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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> |
95e05289 | 36 | #include <linux/parser.h> |
2e635a27 | 37 | #include "ctree.h" |
e20d96d6 | 38 | #include "disk-io.h" |
d5719762 | 39 | #include "transaction.h" |
2c90e5d6 | 40 | #include "btrfs_inode.h" |
c5739bba | 41 | #include "ioctl.h" |
3a686375 | 42 | #include "print-tree.h" |
2e635a27 | 43 | |
5f39d397 | 44 | #define BTRFS_SUPER_MAGIC 0x9123683E |
f254e52c | 45 | |
39279cc3 | 46 | static struct super_operations btrfs_super_ops; |
75dfe396 | 47 | |
39279cc3 | 48 | static void btrfs_put_super (struct super_block * sb) |
b18c6685 | 49 | { |
39279cc3 | 50 | struct btrfs_root *root = btrfs_sb(sb); |
58176a96 | 51 | struct btrfs_fs_info *fs = root->fs_info; |
b18c6685 | 52 | int ret; |
b18c6685 | 53 | |
39279cc3 CM |
54 | ret = close_ctree(root); |
55 | if (ret) { | |
56 | printk("close ctree returns %d\n", ret); | |
75dfe396 | 57 | } |
58176a96 | 58 | btrfs_sysfs_del_super(fs); |
39279cc3 | 59 | sb->s_fs_info = NULL; |
75dfe396 CM |
60 | } |
61 | ||
95e05289 CM |
62 | enum { |
63 | Opt_subvol, Opt_err, | |
64 | }; | |
65 | ||
66 | static match_table_t tokens = { | |
67 | {Opt_subvol, "subvol=%s"}, | |
68 | {Opt_err, NULL} | |
69 | }; | |
70 | ||
71 | static int parse_options (char * options, | |
72 | struct btrfs_root *root, | |
73 | char **subvol_name) | |
74 | { | |
75 | char * p; | |
76 | substring_t args[MAX_OPT_ARGS]; | |
77 | if (!options) | |
78 | return 1; | |
79 | ||
80 | while ((p = strsep (&options, ",")) != NULL) { | |
81 | int token; | |
82 | if (!*p) | |
83 | continue; | |
84 | ||
85 | token = match_token(p, tokens, args); | |
86 | switch (token) { | |
87 | case Opt_subvol: | |
88 | *subvol_name = match_strdup(&args[0]); | |
89 | break; | |
90 | default: | |
91 | return 0; | |
92 | } | |
93 | } | |
94 | return 1; | |
95 | } | |
96 | ||
39279cc3 | 97 | static int btrfs_fill_super(struct super_block * sb, void * data, int silent) |
75dfe396 | 98 | { |
39279cc3 CM |
99 | struct inode * inode; |
100 | struct dentry * root_dentry; | |
101 | struct btrfs_super_block *disk_super; | |
102 | struct btrfs_root *tree_root; | |
103 | struct btrfs_inode *bi; | |
104 | int err; | |
a429e513 | 105 | |
39279cc3 CM |
106 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
107 | sb->s_magic = BTRFS_SUPER_MAGIC; | |
108 | sb->s_op = &btrfs_super_ops; | |
109 | sb->s_time_gran = 1; | |
a429e513 | 110 | |
39279cc3 | 111 | tree_root = open_ctree(sb); |
6567e837 | 112 | |
39279cc3 CM |
113 | if (!tree_root || IS_ERR(tree_root)) { |
114 | printk("btrfs: open_ctree failed\n"); | |
115 | return -EIO; | |
a429e513 | 116 | } |
39279cc3 | 117 | sb->s_fs_info = tree_root; |
5f39d397 | 118 | disk_super = &tree_root->fs_info->super_copy; |
39279cc3 CM |
119 | inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super), |
120 | tree_root); | |
121 | bi = BTRFS_I(inode); | |
122 | bi->location.objectid = inode->i_ino; | |
123 | bi->location.offset = 0; | |
39279cc3 | 124 | bi->root = tree_root; |
b888db2b | 125 | |
39279cc3 | 126 | btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY); |
a429e513 | 127 | |
39279cc3 | 128 | if (!inode) { |
6567e837 | 129 | err = -ENOMEM; |
39279cc3 | 130 | goto fail_close; |
f254e52c | 131 | } |
39279cc3 CM |
132 | if (inode->i_state & I_NEW) { |
133 | btrfs_read_locked_inode(inode); | |
134 | unlock_new_inode(inode); | |
f254e52c | 135 | } |
f254e52c | 136 | |
39279cc3 CM |
137 | root_dentry = d_alloc_root(inode); |
138 | if (!root_dentry) { | |
139 | iput(inode); | |
140 | err = -ENOMEM; | |
141 | goto fail_close; | |
f254e52c | 142 | } |
58176a96 JB |
143 | |
144 | /* this does the super kobj at the same time */ | |
145 | err = btrfs_sysfs_add_super(tree_root->fs_info); | |
146 | if (err) | |
147 | goto fail_close; | |
148 | ||
39279cc3 CM |
149 | sb->s_root = root_dentry; |
150 | btrfs_transaction_queue_work(tree_root, HZ * 30); | |
2619ba1f | 151 | return 0; |
39279cc3 CM |
152 | |
153 | fail_close: | |
154 | close_ctree(tree_root); | |
155 | return err; | |
2619ba1f CM |
156 | } |
157 | ||
39279cc3 | 158 | static int btrfs_sync_fs(struct super_block *sb, int wait) |
c5739bba CM |
159 | { |
160 | struct btrfs_trans_handle *trans; | |
39279cc3 | 161 | struct btrfs_root *root; |
c5739bba | 162 | int ret; |
39279cc3 | 163 | root = btrfs_sb(sb); |
2619ba1f | 164 | |
39279cc3 CM |
165 | sb->s_dirt = 0; |
166 | if (!wait) { | |
167 | filemap_flush(root->fs_info->btree_inode->i_mapping); | |
168 | return 0; | |
169 | } | |
e9d0b13b | 170 | btrfs_clean_old_snapshots(root); |
c5739bba | 171 | mutex_lock(&root->fs_info->fs_mutex); |
e9d0b13b | 172 | btrfs_defrag_dirty_roots(root->fs_info); |
c5739bba | 173 | trans = btrfs_start_transaction(root, 1); |
c5739bba | 174 | ret = btrfs_commit_transaction(trans, root); |
39279cc3 | 175 | sb->s_dirt = 0; |
c5739bba | 176 | mutex_unlock(&root->fs_info->fs_mutex); |
54aa1f4d | 177 | return ret; |
2c90e5d6 CM |
178 | } |
179 | ||
39279cc3 | 180 | static void btrfs_write_super(struct super_block *sb) |
2c90e5d6 | 181 | { |
39279cc3 | 182 | sb->s_dirt = 0; |
2c90e5d6 CM |
183 | } |
184 | ||
4b82d6e4 Y |
185 | /* |
186 | * This is almost a copy of get_sb_bdev in fs/super.c. | |
187 | * We need the local copy to allow direct mounting of | |
188 | * subvolumes, but this could be easily integrated back | |
189 | * into the generic version. --hch | |
190 | */ | |
191 | ||
192 | /* start copy & paste */ | |
193 | static int set_bdev_super(struct super_block *s, void *data) | |
194 | { | |
195 | s->s_bdev = data; | |
196 | s->s_dev = s->s_bdev->bd_dev; | |
197 | return 0; | |
198 | } | |
199 | ||
200 | static int test_bdev_super(struct super_block *s, void *data) | |
201 | { | |
202 | return (void *)s->s_bdev == data; | |
203 | } | |
204 | ||
205 | int btrfs_get_sb_bdev(struct file_system_type *fs_type, | |
206 | int flags, const char *dev_name, void *data, | |
207 | int (*fill_super)(struct super_block *, void *, int), | |
208 | struct vfsmount *mnt, const char *subvol) | |
209 | { | |
210 | struct block_device *bdev = NULL; | |
211 | struct super_block *s; | |
212 | struct dentry *root; | |
213 | int error = 0; | |
214 | ||
215 | bdev = open_bdev_excl(dev_name, flags, fs_type); | |
216 | if (IS_ERR(bdev)) | |
217 | return PTR_ERR(bdev); | |
218 | ||
219 | /* | |
220 | * once the super is inserted into the list by sget, s_umount | |
221 | * will protect the lockfs code from trying to start a snapshot | |
222 | * while we are mounting | |
223 | */ | |
224 | down(&bdev->bd_mount_sem); | |
225 | s = sget(fs_type, test_bdev_super, set_bdev_super, bdev); | |
226 | up(&bdev->bd_mount_sem); | |
227 | if (IS_ERR(s)) | |
228 | goto error_s; | |
229 | ||
230 | if (s->s_root) { | |
231 | if ((flags ^ s->s_flags) & MS_RDONLY) { | |
232 | up_write(&s->s_umount); | |
233 | deactivate_super(s); | |
234 | error = -EBUSY; | |
235 | goto error_bdev; | |
236 | } | |
237 | ||
238 | close_bdev_excl(bdev); | |
239 | } else { | |
240 | char b[BDEVNAME_SIZE]; | |
241 | ||
242 | s->s_flags = flags; | |
243 | strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); | |
244 | sb_set_blocksize(s, block_size(bdev)); | |
245 | error = fill_super(s, data, flags & MS_SILENT ? 1 : 0); | |
246 | if (error) { | |
247 | up_write(&s->s_umount); | |
248 | deactivate_super(s); | |
249 | goto error; | |
250 | } | |
251 | ||
252 | s->s_flags |= MS_ACTIVE; | |
253 | } | |
254 | ||
255 | if (subvol) { | |
256 | root = lookup_one_len(subvol, s->s_root, strlen(subvol)); | |
257 | if (IS_ERR(root)) { | |
258 | up_write(&s->s_umount); | |
259 | deactivate_super(s); | |
260 | error = PTR_ERR(root); | |
261 | goto error; | |
262 | } | |
263 | if (!root->d_inode) { | |
264 | dput(root); | |
265 | up_write(&s->s_umount); | |
266 | deactivate_super(s); | |
267 | error = -ENXIO; | |
268 | goto error; | |
269 | } | |
270 | } else { | |
271 | root = dget(s->s_root); | |
272 | } | |
273 | ||
274 | mnt->mnt_sb = s; | |
275 | mnt->mnt_root = root; | |
276 | return 0; | |
277 | ||
278 | error_s: | |
279 | error = PTR_ERR(s); | |
280 | error_bdev: | |
281 | close_bdev_excl(bdev); | |
282 | error: | |
283 | return error; | |
284 | } | |
285 | /* end copy & paste */ | |
286 | ||
2e635a27 | 287 | static int btrfs_get_sb(struct file_system_type *fs_type, |
95e05289 | 288 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
2e635a27 | 289 | { |
4b82d6e4 | 290 | int ret; |
95e05289 | 291 | char *subvol_name = NULL; |
4b82d6e4 | 292 | |
95e05289 | 293 | parse_options((char *)data, NULL, &subvol_name); |
4b82d6e4 Y |
294 | ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data, |
295 | btrfs_fill_super, mnt, | |
296 | subvol_name ? subvol_name : "default"); | |
4b82d6e4 | 297 | return ret; |
2e635a27 CM |
298 | } |
299 | ||
8fd17795 CM |
300 | static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
301 | { | |
302 | struct btrfs_root *root = btrfs_sb(dentry->d_sb); | |
4b52dff6 | 303 | struct btrfs_super_block *disk_super = &root->fs_info->super_copy; |
db94535d | 304 | int bits = dentry->d_sb->s_blocksize_bits; |
8fd17795 CM |
305 | |
306 | buf->f_namelen = BTRFS_NAME_LEN; | |
db94535d CM |
307 | buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; |
308 | buf->f_bfree = buf->f_blocks - | |
309 | (btrfs_super_bytes_used(disk_super) >> bits); | |
8fd17795 CM |
310 | buf->f_bavail = buf->f_bfree; |
311 | buf->f_bsize = dentry->d_sb->s_blocksize; | |
312 | buf->f_type = BTRFS_SUPER_MAGIC; | |
313 | return 0; | |
314 | } | |
b5133862 | 315 | |
2e635a27 CM |
316 | static struct file_system_type btrfs_fs_type = { |
317 | .owner = THIS_MODULE, | |
318 | .name = "btrfs", | |
319 | .get_sb = btrfs_get_sb, | |
320 | .kill_sb = kill_block_super, | |
321 | .fs_flags = FS_REQUIRES_DEV, | |
322 | }; | |
323 | ||
e20d96d6 | 324 | static struct super_operations btrfs_super_ops = { |
134e9731 | 325 | .delete_inode = btrfs_delete_inode, |
e20d96d6 CM |
326 | .put_super = btrfs_put_super, |
327 | .read_inode = btrfs_read_locked_inode, | |
d5719762 CM |
328 | .write_super = btrfs_write_super, |
329 | .sync_fs = btrfs_sync_fs, | |
4730a4bc | 330 | .write_inode = btrfs_write_inode, |
b5133862 | 331 | .dirty_inode = btrfs_dirty_inode, |
2c90e5d6 CM |
332 | .alloc_inode = btrfs_alloc_inode, |
333 | .destroy_inode = btrfs_destroy_inode, | |
8fd17795 | 334 | .statfs = btrfs_statfs, |
e20d96d6 CM |
335 | }; |
336 | ||
2e635a27 CM |
337 | static int __init init_btrfs_fs(void) |
338 | { | |
2c90e5d6 | 339 | int err; |
58176a96 JB |
340 | |
341 | err = btrfs_init_sysfs(); | |
342 | if (err) | |
343 | return err; | |
344 | ||
08607c1b | 345 | btrfs_init_transaction_sys(); |
39279cc3 | 346 | err = btrfs_init_cachep(); |
2c90e5d6 CM |
347 | if (err) |
348 | return err; | |
a52d9a80 | 349 | extent_map_init(); |
2e635a27 CM |
350 | return register_filesystem(&btrfs_fs_type); |
351 | } | |
352 | ||
353 | static void __exit exit_btrfs_fs(void) | |
354 | { | |
08607c1b | 355 | btrfs_exit_transaction_sys(); |
39279cc3 | 356 | btrfs_destroy_cachep(); |
a52d9a80 | 357 | extent_map_exit(); |
2e635a27 | 358 | unregister_filesystem(&btrfs_fs_type); |
58176a96 | 359 | btrfs_exit_sysfs(); |
2e635a27 CM |
360 | } |
361 | ||
362 | module_init(init_btrfs_fs) | |
363 | module_exit(exit_btrfs_fs) | |
364 | ||
365 | MODULE_LICENSE("GPL"); |