06065bd37fc339070948a141cd8063c9d39af8ad
[linux-2.6.git] / fs / exofs / super.c
1 /*
2  * Copyright (C) 2005, 2006
3  * Avishay Traeger (avishay@gmail.com)
4  * Copyright (C) 2008, 2009
5  * Boaz Harrosh <bharrosh@panasas.com>
6  *
7  * Copyrights for code taken from ext2:
8  *     Copyright (C) 1992, 1993, 1994, 1995
9  *     Remy Card (card@masi.ibp.fr)
10  *     Laboratoire MASI - Institut Blaise Pascal
11  *     Universite Pierre et Marie Curie (Paris VI)
12  *     from
13  *     linux/fs/minix/inode.c
14  *     Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  * This file is part of exofs.
17  *
18  * exofs is free software; you can redistribute it and/or modify
19  * it under the terms of the GNU General Public License as published by
20  * the Free Software Foundation.  Since it is based on ext2, and the only
21  * valid version of GPL for the Linux kernel is version 2, the only valid
22  * version of GPL for exofs is version 2.
23  *
24  * exofs is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with exofs; if not, write to the Free Software
31  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
32  */
33
34 #include <linux/string.h>
35 #include <linux/parser.h>
36 #include <linux/vfs.h>
37 #include <linux/random.h>
38 #include <linux/exportfs.h>
39 #include <linux/slab.h>
40
41 #include "exofs.h"
42
43 /******************************************************************************
44  * MOUNT OPTIONS
45  *****************************************************************************/
46
47 /*
48  * struct to hold what we get from mount options
49  */
50 struct exofs_mountopt {
51         bool is_osdname;
52         const char *dev_name;
53         uint64_t pid;
54         int timeout;
55 };
56
57 /*
58  * exofs-specific mount-time options.
59  */
60 enum { Opt_name, Opt_pid, Opt_to, Opt_err };
61
62 /*
63  * Our mount-time options.  These should ideally be 64-bit unsigned, but the
64  * kernel's parsing functions do not currently support that.  32-bit should be
65  * sufficient for most applications now.
66  */
67 static match_table_t tokens = {
68         {Opt_name, "osdname=%s"},
69         {Opt_pid, "pid=%u"},
70         {Opt_to, "to=%u"},
71         {Opt_err, NULL}
72 };
73
74 /*
75  * The main option parsing method.  Also makes sure that all of the mandatory
76  * mount options were set.
77  */
78 static int parse_options(char *options, struct exofs_mountopt *opts)
79 {
80         char *p;
81         substring_t args[MAX_OPT_ARGS];
82         int option;
83         bool s_pid = false;
84
85         EXOFS_DBGMSG("parse_options %s\n", options);
86         /* defaults */
87         memset(opts, 0, sizeof(*opts));
88         opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
89
90         while ((p = strsep(&options, ",")) != NULL) {
91                 int token;
92                 char str[32];
93
94                 if (!*p)
95                         continue;
96
97                 token = match_token(p, tokens, args);
98                 switch (token) {
99                 case Opt_name:
100                         opts->dev_name = match_strdup(&args[0]);
101                         if (unlikely(!opts->dev_name)) {
102                                 EXOFS_ERR("Error allocating dev_name");
103                                 return -ENOMEM;
104                         }
105                         opts->is_osdname = true;
106                         break;
107                 case Opt_pid:
108                         if (0 == match_strlcpy(str, &args[0], sizeof(str)))
109                                 return -EINVAL;
110                         opts->pid = simple_strtoull(str, NULL, 0);
111                         if (opts->pid < EXOFS_MIN_PID) {
112                                 EXOFS_ERR("Partition ID must be >= %u",
113                                           EXOFS_MIN_PID);
114                                 return -EINVAL;
115                         }
116                         s_pid = 1;
117                         break;
118                 case Opt_to:
119                         if (match_int(&args[0], &option))
120                                 return -EINVAL;
121                         if (option <= 0) {
122                                 EXOFS_ERR("Timout must be > 0");
123                                 return -EINVAL;
124                         }
125                         opts->timeout = option * HZ;
126                         break;
127                 }
128         }
129
130         if (!s_pid) {
131                 EXOFS_ERR("Need to specify the following options:\n");
132                 EXOFS_ERR("    -o pid=pid_no_to_use\n");
133                 return -EINVAL;
134         }
135
136         return 0;
137 }
138
139 /******************************************************************************
140  * INODE CACHE
141  *****************************************************************************/
142
143 /*
144  * Our inode cache.  Isn't it pretty?
145  */
146 static struct kmem_cache *exofs_inode_cachep;
147
148 /*
149  * Allocate an inode in the cache
150  */
151 static struct inode *exofs_alloc_inode(struct super_block *sb)
152 {
153         struct exofs_i_info *oi;
154
155         oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
156         if (!oi)
157                 return NULL;
158
159         oi->vfs_inode.i_version = 1;
160         return &oi->vfs_inode;
161 }
162
163 static void exofs_i_callback(struct rcu_head *head)
164 {
165         struct inode *inode = container_of(head, struct inode, i_rcu);
166         INIT_LIST_HEAD(&inode->i_dentry);
167         kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
168 }
169
170 /*
171  * Remove an inode from the cache
172  */
173 static void exofs_destroy_inode(struct inode *inode)
174 {
175         call_rcu(&inode->i_rcu, exofs_i_callback);
176 }
177
178 /*
179  * Initialize the inode
180  */
181 static void exofs_init_once(void *foo)
182 {
183         struct exofs_i_info *oi = foo;
184
185         inode_init_once(&oi->vfs_inode);
186 }
187
188 /*
189  * Create and initialize the inode cache
190  */
191 static int init_inodecache(void)
192 {
193         exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
194                                 sizeof(struct exofs_i_info), 0,
195                                 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
196                                 exofs_init_once);
197         if (exofs_inode_cachep == NULL)
198                 return -ENOMEM;
199         return 0;
200 }
201
202 /*
203  * Destroy the inode cache
204  */
205 static void destroy_inodecache(void)
206 {
207         kmem_cache_destroy(exofs_inode_cachep);
208 }
209
210 /******************************************************************************
211  * SUPERBLOCK FUNCTIONS
212  *****************************************************************************/
213 static const struct super_operations exofs_sops;
214 static const struct export_operations exofs_export_ops;
215
216 static const struct osd_attr g_attr_sb_stats = ATTR_DEF(
217         EXOFS_APAGE_SB_DATA,
218         EXOFS_ATTR_SB_STATS,
219         sizeof(struct exofs_sb_stats));
220
221 static int __sbi_read_stats(struct exofs_sb_info *sbi)
222 {
223         struct osd_attr attrs[] = {
224                 [0] = g_attr_sb_stats,
225         };
226         struct exofs_io_state *ios;
227         int ret;
228
229         ret = exofs_get_io_state(&sbi->layout, &ios);
230         if (unlikely(ret)) {
231                 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
232                 return ret;
233         }
234
235         ios->cred = sbi->s_cred;
236
237         ios->in_attr = attrs;
238         ios->in_attr_len = ARRAY_SIZE(attrs);
239
240         ret = exofs_sbi_read(ios);
241         if (unlikely(ret)) {
242                 EXOFS_ERR("Error reading super_block stats => %d\n", ret);
243                 goto out;
244         }
245
246         ret = extract_attr_from_ios(ios, &attrs[0]);
247         if (ret) {
248                 EXOFS_ERR("%s: extract_attr of sb_stats failed\n", __func__);
249                 goto out;
250         }
251         if (attrs[0].len) {
252                 struct exofs_sb_stats *ess;
253
254                 if (unlikely(attrs[0].len != sizeof(*ess))) {
255                         EXOFS_ERR("%s: Wrong version of exofs_sb_stats "
256                                   "size(%d) != expected(%zd)\n",
257                                   __func__, attrs[0].len, sizeof(*ess));
258                         goto out;
259                 }
260
261                 ess = attrs[0].val_ptr;
262                 sbi->s_nextid = le64_to_cpu(ess->s_nextid);
263                 sbi->s_numfiles = le32_to_cpu(ess->s_numfiles);
264         }
265
266 out:
267         exofs_put_io_state(ios);
268         return ret;
269 }
270
271 static void stats_done(struct exofs_io_state *ios, void *p)
272 {
273         exofs_put_io_state(ios);
274         /* Good thanks nothing to do anymore */
275 }
276
277 /* Asynchronously write the stats attribute */
278 int exofs_sbi_write_stats(struct exofs_sb_info *sbi)
279 {
280         struct osd_attr attrs[] = {
281                 [0] = g_attr_sb_stats,
282         };
283         struct exofs_io_state *ios;
284         int ret;
285
286         ret = exofs_get_io_state(&sbi->layout, &ios);
287         if (unlikely(ret)) {
288                 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
289                 return ret;
290         }
291
292         sbi->s_ess.s_nextid   = cpu_to_le64(sbi->s_nextid);
293         sbi->s_ess.s_numfiles = cpu_to_le64(sbi->s_numfiles);
294         attrs[0].val_ptr = &sbi->s_ess;
295
296         ios->cred = sbi->s_cred;
297         ios->done = stats_done;
298         ios->private = sbi;
299         ios->out_attr = attrs;
300         ios->out_attr_len = ARRAY_SIZE(attrs);
301
302         ret = exofs_sbi_write(ios);
303         if (unlikely(ret)) {
304                 EXOFS_ERR("%s: exofs_sbi_write failed.\n", __func__);
305                 exofs_put_io_state(ios);
306         }
307
308         return ret;
309 }
310
311 /*
312  * Write the superblock to the OSD
313  */
314 int exofs_sync_fs(struct super_block *sb, int wait)
315 {
316         struct exofs_sb_info *sbi;
317         struct exofs_fscb *fscb;
318         struct exofs_io_state *ios;
319         int ret = -ENOMEM;
320
321         fscb = kmalloc(sizeof(*fscb), GFP_KERNEL);
322         if (unlikely(!fscb))
323                 return -ENOMEM;
324
325         sbi = sb->s_fs_info;
326
327         /* NOTE: We no longer dirty the super_block anywhere in exofs. The
328          * reason we write the fscb here on unmount is so we can stay backwards
329          * compatible with fscb->s_version == 1. (What we are not compatible
330          * with is if a new version FS crashed and then we try to mount an old
331          * version). Otherwise the exofs_fscb is read-only from mkfs time. All
332          * the writeable info is set in exofs_sbi_write_stats() above.
333          */
334         ret = exofs_get_io_state(&sbi->layout, &ios);
335         if (unlikely(ret))
336                 goto out;
337
338         lock_super(sb);
339
340         ios->length = offsetof(struct exofs_fscb, s_dev_table_oid);
341         memset(fscb, 0, ios->length);
342         fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
343         fscb->s_numfiles = cpu_to_le32(sbi->s_numfiles);
344         fscb->s_magic = cpu_to_le16(sb->s_magic);
345         fscb->s_newfs = 0;
346         fscb->s_version = EXOFS_FSCB_VER;
347
348         ios->obj.id = EXOFS_SUPER_ID;
349         ios->offset = 0;
350         ios->kern_buff = fscb;
351         ios->cred = sbi->s_cred;
352
353         ret = exofs_sbi_write(ios);
354         if (unlikely(ret))
355                 EXOFS_ERR("%s: exofs_sbi_write failed.\n", __func__);
356         else
357                 sb->s_dirt = 0;
358
359
360         unlock_super(sb);
361 out:
362         EXOFS_DBGMSG("s_nextid=0x%llx ret=%d\n", _LLU(sbi->s_nextid), ret);
363         exofs_put_io_state(ios);
364         kfree(fscb);
365         return ret;
366 }
367
368 static void exofs_write_super(struct super_block *sb)
369 {
370         if (!(sb->s_flags & MS_RDONLY))
371                 exofs_sync_fs(sb, 1);
372         else
373                 sb->s_dirt = 0;
374 }
375
376 static void _exofs_print_device(const char *msg, const char *dev_path,
377                                 struct osd_dev *od, u64 pid)
378 {
379         const struct osd_dev_info *odi = osduld_device_info(od);
380
381         printk(KERN_NOTICE "exofs: %s %s osd_name-%s pid-0x%llx\n",
382                 msg, dev_path ?: "", odi->osdname, _LLU(pid));
383 }
384
385 void exofs_free_sbi(struct exofs_sb_info *sbi)
386 {
387         while (sbi->layout.s_numdevs) {
388                 int i = --sbi->layout.s_numdevs;
389                 struct osd_dev *od = sbi->layout.s_ods[i];
390
391                 if (od) {
392                         sbi->layout.s_ods[i] = NULL;
393                         osduld_put_device(od);
394                 }
395         }
396         kfree(sbi);
397 }
398
399 /*
400  * This function is called when the vfs is freeing the superblock.  We just
401  * need to free our own part.
402  */
403 static void exofs_put_super(struct super_block *sb)
404 {
405         int num_pend;
406         struct exofs_sb_info *sbi = sb->s_fs_info;
407
408         /* make sure there are no pending commands */
409         for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
410              num_pend = atomic_read(&sbi->s_curr_pending)) {
411                 wait_queue_head_t wq;
412
413                 printk(KERN_NOTICE "%s: !!Pending operations in flight. "
414                        "This is a BUG. please report to osd-dev@open-osd.org\n",
415                        __func__);
416                 init_waitqueue_head(&wq);
417                 wait_event_timeout(wq,
418                                   (atomic_read(&sbi->s_curr_pending) == 0),
419                                   msecs_to_jiffies(100));
420         }
421
422         _exofs_print_device("Unmounting", NULL, sbi->layout.s_ods[0],
423                             sbi->layout.s_pid);
424
425         bdi_destroy(&sbi->bdi);
426         exofs_free_sbi(sbi);
427         sb->s_fs_info = NULL;
428 }
429
430 static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs,
431                                     struct exofs_device_table *dt)
432 {
433         u64 stripe_length;
434
435         sbi->data_map.odm_num_comps   =
436                                 le32_to_cpu(dt->dt_data_map.cb_num_comps);
437         sbi->data_map.odm_stripe_unit =
438                                 le64_to_cpu(dt->dt_data_map.cb_stripe_unit);
439         sbi->data_map.odm_group_width =
440                                 le32_to_cpu(dt->dt_data_map.cb_group_width);
441         sbi->data_map.odm_group_depth =
442                                 le32_to_cpu(dt->dt_data_map.cb_group_depth);
443         sbi->data_map.odm_mirror_cnt  =
444                                 le32_to_cpu(dt->dt_data_map.cb_mirror_cnt);
445         sbi->data_map.odm_raid_algorithm  =
446                                 le32_to_cpu(dt->dt_data_map.cb_raid_algorithm);
447
448 /* FIXME: Only raid0 for now. if not so, do not mount */
449         if (sbi->data_map.odm_num_comps != numdevs) {
450                 EXOFS_ERR("odm_num_comps(%u) != numdevs(%u)\n",
451                           sbi->data_map.odm_num_comps, numdevs);
452                 return -EINVAL;
453         }
454         if (sbi->data_map.odm_raid_algorithm != PNFS_OSD_RAID_0) {
455                 EXOFS_ERR("Only RAID_0 for now\n");
456                 return -EINVAL;
457         }
458         if (0 != (numdevs % (sbi->data_map.odm_mirror_cnt + 1))) {
459                 EXOFS_ERR("Data Map wrong, numdevs=%d mirrors=%d\n",
460                           numdevs, sbi->data_map.odm_mirror_cnt);
461                 return -EINVAL;
462         }
463
464         if (0 != (sbi->data_map.odm_stripe_unit & ~PAGE_MASK)) {
465                 EXOFS_ERR("Stripe Unit(0x%llx)"
466                           " must be Multples of PAGE_SIZE(0x%lx)\n",
467                           _LLU(sbi->data_map.odm_stripe_unit), PAGE_SIZE);
468                 return -EINVAL;
469         }
470
471         sbi->layout.stripe_unit = sbi->data_map.odm_stripe_unit;
472         sbi->layout.mirrors_p1 = sbi->data_map.odm_mirror_cnt + 1;
473
474         if (sbi->data_map.odm_group_width) {
475                 sbi->layout.group_width = sbi->data_map.odm_group_width;
476                 sbi->layout.group_depth = sbi->data_map.odm_group_depth;
477                 if (!sbi->layout.group_depth) {
478                         EXOFS_ERR("group_depth == 0 && group_width != 0\n");
479                         return -EINVAL;
480                 }
481                 sbi->layout.group_count = sbi->data_map.odm_num_comps /
482                                                 sbi->layout.mirrors_p1 /
483                                                 sbi->data_map.odm_group_width;
484         } else {
485                 if (sbi->data_map.odm_group_depth) {
486                         printk(KERN_NOTICE "Warning: group_depth ignored "
487                                 "group_width == 0 && group_depth == %d\n",
488                                 sbi->data_map.odm_group_depth);
489                         sbi->data_map.odm_group_depth = 0;
490                 }
491                 sbi->layout.group_width = sbi->data_map.odm_num_comps /
492                                                         sbi->layout.mirrors_p1;
493                 sbi->layout.group_depth = -1;
494                 sbi->layout.group_count = 1;
495         }
496
497         stripe_length = (u64)sbi->layout.group_width * sbi->layout.stripe_unit;
498         if (stripe_length >= (1ULL << 32)) {
499                 EXOFS_ERR("Total Stripe length(0x%llx)"
500                           " >= 32bit is not supported\n", _LLU(stripe_length));
501                 return -EINVAL;
502         }
503
504         return 0;
505 }
506
507 static unsigned __ra_pages(struct exofs_layout *layout)
508 {
509         const unsigned _MIN_RA = 32; /* min 128K read-ahead */
510         unsigned ra_pages = layout->group_width * layout->stripe_unit /
511                                 PAGE_SIZE;
512         unsigned max_io_pages = exofs_max_io_pages(layout, ~0);
513
514         ra_pages *= 2; /* two stripes */
515         if (ra_pages < _MIN_RA)
516                 ra_pages = roundup(_MIN_RA, ra_pages / 2);
517
518         if (ra_pages > max_io_pages)
519                 ra_pages = max_io_pages;
520
521         return ra_pages;
522 }
523
524 /* @odi is valid only as long as @fscb_dev is valid */
525 static int exofs_devs_2_odi(struct exofs_dt_device_info *dt_dev,
526                              struct osd_dev_info *odi)
527 {
528         odi->systemid_len = le32_to_cpu(dt_dev->systemid_len);
529         memcpy(odi->systemid, dt_dev->systemid, odi->systemid_len);
530
531         odi->osdname_len = le32_to_cpu(dt_dev->osdname_len);
532         odi->osdname = dt_dev->osdname;
533
534         /* FIXME support long names. Will need a _put function */
535         if (dt_dev->long_name_offset)
536                 return -EINVAL;
537
538         /* Make sure osdname is printable!
539          * mkexofs should give us space for a null-terminator else the
540          * device-table is invalid.
541          */
542         if (unlikely(odi->osdname_len >= sizeof(dt_dev->osdname)))
543                 odi->osdname_len = sizeof(dt_dev->osdname) - 1;
544         dt_dev->osdname[odi->osdname_len] = 0;
545
546         /* If it's all zeros something is bad we read past end-of-obj */
547         return !(odi->systemid_len || odi->osdname_len);
548 }
549
550 static int exofs_read_lookup_dev_table(struct exofs_sb_info **psbi,
551                                        unsigned table_count)
552 {
553         struct exofs_sb_info *sbi = *psbi;
554         struct osd_dev *fscb_od;
555         struct osd_obj_id obj = {.partition = sbi->layout.s_pid,
556                                  .id = EXOFS_DEVTABLE_ID};
557         struct exofs_device_table *dt;
558         unsigned table_bytes = table_count * sizeof(dt->dt_dev_table[0]) +
559                                              sizeof(*dt);
560         unsigned numdevs, i;
561         int ret;
562
563         dt = kmalloc(table_bytes, GFP_KERNEL);
564         if (unlikely(!dt)) {
565                 EXOFS_ERR("ERROR: allocating %x bytes for device table\n",
566                           table_bytes);
567                 return -ENOMEM;
568         }
569
570         fscb_od = sbi->layout.s_ods[0];
571         sbi->layout.s_ods[0] = NULL;
572         sbi->layout.s_numdevs = 0;
573         ret = exofs_read_kern(fscb_od, sbi->s_cred, &obj, 0, dt, table_bytes);
574         if (unlikely(ret)) {
575                 EXOFS_ERR("ERROR: reading device table\n");
576                 goto out;
577         }
578
579         numdevs = le64_to_cpu(dt->dt_num_devices);
580         if (unlikely(!numdevs)) {
581                 ret = -EINVAL;
582                 goto out;
583         }
584         WARN_ON(table_count != numdevs);
585
586         ret = _read_and_match_data_map(sbi, numdevs, dt);
587         if (unlikely(ret))
588                 goto out;
589
590         if (likely(numdevs > 1)) {
591                 unsigned size = numdevs * sizeof(sbi->layout.s_ods[0]);
592
593                 sbi = krealloc(sbi, sizeof(*sbi) + size, GFP_KERNEL);
594                 if (unlikely(!sbi)) {
595                         ret = -ENOMEM;
596                         goto out;
597                 }
598                 memset(&sbi->layout.s_ods[1], 0,
599                        size - sizeof(sbi->layout.s_ods[0]));
600                 *psbi = sbi;
601         }
602
603         for (i = 0; i < numdevs; i++) {
604                 struct exofs_fscb fscb;
605                 struct osd_dev_info odi;
606                 struct osd_dev *od;
607
608                 if (exofs_devs_2_odi(&dt->dt_dev_table[i], &odi)) {
609                         EXOFS_ERR("ERROR: Read all-zeros device entry\n");
610                         ret = -EINVAL;
611                         goto out;
612                 }
613
614                 printk(KERN_NOTICE "Add device[%d]: osd_name-%s\n",
615                        i, odi.osdname);
616
617                 /* On all devices the device table is identical. The user can
618                  * specify any one of the participating devices on the command
619                  * line. We always keep them in device-table order.
620                  */
621                 if (fscb_od && osduld_device_same(fscb_od, &odi)) {
622                         sbi->layout.s_ods[i] = fscb_od;
623                         ++sbi->layout.s_numdevs;
624                         fscb_od = NULL;
625                         continue;
626                 }
627
628                 od = osduld_info_lookup(&odi);
629                 if (IS_ERR(od)) {
630                         ret = PTR_ERR(od);
631                         EXOFS_ERR("ERROR: device requested is not found "
632                                   "osd_name-%s =>%d\n", odi.osdname, ret);
633                         goto out;
634                 }
635
636                 sbi->layout.s_ods[i] = od;
637                 ++sbi->layout.s_numdevs;
638
639                 /* Read the fscb of the other devices to make sure the FS
640                  * partition is there.
641                  */
642                 ret = exofs_read_kern(od, sbi->s_cred, &obj, 0, &fscb,
643                                       sizeof(fscb));
644                 if (unlikely(ret)) {
645                         EXOFS_ERR("ERROR: Malformed participating device "
646                                   "error reading fscb osd_name-%s\n",
647                                   odi.osdname);
648                         goto out;
649                 }
650
651                 /* TODO: verify other information is correct and FS-uuid
652                  *       matches. Benny what did you say about device table
653                  *       generation and old devices?
654                  */
655         }
656
657 out:
658         kfree(dt);
659         if (unlikely(!ret && fscb_od)) {
660                 EXOFS_ERR(
661                       "ERROR: Bad device-table container device not present\n");
662                 osduld_put_device(fscb_od);
663                 ret = -EINVAL;
664         }
665
666         return ret;
667 }
668
669 /*
670  * Read the superblock from the OSD and fill in the fields
671  */
672 static int exofs_fill_super(struct super_block *sb, void *data, int silent)
673 {
674         struct inode *root;
675         struct exofs_mountopt *opts = data;
676         struct exofs_sb_info *sbi;      /*extended info                  */
677         struct osd_dev *od;             /* Master device                 */
678         struct exofs_fscb fscb;         /*on-disk superblock info        */
679         struct osd_obj_id obj;
680         unsigned table_count;
681         int ret;
682
683         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
684         if (!sbi)
685                 return -ENOMEM;
686
687         ret = bdi_setup_and_register(&sbi->bdi, "exofs", BDI_CAP_MAP_COPY);
688         if (ret)
689                 goto free_bdi;
690
691         /* use mount options to fill superblock */
692         if (opts->is_osdname) {
693                 struct osd_dev_info odi = {.systemid_len = 0};
694
695                 odi.osdname_len = strlen(opts->dev_name);
696                 odi.osdname = (u8 *)opts->dev_name;
697                 od = osduld_info_lookup(&odi);
698         } else {
699                 od = osduld_path_lookup(opts->dev_name);
700         }
701         if (IS_ERR(od)) {
702                 ret = -EINVAL;
703                 goto free_sbi;
704         }
705
706         /* Default layout in case we do not have a device-table */
707         sbi->layout.stripe_unit = PAGE_SIZE;
708         sbi->layout.mirrors_p1 = 1;
709         sbi->layout.group_width = 1;
710         sbi->layout.group_depth = -1;
711         sbi->layout.group_count = 1;
712         sbi->layout.s_ods[0] = od;
713         sbi->layout.s_numdevs = 1;
714         sbi->layout.s_pid = opts->pid;
715         sbi->s_timeout = opts->timeout;
716
717         /* fill in some other data by hand */
718         memset(sb->s_id, 0, sizeof(sb->s_id));
719         strcpy(sb->s_id, "exofs");
720         sb->s_blocksize = EXOFS_BLKSIZE;
721         sb->s_blocksize_bits = EXOFS_BLKSHIFT;
722         sb->s_maxbytes = MAX_LFS_FILESIZE;
723         atomic_set(&sbi->s_curr_pending, 0);
724         sb->s_bdev = NULL;
725         sb->s_dev = 0;
726
727         obj.partition = sbi->layout.s_pid;
728         obj.id = EXOFS_SUPER_ID;
729         exofs_make_credential(sbi->s_cred, &obj);
730
731         ret = exofs_read_kern(od, sbi->s_cred, &obj, 0, &fscb, sizeof(fscb));
732         if (unlikely(ret))
733                 goto free_sbi;
734
735         sb->s_magic = le16_to_cpu(fscb.s_magic);
736         /* NOTE: we read below to be backward compatible with old versions */
737         sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
738         sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
739
740         /* make sure what we read from the object store is correct */
741         if (sb->s_magic != EXOFS_SUPER_MAGIC) {
742                 if (!silent)
743                         EXOFS_ERR("ERROR: Bad magic value\n");
744                 ret = -EINVAL;
745                 goto free_sbi;
746         }
747         if (le32_to_cpu(fscb.s_version) > EXOFS_FSCB_VER) {
748                 EXOFS_ERR("ERROR: Bad FSCB version expected-%d got-%d\n",
749                           EXOFS_FSCB_VER, le32_to_cpu(fscb.s_version));
750                 ret = -EINVAL;
751                 goto free_sbi;
752         }
753
754         /* start generation numbers from a random point */
755         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
756         spin_lock_init(&sbi->s_next_gen_lock);
757
758         table_count = le64_to_cpu(fscb.s_dev_table_count);
759         if (table_count) {
760                 ret = exofs_read_lookup_dev_table(&sbi, table_count);
761                 if (unlikely(ret))
762                         goto free_sbi;
763         }
764
765         __sbi_read_stats(sbi);
766
767         /* set up operation vectors */
768         sbi->bdi.ra_pages = __ra_pages(&sbi->layout);
769         sb->s_bdi = &sbi->bdi;
770         sb->s_fs_info = sbi;
771         sb->s_op = &exofs_sops;
772         sb->s_export_op = &exofs_export_ops;
773         root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
774         if (IS_ERR(root)) {
775                 EXOFS_ERR("ERROR: exofs_iget failed\n");
776                 ret = PTR_ERR(root);
777                 goto free_sbi;
778         }
779         sb->s_root = d_alloc_root(root);
780         if (!sb->s_root) {
781                 iput(root);
782                 EXOFS_ERR("ERROR: get root inode failed\n");
783                 ret = -ENOMEM;
784                 goto free_sbi;
785         }
786
787         if (!S_ISDIR(root->i_mode)) {
788                 dput(sb->s_root);
789                 sb->s_root = NULL;
790                 EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
791                        root->i_mode);
792                 ret = -EINVAL;
793                 goto free_sbi;
794         }
795
796         _exofs_print_device("Mounting", opts->dev_name, sbi->layout.s_ods[0],
797                             sbi->layout.s_pid);
798         if (opts->is_osdname)
799                 kfree(opts->dev_name);
800         return 0;
801
802 free_sbi:
803         bdi_destroy(&sbi->bdi);
804 free_bdi:
805         EXOFS_ERR("Unable to mount exofs on %s pid=0x%llx err=%d\n",
806                   opts->dev_name, sbi->layout.s_pid, ret);
807         exofs_free_sbi(sbi);
808         if (opts->is_osdname)
809                 kfree(opts->dev_name);
810         return ret;
811 }
812
813 /*
814  * Set up the superblock (calls exofs_fill_super eventually)
815  */
816 static struct dentry *exofs_mount(struct file_system_type *type,
817                           int flags, const char *dev_name,
818                           void *data)
819 {
820         struct exofs_mountopt opts;
821         int ret;
822
823         ret = parse_options(data, &opts);
824         if (ret)
825                 return ERR_PTR(ret);
826
827         if (!opts.dev_name)
828                 opts.dev_name = dev_name;
829         return mount_nodev(type, flags, &opts, exofs_fill_super);
830 }
831
832 /*
833  * Return information about the file system state in the buffer.  This is used
834  * by the 'df' command, for example.
835  */
836 static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
837 {
838         struct super_block *sb = dentry->d_sb;
839         struct exofs_sb_info *sbi = sb->s_fs_info;
840         struct exofs_io_state *ios;
841         struct osd_attr attrs[] = {
842                 ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
843                         OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
844                 ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
845                         OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
846         };
847         uint64_t capacity = ULLONG_MAX;
848         uint64_t used = ULLONG_MAX;
849         uint8_t cred_a[OSD_CAP_LEN];
850         int ret;
851
852         ret = exofs_get_io_state(&sbi->layout, &ios);
853         if (ret) {
854                 EXOFS_DBGMSG("exofs_get_io_state failed.\n");
855                 return ret;
856         }
857
858         exofs_make_credential(cred_a, &ios->obj);
859         ios->cred = sbi->s_cred;
860         ios->in_attr = attrs;
861         ios->in_attr_len = ARRAY_SIZE(attrs);
862
863         ret = exofs_sbi_read(ios);
864         if (unlikely(ret))
865                 goto out;
866
867         ret = extract_attr_from_ios(ios, &attrs[0]);
868         if (likely(!ret)) {
869                 capacity = get_unaligned_be64(attrs[0].val_ptr);
870                 if (unlikely(!capacity))
871                         capacity = ULLONG_MAX;
872         } else
873                 EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
874
875         ret = extract_attr_from_ios(ios, &attrs[1]);
876         if (likely(!ret))
877                 used = get_unaligned_be64(attrs[1].val_ptr);
878         else
879                 EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
880
881         /* fill in the stats buffer */
882         buf->f_type = EXOFS_SUPER_MAGIC;
883         buf->f_bsize = EXOFS_BLKSIZE;
884         buf->f_blocks = capacity >> 9;
885         buf->f_bfree = (capacity - used) >> 9;
886         buf->f_bavail = buf->f_bfree;
887         buf->f_files = sbi->s_numfiles;
888         buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
889         buf->f_namelen = EXOFS_NAME_LEN;
890
891 out:
892         exofs_put_io_state(ios);
893         return ret;
894 }
895
896 static const struct super_operations exofs_sops = {
897         .alloc_inode    = exofs_alloc_inode,
898         .destroy_inode  = exofs_destroy_inode,
899         .write_inode    = exofs_write_inode,
900         .evict_inode    = exofs_evict_inode,
901         .put_super      = exofs_put_super,
902         .write_super    = exofs_write_super,
903         .sync_fs        = exofs_sync_fs,
904         .statfs         = exofs_statfs,
905 };
906
907 /******************************************************************************
908  * EXPORT OPERATIONS
909  *****************************************************************************/
910
911 struct dentry *exofs_get_parent(struct dentry *child)
912 {
913         unsigned long ino = exofs_parent_ino(child);
914
915         if (!ino)
916                 return NULL;
917
918         return d_obtain_alias(exofs_iget(child->d_inode->i_sb, ino));
919 }
920
921 static struct inode *exofs_nfs_get_inode(struct super_block *sb,
922                 u64 ino, u32 generation)
923 {
924         struct inode *inode;
925
926         inode = exofs_iget(sb, ino);
927         if (IS_ERR(inode))
928                 return ERR_CAST(inode);
929         if (generation && inode->i_generation != generation) {
930                 /* we didn't find the right inode.. */
931                 iput(inode);
932                 return ERR_PTR(-ESTALE);
933         }
934         return inode;
935 }
936
937 static struct dentry *exofs_fh_to_dentry(struct super_block *sb,
938                                 struct fid *fid, int fh_len, int fh_type)
939 {
940         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
941                                     exofs_nfs_get_inode);
942 }
943
944 static struct dentry *exofs_fh_to_parent(struct super_block *sb,
945                                 struct fid *fid, int fh_len, int fh_type)
946 {
947         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
948                                     exofs_nfs_get_inode);
949 }
950
951 static const struct export_operations exofs_export_ops = {
952         .fh_to_dentry = exofs_fh_to_dentry,
953         .fh_to_parent = exofs_fh_to_parent,
954         .get_parent = exofs_get_parent,
955 };
956
957 /******************************************************************************
958  * INSMOD/RMMOD
959  *****************************************************************************/
960
961 /*
962  * struct that describes this file system
963  */
964 static struct file_system_type exofs_type = {
965         .owner          = THIS_MODULE,
966         .name           = "exofs",
967         .mount          = exofs_mount,
968         .kill_sb        = generic_shutdown_super,
969 };
970
971 static int __init init_exofs(void)
972 {
973         int err;
974
975         err = init_inodecache();
976         if (err)
977                 goto out;
978
979         err = register_filesystem(&exofs_type);
980         if (err)
981                 goto out_d;
982
983         return 0;
984 out_d:
985         destroy_inodecache();
986 out:
987         return err;
988 }
989
990 static void __exit exit_exofs(void)
991 {
992         unregister_filesystem(&exofs_type);
993         destroy_inodecache();
994 }
995
996 MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
997 MODULE_DESCRIPTION("exofs");
998 MODULE_LICENSE("GPL");
999
1000 module_init(init_exofs)
1001 module_exit(exit_exofs)