Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

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->backing_dev_info = sb->s_bdi;
116         mapping->writeback_index = 0;
117 
118         spin_lock_init(&sdp->sd_log_lock);
119         atomic_set(&sdp->sd_log_pinned, 0);
120         INIT_LIST_HEAD(&sdp->sd_log_le_revoke);
121         INIT_LIST_HEAD(&sdp->sd_log_le_ordered);
122         spin_lock_init(&sdp->sd_ordered_lock);
123 
124         init_waitqueue_head(&sdp->sd_log_waitq);
125         init_waitqueue_head(&sdp->sd_logd_waitq);
126         spin_lock_init(&sdp->sd_ail_lock);
127         INIT_LIST_HEAD(&sdp->sd_ail1_list);
128         INIT_LIST_HEAD(&sdp->sd_ail2_list);
129 
130         init_rwsem(&sdp->sd_log_flush_lock);
131         atomic_set(&sdp->sd_log_in_flight, 0);
132         init_waitqueue_head(&sdp->sd_log_flush_wait);
133         init_waitqueue_head(&sdp->sd_log_frozen_wait);
134         atomic_set(&sdp->sd_log_freeze, 0);
135         atomic_set(&sdp->sd_frozen_root, 0);
136         init_waitqueue_head(&sdp->sd_frozen_root_wait);
137 
138         return sdp;
139 }
140 
141 
142 /**
143  * gfs2_check_sb - Check superblock
144  * @sdp: the filesystem
145  * @sb: The superblock
146  * @silent: Don't print a message if the check fails
147  *
148  * Checks the version code of the FS is one that we understand how to
149  * read and that the sizes of the various on-disk structures have not
150  * changed.
151  */
152 
153 static int gfs2_check_sb(struct gfs2_sbd *sdp, int silent)
154 {
155         struct gfs2_sb_host *sb = &sdp->sd_sb;
156 
157         if (sb->sb_magic != GFS2_MAGIC ||
158             sb->sb_type != GFS2_METATYPE_SB) {
159                 if (!silent)
160                         pr_warn("not a GFS2 filesystem\n");
161                 return -EINVAL;
162         }
163 
164         /*  If format numbers match exactly, we're done.  */
165 
166         if (sb->sb_fs_format == GFS2_FORMAT_FS &&
167             sb->sb_multihost_format == GFS2_FORMAT_MULTI)
168                 return 0;
169 
170         fs_warn(sdp, "Unknown on-disk format, unable to mount\n");
171 
172         return -EINVAL;
173 }
174 
175 static void end_bio_io_page(struct bio *bio, int error)
176 {
177         struct page *page = bio->bi_private;
178 
179         if (!error)
180                 SetPageUptodate(page);
181         else
182                 pr_warn("error %d reading superblock\n", error);
183         unlock_page(page);
184 }
185 
186 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
187 {
188         struct gfs2_sb_host *sb = &sdp->sd_sb;
189         struct super_block *s = sdp->sd_vfs;
190         const struct gfs2_sb *str = buf;
191 
192         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
193         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
194         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
195         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
196         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
197         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
198         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
199         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
200         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
201         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
202         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
203 
204         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
205         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
206         memcpy(s->s_uuid, str->sb_uuid, 16);
207 }
208 
209 /**
210  * gfs2_read_super - Read the gfs2 super block from disk
211  * @sdp: The GFS2 super block
212  * @sector: The location of the super block
213  * @error: The error code to return
214  *
215  * This uses the bio functions to read the super block from disk
216  * because we want to be 100% sure that we never read cached data.
217  * A super block is read twice only during each GFS2 mount and is
218  * never written to by the filesystem. The first time its read no
219  * locks are held, and the only details which are looked at are those
220  * relating to the locking protocol. Once locking is up and working,
221  * the sb is read again under the lock to establish the location of
222  * the master directory (contains pointers to journals etc) and the
223  * root directory.
224  *
225  * Returns: 0 on success or error
226  */
227 
228 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
229 {
230         struct super_block *sb = sdp->sd_vfs;
231         struct gfs2_sb *p;
232         struct page *page;
233         struct bio *bio;
234 
235         page = alloc_page(GFP_NOFS);
236         if (unlikely(!page))
237                 return -ENOMEM;
238 
239         ClearPageUptodate(page);
240         ClearPageDirty(page);
241         lock_page(page);
242 
243         bio = bio_alloc(GFP_NOFS, 1);
244         bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
245         bio->bi_bdev = sb->s_bdev;
246         bio_add_page(bio, page, PAGE_SIZE, 0);
247 
248         bio->bi_end_io = end_bio_io_page;
249         bio->bi_private = page;
250         submit_bio(READ_SYNC | REQ_META, bio);
251         wait_on_page_locked(page);
252         bio_put(bio);
253         if (!PageUptodate(page)) {
254                 __free_page(page);
255                 return -EIO;
256         }
257         p = kmap(page);
258         gfs2_sb_in(sdp, p);
259         kunmap(page);
260         __free_page(page);
261         return gfs2_check_sb(sdp, silent);
262 }
263 
264 /**
265  * gfs2_read_sb - Read super block
266  * @sdp: The GFS2 superblock
267  * @silent: Don't print message if mount fails
268  *
269  */
270 
271 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
272 {
273         u32 hash_blocks, ind_blocks, leaf_blocks;
274         u32 tmp_blocks;
275         unsigned int x;
276         int error;
277 
278         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
279         if (error) {
280                 if (!silent)
281                         fs_err(sdp, "can't read superblock\n");
282                 return error;
283         }
284 
285         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
286                                GFS2_BASIC_BLOCK_SHIFT;
287         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
288         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
289                           sizeof(struct gfs2_dinode)) / sizeof(u64);
290         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
291                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
292         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
293         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
294         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
295         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
296         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
297                                 sizeof(struct gfs2_meta_header)) /
298                                 sizeof(struct gfs2_quota_change);
299         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
300                                      sizeof(struct gfs2_meta_header))
301                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
302 
303         /* Compute maximum reservation required to add a entry to a directory */
304 
305         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
306                              sdp->sd_jbsize);
307 
308         ind_blocks = 0;
309         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
310                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
311                 ind_blocks += tmp_blocks;
312         }
313 
314         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
315 
316         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
317 
318         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
319                                 sizeof(struct gfs2_dinode);
320         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
321         for (x = 2;; x++) {
322                 u64 space, d;
323                 u32 m;
324 
325                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
326                 d = space;
327                 m = do_div(d, sdp->sd_inptrs);
328 
329                 if (d != sdp->sd_heightsize[x - 1] || m)
330                         break;
331                 sdp->sd_heightsize[x] = space;
332         }
333         sdp->sd_max_height = x;
334         sdp->sd_heightsize[x] = ~0;
335         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
336 
337         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
338                                  sizeof(struct gfs2_dinode);
339         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
340         for (x = 2;; x++) {
341                 u64 space, d;
342                 u32 m;
343 
344                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
345                 d = space;
346                 m = do_div(d, sdp->sd_inptrs);
347 
348                 if (d != sdp->sd_jheightsize[x - 1] || m)
349                         break;
350                 sdp->sd_jheightsize[x] = space;
351         }
352         sdp->sd_max_jheight = x;
353         sdp->sd_jheightsize[x] = ~0;
354         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
355 
356         return 0;
357 }
358 
359 static int init_names(struct gfs2_sbd *sdp, int silent)
360 {
361         char *proto, *table;
362         int error = 0;
363 
364         proto = sdp->sd_args.ar_lockproto;
365         table = sdp->sd_args.ar_locktable;
366 
367         /*  Try to autodetect  */
368 
369         if (!proto[0] || !table[0]) {
370                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
371                 if (error)
372                         return error;
373 
374                 if (!proto[0])
375                         proto = sdp->sd_sb.sb_lockproto;
376                 if (!table[0])
377                         table = sdp->sd_sb.sb_locktable;
378         }
379 
380         if (!table[0])
381                 table = sdp->sd_vfs->s_id;
382 
383         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
384         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
385 
386         table = sdp->sd_table_name;
387         while ((table = strchr(table, '/')))
388                 *table = '_';
389 
390         return error;
391 }
392 
393 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
394                         int undo)
395 {
396         int error = 0;
397 
398         if (undo)
399                 goto fail_trans;
400 
401         error = gfs2_glock_nq_num(sdp,
402                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
403                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
404                                   mount_gh);
405         if (error) {
406                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
407                 goto fail;
408         }
409 
410         error = gfs2_glock_nq_num(sdp,
411                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
412                                   LM_ST_SHARED,
413                                   LM_FLAG_NOEXP | GL_EXACT,
414                                   &sdp->sd_live_gh);
415         if (error) {
416                 fs_err(sdp, "can't acquire live glock: %d\n", error);
417                 goto fail_mount;
418         }
419 
420         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
421                                CREATE, &sdp->sd_rename_gl);
422         if (error) {
423                 fs_err(sdp, "can't create rename glock: %d\n", error);
424                 goto fail_live;
425         }
426 
427         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
428                                CREATE, &sdp->sd_freeze_gl);
429         if (error) {
430                 fs_err(sdp, "can't create transaction glock: %d\n", error);
431                 goto fail_rename;
432         }
433 
434         return 0;
435 
436 fail_trans:
437         gfs2_glock_put(sdp->sd_freeze_gl);
438 fail_rename:
439         gfs2_glock_put(sdp->sd_rename_gl);
440 fail_live:
441         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
442 fail_mount:
443         gfs2_glock_dq_uninit(mount_gh);
444 fail:
445         return error;
446 }
447 
448 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
449                             u64 no_addr, const char *name)
450 {
451         struct gfs2_sbd *sdp = sb->s_fs_info;
452         struct dentry *dentry;
453         struct inode *inode;
454 
455         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
456         if (IS_ERR(inode)) {
457                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
458                 return PTR_ERR(inode);
459         }
460         dentry = d_make_root(inode);
461         if (!dentry) {
462                 fs_err(sdp, "can't alloc %s dentry\n", name);
463                 return -ENOMEM;
464         }
465         *dptr = dentry;
466         return 0;
467 }
468 
469 static int init_sb(struct gfs2_sbd *sdp, int silent)
470 {
471         struct super_block *sb = sdp->sd_vfs;
472         struct gfs2_holder sb_gh;
473         u64 no_addr;
474         int ret;
475 
476         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
477                                 LM_ST_SHARED, 0, &sb_gh);
478         if (ret) {
479                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
480                 return ret;
481         }
482 
483         ret = gfs2_read_sb(sdp, silent);
484         if (ret) {
485                 fs_err(sdp, "can't read superblock: %d\n", ret);
486                 goto out;
487         }
488 
489         /* Set up the buffer cache and SB for real */
490         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
491                 ret = -EINVAL;
492                 fs_err(sdp, "FS block size (%u) is too small for device "
493                        "block size (%u)\n",
494                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
495                 goto out;
496         }
497         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
498                 ret = -EINVAL;
499                 fs_err(sdp, "FS block size (%u) is too big for machine "
500                        "page size (%u)\n",
501                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
502                 goto out;
503         }
504         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
505 
506         /* Get the root inode */
507         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
508         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
509         if (ret)
510                 goto out;
511 
512         /* Get the master inode */
513         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
514         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
515         if (ret) {
516                 dput(sdp->sd_root_dir);
517                 goto out;
518         }
519         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
520 out:
521         gfs2_glock_dq_uninit(&sb_gh);
522         return ret;
523 }
524 
525 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
526 {
527         char *message = "FIRSTMOUNT=Done";
528         char *envp[] = { message, NULL };
529 
530         fs_info(sdp, "first mount done, others may mount\n");
531 
532         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
533                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
534 
535         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
536 }
537 
538 /**
539  * gfs2_jindex_hold - Grab a lock on the jindex
540  * @sdp: The GFS2 superblock
541  * @ji_gh: the holder for the jindex glock
542  *
543  * Returns: errno
544  */
545 
546 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
547 {
548         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
549         struct qstr name;
550         char buf[20];
551         struct gfs2_jdesc *jd;
552         int error;
553 
554         name.name = buf;
555 
556         mutex_lock(&sdp->sd_jindex_mutex);
557 
558         for (;;) {
559                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
560                 if (error)
561                         break;
562 
563                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
564                 name.hash = gfs2_disk_hash(name.name, name.len);
565 
566                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
567                 if (error == -ENOENT) {
568                         error = 0;
569                         break;
570                 }
571 
572                 gfs2_glock_dq_uninit(ji_gh);
573 
574                 if (error)
575                         break;
576 
577                 error = -ENOMEM;
578                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
579                 if (!jd)
580                         break;
581 
582                 INIT_LIST_HEAD(&jd->extent_list);
583                 INIT_LIST_HEAD(&jd->jd_revoke_list);
584 
585                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
586                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
587                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
588                         if (!jd->jd_inode)
589                                 error = -ENOENT;
590                         else
591                                 error = PTR_ERR(jd->jd_inode);
592                         kfree(jd);
593                         break;
594                 }
595 
596                 spin_lock(&sdp->sd_jindex_spin);
597                 jd->jd_jid = sdp->sd_journals++;
598                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
599                 spin_unlock(&sdp->sd_jindex_spin);
600         }
601 
602         mutex_unlock(&sdp->sd_jindex_mutex);
603 
604         return error;
605 }
606 
607 /**
608  * check_journal_clean - Make sure a journal is clean for a spectator mount
609  * @sdp: The GFS2 superblock
610  * @jd: The journal descriptor
611  *
612  * Returns: 0 if the journal is clean or locked, else an error
613  */
614 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
615 {
616         int error;
617         struct gfs2_holder j_gh;
618         struct gfs2_log_header_host head;
619         struct gfs2_inode *ip;
620 
621         ip = GFS2_I(jd->jd_inode);
622         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
623                                    GL_EXACT | GL_NOCACHE, &j_gh);
624         if (error) {
625                 fs_err(sdp, "Error locking journal for spectator mount.\n");
626                 return -EPERM;
627         }
628         error = gfs2_jdesc_check(jd);
629         if (error) {
630                 fs_err(sdp, "Error checking journal for spectator mount.\n");
631                 goto out_unlock;
632         }
633         error = gfs2_find_jhead(jd, &head);
634         if (error) {
635                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
636                 goto out_unlock;
637         }
638         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
639                 error = -EPERM;
640                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
641                        "must not be a spectator.\n", jd->jd_jid);
642         }
643 
644 out_unlock:
645         gfs2_glock_dq_uninit(&j_gh);
646         return error;
647 }
648 
649 static int init_journal(struct gfs2_sbd *sdp, int undo)
650 {
651         struct inode *master = sdp->sd_master_dir->d_inode;
652         struct gfs2_holder ji_gh;
653         struct gfs2_inode *ip;
654         int jindex = 1;
655         int error = 0;
656 
657         if (undo) {
658                 jindex = 0;
659                 goto fail_jinode_gh;
660         }
661 
662         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
663         if (IS_ERR(sdp->sd_jindex)) {
664                 fs_err(sdp, "can't lookup journal index: %d\n", error);
665                 return PTR_ERR(sdp->sd_jindex);
666         }
667 
668         /* Load in the journal index special file */
669 
670         error = gfs2_jindex_hold(sdp, &ji_gh);
671         if (error) {
672                 fs_err(sdp, "can't read journal index: %d\n", error);
673                 goto fail;
674         }
675 
676         error = -EUSERS;
677         if (!gfs2_jindex_size(sdp)) {
678                 fs_err(sdp, "no journals!\n");
679                 goto fail_jindex;
680         }
681 
682         if (sdp->sd_args.ar_spectator) {
683                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
684                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
685                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
686                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
687         } else {
688                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
689                         fs_err(sdp, "can't mount journal #%u\n",
690                                sdp->sd_lockstruct.ls_jid);
691                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
692                                gfs2_jindex_size(sdp),
693                                gfs2_jindex_size(sdp) - 1);
694                         goto fail_jindex;
695                 }
696                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
697 
698                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
699                                           &gfs2_journal_glops,
700                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
701                                           &sdp->sd_journal_gh);
702                 if (error) {
703                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
704                         goto fail_jindex;
705                 }
706 
707                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
708                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
709                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
710                                            &sdp->sd_jinode_gh);
711                 if (error) {
712                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
713                                error);
714                         goto fail_journal_gh;
715                 }
716 
717                 error = gfs2_jdesc_check(sdp->sd_jdesc);
718                 if (error) {
719                         fs_err(sdp, "my journal (%u) is bad: %d\n",
720                                sdp->sd_jdesc->jd_jid, error);
721                         goto fail_jinode_gh;
722                 }
723                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
724                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
725                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
726 
727                 /* Map the extents for this journal's blocks */
728                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
729         }
730         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
731 
732         if (sdp->sd_lockstruct.ls_first) {
733                 unsigned int x;
734                 for (x = 0; x < sdp->sd_journals; x++) {
735                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
736 
737                         if (sdp->sd_args.ar_spectator) {
738                                 error = check_journal_clean(sdp, jd);
739                                 if (error)
740                                         goto fail_jinode_gh;
741                                 continue;
742                         }
743                         error = gfs2_recover_journal(jd, true);
744                         if (error) {
745                                 fs_err(sdp, "error recovering journal %u: %d\n",
746                                        x, error);
747                                 goto fail_jinode_gh;
748                         }
749                 }
750 
751                 gfs2_others_may_mount(sdp);
752         } else if (!sdp->sd_args.ar_spectator) {
753                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
754                 if (error) {
755                         fs_err(sdp, "error recovering my journal: %d\n", error);
756                         goto fail_jinode_gh;
757                 }
758         }
759 
760         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
761         gfs2_glock_dq_uninit(&ji_gh);
762         jindex = 0;
763         if (!sdp->sd_args.ar_spectator) {
764                 error = gfs2_glock_nq_init(sdp->sd_freeze_gl, LM_ST_SHARED, 0,
765                                            &sdp->sd_thaw_gh);
766                 if (error) {
767                         fs_err(sdp, "can't acquire freeze glock: %d\n", error);
768                         goto fail_jinode_gh;
769                 }
770         }
771         gfs2_glock_dq_uninit(&sdp->sd_thaw_gh);
772         return 0;
773 
774 fail_jinode_gh:
775         if (!sdp->sd_args.ar_spectator)
776                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
777 fail_journal_gh:
778         if (!sdp->sd_args.ar_spectator)
779                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
780 fail_jindex:
781         gfs2_jindex_free(sdp);
782         if (jindex)
783                 gfs2_glock_dq_uninit(&ji_gh);
784 fail:
785         iput(sdp->sd_jindex);
786         return error;
787 }
788 
789 static struct lock_class_key gfs2_quota_imutex_key;
790 
791 static int init_inodes(struct gfs2_sbd *sdp, int undo)
792 {
793         int error = 0;
794         struct inode *master = sdp->sd_master_dir->d_inode;
795 
796         if (undo)
797                 goto fail_qinode;
798 
799         error = init_journal(sdp, undo);
800         complete_all(&sdp->sd_journal_ready);
801         if (error)
802                 goto fail;
803 
804         /* Read in the master statfs inode */
805         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
806         if (IS_ERR(sdp->sd_statfs_inode)) {
807                 error = PTR_ERR(sdp->sd_statfs_inode);
808                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
809                 goto fail_journal;
810         }
811 
812         /* Read in the resource index inode */
813         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
814         if (IS_ERR(sdp->sd_rindex)) {
815                 error = PTR_ERR(sdp->sd_rindex);
816                 fs_err(sdp, "can't get resource index inode: %d\n", error);
817                 goto fail_statfs;
818         }
819         sdp->sd_rindex_uptodate = 0;
820 
821         /* Read in the quota inode */
822         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
823         if (IS_ERR(sdp->sd_quota_inode)) {
824                 error = PTR_ERR(sdp->sd_quota_inode);
825                 fs_err(sdp, "can't get quota file inode: %d\n", error);
826                 goto fail_rindex;
827         }
828         /*
829          * i_mutex on quota files is special. Since this inode is hidden system
830          * file, we are safe to define locking ourselves.
831          */
832         lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
833                           &gfs2_quota_imutex_key);
834 
835         error = gfs2_rindex_update(sdp);
836         if (error)
837                 goto fail_qinode;
838 
839         return 0;
840 
841 fail_qinode:
842         iput(sdp->sd_quota_inode);
843 fail_rindex:
844         gfs2_clear_rgrpd(sdp);
845         iput(sdp->sd_rindex);
846 fail_statfs:
847         iput(sdp->sd_statfs_inode);
848 fail_journal:
849         init_journal(sdp, UNDO);
850 fail:
851         return error;
852 }
853 
854 static int init_per_node(struct gfs2_sbd *sdp, int undo)
855 {
856         struct inode *pn = NULL;
857         char buf[30];
858         int error = 0;
859         struct gfs2_inode *ip;
860         struct inode *master = sdp->sd_master_dir->d_inode;
861 
862         if (sdp->sd_args.ar_spectator)
863                 return 0;
864 
865         if (undo)
866                 goto fail_qc_gh;
867 
868         pn = gfs2_lookup_simple(master, "per_node");
869         if (IS_ERR(pn)) {
870                 error = PTR_ERR(pn);
871                 fs_err(sdp, "can't find per_node directory: %d\n", error);
872                 return error;
873         }
874 
875         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
876         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
877         if (IS_ERR(sdp->sd_sc_inode)) {
878                 error = PTR_ERR(sdp->sd_sc_inode);
879                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
880                 goto fail;
881         }
882 
883         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
884         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
885         if (IS_ERR(sdp->sd_qc_inode)) {
886                 error = PTR_ERR(sdp->sd_qc_inode);
887                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
888                 goto fail_ut_i;
889         }
890 
891         iput(pn);
892         pn = NULL;
893 
894         ip = GFS2_I(sdp->sd_sc_inode);
895         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
896                                    &sdp->sd_sc_gh);
897         if (error) {
898                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
899                 goto fail_qc_i;
900         }
901 
902         ip = GFS2_I(sdp->sd_qc_inode);
903         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
904                                    &sdp->sd_qc_gh);
905         if (error) {
906                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
907                 goto fail_ut_gh;
908         }
909 
910         return 0;
911 
912 fail_qc_gh:
913         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
914 fail_ut_gh:
915         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
916 fail_qc_i:
917         iput(sdp->sd_qc_inode);
918 fail_ut_i:
919         iput(sdp->sd_sc_inode);
920 fail:
921         if (pn)
922                 iput(pn);
923         return error;
924 }
925 
926 static const match_table_t nolock_tokens = {
927         { Opt_jid, "jid=%d\n", },
928         { Opt_err, NULL },
929 };
930 
931 static const struct lm_lockops nolock_ops = {
932         .lm_proto_name = "lock_nolock",
933         .lm_put_lock = gfs2_glock_free,
934         .lm_tokens = &nolock_tokens,
935 };
936 
937 /**
938  * gfs2_lm_mount - mount a locking protocol
939  * @sdp: the filesystem
940  * @args: mount arguments
941  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
942  *
943  * Returns: errno
944  */
945 
946 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
947 {
948         const struct lm_lockops *lm;
949         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
950         struct gfs2_args *args = &sdp->sd_args;
951         const char *proto = sdp->sd_proto_name;
952         const char *table = sdp->sd_table_name;
953         char *o, *options;
954         int ret;
955 
956         if (!strcmp("lock_nolock", proto)) {
957                 lm = &nolock_ops;
958                 sdp->sd_args.ar_localflocks = 1;
959 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
960         } else if (!strcmp("lock_dlm", proto)) {
961                 lm = &gfs2_dlm_ops;
962 #endif
963         } else {
964                 pr_info("can't find protocol %s\n", proto);
965                 return -ENOENT;
966         }
967 
968         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
969 
970         ls->ls_ops = lm;
971         ls->ls_first = 1;
972 
973         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
974                 substring_t tmp[MAX_OPT_ARGS];
975                 int token, option;
976 
977                 if (!o || !*o)
978                         continue;
979 
980                 token = match_token(o, *lm->lm_tokens, tmp);
981                 switch (token) {
982                 case Opt_jid:
983                         ret = match_int(&tmp[0], &option);
984                         if (ret || option < 0) 
985                                 goto hostdata_error;
986                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
987                                 ls->ls_jid = option;
988                         break;
989                 case Opt_id:
990                 case Opt_nodir:
991                         /* Obsolete, but left for backward compat purposes */
992                         break;
993                 case Opt_first:
994                         ret = match_int(&tmp[0], &option);
995                         if (ret || (option != 0 && option != 1))
996                                 goto hostdata_error;
997                         ls->ls_first = option;
998                         break;
999                 case Opt_err:
1000                 default:
1001 hostdata_error:
1002                         fs_info(sdp, "unknown hostdata (%s)\n", o);
1003                         return -EINVAL;
1004                 }
1005         }
1006 
1007         if (lm->lm_mount == NULL) {
1008                 fs_info(sdp, "Now mounting FS...\n");
1009                 complete_all(&sdp->sd_locking_init);
1010                 return 0;
1011         }
1012         ret = lm->lm_mount(sdp, table);
1013         if (ret == 0)
1014                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1015         complete_all(&sdp->sd_locking_init);
1016         return ret;
1017 }
1018 
1019 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1020 {
1021         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1022         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1023             lm->lm_unmount)
1024                 lm->lm_unmount(sdp);
1025 }
1026 
1027 static int wait_on_journal(struct gfs2_sbd *sdp)
1028 {
1029         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1030                 return 0;
1031 
1032         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1033                 ? -EINTR : 0;
1034 }
1035 
1036 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1037 {
1038         struct super_block *sb = sdp->sd_vfs;
1039         char ro[20];
1040         char spectator[20];
1041         char *envp[] = { ro, spectator, NULL };
1042         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1043         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1044         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1045 }
1046 
1047 /**
1048  * fill_super - Read in superblock
1049  * @sb: The VFS superblock
1050  * @data: Mount options
1051  * @silent: Don't complain if it's not a GFS2 filesystem
1052  *
1053  * Returns: errno
1054  */
1055 
1056 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1057 {
1058         struct gfs2_sbd *sdp;
1059         struct gfs2_holder mount_gh;
1060         int error;
1061 
1062         sdp = init_sbd(sb);
1063         if (!sdp) {
1064                 pr_warn("can't alloc struct gfs2_sbd\n");
1065                 return -ENOMEM;
1066         }
1067         sdp->sd_args = *args;
1068 
1069         if (sdp->sd_args.ar_spectator) {
1070                 sb->s_flags |= MS_RDONLY;
1071                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1072         }
1073         if (sdp->sd_args.ar_posix_acl)
1074                 sb->s_flags |= MS_POSIXACL;
1075         if (sdp->sd_args.ar_nobarrier)
1076                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1077 
1078         sb->s_flags |= MS_NOSEC;
1079         sb->s_magic = GFS2_MAGIC;
1080         sb->s_op = &gfs2_super_ops;
1081         sb->s_d_op = &gfs2_dops;
1082         sb->s_export_op = &gfs2_export_ops;
1083         sb->s_xattr = gfs2_xattr_handlers;
1084         sb->s_qcop = &gfs2_quotactl_ops;
1085         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1086         sb->s_time_gran = 1;
1087         sb->s_maxbytes = MAX_LFS_FILESIZE;
1088 
1089         /* Set up the buffer cache and fill in some fake block size values
1090            to allow us to read-in the on-disk superblock. */
1091         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1092         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1093         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1094                                GFS2_BASIC_BLOCK_SHIFT;
1095         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1096 
1097         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1098         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1099         if (sdp->sd_args.ar_statfs_quantum) {
1100                 sdp->sd_tune.gt_statfs_slow = 0;
1101                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1102         } else {
1103                 sdp->sd_tune.gt_statfs_slow = 1;
1104                 sdp->sd_tune.gt_statfs_quantum = 30;
1105         }
1106 
1107         error = init_names(sdp, silent);
1108         if (error) {
1109                 /* In this case, we haven't initialized sysfs, so we have to
1110                    manually free the sdp. */
1111                 free_percpu(sdp->sd_lkstats);
1112                 kfree(sdp);
1113                 sb->s_fs_info = NULL;
1114                 return error;
1115         }
1116 
1117         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1118 
1119         error = gfs2_sys_fs_add(sdp);
1120         /*
1121          * If we hit an error here, gfs2_sys_fs_add will have called function
1122          * kobject_put which causes the sysfs usage count to go to zero, which
1123          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1124          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1125          * kobject_put to free sdp.
1126          */
1127         if (error)
1128                 return error;
1129 
1130         gfs2_create_debugfs_file(sdp);
1131 
1132         error = gfs2_lm_mount(sdp, silent);
1133         if (error)
1134                 goto fail_debug;
1135 
1136         error = init_locking(sdp, &mount_gh, DO);
1137         if (error)
1138                 goto fail_lm;
1139 
1140         error = init_sb(sdp, silent);
1141         if (error)
1142                 goto fail_locking;
1143 
1144         error = wait_on_journal(sdp);
1145         if (error)
1146                 goto fail_sb;
1147 
1148         /*
1149          * If user space has failed to join the cluster or some similar
1150          * failure has occurred, then the journal id will contain a
1151          * negative (error) number. This will then be returned to the
1152          * caller (of the mount syscall). We do this even for spectator
1153          * mounts (which just write a jid of 0 to indicate "ok" even though
1154          * the jid is unused in the spectator case)
1155          */
1156         if (sdp->sd_lockstruct.ls_jid < 0) {
1157                 error = sdp->sd_lockstruct.ls_jid;
1158                 sdp->sd_lockstruct.ls_jid = 0;
1159                 goto fail_sb;
1160         }
1161 
1162         if (sdp->sd_args.ar_spectator)
1163                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1164                          sdp->sd_table_name);
1165         else
1166                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1167                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1168 
1169         error = init_inodes(sdp, DO);
1170         if (error)
1171                 goto fail_sb;
1172 
1173         error = init_per_node(sdp, DO);
1174         if (error)
1175                 goto fail_inodes;
1176 
1177         error = gfs2_statfs_init(sdp);
1178         if (error) {
1179                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1180                 goto fail_per_node;
1181         }
1182 
1183         if (!(sb->s_flags & MS_RDONLY)) {
1184                 error = gfs2_make_fs_rw(sdp);
1185                 if (error) {
1186                         fs_err(sdp, "can't make FS RW: %d\n", error);
1187                         goto fail_per_node;
1188                 }
1189         }
1190 
1191         gfs2_glock_dq_uninit(&mount_gh);
1192         gfs2_online_uevent(sdp);
1193         return 0;
1194 
1195 fail_per_node:
1196         init_per_node(sdp, UNDO);
1197 fail_inodes:
1198         init_inodes(sdp, UNDO);
1199 fail_sb:
1200         if (sdp->sd_root_dir)
1201                 dput(sdp->sd_root_dir);
1202         if (sdp->sd_master_dir)
1203                 dput(sdp->sd_master_dir);
1204         if (sb->s_root)
1205                 dput(sb->s_root);
1206         sb->s_root = NULL;
1207 fail_locking:
1208         init_locking(sdp, &mount_gh, UNDO);
1209 fail_lm:
1210         complete_all(&sdp->sd_journal_ready);
1211         gfs2_gl_hash_clear(sdp);
1212         gfs2_lm_unmount(sdp);
1213 fail_debug:
1214         gfs2_delete_debugfs_file(sdp);
1215         free_percpu(sdp->sd_lkstats);
1216         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1217          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1218         gfs2_sys_fs_del(sdp);
1219         sb->s_fs_info = NULL;
1220         return error;
1221 }
1222 
1223 static int set_gfs2_super(struct super_block *s, void *data)
1224 {
1225         s->s_bdev = data;
1226         s->s_dev = s->s_bdev->bd_dev;
1227 
1228         /*
1229          * We set the bdi here to the queue backing, file systems can
1230          * overwrite this in ->fill_super()
1231          */
1232         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1233         return 0;
1234 }
1235 
1236 static int test_gfs2_super(struct super_block *s, void *ptr)
1237 {
1238         struct block_device *bdev = ptr;
1239         return (bdev == s->s_bdev);
1240 }
1241 
1242 /**
1243  * gfs2_mount - Get the GFS2 superblock
1244  * @fs_type: The GFS2 filesystem type
1245  * @flags: Mount flags
1246  * @dev_name: The name of the device
1247  * @data: The mount arguments
1248  *
1249  * Q. Why not use get_sb_bdev() ?
1250  * A. We need to select one of two root directories to mount, independent
1251  *    of whether this is the initial, or subsequent, mount of this sb
1252  *
1253  * Returns: 0 or -ve on error
1254  */
1255 
1256 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1257                        const char *dev_name, void *data)
1258 {
1259         struct block_device *bdev;
1260         struct super_block *s;
1261         fmode_t mode = FMODE_READ | FMODE_EXCL;
1262         int error;
1263         struct gfs2_args args;
1264         struct gfs2_sbd *sdp;
1265 
1266         if (!(flags & MS_RDONLY))
1267                 mode |= FMODE_WRITE;
1268 
1269         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1270         if (IS_ERR(bdev))
1271                 return ERR_CAST(bdev);
1272 
1273         /*
1274          * once the super is inserted into the list by sget, s_umount
1275          * will protect the lockfs code from trying to start a snapshot
1276          * while we are mounting
1277          */
1278         mutex_lock(&bdev->bd_fsfreeze_mutex);
1279         if (bdev->bd_fsfreeze_count > 0) {
1280                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1281                 error = -EBUSY;
1282                 goto error_bdev;
1283         }
1284         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1285         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1286         error = PTR_ERR(s);
1287         if (IS_ERR(s))
1288                 goto error_bdev;
1289 
1290         if (s->s_root) {
1291                 /*
1292                  * s_umount nests inside bd_mutex during
1293                  * __invalidate_device().  blkdev_put() acquires
1294                  * bd_mutex and can't be called under s_umount.  Drop
1295                  * s_umount temporarily.  This is safe as we're
1296                  * holding an active reference.
1297                  */
1298                 up_write(&s->s_umount);
1299                 blkdev_put(bdev, mode);
1300                 down_write(&s->s_umount);
1301         }
1302 
1303         memset(&args, 0, sizeof(args));
1304         args.ar_quota = GFS2_QUOTA_DEFAULT;
1305         args.ar_data = GFS2_DATA_DEFAULT;
1306         args.ar_commit = 30;
1307         args.ar_statfs_quantum = 30;
1308         args.ar_quota_quantum = 60;
1309         args.ar_errors = GFS2_ERRORS_DEFAULT;
1310 
1311         error = gfs2_mount_args(&args, data);
1312         if (error) {
1313                 pr_warn("can't parse mount arguments\n");
1314                 goto error_super;
1315         }
1316 
1317         if (s->s_root) {
1318                 error = -EBUSY;
1319                 if ((flags ^ s->s_flags) & MS_RDONLY)
1320                         goto error_super;
1321         } else {
1322                 char b[BDEVNAME_SIZE];
1323 
1324                 s->s_mode = mode;
1325                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1326                 sb_set_blocksize(s, block_size(bdev));
1327                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1328                 if (error)
1329                         goto error_super;
1330                 s->s_flags |= MS_ACTIVE;
1331                 bdev->bd_super = s;
1332         }
1333 
1334         sdp = s->s_fs_info;
1335         if (args.ar_meta)
1336                 return dget(sdp->sd_master_dir);
1337         else
1338                 return dget(sdp->sd_root_dir);
1339 
1340 error_super:
1341         deactivate_locked_super(s);
1342         return ERR_PTR(error);
1343 error_bdev:
1344         blkdev_put(bdev, mode);
1345         return ERR_PTR(error);
1346 }
1347 
1348 static int set_meta_super(struct super_block *s, void *ptr)
1349 {
1350         return -EINVAL;
1351 }
1352 
1353 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1354                         int flags, const char *dev_name, void *data)
1355 {
1356         struct super_block *s;
1357         struct gfs2_sbd *sdp;
1358         struct path path;
1359         int error;
1360 
1361         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1362         if (error) {
1363                 pr_warn("path_lookup on %s returned error %d\n",
1364                         dev_name, error);
1365                 return ERR_PTR(error);
1366         }
1367         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1368                  path.dentry->d_inode->i_sb->s_bdev);
1369         path_put(&path);
1370         if (IS_ERR(s)) {
1371                 pr_warn("gfs2 mount does not exist\n");
1372                 return ERR_CAST(s);
1373         }
1374         if ((flags ^ s->s_flags) & MS_RDONLY) {
1375                 deactivate_locked_super(s);
1376                 return ERR_PTR(-EBUSY);
1377         }
1378         sdp = s->s_fs_info;
1379         return dget(sdp->sd_master_dir);
1380 }
1381 
1382 static void gfs2_kill_sb(struct super_block *sb)
1383 {
1384         struct gfs2_sbd *sdp = sb->s_fs_info;
1385 
1386         if (sdp == NULL) {
1387                 kill_block_super(sb);
1388                 return;
1389         }
1390 
1391         gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1392         dput(sdp->sd_root_dir);
1393         dput(sdp->sd_master_dir);
1394         sdp->sd_root_dir = NULL;
1395         sdp->sd_master_dir = NULL;
1396         shrink_dcache_sb(sb);
1397         gfs2_delete_debugfs_file(sdp);
1398         free_percpu(sdp->sd_lkstats);
1399         kill_block_super(sb);
1400 }
1401 
1402 struct file_system_type gfs2_fs_type = {
1403         .name = "gfs2",
1404         .fs_flags = FS_REQUIRES_DEV,
1405         .mount = gfs2_mount,
1406         .kill_sb = gfs2_kill_sb,
1407         .owner = THIS_MODULE,
1408 };
1409 MODULE_ALIAS_FS("gfs2");
1410 
1411 struct file_system_type gfs2meta_fs_type = {
1412         .name = "gfs2meta",
1413         .fs_flags = FS_REQUIRES_DEV,
1414         .mount = gfs2_mount_meta,
1415         .owner = THIS_MODULE,
1416 };
1417 MODULE_ALIAS_FS("gfs2meta");
1418 

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