blob: 84c3b66564d0f16a34712fc4c0803771904ac362 [file] [log] [blame]
Chris Mason6cbd5572007-06-12 09:07:21 -04001/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
Yan4b82d6e2007-08-29 09:11:44 -040019#include <linux/blkdev.h>
Chris Mason2e635a22007-03-21 11:12:56 -040020#include <linux/module.h>
Chris Masone20d96d2007-03-22 12:13:20 -040021#include <linux/buffer_head.h>
Chris Mason2e635a22007-03-21 11:12:56 -040022#include <linux/fs.h>
23#include <linux/pagemap.h>
24#include <linux/highmem.h>
25#include <linux/time.h>
26#include <linux/init.h>
27#include <linux/string.h>
28#include <linux/smp_lock.h>
29#include <linux/backing-dev.h>
Yan4b82d6e2007-08-29 09:11:44 -040030#include <linux/mount.h>
Chris Masondee26a92007-03-26 16:00:06 -040031#include <linux/mpage.h>
Chris Mason75dfe392007-03-29 11:56:46 -040032#include <linux/swap.h>
33#include <linux/writeback.h>
Chris Mason8fd17792007-04-19 21:01:03 -040034#include <linux/statfs.h>
Chris Mason08607c12007-06-08 15:33:54 -040035#include <linux/compat.h>
Chris Mason95e05282007-08-29 09:11:44 -040036#include <linux/parser.h>
Chris Masonc59f8952007-12-17 20:14:04 -050037#include <linux/ctype.h>
Chris Mason6da6aba2007-12-18 16:15:09 -050038#include <linux/namei.h>
Chris Masona9218f62008-03-24 15:02:04 -040039#include <linux/miscdevice.h>
Chris Mason4b4e25f2008-11-20 10:22:27 -050040#include <linux/version.h>
41#include "compat.h"
Chris Mason2e635a22007-03-21 11:12:56 -040042#include "ctree.h"
Chris Masone20d96d2007-03-22 12:13:20 -040043#include "disk-io.h"
Chris Masond5719762007-03-23 10:01:08 -040044#include "transaction.h"
Chris Mason2c90e5d2007-04-02 10:50:19 -040045#include "btrfs_inode.h"
Chris Masonc5739bb2007-04-10 09:27:04 -040046#include "ioctl.h"
Chris Mason3a686372007-05-24 13:35:57 -040047#include "print-tree.h"
Josef Bacik5103e942007-11-16 11:45:54 -050048#include "xattr.h"
Chris Mason8a4b83c2008-03-24 15:02:07 -040049#include "volumes.h"
Chris Masonb3c3da72008-07-23 12:12:13 -040050#include "version.h"
Balaji Raobe6e8dc2008-07-21 02:01:56 +053051#include "export.h"
Chris Masonc8b97812008-10-29 14:49:59 -040052#include "compression.h"
Chris Mason2e635a22007-03-21 11:12:56 -040053
Chris Mason5f39d392007-10-15 16:14:19 -040054#define BTRFS_SUPER_MAGIC 0x9123683E
Chris Masone20d96d2007-03-22 12:13:20 -040055
Chris Masone20d96d2007-03-22 12:13:20 -040056static struct super_operations btrfs_super_ops;
Chris Masone20d96d2007-03-22 12:13:20 -040057
58static void btrfs_put_super (struct super_block * sb)
59{
60 struct btrfs_root *root = btrfs_sb(sb);
61 int ret;
62
63 ret = close_ctree(root);
64 if (ret) {
65 printk("close ctree returns %d\n", ret);
66 }
Yan Zhenge4404d62008-12-12 10:03:26 -050067#if 0
68 btrfs_sysfs_del_super(root->fs_info);
69#endif
Chris Masone20d96d2007-03-22 12:13:20 -040070 sb->s_fs_info = NULL;
71}
Chris Mason2e635a22007-03-21 11:12:56 -040072
Chris Mason95e05282007-08-29 09:11:44 -040073enum {
Christoph Hellwig43e570b2008-06-10 10:40:46 -040074 Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Chris Masondfe25022008-05-13 13:46:40 -040075 Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Chris Masonc8b97812008-10-29 14:49:59 -040076 Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, Opt_err,
Chris Mason95e05282007-08-29 09:11:44 -040077};
78
79static match_table_t tokens = {
Chris Masondfe25022008-05-13 13:46:40 -040080 {Opt_degraded, "degraded"},
Chris Mason95e05282007-08-29 09:11:44 -040081 {Opt_subvol, "subvol=%s"},
Christoph Hellwig43e570b2008-06-10 10:40:46 -040082 {Opt_device, "device=%s"},
Chris Masonb6cda9b2007-12-14 15:30:32 -050083 {Opt_nodatasum, "nodatasum"},
Chris Masonbe20aa92007-12-17 20:14:01 -050084 {Opt_nodatacow, "nodatacow"},
Chris Mason21ad10c2008-01-09 09:23:21 -050085 {Opt_nobarrier, "nobarrier"},
Chris Masonc59f8952007-12-17 20:14:04 -050086 {Opt_max_extent, "max_extent=%s"},
Chris Mason6f568d32008-01-29 16:03:38 -050087 {Opt_max_inline, "max_inline=%s"},
Chris Mason8f662a72008-01-02 10:01:11 -050088 {Opt_alloc_start, "alloc_start=%s"},
Chris Mason4543df72008-06-11 21:47:56 -040089 {Opt_thread_pool, "thread_pool=%d"},
Chris Masonc8b97812008-10-29 14:49:59 -040090 {Opt_compress, "compress"},
Chris Masone18e4802008-01-18 10:54:22 -050091 {Opt_ssd, "ssd"},
Josef Bacik33268ea2008-07-24 12:16:36 -040092 {Opt_noacl, "noacl"},
93 {Opt_err, NULL},
Chris Mason95e05282007-08-29 09:11:44 -040094};
95
Chris Masonedbd8d42007-12-21 16:27:24 -050096u64 btrfs_parse_size(char *str)
Chris Masonc59f8952007-12-17 20:14:04 -050097{
Chris Masonedbd8d42007-12-21 16:27:24 -050098 u64 res;
Chris Masonc59f8952007-12-17 20:14:04 -050099 int mult = 1;
100 char *end;
101 char last;
102
103 res = simple_strtoul(str, &end, 10);
104
105 last = end[0];
106 if (isalpha(last)) {
107 last = tolower(last);
108 switch (last) {
109 case 'g':
110 mult *= 1024;
111 case 'm':
112 mult *= 1024;
113 case 'k':
114 mult *= 1024;
115 }
116 res = res * mult;
117 }
118 return res;
119}
120
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400121/*
122 * Regular mount options parser. Everything that is needed only when
123 * reading in a new superblock is parsed here.
124 */
125int btrfs_parse_options(struct btrfs_root *root, char *options)
Chris Mason95e05282007-08-29 09:11:44 -0400126{
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400127 struct btrfs_fs_info *info = root->fs_info;
Chris Mason95e05282007-08-29 09:11:44 -0400128 substring_t args[MAX_OPT_ARGS];
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400129 char *p, *num;
Chris Mason4543df72008-06-11 21:47:56 -0400130 int intarg;
Chris Masonb6cda9b2007-12-14 15:30:32 -0500131
Chris Mason95e05282007-08-29 09:11:44 -0400132 if (!options)
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400133 return 0;
Chris Mason95e05282007-08-29 09:11:44 -0400134
Chris Masonbe20aa92007-12-17 20:14:01 -0500135 /*
136 * strsep changes the string, duplicate it because parse_options
137 * gets called twice
138 */
139 options = kstrdup(options, GFP_NOFS);
140 if (!options)
141 return -ENOMEM;
142
Chris Masonbe20aa92007-12-17 20:14:01 -0500143
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400144 while ((p = strsep(&options, ",")) != NULL) {
Chris Mason95e05282007-08-29 09:11:44 -0400145 int token;
146 if (!*p)
147 continue;
148
149 token = match_token(p, tokens, args);
150 switch (token) {
Chris Masondfe25022008-05-13 13:46:40 -0400151 case Opt_degraded:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400152 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
153 btrfs_set_opt(info->mount_opt, DEGRADED);
Chris Masondfe25022008-05-13 13:46:40 -0400154 break;
Chris Mason95e05282007-08-29 09:11:44 -0400155 case Opt_subvol:
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400156 case Opt_device:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400157 /*
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400158 * These are parsed by btrfs_parse_early_options
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400159 * and can be happily ignored here.
160 */
Chris Masonb6cda9b2007-12-14 15:30:32 -0500161 break;
162 case Opt_nodatasum:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400163 printk(KERN_INFO "btrfs: setting nodatacsum\n");
164 btrfs_set_opt(info->mount_opt, NODATASUM);
Chris Masonbe20aa92007-12-17 20:14:01 -0500165 break;
166 case Opt_nodatacow:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400167 printk(KERN_INFO "btrfs: setting nodatacow\n");
168 btrfs_set_opt(info->mount_opt, NODATACOW);
169 btrfs_set_opt(info->mount_opt, NODATASUM);
Chris Mason95e05282007-08-29 09:11:44 -0400170 break;
Chris Masonc8b97812008-10-29 14:49:59 -0400171 case Opt_compress:
172 printk(KERN_INFO "btrfs: use compression\n");
173 btrfs_set_opt(info->mount_opt, COMPRESS);
174 break;
Chris Masone18e4802008-01-18 10:54:22 -0500175 case Opt_ssd:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400176 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
177 btrfs_set_opt(info->mount_opt, SSD);
Chris Masone18e4802008-01-18 10:54:22 -0500178 break;
Chris Mason21ad10c2008-01-09 09:23:21 -0500179 case Opt_nobarrier:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400180 printk(KERN_INFO "btrfs: turning off barriers\n");
181 btrfs_set_opt(info->mount_opt, NOBARRIER);
Chris Mason21ad10c2008-01-09 09:23:21 -0500182 break;
Chris Mason4543df72008-06-11 21:47:56 -0400183 case Opt_thread_pool:
184 intarg = 0;
185 match_int(&args[0], &intarg);
186 if (intarg) {
187 info->thread_pool_size = intarg;
188 printk(KERN_INFO "btrfs: thread pool %d\n",
189 info->thread_pool_size);
190 }
191 break;
Chris Masonc59f8952007-12-17 20:14:04 -0500192 case Opt_max_extent:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400193 num = match_strdup(&args[0]);
194 if (num) {
195 info->max_extent = btrfs_parse_size(num);
196 kfree(num);
Chris Masonc59f8952007-12-17 20:14:04 -0500197
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400198 info->max_extent = max_t(u64,
199 info->max_extent, root->sectorsize);
200 printk(KERN_INFO "btrfs: max_extent at %llu\n",
201 info->max_extent);
Chris Masonc59f8952007-12-17 20:14:04 -0500202 }
203 break;
Chris Mason6f568d32008-01-29 16:03:38 -0500204 case Opt_max_inline:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400205 num = match_strdup(&args[0]);
206 if (num) {
207 info->max_inline = btrfs_parse_size(num);
208 kfree(num);
Chris Mason6f568d32008-01-29 16:03:38 -0500209
Chris Mason15ada042008-06-11 16:51:38 -0400210 if (info->max_inline) {
211 info->max_inline = max_t(u64,
212 info->max_inline,
213 root->sectorsize);
214 }
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400215 printk(KERN_INFO "btrfs: max_inline at %llu\n",
216 info->max_inline);
Chris Mason6f568d32008-01-29 16:03:38 -0500217 }
218 break;
Chris Mason8f662a72008-01-02 10:01:11 -0500219 case Opt_alloc_start:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400220 num = match_strdup(&args[0]);
221 if (num) {
222 info->alloc_start = btrfs_parse_size(num);
223 kfree(num);
224 printk(KERN_INFO
225 "btrfs: allocations start at %llu\n",
226 info->alloc_start);
Chris Mason8f662a72008-01-02 10:01:11 -0500227 }
228 break;
Josef Bacik33268ea2008-07-24 12:16:36 -0400229 case Opt_noacl:
230 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
231 break;
Chris Mason95e05282007-08-29 09:11:44 -0400232 default:
Chris Masonbe20aa92007-12-17 20:14:01 -0500233 break;
Chris Mason95e05282007-08-29 09:11:44 -0400234 }
235 }
Chris Masonbe20aa92007-12-17 20:14:01 -0500236 kfree(options);
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400237 return 0;
238}
239
240/*
241 * Parse mount options that are required early in the mount process.
242 *
243 * All other options will be parsed on much later in the mount process and
244 * only when we need to allocate a new super block.
245 */
Christoph Hellwig97288f22008-12-02 06:36:09 -0500246static int btrfs_parse_early_options(const char *options, fmode_t flags,
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400247 void *holder, char **subvol_name,
248 struct btrfs_fs_devices **fs_devices)
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400249{
250 substring_t args[MAX_OPT_ARGS];
251 char *opts, *p;
252 int error = 0;
253
254 if (!options)
255 goto out;
256
257 /*
258 * strsep changes the string, duplicate it because parse_options
259 * gets called twice
260 */
261 opts = kstrdup(options, GFP_KERNEL);
262 if (!opts)
263 return -ENOMEM;
264
265 while ((p = strsep(&opts, ",")) != NULL) {
266 int token;
267 if (!*p)
268 continue;
269
270 token = match_token(p, tokens, args);
271 switch (token) {
272 case Opt_subvol:
273 *subvol_name = match_strdup(&args[0]);
274 break;
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400275 case Opt_device:
276 error = btrfs_scan_one_device(match_strdup(&args[0]),
277 flags, holder, fs_devices);
278 if (error)
279 goto out_free_opts;
280 break;
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400281 default:
282 break;
283 }
284 }
285
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400286 out_free_opts:
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400287 kfree(opts);
288 out:
289 /*
290 * If no subvolume name is specified we use the default one. Allocate
Chris Mason3de45862008-11-17 21:02:50 -0500291 * a copy of the string "." here so that code later in the
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400292 * mount path doesn't care if it's the default volume or another one.
293 */
294 if (!*subvol_name) {
Chris Mason3de45862008-11-17 21:02:50 -0500295 *subvol_name = kstrdup(".", GFP_KERNEL);
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400296 if (!*subvol_name)
297 return -ENOMEM;
298 }
299 return error;
Chris Mason95e05282007-08-29 09:11:44 -0400300}
301
Chris Mason8a4b83c2008-03-24 15:02:07 -0400302static int btrfs_fill_super(struct super_block * sb,
303 struct btrfs_fs_devices *fs_devices,
304 void * data, int silent)
Chris Mason2e635a22007-03-21 11:12:56 -0400305{
306 struct inode * inode;
Chris Masone20d96d2007-03-22 12:13:20 -0400307 struct dentry * root_dentry;
308 struct btrfs_super_block *disk_super;
Chris Mason0f7d52f2007-04-09 10:42:37 -0400309 struct btrfs_root *tree_root;
Chris Masond6e4a422007-04-06 15:37:36 -0400310 struct btrfs_inode *bi;
Chris Mason39279cc2007-06-12 06:35:45 -0400311 int err;
Chris Mason2e635a22007-03-21 11:12:56 -0400312
313 sb->s_maxbytes = MAX_LFS_FILESIZE;
Chris Mason2e635a22007-03-21 11:12:56 -0400314 sb->s_magic = BTRFS_SUPER_MAGIC;
Chris Masone20d96d2007-03-22 12:13:20 -0400315 sb->s_op = &btrfs_super_ops;
Balaji Raobe6e8dc2008-07-21 02:01:56 +0530316 sb->s_export_op = &btrfs_export_ops;
Josef Bacik5103e942007-11-16 11:45:54 -0500317 sb->s_xattr = btrfs_xattr_handlers;
Chris Mason2e635a22007-03-21 11:12:56 -0400318 sb->s_time_gran = 1;
Josef Bacik33268ea2008-07-24 12:16:36 -0400319 sb->s_flags |= MS_POSIXACL;
Chris Masone20d96d2007-03-22 12:13:20 -0400320
Chris Masondfe25022008-05-13 13:46:40 -0400321 tree_root = open_ctree(sb, fs_devices, (char *)data);
Chris Masond98237b2007-03-28 13:57:48 -0400322
Yane58ca022008-04-01 11:21:34 -0400323 if (IS_ERR(tree_root)) {
Chris Masone20d96d2007-03-22 12:13:20 -0400324 printk("btrfs: open_ctree failed\n");
Yane58ca022008-04-01 11:21:34 -0400325 return PTR_ERR(tree_root);
Chris Masone20d96d2007-03-22 12:13:20 -0400326 }
Chris Mason0f7d52f2007-04-09 10:42:37 -0400327 sb->s_fs_info = tree_root;
Chris Mason5f39d392007-10-15 16:14:19 -0400328 disk_super = &tree_root->fs_info->super_copy;
Chris Mason3de45862008-11-17 21:02:50 -0500329 inode = btrfs_iget_locked(sb, BTRFS_FIRST_FREE_OBJECTID,
330 tree_root->fs_info->fs_root);
Chris Masond6e4a422007-04-06 15:37:36 -0400331 bi = BTRFS_I(inode);
332 bi->location.objectid = inode->i_ino;
333 bi->location.offset = 0;
Chris Mason3de45862008-11-17 21:02:50 -0500334 bi->root = tree_root->fs_info->fs_root;
Chris Masonb888db22007-08-27 16:49:44 -0400335
Chris Masond6e4a422007-04-06 15:37:36 -0400336 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
337
Chris Mason39279cc2007-06-12 06:35:45 -0400338 if (!inode) {
339 err = -ENOMEM;
340 goto fail_close;
341 }
Chris Masone20d96d2007-03-22 12:13:20 -0400342 if (inode->i_state & I_NEW) {
343 btrfs_read_locked_inode(inode);
344 unlock_new_inode(inode);
345 }
Chris Mason2e635a22007-03-21 11:12:56 -0400346
Chris Masone20d96d2007-03-22 12:13:20 -0400347 root_dentry = d_alloc_root(inode);
348 if (!root_dentry) {
Chris Mason2e635a22007-03-21 11:12:56 -0400349 iput(inode);
Chris Mason39279cc2007-06-12 06:35:45 -0400350 err = -ENOMEM;
351 goto fail_close;
Chris Mason2e635a22007-03-21 11:12:56 -0400352 }
Yan Zhenge4404d62008-12-12 10:03:26 -0500353#if 0
Josef Bacik58176a92007-08-29 15:47:34 -0400354 /* this does the super kobj at the same time */
355 err = btrfs_sysfs_add_super(tree_root->fs_info);
356 if (err)
357 goto fail_close;
Yan Zhenge4404d62008-12-12 10:03:26 -0500358#endif
Josef Bacik58176a92007-08-29 15:47:34 -0400359
Chris Masone20d96d2007-03-22 12:13:20 -0400360 sb->s_root = root_dentry;
Chris Mason6885f302008-02-20 16:11:05 -0500361
Chris Mason6885f302008-02-20 16:11:05 -0500362 save_mount_options(sb, data);
Chris Mason2e635a22007-03-21 11:12:56 -0400363 return 0;
Chris Mason2e635a22007-03-21 11:12:56 -0400364
Chris Mason39279cc2007-06-12 06:35:45 -0400365fail_close:
366 close_ctree(tree_root);
Chris Masond5719762007-03-23 10:01:08 -0400367 return err;
368}
369
Sage Weil6bf13c02008-06-10 10:07:39 -0400370int btrfs_sync_fs(struct super_block *sb, int wait)
Chris Masond5719762007-03-23 10:01:08 -0400371{
372 struct btrfs_trans_handle *trans;
373 struct btrfs_root *root;
374 int ret;
Chris Masond98237b2007-03-28 13:57:48 -0400375 root = btrfs_sb(sb);
Chris Masondf2ce342007-03-23 11:00:45 -0400376
Yan Zhengc146afa2008-11-12 14:34:12 -0500377 if (sb->s_flags & MS_RDONLY)
378 return 0;
379
Chris Masond5719762007-03-23 10:01:08 -0400380 sb->s_dirt = 0;
Chris Masond561c022007-03-23 19:47:49 -0400381 if (!wait) {
Chris Mason7cfcc172007-04-02 14:53:59 -0400382 filemap_flush(root->fs_info->btree_inode->i_mapping);
Chris Masond561c022007-03-23 19:47:49 -0400383 return 0;
384 }
Chris Mason771ed682008-11-06 22:02:51 -0500385
386 btrfs_start_delalloc_inodes(root);
387 btrfs_wait_ordered_extents(root, 0);
388
Chris Masone9d0b132007-08-10 14:06:19 -0400389 btrfs_clean_old_snapshots(root);
Chris Masond5719762007-03-23 10:01:08 -0400390 trans = btrfs_start_transaction(root, 1);
391 ret = btrfs_commit_transaction(trans, root);
392 sb->s_dirt = 0;
Chris Mason54aa1f42007-06-22 14:16:25 -0400393 return ret;
Chris Masond5719762007-03-23 10:01:08 -0400394}
395
Chris Masond561c022007-03-23 19:47:49 -0400396static void btrfs_write_super(struct super_block *sb)
397{
Chris Mason08607c12007-06-08 15:33:54 -0400398 sb->s_dirt = 0;
Chris Masond561c022007-03-23 19:47:49 -0400399}
400
Chris Masona061fc82008-05-07 11:43:44 -0400401static int btrfs_test_super(struct super_block *s, void *data)
Chris Mason2e635a22007-03-21 11:12:56 -0400402{
Chris Masona061fc82008-05-07 11:43:44 -0400403 struct btrfs_fs_devices *test_fs_devices = data;
404 struct btrfs_root *root = btrfs_sb(s);
Yan4b82d6e2007-08-29 09:11:44 -0400405
Chris Masona061fc82008-05-07 11:43:44 -0400406 return root->fs_info->fs_devices == test_fs_devices;
Yan4b82d6e2007-08-29 09:11:44 -0400407}
408
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400409/*
410 * Find a superblock for the given device / mount point.
411 *
412 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
413 * for multiple device setup. Make sure to keep it in sync.
414 */
415static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
416 const char *dev_name, void *data, struct vfsmount *mnt)
Yan4b82d6e2007-08-29 09:11:44 -0400417{
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400418 char *subvol_name = NULL;
Yan4b82d6e2007-08-29 09:11:44 -0400419 struct block_device *bdev = NULL;
420 struct super_block *s;
421 struct dentry *root;
Chris Mason8a4b83c2008-03-24 15:02:07 -0400422 struct btrfs_fs_devices *fs_devices = NULL;
Christoph Hellwig97288f22008-12-02 06:36:09 -0500423 fmode_t mode = FMODE_READ;
Yan4b82d6e2007-08-29 09:11:44 -0400424 int error = 0;
425
Christoph Hellwig97288f22008-12-02 06:36:09 -0500426 if (!(flags & MS_RDONLY))
427 mode |= FMODE_WRITE;
428
429 error = btrfs_parse_early_options(data, mode, fs_type,
Christoph Hellwig43e570b2008-06-10 10:40:46 -0400430 &subvol_name, &fs_devices);
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400431 if (error)
432 goto error;
433
Christoph Hellwig97288f22008-12-02 06:36:09 -0500434 error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices);
Chris Mason8a4b83c2008-03-24 15:02:07 -0400435 if (error)
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400436 goto error_free_subvol_name;
Yan4b82d6e2007-08-29 09:11:44 -0400437
Christoph Hellwig97288f22008-12-02 06:36:09 -0500438 error = btrfs_open_devices(fs_devices, mode, fs_type);
Chris Mason8a4b83c2008-03-24 15:02:07 -0400439 if (error)
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400440 goto error_free_subvol_name;
Chris Mason8a4b83c2008-03-24 15:02:07 -0400441
Yan Zheng2b820322008-11-17 21:11:30 -0500442 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
443 error = -EACCES;
444 goto error_close_devices;
445 }
446
Chris Masondfe25022008-05-13 13:46:40 -0400447 bdev = fs_devices->latest_bdev;
Chris Masona061fc82008-05-07 11:43:44 -0400448 s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
Yan4b82d6e2007-08-29 09:11:44 -0400449 if (IS_ERR(s))
450 goto error_s;
451
452 if (s->s_root) {
453 if ((flags ^ s->s_flags) & MS_RDONLY) {
454 up_write(&s->s_umount);
455 deactivate_super(s);
456 error = -EBUSY;
Yan Zhengc146afa2008-11-12 14:34:12 -0500457 goto error_close_devices;
Yan4b82d6e2007-08-29 09:11:44 -0400458 }
459
Yan Zheng2b820322008-11-17 21:11:30 -0500460 btrfs_close_devices(fs_devices);
Yan4b82d6e2007-08-29 09:11:44 -0400461 } else {
462 char b[BDEVNAME_SIZE];
463
464 s->s_flags = flags;
465 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
Chris Mason8a4b83c2008-03-24 15:02:07 -0400466 error = btrfs_fill_super(s, fs_devices, data,
467 flags & MS_SILENT ? 1 : 0);
Yan4b82d6e2007-08-29 09:11:44 -0400468 if (error) {
469 up_write(&s->s_umount);
470 deactivate_super(s);
471 goto error;
472 }
473
Chris Mason788f20e2008-04-28 15:29:42 -0400474 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
Yan4b82d6e2007-08-29 09:11:44 -0400475 s->s_flags |= MS_ACTIVE;
476 }
477
David Woodhouse76fcef12008-08-19 16:49:35 +0100478 if (!strcmp(subvol_name, "."))
479 root = dget(s->s_root);
480 else {
481 mutex_lock(&s->s_root->d_inode->i_mutex);
482 root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
483 mutex_unlock(&s->s_root->d_inode->i_mutex);
484 if (IS_ERR(root)) {
485 up_write(&s->s_umount);
486 deactivate_super(s);
487 error = PTR_ERR(root);
488 goto error;
489 }
490 if (!root->d_inode) {
491 dput(root);
492 up_write(&s->s_umount);
493 deactivate_super(s);
494 error = -ENXIO;
495 goto error;
496 }
Yan4b82d6e2007-08-29 09:11:44 -0400497 }
498
499 mnt->mnt_sb = s;
500 mnt->mnt_root = root;
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400501
502 kfree(subvol_name);
Yan4b82d6e2007-08-29 09:11:44 -0400503 return 0;
504
505error_s:
506 error = PTR_ERR(s);
Yan Zhengc146afa2008-11-12 14:34:12 -0500507error_close_devices:
Chris Mason8a4b83c2008-03-24 15:02:07 -0400508 btrfs_close_devices(fs_devices);
Christoph Hellwigedf24ab2008-06-10 10:40:29 -0400509error_free_subvol_name:
510 kfree(subvol_name);
Yan4b82d6e2007-08-29 09:11:44 -0400511error:
512 return error;
513}
Chris Mason2e635a22007-03-21 11:12:56 -0400514
Yan Zhengc146afa2008-11-12 14:34:12 -0500515static int btrfs_remount(struct super_block *sb, int *flags, char *data)
516{
517 struct btrfs_root *root = btrfs_sb(sb);
518 int ret;
519
520 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
521 return 0;
522
523 if (*flags & MS_RDONLY) {
524 sb->s_flags |= MS_RDONLY;
525
526 ret = btrfs_commit_super(root);
527 WARN_ON(ret);
528 } else {
Yan Zheng2b820322008-11-17 21:11:30 -0500529 if (root->fs_info->fs_devices->rw_devices == 0)
530 return -EACCES;
531
Yan Zhengc146afa2008-11-12 14:34:12 -0500532 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
533 return -EINVAL;
534
535 ret = btrfs_cleanup_reloc_trees(root);
536 WARN_ON(ret);
537
538 ret = btrfs_cleanup_fs_roots(root->fs_info);
539 WARN_ON(ret);
540
541 sb->s_flags &= ~MS_RDONLY;
542 }
543
544 return 0;
545}
546
Chris Mason8fd17792007-04-19 21:01:03 -0400547static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
548{
549 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
Chris Mason4b52dff2007-06-26 10:06:50 -0400550 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
Chris Masondb945352007-10-15 16:15:53 -0400551 int bits = dentry->d_sb->s_blocksize_bits;
David Woodhouse9d036322008-08-18 12:01:52 +0100552 __be32 *fsid = (__be32 *)root->fs_info->fsid;
Chris Mason8fd17792007-04-19 21:01:03 -0400553
554 buf->f_namelen = BTRFS_NAME_LEN;
Chris Masondb945352007-10-15 16:15:53 -0400555 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
556 buf->f_bfree = buf->f_blocks -
557 (btrfs_super_bytes_used(disk_super) >> bits);
Chris Mason8fd17792007-04-19 21:01:03 -0400558 buf->f_bavail = buf->f_bfree;
559 buf->f_bsize = dentry->d_sb->s_blocksize;
560 buf->f_type = BTRFS_SUPER_MAGIC;
David Woodhouse9d036322008-08-18 12:01:52 +0100561 /* We treat it as constant endianness (it doesn't matter _which_)
562 because we want the fsid to come out the same whether mounted
563 on a big-endian or little-endian host */
564 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
565 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
David Woodhouse32d48fa2008-08-18 13:10:20 +0100566 /* Mask in the root object ID too, to disambiguate subvols */
567 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
568 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
569
Chris Mason8fd17792007-04-19 21:01:03 -0400570 return 0;
571}
Chris Masonb5133862007-04-24 11:52:22 -0400572
Chris Mason2e635a22007-03-21 11:12:56 -0400573static struct file_system_type btrfs_fs_type = {
574 .owner = THIS_MODULE,
575 .name = "btrfs",
576 .get_sb = btrfs_get_sb,
Chris Masona061fc82008-05-07 11:43:44 -0400577 .kill_sb = kill_anon_super,
Chris Mason2e635a22007-03-21 11:12:56 -0400578 .fs_flags = FS_REQUIRES_DEV,
579};
Chris Masona9218f62008-03-24 15:02:04 -0400580
Chris Masond352ac62008-09-29 15:18:18 -0400581/*
582 * used by btrfsctl to scan devices when no FS is mounted
583 */
Chris Mason8a4b83c2008-03-24 15:02:07 -0400584static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
585 unsigned long arg)
586{
587 struct btrfs_ioctl_vol_args *vol;
588 struct btrfs_fs_devices *fs_devices;
Linda Knippersf819d832008-06-09 22:17:11 -0400589 int ret = 0;
Chris Mason8a4b83c2008-03-24 15:02:07 -0400590 int len;
591
592 vol = kmalloc(sizeof(*vol), GFP_KERNEL);
593 if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
594 ret = -EFAULT;
595 goto out;
596 }
597 len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
598 switch (cmd) {
599 case BTRFS_IOC_SCAN_DEV:
Christoph Hellwig97288f22008-12-02 06:36:09 -0500600 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
Chris Mason8a4b83c2008-03-24 15:02:07 -0400601 &btrfs_fs_type, &fs_devices);
602 break;
603 }
604out:
605 kfree(vol);
Linda Knippersf819d832008-06-09 22:17:11 -0400606 return ret;
Chris Mason8a4b83c2008-03-24 15:02:07 -0400607}
608
Yaned0dab62008-01-22 12:46:56 -0500609static void btrfs_write_super_lockfs(struct super_block *sb)
610{
611 struct btrfs_root *root = btrfs_sb(sb);
Chris Masona74a4b92008-06-25 16:01:31 -0400612 mutex_lock(&root->fs_info->transaction_kthread_mutex);
613 mutex_lock(&root->fs_info->cleaner_mutex);
Yaned0dab62008-01-22 12:46:56 -0500614}
615
616static void btrfs_unlockfs(struct super_block *sb)
617{
618 struct btrfs_root *root = btrfs_sb(sb);
Chris Masona74a4b92008-06-25 16:01:31 -0400619 mutex_unlock(&root->fs_info->cleaner_mutex);
620 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
Yaned0dab62008-01-22 12:46:56 -0500621}
Chris Mason2e635a22007-03-21 11:12:56 -0400622
Chris Masone20d96d2007-03-22 12:13:20 -0400623static struct super_operations btrfs_super_ops = {
Chris Mason134e9732007-03-25 13:44:56 -0400624 .delete_inode = btrfs_delete_inode,
Chris Masone20d96d2007-03-22 12:13:20 -0400625 .put_super = btrfs_put_super,
Chris Masond5719762007-03-23 10:01:08 -0400626 .write_super = btrfs_write_super,
627 .sync_fs = btrfs_sync_fs,
Chris Mason6885f302008-02-20 16:11:05 -0500628 .show_options = generic_show_options,
Chris Mason4730a4b2007-03-26 12:00:39 -0400629 .write_inode = btrfs_write_inode,
Chris Masonb5133862007-04-24 11:52:22 -0400630 .dirty_inode = btrfs_dirty_inode,
Chris Mason2c90e5d2007-04-02 10:50:19 -0400631 .alloc_inode = btrfs_alloc_inode,
632 .destroy_inode = btrfs_destroy_inode,
Chris Mason8fd17792007-04-19 21:01:03 -0400633 .statfs = btrfs_statfs,
Yan Zhengc146afa2008-11-12 14:34:12 -0500634 .remount_fs = btrfs_remount,
Yaned0dab62008-01-22 12:46:56 -0500635 .write_super_lockfs = btrfs_write_super_lockfs,
636 .unlockfs = btrfs_unlockfs,
Chris Masone20d96d2007-03-22 12:13:20 -0400637};
Chris Masona9218f62008-03-24 15:02:04 -0400638
639static const struct file_operations btrfs_ctl_fops = {
640 .unlocked_ioctl = btrfs_control_ioctl,
641 .compat_ioctl = btrfs_control_ioctl,
642 .owner = THIS_MODULE,
643};
644
645static struct miscdevice btrfs_misc = {
646 .minor = MISC_DYNAMIC_MINOR,
647 .name = "btrfs-control",
648 .fops = &btrfs_ctl_fops
649};
650
651static int btrfs_interface_init(void)
652{
653 return misc_register(&btrfs_misc);
654}
655
Christoph Hellwigb2950862008-12-02 09:54:17 -0500656static void btrfs_interface_exit(void)
Chris Masona9218f62008-03-24 15:02:04 -0400657{
658 if (misc_deregister(&btrfs_misc) < 0)
659 printk("misc_deregister failed for control device");
660}
661
Chris Mason2e635a22007-03-21 11:12:56 -0400662static int __init init_btrfs_fs(void)
663{
Chris Mason2c90e5d2007-04-02 10:50:19 -0400664 int err;
Josef Bacik58176a92007-08-29 15:47:34 -0400665
666 err = btrfs_init_sysfs();
667 if (err)
668 return err;
669
Chris Mason39279cc2007-06-12 06:35:45 -0400670 err = btrfs_init_cachep();
Chris Mason2c90e5d2007-04-02 10:50:19 -0400671 if (err)
Chris Masona74a4b92008-06-25 16:01:31 -0400672 goto free_sysfs;
Chris Masond1310b22008-01-24 16:13:08 -0500673
674 err = extent_io_init();
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500675 if (err)
676 goto free_cachep;
677
Chris Masond1310b22008-01-24 16:13:08 -0500678 err = extent_map_init();
679 if (err)
680 goto free_extent_io;
681
Chris Masona9218f62008-03-24 15:02:04 -0400682 err = btrfs_interface_init();
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500683 if (err)
684 goto free_extent_map;
Chris Masonc8b97812008-10-29 14:49:59 -0400685
Chris Masona9218f62008-03-24 15:02:04 -0400686 err = register_filesystem(&btrfs_fs_type);
687 if (err)
688 goto unregister_ioctl;
Chris Masonb3c3da72008-07-23 12:12:13 -0400689
690 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500691 return 0;
692
Chris Masona9218f62008-03-24 15:02:04 -0400693unregister_ioctl:
694 btrfs_interface_exit();
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500695free_extent_map:
696 extent_map_exit();
Chris Masond1310b22008-01-24 16:13:08 -0500697free_extent_io:
698 extent_io_exit();
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500699free_cachep:
700 btrfs_destroy_cachep();
Chris Masona74a4b92008-06-25 16:01:31 -0400701free_sysfs:
Wyatt Banks2f4cbe62007-11-19 10:22:33 -0500702 btrfs_exit_sysfs();
703 return err;
Chris Mason2e635a22007-03-21 11:12:56 -0400704}
705
706static void __exit exit_btrfs_fs(void)
707{
Chris Mason39279cc2007-06-12 06:35:45 -0400708 btrfs_destroy_cachep();
Chris Masona52d9a82007-08-27 16:49:44 -0400709 extent_map_exit();
Chris Masond1310b22008-01-24 16:13:08 -0500710 extent_io_exit();
Chris Masona9218f62008-03-24 15:02:04 -0400711 btrfs_interface_exit();
Chris Mason2e635a22007-03-21 11:12:56 -0400712 unregister_filesystem(&btrfs_fs_type);
Josef Bacik58176a92007-08-29 15:47:34 -0400713 btrfs_exit_sysfs();
Chris Mason8a4b83c2008-03-24 15:02:07 -0400714 btrfs_cleanup_fs_uuids();
Chris Masonc8b97812008-10-29 14:49:59 -0400715 btrfs_zlib_exit();
Chris Mason2e635a22007-03-21 11:12:56 -0400716}
717
718module_init(init_btrfs_fs)
719module_exit(exit_btrfs_fs)
720
721MODULE_LICENSE("GPL");