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>
40 #include "transaction.h"
41 #include "btrfs_inode.h"
43 #include "print-tree.h"
46 #define BTRFS_SUPER_MAGIC 0x9123683E
48 static struct super_operations btrfs_super_ops;
50 static void btrfs_put_super (struct super_block * sb)
52 struct btrfs_root *root = btrfs_sb(sb);
53 struct btrfs_fs_info *fs = root->fs_info;
56 ret = close_ctree(root);
58 printk("close ctree returns %d\n", ret);
60 btrfs_sysfs_del_super(fs);
65 Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent, Opt_err,
68 static match_table_t tokens = {
69 {Opt_subvol, "subvol=%s"},
70 {Opt_nodatasum, "nodatasum"},
71 {Opt_nodatacow, "nodatacow"},
72 {Opt_max_extent, "max_extent=%s"},
76 static unsigned long parse_size(char *str)
83 res = simple_strtoul(str, &end, 10);
101 static int parse_options (char * options,
102 struct btrfs_root *root,
106 struct btrfs_fs_info *info = NULL;
107 substring_t args[MAX_OPT_ARGS];
113 * strsep changes the string, duplicate it because parse_options
116 options = kstrdup(options, GFP_NOFS);
121 info = root->fs_info;
123 while ((p = strsep (&options, ",")) != NULL) {
128 token = match_token(p, tokens, args);
132 *subvol_name = match_strdup(&args[0]);
137 printk("btrfs: setting nodatacsum\n");
138 btrfs_set_opt(info->mount_opt, NODATASUM);
143 printk("btrfs: setting nodatacow\n");
144 btrfs_set_opt(info->mount_opt, NODATACOW);
145 btrfs_set_opt(info->mount_opt, NODATASUM);
150 char *num = match_strdup(&args[0]);
152 info->max_extent = parse_size(num);
155 info->max_extent = max_t(u64,
158 printk("btrfs: max_extent at %Lu\n",
171 static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
173 struct inode * inode;
174 struct dentry * root_dentry;
175 struct btrfs_super_block *disk_super;
176 struct btrfs_root *tree_root;
177 struct btrfs_inode *bi;
180 sb->s_maxbytes = MAX_LFS_FILESIZE;
181 sb->s_magic = BTRFS_SUPER_MAGIC;
182 sb->s_op = &btrfs_super_ops;
183 sb->s_xattr = btrfs_xattr_handlers;
186 tree_root = open_ctree(sb);
188 if (!tree_root || IS_ERR(tree_root)) {
189 printk("btrfs: open_ctree failed\n");
192 sb->s_fs_info = tree_root;
193 disk_super = &tree_root->fs_info->super_copy;
194 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
197 bi->location.objectid = inode->i_ino;
198 bi->location.offset = 0;
199 bi->root = tree_root;
201 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
207 if (inode->i_state & I_NEW) {
208 btrfs_read_locked_inode(inode);
209 unlock_new_inode(inode);
212 root_dentry = d_alloc_root(inode);
219 parse_options((char *)data, tree_root, NULL);
221 /* this does the super kobj at the same time */
222 err = btrfs_sysfs_add_super(tree_root->fs_info);
226 sb->s_root = root_dentry;
227 btrfs_transaction_queue_work(tree_root, HZ * 30);
231 close_ctree(tree_root);
235 static int btrfs_sync_fs(struct super_block *sb, int wait)
237 struct btrfs_trans_handle *trans;
238 struct btrfs_root *root;
244 filemap_flush(root->fs_info->btree_inode->i_mapping);
247 btrfs_clean_old_snapshots(root);
248 mutex_lock(&root->fs_info->fs_mutex);
249 btrfs_defrag_dirty_roots(root->fs_info);
250 trans = btrfs_start_transaction(root, 1);
251 ret = btrfs_commit_transaction(trans, root);
253 mutex_unlock(&root->fs_info->fs_mutex);
257 static void btrfs_write_super(struct super_block *sb)
263 * This is almost a copy of get_sb_bdev in fs/super.c.
264 * We need the local copy to allow direct mounting of
265 * subvolumes, but this could be easily integrated back
266 * into the generic version. --hch
269 /* start copy & paste */
270 static int set_bdev_super(struct super_block *s, void *data)
273 s->s_dev = s->s_bdev->bd_dev;
277 static int test_bdev_super(struct super_block *s, void *data)
279 return (void *)s->s_bdev == data;
282 int btrfs_get_sb_bdev(struct file_system_type *fs_type,
283 int flags, const char *dev_name, void *data,
284 int (*fill_super)(struct super_block *, void *, int),
285 struct vfsmount *mnt, const char *subvol)
287 struct block_device *bdev = NULL;
288 struct super_block *s;
292 bdev = open_bdev_excl(dev_name, flags, fs_type);
294 return PTR_ERR(bdev);
297 * once the super is inserted into the list by sget, s_umount
298 * will protect the lockfs code from trying to start a snapshot
299 * while we are mounting
301 down(&bdev->bd_mount_sem);
302 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
303 up(&bdev->bd_mount_sem);
308 if ((flags ^ s->s_flags) & MS_RDONLY) {
309 up_write(&s->s_umount);
315 close_bdev_excl(bdev);
317 char b[BDEVNAME_SIZE];
320 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
321 sb_set_blocksize(s, block_size(bdev));
322 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
324 up_write(&s->s_umount);
329 s->s_flags |= MS_ACTIVE;
333 root = lookup_one_len(subvol, s->s_root, strlen(subvol));
335 up_write(&s->s_umount);
337 error = PTR_ERR(root);
340 if (!root->d_inode) {
342 up_write(&s->s_umount);
348 root = dget(s->s_root);
352 mnt->mnt_root = root;
358 close_bdev_excl(bdev);
362 /* end copy & paste */
364 static int btrfs_get_sb(struct file_system_type *fs_type,
365 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
368 char *subvol_name = NULL;
370 parse_options((char *)data, NULL, &subvol_name);
371 ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
372 btrfs_fill_super, mnt,
373 subvol_name ? subvol_name : "default");
379 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
381 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
382 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
383 int bits = dentry->d_sb->s_blocksize_bits;
385 buf->f_namelen = BTRFS_NAME_LEN;
386 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
387 buf->f_bfree = buf->f_blocks -
388 (btrfs_super_bytes_used(disk_super) >> bits);
389 buf->f_bavail = buf->f_bfree;
390 buf->f_bsize = dentry->d_sb->s_blocksize;
391 buf->f_type = BTRFS_SUPER_MAGIC;
395 static struct file_system_type btrfs_fs_type = {
396 .owner = THIS_MODULE,
398 .get_sb = btrfs_get_sb,
399 .kill_sb = kill_block_super,
400 .fs_flags = FS_REQUIRES_DEV,
403 static struct super_operations btrfs_super_ops = {
404 .delete_inode = btrfs_delete_inode,
405 .put_super = btrfs_put_super,
406 .read_inode = btrfs_read_locked_inode,
407 .write_super = btrfs_write_super,
408 .sync_fs = btrfs_sync_fs,
409 .write_inode = btrfs_write_inode,
410 .dirty_inode = btrfs_dirty_inode,
411 .alloc_inode = btrfs_alloc_inode,
412 .destroy_inode = btrfs_destroy_inode,
413 .statfs = btrfs_statfs,
416 static int __init init_btrfs_fs(void)
420 err = btrfs_init_sysfs();
424 btrfs_init_transaction_sys();
425 err = btrfs_init_cachep();
427 goto free_transaction_sys;
428 err = extent_map_init();
432 err = register_filesystem(&btrfs_fs_type);
434 goto free_extent_map;
440 btrfs_destroy_cachep();
441 free_transaction_sys:
442 btrfs_exit_transaction_sys();
447 static void __exit exit_btrfs_fs(void)
449 btrfs_exit_transaction_sys();
450 btrfs_destroy_cachep();
452 unregister_filesystem(&btrfs_fs_type);
456 module_init(init_btrfs_fs)
457 module_exit(exit_btrfs_fs)
459 MODULE_LICENSE("GPL");