gfs2: Convert to properly refcounting bdi
[sfrench/cifs-2.6.git] / fs / gfs2 / ops_fstype.c
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
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
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
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)
176 {
177         struct page *page = bio->bi_private;
178
179         if (!bio->bi_error)
180                 SetPageUptodate(page);
181         else
182                 pr_warn("error %d reading superblock\n", bio->bi_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         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
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_jheightsize[0] = sdp->sd_sb.sb_bsize -
339                                  sizeof(struct gfs2_dinode);
340         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
341         for (x = 2;; x++) {
342                 u64 space, d;
343                 u32 m;
344
345                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
346                 d = space;
347                 m = do_div(d, sdp->sd_inptrs);
348
349                 if (d != sdp->sd_jheightsize[x - 1] || m)
350                         break;
351                 sdp->sd_jheightsize[x] = space;
352         }
353         sdp->sd_max_jheight = x;
354         sdp->sd_jheightsize[x] = ~0;
355         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
356
357         sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
358                                       sizeof(struct gfs2_leaf)) /
359                                      GFS2_MIN_DIRENT_SIZE;
360         return 0;
361 }
362
363 static int init_names(struct gfs2_sbd *sdp, int silent)
364 {
365         char *proto, *table;
366         int error = 0;
367
368         proto = sdp->sd_args.ar_lockproto;
369         table = sdp->sd_args.ar_locktable;
370
371         /*  Try to autodetect  */
372
373         if (!proto[0] || !table[0]) {
374                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
375                 if (error)
376                         return error;
377
378                 if (!proto[0])
379                         proto = sdp->sd_sb.sb_lockproto;
380                 if (!table[0])
381                         table = sdp->sd_sb.sb_locktable;
382         }
383
384         if (!table[0])
385                 table = sdp->sd_vfs->s_id;
386
387         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
388         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
389
390         table = sdp->sd_table_name;
391         while ((table = strchr(table, '/')))
392                 *table = '_';
393
394         return error;
395 }
396
397 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
398                         int undo)
399 {
400         int error = 0;
401
402         if (undo)
403                 goto fail_trans;
404
405         error = gfs2_glock_nq_num(sdp,
406                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
407                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
408                                   mount_gh);
409         if (error) {
410                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
411                 goto fail;
412         }
413
414         error = gfs2_glock_nq_num(sdp,
415                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
416                                   LM_ST_SHARED,
417                                   LM_FLAG_NOEXP | GL_EXACT,
418                                   &sdp->sd_live_gh);
419         if (error) {
420                 fs_err(sdp, "can't acquire live glock: %d\n", error);
421                 goto fail_mount;
422         }
423
424         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
425                                CREATE, &sdp->sd_rename_gl);
426         if (error) {
427                 fs_err(sdp, "can't create rename glock: %d\n", error);
428                 goto fail_live;
429         }
430
431         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
432                                CREATE, &sdp->sd_freeze_gl);
433         if (error) {
434                 fs_err(sdp, "can't create transaction glock: %d\n", error);
435                 goto fail_rename;
436         }
437
438         return 0;
439
440 fail_trans:
441         gfs2_glock_put(sdp->sd_freeze_gl);
442 fail_rename:
443         gfs2_glock_put(sdp->sd_rename_gl);
444 fail_live:
445         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
446 fail_mount:
447         gfs2_glock_dq_uninit(mount_gh);
448 fail:
449         return error;
450 }
451
452 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
453                             u64 no_addr, const char *name)
454 {
455         struct gfs2_sbd *sdp = sb->s_fs_info;
456         struct dentry *dentry;
457         struct inode *inode;
458
459         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0,
460                                   GFS2_BLKST_FREE /* ignore */);
461         if (IS_ERR(inode)) {
462                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
463                 return PTR_ERR(inode);
464         }
465         dentry = d_make_root(inode);
466         if (!dentry) {
467                 fs_err(sdp, "can't alloc %s dentry\n", name);
468                 return -ENOMEM;
469         }
470         *dptr = dentry;
471         return 0;
472 }
473
474 static int init_sb(struct gfs2_sbd *sdp, int silent)
475 {
476         struct super_block *sb = sdp->sd_vfs;
477         struct gfs2_holder sb_gh;
478         u64 no_addr;
479         int ret;
480
481         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
482                                 LM_ST_SHARED, 0, &sb_gh);
483         if (ret) {
484                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
485                 return ret;
486         }
487
488         ret = gfs2_read_sb(sdp, silent);
489         if (ret) {
490                 fs_err(sdp, "can't read superblock: %d\n", ret);
491                 goto out;
492         }
493
494         /* Set up the buffer cache and SB for real */
495         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
496                 ret = -EINVAL;
497                 fs_err(sdp, "FS block size (%u) is too small for device "
498                        "block size (%u)\n",
499                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
500                 goto out;
501         }
502         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
503                 ret = -EINVAL;
504                 fs_err(sdp, "FS block size (%u) is too big for machine "
505                        "page size (%u)\n",
506                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
507                 goto out;
508         }
509         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
510
511         /* Get the root inode */
512         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
513         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
514         if (ret)
515                 goto out;
516
517         /* Get the master inode */
518         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
519         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
520         if (ret) {
521                 dput(sdp->sd_root_dir);
522                 goto out;
523         }
524         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
525 out:
526         gfs2_glock_dq_uninit(&sb_gh);
527         return ret;
528 }
529
530 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
531 {
532         char *message = "FIRSTMOUNT=Done";
533         char *envp[] = { message, NULL };
534
535         fs_info(sdp, "first mount done, others may mount\n");
536
537         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
538                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
539
540         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
541 }
542
543 /**
544  * gfs2_jindex_hold - Grab a lock on the jindex
545  * @sdp: The GFS2 superblock
546  * @ji_gh: the holder for the jindex glock
547  *
548  * Returns: errno
549  */
550
551 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
552 {
553         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
554         struct qstr name;
555         char buf[20];
556         struct gfs2_jdesc *jd;
557         int error;
558
559         name.name = buf;
560
561         mutex_lock(&sdp->sd_jindex_mutex);
562
563         for (;;) {
564                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
565                 if (error)
566                         break;
567
568                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
569                 name.hash = gfs2_disk_hash(name.name, name.len);
570
571                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
572                 if (error == -ENOENT) {
573                         error = 0;
574                         break;
575                 }
576
577                 gfs2_glock_dq_uninit(ji_gh);
578
579                 if (error)
580                         break;
581
582                 error = -ENOMEM;
583                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
584                 if (!jd)
585                         break;
586
587                 INIT_LIST_HEAD(&jd->extent_list);
588                 INIT_LIST_HEAD(&jd->jd_revoke_list);
589
590                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
591                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
592                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
593                         if (!jd->jd_inode)
594                                 error = -ENOENT;
595                         else
596                                 error = PTR_ERR(jd->jd_inode);
597                         kfree(jd);
598                         break;
599                 }
600
601                 spin_lock(&sdp->sd_jindex_spin);
602                 jd->jd_jid = sdp->sd_journals++;
603                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
604                 spin_unlock(&sdp->sd_jindex_spin);
605         }
606
607         mutex_unlock(&sdp->sd_jindex_mutex);
608
609         return error;
610 }
611
612 /**
613  * check_journal_clean - Make sure a journal is clean for a spectator mount
614  * @sdp: The GFS2 superblock
615  * @jd: The journal descriptor
616  *
617  * Returns: 0 if the journal is clean or locked, else an error
618  */
619 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
620 {
621         int error;
622         struct gfs2_holder j_gh;
623         struct gfs2_log_header_host head;
624         struct gfs2_inode *ip;
625
626         ip = GFS2_I(jd->jd_inode);
627         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
628                                    GL_EXACT | GL_NOCACHE, &j_gh);
629         if (error) {
630                 fs_err(sdp, "Error locking journal for spectator mount.\n");
631                 return -EPERM;
632         }
633         error = gfs2_jdesc_check(jd);
634         if (error) {
635                 fs_err(sdp, "Error checking journal for spectator mount.\n");
636                 goto out_unlock;
637         }
638         error = gfs2_find_jhead(jd, &head);
639         if (error) {
640                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
641                 goto out_unlock;
642         }
643         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
644                 error = -EPERM;
645                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
646                        "must not be a spectator.\n", jd->jd_jid);
647         }
648
649 out_unlock:
650         gfs2_glock_dq_uninit(&j_gh);
651         return error;
652 }
653
654 static int init_journal(struct gfs2_sbd *sdp, int undo)
655 {
656         struct inode *master = d_inode(sdp->sd_master_dir);
657         struct gfs2_holder ji_gh;
658         struct gfs2_inode *ip;
659         int jindex = 1;
660         int error = 0;
661
662         if (undo) {
663                 jindex = 0;
664                 goto fail_jinode_gh;
665         }
666
667         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
668         if (IS_ERR(sdp->sd_jindex)) {
669                 fs_err(sdp, "can't lookup journal index: %d\n", error);
670                 return PTR_ERR(sdp->sd_jindex);
671         }
672
673         /* Load in the journal index special file */
674
675         error = gfs2_jindex_hold(sdp, &ji_gh);
676         if (error) {
677                 fs_err(sdp, "can't read journal index: %d\n", error);
678                 goto fail;
679         }
680
681         error = -EUSERS;
682         if (!gfs2_jindex_size(sdp)) {
683                 fs_err(sdp, "no journals!\n");
684                 goto fail_jindex;
685         }
686
687         atomic_set(&sdp->sd_log_blks_needed, 0);
688         if (sdp->sd_args.ar_spectator) {
689                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
690                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
691                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
692                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
693         } else {
694                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
695                         fs_err(sdp, "can't mount journal #%u\n",
696                                sdp->sd_lockstruct.ls_jid);
697                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
698                                gfs2_jindex_size(sdp),
699                                gfs2_jindex_size(sdp) - 1);
700                         goto fail_jindex;
701                 }
702                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
703
704                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
705                                           &gfs2_journal_glops,
706                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
707                                           &sdp->sd_journal_gh);
708                 if (error) {
709                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
710                         goto fail_jindex;
711                 }
712
713                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
714                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
715                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
716                                            &sdp->sd_jinode_gh);
717                 if (error) {
718                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
719                                error);
720                         goto fail_journal_gh;
721                 }
722
723                 error = gfs2_jdesc_check(sdp->sd_jdesc);
724                 if (error) {
725                         fs_err(sdp, "my journal (%u) is bad: %d\n",
726                                sdp->sd_jdesc->jd_jid, error);
727                         goto fail_jinode_gh;
728                 }
729                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
730                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
731                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
732
733                 /* Map the extents for this journal's blocks */
734                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
735         }
736         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
737
738         if (sdp->sd_lockstruct.ls_first) {
739                 unsigned int x;
740                 for (x = 0; x < sdp->sd_journals; x++) {
741                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
742
743                         if (sdp->sd_args.ar_spectator) {
744                                 error = check_journal_clean(sdp, jd);
745                                 if (error)
746                                         goto fail_jinode_gh;
747                                 continue;
748                         }
749                         error = gfs2_recover_journal(jd, true);
750                         if (error) {
751                                 fs_err(sdp, "error recovering journal %u: %d\n",
752                                        x, error);
753                                 goto fail_jinode_gh;
754                         }
755                 }
756
757                 gfs2_others_may_mount(sdp);
758         } else if (!sdp->sd_args.ar_spectator) {
759                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
760                 if (error) {
761                         fs_err(sdp, "error recovering my journal: %d\n", error);
762                         goto fail_jinode_gh;
763                 }
764         }
765
766         sdp->sd_log_idle = 1;
767         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
768         gfs2_glock_dq_uninit(&ji_gh);
769         jindex = 0;
770         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
771         return 0;
772
773 fail_jinode_gh:
774         if (!sdp->sd_args.ar_spectator)
775                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
776 fail_journal_gh:
777         if (!sdp->sd_args.ar_spectator)
778                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
779 fail_jindex:
780         gfs2_jindex_free(sdp);
781         if (jindex)
782                 gfs2_glock_dq_uninit(&ji_gh);
783 fail:
784         iput(sdp->sd_jindex);
785         return error;
786 }
787
788 static struct lock_class_key gfs2_quota_imutex_key;
789
790 static int init_inodes(struct gfs2_sbd *sdp, int undo)
791 {
792         int error = 0;
793         struct inode *master = d_inode(sdp->sd_master_dir);
794
795         if (undo)
796                 goto fail_qinode;
797
798         error = init_journal(sdp, undo);
799         complete_all(&sdp->sd_journal_ready);
800         if (error)
801                 goto fail;
802
803         /* Read in the master statfs inode */
804         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
805         if (IS_ERR(sdp->sd_statfs_inode)) {
806                 error = PTR_ERR(sdp->sd_statfs_inode);
807                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
808                 goto fail_journal;
809         }
810
811         /* Read in the resource index inode */
812         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
813         if (IS_ERR(sdp->sd_rindex)) {
814                 error = PTR_ERR(sdp->sd_rindex);
815                 fs_err(sdp, "can't get resource index inode: %d\n", error);
816                 goto fail_statfs;
817         }
818         sdp->sd_rindex_uptodate = 0;
819
820         /* Read in the quota inode */
821         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
822         if (IS_ERR(sdp->sd_quota_inode)) {
823                 error = PTR_ERR(sdp->sd_quota_inode);
824                 fs_err(sdp, "can't get quota file inode: %d\n", error);
825                 goto fail_rindex;
826         }
827         /*
828          * i_mutex on quota files is special. Since this inode is hidden system
829          * file, we are safe to define locking ourselves.
830          */
831         lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
832                           &gfs2_quota_imutex_key);
833
834         error = gfs2_rindex_update(sdp);
835         if (error)
836                 goto fail_qinode;
837
838         return 0;
839
840 fail_qinode:
841         iput(sdp->sd_quota_inode);
842 fail_rindex:
843         gfs2_clear_rgrpd(sdp);
844         iput(sdp->sd_rindex);
845 fail_statfs:
846         iput(sdp->sd_statfs_inode);
847 fail_journal:
848         init_journal(sdp, UNDO);
849 fail:
850         return error;
851 }
852
853 static int init_per_node(struct gfs2_sbd *sdp, int undo)
854 {
855         struct inode *pn = NULL;
856         char buf[30];
857         int error = 0;
858         struct gfs2_inode *ip;
859         struct inode *master = d_inode(sdp->sd_master_dir);
860
861         if (sdp->sd_args.ar_spectator)
862                 return 0;
863
864         if (undo)
865                 goto fail_qc_gh;
866
867         pn = gfs2_lookup_simple(master, "per_node");
868         if (IS_ERR(pn)) {
869                 error = PTR_ERR(pn);
870                 fs_err(sdp, "can't find per_node directory: %d\n", error);
871                 return error;
872         }
873
874         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
875         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
876         if (IS_ERR(sdp->sd_sc_inode)) {
877                 error = PTR_ERR(sdp->sd_sc_inode);
878                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
879                 goto fail;
880         }
881
882         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
883         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
884         if (IS_ERR(sdp->sd_qc_inode)) {
885                 error = PTR_ERR(sdp->sd_qc_inode);
886                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
887                 goto fail_ut_i;
888         }
889
890         iput(pn);
891         pn = NULL;
892
893         ip = GFS2_I(sdp->sd_sc_inode);
894         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
895                                    &sdp->sd_sc_gh);
896         if (error) {
897                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
898                 goto fail_qc_i;
899         }
900
901         ip = GFS2_I(sdp->sd_qc_inode);
902         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
903                                    &sdp->sd_qc_gh);
904         if (error) {
905                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
906                 goto fail_ut_gh;
907         }
908
909         return 0;
910
911 fail_qc_gh:
912         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
913 fail_ut_gh:
914         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
915 fail_qc_i:
916         iput(sdp->sd_qc_inode);
917 fail_ut_i:
918         iput(sdp->sd_sc_inode);
919 fail:
920         iput(pn);
921         return error;
922 }
923
924 static const match_table_t nolock_tokens = {
925         { Opt_jid, "jid=%d\n", },
926         { Opt_err, NULL },
927 };
928
929 static const struct lm_lockops nolock_ops = {
930         .lm_proto_name = "lock_nolock",
931         .lm_put_lock = gfs2_glock_free,
932         .lm_tokens = &nolock_tokens,
933 };
934
935 /**
936  * gfs2_lm_mount - mount a locking protocol
937  * @sdp: the filesystem
938  * @args: mount arguments
939  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
940  *
941  * Returns: errno
942  */
943
944 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
945 {
946         const struct lm_lockops *lm;
947         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
948         struct gfs2_args *args = &sdp->sd_args;
949         const char *proto = sdp->sd_proto_name;
950         const char *table = sdp->sd_table_name;
951         char *o, *options;
952         int ret;
953
954         if (!strcmp("lock_nolock", proto)) {
955                 lm = &nolock_ops;
956                 sdp->sd_args.ar_localflocks = 1;
957 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
958         } else if (!strcmp("lock_dlm", proto)) {
959                 lm = &gfs2_dlm_ops;
960 #endif
961         } else {
962                 pr_info("can't find protocol %s\n", proto);
963                 return -ENOENT;
964         }
965
966         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
967
968         ls->ls_ops = lm;
969         ls->ls_first = 1;
970
971         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
972                 substring_t tmp[MAX_OPT_ARGS];
973                 int token, option;
974
975                 if (!o || !*o)
976                         continue;
977
978                 token = match_token(o, *lm->lm_tokens, tmp);
979                 switch (token) {
980                 case Opt_jid:
981                         ret = match_int(&tmp[0], &option);
982                         if (ret || option < 0) 
983                                 goto hostdata_error;
984                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
985                                 ls->ls_jid = option;
986                         break;
987                 case Opt_id:
988                 case Opt_nodir:
989                         /* Obsolete, but left for backward compat purposes */
990                         break;
991                 case Opt_first:
992                         ret = match_int(&tmp[0], &option);
993                         if (ret || (option != 0 && option != 1))
994                                 goto hostdata_error;
995                         ls->ls_first = option;
996                         break;
997                 case Opt_err:
998                 default:
999 hostdata_error:
1000                         fs_info(sdp, "unknown hostdata (%s)\n", o);
1001                         return -EINVAL;
1002                 }
1003         }
1004
1005         if (lm->lm_mount == NULL) {
1006                 fs_info(sdp, "Now mounting FS...\n");
1007                 complete_all(&sdp->sd_locking_init);
1008                 return 0;
1009         }
1010         ret = lm->lm_mount(sdp, table);
1011         if (ret == 0)
1012                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1013         complete_all(&sdp->sd_locking_init);
1014         return ret;
1015 }
1016
1017 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1018 {
1019         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1020         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1021             lm->lm_unmount)
1022                 lm->lm_unmount(sdp);
1023 }
1024
1025 static int wait_on_journal(struct gfs2_sbd *sdp)
1026 {
1027         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1028                 return 0;
1029
1030         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1031                 ? -EINTR : 0;
1032 }
1033
1034 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1035 {
1036         struct super_block *sb = sdp->sd_vfs;
1037         char ro[20];
1038         char spectator[20];
1039         char *envp[] = { ro, spectator, NULL };
1040         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1041         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1042         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1043 }
1044
1045 /**
1046  * fill_super - Read in superblock
1047  * @sb: The VFS superblock
1048  * @data: Mount options
1049  * @silent: Don't complain if it's not a GFS2 filesystem
1050  *
1051  * Returns: errno
1052  */
1053
1054 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1055 {
1056         struct gfs2_sbd *sdp;
1057         struct gfs2_holder mount_gh;
1058         int error;
1059
1060         sdp = init_sbd(sb);
1061         if (!sdp) {
1062                 pr_warn("can't alloc struct gfs2_sbd\n");
1063                 return -ENOMEM;
1064         }
1065         sdp->sd_args = *args;
1066
1067         if (sdp->sd_args.ar_spectator) {
1068                 sb->s_flags |= MS_RDONLY;
1069                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1070         }
1071         if (sdp->sd_args.ar_posix_acl)
1072                 sb->s_flags |= MS_POSIXACL;
1073         if (sdp->sd_args.ar_nobarrier)
1074                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1075
1076         sb->s_flags |= MS_NOSEC;
1077         sb->s_magic = GFS2_MAGIC;
1078         sb->s_op = &gfs2_super_ops;
1079         sb->s_d_op = &gfs2_dops;
1080         sb->s_export_op = &gfs2_export_ops;
1081         sb->s_xattr = gfs2_xattr_handlers;
1082         sb->s_qcop = &gfs2_quotactl_ops;
1083         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1084         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1085         sb->s_time_gran = 1;
1086         sb->s_maxbytes = MAX_LFS_FILESIZE;
1087
1088         /* Set up the buffer cache and fill in some fake block size values
1089            to allow us to read-in the on-disk superblock. */
1090         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1091         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1092         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1093                                GFS2_BASIC_BLOCK_SHIFT;
1094         sdp->sd_fsb2bb = BIT(sdp->sd_fsb2bb_shift);
1095
1096         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1097         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1098         if (sdp->sd_args.ar_statfs_quantum) {
1099                 sdp->sd_tune.gt_statfs_slow = 0;
1100                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1101         } else {
1102                 sdp->sd_tune.gt_statfs_slow = 1;
1103                 sdp->sd_tune.gt_statfs_quantum = 30;
1104         }
1105
1106         error = init_names(sdp, silent);
1107         if (error) {
1108                 /* In this case, we haven't initialized sysfs, so we have to
1109                    manually free the sdp. */
1110                 free_percpu(sdp->sd_lkstats);
1111                 kfree(sdp);
1112                 sb->s_fs_info = NULL;
1113                 return error;
1114         }
1115
1116         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1117
1118         error = gfs2_sys_fs_add(sdp);
1119         /*
1120          * If we hit an error here, gfs2_sys_fs_add will have called function
1121          * kobject_put which causes the sysfs usage count to go to zero, which
1122          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1123          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1124          * kobject_put to free sdp.
1125          */
1126         if (error)
1127                 return error;
1128
1129         gfs2_create_debugfs_file(sdp);
1130
1131         error = gfs2_lm_mount(sdp, silent);
1132         if (error)
1133                 goto fail_debug;
1134
1135         error = init_locking(sdp, &mount_gh, DO);
1136         if (error)
1137                 goto fail_lm;
1138
1139         error = init_sb(sdp, silent);
1140         if (error)
1141                 goto fail_locking;
1142
1143         error = wait_on_journal(sdp);
1144         if (error)
1145                 goto fail_sb;
1146
1147         /*
1148          * If user space has failed to join the cluster or some similar
1149          * failure has occurred, then the journal id will contain a
1150          * negative (error) number. This will then be returned to the
1151          * caller (of the mount syscall). We do this even for spectator
1152          * mounts (which just write a jid of 0 to indicate "ok" even though
1153          * the jid is unused in the spectator case)
1154          */
1155         if (sdp->sd_lockstruct.ls_jid < 0) {
1156                 error = sdp->sd_lockstruct.ls_jid;
1157                 sdp->sd_lockstruct.ls_jid = 0;
1158                 goto fail_sb;
1159         }
1160
1161         if (sdp->sd_args.ar_spectator)
1162                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1163                          sdp->sd_table_name);
1164         else
1165                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1166                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1167
1168         error = init_inodes(sdp, DO);
1169         if (error)
1170                 goto fail_sb;
1171
1172         error = init_per_node(sdp, DO);
1173         if (error)
1174                 goto fail_inodes;
1175
1176         error = gfs2_statfs_init(sdp);
1177         if (error) {
1178                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1179                 goto fail_per_node;
1180         }
1181
1182         if (!(sb->s_flags & MS_RDONLY)) {
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
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         s->s_iflags |= SB_I_DYNBDI;
1228         return 0;
1229 }
1230
1231 static int test_gfs2_super(struct super_block *s, void *ptr)
1232 {
1233         struct block_device *bdev = ptr;
1234         return (bdev == s->s_bdev);
1235 }
1236
1237 /**
1238  * gfs2_mount - Get the GFS2 superblock
1239  * @fs_type: The GFS2 filesystem type
1240  * @flags: Mount flags
1241  * @dev_name: The name of the device
1242  * @data: The mount arguments
1243  *
1244  * Q. Why not use get_sb_bdev() ?
1245  * A. We need to select one of two root directories to mount, independent
1246  *    of whether this is the initial, or subsequent, mount of this sb
1247  *
1248  * Returns: 0 or -ve on error
1249  */
1250
1251 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1252                        const char *dev_name, void *data)
1253 {
1254         struct block_device *bdev;
1255         struct super_block *s;
1256         fmode_t mode = FMODE_READ | FMODE_EXCL;
1257         int error;
1258         struct gfs2_args args;
1259         struct gfs2_sbd *sdp;
1260
1261         if (!(flags & MS_RDONLY))
1262                 mode |= FMODE_WRITE;
1263
1264         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1265         if (IS_ERR(bdev))
1266                 return ERR_CAST(bdev);
1267
1268         /*
1269          * once the super is inserted into the list by sget, s_umount
1270          * will protect the lockfs code from trying to start a snapshot
1271          * while we are mounting
1272          */
1273         mutex_lock(&bdev->bd_fsfreeze_mutex);
1274         if (bdev->bd_fsfreeze_count > 0) {
1275                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1276                 error = -EBUSY;
1277                 goto error_bdev;
1278         }
1279         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1280         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1281         error = PTR_ERR(s);
1282         if (IS_ERR(s))
1283                 goto error_bdev;
1284
1285         if (s->s_root) {
1286                 /*
1287                  * s_umount nests inside bd_mutex during
1288                  * __invalidate_device().  blkdev_put() acquires
1289                  * bd_mutex and can't be called under s_umount.  Drop
1290                  * s_umount temporarily.  This is safe as we're
1291                  * holding an active reference.
1292                  */
1293                 up_write(&s->s_umount);
1294                 blkdev_put(bdev, mode);
1295                 down_write(&s->s_umount);
1296         } else {
1297                 /* s_mode must be set before deactivate_locked_super calls */
1298                 s->s_mode = mode;
1299         }
1300
1301         memset(&args, 0, sizeof(args));
1302         args.ar_quota = GFS2_QUOTA_DEFAULT;
1303         args.ar_data = GFS2_DATA_DEFAULT;
1304         args.ar_commit = 30;
1305         args.ar_statfs_quantum = 30;
1306         args.ar_quota_quantum = 60;
1307         args.ar_errors = GFS2_ERRORS_DEFAULT;
1308
1309         error = gfs2_mount_args(&args, data);
1310         if (error) {
1311                 pr_warn("can't parse mount arguments\n");
1312                 goto error_super;
1313         }
1314
1315         if (s->s_root) {
1316                 error = -EBUSY;
1317                 if ((flags ^ s->s_flags) & MS_RDONLY)
1318                         goto error_super;
1319         } else {
1320                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1321                 sb_set_blocksize(s, block_size(bdev));
1322                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1323                 if (error)
1324                         goto error_super;
1325                 s->s_flags |= MS_ACTIVE;
1326                 bdev->bd_super = s;
1327         }
1328
1329         sdp = s->s_fs_info;
1330         if (args.ar_meta)
1331                 return dget(sdp->sd_master_dir);
1332         else
1333                 return dget(sdp->sd_root_dir);
1334
1335 error_super:
1336         deactivate_locked_super(s);
1337         return ERR_PTR(error);
1338 error_bdev:
1339         blkdev_put(bdev, mode);
1340         return ERR_PTR(error);
1341 }
1342
1343 static int set_meta_super(struct super_block *s, void *ptr)
1344 {
1345         return -EINVAL;
1346 }
1347
1348 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1349                         int flags, const char *dev_name, void *data)
1350 {
1351         struct super_block *s;
1352         struct gfs2_sbd *sdp;
1353         struct path path;
1354         int error;
1355
1356         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1357         if (error) {
1358                 pr_warn("path_lookup on %s returned error %d\n",
1359                         dev_name, error);
1360                 return ERR_PTR(error);
1361         }
1362         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1363                  path.dentry->d_sb->s_bdev);
1364         path_put(&path);
1365         if (IS_ERR(s)) {
1366                 pr_warn("gfs2 mount does not exist\n");
1367                 return ERR_CAST(s);
1368         }
1369         if ((flags ^ s->s_flags) & MS_RDONLY) {
1370                 deactivate_locked_super(s);
1371                 return ERR_PTR(-EBUSY);
1372         }
1373         sdp = s->s_fs_info;
1374         return dget(sdp->sd_master_dir);
1375 }
1376
1377 static void gfs2_kill_sb(struct super_block *sb)
1378 {
1379         struct gfs2_sbd *sdp = sb->s_fs_info;
1380
1381         if (sdp == NULL) {
1382                 kill_block_super(sb);
1383                 return;
1384         }
1385
1386         gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1387         dput(sdp->sd_root_dir);
1388         dput(sdp->sd_master_dir);
1389         sdp->sd_root_dir = NULL;
1390         sdp->sd_master_dir = NULL;
1391         shrink_dcache_sb(sb);
1392         gfs2_delete_debugfs_file(sdp);
1393         free_percpu(sdp->sd_lkstats);
1394         kill_block_super(sb);
1395 }
1396
1397 struct file_system_type gfs2_fs_type = {
1398         .name = "gfs2",
1399         .fs_flags = FS_REQUIRES_DEV,
1400         .mount = gfs2_mount,
1401         .kill_sb = gfs2_kill_sb,
1402         .owner = THIS_MODULE,
1403 };
1404 MODULE_ALIAS_FS("gfs2");
1405
1406 struct file_system_type gfs2meta_fs_type = {
1407         .name = "gfs2meta",
1408         .fs_flags = FS_REQUIRES_DEV,
1409         .mount = gfs2_mount_meta,
1410         .owner = THIS_MODULE,
1411 };
1412 MODULE_ALIAS_FS("gfs2meta");