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 
45 #define DO 0
46 #define UNDO 1
47 
48 /**
49  * gfs2_tune_init - Fill a gfs2_tune structure with default values
50  * @gt: tune
51  *
52  */
53 
gfs2_tune_init(struct gfs2_tune * gt)54 static void gfs2_tune_init(struct gfs2_tune *gt)
55 {
56 	spin_lock_init(&gt->gt_spin);
57 
58 	gt->gt_quota_warn_period = 10;
59 	gt->gt_quota_scale_num = 1;
60 	gt->gt_quota_scale_den = 1;
61 	gt->gt_new_files_jdata = 0;
62 	gt->gt_max_readahead = BIT(18);
63 	gt->gt_complain_secs = 10;
64 }
65 
init_sbd(struct super_block * sb)66 static struct gfs2_sbd *init_sbd(struct super_block *sb)
67 {
68 	struct gfs2_sbd *sdp;
69 	struct address_space *mapping;
70 
71 	sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
72 	if (!sdp)
73 		return NULL;
74 
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 	sb->s_fs_info = sdp;
82 
83 	set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
84 	gfs2_tune_init(&sdp->sd_tune);
85 
86 	init_waitqueue_head(&sdp->sd_glock_wait);
87 	atomic_set(&sdp->sd_glock_disposal, 0);
88 	init_completion(&sdp->sd_locking_init);
89 	init_completion(&sdp->sd_wdack);
90 	spin_lock_init(&sdp->sd_statfs_spin);
91 
92 	spin_lock_init(&sdp->sd_rindex_spin);
93 	sdp->sd_rindex_tree.rb_node = NULL;
94 
95 	INIT_LIST_HEAD(&sdp->sd_jindex_list);
96 	spin_lock_init(&sdp->sd_jindex_spin);
97 	mutex_init(&sdp->sd_jindex_mutex);
98 	init_completion(&sdp->sd_journal_ready);
99 
100 	INIT_LIST_HEAD(&sdp->sd_quota_list);
101 	mutex_init(&sdp->sd_quota_mutex);
102 	mutex_init(&sdp->sd_quota_sync_mutex);
103 	init_waitqueue_head(&sdp->sd_quota_wait);
104 	INIT_LIST_HEAD(&sdp->sd_trunc_list);
105 	spin_lock_init(&sdp->sd_trunc_lock);
106 	spin_lock_init(&sdp->sd_bitmap_lock);
107 
108 	mapping = &sdp->sd_aspace;
109 
110 	address_space_init_once(mapping);
111 	mapping->a_ops = &gfs2_rgrp_aops;
112 	mapping->host = sb->s_bdev->bd_inode;
113 	mapping->flags = 0;
114 	mapping_set_gfp_mask(mapping, GFP_NOFS);
115 	mapping->private_data = NULL;
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 	atomic_set(&sdp->sd_reserving_log, 0);
133 	init_waitqueue_head(&sdp->sd_reserving_log_wait);
134 	init_waitqueue_head(&sdp->sd_log_flush_wait);
135 	atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
136 	mutex_init(&sdp->sd_freeze_mutex);
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 
gfs2_check_sb(struct gfs2_sbd * sdp,int silent)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 (sb->sb_fs_format != GFS2_FORMAT_FS ||
165 	    sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
166 		fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
167 		return -EINVAL;
168 	}
169 
170 	if (sb->sb_bsize < 512 || sb->sb_bsize > PAGE_SIZE ||
171 	    (sb->sb_bsize & (sb->sb_bsize - 1))) {
172 		pr_warn("Invalid superblock size\n");
173 		return -EINVAL;
174 	}
175 	if (sb->sb_bsize_shift != ffs(sb->sb_bsize) - 1) {
176 		pr_warn("Invalid block size shift\n");
177 		return -EINVAL;
178 	}
179 	return 0;
180 }
181 
end_bio_io_page(struct bio * bio)182 static void end_bio_io_page(struct bio *bio)
183 {
184 	struct page *page = bio->bi_private;
185 
186 	if (!bio->bi_status)
187 		SetPageUptodate(page);
188 	else
189 		pr_warn("error %d reading superblock\n", bio->bi_status);
190 	unlock_page(page);
191 }
192 
gfs2_sb_in(struct gfs2_sbd * sdp,const void * buf)193 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
194 {
195 	struct gfs2_sb_host *sb = &sdp->sd_sb;
196 	struct super_block *s = sdp->sd_vfs;
197 	const struct gfs2_sb *str = buf;
198 
199 	sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
200 	sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
201 	sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
202 	sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
203 	sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
204 	sb->sb_bsize = be32_to_cpu(str->sb_bsize);
205 	sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
206 	sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
207 	sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
208 	sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
209 	sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
210 
211 	memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
212 	memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
213 	memcpy(&s->s_uuid, str->sb_uuid, 16);
214 }
215 
216 /**
217  * gfs2_read_super - Read the gfs2 super block from disk
218  * @sdp: The GFS2 super block
219  * @sector: The location of the super block
220  * @error: The error code to return
221  *
222  * This uses the bio functions to read the super block from disk
223  * because we want to be 100% sure that we never read cached data.
224  * A super block is read twice only during each GFS2 mount and is
225  * never written to by the filesystem. The first time its read no
226  * locks are held, and the only details which are looked at are those
227  * relating to the locking protocol. Once locking is up and working,
228  * the sb is read again under the lock to establish the location of
229  * the master directory (contains pointers to journals etc) and the
230  * root directory.
231  *
232  * Returns: 0 on success or error
233  */
234 
gfs2_read_super(struct gfs2_sbd * sdp,sector_t sector,int silent)235 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
236 {
237 	struct super_block *sb = sdp->sd_vfs;
238 	struct gfs2_sb *p;
239 	struct page *page;
240 	struct bio *bio;
241 
242 	page = alloc_page(GFP_NOFS);
243 	if (unlikely(!page))
244 		return -ENOMEM;
245 
246 	ClearPageUptodate(page);
247 	ClearPageDirty(page);
248 	lock_page(page);
249 
250 	bio = bio_alloc(GFP_NOFS, 1);
251 	bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
252 	bio_set_dev(bio, sb->s_bdev);
253 	bio_add_page(bio, page, PAGE_SIZE, 0);
254 
255 	bio->bi_end_io = end_bio_io_page;
256 	bio->bi_private = page;
257 	bio_set_op_attrs(bio, REQ_OP_READ, REQ_META);
258 	submit_bio(bio);
259 	wait_on_page_locked(page);
260 	bio_put(bio);
261 	if (!PageUptodate(page)) {
262 		__free_page(page);
263 		return -EIO;
264 	}
265 	p = kmap(page);
266 	gfs2_sb_in(sdp, p);
267 	kunmap(page);
268 	__free_page(page);
269 	return gfs2_check_sb(sdp, silent);
270 }
271 
272 /**
273  * gfs2_read_sb - Read super block
274  * @sdp: The GFS2 superblock
275  * @silent: Don't print message if mount fails
276  *
277  */
278 
gfs2_read_sb(struct gfs2_sbd * sdp,int silent)279 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
280 {
281 	u32 hash_blocks, ind_blocks, leaf_blocks;
282 	u32 tmp_blocks;
283 	unsigned int x;
284 	int error;
285 
286 	error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
287 	if (error) {
288 		if (!silent)
289 			fs_err(sdp, "can't read superblock\n");
290 		return error;
291 	}
292 
293 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
294 			       GFS2_BASIC_BLOCK_SHIFT;
295 	sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
296 	sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
297 			  sizeof(struct gfs2_dinode)) / sizeof(u64);
298 	sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
299 			  sizeof(struct gfs2_meta_header)) / sizeof(u64);
300 	sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
301 	sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
302 	sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
303 	sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
304 	sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
305 				sizeof(struct gfs2_meta_header)) /
306 			        sizeof(struct gfs2_quota_change);
307 	sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
308 				     sizeof(struct gfs2_meta_header))
309 		* GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
310 
311 	/* Compute maximum reservation required to add a entry to a directory */
312 
313 	hash_blocks = DIV_ROUND_UP(sizeof(u64) * BIT(GFS2_DIR_MAX_DEPTH),
314 			     sdp->sd_jbsize);
315 
316 	ind_blocks = 0;
317 	for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
318 		tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
319 		ind_blocks += tmp_blocks;
320 	}
321 
322 	leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
323 
324 	sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
325 
326 	sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
327 				sizeof(struct gfs2_dinode);
328 	sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
329 	for (x = 2;; x++) {
330 		u64 space, d;
331 		u32 m;
332 
333 		space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
334 		d = space;
335 		m = do_div(d, sdp->sd_inptrs);
336 
337 		if (d != sdp->sd_heightsize[x - 1] || m)
338 			break;
339 		sdp->sd_heightsize[x] = space;
340 	}
341 	sdp->sd_max_height = x;
342 	sdp->sd_heightsize[x] = ~0;
343 	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
344 
345 	sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
346 				      sizeof(struct gfs2_leaf)) /
347 				     GFS2_MIN_DIRENT_SIZE;
348 	return 0;
349 }
350 
init_names(struct gfs2_sbd * sdp,int silent)351 static int init_names(struct gfs2_sbd *sdp, int silent)
352 {
353 	char *proto, *table;
354 	int error = 0;
355 
356 	proto = sdp->sd_args.ar_lockproto;
357 	table = sdp->sd_args.ar_locktable;
358 
359 	/*  Try to autodetect  */
360 
361 	if (!proto[0] || !table[0]) {
362 		error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
363 		if (error)
364 			return error;
365 
366 		if (!proto[0])
367 			proto = sdp->sd_sb.sb_lockproto;
368 		if (!table[0])
369 			table = sdp->sd_sb.sb_locktable;
370 	}
371 
372 	if (!table[0])
373 		table = sdp->sd_vfs->s_id;
374 
375 	BUILD_BUG_ON(GFS2_LOCKNAME_LEN > GFS2_FSNAME_LEN);
376 
377 	strscpy(sdp->sd_proto_name, proto, GFS2_LOCKNAME_LEN);
378 	strscpy(sdp->sd_table_name, table, GFS2_LOCKNAME_LEN);
379 
380 	table = sdp->sd_table_name;
381 	while ((table = strchr(table, '/')))
382 		*table = '_';
383 
384 	return error;
385 }
386 
init_locking(struct gfs2_sbd * sdp,struct gfs2_holder * mount_gh,int undo)387 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
388 			int undo)
389 {
390 	int error = 0;
391 
392 	if (undo)
393 		goto fail_trans;
394 
395 	error = gfs2_glock_nq_num(sdp,
396 				  GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
397 				  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
398 				  mount_gh);
399 	if (error) {
400 		fs_err(sdp, "can't acquire mount glock: %d\n", error);
401 		goto fail;
402 	}
403 
404 	error = gfs2_glock_nq_num(sdp,
405 				  GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
406 				  LM_ST_SHARED,
407 				  LM_FLAG_NOEXP | GL_EXACT,
408 				  &sdp->sd_live_gh);
409 	if (error) {
410 		fs_err(sdp, "can't acquire live glock: %d\n", error);
411 		goto fail_mount;
412 	}
413 
414 	error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
415 			       CREATE, &sdp->sd_rename_gl);
416 	if (error) {
417 		fs_err(sdp, "can't create rename glock: %d\n", error);
418 		goto fail_live;
419 	}
420 
421 	error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
422 			       CREATE, &sdp->sd_freeze_gl);
423 	if (error) {
424 		fs_err(sdp, "can't create transaction glock: %d\n", error);
425 		goto fail_rename;
426 	}
427 
428 	return 0;
429 
430 fail_trans:
431 	gfs2_glock_put(sdp->sd_freeze_gl);
432 fail_rename:
433 	gfs2_glock_put(sdp->sd_rename_gl);
434 fail_live:
435 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
436 fail_mount:
437 	gfs2_glock_dq_uninit(mount_gh);
438 fail:
439 	return error;
440 }
441 
gfs2_lookup_root(struct super_block * sb,struct dentry ** dptr,u64 no_addr,const char * name)442 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
443 			    u64 no_addr, const char *name)
444 {
445 	struct gfs2_sbd *sdp = sb->s_fs_info;
446 	struct dentry *dentry;
447 	struct inode *inode;
448 
449 	inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0,
450 				  GFS2_BLKST_FREE /* ignore */);
451 	if (IS_ERR(inode)) {
452 		fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
453 		return PTR_ERR(inode);
454 	}
455 	dentry = d_make_root(inode);
456 	if (!dentry) {
457 		fs_err(sdp, "can't alloc %s dentry\n", name);
458 		return -ENOMEM;
459 	}
460 	*dptr = dentry;
461 	return 0;
462 }
463 
init_sb(struct gfs2_sbd * sdp,int silent)464 static int init_sb(struct gfs2_sbd *sdp, int silent)
465 {
466 	struct super_block *sb = sdp->sd_vfs;
467 	struct gfs2_holder sb_gh;
468 	u64 no_addr;
469 	int ret;
470 
471 	ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
472 				LM_ST_SHARED, 0, &sb_gh);
473 	if (ret) {
474 		fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
475 		return ret;
476 	}
477 
478 	ret = gfs2_read_sb(sdp, silent);
479 	if (ret) {
480 		fs_err(sdp, "can't read superblock: %d\n", ret);
481 		goto out;
482 	}
483 
484 	/* Set up the buffer cache and SB for real */
485 	if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
486 		ret = -EINVAL;
487 		fs_err(sdp, "FS block size (%u) is too small for device "
488 		       "block size (%u)\n",
489 		       sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
490 		goto out;
491 	}
492 	if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
493 		ret = -EINVAL;
494 		fs_err(sdp, "FS block size (%u) is too big for machine "
495 		       "page size (%u)\n",
496 		       sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
497 		goto out;
498 	}
499 	sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
500 
501 	/* Get the root inode */
502 	no_addr = sdp->sd_sb.sb_root_dir.no_addr;
503 	ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
504 	if (ret)
505 		goto out;
506 
507 	/* Get the master inode */
508 	no_addr = sdp->sd_sb.sb_master_dir.no_addr;
509 	ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
510 	if (ret) {
511 		dput(sdp->sd_root_dir);
512 		goto out;
513 	}
514 	sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
515 out:
516 	gfs2_glock_dq_uninit(&sb_gh);
517 	return ret;
518 }
519 
gfs2_others_may_mount(struct gfs2_sbd * sdp)520 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
521 {
522 	char *message = "FIRSTMOUNT=Done";
523 	char *envp[] = { message, NULL };
524 
525 	fs_info(sdp, "first mount done, others may mount\n");
526 
527 	if (sdp->sd_lockstruct.ls_ops->lm_first_done)
528 		sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
529 
530 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
531 }
532 
533 /**
534  * gfs2_jindex_hold - Grab a lock on the jindex
535  * @sdp: The GFS2 superblock
536  * @ji_gh: the holder for the jindex glock
537  *
538  * Returns: errno
539  */
540 
gfs2_jindex_hold(struct gfs2_sbd * sdp,struct gfs2_holder * ji_gh)541 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
542 {
543 	struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
544 	struct qstr name;
545 	char buf[20];
546 	struct gfs2_jdesc *jd;
547 	int error;
548 
549 	name.name = buf;
550 
551 	mutex_lock(&sdp->sd_jindex_mutex);
552 
553 	for (;;) {
554 		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
555 		if (error)
556 			break;
557 
558 		name.len = sprintf(buf, "journal%u", sdp->sd_journals);
559 		name.hash = gfs2_disk_hash(name.name, name.len);
560 
561 		error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
562 		if (error == -ENOENT) {
563 			error = 0;
564 			break;
565 		}
566 
567 		gfs2_glock_dq_uninit(ji_gh);
568 
569 		if (error)
570 			break;
571 
572 		error = -ENOMEM;
573 		jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
574 		if (!jd)
575 			break;
576 
577 		INIT_LIST_HEAD(&jd->extent_list);
578 		INIT_LIST_HEAD(&jd->jd_revoke_list);
579 
580 		INIT_WORK(&jd->jd_work, gfs2_recover_func);
581 		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
582 		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
583 			if (!jd->jd_inode)
584 				error = -ENOENT;
585 			else
586 				error = PTR_ERR(jd->jd_inode);
587 			kfree(jd);
588 			break;
589 		}
590 
591 		spin_lock(&sdp->sd_jindex_spin);
592 		jd->jd_jid = sdp->sd_journals++;
593 		list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
594 		spin_unlock(&sdp->sd_jindex_spin);
595 	}
596 
597 	mutex_unlock(&sdp->sd_jindex_mutex);
598 
599 	return error;
600 }
601 
602 /**
603  * check_journal_clean - Make sure a journal is clean for a spectator mount
604  * @sdp: The GFS2 superblock
605  * @jd: The journal descriptor
606  *
607  * Returns: 0 if the journal is clean or locked, else an error
608  */
check_journal_clean(struct gfs2_sbd * sdp,struct gfs2_jdesc * jd)609 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
610 {
611 	int error;
612 	struct gfs2_holder j_gh;
613 	struct gfs2_log_header_host head;
614 	struct gfs2_inode *ip;
615 
616 	ip = GFS2_I(jd->jd_inode);
617 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
618 				   GL_EXACT | GL_NOCACHE, &j_gh);
619 	if (error) {
620 		fs_err(sdp, "Error locking journal for spectator mount.\n");
621 		return -EPERM;
622 	}
623 	error = gfs2_jdesc_check(jd);
624 	if (error) {
625 		fs_err(sdp, "Error checking journal for spectator mount.\n");
626 		goto out_unlock;
627 	}
628 	error = gfs2_find_jhead(jd, &head);
629 	if (error) {
630 		fs_err(sdp, "Error parsing journal for spectator mount.\n");
631 		goto out_unlock;
632 	}
633 	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
634 		error = -EPERM;
635 		fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
636 		       "must not be a spectator.\n", jd->jd_jid);
637 	}
638 
639 out_unlock:
640 	gfs2_glock_dq_uninit(&j_gh);
641 	return error;
642 }
643 
init_journal(struct gfs2_sbd * sdp,int undo)644 static int init_journal(struct gfs2_sbd *sdp, int undo)
645 {
646 	struct inode *master = d_inode(sdp->sd_master_dir);
647 	struct gfs2_holder ji_gh;
648 	struct gfs2_inode *ip;
649 	int jindex = 1;
650 	int error = 0;
651 
652 	if (undo) {
653 		jindex = 0;
654 		goto fail_jinode_gh;
655 	}
656 
657 	sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
658 	if (IS_ERR(sdp->sd_jindex)) {
659 		fs_err(sdp, "can't lookup journal index: %d\n", error);
660 		return PTR_ERR(sdp->sd_jindex);
661 	}
662 
663 	/* Load in the journal index special file */
664 
665 	error = gfs2_jindex_hold(sdp, &ji_gh);
666 	if (error) {
667 		fs_err(sdp, "can't read journal index: %d\n", error);
668 		goto fail;
669 	}
670 
671 	error = -EUSERS;
672 	if (!gfs2_jindex_size(sdp)) {
673 		fs_err(sdp, "no journals!\n");
674 		goto fail_jindex;
675 	}
676 
677 	atomic_set(&sdp->sd_log_blks_needed, 0);
678 	if (sdp->sd_args.ar_spectator) {
679 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
680 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
681 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
682 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
683 	} else {
684 		if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
685 			fs_err(sdp, "can't mount journal #%u\n",
686 			       sdp->sd_lockstruct.ls_jid);
687 			fs_err(sdp, "there are only %u journals (0 - %u)\n",
688 			       gfs2_jindex_size(sdp),
689 			       gfs2_jindex_size(sdp) - 1);
690 			goto fail_jindex;
691 		}
692 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
693 
694 		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
695 					  &gfs2_journal_glops,
696 					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
697 					  &sdp->sd_journal_gh);
698 		if (error) {
699 			fs_err(sdp, "can't acquire journal glock: %d\n", error);
700 			goto fail_jindex;
701 		}
702 
703 		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
704 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
705 					   LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
706 					   &sdp->sd_jinode_gh);
707 		if (error) {
708 			fs_err(sdp, "can't acquire journal inode glock: %d\n",
709 			       error);
710 			goto fail_journal_gh;
711 		}
712 
713 		error = gfs2_jdesc_check(sdp->sd_jdesc);
714 		if (error) {
715 			fs_err(sdp, "my journal (%u) is bad: %d\n",
716 			       sdp->sd_jdesc->jd_jid, error);
717 			goto fail_jinode_gh;
718 		}
719 		atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
720 		atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
721 		atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
722 
723 		/* Map the extents for this journal's blocks */
724 		gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
725 	}
726 	trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
727 
728 	if (sdp->sd_lockstruct.ls_first) {
729 		unsigned int x;
730 		for (x = 0; x < sdp->sd_journals; x++) {
731 			struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
732 
733 			if (sdp->sd_args.ar_spectator) {
734 				error = check_journal_clean(sdp, jd);
735 				if (error)
736 					goto fail_jinode_gh;
737 				continue;
738 			}
739 			error = gfs2_recover_journal(jd, true);
740 			if (error) {
741 				fs_err(sdp, "error recovering journal %u: %d\n",
742 				       x, error);
743 				goto fail_jinode_gh;
744 			}
745 		}
746 
747 		gfs2_others_may_mount(sdp);
748 	} else if (!sdp->sd_args.ar_spectator) {
749 		error = gfs2_recover_journal(sdp->sd_jdesc, true);
750 		if (error) {
751 			fs_err(sdp, "error recovering my journal: %d\n", error);
752 			goto fail_jinode_gh;
753 		}
754 	}
755 
756 	sdp->sd_log_idle = 1;
757 	set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
758 	gfs2_glock_dq_uninit(&ji_gh);
759 	jindex = 0;
760 	INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
761 	return 0;
762 
763 fail_jinode_gh:
764 	if (!sdp->sd_args.ar_spectator)
765 		gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
766 fail_journal_gh:
767 	if (!sdp->sd_args.ar_spectator)
768 		gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
769 fail_jindex:
770 	gfs2_jindex_free(sdp);
771 	if (jindex)
772 		gfs2_glock_dq_uninit(&ji_gh);
773 fail:
774 	iput(sdp->sd_jindex);
775 	return error;
776 }
777 
778 static struct lock_class_key gfs2_quota_imutex_key;
779 
init_inodes(struct gfs2_sbd * sdp,int undo)780 static int init_inodes(struct gfs2_sbd *sdp, int undo)
781 {
782 	int error = 0;
783 	struct inode *master = d_inode(sdp->sd_master_dir);
784 
785 	if (undo)
786 		goto fail_qinode;
787 
788 	error = init_journal(sdp, undo);
789 	complete_all(&sdp->sd_journal_ready);
790 	if (error)
791 		goto fail;
792 
793 	/* Read in the master statfs inode */
794 	sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
795 	if (IS_ERR(sdp->sd_statfs_inode)) {
796 		error = PTR_ERR(sdp->sd_statfs_inode);
797 		fs_err(sdp, "can't read in statfs inode: %d\n", error);
798 		goto fail_journal;
799 	}
800 
801 	/* Read in the resource index inode */
802 	sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
803 	if (IS_ERR(sdp->sd_rindex)) {
804 		error = PTR_ERR(sdp->sd_rindex);
805 		fs_err(sdp, "can't get resource index inode: %d\n", error);
806 		goto fail_statfs;
807 	}
808 	sdp->sd_rindex_uptodate = 0;
809 
810 	/* Read in the quota inode */
811 	sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
812 	if (IS_ERR(sdp->sd_quota_inode)) {
813 		error = PTR_ERR(sdp->sd_quota_inode);
814 		fs_err(sdp, "can't get quota file inode: %d\n", error);
815 		goto fail_rindex;
816 	}
817 	/*
818 	 * i_rwsem on quota files is special. Since this inode is hidden system
819 	 * file, we are safe to define locking ourselves.
820 	 */
821 	lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
822 			  &gfs2_quota_imutex_key);
823 
824 	error = gfs2_rindex_update(sdp);
825 	if (error)
826 		goto fail_qinode;
827 
828 	return 0;
829 
830 fail_qinode:
831 	iput(sdp->sd_quota_inode);
832 fail_rindex:
833 	gfs2_clear_rgrpd(sdp);
834 	iput(sdp->sd_rindex);
835 fail_statfs:
836 	iput(sdp->sd_statfs_inode);
837 fail_journal:
838 	init_journal(sdp, UNDO);
839 fail:
840 	return error;
841 }
842 
init_per_node(struct gfs2_sbd * sdp,int undo)843 static int init_per_node(struct gfs2_sbd *sdp, int undo)
844 {
845 	struct inode *pn = NULL;
846 	char buf[30];
847 	int error = 0;
848 	struct gfs2_inode *ip;
849 	struct inode *master = d_inode(sdp->sd_master_dir);
850 
851 	if (sdp->sd_args.ar_spectator)
852 		return 0;
853 
854 	if (undo)
855 		goto fail_qc_gh;
856 
857 	pn = gfs2_lookup_simple(master, "per_node");
858 	if (IS_ERR(pn)) {
859 		error = PTR_ERR(pn);
860 		fs_err(sdp, "can't find per_node directory: %d\n", error);
861 		return error;
862 	}
863 
864 	sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
865 	sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
866 	if (IS_ERR(sdp->sd_sc_inode)) {
867 		error = PTR_ERR(sdp->sd_sc_inode);
868 		fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
869 		goto fail;
870 	}
871 
872 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
873 	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
874 	if (IS_ERR(sdp->sd_qc_inode)) {
875 		error = PTR_ERR(sdp->sd_qc_inode);
876 		fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
877 		goto fail_ut_i;
878 	}
879 
880 	iput(pn);
881 	pn = NULL;
882 
883 	ip = GFS2_I(sdp->sd_sc_inode);
884 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
885 				   &sdp->sd_sc_gh);
886 	if (error) {
887 		fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
888 		goto fail_qc_i;
889 	}
890 
891 	ip = GFS2_I(sdp->sd_qc_inode);
892 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
893 				   &sdp->sd_qc_gh);
894 	if (error) {
895 		fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
896 		goto fail_ut_gh;
897 	}
898 
899 	return 0;
900 
901 fail_qc_gh:
902 	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
903 fail_ut_gh:
904 	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
905 fail_qc_i:
906 	iput(sdp->sd_qc_inode);
907 fail_ut_i:
908 	iput(sdp->sd_sc_inode);
909 fail:
910 	iput(pn);
911 	return error;
912 }
913 
914 static const match_table_t nolock_tokens = {
915 	{ Opt_jid, "jid=%d", },
916 	{ Opt_err, NULL },
917 };
918 
919 static const struct lm_lockops nolock_ops = {
920 	.lm_proto_name = "lock_nolock",
921 	.lm_put_lock = gfs2_glock_free,
922 	.lm_tokens = &nolock_tokens,
923 };
924 
925 /**
926  * gfs2_lm_mount - mount a locking protocol
927  * @sdp: the filesystem
928  * @args: mount arguments
929  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
930  *
931  * Returns: errno
932  */
933 
gfs2_lm_mount(struct gfs2_sbd * sdp,int silent)934 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
935 {
936 	const struct lm_lockops *lm;
937 	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
938 	struct gfs2_args *args = &sdp->sd_args;
939 	const char *proto = sdp->sd_proto_name;
940 	const char *table = sdp->sd_table_name;
941 	char *o, *options;
942 	int ret;
943 
944 	if (!strcmp("lock_nolock", proto)) {
945 		lm = &nolock_ops;
946 		sdp->sd_args.ar_localflocks = 1;
947 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
948 	} else if (!strcmp("lock_dlm", proto)) {
949 		lm = &gfs2_dlm_ops;
950 #endif
951 	} else {
952 		pr_info("can't find protocol %s\n", proto);
953 		return -ENOENT;
954 	}
955 
956 	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
957 
958 	ls->ls_ops = lm;
959 	ls->ls_first = 1;
960 
961 	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
962 		substring_t tmp[MAX_OPT_ARGS];
963 		int token, option;
964 
965 		if (!o || !*o)
966 			continue;
967 
968 		token = match_token(o, *lm->lm_tokens, tmp);
969 		switch (token) {
970 		case Opt_jid:
971 			ret = match_int(&tmp[0], &option);
972 			if (ret || option < 0)
973 				goto hostdata_error;
974 			if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
975 				ls->ls_jid = option;
976 			break;
977 		case Opt_id:
978 		case Opt_nodir:
979 			/* Obsolete, but left for backward compat purposes */
980 			break;
981 		case Opt_first:
982 			ret = match_int(&tmp[0], &option);
983 			if (ret || (option != 0 && option != 1))
984 				goto hostdata_error;
985 			ls->ls_first = option;
986 			break;
987 		case Opt_err:
988 		default:
989 hostdata_error:
990 			fs_info(sdp, "unknown hostdata (%s)\n", o);
991 			return -EINVAL;
992 		}
993 	}
994 
995 	if (lm->lm_mount == NULL) {
996 		fs_info(sdp, "Now mounting FS...\n");
997 		complete_all(&sdp->sd_locking_init);
998 		return 0;
999 	}
1000 	ret = lm->lm_mount(sdp, table);
1001 	if (ret == 0)
1002 		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1003 	complete_all(&sdp->sd_locking_init);
1004 	return ret;
1005 }
1006 
gfs2_lm_unmount(struct gfs2_sbd * sdp)1007 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1008 {
1009 	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1010 	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1011 	    lm->lm_unmount)
1012 		lm->lm_unmount(sdp);
1013 }
1014 
wait_on_journal(struct gfs2_sbd * sdp)1015 static int wait_on_journal(struct gfs2_sbd *sdp)
1016 {
1017 	if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1018 		return 0;
1019 
1020 	return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1021 		? -EINTR : 0;
1022 }
1023 
gfs2_online_uevent(struct gfs2_sbd * sdp)1024 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1025 {
1026 	struct super_block *sb = sdp->sd_vfs;
1027 	char ro[20];
1028 	char spectator[20];
1029 	char *envp[] = { ro, spectator, NULL };
1030 	sprintf(ro, "RDONLY=%d", sb_rdonly(sb));
1031 	sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1032 	kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1033 }
1034 
1035 /**
1036  * fill_super - Read in superblock
1037  * @sb: The VFS superblock
1038  * @data: Mount options
1039  * @silent: Don't complain if it's not a GFS2 filesystem
1040  *
1041  * Returns: errno
1042  */
1043 
fill_super(struct super_block * sb,struct gfs2_args * args,int silent)1044 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1045 {
1046 	struct gfs2_sbd *sdp;
1047 	struct gfs2_holder mount_gh;
1048 	int error;
1049 
1050 	sdp = init_sbd(sb);
1051 	if (!sdp) {
1052 		pr_warn("can't alloc struct gfs2_sbd\n");
1053 		return -ENOMEM;
1054 	}
1055 	sdp->sd_args = *args;
1056 
1057 	if (sdp->sd_args.ar_spectator) {
1058                 sb->s_flags |= SB_RDONLY;
1059 		set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1060 	}
1061 	if (sdp->sd_args.ar_posix_acl)
1062 		sb->s_flags |= SB_POSIXACL;
1063 	if (sdp->sd_args.ar_nobarrier)
1064 		set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1065 
1066 	sb->s_flags |= SB_NOSEC;
1067 	sb->s_magic = GFS2_MAGIC;
1068 	sb->s_op = &gfs2_super_ops;
1069 	sb->s_d_op = &gfs2_dops;
1070 	sb->s_export_op = &gfs2_export_ops;
1071 	sb->s_xattr = gfs2_xattr_handlers;
1072 	sb->s_qcop = &gfs2_quotactl_ops;
1073 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1074 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1075 	sb->s_time_gran = 1;
1076 	sb->s_maxbytes = MAX_LFS_FILESIZE;
1077 
1078 	/* Set up the buffer cache and fill in some fake block size values
1079 	   to allow us to read-in the on-disk superblock. */
1080 	sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1081 	sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1082 	sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1083                                GFS2_BASIC_BLOCK_SHIFT;
1084 	sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
1085 
1086 	sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1087 	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1088 	if (sdp->sd_args.ar_statfs_quantum) {
1089 		sdp->sd_tune.gt_statfs_slow = 0;
1090 		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1091 	} else {
1092 		sdp->sd_tune.gt_statfs_slow = 1;
1093 		sdp->sd_tune.gt_statfs_quantum = 30;
1094 	}
1095 
1096 	error = init_names(sdp, silent);
1097 	if (error) {
1098 		/* In this case, we haven't initialized sysfs, so we have to
1099 		   manually free the sdp. */
1100 		free_percpu(sdp->sd_lkstats);
1101 		kfree(sdp);
1102 		sb->s_fs_info = NULL;
1103 		return error;
1104 	}
1105 
1106 	snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s", sdp->sd_table_name);
1107 
1108 	error = gfs2_sys_fs_add(sdp);
1109 	/*
1110 	 * If we hit an error here, gfs2_sys_fs_add will have called function
1111 	 * kobject_put which causes the sysfs usage count to go to zero, which
1112 	 * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1113 	 * Subsequent error paths here will call gfs2_sys_fs_del, which also
1114 	 * kobject_put to free sdp.
1115 	 */
1116 	if (error)
1117 		return error;
1118 
1119 	gfs2_create_debugfs_file(sdp);
1120 
1121 	error = gfs2_lm_mount(sdp, silent);
1122 	if (error)
1123 		goto fail_debug;
1124 
1125 	error = init_locking(sdp, &mount_gh, DO);
1126 	if (error)
1127 		goto fail_lm;
1128 
1129 	error = init_sb(sdp, silent);
1130 	if (error)
1131 		goto fail_locking;
1132 
1133 	error = wait_on_journal(sdp);
1134 	if (error)
1135 		goto fail_sb;
1136 
1137 	/*
1138 	 * If user space has failed to join the cluster or some similar
1139 	 * failure has occurred, then the journal id will contain a
1140 	 * negative (error) number. This will then be returned to the
1141 	 * caller (of the mount syscall). We do this even for spectator
1142 	 * mounts (which just write a jid of 0 to indicate "ok" even though
1143 	 * the jid is unused in the spectator case)
1144 	 */
1145 	if (sdp->sd_lockstruct.ls_jid < 0) {
1146 		error = sdp->sd_lockstruct.ls_jid;
1147 		sdp->sd_lockstruct.ls_jid = 0;
1148 		goto fail_sb;
1149 	}
1150 
1151 	if (sdp->sd_args.ar_spectator)
1152 		snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.s",
1153 			 sdp->sd_table_name);
1154 	else
1155 		snprintf(sdp->sd_fsname, sizeof(sdp->sd_fsname), "%s.%u",
1156 			 sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1157 
1158 	error = init_inodes(sdp, DO);
1159 	if (error)
1160 		goto fail_sb;
1161 
1162 	error = init_per_node(sdp, DO);
1163 	if (error)
1164 		goto fail_inodes;
1165 
1166 	error = gfs2_statfs_init(sdp);
1167 	if (error) {
1168 		fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1169 		goto fail_per_node;
1170 	}
1171 
1172 	if (sb_rdonly(sb)) {
1173 		struct gfs2_holder freeze_gh;
1174 
1175 		error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED,
1176 					   GL_EXACT, &freeze_gh);
1177 		if (error) {
1178 			fs_err(sdp, "can't make FS RO: %d\n", error);
1179 			goto fail_per_node;
1180 		}
1181 		gfs2_glock_dq_uninit(&freeze_gh);
1182 	} else {
1183 		error = gfs2_make_fs_rw(sdp);
1184 		if (error) {
1185 			fs_err(sdp, "can't make FS RW: %d\n", error);
1186 			goto fail_per_node;
1187 		}
1188 	}
1189 
1190 	gfs2_glock_dq_uninit(&mount_gh);
1191 	gfs2_online_uevent(sdp);
1192 	return 0;
1193 
1194 fail_per_node:
1195 	init_per_node(sdp, UNDO);
1196 fail_inodes:
1197 	init_inodes(sdp, UNDO);
1198 fail_sb:
1199 	if (sdp->sd_root_dir)
1200 		dput(sdp->sd_root_dir);
1201 	if (sdp->sd_master_dir)
1202 		dput(sdp->sd_master_dir);
1203 	if (sb->s_root)
1204 		dput(sb->s_root);
1205 	sb->s_root = NULL;
1206 fail_locking:
1207 	init_locking(sdp, &mount_gh, UNDO);
1208 fail_lm:
1209 	complete_all(&sdp->sd_journal_ready);
1210 	gfs2_gl_hash_clear(sdp);
1211 	gfs2_lm_unmount(sdp);
1212 fail_debug:
1213 	gfs2_delete_debugfs_file(sdp);
1214 	free_percpu(sdp->sd_lkstats);
1215 	/* gfs2_sys_fs_del must be the last thing we do, since it causes
1216 	 * sysfs to call function gfs2_sbd_release, which frees sdp. */
1217 	gfs2_sys_fs_del(sdp);
1218 	sb->s_fs_info = NULL;
1219 	return error;
1220 }
1221 
set_gfs2_super(struct super_block * s,void * data)1222 static int set_gfs2_super(struct super_block *s, void *data)
1223 {
1224 	s->s_bdev = data;
1225 	s->s_dev = s->s_bdev->bd_dev;
1226 	s->s_bdi = bdi_get(s->s_bdev->bd_bdi);
1227 	return 0;
1228 }
1229 
test_gfs2_super(struct super_block * s,void * ptr)1230 static int test_gfs2_super(struct super_block *s, void *ptr)
1231 {
1232 	struct block_device *bdev = ptr;
1233 	return (bdev == s->s_bdev);
1234 }
1235 
1236 /**
1237  * gfs2_mount - Get the GFS2 superblock
1238  * @fs_type: The GFS2 filesystem type
1239  * @flags: Mount flags
1240  * @dev_name: The name of the device
1241  * @data: The mount arguments
1242  *
1243  * Q. Why not use get_sb_bdev() ?
1244  * A. We need to select one of two root directories to mount, independent
1245  *    of whether this is the initial, or subsequent, mount of this sb
1246  *
1247  * Returns: 0 or -ve on error
1248  */
1249 
gfs2_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1250 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1251 		       const char *dev_name, void *data)
1252 {
1253 	struct block_device *bdev;
1254 	struct super_block *s;
1255 	fmode_t mode = FMODE_READ | FMODE_EXCL;
1256 	int error;
1257 	struct gfs2_args args;
1258 	struct gfs2_sbd *sdp;
1259 
1260 	if (!(flags & SB_RDONLY))
1261 		mode |= FMODE_WRITE;
1262 
1263 	bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1264 	if (IS_ERR(bdev))
1265 		return ERR_CAST(bdev);
1266 
1267 	/*
1268 	 * once the super is inserted into the list by sget, s_umount
1269 	 * will protect the lockfs code from trying to start a snapshot
1270 	 * while we are mounting
1271 	 */
1272 	mutex_lock(&bdev->bd_fsfreeze_mutex);
1273 	if (bdev->bd_fsfreeze_count > 0) {
1274 		mutex_unlock(&bdev->bd_fsfreeze_mutex);
1275 		error = -EBUSY;
1276 		goto error_bdev;
1277 	}
1278 	s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1279 	mutex_unlock(&bdev->bd_fsfreeze_mutex);
1280 	error = PTR_ERR(s);
1281 	if (IS_ERR(s))
1282 		goto error_bdev;
1283 
1284 	if (s->s_root) {
1285 		/*
1286 		 * s_umount nests inside bd_mutex during
1287 		 * __invalidate_device().  blkdev_put() acquires
1288 		 * bd_mutex and can't be called under s_umount.  Drop
1289 		 * s_umount temporarily.  This is safe as we're
1290 		 * holding an active reference.
1291 		 */
1292 		up_write(&s->s_umount);
1293 		blkdev_put(bdev, mode);
1294 		down_write(&s->s_umount);
1295 	} else {
1296 		/* s_mode must be set before deactivate_locked_super calls */
1297 		s->s_mode = mode;
1298 	}
1299 
1300 	memset(&args, 0, sizeof(args));
1301 	args.ar_quota = GFS2_QUOTA_DEFAULT;
1302 	args.ar_data = GFS2_DATA_DEFAULT;
1303 	args.ar_commit = 30;
1304 	args.ar_statfs_quantum = 30;
1305 	args.ar_quota_quantum = 60;
1306 	args.ar_errors = GFS2_ERRORS_DEFAULT;
1307 
1308 	error = gfs2_mount_args(&args, data);
1309 	if (error) {
1310 		pr_warn("can't parse mount arguments\n");
1311 		goto error_super;
1312 	}
1313 
1314 	if (s->s_root) {
1315 		error = -EBUSY;
1316 		if ((flags ^ s->s_flags) & SB_RDONLY)
1317 			goto error_super;
1318 	} else {
1319 		snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1320 		sb_set_blocksize(s, block_size(bdev));
1321 		error = fill_super(s, &args, flags & SB_SILENT ? 1 : 0);
1322 		if (error)
1323 			goto error_super;
1324 		s->s_flags |= SB_ACTIVE;
1325 		bdev->bd_super = s;
1326 	}
1327 
1328 	sdp = s->s_fs_info;
1329 	if (args.ar_meta)
1330 		return dget(sdp->sd_master_dir);
1331 	else
1332 		return dget(sdp->sd_root_dir);
1333 
1334 error_super:
1335 	deactivate_locked_super(s);
1336 	return ERR_PTR(error);
1337 error_bdev:
1338 	blkdev_put(bdev, mode);
1339 	return ERR_PTR(error);
1340 }
1341 
set_meta_super(struct super_block * s,void * ptr)1342 static int set_meta_super(struct super_block *s, void *ptr)
1343 {
1344 	return -EINVAL;
1345 }
1346 
gfs2_mount_meta(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1347 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1348 			int flags, const char *dev_name, void *data)
1349 {
1350 	struct super_block *s;
1351 	struct gfs2_sbd *sdp;
1352 	struct path path;
1353 	int error;
1354 
1355 	if (!dev_name || !*dev_name)
1356 		return ERR_PTR(-EINVAL);
1357 
1358 	error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1359 	if (error) {
1360 		pr_warn("path_lookup on %s returned error %d\n",
1361 			dev_name, error);
1362 		return ERR_PTR(error);
1363 	}
1364 	s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1365 		 path.dentry->d_sb->s_bdev);
1366 	path_put(&path);
1367 	if (IS_ERR(s)) {
1368 		pr_warn("gfs2 mount does not exist\n");
1369 		return ERR_CAST(s);
1370 	}
1371 	if ((flags ^ s->s_flags) & SB_RDONLY) {
1372 		deactivate_locked_super(s);
1373 		return ERR_PTR(-EBUSY);
1374 	}
1375 	sdp = s->s_fs_info;
1376 	return dget(sdp->sd_master_dir);
1377 }
1378 
gfs2_kill_sb(struct super_block * sb)1379 static void gfs2_kill_sb(struct super_block *sb)
1380 {
1381 	struct gfs2_sbd *sdp = sb->s_fs_info;
1382 
1383 	if (sdp == NULL) {
1384 		kill_block_super(sb);
1385 		return;
1386 	}
1387 
1388 	gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_SYNC | GFS2_LFC_KILL_SB);
1389 	dput(sdp->sd_root_dir);
1390 	dput(sdp->sd_master_dir);
1391 	sdp->sd_root_dir = NULL;
1392 	sdp->sd_master_dir = NULL;
1393 	shrink_dcache_sb(sb);
1394 	free_percpu(sdp->sd_lkstats);
1395 	kill_block_super(sb);
1396 }
1397 
1398 struct file_system_type gfs2_fs_type = {
1399 	.name = "gfs2",
1400 	.fs_flags = FS_REQUIRES_DEV,
1401 	.mount = gfs2_mount,
1402 	.kill_sb = gfs2_kill_sb,
1403 	.owner = THIS_MODULE,
1404 };
1405 MODULE_ALIAS_FS("gfs2");
1406 
1407 struct file_system_type gfs2meta_fs_type = {
1408 	.name = "gfs2meta",
1409 	.fs_flags = FS_REQUIRES_DEV,
1410 	.mount = gfs2_mount_meta,
1411 	.owner = THIS_MODULE,
1412 };
1413 MODULE_ALIAS_FS("gfs2meta");
1414