Version:  2.0.40 2.2.26 2.4.37 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 3.18 3.19 4.0 4.1

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, int error)
175 {
176         struct page *page = bio->bi_private;
177 
178         if (!error)
179                 SetPageUptodate(page);
180         else
181                 pr_warn("error %d reading superblock\n", error);
182         unlock_page(page);
183 }
184 
185 static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)
186 {
187         struct gfs2_sb_host *sb = &sdp->sd_sb;
188         struct super_block *s = sdp->sd_vfs;
189         const struct gfs2_sb *str = buf;
190 
191         sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
192         sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
193         sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
194         sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
195         sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
196         sb->sb_bsize = be32_to_cpu(str->sb_bsize);
197         sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
198         sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
199         sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
200         sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
201         sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
202 
203         memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
204         memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
205         memcpy(s->s_uuid, str->sb_uuid, 16);
206 }
207 
208 /**
209  * gfs2_read_super - Read the gfs2 super block from disk
210  * @sdp: The GFS2 super block
211  * @sector: The location of the super block
212  * @error: The error code to return
213  *
214  * This uses the bio functions to read the super block from disk
215  * because we want to be 100% sure that we never read cached data.
216  * A super block is read twice only during each GFS2 mount and is
217  * never written to by the filesystem. The first time its read no
218  * locks are held, and the only details which are looked at are those
219  * relating to the locking protocol. Once locking is up and working,
220  * the sb is read again under the lock to establish the location of
221  * the master directory (contains pointers to journals etc) and the
222  * root directory.
223  *
224  * Returns: 0 on success or error
225  */
226 
227 static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
228 {
229         struct super_block *sb = sdp->sd_vfs;
230         struct gfs2_sb *p;
231         struct page *page;
232         struct bio *bio;
233 
234         page = alloc_page(GFP_NOFS);
235         if (unlikely(!page))
236                 return -ENOMEM;
237 
238         ClearPageUptodate(page);
239         ClearPageDirty(page);
240         lock_page(page);
241 
242         bio = bio_alloc(GFP_NOFS, 1);
243         bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
244         bio->bi_bdev = sb->s_bdev;
245         bio_add_page(bio, page, PAGE_SIZE, 0);
246 
247         bio->bi_end_io = end_bio_io_page;
248         bio->bi_private = page;
249         submit_bio(READ_SYNC | REQ_META, bio);
250         wait_on_page_locked(page);
251         bio_put(bio);
252         if (!PageUptodate(page)) {
253                 __free_page(page);
254                 return -EIO;
255         }
256         p = kmap(page);
257         gfs2_sb_in(sdp, p);
258         kunmap(page);
259         __free_page(page);
260         return gfs2_check_sb(sdp, silent);
261 }
262 
263 /**
264  * gfs2_read_sb - Read super block
265  * @sdp: The GFS2 superblock
266  * @silent: Don't print message if mount fails
267  *
268  */
269 
270 static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
271 {
272         u32 hash_blocks, ind_blocks, leaf_blocks;
273         u32 tmp_blocks;
274         unsigned int x;
275         int error;
276 
277         error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
278         if (error) {
279                 if (!silent)
280                         fs_err(sdp, "can't read superblock\n");
281                 return error;
282         }
283 
284         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
285                                GFS2_BASIC_BLOCK_SHIFT;
286         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
287         sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
288                           sizeof(struct gfs2_dinode)) / sizeof(u64);
289         sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
290                           sizeof(struct gfs2_meta_header)) / sizeof(u64);
291         sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
292         sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
293         sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
294         sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
295         sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
296                                 sizeof(struct gfs2_meta_header)) /
297                                 sizeof(struct gfs2_quota_change);
298         sdp->sd_blocks_per_bitmap = (sdp->sd_sb.sb_bsize -
299                                      sizeof(struct gfs2_meta_header))
300                 * GFS2_NBBY; /* not the rgrp bitmap, subsequent bitmaps only */
301 
302         /* Compute maximum reservation required to add a entry to a directory */
303 
304         hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
305                              sdp->sd_jbsize);
306 
307         ind_blocks = 0;
308         for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
309                 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
310                 ind_blocks += tmp_blocks;
311         }
312 
313         leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
314 
315         sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
316 
317         sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
318                                 sizeof(struct gfs2_dinode);
319         sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
320         for (x = 2;; x++) {
321                 u64 space, d;
322                 u32 m;
323 
324                 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
325                 d = space;
326                 m = do_div(d, sdp->sd_inptrs);
327 
328                 if (d != sdp->sd_heightsize[x - 1] || m)
329                         break;
330                 sdp->sd_heightsize[x] = space;
331         }
332         sdp->sd_max_height = x;
333         sdp->sd_heightsize[x] = ~0;
334         gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
335 
336         sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
337                                  sizeof(struct gfs2_dinode);
338         sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
339         for (x = 2;; x++) {
340                 u64 space, d;
341                 u32 m;
342 
343                 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
344                 d = space;
345                 m = do_div(d, sdp->sd_inptrs);
346 
347                 if (d != sdp->sd_jheightsize[x - 1] || m)
348                         break;
349                 sdp->sd_jheightsize[x] = space;
350         }
351         sdp->sd_max_jheight = x;
352         sdp->sd_jheightsize[x] = ~0;
353         gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
354 
355         return 0;
356 }
357 
358 static int init_names(struct gfs2_sbd *sdp, int silent)
359 {
360         char *proto, *table;
361         int error = 0;
362 
363         proto = sdp->sd_args.ar_lockproto;
364         table = sdp->sd_args.ar_locktable;
365 
366         /*  Try to autodetect  */
367 
368         if (!proto[0] || !table[0]) {
369                 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, silent);
370                 if (error)
371                         return error;
372 
373                 if (!proto[0])
374                         proto = sdp->sd_sb.sb_lockproto;
375                 if (!table[0])
376                         table = sdp->sd_sb.sb_locktable;
377         }
378 
379         if (!table[0])
380                 table = sdp->sd_vfs->s_id;
381 
382         strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
383         strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
384 
385         table = sdp->sd_table_name;
386         while ((table = strchr(table, '/')))
387                 *table = '_';
388 
389         return error;
390 }
391 
392 static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
393                         int undo)
394 {
395         int error = 0;
396 
397         if (undo)
398                 goto fail_trans;
399 
400         error = gfs2_glock_nq_num(sdp,
401                                   GFS2_MOUNT_LOCK, &gfs2_nondisk_glops,
402                                   LM_ST_EXCLUSIVE, LM_FLAG_NOEXP | GL_NOCACHE,
403                                   mount_gh);
404         if (error) {
405                 fs_err(sdp, "can't acquire mount glock: %d\n", error);
406                 goto fail;
407         }
408 
409         error = gfs2_glock_nq_num(sdp,
410                                   GFS2_LIVE_LOCK, &gfs2_nondisk_glops,
411                                   LM_ST_SHARED,
412                                   LM_FLAG_NOEXP | GL_EXACT,
413                                   &sdp->sd_live_gh);
414         if (error) {
415                 fs_err(sdp, "can't acquire live glock: %d\n", error);
416                 goto fail_mount;
417         }
418 
419         error = gfs2_glock_get(sdp, GFS2_RENAME_LOCK, &gfs2_nondisk_glops,
420                                CREATE, &sdp->sd_rename_gl);
421         if (error) {
422                 fs_err(sdp, "can't create rename glock: %d\n", error);
423                 goto fail_live;
424         }
425 
426         error = gfs2_glock_get(sdp, GFS2_FREEZE_LOCK, &gfs2_freeze_glops,
427                                CREATE, &sdp->sd_freeze_gl);
428         if (error) {
429                 fs_err(sdp, "can't create transaction glock: %d\n", error);
430                 goto fail_rename;
431         }
432 
433         return 0;
434 
435 fail_trans:
436         gfs2_glock_put(sdp->sd_freeze_gl);
437 fail_rename:
438         gfs2_glock_put(sdp->sd_rename_gl);
439 fail_live:
440         gfs2_glock_dq_uninit(&sdp->sd_live_gh);
441 fail_mount:
442         gfs2_glock_dq_uninit(mount_gh);
443 fail:
444         return error;
445 }
446 
447 static int gfs2_lookup_root(struct super_block *sb, struct dentry **dptr,
448                             u64 no_addr, const char *name)
449 {
450         struct gfs2_sbd *sdp = sb->s_fs_info;
451         struct dentry *dentry;
452         struct inode *inode;
453 
454         inode = gfs2_inode_lookup(sb, DT_DIR, no_addr, 0, 0);
455         if (IS_ERR(inode)) {
456                 fs_err(sdp, "can't read in %s inode: %ld\n", name, PTR_ERR(inode));
457                 return PTR_ERR(inode);
458         }
459         dentry = d_make_root(inode);
460         if (!dentry) {
461                 fs_err(sdp, "can't alloc %s dentry\n", name);
462                 return -ENOMEM;
463         }
464         *dptr = dentry;
465         return 0;
466 }
467 
468 static int init_sb(struct gfs2_sbd *sdp, int silent)
469 {
470         struct super_block *sb = sdp->sd_vfs;
471         struct gfs2_holder sb_gh;
472         u64 no_addr;
473         int ret;
474 
475         ret = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
476                                 LM_ST_SHARED, 0, &sb_gh);
477         if (ret) {
478                 fs_err(sdp, "can't acquire superblock glock: %d\n", ret);
479                 return ret;
480         }
481 
482         ret = gfs2_read_sb(sdp, silent);
483         if (ret) {
484                 fs_err(sdp, "can't read superblock: %d\n", ret);
485                 goto out;
486         }
487 
488         /* Set up the buffer cache and SB for real */
489         if (sdp->sd_sb.sb_bsize < bdev_logical_block_size(sb->s_bdev)) {
490                 ret = -EINVAL;
491                 fs_err(sdp, "FS block size (%u) is too small for device "
492                        "block size (%u)\n",
493                        sdp->sd_sb.sb_bsize, bdev_logical_block_size(sb->s_bdev));
494                 goto out;
495         }
496         if (sdp->sd_sb.sb_bsize > PAGE_SIZE) {
497                 ret = -EINVAL;
498                 fs_err(sdp, "FS block size (%u) is too big for machine "
499                        "page size (%u)\n",
500                        sdp->sd_sb.sb_bsize, (unsigned int)PAGE_SIZE);
501                 goto out;
502         }
503         sb_set_blocksize(sb, sdp->sd_sb.sb_bsize);
504 
505         /* Get the root inode */
506         no_addr = sdp->sd_sb.sb_root_dir.no_addr;
507         ret = gfs2_lookup_root(sb, &sdp->sd_root_dir, no_addr, "root");
508         if (ret)
509                 goto out;
510 
511         /* Get the master inode */
512         no_addr = sdp->sd_sb.sb_master_dir.no_addr;
513         ret = gfs2_lookup_root(sb, &sdp->sd_master_dir, no_addr, "master");
514         if (ret) {
515                 dput(sdp->sd_root_dir);
516                 goto out;
517         }
518         sb->s_root = dget(sdp->sd_args.ar_meta ? sdp->sd_master_dir : sdp->sd_root_dir);
519 out:
520         gfs2_glock_dq_uninit(&sb_gh);
521         return ret;
522 }
523 
524 static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
525 {
526         char *message = "FIRSTMOUNT=Done";
527         char *envp[] = { message, NULL };
528 
529         fs_info(sdp, "first mount done, others may mount\n");
530 
531         if (sdp->sd_lockstruct.ls_ops->lm_first_done)
532                 sdp->sd_lockstruct.ls_ops->lm_first_done(sdp);
533 
534         kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
535 }
536 
537 /**
538  * gfs2_jindex_hold - Grab a lock on the jindex
539  * @sdp: The GFS2 superblock
540  * @ji_gh: the holder for the jindex glock
541  *
542  * Returns: errno
543  */
544 
545 static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
546 {
547         struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
548         struct qstr name;
549         char buf[20];
550         struct gfs2_jdesc *jd;
551         int error;
552 
553         name.name = buf;
554 
555         mutex_lock(&sdp->sd_jindex_mutex);
556 
557         for (;;) {
558                 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
559                 if (error)
560                         break;
561 
562                 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
563                 name.hash = gfs2_disk_hash(name.name, name.len);
564 
565                 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
566                 if (error == -ENOENT) {
567                         error = 0;
568                         break;
569                 }
570 
571                 gfs2_glock_dq_uninit(ji_gh);
572 
573                 if (error)
574                         break;
575 
576                 error = -ENOMEM;
577                 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
578                 if (!jd)
579                         break;
580 
581                 INIT_LIST_HEAD(&jd->extent_list);
582                 INIT_LIST_HEAD(&jd->jd_revoke_list);
583 
584                 INIT_WORK(&jd->jd_work, gfs2_recover_func);
585                 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
586                 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
587                         if (!jd->jd_inode)
588                                 error = -ENOENT;
589                         else
590                                 error = PTR_ERR(jd->jd_inode);
591                         kfree(jd);
592                         break;
593                 }
594 
595                 spin_lock(&sdp->sd_jindex_spin);
596                 jd->jd_jid = sdp->sd_journals++;
597                 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
598                 spin_unlock(&sdp->sd_jindex_spin);
599         }
600 
601         mutex_unlock(&sdp->sd_jindex_mutex);
602 
603         return error;
604 }
605 
606 /**
607  * check_journal_clean - Make sure a journal is clean for a spectator mount
608  * @sdp: The GFS2 superblock
609  * @jd: The journal descriptor
610  *
611  * Returns: 0 if the journal is clean or locked, else an error
612  */
613 static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
614 {
615         int error;
616         struct gfs2_holder j_gh;
617         struct gfs2_log_header_host head;
618         struct gfs2_inode *ip;
619 
620         ip = GFS2_I(jd->jd_inode);
621         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
622                                    GL_EXACT | GL_NOCACHE, &j_gh);
623         if (error) {
624                 fs_err(sdp, "Error locking journal for spectator mount.\n");
625                 return -EPERM;
626         }
627         error = gfs2_jdesc_check(jd);
628         if (error) {
629                 fs_err(sdp, "Error checking journal for spectator mount.\n");
630                 goto out_unlock;
631         }
632         error = gfs2_find_jhead(jd, &head);
633         if (error) {
634                 fs_err(sdp, "Error parsing journal for spectator mount.\n");
635                 goto out_unlock;
636         }
637         if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
638                 error = -EPERM;
639                 fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
640                        "must not be a spectator.\n", jd->jd_jid);
641         }
642 
643 out_unlock:
644         gfs2_glock_dq_uninit(&j_gh);
645         return error;
646 }
647 
648 static int init_journal(struct gfs2_sbd *sdp, int undo)
649 {
650         struct inode *master = d_inode(sdp->sd_master_dir);
651         struct gfs2_holder ji_gh;
652         struct gfs2_inode *ip;
653         int jindex = 1;
654         int error = 0;
655 
656         if (undo) {
657                 jindex = 0;
658                 goto fail_jinode_gh;
659         }
660 
661         sdp->sd_jindex = gfs2_lookup_simple(master, "jindex");
662         if (IS_ERR(sdp->sd_jindex)) {
663                 fs_err(sdp, "can't lookup journal index: %d\n", error);
664                 return PTR_ERR(sdp->sd_jindex);
665         }
666 
667         /* Load in the journal index special file */
668 
669         error = gfs2_jindex_hold(sdp, &ji_gh);
670         if (error) {
671                 fs_err(sdp, "can't read journal index: %d\n", error);
672                 goto fail;
673         }
674 
675         error = -EUSERS;
676         if (!gfs2_jindex_size(sdp)) {
677                 fs_err(sdp, "no journals!\n");
678                 goto fail_jindex;
679         }
680 
681         if (sdp->sd_args.ar_spectator) {
682                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, 0);
683                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
684                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
685                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
686         } else {
687                 if (sdp->sd_lockstruct.ls_jid >= gfs2_jindex_size(sdp)) {
688                         fs_err(sdp, "can't mount journal #%u\n",
689                                sdp->sd_lockstruct.ls_jid);
690                         fs_err(sdp, "there are only %u journals (0 - %u)\n",
691                                gfs2_jindex_size(sdp),
692                                gfs2_jindex_size(sdp) - 1);
693                         goto fail_jindex;
694                 }
695                 sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
696 
697                 error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
698                                           &gfs2_journal_glops,
699                                           LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
700                                           &sdp->sd_journal_gh);
701                 if (error) {
702                         fs_err(sdp, "can't acquire journal glock: %d\n", error);
703                         goto fail_jindex;
704                 }
705 
706                 ip = GFS2_I(sdp->sd_jdesc->jd_inode);
707                 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
708                                            LM_FLAG_NOEXP | GL_EXACT | GL_NOCACHE,
709                                            &sdp->sd_jinode_gh);
710                 if (error) {
711                         fs_err(sdp, "can't acquire journal inode glock: %d\n",
712                                error);
713                         goto fail_journal_gh;
714                 }
715 
716                 error = gfs2_jdesc_check(sdp->sd_jdesc);
717                 if (error) {
718                         fs_err(sdp, "my journal (%u) is bad: %d\n",
719                                sdp->sd_jdesc->jd_jid, error);
720                         goto fail_jinode_gh;
721                 }
722                 atomic_set(&sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks);
723                 atomic_set(&sdp->sd_log_thresh1, 2*sdp->sd_jdesc->jd_blocks/5);
724                 atomic_set(&sdp->sd_log_thresh2, 4*sdp->sd_jdesc->jd_blocks/5);
725 
726                 /* Map the extents for this journal's blocks */
727                 gfs2_map_journal_extents(sdp, sdp->sd_jdesc);
728         }
729         trace_gfs2_log_blocks(sdp, atomic_read(&sdp->sd_log_blks_free));
730 
731         if (sdp->sd_lockstruct.ls_first) {
732                 unsigned int x;
733                 for (x = 0; x < sdp->sd_journals; x++) {
734                         struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
735 
736                         if (sdp->sd_args.ar_spectator) {
737                                 error = check_journal_clean(sdp, jd);
738                                 if (error)
739                                         goto fail_jinode_gh;
740                                 continue;
741                         }
742                         error = gfs2_recover_journal(jd, true);
743                         if (error) {
744                                 fs_err(sdp, "error recovering journal %u: %d\n",
745                                        x, error);
746                                 goto fail_jinode_gh;
747                         }
748                 }
749 
750                 gfs2_others_may_mount(sdp);
751         } else if (!sdp->sd_args.ar_spectator) {
752                 error = gfs2_recover_journal(sdp->sd_jdesc, true);
753                 if (error) {
754                         fs_err(sdp, "error recovering my journal: %d\n", error);
755                         goto fail_jinode_gh;
756                 }
757         }
758 
759         set_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags);
760         gfs2_glock_dq_uninit(&ji_gh);
761         jindex = 0;
762         INIT_WORK(&sdp->sd_freeze_work, gfs2_freeze_func);
763         return 0;
764 
765 fail_jinode_gh:
766         if (!sdp->sd_args.ar_spectator)
767                 gfs2_glock_dq_uninit(&sdp->sd_jinode_gh);
768 fail_journal_gh:
769         if (!sdp->sd_args.ar_spectator)
770                 gfs2_glock_dq_uninit(&sdp->sd_journal_gh);
771 fail_jindex:
772         gfs2_jindex_free(sdp);
773         if (jindex)
774                 gfs2_glock_dq_uninit(&ji_gh);
775 fail:
776         iput(sdp->sd_jindex);
777         return error;
778 }
779 
780 static struct lock_class_key gfs2_quota_imutex_key;
781 
782 static int init_inodes(struct gfs2_sbd *sdp, int undo)
783 {
784         int error = 0;
785         struct inode *master = d_inode(sdp->sd_master_dir);
786 
787         if (undo)
788                 goto fail_qinode;
789 
790         error = init_journal(sdp, undo);
791         complete_all(&sdp->sd_journal_ready);
792         if (error)
793                 goto fail;
794 
795         /* Read in the master statfs inode */
796         sdp->sd_statfs_inode = gfs2_lookup_simple(master, "statfs");
797         if (IS_ERR(sdp->sd_statfs_inode)) {
798                 error = PTR_ERR(sdp->sd_statfs_inode);
799                 fs_err(sdp, "can't read in statfs inode: %d\n", error);
800                 goto fail_journal;
801         }
802 
803         /* Read in the resource index inode */
804         sdp->sd_rindex = gfs2_lookup_simple(master, "rindex");
805         if (IS_ERR(sdp->sd_rindex)) {
806                 error = PTR_ERR(sdp->sd_rindex);
807                 fs_err(sdp, "can't get resource index inode: %d\n", error);
808                 goto fail_statfs;
809         }
810         sdp->sd_rindex_uptodate = 0;
811 
812         /* Read in the quota inode */
813         sdp->sd_quota_inode = gfs2_lookup_simple(master, "quota");
814         if (IS_ERR(sdp->sd_quota_inode)) {
815                 error = PTR_ERR(sdp->sd_quota_inode);
816                 fs_err(sdp, "can't get quota file inode: %d\n", error);
817                 goto fail_rindex;
818         }
819         /*
820          * i_mutex on quota files is special. Since this inode is hidden system
821          * file, we are safe to define locking ourselves.
822          */
823         lockdep_set_class(&sdp->sd_quota_inode->i_mutex,
824                           &gfs2_quota_imutex_key);
825 
826         error = gfs2_rindex_update(sdp);
827         if (error)
828                 goto fail_qinode;
829 
830         return 0;
831 
832 fail_qinode:
833         iput(sdp->sd_quota_inode);
834 fail_rindex:
835         gfs2_clear_rgrpd(sdp);
836         iput(sdp->sd_rindex);
837 fail_statfs:
838         iput(sdp->sd_statfs_inode);
839 fail_journal:
840         init_journal(sdp, UNDO);
841 fail:
842         return error;
843 }
844 
845 static int init_per_node(struct gfs2_sbd *sdp, int undo)
846 {
847         struct inode *pn = NULL;
848         char buf[30];
849         int error = 0;
850         struct gfs2_inode *ip;
851         struct inode *master = d_inode(sdp->sd_master_dir);
852 
853         if (sdp->sd_args.ar_spectator)
854                 return 0;
855 
856         if (undo)
857                 goto fail_qc_gh;
858 
859         pn = gfs2_lookup_simple(master, "per_node");
860         if (IS_ERR(pn)) {
861                 error = PTR_ERR(pn);
862                 fs_err(sdp, "can't find per_node directory: %d\n", error);
863                 return error;
864         }
865 
866         sprintf(buf, "statfs_change%u", sdp->sd_jdesc->jd_jid);
867         sdp->sd_sc_inode = gfs2_lookup_simple(pn, buf);
868         if (IS_ERR(sdp->sd_sc_inode)) {
869                 error = PTR_ERR(sdp->sd_sc_inode);
870                 fs_err(sdp, "can't find local \"sc\" file: %d\n", error);
871                 goto fail;
872         }
873 
874         sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
875         sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
876         if (IS_ERR(sdp->sd_qc_inode)) {
877                 error = PTR_ERR(sdp->sd_qc_inode);
878                 fs_err(sdp, "can't find local \"qc\" file: %d\n", error);
879                 goto fail_ut_i;
880         }
881 
882         iput(pn);
883         pn = NULL;
884 
885         ip = GFS2_I(sdp->sd_sc_inode);
886         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
887                                    &sdp->sd_sc_gh);
888         if (error) {
889                 fs_err(sdp, "can't lock local \"sc\" file: %d\n", error);
890                 goto fail_qc_i;
891         }
892 
893         ip = GFS2_I(sdp->sd_qc_inode);
894         error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0,
895                                    &sdp->sd_qc_gh);
896         if (error) {
897                 fs_err(sdp, "can't lock local \"qc\" file: %d\n", error);
898                 goto fail_ut_gh;
899         }
900 
901         return 0;
902 
903 fail_qc_gh:
904         gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
905 fail_ut_gh:
906         gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
907 fail_qc_i:
908         iput(sdp->sd_qc_inode);
909 fail_ut_i:
910         iput(sdp->sd_sc_inode);
911 fail:
912         if (pn)
913                 iput(pn);
914         return error;
915 }
916 
917 static const match_table_t nolock_tokens = {
918         { Opt_jid, "jid=%d\n", },
919         { Opt_err, NULL },
920 };
921 
922 static const struct lm_lockops nolock_ops = {
923         .lm_proto_name = "lock_nolock",
924         .lm_put_lock = gfs2_glock_free,
925         .lm_tokens = &nolock_tokens,
926 };
927 
928 /**
929  * gfs2_lm_mount - mount a locking protocol
930  * @sdp: the filesystem
931  * @args: mount arguments
932  * @silent: if 1, don't complain if the FS isn't a GFS2 fs
933  *
934  * Returns: errno
935  */
936 
937 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
938 {
939         const struct lm_lockops *lm;
940         struct lm_lockstruct *ls = &sdp->sd_lockstruct;
941         struct gfs2_args *args = &sdp->sd_args;
942         const char *proto = sdp->sd_proto_name;
943         const char *table = sdp->sd_table_name;
944         char *o, *options;
945         int ret;
946 
947         if (!strcmp("lock_nolock", proto)) {
948                 lm = &nolock_ops;
949                 sdp->sd_args.ar_localflocks = 1;
950 #ifdef CONFIG_GFS2_FS_LOCKING_DLM
951         } else if (!strcmp("lock_dlm", proto)) {
952                 lm = &gfs2_dlm_ops;
953 #endif
954         } else {
955                 pr_info("can't find protocol %s\n", proto);
956                 return -ENOENT;
957         }
958 
959         fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
960 
961         ls->ls_ops = lm;
962         ls->ls_first = 1;
963 
964         for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
965                 substring_t tmp[MAX_OPT_ARGS];
966                 int token, option;
967 
968                 if (!o || !*o)
969                         continue;
970 
971                 token = match_token(o, *lm->lm_tokens, tmp);
972                 switch (token) {
973                 case Opt_jid:
974                         ret = match_int(&tmp[0], &option);
975                         if (ret || option < 0) 
976                                 goto hostdata_error;
977                         if (test_and_clear_bit(SDF_NOJOURNALID, &sdp->sd_flags))
978                                 ls->ls_jid = option;
979                         break;
980                 case Opt_id:
981                 case Opt_nodir:
982                         /* Obsolete, but left for backward compat purposes */
983                         break;
984                 case Opt_first:
985                         ret = match_int(&tmp[0], &option);
986                         if (ret || (option != 0 && option != 1))
987                                 goto hostdata_error;
988                         ls->ls_first = option;
989                         break;
990                 case Opt_err:
991                 default:
992 hostdata_error:
993                         fs_info(sdp, "unknown hostdata (%s)\n", o);
994                         return -EINVAL;
995                 }
996         }
997 
998         if (lm->lm_mount == NULL) {
999                 fs_info(sdp, "Now mounting FS...\n");
1000                 complete_all(&sdp->sd_locking_init);
1001                 return 0;
1002         }
1003         ret = lm->lm_mount(sdp, table);
1004         if (ret == 0)
1005                 fs_info(sdp, "Joined cluster. Now mounting FS...\n");
1006         complete_all(&sdp->sd_locking_init);
1007         return ret;
1008 }
1009 
1010 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
1011 {
1012         const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
1013         if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
1014             lm->lm_unmount)
1015                 lm->lm_unmount(sdp);
1016 }
1017 
1018 static int wait_on_journal(struct gfs2_sbd *sdp)
1019 {
1020         if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
1021                 return 0;
1022 
1023         return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
1024                 ? -EINTR : 0;
1025 }
1026 
1027 void gfs2_online_uevent(struct gfs2_sbd *sdp)
1028 {
1029         struct super_block *sb = sdp->sd_vfs;
1030         char ro[20];
1031         char spectator[20];
1032         char *envp[] = { ro, spectator, NULL };
1033         sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0);
1034         sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0);
1035         kobject_uevent_env(&sdp->sd_kobj, KOBJ_ONLINE, envp);
1036 }
1037 
1038 /**
1039  * fill_super - Read in superblock
1040  * @sb: The VFS superblock
1041  * @data: Mount options
1042  * @silent: Don't complain if it's not a GFS2 filesystem
1043  *
1044  * Returns: errno
1045  */
1046 
1047 static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent)
1048 {
1049         struct gfs2_sbd *sdp;
1050         struct gfs2_holder mount_gh;
1051         int error;
1052 
1053         sdp = init_sbd(sb);
1054         if (!sdp) {
1055                 pr_warn("can't alloc struct gfs2_sbd\n");
1056                 return -ENOMEM;
1057         }
1058         sdp->sd_args = *args;
1059 
1060         if (sdp->sd_args.ar_spectator) {
1061                 sb->s_flags |= MS_RDONLY;
1062                 set_bit(SDF_RORECOVERY, &sdp->sd_flags);
1063         }
1064         if (sdp->sd_args.ar_posix_acl)
1065                 sb->s_flags |= MS_POSIXACL;
1066         if (sdp->sd_args.ar_nobarrier)
1067                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
1068 
1069         sb->s_flags |= MS_NOSEC;
1070         sb->s_magic = GFS2_MAGIC;
1071         sb->s_op = &gfs2_super_ops;
1072         sb->s_d_op = &gfs2_dops;
1073         sb->s_export_op = &gfs2_export_ops;
1074         sb->s_xattr = gfs2_xattr_handlers;
1075         sb->s_qcop = &gfs2_quotactl_ops;
1076         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
1077         sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
1078         sb->s_time_gran = 1;
1079         sb->s_maxbytes = MAX_LFS_FILESIZE;
1080 
1081         /* Set up the buffer cache and fill in some fake block size values
1082            to allow us to read-in the on-disk superblock. */
1083         sdp->sd_sb.sb_bsize = sb_min_blocksize(sb, GFS2_BASIC_BLOCK);
1084         sdp->sd_sb.sb_bsize_shift = sb->s_blocksize_bits;
1085         sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
1086                                GFS2_BASIC_BLOCK_SHIFT;
1087         sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
1088 
1089         sdp->sd_tune.gt_logd_secs = sdp->sd_args.ar_commit;
1090         sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
1091         if (sdp->sd_args.ar_statfs_quantum) {
1092                 sdp->sd_tune.gt_statfs_slow = 0;
1093                 sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
1094         } else {
1095                 sdp->sd_tune.gt_statfs_slow = 1;
1096                 sdp->sd_tune.gt_statfs_quantum = 30;
1097         }
1098 
1099         error = init_names(sdp, silent);
1100         if (error) {
1101                 /* In this case, we haven't initialized sysfs, so we have to
1102                    manually free the sdp. */
1103                 free_percpu(sdp->sd_lkstats);
1104                 kfree(sdp);
1105                 sb->s_fs_info = NULL;
1106                 return error;
1107         }
1108 
1109         snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s", sdp->sd_table_name);
1110 
1111         error = gfs2_sys_fs_add(sdp);
1112         /*
1113          * If we hit an error here, gfs2_sys_fs_add will have called function
1114          * kobject_put which causes the sysfs usage count to go to zero, which
1115          * causes sysfs to call function gfs2_sbd_release, which frees sdp.
1116          * Subsequent error paths here will call gfs2_sys_fs_del, which also
1117          * kobject_put to free sdp.
1118          */
1119         if (error)
1120                 return error;
1121 
1122         gfs2_create_debugfs_file(sdp);
1123 
1124         error = gfs2_lm_mount(sdp, silent);
1125         if (error)
1126                 goto fail_debug;
1127 
1128         error = init_locking(sdp, &mount_gh, DO);
1129         if (error)
1130                 goto fail_lm;
1131 
1132         error = init_sb(sdp, silent);
1133         if (error)
1134                 goto fail_locking;
1135 
1136         error = wait_on_journal(sdp);
1137         if (error)
1138                 goto fail_sb;
1139 
1140         /*
1141          * If user space has failed to join the cluster or some similar
1142          * failure has occurred, then the journal id will contain a
1143          * negative (error) number. This will then be returned to the
1144          * caller (of the mount syscall). We do this even for spectator
1145          * mounts (which just write a jid of 0 to indicate "ok" even though
1146          * the jid is unused in the spectator case)
1147          */
1148         if (sdp->sd_lockstruct.ls_jid < 0) {
1149                 error = sdp->sd_lockstruct.ls_jid;
1150                 sdp->sd_lockstruct.ls_jid = 0;
1151                 goto fail_sb;
1152         }
1153 
1154         if (sdp->sd_args.ar_spectator)
1155                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.s",
1156                          sdp->sd_table_name);
1157         else
1158                 snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u",
1159                          sdp->sd_table_name, sdp->sd_lockstruct.ls_jid);
1160 
1161         error = init_inodes(sdp, DO);
1162         if (error)
1163                 goto fail_sb;
1164 
1165         error = init_per_node(sdp, DO);
1166         if (error)
1167                 goto fail_inodes;
1168 
1169         error = gfs2_statfs_init(sdp);
1170         if (error) {
1171                 fs_err(sdp, "can't initialize statfs subsystem: %d\n", error);
1172                 goto fail_per_node;
1173         }
1174 
1175         if (!(sb->s_flags & MS_RDONLY)) {
1176                 error = gfs2_make_fs_rw(sdp);
1177                 if (error) {
1178                         fs_err(sdp, "can't make FS RW: %d\n", error);
1179                         goto fail_per_node;
1180                 }
1181         }
1182 
1183         gfs2_glock_dq_uninit(&mount_gh);
1184         gfs2_online_uevent(sdp);
1185         return 0;
1186 
1187 fail_per_node:
1188         init_per_node(sdp, UNDO);
1189 fail_inodes:
1190         init_inodes(sdp, UNDO);
1191 fail_sb:
1192         if (sdp->sd_root_dir)
1193                 dput(sdp->sd_root_dir);
1194         if (sdp->sd_master_dir)
1195                 dput(sdp->sd_master_dir);
1196         if (sb->s_root)
1197                 dput(sb->s_root);
1198         sb->s_root = NULL;
1199 fail_locking:
1200         init_locking(sdp, &mount_gh, UNDO);
1201 fail_lm:
1202         complete_all(&sdp->sd_journal_ready);
1203         gfs2_gl_hash_clear(sdp);
1204         gfs2_lm_unmount(sdp);
1205 fail_debug:
1206         gfs2_delete_debugfs_file(sdp);
1207         free_percpu(sdp->sd_lkstats);
1208         /* gfs2_sys_fs_del must be the last thing we do, since it causes
1209          * sysfs to call function gfs2_sbd_release, which frees sdp. */
1210         gfs2_sys_fs_del(sdp);
1211         sb->s_fs_info = NULL;
1212         return error;
1213 }
1214 
1215 static int set_gfs2_super(struct super_block *s, void *data)
1216 {
1217         s->s_bdev = data;
1218         s->s_dev = s->s_bdev->bd_dev;
1219 
1220         /*
1221          * We set the bdi here to the queue backing, file systems can
1222          * overwrite this in ->fill_super()
1223          */
1224         s->s_bdi = &bdev_get_queue(s->s_bdev)->backing_dev_info;
1225         return 0;
1226 }
1227 
1228 static int test_gfs2_super(struct super_block *s, void *ptr)
1229 {
1230         struct block_device *bdev = ptr;
1231         return (bdev == s->s_bdev);
1232 }
1233 
1234 /**
1235  * gfs2_mount - Get the GFS2 superblock
1236  * @fs_type: The GFS2 filesystem type
1237  * @flags: Mount flags
1238  * @dev_name: The name of the device
1239  * @data: The mount arguments
1240  *
1241  * Q. Why not use get_sb_bdev() ?
1242  * A. We need to select one of two root directories to mount, independent
1243  *    of whether this is the initial, or subsequent, mount of this sb
1244  *
1245  * Returns: 0 or -ve on error
1246  */
1247 
1248 static struct dentry *gfs2_mount(struct file_system_type *fs_type, int flags,
1249                        const char *dev_name, void *data)
1250 {
1251         struct block_device *bdev;
1252         struct super_block *s;
1253         fmode_t mode = FMODE_READ | FMODE_EXCL;
1254         int error;
1255         struct gfs2_args args;
1256         struct gfs2_sbd *sdp;
1257 
1258         if (!(flags & MS_RDONLY))
1259                 mode |= FMODE_WRITE;
1260 
1261         bdev = blkdev_get_by_path(dev_name, mode, fs_type);
1262         if (IS_ERR(bdev))
1263                 return ERR_CAST(bdev);
1264 
1265         /*
1266          * once the super is inserted into the list by sget, s_umount
1267          * will protect the lockfs code from trying to start a snapshot
1268          * while we are mounting
1269          */
1270         mutex_lock(&bdev->bd_fsfreeze_mutex);
1271         if (bdev->bd_fsfreeze_count > 0) {
1272                 mutex_unlock(&bdev->bd_fsfreeze_mutex);
1273                 error = -EBUSY;
1274                 goto error_bdev;
1275         }
1276         s = sget(fs_type, test_gfs2_super, set_gfs2_super, flags, bdev);
1277         mutex_unlock(&bdev->bd_fsfreeze_mutex);
1278         error = PTR_ERR(s);
1279         if (IS_ERR(s))
1280                 goto error_bdev;
1281 
1282         if (s->s_root) {
1283                 /*
1284                  * s_umount nests inside bd_mutex during
1285                  * __invalidate_device().  blkdev_put() acquires
1286                  * bd_mutex and can't be called under s_umount.  Drop
1287                  * s_umount temporarily.  This is safe as we're
1288                  * holding an active reference.
1289                  */
1290                 up_write(&s->s_umount);
1291                 blkdev_put(bdev, mode);
1292                 down_write(&s->s_umount);
1293         }
1294 
1295         memset(&args, 0, sizeof(args));
1296         args.ar_quota = GFS2_QUOTA_DEFAULT;
1297         args.ar_data = GFS2_DATA_DEFAULT;
1298         args.ar_commit = 30;
1299         args.ar_statfs_quantum = 30;
1300         args.ar_quota_quantum = 60;
1301         args.ar_errors = GFS2_ERRORS_DEFAULT;
1302 
1303         error = gfs2_mount_args(&args, data);
1304         if (error) {
1305                 pr_warn("can't parse mount arguments\n");
1306                 goto error_super;
1307         }
1308 
1309         if (s->s_root) {
1310                 error = -EBUSY;
1311                 if ((flags ^ s->s_flags) & MS_RDONLY)
1312                         goto error_super;
1313         } else {
1314                 char b[BDEVNAME_SIZE];
1315 
1316                 s->s_mode = mode;
1317                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1318                 sb_set_blocksize(s, block_size(bdev));
1319                 error = fill_super(s, &args, flags & MS_SILENT ? 1 : 0);
1320                 if (error)
1321                         goto error_super;
1322                 s->s_flags |= MS_ACTIVE;
1323                 bdev->bd_super = s;
1324         }
1325 
1326         sdp = s->s_fs_info;
1327         if (args.ar_meta)
1328                 return dget(sdp->sd_master_dir);
1329         else
1330                 return dget(sdp->sd_root_dir);
1331 
1332 error_super:
1333         deactivate_locked_super(s);
1334         return ERR_PTR(error);
1335 error_bdev:
1336         blkdev_put(bdev, mode);
1337         return ERR_PTR(error);
1338 }
1339 
1340 static int set_meta_super(struct super_block *s, void *ptr)
1341 {
1342         return -EINVAL;
1343 }
1344 
1345 static struct dentry *gfs2_mount_meta(struct file_system_type *fs_type,
1346                         int flags, const char *dev_name, void *data)
1347 {
1348         struct super_block *s;
1349         struct gfs2_sbd *sdp;
1350         struct path path;
1351         int error;
1352 
1353         error = kern_path(dev_name, LOOKUP_FOLLOW, &path);
1354         if (error) {
1355                 pr_warn("path_lookup on %s returned error %d\n",
1356                         dev_name, error);
1357                 return ERR_PTR(error);
1358         }
1359         s = sget(&gfs2_fs_type, test_gfs2_super, set_meta_super, flags,
1360                  d_inode(path.dentry)->i_sb->s_bdev);
1361         path_put(&path);
1362         if (IS_ERR(s)) {
1363                 pr_warn("gfs2 mount does not exist\n");
1364                 return ERR_CAST(s);
1365         }
1366         if ((flags ^ s->s_flags) & MS_RDONLY) {
1367                 deactivate_locked_super(s);
1368                 return ERR_PTR(-EBUSY);
1369         }
1370         sdp = s->s_fs_info;
1371         return dget(sdp->sd_master_dir);
1372 }
1373 
1374 static void gfs2_kill_sb(struct super_block *sb)
1375 {
1376         struct gfs2_sbd *sdp = sb->s_fs_info;
1377 
1378         if (sdp == NULL) {
1379                 kill_block_super(sb);
1380                 return;
1381         }
1382 
1383         gfs2_log_flush(sdp, NULL, SYNC_FLUSH);
1384         dput(sdp->sd_root_dir);
1385         dput(sdp->sd_master_dir);
1386         sdp->sd_root_dir = NULL;
1387         sdp->sd_master_dir = NULL;
1388         shrink_dcache_sb(sb);
1389         gfs2_delete_debugfs_file(sdp);
1390         free_percpu(sdp->sd_lkstats);
1391         kill_block_super(sb);
1392 }
1393 
1394 struct file_system_type gfs2_fs_type = {
1395         .name = "gfs2",
1396         .fs_flags = FS_REQUIRES_DEV,
1397         .mount = gfs2_mount,
1398         .kill_sb = gfs2_kill_sb,
1399         .owner = THIS_MODULE,
1400 };
1401 MODULE_ALIAS_FS("gfs2");
1402 
1403 struct file_system_type gfs2meta_fs_type = {
1404         .name = "gfs2meta",
1405         .fs_flags = FS_REQUIRES_DEV,
1406         .mount = gfs2_mount_meta,
1407         .owner = THIS_MODULE,
1408 };
1409 MODULE_ALIAS_FS("gfs2meta");
1410 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us