1/*
2 * Copyright (C) 2005, 2006
3 * Avishay Traeger (avishay@gmail.com)
4 * Copyright (C) 2008, 2009
5 * Boaz Harrosh <ooo@electrozaur.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/module.h>
39#include <linux/exportfs.h>
40#include <linux/slab.h>
41
42#include "exofs.h"
43
44#define EXOFS_DBGMSG2(M...) do {} while (0)
45
46/******************************************************************************
47 * MOUNT OPTIONS
48 *****************************************************************************/
49
50/*
51 * struct to hold what we get from mount options
52 */
53struct exofs_mountopt {
54	bool is_osdname;
55	const char *dev_name;
56	uint64_t pid;
57	int timeout;
58};
59
60/*
61 * exofs-specific mount-time options.
62 */
63enum { Opt_name, Opt_pid, Opt_to, Opt_err };
64
65/*
66 * Our mount-time options.  These should ideally be 64-bit unsigned, but the
67 * kernel's parsing functions do not currently support that.  32-bit should be
68 * sufficient for most applications now.
69 */
70static match_table_t tokens = {
71	{Opt_name, "osdname=%s"},
72	{Opt_pid, "pid=%u"},
73	{Opt_to, "to=%u"},
74	{Opt_err, NULL}
75};
76
77/*
78 * The main option parsing method.  Also makes sure that all of the mandatory
79 * mount options were set.
80 */
81static int parse_options(char *options, struct exofs_mountopt *opts)
82{
83	char *p;
84	substring_t args[MAX_OPT_ARGS];
85	int option;
86	bool s_pid = false;
87
88	EXOFS_DBGMSG("parse_options %s\n", options);
89	/* defaults */
90	memset(opts, 0, sizeof(*opts));
91	opts->timeout = BLK_DEFAULT_SG_TIMEOUT;
92
93	while ((p = strsep(&options, ",")) != NULL) {
94		int token;
95		char str[32];
96
97		if (!*p)
98			continue;
99
100		token = match_token(p, tokens, args);
101		switch (token) {
102		case Opt_name:
103			opts->dev_name = match_strdup(&args[0]);
104			if (unlikely(!opts->dev_name)) {
105				EXOFS_ERR("Error allocating dev_name");
106				return -ENOMEM;
107			}
108			opts->is_osdname = true;
109			break;
110		case Opt_pid:
111			if (0 == match_strlcpy(str, &args[0], sizeof(str)))
112				return -EINVAL;
113			opts->pid = simple_strtoull(str, NULL, 0);
114			if (opts->pid < EXOFS_MIN_PID) {
115				EXOFS_ERR("Partition ID must be >= %u",
116					  EXOFS_MIN_PID);
117				return -EINVAL;
118			}
119			s_pid = 1;
120			break;
121		case Opt_to:
122			if (match_int(&args[0], &option))
123				return -EINVAL;
124			if (option <= 0) {
125				EXOFS_ERR("Timout must be > 0");
126				return -EINVAL;
127			}
128			opts->timeout = option * HZ;
129			break;
130		}
131	}
132
133	if (!s_pid) {
134		EXOFS_ERR("Need to specify the following options:\n");
135		EXOFS_ERR("    -o pid=pid_no_to_use\n");
136		return -EINVAL;
137	}
138
139	return 0;
140}
141
142/******************************************************************************
143 * INODE CACHE
144 *****************************************************************************/
145
146/*
147 * Our inode cache.  Isn't it pretty?
148 */
149static struct kmem_cache *exofs_inode_cachep;
150
151/*
152 * Allocate an inode in the cache
153 */
154static struct inode *exofs_alloc_inode(struct super_block *sb)
155{
156	struct exofs_i_info *oi;
157
158	oi = kmem_cache_alloc(exofs_inode_cachep, GFP_KERNEL);
159	if (!oi)
160		return NULL;
161
162	oi->vfs_inode.i_version = 1;
163	return &oi->vfs_inode;
164}
165
166static void exofs_i_callback(struct rcu_head *head)
167{
168	struct inode *inode = container_of(head, struct inode, i_rcu);
169	kmem_cache_free(exofs_inode_cachep, exofs_i(inode));
170}
171
172/*
173 * Remove an inode from the cache
174 */
175static void exofs_destroy_inode(struct inode *inode)
176{
177	call_rcu(&inode->i_rcu, exofs_i_callback);
178}
179
180/*
181 * Initialize the inode
182 */
183static void exofs_init_once(void *foo)
184{
185	struct exofs_i_info *oi = foo;
186
187	inode_init_once(&oi->vfs_inode);
188}
189
190/*
191 * Create and initialize the inode cache
192 */
193static int init_inodecache(void)
194{
195	exofs_inode_cachep = kmem_cache_create("exofs_inode_cache",
196				sizeof(struct exofs_i_info), 0,
197				SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
198				exofs_init_once);
199	if (exofs_inode_cachep == NULL)
200		return -ENOMEM;
201	return 0;
202}
203
204/*
205 * Destroy the inode cache
206 */
207static void destroy_inodecache(void)
208{
209	/*
210	 * Make sure all delayed rcu free inodes are flushed before we
211	 * destroy cache.
212	 */
213	rcu_barrier();
214	kmem_cache_destroy(exofs_inode_cachep);
215}
216
217/******************************************************************************
218 * Some osd helpers
219 *****************************************************************************/
220void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
221{
222	osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
223}
224
225static int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
226		    u64 offset, void *p, unsigned length)
227{
228	struct osd_request *or = osd_start_request(od, GFP_KERNEL);
229/*	struct osd_sense_info osi = {.key = 0};*/
230	int ret;
231
232	if (unlikely(!or)) {
233		EXOFS_DBGMSG("%s: osd_start_request failed.\n", __func__);
234		return -ENOMEM;
235	}
236	ret = osd_req_read_kern(or, obj, offset, p, length);
237	if (unlikely(ret)) {
238		EXOFS_DBGMSG("%s: osd_req_read_kern failed.\n", __func__);
239		goto out;
240	}
241
242	ret = osd_finalize_request(or, 0, cred, NULL);
243	if (unlikely(ret)) {
244		EXOFS_DBGMSG("Failed to osd_finalize_request() => %d\n", ret);
245		goto out;
246	}
247
248	ret = osd_execute_request(or);
249	if (unlikely(ret))
250		EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
251	/* osd_req_decode_sense(or, ret); */
252
253out:
254	osd_end_request(or);
255	EXOFS_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
256		      "length=0x%llx dev=%p ret=>%d\n",
257		      _LLU(obj->id), _LLU(offset), _LLU(length), od, ret);
258	return ret;
259}
260
261static const struct osd_attr g_attr_sb_stats = ATTR_DEF(
262	EXOFS_APAGE_SB_DATA,
263	EXOFS_ATTR_SB_STATS,
264	sizeof(struct exofs_sb_stats));
265
266static int __sbi_read_stats(struct exofs_sb_info *sbi)
267{
268	struct osd_attr attrs[] = {
269		[0] = g_attr_sb_stats,
270	};
271	struct ore_io_state *ios;
272	int ret;
273
274	ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
275	if (unlikely(ret)) {
276		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
277		return ret;
278	}
279
280	ios->in_attr = attrs;
281	ios->in_attr_len = ARRAY_SIZE(attrs);
282
283	ret = ore_read(ios);
284	if (unlikely(ret)) {
285		EXOFS_ERR("Error reading super_block stats => %d\n", ret);
286		goto out;
287	}
288
289	ret = extract_attr_from_ios(ios, &attrs[0]);
290	if (ret) {
291		EXOFS_ERR("%s: extract_attr of sb_stats failed\n", __func__);
292		goto out;
293	}
294	if (attrs[0].len) {
295		struct exofs_sb_stats *ess;
296
297		if (unlikely(attrs[0].len != sizeof(*ess))) {
298			EXOFS_ERR("%s: Wrong version of exofs_sb_stats "
299				  "size(%d) != expected(%zd)\n",
300				  __func__, attrs[0].len, sizeof(*ess));
301			goto out;
302		}
303
304		ess = attrs[0].val_ptr;
305		sbi->s_nextid = le64_to_cpu(ess->s_nextid);
306		sbi->s_numfiles = le32_to_cpu(ess->s_numfiles);
307	}
308
309out:
310	ore_put_io_state(ios);
311	return ret;
312}
313
314static void stats_done(struct ore_io_state *ios, void *p)
315{
316	ore_put_io_state(ios);
317	/* Good thanks nothing to do anymore */
318}
319
320/* Asynchronously write the stats attribute */
321int exofs_sbi_write_stats(struct exofs_sb_info *sbi)
322{
323	struct osd_attr attrs[] = {
324		[0] = g_attr_sb_stats,
325	};
326	struct ore_io_state *ios;
327	int ret;
328
329	ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
330	if (unlikely(ret)) {
331		EXOFS_ERR("%s: ore_get_io_state failed.\n", __func__);
332		return ret;
333	}
334
335	sbi->s_ess.s_nextid   = cpu_to_le64(sbi->s_nextid);
336	sbi->s_ess.s_numfiles = cpu_to_le64(sbi->s_numfiles);
337	attrs[0].val_ptr = &sbi->s_ess;
338
339
340	ios->done = stats_done;
341	ios->private = sbi;
342	ios->out_attr = attrs;
343	ios->out_attr_len = ARRAY_SIZE(attrs);
344
345	ret = ore_write(ios);
346	if (unlikely(ret)) {
347		EXOFS_ERR("%s: ore_write failed.\n", __func__);
348		ore_put_io_state(ios);
349	}
350
351	return ret;
352}
353
354/******************************************************************************
355 * SUPERBLOCK FUNCTIONS
356 *****************************************************************************/
357static const struct super_operations exofs_sops;
358static const struct export_operations exofs_export_ops;
359
360/*
361 * Write the superblock to the OSD
362 */
363static int exofs_sync_fs(struct super_block *sb, int wait)
364{
365	struct exofs_sb_info *sbi;
366	struct exofs_fscb *fscb;
367	struct ore_comp one_comp;
368	struct ore_components oc;
369	struct ore_io_state *ios;
370	int ret = -ENOMEM;
371
372	fscb = kmalloc(sizeof(*fscb), GFP_KERNEL);
373	if (unlikely(!fscb))
374		return -ENOMEM;
375
376	sbi = sb->s_fs_info;
377
378	/* NOTE: We no longer dirty the super_block anywhere in exofs. The
379	 * reason we write the fscb here on unmount is so we can stay backwards
380	 * compatible with fscb->s_version == 1. (What we are not compatible
381	 * with is if a new version FS crashed and then we try to mount an old
382	 * version). Otherwise the exofs_fscb is read-only from mkfs time. All
383	 * the writeable info is set in exofs_sbi_write_stats() above.
384	 */
385
386	exofs_init_comps(&oc, &one_comp, sbi, EXOFS_SUPER_ID);
387
388	ret = ore_get_io_state(&sbi->layout, &oc, &ios);
389	if (unlikely(ret))
390		goto out;
391
392	ios->length = offsetof(struct exofs_fscb, s_dev_table_oid);
393	memset(fscb, 0, ios->length);
394	fscb->s_nextid = cpu_to_le64(sbi->s_nextid);
395	fscb->s_numfiles = cpu_to_le64(sbi->s_numfiles);
396	fscb->s_magic = cpu_to_le16(sb->s_magic);
397	fscb->s_newfs = 0;
398	fscb->s_version = EXOFS_FSCB_VER;
399
400	ios->offset = 0;
401	ios->kern_buff = fscb;
402
403	ret = ore_write(ios);
404	if (unlikely(ret))
405		EXOFS_ERR("%s: ore_write failed.\n", __func__);
406
407out:
408	EXOFS_DBGMSG("s_nextid=0x%llx ret=%d\n", _LLU(sbi->s_nextid), ret);
409	ore_put_io_state(ios);
410	kfree(fscb);
411	return ret;
412}
413
414static void _exofs_print_device(const char *msg, const char *dev_path,
415				struct osd_dev *od, u64 pid)
416{
417	const struct osd_dev_info *odi = osduld_device_info(od);
418
419	printk(KERN_NOTICE "exofs: %s %s osd_name-%s pid-0x%llx\n",
420		msg, dev_path ?: "", odi->osdname, _LLU(pid));
421}
422
423static void exofs_free_sbi(struct exofs_sb_info *sbi)
424{
425	unsigned numdevs = sbi->oc.numdevs;
426
427	while (numdevs) {
428		unsigned i = --numdevs;
429		struct osd_dev *od = ore_comp_dev(&sbi->oc, i);
430
431		if (od) {
432			ore_comp_set_dev(&sbi->oc, i, NULL);
433			osduld_put_device(od);
434		}
435	}
436	kfree(sbi->oc.ods);
437	kfree(sbi);
438}
439
440/*
441 * This function is called when the vfs is freeing the superblock.  We just
442 * need to free our own part.
443 */
444static void exofs_put_super(struct super_block *sb)
445{
446	int num_pend;
447	struct exofs_sb_info *sbi = sb->s_fs_info;
448
449	/* make sure there are no pending commands */
450	for (num_pend = atomic_read(&sbi->s_curr_pending); num_pend > 0;
451	     num_pend = atomic_read(&sbi->s_curr_pending)) {
452		wait_queue_head_t wq;
453
454		printk(KERN_NOTICE "%s: !!Pending operations in flight. "
455		       "This is a BUG. please report to osd-dev@open-osd.org\n",
456		       __func__);
457		init_waitqueue_head(&wq);
458		wait_event_timeout(wq,
459				  (atomic_read(&sbi->s_curr_pending) == 0),
460				  msecs_to_jiffies(100));
461	}
462
463	_exofs_print_device("Unmounting", NULL, ore_comp_dev(&sbi->oc, 0),
464			    sbi->one_comp.obj.partition);
465
466	exofs_sysfs_sb_del(sbi);
467	bdi_destroy(&sbi->bdi);
468	exofs_free_sbi(sbi);
469	sb->s_fs_info = NULL;
470}
471
472static int _read_and_match_data_map(struct exofs_sb_info *sbi, unsigned numdevs,
473				    struct exofs_device_table *dt)
474{
475	int ret;
476
477	sbi->layout.stripe_unit =
478				le64_to_cpu(dt->dt_data_map.cb_stripe_unit);
479	sbi->layout.group_width =
480				le32_to_cpu(dt->dt_data_map.cb_group_width);
481	sbi->layout.group_depth =
482				le32_to_cpu(dt->dt_data_map.cb_group_depth);
483	sbi->layout.mirrors_p1  =
484				le32_to_cpu(dt->dt_data_map.cb_mirror_cnt) + 1;
485	sbi->layout.raid_algorithm  =
486				le32_to_cpu(dt->dt_data_map.cb_raid_algorithm);
487
488	ret = ore_verify_layout(numdevs, &sbi->layout);
489
490	EXOFS_DBGMSG("exofs: layout: "
491		"num_comps=%u stripe_unit=0x%x group_width=%u "
492		"group_depth=0x%llx mirrors_p1=%u raid_algorithm=%u\n",
493		numdevs,
494		sbi->layout.stripe_unit,
495		sbi->layout.group_width,
496		_LLU(sbi->layout.group_depth),
497		sbi->layout.mirrors_p1,
498		sbi->layout.raid_algorithm);
499	return ret;
500}
501
502static unsigned __ra_pages(struct ore_layout *layout)
503{
504	const unsigned _MIN_RA = 32; /* min 128K read-ahead */
505	unsigned ra_pages = layout->group_width * layout->stripe_unit /
506				PAGE_SIZE;
507	unsigned max_io_pages = exofs_max_io_pages(layout, ~0);
508
509	ra_pages *= 2; /* two stripes */
510	if (ra_pages < _MIN_RA)
511		ra_pages = roundup(_MIN_RA, ra_pages / 2);
512
513	if (ra_pages > max_io_pages)
514		ra_pages = max_io_pages;
515
516	return ra_pages;
517}
518
519/* @odi is valid only as long as @fscb_dev is valid */
520static int exofs_devs_2_odi(struct exofs_dt_device_info *dt_dev,
521			     struct osd_dev_info *odi)
522{
523	odi->systemid_len = le32_to_cpu(dt_dev->systemid_len);
524	if (likely(odi->systemid_len))
525		memcpy(odi->systemid, dt_dev->systemid, OSD_SYSTEMID_LEN);
526
527	odi->osdname_len = le32_to_cpu(dt_dev->osdname_len);
528	odi->osdname = dt_dev->osdname;
529
530	/* FIXME support long names. Will need a _put function */
531	if (dt_dev->long_name_offset)
532		return -EINVAL;
533
534	/* Make sure osdname is printable!
535	 * mkexofs should give us space for a null-terminator else the
536	 * device-table is invalid.
537	 */
538	if (unlikely(odi->osdname_len >= sizeof(dt_dev->osdname)))
539		odi->osdname_len = sizeof(dt_dev->osdname) - 1;
540	dt_dev->osdname[odi->osdname_len] = 0;
541
542	/* If it's all zeros something is bad we read past end-of-obj */
543	return !(odi->systemid_len || odi->osdname_len);
544}
545
546static int __alloc_dev_table(struct exofs_sb_info *sbi, unsigned numdevs,
547		      struct exofs_dev **peds)
548{
549	struct __alloc_ore_devs_and_exofs_devs {
550		/* Twice bigger table: See exofs_init_comps() and comment at
551		 * exofs_read_lookup_dev_table()
552		 */
553		struct ore_dev *oreds[numdevs * 2 - 1];
554		struct exofs_dev eds[numdevs];
555	} *aoded;
556	struct exofs_dev *eds;
557	unsigned i;
558
559	aoded = kzalloc(sizeof(*aoded), GFP_KERNEL);
560	if (unlikely(!aoded)) {
561		EXOFS_ERR("ERROR: failed allocating Device array[%d]\n",
562			  numdevs);
563		return -ENOMEM;
564	}
565
566	sbi->oc.ods = aoded->oreds;
567	*peds = eds = aoded->eds;
568	for (i = 0; i < numdevs; ++i)
569		aoded->oreds[i] = &eds[i].ored;
570	return 0;
571}
572
573static int exofs_read_lookup_dev_table(struct exofs_sb_info *sbi,
574				       struct osd_dev *fscb_od,
575				       unsigned table_count)
576{
577	struct ore_comp comp;
578	struct exofs_device_table *dt;
579	struct exofs_dev *eds;
580	unsigned table_bytes = table_count * sizeof(dt->dt_dev_table[0]) +
581					     sizeof(*dt);
582	unsigned numdevs, i;
583	int ret;
584
585	dt = kmalloc(table_bytes, GFP_KERNEL);
586	if (unlikely(!dt)) {
587		EXOFS_ERR("ERROR: allocating %x bytes for device table\n",
588			  table_bytes);
589		return -ENOMEM;
590	}
591
592	sbi->oc.numdevs = 0;
593
594	comp.obj.partition = sbi->one_comp.obj.partition;
595	comp.obj.id = EXOFS_DEVTABLE_ID;
596	exofs_make_credential(comp.cred, &comp.obj);
597
598	ret = exofs_read_kern(fscb_od, comp.cred, &comp.obj, 0, dt,
599			      table_bytes);
600	if (unlikely(ret)) {
601		EXOFS_ERR("ERROR: reading device table\n");
602		goto out;
603	}
604
605	numdevs = le64_to_cpu(dt->dt_num_devices);
606	if (unlikely(!numdevs)) {
607		ret = -EINVAL;
608		goto out;
609	}
610	WARN_ON(table_count != numdevs);
611
612	ret = _read_and_match_data_map(sbi, numdevs, dt);
613	if (unlikely(ret))
614		goto out;
615
616	ret = __alloc_dev_table(sbi, numdevs, &eds);
617	if (unlikely(ret))
618		goto out;
619	/* exofs round-robins the device table view according to inode
620	 * number. We hold a: twice bigger table hence inodes can point
621	 * to any device and have a sequential view of the table
622	 * starting at this device. See exofs_init_comps()
623	 */
624	memcpy(&sbi->oc.ods[numdevs], &sbi->oc.ods[0],
625		(numdevs - 1) * sizeof(sbi->oc.ods[0]));
626
627	/* create sysfs subdir under which we put the device table
628	 * And cluster layout. A Superblock is identified by the string:
629	 *	"dev[0].osdname"_"pid"
630	 */
631	exofs_sysfs_sb_add(sbi, &dt->dt_dev_table[0]);
632
633	for (i = 0; i < numdevs; i++) {
634		struct exofs_fscb fscb;
635		struct osd_dev_info odi;
636		struct osd_dev *od;
637
638		if (exofs_devs_2_odi(&dt->dt_dev_table[i], &odi)) {
639			EXOFS_ERR("ERROR: Read all-zeros device entry\n");
640			ret = -EINVAL;
641			goto out;
642		}
643
644		printk(KERN_NOTICE "Add device[%d]: osd_name-%s\n",
645		       i, odi.osdname);
646
647		/* the exofs id is currently the table index */
648		eds[i].did = i;
649
650		/* On all devices the device table is identical. The user can
651		 * specify any one of the participating devices on the command
652		 * line. We always keep them in device-table order.
653		 */
654		if (fscb_od && osduld_device_same(fscb_od, &odi)) {
655			eds[i].ored.od = fscb_od;
656			++sbi->oc.numdevs;
657			fscb_od = NULL;
658			exofs_sysfs_odev_add(&eds[i], sbi);
659			continue;
660		}
661
662		od = osduld_info_lookup(&odi);
663		if (IS_ERR(od)) {
664			ret = PTR_ERR(od);
665			EXOFS_ERR("ERROR: device requested is not found "
666				  "osd_name-%s =>%d\n", odi.osdname, ret);
667			goto out;
668		}
669
670		eds[i].ored.od = od;
671		++sbi->oc.numdevs;
672
673		/* Read the fscb of the other devices to make sure the FS
674		 * partition is there.
675		 */
676		ret = exofs_read_kern(od, comp.cred, &comp.obj, 0, &fscb,
677				      sizeof(fscb));
678		if (unlikely(ret)) {
679			EXOFS_ERR("ERROR: Malformed participating device "
680				  "error reading fscb osd_name-%s\n",
681				  odi.osdname);
682			goto out;
683		}
684		exofs_sysfs_odev_add(&eds[i], sbi);
685
686		/* TODO: verify other information is correct and FS-uuid
687		 *	 matches. Benny what did you say about device table
688		 *	 generation and old devices?
689		 */
690	}
691
692out:
693	kfree(dt);
694	if (unlikely(fscb_od && !ret)) {
695			EXOFS_ERR("ERROR: Bad device-table container device not present\n");
696			osduld_put_device(fscb_od);
697			return -EINVAL;
698	}
699	return ret;
700}
701
702/*
703 * Read the superblock from the OSD and fill in the fields
704 */
705static int exofs_fill_super(struct super_block *sb, void *data, int silent)
706{
707	struct inode *root;
708	struct exofs_mountopt *opts = data;
709	struct exofs_sb_info *sbi;	/*extended info                  */
710	struct osd_dev *od;		/* Master device                 */
711	struct exofs_fscb fscb;		/*on-disk superblock info        */
712	struct ore_comp comp;
713	unsigned table_count;
714	int ret;
715
716	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
717	if (!sbi)
718		return -ENOMEM;
719
720	/* use mount options to fill superblock */
721	if (opts->is_osdname) {
722		struct osd_dev_info odi = {.systemid_len = 0};
723
724		odi.osdname_len = strlen(opts->dev_name);
725		odi.osdname = (u8 *)opts->dev_name;
726		od = osduld_info_lookup(&odi);
727		kfree(opts->dev_name);
728		opts->dev_name = NULL;
729	} else {
730		od = osduld_path_lookup(opts->dev_name);
731	}
732	if (IS_ERR(od)) {
733		ret = -EINVAL;
734		goto free_sbi;
735	}
736
737	/* Default layout in case we do not have a device-table */
738	sbi->layout.stripe_unit = PAGE_SIZE;
739	sbi->layout.mirrors_p1 = 1;
740	sbi->layout.group_width = 1;
741	sbi->layout.group_depth = -1;
742	sbi->layout.group_count = 1;
743	sbi->s_timeout = opts->timeout;
744
745	sbi->one_comp.obj.partition = opts->pid;
746	sbi->one_comp.obj.id = 0;
747	exofs_make_credential(sbi->one_comp.cred, &sbi->one_comp.obj);
748	sbi->oc.single_comp = EC_SINGLE_COMP;
749	sbi->oc.comps = &sbi->one_comp;
750
751	/* fill in some other data by hand */
752	memset(sb->s_id, 0, sizeof(sb->s_id));
753	strcpy(sb->s_id, "exofs");
754	sb->s_blocksize = EXOFS_BLKSIZE;
755	sb->s_blocksize_bits = EXOFS_BLKSHIFT;
756	sb->s_maxbytes = MAX_LFS_FILESIZE;
757	sb->s_max_links = EXOFS_LINK_MAX;
758	atomic_set(&sbi->s_curr_pending, 0);
759	sb->s_bdev = NULL;
760	sb->s_dev = 0;
761
762	comp.obj.partition = sbi->one_comp.obj.partition;
763	comp.obj.id = EXOFS_SUPER_ID;
764	exofs_make_credential(comp.cred, &comp.obj);
765
766	ret = exofs_read_kern(od, comp.cred, &comp.obj, 0, &fscb, sizeof(fscb));
767	if (unlikely(ret))
768		goto free_sbi;
769
770	sb->s_magic = le16_to_cpu(fscb.s_magic);
771	/* NOTE: we read below to be backward compatible with old versions */
772	sbi->s_nextid = le64_to_cpu(fscb.s_nextid);
773	sbi->s_numfiles = le32_to_cpu(fscb.s_numfiles);
774
775	/* make sure what we read from the object store is correct */
776	if (sb->s_magic != EXOFS_SUPER_MAGIC) {
777		if (!silent)
778			EXOFS_ERR("ERROR: Bad magic value\n");
779		ret = -EINVAL;
780		goto free_sbi;
781	}
782	if (le32_to_cpu(fscb.s_version) > EXOFS_FSCB_VER) {
783		EXOFS_ERR("ERROR: Bad FSCB version expected-%d got-%d\n",
784			  EXOFS_FSCB_VER, le32_to_cpu(fscb.s_version));
785		ret = -EINVAL;
786		goto free_sbi;
787	}
788
789	/* start generation numbers from a random point */
790	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
791	spin_lock_init(&sbi->s_next_gen_lock);
792
793	table_count = le64_to_cpu(fscb.s_dev_table_count);
794	if (table_count) {
795		ret = exofs_read_lookup_dev_table(sbi, od, table_count);
796		if (unlikely(ret))
797			goto free_sbi;
798	} else {
799		struct exofs_dev *eds;
800
801		ret = __alloc_dev_table(sbi, 1, &eds);
802		if (unlikely(ret))
803			goto free_sbi;
804
805		ore_comp_set_dev(&sbi->oc, 0, od);
806		sbi->oc.numdevs = 1;
807	}
808
809	__sbi_read_stats(sbi);
810
811	/* set up operation vectors */
812	sbi->bdi.ra_pages = __ra_pages(&sbi->layout);
813	sb->s_bdi = &sbi->bdi;
814	sb->s_fs_info = sbi;
815	sb->s_op = &exofs_sops;
816	sb->s_export_op = &exofs_export_ops;
817	root = exofs_iget(sb, EXOFS_ROOT_ID - EXOFS_OBJ_OFF);
818	if (IS_ERR(root)) {
819		EXOFS_ERR("ERROR: exofs_iget failed\n");
820		ret = PTR_ERR(root);
821		goto free_sbi;
822	}
823	sb->s_root = d_make_root(root);
824	if (!sb->s_root) {
825		EXOFS_ERR("ERROR: get root inode failed\n");
826		ret = -ENOMEM;
827		goto free_sbi;
828	}
829
830	if (!S_ISDIR(root->i_mode)) {
831		dput(sb->s_root);
832		sb->s_root = NULL;
833		EXOFS_ERR("ERROR: corrupt root inode (mode = %hd)\n",
834		       root->i_mode);
835		ret = -EINVAL;
836		goto free_sbi;
837	}
838
839	ret = bdi_setup_and_register(&sbi->bdi, "exofs");
840	if (ret) {
841		EXOFS_DBGMSG("Failed to bdi_setup_and_register\n");
842		dput(sb->s_root);
843		sb->s_root = NULL;
844		goto free_sbi;
845	}
846
847	exofs_sysfs_dbg_print();
848	_exofs_print_device("Mounting", opts->dev_name,
849			    ore_comp_dev(&sbi->oc, 0),
850			    sbi->one_comp.obj.partition);
851	return 0;
852
853free_sbi:
854	EXOFS_ERR("Unable to mount exofs on %s pid=0x%llx err=%d\n",
855		  opts->dev_name, sbi->one_comp.obj.partition, ret);
856	exofs_free_sbi(sbi);
857	return ret;
858}
859
860/*
861 * Set up the superblock (calls exofs_fill_super eventually)
862 */
863static struct dentry *exofs_mount(struct file_system_type *type,
864			  int flags, const char *dev_name,
865			  void *data)
866{
867	struct exofs_mountopt opts;
868	int ret;
869
870	ret = parse_options(data, &opts);
871	if (ret)
872		return ERR_PTR(ret);
873
874	if (!opts.dev_name)
875		opts.dev_name = dev_name;
876	return mount_nodev(type, flags, &opts, exofs_fill_super);
877}
878
879/*
880 * Return information about the file system state in the buffer.  This is used
881 * by the 'df' command, for example.
882 */
883static int exofs_statfs(struct dentry *dentry, struct kstatfs *buf)
884{
885	struct super_block *sb = dentry->d_sb;
886	struct exofs_sb_info *sbi = sb->s_fs_info;
887	struct ore_io_state *ios;
888	struct osd_attr attrs[] = {
889		ATTR_DEF(OSD_APAGE_PARTITION_QUOTAS,
890			OSD_ATTR_PQ_CAPACITY_QUOTA, sizeof(__be64)),
891		ATTR_DEF(OSD_APAGE_PARTITION_INFORMATION,
892			OSD_ATTR_PI_USED_CAPACITY, sizeof(__be64)),
893	};
894	uint64_t capacity = ULLONG_MAX;
895	uint64_t used = ULLONG_MAX;
896	int ret;
897
898	ret = ore_get_io_state(&sbi->layout, &sbi->oc, &ios);
899	if (ret) {
900		EXOFS_DBGMSG("ore_get_io_state failed.\n");
901		return ret;
902	}
903
904	ios->in_attr = attrs;
905	ios->in_attr_len = ARRAY_SIZE(attrs);
906
907	ret = ore_read(ios);
908	if (unlikely(ret))
909		goto out;
910
911	ret = extract_attr_from_ios(ios, &attrs[0]);
912	if (likely(!ret)) {
913		capacity = get_unaligned_be64(attrs[0].val_ptr);
914		if (unlikely(!capacity))
915			capacity = ULLONG_MAX;
916	} else
917		EXOFS_DBGMSG("exofs_statfs: get capacity failed.\n");
918
919	ret = extract_attr_from_ios(ios, &attrs[1]);
920	if (likely(!ret))
921		used = get_unaligned_be64(attrs[1].val_ptr);
922	else
923		EXOFS_DBGMSG("exofs_statfs: get used-space failed.\n");
924
925	/* fill in the stats buffer */
926	buf->f_type = EXOFS_SUPER_MAGIC;
927	buf->f_bsize = EXOFS_BLKSIZE;
928	buf->f_blocks = capacity >> 9;
929	buf->f_bfree = (capacity - used) >> 9;
930	buf->f_bavail = buf->f_bfree;
931	buf->f_files = sbi->s_numfiles;
932	buf->f_ffree = EXOFS_MAX_ID - sbi->s_numfiles;
933	buf->f_namelen = EXOFS_NAME_LEN;
934
935out:
936	ore_put_io_state(ios);
937	return ret;
938}
939
940static const struct super_operations exofs_sops = {
941	.alloc_inode    = exofs_alloc_inode,
942	.destroy_inode  = exofs_destroy_inode,
943	.write_inode    = exofs_write_inode,
944	.evict_inode    = exofs_evict_inode,
945	.put_super      = exofs_put_super,
946	.sync_fs	= exofs_sync_fs,
947	.statfs         = exofs_statfs,
948};
949
950/******************************************************************************
951 * EXPORT OPERATIONS
952 *****************************************************************************/
953
954static struct dentry *exofs_get_parent(struct dentry *child)
955{
956	unsigned long ino = exofs_parent_ino(child);
957
958	if (!ino)
959		return ERR_PTR(-ESTALE);
960
961	return d_obtain_alias(exofs_iget(d_inode(child)->i_sb, ino));
962}
963
964static struct inode *exofs_nfs_get_inode(struct super_block *sb,
965		u64 ino, u32 generation)
966{
967	struct inode *inode;
968
969	inode = exofs_iget(sb, ino);
970	if (IS_ERR(inode))
971		return ERR_CAST(inode);
972	if (generation && inode->i_generation != generation) {
973		/* we didn't find the right inode.. */
974		iput(inode);
975		return ERR_PTR(-ESTALE);
976	}
977	return inode;
978}
979
980static struct dentry *exofs_fh_to_dentry(struct super_block *sb,
981				struct fid *fid, int fh_len, int fh_type)
982{
983	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
984				    exofs_nfs_get_inode);
985}
986
987static struct dentry *exofs_fh_to_parent(struct super_block *sb,
988				struct fid *fid, int fh_len, int fh_type)
989{
990	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
991				    exofs_nfs_get_inode);
992}
993
994static const struct export_operations exofs_export_ops = {
995	.fh_to_dentry = exofs_fh_to_dentry,
996	.fh_to_parent = exofs_fh_to_parent,
997	.get_parent = exofs_get_parent,
998};
999
1000/******************************************************************************
1001 * INSMOD/RMMOD
1002 *****************************************************************************/
1003
1004/*
1005 * struct that describes this file system
1006 */
1007static struct file_system_type exofs_type = {
1008	.owner          = THIS_MODULE,
1009	.name           = "exofs",
1010	.mount          = exofs_mount,
1011	.kill_sb        = generic_shutdown_super,
1012};
1013MODULE_ALIAS_FS("exofs");
1014
1015static int __init init_exofs(void)
1016{
1017	int err;
1018
1019	err = init_inodecache();
1020	if (err)
1021		goto out;
1022
1023	err = register_filesystem(&exofs_type);
1024	if (err)
1025		goto out_d;
1026
1027	/* We don't fail if sysfs creation failed */
1028	exofs_sysfs_init();
1029
1030	return 0;
1031out_d:
1032	destroy_inodecache();
1033out:
1034	return err;
1035}
1036
1037static void __exit exit_exofs(void)
1038{
1039	exofs_sysfs_uninit();
1040	unregister_filesystem(&exofs_type);
1041	destroy_inodecache();
1042}
1043
1044MODULE_AUTHOR("Avishay Traeger <avishay@gmail.com>");
1045MODULE_DESCRIPTION("exofs");
1046MODULE_LICENSE("GPL");
1047
1048module_init(init_exofs)
1049module_exit(exit_exofs)
1050