xref: /openbmc/linux/fs/gfs2/ops_fstype.c (revision 96ac6d43)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/completion.h>
16 #include <linux/buffer_head.h>
17 #include <linux/blkdev.h>
18 #include <linux/kthread.h>
19 #include <linux/export.h>
20 #include <linux/namei.h>
21 #include <linux/mount.h>
22 #include <linux/gfs2_ondisk.h>
23 #include <linux/quotaops.h>
24 #include <linux/lockdep.h>
25 #include <linux/module.h>
26 #include <linux/backing-dev.h>
27 
28 #include "gfs2.h"
29 #include "incore.h"
30 #include "bmap.h"
31 #include "glock.h"
32 #include "glops.h"
33 #include "inode.h"
34 #include "recovery.h"
35 #include "rgrp.h"
36 #include "super.h"
37 #include "sys.h"
38 #include "util.h"
39 #include "log.h"
40 #include "quota.h"
41 #include "dir.h"
42 #include "meta_io.h"
43 #include "trace_gfs2.h"
44 #include "lops.h"
45 
46 #define DO 0
47 #define UNDO 1
48 
49 /**
50  * gfs2_tune_init - Fill a gfs2_tune structure with default values
51  * @gt: tune
52  *
53  */
54 
55 static void gfs2_tune_init(struct gfs2_tune *gt)
56 {
57 	spin_lock_init(&gt->gt_spin);
58 
59 	gt->gt_quota_warn_period = 10;
60 	gt->gt_quota_scale_num = 1;
61 	gt->gt_quota_scale_den = 1;
62 	gt->gt_new_files_jdata = 0;
63 	gt->gt_max_readahead = BIT(18);
64 	gt->gt_complain_secs = 10;
65 }
66 
67 static struct gfs2_sbd *init_sbd(struct super_block *sb)
68 {
69 	struct gfs2_sbd *sdp;
70 	struct address_space *mapping;
71 
72 	sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
73 	if (!sdp)
74 		return NULL;
75 
76 	sdp->sd_vfs = sb;
77 	sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
78 	if (!sdp->sd_lkstats) {
79 		kfree(sdp);
80 		return NULL;
81 	}
82 	sb->s_fs_info = sdp;
83 
84 	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
85 	gfs2_tune_init(&sdp->sd_tune);
86 
87 	init_waitqueue_head(&sdp->sd_glock_wait);
88 	atomic_set(&sdp->sd_glock_disposal, 0);
89 	init_completion(&sdp->sd_locking_init);
90 	init_completion(&sdp->sd_wdack);
91 	spin_lock_init(&sdp->sd_statfs_spin);
92 
93 	spin_lock_init(&sdp->sd_rindex_spin);
94 	sdp->sd_rindex_tree.rb_node = NULL;
95 
96 	INIT_LIST_HEAD(&sdp->sd_jindex_list);
97 	spin_lock_init(&sdp->sd_jindex_spin);
98 	mutex_init(&sdp->sd_jindex_mutex);
99 	init_completion(&sdp->sd_journal_ready);
100 
101 	INIT_LIST_HEAD(&sdp->sd_quota_list);
102 	mutex_init(&sdp->sd_quota_mutex);
103 	mutex_init(&sdp->sd_quota_sync_mutex);
104 	init_waitqueue_head(&sdp->sd_quota_wait);
105 	INIT_LIST_HEAD(&sdp->sd_trunc_list);
106 	spin_lock_init(&sdp->sd_trunc_lock);
107 	spin_lock_init(&sdp->sd_bitmap_lock);
108 
109 	mapping = &sdp->sd_aspace;
110 
111 	address_space_init_once(mapping);
112 	mapping->a_ops = &gfs2_rgrp_aops;
113 	mapping->host = sb->s_bdev->bd_inode;
114 	mapping->flags = 0;
115 	mapping_set_gfp_mask(mapping, GFP_NOFS);
116 	mapping->private_data = NULL;
117 	mapping->writeback_index = 0;
118 
119 	spin_lock_init(&sdp->sd_log_lock);
120 	atomic_set(&sdp->sd_log_pinned, 0);
121 	INIT_LIST_HEAD(&sdp->sd_log_revokes);
122 	INIT_LIST_HEAD(&sdp->sd_log_ordered);
123 	spin_lock_init(&sdp->sd_ordered_lock);
124 
125 	init_waitqueue_head(&sdp->sd_log_waitq);
126 	init_waitqueue_head(&sdp->sd_logd_waitq);
127 	spin_lock_init(&sdp->sd_ail_lock);
128 	INIT_LIST_HEAD(&sdp->sd_ail1_list);
129 	INIT_LIST_HEAD(&sdp->sd_ail2_list);
130 
131 	init_rwsem(&sdp->sd_log_flush_lock);
132 	atomic_set(&sdp->sd_log_in_flight, 0);
133 	atomic_set(&sdp->sd_reserving_log, 0);
134 	init_waitqueue_head(&sdp->sd_reserving_log_wait);
135 	init_waitqueue_head(&sdp->sd_log_flush_wait);
136 	atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
137 	mutex_init(&sdp->sd_freeze_mutex);
138 
139 	return sdp;
140 }
141 
142 
143 /**
144  * gfs2_check_sb - Check superblock
145  * @sdp: the filesystem
146  * @sb: The superblock
147  * @silent: Don't print a message if the check fails
148  *
149  * Checks the version code of the FS is one that we understand how to
150  * read and that the sizes of the various on-disk structures have not
151  * changed.
152  */
153 
154 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
155 {
156 	struct gfs2_sb_host *sb = &sdp->sd_sb;
157 
158 	if (sb->sb_magic != GFS2_MAGIC ||
159 	    sb->sb_type != GFS2_METATYPE_SB) {
160 		if (!silent)
161 			pr_warn("not a GFS2 filesystem\n");
162 		return -EINVAL;
163 	}
164 
165 	/*  If format numbers match exactly, we're done.  */
166 
167 	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
168 	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
169 		return 0;
170 
171 	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
172 
173 	return -EINVAL;
174 }
175 
176 static void end_bio_io_page(struct bio *bio)
177 {
178 	struct page *page = bio->bi_private;
179 
180 	if (!bio->bi_status)
181 		SetPageUptodate(page);
182 	else
183 		pr_warn("error %d reading superblock\n", bio->bi_status);
184 	unlock_page(page);
185 }
186 
187 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
188 {
189 	struct gfs2_sb_host *sb = &sdp->sd_sb;
190 	struct super_block *s = sdp->sd_vfs;
191 	const struct gfs2_sb *str = buf;
192 
193 	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
194 	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
195 	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
196 	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
197 	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
198 	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
199 	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
200 	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
201 	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
202 	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
203 	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
204 
205 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
206 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
207 	memcpy(&s->s_uuid, str->sb_uuid, 16);
208 }
209 
210 /**
211  * gfs2_read_super - Read the gfs2 super block from disk
212  * @sdp: The GFS2 super block
213  * @sector: The location of the super block
214  * @error: The error code to return
215  *
216  * This uses the bio functions to read the super block from disk
217  * because we want to be 100% sure that we never read cached data.
218  * A super block is read twice only during each GFS2 mount and is
219  * never written to by the filesystem. The first time its read no
220  * locks are held, and the only details which are looked at are those
221  * relating to the locking protocol. Once locking is up and working,
222  * the sb is read again under the lock to establish the location of
223  * the master directory (contains pointers to journals etc) and the
224  * root directory.
225  *
226  * Returns: 0 on success or error
227  */
228 
229 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
230 {
231 	struct super_block *sb = sdp->sd_vfs;
232 	struct gfs2_sb *p;
233 	struct page *page;
234 	struct bio *bio;
235 
236 	page = alloc_page(GFP_NOFS);
237 	if (unlikely(!page))
238 		return -ENOMEM;
239 
240 	ClearPageUptodate(page);
241 	ClearPageDirty(page);
242 	lock_page(page);
243 
244 	bio = bio_alloc(GFP_NOFS, 1);
245 	bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
246 	bio_set_dev(bio, sb->s_bdev);
247 	bio_add_page(bio, page, PAGE_SIZE, 0);
248 
249 	bio->bi_end_io = end_bio_io_page;
250 	bio->bi_private = page;
251 	bio_set_op_attrs(bio, REQ_OP_READ, REQ_META);
252 	submit_bio(bio);
253 	wait_on_page_locked(page);
254 	bio_put(bio);
255 	if (!PageUptodate(page)) {
256 		__free_page(page);
257 		return -EIO;
258 	}
259 	p = kmap(page);
260 	gfs2_sb_in(sdp, p);
261 	kunmap(page);
262 	__free_page(page);
263 	return gfs2_check_sb(sdp, silent);
264 }
265 
266 /**
267  * gfs2_read_sb - Read super block
268  * @sdp: The GFS2 superblock
269  * @silent: Don't print message if mount fails
270  *
271  */
272 
273 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
274 {
275 	u32 hash_blocks, ind_blocks, leaf_blocks;
276 	u32 tmp_blocks;
277 	unsigned int x;
278 	int error;
279 
280 	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
281 	if (error) {
282 		if (!silent)
283 			fs_err(sdp, "can't read superblock\n");
284 		return error;
285 	}
286 
287 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
288 			       GFS2_BASIC_BLOCK_SHIFT;
289 	sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
290 	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
291 			  sizeof(struct gfs2_dinode)) / sizeof(u64);
292 	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
293 			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
294 	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
295 	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
296 	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
297 	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
298 	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
299 				sizeof(struct gfs2_meta_header)) /
300 			        sizeof(struct gfs2_quota_change);
301 	sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
302 				     sizeof(struct gfs2_meta_header))
303 		* GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
304 
305 	/* Compute maximum reservation required to add a entry to a directory */
306 
307 	hash_blocks = DIV_ROUND_UP(sizeof(u64) * BIT(GFS2_DIR_MAX_DEPTH),
308 			     sdp->sd_jbsize);
309 
310 	ind_blocks = 0;
311 	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
312 		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
313 		ind_blocks += tmp_blocks;
314 	}
315 
316 	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
317 
318 	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
319 
320 	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
321 				sizeof(struct gfs2_dinode);
322 	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
323 	for (x = 2;; x++) {
324 		u64 space, d;
325 		u32 m;
326 
327 		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
328 		d = space;
329 		m = do_div(d, sdp->sd_inptrs);
330 
331 		if (d != sdp->sd_heightsize[x - 1] || m)
332 			break;
333 		sdp->sd_heightsize[x] = space;
334 	}
335 	sdp->sd_max_height = x;
336 	sdp->sd_heightsize[x] = ~0;
337 	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
338 
339 	sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
340 				      sizeof(struct gfs2_leaf)) /
341 				     GFS2_MIN_DIRENT_SIZE;
342 	return 0;
343 }
344 
345 static int init_names(struct gfs2_sbd *sdp, int silent)
346 {
347 	char *proto, *table;
348 	int error = 0;
349 
350 	proto = sdp->sd_args.ar_lockproto;
351 	table = sdp->sd_args.ar_locktable;
352 
353 	/*  Try to autodetect  */
354 
355 	if (!proto[0] || !table[0]) {
356 		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
357 		if (error)
358 			return error;
359 
360 		if (!proto[0])
361 			proto = sdp->sd_sb.sb_lockproto;
362 		if (!table[0])
363 			table = sdp->sd_sb.sb_locktable;
364 	}
365 
366 	if (!table[0])
367 		table = sdp->sd_vfs->s_id;
368 
369 	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
370 	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
371 
372 	table = sdp->sd_table_name;
373 	while ((table = strchr(table, '/')))
374 		*table = '_';
375 
376 	return error;
377 }
378 
379 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
380 			int undo)
381 {
382 	int error = 0;
383 
384 	if (undo)
385 		goto fail_trans;
386 
387 	error = gfs2_glock_nq_num(sdp,
388 				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
389 				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
390 				  mount_gh);
391 	if (error) {
392 		fs_err(sdp, "can't acquire mount glock: %d\n", error);
393 		goto fail;
394 	}
395 
396 	error = gfs2_glock_nq_num(sdp,
397 				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
398 				  LM_ST_SHARED,
399 				  LM_FLAG_NOEXP | GL_EXACT,
400 				  &sdp->sd_live_gh);
401 	if (error) {
402 		fs_err(sdp, "can't acquire live glock: %d\n", error);
403 		goto fail_mount;
404 	}
405 
406 	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
407 			       CREATE, &sdp->sd_rename_gl);
408 	if (error) {
409 		fs_err(sdp, "can't create rename glock: %d\n", error);
410 		goto fail_live;
411 	}
412 
413 	error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
414 			       CREATE, &sdp->sd_freeze_gl);
415 	if (error) {
416 		fs_err(sdp, "can't create transaction glock: %d\n", error);
417 		goto fail_rename;
418 	}
419 
420 	return 0;
421 
422 fail_trans:
423 	gfs2_glock_put(sdp->sd_freeze_gl);
424 fail_rename:
425 	gfs2_glock_put(sdp->sd_rename_gl);
426 fail_live:
427 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
428 fail_mount:
429 	gfs2_glock_dq_uninit(mount_gh);
430 fail:
431 	return error;
432 }
433 
434 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
435 			    u64 no_addr, const char *name)
436 {
437 	struct gfs2_sbd *sdp = sb->s_fs_info;
438 	struct dentry *dentry;
439 	struct inode *inode;
440 
441 	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0,
442 				  GFS2_BLKST_FREE /* ignore */);
443 	if (IS_ERR(inode)) {
444 		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
445 		return PTR_ERR(inode);
446 	}
447 	dentry = d_make_root(inode);
448 	if (!dentry) {
449 		fs_err(sdp, "can't alloc %s dentry\n", name);
450 		return -ENOMEM;
451 	}
452 	*dptr = dentry;
453 	return 0;
454 }
455 
456 static int init_sb(struct gfs2_sbd *sdp, int silent)
457 {
458 	struct super_block *sb = sdp->sd_vfs;
459 	struct gfs2_holder sb_gh;
460 	u64 no_addr;
461 	int ret;
462 
463 	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
464 				LM_ST_SHARED, 0, &sb_gh);
465 	if (ret) {
466 		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
467 		return ret;
468 	}
469 
470 	ret = gfs2_read_sb(sdp, silent);
471 	if (ret) {
472 		fs_err(sdp, "can't read superblock: %d\n", ret);
473 		goto out;
474 	}
475 
476 	/* Set up the buffer cache and SB for real */
477 	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
478 		ret = -EINVAL;
479 		fs_err(sdp, "FS block size (%u) is too small for device "
480 		       "block size (%u)\n",
481 		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
482 		goto out;
483 	}
484 	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
485 		ret = -EINVAL;
486 		fs_err(sdp, "FS block size (%u) is too big for machine "
487 		       "page size (%u)\n",
488 		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
489 		goto out;
490 	}
491 	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
492 
493 	/* Get the root inode */
494 	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
495 	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
496 	if (ret)
497 		goto out;
498 
499 	/* Get the master inode */
500 	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
501 	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
502 	if (ret) {
503 		dput(sdp->sd_root_dir);
504 		goto out;
505 	}
506 	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
507 out:
508 	gfs2_glock_dq_uninit(&sb_gh);
509 	return ret;
510 }
511 
512 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
513 {
514 	char *message = "FIRSTMOUNT=Done";
515 	char *envp[] = { message, NULL };
516 
517 	fs_info(sdp, "first mount done, others may mount\n");
518 
519 	if (sdp->sd_lockstruct.ls_ops->lm_first_done)
520 		sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
521 
522 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
523 }
524 
525 /**
526  * gfs2_jindex_hold - Grab a lock on the jindex
527  * @sdp: The GFS2 superblock
528  * @ji_gh: the holder for the jindex glock
529  *
530  * Returns: errno
531  */
532 
533 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
534 {
535 	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
536 	struct qstr name;
537 	char buf[20];
538 	struct gfs2_jdesc *jd;
539 	int error;
540 
541 	name.name = buf;
542 
543 	mutex_lock(&sdp->sd_jindex_mutex);
544 
545 	for (;;) {
546 		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
547 		if (error)
548 			break;
549 
550 		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
551 		name.hash = gfs2_disk_hash(name.name, name.len);
552 
553 		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
554 		if (error == -ENOENT) {
555 			error = 0;
556 			break;
557 		}
558 
559 		gfs2_glock_dq_uninit(ji_gh);
560 
561 		if (error)
562 			break;
563 
564 		error = -ENOMEM;
565 		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
566 		if (!jd)
567 			break;
568 
569 		INIT_LIST_HEAD(&jd->extent_list);
570 		INIT_LIST_HEAD(&jd->jd_revoke_list);
571 
572 		INIT_WORK(&jd->jd_work, gfs2_recover_func);
573 		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
574 		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
575 			if (!jd->jd_inode)
576 				error = -ENOENT;
577 			else
578 				error = PTR_ERR(jd->jd_inode);
579 			kfree(jd);
580 			break;
581 		}
582 
583 		spin_lock(&sdp->sd_jindex_spin);
584 		jd->jd_jid = sdp->sd_journals++;
585 		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
586 		spin_unlock(&sdp->sd_jindex_spin);
587 	}
588 
589 	mutex_unlock(&sdp->sd_jindex_mutex);
590 
591 	return error;
592 }
593 
594 /**
595  * check_journal_clean - Make sure a journal is clean for a spectator mount
596  * @sdp: The GFS2 superblock
597  * @jd: The journal descriptor
598  *
599  * Returns: 0 if the journal is clean or locked, else an error
600  */
601 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
602 {
603 	int error;
604 	struct gfs2_holder j_gh;
605 	struct gfs2_log_header_host head;
606 	struct gfs2_inode *ip;
607 
608 	ip = GFS2_I(jd->jd_inode);
609 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
610 				   GL_EXACT | GL_NOCACHE, &j_gh);
611 	if (error) {
612 		fs_err(sdp, "Error locking journal for spectator mount.\n");
613 		return -EPERM;
614 	}
615 	error = gfs2_jdesc_check(jd);
616 	if (error) {
617 		fs_err(sdp, "Error checking journal for spectator mount.\n");
618 		goto out_unlock;
619 	}
620 	error = gfs2_find_jhead(jd, &head, false);
621 	if (error) {
622 		fs_err(sdp, "Error parsing journal for spectator mount.\n");
623 		goto out_unlock;
624 	}
625 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
626 		error = -EPERM;
627 		fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
628 		       "must not be a spectator.\n", jd->jd_jid);
629 	}
630 
631 out_unlock:
632 	gfs2_glock_dq_uninit(&j_gh);
633 	return error;
634 }
635 
636 static int init_journal(struct gfs2_sbd *sdp, int undo)
637 {
638 	struct inode *master = d_inode(sdp->sd_master_dir);
639 	struct gfs2_holder ji_gh;
640 	struct gfs2_inode *ip;
641 	int jindex = 1;
642 	int error = 0;
643 
644 	if (undo) {
645 		jindex = 0;
646 		goto fail_jinode_gh;
647 	}
648 
649 	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
650 	if (IS_ERR(sdp->sd_jindex)) {
651 		fs_err(sdp, "can't lookup journal index: %d\n", error);
652 		return PTR_ERR(sdp->sd_jindex);
653 	}
654 
655 	/* Load in the journal index special file */
656 
657 	error = gfs2_jindex_hold(sdp, &ji_gh);
658 	if (error) {
659 		fs_err(sdp, "can't read journal index: %d\n", error);
660 		goto fail;
661 	}
662 
663 	error = -EUSERS;
664 	if (!gfs2_jindex_size(sdp)) {
665 		fs_err(sdp, "no journals!\n");
666 		goto fail_jindex;
667 	}
668 
669 	atomic_set(&sdp->sd_log_blks_needed, 0);
670 	if (sdp->sd_args.ar_spectator) {
671 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
672 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
673 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
674 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
675 	} else {
676 		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
677 			fs_err(sdp, "can't mount journal #%u\n",
678 			       sdp->sd_lockstruct.ls_jid);
679 			fs_err(sdp, "there are only %u journals (0 - %u)\n",
680 			       gfs2_jindex_size(sdp),
681 			       gfs2_jindex_size(sdp) - 1);
682 			goto fail_jindex;
683 		}
684 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
685 
686 		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
687 					  &gfs2_journal_glops,
688 					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
689 					  &sdp->sd_journal_gh);
690 		if (error) {
691 			fs_err(sdp, "can't acquire journal glock: %d\n", error);
692 			goto fail_jindex;
693 		}
694 
695 		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
696 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
697 					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
698 					   &sdp->sd_jinode_gh);
699 		if (error) {
700 			fs_err(sdp, "can't acquire journal inode glock: %d\n",
701 			       error);
702 			goto fail_journal_gh;
703 		}
704 
705 		error = gfs2_jdesc_check(sdp->sd_jdesc);
706 		if (error) {
707 			fs_err(sdp, "my journal (%u) is bad: %d\n",
708 			       sdp->sd_jdesc->jd_jid, error);
709 			goto fail_jinode_gh;
710 		}
711 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
712 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
713 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
714 
715 		/* Map the extents for this journal's blocks */
716 		gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
717 	}
718 	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
719 
720 	if (sdp->sd_lockstruct.ls_first) {
721 		unsigned int x;
722 		for (x = 0; x < sdp->sd_journals; x++) {
723 			struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
724 
725 			if (sdp->sd_args.ar_spectator) {
726 				error = check_journal_clean(sdp, jd);
727 				if (error)
728 					goto fail_jinode_gh;
729 				continue;
730 			}
731 			error = gfs2_recover_journal(jd, true);
732 			if (error) {
733 				fs_err(sdp, "error recovering journal %u: %d\n",
734 				       x, error);
735 				goto fail_jinode_gh;
736 			}
737 		}
738 
739 		gfs2_others_may_mount(sdp);
740 	} else if (!sdp->sd_args.ar_spectator) {
741 		error = gfs2_recover_journal(sdp->sd_jdesc, true);
742 		if (error) {
743 			fs_err(sdp, "error recovering my journal: %d\n", error);
744 			goto fail_jinode_gh;
745 		}
746 	}
747 
748 	sdp->sd_log_idle = 1;
749 	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
750 	gfs2_glock_dq_uninit(&ji_gh);
751 	jindex = 0;
752 	INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
753 	return 0;
754 
755 fail_jinode_gh:
756 	if (!sdp->sd_args.ar_spectator)
757 		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
758 fail_journal_gh:
759 	if (!sdp->sd_args.ar_spectator)
760 		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
761 fail_jindex:
762 	gfs2_jindex_free(sdp);
763 	if (jindex)
764 		gfs2_glock_dq_uninit(&ji_gh);
765 fail:
766 	iput(sdp->sd_jindex);
767 	return error;
768 }
769 
770 static struct lock_class_key gfs2_quota_imutex_key;
771 
772 static int init_inodes(struct gfs2_sbd *sdp, int undo)
773 {
774 	int error = 0;
775 	struct inode *master = d_inode(sdp->sd_master_dir);
776 
777 	if (undo)
778 		goto fail_qinode;
779 
780 	error = init_journal(sdp, undo);
781 	complete_all(&sdp->sd_journal_ready);
782 	if (error)
783 		goto fail;
784 
785 	/* Read in the master statfs inode */
786 	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
787 	if (IS_ERR(sdp->sd_statfs_inode)) {
788 		error = PTR_ERR(sdp->sd_statfs_inode);
789 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
790 		goto fail_journal;
791 	}
792 
793 	/* Read in the resource index inode */
794 	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
795 	if (IS_ERR(sdp->sd_rindex)) {
796 		error = PTR_ERR(sdp->sd_rindex);
797 		fs_err(sdp, "can't get resource index inode: %d\n", error);
798 		goto fail_statfs;
799 	}
800 	sdp->sd_rindex_uptodate = 0;
801 
802 	/* Read in the quota inode */
803 	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
804 	if (IS_ERR(sdp->sd_quota_inode)) {
805 		error = PTR_ERR(sdp->sd_quota_inode);
806 		fs_err(sdp, "can't get quota file inode: %d\n", error);
807 		goto fail_rindex;
808 	}
809 	/*
810 	 * i_rwsem on quota files is special. Since this inode is hidden system
811 	 * file, we are safe to define locking ourselves.
812 	 */
813 	lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
814 			  &gfs2_quota_imutex_key);
815 
816 	error = gfs2_rindex_update(sdp);
817 	if (error)
818 		goto fail_qinode;
819 
820 	return 0;
821 
822 fail_qinode:
823 	iput(sdp->sd_quota_inode);
824 fail_rindex:
825 	gfs2_clear_rgrpd(sdp);
826 	iput(sdp->sd_rindex);
827 fail_statfs:
828 	iput(sdp->sd_statfs_inode);
829 fail_journal:
830 	init_journal(sdp, UNDO);
831 fail:
832 	return error;
833 }
834 
835 static int init_per_node(struct gfs2_sbd *sdp, int undo)
836 {
837 	struct inode *pn = NULL;
838 	char buf[30];
839 	int error = 0;
840 	struct gfs2_inode *ip;
841 	struct inode *master = d_inode(sdp->sd_master_dir);
842 
843 	if (sdp->sd_args.ar_spectator)
844 		return 0;
845 
846 	if (undo)
847 		goto fail_qc_gh;
848 
849 	pn = gfs2_lookup_simple(master, "per_node");
850 	if (IS_ERR(pn)) {
851 		error = PTR_ERR(pn);
852 		fs_err(sdp, "can't find per_node directory: %d\n", error);
853 		return error;
854 	}
855 
856 	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
857 	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
858 	if (IS_ERR(sdp->sd_sc_inode)) {
859 		error = PTR_ERR(sdp->sd_sc_inode);
860 		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
861 		goto fail;
862 	}
863 
864 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
865 	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
866 	if (IS_ERR(sdp->sd_qc_inode)) {
867 		error = PTR_ERR(sdp->sd_qc_inode);
868 		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
869 		goto fail_ut_i;
870 	}
871 
872 	iput(pn);
873 	pn = NULL;
874 
875 	ip = GFS2_I(sdp->sd_sc_inode);
876 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
877 				   &sdp->sd_sc_gh);
878 	if (error) {
879 		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
880 		goto fail_qc_i;
881 	}
882 
883 	ip = GFS2_I(sdp->sd_qc_inode);
884 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
885 				   &sdp->sd_qc_gh);
886 	if (error) {
887 		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
888 		goto fail_ut_gh;
889 	}
890 
891 	return 0;
892 
893 fail_qc_gh:
894 	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
895 fail_ut_gh:
896 	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
897 fail_qc_i:
898 	iput(sdp->sd_qc_inode);
899 fail_ut_i:
900 	iput(sdp->sd_sc_inode);
901 fail:
902 	iput(pn);
903 	return error;
904 }
905 
906 static const match_table_t nolock_tokens = {
907 	{ Opt_jid, "jid=%d\n", },
908 	{ Opt_err, NULL },
909 };
910 
911 static const struct lm_lockops nolock_ops = {
912 	.lm_proto_name = "lock_nolock",
913 	.lm_put_lock = gfs2_glock_free,
914 	.lm_tokens = &nolock_tokens,
915 };
916 
917 /**
918  * gfs2_lm_mount - mount a locking protocol
919  * @sdp: the filesystem
920  * @args: mount arguments
921  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
922  *
923  * Returns: errno
924  */
925 
926 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
927 {
928 	const struct lm_lockops *lm;
929 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
930 	struct gfs2_args *args = &sdp->sd_args;
931 	const char *proto = sdp->sd_proto_name;
932 	const char *table = sdp->sd_table_name;
933 	char *o, *options;
934 	int ret;
935 
936 	if (!strcmp("lock_nolock", proto)) {
937 		lm = &nolock_ops;
938 		sdp->sd_args.ar_localflocks = 1;
939 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
940 	} else if (!strcmp("lock_dlm", proto)) {
941 		lm = &gfs2_dlm_ops;
942 #endif
943 	} else {
944 		pr_info("can't find protocol %s\n", proto);
945 		return -ENOENT;
946 	}
947 
948 	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
949 
950 	ls->ls_ops = lm;
951 	ls->ls_first = 1;
952 
953 	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
954 		substring_t tmp[MAX_OPT_ARGS];
955 		int token, option;
956 
957 		if (!o || !*o)
958 			continue;
959 
960 		token = match_token(o, *lm->lm_tokens, tmp);
961 		switch (token) {
962 		case Opt_jid:
963 			ret = match_int(&tmp[0], &option);
964 			if (ret || option < 0)
965 				goto hostdata_error;
966 			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
967 				ls->ls_jid = option;
968 			break;
969 		case Opt_id:
970 		case Opt_nodir:
971 			/* Obsolete, but left for backward compat purposes */
972 			break;
973 		case Opt_first:
974 			ret = match_int(&tmp[0], &option);
975 			if (ret || (option != 0 && option != 1))
976 				goto hostdata_error;
977 			ls->ls_first = option;
978 			break;
979 		case Opt_err:
980 		default:
981 hostdata_error:
982 			fs_info(sdp, "unknown hostdata (%s)\n", o);
983 			return -EINVAL;
984 		}
985 	}
986 
987 	if (lm->lm_mount == NULL) {
988 		fs_info(sdp, "Now mounting FS...\n");
989 		complete_all(&sdp->sd_locking_init);
990 		return 0;
991 	}
992 	ret = lm->lm_mount(sdp, table);
993 	if (ret == 0)
994 		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
995 	complete_all(&sdp->sd_locking_init);
996 	return ret;
997 }
998 
999 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1000 {
1001 	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1002 	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1003 	    lm->lm_unmount)
1004 		lm->lm_unmount(sdp);
1005 }
1006 
1007 static int wait_on_journal(struct gfs2_sbd *sdp)
1008 {
1009 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1010 		return 0;
1011 
1012 	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1013 		? -EINTR : 0;
1014 }
1015 
1016 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1017 {
1018 	struct super_block *sb = sdp->sd_vfs;
1019 	char ro[20];
1020 	char spectator[20];
1021 	char *envp[] = { ro, spectator, NULL };
1022 	sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
1023 	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1024 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1025 }
1026 
1027 /**
1028  * fill_super - Read in superblock
1029  * @sb: The VFS superblock
1030  * @data: Mount options
1031  * @silent: Don't complain if it's not a GFS2 filesystem
1032  *
1033  * Returns: errno
1034  */
1035 
1036 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1037 {
1038 	struct gfs2_sbd *sdp;
1039 	struct gfs2_holder mount_gh;
1040 	int error;
1041 
1042 	sdp = init_sbd(sb);
1043 	if (!sdp) {
1044 		pr_warn("can't alloc struct gfs2_sbd\n");
1045 		return -ENOMEM;
1046 	}
1047 	sdp->sd_args = *args;
1048 
1049 	if (sdp->sd_args.ar_spectator) {
1050                 sb->s_flags |= SB_RDONLY;
1051 		set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1052 	}
1053 	if (sdp->sd_args.ar_posix_acl)
1054 		sb->s_flags |= SB_POSIXACL;
1055 	if (sdp->sd_args.ar_nobarrier)
1056 		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1057 
1058 	sb->s_flags |= SB_NOSEC;
1059 	sb->s_magic = GFS2_MAGIC;
1060 	sb->s_op = &gfs2_super_ops;
1061 	sb->s_d_op = &gfs2_dops;
1062 	sb->s_export_op = &gfs2_export_ops;
1063 	sb->s_xattr = gfs2_xattr_handlers;
1064 	sb->s_qcop = &gfs2_quotactl_ops;
1065 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1066 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1067 	sb->s_time_gran = 1;
1068 	sb->s_maxbytes = MAX_LFS_FILESIZE;
1069 
1070 	/* Set up the buffer cache and fill in some fake block size values
1071 	   to allow us to read-in the on-disk superblock. */
1072 	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1073 	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1074 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1075                                GFS2_BASIC_BLOCK_SHIFT;
1076 	sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
1077 
1078 	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1079 	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1080 	if (sdp->sd_args.ar_statfs_quantum) {
1081 		sdp->sd_tune.gt_statfs_slow = 0;
1082 		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1083 	} else {
1084 		sdp->sd_tune.gt_statfs_slow = 1;
1085 		sdp->sd_tune.gt_statfs_quantum = 30;
1086 	}
1087 
1088 	error = init_names(sdp, silent);
1089 	if (error) {
1090 		/* In this case, we haven't initialized sysfs, so we have to
1091 		   manually free the sdp. */
1092 		free_percpu(sdp->sd_lkstats);
1093 		kfree(sdp);
1094 		sb->s_fs_info = NULL;
1095 		return error;
1096 	}
1097 
1098 	snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s", sdp->sd_table_name);
1099 
1100 	error = gfs2_sys_fs_add(sdp);
1101 	/*
1102 	 * If we hit an error here, gfs2_sys_fs_add will have called function
1103 	 * kobject_put which causes the sysfs usage count to go to zero, which
1104 	 * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1105 	 * Subsequent error paths here will call gfs2_sys_fs_del, which also
1106 	 * kobject_put to free sdp.
1107 	 */
1108 	if (error)
1109 		return error;
1110 
1111 	gfs2_create_debugfs_file(sdp);
1112 
1113 	error = gfs2_lm_mount(sdp, silent);
1114 	if (error)
1115 		goto fail_debug;
1116 
1117 	error = init_locking(sdp, &mount_gh, DO);
1118 	if (error)
1119 		goto fail_lm;
1120 
1121 	error = init_sb(sdp, silent);
1122 	if (error)
1123 		goto fail_locking;
1124 
1125 	error = wait_on_journal(sdp);
1126 	if (error)
1127 		goto fail_sb;
1128 
1129 	/*
1130 	 * If user space has failed to join the cluster or some similar
1131 	 * failure has occurred, then the journal id will contain a
1132 	 * negative (error) number. This will then be returned to the
1133 	 * caller (of the mount syscall). We do this even for spectator
1134 	 * mounts (which just write a jid of 0 to indicate "ok" even though
1135 	 * the jid is unused in the spectator case)
1136 	 */
1137 	if (sdp->sd_lockstruct.ls_jid < 0) {
1138 		error = sdp->sd_lockstruct.ls_jid;
1139 		sdp->sd_lockstruct.ls_jid = 0;
1140 		goto fail_sb;
1141 	}
1142 
1143 	if (sdp->sd_args.ar_spectator)
1144 		snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.s",
1145 			 sdp->sd_table_name);
1146 	else
1147 		snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.%u",
1148 			 sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1149 
1150 	error = init_inodes(sdp, DO);
1151 	if (error)
1152 		goto fail_sb;
1153 
1154 	error = init_per_node(sdp, DO);
1155 	if (error)
1156 		goto fail_inodes;
1157 
1158 	error = gfs2_statfs_init(sdp);
1159 	if (error) {
1160 		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1161 		goto fail_per_node;
1162 	}
1163 
1164 	if (!sb_rdonly(sb)) {
1165 		error = gfs2_make_fs_rw(sdp);
1166 		if (error) {
1167 			fs_err(sdp, "can't make FS RW: %d\n", error);
1168 			goto fail_per_node;
1169 		}
1170 	}
1171 
1172 	gfs2_glock_dq_uninit(&mount_gh);
1173 	gfs2_online_uevent(sdp);
1174 	return 0;
1175 
1176 fail_per_node:
1177 	init_per_node(sdp, UNDO);
1178 fail_inodes:
1179 	init_inodes(sdp, UNDO);
1180 fail_sb:
1181 	if (sdp->sd_root_dir)
1182 		dput(sdp->sd_root_dir);
1183 	if (sdp->sd_master_dir)
1184 		dput(sdp->sd_master_dir);
1185 	if (sb->s_root)
1186 		dput(sb->s_root);
1187 	sb->s_root = NULL;
1188 fail_locking:
1189 	init_locking(sdp, &mount_gh, UNDO);
1190 fail_lm:
1191 	complete_all(&sdp->sd_journal_ready);
1192 	gfs2_gl_hash_clear(sdp);
1193 	gfs2_lm_unmount(sdp);
1194 fail_debug:
1195 	gfs2_delete_debugfs_file(sdp);
1196 	free_percpu(sdp->sd_lkstats);
1197 	/* gfs2_sys_fs_del must be the last thing we do, since it causes
1198 	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
1199 	gfs2_sys_fs_del(sdp);
1200 	sb->s_fs_info = NULL;
1201 	return error;
1202 }
1203 
1204 static int set_gfs2_super(struct super_block *s, void *data)
1205 {
1206 	s->s_bdev = data;
1207 	s->s_dev = s->s_bdev->bd_dev;
1208 	s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
1209 	return 0;
1210 }
1211 
1212 static int test_gfs2_super(struct super_block *s, void *ptr)
1213 {
1214 	struct block_device *bdev = ptr;
1215 	return (bdev == s->s_bdev);
1216 }
1217 
1218 /**
1219  * gfs2_mount - Get the GFS2 superblock
1220  * @fs_type: The GFS2 filesystem type
1221  * @flags: Mount flags
1222  * @dev_name: The name of the device
1223  * @data: The mount arguments
1224  *
1225  * Q. Why not use get_sb_bdev() ?
1226  * A. We need to select one of two root directories to mount, independent
1227  *    of whether this is the initial, or subsequent, mount of this sb
1228  *
1229  * Returns: 0 or -ve on error
1230  */
1231 
1232 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1233 		       const char *dev_name, void *data)
1234 {
1235 	struct block_device *bdev;
1236 	struct super_block *s;
1237 	fmode_t mode = FMODE_READ | FMODE_EXCL;
1238 	int error;
1239 	struct gfs2_args args;
1240 	struct gfs2_sbd *sdp;
1241 
1242 	if (!(flags & SB_RDONLY))
1243 		mode |= FMODE_WRITE;
1244 
1245 	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1246 	if (IS_ERR(bdev))
1247 		return ERR_CAST(bdev);
1248 
1249 	/*
1250 	 * once the super is inserted into the list by sget, s_umount
1251 	 * will protect the lockfs code from trying to start a snapshot
1252 	 * while we are mounting
1253 	 */
1254 	mutex_lock(&bdev->bd_fsfreeze_mutex);
1255 	if (bdev->bd_fsfreeze_count > 0) {
1256 		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1257 		error = -EBUSY;
1258 		goto error_bdev;
1259 	}
1260 	s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1261 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1262 	error = PTR_ERR(s);
1263 	if (IS_ERR(s))
1264 		goto error_bdev;
1265 
1266 	if (s->s_root) {
1267 		/*
1268 		 * s_umount nests inside bd_mutex during
1269 		 * __invalidate_device().  blkdev_put() acquires
1270 		 * bd_mutex and can't be called under s_umount.  Drop
1271 		 * s_umount temporarily.  This is safe as we're
1272 		 * holding an active reference.
1273 		 */
1274 		up_write(&s->s_umount);
1275 		blkdev_put(bdev, mode);
1276 		down_write(&s->s_umount);
1277 	} else {
1278 		/* s_mode must be set before deactivate_locked_super calls */
1279 		s->s_mode = mode;
1280 	}
1281 
1282 	memset(&args, 0, sizeof(args));
1283 	args.ar_quota = GFS2_QUOTA_DEFAULT;
1284 	args.ar_data = GFS2_DATA_DEFAULT;
1285 	args.ar_commit = 30;
1286 	args.ar_statfs_quantum = 30;
1287 	args.ar_quota_quantum = 60;
1288 	args.ar_errors = GFS2_ERRORS_DEFAULT;
1289 
1290 	error = gfs2_mount_args(&args, data);
1291 	if (error) {
1292 		pr_warn("can't parse mount arguments\n");
1293 		goto error_super;
1294 	}
1295 
1296 	if (s->s_root) {
1297 		error = -EBUSY;
1298 		if ((flags ^ s->s_flags) & SB_RDONLY)
1299 			goto error_super;
1300 	} else {
1301 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1302 		sb_set_blocksize(s, block_size(bdev));
1303 		error = fill_super(s, &args, flags & SB_SILENT ? 1 : 0);
1304 		if (error)
1305 			goto error_super;
1306 		s->s_flags |= SB_ACTIVE;
1307 		bdev->bd_super = s;
1308 	}
1309 
1310 	sdp = s->s_fs_info;
1311 	if (args.ar_meta)
1312 		return dget(sdp->sd_master_dir);
1313 	else
1314 		return dget(sdp->sd_root_dir);
1315 
1316 error_super:
1317 	deactivate_locked_super(s);
1318 	return ERR_PTR(error);
1319 error_bdev:
1320 	blkdev_put(bdev, mode);
1321 	return ERR_PTR(error);
1322 }
1323 
1324 static int set_meta_super(struct super_block *s, void *ptr)
1325 {
1326 	return -EINVAL;
1327 }
1328 
1329 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1330 			int flags, const char *dev_name, void *data)
1331 {
1332 	struct super_block *s;
1333 	struct gfs2_sbd *sdp;
1334 	struct path path;
1335 	int error;
1336 
1337 	if (!dev_name || !*dev_name)
1338 		return ERR_PTR(-EINVAL);
1339 
1340 	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1341 	if (error) {
1342 		pr_warn("path_lookup on %s returned error %d\n",
1343 			dev_name, error);
1344 		return ERR_PTR(error);
1345 	}
1346 	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1347 		 path.dentry->d_sb->s_bdev);
1348 	path_put(&path);
1349 	if (IS_ERR(s)) {
1350 		pr_warn("gfs2 mount does not exist\n");
1351 		return ERR_CAST(s);
1352 	}
1353 	if ((flags ^ s->s_flags) & SB_RDONLY) {
1354 		deactivate_locked_super(s);
1355 		return ERR_PTR(-EBUSY);
1356 	}
1357 	sdp = s->s_fs_info;
1358 	return dget(sdp->sd_master_dir);
1359 }
1360 
1361 static void gfs2_kill_sb(struct super_block *sb)
1362 {
1363 	struct gfs2_sbd *sdp = sb->s_fs_info;
1364 
1365 	if (sdp == NULL) {
1366 		kill_block_super(sb);
1367 		return;
1368 	}
1369 
1370 	gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SYNC | GFS2_LFC_KILL_SB);
1371 	dput(sdp->sd_root_dir);
1372 	dput(sdp->sd_master_dir);
1373 	sdp->sd_root_dir = NULL;
1374 	sdp->sd_master_dir = NULL;
1375 	shrink_dcache_sb(sb);
1376 	free_percpu(sdp->sd_lkstats);
1377 	kill_block_super(sb);
1378 }
1379 
1380 struct file_system_type gfs2_fs_type = {
1381 	.name = "gfs2",
1382 	.fs_flags = FS_REQUIRES_DEV,
1383 	.mount = gfs2_mount,
1384 	.kill_sb = gfs2_kill_sb,
1385 	.owner = THIS_MODULE,
1386 };
1387 MODULE_ALIAS_FS("gfs2");
1388 
1389 struct file_system_type gfs2meta_fs_type = {
1390 	.name = "gfs2meta",
1391 	.fs_flags = FS_REQUIRES_DEV,
1392 	.mount = gfs2_mount_meta,
1393 	.owner = THIS_MODULE,
1394 };
1395 MODULE_ALIAS_FS("gfs2meta");
1396