2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.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>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
41 #include "transaction.h"
42 #include "btrfs_inode.h"
44 #include "print-tree.h"
47 #define BTRFS_SUPER_MAGIC 0x9123683E
49 static struct super_operations btrfs_super_ops;
51 static void btrfs_put_super (struct super_block * sb)
53 struct btrfs_root *root = btrfs_sb(sb);
54 struct btrfs_fs_info *fs = root->fs_info;
57 ret = close_ctree(root);
59 printk("close ctree returns %d\n", ret);
61 btrfs_sysfs_del_super(fs);
66 Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent,
67 Opt_alloc_start, Opt_nobarrier, Opt_err,
70 static match_table_t tokens = {
71 {Opt_subvol, "subvol=%s"},
72 {Opt_nodatasum, "nodatasum"},
73 {Opt_nodatacow, "nodatacow"},
74 {Opt_nobarrier, "nobarrier"},
75 {Opt_max_extent, "max_extent=%s"},
76 {Opt_alloc_start, "alloc_start=%s"},
80 u64 btrfs_parse_size(char *str)
87 res = simple_strtoul(str, &end, 10);
105 static int parse_options (char * options,
106 struct btrfs_root *root,
110 struct btrfs_fs_info *info = NULL;
111 substring_t args[MAX_OPT_ARGS];
117 * strsep changes the string, duplicate it because parse_options
120 options = kstrdup(options, GFP_NOFS);
125 info = root->fs_info;
127 while ((p = strsep (&options, ",")) != NULL) {
132 token = match_token(p, tokens, args);
136 *subvol_name = match_strdup(&args[0]);
141 printk("btrfs: setting nodatacsum\n");
142 btrfs_set_opt(info->mount_opt, NODATASUM);
147 printk("btrfs: setting nodatacow\n");
148 btrfs_set_opt(info->mount_opt, NODATACOW);
149 btrfs_set_opt(info->mount_opt, NODATASUM);
154 printk("btrfs: turning off barriers\n");
155 btrfs_set_opt(info->mount_opt, NOBARRIER);
160 char *num = match_strdup(&args[0]);
163 btrfs_parse_size(num);
166 info->max_extent = max_t(u64,
169 printk("btrfs: max_extent at %Lu\n",
174 case Opt_alloc_start:
176 char *num = match_strdup(&args[0]);
179 btrfs_parse_size(num);
181 printk("btrfs: allocations start at "
182 "%Lu\n", info->alloc_start);
194 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
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;
203 sb->s_maxbytes = MAX_LFS_FILESIZE;
204 sb->s_magic = BTRFS_SUPER_MAGIC;
205 sb->s_op = &btrfs_super_ops;
206 sb->s_xattr = btrfs_xattr_handlers;
209 tree_root = open_ctree(sb);
211 if (!tree_root || IS_ERR(tree_root)) {
212 printk("btrfs: open_ctree failed\n");
215 sb->s_fs_info = tree_root;
216 disk_super = &tree_root->fs_info->super_copy;
217 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
220 bi->location.objectid = inode->i_ino;
221 bi->location.offset = 0;
222 bi->root = tree_root;
224 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
230 if (inode->i_state & I_NEW) {
231 btrfs_read_locked_inode(inode);
232 unlock_new_inode(inode);
235 root_dentry = d_alloc_root(inode);
242 parse_options((char *)data, tree_root, NULL);
244 /* this does the super kobj at the same time */
245 err = btrfs_sysfs_add_super(tree_root->fs_info);
249 sb->s_root = root_dentry;
250 btrfs_transaction_queue_work(tree_root, HZ * 30);
254 close_ctree(tree_root);
258 static int btrfs_sync_fs(struct super_block *sb, int wait)
260 struct btrfs_trans_handle *trans;
261 struct btrfs_root *root;
267 filemap_flush(root->fs_info->btree_inode->i_mapping);
270 btrfs_clean_old_snapshots(root);
271 mutex_lock(&root->fs_info->fs_mutex);
272 btrfs_defrag_dirty_roots(root->fs_info);
273 trans = btrfs_start_transaction(root, 1);
274 ret = btrfs_commit_transaction(trans, root);
276 mutex_unlock(&root->fs_info->fs_mutex);
280 static void btrfs_write_super(struct super_block *sb)
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
292 /* start copy & paste */
293 static int set_bdev_super(struct super_block *s, void *data)
296 s->s_dev = s->s_bdev->bd_dev;
300 static int test_bdev_super(struct super_block *s, void *data)
302 return (void *)s->s_bdev == data;
305 int 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)
310 struct block_device *bdev = NULL;
311 struct super_block *s;
315 bdev = open_bdev_excl(dev_name, flags, fs_type);
317 return PTR_ERR(bdev);
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
324 down(&bdev->bd_mount_sem);
325 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
326 up(&bdev->bd_mount_sem);
331 if ((flags ^ s->s_flags) & MS_RDONLY) {
332 up_write(&s->s_umount);
338 close_bdev_excl(bdev);
340 char b[BDEVNAME_SIZE];
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);
347 up_write(&s->s_umount);
352 s->s_flags |= MS_ACTIVE;
356 root = lookup_one_len(subvol, s->s_root, strlen(subvol));
358 up_write(&s->s_umount);
360 error = PTR_ERR(root);
363 if (!root->d_inode) {
365 up_write(&s->s_umount);
371 root = dget(s->s_root);
375 mnt->mnt_root = root;
381 close_bdev_excl(bdev);
385 /* end copy & paste */
387 static int btrfs_get_sb(struct file_system_type *fs_type,
388 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
391 char *subvol_name = NULL;
393 parse_options((char *)data, NULL, &subvol_name);
394 ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
395 btrfs_fill_super, mnt,
396 subvol_name ? subvol_name : "default");
402 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
404 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
405 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
406 int bits = dentry->d_sb->s_blocksize_bits;
408 buf->f_namelen = BTRFS_NAME_LEN;
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);
412 buf->f_bavail = buf->f_bfree;
413 buf->f_bsize = dentry->d_sb->s_blocksize;
414 buf->f_type = BTRFS_SUPER_MAGIC;
418 static struct file_system_type btrfs_fs_type = {
419 .owner = THIS_MODULE,
421 .get_sb = btrfs_get_sb,
422 .kill_sb = kill_block_super,
423 .fs_flags = FS_REQUIRES_DEV,
426 static struct super_operations btrfs_super_ops = {
427 .delete_inode = btrfs_delete_inode,
428 .put_super = btrfs_put_super,
429 .read_inode = btrfs_read_locked_inode,
430 .write_super = btrfs_write_super,
431 .sync_fs = btrfs_sync_fs,
432 .write_inode = btrfs_write_inode,
433 .dirty_inode = btrfs_dirty_inode,
434 .alloc_inode = btrfs_alloc_inode,
435 .destroy_inode = btrfs_destroy_inode,
436 .statfs = btrfs_statfs,
439 static int __init init_btrfs_fs(void)
443 err = btrfs_init_sysfs();
447 btrfs_init_transaction_sys();
448 err = btrfs_init_cachep();
450 goto free_transaction_sys;
451 err = extent_map_init();
455 err = register_filesystem(&btrfs_fs_type);
457 goto free_extent_map;
463 btrfs_destroy_cachep();
464 free_transaction_sys:
465 btrfs_exit_transaction_sys();
470 static void __exit exit_btrfs_fs(void)
472 btrfs_exit_transaction_sys();
473 btrfs_destroy_cachep();
475 unregister_filesystem(&btrfs_fs_type);
479 module_init(init_btrfs_fs)
480 module_exit(exit_btrfs_fs)
482 MODULE_LICENSE("GPL");