Merge branch 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm
[pandora-kernel.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 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/blkdev.h>
16 #include <linux/kthread.h>
17 #include <linux/namei.h>
18 #include <linux/mount.h>
19 #include <linux/gfs2_ondisk.h>
20 #include <linux/quotaops.h>
21
22 #include "gfs2.h"
23 #include "incore.h"
24 #include "bmap.h"
25 #include "glock.h"
26 #include "glops.h"
27 #include "inode.h"
28 #include "recovery.h"
29 #include "rgrp.h"
30 #include "super.h"
31 #include "sys.h"
32 #include "util.h"
33 #include "log.h"
34 #include "quota.h"
35 #include "dir.h"
36 #include "trace_gfs2.h"
37
38 #define DO 0
39 #define UNDO 1
40
41 /**
42  * gfs2_tune_init - Fill a gfs2_tune structure with default values
43  * @gt: tune
44  *
45  */
46
47 static void gfs2_tune_init(struct gfs2_tune *gt)
48 {
49         spin_lock_init(&gt->gt_spin);
50
51         gt->gt_quota_simul_sync = 64;
52         gt->gt_quota_warn_period = 10;
53         gt->gt_quota_scale_num = 1;
54         gt->gt_quota_scale_den = 1;
55         gt->gt_new_files_jdata = 0;
56         gt->gt_max_readahead = 1 << 18;
57         gt->gt_complain_secs = 10;
58 }
59
60 static struct gfs2_sbd *init_sbd(struct super_block *sb)
61 {
62         struct gfs2_sbd *sdp;
63
64         sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
65         if (!sdp)
66                 return NULL;
67
68         sb->s_fs_info = sdp;
69         sdp->sd_vfs = sb;
70         set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
71         gfs2_tune_init(&sdp->sd_tune);
72
73         init_waitqueue_head(&sdp->sd_glock_wait);
74         atomic_set(&sdp->sd_glock_disposal, 0);
75         spin_lock_init(&sdp->sd_statfs_spin);
76
77         spin_lock_init(&sdp->sd_rindex_spin);
78         mutex_init(&sdp->sd_rindex_mutex);
79         INIT_LIST_HEAD(&sdp->sd_rindex_list);
80         INIT_LIST_HEAD(&sdp->sd_rindex_mru_list);
81
82         INIT_LIST_HEAD(&sdp->sd_jindex_list);
83         spin_lock_init(&sdp->sd_jindex_spin);
84         mutex_init(&sdp->sd_jindex_mutex);
85
86         INIT_LIST_HEAD(&sdp->sd_quota_list);
87         mutex_init(&sdp->sd_quota_mutex);
88         init_waitqueue_head(&sdp->sd_quota_wait);
89         INIT_LIST_HEAD(&sdp->sd_trunc_list);
90         spin_lock_init(&sdp->sd_trunc_lock);
91
92         spin_lock_init(&sdp->sd_log_lock);
93         atomic_set(&sdp->sd_log_pinned, 0);
94         INIT_LIST_HEAD(&sdp->sd_log_le_buf);
95         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
96         INIT_LIST_HEAD(&sdp->sd_log_le_rg);
97         INIT_LIST_HEAD(&sdp->sd_log_le_databuf);
98         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
99
100         init_waitqueue_head(&sdp->sd_log_waitq);
101         init_waitqueue_head(&sdp->sd_logd_waitq);
102         INIT_LIST_HEAD(&sdp->sd_ail1_list);
103         INIT_LIST_HEAD(&sdp->sd_ail2_list);
104
105         init_rwsem(&sdp->sd_log_flush_lock);
106         atomic_set(&sdp->sd_log_in_flight, 0);
107         init_waitqueue_head(&sdp->sd_log_flush_wait);
108
109         INIT_LIST_HEAD(&sdp->sd_revoke_list);
110
111         mutex_init(&sdp->sd_freeze_lock);
112
113         return sdp;
114 }
115
116
117 /**
118  * gfs2_check_sb - Check superblock
119  * @sdp: the filesystem
120  * @sb: The superblock
121  * @silent: Don't print a message if the check fails
122  *
123  * Checks the version code of the FS is one that we understand how to
124  * read and that the sizes of the various on-disk structures have not
125  * changed.
126  */
127
128 static int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
129 {
130         if (sb->sb_magic != GFS2_MAGIC ||
131             sb->sb_type != GFS2_METATYPE_SB) {
132                 if (!silent)
133                         printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
134                 return -EINVAL;
135         }
136
137         /*  If format numbers match exactly, we're done.  */
138
139         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
140             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
141                 return 0;
142
143         fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
144
145         return -EINVAL;
146 }
147
148 static void end_bio_io_page(struct bio *bio, int error)
149 {
150         struct page *page = bio->bi_private;
151
152         if (!error)
153                 SetPageUptodate(page);
154         else
155                 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
156         unlock_page(page);
157 }
158
159 static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
160 {
161         const struct gfs2_sb *str = buf;
162
163         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
164         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
165         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
166         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
167         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
168         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
169         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
170         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
171         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
172         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
173         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
174
175         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
176         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
177         memcpy(sb->sb_uuid, str->sb_uuid, 16);
178 }
179
180 /**
181  * gfs2_read_super - Read the gfs2 super block from disk
182  * @sdp: The GFS2 super block
183  * @sector: The location of the super block
184  * @error: The error code to return
185  *
186  * This uses the bio functions to read the super block from disk
187  * because we want to be 100% sure that we never read cached data.
188  * A super block is read twice only during each GFS2 mount and is
189  * never written to by the filesystem. The first time its read no
190  * locks are held, and the only details which are looked at are those
191  * relating to the locking protocol. Once locking is up and working,
192  * the sb is read again under the lock to establish the location of
193  * the master directory (contains pointers to journals etc) and the
194  * root directory.
195  *
196  * Returns: 0 on success or error
197  */
198
199 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
200 {
201         struct super_block *sb = sdp->sd_vfs;
202         struct gfs2_sb *p;
203         struct page *page;
204         struct bio *bio;
205
206         page = alloc_page(GFP_NOFS);
207         if (unlikely(!page))
208                 return -ENOBUFS;
209
210         ClearPageUptodate(page);
211         ClearPageDirty(page);
212         lock_page(page);
213
214         bio = bio_alloc(GFP_NOFS, 1);
215         bio->bi_sector = sector * (sb->s_blocksize >> 9);
216         bio->bi_bdev = sb->s_bdev;
217         bio_add_page(bio, page, PAGE_SIZE, 0);
218
219         bio->bi_end_io = end_bio_io_page;
220         bio->bi_private = page;
221         submit_bio(READ_SYNC | REQ_META, bio);
222         wait_on_page_locked(page);
223         bio_put(bio);
224         if (!PageUptodate(page)) {
225                 __free_page(page);
226                 return -EIO;
227         }
228         p = kmap(page);
229         gfs2_sb_in(&sdp->sd_sb, p);
230         kunmap(page);
231         __free_page(page);
232         return 0;
233 }
234
235 /**
236  * gfs2_read_sb - Read super block
237  * @sdp: The GFS2 superblock
238  * @silent: Don't print message if mount fails
239  *
240  */
241
242 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
243 {
244         u32 hash_blocks, ind_blocks, leaf_blocks;
245         u32 tmp_blocks;
246         unsigned int x;
247         int error;
248
249         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
250         if (error) {
251                 if (!silent)
252                         fs_err(sdp, "can't read superblock\n");
253                 return error;
254         }
255
256         error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
257         if (error)
258                 return error;
259
260         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
261                                GFS2_BASIC_BLOCK_SHIFT;
262         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
263         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
264                           sizeof(struct gfs2_dinode)) / sizeof(u64);
265         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
266                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
267         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
268         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
269         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
270         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
271         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
272                                 sizeof(struct gfs2_meta_header)) /
273                                 sizeof(struct gfs2_quota_change);
274
275         /* Compute maximum reservation required to add a entry to a directory */
276
277         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
278                              sdp->sd_jbsize);
279
280         ind_blocks = 0;
281         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
282                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
283                 ind_blocks += tmp_blocks;
284         }
285
286         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
287
288         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
289
290         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
291                                 sizeof(struct gfs2_dinode);
292         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
293         for (x = 2;; x++) {
294                 u64 space, d;
295                 u32 m;
296
297                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
298                 d = space;
299                 m = do_div(d, sdp->sd_inptrs);
300
301                 if (d != sdp->sd_heightsize[x - 1] || m)
302                         break;
303                 sdp->sd_heightsize[x] = space;
304         }
305         sdp->sd_max_height = x;
306         sdp->sd_heightsize[x] = ~0;
307         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
308
309         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
310                                  sizeof(struct gfs2_dinode);
311         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
312         for (x = 2;; x++) {
313                 u64 space, d;
314                 u32 m;
315
316                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
317                 d = space;
318                 m = do_div(d, sdp->sd_inptrs);
319
320                 if (d != sdp->sd_jheightsize[x - 1] || m)
321                         break;
322                 sdp->sd_jheightsize[x] = space;
323         }
324         sdp->sd_max_jheight = x;
325         sdp->sd_jheightsize[x] = ~0;
326         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
327
328         return 0;
329 }
330
331 static int init_names(struct gfs2_sbd *sdp, int silent)
332 {
333         char *proto, *table;
334         int error = 0;
335
336         proto = sdp->sd_args.ar_lockproto;
337         table = sdp->sd_args.ar_locktable;
338
339         /*  Try to autodetect  */
340
341         if (!proto[0] || !table[0]) {
342                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
343                 if (error)
344                         return error;
345
346                 error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
347                 if (error)
348                         goto out;
349
350                 if (!proto[0])
351                         proto = sdp->sd_sb.sb_lockproto;
352                 if (!table[0])
353                         table = sdp->sd_sb.sb_locktable;
354         }
355
356         if (!table[0])
357                 table = sdp->sd_vfs->s_id;
358
359         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
360         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
361
362         table = sdp->sd_table_name;
363         while ((table = strchr(table, '/')))
364                 *table = '_';
365
366 out:
367         return error;
368 }
369
370 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
371                         int undo)
372 {
373         int error = 0;
374
375         if (undo)
376                 goto fail_trans;
377
378         error = gfs2_glock_nq_num(sdp,
379                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
380                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
381                                   mount_gh);
382         if (error) {
383                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
384                 goto fail;
385         }
386
387         error = gfs2_glock_nq_num(sdp,
388                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
389                                   LM_ST_SHARED,
390                                   LM_FLAG_NOEXP | GL_EXACT,
391                                   &sdp->sd_live_gh);
392         if (error) {
393                 fs_err(sdp, "can't acquire live glock: %d\n", error);
394                 goto fail_mount;
395         }
396
397         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
398                                CREATE, &sdp->sd_rename_gl);
399         if (error) {
400                 fs_err(sdp, "can't create rename glock: %d\n", error);
401                 goto fail_live;
402         }
403
404         error = gfs2_glock_get(sdp, GFS2_TRANS_LOCK, &gfs2_trans_glops,
405                                CREATE, &sdp->sd_trans_gl);
406         if (error) {
407                 fs_err(sdp, "can't create transaction glock: %d\n", error);
408                 goto fail_rename;
409         }
410
411         return 0;
412
413 fail_trans:
414         gfs2_glock_put(sdp->sd_trans_gl);
415 fail_rename:
416         gfs2_glock_put(sdp->sd_rename_gl);
417 fail_live:
418         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
419 fail_mount:
420         gfs2_glock_dq_uninit(mount_gh);
421 fail:
422         return error;
423 }
424
425 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
426                             u64 no_addr, const char *name)
427 {
428         struct gfs2_sbd *sdp = sb->s_fs_info;
429         struct dentry *dentry;
430         struct inode *inode;
431
432         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0);
433         if (IS_ERR(inode)) {
434                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
435                 return PTR_ERR(inode);
436         }
437         dentry = d_alloc_root(inode);
438         if (!dentry) {
439                 fs_err(sdp, "can't alloc %s dentry\n", name);
440                 iput(inode);
441                 return -ENOMEM;
442         }
443         *dptr = dentry;
444         return 0;
445 }
446
447 static int init_sb(struct gfs2_sbd *sdp, int silent)
448 {
449         struct super_block *sb = sdp->sd_vfs;
450         struct gfs2_holder sb_gh;
451         u64 no_addr;
452         int ret;
453
454         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
455                                 LM_ST_SHARED, 0, &sb_gh);
456         if (ret) {
457                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
458                 return ret;
459         }
460
461         ret = gfs2_read_sb(sdp, silent);
462         if (ret) {
463                 fs_err(sdp, "can't read superblock: %d\n", ret);
464                 goto out;
465         }
466
467         /* Set up the buffer cache and SB for real */
468         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
469                 ret = -EINVAL;
470                 fs_err(sdp, "FS block size (%u) is too small for device "
471                        "block size (%u)\n",
472                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
473                 goto out;
474         }
475         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
476                 ret = -EINVAL;
477                 fs_err(sdp, "FS block size (%u) is too big for machine "
478                        "page size (%u)\n",
479                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
480                 goto out;
481         }
482         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
483
484         /* Get the root inode */
485         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
486         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
487         if (ret)
488                 goto out;
489
490         /* Get the master inode */
491         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
492         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
493         if (ret) {
494                 dput(sdp->sd_root_dir);
495                 goto out;
496         }
497         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
498 out:
499         gfs2_glock_dq_uninit(&sb_gh);
500         return ret;
501 }
502
503 /**
504  * map_journal_extents - create a reusable "extent" mapping from all logical
505  * blocks to all physical blocks for the given journal.  This will save
506  * us time when writing journal blocks.  Most journals will have only one
507  * extent that maps all their logical blocks.  That's because gfs2.mkfs
508  * arranges the journal blocks sequentially to maximize performance.
509  * So the extent would map the first block for the entire file length.
510  * However, gfs2_jadd can happen while file activity is happening, so
511  * those journals may not be sequential.  Less likely is the case where
512  * the users created their own journals by mounting the metafs and
513  * laying it out.  But it's still possible.  These journals might have
514  * several extents.
515  *
516  * TODO: This should be done in bigger chunks rather than one block at a time,
517  *       but since it's only done at mount time, I'm not worried about the
518  *       time it takes.
519  */
520 static int map_journal_extents(struct gfs2_sbd *sdp)
521 {
522         struct gfs2_jdesc *jd = sdp->sd_jdesc;
523         unsigned int lb;
524         u64 db, prev_db; /* logical block, disk block, prev disk block */
525         struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
526         struct gfs2_journal_extent *jext = NULL;
527         struct buffer_head bh;
528         int rc = 0;
529
530         prev_db = 0;
531
532         for (lb = 0; lb < i_size_read(jd->jd_inode) >> sdp->sd_sb.sb_bsize_shift; lb++) {
533                 bh.b_state = 0;
534                 bh.b_blocknr = 0;
535                 bh.b_size = 1 << ip->i_inode.i_blkbits;
536                 rc = gfs2_block_map(jd->jd_inode, lb, &bh, 0);
537                 db = bh.b_blocknr;
538                 if (rc || !db) {
539                         printk(KERN_INFO "GFS2 journal mapping error %d: lb="
540                                "%u db=%llu\n", rc, lb, (unsigned long long)db);
541                         break;
542                 }
543                 if (!prev_db || db != prev_db + 1) {
544                         jext = kzalloc(sizeof(struct gfs2_journal_extent),
545                                        GFP_KERNEL);
546                         if (!jext) {
547                                 printk(KERN_INFO "GFS2 error: out of memory "
548                                        "mapping journal extents.\n");
549                                 rc = -ENOMEM;
550                                 break;
551                         }
552                         jext->dblock = db;
553                         jext->lblock = lb;
554                         jext->blocks = 1;
555                         list_add_tail(&jext->extent_list, &jd->extent_list);
556                 } else {
557                         jext->blocks++;
558                 }
559                 prev_db = db;
560         }
561         return rc;
562 }
563
564 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
565 {
566         char *message = "FIRSTMOUNT=Done";
567         char *envp[] = { message, NULL };
568         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
569         ls->ls_first_done = 1;
570         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
571 }
572
573 /**
574  * gfs2_jindex_hold - Grab a lock on the jindex
575  * @sdp: The GFS2 superblock
576  * @ji_gh: the holder for the jindex glock
577  *
578  * Returns: errno
579  */
580
581 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
582 {
583         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
584         struct qstr name;
585         char buf[20];
586         struct gfs2_jdesc *jd;
587         int error;
588
589         name.name = buf;
590
591         mutex_lock(&sdp->sd_jindex_mutex);
592
593         for (;;) {
594                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
595                 if (error)
596                         break;
597
598                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
599                 name.hash = gfs2_disk_hash(name.name, name.len);
600
601                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
602                 if (error == -ENOENT) {
603                         error = 0;
604                         break;
605                 }
606
607                 gfs2_glock_dq_uninit(ji_gh);
608
609                 if (error)
610                         break;
611
612                 error = -ENOMEM;
613                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
614                 if (!jd)
615                         break;
616
617                 INIT_LIST_HEAD(&jd->extent_list);
618                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
619                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
620                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
621                         if (!jd->jd_inode)
622                                 error = -ENOENT;
623                         else
624                                 error = PTR_ERR(jd->jd_inode);
625                         kfree(jd);
626                         break;
627                 }
628
629                 spin_lock(&sdp->sd_jindex_spin);
630                 jd->jd_jid = sdp->sd_journals++;
631                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
632                 spin_unlock(&sdp->sd_jindex_spin);
633         }
634
635         mutex_unlock(&sdp->sd_jindex_mutex);
636
637         return error;
638 }
639
640 static int init_journal(struct gfs2_sbd *sdp, int undo)
641 {
642         struct inode *master = sdp->sd_master_dir->d_inode;
643         struct gfs2_holder ji_gh;
644         struct gfs2_inode *ip;
645         int jindex = 1;
646         int error = 0;
647
648         if (undo) {
649                 jindex = 0;
650                 goto fail_jinode_gh;
651         }
652
653         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
654         if (IS_ERR(sdp->sd_jindex)) {
655                 fs_err(sdp, "can't lookup journal index: %d\n", error);
656                 return PTR_ERR(sdp->sd_jindex);
657         }
658         ip = GFS2_I(sdp->sd_jindex);
659
660         /* Load in the journal index special file */
661
662         error = gfs2_jindex_hold(sdp, &ji_gh);
663         if (error) {
664                 fs_err(sdp, "can't read journal index: %d\n", error);
665                 goto fail;
666         }
667
668         error = -EUSERS;
669         if (!gfs2_jindex_size(sdp)) {
670                 fs_err(sdp, "no journals!\n");
671                 goto fail_jindex;
672         }
673
674         if (sdp->sd_args.ar_spectator) {
675                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
676                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
677                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
678                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
679         } else {
680                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
681                         fs_err(sdp, "can't mount journal #%u\n",
682                                sdp->sd_lockstruct.ls_jid);
683                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
684                                gfs2_jindex_size(sdp),
685                                gfs2_jindex_size(sdp) - 1);
686                         goto fail_jindex;
687                 }
688                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
689
690                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
691                                           &gfs2_journal_glops,
692                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
693                                           &sdp->sd_journal_gh);
694                 if (error) {
695                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
696                         goto fail_jindex;
697                 }
698
699                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
700                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
701                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
702                                            &sdp->sd_jinode_gh);
703                 if (error) {
704                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
705                                error);
706                         goto fail_journal_gh;
707                 }
708
709                 error = gfs2_jdesc_check(sdp->sd_jdesc);
710                 if (error) {
711                         fs_err(sdp, "my journal (%u) is bad: %d\n",
712                                sdp->sd_jdesc->jd_jid, error);
713                         goto fail_jinode_gh;
714                 }
715                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
716                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
717                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
718
719                 /* Map the extents for this journal's blocks */
720                 map_journal_extents(sdp);
721         }
722         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
723
724         if (sdp->sd_lockstruct.ls_first) {
725                 unsigned int x;
726                 for (x = 0; x < sdp->sd_journals; x++) {
727                         error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
728                                                      true);
729                         if (error) {
730                                 fs_err(sdp, "error recovering journal %u: %d\n",
731                                        x, error);
732                                 goto fail_jinode_gh;
733                         }
734                 }
735
736                 gfs2_others_may_mount(sdp);
737         } else if (!sdp->sd_args.ar_spectator) {
738                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
739                 if (error) {
740                         fs_err(sdp, "error recovering my journal: %d\n", error);
741                         goto fail_jinode_gh;
742                 }
743         }
744
745         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
746         gfs2_glock_dq_uninit(&ji_gh);
747         jindex = 0;
748
749         return 0;
750
751 fail_jinode_gh:
752         if (!sdp->sd_args.ar_spectator)
753                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
754 fail_journal_gh:
755         if (!sdp->sd_args.ar_spectator)
756                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
757 fail_jindex:
758         gfs2_jindex_free(sdp);
759         if (jindex)
760                 gfs2_glock_dq_uninit(&ji_gh);
761 fail:
762         iput(sdp->sd_jindex);
763         return error;
764 }
765
766
767 static int init_inodes(struct gfs2_sbd *sdp, int undo)
768 {
769         int error = 0;
770         struct gfs2_inode *ip;
771         struct inode *master = sdp->sd_master_dir->d_inode;
772
773         if (undo)
774                 goto fail_qinode;
775
776         error = init_journal(sdp, undo);
777         if (error)
778                 goto fail;
779
780         /* Read in the master statfs inode */
781         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
782         if (IS_ERR(sdp->sd_statfs_inode)) {
783                 error = PTR_ERR(sdp->sd_statfs_inode);
784                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
785                 goto fail_journal;
786         }
787
788         /* Read in the resource index inode */
789         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
790         if (IS_ERR(sdp->sd_rindex)) {
791                 error = PTR_ERR(sdp->sd_rindex);
792                 fs_err(sdp, "can't get resource index inode: %d\n", error);
793                 goto fail_statfs;
794         }
795         ip = GFS2_I(sdp->sd_rindex);
796         sdp->sd_rindex_uptodate = 0;
797
798         /* Read in the quota inode */
799         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
800         if (IS_ERR(sdp->sd_quota_inode)) {
801                 error = PTR_ERR(sdp->sd_quota_inode);
802                 fs_err(sdp, "can't get quota file inode: %d\n", error);
803                 goto fail_rindex;
804         }
805         return 0;
806
807 fail_qinode:
808         iput(sdp->sd_quota_inode);
809 fail_rindex:
810         gfs2_clear_rgrpd(sdp);
811         iput(sdp->sd_rindex);
812 fail_statfs:
813         iput(sdp->sd_statfs_inode);
814 fail_journal:
815         init_journal(sdp, UNDO);
816 fail:
817         return error;
818 }
819
820 static int init_per_node(struct gfs2_sbd *sdp, int undo)
821 {
822         struct inode *pn = NULL;
823         char buf[30];
824         int error = 0;
825         struct gfs2_inode *ip;
826         struct inode *master = sdp->sd_master_dir->d_inode;
827
828         if (sdp->sd_args.ar_spectator)
829                 return 0;
830
831         if (undo)
832                 goto fail_qc_gh;
833
834         pn = gfs2_lookup_simple(master, "per_node");
835         if (IS_ERR(pn)) {
836                 error = PTR_ERR(pn);
837                 fs_err(sdp, "can't find per_node directory: %d\n", error);
838                 return error;
839         }
840
841         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
842         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
843         if (IS_ERR(sdp->sd_sc_inode)) {
844                 error = PTR_ERR(sdp->sd_sc_inode);
845                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
846                 goto fail;
847         }
848
849         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
850         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
851         if (IS_ERR(sdp->sd_qc_inode)) {
852                 error = PTR_ERR(sdp->sd_qc_inode);
853                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
854                 goto fail_ut_i;
855         }
856
857         iput(pn);
858         pn = NULL;
859
860         ip = GFS2_I(sdp->sd_sc_inode);
861         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
862                                    &sdp->sd_sc_gh);
863         if (error) {
864                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
865                 goto fail_qc_i;
866         }
867
868         ip = GFS2_I(sdp->sd_qc_inode);
869         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
870                                    &sdp->sd_qc_gh);
871         if (error) {
872                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
873                 goto fail_ut_gh;
874         }
875
876         return 0;
877
878 fail_qc_gh:
879         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
880 fail_ut_gh:
881         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
882 fail_qc_i:
883         iput(sdp->sd_qc_inode);
884 fail_ut_i:
885         iput(sdp->sd_sc_inode);
886 fail:
887         if (pn)
888                 iput(pn);
889         return error;
890 }
891
892 static int init_threads(struct gfs2_sbd *sdp, int undo)
893 {
894         struct task_struct *p;
895         int error = 0;
896
897         if (undo)
898                 goto fail_quotad;
899
900         p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
901         error = IS_ERR(p);
902         if (error) {
903                 fs_err(sdp, "can't start logd thread: %d\n", error);
904                 return error;
905         }
906         sdp->sd_logd_process = p;
907
908         p = kthread_run(gfs2_quotad, sdp, "gfs2_quotad");
909         error = IS_ERR(p);
910         if (error) {
911                 fs_err(sdp, "can't start quotad thread: %d\n", error);
912                 goto fail;
913         }
914         sdp->sd_quotad_process = p;
915
916         return 0;
917
918
919 fail_quotad:
920         kthread_stop(sdp->sd_quotad_process);
921 fail:
922         kthread_stop(sdp->sd_logd_process);
923         return error;
924 }
925
926 static const match_table_t nolock_tokens = {
927         { Opt_jid, "jid=%d\n", },
928         { Opt_err, NULL },
929 };
930
931 static void nolock_put_lock(struct kmem_cache *cachep, struct gfs2_glock *gl)
932 {
933         struct gfs2_sbd *sdp = gl->gl_sbd;
934         kmem_cache_free(cachep, gl);
935         if (atomic_dec_and_test(&sdp->sd_glock_disposal))
936                 wake_up(&sdp->sd_glock_wait);
937 }
938
939 static const struct lm_lockops nolock_ops = {
940         .lm_proto_name = "lock_nolock",
941         .lm_put_lock = nolock_put_lock,
942         .lm_tokens = &nolock_tokens,
943 };
944
945 /**
946  * gfs2_lm_mount - mount a locking protocol
947  * @sdp: the filesystem
948  * @args: mount arguments
949  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
950  *
951  * Returns: errno
952  */
953
954 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
955 {
956         const struct lm_lockops *lm;
957         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
958         struct gfs2_args *args = &sdp->sd_args;
959         const char *proto = sdp->sd_proto_name;
960         const char *table = sdp->sd_table_name;
961         const char *fsname;
962         char *o, *options;
963         int ret;
964
965         if (!strcmp("lock_nolock", proto)) {
966                 lm = &nolock_ops;
967                 sdp->sd_args.ar_localflocks = 1;
968 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
969         } else if (!strcmp("lock_dlm", proto)) {
970                 lm = &gfs2_dlm_ops;
971 #endif
972         } else {
973                 printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
974                 return -ENOENT;
975         }
976
977         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
978
979         ls->ls_ops = lm;
980         ls->ls_first = 1;
981
982         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
983                 substring_t tmp[MAX_OPT_ARGS];
984                 int token, option;
985
986                 if (!o || !*o)
987                         continue;
988
989                 token = match_token(o, *lm->lm_tokens, tmp);
990                 switch (token) {
991                 case Opt_jid:
992                         ret = match_int(&tmp[0], &option);
993                         if (ret || option < 0) 
994                                 goto hostdata_error;
995                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
996                                 ls->ls_jid = option;
997                         break;
998                 case Opt_id:
999                         /* Obsolete, but left for backward compat purposes */
1000                         break;
1001                 case Opt_first:
1002                         ret = match_int(&tmp[0], &option);
1003                         if (ret || (option != 0 && option != 1))
1004                                 goto hostdata_error;
1005                         ls->ls_first = option;
1006                         break;
1007                 case Opt_nodir:
1008                         ret = match_int(&tmp[0], &option);
1009                         if (ret || (option != 0 && option != 1))
1010                                 goto hostdata_error;
1011                         ls->ls_nodir = option;
1012                         break;
1013                 case Opt_err:
1014                 default:
1015 hostdata_error:
1016                         fs_info(sdp, "unknown hostdata (%s)\n", o);
1017                         return -EINVAL;
1018                 }
1019         }
1020
1021         if (sdp->sd_args.ar_spectator)
1022                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s", table);
1023         else
1024                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u", table,
1025                          sdp->sd_lockstruct.ls_jid);
1026
1027         fsname = strchr(table, ':');
1028         if (fsname)
1029                 fsname++;
1030         if (lm->lm_mount == NULL) {
1031                 fs_info(sdp, "Now mounting FS...\n");
1032                 return 0;
1033         }
1034         ret = lm->lm_mount(sdp, fsname);
1035         if (ret == 0)
1036                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1037         return ret;
1038 }
1039
1040 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1041 {
1042         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1043         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1044             lm->lm_unmount)
1045                 lm->lm_unmount(sdp);
1046 }
1047
1048 static int gfs2_journalid_wait(void *word)
1049 {
1050         if (signal_pending(current))
1051                 return -EINTR;
1052         schedule();
1053         return 0;
1054 }
1055
1056 static int wait_on_journal(struct gfs2_sbd *sdp)
1057 {
1058         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1059                 return 0;
1060
1061         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
1062 }
1063
1064 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1065 {
1066         struct super_block *sb = sdp->sd_vfs;
1067         char ro[20];
1068         char spectator[20];
1069         char *envp[] = { ro, spectator, NULL };
1070         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1071         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1072         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1073 }
1074
1075 /**
1076  * fill_super - Read in superblock
1077  * @sb: The VFS superblock
1078  * @data: Mount options
1079  * @silent: Don't complain if it's not a GFS2 filesystem
1080  *
1081  * Returns: errno
1082  */
1083
1084 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1085 {
1086         struct gfs2_sbd *sdp;
1087         struct gfs2_holder mount_gh;
1088         int error;
1089
1090         sdp = init_sbd(sb);
1091         if (!sdp) {
1092                 printk(KERN_WARNING "GFS2: can't alloc struct gfs2_sbd\n");
1093                 return -ENOMEM;
1094         }
1095         sdp->sd_args = *args;
1096
1097         if (sdp->sd_args.ar_spectator) {
1098                 sb->s_flags |= MS_RDONLY;
1099                 set_bit(SDF_NORECOVERY, &sdp->sd_flags);
1100         }
1101         if (sdp->sd_args.ar_posix_acl)
1102                 sb->s_flags |= MS_POSIXACL;
1103         if (sdp->sd_args.ar_nobarrier)
1104                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1105
1106         sb->s_magic = GFS2_MAGIC;
1107         sb->s_op = &gfs2_super_ops;
1108         sb->s_d_op = &gfs2_dops;
1109         sb->s_export_op = &gfs2_export_ops;
1110         sb->s_xattr = gfs2_xattr_handlers;
1111         sb->s_qcop = &gfs2_quotactl_ops;
1112         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1113         sb->s_time_gran = 1;
1114         sb->s_maxbytes = MAX_LFS_FILESIZE;
1115
1116         /* Set up the buffer cache and fill in some fake block size values
1117            to allow us to read-in the on-disk superblock. */
1118         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1119         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1120         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1121                                GFS2_BASIC_BLOCK_SHIFT;
1122         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1123
1124         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1125         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1126         if (sdp->sd_args.ar_statfs_quantum) {
1127                 sdp->sd_tune.gt_statfs_slow = 0;
1128                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1129         }
1130         else {
1131                 sdp->sd_tune.gt_statfs_slow = 1;
1132                 sdp->sd_tune.gt_statfs_quantum = 30;
1133         }
1134
1135         error = init_names(sdp, silent);
1136         if (error)
1137                 goto fail;
1138
1139         gfs2_create_debugfs_file(sdp);
1140
1141         error = gfs2_sys_fs_add(sdp);
1142         if (error)
1143                 goto fail;
1144
1145         error = gfs2_lm_mount(sdp, silent);
1146         if (error)
1147                 goto fail_sys;
1148
1149         error = init_locking(sdp, &mount_gh, DO);
1150         if (error)
1151                 goto fail_lm;
1152
1153         error = init_sb(sdp, silent);
1154         if (error)
1155                 goto fail_locking;
1156
1157         error = wait_on_journal(sdp);
1158         if (error)
1159                 goto fail_sb;
1160
1161         /*
1162          * If user space has failed to join the cluster or some similar
1163          * failure has occurred, then the journal id will contain a
1164          * negative (error) number. This will then be returned to the
1165          * caller (of the mount syscall). We do this even for spectator
1166          * mounts (which just write a jid of 0 to indicate "ok" even though
1167          * the jid is unused in the spectator case)
1168          */
1169         if (sdp->sd_lockstruct.ls_jid < 0) {
1170                 error = sdp->sd_lockstruct.ls_jid;
1171                 sdp->sd_lockstruct.ls_jid = 0;
1172                 goto fail_sb;
1173         }
1174
1175         error = init_inodes(sdp, DO);
1176         if (error)
1177                 goto fail_sb;
1178
1179         error = init_per_node(sdp, DO);
1180         if (error)
1181                 goto fail_inodes;
1182
1183         error = gfs2_statfs_init(sdp);
1184         if (error) {
1185                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1186                 goto fail_per_node;
1187         }
1188
1189         error = init_threads(sdp, DO);
1190         if (error)
1191                 goto fail_per_node;
1192
1193         if (!(sb->s_flags & MS_RDONLY)) {
1194                 error = gfs2_make_fs_rw(sdp);
1195                 if (error) {
1196                         fs_err(sdp, "can't make FS RW: %d\n", error);
1197                         goto fail_threads;
1198                 }
1199         }
1200
1201         gfs2_glock_dq_uninit(&mount_gh);
1202         gfs2_online_uevent(sdp);
1203         return 0;
1204
1205 fail_threads:
1206         init_threads(sdp, UNDO);
1207 fail_per_node:
1208         init_per_node(sdp, UNDO);
1209 fail_inodes:
1210         init_inodes(sdp, UNDO);
1211 fail_sb:
1212         if (sdp->sd_root_dir)
1213                 dput(sdp->sd_root_dir);
1214         if (sdp->sd_master_dir)
1215                 dput(sdp->sd_master_dir);
1216         if (sb->s_root)
1217                 dput(sb->s_root);
1218         sb->s_root = NULL;
1219 fail_locking:
1220         init_locking(sdp, &mount_gh, UNDO);
1221 fail_lm:
1222         gfs2_gl_hash_clear(sdp);
1223         gfs2_lm_unmount(sdp);
1224 fail_sys:
1225         gfs2_sys_fs_del(sdp);
1226 fail:
1227         gfs2_delete_debugfs_file(sdp);
1228         kfree(sdp);
1229         sb->s_fs_info = NULL;
1230         return error;
1231 }
1232
1233 static int set_gfs2_super(struct super_block *s, void *data)
1234 {
1235         s->s_bdev = data;
1236         s->s_dev = s->s_bdev->bd_dev;
1237
1238         /*
1239          * We set the bdi here to the queue backing, file systems can
1240          * overwrite this in ->fill_super()
1241          */
1242         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1243         return 0;
1244 }
1245
1246 static int test_gfs2_super(struct super_block *s, void *ptr)
1247 {
1248         struct block_device *bdev = ptr;
1249         return (bdev == s->s_bdev);
1250 }
1251
1252 /**
1253  * gfs2_mount - Get the GFS2 superblock
1254  * @fs_type: The GFS2 filesystem type
1255  * @flags: Mount flags
1256  * @dev_name: The name of the device
1257  * @data: The mount arguments
1258  *
1259  * Q. Why not use get_sb_bdev() ?
1260  * A. We need to select one of two root directories to mount, independent
1261  *    of whether this is the initial, or subsequent, mount of this sb
1262  *
1263  * Returns: 0 or -ve on error
1264  */
1265
1266 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1267                        const char *dev_name, void *data)
1268 {
1269         struct block_device *bdev;
1270         struct super_block *s;
1271         fmode_t mode = FMODE_READ | FMODE_EXCL;
1272         int error;
1273         struct gfs2_args args;
1274         struct gfs2_sbd *sdp;
1275
1276         if (!(flags & MS_RDONLY))
1277                 mode |= FMODE_WRITE;
1278
1279         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1280         if (IS_ERR(bdev))
1281                 return ERR_CAST(bdev);
1282
1283         /*
1284          * once the super is inserted into the list by sget, s_umount
1285          * will protect the lockfs code from trying to start a snapshot
1286          * while we are mounting
1287          */
1288         mutex_lock(&bdev->bd_fsfreeze_mutex);
1289         if (bdev->bd_fsfreeze_count > 0) {
1290                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1291                 error = -EBUSY;
1292                 goto error_bdev;
1293         }
1294         s = sget(fs_type, test_gfs2_super, set_gfs2_super, bdev);
1295         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1296         error = PTR_ERR(s);
1297         if (IS_ERR(s))
1298                 goto error_bdev;
1299
1300         if (s->s_root)
1301                 blkdev_put(bdev, mode);
1302
1303         memset(&args, 0, sizeof(args));
1304         args.ar_quota = GFS2_QUOTA_DEFAULT;
1305         args.ar_data = GFS2_DATA_DEFAULT;
1306         args.ar_commit = 30;
1307         args.ar_statfs_quantum = 30;
1308         args.ar_quota_quantum = 60;
1309         args.ar_errors = GFS2_ERRORS_DEFAULT;
1310
1311         error = gfs2_mount_args(&args, data);
1312         if (error) {
1313                 printk(KERN_WARNING "GFS2: can't parse mount arguments\n");
1314                 goto error_super;
1315         }
1316
1317         if (s->s_root) {
1318                 error = -EBUSY;
1319                 if ((flags ^ s->s_flags) & MS_RDONLY)
1320                         goto error_super;
1321         } else {
1322                 char b[BDEVNAME_SIZE];
1323
1324                 s->s_flags = flags;
1325                 s->s_mode = mode;
1326                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1327                 sb_set_blocksize(s, block_size(bdev));
1328                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1329                 if (error)
1330                         goto error_super;
1331                 s->s_flags |= MS_ACTIVE;
1332                 bdev->bd_super = s;
1333         }
1334
1335         sdp = s->s_fs_info;
1336         if (args.ar_meta)
1337                 return dget(sdp->sd_master_dir);
1338         else
1339                 return dget(sdp->sd_root_dir);
1340
1341 error_super:
1342         deactivate_locked_super(s);
1343         return ERR_PTR(error);
1344 error_bdev:
1345         blkdev_put(bdev, mode);
1346         return ERR_PTR(error);
1347 }
1348
1349 static int set_meta_super(struct super_block *s, void *ptr)
1350 {
1351         return -EINVAL;
1352 }
1353
1354 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1355                         int flags, const char *dev_name, void *data)
1356 {
1357         struct super_block *s;
1358         struct gfs2_sbd *sdp;
1359         struct path path;
1360         int error;
1361
1362         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1363         if (error) {
1364                 printk(KERN_WARNING "GFS2: path_lookup on %s returned error %d\n",
1365                        dev_name, error);
1366                 return ERR_PTR(error);
1367         }
1368         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super,
1369                  path.dentry->d_inode->i_sb->s_bdev);
1370         path_put(&path);
1371         if (IS_ERR(s)) {
1372                 printk(KERN_WARNING "GFS2: gfs2 mount does not exist\n");
1373                 return ERR_CAST(s);
1374         }
1375         if ((flags ^ s->s_flags) & MS_RDONLY) {
1376                 deactivate_locked_super(s);
1377                 return ERR_PTR(-EBUSY);
1378         }
1379         sdp = s->s_fs_info;
1380         return dget(sdp->sd_master_dir);
1381 }
1382
1383 static void gfs2_kill_sb(struct super_block *sb)
1384 {
1385         struct gfs2_sbd *sdp = sb->s_fs_info;
1386
1387         if (sdp == NULL) {
1388                 kill_block_super(sb);
1389                 return;
1390         }
1391
1392         gfs2_meta_syncfs(sdp);
1393         dput(sdp->sd_root_dir);
1394         dput(sdp->sd_master_dir);
1395         sdp->sd_root_dir = NULL;
1396         sdp->sd_master_dir = NULL;
1397         shrink_dcache_sb(sb);
1398         kill_block_super(sb);
1399         gfs2_delete_debugfs_file(sdp);
1400         kfree(sdp);
1401 }
1402
1403 struct file_system_type gfs2_fs_type = {
1404         .name = "gfs2",
1405         .fs_flags = FS_REQUIRES_DEV,
1406         .mount = gfs2_mount,
1407         .kill_sb = gfs2_kill_sb,
1408         .owner = THIS_MODULE,
1409 };
1410
1411 struct file_system_type gfs2meta_fs_type = {
1412         .name = "gfs2meta",
1413         .fs_flags = FS_REQUIRES_DEV,
1414         .mount = gfs2_mount_meta,
1415         .owner = THIS_MODULE,
1416 };
1417