xref: /openbmc/linux/fs/gfs2/super.c (revision 736b2f77)
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_holder freeze_gh;
162 	struct gfs2_log_header_host head;
163 	int error;
164 
165 	error = init_threads(sdp);
166 	if (error)
167 		return error;
168 
169 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
170 				   LM_FLAG_NOEXP | GL_EXACT,
171 				   &freeze_gh);
172 	if (error)
173 		goto fail_threads;
174 
175 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
176 	if (gfs2_withdrawn(sdp)) {
177 		error = -EIO;
178 		goto fail;
179 	}
180 
181 	error = gfs2_find_jhead(sdp->sd_jdesc, &head, false);
182 	if (error || gfs2_withdrawn(sdp))
183 		goto fail;
184 
185 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
186 		gfs2_consist(sdp);
187 		error = -EIO;
188 		goto fail;
189 	}
190 
191 	/*  Initialize some head of the log stuff  */
192 	sdp->sd_log_sequence = head.lh_sequence + 1;
193 	gfs2_log_pointers_init(sdp, head.lh_blkno);
194 
195 	error = gfs2_quota_init(sdp);
196 	if (error || gfs2_withdrawn(sdp))
197 		goto fail;
198 
199 	set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
200 
201 	gfs2_glock_dq_uninit(&freeze_gh);
202 
203 	return 0;
204 
205 fail:
206 	gfs2_glock_dq_uninit(&freeze_gh);
207 fail_threads:
208 	if (sdp->sd_quotad_process)
209 		kthread_stop(sdp->sd_quotad_process);
210 	sdp->sd_quotad_process = NULL;
211 	if (sdp->sd_logd_process)
212 		kthread_stop(sdp->sd_logd_process);
213 	sdp->sd_logd_process = NULL;
214 	return error;
215 }
216 
217 void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
218 {
219 	const struct gfs2_statfs_change *str = buf;
220 
221 	sc->sc_total = be64_to_cpu(str->sc_total);
222 	sc->sc_free = be64_to_cpu(str->sc_free);
223 	sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
224 }
225 
226 void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
227 {
228 	struct gfs2_statfs_change *str = buf;
229 
230 	str->sc_total = cpu_to_be64(sc->sc_total);
231 	str->sc_free = cpu_to_be64(sc->sc_free);
232 	str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
233 }
234 
235 int gfs2_statfs_init(struct gfs2_sbd *sdp)
236 {
237 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
238 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
239 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
240 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
241 	struct buffer_head *m_bh, *l_bh;
242 	struct gfs2_holder gh;
243 	int error;
244 
245 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
246 				   &gh);
247 	if (error)
248 		return error;
249 
250 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
251 	if (error)
252 		goto out;
253 
254 	if (sdp->sd_args.ar_spectator) {
255 		spin_lock(&sdp->sd_statfs_spin);
256 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
257 				      sizeof(struct gfs2_dinode));
258 		spin_unlock(&sdp->sd_statfs_spin);
259 	} else {
260 		error = gfs2_meta_inode_buffer(l_ip, &l_bh);
261 		if (error)
262 			goto out_m_bh;
263 
264 		spin_lock(&sdp->sd_statfs_spin);
265 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
266 				      sizeof(struct gfs2_dinode));
267 		gfs2_statfs_change_in(l_sc, l_bh->b_data +
268 				      sizeof(struct gfs2_dinode));
269 		spin_unlock(&sdp->sd_statfs_spin);
270 
271 		brelse(l_bh);
272 	}
273 
274 out_m_bh:
275 	brelse(m_bh);
276 out:
277 	gfs2_glock_dq_uninit(&gh);
278 	return 0;
279 }
280 
281 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
282 			s64 dinodes)
283 {
284 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
285 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
286 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
287 	struct buffer_head *l_bh;
288 	s64 x, y;
289 	int need_sync = 0;
290 	int error;
291 
292 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
293 	if (error)
294 		return;
295 
296 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
297 
298 	spin_lock(&sdp->sd_statfs_spin);
299 	l_sc->sc_total += total;
300 	l_sc->sc_free += free;
301 	l_sc->sc_dinodes += dinodes;
302 	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
303 	if (sdp->sd_args.ar_statfs_percent) {
304 		x = 100 * l_sc->sc_free;
305 		y = m_sc->sc_free * sdp->sd_args.ar_statfs_percent;
306 		if (x >= y || x <= -y)
307 			need_sync = 1;
308 	}
309 	spin_unlock(&sdp->sd_statfs_spin);
310 
311 	brelse(l_bh);
312 	if (need_sync)
313 		gfs2_wake_up_statfs(sdp);
314 }
315 
316 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
317 		   struct buffer_head *l_bh)
318 {
319 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
320 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
321 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
322 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
323 
324 	gfs2_trans_add_meta(l_ip->i_gl, l_bh);
325 	gfs2_trans_add_meta(m_ip->i_gl, m_bh);
326 
327 	spin_lock(&sdp->sd_statfs_spin);
328 	m_sc->sc_total += l_sc->sc_total;
329 	m_sc->sc_free += l_sc->sc_free;
330 	m_sc->sc_dinodes += l_sc->sc_dinodes;
331 	memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
332 	memset(l_bh->b_data + sizeof(struct gfs2_dinode),
333 	       0, sizeof(struct gfs2_statfs_change));
334 	gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
335 	spin_unlock(&sdp->sd_statfs_spin);
336 }
337 
338 int gfs2_statfs_sync(struct super_block *sb, int type)
339 {
340 	struct gfs2_sbd *sdp = sb->s_fs_info;
341 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
342 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
343 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
344 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
345 	struct gfs2_holder gh;
346 	struct buffer_head *m_bh, *l_bh;
347 	int error;
348 
349 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
350 				   &gh);
351 	if (error)
352 		goto out;
353 
354 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
355 	if (error)
356 		goto out_unlock;
357 
358 	spin_lock(&sdp->sd_statfs_spin);
359 	gfs2_statfs_change_in(m_sc, m_bh->b_data +
360 			      sizeof(struct gfs2_dinode));
361 	if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
362 		spin_unlock(&sdp->sd_statfs_spin);
363 		goto out_bh;
364 	}
365 	spin_unlock(&sdp->sd_statfs_spin);
366 
367 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
368 	if (error)
369 		goto out_bh;
370 
371 	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
372 	if (error)
373 		goto out_bh2;
374 
375 	update_statfs(sdp, m_bh, l_bh);
376 	sdp->sd_statfs_force_sync = 0;
377 
378 	gfs2_trans_end(sdp);
379 
380 out_bh2:
381 	brelse(l_bh);
382 out_bh:
383 	brelse(m_bh);
384 out_unlock:
385 	gfs2_glock_dq_uninit(&gh);
386 out:
387 	return error;
388 }
389 
390 struct lfcc {
391 	struct list_head list;
392 	struct gfs2_holder gh;
393 };
394 
395 /**
396  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
397  *                            journals are clean
398  * @sdp: the file system
399  * @state: the state to put the transaction lock into
400  * @t_gh: the hold on the transaction lock
401  *
402  * Returns: errno
403  */
404 
405 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp)
406 {
407 	struct gfs2_inode *ip;
408 	struct gfs2_jdesc *jd;
409 	struct lfcc *lfcc;
410 	LIST_HEAD(list);
411 	struct gfs2_log_header_host lh;
412 	int error;
413 
414 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
415 		lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
416 		if (!lfcc) {
417 			error = -ENOMEM;
418 			goto out;
419 		}
420 		ip = GFS2_I(jd->jd_inode);
421 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
422 		if (error) {
423 			kfree(lfcc);
424 			goto out;
425 		}
426 		list_add(&lfcc->list, &list);
427 	}
428 
429 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_EXCLUSIVE,
430 				   LM_FLAG_NOEXP, &sdp->sd_freeze_gh);
431 	if (error)
432 		goto out;
433 
434 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
435 		error = gfs2_jdesc_check(jd);
436 		if (error)
437 			break;
438 		error = gfs2_find_jhead(jd, &lh, false);
439 		if (error)
440 			break;
441 		if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
442 			error = -EBUSY;
443 			break;
444 		}
445 	}
446 
447 	if (error)
448 		gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
449 
450 out:
451 	while (!list_empty(&list)) {
452 		lfcc = list_first_entry(&list, struct lfcc, list);
453 		list_del(&lfcc->list);
454 		gfs2_glock_dq_uninit(&lfcc->gh);
455 		kfree(lfcc);
456 	}
457 	return error;
458 }
459 
460 void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf)
461 {
462 	struct gfs2_dinode *str = buf;
463 
464 	str->di_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
465 	str->di_header.mh_type = cpu_to_be32(GFS2_METATYPE_DI);
466 	str->di_header.mh_format = cpu_to_be32(GFS2_FORMAT_DI);
467 	str->di_num.no_addr = cpu_to_be64(ip->i_no_addr);
468 	str->di_num.no_formal_ino = cpu_to_be64(ip->i_no_formal_ino);
469 	str->di_mode = cpu_to_be32(ip->i_inode.i_mode);
470 	str->di_uid = cpu_to_be32(i_uid_read(&ip->i_inode));
471 	str->di_gid = cpu_to_be32(i_gid_read(&ip->i_inode));
472 	str->di_nlink = cpu_to_be32(ip->i_inode.i_nlink);
473 	str->di_size = cpu_to_be64(i_size_read(&ip->i_inode));
474 	str->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
475 	str->di_atime = cpu_to_be64(ip->i_inode.i_atime.tv_sec);
476 	str->di_mtime = cpu_to_be64(ip->i_inode.i_mtime.tv_sec);
477 	str->di_ctime = cpu_to_be64(ip->i_inode.i_ctime.tv_sec);
478 
479 	str->di_goal_meta = cpu_to_be64(ip->i_goal);
480 	str->di_goal_data = cpu_to_be64(ip->i_goal);
481 	str->di_generation = cpu_to_be64(ip->i_generation);
482 
483 	str->di_flags = cpu_to_be32(ip->i_diskflags);
484 	str->di_height = cpu_to_be16(ip->i_height);
485 	str->di_payload_format = cpu_to_be32(S_ISDIR(ip->i_inode.i_mode) &&
486 					     !(ip->i_diskflags & GFS2_DIF_EXHASH) ?
487 					     GFS2_FORMAT_DE : 0);
488 	str->di_depth = cpu_to_be16(ip->i_depth);
489 	str->di_entries = cpu_to_be32(ip->i_entries);
490 
491 	str->di_eattr = cpu_to_be64(ip->i_eattr);
492 	str->di_atime_nsec = cpu_to_be32(ip->i_inode.i_atime.tv_nsec);
493 	str->di_mtime_nsec = cpu_to_be32(ip->i_inode.i_mtime.tv_nsec);
494 	str->di_ctime_nsec = cpu_to_be32(ip->i_inode.i_ctime.tv_nsec);
495 }
496 
497 /**
498  * gfs2_write_inode - Make sure the inode is stable on the disk
499  * @inode: The inode
500  * @wbc: The writeback control structure
501  *
502  * Returns: errno
503  */
504 
505 static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
506 {
507 	struct gfs2_inode *ip = GFS2_I(inode);
508 	struct gfs2_sbd *sdp = GFS2_SB(inode);
509 	struct address_space *metamapping = gfs2_glock2aspace(ip->i_gl);
510 	struct backing_dev_info *bdi = inode_to_bdi(metamapping->host);
511 	int ret = 0;
512 	bool flush_all = (wbc->sync_mode == WB_SYNC_ALL || gfs2_is_jdata(ip));
513 
514 	if (flush_all)
515 		gfs2_log_flush(GFS2_SB(inode), ip->i_gl,
516 			       GFS2_LOG_HEAD_FLUSH_NORMAL |
517 			       GFS2_LFC_WRITE_INODE);
518 	if (bdi->wb.dirty_exceeded)
519 		gfs2_ail1_flush(sdp, wbc);
520 	else
521 		filemap_fdatawrite(metamapping);
522 	if (flush_all)
523 		ret = filemap_fdatawait(metamapping);
524 	if (ret)
525 		mark_inode_dirty_sync(inode);
526 	else {
527 		spin_lock(&inode->i_lock);
528 		if (!(inode->i_flags & I_DIRTY))
529 			gfs2_ordered_del_inode(ip);
530 		spin_unlock(&inode->i_lock);
531 	}
532 	return ret;
533 }
534 
535 /**
536  * gfs2_dirty_inode - check for atime updates
537  * @inode: The inode in question
538  * @flags: The type of dirty
539  *
540  * Unfortunately it can be called under any combination of inode
541  * glock and transaction lock, so we have to check carefully.
542  *
543  * At the moment this deals only with atime - it should be possible
544  * to expand that role in future, once a review of the locking has
545  * been carried out.
546  */
547 
548 static void gfs2_dirty_inode(struct inode *inode, int flags)
549 {
550 	struct gfs2_inode *ip = GFS2_I(inode);
551 	struct gfs2_sbd *sdp = GFS2_SB(inode);
552 	struct buffer_head *bh;
553 	struct gfs2_holder gh;
554 	int need_unlock = 0;
555 	int need_endtrans = 0;
556 	int ret;
557 
558 	if (!(flags & I_DIRTY_INODE))
559 		return;
560 	if (unlikely(gfs2_withdrawn(sdp)))
561 		return;
562 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
563 		ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
564 		if (ret) {
565 			fs_err(sdp, "dirty_inode: glock %d\n", ret);
566 			gfs2_dump_glock(NULL, ip->i_gl, true);
567 			return;
568 		}
569 		need_unlock = 1;
570 	} else if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE))
571 		return;
572 
573 	if (current->journal_info == NULL) {
574 		ret = gfs2_trans_begin(sdp, RES_DINODE, 0);
575 		if (ret) {
576 			fs_err(sdp, "dirty_inode: gfs2_trans_begin %d\n", ret);
577 			goto out;
578 		}
579 		need_endtrans = 1;
580 	}
581 
582 	ret = gfs2_meta_inode_buffer(ip, &bh);
583 	if (ret == 0) {
584 		gfs2_trans_add_meta(ip->i_gl, bh);
585 		gfs2_dinode_out(ip, bh->b_data);
586 		brelse(bh);
587 	}
588 
589 	if (need_endtrans)
590 		gfs2_trans_end(sdp);
591 out:
592 	if (need_unlock)
593 		gfs2_glock_dq_uninit(&gh);
594 }
595 
596 /**
597  * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
598  * @sdp: the filesystem
599  *
600  * Returns: errno
601  */
602 
603 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
604 {
605 	struct gfs2_holder freeze_gh;
606 	int error = 0;
607 	int log_write_allowed = test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
608 
609 	gfs2_holder_mark_uninitialized(&freeze_gh);
610 	if (sdp->sd_freeze_gl &&
611 	    !gfs2_glock_is_locked_by_me(sdp->sd_freeze_gl)) {
612 		if (!log_write_allowed) {
613 			error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
614 						   LM_ST_SHARED, LM_FLAG_TRY |
615 						   LM_FLAG_NOEXP | GL_EXACT,
616 						   &freeze_gh);
617 			if (error == GLR_TRYFAILED)
618 				error = 0;
619 		} else {
620 			error = gfs2_glock_nq_init(sdp->sd_freeze_gl,
621 						   LM_ST_SHARED,
622 						   LM_FLAG_NOEXP | GL_EXACT,
623 						   &freeze_gh);
624 			if (error && !gfs2_withdrawn(sdp))
625 				return error;
626 		}
627 	}
628 
629 	gfs2_flush_delete_work(sdp);
630 	if (!log_write_allowed && current == sdp->sd_quotad_process)
631 		fs_warn(sdp, "The quotad daemon is withdrawing.\n");
632 	else if (sdp->sd_quotad_process)
633 		kthread_stop(sdp->sd_quotad_process);
634 	sdp->sd_quotad_process = NULL;
635 
636 	if (!log_write_allowed && current == sdp->sd_logd_process)
637 		fs_warn(sdp, "The logd daemon is withdrawing.\n");
638 	else if (sdp->sd_logd_process)
639 		kthread_stop(sdp->sd_logd_process);
640 	sdp->sd_logd_process = NULL;
641 
642 	if (log_write_allowed) {
643 		gfs2_quota_sync(sdp->sd_vfs, 0);
644 		gfs2_statfs_sync(sdp->sd_vfs, 0);
645 
646 		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
647 			       GFS2_LFC_MAKE_FS_RO);
648 		wait_event(sdp->sd_reserving_log_wait,
649 			   atomic_read(&sdp->sd_reserving_log) == 0);
650 		gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) ==
651 				 sdp->sd_jdesc->jd_blocks);
652 	} else {
653 		wait_event_timeout(sdp->sd_reserving_log_wait,
654 				   atomic_read(&sdp->sd_reserving_log) == 0,
655 				   HZ * 5);
656 	}
657 	if (gfs2_holder_initialized(&freeze_gh))
658 		gfs2_glock_dq_uninit(&freeze_gh);
659 
660 	gfs2_quota_cleanup(sdp);
661 
662 	if (!log_write_allowed)
663 		sdp->sd_vfs->s_flags |= SB_RDONLY;
664 
665 	return error;
666 }
667 
668 /**
669  * gfs2_put_super - Unmount the filesystem
670  * @sb: The VFS superblock
671  *
672  */
673 
674 static void gfs2_put_super(struct super_block *sb)
675 {
676 	struct gfs2_sbd *sdp = sb->s_fs_info;
677 	int error;
678 	struct gfs2_jdesc *jd;
679 
680 	/* No more recovery requests */
681 	set_bit(SDF_NORECOVERY, &sdp->sd_flags);
682 	smp_mb();
683 
684 	/* Wait on outstanding recovery */
685 restart:
686 	spin_lock(&sdp->sd_jindex_spin);
687 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
688 		if (!test_bit(JDF_RECOVERY, &jd->jd_flags))
689 			continue;
690 		spin_unlock(&sdp->sd_jindex_spin);
691 		wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
692 			    TASK_UNINTERRUPTIBLE);
693 		goto restart;
694 	}
695 	spin_unlock(&sdp->sd_jindex_spin);
696 
697 	if (!sb_rdonly(sb)) {
698 		error = gfs2_make_fs_ro(sdp);
699 		if (error)
700 			gfs2_io_error(sdp);
701 	}
702 	WARN_ON(gfs2_withdrawing(sdp));
703 
704 	/*  At this point, we're through modifying the disk  */
705 
706 	/*  Release stuff  */
707 
708 	iput(sdp->sd_jindex);
709 	iput(sdp->sd_statfs_inode);
710 	iput(sdp->sd_rindex);
711 	iput(sdp->sd_quota_inode);
712 
713 	gfs2_glock_put(sdp->sd_rename_gl);
714 	gfs2_glock_put(sdp->sd_freeze_gl);
715 
716 	if (!sdp->sd_args.ar_spectator) {
717 		if (gfs2_holder_initialized(&sdp->sd_journal_gh))
718 			gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
719 		if (gfs2_holder_initialized(&sdp->sd_jinode_gh))
720 			gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
721 		gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
722 		gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
723 		free_local_statfs_inodes(sdp);
724 		iput(sdp->sd_qc_inode);
725 	}
726 
727 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
728 	gfs2_clear_rgrpd(sdp);
729 	gfs2_jindex_free(sdp);
730 	/*  Take apart glock structures and buffer lists  */
731 	gfs2_gl_hash_clear(sdp);
732 	truncate_inode_pages_final(&sdp->sd_aspace);
733 	gfs2_delete_debugfs_file(sdp);
734 	/*  Unmount the locking protocol  */
735 	gfs2_lm_unmount(sdp);
736 
737 	/*  At this point, we're through participating in the lockspace  */
738 	gfs2_sys_fs_del(sdp);
739 	free_sbd(sdp);
740 }
741 
742 /**
743  * gfs2_sync_fs - sync the filesystem
744  * @sb: the superblock
745  *
746  * Flushes the log to disk.
747  */
748 
749 static int gfs2_sync_fs(struct super_block *sb, int wait)
750 {
751 	struct gfs2_sbd *sdp = sb->s_fs_info;
752 
753 	gfs2_quota_sync(sb, -1);
754 	if (wait)
755 		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
756 			       GFS2_LFC_SYNC_FS);
757 	return sdp->sd_log_error;
758 }
759 
760 void gfs2_freeze_func(struct work_struct *work)
761 {
762 	int error;
763 	struct gfs2_holder freeze_gh;
764 	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_freeze_work);
765 	struct super_block *sb = sdp->sd_vfs;
766 
767 	atomic_inc(&sb->s_active);
768 	error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
769 				   LM_FLAG_NOEXP | GL_EXACT, &freeze_gh);
770 	if (error) {
771 		fs_info(sdp, "GFS2: couldn't get freeze lock : %d\n", error);
772 		gfs2_assert_withdraw(sdp, 0);
773 	} else {
774 		atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
775 		error = thaw_super(sb);
776 		if (error) {
777 			fs_info(sdp, "GFS2: couldn't thaw filesystem: %d\n",
778 				error);
779 			gfs2_assert_withdraw(sdp, 0);
780 		}
781 		gfs2_glock_dq_uninit(&freeze_gh);
782 	}
783 	deactivate_super(sb);
784 	clear_bit_unlock(SDF_FS_FROZEN, &sdp->sd_flags);
785 	wake_up_bit(&sdp->sd_flags, SDF_FS_FROZEN);
786 	return;
787 }
788 
789 /**
790  * gfs2_freeze - prevent further writes to the filesystem
791  * @sb: the VFS structure for the filesystem
792  *
793  */
794 
795 static int gfs2_freeze(struct super_block *sb)
796 {
797 	struct gfs2_sbd *sdp = sb->s_fs_info;
798 	int error = 0;
799 
800 	mutex_lock(&sdp->sd_freeze_mutex);
801 	if (atomic_read(&sdp->sd_freeze_state) != SFS_UNFROZEN)
802 		goto out;
803 
804 	for (;;) {
805 		if (gfs2_withdrawn(sdp)) {
806 			error = -EINVAL;
807 			goto out;
808 		}
809 
810 		error = gfs2_lock_fs_check_clean(sdp);
811 		if (!error)
812 			break;
813 
814 		if (error == -EBUSY)
815 			fs_err(sdp, "waiting for recovery before freeze\n");
816 		else if (error == -EIO) {
817 			fs_err(sdp, "Fatal IO error: cannot freeze gfs2 due "
818 			       "to recovery error.\n");
819 			goto out;
820 		} else {
821 			fs_err(sdp, "error freezing FS: %d\n", error);
822 		}
823 		fs_err(sdp, "retrying...\n");
824 		msleep(1000);
825 	}
826 	set_bit(SDF_FS_FROZEN, &sdp->sd_flags);
827 out:
828 	mutex_unlock(&sdp->sd_freeze_mutex);
829 	return error;
830 }
831 
832 /**
833  * gfs2_unfreeze - reallow writes to the filesystem
834  * @sb: the VFS structure for the filesystem
835  *
836  */
837 
838 static int gfs2_unfreeze(struct super_block *sb)
839 {
840 	struct gfs2_sbd *sdp = sb->s_fs_info;
841 
842 	mutex_lock(&sdp->sd_freeze_mutex);
843         if (atomic_read(&sdp->sd_freeze_state) != SFS_FROZEN ||
844 	    !gfs2_holder_initialized(&sdp->sd_freeze_gh)) {
845 		mutex_unlock(&sdp->sd_freeze_mutex);
846                 return 0;
847 	}
848 
849 	gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
850 	mutex_unlock(&sdp->sd_freeze_mutex);
851 	return wait_on_bit(&sdp->sd_flags, SDF_FS_FROZEN, TASK_INTERRUPTIBLE);
852 }
853 
854 /**
855  * statfs_fill - fill in the sg for a given RG
856  * @rgd: the RG
857  * @sc: the sc structure
858  *
859  * Returns: 0 on success, -ESTALE if the LVB is invalid
860  */
861 
862 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
863 			    struct gfs2_statfs_change_host *sc)
864 {
865 	gfs2_rgrp_verify(rgd);
866 	sc->sc_total += rgd->rd_data;
867 	sc->sc_free += rgd->rd_free;
868 	sc->sc_dinodes += rgd->rd_dinodes;
869 	return 0;
870 }
871 
872 /**
873  * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
874  * @sdp: the filesystem
875  * @sc: the sc info that will be returned
876  *
877  * Any error (other than a signal) will cause this routine to fall back
878  * to the synchronous version.
879  *
880  * FIXME: This really shouldn't busy wait like this.
881  *
882  * Returns: errno
883  */
884 
885 static int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
886 {
887 	struct gfs2_rgrpd *rgd_next;
888 	struct gfs2_holder *gha, *gh;
889 	unsigned int slots = 64;
890 	unsigned int x;
891 	int done;
892 	int error = 0, err;
893 
894 	memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
895 	gha = kmalloc_array(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
896 	if (!gha)
897 		return -ENOMEM;
898 	for (x = 0; x < slots; x++)
899 		gfs2_holder_mark_uninitialized(gha + x);
900 
901 	rgd_next = gfs2_rgrpd_get_first(sdp);
902 
903 	for (;;) {
904 		done = 1;
905 
906 		for (x = 0; x < slots; x++) {
907 			gh = gha + x;
908 
909 			if (gfs2_holder_initialized(gh) && gfs2_glock_poll(gh)) {
910 				err = gfs2_glock_wait(gh);
911 				if (err) {
912 					gfs2_holder_uninit(gh);
913 					error = err;
914 				} else {
915 					if (!error) {
916 						struct gfs2_rgrpd *rgd =
917 							gfs2_glock2rgrp(gh->gh_gl);
918 
919 						error = statfs_slow_fill(rgd, sc);
920 					}
921 					gfs2_glock_dq_uninit(gh);
922 				}
923 			}
924 
925 			if (gfs2_holder_initialized(gh))
926 				done = 0;
927 			else if (rgd_next && !error) {
928 				error = gfs2_glock_nq_init(rgd_next->rd_gl,
929 							   LM_ST_SHARED,
930 							   GL_ASYNC,
931 							   gh);
932 				rgd_next = gfs2_rgrpd_get_next(rgd_next);
933 				done = 0;
934 			}
935 
936 			if (signal_pending(current))
937 				error = -ERESTARTSYS;
938 		}
939 
940 		if (done)
941 			break;
942 
943 		yield();
944 	}
945 
946 	kfree(gha);
947 	return error;
948 }
949 
950 /**
951  * gfs2_statfs_i - Do a statfs
952  * @sdp: the filesystem
953  * @sg: the sg structure
954  *
955  * Returns: errno
956  */
957 
958 static int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
959 {
960 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
961 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
962 
963 	spin_lock(&sdp->sd_statfs_spin);
964 
965 	*sc = *m_sc;
966 	sc->sc_total += l_sc->sc_total;
967 	sc->sc_free += l_sc->sc_free;
968 	sc->sc_dinodes += l_sc->sc_dinodes;
969 
970 	spin_unlock(&sdp->sd_statfs_spin);
971 
972 	if (sc->sc_free < 0)
973 		sc->sc_free = 0;
974 	if (sc->sc_free > sc->sc_total)
975 		sc->sc_free = sc->sc_total;
976 	if (sc->sc_dinodes < 0)
977 		sc->sc_dinodes = 0;
978 
979 	return 0;
980 }
981 
982 /**
983  * gfs2_statfs - Gather and return stats about the filesystem
984  * @sb: The superblock
985  * @statfsbuf: The buffer
986  *
987  * Returns: 0 on success or error code
988  */
989 
990 static int gfs2_statfs(struct dentry *dentry, struct kstatfs *buf)
991 {
992 	struct super_block *sb = dentry->d_sb;
993 	struct gfs2_sbd *sdp = sb->s_fs_info;
994 	struct gfs2_statfs_change_host sc;
995 	int error;
996 
997 	error = gfs2_rindex_update(sdp);
998 	if (error)
999 		return error;
1000 
1001 	if (gfs2_tune_get(sdp, gt_statfs_slow))
1002 		error = gfs2_statfs_slow(sdp, &sc);
1003 	else
1004 		error = gfs2_statfs_i(sdp, &sc);
1005 
1006 	if (error)
1007 		return error;
1008 
1009 	buf->f_type = GFS2_MAGIC;
1010 	buf->f_bsize = sdp->sd_sb.sb_bsize;
1011 	buf->f_blocks = sc.sc_total;
1012 	buf->f_bfree = sc.sc_free;
1013 	buf->f_bavail = sc.sc_free;
1014 	buf->f_files = sc.sc_dinodes + sc.sc_free;
1015 	buf->f_ffree = sc.sc_free;
1016 	buf->f_namelen = GFS2_FNAMESIZE;
1017 
1018 	return 0;
1019 }
1020 
1021 /**
1022  * gfs2_drop_inode - Drop an inode (test for remote unlink)
1023  * @inode: The inode to drop
1024  *
1025  * If we've received a callback on an iopen lock then it's because a
1026  * remote node tried to deallocate the inode but failed due to this node
1027  * still having the inode open. Here we mark the link count zero
1028  * since we know that it must have reached zero if the GLF_DEMOTE flag
1029  * is set on the iopen glock. If we didn't do a disk read since the
1030  * remote node removed the final link then we might otherwise miss
1031  * this event. This check ensures that this node will deallocate the
1032  * inode's blocks, or alternatively pass the baton on to another
1033  * node for later deallocation.
1034  */
1035 
1036 static int gfs2_drop_inode(struct inode *inode)
1037 {
1038 	struct gfs2_inode *ip = GFS2_I(inode);
1039 
1040 	if (!test_bit(GIF_FREE_VFS_INODE, &ip->i_flags) &&
1041 	    inode->i_nlink &&
1042 	    gfs2_holder_initialized(&ip->i_iopen_gh)) {
1043 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1044 		if (test_bit(GLF_DEMOTE, &gl->gl_flags))
1045 			clear_nlink(inode);
1046 	}
1047 
1048 	/*
1049 	 * When under memory pressure when an inode's link count has dropped to
1050 	 * zero, defer deleting the inode to the delete workqueue.  This avoids
1051 	 * calling into DLM under memory pressure, which can deadlock.
1052 	 */
1053 	if (!inode->i_nlink &&
1054 	    unlikely(current->flags & PF_MEMALLOC) &&
1055 	    gfs2_holder_initialized(&ip->i_iopen_gh)) {
1056 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1057 
1058 		gfs2_glock_hold(gl);
1059 		if (!gfs2_queue_delete_work(gl, 0))
1060 			gfs2_glock_queue_put(gl);
1061 		return false;
1062 	}
1063 
1064 	return generic_drop_inode(inode);
1065 }
1066 
1067 static int is_ancestor(const struct dentry *d1, const struct dentry *d2)
1068 {
1069 	do {
1070 		if (d1 == d2)
1071 			return 1;
1072 		d1 = d1->d_parent;
1073 	} while (!IS_ROOT(d1));
1074 	return 0;
1075 }
1076 
1077 /**
1078  * gfs2_show_options - Show mount options for /proc/mounts
1079  * @s: seq_file structure
1080  * @root: root of this (sub)tree
1081  *
1082  * Returns: 0 on success or error code
1083  */
1084 
1085 static int gfs2_show_options(struct seq_file *s, struct dentry *root)
1086 {
1087 	struct gfs2_sbd *sdp = root->d_sb->s_fs_info;
1088 	struct gfs2_args *args = &sdp->sd_args;
1089 	int val;
1090 
1091 	if (is_ancestor(root, sdp->sd_master_dir))
1092 		seq_puts(s, ",meta");
1093 	if (args->ar_lockproto[0])
1094 		seq_show_option(s, "lockproto", args->ar_lockproto);
1095 	if (args->ar_locktable[0])
1096 		seq_show_option(s, "locktable", args->ar_locktable);
1097 	if (args->ar_hostdata[0])
1098 		seq_show_option(s, "hostdata", args->ar_hostdata);
1099 	if (args->ar_spectator)
1100 		seq_puts(s, ",spectator");
1101 	if (args->ar_localflocks)
1102 		seq_puts(s, ",localflocks");
1103 	if (args->ar_debug)
1104 		seq_puts(s, ",debug");
1105 	if (args->ar_posix_acl)
1106 		seq_puts(s, ",acl");
1107 	if (args->ar_quota != GFS2_QUOTA_DEFAULT) {
1108 		char *state;
1109 		switch (args->ar_quota) {
1110 		case GFS2_QUOTA_OFF:
1111 			state = "off";
1112 			break;
1113 		case GFS2_QUOTA_ACCOUNT:
1114 			state = "account";
1115 			break;
1116 		case GFS2_QUOTA_ON:
1117 			state = "on";
1118 			break;
1119 		default:
1120 			state = "unknown";
1121 			break;
1122 		}
1123 		seq_printf(s, ",quota=%s", state);
1124 	}
1125 	if (args->ar_suiddir)
1126 		seq_puts(s, ",suiddir");
1127 	if (args->ar_data != GFS2_DATA_DEFAULT) {
1128 		char *state;
1129 		switch (args->ar_data) {
1130 		case GFS2_DATA_WRITEBACK:
1131 			state = "writeback";
1132 			break;
1133 		case GFS2_DATA_ORDERED:
1134 			state = "ordered";
1135 			break;
1136 		default:
1137 			state = "unknown";
1138 			break;
1139 		}
1140 		seq_printf(s, ",data=%s", state);
1141 	}
1142 	if (args->ar_discard)
1143 		seq_puts(s, ",discard");
1144 	val = sdp->sd_tune.gt_logd_secs;
1145 	if (val != 30)
1146 		seq_printf(s, ",commit=%d", val);
1147 	val = sdp->sd_tune.gt_statfs_quantum;
1148 	if (val != 30)
1149 		seq_printf(s, ",statfs_quantum=%d", val);
1150 	else if (sdp->sd_tune.gt_statfs_slow)
1151 		seq_puts(s, ",statfs_quantum=0");
1152 	val = sdp->sd_tune.gt_quota_quantum;
1153 	if (val != 60)
1154 		seq_printf(s, ",quota_quantum=%d", val);
1155 	if (args->ar_statfs_percent)
1156 		seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
1157 	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
1158 		const char *state;
1159 
1160 		switch (args->ar_errors) {
1161 		case GFS2_ERRORS_WITHDRAW:
1162 			state = "withdraw";
1163 			break;
1164 		case GFS2_ERRORS_PANIC:
1165 			state = "panic";
1166 			break;
1167 		default:
1168 			state = "unknown";
1169 			break;
1170 		}
1171 		seq_printf(s, ",errors=%s", state);
1172 	}
1173 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
1174 		seq_puts(s, ",nobarrier");
1175 	if (test_bit(SDF_DEMOTE, &sdp->sd_flags))
1176 		seq_puts(s, ",demote_interface_used");
1177 	if (args->ar_rgrplvb)
1178 		seq_puts(s, ",rgrplvb");
1179 	if (args->ar_loccookie)
1180 		seq_puts(s, ",loccookie");
1181 	return 0;
1182 }
1183 
1184 static void gfs2_final_release_pages(struct gfs2_inode *ip)
1185 {
1186 	struct inode *inode = &ip->i_inode;
1187 	struct gfs2_glock *gl = ip->i_gl;
1188 
1189 	truncate_inode_pages(gfs2_glock2aspace(ip->i_gl), 0);
1190 	truncate_inode_pages(&inode->i_data, 0);
1191 
1192 	if (atomic_read(&gl->gl_revokes) == 0) {
1193 		clear_bit(GLF_LFLUSH, &gl->gl_flags);
1194 		clear_bit(GLF_DIRTY, &gl->gl_flags);
1195 	}
1196 }
1197 
1198 static int gfs2_dinode_dealloc(struct gfs2_inode *ip)
1199 {
1200 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
1201 	struct gfs2_rgrpd *rgd;
1202 	struct gfs2_holder gh;
1203 	int error;
1204 
1205 	if (gfs2_get_inode_blocks(&ip->i_inode) != 1) {
1206 		gfs2_consist_inode(ip);
1207 		return -EIO;
1208 	}
1209 
1210 	error = gfs2_rindex_update(sdp);
1211 	if (error)
1212 		return error;
1213 
1214 	error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
1215 	if (error)
1216 		return error;
1217 
1218 	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1219 	if (!rgd) {
1220 		gfs2_consist_inode(ip);
1221 		error = -EIO;
1222 		goto out_qs;
1223 	}
1224 
1225 	error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE, 0, &gh);
1226 	if (error)
1227 		goto out_qs;
1228 
1229 	error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_STATFS + RES_QUOTA,
1230 				 sdp->sd_jdesc->jd_blocks);
1231 	if (error)
1232 		goto out_rg_gunlock;
1233 
1234 	gfs2_free_di(rgd, ip);
1235 
1236 	gfs2_final_release_pages(ip);
1237 
1238 	gfs2_trans_end(sdp);
1239 
1240 out_rg_gunlock:
1241 	gfs2_glock_dq_uninit(&gh);
1242 out_qs:
1243 	gfs2_quota_unhold(ip);
1244 	return error;
1245 }
1246 
1247 /**
1248  * gfs2_glock_put_eventually
1249  * @gl:	The glock to put
1250  *
1251  * When under memory pressure, trigger a deferred glock put to make sure we
1252  * won't call into DLM and deadlock.  Otherwise, put the glock directly.
1253  */
1254 
1255 static void gfs2_glock_put_eventually(struct gfs2_glock *gl)
1256 {
1257 	if (current->flags & PF_MEMALLOC)
1258 		gfs2_glock_queue_put(gl);
1259 	else
1260 		gfs2_glock_put(gl);
1261 }
1262 
1263 static bool gfs2_upgrade_iopen_glock(struct inode *inode)
1264 {
1265 	struct gfs2_inode *ip = GFS2_I(inode);
1266 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1267 	struct gfs2_holder *gh = &ip->i_iopen_gh;
1268 	long timeout = 5 * HZ;
1269 	int error;
1270 
1271 	gh->gh_flags |= GL_NOCACHE;
1272 	gfs2_glock_dq_wait(gh);
1273 
1274 	/*
1275 	 * If there are no other lock holders, we'll get the lock immediately.
1276 	 * Otherwise, the other nodes holding the lock will be notified about
1277 	 * our locking request.  If they don't have the inode open, they'll
1278 	 * evict the cached inode and release the lock.  Otherwise, if they
1279 	 * poke the inode glock, we'll take this as an indication that they
1280 	 * still need the iopen glock and that they'll take care of deleting
1281 	 * the inode when they're done.  As a last resort, if another node
1282 	 * keeps holding the iopen glock without showing any activity on the
1283 	 * inode glock, we'll eventually time out.
1284 	 *
1285 	 * Note that we're passing the LM_FLAG_TRY_1CB flag to the first
1286 	 * locking request as an optimization to notify lock holders as soon as
1287 	 * possible.  Without that flag, they'd be notified implicitly by the
1288 	 * second locking request.
1289 	 */
1290 
1291 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB | GL_NOCACHE, gh);
1292 	error = gfs2_glock_nq(gh);
1293 	if (error != GLR_TRYFAILED)
1294 		return !error;
1295 
1296 	gfs2_holder_reinit(LM_ST_EXCLUSIVE, GL_ASYNC | GL_NOCACHE, gh);
1297 	error = gfs2_glock_nq(gh);
1298 	if (error)
1299 		return false;
1300 
1301 	timeout = wait_event_interruptible_timeout(sdp->sd_async_glock_wait,
1302 		!test_bit(HIF_WAIT, &gh->gh_iflags) ||
1303 		test_bit(GLF_DEMOTE, &ip->i_gl->gl_flags),
1304 		timeout);
1305 	if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) {
1306 		gfs2_glock_dq(gh);
1307 		return false;
1308 	}
1309 	return true;
1310 }
1311 
1312 /**
1313  * evict_should_delete - determine whether the inode is eligible for deletion
1314  * @inode: The inode to evict
1315  *
1316  * This function determines whether the evicted inode is eligible to be deleted
1317  * and locks the inode glock.
1318  *
1319  * Returns: the fate of the dinode
1320  */
1321 static enum dinode_demise evict_should_delete(struct inode *inode,
1322 					      struct gfs2_holder *gh)
1323 {
1324 	struct gfs2_inode *ip = GFS2_I(inode);
1325 	struct super_block *sb = inode->i_sb;
1326 	struct gfs2_sbd *sdp = sb->s_fs_info;
1327 	int ret;
1328 
1329 	if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
1330 		BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
1331 		goto should_delete;
1332 	}
1333 
1334 	if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
1335 		return SHOULD_DEFER_EVICTION;
1336 
1337 	/* Deletes should never happen under memory pressure anymore.  */
1338 	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
1339 		return SHOULD_DEFER_EVICTION;
1340 
1341 	/* Must not read inode block until block type has been verified */
1342 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, gh);
1343 	if (unlikely(ret)) {
1344 		glock_clear_object(ip->i_iopen_gh.gh_gl, ip);
1345 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1346 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
1347 		return SHOULD_DEFER_EVICTION;
1348 	}
1349 
1350 	if (gfs2_inode_already_deleted(ip->i_gl, ip->i_no_formal_ino))
1351 		return SHOULD_NOT_DELETE_DINODE;
1352 	ret = gfs2_check_blk_type(sdp, ip->i_no_addr, GFS2_BLKST_UNLINKED);
1353 	if (ret)
1354 		return SHOULD_NOT_DELETE_DINODE;
1355 
1356 	if (test_bit(GIF_INVALID, &ip->i_flags)) {
1357 		ret = gfs2_inode_refresh(ip);
1358 		if (ret)
1359 			return SHOULD_NOT_DELETE_DINODE;
1360 	}
1361 
1362 	/*
1363 	 * The inode may have been recreated in the meantime.
1364 	 */
1365 	if (inode->i_nlink)
1366 		return SHOULD_NOT_DELETE_DINODE;
1367 
1368 should_delete:
1369 	if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
1370 	    test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1371 		if (!gfs2_upgrade_iopen_glock(inode)) {
1372 			gfs2_holder_uninit(&ip->i_iopen_gh);
1373 			return SHOULD_NOT_DELETE_DINODE;
1374 		}
1375 	}
1376 	return SHOULD_DELETE_DINODE;
1377 }
1378 
1379 /**
1380  * evict_unlinked_inode - delete the pieces of an unlinked evicted inode
1381  * @inode: The inode to evict
1382  */
1383 static int evict_unlinked_inode(struct inode *inode)
1384 {
1385 	struct gfs2_inode *ip = GFS2_I(inode);
1386 	int ret;
1387 
1388 	if (S_ISDIR(inode->i_mode) &&
1389 	    (ip->i_diskflags & GFS2_DIF_EXHASH)) {
1390 		ret = gfs2_dir_exhash_dealloc(ip);
1391 		if (ret)
1392 			goto out;
1393 	}
1394 
1395 	if (ip->i_eattr) {
1396 		ret = gfs2_ea_dealloc(ip);
1397 		if (ret)
1398 			goto out;
1399 	}
1400 
1401 	if (!gfs2_is_stuffed(ip)) {
1402 		ret = gfs2_file_dealloc(ip);
1403 		if (ret)
1404 			goto out;
1405 	}
1406 
1407 	/* We're about to clear the bitmap for the dinode, but as soon as we
1408 	   do, gfs2_create_inode can create another inode at the same block
1409 	   location and try to set gl_object again. We clear gl_object here so
1410 	   that subsequent inode creates don't see an old gl_object. */
1411 	glock_clear_object(ip->i_gl, ip);
1412 	ret = gfs2_dinode_dealloc(ip);
1413 	gfs2_inode_remember_delete(ip->i_gl, ip->i_no_formal_ino);
1414 out:
1415 	return ret;
1416 }
1417 
1418 /*
1419  * evict_linked_inode - evict an inode whose dinode has not been unlinked
1420  * @inode: The inode to evict
1421  */
1422 static int evict_linked_inode(struct inode *inode)
1423 {
1424 	struct super_block *sb = inode->i_sb;
1425 	struct gfs2_sbd *sdp = sb->s_fs_info;
1426 	struct gfs2_inode *ip = GFS2_I(inode);
1427 	struct address_space *metamapping;
1428 	int ret;
1429 
1430 	gfs2_log_flush(sdp, ip->i_gl, GFS2_LOG_HEAD_FLUSH_NORMAL |
1431 		       GFS2_LFC_EVICT_INODE);
1432 	metamapping = gfs2_glock2aspace(ip->i_gl);
1433 	if (test_bit(GLF_DIRTY, &ip->i_gl->gl_flags)) {
1434 		filemap_fdatawrite(metamapping);
1435 		filemap_fdatawait(metamapping);
1436 	}
1437 	write_inode_now(inode, 1);
1438 	gfs2_ail_flush(ip->i_gl, 0);
1439 
1440 	ret = gfs2_trans_begin(sdp, 0, sdp->sd_jdesc->jd_blocks);
1441 	if (ret)
1442 		return ret;
1443 
1444 	/* Needs to be done before glock release & also in a transaction */
1445 	truncate_inode_pages(&inode->i_data, 0);
1446 	truncate_inode_pages(metamapping, 0);
1447 	gfs2_trans_end(sdp);
1448 	return 0;
1449 }
1450 
1451 /**
1452  * gfs2_evict_inode - Remove an inode from cache
1453  * @inode: The inode to evict
1454  *
1455  * There are three cases to consider:
1456  * 1. i_nlink == 0, we are final opener (and must deallocate)
1457  * 2. i_nlink == 0, we are not the final opener (and cannot deallocate)
1458  * 3. i_nlink > 0
1459  *
1460  * If the fs is read only, then we have to treat all cases as per #3
1461  * since we are unable to do any deallocation. The inode will be
1462  * deallocated by the next read/write node to attempt an allocation
1463  * in the same resource group
1464  *
1465  * We have to (at the moment) hold the inodes main lock to cover
1466  * the gap between unlocking the shared lock on the iopen lock and
1467  * taking the exclusive lock. I'd rather do a shared -> exclusive
1468  * conversion on the iopen lock, but we can change that later. This
1469  * is safe, just less efficient.
1470  */
1471 
1472 static void gfs2_evict_inode(struct inode *inode)
1473 {
1474 	struct super_block *sb = inode->i_sb;
1475 	struct gfs2_sbd *sdp = sb->s_fs_info;
1476 	struct gfs2_inode *ip = GFS2_I(inode);
1477 	struct gfs2_holder gh;
1478 	int ret;
1479 
1480 	if (test_bit(GIF_FREE_VFS_INODE, &ip->i_flags)) {
1481 		clear_inode(inode);
1482 		return;
1483 	}
1484 
1485 	if (inode->i_nlink || sb_rdonly(sb))
1486 		goto out;
1487 
1488 	gfs2_holder_mark_uninitialized(&gh);
1489 	ret = evict_should_delete(inode, &gh);
1490 	if (ret == SHOULD_DEFER_EVICTION)
1491 		goto out;
1492 	if (ret == SHOULD_DELETE_DINODE)
1493 		ret = evict_unlinked_inode(inode);
1494 	else
1495 		ret = evict_linked_inode(inode);
1496 
1497 	if (gfs2_rs_active(&ip->i_res))
1498 		gfs2_rs_deltree(&ip->i_res);
1499 
1500 	if (gfs2_holder_initialized(&gh)) {
1501 		glock_clear_object(ip->i_gl, ip);
1502 		gfs2_glock_dq_uninit(&gh);
1503 	}
1504 	if (ret && ret != GLR_TRYFAILED && ret != -EROFS)
1505 		fs_warn(sdp, "gfs2_evict_inode: %d\n", ret);
1506 out:
1507 	truncate_inode_pages_final(&inode->i_data);
1508 	if (ip->i_qadata)
1509 		gfs2_assert_warn(sdp, ip->i_qadata->qa_ref == 0);
1510 	gfs2_rs_delete(ip, NULL);
1511 	gfs2_ordered_del_inode(ip);
1512 	clear_inode(inode);
1513 	gfs2_dir_hash_inval(ip);
1514 	if (ip->i_gl) {
1515 		glock_clear_object(ip->i_gl, ip);
1516 		wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);
1517 		gfs2_glock_add_to_lru(ip->i_gl);
1518 		gfs2_glock_put_eventually(ip->i_gl);
1519 		ip->i_gl = NULL;
1520 	}
1521 	if (gfs2_holder_initialized(&ip->i_iopen_gh)) {
1522 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
1523 
1524 		glock_clear_object(gl, ip);
1525 		if (test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
1526 			ip->i_iopen_gh.gh_flags |= GL_NOCACHE;
1527 			gfs2_glock_dq(&ip->i_iopen_gh);
1528 		}
1529 		gfs2_glock_hold(gl);
1530 		gfs2_holder_uninit(&ip->i_iopen_gh);
1531 		gfs2_glock_put_eventually(gl);
1532 	}
1533 }
1534 
1535 static struct inode *gfs2_alloc_inode(struct super_block *sb)
1536 {
1537 	struct gfs2_inode *ip;
1538 
1539 	ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
1540 	if (!ip)
1541 		return NULL;
1542 	ip->i_flags = 0;
1543 	ip->i_gl = NULL;
1544 	gfs2_holder_mark_uninitialized(&ip->i_iopen_gh);
1545 	memset(&ip->i_res, 0, sizeof(ip->i_res));
1546 	RB_CLEAR_NODE(&ip->i_res.rs_node);
1547 	ip->i_rahead = 0;
1548 	return &ip->i_inode;
1549 }
1550 
1551 static void gfs2_free_inode(struct inode *inode)
1552 {
1553 	kmem_cache_free(gfs2_inode_cachep, GFS2_I(inode));
1554 }
1555 
1556 extern void free_local_statfs_inodes(struct gfs2_sbd *sdp)
1557 {
1558 	struct local_statfs_inode *lsi, *safe;
1559 
1560 	/* Run through the statfs inodes list to iput and free memory */
1561 	list_for_each_entry_safe(lsi, safe, &sdp->sd_sc_inodes_list, si_list) {
1562 		if (lsi->si_jid == sdp->sd_jdesc->jd_jid)
1563 			sdp->sd_sc_inode = NULL; /* belongs to this node */
1564 		if (lsi->si_sc_inode)
1565 			iput(lsi->si_sc_inode);
1566 		list_del(&lsi->si_list);
1567 		kfree(lsi);
1568 	}
1569 }
1570 
1571 extern struct inode *find_local_statfs_inode(struct gfs2_sbd *sdp,
1572 					     unsigned int index)
1573 {
1574 	struct local_statfs_inode *lsi;
1575 
1576 	/* Return the local (per node) statfs inode in the
1577 	 * sdp->sd_sc_inodes_list corresponding to the 'index'. */
1578 	list_for_each_entry(lsi, &sdp->sd_sc_inodes_list, si_list) {
1579 		if (lsi->si_jid == index)
1580 			return lsi->si_sc_inode;
1581 	}
1582 	return NULL;
1583 }
1584 
1585 const struct super_operations gfs2_super_ops = {
1586 	.alloc_inode		= gfs2_alloc_inode,
1587 	.free_inode		= gfs2_free_inode,
1588 	.write_inode		= gfs2_write_inode,
1589 	.dirty_inode		= gfs2_dirty_inode,
1590 	.evict_inode		= gfs2_evict_inode,
1591 	.put_super		= gfs2_put_super,
1592 	.sync_fs		= gfs2_sync_fs,
1593 	.freeze_super		= gfs2_freeze,
1594 	.thaw_super		= gfs2_unfreeze,
1595 	.statfs			= gfs2_statfs,
1596 	.drop_inode		= gfs2_drop_inode,
1597 	.show_options		= gfs2_show_options,
1598 };
1599 
1600