xref: /openbmc/linux/fs/gfs2/ops_fstype.c (revision 94c7b6fc)
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->backing_dev_info = sb->s_bdi;
116 	mapping->writeback_index = 0;
117 
118 	spin_lock_init(&sdp->sd_log_lock);
119 	atomic_set(&sdp->sd_log_pinned, 0);
120 	INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
121 	INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
122 	spin_lock_init(&sdp->sd_ordered_lock);
123 
124 	init_waitqueue_head(&sdp->sd_log_waitq);
125 	init_waitqueue_head(&sdp->sd_logd_waitq);
126 	spin_lock_init(&sdp->sd_ail_lock);
127 	INIT_LIST_HEAD(&sdp->sd_ail1_list);
128 	INIT_LIST_HEAD(&sdp->sd_ail2_list);
129 
130 	init_rwsem(&sdp->sd_log_flush_lock);
131 	atomic_set(&sdp->sd_log_in_flight, 0);
132 	init_waitqueue_head(&sdp->sd_log_flush_wait);
133 	init_waitqueue_head(&sdp->sd_log_frozen_wait);
134 	atomic_set(&sdp->sd_log_freeze, 0);
135 	atomic_set(&sdp->sd_frozen_root, 0);
136 	init_waitqueue_head(&sdp->sd_frozen_root_wait);
137 
138 	return sdp;
139 }
140 
141 
142 /**
143  * gfs2_check_sb - Check superblock
144  * @sdp: the filesystem
145  * @sb: The superblock
146  * @silent: Don't print a message if the check fails
147  *
148  * Checks the version code of the FS is one that we understand how to
149  * read and that the sizes of the various on-disk structures have not
150  * changed.
151  */
152 
153 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
154 {
155 	struct gfs2_sb_host *sb = &sdp->sd_sb;
156 
157 	if (sb->sb_magic != GFS2_MAGIC ||
158 	    sb->sb_type != GFS2_METATYPE_SB) {
159 		if (!silent)
160 			pr_warn("not a GFS2 filesystem\n");
161 		return -EINVAL;
162 	}
163 
164 	/*  If format numbers match exactly, we're done.  */
165 
166 	if (sb->sb_fs_format == GFS2_FORMAT_FS &&
167 	    sb->sb_multihost_format == GFS2_FORMAT_MULTI)
168 		return 0;
169 
170 	fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
171 
172 	return -EINVAL;
173 }
174 
175 static void end_bio_io_page(struct bio *bio, int error)
176 {
177 	struct page *page = bio->bi_private;
178 
179 	if (!error)
180 		SetPageUptodate(page);
181 	else
182 		pr_warn("error %d reading superblock\n", error);
183 	unlock_page(page);
184 }
185 
186 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
187 {
188 	struct gfs2_sb_host *sb = &sdp->sd_sb;
189 	struct super_block *s = sdp->sd_vfs;
190 	const struct gfs2_sb *str = buf;
191 
192 	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
193 	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
194 	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
195 	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
196 	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
197 	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
198 	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
199 	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
200 	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
201 	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
202 	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
203 
204 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
205 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
206 	memcpy(s->s_uuid, str->sb_uuid, 16);
207 }
208 
209 /**
210  * gfs2_read_super - Read the gfs2 super block from disk
211  * @sdp: The GFS2 super block
212  * @sector: The location of the super block
213  * @error: The error code to return
214  *
215  * This uses the bio functions to read the super block from disk
216  * because we want to be 100% sure that we never read cached data.
217  * A super block is read twice only during each GFS2 mount and is
218  * never written to by the filesystem. The first time its read no
219  * locks are held, and the only details which are looked at are those
220  * relating to the locking protocol. Once locking is up and working,
221  * the sb is read again under the lock to establish the location of
222  * the master directory (contains pointers to journals etc) and the
223  * root directory.
224  *
225  * Returns: 0 on success or error
226  */
227 
228 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
229 {
230 	struct super_block *sb = sdp->sd_vfs;
231 	struct gfs2_sb *p;
232 	struct page *page;
233 	struct bio *bio;
234 
235 	page = alloc_page(GFP_NOFS);
236 	if (unlikely(!page))
237 		return -ENOMEM;
238 
239 	ClearPageUptodate(page);
240 	ClearPageDirty(page);
241 	lock_page(page);
242 
243 	bio = bio_alloc(GFP_NOFS, 1);
244 	bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
245 	bio->bi_bdev = sb->s_bdev;
246 	bio_add_page(bio, page, PAGE_SIZE, 0);
247 
248 	bio->bi_end_io = end_bio_io_page;
249 	bio->bi_private = page;
250 	submit_bio(READ_SYNC | REQ_META, bio);
251 	wait_on_page_locked(page);
252 	bio_put(bio);
253 	if (!PageUptodate(page)) {
254 		__free_page(page);
255 		return -EIO;
256 	}
257 	p = kmap(page);
258 	gfs2_sb_in(sdp, p);
259 	kunmap(page);
260 	__free_page(page);
261 	return gfs2_check_sb(sdp, silent);
262 }
263 
264 /**
265  * gfs2_read_sb - Read super block
266  * @sdp: The GFS2 superblock
267  * @silent: Don't print message if mount fails
268  *
269  */
270 
271 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
272 {
273 	u32 hash_blocks, ind_blocks, leaf_blocks;
274 	u32 tmp_blocks;
275 	unsigned int x;
276 	int error;
277 
278 	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
279 	if (error) {
280 		if (!silent)
281 			fs_err(sdp, "can't read superblock\n");
282 		return error;
283 	}
284 
285 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
286 			       GFS2_BASIC_BLOCK_SHIFT;
287 	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
288 	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
289 			  sizeof(struct gfs2_dinode)) / sizeof(u64);
290 	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
291 			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
292 	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
293 	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
294 	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
295 	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
296 	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
297 				sizeof(struct gfs2_meta_header)) /
298 			        sizeof(struct gfs2_quota_change);
299 	sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
300 				     sizeof(struct gfs2_meta_header))
301 		* GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
302 
303 	/* Compute maximum reservation required to add a entry to a directory */
304 
305 	hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
306 			     sdp->sd_jbsize);
307 
308 	ind_blocks = 0;
309 	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
310 		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
311 		ind_blocks += tmp_blocks;
312 	}
313 
314 	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
315 
316 	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
317 
318 	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
319 				sizeof(struct gfs2_dinode);
320 	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
321 	for (x = 2;; x++) {
322 		u64 space, d;
323 		u32 m;
324 
325 		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
326 		d = space;
327 		m = do_div(d, sdp->sd_inptrs);
328 
329 		if (d != sdp->sd_heightsize[x - 1] || m)
330 			break;
331 		sdp->sd_heightsize[x] = space;
332 	}
333 	sdp->sd_max_height = x;
334 	sdp->sd_heightsize[x] = ~0;
335 	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
336 
337 	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
338 				 sizeof(struct gfs2_dinode);
339 	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
340 	for (x = 2;; x++) {
341 		u64 space, d;
342 		u32 m;
343 
344 		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
345 		d = space;
346 		m = do_div(d, sdp->sd_inptrs);
347 
348 		if (d != sdp->sd_jheightsize[x - 1] || m)
349 			break;
350 		sdp->sd_jheightsize[x] = space;
351 	}
352 	sdp->sd_max_jheight = x;
353 	sdp->sd_jheightsize[x] = ~0;
354 	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
355 
356 	return 0;
357 }
358 
359 static int init_names(struct gfs2_sbd *sdp, int silent)
360 {
361 	char *proto, *table;
362 	int error = 0;
363 
364 	proto = sdp->sd_args.ar_lockproto;
365 	table = sdp->sd_args.ar_locktable;
366 
367 	/*  Try to autodetect  */
368 
369 	if (!proto[0] || !table[0]) {
370 		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
371 		if (error)
372 			return error;
373 
374 		if (!proto[0])
375 			proto = sdp->sd_sb.sb_lockproto;
376 		if (!table[0])
377 			table = sdp->sd_sb.sb_locktable;
378 	}
379 
380 	if (!table[0])
381 		table = sdp->sd_vfs->s_id;
382 
383 	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
384 	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
385 
386 	table = sdp->sd_table_name;
387 	while ((table = strchr(table, '/')))
388 		*table = '_';
389 
390 	return error;
391 }
392 
393 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
394 			int undo)
395 {
396 	int error = 0;
397 
398 	if (undo)
399 		goto fail_trans;
400 
401 	error = gfs2_glock_nq_num(sdp,
402 				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
403 				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
404 				  mount_gh);
405 	if (error) {
406 		fs_err(sdp, "can't acquire mount glock: %d\n", error);
407 		goto fail;
408 	}
409 
410 	error = gfs2_glock_nq_num(sdp,
411 				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
412 				  LM_ST_SHARED,
413 				  LM_FLAG_NOEXP | GL_EXACT,
414 				  &sdp->sd_live_gh);
415 	if (error) {
416 		fs_err(sdp, "can't acquire live glock: %d\n", error);
417 		goto fail_mount;
418 	}
419 
420 	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
421 			       CREATE, &sdp->sd_rename_gl);
422 	if (error) {
423 		fs_err(sdp, "can't create rename glock: %d\n", error);
424 		goto fail_live;
425 	}
426 
427 	error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
428 			       CREATE, &sdp->sd_freeze_gl);
429 	if (error) {
430 		fs_err(sdp, "can't create transaction glock: %d\n", error);
431 		goto fail_rename;
432 	}
433 
434 	return 0;
435 
436 fail_trans:
437 	gfs2_glock_put(sdp->sd_freeze_gl);
438 fail_rename:
439 	gfs2_glock_put(sdp->sd_rename_gl);
440 fail_live:
441 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
442 fail_mount:
443 	gfs2_glock_dq_uninit(mount_gh);
444 fail:
445 	return error;
446 }
447 
448 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
449 			    u64 no_addr, const char *name)
450 {
451 	struct gfs2_sbd *sdp = sb->s_fs_info;
452 	struct dentry *dentry;
453 	struct inode *inode;
454 
455 	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
456 	if (IS_ERR(inode)) {
457 		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
458 		return PTR_ERR(inode);
459 	}
460 	dentry = d_make_root(inode);
461 	if (!dentry) {
462 		fs_err(sdp, "can't alloc %s dentry\n", name);
463 		return -ENOMEM;
464 	}
465 	*dptr = dentry;
466 	return 0;
467 }
468 
469 static int init_sb(struct gfs2_sbd *sdp, int silent)
470 {
471 	struct super_block *sb = sdp->sd_vfs;
472 	struct gfs2_holder sb_gh;
473 	u64 no_addr;
474 	int ret;
475 
476 	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
477 				LM_ST_SHARED, 0, &sb_gh);
478 	if (ret) {
479 		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
480 		return ret;
481 	}
482 
483 	ret = gfs2_read_sb(sdp, silent);
484 	if (ret) {
485 		fs_err(sdp, "can't read superblock: %d\n", ret);
486 		goto out;
487 	}
488 
489 	/* Set up the buffer cache and SB for real */
490 	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
491 		ret = -EINVAL;
492 		fs_err(sdp, "FS block size (%u) is too small for device "
493 		       "block size (%u)\n",
494 		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
495 		goto out;
496 	}
497 	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
498 		ret = -EINVAL;
499 		fs_err(sdp, "FS block size (%u) is too big for machine "
500 		       "page size (%u)\n",
501 		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
502 		goto out;
503 	}
504 	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
505 
506 	/* Get the root inode */
507 	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
508 	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
509 	if (ret)
510 		goto out;
511 
512 	/* Get the master inode */
513 	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
514 	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
515 	if (ret) {
516 		dput(sdp->sd_root_dir);
517 		goto out;
518 	}
519 	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
520 out:
521 	gfs2_glock_dq_uninit(&sb_gh);
522 	return ret;
523 }
524 
525 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
526 {
527 	char *message = "FIRSTMOUNT=Done";
528 	char *envp[] = { message, NULL };
529 
530 	fs_info(sdp, "first mount done, others may mount\n");
531 
532 	if (sdp->sd_lockstruct.ls_ops->lm_first_done)
533 		sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
534 
535 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
536 }
537 
538 /**
539  * gfs2_jindex_hold - Grab a lock on the jindex
540  * @sdp: The GFS2 superblock
541  * @ji_gh: the holder for the jindex glock
542  *
543  * Returns: errno
544  */
545 
546 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
547 {
548 	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
549 	struct qstr name;
550 	char buf[20];
551 	struct gfs2_jdesc *jd;
552 	int error;
553 
554 	name.name = buf;
555 
556 	mutex_lock(&sdp->sd_jindex_mutex);
557 
558 	for (;;) {
559 		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
560 		if (error)
561 			break;
562 
563 		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
564 		name.hash = gfs2_disk_hash(name.name, name.len);
565 
566 		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
567 		if (error == -ENOENT) {
568 			error = 0;
569 			break;
570 		}
571 
572 		gfs2_glock_dq_uninit(ji_gh);
573 
574 		if (error)
575 			break;
576 
577 		error = -ENOMEM;
578 		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
579 		if (!jd)
580 			break;
581 
582 		INIT_LIST_HEAD(&jd->extent_list);
583 		INIT_LIST_HEAD(&jd->jd_revoke_list);
584 
585 		INIT_WORK(&jd->jd_work, gfs2_recover_func);
586 		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
587 		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
588 			if (!jd->jd_inode)
589 				error = -ENOENT;
590 			else
591 				error = PTR_ERR(jd->jd_inode);
592 			kfree(jd);
593 			break;
594 		}
595 
596 		spin_lock(&sdp->sd_jindex_spin);
597 		jd->jd_jid = sdp->sd_journals++;
598 		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
599 		spin_unlock(&sdp->sd_jindex_spin);
600 	}
601 
602 	mutex_unlock(&sdp->sd_jindex_mutex);
603 
604 	return error;
605 }
606 
607 /**
608  * check_journal_clean - Make sure a journal is clean for a spectator mount
609  * @sdp: The GFS2 superblock
610  * @jd: The journal descriptor
611  *
612  * Returns: 0 if the journal is clean or locked, else an error
613  */
614 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
615 {
616 	int error;
617 	struct gfs2_holder j_gh;
618 	struct gfs2_log_header_host head;
619 	struct gfs2_inode *ip;
620 
621 	ip = GFS2_I(jd->jd_inode);
622 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
623 				   GL_EXACT | GL_NOCACHE, &j_gh);
624 	if (error) {
625 		fs_err(sdp, "Error locking journal for spectator mount.\n");
626 		return -EPERM;
627 	}
628 	error = gfs2_jdesc_check(jd);
629 	if (error) {
630 		fs_err(sdp, "Error checking journal for spectator mount.\n");
631 		goto out_unlock;
632 	}
633 	error = gfs2_find_jhead(jd, &head);
634 	if (error) {
635 		fs_err(sdp, "Error parsing journal for spectator mount.\n");
636 		goto out_unlock;
637 	}
638 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
639 		error = -EPERM;
640 		fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
641 		       "must not be a spectator.\n", jd->jd_jid);
642 	}
643 
644 out_unlock:
645 	gfs2_glock_dq_uninit(&j_gh);
646 	return error;
647 }
648 
649 static int init_journal(struct gfs2_sbd *sdp, int undo)
650 {
651 	struct inode *master = sdp->sd_master_dir->d_inode;
652 	struct gfs2_holder ji_gh;
653 	struct gfs2_inode *ip;
654 	int jindex = 1;
655 	int error = 0;
656 
657 	if (undo) {
658 		jindex = 0;
659 		goto fail_jinode_gh;
660 	}
661 
662 	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
663 	if (IS_ERR(sdp->sd_jindex)) {
664 		fs_err(sdp, "can't lookup journal index: %d\n", error);
665 		return PTR_ERR(sdp->sd_jindex);
666 	}
667 
668 	/* Load in the journal index special file */
669 
670 	error = gfs2_jindex_hold(sdp, &ji_gh);
671 	if (error) {
672 		fs_err(sdp, "can't read journal index: %d\n", error);
673 		goto fail;
674 	}
675 
676 	error = -EUSERS;
677 	if (!gfs2_jindex_size(sdp)) {
678 		fs_err(sdp, "no journals!\n");
679 		goto fail_jindex;
680 	}
681 
682 	if (sdp->sd_args.ar_spectator) {
683 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
684 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
685 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
686 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
687 	} else {
688 		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
689 			fs_err(sdp, "can't mount journal #%u\n",
690 			       sdp->sd_lockstruct.ls_jid);
691 			fs_err(sdp, "there are only %u journals (0 - %u)\n",
692 			       gfs2_jindex_size(sdp),
693 			       gfs2_jindex_size(sdp) - 1);
694 			goto fail_jindex;
695 		}
696 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
697 
698 		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
699 					  &gfs2_journal_glops,
700 					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
701 					  &sdp->sd_journal_gh);
702 		if (error) {
703 			fs_err(sdp, "can't acquire journal glock: %d\n", error);
704 			goto fail_jindex;
705 		}
706 
707 		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
708 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
709 					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
710 					   &sdp->sd_jinode_gh);
711 		if (error) {
712 			fs_err(sdp, "can't acquire journal inode glock: %d\n",
713 			       error);
714 			goto fail_journal_gh;
715 		}
716 
717 		error = gfs2_jdesc_check(sdp->sd_jdesc);
718 		if (error) {
719 			fs_err(sdp, "my journal (%u) is bad: %d\n",
720 			       sdp->sd_jdesc->jd_jid, error);
721 			goto fail_jinode_gh;
722 		}
723 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
724 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
725 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
726 
727 		/* Map the extents for this journal's blocks */
728 		gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
729 	}
730 	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
731 
732 	if (sdp->sd_lockstruct.ls_first) {
733 		unsigned int x;
734 		for (x = 0; x < sdp->sd_journals; x++) {
735 			struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
736 
737 			if (sdp->sd_args.ar_spectator) {
738 				error = check_journal_clean(sdp, jd);
739 				if (error)
740 					goto fail_jinode_gh;
741 				continue;
742 			}
743 			error = gfs2_recover_journal(jd, true);
744 			if (error) {
745 				fs_err(sdp, "error recovering journal %u: %d\n",
746 				       x, error);
747 				goto fail_jinode_gh;
748 			}
749 		}
750 
751 		gfs2_others_may_mount(sdp);
752 	} else if (!sdp->sd_args.ar_spectator) {
753 		error = gfs2_recover_journal(sdp->sd_jdesc, true);
754 		if (error) {
755 			fs_err(sdp, "error recovering my journal: %d\n", error);
756 			goto fail_jinode_gh;
757 		}
758 	}
759 
760 	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
761 	gfs2_glock_dq_uninit(&ji_gh);
762 	jindex = 0;
763 	if (!sdp->sd_args.ar_spectator) {
764 		error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, 0,
765 					   &sdp->sd_thaw_gh);
766 		if (error) {
767 			fs_err(sdp, "can't acquire freeze glock: %d\n", error);
768 			goto fail_jinode_gh;
769 		}
770 	}
771 	gfs2_glock_dq_uninit(&sdp->sd_thaw_gh);
772 	return 0;
773 
774 fail_jinode_gh:
775 	if (!sdp->sd_args.ar_spectator)
776 		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
777 fail_journal_gh:
778 	if (!sdp->sd_args.ar_spectator)
779 		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
780 fail_jindex:
781 	gfs2_jindex_free(sdp);
782 	if (jindex)
783 		gfs2_glock_dq_uninit(&ji_gh);
784 fail:
785 	iput(sdp->sd_jindex);
786 	return error;
787 }
788 
789 static struct lock_class_key gfs2_quota_imutex_key;
790 
791 static int init_inodes(struct gfs2_sbd *sdp, int undo)
792 {
793 	int error = 0;
794 	struct inode *master = sdp->sd_master_dir->d_inode;
795 
796 	if (undo)
797 		goto fail_qinode;
798 
799 	error = init_journal(sdp, undo);
800 	complete_all(&sdp->sd_journal_ready);
801 	if (error)
802 		goto fail;
803 
804 	/* Read in the master statfs inode */
805 	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
806 	if (IS_ERR(sdp->sd_statfs_inode)) {
807 		error = PTR_ERR(sdp->sd_statfs_inode);
808 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
809 		goto fail_journal;
810 	}
811 
812 	/* Read in the resource index inode */
813 	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
814 	if (IS_ERR(sdp->sd_rindex)) {
815 		error = PTR_ERR(sdp->sd_rindex);
816 		fs_err(sdp, "can't get resource index inode: %d\n", error);
817 		goto fail_statfs;
818 	}
819 	sdp->sd_rindex_uptodate = 0;
820 
821 	/* Read in the quota inode */
822 	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
823 	if (IS_ERR(sdp->sd_quota_inode)) {
824 		error = PTR_ERR(sdp->sd_quota_inode);
825 		fs_err(sdp, "can't get quota file inode: %d\n", error);
826 		goto fail_rindex;
827 	}
828 	/*
829 	 * i_mutex on quota files is special. Since this inode is hidden system
830 	 * file, we are safe to define locking ourselves.
831 	 */
832 	lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
833 			  &gfs2_quota_imutex_key);
834 
835 	error = gfs2_rindex_update(sdp);
836 	if (error)
837 		goto fail_qinode;
838 
839 	return 0;
840 
841 fail_qinode:
842 	iput(sdp->sd_quota_inode);
843 fail_rindex:
844 	gfs2_clear_rgrpd(sdp);
845 	iput(sdp->sd_rindex);
846 fail_statfs:
847 	iput(sdp->sd_statfs_inode);
848 fail_journal:
849 	init_journal(sdp, UNDO);
850 fail:
851 	return error;
852 }
853 
854 static int init_per_node(struct gfs2_sbd *sdp, int undo)
855 {
856 	struct inode *pn = NULL;
857 	char buf[30];
858 	int error = 0;
859 	struct gfs2_inode *ip;
860 	struct inode *master = sdp->sd_master_dir->d_inode;
861 
862 	if (sdp->sd_args.ar_spectator)
863 		return 0;
864 
865 	if (undo)
866 		goto fail_qc_gh;
867 
868 	pn = gfs2_lookup_simple(master, "per_node");
869 	if (IS_ERR(pn)) {
870 		error = PTR_ERR(pn);
871 		fs_err(sdp, "can't find per_node directory: %d\n", error);
872 		return error;
873 	}
874 
875 	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
876 	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
877 	if (IS_ERR(sdp->sd_sc_inode)) {
878 		error = PTR_ERR(sdp->sd_sc_inode);
879 		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
880 		goto fail;
881 	}
882 
883 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
884 	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
885 	if (IS_ERR(sdp->sd_qc_inode)) {
886 		error = PTR_ERR(sdp->sd_qc_inode);
887 		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
888 		goto fail_ut_i;
889 	}
890 
891 	iput(pn);
892 	pn = NULL;
893 
894 	ip = GFS2_I(sdp->sd_sc_inode);
895 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
896 				   &sdp->sd_sc_gh);
897 	if (error) {
898 		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
899 		goto fail_qc_i;
900 	}
901 
902 	ip = GFS2_I(sdp->sd_qc_inode);
903 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
904 				   &sdp->sd_qc_gh);
905 	if (error) {
906 		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
907 		goto fail_ut_gh;
908 	}
909 
910 	return 0;
911 
912 fail_qc_gh:
913 	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
914 fail_ut_gh:
915 	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
916 fail_qc_i:
917 	iput(sdp->sd_qc_inode);
918 fail_ut_i:
919 	iput(sdp->sd_sc_inode);
920 fail:
921 	if (pn)
922 		iput(pn);
923 	return error;
924 }
925 
926 static const match_table_t nolock_tokens = {
927 	{ Opt_jid, "jid=%d\n", },
928 	{ Opt_err, NULL },
929 };
930 
931 static const struct lm_lockops nolock_ops = {
932 	.lm_proto_name = "lock_nolock",
933 	.lm_put_lock = gfs2_glock_free,
934 	.lm_tokens = &nolock_tokens,
935 };
936 
937 /**
938  * gfs2_lm_mount - mount a locking protocol
939  * @sdp: the filesystem
940  * @args: mount arguments
941  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
942  *
943  * Returns: errno
944  */
945 
946 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
947 {
948 	const struct lm_lockops *lm;
949 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
950 	struct gfs2_args *args = &sdp->sd_args;
951 	const char *proto = sdp->sd_proto_name;
952 	const char *table = sdp->sd_table_name;
953 	char *o, *options;
954 	int ret;
955 
956 	if (!strcmp("lock_nolock", proto)) {
957 		lm = &nolock_ops;
958 		sdp->sd_args.ar_localflocks = 1;
959 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
960 	} else if (!strcmp("lock_dlm", proto)) {
961 		lm = &gfs2_dlm_ops;
962 #endif
963 	} else {
964 		pr_info("can't find protocol %s\n", proto);
965 		return -ENOENT;
966 	}
967 
968 	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
969 
970 	ls->ls_ops = lm;
971 	ls->ls_first = 1;
972 
973 	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
974 		substring_t tmp[MAX_OPT_ARGS];
975 		int token, option;
976 
977 		if (!o || !*o)
978 			continue;
979 
980 		token = match_token(o, *lm->lm_tokens, tmp);
981 		switch (token) {
982 		case Opt_jid:
983 			ret = match_int(&tmp[0], &option);
984 			if (ret || option < 0)
985 				goto hostdata_error;
986 			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
987 				ls->ls_jid = option;
988 			break;
989 		case Opt_id:
990 		case Opt_nodir:
991 			/* Obsolete, but left for backward compat purposes */
992 			break;
993 		case Opt_first:
994 			ret = match_int(&tmp[0], &option);
995 			if (ret || (option != 0 && option != 1))
996 				goto hostdata_error;
997 			ls->ls_first = option;
998 			break;
999 		case Opt_err:
1000 		default:
1001 hostdata_error:
1002 			fs_info(sdp, "unknown hostdata (%s)\n", o);
1003 			return -EINVAL;
1004 		}
1005 	}
1006 
1007 	if (lm->lm_mount == NULL) {
1008 		fs_info(sdp, "Now mounting FS...\n");
1009 		complete_all(&sdp->sd_locking_init);
1010 		return 0;
1011 	}
1012 	ret = lm->lm_mount(sdp, table);
1013 	if (ret == 0)
1014 		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1015 	complete_all(&sdp->sd_locking_init);
1016 	return ret;
1017 }
1018 
1019 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1020 {
1021 	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1022 	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1023 	    lm->lm_unmount)
1024 		lm->lm_unmount(sdp);
1025 }
1026 
1027 static int gfs2_journalid_wait(void *word)
1028 {
1029 	if (signal_pending(current))
1030 		return -EINTR;
1031 	schedule();
1032 	return 0;
1033 }
1034 
1035 static int wait_on_journal(struct gfs2_sbd *sdp)
1036 {
1037 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1038 		return 0;
1039 
1040 	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
1041 }
1042 
1043 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1044 {
1045 	struct super_block *sb = sdp->sd_vfs;
1046 	char ro[20];
1047 	char spectator[20];
1048 	char *envp[] = { ro, spectator, NULL };
1049 	sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1050 	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1051 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1052 }
1053 
1054 /**
1055  * fill_super - Read in superblock
1056  * @sb: The VFS superblock
1057  * @data: Mount options
1058  * @silent: Don't complain if it's not a GFS2 filesystem
1059  *
1060  * Returns: errno
1061  */
1062 
1063 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1064 {
1065 	struct gfs2_sbd *sdp;
1066 	struct gfs2_holder mount_gh;
1067 	int error;
1068 
1069 	sdp = init_sbd(sb);
1070 	if (!sdp) {
1071 		pr_warn("can't alloc struct gfs2_sbd\n");
1072 		return -ENOMEM;
1073 	}
1074 	sdp->sd_args = *args;
1075 
1076 	if (sdp->sd_args.ar_spectator) {
1077                 sb->s_flags |= MS_RDONLY;
1078 		set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1079 	}
1080 	if (sdp->sd_args.ar_posix_acl)
1081 		sb->s_flags |= MS_POSIXACL;
1082 	if (sdp->sd_args.ar_nobarrier)
1083 		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1084 
1085 	sb->s_flags |= MS_NOSEC;
1086 	sb->s_magic = GFS2_MAGIC;
1087 	sb->s_op = &gfs2_super_ops;
1088 	sb->s_d_op = &gfs2_dops;
1089 	sb->s_export_op = &gfs2_export_ops;
1090 	sb->s_xattr = gfs2_xattr_handlers;
1091 	sb->s_qcop = &gfs2_quotactl_ops;
1092 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1093 	sb->s_time_gran = 1;
1094 	sb->s_maxbytes = MAX_LFS_FILESIZE;
1095 
1096 	/* Set up the buffer cache and fill in some fake block size values
1097 	   to allow us to read-in the on-disk superblock. */
1098 	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1099 	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1100 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1101                                GFS2_BASIC_BLOCK_SHIFT;
1102 	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1103 
1104 	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1105 	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1106 	if (sdp->sd_args.ar_statfs_quantum) {
1107 		sdp->sd_tune.gt_statfs_slow = 0;
1108 		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1109 	} else {
1110 		sdp->sd_tune.gt_statfs_slow = 1;
1111 		sdp->sd_tune.gt_statfs_quantum = 30;
1112 	}
1113 
1114 	error = init_names(sdp, silent);
1115 	if (error) {
1116 		/* In this case, we haven't initialized sysfs, so we have to
1117 		   manually free the sdp. */
1118 		free_percpu(sdp->sd_lkstats);
1119 		kfree(sdp);
1120 		sb->s_fs_info = NULL;
1121 		return error;
1122 	}
1123 
1124 	snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1125 
1126 	error = gfs2_sys_fs_add(sdp);
1127 	/*
1128 	 * If we hit an error here, gfs2_sys_fs_add will have called function
1129 	 * kobject_put which causes the sysfs usage count to go to zero, which
1130 	 * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1131 	 * Subsequent error paths here will call gfs2_sys_fs_del, which also
1132 	 * kobject_put to free sdp.
1133 	 */
1134 	if (error)
1135 		return error;
1136 
1137 	gfs2_create_debugfs_file(sdp);
1138 
1139 	error = gfs2_lm_mount(sdp, silent);
1140 	if (error)
1141 		goto fail_debug;
1142 
1143 	error = init_locking(sdp, &mount_gh, DO);
1144 	if (error)
1145 		goto fail_lm;
1146 
1147 	error = init_sb(sdp, silent);
1148 	if (error)
1149 		goto fail_locking;
1150 
1151 	error = wait_on_journal(sdp);
1152 	if (error)
1153 		goto fail_sb;
1154 
1155 	/*
1156 	 * If user space has failed to join the cluster or some similar
1157 	 * failure has occurred, then the journal id will contain a
1158 	 * negative (error) number. This will then be returned to the
1159 	 * caller (of the mount syscall). We do this even for spectator
1160 	 * mounts (which just write a jid of 0 to indicate "ok" even though
1161 	 * the jid is unused in the spectator case)
1162 	 */
1163 	if (sdp->sd_lockstruct.ls_jid < 0) {
1164 		error = sdp->sd_lockstruct.ls_jid;
1165 		sdp->sd_lockstruct.ls_jid = 0;
1166 		goto fail_sb;
1167 	}
1168 
1169 	if (sdp->sd_args.ar_spectator)
1170 		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1171 			 sdp->sd_table_name);
1172 	else
1173 		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1174 			 sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1175 
1176 	error = init_inodes(sdp, DO);
1177 	if (error)
1178 		goto fail_sb;
1179 
1180 	error = init_per_node(sdp, DO);
1181 	if (error)
1182 		goto fail_inodes;
1183 
1184 	error = gfs2_statfs_init(sdp);
1185 	if (error) {
1186 		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1187 		goto fail_per_node;
1188 	}
1189 
1190 	if (!(sb->s_flags & MS_RDONLY)) {
1191 		error = gfs2_make_fs_rw(sdp);
1192 		if (error) {
1193 			fs_err(sdp, "can't make FS RW: %d\n", error);
1194 			goto fail_per_node;
1195 		}
1196 	}
1197 
1198 	gfs2_glock_dq_uninit(&mount_gh);
1199 	gfs2_online_uevent(sdp);
1200 	return 0;
1201 
1202 fail_per_node:
1203 	init_per_node(sdp, UNDO);
1204 fail_inodes:
1205 	init_inodes(sdp, UNDO);
1206 fail_sb:
1207 	if (sdp->sd_root_dir)
1208 		dput(sdp->sd_root_dir);
1209 	if (sdp->sd_master_dir)
1210 		dput(sdp->sd_master_dir);
1211 	if (sb->s_root)
1212 		dput(sb->s_root);
1213 	sb->s_root = NULL;
1214 fail_locking:
1215 	init_locking(sdp, &mount_gh, UNDO);
1216 fail_lm:
1217 	complete_all(&sdp->sd_journal_ready);
1218 	gfs2_gl_hash_clear(sdp);
1219 	gfs2_lm_unmount(sdp);
1220 fail_debug:
1221 	gfs2_delete_debugfs_file(sdp);
1222 	free_percpu(sdp->sd_lkstats);
1223 	/* gfs2_sys_fs_del must be the last thing we do, since it causes
1224 	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
1225 	gfs2_sys_fs_del(sdp);
1226 	sb->s_fs_info = NULL;
1227 	return error;
1228 }
1229 
1230 static int set_gfs2_super(struct super_block *s, void *data)
1231 {
1232 	s->s_bdev = data;
1233 	s->s_dev = s->s_bdev->bd_dev;
1234 
1235 	/*
1236 	 * We set the bdi here to the queue backing, file systems can
1237 	 * overwrite this in ->fill_super()
1238 	 */
1239 	s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1240 	return 0;
1241 }
1242 
1243 static int test_gfs2_super(struct super_block *s, void *ptr)
1244 {
1245 	struct block_device *bdev = ptr;
1246 	return (bdev == s->s_bdev);
1247 }
1248 
1249 /**
1250  * gfs2_mount - Get the GFS2 superblock
1251  * @fs_type: The GFS2 filesystem type
1252  * @flags: Mount flags
1253  * @dev_name: The name of the device
1254  * @data: The mount arguments
1255  *
1256  * Q. Why not use get_sb_bdev() ?
1257  * A. We need to select one of two root directories to mount, independent
1258  *    of whether this is the initial, or subsequent, mount of this sb
1259  *
1260  * Returns: 0 or -ve on error
1261  */
1262 
1263 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1264 		       const char *dev_name, void *data)
1265 {
1266 	struct block_device *bdev;
1267 	struct super_block *s;
1268 	fmode_t mode = FMODE_READ | FMODE_EXCL;
1269 	int error;
1270 	struct gfs2_args args;
1271 	struct gfs2_sbd *sdp;
1272 
1273 	if (!(flags & MS_RDONLY))
1274 		mode |= FMODE_WRITE;
1275 
1276 	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1277 	if (IS_ERR(bdev))
1278 		return ERR_CAST(bdev);
1279 
1280 	/*
1281 	 * once the super is inserted into the list by sget, s_umount
1282 	 * will protect the lockfs code from trying to start a snapshot
1283 	 * while we are mounting
1284 	 */
1285 	mutex_lock(&bdev->bd_fsfreeze_mutex);
1286 	if (bdev->bd_fsfreeze_count > 0) {
1287 		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1288 		error = -EBUSY;
1289 		goto error_bdev;
1290 	}
1291 	s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1292 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1293 	error = PTR_ERR(s);
1294 	if (IS_ERR(s))
1295 		goto error_bdev;
1296 
1297 	if (s->s_root) {
1298 		/*
1299 		 * s_umount nests inside bd_mutex during
1300 		 * __invalidate_device().  blkdev_put() acquires
1301 		 * bd_mutex and can't be called under s_umount.  Drop
1302 		 * s_umount temporarily.  This is safe as we're
1303 		 * holding an active reference.
1304 		 */
1305 		up_write(&s->s_umount);
1306 		blkdev_put(bdev, mode);
1307 		down_write(&s->s_umount);
1308 	}
1309 
1310 	memset(&args, 0, sizeof(args));
1311 	args.ar_quota = GFS2_QUOTA_DEFAULT;
1312 	args.ar_data = GFS2_DATA_DEFAULT;
1313 	args.ar_commit = 30;
1314 	args.ar_statfs_quantum = 30;
1315 	args.ar_quota_quantum = 60;
1316 	args.ar_errors = GFS2_ERRORS_DEFAULT;
1317 
1318 	error = gfs2_mount_args(&args, data);
1319 	if (error) {
1320 		pr_warn("can't parse mount arguments\n");
1321 		goto error_super;
1322 	}
1323 
1324 	if (s->s_root) {
1325 		error = -EBUSY;
1326 		if ((flags ^ s->s_flags) & MS_RDONLY)
1327 			goto error_super;
1328 	} else {
1329 		char b[BDEVNAME_SIZE];
1330 
1331 		s->s_mode = mode;
1332 		strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1333 		sb_set_blocksize(s, block_size(bdev));
1334 		error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1335 		if (error)
1336 			goto error_super;
1337 		s->s_flags |= MS_ACTIVE;
1338 		bdev->bd_super = s;
1339 	}
1340 
1341 	sdp = s->s_fs_info;
1342 	if (args.ar_meta)
1343 		return dget(sdp->sd_master_dir);
1344 	else
1345 		return dget(sdp->sd_root_dir);
1346 
1347 error_super:
1348 	deactivate_locked_super(s);
1349 	return ERR_PTR(error);
1350 error_bdev:
1351 	blkdev_put(bdev, mode);
1352 	return ERR_PTR(error);
1353 }
1354 
1355 static int set_meta_super(struct super_block *s, void *ptr)
1356 {
1357 	return -EINVAL;
1358 }
1359 
1360 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1361 			int flags, const char *dev_name, void *data)
1362 {
1363 	struct super_block *s;
1364 	struct gfs2_sbd *sdp;
1365 	struct path path;
1366 	int error;
1367 
1368 	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1369 	if (error) {
1370 		pr_warn("path_lookup on %s returned error %d\n",
1371 			dev_name, error);
1372 		return ERR_PTR(error);
1373 	}
1374 	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1375 		 path.dentry->d_inode->i_sb->s_bdev);
1376 	path_put(&path);
1377 	if (IS_ERR(s)) {
1378 		pr_warn("gfs2 mount does not exist\n");
1379 		return ERR_CAST(s);
1380 	}
1381 	if ((flags ^ s->s_flags) & MS_RDONLY) {
1382 		deactivate_locked_super(s);
1383 		return ERR_PTR(-EBUSY);
1384 	}
1385 	sdp = s->s_fs_info;
1386 	return dget(sdp->sd_master_dir);
1387 }
1388 
1389 static void gfs2_kill_sb(struct super_block *sb)
1390 {
1391 	struct gfs2_sbd *sdp = sb->s_fs_info;
1392 
1393 	if (sdp == NULL) {
1394 		kill_block_super(sb);
1395 		return;
1396 	}
1397 
1398 	gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1399 	dput(sdp->sd_root_dir);
1400 	dput(sdp->sd_master_dir);
1401 	sdp->sd_root_dir = NULL;
1402 	sdp->sd_master_dir = NULL;
1403 	shrink_dcache_sb(sb);
1404 	gfs2_delete_debugfs_file(sdp);
1405 	free_percpu(sdp->sd_lkstats);
1406 	kill_block_super(sb);
1407 }
1408 
1409 struct file_system_type gfs2_fs_type = {
1410 	.name = "gfs2",
1411 	.fs_flags = FS_REQUIRES_DEV,
1412 	.mount = gfs2_mount,
1413 	.kill_sb = gfs2_kill_sb,
1414 	.owner = THIS_MODULE,
1415 };
1416 MODULE_ALIAS_FS("gfs2");
1417 
1418 struct file_system_type gfs2meta_fs_type = {
1419 	.name = "gfs2meta",
1420 	.fs_flags = FS_REQUIRES_DEV,
1421 	.mount = gfs2_mount_meta,
1422 	.owner = THIS_MODULE,
1423 };
1424 MODULE_ALIAS_FS("gfs2meta");
1425