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|
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/mount.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/parser.h>
#include <linux/ctype.h>
#include <linux/namei.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "xattr.h"
#define BTRFS_SUPER_MAGIC 0x9123683E
static struct super_operations btrfs_super_ops;
static void btrfs_put_super (struct super_block * sb)
{
struct btrfs_root *root = btrfs_sb(sb);
struct btrfs_fs_info *fs = root->fs_info;
int ret;
ret = close_ctree(root);
if (ret) {
printk("close ctree returns %d\n", ret);
}
btrfs_sysfs_del_super(fs);
sb->s_fs_info = NULL;
}
enum {
Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent,
Opt_alloc_start, Opt_nobarrier, Opt_err,
};
static match_table_t tokens = {
{Opt_subvol, "subvol=%s"},
{Opt_nodatasum, "nodatasum"},
{Opt_nodatacow, "nodatacow"},
{Opt_nobarrier, "nobarrier"},
{Opt_max_extent, "max_extent=%s"},
{Opt_alloc_start, "alloc_start=%s"},
{Opt_err, NULL}
};
u64 btrfs_parse_size(char *str)
{
u64 res;
int mult = 1;
char *end;
char last;
res = simple_strtoul(str, &end, 10);
last = end[0];
if (isalpha(last)) {
last = tolower(last);
switch (last) {
case 'g':
mult *= 1024;
case 'm':
mult *= 1024;
case 'k':
mult *= 1024;
}
res = res * mult;
}
return res;
}
static int parse_options (char * options,
struct btrfs_root *root,
char **subvol_name)
{
char * p;
struct btrfs_fs_info *info = NULL;
substring_t args[MAX_OPT_ARGS];
if (!options)
return 1;
/*
* strsep changes the string, duplicate it because parse_options
* gets called twice
*/
options = kstrdup(options, GFP_NOFS);
if (!options)
return -ENOMEM;
if (root)
info = root->fs_info;
while ((p = strsep (&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_subvol:
if (subvol_name) {
*subvol_name = match_strdup(&args[0]);
}
break;
case Opt_nodatasum:
if (info) {
printk("btrfs: setting nodatacsum\n");
btrfs_set_opt(info->mount_opt, NODATASUM);
}
break;
case Opt_nodatacow:
if (info) {
printk("btrfs: setting nodatacow\n");
btrfs_set_opt(info->mount_opt, NODATACOW);
btrfs_set_opt(info->mount_opt, NODATASUM);
}
break;
case Opt_nobarrier:
if (info) {
printk("btrfs: turning off barriers\n");
btrfs_set_opt(info->mount_opt, NOBARRIER);
}
break;
case Opt_max_extent:
if (info) {
char *num = match_strdup(&args[0]);
if (num) {
info->max_extent =
btrfs_parse_size(num);
kfree(num);
info->max_extent = max_t(u64,
info->max_extent,
root->sectorsize);
printk("btrfs: max_extent at %Lu\n",
info->max_extent);
}
}
break;
case Opt_alloc_start:
if (info) {
char *num = match_strdup(&args[0]);
if (num) {
info->alloc_start =
btrfs_parse_size(num);
kfree(num);
printk("btrfs: allocations start at "
"%Lu\n", info->alloc_start);
}
}
break;
default:
break;
}
}
kfree(options);
return 1;
}
static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
{
struct inode * inode;
struct dentry * root_dentry;
struct btrfs_super_block *disk_super;
struct btrfs_root *tree_root;
struct btrfs_inode *bi;
int err;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_magic = BTRFS_SUPER_MAGIC;
sb->s_op = &btrfs_super_ops;
sb->s_xattr = btrfs_xattr_handlers;
sb->s_time_gran = 1;
tree_root = open_ctree(sb);
if (!tree_root || IS_ERR(tree_root)) {
printk("btrfs: open_ctree failed\n");
return -EIO;
}
sb->s_fs_info = tree_root;
disk_super = &tree_root->fs_info->super_copy;
inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
tree_root);
bi = BTRFS_I(inode);
bi->location.objectid = inode->i_ino;
bi->location.offset = 0;
bi->root = tree_root;
btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
if (!inode) {
err = -ENOMEM;
goto fail_close;
}
if (inode->i_state & I_NEW) {
btrfs_read_locked_inode(inode);
unlock_new_inode(inode);
}
root_dentry = d_alloc_root(inode);
if (!root_dentry) {
iput(inode);
err = -ENOMEM;
goto fail_close;
}
parse_options((char *)data, tree_root, NULL);
/* this does the super kobj at the same time */
err = btrfs_sysfs_add_super(tree_root->fs_info);
if (err)
goto fail_close;
sb->s_root = root_dentry;
btrfs_transaction_queue_work(tree_root, HZ * 30);
return 0;
fail_close:
close_ctree(tree_root);
return err;
}
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
root = btrfs_sb(sb);
sb->s_dirt = 0;
if (!wait) {
filemap_flush(root->fs_info->btree_inode->i_mapping);
return 0;
}
btrfs_clean_old_snapshots(root);
mutex_lock(&root->fs_info->fs_mutex);
btrfs_defrag_dirty_roots(root->fs_info);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sb->s_dirt = 0;
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static void btrfs_write_super(struct super_block *sb)
{
sb->s_dirt = 0;
}
/*
* This is almost a copy of get_sb_bdev in fs/super.c.
* We need the local copy to allow direct mounting of
* subvolumes, but this could be easily integrated back
* into the generic version. --hch
*/
/* start copy & paste */
static int set_bdev_super(struct super_block *s, void *data)
{
s->s_bdev = data;
s->s_dev = s->s_bdev->bd_dev;
return 0;
}
static int test_bdev_super(struct super_block *s, void *data)
{
return (void *)s->s_bdev == data;
}
int btrfs_get_sb_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int),
struct vfsmount *mnt, const char *subvol)
{
struct block_device *bdev = NULL;
struct super_block *s;
struct dentry *root;
int error = 0;
bdev = open_bdev_excl(dev_name, flags, fs_type);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
/*
* once the super is inserted into the list by sget, s_umount
* will protect the lockfs code from trying to start a snapshot
* while we are mounting
*/
down(&bdev->bd_mount_sem);
s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
up(&bdev->bd_mount_sem);
if (IS_ERR(s))
goto error_s;
if (s->s_root) {
if ((flags ^ s->s_flags) & MS_RDONLY) {
up_write(&s->s_umount);
deactivate_super(s);
error = -EBUSY;
goto error_bdev;
}
close_bdev_excl(bdev);
} else {
char b[BDEVNAME_SIZE];
s->s_flags = flags;
strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
sb_set_blocksize(s, block_size(bdev));
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
up_write(&s->s_umount);
deactivate_super(s);
goto error;
}
s->s_flags |= MS_ACTIVE;
}
if (subvol) {
root = lookup_one_len(subvol, s->s_root, strlen(subvol));
if (IS_ERR(root)) {
up_write(&s->s_umount);
deactivate_super(s);
error = PTR_ERR(root);
goto error;
}
if (!root->d_inode) {
dput(root);
up_write(&s->s_umount);
deactivate_super(s);
error = -ENXIO;
goto error;
}
} else {
root = dget(s->s_root);
}
mnt->mnt_sb = s;
mnt->mnt_root = root;
return 0;
error_s:
error = PTR_ERR(s);
error_bdev:
close_bdev_excl(bdev);
error:
return error;
}
/* end copy & paste */
static int btrfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
int ret;
char *subvol_name = NULL;
parse_options((char *)data, NULL, &subvol_name);
ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
btrfs_fill_super, mnt,
subvol_name ? subvol_name : "default");
if (subvol_name)
kfree(subvol_name);
return ret;
}
static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct btrfs_root *root = btrfs_sb(dentry->d_sb);
struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
int bits = dentry->d_sb->s_blocksize_bits;
buf->f_namelen = BTRFS_NAME_LEN;
buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
buf->f_bfree = buf->f_blocks -
(btrfs_super_bytes_used(disk_super) >> bits);
buf->f_bavail = buf->f_bfree;
buf->f_bsize = dentry->d_sb->s_blocksize;
buf->f_type = BTRFS_SUPER_MAGIC;
return 0;
}
static struct file_system_type btrfs_fs_type = {
.owner = THIS_MODULE,
.name = "btrfs",
.get_sb = btrfs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static struct super_operations btrfs_super_ops = {
.delete_inode = btrfs_delete_inode,
.put_inode = btrfs_put_inode,
.put_super = btrfs_put_super,
.read_inode = btrfs_read_locked_inode,
.write_super = btrfs_write_super,
.sync_fs = btrfs_sync_fs,
.write_inode = btrfs_write_inode,
.dirty_inode = btrfs_dirty_inode,
.alloc_inode = btrfs_alloc_inode,
.destroy_inode = btrfs_destroy_inode,
.statfs = btrfs_statfs,
};
static int __init init_btrfs_fs(void)
{
int err;
err = btrfs_init_sysfs();
if (err)
return err;
btrfs_init_transaction_sys();
err = btrfs_init_cachep();
if (err)
goto free_transaction_sys;
err = extent_map_init();
if (err)
goto free_cachep;
err = register_filesystem(&btrfs_fs_type);
if (err)
goto free_extent_map;
return 0;
free_extent_map:
extent_map_exit();
free_cachep:
btrfs_destroy_cachep();
free_transaction_sys:
btrfs_exit_transaction_sys();
btrfs_exit_sysfs();
return err;
}
static void __exit exit_btrfs_fs(void)
{
btrfs_exit_transaction_sys();
btrfs_destroy_cachep();
extent_map_exit();
unregister_filesystem(&btrfs_fs_type);
btrfs_exit_sysfs();
}
module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");
|