xref: /linux/fs/gfs2/super.c (revision 18ca45f5ba1e31704bcca038b8b612e9b1f52b4f)
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 
85 	list_for_each_entry(jd, head, jd_list) {
86 		if (jd->jd_jid == jid)
87 			return jd;
88 	}
89 	return NULL;
90 }
91 
92 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
93 {
94 	struct gfs2_jdesc *jd;
95 
96 	spin_lock(&sdp->sd_jindex_spin);
97 	jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
98 	spin_unlock(&sdp->sd_jindex_spin);
99 
100 	return jd;
101 }
102 
103 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
104 {
105 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
106 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
107 	u64 size = i_size_read(jd->jd_inode);
108 
109 	if (gfs2_check_internal_file_size(jd->jd_inode, 8 << 20, BIT(30)))
110 		return -EIO;
111 
112 	jd->jd_blocks = size >> sdp->sd_sb.sb_bsize_shift;
113 
114 	if (gfs2_write_alloc_required(ip, 0, size)) {
115 		gfs2_consist_inode(ip);
116 		return -EIO;
117 	}
118 
119 	return 0;
120 }
121 
122 static int init_threads(struct gfs2_sbd *sdp)
123 {
124 	struct task_struct *p;
125 	int error = 0;
126 
127 	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
128 	if (IS_ERR(p)) {
129 		error = PTR_ERR(p);
130 		fs_err(sdp, "can't start logd thread: %d\n", error);
131 		return error;
132 	}
133 	sdp->sd_logd_process = p;
134 
135 	p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
136 	if (IS_ERR(p)) {
137 		error = PTR_ERR(p);
138 		fs_err(sdp, "can't start quotad thread: %d\n", error);
139 		goto fail;
140 	}
141 	sdp->sd_quotad_process = p;
142 	return 0;
143 
144 fail:
145 	kthread_stop(sdp->sd_logd_process);
146 	sdp->sd_logd_process = NULL;
147 	return error;
148 }
149 
150 /**
151  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
152  * @sdp: the filesystem
153  *
154  * Returns: errno
155  */
156 
157 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
158 {
159 	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
160 	struct gfs2_glock *j_gl = ip->i_gl;
161 	struct gfs2_log_header_host head;
162 	int error;
163 
164 	error = init_threads(sdp);
165 	if (error) {
166 		gfs2_withdraw_delayed(sdp);
167 		return error;
168 	}
169 
170 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
171 	if (gfs2_withdrawn(sdp)) {
172 		error = -EIO;
173 		goto fail;
174 	}
175 
176 	error = gfs2_find_jhead(sdp->sd_jdesc, &head, false);
177 	if (error || gfs2_withdrawn(sdp))
178 		goto fail;
179 
180 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
181 		gfs2_consist(sdp);
182 		error = -EIO;
183 		goto fail;
184 	}
185 
186 	/*  Initialize some head of the log stuff  */
187 	sdp->sd_log_sequence = head.lh_sequence + 1;
188 	gfs2_log_pointers_init(sdp, head.lh_blkno);
189 
190 	error = gfs2_quota_init(sdp);
191 	if (error || gfs2_withdrawn(sdp))
192 		goto fail;
193 
194 	set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
195 
196 	return 0;
197 
198 fail:
199 	if (sdp->sd_quotad_process)
200 		kthread_stop(sdp->sd_quotad_process);
201 	sdp->sd_quotad_process = NULL;
202 	if (sdp->sd_logd_process)
203 		kthread_stop(sdp->sd_logd_process);
204 	sdp->sd_logd_process = NULL;
205 	return error;
206 }
207 
208 void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
209 {
210 	const struct gfs2_statfs_change *str = buf;
211 
212 	sc->sc_total = be64_to_cpu(str->sc_total);
213 	sc->sc_free = be64_to_cpu(str->sc_free);
214 	sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
215 }
216 
217 void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
218 {
219 	struct gfs2_statfs_change *str = buf;
220 
221 	str->sc_total = cpu_to_be64(sc->sc_total);
222 	str->sc_free = cpu_to_be64(sc->sc_free);
223 	str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
224 }
225 
226 int gfs2_statfs_init(struct gfs2_sbd *sdp)
227 {
228 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
229 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
230 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
231 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
232 	struct buffer_head *m_bh, *l_bh;
233 	struct gfs2_holder gh;
234 	int error;
235 
236 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
237 				   &gh);
238 	if (error)
239 		return error;
240 
241 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
242 	if (error)
243 		goto out;
244 
245 	if (sdp->sd_args.ar_spectator) {
246 		spin_lock(&sdp->sd_statfs_spin);
247 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
248 				      sizeof(struct gfs2_dinode));
249 		spin_unlock(&sdp->sd_statfs_spin);
250 	} else {
251 		error = gfs2_meta_inode_buffer(l_ip, &l_bh);
252 		if (error)
253 			goto out_m_bh;
254 
255 		spin_lock(&sdp->sd_statfs_spin);
256 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
257 				      sizeof(struct gfs2_dinode));
258 		gfs2_statfs_change_in(l_sc, l_bh->b_data +
259 				      sizeof(struct gfs2_dinode));
260 		spin_unlock(&sdp->sd_statfs_spin);
261 
262 		brelse(l_bh);
263 	}
264 
265 out_m_bh:
266 	brelse(m_bh);
267 out:
268 	gfs2_glock_dq_uninit(&gh);
269 	return 0;
270 }
271 
272 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
273 			s64 dinodes)
274 {
275 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
276 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
277 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
278 	struct buffer_head *l_bh;
279 	s64 x, y;
280 	int need_sync = 0;
281 	int error;
282 
283 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
284 	if (error)
285 		return;
286 
287 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
288 
289 	spin_lock(&sdp->sd_statfs_spin);
290 	l_sc->sc_total += total;
291 	l_sc->sc_free += free;
292 	l_sc->sc_dinodes += dinodes;
293 	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
294 	if (sdp->sd_args.ar_statfs_percent) {
295 		x = 100 * l_sc->sc_free;
296 		y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
297 		if (x >= y || x <= -y)
298 			need_sync = 1;
299 	}
300 	spin_unlock(&sdp->sd_statfs_spin);
301 
302 	brelse(l_bh);
303 	if (need_sync)
304 		gfs2_wake_up_statfs(sdp);
305 }
306 
307 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
308 		   struct buffer_head *l_bh)
309 {
310 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
311 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
312 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
313 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
314 
315 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
316 	gfs2_trans_add_meta(m_ip->i_gl, m_bh);
317 
318 	spin_lock(&sdp->sd_statfs_spin);
319 	m_sc->sc_total += l_sc->sc_total;
320 	m_sc->sc_free += l_sc->sc_free;
321 	m_sc->sc_dinodes += l_sc->sc_dinodes;
322 	memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
323 	memset(l_bh->b_data + sizeof(struct gfs2_dinode),
324 	       0, sizeof(struct gfs2_statfs_change));
325 	gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
326 	spin_unlock(&sdp->sd_statfs_spin);
327 }
328 
329 int gfs2_statfs_sync(struct super_block *sb, int type)
330 {
331 	struct gfs2_sbd *sdp = sb->s_fs_info;
332 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
333 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
334 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
335 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
336 	struct gfs2_holder gh;
337 	struct buffer_head *m_bh, *l_bh;
338 	int error;
339 
340 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
341 				   &gh);
342 	if (error)
343 		goto out;
344 
345 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
346 	if (error)
347 		goto out_unlock;
348 
349 	spin_lock(&sdp->sd_statfs_spin);
350 	gfs2_statfs_change_in(m_sc, m_bh->b_data +
351 			      sizeof(struct gfs2_dinode));
352 	if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
353 		spin_unlock(&sdp->sd_statfs_spin);
354 		goto out_bh;
355 	}
356 	spin_unlock(&sdp->sd_statfs_spin);
357 
358 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
359 	if (error)
360 		goto out_bh;
361 
362 	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
363 	if (error)
364 		goto out_bh2;
365 
366 	update_statfs(sdp, m_bh, l_bh);
367 	sdp->sd_statfs_force_sync = 0;
368 
369 	gfs2_trans_end(sdp);
370 
371 out_bh2:
372 	brelse(l_bh);
373 out_bh:
374 	brelse(m_bh);
375 out_unlock:
376 	gfs2_glock_dq_uninit(&gh);
377 out:
378 	return error;
379 }
380 
381 struct lfcc {
382 	struct list_head list;
383 	struct gfs2_holder gh;
384 };
385 
386 /**
387  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
388  *                            journals are clean
389  * @sdp: the file system
390  *
391  * Returns: errno
392  */
393 
394 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp)
395 {
396 	struct gfs2_inode *ip;
397 	struct gfs2_jdesc *jd;
398 	struct lfcc *lfcc;
399 	LIST_HEAD(list);
400 	struct gfs2_log_header_host lh;
401 	int error;
402 
403 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
404 		lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
405 		if (!lfcc) {
406 			error = -ENOMEM;
407 			goto out;
408 		}
409 		ip = GFS2_I(jd->jd_inode);
410 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
411 		if (error) {
412 			kfree(lfcc);
413 			goto out;
414 		}
415 		list_add(&lfcc->list, &list);
416 	}
417 
418 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
419 				   LM_FLAG_NOEXP, &sdp->sd_freeze_gh);
420 	if (error)
421 		goto out;
422 
423 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
424 		error = gfs2_jdesc_check(jd);
425 		if (error)
426 			break;
427 		error = gfs2_find_jhead(jd, &lh, false);
428 		if (error)
429 			break;
430 		if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
431 			error = -EBUSY;
432 			break;
433 		}
434 	}
435 
436 	if (error)
437 		gfs2_freeze_unlock(&sdp->sd_freeze_gh);
438 
439 out:
440 	while (!list_empty(&list)) {
441 		lfcc = list_first_entry(&list, struct lfcc, list);
442 		list_del(&lfcc->list);
443 		gfs2_glock_dq_uninit(&lfcc->gh);
444 		kfree(lfcc);
445 	}
446 	return error;
447 }
448 
449 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
450 {
451 	struct gfs2_dinode *str = buf;
452 
453 	str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
454 	str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
455 	str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
456 	str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
457 	str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
458 	str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
459 	str->di_uid = cpu_to_be32(i_uid_read(&ip->i_inode));
460 	str->di_gid = cpu_to_be32(i_gid_read(&ip->i_inode));
461 	str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
462 	str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
463 	str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
464 	str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
465 	str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
466 	str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
467 
468 	str->di_goal_meta = cpu_to_be64(ip->i_goal);
469 	str->di_goal_data = cpu_to_be64(ip->i_goal);
470 	str->di_generation = cpu_to_be64(ip->i_generation);
471 
472 	str->di_flags = cpu_to_be32(ip->i_diskflags);
473 	str->di_height = cpu_to_be16(ip->i_height);
474 	str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
475 					     !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
476 					     GFS2_FORMAT_DE : 0);
477 	str->di_depth = cpu_to_be16(ip->i_depth);
478 	str->di_entries = cpu_to_be32(ip->i_entries);
479 
480 	str->di_eattr = cpu_to_be64(ip->i_eattr);
481 	str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
482 	str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
483 	str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
484 }
485 
486 /**
487  * gfs2_write_inode - Make sure the inode is stable on the disk
488  * @inode: The inode
489  * @wbc: The writeback control structure
490  *
491  * Returns: errno
492  */
493 
494 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
495 {
496 	struct gfs2_inode *ip = GFS2_I(inode);
497 	struct gfs2_sbd *sdp = GFS2_SB(inode);
498 	struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
499 	struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
500 	int ret = 0;
501 	bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
502 
503 	if (flush_all)
504 		gfs2_log_flush(GFS2_SB(inode), ip->i_gl,
505 			       GFS2_LOG_HEAD_FLUSH_NORMAL |
506 			       GFS2_LFC_WRITE_INODE);
507 	if (bdi->wb.dirty_exceeded)
508 		gfs2_ail1_flush(sdp, wbc);
509 	else
510 		filemap_fdatawrite(metamapping);
511 	if (flush_all)
512 		ret = filemap_fdatawait(metamapping);
513 	if (ret)
514 		mark_inode_dirty_sync(inode);
515 	else {
516 		spin_lock(&inode->i_lock);
517 		if (!(inode->i_flags & I_DIRTY))
518 			gfs2_ordered_del_inode(ip);
519 		spin_unlock(&inode->i_lock);
520 	}
521 	return ret;
522 }
523 
524 /**
525  * gfs2_dirty_inode - check for atime updates
526  * @inode: The inode in question
527  * @flags: The type of dirty
528  *
529  * Unfortunately it can be called under any combination of inode
530  * glock and transaction lock, so we have to check carefully.
531  *
532  * At the moment this deals only with atime - it should be possible
533  * to expand that role in future, once a review of the locking has
534  * been carried out.
535  */
536 
537 static void gfs2_dirty_inode(struct inode *inode, int flags)
538 {
539 	struct gfs2_inode *ip = GFS2_I(inode);
540 	struct gfs2_sbd *sdp = GFS2_SB(inode);
541 	struct buffer_head *bh;
542 	struct gfs2_holder gh;
543 	int need_unlock = 0;
544 	int need_endtrans = 0;
545 	int ret;
546 
547 	if (unlikely(gfs2_withdrawn(sdp)))
548 		return;
549 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
550 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
551 		if (ret) {
552 			fs_err(sdp, "dirty_inode: glock %d\n", ret);
553 			gfs2_dump_glock(NULL, ip->i_gl, true);
554 			return;
555 		}
556 		need_unlock = 1;
557 	} else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
558 		return;
559 
560 	if (current->journal_info == NULL) {
561 		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
562 		if (ret) {
563 			fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
564 			goto out;
565 		}
566 		need_endtrans = 1;
567 	}
568 
569 	ret = gfs2_meta_inode_buffer(ip, &bh);
570 	if (ret == 0) {
571 		gfs2_trans_add_meta(ip->i_gl, bh);
572 		gfs2_dinode_out(ip, bh->b_data);
573 		brelse(bh);
574 	}
575 
576 	if (need_endtrans)
577 		gfs2_trans_end(sdp);
578 out:
579 	if (need_unlock)
580 		gfs2_glock_dq_uninit(&gh);
581 }
582 
583 /**
584  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
585  * @sdp: the filesystem
586  *
587  * Returns: errno
588  */
589 
590 void gfs2_make_fs_ro(struct gfs2_sbd *sdp)
591 {
592 	int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
593 
594 	gfs2_flush_delete_work(sdp);
595 	if (!log_write_allowed && current == sdp->sd_quotad_process)
596 		fs_warn(sdp, "The quotad daemon is withdrawing.\n");
597 	else if (sdp->sd_quotad_process)
598 		kthread_stop(sdp->sd_quotad_process);
599 	sdp->sd_quotad_process = NULL;
600 
601 	if (!log_write_allowed && current == sdp->sd_logd_process)
602 		fs_warn(sdp, "The logd daemon is withdrawing.\n");
603 	else if (sdp->sd_logd_process)
604 		kthread_stop(sdp->sd_logd_process);
605 	sdp->sd_logd_process = NULL;
606 
607 	if (log_write_allowed) {
608 		gfs2_quota_sync(sdp->sd_vfs, 0);
609 		gfs2_statfs_sync(sdp->sd_vfs, 0);
610 
611 		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
612 			       GFS2_LFC_MAKE_FS_RO);
613 		wait_event_timeout(sdp->sd_log_waitq,
614 				   gfs2_log_is_empty(sdp),
615 				   HZ * 5);
616 		gfs2_assert_warn(sdp, gfs2_log_is_empty(sdp));
617 	} else {
618 		wait_event_timeout(sdp->sd_log_waitq,
619 				   gfs2_log_is_empty(sdp),
620 				   HZ * 5);
621 	}
622 	gfs2_quota_cleanup(sdp);
623 
624 	if (!log_write_allowed)
625 		sdp->sd_vfs->s_flags |= SB_RDONLY;
626 }
627 
628 /**
629  * gfs2_put_super - Unmount the filesystem
630  * @sb: The VFS superblock
631  *
632  */
633 
634 static void gfs2_put_super(struct super_block *sb)
635 {
636 	struct gfs2_sbd *sdp = sb->s_fs_info;
637 	struct gfs2_jdesc *jd;
638 
639 	/* No more recovery requests */
640 	set_bit(SDF_NORECOVERY, &sdp->sd_flags);
641 	smp_mb();
642 
643 	/* Wait on outstanding recovery */
644 restart:
645 	spin_lock(&sdp->sd_jindex_spin);
646 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
647 		if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
648 			continue;
649 		spin_unlock(&sdp->sd_jindex_spin);
650 		wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
651 			    TASK_UNINTERRUPTIBLE);
652 		goto restart;
653 	}
654 	spin_unlock(&sdp->sd_jindex_spin);
655 
656 	if (!sb_rdonly(sb)) {
657 		gfs2_make_fs_ro(sdp);
658 	}
659 	WARN_ON(gfs2_withdrawing(sdp));
660 
661 	/*  At this point, we're through modifying the disk  */
662 
663 	/*  Release stuff  */
664 
665 	iput(sdp->sd_jindex);
666 	iput(sdp->sd_statfs_inode);
667 	iput(sdp->sd_rindex);
668 	iput(sdp->sd_quota_inode);
669 
670 	gfs2_glock_put(sdp->sd_rename_gl);
671 	gfs2_glock_put(sdp->sd_freeze_gl);
672 
673 	if (!sdp->sd_args.ar_spectator) {
674 		if (gfs2_holder_initialized(&sdp->sd_journal_gh))
675 			gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
676 		if (gfs2_holder_initialized(&sdp->sd_jinode_gh))
677 			gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
678 		gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
679 		gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
680 		free_local_statfs_inodes(sdp);
681 		iput(sdp->sd_qc_inode);
682 	}
683 
684 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
685 	gfs2_clear_rgrpd(sdp);
686 	gfs2_jindex_free(sdp);
687 	/*  Take apart glock structures and buffer lists  */
688 	gfs2_gl_hash_clear(sdp);
689 	truncate_inode_pages_final(&sdp->sd_aspace);
690 	gfs2_delete_debugfs_file(sdp);
691 	/*  Unmount the locking protocol  */
692 	gfs2_lm_unmount(sdp);
693 
694 	/*  At this point, we're through participating in the lockspace  */
695 	gfs2_sys_fs_del(sdp);
696 	free_sbd(sdp);
697 }
698 
699 /**
700  * gfs2_sync_fs - sync the filesystem
701  * @sb: the superblock
702  * @wait: true to wait for completion
703  *
704  * Flushes the log to disk.
705  */
706 
707 static int gfs2_sync_fs(struct super_block *sb, int wait)
708 {
709 	struct gfs2_sbd *sdp = sb->s_fs_info;
710 
711 	gfs2_quota_sync(sb, -1);
712 	if (wait)
713 		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
714 			       GFS2_LFC_SYNC_FS);
715 	return sdp->sd_log_error;
716 }
717 
718 void gfs2_freeze_func(struct work_struct *work)
719 {
720 	int error;
721 	struct gfs2_holder freeze_gh;
722 	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
723 	struct super_block *sb = sdp->sd_vfs;
724 
725 	atomic_inc(&sb->s_active);
726 	error = gfs2_freeze_lock(sdp, &freeze_gh, 0);
727 	if (error) {
728 		gfs2_assert_withdraw(sdp, 0);
729 	} else {
730 		atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
731 		error = thaw_super(sb);
732 		if (error) {
733 			fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
734 				error);
735 			gfs2_assert_withdraw(sdp, 0);
736 		}
737 		gfs2_freeze_unlock(&freeze_gh);
738 	}
739 	deactivate_super(sb);
740 	clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
741 	wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
742 	return;
743 }
744 
745 /**
746  * gfs2_freeze - prevent further writes to the filesystem
747  * @sb: the VFS structure for the filesystem
748  *
749  */
750 
751 static int gfs2_freeze(struct super_block *sb)
752 {
753 	struct gfs2_sbd *sdp = sb->s_fs_info;
754 	int error;
755 
756 	mutex_lock(&sdp->sd_freeze_mutex);
757 	if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN) {
758 		error = -EBUSY;
759 		goto out;
760 	}
761 
762 	for (;;) {
763 		if (gfs2_withdrawn(sdp)) {
764 			error = -EINVAL;
765 			goto out;
766 		}
767 
768 		error = gfs2_lock_fs_check_clean(sdp);
769 		if (!error)
770 			break;
771 
772 		if (error == -EBUSY)
773 			fs_err(sdp, "waiting for recovery before freeze\n");
774 		else if (error == -EIO) {
775 			fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
776 			       "to recovery error.\n");
777 			goto out;
778 		} else {
779 			fs_err(sdp, "error freezing FS: %d\n", error);
780 		}
781 		fs_err(sdp, "retrying...\n");
782 		msleep(1000);
783 	}
784 	set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
785 out:
786 	mutex_unlock(&sdp->sd_freeze_mutex);
787 	return error;
788 }
789 
790 /**
791  * gfs2_unfreeze - reallow writes to the filesystem
792  * @sb: the VFS structure for the filesystem
793  *
794  */
795 
796 static int gfs2_unfreeze(struct super_block *sb)
797 {
798 	struct gfs2_sbd *sdp = sb->s_fs_info;
799 
800 	mutex_lock(&sdp->sd_freeze_mutex);
801 	if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
802 	    !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
803 		mutex_unlock(&sdp->sd_freeze_mutex);
804 		return -EINVAL;
805 	}
806 
807 	gfs2_freeze_unlock(&sdp->sd_freeze_gh);
808 	mutex_unlock(&sdp->sd_freeze_mutex);
809 	return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
810 }
811 
812 /**
813  * statfs_slow_fill - fill in the sg for a given RG
814  * @rgd: the RG
815  * @sc: the sc structure
816  *
817  * Returns: 0 on success, -ESTALE if the LVB is invalid
818  */
819 
820 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
821 			    struct gfs2_statfs_change_host *sc)
822 {
823 	gfs2_rgrp_verify(rgd);
824 	sc->sc_total += rgd->rd_data;
825 	sc->sc_free += rgd->rd_free;
826 	sc->sc_dinodes += rgd->rd_dinodes;
827 	return 0;
828 }
829 
830 /**
831  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
832  * @sdp: the filesystem
833  * @sc: the sc info that will be returned
834  *
835  * Any error (other than a signal) will cause this routine to fall back
836  * to the synchronous version.
837  *
838  * FIXME: This really shouldn't busy wait like this.
839  *
840  * Returns: errno
841  */
842 
843 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
844 {
845 	struct gfs2_rgrpd *rgd_next;
846 	struct gfs2_holder *gha, *gh;
847 	unsigned int slots = 64;
848 	unsigned int x;
849 	int done;
850 	int error = 0, err;
851 
852 	memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
853 	gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
854 	if (!gha)
855 		return -ENOMEM;
856 	for (x = 0; x < slots; x++)
857 		gfs2_holder_mark_uninitialized(gha + x);
858 
859 	rgd_next = gfs2_rgrpd_get_first(sdp);
860 
861 	for (;;) {
862 		done = 1;
863 
864 		for (x = 0; x < slots; x++) {
865 			gh = gha + x;
866 
867 			if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
868 				err = gfs2_glock_wait(gh);
869 				if (err) {
870 					gfs2_holder_uninit(gh);
871 					error = err;
872 				} else {
873 					if (!error) {
874 						struct gfs2_rgrpd *rgd =
875 							gfs2_glock2rgrp(gh->gh_gl);
876 
877 						error = statfs_slow_fill(rgd, sc);
878 					}
879 					gfs2_glock_dq_uninit(gh);
880 				}
881 			}
882 
883 			if (gfs2_holder_initialized(gh))
884 				done = 0;
885 			else if (rgd_next && !error) {
886 				error = gfs2_glock_nq_init(rgd_next->rd_gl,
887 							   LM_ST_SHARED,
888 							   GL_ASYNC,
889 							   gh);
890 				rgd_next = gfs2_rgrpd_get_next(rgd_next);
891 				done = 0;
892 			}
893 
894 			if (signal_pending(current))
895 				error = -ERESTARTSYS;
896 		}
897 
898 		if (done)
899 			break;
900 
901 		yield();
902 	}
903 
904 	kfree(gha);
905 	return error;
906 }
907 
908 /**
909  * gfs2_statfs_i - Do a statfs
910  * @sdp: the filesystem
911  * @sc: the sc structure
912  *
913  * Returns: errno
914  */
915 
916 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
917 {
918 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
919 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
920 
921 	spin_lock(&sdp->sd_statfs_spin);
922 
923 	*sc = *m_sc;
924 	sc->sc_total += l_sc->sc_total;
925 	sc->sc_free += l_sc->sc_free;
926 	sc->sc_dinodes += l_sc->sc_dinodes;
927 
928 	spin_unlock(&sdp->sd_statfs_spin);
929 
930 	if (sc->sc_free < 0)
931 		sc->sc_free = 0;
932 	if (sc->sc_free > sc->sc_total)
933 		sc->sc_free = sc->sc_total;
934 	if (sc->sc_dinodes < 0)
935 		sc->sc_dinodes = 0;
936 
937 	return 0;
938 }
939 
940 /**
941  * gfs2_statfs - Gather and return stats about the filesystem
942  * @dentry: The name of the link
943  * @buf: The buffer
944  *
945  * Returns: 0 on success or error code
946  */
947 
948 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
949 {
950 	struct super_block *sb = dentry->d_sb;
951 	struct gfs2_sbd *sdp = sb->s_fs_info;
952 	struct gfs2_statfs_change_host sc;
953 	int error;
954 
955 	error = gfs2_rindex_update(sdp);
956 	if (error)
957 		return error;
958 
959 	if (gfs2_tune_get(sdp, gt_statfs_slow))
960 		error = gfs2_statfs_slow(sdp, &sc);
961 	else
962 		error = gfs2_statfs_i(sdp, &sc);
963 
964 	if (error)
965 		return error;
966 
967 	buf->f_type = GFS2_MAGIC;
968 	buf->f_bsize = sdp->sd_sb.sb_bsize;
969 	buf->f_blocks = sc.sc_total;
970 	buf->f_bfree = sc.sc_free;
971 	buf->f_bavail = sc.sc_free;
972 	buf->f_files = sc.sc_dinodes + sc.sc_free;
973 	buf->f_ffree = sc.sc_free;
974 	buf->f_namelen = GFS2_FNAMESIZE;
975 
976 	return 0;
977 }
978 
979 /**
980  * gfs2_drop_inode - Drop an inode (test for remote unlink)
981  * @inode: The inode to drop
982  *
983  * If we've received a callback on an iopen lock then it's because a
984  * remote node tried to deallocate the inode but failed due to this node
985  * still having the inode open. Here we mark the link count zero
986  * since we know that it must have reached zero if the GLF_DEMOTE flag
987  * is set on the iopen glock. If we didn't do a disk read since the
988  * remote node removed the final link then we might otherwise miss
989  * this event. This check ensures that this node will deallocate the
990  * inode's blocks, or alternatively pass the baton on to another
991  * node for later deallocation.
992  */
993 
994 static int gfs2_drop_inode(struct inode *inode)
995 {
996 	struct gfs2_inode *ip = GFS2_I(inode);
997 
998 	if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) &&
999 	    inode->i_nlink &&
1000 	    gfs2_holder_initialized(&ip->i_iopen_gh)) {
1001 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1002 		if (test_bit(GLF_DEMOTE, &gl->gl_flags))
1003 			clear_nlink(inode);
1004 	}
1005 
1006 	/*
1007 	 * When under memory pressure when an inode's link count has dropped to
1008 	 * zero, defer deleting the inode to the delete workqueue.  This avoids
1009 	 * calling into DLM under memory pressure, which can deadlock.
1010 	 */
1011 	if (!inode->i_nlink &&
1012 	    unlikely(current->flags & PF_MEMALLOC) &&
1013 	    gfs2_holder_initialized(&ip->i_iopen_gh)) {
1014 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1015 
1016 		gfs2_glock_hold(gl);
1017 		if (!gfs2_queue_delete_work(gl, 0))
1018 			gfs2_glock_queue_put(gl);
1019 		return false;
1020 	}
1021 
1022 	return generic_drop_inode(inode);
1023 }
1024 
1025 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1026 {
1027 	do {
1028 		if (d1 == d2)
1029 			return 1;
1030 		d1 = d1->d_parent;
1031 	} while (!IS_ROOT(d1));
1032 	return 0;
1033 }
1034 
1035 /**
1036  * gfs2_show_options - Show mount options for /proc/mounts
1037  * @s: seq_file structure
1038  * @root: root of this (sub)tree
1039  *
1040  * Returns: 0 on success or error code
1041  */
1042 
1043 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1044 {
1045 	struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1046 	struct gfs2_args *args = &sdp->sd_args;
1047 	int val;
1048 
1049 	if (is_ancestor(root, sdp->sd_master_dir))
1050 		seq_puts(s, ",meta");
1051 	if (args->ar_lockproto[0])
1052 		seq_show_option(s, "lockproto", args->ar_lockproto);
1053 	if (args->ar_locktable[0])
1054 		seq_show_option(s, "locktable", args->ar_locktable);
1055 	if (args->ar_hostdata[0])
1056 		seq_show_option(s, "hostdata", args->ar_hostdata);
1057 	if (args->ar_spectator)
1058 		seq_puts(s, ",spectator");
1059 	if (args->ar_localflocks)
1060 		seq_puts(s, ",localflocks");
1061 	if (args->ar_debug)
1062 		seq_puts(s, ",debug");
1063 	if (args->ar_posix_acl)
1064 		seq_puts(s, ",acl");
1065 	if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1066 		char *state;
1067 		switch (args->ar_quota) {
1068 		case GFS2_QUOTA_OFF:
1069 			state = "off";
1070 			break;
1071 		case GFS2_QUOTA_ACCOUNT:
1072 			state = "account";
1073 			break;
1074 		case GFS2_QUOTA_ON:
1075 			state = "on";
1076 			break;
1077 		default:
1078 			state = "unknown";
1079 			break;
1080 		}
1081 		seq_printf(s, ",quota=%s", state);
1082 	}
1083 	if (args->ar_suiddir)
1084 		seq_puts(s, ",suiddir");
1085 	if (args->ar_data != GFS2_DATA_DEFAULT) {
1086 		char *state;
1087 		switch (args->ar_data) {
1088 		case GFS2_DATA_WRITEBACK:
1089 			state = "writeback";
1090 			break;
1091 		case GFS2_DATA_ORDERED:
1092 			state = "ordered";
1093 			break;
1094 		default:
1095 			state = "unknown";
1096 			break;
1097 		}
1098 		seq_printf(s, ",data=%s", state);
1099 	}
1100 	if (args->ar_discard)
1101 		seq_puts(s, ",discard");
1102 	val = sdp->sd_tune.gt_logd_secs;
1103 	if (val != 30)
1104 		seq_printf(s, ",commit=%d", val);
1105 	val = sdp->sd_tune.gt_statfs_quantum;
1106 	if (val != 30)
1107 		seq_printf(s, ",statfs_quantum=%d", val);
1108 	else if (sdp->sd_tune.gt_statfs_slow)
1109 		seq_puts(s, ",statfs_quantum=0");
1110 	val = sdp->sd_tune.gt_quota_quantum;
1111 	if (val != 60)
1112 		seq_printf(s, ",quota_quantum=%d", val);
1113 	if (args->ar_statfs_percent)
1114 		seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1115 	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1116 		const char *state;
1117 
1118 		switch (args->ar_errors) {
1119 		case GFS2_ERRORS_WITHDRAW:
1120 			state = "withdraw";
1121 			break;
1122 		case GFS2_ERRORS_PANIC:
1123 			state = "panic";
1124 			break;
1125 		default:
1126 			state = "unknown";
1127 			break;
1128 		}
1129 		seq_printf(s, ",errors=%s", state);
1130 	}
1131 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1132 		seq_puts(s, ",nobarrier");
1133 	if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1134 		seq_puts(s, ",demote_interface_used");
1135 	if (args->ar_rgrplvb)
1136 		seq_puts(s, ",rgrplvb");
1137 	if (args->ar_loccookie)
1138 		seq_puts(s, ",loccookie");
1139 	return 0;
1140 }
1141 
1142 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1143 {
1144 	struct inode *inode = &ip->i_inode;
1145 	struct gfs2_glock *gl = ip->i_gl;
1146 
1147 	truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1148 	truncate_inode_pages(&inode->i_data, 0);
1149 
1150 	if (atomic_read(&gl->gl_revokes) == 0) {
1151 		clear_bit(GLF_LFLUSH, &gl->gl_flags);
1152 		clear_bit(GLF_DIRTY, &gl->gl_flags);
1153 	}
1154 }
1155 
1156 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1157 {
1158 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1159 	struct gfs2_rgrpd *rgd;
1160 	struct gfs2_holder gh;
1161 	int error;
1162 
1163 	if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1164 		gfs2_consist_inode(ip);
1165 		return -EIO;
1166 	}
1167 
1168 	error = gfs2_rindex_update(sdp);
1169 	if (error)
1170 		return error;
1171 
1172 	error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1173 	if (error)
1174 		return error;
1175 
1176 	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1177 	if (!rgd) {
1178 		gfs2_consist_inode(ip);
1179 		error = -EIO;
1180 		goto out_qs;
1181 	}
1182 
1183 	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
1184 				   LM_FLAG_NODE_SCOPE, &gh);
1185 	if (error)
1186 		goto out_qs;
1187 
1188 	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1189 				 sdp->sd_jdesc->jd_blocks);
1190 	if (error)
1191 		goto out_rg_gunlock;
1192 
1193 	gfs2_free_di(rgd, ip);
1194 
1195 	gfs2_final_release_pages(ip);
1196 
1197 	gfs2_trans_end(sdp);
1198 
1199 out_rg_gunlock:
1200 	gfs2_glock_dq_uninit(&gh);
1201 out_qs:
1202 	gfs2_quota_unhold(ip);
1203 	return error;
1204 }
1205 
1206 /**
1207  * gfs2_glock_put_eventually
1208  * @gl:	The glock to put
1209  *
1210  * When under memory pressure, trigger a deferred glock put to make sure we
1211  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1212  */
1213 
1214 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1215 {
1216 	if (current->flags & PF_MEMALLOC)
1217 		gfs2_glock_queue_put(gl);
1218 	else
1219 		gfs2_glock_put(gl);
1220 }
1221 
1222 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1223 {
1224 	struct gfs2_inode *ip = GFS2_I(inode);
1225 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1226 	struct gfs2_holder *gh = &ip->i_iopen_gh;
1227 	long timeout = 5 * HZ;
1228 	int error;
1229 
1230 	gh->gh_flags |= GL_NOCACHE;
1231 	gfs2_glock_dq_wait(gh);
1232 
1233 	/*
1234 	 * If there are no other lock holders, we'll get the lock immediately.
1235 	 * Otherwise, the other nodes holding the lock will be notified about
1236 	 * our locking request.  If they don't have the inode open, they'll
1237 	 * evict the cached inode and release the lock.  Otherwise, if they
1238 	 * poke the inode glock, we'll take this as an indication that they
1239 	 * still need the iopen glock and that they'll take care of deleting
1240 	 * the inode when they're done.  As a last resort, if another node
1241 	 * keeps holding the iopen glock without showing any activity on the
1242 	 * inode glock, we'll eventually time out.
1243 	 *
1244 	 * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1245 	 * locking request as an optimization to notify lock holders as soon as
1246 	 * possible.  Without that flag, they'd be notified implicitly by the
1247 	 * second locking request.
1248 	 */
1249 
1250 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1251 	error = gfs2_glock_nq(gh);
1252 	if (error != GLR_TRYFAILED)
1253 		return !error;
1254 
1255 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1256 	error = gfs2_glock_nq(gh);
1257 	if (error)
1258 		return false;
1259 
1260 	timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1261 		!test_bit(HIF_WAIT, &gh->gh_iflags) ||
1262 		test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1263 		timeout);
1264 	if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1265 		gfs2_glock_dq(gh);
1266 		return false;
1267 	}
1268 	return true;
1269 }
1270 
1271 /**
1272  * evict_should_delete - determine whether the inode is eligible for deletion
1273  * @inode: The inode to evict
1274  * @gh: The glock holder structure
1275  *
1276  * This function determines whether the evicted inode is eligible to be deleted
1277  * and locks the inode glock.
1278  *
1279  * Returns: the fate of the dinode
1280  */
1281 static enum dinode_demise evict_should_delete(struct inode *inode,
1282 					      struct gfs2_holder *gh)
1283 {
1284 	struct gfs2_inode *ip = GFS2_I(inode);
1285 	struct super_block *sb = inode->i_sb;
1286 	struct gfs2_sbd *sdp = sb->s_fs_info;
1287 	int ret;
1288 
1289 	if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1290 		BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
1291 		goto should_delete;
1292 	}
1293 
1294 	if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1295 		return SHOULD_DEFER_EVICTION;
1296 
1297 	/* Deletes should never happen under memory pressure anymore.  */
1298 	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1299 		return SHOULD_DEFER_EVICTION;
1300 
1301 	/* Must not read inode block until block type has been verified */
1302 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1303 	if (unlikely(ret)) {
1304 		glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1305 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1306 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1307 		return SHOULD_DEFER_EVICTION;
1308 	}
1309 
1310 	if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1311 		return SHOULD_NOT_DELETE_DINODE;
1312 	ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1313 	if (ret)
1314 		return SHOULD_NOT_DELETE_DINODE;
1315 
1316 	if (test_bit(GIF_INVALID, &ip->i_flags)) {
1317 		ret = gfs2_inode_refresh(ip);
1318 		if (ret)
1319 			return SHOULD_NOT_DELETE_DINODE;
1320 	}
1321 
1322 	/*
1323 	 * The inode may have been recreated in the meantime.
1324 	 */
1325 	if (inode->i_nlink)
1326 		return SHOULD_NOT_DELETE_DINODE;
1327 
1328 should_delete:
1329 	if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1330 	    test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1331 		if (!gfs2_upgrade_iopen_glock(inode)) {
1332 			gfs2_holder_uninit(&ip->i_iopen_gh);
1333 			return SHOULD_NOT_DELETE_DINODE;
1334 		}
1335 	}
1336 	return SHOULD_DELETE_DINODE;
1337 }
1338 
1339 /**
1340  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1341  * @inode: The inode to evict
1342  */
1343 static int evict_unlinked_inode(struct inode *inode)
1344 {
1345 	struct gfs2_inode *ip = GFS2_I(inode);
1346 	int ret;
1347 
1348 	if (S_ISDIR(inode->i_mode) &&
1349 	    (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1350 		ret = gfs2_dir_exhash_dealloc(ip);
1351 		if (ret)
1352 			goto out;
1353 	}
1354 
1355 	if (ip->i_eattr) {
1356 		ret = gfs2_ea_dealloc(ip);
1357 		if (ret)
1358 			goto out;
1359 	}
1360 
1361 	if (!gfs2_is_stuffed(ip)) {
1362 		ret = gfs2_file_dealloc(ip);
1363 		if (ret)
1364 			goto out;
1365 	}
1366 
1367 	/* We're about to clear the bitmap for the dinode, but as soon as we
1368 	   do, gfs2_create_inode can create another inode at the same block
1369 	   location and try to set gl_object again. We clear gl_object here so
1370 	   that subsequent inode creates don't see an old gl_object. */
1371 	glock_clear_object(ip->i_gl, ip);
1372 	ret = gfs2_dinode_dealloc(ip);
1373 	gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1374 out:
1375 	return ret;
1376 }
1377 
1378 /*
1379  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1380  * @inode: The inode to evict
1381  */
1382 static int evict_linked_inode(struct inode *inode)
1383 {
1384 	struct super_block *sb = inode->i_sb;
1385 	struct gfs2_sbd *sdp = sb->s_fs_info;
1386 	struct gfs2_inode *ip = GFS2_I(inode);
1387 	struct address_space *metamapping;
1388 	int ret;
1389 
1390 	gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1391 		       GFS2_LFC_EVICT_INODE);
1392 	metamapping = gfs2_glock2aspace(ip->i_gl);
1393 	if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1394 		filemap_fdatawrite(metamapping);
1395 		filemap_fdatawait(metamapping);
1396 	}
1397 	write_inode_now(inode, 1);
1398 	gfs2_ail_flush(ip->i_gl, 0);
1399 
1400 	ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1401 	if (ret)
1402 		return ret;
1403 
1404 	/* Needs to be done before glock release & also in a transaction */
1405 	truncate_inode_pages(&inode->i_data, 0);
1406 	truncate_inode_pages(metamapping, 0);
1407 	gfs2_trans_end(sdp);
1408 	return 0;
1409 }
1410 
1411 /**
1412  * gfs2_evict_inode - Remove an inode from cache
1413  * @inode: The inode to evict
1414  *
1415  * There are three cases to consider:
1416  * 1. i_nlink == 0, we are final opener (and must deallocate)
1417  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1418  * 3. i_nlink > 0
1419  *
1420  * If the fs is read only, then we have to treat all cases as per #3
1421  * since we are unable to do any deallocation. The inode will be
1422  * deallocated by the next read/write node to attempt an allocation
1423  * in the same resource group
1424  *
1425  * We have to (at the moment) hold the inodes main lock to cover
1426  * the gap between unlocking the shared lock on the iopen lock and
1427  * taking the exclusive lock. I'd rather do a shared -> exclusive
1428  * conversion on the iopen lock, but we can change that later. This
1429  * is safe, just less efficient.
1430  */
1431 
1432 static void gfs2_evict_inode(struct inode *inode)
1433 {
1434 	struct super_block *sb = inode->i_sb;
1435 	struct gfs2_sbd *sdp = sb->s_fs_info;
1436 	struct gfs2_inode *ip = GFS2_I(inode);
1437 	struct gfs2_holder gh;
1438 	int ret;
1439 
1440 	if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1441 		clear_inode(inode);
1442 		return;
1443 	}
1444 
1445 	if (inode->i_nlink || sb_rdonly(sb))
1446 		goto out;
1447 
1448 	gfs2_holder_mark_uninitialized(&gh);
1449 	ret = evict_should_delete(inode, &gh);
1450 	if (ret == SHOULD_DEFER_EVICTION)
1451 		goto out;
1452 	if (ret == SHOULD_DELETE_DINODE)
1453 		ret = evict_unlinked_inode(inode);
1454 	else
1455 		ret = evict_linked_inode(inode);
1456 
1457 	if (gfs2_rs_active(&ip->i_res))
1458 		gfs2_rs_deltree(&ip->i_res);
1459 
1460 	if (gfs2_holder_initialized(&gh)) {
1461 		glock_clear_object(ip->i_gl, ip);
1462 		gfs2_glock_dq_uninit(&gh);
1463 	}
1464 	if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1465 		fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1466 out:
1467 	truncate_inode_pages_final(&inode->i_data);
1468 	if (ip->i_qadata)
1469 		gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1470 	gfs2_rs_delete(ip, NULL);
1471 	gfs2_ordered_del_inode(ip);
1472 	clear_inode(inode);
1473 	gfs2_dir_hash_inval(ip);
1474 	if (ip->i_gl) {
1475 		glock_clear_object(ip->i_gl, ip);
1476 		wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1477 		gfs2_glock_add_to_lru(ip->i_gl);
1478 		gfs2_glock_put_eventually(ip->i_gl);
1479 		ip->i_gl = NULL;
1480 	}
1481 	if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1482 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1483 
1484 		glock_clear_object(gl, ip);
1485 		if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1486 			ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1487 			gfs2_glock_dq(&ip->i_iopen_gh);
1488 		}
1489 		gfs2_glock_hold(gl);
1490 		gfs2_holder_uninit(&ip->i_iopen_gh);
1491 		gfs2_glock_put_eventually(gl);
1492 	}
1493 }
1494 
1495 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1496 {
1497 	struct gfs2_inode *ip;
1498 
1499 	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1500 	if (!ip)
1501 		return NULL;
1502 	ip->i_flags = 0;
1503 	ip->i_gl = NULL;
1504 	gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1505 	memset(&ip->i_res, 0, sizeof(ip->i_res));
1506 	RB_CLEAR_NODE(&ip->i_res.rs_node);
1507 	ip->i_rahead = 0;
1508 	return &ip->i_inode;
1509 }
1510 
1511 static void gfs2_free_inode(struct inode *inode)
1512 {
1513 	kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1514 }
1515 
1516 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1517 {
1518 	struct local_statfs_inode *lsi, *safe;
1519 
1520 	/* Run through the statfs inodes list to iput and free memory */
1521 	list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1522 		if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1523 			sdp->sd_sc_inode = NULL; /* belongs to this node */
1524 		if (lsi->si_sc_inode)
1525 			iput(lsi->si_sc_inode);
1526 		list_del(&lsi->si_list);
1527 		kfree(lsi);
1528 	}
1529 }
1530 
1531 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1532 					     unsigned int index)
1533 {
1534 	struct local_statfs_inode *lsi;
1535 
1536 	/* Return the local (per node) statfs inode in the
1537 	 * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1538 	list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1539 		if (lsi->si_jid == index)
1540 			return lsi->si_sc_inode;
1541 	}
1542 	return NULL;
1543 }
1544 
1545 const struct super_operations gfs2_super_ops = {
1546 	.alloc_inode		= gfs2_alloc_inode,
1547 	.free_inode		= gfs2_free_inode,
1548 	.write_inode		= gfs2_write_inode,
1549 	.dirty_inode		= gfs2_dirty_inode,
1550 	.evict_inode		= gfs2_evict_inode,
1551 	.put_super		= gfs2_put_super,
1552 	.sync_fs		= gfs2_sync_fs,
1553 	.freeze_super		= gfs2_freeze,
1554 	.thaw_super		= gfs2_unfreeze,
1555 	.statfs			= gfs2_statfs,
1556 	.drop_inode		= gfs2_drop_inode,
1557 	.show_options		= gfs2_show_options,
1558 };
1559 
1560