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