mirror of
https://github.com/FEX-Emu/linux.git
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db94535db7
Signed-off-by: Chris Mason <chris.mason@oracle.com>
368 lines
8.3 KiB
C
368 lines
8.3 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/blkdev.h>
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#include <linux/module.h>
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#include <linux/buffer_head.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/time.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/smp_lock.h>
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#include <linux/backing-dev.h>
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#include <linux/mount.h>
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#include <linux/mpage.h>
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#include <linux/swap.h>
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#include <linux/writeback.h>
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#include <linux/statfs.h>
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#include <linux/compat.h>
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#include <linux/parser.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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#include "btrfs_inode.h"
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#include "ioctl.h"
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#include "print-tree.h"
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#define BTRFS_SUPER_MAGIC 0x9123683E
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static struct super_operations btrfs_super_ops;
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static void btrfs_put_super (struct super_block * sb)
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{
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struct btrfs_root *root = btrfs_sb(sb);
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struct btrfs_fs_info *fs = root->fs_info;
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int ret;
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ret = close_ctree(root);
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if (ret) {
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printk("close ctree returns %d\n", ret);
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}
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btrfs_sysfs_del_super(fs);
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sb->s_fs_info = NULL;
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}
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enum {
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Opt_subvol, Opt_err,
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};
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static match_table_t tokens = {
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{Opt_subvol, "subvol=%s"},
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{Opt_err, NULL}
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};
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static int parse_options (char * options,
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struct btrfs_root *root,
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char **subvol_name)
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{
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char * p;
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substring_t args[MAX_OPT_ARGS];
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if (!options)
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return 1;
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while ((p = strsep (&options, ",")) != NULL) {
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int token;
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case Opt_subvol:
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*subvol_name = match_strdup(&args[0]);
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break;
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default:
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return 0;
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}
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}
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return 1;
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}
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static int btrfs_fill_super(struct super_block * sb, void * data, int silent)
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{
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struct inode * inode;
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struct dentry * root_dentry;
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struct btrfs_super_block *disk_super;
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struct btrfs_root *tree_root;
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struct btrfs_inode *bi;
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int err;
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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sb->s_magic = BTRFS_SUPER_MAGIC;
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sb->s_op = &btrfs_super_ops;
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sb->s_time_gran = 1;
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tree_root = open_ctree(sb);
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if (!tree_root || IS_ERR(tree_root)) {
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printk("btrfs: open_ctree failed\n");
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return -EIO;
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}
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sb->s_fs_info = tree_root;
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disk_super = &tree_root->fs_info->super_copy;
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inode = btrfs_iget_locked(sb, btrfs_super_root_dir(disk_super),
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tree_root);
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bi = BTRFS_I(inode);
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bi->location.objectid = inode->i_ino;
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bi->location.offset = 0;
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bi->root = tree_root;
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btrfs_set_key_type(&bi->location, BTRFS_INODE_ITEM_KEY);
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if (!inode) {
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err = -ENOMEM;
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goto fail_close;
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}
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if (inode->i_state & I_NEW) {
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btrfs_read_locked_inode(inode);
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unlock_new_inode(inode);
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}
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root_dentry = d_alloc_root(inode);
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if (!root_dentry) {
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iput(inode);
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err = -ENOMEM;
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goto fail_close;
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}
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/* this does the super kobj at the same time */
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err = btrfs_sysfs_add_super(tree_root->fs_info);
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if (err)
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goto fail_close;
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sb->s_root = root_dentry;
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btrfs_transaction_queue_work(tree_root, HZ * 30);
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return 0;
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fail_close:
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close_ctree(tree_root);
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return err;
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}
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static int btrfs_sync_fs(struct super_block *sb, int wait)
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{
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struct btrfs_trans_handle *trans;
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struct btrfs_root *root;
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int ret;
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root = btrfs_sb(sb);
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sb->s_dirt = 0;
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if (!wait) {
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filemap_flush(root->fs_info->btree_inode->i_mapping);
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return 0;
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}
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btrfs_clean_old_snapshots(root);
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mutex_lock(&root->fs_info->fs_mutex);
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btrfs_defrag_dirty_roots(root->fs_info);
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trans = btrfs_start_transaction(root, 1);
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ret = btrfs_commit_transaction(trans, root);
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sb->s_dirt = 0;
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mutex_unlock(&root->fs_info->fs_mutex);
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return ret;
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}
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static void btrfs_write_super(struct super_block *sb)
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{
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sb->s_dirt = 0;
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}
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/*
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* This is almost a copy of get_sb_bdev in fs/super.c.
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* We need the local copy to allow direct mounting of
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* subvolumes, but this could be easily integrated back
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* into the generic version. --hch
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*/
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/* start copy & paste */
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static int set_bdev_super(struct super_block *s, void *data)
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{
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s->s_bdev = data;
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s->s_dev = s->s_bdev->bd_dev;
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return 0;
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}
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static int test_bdev_super(struct super_block *s, void *data)
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{
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return (void *)s->s_bdev == data;
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}
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int btrfs_get_sb_bdev(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data,
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int (*fill_super)(struct super_block *, void *, int),
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struct vfsmount *mnt, const char *subvol)
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{
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struct block_device *bdev = NULL;
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struct super_block *s;
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struct dentry *root;
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int error = 0;
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bdev = open_bdev_excl(dev_name, flags, fs_type);
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if (IS_ERR(bdev))
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return PTR_ERR(bdev);
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/*
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* once the super is inserted into the list by sget, s_umount
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* will protect the lockfs code from trying to start a snapshot
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* while we are mounting
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*/
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down(&bdev->bd_mount_sem);
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s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
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up(&bdev->bd_mount_sem);
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if (IS_ERR(s))
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goto error_s;
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if (s->s_root) {
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if ((flags ^ s->s_flags) & MS_RDONLY) {
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up_write(&s->s_umount);
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deactivate_super(s);
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error = -EBUSY;
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goto error_bdev;
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}
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close_bdev_excl(bdev);
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} else {
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char b[BDEVNAME_SIZE];
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s->s_flags = flags;
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strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
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sb_set_blocksize(s, block_size(bdev));
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error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
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if (error) {
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up_write(&s->s_umount);
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deactivate_super(s);
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goto error;
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}
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s->s_flags |= MS_ACTIVE;
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}
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if (subvol) {
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root = lookup_one_len(subvol, s->s_root, strlen(subvol));
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if (IS_ERR(root)) {
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up_write(&s->s_umount);
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deactivate_super(s);
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error = PTR_ERR(root);
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goto error;
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}
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if (!root->d_inode) {
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dput(root);
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up_write(&s->s_umount);
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deactivate_super(s);
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error = -ENXIO;
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goto error;
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}
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} else {
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root = dget(s->s_root);
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}
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mnt->mnt_sb = s;
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mnt->mnt_root = root;
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return 0;
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error_s:
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error = PTR_ERR(s);
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error_bdev:
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close_bdev_excl(bdev);
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error:
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printk("get_sb failed\n");
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return error;
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}
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/* end copy & paste */
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static int btrfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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int ret;
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char *subvol_name = NULL;
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parse_options((char *)data, NULL, &subvol_name);
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ret = btrfs_get_sb_bdev(fs_type, flags, dev_name, data,
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btrfs_fill_super, mnt,
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subvol_name ? subvol_name : "default");
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printk("btrfs_get_sb returns %d\n", ret);
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return ret;
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}
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static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct btrfs_root *root = btrfs_sb(dentry->d_sb);
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struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
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int bits = dentry->d_sb->s_blocksize_bits;
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buf->f_namelen = BTRFS_NAME_LEN;
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buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
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buf->f_bfree = buf->f_blocks -
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(btrfs_super_bytes_used(disk_super) >> bits);
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buf->f_bavail = buf->f_bfree;
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buf->f_bsize = dentry->d_sb->s_blocksize;
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buf->f_type = BTRFS_SUPER_MAGIC;
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return 0;
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}
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static struct file_system_type btrfs_fs_type = {
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.owner = THIS_MODULE,
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.name = "btrfs",
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.get_sb = btrfs_get_sb,
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.kill_sb = kill_block_super,
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.fs_flags = FS_REQUIRES_DEV,
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};
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static struct super_operations btrfs_super_ops = {
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.delete_inode = btrfs_delete_inode,
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.put_super = btrfs_put_super,
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.read_inode = btrfs_read_locked_inode,
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.write_super = btrfs_write_super,
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.sync_fs = btrfs_sync_fs,
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.write_inode = btrfs_write_inode,
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.dirty_inode = btrfs_dirty_inode,
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.alloc_inode = btrfs_alloc_inode,
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.destroy_inode = btrfs_destroy_inode,
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.statfs = btrfs_statfs,
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};
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static int __init init_btrfs_fs(void)
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{
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int err;
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err = btrfs_init_sysfs();
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if (err)
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return err;
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btrfs_init_transaction_sys();
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err = btrfs_init_cachep();
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if (err)
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return err;
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extent_map_init();
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return register_filesystem(&btrfs_fs_type);
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}
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static void __exit exit_btrfs_fs(void)
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{
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btrfs_exit_transaction_sys();
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btrfs_destroy_cachep();
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extent_map_exit();
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unregister_filesystem(&btrfs_fs_type);
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btrfs_exit_sysfs();
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}
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module_init(init_btrfs_fs)
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module_exit(exit_btrfs_fs)
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MODULE_LICENSE("GPL");
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