Btrfs: Use blk_congestion_wait on older kernels
[linux-2.6-block.git] / fs / btrfs / super.c
CommitLineData
6cbd5570
CM
1/*
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
4b82d6e4 19#include <linux/blkdev.h>
2e635a27 20#include <linux/module.h>
e20d96d6 21#include <linux/buffer_head.h>
2e635a27
CM
22#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>
4b82d6e4 30#include <linux/mount.h>
dee26a9f 31#include <linux/mpage.h>
75dfe396
CM
32#include <linux/swap.h>
33#include <linux/writeback.h>
8fd17795 34#include <linux/statfs.h>
08607c1b 35#include <linux/compat.h>
95e05289 36#include <linux/parser.h>
c59f8951 37#include <linux/ctype.h>
6da6abae 38#include <linux/namei.h>
2e635a27 39#include "ctree.h"
e20d96d6 40#include "disk-io.h"
d5719762 41#include "transaction.h"
2c90e5d6 42#include "btrfs_inode.h"
c5739bba 43#include "ioctl.h"
3a686375 44#include "print-tree.h"
5103e947 45#include "xattr.h"
2e635a27 46
5f39d397 47#define BTRFS_SUPER_MAGIC 0x9123683E
f254e52c 48
39279cc3 49static struct super_operations btrfs_super_ops;
75dfe396 50
39279cc3 51static void btrfs_put_super (struct super_block * sb)
b18c6685 52{
39279cc3 53 struct btrfs_root *root = btrfs_sb(sb);
58176a96 54 struct btrfs_fs_info *fs = root->fs_info;
b18c6685 55 int ret;
b18c6685 56
39279cc3
CM
57 ret = close_ctree(root);
58 if (ret) {
59 printk("close ctree returns %d\n", ret);
75dfe396 60 }
58176a96 61 btrfs_sysfs_del_super(fs);
39279cc3 62 sb->s_fs_info = NULL;
75dfe396
CM
63}
64
95e05289 65enum {
8f662a76 66 Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent,
21ad10cf 67 Opt_alloc_start, Opt_nobarrier, Opt_err,
95e05289
CM
68};
69
70static match_table_t tokens = {
71 {Opt_subvol, "subvol=%s"},
b6cda9bc 72 {Opt_nodatasum, "nodatasum"},
be20aa9d 73 {Opt_nodatacow, "nodatacow"},
21ad10cf 74 {Opt_nobarrier, "nobarrier"},
c59f8951 75 {Opt_max_extent, "max_extent=%s"},
8f662a76 76 {Opt_alloc_start, "alloc_start=%s"},
95e05289
CM
77 {Opt_err, NULL}
78};
79
edbd8d4e 80u64 btrfs_parse_size(char *str)
c59f8951 81{
edbd8d4e 82 u64 res;
c59f8951
CM
83 int mult = 1;
84 char *end;
85 char last;
86
87 res = simple_strtoul(str, &end, 10);
88
89 last = end[0];
90 if (isalpha(last)) {
91 last = tolower(last);
92 switch (last) {
93 case 'g':
94 mult *= 1024;
95 case 'm':
96 mult *= 1024;
97 case 'k':
98 mult *= 1024;
99 }
100 res = res * mult;
101 }
102 return res;
103}
104
95e05289
CM
105static int parse_options (char * options,
106 struct btrfs_root *root,
107 char **subvol_name)
108{
109 char * p;
b6cda9bc 110 struct btrfs_fs_info *info = NULL;
95e05289 111 substring_t args[MAX_OPT_ARGS];
b6cda9bc 112
95e05289
CM
113 if (!options)
114 return 1;
115
be20aa9d
CM
116 /*
117 * strsep changes the string, duplicate it because parse_options
118 * gets called twice
119 */
120 options = kstrdup(options, GFP_NOFS);
121 if (!options)
122 return -ENOMEM;
123
124 if (root)
125 info = root->fs_info;
126
95e05289
CM
127 while ((p = strsep (&options, ",")) != NULL) {
128 int token;
129 if (!*p)
130 continue;
131
132 token = match_token(p, tokens, args);
133 switch (token) {
134 case Opt_subvol:
be20aa9d 135 if (subvol_name) {
b6cda9bc 136 *subvol_name = match_strdup(&args[0]);
be20aa9d 137 }
b6cda9bc
CM
138 break;
139 case Opt_nodatasum:
be20aa9d
CM
140 if (info) {
141 printk("btrfs: setting nodatacsum\n");
b6cda9bc 142 btrfs_set_opt(info->mount_opt, NODATASUM);
be20aa9d
CM
143 }
144 break;
145 case Opt_nodatacow:
146 if (info) {
147 printk("btrfs: setting nodatacow\n");
148 btrfs_set_opt(info->mount_opt, NODATACOW);
149 btrfs_set_opt(info->mount_opt, NODATASUM);
150 }
95e05289 151 break;
21ad10cf
CM
152 case Opt_nobarrier:
153 if (info) {
154 printk("btrfs: turning off barriers\n");
155 btrfs_set_opt(info->mount_opt, NOBARRIER);
156 }
157 break;
c59f8951
CM
158 case Opt_max_extent:
159 if (info) {
160 char *num = match_strdup(&args[0]);
161 if (num) {
edbd8d4e
CM
162 info->max_extent =
163 btrfs_parse_size(num);
c59f8951
CM
164 kfree(num);
165
166 info->max_extent = max_t(u64,
167 info->max_extent,
168 root->sectorsize);
169 printk("btrfs: max_extent at %Lu\n",
170 info->max_extent);
171 }
172 }
173 break;
8f662a76
CM
174 case Opt_alloc_start:
175 if (info) {
176 char *num = match_strdup(&args[0]);
177 if (num) {
178 info->alloc_start =
179 btrfs_parse_size(num);
180 kfree(num);
181 printk("btrfs: allocations start at "
182 "%Lu\n", info->alloc_start);
183 }
184 }
185 break;
95e05289 186 default:
be20aa9d 187 break;
95e05289
CM
188 }
189 }
be20aa9d 190 kfree(options);
95e05289
CM
191 return 1;
192}
193
39279cc3 194static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
75dfe396 195{
39279cc3
CM
196 struct inode * inode;
197 struct dentry * root_dentry;
198 struct btrfs_super_block *disk_super;
199 struct btrfs_root *tree_root;
200 struct btrfs_inode *bi;
201 int err;
a429e513 202
39279cc3
CM
203 sb->s_maxbytes = MAX_LFS_FILESIZE;
204 sb->s_magic = BTRFS_SUPER_MAGIC;
205 sb->s_op = &btrfs_super_ops;
5103e947 206 sb->s_xattr = btrfs_xattr_handlers;
39279cc3 207 sb->s_time_gran = 1;
a429e513 208
39279cc3 209 tree_root = open_ctree(sb);
6567e837 210
39279cc3
CM
211 if (!tree_root || IS_ERR(tree_root)) {
212 printk("btrfs: open_ctree failed\n");
213 return -EIO;
a429e513 214 }
39279cc3 215 sb->s_fs_info = tree_root;
5f39d397 216 disk_super = &tree_root->fs_info->super_copy;
39279cc3
CM
217 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
218 tree_root);
219 bi = BTRFS_I(inode);
220 bi->location.objectid = inode->i_ino;
221 bi->location.offset = 0;
39279cc3 222 bi->root = tree_root;
b888db2b 223
39279cc3 224 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
a429e513 225
39279cc3 226 if (!inode) {
6567e837 227 err = -ENOMEM;
39279cc3 228 goto fail_close;
f254e52c 229 }
39279cc3
CM
230 if (inode->i_state & I_NEW) {
231 btrfs_read_locked_inode(inode);
232 unlock_new_inode(inode);
f254e52c 233 }
f254e52c 234
39279cc3
CM
235 root_dentry = d_alloc_root(inode);
236 if (!root_dentry) {
237 iput(inode);
238 err = -ENOMEM;
239 goto fail_close;
f254e52c 240 }
58176a96 241
b6cda9bc
CM
242 parse_options((char *)data, tree_root, NULL);
243
58176a96
JB
244 /* this does the super kobj at the same time */
245 err = btrfs_sysfs_add_super(tree_root->fs_info);
246 if (err)
247 goto fail_close;
248
39279cc3
CM
249 sb->s_root = root_dentry;
250 btrfs_transaction_queue_work(tree_root, HZ * 30);
2619ba1f 251 return 0;
39279cc3
CM
252
253fail_close:
254 close_ctree(tree_root);
255 return err;
2619ba1f
CM
256}
257
39279cc3 258static int btrfs_sync_fs(struct super_block *sb, int wait)
c5739bba
CM
259{
260 struct btrfs_trans_handle *trans;
39279cc3 261 struct btrfs_root *root;
c5739bba 262 int ret;
39279cc3 263 root = btrfs_sb(sb);
2619ba1f 264
39279cc3
CM
265 sb->s_dirt = 0;
266 if (!wait) {
267 filemap_flush(root->fs_info->btree_inode->i_mapping);
268 return 0;
269 }
e9d0b13b 270 btrfs_clean_old_snapshots(root);
c5739bba 271 mutex_lock(&root->fs_info->fs_mutex);
e9d0b13b 272 btrfs_defrag_dirty_roots(root->fs_info);
c5739bba 273 trans = btrfs_start_transaction(root, 1);
c5739bba 274 ret = btrfs_commit_transaction(trans, root);
39279cc3 275 sb->s_dirt = 0;
c5739bba 276 mutex_unlock(&root->fs_info->fs_mutex);
54aa1f4d 277 return ret;
2c90e5d6
CM
278}
279
39279cc3 280static void btrfs_write_super(struct super_block *sb)
2c90e5d6 281{
39279cc3 282 sb->s_dirt = 0;
2c90e5d6
CM
283}
284
4b82d6e4
Y
285/*
286 * This is almost a copy of get_sb_bdev in fs/super.c.
287 * We need the local copy to allow direct mounting of
288 * subvolumes, but this could be easily integrated back
289 * into the generic version. --hch
290 */
291
292/* start copy & paste */
293static int set_bdev_super(struct super_block *s, void *data)
294{
295 s->s_bdev = data;
296 s->s_dev = s->s_bdev->bd_dev;
297 return 0;
298}
299
300static int test_bdev_super(struct super_block *s, void *data)
301{
302 return (void *)s->s_bdev == data;
303}
304
305int btrfs_get_sb_bdev(struct file_system_type *fs_type,
306 int flags, const char *dev_name, void *data,
307 int (*fill_super)(struct super_block *, void *, int),
308 struct vfsmount *mnt, const char *subvol)
309{
310 struct block_device *bdev = NULL;
311 struct super_block *s;
312 struct dentry *root;
313 int error = 0;
314
315 bdev = open_bdev_excl(dev_name, flags, fs_type);
316 if (IS_ERR(bdev))
317 return PTR_ERR(bdev);
318
319 /*
320 * once the super is inserted into the list by sget, s_umount
321 * will protect the lockfs code from trying to start a snapshot
322 * while we are mounting
323 */
324 down(&bdev->bd_mount_sem);
325 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
326 up(&bdev->bd_mount_sem);
327 if (IS_ERR(s))
328 goto error_s;
329
330 if (s->s_root) {
331 if ((flags ^ s->s_flags) & MS_RDONLY) {
332 up_write(&s->s_umount);
333 deactivate_super(s);
334 error = -EBUSY;
335 goto error_bdev;
336 }
337
338 close_bdev_excl(bdev);
339 } else {
340 char b[BDEVNAME_SIZE];
341
342 s->s_flags = flags;
343 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
344 sb_set_blocksize(s, block_size(bdev));
345 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
346 if (error) {
347 up_write(&s->s_umount);
348 deactivate_super(s);
349 goto error;
350 }
351
352 s->s_flags |= MS_ACTIVE;
353 }
354
355 if (subvol) {
356 root = lookup_one_len(subvol, s->s_root, strlen(subvol));
357 if (IS_ERR(root)) {
358 up_write(&s->s_umount);
359 deactivate_super(s);
360 error = PTR_ERR(root);
361 goto error;
362 }
363 if (!root->d_inode) {
364 dput(root);
365 up_write(&s->s_umount);
366 deactivate_super(s);
367 error = -ENXIO;
368 goto error;
369 }
370 } else {
371 root = dget(s->s_root);
372 }
373
374 mnt->mnt_sb = s;
375 mnt->mnt_root = root;
376 return 0;
377
378error_s:
379 error = PTR_ERR(s);
380error_bdev:
381 close_bdev_excl(bdev);
382error:
383 return error;
384}
385/* end copy & paste */
386
2e635a27 387static int btrfs_get_sb(struct file_system_type *fs_type,
95e05289 388 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
2e635a27 389{
4b82d6e4 390 int ret;
95e05289 391 char *subvol_name = NULL;
4b82d6e4 392
95e05289 393 parse_options((char *)data, NULL, &subvol_name);
4b82d6e4
Y
394 ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
395 btrfs_fill_super, mnt,
396 subvol_name ? subvol_name : "default");
c59f8951
CM
397 if (subvol_name)
398 kfree(subvol_name);
4b82d6e4 399 return ret;
2e635a27
CM
400}
401
8fd17795
CM
402static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
403{
404 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
4b52dff6 405 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
db94535d 406 int bits = dentry->d_sb->s_blocksize_bits;
8fd17795
CM
407
408 buf->f_namelen = BTRFS_NAME_LEN;
db94535d
CM
409 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
410 buf->f_bfree = buf->f_blocks -
411 (btrfs_super_bytes_used(disk_super) >> bits);
8fd17795
CM
412 buf->f_bavail = buf->f_bfree;
413 buf->f_bsize = dentry->d_sb->s_blocksize;
414 buf->f_type = BTRFS_SUPER_MAGIC;
415 return 0;
416}
b5133862 417
2e635a27
CM
418static struct file_system_type btrfs_fs_type = {
419 .owner = THIS_MODULE,
420 .name = "btrfs",
421 .get_sb = btrfs_get_sb,
422 .kill_sb = kill_block_super,
423 .fs_flags = FS_REQUIRES_DEV,
424};
425
e20d96d6 426static struct super_operations btrfs_super_ops = {
134e9731 427 .delete_inode = btrfs_delete_inode,
2da98f00 428 .put_inode = btrfs_put_inode,
e20d96d6
CM
429 .put_super = btrfs_put_super,
430 .read_inode = btrfs_read_locked_inode,
d5719762
CM
431 .write_super = btrfs_write_super,
432 .sync_fs = btrfs_sync_fs,
4730a4bc 433 .write_inode = btrfs_write_inode,
b5133862 434 .dirty_inode = btrfs_dirty_inode,
2c90e5d6
CM
435 .alloc_inode = btrfs_alloc_inode,
436 .destroy_inode = btrfs_destroy_inode,
8fd17795 437 .statfs = btrfs_statfs,
e20d96d6
CM
438};
439
2e635a27
CM
440static int __init init_btrfs_fs(void)
441{
2c90e5d6 442 int err;
58176a96
JB
443
444 err = btrfs_init_sysfs();
445 if (err)
446 return err;
447
08607c1b 448 btrfs_init_transaction_sys();
39279cc3 449 err = btrfs_init_cachep();
2c90e5d6 450 if (err)
2f4cbe64
WB
451 goto free_transaction_sys;
452 err = extent_map_init();
453 if (err)
454 goto free_cachep;
455
456 err = register_filesystem(&btrfs_fs_type);
457 if (err)
458 goto free_extent_map;
459 return 0;
460
461free_extent_map:
462 extent_map_exit();
463free_cachep:
464 btrfs_destroy_cachep();
465free_transaction_sys:
466 btrfs_exit_transaction_sys();
467 btrfs_exit_sysfs();
468 return err;
2e635a27
CM
469}
470
471static void __exit exit_btrfs_fs(void)
472{
08607c1b 473 btrfs_exit_transaction_sys();
39279cc3 474 btrfs_destroy_cachep();
a52d9a80 475 extent_map_exit();
2e635a27 476 unregister_filesystem(&btrfs_fs_type);
58176a96 477 btrfs_exit_sysfs();
2e635a27
CM
478}
479
480module_init(init_btrfs_fs)
481module_exit(exit_btrfs_fs)
482
483MODULE_LICENSE("GPL");