xref: /openbmc/linux/fs/gfs2/ops_fstype.c (revision e0bf6c5c)
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 
27 #include "gfs2.h"
28 #include "incore.h"
29 #include "bmap.h"
30 #include "glock.h"
31 #include "glops.h"
32 #include "inode.h"
33 #include "recovery.h"
34 #include "rgrp.h"
35 #include "super.h"
36 #include "sys.h"
37 #include "util.h"
38 #include "log.h"
39 #include "quota.h"
40 #include "dir.h"
41 #include "meta_io.h"
42 #include "trace_gfs2.h"
43 
44 #define DO 0
45 #define UNDO 1
46 
47 /**
48  * gfs2_tune_init - Fill a gfs2_tune structure with default values
49  * @gt: tune
50  *
51  */
52 
53 static void gfs2_tune_init(struct gfs2_tune *gt)
54 {
55 	spin_lock_init(&gt->gt_spin);
56 
57 	gt->gt_quota_warn_period = 10;
58 	gt->gt_quota_scale_num = 1;
59 	gt->gt_quota_scale_den = 1;
60 	gt->gt_new_files_jdata = 0;
61 	gt->gt_max_readahead = 1 << 18;
62 	gt->gt_complain_secs = 10;
63 }
64 
65 static struct gfs2_sbd *init_sbd(struct super_block *sb)
66 {
67 	struct gfs2_sbd *sdp;
68 	struct address_space *mapping;
69 
70 	sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
71 	if (!sdp)
72 		return NULL;
73 
74 	sb->s_fs_info = sdp;
75 	sdp->sd_vfs = sb;
76 	sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
77 	if (!sdp->sd_lkstats) {
78 		kfree(sdp);
79 		return NULL;
80 	}
81 
82 	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
83 	gfs2_tune_init(&sdp->sd_tune);
84 
85 	init_waitqueue_head(&sdp->sd_glock_wait);
86 	atomic_set(&sdp->sd_glock_disposal, 0);
87 	init_completion(&sdp->sd_locking_init);
88 	init_completion(&sdp->sd_wdack);
89 	spin_lock_init(&sdp->sd_statfs_spin);
90 
91 	spin_lock_init(&sdp->sd_rindex_spin);
92 	sdp->sd_rindex_tree.rb_node = NULL;
93 
94 	INIT_LIST_HEAD(&sdp->sd_jindex_list);
95 	spin_lock_init(&sdp->sd_jindex_spin);
96 	mutex_init(&sdp->sd_jindex_mutex);
97 	init_completion(&sdp->sd_journal_ready);
98 
99 	INIT_LIST_HEAD(&sdp->sd_quota_list);
100 	mutex_init(&sdp->sd_quota_mutex);
101 	mutex_init(&sdp->sd_quota_sync_mutex);
102 	init_waitqueue_head(&sdp->sd_quota_wait);
103 	INIT_LIST_HEAD(&sdp->sd_trunc_list);
104 	spin_lock_init(&sdp->sd_trunc_lock);
105 	spin_lock_init(&sdp->sd_bitmap_lock);
106 
107 	mapping = &sdp->sd_aspace;
108 
109 	address_space_init_once(mapping);
110 	mapping->a_ops = &gfs2_rgrp_aops;
111 	mapping->host = sb->s_bdev->bd_inode;
112 	mapping->flags = 0;
113 	mapping_set_gfp_mask(mapping, GFP_NOFS);
114 	mapping->private_data = NULL;
115 	mapping->writeback_index = 0;
116 
117 	spin_lock_init(&sdp->sd_log_lock);
118 	atomic_set(&sdp->sd_log_pinned, 0);
119 	INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
120 	INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
121 	spin_lock_init(&sdp->sd_ordered_lock);
122 
123 	init_waitqueue_head(&sdp->sd_log_waitq);
124 	init_waitqueue_head(&sdp->sd_logd_waitq);
125 	spin_lock_init(&sdp->sd_ail_lock);
126 	INIT_LIST_HEAD(&sdp->sd_ail1_list);
127 	INIT_LIST_HEAD(&sdp->sd_ail2_list);
128 
129 	init_rwsem(&sdp->sd_log_flush_lock);
130 	atomic_set(&sdp->sd_log_in_flight, 0);
131 	atomic_set(&sdp->sd_reserving_log, 0);
132 	init_waitqueue_head(&sdp->sd_reserving_log_wait);
133 	init_waitqueue_head(&sdp->sd_log_flush_wait);
134 	atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
135 	mutex_init(&sdp->sd_freeze_mutex);
136 
137 	return sdp;
138 }
139 
140 
141 /**
142  * gfs2_check_sb - Check superblock
143  * @sdp: the filesystem
144  * @sb: The superblock
145  * @silent: Don't print a message if the check fails
146  *
147  * Checks the version code of the FS is one that we understand how to
148  * read and that the sizes of the various on-disk structures have not
149  * changed.
150  */
151 
152 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
153 {
154 	struct gfs2_sb_host *sb = &sdp->sd_sb;
155 
156 	if (sb->sb_magic != GFS2_MAGIC ||
157 	    sb->sb_type != GFS2_METATYPE_SB) {
158 		if (!silent)
159 			pr_warn("not a GFS2 filesystem\n");
160 		return -EINVAL;
161 	}
162 
163 	/*  If format numbers match exactly, we're done.  */
164 
165 	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
166 	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
167 		return 0;
168 
169 	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
170 
171 	return -EINVAL;
172 }
173 
174 static void end_bio_io_page(struct bio *bio, int error)
175 {
176 	struct page *page = bio->bi_private;
177 
178 	if (!error)
179 		SetPageUptodate(page);
180 	else
181 		pr_warn("error %d reading superblock\n", error);
182 	unlock_page(page);
183 }
184 
185 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
186 {
187 	struct gfs2_sb_host *sb = &sdp->sd_sb;
188 	struct super_block *s = sdp->sd_vfs;
189 	const struct gfs2_sb *str = buf;
190 
191 	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
192 	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
193 	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
194 	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
195 	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
196 	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
197 	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
198 	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
199 	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
200 	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
201 	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
202 
203 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
204 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
205 	memcpy(s->s_uuid, str->sb_uuid, 16);
206 }
207 
208 /**
209  * gfs2_read_super - Read the gfs2 super block from disk
210  * @sdp: The GFS2 super block
211  * @sector: The location of the super block
212  * @error: The error code to return
213  *
214  * This uses the bio functions to read the super block from disk
215  * because we want to be 100% sure that we never read cached data.
216  * A super block is read twice only during each GFS2 mount and is
217  * never written to by the filesystem. The first time its read no
218  * locks are held, and the only details which are looked at are those
219  * relating to the locking protocol. Once locking is up and working,
220  * the sb is read again under the lock to establish the location of
221  * the master directory (contains pointers to journals etc) and the
222  * root directory.
223  *
224  * Returns: 0 on success or error
225  */
226 
227 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
228 {
229 	struct super_block *sb = sdp->sd_vfs;
230 	struct gfs2_sb *p;
231 	struct page *page;
232 	struct bio *bio;
233 
234 	page = alloc_page(GFP_NOFS);
235 	if (unlikely(!page))
236 		return -ENOMEM;
237 
238 	ClearPageUptodate(page);
239 	ClearPageDirty(page);
240 	lock_page(page);
241 
242 	bio = bio_alloc(GFP_NOFS, 1);
243 	bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
244 	bio->bi_bdev = sb->s_bdev;
245 	bio_add_page(bio, page, PAGE_SIZE, 0);
246 
247 	bio->bi_end_io = end_bio_io_page;
248 	bio->bi_private = page;
249 	submit_bio(READ_SYNC | REQ_META, bio);
250 	wait_on_page_locked(page);
251 	bio_put(bio);
252 	if (!PageUptodate(page)) {
253 		__free_page(page);
254 		return -EIO;
255 	}
256 	p = kmap(page);
257 	gfs2_sb_in(sdp, p);
258 	kunmap(page);
259 	__free_page(page);
260 	return gfs2_check_sb(sdp, silent);
261 }
262 
263 /**
264  * gfs2_read_sb - Read super block
265  * @sdp: The GFS2 superblock
266  * @silent: Don't print message if mount fails
267  *
268  */
269 
270 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
271 {
272 	u32 hash_blocks, ind_blocks, leaf_blocks;
273 	u32 tmp_blocks;
274 	unsigned int x;
275 	int error;
276 
277 	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
278 	if (error) {
279 		if (!silent)
280 			fs_err(sdp, "can't read superblock\n");
281 		return error;
282 	}
283 
284 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
285 			       GFS2_BASIC_BLOCK_SHIFT;
286 	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
287 	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
288 			  sizeof(struct gfs2_dinode)) / sizeof(u64);
289 	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
290 			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
291 	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
292 	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
293 	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
294 	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
295 	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
296 				sizeof(struct gfs2_meta_header)) /
297 			        sizeof(struct gfs2_quota_change);
298 	sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
299 				     sizeof(struct gfs2_meta_header))
300 		* GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
301 
302 	/* Compute maximum reservation required to add a entry to a directory */
303 
304 	hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
305 			     sdp->sd_jbsize);
306 
307 	ind_blocks = 0;
308 	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
309 		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
310 		ind_blocks += tmp_blocks;
311 	}
312 
313 	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
314 
315 	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
316 
317 	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
318 				sizeof(struct gfs2_dinode);
319 	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
320 	for (x = 2;; x++) {
321 		u64 space, d;
322 		u32 m;
323 
324 		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
325 		d = space;
326 		m = do_div(d, sdp->sd_inptrs);
327 
328 		if (d != sdp->sd_heightsize[x - 1] || m)
329 			break;
330 		sdp->sd_heightsize[x] = space;
331 	}
332 	sdp->sd_max_height = x;
333 	sdp->sd_heightsize[x] = ~0;
334 	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
335 
336 	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
337 				 sizeof(struct gfs2_dinode);
338 	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
339 	for (x = 2;; x++) {
340 		u64 space, d;
341 		u32 m;
342 
343 		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
344 		d = space;
345 		m = do_div(d, sdp->sd_inptrs);
346 
347 		if (d != sdp->sd_jheightsize[x - 1] || m)
348 			break;
349 		sdp->sd_jheightsize[x] = space;
350 	}
351 	sdp->sd_max_jheight = x;
352 	sdp->sd_jheightsize[x] = ~0;
353 	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
354 
355 	return 0;
356 }
357 
358 static int init_names(struct gfs2_sbd *sdp, int silent)
359 {
360 	char *proto, *table;
361 	int error = 0;
362 
363 	proto = sdp->sd_args.ar_lockproto;
364 	table = sdp->sd_args.ar_locktable;
365 
366 	/*  Try to autodetect  */
367 
368 	if (!proto[0] || !table[0]) {
369 		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
370 		if (error)
371 			return error;
372 
373 		if (!proto[0])
374 			proto = sdp->sd_sb.sb_lockproto;
375 		if (!table[0])
376 			table = sdp->sd_sb.sb_locktable;
377 	}
378 
379 	if (!table[0])
380 		table = sdp->sd_vfs->s_id;
381 
382 	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
383 	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
384 
385 	table = sdp->sd_table_name;
386 	while ((table = strchr(table, '/')))
387 		*table = '_';
388 
389 	return error;
390 }
391 
392 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
393 			int undo)
394 {
395 	int error = 0;
396 
397 	if (undo)
398 		goto fail_trans;
399 
400 	error = gfs2_glock_nq_num(sdp,
401 				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
402 				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
403 				  mount_gh);
404 	if (error) {
405 		fs_err(sdp, "can't acquire mount glock: %d\n", error);
406 		goto fail;
407 	}
408 
409 	error = gfs2_glock_nq_num(sdp,
410 				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
411 				  LM_ST_SHARED,
412 				  LM_FLAG_NOEXP | GL_EXACT,
413 				  &sdp->sd_live_gh);
414 	if (error) {
415 		fs_err(sdp, "can't acquire live glock: %d\n", error);
416 		goto fail_mount;
417 	}
418 
419 	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
420 			       CREATE, &sdp->sd_rename_gl);
421 	if (error) {
422 		fs_err(sdp, "can't create rename glock: %d\n", error);
423 		goto fail_live;
424 	}
425 
426 	error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
427 			       CREATE, &sdp->sd_freeze_gl);
428 	if (error) {
429 		fs_err(sdp, "can't create transaction glock: %d\n", error);
430 		goto fail_rename;
431 	}
432 
433 	return 0;
434 
435 fail_trans:
436 	gfs2_glock_put(sdp->sd_freeze_gl);
437 fail_rename:
438 	gfs2_glock_put(sdp->sd_rename_gl);
439 fail_live:
440 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
441 fail_mount:
442 	gfs2_glock_dq_uninit(mount_gh);
443 fail:
444 	return error;
445 }
446 
447 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
448 			    u64 no_addr, const char *name)
449 {
450 	struct gfs2_sbd *sdp = sb->s_fs_info;
451 	struct dentry *dentry;
452 	struct inode *inode;
453 
454 	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
455 	if (IS_ERR(inode)) {
456 		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
457 		return PTR_ERR(inode);
458 	}
459 	dentry = d_make_root(inode);
460 	if (!dentry) {
461 		fs_err(sdp, "can't alloc %s dentry\n", name);
462 		return -ENOMEM;
463 	}
464 	*dptr = dentry;
465 	return 0;
466 }
467 
468 static int init_sb(struct gfs2_sbd *sdp, int silent)
469 {
470 	struct super_block *sb = sdp->sd_vfs;
471 	struct gfs2_holder sb_gh;
472 	u64 no_addr;
473 	int ret;
474 
475 	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
476 				LM_ST_SHARED, 0, &sb_gh);
477 	if (ret) {
478 		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
479 		return ret;
480 	}
481 
482 	ret = gfs2_read_sb(sdp, silent);
483 	if (ret) {
484 		fs_err(sdp, "can't read superblock: %d\n", ret);
485 		goto out;
486 	}
487 
488 	/* Set up the buffer cache and SB for real */
489 	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
490 		ret = -EINVAL;
491 		fs_err(sdp, "FS block size (%u) is too small for device "
492 		       "block size (%u)\n",
493 		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
494 		goto out;
495 	}
496 	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
497 		ret = -EINVAL;
498 		fs_err(sdp, "FS block size (%u) is too big for machine "
499 		       "page size (%u)\n",
500 		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
501 		goto out;
502 	}
503 	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
504 
505 	/* Get the root inode */
506 	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
507 	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
508 	if (ret)
509 		goto out;
510 
511 	/* Get the master inode */
512 	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
513 	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
514 	if (ret) {
515 		dput(sdp->sd_root_dir);
516 		goto out;
517 	}
518 	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
519 out:
520 	gfs2_glock_dq_uninit(&sb_gh);
521 	return ret;
522 }
523 
524 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
525 {
526 	char *message = "FIRSTMOUNT=Done";
527 	char *envp[] = { message, NULL };
528 
529 	fs_info(sdp, "first mount done, others may mount\n");
530 
531 	if (sdp->sd_lockstruct.ls_ops->lm_first_done)
532 		sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
533 
534 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
535 }
536 
537 /**
538  * gfs2_jindex_hold - Grab a lock on the jindex
539  * @sdp: The GFS2 superblock
540  * @ji_gh: the holder for the jindex glock
541  *
542  * Returns: errno
543  */
544 
545 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
546 {
547 	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
548 	struct qstr name;
549 	char buf[20];
550 	struct gfs2_jdesc *jd;
551 	int error;
552 
553 	name.name = buf;
554 
555 	mutex_lock(&sdp->sd_jindex_mutex);
556 
557 	for (;;) {
558 		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
559 		if (error)
560 			break;
561 
562 		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
563 		name.hash = gfs2_disk_hash(name.name, name.len);
564 
565 		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
566 		if (error == -ENOENT) {
567 			error = 0;
568 			break;
569 		}
570 
571 		gfs2_glock_dq_uninit(ji_gh);
572 
573 		if (error)
574 			break;
575 
576 		error = -ENOMEM;
577 		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
578 		if (!jd)
579 			break;
580 
581 		INIT_LIST_HEAD(&jd->extent_list);
582 		INIT_LIST_HEAD(&jd->jd_revoke_list);
583 
584 		INIT_WORK(&jd->jd_work, gfs2_recover_func);
585 		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
586 		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
587 			if (!jd->jd_inode)
588 				error = -ENOENT;
589 			else
590 				error = PTR_ERR(jd->jd_inode);
591 			kfree(jd);
592 			break;
593 		}
594 
595 		spin_lock(&sdp->sd_jindex_spin);
596 		jd->jd_jid = sdp->sd_journals++;
597 		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
598 		spin_unlock(&sdp->sd_jindex_spin);
599 	}
600 
601 	mutex_unlock(&sdp->sd_jindex_mutex);
602 
603 	return error;
604 }
605 
606 /**
607  * check_journal_clean - Make sure a journal is clean for a spectator mount
608  * @sdp: The GFS2 superblock
609  * @jd: The journal descriptor
610  *
611  * Returns: 0 if the journal is clean or locked, else an error
612  */
613 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
614 {
615 	int error;
616 	struct gfs2_holder j_gh;
617 	struct gfs2_log_header_host head;
618 	struct gfs2_inode *ip;
619 
620 	ip = GFS2_I(jd->jd_inode);
621 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
622 				   GL_EXACT | GL_NOCACHE, &j_gh);
623 	if (error) {
624 		fs_err(sdp, "Error locking journal for spectator mount.\n");
625 		return -EPERM;
626 	}
627 	error = gfs2_jdesc_check(jd);
628 	if (error) {
629 		fs_err(sdp, "Error checking journal for spectator mount.\n");
630 		goto out_unlock;
631 	}
632 	error = gfs2_find_jhead(jd, &head);
633 	if (error) {
634 		fs_err(sdp, "Error parsing journal for spectator mount.\n");
635 		goto out_unlock;
636 	}
637 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
638 		error = -EPERM;
639 		fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
640 		       "must not be a spectator.\n", jd->jd_jid);
641 	}
642 
643 out_unlock:
644 	gfs2_glock_dq_uninit(&j_gh);
645 	return error;
646 }
647 
648 static int init_journal(struct gfs2_sbd *sdp, int undo)
649 {
650 	struct inode *master = sdp->sd_master_dir->d_inode;
651 	struct gfs2_holder ji_gh;
652 	struct gfs2_inode *ip;
653 	int jindex = 1;
654 	int error = 0;
655 
656 	if (undo) {
657 		jindex = 0;
658 		goto fail_jinode_gh;
659 	}
660 
661 	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
662 	if (IS_ERR(sdp->sd_jindex)) {
663 		fs_err(sdp, "can't lookup journal index: %d\n", error);
664 		return PTR_ERR(sdp->sd_jindex);
665 	}
666 
667 	/* Load in the journal index special file */
668 
669 	error = gfs2_jindex_hold(sdp, &ji_gh);
670 	if (error) {
671 		fs_err(sdp, "can't read journal index: %d\n", error);
672 		goto fail;
673 	}
674 
675 	error = -EUSERS;
676 	if (!gfs2_jindex_size(sdp)) {
677 		fs_err(sdp, "no journals!\n");
678 		goto fail_jindex;
679 	}
680 
681 	if (sdp->sd_args.ar_spectator) {
682 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
683 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
684 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
685 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
686 	} else {
687 		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
688 			fs_err(sdp, "can't mount journal #%u\n",
689 			       sdp->sd_lockstruct.ls_jid);
690 			fs_err(sdp, "there are only %u journals (0 - %u)\n",
691 			       gfs2_jindex_size(sdp),
692 			       gfs2_jindex_size(sdp) - 1);
693 			goto fail_jindex;
694 		}
695 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
696 
697 		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
698 					  &gfs2_journal_glops,
699 					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
700 					  &sdp->sd_journal_gh);
701 		if (error) {
702 			fs_err(sdp, "can't acquire journal glock: %d\n", error);
703 			goto fail_jindex;
704 		}
705 
706 		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
707 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
708 					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
709 					   &sdp->sd_jinode_gh);
710 		if (error) {
711 			fs_err(sdp, "can't acquire journal inode glock: %d\n",
712 			       error);
713 			goto fail_journal_gh;
714 		}
715 
716 		error = gfs2_jdesc_check(sdp->sd_jdesc);
717 		if (error) {
718 			fs_err(sdp, "my journal (%u) is bad: %d\n",
719 			       sdp->sd_jdesc->jd_jid, error);
720 			goto fail_jinode_gh;
721 		}
722 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
723 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
724 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
725 
726 		/* Map the extents for this journal's blocks */
727 		gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
728 	}
729 	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
730 
731 	if (sdp->sd_lockstruct.ls_first) {
732 		unsigned int x;
733 		for (x = 0; x < sdp->sd_journals; x++) {
734 			struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
735 
736 			if (sdp->sd_args.ar_spectator) {
737 				error = check_journal_clean(sdp, jd);
738 				if (error)
739 					goto fail_jinode_gh;
740 				continue;
741 			}
742 			error = gfs2_recover_journal(jd, true);
743 			if (error) {
744 				fs_err(sdp, "error recovering journal %u: %d\n",
745 				       x, error);
746 				goto fail_jinode_gh;
747 			}
748 		}
749 
750 		gfs2_others_may_mount(sdp);
751 	} else if (!sdp->sd_args.ar_spectator) {
752 		error = gfs2_recover_journal(sdp->sd_jdesc, true);
753 		if (error) {
754 			fs_err(sdp, "error recovering my journal: %d\n", error);
755 			goto fail_jinode_gh;
756 		}
757 	}
758 
759 	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
760 	gfs2_glock_dq_uninit(&ji_gh);
761 	jindex = 0;
762 	INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
763 	return 0;
764 
765 fail_jinode_gh:
766 	if (!sdp->sd_args.ar_spectator)
767 		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
768 fail_journal_gh:
769 	if (!sdp->sd_args.ar_spectator)
770 		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
771 fail_jindex:
772 	gfs2_jindex_free(sdp);
773 	if (jindex)
774 		gfs2_glock_dq_uninit(&ji_gh);
775 fail:
776 	iput(sdp->sd_jindex);
777 	return error;
778 }
779 
780 static struct lock_class_key gfs2_quota_imutex_key;
781 
782 static int init_inodes(struct gfs2_sbd *sdp, int undo)
783 {
784 	int error = 0;
785 	struct inode *master = sdp->sd_master_dir->d_inode;
786 
787 	if (undo)
788 		goto fail_qinode;
789 
790 	error = init_journal(sdp, undo);
791 	complete_all(&sdp->sd_journal_ready);
792 	if (error)
793 		goto fail;
794 
795 	/* Read in the master statfs inode */
796 	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
797 	if (IS_ERR(sdp->sd_statfs_inode)) {
798 		error = PTR_ERR(sdp->sd_statfs_inode);
799 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
800 		goto fail_journal;
801 	}
802 
803 	/* Read in the resource index inode */
804 	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
805 	if (IS_ERR(sdp->sd_rindex)) {
806 		error = PTR_ERR(sdp->sd_rindex);
807 		fs_err(sdp, "can't get resource index inode: %d\n", error);
808 		goto fail_statfs;
809 	}
810 	sdp->sd_rindex_uptodate = 0;
811 
812 	/* Read in the quota inode */
813 	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
814 	if (IS_ERR(sdp->sd_quota_inode)) {
815 		error = PTR_ERR(sdp->sd_quota_inode);
816 		fs_err(sdp, "can't get quota file inode: %d\n", error);
817 		goto fail_rindex;
818 	}
819 	/*
820 	 * i_mutex on quota files is special. Since this inode is hidden system
821 	 * file, we are safe to define locking ourselves.
822 	 */
823 	lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
824 			  &gfs2_quota_imutex_key);
825 
826 	error = gfs2_rindex_update(sdp);
827 	if (error)
828 		goto fail_qinode;
829 
830 	return 0;
831 
832 fail_qinode:
833 	iput(sdp->sd_quota_inode);
834 fail_rindex:
835 	gfs2_clear_rgrpd(sdp);
836 	iput(sdp->sd_rindex);
837 fail_statfs:
838 	iput(sdp->sd_statfs_inode);
839 fail_journal:
840 	init_journal(sdp, UNDO);
841 fail:
842 	return error;
843 }
844 
845 static int init_per_node(struct gfs2_sbd *sdp, int undo)
846 {
847 	struct inode *pn = NULL;
848 	char buf[30];
849 	int error = 0;
850 	struct gfs2_inode *ip;
851 	struct inode *master = sdp->sd_master_dir->d_inode;
852 
853 	if (sdp->sd_args.ar_spectator)
854 		return 0;
855 
856 	if (undo)
857 		goto fail_qc_gh;
858 
859 	pn = gfs2_lookup_simple(master, "per_node");
860 	if (IS_ERR(pn)) {
861 		error = PTR_ERR(pn);
862 		fs_err(sdp, "can't find per_node directory: %d\n", error);
863 		return error;
864 	}
865 
866 	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
867 	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
868 	if (IS_ERR(sdp->sd_sc_inode)) {
869 		error = PTR_ERR(sdp->sd_sc_inode);
870 		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
871 		goto fail;
872 	}
873 
874 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
875 	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
876 	if (IS_ERR(sdp->sd_qc_inode)) {
877 		error = PTR_ERR(sdp->sd_qc_inode);
878 		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
879 		goto fail_ut_i;
880 	}
881 
882 	iput(pn);
883 	pn = NULL;
884 
885 	ip = GFS2_I(sdp->sd_sc_inode);
886 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
887 				   &sdp->sd_sc_gh);
888 	if (error) {
889 		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
890 		goto fail_qc_i;
891 	}
892 
893 	ip = GFS2_I(sdp->sd_qc_inode);
894 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
895 				   &sdp->sd_qc_gh);
896 	if (error) {
897 		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
898 		goto fail_ut_gh;
899 	}
900 
901 	return 0;
902 
903 fail_qc_gh:
904 	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
905 fail_ut_gh:
906 	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
907 fail_qc_i:
908 	iput(sdp->sd_qc_inode);
909 fail_ut_i:
910 	iput(sdp->sd_sc_inode);
911 fail:
912 	if (pn)
913 		iput(pn);
914 	return error;
915 }
916 
917 static const match_table_t nolock_tokens = {
918 	{ Opt_jid, "jid=%d\n", },
919 	{ Opt_err, NULL },
920 };
921 
922 static const struct lm_lockops nolock_ops = {
923 	.lm_proto_name = "lock_nolock",
924 	.lm_put_lock = gfs2_glock_free,
925 	.lm_tokens = &nolock_tokens,
926 };
927 
928 /**
929  * gfs2_lm_mount - mount a locking protocol
930  * @sdp: the filesystem
931  * @args: mount arguments
932  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
933  *
934  * Returns: errno
935  */
936 
937 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
938 {
939 	const struct lm_lockops *lm;
940 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
941 	struct gfs2_args *args = &sdp->sd_args;
942 	const char *proto = sdp->sd_proto_name;
943 	const char *table = sdp->sd_table_name;
944 	char *o, *options;
945 	int ret;
946 
947 	if (!strcmp("lock_nolock", proto)) {
948 		lm = &nolock_ops;
949 		sdp->sd_args.ar_localflocks = 1;
950 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
951 	} else if (!strcmp("lock_dlm", proto)) {
952 		lm = &gfs2_dlm_ops;
953 #endif
954 	} else {
955 		pr_info("can't find protocol %s\n", proto);
956 		return -ENOENT;
957 	}
958 
959 	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
960 
961 	ls->ls_ops = lm;
962 	ls->ls_first = 1;
963 
964 	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
965 		substring_t tmp[MAX_OPT_ARGS];
966 		int token, option;
967 
968 		if (!o || !*o)
969 			continue;
970 
971 		token = match_token(o, *lm->lm_tokens, tmp);
972 		switch (token) {
973 		case Opt_jid:
974 			ret = match_int(&tmp[0], &option);
975 			if (ret || option < 0)
976 				goto hostdata_error;
977 			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
978 				ls->ls_jid = option;
979 			break;
980 		case Opt_id:
981 		case Opt_nodir:
982 			/* Obsolete, but left for backward compat purposes */
983 			break;
984 		case Opt_first:
985 			ret = match_int(&tmp[0], &option);
986 			if (ret || (option != 0 && option != 1))
987 				goto hostdata_error;
988 			ls->ls_first = option;
989 			break;
990 		case Opt_err:
991 		default:
992 hostdata_error:
993 			fs_info(sdp, "unknown hostdata (%s)\n", o);
994 			return -EINVAL;
995 		}
996 	}
997 
998 	if (lm->lm_mount == NULL) {
999 		fs_info(sdp, "Now mounting FS...\n");
1000 		complete_all(&sdp->sd_locking_init);
1001 		return 0;
1002 	}
1003 	ret = lm->lm_mount(sdp, table);
1004 	if (ret == 0)
1005 		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1006 	complete_all(&sdp->sd_locking_init);
1007 	return ret;
1008 }
1009 
1010 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1011 {
1012 	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1013 	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1014 	    lm->lm_unmount)
1015 		lm->lm_unmount(sdp);
1016 }
1017 
1018 static int wait_on_journal(struct gfs2_sbd *sdp)
1019 {
1020 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1021 		return 0;
1022 
1023 	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1024 		? -EINTR : 0;
1025 }
1026 
1027 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1028 {
1029 	struct super_block *sb = sdp->sd_vfs;
1030 	char ro[20];
1031 	char spectator[20];
1032 	char *envp[] = { ro, spectator, NULL };
1033 	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1034 	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1035 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1036 }
1037 
1038 /**
1039  * fill_super - Read in superblock
1040  * @sb: The VFS superblock
1041  * @data: Mount options
1042  * @silent: Don't complain if it's not a GFS2 filesystem
1043  *
1044  * Returns: errno
1045  */
1046 
1047 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1048 {
1049 	struct gfs2_sbd *sdp;
1050 	struct gfs2_holder mount_gh;
1051 	int error;
1052 
1053 	sdp = init_sbd(sb);
1054 	if (!sdp) {
1055 		pr_warn("can't alloc struct gfs2_sbd\n");
1056 		return -ENOMEM;
1057 	}
1058 	sdp->sd_args = *args;
1059 
1060 	if (sdp->sd_args.ar_spectator) {
1061                 sb->s_flags |= MS_RDONLY;
1062 		set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1063 	}
1064 	if (sdp->sd_args.ar_posix_acl)
1065 		sb->s_flags |= MS_POSIXACL;
1066 	if (sdp->sd_args.ar_nobarrier)
1067 		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1068 
1069 	sb->s_flags |= MS_NOSEC;
1070 	sb->s_magic = GFS2_MAGIC;
1071 	sb->s_op = &gfs2_super_ops;
1072 	sb->s_d_op = &gfs2_dops;
1073 	sb->s_export_op = &gfs2_export_ops;
1074 	sb->s_xattr = gfs2_xattr_handlers;
1075 	sb->s_qcop = &gfs2_quotactl_ops;
1076 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1077 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1078 	sb->s_time_gran = 1;
1079 	sb->s_maxbytes = MAX_LFS_FILESIZE;
1080 
1081 	/* Set up the buffer cache and fill in some fake block size values
1082 	   to allow us to read-in the on-disk superblock. */
1083 	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1084 	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1085 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1086                                GFS2_BASIC_BLOCK_SHIFT;
1087 	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1088 
1089 	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1090 	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1091 	if (sdp->sd_args.ar_statfs_quantum) {
1092 		sdp->sd_tune.gt_statfs_slow = 0;
1093 		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1094 	} else {
1095 		sdp->sd_tune.gt_statfs_slow = 1;
1096 		sdp->sd_tune.gt_statfs_quantum = 30;
1097 	}
1098 
1099 	error = init_names(sdp, silent);
1100 	if (error) {
1101 		/* In this case, we haven't initialized sysfs, so we have to
1102 		   manually free the sdp. */
1103 		free_percpu(sdp->sd_lkstats);
1104 		kfree(sdp);
1105 		sb->s_fs_info = NULL;
1106 		return error;
1107 	}
1108 
1109 	snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1110 
1111 	error = gfs2_sys_fs_add(sdp);
1112 	/*
1113 	 * If we hit an error here, gfs2_sys_fs_add will have called function
1114 	 * kobject_put which causes the sysfs usage count to go to zero, which
1115 	 * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1116 	 * Subsequent error paths here will call gfs2_sys_fs_del, which also
1117 	 * kobject_put to free sdp.
1118 	 */
1119 	if (error)
1120 		return error;
1121 
1122 	gfs2_create_debugfs_file(sdp);
1123 
1124 	error = gfs2_lm_mount(sdp, silent);
1125 	if (error)
1126 		goto fail_debug;
1127 
1128 	error = init_locking(sdp, &mount_gh, DO);
1129 	if (error)
1130 		goto fail_lm;
1131 
1132 	error = init_sb(sdp, silent);
1133 	if (error)
1134 		goto fail_locking;
1135 
1136 	error = wait_on_journal(sdp);
1137 	if (error)
1138 		goto fail_sb;
1139 
1140 	/*
1141 	 * If user space has failed to join the cluster or some similar
1142 	 * failure has occurred, then the journal id will contain a
1143 	 * negative (error) number. This will then be returned to the
1144 	 * caller (of the mount syscall). We do this even for spectator
1145 	 * mounts (which just write a jid of 0 to indicate "ok" even though
1146 	 * the jid is unused in the spectator case)
1147 	 */
1148 	if (sdp->sd_lockstruct.ls_jid < 0) {
1149 		error = sdp->sd_lockstruct.ls_jid;
1150 		sdp->sd_lockstruct.ls_jid = 0;
1151 		goto fail_sb;
1152 	}
1153 
1154 	if (sdp->sd_args.ar_spectator)
1155 		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1156 			 sdp->sd_table_name);
1157 	else
1158 		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1159 			 sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1160 
1161 	error = init_inodes(sdp, DO);
1162 	if (error)
1163 		goto fail_sb;
1164 
1165 	error = init_per_node(sdp, DO);
1166 	if (error)
1167 		goto fail_inodes;
1168 
1169 	error = gfs2_statfs_init(sdp);
1170 	if (error) {
1171 		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1172 		goto fail_per_node;
1173 	}
1174 
1175 	if (!(sb->s_flags & MS_RDONLY)) {
1176 		error = gfs2_make_fs_rw(sdp);
1177 		if (error) {
1178 			fs_err(sdp, "can't make FS RW: %d\n", error);
1179 			goto fail_per_node;
1180 		}
1181 	}
1182 
1183 	gfs2_glock_dq_uninit(&mount_gh);
1184 	gfs2_online_uevent(sdp);
1185 	return 0;
1186 
1187 fail_per_node:
1188 	init_per_node(sdp, UNDO);
1189 fail_inodes:
1190 	init_inodes(sdp, UNDO);
1191 fail_sb:
1192 	if (sdp->sd_root_dir)
1193 		dput(sdp->sd_root_dir);
1194 	if (sdp->sd_master_dir)
1195 		dput(sdp->sd_master_dir);
1196 	if (sb->s_root)
1197 		dput(sb->s_root);
1198 	sb->s_root = NULL;
1199 fail_locking:
1200 	init_locking(sdp, &mount_gh, UNDO);
1201 fail_lm:
1202 	complete_all(&sdp->sd_journal_ready);
1203 	gfs2_gl_hash_clear(sdp);
1204 	gfs2_lm_unmount(sdp);
1205 fail_debug:
1206 	gfs2_delete_debugfs_file(sdp);
1207 	free_percpu(sdp->sd_lkstats);
1208 	/* gfs2_sys_fs_del must be the last thing we do, since it causes
1209 	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
1210 	gfs2_sys_fs_del(sdp);
1211 	sb->s_fs_info = NULL;
1212 	return error;
1213 }
1214 
1215 static int set_gfs2_super(struct super_block *s, void *data)
1216 {
1217 	s->s_bdev = data;
1218 	s->s_dev = s->s_bdev->bd_dev;
1219 
1220 	/*
1221 	 * We set the bdi here to the queue backing, file systems can
1222 	 * overwrite this in ->fill_super()
1223 	 */
1224 	s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1225 	return 0;
1226 }
1227 
1228 static int test_gfs2_super(struct super_block *s, void *ptr)
1229 {
1230 	struct block_device *bdev = ptr;
1231 	return (bdev == s->s_bdev);
1232 }
1233 
1234 /**
1235  * gfs2_mount - Get the GFS2 superblock
1236  * @fs_type: The GFS2 filesystem type
1237  * @flags: Mount flags
1238  * @dev_name: The name of the device
1239  * @data: The mount arguments
1240  *
1241  * Q. Why not use get_sb_bdev() ?
1242  * A. We need to select one of two root directories to mount, independent
1243  *    of whether this is the initial, or subsequent, mount of this sb
1244  *
1245  * Returns: 0 or -ve on error
1246  */
1247 
1248 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1249 		       const char *dev_name, void *data)
1250 {
1251 	struct block_device *bdev;
1252 	struct super_block *s;
1253 	fmode_t mode = FMODE_READ | FMODE_EXCL;
1254 	int error;
1255 	struct gfs2_args args;
1256 	struct gfs2_sbd *sdp;
1257 
1258 	if (!(flags & MS_RDONLY))
1259 		mode |= FMODE_WRITE;
1260 
1261 	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1262 	if (IS_ERR(bdev))
1263 		return ERR_CAST(bdev);
1264 
1265 	/*
1266 	 * once the super is inserted into the list by sget, s_umount
1267 	 * will protect the lockfs code from trying to start a snapshot
1268 	 * while we are mounting
1269 	 */
1270 	mutex_lock(&bdev->bd_fsfreeze_mutex);
1271 	if (bdev->bd_fsfreeze_count > 0) {
1272 		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1273 		error = -EBUSY;
1274 		goto error_bdev;
1275 	}
1276 	s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1277 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1278 	error = PTR_ERR(s);
1279 	if (IS_ERR(s))
1280 		goto error_bdev;
1281 
1282 	if (s->s_root) {
1283 		/*
1284 		 * s_umount nests inside bd_mutex during
1285 		 * __invalidate_device().  blkdev_put() acquires
1286 		 * bd_mutex and can't be called under s_umount.  Drop
1287 		 * s_umount temporarily.  This is safe as we're
1288 		 * holding an active reference.
1289 		 */
1290 		up_write(&s->s_umount);
1291 		blkdev_put(bdev, mode);
1292 		down_write(&s->s_umount);
1293 	}
1294 
1295 	memset(&args, 0, sizeof(args));
1296 	args.ar_quota = GFS2_QUOTA_DEFAULT;
1297 	args.ar_data = GFS2_DATA_DEFAULT;
1298 	args.ar_commit = 30;
1299 	args.ar_statfs_quantum = 30;
1300 	args.ar_quota_quantum = 60;
1301 	args.ar_errors = GFS2_ERRORS_DEFAULT;
1302 
1303 	error = gfs2_mount_args(&args, data);
1304 	if (error) {
1305 		pr_warn("can't parse mount arguments\n");
1306 		goto error_super;
1307 	}
1308 
1309 	if (s->s_root) {
1310 		error = -EBUSY;
1311 		if ((flags ^ s->s_flags) & MS_RDONLY)
1312 			goto error_super;
1313 	} else {
1314 		char b[BDEVNAME_SIZE];
1315 
1316 		s->s_mode = mode;
1317 		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1318 		sb_set_blocksize(s, block_size(bdev));
1319 		error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1320 		if (error)
1321 			goto error_super;
1322 		s->s_flags |= MS_ACTIVE;
1323 		bdev->bd_super = s;
1324 	}
1325 
1326 	sdp = s->s_fs_info;
1327 	if (args.ar_meta)
1328 		return dget(sdp->sd_master_dir);
1329 	else
1330 		return dget(sdp->sd_root_dir);
1331 
1332 error_super:
1333 	deactivate_locked_super(s);
1334 	return ERR_PTR(error);
1335 error_bdev:
1336 	blkdev_put(bdev, mode);
1337 	return ERR_PTR(error);
1338 }
1339 
1340 static int set_meta_super(struct super_block *s, void *ptr)
1341 {
1342 	return -EINVAL;
1343 }
1344 
1345 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1346 			int flags, const char *dev_name, void *data)
1347 {
1348 	struct super_block *s;
1349 	struct gfs2_sbd *sdp;
1350 	struct path path;
1351 	int error;
1352 
1353 	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1354 	if (error) {
1355 		pr_warn("path_lookup on %s returned error %d\n",
1356 			dev_name, error);
1357 		return ERR_PTR(error);
1358 	}
1359 	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1360 		 path.dentry->d_inode->i_sb->s_bdev);
1361 	path_put(&path);
1362 	if (IS_ERR(s)) {
1363 		pr_warn("gfs2 mount does not exist\n");
1364 		return ERR_CAST(s);
1365 	}
1366 	if ((flags ^ s->s_flags) & MS_RDONLY) {
1367 		deactivate_locked_super(s);
1368 		return ERR_PTR(-EBUSY);
1369 	}
1370 	sdp = s->s_fs_info;
1371 	return dget(sdp->sd_master_dir);
1372 }
1373 
1374 static void gfs2_kill_sb(struct super_block *sb)
1375 {
1376 	struct gfs2_sbd *sdp = sb->s_fs_info;
1377 
1378 	if (sdp == NULL) {
1379 		kill_block_super(sb);
1380 		return;
1381 	}
1382 
1383 	gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1384 	dput(sdp->sd_root_dir);
1385 	dput(sdp->sd_master_dir);
1386 	sdp->sd_root_dir = NULL;
1387 	sdp->sd_master_dir = NULL;
1388 	shrink_dcache_sb(sb);
1389 	gfs2_delete_debugfs_file(sdp);
1390 	free_percpu(sdp->sd_lkstats);
1391 	kill_block_super(sb);
1392 }
1393 
1394 struct file_system_type gfs2_fs_type = {
1395 	.name = "gfs2",
1396 	.fs_flags = FS_REQUIRES_DEV,
1397 	.mount = gfs2_mount,
1398 	.kill_sb = gfs2_kill_sb,
1399 	.owner = THIS_MODULE,
1400 };
1401 MODULE_ALIAS_FS("gfs2");
1402 
1403 struct file_system_type gfs2meta_fs_type = {
1404 	.name = "gfs2meta",
1405 	.fs_flags = FS_REQUIRES_DEV,
1406 	.mount = gfs2_mount_meta,
1407 	.owner = THIS_MODULE,
1408 };
1409 MODULE_ALIAS_FS("gfs2meta");
1410