_cpu(str->sc_free);
230         sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
231 }
232
233 void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
234 {
235         struct gfs2_statfs_change *str = buf;
236
237         str->sc_total = cpu_to_be64(sc->sc_total);
238         str->sc_free = cpu_to_be64(sc->sc_free);
239         str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
240 }
241
242 int gfs2_statfs_init(struct gfs2_sbd *sdp)
243 {
244         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
245         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
246         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
247         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
248         struct buffer_head *m_bh, *l_bh;
249         struct gfs2_holder gh;
250         int error;
251
252         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
253                                    &gh);
254         if (error)
255                 return error;
256
257         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
258         if (error)
259                 goto out;
260
261         if (sdp->sd_args.ar_spectator) {
262                 spin_lock(&sdp->sd_statfs_spin);
263                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
264                                       sizeof(struct gfs2_dinode));
265                 spin_unlock(&sdp->sd_statfs_spin);
266         } else {
267                 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
268                 if (error)
269                         goto out_m_bh;
270
271                 spin_lock(&sdp->sd_statfs_spin);
272                 gfs2_statfs_change_in(m_sc, m_bh->b_data +
273                                       sizeof(struct gfs2_dinode));
274                 gfs2_statfs_change_in(l_sc, l_bh->b_data +
275                                       sizeof(struct gfs2_dinode));
276                 spin_unlock(&sdp->sd_statfs_spin);
277
278                 brelse(l_bh);
279         }
280
281 out_m_bh:
282         brelse(m_bh);
283 out:
284         gfs2_glock_dq_uninit(&gh);
285         return 0;
286 }
287
288 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
289                         s64 dinodes)
290 {
291         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
292         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
293         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
294         struct buffer_head *l_bh;
295         s64 x, y;
296         int need_sync = 0;
297         int error;
298
299         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
300         if (error)
301                 return;
302
303         gfs2_trans_add_meta(l_ip->i_gl, l_bh);
304
305         spin_lock(&sdp->sd_statfs_spin);
306         l_sc->sc_total += total;
307         l_sc->sc_free += free;
308         l_sc->sc_dinodes += dinodes;
309         gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
310         if (sdp->sd_args.ar_statfs_percent) {
311                 x = 100 * l_sc->sc_free;
312                 y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
313                 if (x >= y || x <= -y)
314                         need_sync = 1;
315         }
316         spin_unlock(&sdp->sd_statfs_spin);
317
318         brelse(l_bh);
319         if (need_sync)
320                 gfs2_wake_up_statfs(sdp);
321 }
322
323 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
324                    struct buffer_head *l_bh)
325 {
326         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
327         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
328         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
329         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
330
331         gfs2_trans_add_meta(l_ip->i_gl, l_bh);
332         gfs2_trans_add_meta(m_ip->i_gl, m_bh);
333
334         spin_lock(&sdp->sd_statfs_spin);
335         m_sc->sc_total += l_sc->sc_total;
336         m_sc->sc_free += l_sc->sc_free;
337         m_sc->sc_dinodes += l_sc->sc_dinodes;
338         memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
339         memset(l_bh->b_data + sizeof(struct gfs2_dinode),
340                0, sizeof(struct gfs2_statfs_change));
341         gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
342         spin_unlock(&sdp->sd_statfs_spin);
343 }
344
345 int gfs2_statfs_sync(struct super_block *sb, int type)
346 {
347         struct gfs2_sbd *sdp = sb->s_fs_info;
348         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
349         struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
350         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
351         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
352         struct gfs2_holder gh;
353         struct buffer_head *m_bh, *l_bh;
354         int error;
355
356         sb_start_write(sb);
357         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
358                                    &gh);
359         if (error)
360                 goto out;
361
362         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
363         if (error)
364                 goto out_unlock;
365
366         spin_lock(&sdp->sd_statfs_spin);
367         gfs2_statfs_change_in(m_sc, m_bh->b_data +
368                               sizeof(struct gfs2_dinode));
369         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
370                 spin_unlock(&sdp->sd_statfs_spin);
371                 goto out_bh;
372         }
373         spin_unlock(&sdp->sd_statfs_spin);
374
375         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
376         if (error)
377                 goto out_bh;
378
379         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
380         if (error)
381                 goto out_bh2;
382
383         update_statfs(sdp, m_bh, l_bh);
384         sdp->sd_statfs_force_sync = 0;
385
386         gfs2_trans_end(sdp);
387
388 out_bh2:
389         brelse(l_bh);
390 out_bh:
391         brelse(m_bh);
392 out_unlock:
393         gfs2_glock_dq_uninit(&gh);
394 out:
395         sb_end_write(sb);
396         return error;
397 }
398
399 struct lfcc {
400         struct list_head list;
401         struct gfs2_holder gh;
402 };
403
404 /**
405  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
406  *                            journals are clean
407  * @sdp: the file system
408  * @state: the state to put the transaction lock into
409  * @t_gh: the hold on the transaction lock
410  *
411  * Returns: errno
412  */
413
414 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp)
415 {
416         struct gfs2_inode *ip;
417         struct gfs2_jdesc *jd;
418         struct lfcc *lfcc;
419         LIST_HEAD(list);
420         struct gfs2_log_header_host lh;
421         int error;
422
423         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
424                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
425                 if (!lfcc) {
426                         error = -ENOMEM;
427                         goto out;
428                 }
429                 ip = GFS2_I(jd->jd_inode);
430                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
431                 if (error) {
432                         kfree(lfcc);
433                         goto out;
434                 }
435                 list_add(&lfcc->list, &list);
436         }
437
438         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
439                                    LM_FLAG_NOEXP, &sdp->sd_freeze_gh);
440         if (error)
441                 goto out;
442
443         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
444                 error = gfs2_jdesc_check(jd);
445                 if (error)
446                         break;
447                 error = gfs2_find_jhead(jd, &lh, false);
448                 if (error)
449                         break;
450                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
451                         error = -EBUSY;
452                         break;
453                 }
454         }
455
456         if (error)
457                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
458
459 out:
460         while (!list_empty(&list)) {
461                 lfcc = list_first_entry(&list, struct lfcc, list);
462                 list_del(&lfcc->list);
463                 gfs2_glock_dq_uninit(&lfcc->gh);
464                 kfree(lfcc);
465         }
466         return error;
467 }
468
469 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
470 {
471         struct gfs2_dinode *str = buf;
472
473         str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
474         str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
475         str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
476         str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
477         str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
478         str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
479         str->di_uid = cpu_to_be32(i_uid_read(&ip->i_inode));
480         str->di_gid = cpu_to_be32(i_gid_read(&ip->i_inode));
481         str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
482         str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
483         str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
484         str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
485         str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
486         str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
487
488         str->di_goal_meta = cpu_to_be64(ip->i_goal);
489         str->di_goal_data = cpu_to_be64(ip->i_goal);
490         str->di_generation = cpu_to_be64(ip->i_generation);
491
492         str->di_flags = cpu_to_be32(ip->i_diskflags);
493         str->di_height = cpu_to_be16(ip->i_height);
494         str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
495                                              !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
496                                              GFS2_FORMAT_DE : 0);
497         str->di_depth = cpu_to_be16(ip->i_depth);
498         str->di_entries = cpu_to_be32(ip->i_entries);
499
500         str->di_eattr = cpu_to_be64(ip->i_eattr);
501         str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
502         str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
503         str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
504 }
505
506 /**
507  * gfs2_write_inode - Make sure the inode is stable on the disk
508  * @inode: The inode
509  * @wbc: The writeback control structure
510  *
511  * Returns: errno
512  */
513
514 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
515 {
516         struct gfs2_inode *ip = GFS2_I(inode);
517         struct gfs2_sbd *sdp = GFS2_SB(inode);
518         struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
519         struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
520         int ret = 0;
521         bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
522
523         if (flush_all)
524                 gfs2_log_flush(GFS2_SB(inode), ip->i_gl,
525                                GFS2_LOG_HEAD_FLUSH_NORMAL |
526                                GFS2_LFC_WRITE_INODE);
527         if (bdi->wb.dirty_exceeded)
528                 gfs2_ail1_flush(sdp, wbc);
529         else
530                 filemap_fdatawrite(metamapping);
531         if (flush_all)
532                 ret = filemap_fdatawait(metamapping);
533         if (ret)
534                 mark_inode_dirty_sync(inode);
535         else {
536                 spin_lock(&inode->i_lock);
537                 if (!(inode->i_flags & I_DIRTY))
538                         gfs2_ordered_del_inode(ip);
539                 spin_unlock(&inode->i_lock);
540         }
541         return ret;
542 }
543
544 /**
545  * gfs2_dirty_inode - check for atime updates
546  * @inode: The inode in question
547  * @flags: The type of dirty
548  *
549  * Unfortunately it can be called under any combination of inode
550  * glock and transaction lock, so we have to check carefully.
551  *
552  * At the moment this deals only with atime - it should be possible
553  * to expand that role in future, once a review of the locking has
554  * been carried out.
555  */
556
557 static void gfs2_dirty_inode(struct inode *inode, int flags)
558 {
559         struct gfs2_inode *ip = GFS2_I(inode);
560         struct gfs2_sbd *sdp = GFS2_SB(inode);
561         struct buffer_head *bh;
562         struct gfs2_holder gh;
563         int need_unlock = 0;
564         int need_endtrans = 0;
565         int ret;
566
567         if (!(flags & I_DIRTY_INODE))
568                 return;
569         if (unlikely(gfs2_withdrawn(sdp)))
570                 return;
571         if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
572                 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
573                 if (ret) {
574                         fs_err(sdp, "dirty_inode: glock %d\n", ret);
575                         gfs2_dump_glock(NULL, ip->i_gl, true);
576                         return;
577                 }
578                 need_unlock = 1;
579         } else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
580                 return;
581
582         if (current->journal_info == NULL) {
583                 ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
584                 if (ret) {
585                         fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
586                         goto out;
587                 }
588                 need_endtrans = 1;
589         }
590
591         ret = gfs2_meta_inode_buffer(ip, &bh);
592         if (ret == 0) {
593                 gfs2_trans_add_meta(ip->i_gl, bh);
594                 gfs2_dinode_out(ip, bh->b_data);
595                 brelse(bh);
596         }
597
598         if (need_endtrans)
599                 gfs2_trans_end(sdp);
600 out:
601         if (need_unlock)
602                 gfs2_glock_dq_uninit(&gh);
603 }
604
605 /**
606  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
607  * @sdp: the filesystem
608  *
609  * Returns: errno
610  */
611
612 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
613 {
614         struct gfs2_holder freeze_gh;
615         int error = 0;
616         int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
617
618         gfs2_holder_mark_uninitialized(&freeze_gh);
619         if (sdp->sd_freeze_gl &&
620             !gfs2_glock_is_locked_by_me(sdp->sd_freeze_gl)) {
621                 if (!log_write_allowed) {
622                         error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
623                                                    LM_ST_SHARED, LM_FLAG_TRY |
624                                                    LM_FLAG_NOEXP | GL_EXACT,
625                                                    &freeze_gh);
626                         if (error == GLR_TRYFAILED)
627                                 error = 0;
628                 } else {
629                         error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
630                                                    LM_ST_SHARED,
631                                                    LM_FLAG_NOEXP | GL_EXACT,
632                                                    &freeze_gh);
633                         if (error && !gfs2_withdrawn(sdp))
634                                 return error;
635                 }
636         }
637
638         gfs2_flush_delete_work(sdp);
639         if (!log_write_allowed && current == sdp->sd_quotad_process)
640                 fs_warn(sdp, "The quotad daemon is withdrawing.\n");
641         else if (sdp->sd_quotad_process)
642                 kthread_stop(sdp->sd_quotad_process);
643         sdp->sd_quotad_process = NULL;
644
645         if (!log_write_allowed && current == sdp->sd_logd_process)
646                 fs_warn(sdp, "The logd daemon is withdrawing.\n");
647         else if (sdp->sd_logd_process)
648                 kthread_stop(sdp->sd_logd_process);
649         sdp->sd_logd_process = NULL;
650
651         if (log_write_allowed) {
652                 gfs2_quota_sync(sdp->sd_vfs, 0);
653                 gfs2_statfs_sync(sdp->sd_vfs, 0);
654
655                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
656                                GFS2_LFC_MAKE_FS_RO);
657                 wait_event(sdp->sd_reserving_log_wait,
658                            atomic_read(&sdp->sd_reserving_log) == 0);
659                 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) ==
660                                  sdp->sd_jdesc->jd_blocks);
661         } else {
662                 wait_event_timeout(sdp->sd_reserving_log_wait,
663                                    atomic_read(&sdp->sd_reserving_log) == 0,
664                                    HZ * 5);
665         }
666         if (gfs2_holder_initialized(&freeze_gh))
667                 gfs2_glock_dq_uninit(&freeze_gh);
668
669         gfs2_quota_cleanup(sdp);
670
671         if (!log_write_allowed)
672                 sdp->sd_vfs->s_flags |= SB_RDONLY;
673
674         return error;
675 }
676
677 /**
678  * gfs2_put_super - Unmount the filesystem
679  * @sb: The VFS superblock
680  *
681  */
682
683 static void gfs2_put_super(struct super_block *sb)
684 {
685         struct gfs2_sbd *sdp = sb->s_fs_info;
686         int error;
687         struct gfs2_jdesc *jd;
688
689         /* No more recovery requests */
690         set_bit(SDF_NORECOVERY, &sdp->sd_flags);
691         smp_mb();
692
693         /* Wait on outstanding recovery */
694 restart:
695         spin_lock(&sdp->sd_jindex_spin);
696         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
697                 if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
698                         continue;
699                 spin_unlock(&sdp->sd_jindex_spin);
700                 wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
701                             TASK_UNINTERRUPTIBLE);
702                 goto restart;
703         }
704         spin_unlock(&sdp->sd_jindex_spin);
705
706         if (!sb_rdonly(sb)) {
707                 error = gfs2_make_fs_ro(sdp);
708                 if (error)
709                         gfs2_io_error(sdp);
710         }
711         WARN_ON(gfs2_withdrawing(sdp));
712
713         /*  At this point, we're through modifying the disk  */
714
715         /*  Release stuff  */
716
717         iput(sdp->sd_jindex);
718         iput(sdp->sd_statfs_inode);
719         iput(sdp->sd_rindex);
720         iput(sdp->sd_quota_inode);
721
722         gfs2_glock_put(sdp->sd_rename_gl);
723         gfs2_glock_put(sdp->sd_freeze_gl);
724
725         if (!sdp->sd_args.ar_spectator) {
726                 if (gfs2_holder_initialized(&sdp->sd_journal_gh))
727                         gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
728                 if (gfs2_holder_initialized(&sdp->sd_jinode_gh))
729                         gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
730                 gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
731                 gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
732                 free_local_statfs_inodes(sdp);
733                 iput(sdp->sd_qc_inode);
734         }
735
736         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
737         gfs2_clear_rgrpd(sdp);
738         gfs2_jindex_free(sdp);
739         /*  Take apart glock structures and buffer lists  */
740         gfs2_gl_hash_clear(sdp);
741         truncate_inode_pages_final(&sdp->sd_aspace);
742         gfs2_delete_debugfs_file(sdp);
743         /*  Unmount the locking protocol  */
744         gfs2_lm_unmount(sdp);
745
746         /*  At this point, we're through participating in the lockspace  */
747         gfs2_sys_fs_del(sdp);
748         free_sbd(sdp);
749 }
750
751 /**
752  * gfs2_sync_fs - sync the filesystem
753  * @sb: the superblock
754  *
755  * Flushes the log to disk.
756  */
757
758 static int gfs2_sync_fs(struct super_block *sb, int wait)
759 {
760         struct gfs2_sbd *sdp = sb->s_fs_info;
761
762         gfs2_quota_sync(sb, -1);
763         if (wait)
764                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
765                                GFS2_LFC_SYNC_FS);
766         return sdp->sd_log_error;
767 }
768
769 void gfs2_freeze_func(struct work_struct *work)
770 {
771         int error;
772         struct gfs2_holder freeze_gh;
773         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
774         struct super_block *sb = sdp->sd_vfs;
775
776         atomic_inc(&sb->s_active);
777         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
778                                    LM_FLAG_NOEXP | GL_EXACT, &freeze_gh);
779         if (error) {
780                 fs_info(sdp, "GFS2: couldn't get freeze lock : %d\n", error);
781                 gfs2_assert_withdraw(sdp, 0);
782         } else {
783                 atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
784                 error = thaw_super(sb);
785                 if (error) {
786                         fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
787                                 error);
788                         gfs2_assert_withdraw(sdp, 0);
789                 }
790                 gfs2_glock_dq_uninit(&freeze_gh);
791         }
792         deactivate_super(sb);
793         clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
794         wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
795         return;
796 }
797
798 /**
799  * gfs2_freeze - prevent further writes to the filesystem
800  * @sb: the VFS structure for the filesystem
801  *
802  */
803
804 static int gfs2_freeze(struct super_block *sb)
805 {
806         struct gfs2_sbd *sdp = sb->s_fs_info;
807         int error = 0;
808
809         mutex_lock(&sdp->sd_freeze_mutex);
810         if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN)
811                 goto out;
812
813         for (;;) {
814                 if (gfs2_withdrawn(sdp)) {
815                         error = -EINVAL;
816                         goto out;
817                 }
818
819                 error = gfs2_lock_fs_check_clean(sdp);
820                 if (!error)
821                         break;
822
823                 if (error == -EBUSY)
824                         fs_err(sdp, "waiting for recovery before freeze\n");
825                 else if (error == -EIO) {
826                         fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
827                                "to recovery error.\n");
828                         goto out;
829                 } else {
830                         fs_err(sdp, "error freezing FS: %d\n", error);
831                 }
832                 fs_err(sdp, "retrying...\n");
833                 msleep(1000);
834         }
835         set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
836 out:
837         mutex_unlock(&sdp->sd_freeze_mutex);
838         return error;
839 }
840
841 /**
842  * gfs2_unfreeze - reallow writes to the filesystem
843  * @sb: the VFS structure for the filesystem
844  *
845  */
846
847 static int gfs2_unfreeze(struct super_block *sb)
848 {
849         struct gfs2_sbd *sdp = sb->s_fs_info;
850
851         mutex_lock(&sdp->sd_freeze_mutex);
852         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
853             !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
854                 mutex_unlock(&sdp->sd_freeze_mutex);
855                 return 0;
856         }
857
858         gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
859         mutex_unlock(&sdp->sd_freeze_mutex);
860         return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
861 }
862
863 /**
864  * statfs_fill - fill in the sg for a given RG
865  * @rgd: the RG
866  * @sc: the sc structure
867  *
868  * Returns: 0 on success, -ESTALE if the LVB is invalid
869  */
870
871 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
872                             struct gfs2_statfs_change_host *sc)
873 {
874         gfs2_rgrp_verify(rgd);
875         sc->sc_total += rgd->rd_data;
876         sc->sc_free += rgd->rd_free;
877         sc->sc_dinodes += rgd->rd_dinodes;
878         return 0;
879 }
880
881 /**
882  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
883  * @sdp: the filesystem
884  * @sc: the sc info that will be returned
885  *
886  * Any error (other than a signal) will cause this routine to fall back
887  * to the synchronous version.
888  *
889  * FIXME: This really shouldn't busy wait like this.
890  *
891  * Returns: errno
892  */
893
894 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
895 {
896         struct gfs2_rgrpd *rgd_next;
897         struct gfs2_holder *gha, *gh;
898         unsigned int slots = 64;
899         unsigned int x;
900         int done;
901         int error = 0, err;
902
903         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
904         gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
905         if (!gha)
906                 return -ENOMEM;
907         for (x = 0; x < slots; x++)
908                 gfs2_holder_mark_uninitialized(gha + x);
909
910         rgd_next = gfs2_rgrpd_get_first(sdp);
911
912         for (;;) {
913                 done = 1;
914
915                 for (x = 0; x < slots; x++) {
916                         gh = gha + x;
917
918                         if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
919                                 err = gfs2_glock_wait(gh);
920                                 if (err) {
921                                         gfs2_holder_uninit(gh);
922                                         error = err;
923                                 } else {
924                                         if (!error) {
925                                                 struct gfs2_rgrpd *rgd =
926                                                         gfs2_glock2rgrp(gh->gh_gl);
927
928                                                 error = statfs_slow_fill(rgd, sc);
929                                         }
930                                         gfs2_glock_dq_uninit(gh);
931                                 }
932                         }
933
934                         if (gfs2_holder_initialized(gh))
935                                 done = 0;
936                         else if (rgd_next && !error) {
937                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
938                                                            LM_ST_SHARED,
939                                                            GL_ASYNC,
940                                                            gh);
941                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
942                                 done = 0;
943                         }
944
945                         if (signal_pending(current))
946                                 error = -ERESTARTSYS;
947                 }
948
949                 if (done)
950                         break;
951
952                 yield();
953         }
954
955         kfree(gha);
956         return error;
957 }
958
959 /**
960  * gfs2_statfs_i - Do a statfs
961  * @sdp: the filesystem
962  * @sg: the sg structure
963  *
964  * Returns: errno
965  */
966
967 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
968 {
969         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
970         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
971
972         spin_lock(&sdp->sd_statfs_spin);
973
974         *sc = *m_sc;
975         sc->sc_total += l_sc->sc_total;
976         sc->sc_free += l_sc->sc_free;
977         sc->sc_dinodes += l_sc->sc_dinodes;
978
979         spin_unlock(&sdp->sd_statfs_spin);
980
981         if (sc->sc_free < 0)
982                 sc->sc_free = 0;
983         if (sc->sc_free > sc->sc_total)
984                 sc->sc_free = sc->sc_total;
985         if (sc->sc_dinodes < 0)
986                 sc->sc_dinodes = 0;
987
988         return 0;
989 }
990
991 /**
992  * gfs2_statfs - Gather and return stats about the filesystem
993  * @sb: The superblock
994  * @statfsbuf: The buffer
995  *
996  * Returns: 0 on success or error code
997  */
998
999 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
1000 {
1001         struct super_block *sb = dentry->d_sb;
1002         struct gfs2_sbd *sdp = sb->s_fs_info;
1003         struct gfs2_statfs_change_host sc;
1004         int error;
1005
1006         error = gfs2_rindex_update(sdp);
1007         if (error)
1008                 return error;
1009
1010         if (gfs2_tune_get(sdp, gt_statfs_slow))
1011                 error = gfs2_statfs_slow(sdp, &sc);
1012         else
1013                 error = gfs2_statfs_i(sdp, &sc);
1014
1015         if (error)
1016                 return error;
1017
1018         buf->f_type = GFS2_MAGIC;
1019         buf->f_bsize = sdp->sd_sb.sb_bsize;
1020         buf->f_blocks = sc.sc_total;
1021         buf->f_bfree = sc.sc_free;
1022         buf->f_bavail = sc.sc_free;
1023         buf->f_files = sc.sc_dinodes + sc.sc_free;
1024         buf->f_ffree = sc.sc_free;
1025         buf->f_namelen = GFS2_FNAMESIZE;
1026
1027         return 0;
1028 }
1029
1030 /**
1031  * gfs2_drop_inode - Drop an inode (test for remote unlink)
1032  * @inode: The inode to drop
1033  *
1034  * If we've received a callback on an iopen lock then it's because a
1035  * remote node tried to deallocate the inode but failed due to this node
1036  * still having the inode open. Here we mark the link count zero
1037  * since we know that it must have reached zero if the GLF_DEMOTE flag
1038  * is set on the iopen glock. If we didn't do a disk read since the
1039  * remote node removed the final link then we might otherwise miss
1040  * this event. This check ensures that this node will deallocate the
1041  * inode's blocks, or alternatively pass the baton on to another
1042  * node for later deallocation.
1043  */
1044
1045 static int gfs2_drop_inode(struct inode *inode)
1046 {
1047         struct gfs2_inode *ip = GFS2_I(inode);
1048
1049         if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) &&
1050             inode->i_nlink &&
1051             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1052                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1053                 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
1054                         clear_nlink(inode);
1055         }
1056
1057         /*
1058          * When under memory pressure when an inode's link count has dropped to
1059          * zero, defer deleting the inode to the delete workqueue.  This avoids
1060          * calling into DLM under memory pressure, which can deadlock.
1061          */
1062         if (!inode->i_nlink &&
1063             unlikely(current->flags & PF_MEMALLOC) &&
1064             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1065                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1066
1067                 gfs2_glock_hold(gl);
1068                 if (!gfs2_queue_delete_work(gl, 0))
1069                         gfs2_glock_queue_put(gl);
1070                 return false;
1071         }
1072
1073         return generic_drop_inode(inode);
1074 }
1075
1076 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1077 {
1078         do {
1079                 if (d1 == d2)
1080                         return 1;
1081                 d1 = d1->d_parent;
1082         } while (!IS_ROOT(d1));
1083         return 0;
1084 }
1085
1086 /**
1087  * gfs2_show_options - Show mount options for /proc/mounts
1088  * @s: seq_file structure
1089  * @root: root of this (sub)tree
1090  *
1091  * Returns: 0 on success or error code
1092  */
1093
1094 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1095 {
1096         struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1097         struct gfs2_args *args = &sdp->sd_args;
1098         int val;
1099
1100         if (is_ancestor(root, sdp->sd_master_dir))
1101                 seq_puts(s, ",meta");
1102         if (args->ar_lockproto[0])
1103                 seq_show_option(s, "lockproto", args->ar_lockproto);
1104         if (args->ar_locktable[0])
1105                 seq_show_option(s, "locktable", args->ar_locktable);
1106         if (args->ar_hostdata[0])
1107                 seq_show_option(s, "hostdata", args->ar_hostdata);
1108         if (args->ar_spectator)
1109                 seq_puts(s, ",spectator");
1110         if (args->ar_localflocks)
1111                 seq_puts(s, ",localflocks");
1112         if (args->ar_debug)
1113                 seq_puts(s, ",debug");
1114         if (args->ar_posix_acl)
1115                 seq_puts(s, ",acl");
1116         if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1117                 char *state;
1118                 switch (args->ar_quota) {
1119                 case GFS2_QUOTA_OFF:
1120                         state = "off";
1121                         break;
1122                 case GFS2_QUOTA_ACCOUNT:
1123                         state = "account";
1124                         break;
1125                 case GFS2_QUOTA_ON:
1126                         state = "on";
1127                         break;
1128                 default:
1129                         state = "unknown";
1130                         break;
1131                 }
1132                 seq_printf(s, ",quota=%s", state);
1133         }
1134         if (args->ar_suiddir)
1135                 seq_puts(s, ",suiddir");
1136         if (args->ar_data != GFS2_DATA_DEFAULT) {
1137                 char *state;
1138                 switch (args->ar_data) {
1139                 case GFS2_DATA_WRITEBACK:
1140                         state = "writeback";
1141                         break;
1142                 case GFS2_DATA_ORDERED:
1143                         state = "ordered";
1144                         break;
1145                 default:
1146                         state = "unknown";
1147                         break;
1148                 }
1149                 seq_printf(s, ",data=%s", state);
1150         }
1151         if (args->ar_discard)
1152                 seq_puts(s, ",discard");
1153         val = sdp->sd_tune.gt_logd_secs;
1154         if (val != 30)
1155                 seq_printf(s, ",commit=%d", val);
1156         val = sdp->sd_tune.gt_statfs_quantum;
1157         if (val != 30)
1158                 seq_printf(s, ",statfs_quantum=%d", val);
1159         else if (sdp->sd_tune.gt_statfs_slow)
1160                 seq_puts(s, ",statfs_quantum=0");
1161         val = sdp->sd_tune.gt_quota_quantum;
1162         if (val != 60)
1163                 seq_printf(s, ",quota_quantum=%d", val);
1164         if (args->ar_statfs_percent)
1165                 seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1166         if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1167                 const char *state;
1168
1169                 switch (args->ar_errors) {
1170                 case GFS2_ERRORS_WITHDRAW:
1171                         state = "withdraw";
1172                         break;
1173                 case GFS2_ERRORS_PANIC:
1174                         state = "panic";
1175                         break;
1176                 default:
1177                         state = "unknown";
1178                         break;
1179                 }
1180                 seq_printf(s, ",errors=%s", state);
1181         }
1182         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1183                 seq_puts(s, ",nobarrier");
1184         if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1185                 seq_puts(s, ",demote_interface_used");
1186         if (args->ar_rgrplvb)
1187                 seq_puts(s, ",rgrplvb");
1188         if (args->ar_loccookie)
1189                 seq_puts(s, ",loccookie");
1190         return 0;
1191 }
1192
1193 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1194 {
1195         struct inode *inode = &ip->i_inode;
1196         struct gfs2_glock *gl = ip->i_gl;
1197
1198         truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1199         truncate_inode_pages(&inode->i_data, 0);
1200
1201         if (atomic_read(&gl->gl_revokes) == 0) {
1202                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
1203                 clear_bit(GLF_DIRTY, &gl->gl_flags);
1204         }
1205 }
1206
1207 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1208 {
1209         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1210         struct gfs2_rgrpd *rgd;
1211         struct gfs2_holder gh;
1212         int error;
1213
1214         if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1215                 gfs2_consist_inode(ip);
1216                 return -EIO;
1217         }
1218
1219         error = gfs2_rindex_update(sdp);
1220         if (error)
1221                 return error;
1222
1223         error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1224         if (error)
1225                 return error;
1226
1227         rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1228         if (!rgd) {
1229                 gfs2_consist_inode(ip);
1230                 error = -EIO;
1231                 goto out_qs;
1232         }
1233
1234         error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
1235         if (error)
1236                 goto out_qs;
1237
1238         error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1239                                  sdp->sd_jdesc->jd_blocks);
1240         if (error)
1241                 goto out_rg_gunlock;
1242
1243         gfs2_free_di(rgd, ip);
1244
1245         gfs2_final_release_pages(ip);
1246
1247         gfs2_trans_end(sdp);
1248
1249 out_rg_gunlock:
1250         gfs2_glock_dq_uninit(&gh);
1251 out_qs:
1252         gfs2_quota_unhold(ip);
1253         return error;
1254 }
1255
1256 /**
1257  * gfs2_glock_put_eventually
1258  * @gl: The glock to put
1259  *
1260  * When under memory pressure, trigger a deferred glock put to make sure we
1261  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1262  */
1263
1264 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1265 {
1266         if (current->flags & PF_MEMALLOC)
1267                 gfs2_glock_queue_put(gl);
1268         else
1269                 gfs2_glock_put(gl);
1270 }
1271
1272 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1273 {
1274         struct gfs2_inode *ip = GFS2_I(inode);
1275         struct gfs2_sbd *sdp = GFS2_SB(inode);
1276         struct gfs2_holder *gh = &ip->i_iopen_gh;
1277         long timeout = 5 * HZ;
1278         int error;
1279
1280         gh->gh_flags |= GL_NOCACHE;
1281         gfs2_glock_dq_wait(gh);
1282
1283         /*
1284          * If there are no other lock holders, we'll get the lock immediately.
1285          * Otherwise, the other nodes holding the lock will be notified about
1286          * our locking request.  If they don't have the inode open, they'll
1287          * evict the cached inode and release the lock.  Otherwise, if they
1288          * poke the inode glock, we'll take this as an indication that they
1289          * still need the iopen glock and that they'll take care of deleting
1290          * the inode when they're done.  As a last resort, if another node
1291          * keeps holding the iopen glock without showing any activity on the
1292          * inode glock, we'll eventually time out.
1293          *
1294          * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1295          * locking request as an optimization to notify lock holders as soon as
1296          * possible.  Without that flag, they'd be notified implicitly by the
1297          * second locking request.
1298          */
1299
1300         gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1301         error = gfs2_glock_nq(gh);
1302         if (error != GLR_TRYFAILED)
1303                 return !error;
1304
1305         gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1306         error = gfs2_glock_nq(gh);
1307         if (error)
1308                 return false;
1309
1310         timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1311                 !test_bit(HIF_WAIT, &gh->gh_iflags) ||
1312                 test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1313                 timeout);
1314         if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1315                 gfs2_glock_dq(gh);
1316                 return false;
1317         }
1318         return true;
1319 }
1320
1321 /**
1322  * evict_should_delete - determine whether the inode is eligible for deletion
1323  * @inode: The inode to evict
1324  *
1325  * This function determines whether the evicted inode is eligible to be deleted
1326  * and locks the inode glock.
1327  *
1328  * Returns: the fate of the dinode
1329  */
1330 static enum dinode_demise evict_should_delete(struct inode *inode,
1331                                               struct gfs2_holder *gh)
1332 {
1333         struct gfs2_inode *ip = GFS2_I(inode);
1334         struct super_block *sb = inode->i_sb;
1335         struct gfs2_sbd *sdp = sb->s_fs_info;
1336         int ret;
1337
1338         if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1339                 BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
1340                 goto should_delete;
1341         }
1342
1343         if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1344                 return SHOULD_DEFER_EVICTION;
1345
1346         /* Deletes should never happen under memory pressure anymore.  */
1347         if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1348                 return SHOULD_DEFER_EVICTION;
1349
1350         /* Must not read inode block until block type has been verified */
1351         ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1352         if (unlikely(ret)) {
1353                 glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1354                 ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1355                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1356                 return SHOULD_DEFER_EVICTION;
1357         }
1358
1359         if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1360                 return SHOULD_NOT_DELETE_DINODE;
1361         ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1362         if (ret)
1363                 return SHOULD_NOT_DELETE_DINODE;
1364
1365         if (test_bit(GIF_INVALID, &ip->i_flags)) {
1366                 ret = gfs2_inode_refresh(ip);
1367                 if (ret)
1368                         return SHOULD_NOT_DELETE_DINODE;
1369         }
1370
1371         /*
1372          * The inode may have been recreated in the meantime.
1373          */
1374         if (inode->i_nlink)
1375                 return SHOULD_NOT_DELETE_DINODE;
1376
1377 should_delete:
1378         if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1379             test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1380                 if (!gfs2_upgrade_iopen_glock(inode)) {
1381                         gfs2_holder_uninit(&ip->i_iopen_gh);
1382                         return SHOULD_NOT_DELETE_DINODE;
1383                 }
1384         }
1385         return SHOULD_DELETE_DINODE;
1386 }
1387
1388 /**
1389  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1390  * @inode: The inode to evict
1391  */
1392 static int evict_unlinked_inode(struct inode *inode)
1393 {
1394         struct gfs2_inode *ip = GFS2_I(inode);
1395         int ret;
1396
1397         if (S_ISDIR(inode->i_mode) &&
1398             (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1399                 ret = gfs2_dir_exhash_dealloc(ip);
1400                 if (ret)
1401                         goto out;
1402         }
1403
1404         if (ip->i_eattr) {
1405                 ret = gfs2_ea_dealloc(ip);
1406                 if (ret)
1407                         goto out;
1408         }
1409
1410         if (!gfs2_is_stuffed(ip)) {
1411                 ret = gfs2_file_dealloc(ip);
1412                 if (ret)
1413                         goto out;
1414         }
1415
1416         /* We're about to clear the bitmap for the dinode, but as soon as we
1417            do, gfs2_create_inode can create another inode at the same block
1418            location and try to set gl_object again. We clear gl_object here so
1419            that subsequent inode creates don't see an old gl_object. */
1420         glock_clear_object(ip->i_gl, ip);
1421         ret = gfs2_dinode_dealloc(ip);
1422         gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1423 out:
1424         return ret;
1425 }
1426
1427 /*
1428  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1429  * @inode: The inode to evict
1430  */
1431 static int evict_linked_inode(struct inode *inode)
1432 {
1433         struct super_block *sb = inode->i_sb;
1434         struct gfs2_sbd *sdp = sb->s_fs_info;
1435         struct gfs2_inode *ip = GFS2_I(inode);
1436         struct address_space *metamapping;
1437         int ret;
1438
1439         gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1440                        GFS2_LFC_EVICT_INODE);
1441         metamapping = gfs2_glock2aspace(ip->i_gl);
1442         if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1443                 filemap_fdatawrite(metamapping);
1444                 filemap_fdatawait(metamapping);
1445         }
1446         write_inode_now(inode, 1);
1447         gfs2_ail_flush(ip->i_gl, 0);
1448
1449         ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1450         if (ret)
1451                 return ret;
1452
1453         /* Needs to be done before glock release & also in a transaction */
1454         truncate_inode_pages(&inode->i_data, 0);
1455         truncate_inode_pages(metamapping, 0);
1456         gfs2_trans_end(sdp);
1457         return 0;
1458 }
1459
1460 /**
1461  * gfs2_evict_inode - Remove an inode from cache
1462  * @inode: The inode to evict
1463  *
1464  * There are three cases to consider:
1465  * 1. i_nlink == 0, we are final opener (and must deallocate)
1466  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1467  * 3. i_nlink > 0
1468  *
1469  * If the fs is read only, then we have to treat all cases as per #3
1470  * since we are unable to do any deallocation. The inode will be
1471  * deallocated by the next read/write node to attempt an allocation
1472  * in the same resource group
1473  *
1474  * We have to (at the moment) hold the inodes main lock to cover
1475  * the gap between unlocking the shared lock on the iopen lock and
1476  * taking the exclusive lock. I'd rather do a shared -> exclusive
1477  * conversion on the iopen lock, but we can change that later. This
1478  * is safe, just less efficient.
1479  */
1480
1481 static void gfs2_evict_inode(struct inode *inode)
1482 {
1483         struct super_block *sb = inode->i_sb;
1484         struct gfs2_sbd *sdp = sb->s_fs_info;
1485         struct gfs2_inode *ip = GFS2_I(inode);
1486         struct gfs2_holder gh;
1487         int ret;
1488
1489         if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1490                 clear_inode(inode);
1491                 return;
1492         }
1493
1494         if (inode->i_nlink || sb_rdonly(sb))
1495                 goto out;
1496
1497         gfs2_holder_mark_uninitialized(&gh);
1498         ret = evict_should_delete(inode, &gh);
1499         if (ret == SHOULD_DEFER_EVICTION)
1500                 goto out;
1501         if (ret == SHOULD_DELETE_DINODE)
1502                 ret = evict_unlinked_inode(inode);
1503         else
1504                 ret = evict_linked_inode(inode);
1505
1506         if (gfs2_rs_active(&ip->i_res))
1507                 gfs2_rs_deltree(&ip->i_res);
1508
1509         if (gfs2_holder_initialized(&gh)) {
1510                 glock_clear_object(ip->i_gl, ip);
1511                 gfs2_glock_dq_uninit(&gh);
1512         }
1513         if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1514                 fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1515 out:
1516         truncate_inode_pages_final(&inode->i_data);
1517         if (ip->i_qadata)
1518                 gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1519         gfs2_rs_delete(ip, NULL);
1520         gfs2_ordered_del_inode(ip);
1521         clear_inode(inode);
1522         gfs2_dir_hash_inval(ip);
1523         if (ip->i_gl) {
1524                 glock_clear_object(ip->i_gl, ip);
1525                 wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1526                 gfs2_glock_add_to_lru(ip->i_gl);
1527                 gfs2_glock_put_eventually(ip->i_gl);
1528                 ip->i_gl = NULL;
1529         }
1530         if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1531                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1532
1533                 glock_clear_object(gl, ip);
1534                 if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1535                         ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1536                         gfs2_glock_dq(&ip->i_iopen_gh);
1537                 }
1538                 gfs2_glock_hold(gl);
1539                 gfs2_holder_uninit(&ip->i_iopen_gh);
1540                 gfs2_glock_put_eventually(gl);
1541         }
1542 }
1543
1544 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1545 {
1546         struct gfs2_inode *ip;
1547
1548         ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1549         if (!ip)
1550                 return NULL;
1551         ip->i_flags = 0;
1552         ip->i_gl = NULL;
1553         gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1554         memset(&ip->i_res, 0, sizeof(ip->i_res));
1555         RB_CLEAR_NODE(&ip->i_res.rs_node);
1556         ip->i_rahead = 0;
1557         return &ip->i_inode;
1558 }
1559
1560 static void gfs2_free_inode(struct inode *inode)
1561 {
1562         kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1563 }
1564
1565 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1566 {
1567         struct local_statfs_inode *lsi, *safe;
1568
1569         /* Run through the statfs inodes list to iput and free memory */
1570         list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1571                 if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1572                         sdp->sd_sc_inode = NULL; /* belongs to this node */
1573                 if (lsi->si_sc_inode)
1574                         iput(lsi->si_sc_inode);
1575                 list_del(&lsi->si_list);
1576                 kfree(lsi);
1577         }
1578 }
1579
1580 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1581                                              unsigned int index)
1582 {
1583         struct local_statfs_inode *lsi;
1584
1585         /* Return the local (per node) statfs inode in the
1586          * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1587         list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1588                 if (lsi->si_jid == index)
1589                         return lsi->si_sc_inode;
1590         }
1591         return NULL;
1592 }
1593
1594 const struct super_operations gfs2_super_ops = {
1595         .alloc_inode            = gfs2_alloc_inode,
1596         .free_inode             = gfs2_free_inode,
1597         .write_inode            = gfs2_write_inode,
1598         .dirty_inode            = gfs2_dirty_inode,
1599         .evict_inode            = gfs2_evict_inode,
1600         .put_super              = gfs2_put_super,
1601         .sync_fs                = gfs2_sync_fs,
1602         .freeze_super           = gfs2_freeze,
1603         .thaw_super             = gfs2_unfreeze,
1604         .statfs                 = gfs2_statfs,
1605         .drop_inode             = gfs2_drop_inode,
1606         .show_options           = gfs2_show_options,
1607 };
1608