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>
39 #include <linux/miscdevice.h>
42 #include "transaction.h"
43 #include "btrfs_inode.h"
45 #include "print-tree.h"
49 #define BTRFS_SUPER_MAGIC 0x9123683E
51 static struct super_operations btrfs_super_ops;
53 static void btrfs_put_super (struct super_block * sb)
55 struct btrfs_root *root = btrfs_sb(sb);
56 struct btrfs_fs_info *fs = root->fs_info;
59 ret = close_ctree(root);
61 printk("close ctree returns %d\n", ret);
63 btrfs_sysfs_del_super(fs);
68 Opt_degraded, Opt_subvol, Opt_nodatasum, Opt_nodatacow,
69 Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
73 static match_table_t tokens = {
74 {Opt_degraded, "degraded"},
75 {Opt_subvol, "subvol=%s"},
76 {Opt_nodatasum, "nodatasum"},
77 {Opt_nodatacow, "nodatacow"},
78 {Opt_nobarrier, "nobarrier"},
79 {Opt_max_extent, "max_extent=%s"},
80 {Opt_max_inline, "max_inline=%s"},
81 {Opt_alloc_start, "alloc_start=%s"},
86 u64 btrfs_parse_size(char *str)
93 res = simple_strtoul(str, &end, 10);
112 * Regular mount options parser. Everything that is needed only when
113 * reading in a new superblock is parsed here.
115 int btrfs_parse_options(struct btrfs_root *root, char *options)
117 struct btrfs_fs_info *info = root->fs_info;
118 substring_t args[MAX_OPT_ARGS];
125 * strsep changes the string, duplicate it because parse_options
128 options = kstrdup(options, GFP_NOFS);
133 while ((p = strsep(&options, ",")) != NULL) {
138 token = match_token(p, tokens, args);
141 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
142 btrfs_set_opt(info->mount_opt, DEGRADED);
146 * This one is parsed by btrfs_parse_early_options
147 * and can be happily ignored here.
151 printk(KERN_INFO "btrfs: setting nodatacsum\n");
152 btrfs_set_opt(info->mount_opt, NODATASUM);
155 printk(KERN_INFO "btrfs: setting nodatacow\n");
156 btrfs_set_opt(info->mount_opt, NODATACOW);
157 btrfs_set_opt(info->mount_opt, NODATASUM);
160 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
161 btrfs_set_opt(info->mount_opt, SSD);
164 printk(KERN_INFO "btrfs: turning off barriers\n");
165 btrfs_set_opt(info->mount_opt, NOBARRIER);
168 num = match_strdup(&args[0]);
170 info->max_extent = btrfs_parse_size(num);
173 info->max_extent = max_t(u64,
174 info->max_extent, root->sectorsize);
175 printk(KERN_INFO "btrfs: max_extent at %llu\n",
180 num = match_strdup(&args[0]);
182 info->max_inline = btrfs_parse_size(num);
185 info->max_inline = max_t(u64,
186 info->max_inline, root->sectorsize);
187 printk(KERN_INFO "btrfs: max_inline at %llu\n",
191 case Opt_alloc_start:
192 num = match_strdup(&args[0]);
194 info->alloc_start = btrfs_parse_size(num);
197 "btrfs: allocations start at %llu\n",
210 * Parse mount options that are required early in the mount process.
212 * All other options will be parsed on much later in the mount process and
213 * only when we need to allocate a new super block.
215 static int btrfs_parse_early_options(const char *options,
218 substring_t args[MAX_OPT_ARGS];
226 * strsep changes the string, duplicate it because parse_options
229 opts = kstrdup(options, GFP_KERNEL);
233 while ((p = strsep(&opts, ",")) != NULL) {
238 token = match_token(p, tokens, args);
241 *subvol_name = match_strdup(&args[0]);
251 * If no subvolume name is specified we use the default one. Allocate
252 * a copy of the string "default" here so that code later in the
253 * mount path doesn't care if it's the default volume or another one.
256 *subvol_name = kstrdup("default", GFP_KERNEL);
263 static int btrfs_fill_super(struct super_block * sb,
264 struct btrfs_fs_devices *fs_devices,
265 void * data, int silent)
267 struct inode * inode;
268 struct dentry * root_dentry;
269 struct btrfs_super_block *disk_super;
270 struct btrfs_root *tree_root;
271 struct btrfs_inode *bi;
274 sb->s_maxbytes = MAX_LFS_FILESIZE;
275 sb->s_magic = BTRFS_SUPER_MAGIC;
276 sb->s_op = &btrfs_super_ops;
277 sb->s_xattr = btrfs_xattr_handlers;
280 tree_root = open_ctree(sb, fs_devices, (char *)data);
282 if (IS_ERR(tree_root)) {
283 printk("btrfs: open_ctree failed\n");
284 return PTR_ERR(tree_root);
286 sb->s_fs_info = tree_root;
287 disk_super = &tree_root->fs_info->super_copy;
288 inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
291 bi->location.objectid = inode->i_ino;
292 bi->location.offset = 0;
293 bi->root = tree_root;
295 btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
301 if (inode->i_state & I_NEW) {
302 btrfs_read_locked_inode(inode);
303 unlock_new_inode(inode);
306 root_dentry = d_alloc_root(inode);
313 /* this does the super kobj at the same time */
314 err = btrfs_sysfs_add_super(tree_root->fs_info);
318 sb->s_root = root_dentry;
319 btrfs_transaction_queue_work(tree_root, HZ * 30);
321 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
322 save_mount_options(sb, data);
328 close_ctree(tree_root);
332 int btrfs_sync_fs(struct super_block *sb, int wait)
334 struct btrfs_trans_handle *trans;
335 struct btrfs_root *root;
341 filemap_flush(root->fs_info->btree_inode->i_mapping);
344 btrfs_clean_old_snapshots(root);
345 mutex_lock(&root->fs_info->fs_mutex);
346 btrfs_defrag_dirty_roots(root->fs_info);
347 trans = btrfs_start_transaction(root, 1);
348 ret = btrfs_commit_transaction(trans, root);
350 mutex_unlock(&root->fs_info->fs_mutex);
354 static void btrfs_write_super(struct super_block *sb)
359 static int btrfs_test_super(struct super_block *s, void *data)
361 struct btrfs_fs_devices *test_fs_devices = data;
362 struct btrfs_root *root = btrfs_sb(s);
364 return root->fs_info->fs_devices == test_fs_devices;
368 * Find a superblock for the given device / mount point.
370 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
371 * for multiple device setup. Make sure to keep it in sync.
373 static int btrfs_get_sb(struct file_system_type *fs_type, int flags,
374 const char *dev_name, void *data, struct vfsmount *mnt)
376 char *subvol_name = NULL;
377 struct block_device *bdev = NULL;
378 struct super_block *s;
380 struct btrfs_fs_devices *fs_devices = NULL;
383 error = btrfs_parse_early_options(data, &subvol_name);
387 error = btrfs_scan_one_device(dev_name, flags, fs_type, &fs_devices);
389 goto error_free_subvol_name;
391 error = btrfs_open_devices(fs_devices, flags, fs_type);
393 goto error_free_subvol_name;
395 bdev = fs_devices->latest_bdev;
396 btrfs_lock_volumes();
397 s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
398 btrfs_unlock_volumes();
403 if ((flags ^ s->s_flags) & MS_RDONLY) {
404 up_write(&s->s_umount);
411 char b[BDEVNAME_SIZE];
414 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
415 error = btrfs_fill_super(s, fs_devices, data,
416 flags & MS_SILENT ? 1 : 0);
418 up_write(&s->s_umount);
423 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
424 s->s_flags |= MS_ACTIVE;
427 root = lookup_one_len(subvol_name, s->s_root, strlen(subvol_name));
429 up_write(&s->s_umount);
431 error = PTR_ERR(root);
434 if (!root->d_inode) {
436 up_write(&s->s_umount);
443 mnt->mnt_root = root;
451 btrfs_close_devices(fs_devices);
452 error_free_subvol_name:
458 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
460 struct btrfs_root *root = btrfs_sb(dentry->d_sb);
461 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
462 int bits = dentry->d_sb->s_blocksize_bits;
464 buf->f_namelen = BTRFS_NAME_LEN;
465 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
466 buf->f_bfree = buf->f_blocks -
467 (btrfs_super_bytes_used(disk_super) >> bits);
468 buf->f_bavail = buf->f_bfree;
469 buf->f_bsize = dentry->d_sb->s_blocksize;
470 buf->f_type = BTRFS_SUPER_MAGIC;
474 static struct file_system_type btrfs_fs_type = {
475 .owner = THIS_MODULE,
477 .get_sb = btrfs_get_sb,
478 .kill_sb = kill_anon_super,
479 .fs_flags = FS_REQUIRES_DEV,
482 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
485 struct btrfs_ioctl_vol_args *vol;
486 struct btrfs_fs_devices *fs_devices;
490 vol = kmalloc(sizeof(*vol), GFP_KERNEL);
491 if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
495 len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
497 case BTRFS_IOC_SCAN_DEV:
498 ret = btrfs_scan_one_device(vol->name, MS_RDONLY,
499 &btrfs_fs_type, &fs_devices);
507 static void btrfs_write_super_lockfs(struct super_block *sb)
509 struct btrfs_root *root = btrfs_sb(sb);
510 btrfs_transaction_flush_work(root);
513 static void btrfs_unlockfs(struct super_block *sb)
515 struct btrfs_root *root = btrfs_sb(sb);
516 btrfs_transaction_queue_work(root, HZ * 30);
519 static struct super_operations btrfs_super_ops = {
520 .delete_inode = btrfs_delete_inode,
521 .put_super = btrfs_put_super,
522 .write_super = btrfs_write_super,
523 .sync_fs = btrfs_sync_fs,
524 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
525 .read_inode = btrfs_read_locked_inode,
527 .show_options = generic_show_options,
529 .write_inode = btrfs_write_inode,
530 .dirty_inode = btrfs_dirty_inode,
531 .alloc_inode = btrfs_alloc_inode,
532 .destroy_inode = btrfs_destroy_inode,
533 .statfs = btrfs_statfs,
534 .write_super_lockfs = btrfs_write_super_lockfs,
535 .unlockfs = btrfs_unlockfs,
538 static const struct file_operations btrfs_ctl_fops = {
539 .unlocked_ioctl = btrfs_control_ioctl,
540 .compat_ioctl = btrfs_control_ioctl,
541 .owner = THIS_MODULE,
544 static struct miscdevice btrfs_misc = {
545 .minor = MISC_DYNAMIC_MINOR,
546 .name = "btrfs-control",
547 .fops = &btrfs_ctl_fops
550 static int btrfs_interface_init(void)
552 return misc_register(&btrfs_misc);
555 void btrfs_interface_exit(void)
557 if (misc_deregister(&btrfs_misc) < 0)
558 printk("misc_deregister failed for control device");
561 static int __init init_btrfs_fs(void)
565 err = btrfs_init_sysfs();
569 btrfs_init_transaction_sys();
570 err = btrfs_init_cachep();
572 goto free_transaction_sys;
574 err = extent_io_init();
578 err = extent_map_init();
582 err = btrfs_interface_init();
584 goto free_extent_map;
585 err = register_filesystem(&btrfs_fs_type);
587 goto unregister_ioctl;
591 btrfs_interface_exit();
597 btrfs_destroy_cachep();
598 free_transaction_sys:
599 btrfs_exit_transaction_sys();
604 static void __exit exit_btrfs_fs(void)
606 btrfs_exit_transaction_sys();
607 btrfs_destroy_cachep();
610 btrfs_interface_exit();
611 unregister_filesystem(&btrfs_fs_type);
613 btrfs_cleanup_fs_uuids();
616 module_init(init_btrfs_fs)
617 module_exit(exit_btrfs_fs)
619 MODULE_LICENSE("GPL");