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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> |
2e635a27 | 36 | #include "ctree.h" |
e20d96d6 | 37 | #include "disk-io.h" |
d5719762 | 38 | #include "transaction.h" |
2c90e5d6 | 39 | #include "btrfs_inode.h" |
c5739bba | 40 | #include "ioctl.h" |
3a686375 | 41 | #include "print-tree.h" |
2e635a27 | 42 | |
39279cc3 | 43 | #define BTRFS_SUPER_MAGIC 0x9123682E |
f254e52c | 44 | |
39279cc3 | 45 | static struct super_operations btrfs_super_ops; |
75dfe396 | 46 | |
39279cc3 | 47 | static void btrfs_put_super (struct super_block * sb) |
b18c6685 | 48 | { |
39279cc3 | 49 | struct btrfs_root *root = btrfs_sb(sb); |
58176a96 | 50 | struct btrfs_fs_info *fs = root->fs_info; |
b18c6685 | 51 | int ret; |
b18c6685 | 52 | |
39279cc3 CM |
53 | ret = close_ctree(root); |
54 | if (ret) { | |
55 | printk("close ctree returns %d\n", ret); | |
75dfe396 | 56 | } |
58176a96 | 57 | btrfs_sysfs_del_super(fs); |
39279cc3 | 58 | sb->s_fs_info = NULL; |
75dfe396 CM |
59 | } |
60 | ||
39279cc3 | 61 | static int btrfs_fill_super(struct super_block * sb, void * data, int silent) |
75dfe396 | 62 | { |
39279cc3 CM |
63 | struct inode * inode; |
64 | struct dentry * root_dentry; | |
65 | struct btrfs_super_block *disk_super; | |
66 | struct btrfs_root *tree_root; | |
67 | struct btrfs_inode *bi; | |
68 | int err; | |
a429e513 | 69 | |
39279cc3 CM |
70 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
71 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
72 | sb->s_op = &btrfs_super_ops; | |
73 | sb->s_time_gran = 1; | |
a429e513 | 74 | |
39279cc3 | 75 | tree_root = open_ctree(sb); |
6567e837 | 76 | |
39279cc3 CM |
77 | if (!tree_root || IS_ERR(tree_root)) { |
78 | printk("btrfs: open_ctree failed\n"); | |
79 | return -EIO; | |
a429e513 | 80 | } |
39279cc3 CM |
81 | sb->s_fs_info = tree_root; |
82 | disk_super = tree_root->fs_info->disk_super; | |
83 | inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super), | |
84 | tree_root); | |
85 | bi = BTRFS_I(inode); | |
86 | bi->location.objectid = inode->i_ino; | |
87 | bi->location.offset = 0; | |
88 | bi->location.flags = 0; | |
89 | bi->root = tree_root; | |
b888db2b | 90 | |
39279cc3 | 91 | btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); |
a429e513 | 92 | |
39279cc3 | 93 | if (!inode) { |
6567e837 | 94 | err = -ENOMEM; |
39279cc3 | 95 | goto fail_close; |
f254e52c | 96 | } |
39279cc3 CM |
97 | if (inode->i_state & I_NEW) { |
98 | btrfs_read_locked_inode(inode); | |
99 | unlock_new_inode(inode); | |
f254e52c | 100 | } |
f254e52c | 101 | |
39279cc3 CM |
102 | root_dentry = d_alloc_root(inode); |
103 | if (!root_dentry) { | |
104 | iput(inode); | |
105 | err = -ENOMEM; | |
106 | goto fail_close; | |
f254e52c | 107 | } |
58176a96 JB |
108 | |
109 | /* this does the super kobj at the same time */ | |
110 | err = btrfs_sysfs_add_super(tree_root->fs_info); | |
111 | if (err) | |
112 | goto fail_close; | |
113 | ||
39279cc3 CM |
114 | sb->s_root = root_dentry; |
115 | btrfs_transaction_queue_work(tree_root, HZ * 30); | |
2619ba1f | 116 | return 0; |
39279cc3 CM |
117 | |
118 | fail_close: | |
119 | close_ctree(tree_root); | |
120 | return err; | |
2619ba1f CM |
121 | } |
122 | ||
39279cc3 | 123 | static int btrfs_sync_fs(struct super_block *sb, int wait) |
c5739bba CM |
124 | { |
125 | struct btrfs_trans_handle *trans; | |
39279cc3 | 126 | struct btrfs_root *root; |
c5739bba | 127 | int ret; |
39279cc3 | 128 | root = btrfs_sb(sb); |
2619ba1f | 129 | |
39279cc3 CM |
130 | sb->s_dirt = 0; |
131 | if (!wait) { | |
132 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
133 | return 0; | |
134 | } | |
e9d0b13b | 135 | btrfs_clean_old_snapshots(root); |
c5739bba | 136 | mutex_lock(&root->fs_info->fs_mutex); |
e9d0b13b | 137 | btrfs_defrag_dirty_roots(root->fs_info); |
c5739bba | 138 | trans = btrfs_start_transaction(root, 1); |
c5739bba | 139 | ret = btrfs_commit_transaction(trans, root); |
39279cc3 | 140 | sb->s_dirt = 0; |
c5739bba | 141 | mutex_unlock(&root->fs_info->fs_mutex); |
54aa1f4d | 142 | return ret; |
2c90e5d6 CM |
143 | } |
144 | ||
39279cc3 | 145 | static void btrfs_write_super(struct super_block *sb) |
2c90e5d6 | 146 | { |
39279cc3 | 147 | sb->s_dirt = 0; |
2c90e5d6 CM |
148 | } |
149 | ||
4b82d6e4 Y |
150 | /* |
151 | * This is almost a copy of get_sb_bdev in fs/super.c. | |
152 | * We need the local copy to allow direct mounting of | |
153 | * subvolumes, but this could be easily integrated back | |
154 | * into the generic version. --hch | |
155 | */ | |
156 | ||
157 | /* start copy & paste */ | |
158 | static int set_bdev_super(struct super_block *s, void *data) | |
159 | { | |
160 | s->s_bdev = data; | |
161 | s->s_dev = s->s_bdev->bd_dev; | |
162 | return 0; | |
163 | } | |
164 | ||
165 | static int test_bdev_super(struct super_block *s, void *data) | |
166 | { | |
167 | return (void *)s->s_bdev == data; | |
168 | } | |
169 | ||
170 | int btrfs_get_sb_bdev(struct file_system_type *fs_type, | |
171 | int flags, const char *dev_name, void *data, | |
172 | int (*fill_super)(struct super_block *, void *, int), | |
173 | struct vfsmount *mnt, const char *subvol) | |
174 | { | |
175 | struct block_device *bdev = NULL; | |
176 | struct super_block *s; | |
177 | struct dentry *root; | |
178 | int error = 0; | |
179 | ||
180 | bdev = open_bdev_excl(dev_name, flags, fs_type); | |
181 | if (IS_ERR(bdev)) | |
182 | return PTR_ERR(bdev); | |
183 | ||
184 | /* | |
185 | * once the super is inserted into the list by sget, s_umount | |
186 | * will protect the lockfs code from trying to start a snapshot | |
187 | * while we are mounting | |
188 | */ | |
189 | down(&bdev->bd_mount_sem); | |
190 | s = sget(fs_type, test_bdev_super, set_bdev_super, bdev); | |
191 | up(&bdev->bd_mount_sem); | |
192 | if (IS_ERR(s)) | |
193 | goto error_s; | |
194 | ||
195 | if (s->s_root) { | |
196 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
197 | up_write(&s->s_umount); | |
198 | deactivate_super(s); | |
199 | error = -EBUSY; | |
200 | goto error_bdev; | |
201 | } | |
202 | ||
203 | close_bdev_excl(bdev); | |
204 | } else { | |
205 | char b[BDEVNAME_SIZE]; | |
206 | ||
207 | s->s_flags = flags; | |
208 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); | |
209 | sb_set_blocksize(s, block_size(bdev)); | |
210 | error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); | |
211 | if (error) { | |
212 | up_write(&s->s_umount); | |
213 | deactivate_super(s); | |
214 | goto error; | |
215 | } | |
216 | ||
217 | s->s_flags |= MS_ACTIVE; | |
218 | } | |
219 | ||
220 | if (subvol) { | |
221 | root = lookup_one_len(subvol, s->s_root, strlen(subvol)); | |
222 | if (IS_ERR(root)) { | |
223 | up_write(&s->s_umount); | |
224 | deactivate_super(s); | |
225 | error = PTR_ERR(root); | |
226 | goto error; | |
227 | } | |
228 | if (!root->d_inode) { | |
229 | dput(root); | |
230 | up_write(&s->s_umount); | |
231 | deactivate_super(s); | |
232 | error = -ENXIO; | |
233 | goto error; | |
234 | } | |
235 | } else { | |
236 | root = dget(s->s_root); | |
237 | } | |
238 | ||
239 | mnt->mnt_sb = s; | |
240 | mnt->mnt_root = root; | |
241 | return 0; | |
242 | ||
243 | error_s: | |
244 | error = PTR_ERR(s); | |
245 | error_bdev: | |
246 | close_bdev_excl(bdev); | |
247 | error: | |
248 | return error; | |
249 | } | |
250 | /* end copy & paste */ | |
251 | ||
2e635a27 | 252 | static int btrfs_get_sb(struct file_system_type *fs_type, |
4b82d6e4 | 253 | int flags, const char *identifier, void *data, struct vfsmount *mnt) |
2e635a27 | 254 | { |
4b82d6e4 Y |
255 | int ret; |
256 | char *_identifier = kstrdup(identifier, GFP_KERNEL); | |
257 | char *subvol_name; | |
258 | const char *dev_name; | |
259 | ||
260 | subvol_name = _identifier; | |
261 | dev_name = strsep(&subvol_name, ":"); | |
262 | if (!dev_name) | |
263 | return -ENOMEM; | |
264 | ||
265 | ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data, | |
266 | btrfs_fill_super, mnt, | |
267 | subvol_name ? subvol_name : "default"); | |
268 | kfree(_identifier); | |
269 | return ret; | |
2e635a27 CM |
270 | } |
271 | ||
8fd17795 CM |
272 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
273 | { | |
274 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
4b52dff6 | 275 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; |
8fd17795 CM |
276 | |
277 | buf->f_namelen = BTRFS_NAME_LEN; | |
278 | buf->f_blocks = btrfs_super_total_blocks(disk_super); | |
279 | buf->f_bfree = buf->f_blocks - btrfs_super_blocks_used(disk_super); | |
280 | buf->f_bavail = buf->f_bfree; | |
281 | buf->f_bsize = dentry->d_sb->s_blocksize; | |
282 | buf->f_type = BTRFS_SUPER_MAGIC; | |
283 | return 0; | |
284 | } | |
b5133862 | 285 | |
2e635a27 CM |
286 | static struct file_system_type btrfs_fs_type = { |
287 | .owner = THIS_MODULE, | |
288 | .name = "btrfs", | |
289 | .get_sb = btrfs_get_sb, | |
290 | .kill_sb = kill_block_super, | |
291 | .fs_flags = FS_REQUIRES_DEV, | |
292 | }; | |
293 | ||
e20d96d6 | 294 | static struct super_operations btrfs_super_ops = { |
134e9731 | 295 | .delete_inode = btrfs_delete_inode, |
e20d96d6 CM |
296 | .put_super = btrfs_put_super, |
297 | .read_inode = btrfs_read_locked_inode, | |
d5719762 CM |
298 | .write_super = btrfs_write_super, |
299 | .sync_fs = btrfs_sync_fs, | |
4730a4bc | 300 | .write_inode = btrfs_write_inode, |
b5133862 | 301 | .dirty_inode = btrfs_dirty_inode, |
2c90e5d6 CM |
302 | .alloc_inode = btrfs_alloc_inode, |
303 | .destroy_inode = btrfs_destroy_inode, | |
8fd17795 | 304 | .statfs = btrfs_statfs, |
e20d96d6 CM |
305 | }; |
306 | ||
2e635a27 CM |
307 | static int __init init_btrfs_fs(void) |
308 | { | |
2c90e5d6 | 309 | int err; |
58176a96 JB |
310 | |
311 | err = btrfs_init_sysfs(); | |
312 | if (err) | |
313 | return err; | |
314 | ||
08607c1b | 315 | btrfs_init_transaction_sys(); |
39279cc3 | 316 | err = btrfs_init_cachep(); |
2c90e5d6 CM |
317 | if (err) |
318 | return err; | |
a52d9a80 | 319 | extent_map_init(); |
2e635a27 CM |
320 | return register_filesystem(&btrfs_fs_type); |
321 | } | |
322 | ||
323 | static void __exit exit_btrfs_fs(void) | |
324 | { | |
08607c1b | 325 | btrfs_exit_transaction_sys(); |
39279cc3 | 326 | btrfs_destroy_cachep(); |
a52d9a80 | 327 | extent_map_exit(); |
2e635a27 | 328 | unregister_filesystem(&btrfs_fs_type); |
58176a96 | 329 | btrfs_exit_sysfs(); |
2e635a27 CM |
330 | } |
331 | ||
332 | module_init(init_btrfs_fs) | |
333 | module_exit(exit_btrfs_fs) | |
334 | ||
335 | MODULE_LICENSE("GPL"); |