xref: /linux/fs/gfs2/super.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/bio.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/completion.h>
17 #include <linux/buffer_head.h>
18 #include <linux/statfs.h>
19 #include <linux/seq_file.h>
20 #include <linux/mount.h>
21 #include <linux/kthread.h>
22 #include <linux/delay.h>
23 #include <linux/gfs2_ondisk.h>
24 #include <linux/crc32.h>
25 #include <linux/time.h>
26 #include <linux/wait.h>
27 #include <linux/writeback.h>
28 #include <linux/backing-dev.h>
29 #include <linux/kernel.h>
30 
31 #include "gfs2.h"
32 #include "incore.h"
33 #include "bmap.h"
34 #include "dir.h"
35 #include "glock.h"
36 #include "glops.h"
37 #include "inode.h"
38 #include "log.h"
39 #include "meta_io.h"
40 #include "quota.h"
41 #include "recovery.h"
42 #include "rgrp.h"
43 #include "super.h"
44 #include "trans.h"
45 #include "util.h"
46 #include "sys.h"
47 #include "xattr.h"
48 
49 #define args_neq(a1, a2, x) ((a1)->ar_##x != (a2)->ar_##x)
50 
51 enum {
52 	Opt_lockproto,
53 	Opt_locktable,
54 	Opt_hostdata,
55 	Opt_spectator,
56 	Opt_ignore_local_fs,
57 	Opt_localflocks,
58 	Opt_localcaching,
59 	Opt_debug,
60 	Opt_nodebug,
61 	Opt_upgrade,
62 	Opt_acl,
63 	Opt_noacl,
64 	Opt_quota_off,
65 	Opt_quota_account,
66 	Opt_quota_on,
67 	Opt_quota,
68 	Opt_noquota,
69 	Opt_suiddir,
70 	Opt_nosuiddir,
71 	Opt_data_writeback,
72 	Opt_data_ordered,
73 	Opt_meta,
74 	Opt_discard,
75 	Opt_nodiscard,
76 	Opt_commit,
77 	Opt_err_withdraw,
78 	Opt_err_panic,
79 	Opt_statfs_quantum,
80 	Opt_statfs_percent,
81 	Opt_quota_quantum,
82 	Opt_barrier,
83 	Opt_nobarrier,
84 	Opt_rgrplvb,
85 	Opt_norgrplvb,
86 	Opt_error,
87 };
88 
89 static const match_table_t tokens = {
90 	{Opt_lockproto, "lockproto=%s"},
91 	{Opt_locktable, "locktable=%s"},
92 	{Opt_hostdata, "hostdata=%s"},
93 	{Opt_spectator, "spectator"},
94 	{Opt_spectator, "norecovery"},
95 	{Opt_ignore_local_fs, "ignore_local_fs"},
96 	{Opt_localflocks, "localflocks"},
97 	{Opt_localcaching, "localcaching"},
98 	{Opt_debug, "debug"},
99 	{Opt_nodebug, "nodebug"},
100 	{Opt_upgrade, "upgrade"},
101 	{Opt_acl, "acl"},
102 	{Opt_noacl, "noacl"},
103 	{Opt_quota_off, "quota=off"},
104 	{Opt_quota_account, "quota=account"},
105 	{Opt_quota_on, "quota=on"},
106 	{Opt_quota, "quota"},
107 	{Opt_noquota, "noquota"},
108 	{Opt_suiddir, "suiddir"},
109 	{Opt_nosuiddir, "nosuiddir"},
110 	{Opt_data_writeback, "data=writeback"},
111 	{Opt_data_ordered, "data=ordered"},
112 	{Opt_meta, "meta"},
113 	{Opt_discard, "discard"},
114 	{Opt_nodiscard, "nodiscard"},
115 	{Opt_commit, "commit=%d"},
116 	{Opt_err_withdraw, "errors=withdraw"},
117 	{Opt_err_panic, "errors=panic"},
118 	{Opt_statfs_quantum, "statfs_quantum=%d"},
119 	{Opt_statfs_percent, "statfs_percent=%d"},
120 	{Opt_quota_quantum, "quota_quantum=%d"},
121 	{Opt_barrier, "barrier"},
122 	{Opt_nobarrier, "nobarrier"},
123 	{Opt_rgrplvb, "rgrplvb"},
124 	{Opt_norgrplvb, "norgrplvb"},
125 	{Opt_error, NULL}
126 };
127 
128 /**
129  * gfs2_mount_args - Parse mount options
130  * @args: The structure into which the parsed options will be written
131  * @options: The options to parse
132  *
133  * Return: errno
134  */
135 
136 int gfs2_mount_args(struct gfs2_args *args, char *options)
137 {
138 	char *o;
139 	int token;
140 	substring_t tmp[MAX_OPT_ARGS];
141 	int rv;
142 
143 	/* Split the options into tokens with the "," character and
144 	   process them */
145 
146 	while (1) {
147 		o = strsep(&options, ",");
148 		if (o == NULL)
149 			break;
150 		if (*o == '\0')
151 			continue;
152 
153 		token = match_token(o, tokens, tmp);
154 		switch (token) {
155 		case Opt_lockproto:
156 			match_strlcpy(args->ar_lockproto, &tmp[0],
157 				      GFS2_LOCKNAME_LEN);
158 			break;
159 		case Opt_locktable:
160 			match_strlcpy(args->ar_locktable, &tmp[0],
161 				      GFS2_LOCKNAME_LEN);
162 			break;
163 		case Opt_hostdata:
164 			match_strlcpy(args->ar_hostdata, &tmp[0],
165 				      GFS2_LOCKNAME_LEN);
166 			break;
167 		case Opt_spectator:
168 			args->ar_spectator = 1;
169 			break;
170 		case Opt_ignore_local_fs:
171 			/* Retained for backwards compat only */
172 			break;
173 		case Opt_localflocks:
174 			args->ar_localflocks = 1;
175 			break;
176 		case Opt_localcaching:
177 			/* Retained for backwards compat only */
178 			break;
179 		case Opt_debug:
180 			if (args->ar_errors == GFS2_ERRORS_PANIC) {
181 				pr_warn("-o debug and -o errors=panic are mutually exclusive\n");
182 				return -EINVAL;
183 			}
184 			args->ar_debug = 1;
185 			break;
186 		case Opt_nodebug:
187 			args->ar_debug = 0;
188 			break;
189 		case Opt_upgrade:
190 			/* Retained for backwards compat only */
191 			break;
192 		case Opt_acl:
193 			args->ar_posix_acl = 1;
194 			break;
195 		case Opt_noacl:
196 			args->ar_posix_acl = 0;
197 			break;
198 		case Opt_quota_off:
199 		case Opt_noquota:
200 			args->ar_quota = GFS2_QUOTA_OFF;
201 			break;
202 		case Opt_quota_account:
203 			args->ar_quota = GFS2_QUOTA_ACCOUNT;
204 			break;
205 		case Opt_quota_on:
206 		case Opt_quota:
207 			args->ar_quota = GFS2_QUOTA_ON;
208 			break;
209 		case Opt_suiddir:
210 			args->ar_suiddir = 1;
211 			break;
212 		case Opt_nosuiddir:
213 			args->ar_suiddir = 0;
214 			break;
215 		case Opt_data_writeback:
216 			args->ar_data = GFS2_DATA_WRITEBACK;
217 			break;
218 		case Opt_data_ordered:
219 			args->ar_data = GFS2_DATA_ORDERED;
220 			break;
221 		case Opt_meta:
222 			args->ar_meta = 1;
223 			break;
224 		case Opt_discard:
225 			args->ar_discard = 1;
226 			break;
227 		case Opt_nodiscard:
228 			args->ar_discard = 0;
229 			break;
230 		case Opt_commit:
231 			rv = match_int(&tmp[0], &args->ar_commit);
232 			if (rv || args->ar_commit <= 0) {
233 				pr_warn("commit mount option requires a positive numeric argument\n");
234 				return rv ? rv : -EINVAL;
235 			}
236 			break;
237 		case Opt_statfs_quantum:
238 			rv = match_int(&tmp[0], &args->ar_statfs_quantum);
239 			if (rv || args->ar_statfs_quantum < 0) {
240 				pr_warn("statfs_quantum mount option requires a non-negative numeric argument\n");
241 				return rv ? rv : -EINVAL;
242 			}
243 			break;
244 		case Opt_quota_quantum:
245 			rv = match_int(&tmp[0], &args->ar_quota_quantum);
246 			if (rv || args->ar_quota_quantum <= 0) {
247 				pr_warn("quota_quantum mount option requires a positive numeric argument\n");
248 				return rv ? rv : -EINVAL;
249 			}
250 			break;
251 		case Opt_statfs_percent:
252 			rv = match_int(&tmp[0], &args->ar_statfs_percent);
253 			if (rv || args->ar_statfs_percent < 0 ||
254 			    args->ar_statfs_percent > 100) {
255 				pr_warn("statfs_percent mount option requires a numeric argument between 0 and 100\n");
256 				return rv ? rv : -EINVAL;
257 			}
258 			break;
259 		case Opt_err_withdraw:
260 			args->ar_errors = GFS2_ERRORS_WITHDRAW;
261 			break;
262 		case Opt_err_panic:
263 			if (args->ar_debug) {
264 				pr_warn("-o debug and -o errors=panic are mutually exclusive\n");
265 				return -EINVAL;
266 			}
267 			args->ar_errors = GFS2_ERRORS_PANIC;
268 			break;
269 		case Opt_barrier:
270 			args->ar_nobarrier = 0;
271 			break;
272 		case Opt_nobarrier:
273 			args->ar_nobarrier = 1;
274 			break;
275 		case Opt_rgrplvb:
276 			args->ar_rgrplvb = 1;
277 			break;
278 		case Opt_norgrplvb:
279 			args->ar_rgrplvb = 0;
280 			break;
281 		case Opt_error:
282 		default:
283 			pr_warn("invalid mount option: %s\n", o);
284 			return -EINVAL;
285 		}
286 	}
287 
288 	return 0;
289 }
290 
291 /**
292  * gfs2_jindex_free - Clear all the journal index information
293  * @sdp: The GFS2 superblock
294  *
295  */
296 
297 void gfs2_jindex_free(struct gfs2_sbd *sdp)
298 {
299 	struct list_head list;
300 	struct gfs2_jdesc *jd;
301 
302 	spin_lock(&sdp->sd_jindex_spin);
303 	list_add(&list, &sdp->sd_jindex_list);
304 	list_del_init(&sdp->sd_jindex_list);
305 	sdp->sd_journals = 0;
306 	spin_unlock(&sdp->sd_jindex_spin);
307 
308 	while (!list_empty(&list)) {
309 		jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
310 		gfs2_free_journal_extents(jd);
311 		list_del(&jd->jd_list);
312 		iput(jd->jd_inode);
313 		kfree(jd);
314 	}
315 }
316 
317 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
318 {
319 	struct gfs2_jdesc *jd;
320 	int found = 0;
321 
322 	list_for_each_entry(jd, head, jd_list) {
323 		if (jd->jd_jid == jid) {
324 			found = 1;
325 			break;
326 		}
327 	}
328 
329 	if (!found)
330 		jd = NULL;
331 
332 	return jd;
333 }
334 
335 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
336 {
337 	struct gfs2_jdesc *jd;
338 
339 	spin_lock(&sdp->sd_jindex_spin);
340 	jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
341 	spin_unlock(&sdp->sd_jindex_spin);
342 
343 	return jd;
344 }
345 
346 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
347 {
348 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
349 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
350 	u64 size = i_size_read(jd->jd_inode);
351 
352 	if (gfs2_check_internal_file_size(jd->jd_inode, 8 << 20, 1 << 30))
353 		return -EIO;
354 
355 	jd->jd_blocks = size >> sdp->sd_sb.sb_bsize_shift;
356 
357 	if (gfs2_write_alloc_required(ip, 0, size)) {
358 		gfs2_consist_inode(ip);
359 		return -EIO;
360 	}
361 
362 	return 0;
363 }
364 
365 static int init_threads(struct gfs2_sbd *sdp)
366 {
367 	struct task_struct *p;
368 	int error = 0;
369 
370 	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
371 	if (IS_ERR(p)) {
372 		error = PTR_ERR(p);
373 		fs_err(sdp, "can't start logd thread: %d\n", error);
374 		return error;
375 	}
376 	sdp->sd_logd_process = p;
377 
378 	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
379 	if (IS_ERR(p)) {
380 		error = PTR_ERR(p);
381 		fs_err(sdp, "can't start quotad thread: %d\n", error);
382 		goto fail;
383 	}
384 	sdp->sd_quotad_process = p;
385 	return 0;
386 
387 fail:
388 	kthread_stop(sdp->sd_logd_process);
389 	return error;
390 }
391 
392 /**
393  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
394  * @sdp: the filesystem
395  *
396  * Returns: errno
397  */
398 
399 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
400 {
401 	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
402 	struct gfs2_glock *j_gl = ip->i_gl;
403 	struct gfs2_holder freeze_gh;
404 	struct gfs2_log_header_host head;
405 	int error;
406 
407 	error = init_threads(sdp);
408 	if (error)
409 		return error;
410 
411 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, 0,
412 				   &freeze_gh);
413 	if (error)
414 		goto fail_threads;
415 
416 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
417 
418 	error = gfs2_find_jhead(sdp->sd_jdesc, &head);
419 	if (error)
420 		goto fail;
421 
422 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
423 		gfs2_consist(sdp);
424 		error = -EIO;
425 		goto fail;
426 	}
427 
428 	/*  Initialize some head of the log stuff  */
429 	sdp->sd_log_sequence = head.lh_sequence + 1;
430 	gfs2_log_pointers_init(sdp, head.lh_blkno);
431 
432 	error = gfs2_quota_init(sdp);
433 	if (error)
434 		goto fail;
435 
436 	set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
437 
438 	gfs2_glock_dq_uninit(&freeze_gh);
439 
440 	return 0;
441 
442 fail:
443 	freeze_gh.gh_flags |= GL_NOCACHE;
444 	gfs2_glock_dq_uninit(&freeze_gh);
445 fail_threads:
446 	kthread_stop(sdp->sd_quotad_process);
447 	kthread_stop(sdp->sd_logd_process);
448 	return error;
449 }
450 
451 void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
452 {
453 	const struct gfs2_statfs_change *str = buf;
454 
455 	sc->sc_total = be64_to_cpu(str->sc_total);
456 	sc->sc_free = be64_to_cpu(str->sc_free);
457 	sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
458 }
459 
460 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
461 {
462 	struct gfs2_statfs_change *str = buf;
463 
464 	str->sc_total = cpu_to_be64(sc->sc_total);
465 	str->sc_free = cpu_to_be64(sc->sc_free);
466 	str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
467 }
468 
469 int gfs2_statfs_init(struct gfs2_sbd *sdp)
470 {
471 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
472 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
473 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
474 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
475 	struct buffer_head *m_bh, *l_bh;
476 	struct gfs2_holder gh;
477 	int error;
478 
479 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
480 				   &gh);
481 	if (error)
482 		return error;
483 
484 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
485 	if (error)
486 		goto out;
487 
488 	if (sdp->sd_args.ar_spectator) {
489 		spin_lock(&sdp->sd_statfs_spin);
490 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
491 				      sizeof(struct gfs2_dinode));
492 		spin_unlock(&sdp->sd_statfs_spin);
493 	} else {
494 		error = gfs2_meta_inode_buffer(l_ip, &l_bh);
495 		if (error)
496 			goto out_m_bh;
497 
498 		spin_lock(&sdp->sd_statfs_spin);
499 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
500 				      sizeof(struct gfs2_dinode));
501 		gfs2_statfs_change_in(l_sc, l_bh->b_data +
502 				      sizeof(struct gfs2_dinode));
503 		spin_unlock(&sdp->sd_statfs_spin);
504 
505 		brelse(l_bh);
506 	}
507 
508 out_m_bh:
509 	brelse(m_bh);
510 out:
511 	gfs2_glock_dq_uninit(&gh);
512 	return 0;
513 }
514 
515 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
516 			s64 dinodes)
517 {
518 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
519 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
520 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
521 	struct buffer_head *l_bh;
522 	s64 x, y;
523 	int need_sync = 0;
524 	int error;
525 
526 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
527 	if (error)
528 		return;
529 
530 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
531 
532 	spin_lock(&sdp->sd_statfs_spin);
533 	l_sc->sc_total += total;
534 	l_sc->sc_free += free;
535 	l_sc->sc_dinodes += dinodes;
536 	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
537 	if (sdp->sd_args.ar_statfs_percent) {
538 		x = 100 * l_sc->sc_free;
539 		y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
540 		if (x >= y || x <= -y)
541 			need_sync = 1;
542 	}
543 	spin_unlock(&sdp->sd_statfs_spin);
544 
545 	brelse(l_bh);
546 	if (need_sync)
547 		gfs2_wake_up_statfs(sdp);
548 }
549 
550 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
551 		   struct buffer_head *l_bh)
552 {
553 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
554 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
555 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
556 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
557 
558 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
559 
560 	spin_lock(&sdp->sd_statfs_spin);
561 	m_sc->sc_total += l_sc->sc_total;
562 	m_sc->sc_free += l_sc->sc_free;
563 	m_sc->sc_dinodes += l_sc->sc_dinodes;
564 	memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
565 	memset(l_bh->b_data + sizeof(struct gfs2_dinode),
566 	       0, sizeof(struct gfs2_statfs_change));
567 	spin_unlock(&sdp->sd_statfs_spin);
568 
569 	gfs2_trans_add_meta(m_ip->i_gl, m_bh);
570 	gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
571 }
572 
573 int gfs2_statfs_sync(struct super_block *sb, int type)
574 {
575 	struct gfs2_sbd *sdp = sb->s_fs_info;
576 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
577 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
578 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
579 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
580 	struct gfs2_holder gh;
581 	struct buffer_head *m_bh, *l_bh;
582 	int error;
583 
584 	sb_start_write(sb);
585 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
586 				   &gh);
587 	if (error)
588 		goto out;
589 
590 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
591 	if (error)
592 		goto out_unlock;
593 
594 	spin_lock(&sdp->sd_statfs_spin);
595 	gfs2_statfs_change_in(m_sc, m_bh->b_data +
596 			      sizeof(struct gfs2_dinode));
597 	if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
598 		spin_unlock(&sdp->sd_statfs_spin);
599 		goto out_bh;
600 	}
601 	spin_unlock(&sdp->sd_statfs_spin);
602 
603 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
604 	if (error)
605 		goto out_bh;
606 
607 	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
608 	if (error)
609 		goto out_bh2;
610 
611 	update_statfs(sdp, m_bh, l_bh);
612 	sdp->sd_statfs_force_sync = 0;
613 
614 	gfs2_trans_end(sdp);
615 
616 out_bh2:
617 	brelse(l_bh);
618 out_bh:
619 	brelse(m_bh);
620 out_unlock:
621 	gfs2_glock_dq_uninit(&gh);
622 out:
623 	sb_end_write(sb);
624 	return error;
625 }
626 
627 struct lfcc {
628 	struct list_head list;
629 	struct gfs2_holder gh;
630 };
631 
632 /**
633  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
634  *                            journals are clean
635  * @sdp: the file system
636  * @state: the state to put the transaction lock into
637  * @t_gh: the hold on the transaction lock
638  *
639  * Returns: errno
640  */
641 
642 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
643 				    struct gfs2_holder *freeze_gh)
644 {
645 	struct gfs2_inode *ip;
646 	struct gfs2_jdesc *jd;
647 	struct lfcc *lfcc;
648 	LIST_HEAD(list);
649 	struct gfs2_log_header_host lh;
650 	int error;
651 
652 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
653 		lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
654 		if (!lfcc) {
655 			error = -ENOMEM;
656 			goto out;
657 		}
658 		ip = GFS2_I(jd->jd_inode);
659 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
660 		if (error) {
661 			kfree(lfcc);
662 			goto out;
663 		}
664 		list_add(&lfcc->list, &list);
665 	}
666 
667 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
668 				   GL_NOCACHE, freeze_gh);
669 
670 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
671 		error = gfs2_jdesc_check(jd);
672 		if (error)
673 			break;
674 		error = gfs2_find_jhead(jd, &lh);
675 		if (error)
676 			break;
677 		if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
678 			error = -EBUSY;
679 			break;
680 		}
681 	}
682 
683 	if (error)
684 		gfs2_glock_dq_uninit(freeze_gh);
685 
686 out:
687 	while (!list_empty(&list)) {
688 		lfcc = list_entry(list.next, struct lfcc, list);
689 		list_del(&lfcc->list);
690 		gfs2_glock_dq_uninit(&lfcc->gh);
691 		kfree(lfcc);
692 	}
693 	return error;
694 }
695 
696 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
697 {
698 	struct gfs2_dinode *str = buf;
699 
700 	str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
701 	str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
702 	str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
703 	str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
704 	str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
705 	str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
706 	str->di_uid = cpu_to_be32(i_uid_read(&ip->i_inode));
707 	str->di_gid = cpu_to_be32(i_gid_read(&ip->i_inode));
708 	str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
709 	str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
710 	str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
711 	str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
712 	str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
713 	str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
714 
715 	str->di_goal_meta = cpu_to_be64(ip->i_goal);
716 	str->di_goal_data = cpu_to_be64(ip->i_goal);
717 	str->di_generation = cpu_to_be64(ip->i_generation);
718 
719 	str->di_flags = cpu_to_be32(ip->i_diskflags);
720 	str->di_height = cpu_to_be16(ip->i_height);
721 	str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
722 					     !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
723 					     GFS2_FORMAT_DE : 0);
724 	str->di_depth = cpu_to_be16(ip->i_depth);
725 	str->di_entries = cpu_to_be32(ip->i_entries);
726 
727 	str->di_eattr = cpu_to_be64(ip->i_eattr);
728 	str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
729 	str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
730 	str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
731 }
732 
733 /**
734  * gfs2_write_inode - Make sure the inode is stable on the disk
735  * @inode: The inode
736  * @wbc: The writeback control structure
737  *
738  * Returns: errno
739  */
740 
741 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
742 {
743 	struct gfs2_inode *ip = GFS2_I(inode);
744 	struct gfs2_sbd *sdp = GFS2_SB(inode);
745 	struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
746 	struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
747 	int ret = 0;
748 
749 	if (wbc->sync_mode == WB_SYNC_ALL)
750 		gfs2_log_flush(GFS2_SB(inode), ip->i_gl, NORMAL_FLUSH);
751 	if (bdi->wb.dirty_exceeded)
752 		gfs2_ail1_flush(sdp, wbc);
753 	else
754 		filemap_fdatawrite(metamapping);
755 	if (wbc->sync_mode == WB_SYNC_ALL)
756 		ret = filemap_fdatawait(metamapping);
757 	if (ret)
758 		mark_inode_dirty_sync(inode);
759 	return ret;
760 }
761 
762 /**
763  * gfs2_dirty_inode - check for atime updates
764  * @inode: The inode in question
765  * @flags: The type of dirty
766  *
767  * Unfortunately it can be called under any combination of inode
768  * glock and transaction lock, so we have to check carefully.
769  *
770  * At the moment this deals only with atime - it should be possible
771  * to expand that role in future, once a review of the locking has
772  * been carried out.
773  */
774 
775 static void gfs2_dirty_inode(struct inode *inode, int flags)
776 {
777 	struct gfs2_inode *ip = GFS2_I(inode);
778 	struct gfs2_sbd *sdp = GFS2_SB(inode);
779 	struct buffer_head *bh;
780 	struct gfs2_holder gh;
781 	int need_unlock = 0;
782 	int need_endtrans = 0;
783 	int ret;
784 
785 	if (!(flags & (I_DIRTY_DATASYNC|I_DIRTY_SYNC)))
786 		return;
787 
788 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
789 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
790 		if (ret) {
791 			fs_err(sdp, "dirty_inode: glock %d\n", ret);
792 			return;
793 		}
794 		need_unlock = 1;
795 	} else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
796 		return;
797 
798 	if (current->journal_info == NULL) {
799 		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
800 		if (ret) {
801 			fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
802 			goto out;
803 		}
804 		need_endtrans = 1;
805 	}
806 
807 	ret = gfs2_meta_inode_buffer(ip, &bh);
808 	if (ret == 0) {
809 		gfs2_trans_add_meta(ip->i_gl, bh);
810 		gfs2_dinode_out(ip, bh->b_data);
811 		brelse(bh);
812 	}
813 
814 	if (need_endtrans)
815 		gfs2_trans_end(sdp);
816 out:
817 	if (need_unlock)
818 		gfs2_glock_dq_uninit(&gh);
819 }
820 
821 /**
822  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
823  * @sdp: the filesystem
824  *
825  * Returns: errno
826  */
827 
828 static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
829 {
830 	struct gfs2_holder freeze_gh;
831 	int error;
832 
833 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, GL_NOCACHE,
834 				   &freeze_gh);
835 	if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
836 		return error;
837 
838 	kthread_stop(sdp->sd_quotad_process);
839 	kthread_stop(sdp->sd_logd_process);
840 
841 	flush_workqueue(gfs2_delete_workqueue);
842 	gfs2_quota_sync(sdp->sd_vfs, 0);
843 	gfs2_statfs_sync(sdp->sd_vfs, 0);
844 
845 	down_write(&sdp->sd_log_flush_lock);
846 	clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
847 	up_write(&sdp->sd_log_flush_lock);
848 
849 	gfs2_log_flush(sdp, NULL, SHUTDOWN_FLUSH);
850 	wait_event(sdp->sd_reserving_log_wait, atomic_read(&sdp->sd_reserving_log) == 0);
851 	gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
852 
853 	if (freeze_gh.gh_gl)
854 		gfs2_glock_dq_uninit(&freeze_gh);
855 
856 	gfs2_quota_cleanup(sdp);
857 
858 	return error;
859 }
860 
861 /**
862  * gfs2_put_super - Unmount the filesystem
863  * @sb: The VFS superblock
864  *
865  */
866 
867 static void gfs2_put_super(struct super_block *sb)
868 {
869 	struct gfs2_sbd *sdp = sb->s_fs_info;
870 	int error;
871 	struct gfs2_jdesc *jd;
872 
873 	/* No more recovery requests */
874 	set_bit(SDF_NORECOVERY, &sdp->sd_flags);
875 	smp_mb();
876 
877 	/* Wait on outstanding recovery */
878 restart:
879 	spin_lock(&sdp->sd_jindex_spin);
880 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
881 		if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
882 			continue;
883 		spin_unlock(&sdp->sd_jindex_spin);
884 		wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
885 			    TASK_UNINTERRUPTIBLE);
886 		goto restart;
887 	}
888 	spin_unlock(&sdp->sd_jindex_spin);
889 
890 	if (!(sb->s_flags & MS_RDONLY)) {
891 		error = gfs2_make_fs_ro(sdp);
892 		if (error)
893 			gfs2_io_error(sdp);
894 	}
895 	/*  At this point, we're through modifying the disk  */
896 
897 	/*  Release stuff  */
898 
899 	iput(sdp->sd_jindex);
900 	iput(sdp->sd_statfs_inode);
901 	iput(sdp->sd_rindex);
902 	iput(sdp->sd_quota_inode);
903 
904 	gfs2_glock_put(sdp->sd_rename_gl);
905 	gfs2_glock_put(sdp->sd_freeze_gl);
906 
907 	if (!sdp->sd_args.ar_spectator) {
908 		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
909 		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
910 		gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
911 		gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
912 		iput(sdp->sd_sc_inode);
913 		iput(sdp->sd_qc_inode);
914 	}
915 
916 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
917 	gfs2_clear_rgrpd(sdp);
918 	gfs2_jindex_free(sdp);
919 	/*  Take apart glock structures and buffer lists  */
920 	gfs2_gl_hash_clear(sdp);
921 	/*  Unmount the locking protocol  */
922 	gfs2_lm_unmount(sdp);
923 
924 	/*  At this point, we're through participating in the lockspace  */
925 	gfs2_sys_fs_del(sdp);
926 }
927 
928 /**
929  * gfs2_sync_fs - sync the filesystem
930  * @sb: the superblock
931  *
932  * Flushes the log to disk.
933  */
934 
935 static int gfs2_sync_fs(struct super_block *sb, int wait)
936 {
937 	struct gfs2_sbd *sdp = sb->s_fs_info;
938 
939 	gfs2_quota_sync(sb, -1);
940 	if (wait && sdp)
941 		gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
942 	return 0;
943 }
944 
945 void gfs2_freeze_func(struct work_struct *work)
946 {
947 	int error;
948 	struct gfs2_holder freeze_gh;
949 	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
950 	struct super_block *sb = sdp->sd_vfs;
951 
952 	atomic_inc(&sb->s_active);
953 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, 0,
954 				   &freeze_gh);
955 	if (error) {
956 		printk(KERN_INFO "GFS2: couln't get freeze lock : %d\n", error);
957 		gfs2_assert_withdraw(sdp, 0);
958 	}
959 	else {
960 		atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
961 		error = thaw_super(sb);
962 		if (error) {
963 			printk(KERN_INFO "GFS2: couldn't thaw filesystem: %d\n",
964 			       error);
965 			gfs2_assert_withdraw(sdp, 0);
966 		}
967 		if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
968 			freeze_gh.gh_flags |= GL_NOCACHE;
969 		gfs2_glock_dq_uninit(&freeze_gh);
970 	}
971 	deactivate_super(sb);
972 	return;
973 }
974 
975 /**
976  * gfs2_freeze - prevent further writes to the filesystem
977  * @sb: the VFS structure for the filesystem
978  *
979  */
980 
981 static int gfs2_freeze(struct super_block *sb)
982 {
983 	struct gfs2_sbd *sdp = sb->s_fs_info;
984 	int error = 0;
985 
986 	mutex_lock(&sdp->sd_freeze_mutex);
987 	if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN)
988 		goto out;
989 
990 	if (test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) {
991 		error = -EINVAL;
992 		goto out;
993 	}
994 
995 	for (;;) {
996 		error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
997 		if (!error)
998 			break;
999 
1000 		switch (error) {
1001 		case -EBUSY:
1002 			fs_err(sdp, "waiting for recovery before freeze\n");
1003 			break;
1004 
1005 		default:
1006 			fs_err(sdp, "error freezing FS: %d\n", error);
1007 			break;
1008 		}
1009 
1010 		fs_err(sdp, "retrying...\n");
1011 		msleep(1000);
1012 	}
1013 	error = 0;
1014 out:
1015 	mutex_unlock(&sdp->sd_freeze_mutex);
1016 	return error;
1017 }
1018 
1019 /**
1020  * gfs2_unfreeze - reallow writes to the filesystem
1021  * @sb: the VFS structure for the filesystem
1022  *
1023  */
1024 
1025 static int gfs2_unfreeze(struct super_block *sb)
1026 {
1027 	struct gfs2_sbd *sdp = sb->s_fs_info;
1028 
1029 	mutex_lock(&sdp->sd_freeze_mutex);
1030         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
1031 	    sdp->sd_freeze_gh.gh_gl == NULL) {
1032 		mutex_unlock(&sdp->sd_freeze_mutex);
1033                 return 0;
1034 	}
1035 
1036 	gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
1037 	mutex_unlock(&sdp->sd_freeze_mutex);
1038 	return 0;
1039 }
1040 
1041 /**
1042  * statfs_fill - fill in the sg for a given RG
1043  * @rgd: the RG
1044  * @sc: the sc structure
1045  *
1046  * Returns: 0 on success, -ESTALE if the LVB is invalid
1047  */
1048 
1049 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
1050 			    struct gfs2_statfs_change_host *sc)
1051 {
1052 	gfs2_rgrp_verify(rgd);
1053 	sc->sc_total += rgd->rd_data;
1054 	sc->sc_free += rgd->rd_free;
1055 	sc->sc_dinodes += rgd->rd_dinodes;
1056 	return 0;
1057 }
1058 
1059 /**
1060  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
1061  * @sdp: the filesystem
1062  * @sc: the sc info that will be returned
1063  *
1064  * Any error (other than a signal) will cause this routine to fall back
1065  * to the synchronous version.
1066  *
1067  * FIXME: This really shouldn't busy wait like this.
1068  *
1069  * Returns: errno
1070  */
1071 
1072 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
1073 {
1074 	struct gfs2_rgrpd *rgd_next;
1075 	struct gfs2_holder *gha, *gh;
1076 	unsigned int slots = 64;
1077 	unsigned int x;
1078 	int done;
1079 	int error = 0, err;
1080 
1081 	memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
1082 	gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
1083 	if (!gha)
1084 		return -ENOMEM;
1085 
1086 	rgd_next = gfs2_rgrpd_get_first(sdp);
1087 
1088 	for (;;) {
1089 		done = 1;
1090 
1091 		for (x = 0; x < slots; x++) {
1092 			gh = gha + x;
1093 
1094 			if (gh->gh_gl && gfs2_glock_poll(gh)) {
1095 				err = gfs2_glock_wait(gh);
1096 				if (err) {
1097 					gfs2_holder_uninit(gh);
1098 					error = err;
1099 				} else {
1100 					if (!error)
1101 						error = statfs_slow_fill(
1102 							gh->gh_gl->gl_object, sc);
1103 					gfs2_glock_dq_uninit(gh);
1104 				}
1105 			}
1106 
1107 			if (gh->gh_gl)
1108 				done = 0;
1109 			else if (rgd_next && !error) {
1110 				error = gfs2_glock_nq_init(rgd_next->rd_gl,
1111 							   LM_ST_SHARED,
1112 							   GL_ASYNC,
1113 							   gh);
1114 				rgd_next = gfs2_rgrpd_get_next(rgd_next);
1115 				done = 0;
1116 			}
1117 
1118 			if (signal_pending(current))
1119 				error = -ERESTARTSYS;
1120 		}
1121 
1122 		if (done)
1123 			break;
1124 
1125 		yield();
1126 	}
1127 
1128 	kfree(gha);
1129 	return error;
1130 }
1131 
1132 /**
1133  * gfs2_statfs_i - Do a statfs
1134  * @sdp: the filesystem
1135  * @sg: the sg structure
1136  *
1137  * Returns: errno
1138  */
1139 
1140 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
1141 {
1142 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
1143 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
1144 
1145 	spin_lock(&sdp->sd_statfs_spin);
1146 
1147 	*sc = *m_sc;
1148 	sc->sc_total += l_sc->sc_total;
1149 	sc->sc_free += l_sc->sc_free;
1150 	sc->sc_dinodes += l_sc->sc_dinodes;
1151 
1152 	spin_unlock(&sdp->sd_statfs_spin);
1153 
1154 	if (sc->sc_free < 0)
1155 		sc->sc_free = 0;
1156 	if (sc->sc_free > sc->sc_total)
1157 		sc->sc_free = sc->sc_total;
1158 	if (sc->sc_dinodes < 0)
1159 		sc->sc_dinodes = 0;
1160 
1161 	return 0;
1162 }
1163 
1164 /**
1165  * gfs2_statfs - Gather and return stats about the filesystem
1166  * @sb: The superblock
1167  * @statfsbuf: The buffer
1168  *
1169  * Returns: 0 on success or error code
1170  */
1171 
1172 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
1173 {
1174 	struct super_block *sb = d_inode(dentry)->i_sb;
1175 	struct gfs2_sbd *sdp = sb->s_fs_info;
1176 	struct gfs2_statfs_change_host sc;
1177 	int error;
1178 
1179 	error = gfs2_rindex_update(sdp);
1180 	if (error)
1181 		return error;
1182 
1183 	if (gfs2_tune_get(sdp, gt_statfs_slow))
1184 		error = gfs2_statfs_slow(sdp, &sc);
1185 	else
1186 		error = gfs2_statfs_i(sdp, &sc);
1187 
1188 	if (error)
1189 		return error;
1190 
1191 	buf->f_type = GFS2_MAGIC;
1192 	buf->f_bsize = sdp->sd_sb.sb_bsize;
1193 	buf->f_blocks = sc.sc_total;
1194 	buf->f_bfree = sc.sc_free;
1195 	buf->f_bavail = sc.sc_free;
1196 	buf->f_files = sc.sc_dinodes + sc.sc_free;
1197 	buf->f_ffree = sc.sc_free;
1198 	buf->f_namelen = GFS2_FNAMESIZE;
1199 
1200 	return 0;
1201 }
1202 
1203 /**
1204  * gfs2_remount_fs - called when the FS is remounted
1205  * @sb:  the filesystem
1206  * @flags:  the remount flags
1207  * @data:  extra data passed in (not used right now)
1208  *
1209  * Returns: errno
1210  */
1211 
1212 static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
1213 {
1214 	struct gfs2_sbd *sdp = sb->s_fs_info;
1215 	struct gfs2_args args = sdp->sd_args; /* Default to current settings */
1216 	struct gfs2_tune *gt = &sdp->sd_tune;
1217 	int error;
1218 
1219 	sync_filesystem(sb);
1220 
1221 	spin_lock(&gt->gt_spin);
1222 	args.ar_commit = gt->gt_logd_secs;
1223 	args.ar_quota_quantum = gt->gt_quota_quantum;
1224 	if (gt->gt_statfs_slow)
1225 		args.ar_statfs_quantum = 0;
1226 	else
1227 		args.ar_statfs_quantum = gt->gt_statfs_quantum;
1228 	spin_unlock(&gt->gt_spin);
1229 	error = gfs2_mount_args(&args, data);
1230 	if (error)
1231 		return error;
1232 
1233 	/* Not allowed to change locking details */
1234 	if (strcmp(args.ar_lockproto, sdp->sd_args.ar_lockproto) ||
1235 	    strcmp(args.ar_locktable, sdp->sd_args.ar_locktable) ||
1236 	    strcmp(args.ar_hostdata, sdp->sd_args.ar_hostdata))
1237 		return -EINVAL;
1238 
1239 	/* Some flags must not be changed */
1240 	if (args_neq(&args, &sdp->sd_args, spectator) ||
1241 	    args_neq(&args, &sdp->sd_args, localflocks) ||
1242 	    args_neq(&args, &sdp->sd_args, meta))
1243 		return -EINVAL;
1244 
1245 	if (sdp->sd_args.ar_spectator)
1246 		*flags |= MS_RDONLY;
1247 
1248 	if ((sb->s_flags ^ *flags) & MS_RDONLY) {
1249 		if (*flags & MS_RDONLY)
1250 			error = gfs2_make_fs_ro(sdp);
1251 		else
1252 			error = gfs2_make_fs_rw(sdp);
1253 		if (error)
1254 			return error;
1255 	}
1256 
1257 	sdp->sd_args = args;
1258 	if (sdp->sd_args.ar_posix_acl)
1259 		sb->s_flags |= MS_POSIXACL;
1260 	else
1261 		sb->s_flags &= ~MS_POSIXACL;
1262 	if (sdp->sd_args.ar_nobarrier)
1263 		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1264 	else
1265 		clear_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1266 	spin_lock(&gt->gt_spin);
1267 	gt->gt_logd_secs = args.ar_commit;
1268 	gt->gt_quota_quantum = args.ar_quota_quantum;
1269 	if (args.ar_statfs_quantum) {
1270 		gt->gt_statfs_slow = 0;
1271 		gt->gt_statfs_quantum = args.ar_statfs_quantum;
1272 	}
1273 	else {
1274 		gt->gt_statfs_slow = 1;
1275 		gt->gt_statfs_quantum = 30;
1276 	}
1277 	spin_unlock(&gt->gt_spin);
1278 
1279 	gfs2_online_uevent(sdp);
1280 	return 0;
1281 }
1282 
1283 /**
1284  * gfs2_drop_inode - Drop an inode (test for remote unlink)
1285  * @inode: The inode to drop
1286  *
1287  * If we've received a callback on an iopen lock then its because a
1288  * remote node tried to deallocate the inode but failed due to this node
1289  * still having the inode open. Here we mark the link count zero
1290  * since we know that it must have reached zero if the GLF_DEMOTE flag
1291  * is set on the iopen glock. If we didn't do a disk read since the
1292  * remote node removed the final link then we might otherwise miss
1293  * this event. This check ensures that this node will deallocate the
1294  * inode's blocks, or alternatively pass the baton on to another
1295  * node for later deallocation.
1296  */
1297 
1298 static int gfs2_drop_inode(struct inode *inode)
1299 {
1300 	struct gfs2_inode *ip = GFS2_I(inode);
1301 
1302 	if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) && inode->i_nlink) {
1303 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1304 		if (gl && test_bit(GLF_DEMOTE, &gl->gl_flags))
1305 			clear_nlink(inode);
1306 	}
1307 	return generic_drop_inode(inode);
1308 }
1309 
1310 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1311 {
1312 	do {
1313 		if (d1 == d2)
1314 			return 1;
1315 		d1 = d1->d_parent;
1316 	} while (!IS_ROOT(d1));
1317 	return 0;
1318 }
1319 
1320 /**
1321  * gfs2_show_options - Show mount options for /proc/mounts
1322  * @s: seq_file structure
1323  * @root: root of this (sub)tree
1324  *
1325  * Returns: 0 on success or error code
1326  */
1327 
1328 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1329 {
1330 	struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1331 	struct gfs2_args *args = &sdp->sd_args;
1332 	int val;
1333 
1334 	if (is_ancestor(root, sdp->sd_master_dir))
1335 		seq_puts(s, ",meta");
1336 	if (args->ar_lockproto[0])
1337 		seq_show_option(s, "lockproto", args->ar_lockproto);
1338 	if (args->ar_locktable[0])
1339 		seq_show_option(s, "locktable", args->ar_locktable);
1340 	if (args->ar_hostdata[0])
1341 		seq_show_option(s, "hostdata", args->ar_hostdata);
1342 	if (args->ar_spectator)
1343 		seq_puts(s, ",spectator");
1344 	if (args->ar_localflocks)
1345 		seq_puts(s, ",localflocks");
1346 	if (args->ar_debug)
1347 		seq_puts(s, ",debug");
1348 	if (args->ar_posix_acl)
1349 		seq_puts(s, ",acl");
1350 	if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1351 		char *state;
1352 		switch (args->ar_quota) {
1353 		case GFS2_QUOTA_OFF:
1354 			state = "off";
1355 			break;
1356 		case GFS2_QUOTA_ACCOUNT:
1357 			state = "account";
1358 			break;
1359 		case GFS2_QUOTA_ON:
1360 			state = "on";
1361 			break;
1362 		default:
1363 			state = "unknown";
1364 			break;
1365 		}
1366 		seq_printf(s, ",quota=%s", state);
1367 	}
1368 	if (args->ar_suiddir)
1369 		seq_puts(s, ",suiddir");
1370 	if (args->ar_data != GFS2_DATA_DEFAULT) {
1371 		char *state;
1372 		switch (args->ar_data) {
1373 		case GFS2_DATA_WRITEBACK:
1374 			state = "writeback";
1375 			break;
1376 		case GFS2_DATA_ORDERED:
1377 			state = "ordered";
1378 			break;
1379 		default:
1380 			state = "unknown";
1381 			break;
1382 		}
1383 		seq_printf(s, ",data=%s", state);
1384 	}
1385 	if (args->ar_discard)
1386 		seq_puts(s, ",discard");
1387 	val = sdp->sd_tune.gt_logd_secs;
1388 	if (val != 30)
1389 		seq_printf(s, ",commit=%d", val);
1390 	val = sdp->sd_tune.gt_statfs_quantum;
1391 	if (val != 30)
1392 		seq_printf(s, ",statfs_quantum=%d", val);
1393 	else if (sdp->sd_tune.gt_statfs_slow)
1394 		seq_puts(s, ",statfs_quantum=0");
1395 	val = sdp->sd_tune.gt_quota_quantum;
1396 	if (val != 60)
1397 		seq_printf(s, ",quota_quantum=%d", val);
1398 	if (args->ar_statfs_percent)
1399 		seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1400 	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1401 		const char *state;
1402 
1403 		switch (args->ar_errors) {
1404 		case GFS2_ERRORS_WITHDRAW:
1405 			state = "withdraw";
1406 			break;
1407 		case GFS2_ERRORS_PANIC:
1408 			state = "panic";
1409 			break;
1410 		default:
1411 			state = "unknown";
1412 			break;
1413 		}
1414 		seq_printf(s, ",errors=%s", state);
1415 	}
1416 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1417 		seq_puts(s, ",nobarrier");
1418 	if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1419 		seq_puts(s, ",demote_interface_used");
1420 	if (args->ar_rgrplvb)
1421 		seq_puts(s, ",rgrplvb");
1422 	return 0;
1423 }
1424 
1425 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1426 {
1427 	struct inode *inode = &ip->i_inode;
1428 	struct gfs2_glock *gl = ip->i_gl;
1429 
1430 	truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1431 	truncate_inode_pages(&inode->i_data, 0);
1432 
1433 	if (atomic_read(&gl->gl_revokes) == 0) {
1434 		clear_bit(GLF_LFLUSH, &gl->gl_flags);
1435 		clear_bit(GLF_DIRTY, &gl->gl_flags);
1436 	}
1437 }
1438 
1439 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1440 {
1441 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1442 	struct gfs2_rgrpd *rgd;
1443 	struct gfs2_holder gh;
1444 	int error;
1445 
1446 	if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1447 		gfs2_consist_inode(ip);
1448 		return -EIO;
1449 	}
1450 
1451 	error = gfs2_rindex_update(sdp);
1452 	if (error)
1453 		return error;
1454 
1455 	error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1456 	if (error)
1457 		return error;
1458 
1459 	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1460 	if (!rgd) {
1461 		gfs2_consist_inode(ip);
1462 		error = -EIO;
1463 		goto out_qs;
1464 	}
1465 
1466 	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
1467 	if (error)
1468 		goto out_qs;
1469 
1470 	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1471 				 sdp->sd_jdesc->jd_blocks);
1472 	if (error)
1473 		goto out_rg_gunlock;
1474 
1475 	gfs2_free_di(rgd, ip);
1476 
1477 	gfs2_final_release_pages(ip);
1478 
1479 	gfs2_trans_end(sdp);
1480 
1481 out_rg_gunlock:
1482 	gfs2_glock_dq_uninit(&gh);
1483 out_qs:
1484 	gfs2_quota_unhold(ip);
1485 	return error;
1486 }
1487 
1488 /**
1489  * gfs2_evict_inode - Remove an inode from cache
1490  * @inode: The inode to evict
1491  *
1492  * There are three cases to consider:
1493  * 1. i_nlink == 0, we are final opener (and must deallocate)
1494  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1495  * 3. i_nlink > 0
1496  *
1497  * If the fs is read only, then we have to treat all cases as per #3
1498  * since we are unable to do any deallocation. The inode will be
1499  * deallocated by the next read/write node to attempt an allocation
1500  * in the same resource group
1501  *
1502  * We have to (at the moment) hold the inodes main lock to cover
1503  * the gap between unlocking the shared lock on the iopen lock and
1504  * taking the exclusive lock. I'd rather do a shared -> exclusive
1505  * conversion on the iopen lock, but we can change that later. This
1506  * is safe, just less efficient.
1507  */
1508 
1509 static void gfs2_evict_inode(struct inode *inode)
1510 {
1511 	struct super_block *sb = inode->i_sb;
1512 	struct gfs2_sbd *sdp = sb->s_fs_info;
1513 	struct gfs2_inode *ip = GFS2_I(inode);
1514 	struct gfs2_holder gh;
1515 	int error;
1516 
1517 	if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1518 		clear_inode(inode);
1519 		return;
1520 	}
1521 
1522 	if (inode->i_nlink || (sb->s_flags & MS_RDONLY))
1523 		goto out;
1524 
1525 	/* Must not read inode block until block type has been verified */
1526 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, &gh);
1527 	if (unlikely(error)) {
1528 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1529 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1530 		goto out;
1531 	}
1532 
1533 	if (!test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1534 		error = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1535 		if (error)
1536 			goto out_truncate;
1537 	}
1538 
1539 	if (test_bit(GIF_INVALID, &ip->i_flags)) {
1540 		error = gfs2_inode_refresh(ip);
1541 		if (error)
1542 			goto out_truncate;
1543 	}
1544 
1545 	ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1546 	gfs2_glock_dq_wait(&ip->i_iopen_gh);
1547 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, &ip->i_iopen_gh);
1548 	error = gfs2_glock_nq(&ip->i_iopen_gh);
1549 	if (error)
1550 		goto out_truncate;
1551 
1552 	/* Case 1 starts here */
1553 
1554 	if (S_ISDIR(inode->i_mode) &&
1555 	    (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1556 		error = gfs2_dir_exhash_dealloc(ip);
1557 		if (error)
1558 			goto out_unlock;
1559 	}
1560 
1561 	if (ip->i_eattr) {
1562 		error = gfs2_ea_dealloc(ip);
1563 		if (error)
1564 			goto out_unlock;
1565 	}
1566 
1567 	if (!gfs2_is_stuffed(ip)) {
1568 		error = gfs2_file_dealloc(ip);
1569 		if (error)
1570 			goto out_unlock;
1571 	}
1572 
1573 	error = gfs2_dinode_dealloc(ip);
1574 	goto out_unlock;
1575 
1576 out_truncate:
1577 	gfs2_log_flush(sdp, ip->i_gl, NORMAL_FLUSH);
1578 	if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1579 		struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
1580 		filemap_fdatawrite(metamapping);
1581 		filemap_fdatawait(metamapping);
1582 	}
1583 	write_inode_now(inode, 1);
1584 	gfs2_ail_flush(ip->i_gl, 0);
1585 
1586 	/* Case 2 starts here */
1587 	error = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1588 	if (error)
1589 		goto out_unlock;
1590 	/* Needs to be done before glock release & also in a transaction */
1591 	truncate_inode_pages(&inode->i_data, 0);
1592 	gfs2_trans_end(sdp);
1593 
1594 out_unlock:
1595 	/* Error path for case 1 */
1596 	if (gfs2_rs_active(ip->i_res))
1597 		gfs2_rs_deltree(ip->i_res);
1598 
1599 	if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1600 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1601 		gfs2_glock_dq(&ip->i_iopen_gh);
1602 	}
1603 	gfs2_holder_uninit(&ip->i_iopen_gh);
1604 	gfs2_glock_dq_uninit(&gh);
1605 	if (error && error != GLR_TRYFAILED && error != -EROFS)
1606 		fs_warn(sdp, "gfs2_evict_inode: %d\n", error);
1607 out:
1608 	/* Case 3 starts here */
1609 	truncate_inode_pages_final(&inode->i_data);
1610 	gfs2_rs_delete(ip, NULL);
1611 	gfs2_ordered_del_inode(ip);
1612 	clear_inode(inode);
1613 	gfs2_dir_hash_inval(ip);
1614 	ip->i_gl->gl_object = NULL;
1615 	flush_delayed_work(&ip->i_gl->gl_work);
1616 	gfs2_glock_add_to_lru(ip->i_gl);
1617 	gfs2_glock_put(ip->i_gl);
1618 	ip->i_gl = NULL;
1619 	if (ip->i_iopen_gh.gh_gl) {
1620 		ip->i_iopen_gh.gh_gl->gl_object = NULL;
1621 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1622 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1623 	}
1624 }
1625 
1626 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1627 {
1628 	struct gfs2_inode *ip;
1629 
1630 	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1631 	if (ip) {
1632 		ip->i_flags = 0;
1633 		ip->i_gl = NULL;
1634 		ip->i_rgd = NULL;
1635 		ip->i_res = NULL;
1636 	}
1637 	return &ip->i_inode;
1638 }
1639 
1640 static void gfs2_i_callback(struct rcu_head *head)
1641 {
1642 	struct inode *inode = container_of(head, struct inode, i_rcu);
1643 	kmem_cache_free(gfs2_inode_cachep, inode);
1644 }
1645 
1646 static void gfs2_destroy_inode(struct inode *inode)
1647 {
1648 	call_rcu(&inode->i_rcu, gfs2_i_callback);
1649 }
1650 
1651 const struct super_operations gfs2_super_ops = {
1652 	.alloc_inode		= gfs2_alloc_inode,
1653 	.destroy_inode		= gfs2_destroy_inode,
1654 	.write_inode		= gfs2_write_inode,
1655 	.dirty_inode		= gfs2_dirty_inode,
1656 	.evict_inode		= gfs2_evict_inode,
1657 	.put_super		= gfs2_put_super,
1658 	.sync_fs		= gfs2_sync_fs,
1659 	.freeze_super		= gfs2_freeze,
1660 	.thaw_super		= gfs2_unfreeze,
1661 	.statfs			= gfs2_statfs,
1662 	.remount_fs		= gfs2_remount_fs,
1663 	.drop_inode		= gfs2_drop_inode,
1664 	.show_options		= gfs2_show_options,
1665 };
1666 
1667