Merge tag 'gfs2-for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux...
[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         error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
357                                    &gh);
358         if (error)
359                 goto out;
360
361         error = gfs2_meta_inode_buffer(m_ip, &m_bh);
362         if (error)
363                 goto out_unlock;
364
365         spin_lock(&sdp->sd_statfs_spin);
366         gfs2_statfs_change_in(m_sc, m_bh->b_data +
367                               sizeof(struct gfs2_dinode));
368         if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
369                 spin_unlock(&sdp->sd_statfs_spin);
370                 goto out_bh;
371         }
372         spin_unlock(&sdp->sd_statfs_spin);
373
374         error = gfs2_meta_inode_buffer(l_ip, &l_bh);
375         if (error)
376                 goto out_bh;
377
378         error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
379         if (error)
380                 goto out_bh2;
381
382         update_statfs(sdp, m_bh, l_bh);
383         sdp->sd_statfs_force_sync = 0;
384
385         gfs2_trans_end(sdp);
386
387 out_bh2:
388         brelse(l_bh);
389 out_bh:
390         brelse(m_bh);
391 out_unlock:
392         gfs2_glock_dq_uninit(&gh);
393 out:
394         return error;
395 }
396
397 struct lfcc {
398         struct list_head list;
399         struct gfs2_holder gh;
400 };
401
402 /**
403  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
404  *                            journals are clean
405  * @sdp: the file system
406  * @state: the state to put the transaction lock into
407  * @t_gh: the hold on the transaction lock
408  *
409  * Returns: errno
410  */
411
412 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp)
413 {
414         struct gfs2_inode *ip;
415         struct gfs2_jdesc *jd;
416         struct lfcc *lfcc;
417         LIST_HEAD(list);
418         struct gfs2_log_header_host lh;
419         int error;
420
421         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
422                 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
423                 if (!lfcc) {
424                         error = -ENOMEM;
425                         goto out;
426                 }
427                 ip = GFS2_I(jd->jd_inode);
428                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
429                 if (error) {
430                         kfree(lfcc);
431                         goto out;
432                 }
433                 list_add(&lfcc->list, &list);
434         }
435
436         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
437                                    LM_FLAG_NOEXP, &sdp->sd_freeze_gh);
438         if (error)
439                 goto out;
440
441         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
442                 error = gfs2_jdesc_check(jd);
443                 if (error)
444                         break;
445                 error = gfs2_find_jhead(jd, &lh, false);
446                 if (error)
447                         break;
448                 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
449                         error = -EBUSY;
450                         break;
451                 }
452         }
453
454         if (error)
455                 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
456
457 out:
458         while (!list_empty(&list)) {
459                 lfcc = list_first_entry(&list, struct lfcc, list);
460                 list_del(&lfcc->list);
461                 gfs2_glock_dq_uninit(&lfcc->gh);
462                 kfree(lfcc);
463         }
464         return error;
465 }
466
467 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
468 {
469         struct gfs2_dinode *str = buf;
470
471         str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
472         str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
473         str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
474         str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
475         str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
476         str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
477         str->di_uid = cpu_to_be32(i_uid_read(&ip->i_inode));
478         str->di_gid = cpu_to_be32(i_gid_read(&ip->i_inode));
479         str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
480         str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
481         str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
482         str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
483         str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
484         str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
485
486         str->di_goal_meta = cpu_to_be64(ip->i_goal);
487         str->di_goal_data = cpu_to_be64(ip->i_goal);
488         str->di_generation = cpu_to_be64(ip->i_generation);
489
490         str->di_flags = cpu_to_be32(ip->i_diskflags);
491         str->di_height = cpu_to_be16(ip->i_height);
492         str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
493                                              !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
494                                              GFS2_FORMAT_DE : 0);
495         str->di_depth = cpu_to_be16(ip->i_depth);
496         str->di_entries = cpu_to_be32(ip->i_entries);
497
498         str->di_eattr = cpu_to_be64(ip->i_eattr);
499         str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
500         str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
501         str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
502 }
503
504 /**
505  * gfs2_write_inode - Make sure the inode is stable on the disk
506  * @inode: The inode
507  * @wbc: The writeback control structure
508  *
509  * Returns: errno
510  */
511
512 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
513 {
514         struct gfs2_inode *ip = GFS2_I(inode);
515         struct gfs2_sbd *sdp = GFS2_SB(inode);
516         struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
517         struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
518         int ret = 0;
519         bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
520
521         if (flush_all)
522                 gfs2_log_flush(GFS2_SB(inode), ip->i_gl,
523                                GFS2_LOG_HEAD_FLUSH_NORMAL |
524                                GFS2_LFC_WRITE_INODE);
525         if (bdi->wb.dirty_exceeded)
526                 gfs2_ail1_flush(sdp, wbc);
527         else
528                 filemap_fdatawrite(metamapping);
529         if (flush_all)
530                 ret = filemap_fdatawait(metamapping);
531         if (ret)
532                 mark_inode_dirty_sync(inode);
533         else {
534                 spin_lock(&inode->i_lock);
535                 if (!(inode->i_flags & I_DIRTY))
536                         gfs2_ordered_del_inode(ip);
537                 spin_unlock(&inode->i_lock);
538         }
539         return ret;
540 }
541
542 /**
543  * gfs2_dirty_inode - check for atime updates
544  * @inode: The inode in question
545  * @flags: The type of dirty
546  *
547  * Unfortunately it can be called under any combination of inode
548  * glock and transaction lock, so we have to check carefully.
549  *
550  * At the moment this deals only with atime - it should be possible
551  * to expand that role in future, once a review of the locking has
552  * been carried out.
553  */
554
555 static void gfs2_dirty_inode(struct inode *inode, int flags)
556 {
557         struct gfs2_inode *ip = GFS2_I(inode);
558         struct gfs2_sbd *sdp = GFS2_SB(inode);
559         struct buffer_head *bh;
560         struct gfs2_holder gh;
561         int need_unlock = 0;
562         int need_endtrans = 0;
563         int ret;
564
565         if (!(flags & I_DIRTY_INODE))
566                 return;
567         if (unlikely(gfs2_withdrawn(sdp)))
568                 return;
569         if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
570                 ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
571                 if (ret) {
572                         fs_err(sdp, "dirty_inode: glock %d\n", ret);
573                         gfs2_dump_glock(NULL, ip->i_gl, true);
574                         return;
575                 }
576                 need_unlock = 1;
577         } else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
578                 return;
579
580         if (current->journal_info == NULL) {
581                 ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
582                 if (ret) {
583                         fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
584                         goto out;
585                 }
586                 need_endtrans = 1;
587         }
588
589         ret = gfs2_meta_inode_buffer(ip, &bh);
590         if (ret == 0) {
591                 gfs2_trans_add_meta(ip->i_gl, bh);
592                 gfs2_dinode_out(ip, bh->b_data);
593                 brelse(bh);
594         }
595
596         if (need_endtrans)
597                 gfs2_trans_end(sdp);
598 out:
599         if (need_unlock)
600                 gfs2_glock_dq_uninit(&gh);
601 }
602
603 /**
604  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
605  * @sdp: the filesystem
606  *
607  * Returns: errno
608  */
609
610 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
611 {
612         struct gfs2_holder freeze_gh;
613         int error = 0;
614         int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
615
616         gfs2_holder_mark_uninitialized(&freeze_gh);
617         if (sdp->sd_freeze_gl &&
618             !gfs2_glock_is_locked_by_me(sdp->sd_freeze_gl)) {
619                 if (!log_write_allowed) {
620                         error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
621                                                    LM_ST_SHARED, LM_FLAG_TRY |
622                                                    LM_FLAG_NOEXP | GL_EXACT,
623                                                    &freeze_gh);
624                         if (error == GLR_TRYFAILED)
625                                 error = 0;
626                 } else {
627                         error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
628                                                    LM_ST_SHARED,
629                                                    LM_FLAG_NOEXP | GL_EXACT,
630                                                    &freeze_gh);
631                         if (error && !gfs2_withdrawn(sdp))
632                                 return error;
633                 }
634         }
635
636         gfs2_flush_delete_work(sdp);
637         if (!log_write_allowed && current == sdp->sd_quotad_process)
638                 fs_warn(sdp, "The quotad daemon is withdrawing.\n");
639         else if (sdp->sd_quotad_process)
640                 kthread_stop(sdp->sd_quotad_process);
641         sdp->sd_quotad_process = NULL;
642
643         if (!log_write_allowed && current == sdp->sd_logd_process)
644                 fs_warn(sdp, "The logd daemon is withdrawing.\n");
645         else if (sdp->sd_logd_process)
646                 kthread_stop(sdp->sd_logd_process);
647         sdp->sd_logd_process = NULL;
648
649         if (log_write_allowed) {
650                 gfs2_quota_sync(sdp->sd_vfs, 0);
651                 gfs2_statfs_sync(sdp->sd_vfs, 0);
652
653                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
654                                GFS2_LFC_MAKE_FS_RO);
655                 wait_event(sdp->sd_reserving_log_wait,
656                            atomic_read(&sdp->sd_reserving_log) == 0);
657                 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) ==
658                                  sdp->sd_jdesc->jd_blocks);
659         } else {
660                 wait_event_timeout(sdp->sd_reserving_log_wait,
661                                    atomic_read(&sdp->sd_reserving_log) == 0,
662                                    HZ * 5);
663         }
664         if (gfs2_holder_initialized(&freeze_gh))
665                 gfs2_glock_dq_uninit(&freeze_gh);
666
667         gfs2_quota_cleanup(sdp);
668
669         if (!log_write_allowed)
670                 sdp->sd_vfs->s_flags |= SB_RDONLY;
671
672         return error;
673 }
674
675 /**
676  * gfs2_put_super - Unmount the filesystem
677  * @sb: The VFS superblock
678  *
679  */
680
681 static void gfs2_put_super(struct super_block *sb)
682 {
683         struct gfs2_sbd *sdp = sb->s_fs_info;
684         int error;
685         struct gfs2_jdesc *jd;
686
687         /* No more recovery requests */
688         set_bit(SDF_NORECOVERY, &sdp->sd_flags);
689         smp_mb();
690
691         /* Wait on outstanding recovery */
692 restart:
693         spin_lock(&sdp->sd_jindex_spin);
694         list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
695                 if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
696                         continue;
697                 spin_unlock(&sdp->sd_jindex_spin);
698                 wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
699                             TASK_UNINTERRUPTIBLE);
700                 goto restart;
701         }
702         spin_unlock(&sdp->sd_jindex_spin);
703
704         if (!sb_rdonly(sb)) {
705                 error = gfs2_make_fs_ro(sdp);
706                 if (error)
707                         gfs2_io_error(sdp);
708         }
709         WARN_ON(gfs2_withdrawing(sdp));
710
711         /*  At this point, we're through modifying the disk  */
712
713         /*  Release stuff  */
714
715         iput(sdp->sd_jindex);
716         iput(sdp->sd_statfs_inode);
717         iput(sdp->sd_rindex);
718         iput(sdp->sd_quota_inode);
719
720         gfs2_glock_put(sdp->sd_rename_gl);
721         gfs2_glock_put(sdp->sd_freeze_gl);
722
723         if (!sdp->sd_args.ar_spectator) {
724                 if (gfs2_holder_initialized(&sdp->sd_journal_gh))
725                         gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
726                 if (gfs2_holder_initialized(&sdp->sd_jinode_gh))
727                         gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
728                 gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
729                 gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
730                 free_local_statfs_inodes(sdp);
731                 iput(sdp->sd_qc_inode);
732         }
733
734         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
735         gfs2_clear_rgrpd(sdp);
736         gfs2_jindex_free(sdp);
737         /*  Take apart glock structures and buffer lists  */
738         gfs2_gl_hash_clear(sdp);
739         truncate_inode_pages_final(&sdp->sd_aspace);
740         gfs2_delete_debugfs_file(sdp);
741         /*  Unmount the locking protocol  */
742         gfs2_lm_unmount(sdp);
743
744         /*  At this point, we're through participating in the lockspace  */
745         gfs2_sys_fs_del(sdp);
746         free_sbd(sdp);
747 }
748
749 /**
750  * gfs2_sync_fs - sync the filesystem
751  * @sb: the superblock
752  *
753  * Flushes the log to disk.
754  */
755
756 static int gfs2_sync_fs(struct super_block *sb, int wait)
757 {
758         struct gfs2_sbd *sdp = sb->s_fs_info;
759
760         gfs2_quota_sync(sb, -1);
761         if (wait)
762                 gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
763                                GFS2_LFC_SYNC_FS);
764         return sdp->sd_log_error;
765 }
766
767 void gfs2_freeze_func(struct work_struct *work)
768 {
769         int error;
770         struct gfs2_holder freeze_gh;
771         struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
772         struct super_block *sb = sdp->sd_vfs;
773
774         atomic_inc(&sb->s_active);
775         error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
776                                    LM_FLAG_NOEXP | GL_EXACT, &freeze_gh);
777         if (error) {
778                 fs_info(sdp, "GFS2: couldn't get freeze lock : %d\n", error);
779                 gfs2_assert_withdraw(sdp, 0);
780         } else {
781                 atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
782                 error = thaw_super(sb);
783                 if (error) {
784                         fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
785                                 error);
786                         gfs2_assert_withdraw(sdp, 0);
787                 }
788                 gfs2_glock_dq_uninit(&freeze_gh);
789         }
790         deactivate_super(sb);
791         clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
792         wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
793         return;
794 }
795
796 /**
797  * gfs2_freeze - prevent further writes to the filesystem
798  * @sb: the VFS structure for the filesystem
799  *
800  */
801
802 static int gfs2_freeze(struct super_block *sb)
803 {
804         struct gfs2_sbd *sdp = sb->s_fs_info;
805         int error = 0;
806
807         mutex_lock(&sdp->sd_freeze_mutex);
808         if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN)
809                 goto out;
810
811         for (;;) {
812                 if (gfs2_withdrawn(sdp)) {
813                         error = -EINVAL;
814                         goto out;
815                 }
816
817                 error = gfs2_lock_fs_check_clean(sdp);
818                 if (!error)
819                         break;
820
821                 if (error == -EBUSY)
822                         fs_err(sdp, "waiting for recovery before freeze\n");
823                 else if (error == -EIO) {
824                         fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
825                                "to recovery error.\n");
826                         goto out;
827                 } else {
828                         fs_err(sdp, "error freezing FS: %d\n", error);
829                 }
830                 fs_err(sdp, "retrying...\n");
831                 msleep(1000);
832         }
833         set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
834 out:
835         mutex_unlock(&sdp->sd_freeze_mutex);
836         return error;
837 }
838
839 /**
840  * gfs2_unfreeze - reallow writes to the filesystem
841  * @sb: the VFS structure for the filesystem
842  *
843  */
844
845 static int gfs2_unfreeze(struct super_block *sb)
846 {
847         struct gfs2_sbd *sdp = sb->s_fs_info;
848
849         mutex_lock(&sdp->sd_freeze_mutex);
850         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
851             !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
852                 mutex_unlock(&sdp->sd_freeze_mutex);
853                 return 0;
854         }
855
856         gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
857         mutex_unlock(&sdp->sd_freeze_mutex);
858         return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
859 }
860
861 /**
862  * statfs_fill - fill in the sg for a given RG
863  * @rgd: the RG
864  * @sc: the sc structure
865  *
866  * Returns: 0 on success, -ESTALE if the LVB is invalid
867  */
868
869 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
870                             struct gfs2_statfs_change_host *sc)
871 {
872         gfs2_rgrp_verify(rgd);
873         sc->sc_total += rgd->rd_data;
874         sc->sc_free += rgd->rd_free;
875         sc->sc_dinodes += rgd->rd_dinodes;
876         return 0;
877 }
878
879 /**
880  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
881  * @sdp: the filesystem
882  * @sc: the sc info that will be returned
883  *
884  * Any error (other than a signal) will cause this routine to fall back
885  * to the synchronous version.
886  *
887  * FIXME: This really shouldn't busy wait like this.
888  *
889  * Returns: errno
890  */
891
892 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
893 {
894         struct gfs2_rgrpd *rgd_next;
895         struct gfs2_holder *gha, *gh;
896         unsigned int slots = 64;
897         unsigned int x;
898         int done;
899         int error = 0, err;
900
901         memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
902         gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
903         if (!gha)
904                 return -ENOMEM;
905         for (x = 0; x < slots; x++)
906                 gfs2_holder_mark_uninitialized(gha + x);
907
908         rgd_next = gfs2_rgrpd_get_first(sdp);
909
910         for (;;) {
911                 done = 1;
912
913                 for (x = 0; x < slots; x++) {
914                         gh = gha + x;
915
916                         if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
917                                 err = gfs2_glock_wait(gh);
918                                 if (err) {
919                                         gfs2_holder_uninit(gh);
920                                         error = err;
921                                 } else {
922                                         if (!error) {
923                                                 struct gfs2_rgrpd *rgd =
924                                                         gfs2_glock2rgrp(gh->gh_gl);
925
926                                                 error = statfs_slow_fill(rgd, sc);
927                                         }
928                                         gfs2_glock_dq_uninit(gh);
929                                 }
930                         }
931
932                         if (gfs2_holder_initialized(gh))
933                                 done = 0;
934                         else if (rgd_next && !error) {
935                                 error = gfs2_glock_nq_init(rgd_next->rd_gl,
936                                                            LM_ST_SHARED,
937                                                            GL_ASYNC,
938                                                            gh);
939                                 rgd_next = gfs2_rgrpd_get_next(rgd_next);
940                                 done = 0;
941                         }
942
943                         if (signal_pending(current))
944                                 error = -ERESTARTSYS;
945                 }
946
947                 if (done)
948                         break;
949
950                 yield();
951         }
952
953         kfree(gha);
954         return error;
955 }
956
957 /**
958  * gfs2_statfs_i - Do a statfs
959  * @sdp: the filesystem
960  * @sg: the sg structure
961  *
962  * Returns: errno
963  */
964
965 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
966 {
967         struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
968         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
969
970         spin_lock(&sdp->sd_statfs_spin);
971
972         *sc = *m_sc;
973         sc->sc_total += l_sc->sc_total;
974         sc->sc_free += l_sc->sc_free;
975         sc->sc_dinodes += l_sc->sc_dinodes;
976
977         spin_unlock(&sdp->sd_statfs_spin);
978
979         if (sc->sc_free < 0)
980                 sc->sc_free = 0;
981         if (sc->sc_free > sc->sc_total)
982                 sc->sc_free = sc->sc_total;
983         if (sc->sc_dinodes < 0)
984                 sc->sc_dinodes = 0;
985
986         return 0;
987 }
988
989 /**
990  * gfs2_statfs - Gather and return stats about the filesystem
991  * @sb: The superblock
992  * @statfsbuf: The buffer
993  *
994  * Returns: 0 on success or error code
995  */
996
997 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
998 {
999         struct super_block *sb = dentry->d_sb;
1000         struct gfs2_sbd *sdp = sb->s_fs_info;
1001         struct gfs2_statfs_change_host sc;
1002         int error;
1003
1004         error = gfs2_rindex_update(sdp);
1005         if (error)
1006                 return error;
1007
1008         if (gfs2_tune_get(sdp, gt_statfs_slow))
1009                 error = gfs2_statfs_slow(sdp, &sc);
1010         else
1011                 error = gfs2_statfs_i(sdp, &sc);
1012
1013         if (error)
1014                 return error;
1015
1016         buf->f_type = GFS2_MAGIC;
1017         buf->f_bsize = sdp->sd_sb.sb_bsize;
1018         buf->f_blocks = sc.sc_total;
1019         buf->f_bfree = sc.sc_free;
1020         buf->f_bavail = sc.sc_free;
1021         buf->f_files = sc.sc_dinodes + sc.sc_free;
1022         buf->f_ffree = sc.sc_free;
1023         buf->f_namelen = GFS2_FNAMESIZE;
1024
1025         return 0;
1026 }
1027
1028 /**
1029  * gfs2_drop_inode - Drop an inode (test for remote unlink)
1030  * @inode: The inode to drop
1031  *
1032  * If we've received a callback on an iopen lock then it's because a
1033  * remote node tried to deallocate the inode but failed due to this node
1034  * still having the inode open. Here we mark the link count zero
1035  * since we know that it must have reached zero if the GLF_DEMOTE flag
1036  * is set on the iopen glock. If we didn't do a disk read since the
1037  * remote node removed the final link then we might otherwise miss
1038  * this event. This check ensures that this node will deallocate the
1039  * inode's blocks, or alternatively pass the baton on to another
1040  * node for later deallocation.
1041  */
1042
1043 static int gfs2_drop_inode(struct inode *inode)
1044 {
1045         struct gfs2_inode *ip = GFS2_I(inode);
1046
1047         if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) &&
1048             inode->i_nlink &&
1049             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1050                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1051                 if (test_bit(GLF_DEMOTE, &gl->gl_flags))
1052                         clear_nlink(inode);
1053         }
1054
1055         /*
1056          * When under memory pressure when an inode's link count has dropped to
1057          * zero, defer deleting the inode to the delete workqueue.  This avoids
1058          * calling into DLM under memory pressure, which can deadlock.
1059          */
1060         if (!inode->i_nlink &&
1061             unlikely(current->flags & PF_MEMALLOC) &&
1062             gfs2_holder_initialized(&ip->i_iopen_gh)) {
1063                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1064
1065                 gfs2_glock_hold(gl);
1066                 if (!gfs2_queue_delete_work(gl, 0))
1067                         gfs2_glock_queue_put(gl);
1068                 return false;
1069         }
1070
1071         return generic_drop_inode(inode);
1072 }
1073
1074 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1075 {
1076         do {
1077                 if (d1 == d2)
1078                         return 1;
1079                 d1 = d1->d_parent;
1080         } while (!IS_ROOT(d1));
1081         return 0;
1082 }
1083
1084 /**
1085  * gfs2_show_options - Show mount options for /proc/mounts
1086  * @s: seq_file structure
1087  * @root: root of this (sub)tree
1088  *
1089  * Returns: 0 on success or error code
1090  */
1091
1092 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1093 {
1094         struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1095         struct gfs2_args *args = &sdp->sd_args;
1096         int val;
1097
1098         if (is_ancestor(root, sdp->sd_master_dir))
1099                 seq_puts(s, ",meta");
1100         if (args->ar_lockproto[0])
1101                 seq_show_option(s, "lockproto", args->ar_lockproto);
1102         if (args->ar_locktable[0])
1103                 seq_show_option(s, "locktable", args->ar_locktable);
1104         if (args->ar_hostdata[0])
1105                 seq_show_option(s, "hostdata", args->ar_hostdata);
1106         if (args->ar_spectator)
1107                 seq_puts(s, ",spectator");
1108         if (args->ar_localflocks)
1109                 seq_puts(s, ",localflocks");
1110         if (args->ar_debug)
1111                 seq_puts(s, ",debug");
1112         if (args->ar_posix_acl)
1113                 seq_puts(s, ",acl");
1114         if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1115                 char *state;
1116                 switch (args->ar_quota) {
1117                 case GFS2_QUOTA_OFF:
1118                         state = "off";
1119                         break;
1120                 case GFS2_QUOTA_ACCOUNT:
1121                         state = "account";
1122                         break;
1123                 case GFS2_QUOTA_ON:
1124                         state = "on";
1125                         break;
1126                 default:
1127                         state = "unknown";
1128                         break;
1129                 }
1130                 seq_printf(s, ",quota=%s", state);
1131         }
1132         if (args->ar_suiddir)
1133                 seq_puts(s, ",suiddir");
1134         if (args->ar_data != GFS2_DATA_DEFAULT) {
1135                 char *state;
1136                 switch (args->ar_data) {
1137                 case GFS2_DATA_WRITEBACK:
1138                         state = "writeback";
1139                         break;
1140                 case GFS2_DATA_ORDERED:
1141                         state = "ordered";
1142                         break;
1143                 default:
1144                         state = "unknown";
1145                         break;
1146                 }
1147                 seq_printf(s, ",data=%s", state);
1148         }
1149         if (args->ar_discard)
1150                 seq_puts(s, ",discard");
1151         val = sdp->sd_tune.gt_logd_secs;
1152         if (val != 30)
1153                 seq_printf(s, ",commit=%d", val);
1154         val = sdp->sd_tune.gt_statfs_quantum;
1155         if (val != 30)
1156                 seq_printf(s, ",statfs_quantum=%d", val);
1157         else if (sdp->sd_tune.gt_statfs_slow)
1158                 seq_puts(s, ",statfs_quantum=0");
1159         val = sdp->sd_tune.gt_quota_quantum;
1160         if (val != 60)
1161                 seq_printf(s, ",quota_quantum=%d", val);
1162         if (args->ar_statfs_percent)
1163                 seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1164         if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1165                 const char *state;
1166
1167                 switch (args->ar_errors) {
1168                 case GFS2_ERRORS_WITHDRAW:
1169                         state = "withdraw";
1170                         break;
1171                 case GFS2_ERRORS_PANIC:
1172                         state = "panic";
1173                         break;
1174                 default:
1175                         state = "unknown";
1176                         break;
1177                 }
1178                 seq_printf(s, ",errors=%s", state);
1179         }
1180         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1181                 seq_puts(s, ",nobarrier");
1182         if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1183                 seq_puts(s, ",demote_interface_used");
1184         if (args->ar_rgrplvb)
1185                 seq_puts(s, ",rgrplvb");
1186         if (args->ar_loccookie)
1187                 seq_puts(s, ",loccookie");
1188         return 0;
1189 }
1190
1191 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1192 {
1193         struct inode *inode = &ip->i_inode;
1194         struct gfs2_glock *gl = ip->i_gl;
1195
1196         truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1197         truncate_inode_pages(&inode->i_data, 0);
1198
1199         if (atomic_read(&gl->gl_revokes) == 0) {
1200                 clear_bit(GLF_LFLUSH, &gl->gl_flags);
1201                 clear_bit(GLF_DIRTY, &gl->gl_flags);
1202         }
1203 }
1204
1205 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1206 {
1207         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1208         struct gfs2_rgrpd *rgd;
1209         struct gfs2_holder gh;
1210         int error;
1211
1212         if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1213                 gfs2_consist_inode(ip);
1214                 return -EIO;
1215         }
1216
1217         error = gfs2_rindex_update(sdp);
1218         if (error)
1219                 return error;
1220
1221         error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1222         if (error)
1223                 return error;
1224
1225         rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1226         if (!rgd) {
1227                 gfs2_consist_inode(ip);
1228                 error = -EIO;
1229                 goto out_qs;
1230         }
1231
1232         error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
1233         if (error)
1234                 goto out_qs;
1235
1236         error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1237                                  sdp->sd_jdesc->jd_blocks);
1238         if (error)
1239                 goto out_rg_gunlock;
1240
1241         gfs2_free_di(rgd, ip);
1242
1243         gfs2_final_release_pages(ip);
1244
1245         gfs2_trans_end(sdp);
1246
1247 out_rg_gunlock:
1248         gfs2_glock_dq_uninit(&gh);
1249 out_qs:
1250         gfs2_quota_unhold(ip);
1251         return error;
1252 }
1253
1254 /**
1255  * gfs2_glock_put_eventually
1256  * @gl: The glock to put
1257  *
1258  * When under memory pressure, trigger a deferred glock put to make sure we
1259  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1260  */
1261
1262 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1263 {
1264         if (current->flags & PF_MEMALLOC)
1265                 gfs2_glock_queue_put(gl);
1266         else
1267                 gfs2_glock_put(gl);
1268 }
1269
1270 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1271 {
1272         struct gfs2_inode *ip = GFS2_I(inode);
1273         struct gfs2_sbd *sdp = GFS2_SB(inode);
1274         struct gfs2_holder *gh = &ip->i_iopen_gh;
1275         long timeout = 5 * HZ;
1276         int error;
1277
1278         gh->gh_flags |= GL_NOCACHE;
1279         gfs2_glock_dq_wait(gh);
1280
1281         /*
1282          * If there are no other lock holders, we'll get the lock immediately.
1283          * Otherwise, the other nodes holding the lock will be notified about
1284          * our locking request.  If they don't have the inode open, they'll
1285          * evict the cached inode and release the lock.  Otherwise, if they
1286          * poke the inode glock, we'll take this as an indication that they
1287          * still need the iopen glock and that they'll take care of deleting
1288          * the inode when they're done.  As a last resort, if another node
1289          * keeps holding the iopen glock without showing any activity on the
1290          * inode glock, we'll eventually time out.
1291          *
1292          * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1293          * locking request as an optimization to notify lock holders as soon as
1294          * possible.  Without that flag, they'd be notified implicitly by the
1295          * second locking request.
1296          */
1297
1298         gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1299         error = gfs2_glock_nq(gh);
1300         if (error != GLR_TRYFAILED)
1301                 return !error;
1302
1303         gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1304         error = gfs2_glock_nq(gh);
1305         if (error)
1306                 return false;
1307
1308         timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1309                 !test_bit(HIF_WAIT, &gh->gh_iflags) ||
1310                 test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1311                 timeout);
1312         if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1313                 gfs2_glock_dq(gh);
1314                 return false;
1315         }
1316         return true;
1317 }
1318
1319 /**
1320  * evict_should_delete - determine whether the inode is eligible for deletion
1321  * @inode: The inode to evict
1322  *
1323  * This function determines whether the evicted inode is eligible to be deleted
1324  * and locks the inode glock.
1325  *
1326  * Returns: the fate of the dinode
1327  */
1328 static enum dinode_demise evict_should_delete(struct inode *inode,
1329                                               struct gfs2_holder *gh)
1330 {
1331         struct gfs2_inode *ip = GFS2_I(inode);
1332         struct super_block *sb = inode->i_sb;
1333         struct gfs2_sbd *sdp = sb->s_fs_info;
1334         int ret;
1335
1336         if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1337                 BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
1338                 goto should_delete;
1339         }
1340
1341         if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1342                 return SHOULD_DEFER_EVICTION;
1343
1344         /* Deletes should never happen under memory pressure anymore.  */
1345         if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1346                 return SHOULD_DEFER_EVICTION;
1347
1348         /* Must not read inode block until block type has been verified */
1349         ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1350         if (unlikely(ret)) {
1351                 glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1352                 ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1353                 gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1354                 return SHOULD_DEFER_EVICTION;
1355         }
1356
1357         if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1358                 return SHOULD_NOT_DELETE_DINODE;
1359         ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1360         if (ret)
1361                 return SHOULD_NOT_DELETE_DINODE;
1362
1363         if (test_bit(GIF_INVALID, &ip->i_flags)) {
1364                 ret = gfs2_inode_refresh(ip);
1365                 if (ret)
1366                         return SHOULD_NOT_DELETE_DINODE;
1367         }
1368
1369         /*
1370          * The inode may have been recreated in the meantime.
1371          */
1372         if (inode->i_nlink)
1373                 return SHOULD_NOT_DELETE_DINODE;
1374
1375 should_delete:
1376         if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1377             test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1378                 if (!gfs2_upgrade_iopen_glock(inode)) {
1379                         gfs2_holder_uninit(&ip->i_iopen_gh);
1380                         return SHOULD_NOT_DELETE_DINODE;
1381                 }
1382         }
1383         return SHOULD_DELETE_DINODE;
1384 }
1385
1386 /**
1387  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1388  * @inode: The inode to evict
1389  */
1390 static int evict_unlinked_inode(struct inode *inode)
1391 {
1392         struct gfs2_inode *ip = GFS2_I(inode);
1393         int ret;
1394
1395         if (S_ISDIR(inode->i_mode) &&
1396             (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1397                 ret = gfs2_dir_exhash_dealloc(ip);
1398                 if (ret)
1399                         goto out;
1400         }
1401
1402         if (ip->i_eattr) {
1403                 ret = gfs2_ea_dealloc(ip);
1404                 if (ret)
1405                         goto out;
1406         }
1407
1408         if (!gfs2_is_stuffed(ip)) {
1409                 ret = gfs2_file_dealloc(ip);
1410                 if (ret)
1411                         goto out;
1412         }
1413
1414         /* We're about to clear the bitmap for the dinode, but as soon as we
1415            do, gfs2_create_inode can create another inode at the same block
1416            location and try to set gl_object again. We clear gl_object here so
1417            that subsequent inode creates don't see an old gl_object. */
1418         glock_clear_object(ip->i_gl, ip);
1419         ret = gfs2_dinode_dealloc(ip);
1420         gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1421 out:
1422         return ret;
1423 }
1424
1425 /*
1426  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1427  * @inode: The inode to evict
1428  */
1429 static int evict_linked_inode(struct inode *inode)
1430 {
1431         struct super_block *sb = inode->i_sb;
1432         struct gfs2_sbd *sdp = sb->s_fs_info;
1433         struct gfs2_inode *ip = GFS2_I(inode);
1434         struct address_space *metamapping;
1435         int ret;
1436
1437         gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1438                        GFS2_LFC_EVICT_INODE);
1439         metamapping = gfs2_glock2aspace(ip->i_gl);
1440         if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1441                 filemap_fdatawrite(metamapping);
1442                 filemap_fdatawait(metamapping);
1443         }
1444         write_inode_now(inode, 1);
1445         gfs2_ail_flush(ip->i_gl, 0);
1446
1447         ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1448         if (ret)
1449                 return ret;
1450
1451         /* Needs to be done before glock release & also in a transaction */
1452         truncate_inode_pages(&inode->i_data, 0);
1453         truncate_inode_pages(metamapping, 0);
1454         gfs2_trans_end(sdp);
1455         return 0;
1456 }
1457
1458 /**
1459  * gfs2_evict_inode - Remove an inode from cache
1460  * @inode: The inode to evict
1461  *
1462  * There are three cases to consider:
1463  * 1. i_nlink == 0, we are final opener (and must deallocate)
1464  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1465  * 3. i_nlink > 0
1466  *
1467  * If the fs is read only, then we have to treat all cases as per #3
1468  * since we are unable to do any deallocation. The inode will be
1469  * deallocated by the next read/write node to attempt an allocation
1470  * in the same resource group
1471  *
1472  * We have to (at the moment) hold the inodes main lock to cover
1473  * the gap between unlocking the shared lock on the iopen lock and
1474  * taking the exclusive lock. I'd rather do a shared -> exclusive
1475  * conversion on the iopen lock, but we can change that later. This
1476  * is safe, just less efficient.
1477  */
1478
1479 static void gfs2_evict_inode(struct inode *inode)
1480 {
1481         struct super_block *sb = inode->i_sb;
1482         struct gfs2_sbd *sdp = sb->s_fs_info;
1483         struct gfs2_inode *ip = GFS2_I(inode);
1484         struct gfs2_holder gh;
1485         int ret;
1486
1487         if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1488                 clear_inode(inode);
1489                 return;
1490         }
1491
1492         if (inode->i_nlink || sb_rdonly(sb))
1493                 goto out;
1494
1495         gfs2_holder_mark_uninitialized(&gh);
1496         ret = evict_should_delete(inode, &gh);
1497         if (ret == SHOULD_DEFER_EVICTION)
1498                 goto out;
1499         if (ret == SHOULD_DELETE_DINODE)
1500                 ret = evict_unlinked_inode(inode);
1501         else
1502                 ret = evict_linked_inode(inode);
1503
1504         if (gfs2_rs_active(&ip->i_res))
1505                 gfs2_rs_deltree(&ip->i_res);
1506
1507         if (gfs2_holder_initialized(&gh)) {
1508                 glock_clear_object(ip->i_gl, ip);
1509                 gfs2_glock_dq_uninit(&gh);
1510         }
1511         if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1512                 fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1513 out:
1514         truncate_inode_pages_final(&inode->i_data);
1515         if (ip->i_qadata)
1516                 gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1517         gfs2_rs_delete(ip, NULL);
1518         gfs2_ordered_del_inode(ip);
1519         clear_inode(inode);
1520         gfs2_dir_hash_inval(ip);
1521         if (ip->i_gl) {
1522                 glock_clear_object(ip->i_gl, ip);
1523                 wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1524                 gfs2_glock_add_to_lru(ip->i_gl);
1525                 gfs2_glock_put_eventually(ip->i_gl);
1526                 ip->i_gl = NULL;
1527         }
1528         if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1529                 struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1530
1531                 glock_clear_object(gl, ip);
1532                 if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1533                         ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1534                         gfs2_glock_dq(&ip->i_iopen_gh);
1535                 }
1536                 gfs2_glock_hold(gl);
1537                 gfs2_holder_uninit(&ip->i_iopen_gh);
1538                 gfs2_glock_put_eventually(gl);
1539         }
1540 }
1541
1542 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1543 {
1544         struct gfs2_inode *ip;
1545
1546         ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1547         if (!ip)
1548                 return NULL;
1549         ip->i_flags = 0;
1550         ip->i_gl = NULL;
1551         gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1552         memset(&ip->i_res, 0, sizeof(ip->i_res));
1553         RB_CLEAR_NODE(&ip->i_res.rs_node);
1554         ip->i_rahead = 0;
1555         return &ip->i_inode;
1556 }
1557
1558 static void gfs2_free_inode(struct inode *inode)
1559 {
1560         kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1561 }
1562
1563 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1564 {
1565         struct local_statfs_inode *lsi, *safe;
1566
1567         /* Run through the statfs inodes list to iput and free memory */
1568         list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1569                 if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1570                         sdp->sd_sc_inode = NULL; /* belongs to this node */
1571                 if (lsi->si_sc_inode)
1572                         iput(lsi->si_sc_inode);
1573                 list_del(&lsi->si_list);
1574                 kfree(lsi);
1575         }
1576 }
1577
1578 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1579                                              unsigned int index)
1580 {
1581         struct local_statfs_inode *lsi;
1582
1583         /* Return the local (per node) statfs inode in the
1584          * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1585         list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1586                 if (lsi->si_jid == index)
1587                         return lsi->si_sc_inode;
1588         }
1589         return NULL;
1590 }
1591
1592 const struct super_operations gfs2_super_ops = {
1593         .alloc_inode            = gfs2_alloc_inode,
1594         .free_inode             = gfs2_free_inode,
1595         .write_inode            = gfs2_write_inode,
1596         .dirty_inode            = gfs2_dirty_inode,
1597         .evict_inode            = gfs2_evict_inode,
1598         .put_super              = gfs2_put_super,
1599         .sync_fs                = gfs2_sync_fs,
1600         .freeze_super           = gfs2_freeze,
1601         .thaw_super             = gfs2_unfreeze,
1602         .statfs                 = gfs2_statfs,
1603         .drop_inode             = gfs2_drop_inode,
1604         .show_options           = gfs2_show_options,
1605 };
1606