xref: /linux/fs/gfs2/super.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #include <linux/sched.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/crc32.h>
16 #include <linux/gfs2_ondisk.h>
17 #include <linux/bio.h>
18 
19 #include "gfs2.h"
20 #include "incore.h"
21 #include "bmap.h"
22 #include "dir.h"
23 #include "glock.h"
24 #include "glops.h"
25 #include "inode.h"
26 #include "log.h"
27 #include "meta_io.h"
28 #include "quota.h"
29 #include "recovery.h"
30 #include "rgrp.h"
31 #include "super.h"
32 #include "trans.h"
33 #include "util.h"
34 
35 /**
36  * gfs2_jindex_free - Clear all the journal index information
37  * @sdp: The GFS2 superblock
38  *
39  */
40 
41 void gfs2_jindex_free(struct gfs2_sbd *sdp)
42 {
43 	struct list_head list, *head;
44 	struct gfs2_jdesc *jd;
45 	struct gfs2_journal_extent *jext;
46 
47 	spin_lock(&sdp->sd_jindex_spin);
48 	list_add(&list, &sdp->sd_jindex_list);
49 	list_del_init(&sdp->sd_jindex_list);
50 	sdp->sd_journals = 0;
51 	spin_unlock(&sdp->sd_jindex_spin);
52 
53 	while (!list_empty(&list)) {
54 		jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
55 		head = &jd->extent_list;
56 		while (!list_empty(head)) {
57 			jext = list_entry(head->next,
58 					  struct gfs2_journal_extent,
59 					  extent_list);
60 			list_del(&jext->extent_list);
61 			kfree(jext);
62 		}
63 		list_del(&jd->jd_list);
64 		iput(jd->jd_inode);
65 		kfree(jd);
66 	}
67 }
68 
69 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
70 {
71 	struct gfs2_jdesc *jd;
72 	int found = 0;
73 
74 	list_for_each_entry(jd, head, jd_list) {
75 		if (jd->jd_jid == jid) {
76 			found = 1;
77 			break;
78 		}
79 	}
80 
81 	if (!found)
82 		jd = NULL;
83 
84 	return jd;
85 }
86 
87 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
88 {
89 	struct gfs2_jdesc *jd;
90 
91 	spin_lock(&sdp->sd_jindex_spin);
92 	jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
93 	spin_unlock(&sdp->sd_jindex_spin);
94 
95 	return jd;
96 }
97 
98 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
99 {
100 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
101 	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
102 	int ar;
103 	int error;
104 
105 	if (ip->i_disksize < (8 << 20) || ip->i_disksize > (1 << 30) ||
106 	    (ip->i_disksize & (sdp->sd_sb.sb_bsize - 1))) {
107 		gfs2_consist_inode(ip);
108 		return -EIO;
109 	}
110 	jd->jd_blocks = ip->i_disksize >> sdp->sd_sb.sb_bsize_shift;
111 
112 	error = gfs2_write_alloc_required(ip, 0, ip->i_disksize, &ar);
113 	if (!error && ar) {
114 		gfs2_consist_inode(ip);
115 		error = -EIO;
116 	}
117 
118 	return error;
119 }
120 
121 /**
122  * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
123  * @sdp: the filesystem
124  *
125  * Returns: errno
126  */
127 
128 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
129 {
130 	struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
131 	struct gfs2_glock *j_gl = ip->i_gl;
132 	struct gfs2_holder t_gh;
133 	struct gfs2_log_header_host head;
134 	int error;
135 
136 	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
137 	if (error)
138 		return error;
139 
140 	j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
141 
142 	error = gfs2_find_jhead(sdp->sd_jdesc, &head);
143 	if (error)
144 		goto fail;
145 
146 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
147 		gfs2_consist(sdp);
148 		error = -EIO;
149 		goto fail;
150 	}
151 
152 	/*  Initialize some head of the log stuff  */
153 	sdp->sd_log_sequence = head.lh_sequence + 1;
154 	gfs2_log_pointers_init(sdp, head.lh_blkno);
155 
156 	error = gfs2_quota_init(sdp);
157 	if (error)
158 		goto fail;
159 
160 	set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
161 
162 	gfs2_glock_dq_uninit(&t_gh);
163 
164 	return 0;
165 
166 fail:
167 	t_gh.gh_flags |= GL_NOCACHE;
168 	gfs2_glock_dq_uninit(&t_gh);
169 
170 	return error;
171 }
172 
173 static void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
174 {
175 	const struct gfs2_statfs_change *str = buf;
176 
177 	sc->sc_total = be64_to_cpu(str->sc_total);
178 	sc->sc_free = be64_to_cpu(str->sc_free);
179 	sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
180 }
181 
182 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
183 {
184 	struct gfs2_statfs_change *str = buf;
185 
186 	str->sc_total = cpu_to_be64(sc->sc_total);
187 	str->sc_free = cpu_to_be64(sc->sc_free);
188 	str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
189 }
190 
191 int gfs2_statfs_init(struct gfs2_sbd *sdp)
192 {
193 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
194 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
195 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
196 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
197 	struct buffer_head *m_bh, *l_bh;
198 	struct gfs2_holder gh;
199 	int error;
200 
201 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
202 				   &gh);
203 	if (error)
204 		return error;
205 
206 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
207 	if (error)
208 		goto out;
209 
210 	if (sdp->sd_args.ar_spectator) {
211 		spin_lock(&sdp->sd_statfs_spin);
212 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
213 				      sizeof(struct gfs2_dinode));
214 		spin_unlock(&sdp->sd_statfs_spin);
215 	} else {
216 		error = gfs2_meta_inode_buffer(l_ip, &l_bh);
217 		if (error)
218 			goto out_m_bh;
219 
220 		spin_lock(&sdp->sd_statfs_spin);
221 		gfs2_statfs_change_in(m_sc, m_bh->b_data +
222 				      sizeof(struct gfs2_dinode));
223 		gfs2_statfs_change_in(l_sc, l_bh->b_data +
224 				      sizeof(struct gfs2_dinode));
225 		spin_unlock(&sdp->sd_statfs_spin);
226 
227 		brelse(l_bh);
228 	}
229 
230 out_m_bh:
231 	brelse(m_bh);
232 out:
233 	gfs2_glock_dq_uninit(&gh);
234 	return 0;
235 }
236 
237 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
238 			s64 dinodes)
239 {
240 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
241 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
242 	struct buffer_head *l_bh;
243 	int error;
244 
245 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
246 	if (error)
247 		return;
248 
249 	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
250 
251 	spin_lock(&sdp->sd_statfs_spin);
252 	l_sc->sc_total += total;
253 	l_sc->sc_free += free;
254 	l_sc->sc_dinodes += dinodes;
255 	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
256 	spin_unlock(&sdp->sd_statfs_spin);
257 
258 	brelse(l_bh);
259 }
260 
261 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
262 {
263 	struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
264 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
265 	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
266 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
267 	struct gfs2_holder gh;
268 	struct buffer_head *m_bh, *l_bh;
269 	int error;
270 
271 	error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
272 				   &gh);
273 	if (error)
274 		return error;
275 
276 	error = gfs2_meta_inode_buffer(m_ip, &m_bh);
277 	if (error)
278 		goto out;
279 
280 	spin_lock(&sdp->sd_statfs_spin);
281 	gfs2_statfs_change_in(m_sc, m_bh->b_data +
282 			      sizeof(struct gfs2_dinode));
283 	if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
284 		spin_unlock(&sdp->sd_statfs_spin);
285 		goto out_bh;
286 	}
287 	spin_unlock(&sdp->sd_statfs_spin);
288 
289 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
290 	if (error)
291 		goto out_bh;
292 
293 	error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
294 	if (error)
295 		goto out_bh2;
296 
297 	gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
298 
299 	spin_lock(&sdp->sd_statfs_spin);
300 	m_sc->sc_total += l_sc->sc_total;
301 	m_sc->sc_free += l_sc->sc_free;
302 	m_sc->sc_dinodes += l_sc->sc_dinodes;
303 	memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
304 	memset(l_bh->b_data + sizeof(struct gfs2_dinode),
305 	       0, sizeof(struct gfs2_statfs_change));
306 	spin_unlock(&sdp->sd_statfs_spin);
307 
308 	gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
309 	gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
310 
311 	gfs2_trans_end(sdp);
312 
313 out_bh2:
314 	brelse(l_bh);
315 out_bh:
316 	brelse(m_bh);
317 out:
318 	gfs2_glock_dq_uninit(&gh);
319 	return error;
320 }
321 
322 struct lfcc {
323 	struct list_head list;
324 	struct gfs2_holder gh;
325 };
326 
327 /**
328  * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
329  *                            journals are clean
330  * @sdp: the file system
331  * @state: the state to put the transaction lock into
332  * @t_gh: the hold on the transaction lock
333  *
334  * Returns: errno
335  */
336 
337 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
338 				    struct gfs2_holder *t_gh)
339 {
340 	struct gfs2_inode *ip;
341 	struct gfs2_jdesc *jd;
342 	struct lfcc *lfcc;
343 	LIST_HEAD(list);
344 	struct gfs2_log_header_host lh;
345 	int error;
346 
347 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
348 		lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
349 		if (!lfcc) {
350 			error = -ENOMEM;
351 			goto out;
352 		}
353 		ip = GFS2_I(jd->jd_inode);
354 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
355 		if (error) {
356 			kfree(lfcc);
357 			goto out;
358 		}
359 		list_add(&lfcc->list, &list);
360 	}
361 
362 	error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
363 				   GL_NOCACHE, t_gh);
364 
365 	list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
366 		error = gfs2_jdesc_check(jd);
367 		if (error)
368 			break;
369 		error = gfs2_find_jhead(jd, &lh);
370 		if (error)
371 			break;
372 		if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
373 			error = -EBUSY;
374 			break;
375 		}
376 	}
377 
378 	if (error)
379 		gfs2_glock_dq_uninit(t_gh);
380 
381 out:
382 	while (!list_empty(&list)) {
383 		lfcc = list_entry(list.next, struct lfcc, list);
384 		list_del(&lfcc->list);
385 		gfs2_glock_dq_uninit(&lfcc->gh);
386 		kfree(lfcc);
387 	}
388 	return error;
389 }
390 
391 /**
392  * gfs2_freeze_fs - freezes the file system
393  * @sdp: the file system
394  *
395  * This function flushes data and meta data for all machines by
396  * aquiring the transaction log exclusively.  All journals are
397  * ensured to be in a clean state as well.
398  *
399  * Returns: errno
400  */
401 
402 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
403 {
404 	int error = 0;
405 
406 	mutex_lock(&sdp->sd_freeze_lock);
407 
408 	if (!sdp->sd_freeze_count++) {
409 		error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
410 		if (error)
411 			sdp->sd_freeze_count--;
412 	}
413 
414 	mutex_unlock(&sdp->sd_freeze_lock);
415 
416 	return error;
417 }
418 
419 /**
420  * gfs2_unfreeze_fs - unfreezes the file system
421  * @sdp: the file system
422  *
423  * This function allows the file system to proceed by unlocking
424  * the exclusively held transaction lock.  Other GFS2 nodes are
425  * now free to acquire the lock shared and go on with their lives.
426  *
427  */
428 
429 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
430 {
431 	mutex_lock(&sdp->sd_freeze_lock);
432 
433 	if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
434 		gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
435 
436 	mutex_unlock(&sdp->sd_freeze_lock);
437 }
438 
439