Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

Linux/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 
 27 #include "gfs2.h"
 28 #include "incore.h"
 29 #include "bmap.h"
 30 #include "glock.h"
 31 #include "glops.h"
 32 #include "inode.h"
 33 #include "recovery.h"
 34 #include "rgrp.h"
 35 #include "super.h"
 36 #include "sys.h"
 37 #include "util.h"
 38 #include "log.h"
 39 #include "quota.h"
 40 #include "dir.h"
 41 #include "meta_io.h"
 42 #include "trace_gfs2.h"
 43 
 44 #define DO 0
 45 #define UNDO 1
 46 
 47 /**
 48  * gfs2_tune_init - Fill a gfs2_tune structure with default values
 49  * @gt: tune
 50  *
 51  */
 52 
 53 static void gfs2_tune_init(struct gfs2_tune *gt)
 54 {
 55         spin_lock_init(&gt->gt_spin);
 56 
 57         gt->gt_quota_warn_period = 10;
 58         gt->gt_quota_scale_num = 1;
 59         gt->gt_quota_scale_den = 1;
 60         gt->gt_new_files_jdata = 0;
 61         gt->gt_max_readahead = 1 << 18;
 62         gt->gt_complain_secs = 10;
 63 }
 64 
 65 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 66 {
 67         struct gfs2_sbd *sdp;
 68         struct address_space *mapping;
 69 
 70         sdp = kzalloc(sizeof(struct gfs2_sbd), GFP_KERNEL);
 71         if (!sdp)
 72                 return NULL;
 73 
 74         sb->s_fs_info = sdp;
 75         sdp->sd_vfs = sb;
 76         sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats);
 77         if (!sdp->sd_lkstats) {
 78                 kfree(sdp);
 79                 return NULL;
 80         }
 81 
 82         set_bit(SDF_NOJOURNALID, &sdp->sd_flags);
 83         gfs2_tune_init(&sdp->sd_tune);
 84 
 85         init_waitqueue_head(&sdp->sd_glock_wait);
 86         atomic_set(&sdp->sd_glock_disposal, 0);
 87         init_completion(&sdp->sd_locking_init);
 88         init_completion(&sdp->sd_wdack);
 89         spin_lock_init(&sdp->sd_statfs_spin);
 90 
 91         spin_lock_init(&sdp->sd_rindex_spin);
 92         sdp->sd_rindex_tree.rb_node = NULL;
 93 
 94         INIT_LIST_HEAD(&sdp->sd_jindex_list);
 95         spin_lock_init(&sdp->sd_jindex_spin);
 96         mutex_init(&sdp->sd_jindex_mutex);
 97         init_completion(&sdp->sd_journal_ready);
 98 
 99         INIT_LIST_HEAD(&sdp->sd_quota_list);
100         mutex_init(&sdp->sd_quota_mutex);
101         mutex_init(&sdp->sd_quota_sync_mutex);
102         init_waitqueue_head(&sdp->sd_quota_wait);
103         INIT_LIST_HEAD(&sdp->sd_trunc_list);
104         spin_lock_init(&sdp->sd_trunc_lock);
105         spin_lock_init(&sdp->sd_bitmap_lock);
106 
107         mapping = &sdp->sd_aspace;
108 
109         address_space_init_once(mapping);
110         mapping->a_ops = &gfs2_rgrp_aops;
111         mapping->host = sb->s_bdev->bd_inode;
112         mapping->flags = 0;
113         mapping_set_gfp_mask(mapping, GFP_NOFS);
114         mapping->private_data = NULL;
115         mapping->writeback_index = 0;
116 
117         spin_lock_init(&sdp->sd_log_lock);
118         atomic_set(&sdp->sd_log_pinned, 0);
119         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
120         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
121         spin_lock_init(&sdp->sd_ordered_lock);
122 
123         init_waitqueue_head(&sdp->sd_log_waitq);
124         init_waitqueue_head(&sdp->sd_logd_waitq);
125         spin_lock_init(&sdp->sd_ail_lock);
126         INIT_LIST_HEAD(&sdp->sd_ail1_list);
127         INIT_LIST_HEAD(&sdp->sd_ail2_list);
128 
129         init_rwsem(&sdp->sd_log_flush_lock);
130         atomic_set(&sdp->sd_log_in_flight, 0);
131         atomic_set(&sdp->sd_reserving_log, 0);
132         init_waitqueue_head(&sdp->sd_reserving_log_wait);
133         init_waitqueue_head(&sdp->sd_log_flush_wait);
134         atomic_set(&sdp->sd_freeze_state, SFS_UNFROZEN);
135         mutex_init(&sdp->sd_freeze_mutex);
136 
137         return sdp;
138 }
139 
140 
141 /**
142  * gfs2_check_sb - Check superblock
143  * @sdp: the filesystem
144  * @sb: The superblock
145  * @silent: Don't print a message if the check fails
146  *
147  * Checks the version code of the FS is one that we understand how to
148  * read and that the sizes of the various on-disk structures have not
149  * changed.
150  */
151 
152 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
153 {
154         struct gfs2_sb_host *sb = &sdp->sd_sb;
155 
156         if (sb->sb_magic != GFS2_MAGIC ||
157             sb->sb_type != GFS2_METATYPE_SB) {
158                 if (!silent)
159                         pr_warn("not a GFS2 filesystem\n");
160                 return -EINVAL;
161         }
162 
163         /*  If format numbers match exactly, we're done.  */
164 
165         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
166             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
167                 return 0;
168 
169         fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
170 
171         return -EINVAL;
172 }
173 
174 static void end_bio_io_page(struct bio *bio)
175 {
176         struct page *page = bio->bi_private;
177 
178         if (!bio->bi_error)
179                 SetPageUptodate(page);
180         else
181                 pr_warn("error %d reading superblock\n", bio->bi_error);
182         unlock_page(page);
183 }
184 
185 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
186 {
187         struct gfs2_sb_host *sb = &sdp->sd_sb;
188         struct super_block *s = sdp->sd_vfs;
189         const struct gfs2_sb *str = buf;
190 
191         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
192         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
193         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
194         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
195         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
196         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
197         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
198         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
199         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
200         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
201         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
202 
203         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
204         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
205         memcpy(s->s_uuid, str->sb_uuid, 16);
206 }
207 
208 /**
209  * gfs2_read_super - Read the gfs2 super block from disk
210  * @sdp: The GFS2 super block
211  * @sector: The location of the super block
212  * @error: The error code to return
213  *
214  * This uses the bio functions to read the super block from disk
215  * because we want to be 100% sure that we never read cached data.
216  * A super block is read twice only during each GFS2 mount and is
217  * never written to by the filesystem. The first time its read no
218  * locks are held, and the only details which are looked at are those
219  * relating to the locking protocol. Once locking is up and working,
220  * the sb is read again under the lock to establish the location of
221  * the master directory (contains pointers to journals etc) and the
222  * root directory.
223  *
224  * Returns: 0 on success or error
225  */
226 
227 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
228 {
229         struct super_block *sb = sdp->sd_vfs;
230         struct gfs2_sb *p;
231         struct page *page;
232         struct bio *bio;
233 
234         page = alloc_page(GFP_NOFS);
235         if (unlikely(!page))
236                 return -ENOMEM;
237 
238         ClearPageUptodate(page);
239         ClearPageDirty(page);
240         lock_page(page);
241 
242         bio = bio_alloc(GFP_NOFS, 1);
243         bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
244         bio->bi_bdev = sb->s_bdev;
245         bio_add_page(bio, page, PAGE_SIZE, 0);
246 
247         bio->bi_end_io = end_bio_io_page;
248         bio->bi_private = page;
249         submit_bio(READ_SYNC | REQ_META, bio);
250         wait_on_page_locked(page);
251         bio_put(bio);
252         if (!PageUptodate(page)) {
253                 __free_page(page);
254                 return -EIO;
255         }
256         p = kmap(page);
257         gfs2_sb_in(sdp, p);
258         kunmap(page);
259         __free_page(page);
260         return gfs2_check_sb(sdp, silent);
261 }
262 
263 /**
264  * gfs2_read_sb - Read super block
265  * @sdp: The GFS2 superblock
266  * @silent: Don't print message if mount fails
267  *
268  */
269 
270 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
271 {
272         u32 hash_blocks, ind_blocks, leaf_blocks;
273         u32 tmp_blocks;
274         unsigned int x;
275         int error;
276 
277         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
278         if (error) {
279                 if (!silent)
280                         fs_err(sdp, "can't read superblock\n");
281                 return error;
282         }
283 
284         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
285                                GFS2_BASIC_BLOCK_SHIFT;
286         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
287         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
288                           sizeof(struct gfs2_dinode)) / sizeof(u64);
289         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
290                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
291         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
292         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
293         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
294         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
295         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
296                                 sizeof(struct gfs2_meta_header)) /
297                                 sizeof(struct gfs2_quota_change);
298         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
299                                      sizeof(struct gfs2_meta_header))
300                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
301 
302         /* Compute maximum reservation required to add a entry to a directory */
303 
304         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
305                              sdp->sd_jbsize);
306 
307         ind_blocks = 0;
308         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
309                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
310                 ind_blocks += tmp_blocks;
311         }
312 
313         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
314 
315         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
316 
317         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
318                                 sizeof(struct gfs2_dinode);
319         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
320         for (x = 2;; x++) {
321                 u64 space, d;
322                 u32 m;
323 
324                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
325                 d = space;
326                 m = do_div(d, sdp->sd_inptrs);
327 
328                 if (d != sdp->sd_heightsize[x - 1] || m)
329                         break;
330                 sdp->sd_heightsize[x] = space;
331         }
332         sdp->sd_max_height = x;
333         sdp->sd_heightsize[x] = ~0;
334         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
335 
336         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
337                                  sizeof(struct gfs2_dinode);
338         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
339         for (x = 2;; x++) {
340                 u64 space, d;
341                 u32 m;
342 
343                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
344                 d = space;
345                 m = do_div(d, sdp->sd_inptrs);
346 
347                 if (d != sdp->sd_jheightsize[x - 1] || m)
348                         break;
349                 sdp->sd_jheightsize[x] = space;
350         }
351         sdp->sd_max_jheight = x;
352         sdp->sd_jheightsize[x] = ~0;
353         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
354 
355         return 0;
356 }
357 
358 static int init_names(struct gfs2_sbd *sdp, int silent)
359 {
360         char *proto, *table;
361         int error = 0;
362 
363         proto = sdp->sd_args.ar_lockproto;
364         table = sdp->sd_args.ar_locktable;
365 
366         /*  Try to autodetect  */
367 
368         if (!proto[0] || !table[0]) {
369                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
370                 if (error)
371                         return error;
372 
373                 if (!proto[0])
374                         proto = sdp->sd_sb.sb_lockproto;
375                 if (!table[0])
376                         table = sdp->sd_sb.sb_locktable;
377         }
378 
379         if (!table[0])
380                 table = sdp->sd_vfs->s_id;
381 
382         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
383         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
384 
385         table = sdp->sd_table_name;
386         while ((table = strchr(table, '/')))
387                 *table = '_';
388 
389         return error;
390 }
391 
392 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
393                         int undo)
394 {
395         int error = 0;
396 
397         if (undo)
398                 goto fail_trans;
399 
400         error = gfs2_glock_nq_num(sdp,
401                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
402                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
403                                   mount_gh);
404         if (error) {
405                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
406                 goto fail;
407         }
408 
409         error = gfs2_glock_nq_num(sdp,
410                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
411                                   LM_ST_SHARED,
412                                   LM_FLAG_NOEXP | GL_EXACT,
413                                   &sdp->sd_live_gh);
414         if (error) {
415                 fs_err(sdp, "can't acquire live glock: %d\n", error);
416                 goto fail_mount;
417         }
418 
419         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
420                                CREATE, &sdp->sd_rename_gl);
421         if (error) {
422                 fs_err(sdp, "can't create rename glock: %d\n", error);
423                 goto fail_live;
424         }
425 
426         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
427                                CREATE, &sdp->sd_freeze_gl);
428         if (error) {
429                 fs_err(sdp, "can't create transaction glock: %d\n", error);
430                 goto fail_rename;
431         }
432 
433         return 0;
434 
435 fail_trans:
436         gfs2_glock_put(sdp->sd_freeze_gl);
437 fail_rename:
438         gfs2_glock_put(sdp->sd_rename_gl);
439 fail_live:
440         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
441 fail_mount:
442         gfs2_glock_dq_uninit(mount_gh);
443 fail:
444         return error;
445 }
446 
447 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
448                             u64 no_addr, const char *name)
449 {
450         struct gfs2_sbd *sdp = sb->s_fs_info;
451         struct dentry *dentry;
452         struct inode *inode;
453 
454         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
455         if (IS_ERR(inode)) {
456                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
457                 return PTR_ERR(inode);
458         }
459         dentry = d_make_root(inode);
460         if (!dentry) {
461                 fs_err(sdp, "can't alloc %s dentry\n", name);
462                 return -ENOMEM;
463         }
464         *dptr = dentry;
465         return 0;
466 }
467 
468 static int init_sb(struct gfs2_sbd *sdp, int silent)
469 {
470         struct super_block *sb = sdp->sd_vfs;
471         struct gfs2_holder sb_gh;
472         u64 no_addr;
473         int ret;
474 
475         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
476                                 LM_ST_SHARED, 0, &sb_gh);
477         if (ret) {
478                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
479                 return ret;
480         }
481 
482         ret = gfs2_read_sb(sdp, silent);
483         if (ret) {
484                 fs_err(sdp, "can't read superblock: %d\n", ret);
485                 goto out;
486         }
487 
488         /* Set up the buffer cache and SB for real */
489         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
490                 ret = -EINVAL;
491                 fs_err(sdp, "FS block size (%u) is too small for device "
492                        "block size (%u)\n",
493                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
494                 goto out;
495         }
496         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
497                 ret = -EINVAL;
498                 fs_err(sdp, "FS block size (%u) is too big for machine "
499                        "page size (%u)\n",
500                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
501                 goto out;
502         }
503         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
504 
505         /* Get the root inode */
506         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
507         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
508         if (ret)
509                 goto out;
510 
511         /* Get the master inode */
512         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
513         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
514         if (ret) {
515                 dput(sdp->sd_root_dir);
516                 goto out;
517         }
518         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
519 out:
520         gfs2_glock_dq_uninit(&sb_gh);
521         return ret;
522 }
523 
524 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
525 {
526         char *message = "FIRSTMOUNT=Done";
527         char *envp[] = { message, NULL };
528 
529         fs_info(sdp, "first mount done, others may mount\n");
530 
531         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
532                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
533 
534         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
535 }
536 
537 /**
538  * gfs2_jindex_hold - Grab a lock on the jindex
539  * @sdp: The GFS2 superblock
540  * @ji_gh: the holder for the jindex glock
541  *
542  * Returns: errno
543  */
544 
545 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
546 {
547         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
548         struct qstr name;
549         char buf[20];
550         struct gfs2_jdesc *jd;
551         int error;
552 
553         name.name = buf;
554 
555         mutex_lock(&sdp->sd_jindex_mutex);
556 
557         for (;;) {
558                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
559                 if (error)
560                         break;
561 
562                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
563                 name.hash = gfs2_disk_hash(name.name, name.len);
564 
565                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
566                 if (error == -ENOENT) {
567                         error = 0;
568                         break;
569                 }
570 
571                 gfs2_glock_dq_uninit(ji_gh);
572 
573                 if (error)
574                         break;
575 
576                 error = -ENOMEM;
577                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
578                 if (!jd)
579                         break;
580 
581                 INIT_LIST_HEAD(&jd->extent_list);
582                 INIT_LIST_HEAD(&jd->jd_revoke_list);
583 
584                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
585                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
586                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
587                         if (!jd->jd_inode)
588                                 error = -ENOENT;
589                         else
590                                 error = PTR_ERR(jd->jd_inode);
591                         kfree(jd);
592                         break;
593                 }
594 
595                 spin_lock(&sdp->sd_jindex_spin);
596                 jd->jd_jid = sdp->sd_journals++;
597                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
598                 spin_unlock(&sdp->sd_jindex_spin);
599         }
600 
601         mutex_unlock(&sdp->sd_jindex_mutex);
602 
603         return error;
604 }
605 
606 /**
607  * check_journal_clean - Make sure a journal is clean for a spectator mount
608  * @sdp: The GFS2 superblock
609  * @jd: The journal descriptor
610  *
611  * Returns: 0 if the journal is clean or locked, else an error
612  */
613 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
614 {
615         int error;
616         struct gfs2_holder j_gh;
617         struct gfs2_log_header_host head;
618         struct gfs2_inode *ip;
619 
620         ip = GFS2_I(jd->jd_inode);
621         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
622                                    GL_EXACT | GL_NOCACHE, &j_gh);
623         if (error) {
624                 fs_err(sdp, "Error locking journal for spectator mount.\n");
625                 return -EPERM;
626         }
627         error = gfs2_jdesc_check(jd);
628         if (error) {
629                 fs_err(sdp, "Error checking journal for spectator mount.\n");
630                 goto out_unlock;
631         }
632         error = gfs2_find_jhead(jd, &head);
633         if (error) {
634                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
635                 goto out_unlock;
636         }
637         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
638                 error = -EPERM;
639                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
640                        "must not be a spectator.\n", jd->jd_jid);
641         }
642 
643 out_unlock:
644         gfs2_glock_dq_uninit(&j_gh);
645         return error;
646 }
647 
648 static int init_journal(struct gfs2_sbd *sdp, int undo)
649 {
650         struct inode *master = d_inode(sdp->sd_master_dir);
651         struct gfs2_holder ji_gh;
652         struct gfs2_inode *ip;
653         int jindex = 1;
654         int error = 0;
655 
656         if (undo) {
657                 jindex = 0;
658                 goto fail_jinode_gh;
659         }
660 
661         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
662         if (IS_ERR(sdp->sd_jindex)) {
663                 fs_err(sdp, "can't lookup journal index: %d\n", error);
664                 return PTR_ERR(sdp->sd_jindex);
665         }
666 
667         /* Load in the journal index special file */
668 
669         error = gfs2_jindex_hold(sdp, &ji_gh);
670         if (error) {
671                 fs_err(sdp, "can't read journal index: %d\n", error);
672                 goto fail;
673         }
674 
675         error = -EUSERS;
676         if (!gfs2_jindex_size(sdp)) {
677                 fs_err(sdp, "no journals!\n");
678                 goto fail_jindex;
679         }
680 
681         if (sdp->sd_args.ar_spectator) {
682                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
683                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
684                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
685                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
686         } else {
687                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
688                         fs_err(sdp, "can't mount journal #%u\n",
689                                sdp->sd_lockstruct.ls_jid);
690                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
691                                gfs2_jindex_size(sdp),
692                                gfs2_jindex_size(sdp) - 1);
693                         goto fail_jindex;
694                 }
695                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
696 
697                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
698                                           &gfs2_journal_glops,
699                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
700                                           &sdp->sd_journal_gh);
701                 if (error) {
702                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
703                         goto fail_jindex;
704                 }
705 
706                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
707                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
708                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
709                                            &sdp->sd_jinode_gh);
710                 if (error) {
711                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
712                                error);
713                         goto fail_journal_gh;
714                 }
715 
716                 error = gfs2_jdesc_check(sdp->sd_jdesc);
717                 if (error) {
718                         fs_err(sdp, "my journal (%u) is bad: %d\n",
719                                sdp->sd_jdesc->jd_jid, error);
720                         goto fail_jinode_gh;
721                 }
722                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
723                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
724                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
725 
726                 /* Map the extents for this journal's blocks */
727                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
728         }
729         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
730 
731         if (sdp->sd_lockstruct.ls_first) {
732                 unsigned int x;
733                 for (x = 0; x < sdp->sd_journals; x++) {
734                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
735 
736                         if (sdp->sd_args.ar_spectator) {
737                                 error = check_journal_clean(sdp, jd);
738                                 if (error)
739                                         goto fail_jinode_gh;
740                                 continue;
741                         }
742                         error = gfs2_recover_journal(jd, true);
743                         if (error) {
744                                 fs_err(sdp, "error recovering journal %u: %d\n",
745                                        x, error);
746                                 goto fail_jinode_gh;
747                         }
748                 }
749 
750                 gfs2_others_may_mount(sdp);
751         } else if (!sdp->sd_args.ar_spectator) {
752                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
753                 if (error) {
754                         fs_err(sdp, "error recovering my journal: %d\n", error);
755                         goto fail_jinode_gh;
756                 }
757         }
758 
759         sdp->sd_log_idle = 1;
760         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
761         gfs2_glock_dq_uninit(&ji_gh);
762         jindex = 0;
763         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
764         return 0;
765 
766 fail_jinode_gh:
767         if (!sdp->sd_args.ar_spectator)
768                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
769 fail_journal_gh:
770         if (!sdp->sd_args.ar_spectator)
771                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
772 fail_jindex:
773         gfs2_jindex_free(sdp);
774         if (jindex)
775                 gfs2_glock_dq_uninit(&ji_gh);
776 fail:
777         iput(sdp->sd_jindex);
778         return error;
779 }
780 
781 static struct lock_class_key gfs2_quota_imutex_key;
782 
783 static int init_inodes(struct gfs2_sbd *sdp, int undo)
784 {
785         int error = 0;
786         struct inode *master = d_inode(sdp->sd_master_dir);
787 
788         if (undo)
789                 goto fail_qinode;
790 
791         error = init_journal(sdp, undo);
792         complete_all(&sdp->sd_journal_ready);
793         if (error)
794                 goto fail;
795 
796         /* Read in the master statfs inode */
797         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
798         if (IS_ERR(sdp->sd_statfs_inode)) {
799                 error = PTR_ERR(sdp->sd_statfs_inode);
800                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
801                 goto fail_journal;
802         }
803 
804         /* Read in the resource index inode */
805         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
806         if (IS_ERR(sdp->sd_rindex)) {
807                 error = PTR_ERR(sdp->sd_rindex);
808                 fs_err(sdp, "can't get resource index inode: %d\n", error);
809                 goto fail_statfs;
810         }
811         sdp->sd_rindex_uptodate = 0;
812 
813         /* Read in the quota inode */
814         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
815         if (IS_ERR(sdp->sd_quota_inode)) {
816                 error = PTR_ERR(sdp->sd_quota_inode);
817                 fs_err(sdp, "can't get quota file inode: %d\n", error);
818                 goto fail_rindex;
819         }
820         /*
821          * i_mutex on quota files is special. Since this inode is hidden system
822          * file, we are safe to define locking ourselves.
823          */
824         lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
825                           &gfs2_quota_imutex_key);
826 
827         error = gfs2_rindex_update(sdp);
828         if (error)
829                 goto fail_qinode;
830 
831         return 0;
832 
833 fail_qinode:
834         iput(sdp->sd_quota_inode);
835 fail_rindex:
836         gfs2_clear_rgrpd(sdp);
837         iput(sdp->sd_rindex);
838 fail_statfs:
839         iput(sdp->sd_statfs_inode);
840 fail_journal:
841         init_journal(sdp, UNDO);
842 fail:
843         return error;
844 }
845 
846 static int init_per_node(struct gfs2_sbd *sdp, int undo)
847 {
848         struct inode *pn = NULL;
849         char buf[30];
850         int error = 0;
851         struct gfs2_inode *ip;
852         struct inode *master = d_inode(sdp->sd_master_dir);
853 
854         if (sdp->sd_args.ar_spectator)
855                 return 0;
856 
857         if (undo)
858                 goto fail_qc_gh;
859 
860         pn = gfs2_lookup_simple(master, "per_node");
861         if (IS_ERR(pn)) {
862                 error = PTR_ERR(pn);
863                 fs_err(sdp, "can't find per_node directory: %d\n", error);
864                 return error;
865         }
866 
867         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
868         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
869         if (IS_ERR(sdp->sd_sc_inode)) {
870                 error = PTR_ERR(sdp->sd_sc_inode);
871                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
872                 goto fail;
873         }
874 
875         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
876         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
877         if (IS_ERR(sdp->sd_qc_inode)) {
878                 error = PTR_ERR(sdp->sd_qc_inode);
879                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
880                 goto fail_ut_i;
881         }
882 
883         iput(pn);
884         pn = NULL;
885 
886         ip = GFS2_I(sdp->sd_sc_inode);
887         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
888                                    &sdp->sd_sc_gh);
889         if (error) {
890                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
891                 goto fail_qc_i;
892         }
893 
894         ip = GFS2_I(sdp->sd_qc_inode);
895         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
896                                    &sdp->sd_qc_gh);
897         if (error) {
898                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
899                 goto fail_ut_gh;
900         }
901 
902         return 0;
903 
904 fail_qc_gh:
905         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
906 fail_ut_gh:
907         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
908 fail_qc_i:
909         iput(sdp->sd_qc_inode);
910 fail_ut_i:
911         iput(sdp->sd_sc_inode);
912 fail:
913         if (pn)
914                 iput(pn);
915         return error;
916 }
917 
918 static const match_table_t nolock_tokens = {
919         { Opt_jid, "jid=%d\n", },
920         { Opt_err, NULL },
921 };
922 
923 static const struct lm_lockops nolock_ops = {
924         .lm_proto_name = "lock_nolock",
925         .lm_put_lock = gfs2_glock_free,
926         .lm_tokens = &nolock_tokens,
927 };
928 
929 /**
930  * gfs2_lm_mount - mount a locking protocol
931  * @sdp: the filesystem
932  * @args: mount arguments
933  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
934  *
935  * Returns: errno
936  */
937 
938 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
939 {
940         const struct lm_lockops *lm;
941         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
942         struct gfs2_args *args = &sdp->sd_args;
943         const char *proto = sdp->sd_proto_name;
944         const char *table = sdp->sd_table_name;
945         char *o, *options;
946         int ret;
947 
948         if (!strcmp("lock_nolock", proto)) {
949                 lm = &nolock_ops;
950                 sdp->sd_args.ar_localflocks = 1;
951 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
952         } else if (!strcmp("lock_dlm", proto)) {
953                 lm = &gfs2_dlm_ops;
954 #endif
955         } else {
956                 pr_info("can't find protocol %s\n", proto);
957                 return -ENOENT;
958         }
959 
960         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
961 
962         ls->ls_ops = lm;
963         ls->ls_first = 1;
964 
965         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
966                 substring_t tmp[MAX_OPT_ARGS];
967                 int token, option;
968 
969                 if (!o || !*o)
970                         continue;
971 
972                 token = match_token(o, *lm->lm_tokens, tmp);
973                 switch (token) {
974                 case Opt_jid:
975                         ret = match_int(&tmp[0], &option);
976                         if (ret || option < 0) 
977                                 goto hostdata_error;
978                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
979                                 ls->ls_jid = option;
980                         break;
981                 case Opt_id:
982                 case Opt_nodir:
983                         /* Obsolete, but left for backward compat purposes */
984                         break;
985                 case Opt_first:
986                         ret = match_int(&tmp[0], &option);
987                         if (ret || (option != 0 && option != 1))
988                                 goto hostdata_error;
989                         ls->ls_first = option;
990                         break;
991                 case Opt_err:
992                 default:
993 hostdata_error:
994                         fs_info(sdp, "unknown hostdata (%s)\n", o);
995                         return -EINVAL;
996                 }
997         }
998 
999         if (lm->lm_mount == NULL) {
1000                 fs_info(sdp, "Now mounting FS...\n");
1001                 complete_all(&sdp->sd_locking_init);
1002                 return 0;
1003         }
1004         ret = lm->lm_mount(sdp, table);
1005         if (ret == 0)
1006                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1007         complete_all(&sdp->sd_locking_init);
1008         return ret;
1009 }
1010 
1011 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1012 {
1013         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1014         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1015             lm->lm_unmount)
1016                 lm->lm_unmount(sdp);
1017 }
1018 
1019 static int wait_on_journal(struct gfs2_sbd *sdp)
1020 {
1021         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1022                 return 0;
1023 
1024         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1025                 ? -EINTR : 0;
1026 }
1027 
1028 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1029 {
1030         struct super_block *sb = sdp->sd_vfs;
1031         char ro[20];
1032         char spectator[20];
1033         char *envp[] = { ro, spectator, NULL };
1034         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1035         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1036         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1037 }
1038 
1039 /**
1040  * fill_super - Read in superblock
1041  * @sb: The VFS superblock
1042  * @data: Mount options
1043  * @silent: Don't complain if it's not a GFS2 filesystem
1044  *
1045  * Returns: errno
1046  */
1047 
1048 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1049 {
1050         struct gfs2_sbd *sdp;
1051         struct gfs2_holder mount_gh;
1052         int error;
1053 
1054         sdp = init_sbd(sb);
1055         if (!sdp) {
1056                 pr_warn("can't alloc struct gfs2_sbd\n");
1057                 return -ENOMEM;
1058         }
1059         sdp->sd_args = *args;
1060 
1061         if (sdp->sd_args.ar_spectator) {
1062                 sb->s_flags |= MS_RDONLY;
1063                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1064         }
1065         if (sdp->sd_args.ar_posix_acl)
1066                 sb->s_flags |= MS_POSIXACL;
1067         if (sdp->sd_args.ar_nobarrier)
1068                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1069 
1070         sb->s_flags |= MS_NOSEC;
1071         sb->s_magic = GFS2_MAGIC;
1072         sb->s_op = &gfs2_super_ops;
1073         sb->s_d_op = &gfs2_dops;
1074         sb->s_export_op = &gfs2_export_ops;
1075         sb->s_xattr = gfs2_xattr_handlers;
1076         sb->s_qcop = &gfs2_quotactl_ops;
1077         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1078         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1079         sb->s_time_gran = 1;
1080         sb->s_maxbytes = MAX_LFS_FILESIZE;
1081 
1082         /* Set up the buffer cache and fill in some fake block size values
1083            to allow us to read-in the on-disk superblock. */
1084         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1085         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1086         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1087                                GFS2_BASIC_BLOCK_SHIFT;
1088         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1089 
1090         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1091         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1092         if (sdp->sd_args.ar_statfs_quantum) {
1093                 sdp->sd_tune.gt_statfs_slow = 0;
1094                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1095         } else {
1096                 sdp->sd_tune.gt_statfs_slow = 1;
1097                 sdp->sd_tune.gt_statfs_quantum = 30;
1098         }
1099 
1100         error = init_names(sdp, silent);
1101         if (error) {
1102                 /* In this case, we haven't initialized sysfs, so we have to
1103                    manually free the sdp. */
1104                 free_percpu(sdp->sd_lkstats);
1105                 kfree(sdp);
1106                 sb->s_fs_info = NULL;
1107                 return error;
1108         }
1109 
1110         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1111 
1112         error = gfs2_sys_fs_add(sdp);
1113         /*
1114          * If we hit an error here, gfs2_sys_fs_add will have called function
1115          * kobject_put which causes the sysfs usage count to go to zero, which
1116          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1117          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1118          * kobject_put to free sdp.
1119          */
1120         if (error)
1121                 return error;
1122 
1123         gfs2_create_debugfs_file(sdp);
1124 
1125         error = gfs2_lm_mount(sdp, silent);
1126         if (error)
1127                 goto fail_debug;
1128 
1129         error = init_locking(sdp, &mount_gh, DO);
1130         if (error)
1131                 goto fail_lm;
1132 
1133         error = init_sb(sdp, silent);
1134         if (error)
1135                 goto fail_locking;
1136 
1137         error = wait_on_journal(sdp);
1138         if (error)
1139                 goto fail_sb;
1140 
1141         /*
1142          * If user space has failed to join the cluster or some similar
1143          * failure has occurred, then the journal id will contain a
1144          * negative (error) number. This will then be returned to the
1145          * caller (of the mount syscall). We do this even for spectator
1146          * mounts (which just write a jid of 0 to indicate "ok" even though
1147          * the jid is unused in the spectator case)
1148          */
1149         if (sdp->sd_lockstruct.ls_jid < 0) {
1150                 error = sdp->sd_lockstruct.ls_jid;
1151                 sdp->sd_lockstruct.ls_jid = 0;
1152                 goto fail_sb;
1153         }
1154 
1155         if (sdp->sd_args.ar_spectator)
1156                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1157                          sdp->sd_table_name);
1158         else
1159                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1160                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1161 
1162         error = init_inodes(sdp, DO);
1163         if (error)
1164                 goto fail_sb;
1165 
1166         error = init_per_node(sdp, DO);
1167         if (error)
1168                 goto fail_inodes;
1169 
1170         error = gfs2_statfs_init(sdp);
1171         if (error) {
1172                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1173                 goto fail_per_node;
1174         }
1175 
1176         if (!(sb->s_flags & MS_RDONLY)) {
1177                 error = gfs2_make_fs_rw(sdp);
1178                 if (error) {
1179                         fs_err(sdp, "can't make FS RW: %d\n", error);
1180                         goto fail_per_node;
1181                 }
1182         }
1183 
1184         gfs2_glock_dq_uninit(&mount_gh);
1185         gfs2_online_uevent(sdp);
1186         return 0;
1187 
1188 fail_per_node:
1189         init_per_node(sdp, UNDO);
1190 fail_inodes:
1191         init_inodes(sdp, UNDO);
1192 fail_sb:
1193         if (sdp->sd_root_dir)
1194                 dput(sdp->sd_root_dir);
1195         if (sdp->sd_master_dir)
1196                 dput(sdp->sd_master_dir);
1197         if (sb->s_root)
1198                 dput(sb->s_root);
1199         sb->s_root = NULL;
1200 fail_locking:
1201         init_locking(sdp, &mount_gh, UNDO);
1202 fail_lm:
1203         complete_all(&sdp->sd_journal_ready);
1204         gfs2_gl_hash_clear(sdp);
1205         gfs2_lm_unmount(sdp);
1206 fail_debug:
1207         gfs2_delete_debugfs_file(sdp);
1208         free_percpu(sdp->sd_lkstats);
1209         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1210          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1211         gfs2_sys_fs_del(sdp);
1212         sb->s_fs_info = NULL;
1213         return error;
1214 }
1215 
1216 static int set_gfs2_super(struct super_block *s, void *data)
1217 {
1218         s->s_bdev = data;
1219         s->s_dev = s->s_bdev->bd_dev;
1220 
1221         /*
1222          * We set the bdi here to the queue backing, file systems can
1223          * overwrite this in ->fill_super()
1224          */
1225         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1226         return 0;
1227 }
1228 
1229 static int test_gfs2_super(struct super_block *s, void *ptr)
1230 {
1231         struct block_device *bdev = ptr;
1232         return (bdev == s->s_bdev);
1233 }
1234 
1235 /**
1236  * gfs2_mount - Get the GFS2 superblock
1237  * @fs_type: The GFS2 filesystem type
1238  * @flags: Mount flags
1239  * @dev_name: The name of the device
1240  * @data: The mount arguments
1241  *
1242  * Q. Why not use get_sb_bdev() ?
1243  * A. We need to select one of two root directories to mount, independent
1244  *    of whether this is the initial, or subsequent, mount of this sb
1245  *
1246  * Returns: 0 or -ve on error
1247  */
1248 
1249 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1250                        const char *dev_name, void *data)
1251 {
1252         struct block_device *bdev;
1253         struct super_block *s;
1254         fmode_t mode = FMODE_READ | FMODE_EXCL;
1255         int error;
1256         struct gfs2_args args;
1257         struct gfs2_sbd *sdp;
1258 
1259         if (!(flags & MS_RDONLY))
1260                 mode |= FMODE_WRITE;
1261 
1262         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1263         if (IS_ERR(bdev))
1264                 return ERR_CAST(bdev);
1265 
1266         /*
1267          * once the super is inserted into the list by sget, s_umount
1268          * will protect the lockfs code from trying to start a snapshot
1269          * while we are mounting
1270          */
1271         mutex_lock(&bdev->bd_fsfreeze_mutex);
1272         if (bdev->bd_fsfreeze_count > 0) {
1273                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1274                 error = -EBUSY;
1275                 goto error_bdev;
1276         }
1277         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1278         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1279         error = PTR_ERR(s);
1280         if (IS_ERR(s))
1281                 goto error_bdev;
1282 
1283         if (s->s_root) {
1284                 /*
1285                  * s_umount nests inside bd_mutex during
1286                  * __invalidate_device().  blkdev_put() acquires
1287                  * bd_mutex and can't be called under s_umount.  Drop
1288                  * s_umount temporarily.  This is safe as we're
1289                  * holding an active reference.
1290                  */
1291                 up_write(&s->s_umount);
1292                 blkdev_put(bdev, mode);
1293                 down_write(&s->s_umount);
1294         } else {
1295                 /* s_mode must be set before deactivate_locked_super calls */
1296                 s->s_mode = mode;
1297         }
1298 
1299         memset(&args, 0, sizeof(args));
1300         args.ar_quota = GFS2_QUOTA_DEFAULT;
1301         args.ar_data = GFS2_DATA_DEFAULT;
1302         args.ar_commit = 30;
1303         args.ar_statfs_quantum = 30;
1304         args.ar_quota_quantum = 60;
1305         args.ar_errors = GFS2_ERRORS_DEFAULT;
1306 
1307         error = gfs2_mount_args(&args, data);
1308         if (error) {
1309                 pr_warn("can't parse mount arguments\n");
1310                 goto error_super;
1311         }
1312 
1313         if (s->s_root) {
1314                 error = -EBUSY;
1315                 if ((flags ^ s->s_flags) & MS_RDONLY)
1316                         goto error_super;
1317         } else {
1318                 char b[BDEVNAME_SIZE];
1319 
1320                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
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                  d_inode(path.dentry)->i_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");
1413 

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