EDAC/igen6: ecclog_llist can be static
[sfrench/cifs-2.6.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         gfs2_delete_debugfs_file(sdp);
742         /*  Unmount the locking protocol  */
743         gfs2_lm_unmount(sdp);
744
745         /*  At this point, we're through participating in the lockspace  */
746         gfs2_sys_fs_del(sdp);
747         free_sbd(sdp);
748 }
749
750 /**
751  * gfs2_sync_fs - sync the filesystem
752  * @sb: the superblock
753  *
754  * Flushes the log to disk.
755  */
756
757 static int gfs2_sync_fs(struct super_block *sb, int wait)
758 {
759         struct gfs2_sbd *sdp = sb->s_fs_info;
760
761         gfs2_quota_sync(sb, -1);
762         if (wait)
763                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
764                                GFS2_LFC_SYNC_FS);
765         return sdp->sd_log_error;
766 }
767
768 void gfs2_freeze_func(struct work_struct *work)
769 {
770         int error;
771         struct gfs2_holder freeze_gh;
772         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
773         struct super_block *sb = sdp->sd_vfs;
774
775         atomic_inc(&sb->s_active);
776         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
777                                    LM_FLAG_NOEXP | GL_EXACT, &freeze_gh);
778         if (error) {
779                 fs_info(sdp, "GFS2: couldn't get freeze lock : %d\n", error);
780                 gfs2_assert_withdraw(sdp, 0);
781         } else {
782                 atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
783                 error = thaw_super(sb);
784                 if (error) {
785                         fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
786                                 error);
787                         gfs2_assert_withdraw(sdp, 0);
788                 }
789                 gfs2_glock_dq_uninit(&freeze_gh);
790         }
791         deactivate_super(sb);
792         clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
793         wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
794         return;
795 }
796
797 /**
798  * gfs2_freeze - prevent further writes to the filesystem
799  * @sb: the VFS structure for the filesystem
800  *
801  */
802
803 static int gfs2_freeze(struct super_block *sb)
804 {
805         struct gfs2_sbd *sdp = sb->s_fs_info;
806         int error = 0;
807
808         mutex_lock(&sdp->sd_freeze_mutex);
809         if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN)
810                 goto out;
811
812         for (;;) {
813                 if (gfs2_withdrawn(sdp)) {
814                         error = -EINVAL;
815                         goto out;
816                 }
817
818                 error = gfs2_lock_fs_check_clean(sdp);
819                 if (!error)
820                         break;
821
822                 if (error == -EBUSY)
823                         fs_err(sdp, "waiting for recovery before freeze\n");
824                 else if (error == -EIO) {
825                         fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
826                                "to recovery error.\n");
827                         goto out;
828                 } else {
829                         fs_err(sdp, "error freezing FS: %d\n", error);
830                 }
831                 fs_err(sdp, "retrying...\n");
832                 msleep(1000);
833         }
834         set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
835 out:
836         mutex_unlock(&sdp->sd_freeze_mutex);
837         return error;
838 }
839
840 /**
841  * gfs2_unfreeze - reallow writes to the filesystem
842  * @sb: the VFS structure for the filesystem
843  *
844  */
845
846 static int gfs2_unfreeze(struct super_block *sb)
847 {
848         struct gfs2_sbd *sdp = sb->s_fs_info;
849
850         mutex_lock(&sdp->sd_freeze_mutex);
851         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
852             !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
853                 mutex_unlock(&sdp->sd_freeze_mutex);
854                 return 0;
855         }
856
857         gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
858         mutex_unlock(&sdp->sd_freeze_mutex);
859         return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
860 }
861
862 /**
863  * statfs_fill - fill in the sg for a given RG
864  * @rgd: the RG
865  * @sc: the sc structure
866  *
867  * Returns: 0 on success, -ESTALE if the LVB is invalid
868  */
869
870 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
871                             struct gfs2_statfs_change_host *sc)
872 {
873         gfs2_rgrp_verify(rgd);
874         sc->sc_total += rgd->rd_data;
875         sc->sc_free += rgd->rd_free;
876         sc->sc_dinodes += rgd->rd_dinodes;
877         return 0;
878 }
879
880 /**
881  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
882  * @sdp: the filesystem
883  * @sc: the sc info that will be returned
884  *
885  * Any error (other than a signal) will cause this routine to fall back
886  * to the synchronous version.
887  *
888  * FIXME: This really shouldn't busy wait like this.
889  *
890  * Returns: errno
891  */
892
893 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
894 {
895         struct gfs2_rgrpd *rgd_next;
896         struct gfs2_holder *gha, *gh;
897         unsigned int slots = 64;
898         unsigned int x;
899         int done;
900         int error = 0, err;
901
902         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
903         gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
904         if (!gha)
905                 return -ENOMEM;
906         for (x = 0; x < slots; x++)
907                 gfs2_holder_mark_uninitialized(gha + x);
908
909         rgd_next = gfs2_rgrpd_get_first(sdp);
910
911         for (;;) {
912                 done = 1;
913
914                 for (x = 0; x < slots; x++) {
915                         gh = gha + x;
916
917                         if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
918                                 err = gfs2_glock_wait(gh);
919                                 if (err) {
920                                         gfs2_holder_uninit(gh);
921                                         error = err;
922                                 } else {
923                                         if (!error) {
924                                                 struct gfs2_rgrpd *rgd =
925                                                         gfs2_glock2rgrp(gh->gh_gl);
926
927                                                 error = statfs_slow_fill(rgd, sc);
928                                         }
929                                         gfs2_glock_dq_uninit(gh);
930                                 }
931                         }
932
933                         if (gfs2_holder_initialized(gh))
934                                 done = 0;
935                         else if (rgd_next && !error) {
936                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
937                                                            LM_ST_SHARED,
938                                                            GL_ASYNC,
939                                                            gh);
940                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
941                                 done = 0;
942                         }
943
944                         if (signal_pending(current))
945                                 error = -ERESTARTSYS;
946                 }
947
948                 if (done)
949                         break;
950
951                 yield();
952         }
953
954         kfree(gha);
955         return error;
956 }
957
958 /**
959  * gfs2_statfs_i - Do a statfs
960  * @sdp: the filesystem
961  * @sg: the sg structure
962  *
963  * Returns: errno
964  */
965
966 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
967 {
968         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
969         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
970
971         spin_lock(&sdp->sd_statfs_spin);
972
973         *sc = *m_sc;
974         sc->sc_total += l_sc->sc_total;
975         sc->sc_free += l_sc->sc_free;
976         sc->sc_dinodes += l_sc->sc_dinodes;
977
978         spin_unlock(&sdp->sd_statfs_spin);
979
980         if (sc->sc_free < 0)
981                 sc->sc_free = 0;
982         if (sc->sc_free > sc->sc_total)
983                 sc->sc_free = sc->sc_total;
984         if (sc->sc_dinodes < 0)
985                 sc->sc_dinodes = 0;
986
987         return 0;
988 }
989
990 /**
991  * gfs2_statfs - Gather and return stats about the filesystem
992  * @sb: The superblock
993  * @statfsbuf: The buffer
994  *
995  * Returns: 0 on success or error code
996  */
997
998 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
999 {
1000         struct super_block *sb = dentry->d_sb;
1001         struct gfs2_sbd *sdp = sb->s_fs_info;
1002         struct gfs2_statfs_change_host sc;
1003         int error;
1004
1005         error = gfs2_rindex_update(sdp);
1006         if (error)
1007                 return error;
1008
1009         if (gfs2_tune_get(sdp, gt_statfs_slow))
1010                 error = gfs2_statfs_slow(sdp, &sc);
1011         else
1012                 error = gfs2_statfs_i(sdp, &sc);
1013
1014         if (error)
1015                 return error;
1016
1017         buf->f_type = GFS2_MAGIC;
1018         buf->f_bsize = sdp->sd_sb.sb_bsize;
1019         buf->f_blocks = sc.sc_total;
1020         buf->f_bfree = sc.sc_free;
1021         buf->f_bavail = sc.sc_free;
1022         buf->f_files = sc.sc_dinodes + sc.sc_free;
1023         buf->f_ffree = sc.sc_free;
1024         buf->f_namelen = GFS2_FNAMESIZE;
1025
1026         return 0;
1027 }
1028
1029 /**
1030  * gfs2_drop_inode - Drop an inode (test for remote unlink)
1031  * @inode: The inode to drop
1032  *
1033  * If we've received a callback on an iopen lock then it's because a
1034  * remote node tried to deallocate the inode but failed due to this node
1035  * still having the inode open. Here we mark the link count zero
1036  * since we know that it must have reached zero if the GLF_DEMOTE flag
1037  * is set on the iopen glock. If we didn't do a disk read since the
1038  * remote node removed the final link then we might otherwise miss
1039  * this event. This check ensures that this node will deallocate the
1040  * inode's blocks, or alternatively pass the baton on to another
1041  * node for later deallocation.
1042  */
1043
1044 static int gfs2_drop_inode(struct inode *inode)
1045 {
1046         struct gfs2_inode *ip = GFS2_I(inode);
1047
1048         if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) &&
1049             inode->i_nlink &&
1050             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1051                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1052                 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
1053                         clear_nlink(inode);
1054         }
1055
1056         /*
1057          * When under memory pressure when an inode's link count has dropped to
1058          * zero, defer deleting the inode to the delete workqueue.  This avoids
1059          * calling into DLM under memory pressure, which can deadlock.
1060          */
1061         if (!inode->i_nlink &&
1062             unlikely(current->flags & PF_MEMALLOC) &&
1063             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1064                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1065
1066                 gfs2_glock_hold(gl);
1067                 if (!gfs2_queue_delete_work(gl, 0))
1068                         gfs2_glock_queue_put(gl);
1069                 return false;
1070         }
1071
1072         return generic_drop_inode(inode);
1073 }
1074
1075 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1076 {
1077         do {
1078                 if (d1 == d2)
1079                         return 1;
1080                 d1 = d1->d_parent;
1081         } while (!IS_ROOT(d1));
1082         return 0;
1083 }
1084
1085 /**
1086  * gfs2_show_options - Show mount options for /proc/mounts
1087  * @s: seq_file structure
1088  * @root: root of this (sub)tree
1089  *
1090  * Returns: 0 on success or error code
1091  */
1092
1093 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1094 {
1095         struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1096         struct gfs2_args *args = &sdp->sd_args;
1097         int val;
1098
1099         if (is_ancestor(root, sdp->sd_master_dir))
1100                 seq_puts(s, ",meta");
1101         if (args->ar_lockproto[0])
1102                 seq_show_option(s, "lockproto", args->ar_lockproto);
1103         if (args->ar_locktable[0])
1104                 seq_show_option(s, "locktable", args->ar_locktable);
1105         if (args->ar_hostdata[0])
1106                 seq_show_option(s, "hostdata", args->ar_hostdata);
1107         if (args->ar_spectator)
1108                 seq_puts(s, ",spectator");
1109         if (args->ar_localflocks)
1110                 seq_puts(s, ",localflocks");
1111         if (args->ar_debug)
1112                 seq_puts(s, ",debug");
1113         if (args->ar_posix_acl)
1114                 seq_puts(s, ",acl");
1115         if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1116                 char *state;
1117                 switch (args->ar_quota) {
1118                 case GFS2_QUOTA_OFF:
1119                         state = "off";
1120                         break;
1121                 case GFS2_QUOTA_ACCOUNT:
1122                         state = "account";
1123                         break;
1124                 case GFS2_QUOTA_ON:
1125                         state = "on";
1126                         break;
1127                 default:
1128                         state = "unknown";
1129                         break;
1130                 }
1131                 seq_printf(s, ",quota=%s", state);
1132         }
1133         if (args->ar_suiddir)
1134                 seq_puts(s, ",suiddir");
1135         if (args->ar_data != GFS2_DATA_DEFAULT) {
1136                 char *state;
1137                 switch (args->ar_data) {
1138                 case GFS2_DATA_WRITEBACK:
1139                         state = "writeback";
1140                         break;
1141                 case GFS2_DATA_ORDERED:
1142                         state = "ordered";
1143                         break;
1144                 default:
1145                         state = "unknown";
1146                         break;
1147                 }
1148                 seq_printf(s, ",data=%s", state);
1149         }
1150         if (args->ar_discard)
1151                 seq_puts(s, ",discard");
1152         val = sdp->sd_tune.gt_logd_secs;
1153         if (val != 30)
1154                 seq_printf(s, ",commit=%d", val);
1155         val = sdp->sd_tune.gt_statfs_quantum;
1156         if (val != 30)
1157                 seq_printf(s, ",statfs_quantum=%d", val);
1158         else if (sdp->sd_tune.gt_statfs_slow)
1159                 seq_puts(s, ",statfs_quantum=0");
1160         val = sdp->sd_tune.gt_quota_quantum;
1161         if (val != 60)
1162                 seq_printf(s, ",quota_quantum=%d", val);
1163         if (args->ar_statfs_percent)
1164                 seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1165         if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1166                 const char *state;
1167
1168                 switch (args->ar_errors) {
1169                 case GFS2_ERRORS_WITHDRAW:
1170                         state = "withdraw";
1171                         break;
1172                 case GFS2_ERRORS_PANIC:
1173                         state = "panic";
1174                         break;
1175                 default:
1176                         state = "unknown";
1177                         break;
1178                 }
1179                 seq_printf(s, ",errors=%s", state);
1180         }
1181         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1182                 seq_puts(s, ",nobarrier");
1183         if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1184                 seq_puts(s, ",demote_interface_used");
1185         if (args->ar_rgrplvb)
1186                 seq_puts(s, ",rgrplvb");
1187         if (args->ar_loccookie)
1188                 seq_puts(s, ",loccookie");
1189         return 0;
1190 }
1191
1192 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1193 {
1194         struct inode *inode = &ip->i_inode;
1195         struct gfs2_glock *gl = ip->i_gl;
1196
1197         truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1198         truncate_inode_pages(&inode->i_data, 0);
1199
1200         if (atomic_read(&gl->gl_revokes) == 0) {
1201                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
1202                 clear_bit(GLF_DIRTY, &gl->gl_flags);
1203         }
1204 }
1205
1206 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1207 {
1208         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1209         struct gfs2_rgrpd *rgd;
1210         struct gfs2_holder gh;
1211         int error;
1212
1213         if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1214                 gfs2_consist_inode(ip);
1215                 return -EIO;
1216         }
1217
1218         error = gfs2_rindex_update(sdp);
1219         if (error)
1220                 return error;
1221
1222         error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1223         if (error)
1224                 return error;
1225
1226         rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1227         if (!rgd) {
1228                 gfs2_consist_inode(ip);
1229                 error = -EIO;
1230                 goto out_qs;
1231         }
1232
1233         error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
1234         if (error)
1235                 goto out_qs;
1236
1237         error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1238                                  sdp->sd_jdesc->jd_blocks);
1239         if (error)
1240                 goto out_rg_gunlock;
1241
1242         gfs2_free_di(rgd, ip);
1243
1244         gfs2_final_release_pages(ip);
1245
1246         gfs2_trans_end(sdp);
1247
1248 out_rg_gunlock:
1249         gfs2_glock_dq_uninit(&gh);
1250 out_qs:
1251         gfs2_quota_unhold(ip);
1252         return error;
1253 }
1254
1255 /**
1256  * gfs2_glock_put_eventually
1257  * @gl: The glock to put
1258  *
1259  * When under memory pressure, trigger a deferred glock put to make sure we
1260  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1261  */
1262
1263 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1264 {
1265         if (current->flags & PF_MEMALLOC)
1266                 gfs2_glock_queue_put(gl);
1267         else
1268                 gfs2_glock_put(gl);
1269 }
1270
1271 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1272 {
1273         struct gfs2_inode *ip = GFS2_I(inode);
1274         struct gfs2_sbd *sdp = GFS2_SB(inode);
1275         struct gfs2_holder *gh = &ip->i_iopen_gh;
1276         long timeout = 5 * HZ;
1277         int error;
1278
1279         gh->gh_flags |= GL_NOCACHE;
1280         gfs2_glock_dq_wait(gh);
1281
1282         /*
1283          * If there are no other lock holders, we'll get the lock immediately.
1284          * Otherwise, the other nodes holding the lock will be notified about
1285          * our locking request.  If they don't have the inode open, they'll
1286          * evict the cached inode and release the lock.  Otherwise, if they
1287          * poke the inode glock, we'll take this as an indication that they
1288          * still need the iopen glock and that they'll take care of deleting
1289          * the inode when they're done.  As a last resort, if another node
1290          * keeps holding the iopen glock without showing any activity on the
1291          * inode glock, we'll eventually time out.
1292          *
1293          * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1294          * locking request as an optimization to notify lock holders as soon as
1295          * possible.  Without that flag, they'd be notified implicitly by the
1296          * second locking request.
1297          */
1298
1299         gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1300         error = gfs2_glock_nq(gh);
1301         if (error != GLR_TRYFAILED)
1302                 return !error;
1303
1304         gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1305         error = gfs2_glock_nq(gh);
1306         if (error)
1307                 return false;
1308
1309         timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1310                 !test_bit(HIF_WAIT, &gh->gh_iflags) ||
1311                 test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1312                 timeout);
1313         if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1314                 gfs2_glock_dq(gh);
1315                 return false;
1316         }
1317         return true;
1318 }
1319
1320 /**
1321  * evict_should_delete - determine whether the inode is eligible for deletion
1322  * @inode: The inode to evict
1323  *
1324  * This function determines whether the evicted inode is eligible to be deleted
1325  * and locks the inode glock.
1326  *
1327  * Returns: the fate of the dinode
1328  */
1329 static enum dinode_demise evict_should_delete(struct inode *inode,
1330                                               struct gfs2_holder *gh)
1331 {
1332         struct gfs2_inode *ip = GFS2_I(inode);
1333         struct super_block *sb = inode->i_sb;
1334         struct gfs2_sbd *sdp = sb->s_fs_info;
1335         int ret;
1336
1337         if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1338                 BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
1339                 goto should_delete;
1340         }
1341
1342         if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1343                 return SHOULD_DEFER_EVICTION;
1344
1345         /* Deletes should never happen under memory pressure anymore.  */
1346         if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1347                 return SHOULD_DEFER_EVICTION;
1348
1349         /* Must not read inode block until block type has been verified */
1350         ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1351         if (unlikely(ret)) {
1352                 glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1353                 ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1354                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1355                 return SHOULD_DEFER_EVICTION;
1356         }
1357
1358         if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1359                 return SHOULD_NOT_DELETE_DINODE;
1360         ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1361         if (ret)
1362                 return SHOULD_NOT_DELETE_DINODE;
1363
1364         if (test_bit(GIF_INVALID, &ip->i_flags)) {
1365                 ret = gfs2_inode_refresh(ip);
1366                 if (ret)
1367                         return SHOULD_NOT_DELETE_DINODE;
1368         }
1369
1370         /*
1371          * The inode may have been recreated in the meantime.
1372          */
1373         if (inode->i_nlink)
1374                 return SHOULD_NOT_DELETE_DINODE;
1375
1376 should_delete:
1377         if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1378             test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1379                 if (!gfs2_upgrade_iopen_glock(inode)) {
1380                         gfs2_holder_uninit(&ip->i_iopen_gh);
1381                         return SHOULD_NOT_DELETE_DINODE;
1382                 }
1383         }
1384         return SHOULD_DELETE_DINODE;
1385 }
1386
1387 /**
1388  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1389  * @inode: The inode to evict
1390  */
1391 static int evict_unlinked_inode(struct inode *inode)
1392 {
1393         struct gfs2_inode *ip = GFS2_I(inode);
1394         int ret;
1395
1396         if (S_ISDIR(inode->i_mode) &&
1397             (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1398                 ret = gfs2_dir_exhash_dealloc(ip);
1399                 if (ret)
1400                         goto out;
1401         }
1402
1403         if (ip->i_eattr) {
1404                 ret = gfs2_ea_dealloc(ip);
1405                 if (ret)
1406                         goto out;
1407         }
1408
1409         if (!gfs2_is_stuffed(ip)) {
1410                 ret = gfs2_file_dealloc(ip);
1411                 if (ret)
1412                         goto out;
1413         }
1414
1415         /* We're about to clear the bitmap for the dinode, but as soon as we
1416            do, gfs2_create_inode can create another inode at the same block
1417            location and try to set gl_object again. We clear gl_object here so
1418            that subsequent inode creates don't see an old gl_object. */
1419         glock_clear_object(ip->i_gl, ip);
1420         ret = gfs2_dinode_dealloc(ip);
1421         gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1422 out:
1423         return ret;
1424 }
1425
1426 /*
1427  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1428  * @inode: The inode to evict
1429  */
1430 static int evict_linked_inode(struct inode *inode)
1431 {
1432         struct super_block *sb = inode->i_sb;
1433         struct gfs2_sbd *sdp = sb->s_fs_info;
1434         struct gfs2_inode *ip = GFS2_I(inode);
1435         struct address_space *metamapping;
1436         int ret;
1437
1438         gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1439                        GFS2_LFC_EVICT_INODE);
1440         metamapping = gfs2_glock2aspace(ip->i_gl);
1441         if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1442                 filemap_fdatawrite(metamapping);
1443                 filemap_fdatawait(metamapping);
1444         }
1445         write_inode_now(inode, 1);
1446         gfs2_ail_flush(ip->i_gl, 0);
1447
1448         ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1449         if (ret)
1450                 return ret;
1451
1452         /* Needs to be done before glock release & also in a transaction */
1453         truncate_inode_pages(&inode->i_data, 0);
1454         truncate_inode_pages(metamapping, 0);
1455         gfs2_trans_end(sdp);
1456         return 0;
1457 }
1458
1459 /**
1460  * gfs2_evict_inode - Remove an inode from cache
1461  * @inode: The inode to evict
1462  *
1463  * There are three cases to consider:
1464  * 1. i_nlink == 0, we are final opener (and must deallocate)
1465  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1466  * 3. i_nlink > 0
1467  *
1468  * If the fs is read only, then we have to treat all cases as per #3
1469  * since we are unable to do any deallocation. The inode will be
1470  * deallocated by the next read/write node to attempt an allocation
1471  * in the same resource group
1472  *
1473  * We have to (at the moment) hold the inodes main lock to cover
1474  * the gap between unlocking the shared lock on the iopen lock and
1475  * taking the exclusive lock. I'd rather do a shared -> exclusive
1476  * conversion on the iopen lock, but we can change that later. This
1477  * is safe, just less efficient.
1478  */
1479
1480 static void gfs2_evict_inode(struct inode *inode)
1481 {
1482         struct super_block *sb = inode->i_sb;
1483         struct gfs2_sbd *sdp = sb->s_fs_info;
1484         struct gfs2_inode *ip = GFS2_I(inode);
1485         struct gfs2_holder gh;
1486         int ret;
1487
1488         if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1489                 clear_inode(inode);
1490                 return;
1491         }
1492
1493         if (inode->i_nlink || sb_rdonly(sb))
1494                 goto out;
1495
1496         gfs2_holder_mark_uninitialized(&gh);
1497         ret = evict_should_delete(inode, &gh);
1498         if (ret == SHOULD_DEFER_EVICTION)
1499                 goto out;
1500         if (ret == SHOULD_DELETE_DINODE)
1501                 ret = evict_unlinked_inode(inode);
1502         else
1503                 ret = evict_linked_inode(inode);
1504
1505         if (gfs2_rs_active(&ip->i_res))
1506                 gfs2_rs_deltree(&ip->i_res);
1507
1508         if (gfs2_holder_initialized(&gh)) {
1509                 glock_clear_object(ip->i_gl, ip);
1510                 gfs2_glock_dq_uninit(&gh);
1511         }
1512         if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1513                 fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1514 out:
1515         truncate_inode_pages_final(&inode->i_data);
1516         if (ip->i_qadata)
1517                 gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1518         gfs2_rs_delete(ip, NULL);
1519         gfs2_ordered_del_inode(ip);
1520         clear_inode(inode);
1521         gfs2_dir_hash_inval(ip);
1522         if (ip->i_gl) {
1523                 glock_clear_object(ip->i_gl, ip);
1524                 wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1525                 gfs2_glock_add_to_lru(ip->i_gl);
1526                 gfs2_glock_put_eventually(ip->i_gl);
1527                 ip->i_gl = NULL;
1528         }
1529         if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1530                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1531
1532                 glock_clear_object(gl, ip);
1533                 if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1534                         ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1535                         gfs2_glock_dq(&ip->i_iopen_gh);
1536                 }
1537                 gfs2_glock_hold(gl);
1538                 gfs2_holder_uninit(&ip->i_iopen_gh);
1539                 gfs2_glock_put_eventually(gl);
1540         }
1541 }
1542
1543 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1544 {
1545         struct gfs2_inode *ip;
1546
1547         ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1548         if (!ip)
1549                 return NULL;
1550         ip->i_flags = 0;
1551         ip->i_gl = NULL;
1552         gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1553         memset(&ip->i_res, 0, sizeof(ip->i_res));
1554         RB_CLEAR_NODE(&ip->i_res.rs_node);
1555         ip->i_rahead = 0;
1556         return &ip->i_inode;
1557 }
1558
1559 static void gfs2_free_inode(struct inode *inode)
1560 {
1561         kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1562 }
1563
1564 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1565 {
1566         struct local_statfs_inode *lsi, *safe;
1567
1568         /* Run through the statfs inodes list to iput and free memory */
1569         list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1570                 if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1571                         sdp->sd_sc_inode = NULL; /* belongs to this node */
1572                 if (lsi->si_sc_inode)
1573                         iput(lsi->si_sc_inode);
1574                 list_del(&lsi->si_list);
1575                 kfree(lsi);
1576         }
1577 }
1578
1579 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1580                                              unsigned int index)
1581 {
1582         struct local_statfs_inode *lsi;
1583
1584         /* Return the local (per node) statfs inode in the
1585          * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1586         list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1587                 if (lsi->si_jid == index)
1588                         return lsi->si_sc_inode;
1589         }
1590         return NULL;
1591 }
1592
1593 const struct super_operations gfs2_super_ops = {
1594         .alloc_inode            = gfs2_alloc_inode,
1595         .free_inode             = gfs2_free_inode,
1596         .write_inode            = gfs2_write_inode,
1597         .dirty_inode            = gfs2_dirty_inode,
1598         .evict_inode            = gfs2_evict_inode,
1599         .put_super              = gfs2_put_super,
1600         .sync_fs                = gfs2_sync_fs,
1601         .freeze_super           = gfs2_freeze,
1602         .thaw_super             = gfs2_unfreeze,
1603         .statfs                 = gfs2_statfs,
1604         .drop_inode             = gfs2_drop_inode,
1605         .show_options           = gfs2_show_options,
1606 };
1607