Version:  2.0.40 2.2.26 2.4.37 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 4.5 4.6 4.7

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         sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
356                                       sizeof(struct gfs2_leaf)) /
357                                      GFS2_MIN_DIRENT_SIZE;
358         return 0;
359 }
360 
361 static int init_names(struct gfs2_sbd *sdp, int silent)
362 {
363         char *proto, *table;
364         int error = 0;
365 
366         proto = sdp->sd_args.ar_lockproto;
367         table = sdp->sd_args.ar_locktable;
368 
369         /*  Try to autodetect  */
370 
371         if (!proto[0] || !table[0]) {
372                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
373                 if (error)
374                         return error;
375 
376                 if (!proto[0])
377                         proto = sdp->sd_sb.sb_lockproto;
378                 if (!table[0])
379                         table = sdp->sd_sb.sb_locktable;
380         }
381 
382         if (!table[0])
383                 table = sdp->sd_vfs->s_id;
384 
385         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
386         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
387 
388         table = sdp->sd_table_name;
389         while ((table = strchr(table, '/')))
390                 *table = '_';
391 
392         return error;
393 }
394 
395 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
396                         int undo)
397 {
398         int error = 0;
399 
400         if (undo)
401                 goto fail_trans;
402 
403         error = gfs2_glock_nq_num(sdp,
404                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
405                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
406                                   mount_gh);
407         if (error) {
408                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
409                 goto fail;
410         }
411 
412         error = gfs2_glock_nq_num(sdp,
413                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
414                                   LM_ST_SHARED,
415                                   LM_FLAG_NOEXP | GL_EXACT,
416                                   &sdp->sd_live_gh);
417         if (error) {
418                 fs_err(sdp, "can't acquire live glock: %d\n", error);
419                 goto fail_mount;
420         }
421 
422         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
423                                CREATE, &sdp->sd_rename_gl);
424         if (error) {
425                 fs_err(sdp, "can't create rename glock: %d\n", error);
426                 goto fail_live;
427         }
428 
429         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
430                                CREATE, &sdp->sd_freeze_gl);
431         if (error) {
432                 fs_err(sdp, "can't create transaction glock: %d\n", error);
433                 goto fail_rename;
434         }
435 
436         return 0;
437 
438 fail_trans:
439         gfs2_glock_put(sdp->sd_freeze_gl);
440 fail_rename:
441         gfs2_glock_put(sdp->sd_rename_gl);
442 fail_live:
443         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
444 fail_mount:
445         gfs2_glock_dq_uninit(mount_gh);
446 fail:
447         return error;
448 }
449 
450 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
451                             u64 no_addr, const char *name)
452 {
453         struct gfs2_sbd *sdp = sb->s_fs_info;
454         struct dentry *dentry;
455         struct inode *inode;
456 
457         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0);
458         if (IS_ERR(inode)) {
459                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
460                 return PTR_ERR(inode);
461         }
462         dentry = d_make_root(inode);
463         if (!dentry) {
464                 fs_err(sdp, "can't alloc %s dentry\n", name);
465                 return -ENOMEM;
466         }
467         *dptr = dentry;
468         return 0;
469 }
470 
471 static int init_sb(struct gfs2_sbd *sdp, int silent)
472 {
473         struct super_block *sb = sdp->sd_vfs;
474         struct gfs2_holder sb_gh;
475         u64 no_addr;
476         int ret;
477 
478         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
479                                 LM_ST_SHARED, 0, &sb_gh);
480         if (ret) {
481                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
482                 return ret;
483         }
484 
485         ret = gfs2_read_sb(sdp, silent);
486         if (ret) {
487                 fs_err(sdp, "can't read superblock: %d\n", ret);
488                 goto out;
489         }
490 
491         /* Set up the buffer cache and SB for real */
492         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
493                 ret = -EINVAL;
494                 fs_err(sdp, "FS block size (%u) is too small for device "
495                        "block size (%u)\n",
496                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
497                 goto out;
498         }
499         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
500                 ret = -EINVAL;
501                 fs_err(sdp, "FS block size (%u) is too big for machine "
502                        "page size (%u)\n",
503                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
504                 goto out;
505         }
506         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
507 
508         /* Get the root inode */
509         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
510         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
511         if (ret)
512                 goto out;
513 
514         /* Get the master inode */
515         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
516         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
517         if (ret) {
518                 dput(sdp->sd_root_dir);
519                 goto out;
520         }
521         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
522 out:
523         gfs2_glock_dq_uninit(&sb_gh);
524         return ret;
525 }
526 
527 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
528 {
529         char *message = "FIRSTMOUNT=Done";
530         char *envp[] = { message, NULL };
531 
532         fs_info(sdp, "first mount done, others may mount\n");
533 
534         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
535                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
536 
537         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
538 }
539 
540 /**
541  * gfs2_jindex_hold - Grab a lock on the jindex
542  * @sdp: The GFS2 superblock
543  * @ji_gh: the holder for the jindex glock
544  *
545  * Returns: errno
546  */
547 
548 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
549 {
550         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
551         struct qstr name;
552         char buf[20];
553         struct gfs2_jdesc *jd;
554         int error;
555 
556         name.name = buf;
557 
558         mutex_lock(&sdp->sd_jindex_mutex);
559 
560         for (;;) {
561                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
562                 if (error)
563                         break;
564 
565                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
566                 name.hash = gfs2_disk_hash(name.name, name.len);
567 
568                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
569                 if (error == -ENOENT) {
570                         error = 0;
571                         break;
572                 }
573 
574                 gfs2_glock_dq_uninit(ji_gh);
575 
576                 if (error)
577                         break;
578 
579                 error = -ENOMEM;
580                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
581                 if (!jd)
582                         break;
583 
584                 INIT_LIST_HEAD(&jd->extent_list);
585                 INIT_LIST_HEAD(&jd->jd_revoke_list);
586 
587                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
588                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
589                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
590                         if (!jd->jd_inode)
591                                 error = -ENOENT;
592                         else
593                                 error = PTR_ERR(jd->jd_inode);
594                         kfree(jd);
595                         break;
596                 }
597 
598                 spin_lock(&sdp->sd_jindex_spin);
599                 jd->jd_jid = sdp->sd_journals++;
600                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
601                 spin_unlock(&sdp->sd_jindex_spin);
602         }
603 
604         mutex_unlock(&sdp->sd_jindex_mutex);
605 
606         return error;
607 }
608 
609 /**
610  * check_journal_clean - Make sure a journal is clean for a spectator mount
611  * @sdp: The GFS2 superblock
612  * @jd: The journal descriptor
613  *
614  * Returns: 0 if the journal is clean or locked, else an error
615  */
616 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
617 {
618         int error;
619         struct gfs2_holder j_gh;
620         struct gfs2_log_header_host head;
621         struct gfs2_inode *ip;
622 
623         ip = GFS2_I(jd->jd_inode);
624         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
625                                    GL_EXACT | GL_NOCACHE, &j_gh);
626         if (error) {
627                 fs_err(sdp, "Error locking journal for spectator mount.\n");
628                 return -EPERM;
629         }
630         error = gfs2_jdesc_check(jd);
631         if (error) {
632                 fs_err(sdp, "Error checking journal for spectator mount.\n");
633                 goto out_unlock;
634         }
635         error = gfs2_find_jhead(jd, &head);
636         if (error) {
637                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
638                 goto out_unlock;
639         }
640         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
641                 error = -EPERM;
642                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
643                        "must not be a spectator.\n", jd->jd_jid);
644         }
645 
646 out_unlock:
647         gfs2_glock_dq_uninit(&j_gh);
648         return error;
649 }
650 
651 static int init_journal(struct gfs2_sbd *sdp, int undo)
652 {
653         struct inode *master = d_inode(sdp->sd_master_dir);
654         struct gfs2_holder ji_gh;
655         struct gfs2_inode *ip;
656         int jindex = 1;
657         int error = 0;
658 
659         if (undo) {
660                 jindex = 0;
661                 goto fail_jinode_gh;
662         }
663 
664         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
665         if (IS_ERR(sdp->sd_jindex)) {
666                 fs_err(sdp, "can't lookup journal index: %d\n", error);
667                 return PTR_ERR(sdp->sd_jindex);
668         }
669 
670         /* Load in the journal index special file */
671 
672         error = gfs2_jindex_hold(sdp, &ji_gh);
673         if (error) {
674                 fs_err(sdp, "can't read journal index: %d\n", error);
675                 goto fail;
676         }
677 
678         error = -EUSERS;
679         if (!gfs2_jindex_size(sdp)) {
680                 fs_err(sdp, "no journals!\n");
681                 goto fail_jindex;
682         }
683 
684         if (sdp->sd_args.ar_spectator) {
685                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
686                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
687                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
688                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
689         } else {
690                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
691                         fs_err(sdp, "can't mount journal #%u\n",
692                                sdp->sd_lockstruct.ls_jid);
693                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
694                                gfs2_jindex_size(sdp),
695                                gfs2_jindex_size(sdp) - 1);
696                         goto fail_jindex;
697                 }
698                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
699 
700                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
701                                           &gfs2_journal_glops,
702                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
703                                           &sdp->sd_journal_gh);
704                 if (error) {
705                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
706                         goto fail_jindex;
707                 }
708 
709                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
710                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
711                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
712                                            &sdp->sd_jinode_gh);
713                 if (error) {
714                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
715                                error);
716                         goto fail_journal_gh;
717                 }
718 
719                 error = gfs2_jdesc_check(sdp->sd_jdesc);
720                 if (error) {
721                         fs_err(sdp, "my journal (%u) is bad: %d\n",
722                                sdp->sd_jdesc->jd_jid, error);
723                         goto fail_jinode_gh;
724                 }
725                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
726                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
727                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
728 
729                 /* Map the extents for this journal's blocks */
730                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
731         }
732         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
733 
734         if (sdp->sd_lockstruct.ls_first) {
735                 unsigned int x;
736                 for (x = 0; x < sdp->sd_journals; x++) {
737                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
738 
739                         if (sdp->sd_args.ar_spectator) {
740                                 error = check_journal_clean(sdp, jd);
741                                 if (error)
742                                         goto fail_jinode_gh;
743                                 continue;
744                         }
745                         error = gfs2_recover_journal(jd, true);
746                         if (error) {
747                                 fs_err(sdp, "error recovering journal %u: %d\n",
748                                        x, error);
749                                 goto fail_jinode_gh;
750                         }
751                 }
752 
753                 gfs2_others_may_mount(sdp);
754         } else if (!sdp->sd_args.ar_spectator) {
755                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
756                 if (error) {
757                         fs_err(sdp, "error recovering my journal: %d\n", error);
758                         goto fail_jinode_gh;
759                 }
760         }
761 
762         sdp->sd_log_idle = 1;
763         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
764         gfs2_glock_dq_uninit(&ji_gh);
765         jindex = 0;
766         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
767         return 0;
768 
769 fail_jinode_gh:
770         if (!sdp->sd_args.ar_spectator)
771                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
772 fail_journal_gh:
773         if (!sdp->sd_args.ar_spectator)
774                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
775 fail_jindex:
776         gfs2_jindex_free(sdp);
777         if (jindex)
778                 gfs2_glock_dq_uninit(&ji_gh);
779 fail:
780         iput(sdp->sd_jindex);
781         return error;
782 }
783 
784 static struct lock_class_key gfs2_quota_imutex_key;
785 
786 static int init_inodes(struct gfs2_sbd *sdp, int undo)
787 {
788         int error = 0;
789         struct inode *master = d_inode(sdp->sd_master_dir);
790 
791         if (undo)
792                 goto fail_qinode;
793 
794         error = init_journal(sdp, undo);
795         complete_all(&sdp->sd_journal_ready);
796         if (error)
797                 goto fail;
798 
799         /* Read in the master statfs inode */
800         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
801         if (IS_ERR(sdp->sd_statfs_inode)) {
802                 error = PTR_ERR(sdp->sd_statfs_inode);
803                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
804                 goto fail_journal;
805         }
806 
807         /* Read in the resource index inode */
808         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
809         if (IS_ERR(sdp->sd_rindex)) {
810                 error = PTR_ERR(sdp->sd_rindex);
811                 fs_err(sdp, "can't get resource index inode: %d\n", error);
812                 goto fail_statfs;
813         }
814         sdp->sd_rindex_uptodate = 0;
815 
816         /* Read in the quota inode */
817         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
818         if (IS_ERR(sdp->sd_quota_inode)) {
819                 error = PTR_ERR(sdp->sd_quota_inode);
820                 fs_err(sdp, "can't get quota file inode: %d\n", error);
821                 goto fail_rindex;
822         }
823         /*
824          * i_mutex on quota files is special. Since this inode is hidden system
825          * file, we are safe to define locking ourselves.
826          */
827         lockdep_set_class(&sdp->sd_quota_inode->i_rwsem,
828                           &gfs2_quota_imutex_key);
829 
830         error = gfs2_rindex_update(sdp);
831         if (error)
832                 goto fail_qinode;
833 
834         return 0;
835 
836 fail_qinode:
837         iput(sdp->sd_quota_inode);
838 fail_rindex:
839         gfs2_clear_rgrpd(sdp);
840         iput(sdp->sd_rindex);
841 fail_statfs:
842         iput(sdp->sd_statfs_inode);
843 fail_journal:
844         init_journal(sdp, UNDO);
845 fail:
846         return error;
847 }
848 
849 static int init_per_node(struct gfs2_sbd *sdp, int undo)
850 {
851         struct inode *pn = NULL;
852         char buf[30];
853         int error = 0;
854         struct gfs2_inode *ip;
855         struct inode *master = d_inode(sdp->sd_master_dir);
856 
857         if (sdp->sd_args.ar_spectator)
858                 return 0;
859 
860         if (undo)
861                 goto fail_qc_gh;
862 
863         pn = gfs2_lookup_simple(master, "per_node");
864         if (IS_ERR(pn)) {
865                 error = PTR_ERR(pn);
866                 fs_err(sdp, "can't find per_node directory: %d\n", error);
867                 return error;
868         }
869 
870         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
871         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
872         if (IS_ERR(sdp->sd_sc_inode)) {
873                 error = PTR_ERR(sdp->sd_sc_inode);
874                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
875                 goto fail;
876         }
877 
878         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
879         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
880         if (IS_ERR(sdp->sd_qc_inode)) {
881                 error = PTR_ERR(sdp->sd_qc_inode);
882                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
883                 goto fail_ut_i;
884         }
885 
886         iput(pn);
887         pn = NULL;
888 
889         ip = GFS2_I(sdp->sd_sc_inode);
890         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
891                                    &sdp->sd_sc_gh);
892         if (error) {
893                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
894                 goto fail_qc_i;
895         }
896 
897         ip = GFS2_I(sdp->sd_qc_inode);
898         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
899                                    &sdp->sd_qc_gh);
900         if (error) {
901                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
902                 goto fail_ut_gh;
903         }
904 
905         return 0;
906 
907 fail_qc_gh:
908         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
909 fail_ut_gh:
910         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
911 fail_qc_i:
912         iput(sdp->sd_qc_inode);
913 fail_ut_i:
914         iput(sdp->sd_sc_inode);
915 fail:
916         iput(pn);
917         return error;
918 }
919 
920 static const match_table_t nolock_tokens = {
921         { Opt_jid, "jid=%d\n", },
922         { Opt_err, NULL },
923 };
924 
925 static const struct lm_lockops nolock_ops = {
926         .lm_proto_name = "lock_nolock",
927         .lm_put_lock = gfs2_glock_free,
928         .lm_tokens = &nolock_tokens,
929 };
930 
931 /**
932  * gfs2_lm_mount - mount a locking protocol
933  * @sdp: the filesystem
934  * @args: mount arguments
935  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
936  *
937  * Returns: errno
938  */
939 
940 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
941 {
942         const struct lm_lockops *lm;
943         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
944         struct gfs2_args *args = &sdp->sd_args;
945         const char *proto = sdp->sd_proto_name;
946         const char *table = sdp->sd_table_name;
947         char *o, *options;
948         int ret;
949 
950         if (!strcmp("lock_nolock", proto)) {
951                 lm = &nolock_ops;
952                 sdp->sd_args.ar_localflocks = 1;
953 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
954         } else if (!strcmp("lock_dlm", proto)) {
955                 lm = &gfs2_dlm_ops;
956 #endif
957         } else {
958                 pr_info("can't find protocol %s\n", proto);
959                 return -ENOENT;
960         }
961 
962         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
963 
964         ls->ls_ops = lm;
965         ls->ls_first = 1;
966 
967         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
968                 substring_t tmp[MAX_OPT_ARGS];
969                 int token, option;
970 
971                 if (!o || !*o)
972                         continue;
973 
974                 token = match_token(o, *lm->lm_tokens, tmp);
975                 switch (token) {
976                 case Opt_jid:
977                         ret = match_int(&tmp[0], &option);
978                         if (ret || option < 0) 
979                                 goto hostdata_error;
980                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
981                                 ls->ls_jid = option;
982                         break;
983                 case Opt_id:
984                 case Opt_nodir:
985                         /* Obsolete, but left for backward compat purposes */
986                         break;
987                 case Opt_first:
988                         ret = match_int(&tmp[0], &option);
989                         if (ret || (option != 0 && option != 1))
990                                 goto hostdata_error;
991                         ls->ls_first = option;
992                         break;
993                 case Opt_err:
994                 default:
995 hostdata_error:
996                         fs_info(sdp, "unknown hostdata (%s)\n", o);
997                         return -EINVAL;
998                 }
999         }
1000 
1001         if (lm->lm_mount == NULL) {
1002                 fs_info(sdp, "Now mounting FS...\n");
1003                 complete_all(&sdp->sd_locking_init);
1004                 return 0;
1005         }
1006         ret = lm->lm_mount(sdp, table);
1007         if (ret == 0)
1008                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1009         complete_all(&sdp->sd_locking_init);
1010         return ret;
1011 }
1012 
1013 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1014 {
1015         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1016         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1017             lm->lm_unmount)
1018                 lm->lm_unmount(sdp);
1019 }
1020 
1021 static int wait_on_journal(struct gfs2_sbd *sdp)
1022 {
1023         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1024                 return 0;
1025 
1026         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1027                 ? -EINTR : 0;
1028 }
1029 
1030 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1031 {
1032         struct super_block *sb = sdp->sd_vfs;
1033         char ro[20];
1034         char spectator[20];
1035         char *envp[] = { ro, spectator, NULL };
1036         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1037         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1038         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1039 }
1040 
1041 /**
1042  * fill_super - Read in superblock
1043  * @sb: The VFS superblock
1044  * @data: Mount options
1045  * @silent: Don't complain if it's not a GFS2 filesystem
1046  *
1047  * Returns: errno
1048  */
1049 
1050 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1051 {
1052         struct gfs2_sbd *sdp;
1053         struct gfs2_holder mount_gh;
1054         int error;
1055 
1056         sdp = init_sbd(sb);
1057         if (!sdp) {
1058                 pr_warn("can't alloc struct gfs2_sbd\n");
1059                 return -ENOMEM;
1060         }
1061         sdp->sd_args = *args;
1062 
1063         if (sdp->sd_args.ar_spectator) {
1064                 sb->s_flags |= MS_RDONLY;
1065                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1066         }
1067         if (sdp->sd_args.ar_posix_acl)
1068                 sb->s_flags |= MS_POSIXACL;
1069         if (sdp->sd_args.ar_nobarrier)
1070                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1071 
1072         sb->s_flags |= MS_NOSEC;
1073         sb->s_magic = GFS2_MAGIC;
1074         sb->s_op = &gfs2_super_ops;
1075         sb->s_d_op = &gfs2_dops;
1076         sb->s_export_op = &gfs2_export_ops;
1077         sb->s_xattr = gfs2_xattr_handlers;
1078         sb->s_qcop = &gfs2_quotactl_ops;
1079         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1080         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1081         sb->s_time_gran = 1;
1082         sb->s_maxbytes = MAX_LFS_FILESIZE;
1083 
1084         /* Set up the buffer cache and fill in some fake block size values
1085            to allow us to read-in the on-disk superblock. */
1086         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1087         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1088         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1089                                GFS2_BASIC_BLOCK_SHIFT;
1090         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1091 
1092         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1093         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1094         if (sdp->sd_args.ar_statfs_quantum) {
1095                 sdp->sd_tune.gt_statfs_slow = 0;
1096                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1097         } else {
1098                 sdp->sd_tune.gt_statfs_slow = 1;
1099                 sdp->sd_tune.gt_statfs_quantum = 30;
1100         }
1101 
1102         error = init_names(sdp, silent);
1103         if (error) {
1104                 /* In this case, we haven't initialized sysfs, so we have to
1105                    manually free the sdp. */
1106                 free_percpu(sdp->sd_lkstats);
1107                 kfree(sdp);
1108                 sb->s_fs_info = NULL;
1109                 return error;
1110         }
1111 
1112         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1113 
1114         error = gfs2_sys_fs_add(sdp);
1115         /*
1116          * If we hit an error here, gfs2_sys_fs_add will have called function
1117          * kobject_put which causes the sysfs usage count to go to zero, which
1118          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1119          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1120          * kobject_put to free sdp.
1121          */
1122         if (error)
1123                 return error;
1124 
1125         gfs2_create_debugfs_file(sdp);
1126 
1127         error = gfs2_lm_mount(sdp, silent);
1128         if (error)
1129                 goto fail_debug;
1130 
1131         error = init_locking(sdp, &mount_gh, DO);
1132         if (error)
1133                 goto fail_lm;
1134 
1135         error = init_sb(sdp, silent);
1136         if (error)
1137                 goto fail_locking;
1138 
1139         error = wait_on_journal(sdp);
1140         if (error)
1141                 goto fail_sb;
1142 
1143         /*
1144          * If user space has failed to join the cluster or some similar
1145          * failure has occurred, then the journal id will contain a
1146          * negative (error) number. This will then be returned to the
1147          * caller (of the mount syscall). We do this even for spectator
1148          * mounts (which just write a jid of 0 to indicate "ok" even though
1149          * the jid is unused in the spectator case)
1150          */
1151         if (sdp->sd_lockstruct.ls_jid < 0) {
1152                 error = sdp->sd_lockstruct.ls_jid;
1153                 sdp->sd_lockstruct.ls_jid = 0;
1154                 goto fail_sb;
1155         }
1156 
1157         if (sdp->sd_args.ar_spectator)
1158                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1159                          sdp->sd_table_name);
1160         else
1161                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1162                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1163 
1164         error = init_inodes(sdp, DO);
1165         if (error)
1166                 goto fail_sb;
1167 
1168         error = init_per_node(sdp, DO);
1169         if (error)
1170                 goto fail_inodes;
1171 
1172         error = gfs2_statfs_init(sdp);
1173         if (error) {
1174                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1175                 goto fail_per_node;
1176         }
1177 
1178         if (!(sb->s_flags & MS_RDONLY)) {
1179                 error = gfs2_make_fs_rw(sdp);
1180                 if (error) {
1181                         fs_err(sdp, "can't make FS RW: %d\n", error);
1182                         goto fail_per_node;
1183                 }
1184         }
1185 
1186         gfs2_glock_dq_uninit(&mount_gh);
1187         gfs2_online_uevent(sdp);
1188         return 0;
1189 
1190 fail_per_node:
1191         init_per_node(sdp, UNDO);
1192 fail_inodes:
1193         init_inodes(sdp, UNDO);
1194 fail_sb:
1195         if (sdp->sd_root_dir)
1196                 dput(sdp->sd_root_dir);
1197         if (sdp->sd_master_dir)
1198                 dput(sdp->sd_master_dir);
1199         if (sb->s_root)
1200                 dput(sb->s_root);
1201         sb->s_root = NULL;
1202 fail_locking:
1203         init_locking(sdp, &mount_gh, UNDO);
1204 fail_lm:
1205         complete_all(&sdp->sd_journal_ready);
1206         gfs2_gl_hash_clear(sdp);
1207         gfs2_lm_unmount(sdp);
1208 fail_debug:
1209         gfs2_delete_debugfs_file(sdp);
1210         free_percpu(sdp->sd_lkstats);
1211         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1212          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1213         gfs2_sys_fs_del(sdp);
1214         sb->s_fs_info = NULL;
1215         return error;
1216 }
1217 
1218 static int set_gfs2_super(struct super_block *s, void *data)
1219 {
1220         s->s_bdev = data;
1221         s->s_dev = s->s_bdev->bd_dev;
1222 
1223         /*
1224          * We set the bdi here to the queue backing, file systems can
1225          * overwrite this in ->fill_super()
1226          */
1227         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1228         return 0;
1229 }
1230 
1231 static int test_gfs2_super(struct super_block *s, void *ptr)
1232 {
1233         struct block_device *bdev = ptr;
1234         return (bdev == s->s_bdev);
1235 }
1236 
1237 /**
1238  * gfs2_mount - Get the GFS2 superblock
1239  * @fs_type: The GFS2 filesystem type
1240  * @flags: Mount flags
1241  * @dev_name: The name of the device
1242  * @data: The mount arguments
1243  *
1244  * Q. Why not use get_sb_bdev() ?
1245  * A. We need to select one of two root directories to mount, independent
1246  *    of whether this is the initial, or subsequent, mount of this sb
1247  *
1248  * Returns: 0 or -ve on error
1249  */
1250 
1251 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1252                        const char *dev_name, void *data)
1253 {
1254         struct block_device *bdev;
1255         struct super_block *s;
1256         fmode_t mode = FMODE_READ | FMODE_EXCL;
1257         int error;
1258         struct gfs2_args args;
1259         struct gfs2_sbd *sdp;
1260 
1261         if (!(flags & MS_RDONLY))
1262                 mode |= FMODE_WRITE;
1263 
1264         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1265         if (IS_ERR(bdev))
1266                 return ERR_CAST(bdev);
1267 
1268         /*
1269          * once the super is inserted into the list by sget, s_umount
1270          * will protect the lockfs code from trying to start a snapshot
1271          * while we are mounting
1272          */
1273         mutex_lock(&bdev->bd_fsfreeze_mutex);
1274         if (bdev->bd_fsfreeze_count > 0) {
1275                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1276                 error = -EBUSY;
1277                 goto error_bdev;
1278         }
1279         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1280         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1281         error = PTR_ERR(s);
1282         if (IS_ERR(s))
1283                 goto error_bdev;
1284 
1285         if (s->s_root) {
1286                 /*
1287                  * s_umount nests inside bd_mutex during
1288                  * __invalidate_device().  blkdev_put() acquires
1289                  * bd_mutex and can't be called under s_umount.  Drop
1290                  * s_umount temporarily.  This is safe as we're
1291                  * holding an active reference.
1292                  */
1293                 up_write(&s->s_umount);
1294                 blkdev_put(bdev, mode);
1295                 down_write(&s->s_umount);
1296         } else {
1297                 /* s_mode must be set before deactivate_locked_super calls */
1298                 s->s_mode = mode;
1299         }
1300 
1301         memset(&args, 0, sizeof(args));
1302         args.ar_quota = GFS2_QUOTA_DEFAULT;
1303         args.ar_data = GFS2_DATA_DEFAULT;
1304         args.ar_commit = 30;
1305         args.ar_statfs_quantum = 30;
1306         args.ar_quota_quantum = 60;
1307         args.ar_errors = GFS2_ERRORS_DEFAULT;
1308 
1309         error = gfs2_mount_args(&args, data);
1310         if (error) {
1311                 pr_warn("can't parse mount arguments\n");
1312                 goto error_super;
1313         }
1314 
1315         if (s->s_root) {
1316                 error = -EBUSY;
1317                 if ((flags ^ s->s_flags) & MS_RDONLY)
1318                         goto error_super;
1319         } else {
1320                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1321                 sb_set_blocksize(s, block_size(bdev));
1322                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1323                 if (error)
1324                         goto error_super;
1325                 s->s_flags |= MS_ACTIVE;
1326                 bdev->bd_super = s;
1327         }
1328 
1329         sdp = s->s_fs_info;
1330         if (args.ar_meta)
1331                 return dget(sdp->sd_master_dir);
1332         else
1333                 return dget(sdp->sd_root_dir);
1334 
1335 error_super:
1336         deactivate_locked_super(s);
1337         return ERR_PTR(error);
1338 error_bdev:
1339         blkdev_put(bdev, mode);
1340         return ERR_PTR(error);
1341 }
1342 
1343 static int set_meta_super(struct super_block *s, void *ptr)
1344 {
1345         return -EINVAL;
1346 }
1347 
1348 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1349                         int flags, const char *dev_name, void *data)
1350 {
1351         struct super_block *s;
1352         struct gfs2_sbd *sdp;
1353         struct path path;
1354         int error;
1355 
1356         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1357         if (error) {
1358                 pr_warn("path_lookup on %s returned error %d\n",
1359                         dev_name, error);
1360                 return ERR_PTR(error);
1361         }
1362         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1363                  path.dentry->d_sb->s_bdev);
1364         path_put(&path);
1365         if (IS_ERR(s)) {
1366                 pr_warn("gfs2 mount does not exist\n");
1367                 return ERR_CAST(s);
1368         }
1369         if ((flags ^ s->s_flags) & MS_RDONLY) {
1370                 deactivate_locked_super(s);
1371                 return ERR_PTR(-EBUSY);
1372         }
1373         sdp = s->s_fs_info;
1374         return dget(sdp->sd_master_dir);
1375 }
1376 
1377 static void gfs2_kill_sb(struct super_block *sb)
1378 {
1379         struct gfs2_sbd *sdp = sb->s_fs_info;
1380 
1381         if (sdp == NULL) {
1382                 kill_block_super(sb);
1383                 return;
1384         }
1385 
1386         gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1387         dput(sdp->sd_root_dir);
1388         dput(sdp->sd_master_dir);
1389         sdp->sd_root_dir = NULL;
1390         sdp->sd_master_dir = NULL;
1391         shrink_dcache_sb(sb);
1392         gfs2_delete_debugfs_file(sdp);
1393         free_percpu(sdp->sd_lkstats);
1394         kill_block_super(sb);
1395 }
1396 
1397 struct file_system_type gfs2_fs_type = {
1398         .name = "gfs2",
1399         .fs_flags = FS_REQUIRES_DEV,
1400         .mount = gfs2_mount,
1401         .kill_sb = gfs2_kill_sb,
1402         .owner = THIS_MODULE,
1403 };
1404 MODULE_ALIAS_FS("gfs2");
1405 
1406 struct file_system_type gfs2meta_fs_type = {
1407         .name = "gfs2meta",
1408         .fs_flags = FS_REQUIRES_DEV,
1409         .mount = gfs2_mount_meta,
1410         .owner = THIS_MODULE,
1411 };
1412 MODULE_ALIAS_FS("gfs2meta");
1413 

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