585 lines
13 KiB
C
585 lines
13 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 <linux/ctype.h>
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#include <linux/namei.h>
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#include <linux/miscdevice.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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#include "xattr.h"
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#include "volumes.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_nodatasum, Opt_nodatacow, Opt_max_extent,
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Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 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_nodatasum, "nodatasum"},
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{Opt_nodatacow, "nodatacow"},
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{Opt_nobarrier, "nobarrier"},
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{Opt_max_extent, "max_extent=%s"},
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{Opt_max_inline, "max_inline=%s"},
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{Opt_alloc_start, "alloc_start=%s"},
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{Opt_ssd, "ssd"},
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{Opt_err, NULL}
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};
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u64 btrfs_parse_size(char *str)
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{
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u64 res;
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int mult = 1;
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char *end;
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char last;
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res = simple_strtoul(str, &end, 10);
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last = end[0];
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if (isalpha(last)) {
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last = tolower(last);
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switch (last) {
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case 'g':
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mult *= 1024;
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case 'm':
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mult *= 1024;
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case 'k':
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mult *= 1024;
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}
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res = res * mult;
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}
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return res;
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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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struct btrfs_fs_info *info = NULL;
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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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/*
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* strsep changes the string, duplicate it because parse_options
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* gets called twice
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*/
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options = kstrdup(options, GFP_NOFS);
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if (!options)
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return -ENOMEM;
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if (root)
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info = root->fs_info;
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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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if (subvol_name) {
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*subvol_name = match_strdup(&args[0]);
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}
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break;
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case Opt_nodatasum:
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if (info) {
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printk("btrfs: setting nodatacsum\n");
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btrfs_set_opt(info->mount_opt, NODATASUM);
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}
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break;
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case Opt_nodatacow:
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if (info) {
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printk("btrfs: setting nodatacow\n");
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btrfs_set_opt(info->mount_opt, NODATACOW);
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btrfs_set_opt(info->mount_opt, NODATASUM);
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}
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break;
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case Opt_ssd:
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if (info) {
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printk("btrfs: use ssd allocation scheme\n");
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btrfs_set_opt(info->mount_opt, SSD);
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}
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break;
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case Opt_nobarrier:
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if (info) {
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printk("btrfs: turning off barriers\n");
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btrfs_set_opt(info->mount_opt, NOBARRIER);
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}
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break;
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case Opt_max_extent:
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if (info) {
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char *num = match_strdup(&args[0]);
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if (num) {
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info->max_extent =
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btrfs_parse_size(num);
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kfree(num);
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info->max_extent = max_t(u64,
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info->max_extent,
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root->sectorsize);
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printk("btrfs: max_extent at %Lu\n",
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info->max_extent);
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}
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}
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break;
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case Opt_max_inline:
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if (info) {
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char *num = match_strdup(&args[0]);
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if (num) {
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info->max_inline =
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btrfs_parse_size(num);
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kfree(num);
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info->max_inline = max_t(u64,
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info->max_inline,
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root->sectorsize);
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printk("btrfs: max_inline at %Lu\n",
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info->max_inline);
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}
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}
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break;
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case Opt_alloc_start:
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if (info) {
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char *num = match_strdup(&args[0]);
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if (num) {
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info->alloc_start =
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btrfs_parse_size(num);
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kfree(num);
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printk("btrfs: allocations start at "
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"%Lu\n", info->alloc_start);
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}
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}
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break;
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default:
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break;
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}
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}
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kfree(options);
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return 1;
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}
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static int btrfs_fill_super(struct super_block * sb,
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struct btrfs_fs_devices *fs_devices,
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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_xattr = btrfs_xattr_handlers;
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sb->s_time_gran = 1;
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tree_root = open_ctree(sb, fs_devices);
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if (IS_ERR(tree_root)) {
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printk("btrfs: open_ctree failed\n");
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return PTR_ERR(tree_root);
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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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parse_options((char *)data, tree_root, NULL);
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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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#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,25)
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save_mount_options(sb, data);
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#endif
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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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static int btrfs_test_super(struct super_block *s, void *data)
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{
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struct btrfs_fs_devices *test_fs_devices = data;
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struct btrfs_root *root = btrfs_sb(s);
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return root->fs_info->fs_devices == test_fs_devices;
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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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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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struct btrfs_fs_devices *fs_devices = NULL;
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int error = 0;
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error = btrfs_scan_one_device(dev_name, flags, fs_type, &fs_devices);
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if (error)
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return error;
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error = btrfs_open_devices(fs_devices, flags, fs_type);
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if (error)
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return error;
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bdev = fs_devices->lowest_bdev;
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btrfs_lock_volumes();
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s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
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btrfs_unlock_volumes();
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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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} 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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error = btrfs_fill_super(s, fs_devices, data,
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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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btrfs_sb(s)->fs_info->bdev_holder = fs_type;
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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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btrfs_close_devices(fs_devices);
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error:
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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, mnt,
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subvol_name ? subvol_name : "default");
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if (subvol_name)
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kfree(subvol_name);
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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_anon_super,
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.fs_flags = FS_REQUIRES_DEV,
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};
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static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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struct btrfs_ioctl_vol_args *vol;
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struct btrfs_fs_devices *fs_devices;
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int ret;
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int len;
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vol = kmalloc(sizeof(*vol), GFP_KERNEL);
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if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
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ret = -EFAULT;
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goto out;
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}
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len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
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switch (cmd) {
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case BTRFS_IOC_SCAN_DEV:
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ret = btrfs_scan_one_device(vol->name, MS_RDONLY,
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&btrfs_fs_type, &fs_devices);
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break;
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}
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out:
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kfree(vol);
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return 0;
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}
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static void btrfs_write_super_lockfs(struct super_block *sb)
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{
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struct btrfs_root *root = btrfs_sb(sb);
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btrfs_transaction_flush_work(root);
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}
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static void btrfs_unlockfs(struct super_block *sb)
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{
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struct btrfs_root *root = btrfs_sb(sb);
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btrfs_transaction_queue_work(root, HZ * 30);
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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_inode = btrfs_put_inode,
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.put_super = btrfs_put_super,
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.write_super = btrfs_write_super,
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.sync_fs = btrfs_sync_fs,
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#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,25)
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.read_inode = btrfs_read_locked_inode,
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#else
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.show_options = generic_show_options,
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#endif
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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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.write_super_lockfs = btrfs_write_super_lockfs,
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.unlockfs = btrfs_unlockfs,
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};
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static const struct file_operations btrfs_ctl_fops = {
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.unlocked_ioctl = btrfs_control_ioctl,
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.compat_ioctl = btrfs_control_ioctl,
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.owner = THIS_MODULE,
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};
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static struct miscdevice btrfs_misc = {
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.minor = MISC_DYNAMIC_MINOR,
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.name = "btrfs-control",
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.fops = &btrfs_ctl_fops
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};
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static int btrfs_interface_init(void)
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{
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return misc_register(&btrfs_misc);
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}
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void btrfs_interface_exit(void)
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{
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if (misc_deregister(&btrfs_misc) < 0)
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printk("misc_deregister failed for control device");
|
|
}
|
|
|
|
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_io_init();
|
|
if (err)
|
|
goto free_cachep;
|
|
|
|
err = extent_map_init();
|
|
if (err)
|
|
goto free_extent_io;
|
|
|
|
err = btrfs_interface_init();
|
|
if (err)
|
|
goto free_extent_map;
|
|
err = register_filesystem(&btrfs_fs_type);
|
|
if (err)
|
|
goto unregister_ioctl;
|
|
return 0;
|
|
|
|
unregister_ioctl:
|
|
btrfs_interface_exit();
|
|
free_extent_map:
|
|
extent_map_exit();
|
|
free_extent_io:
|
|
extent_io_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();
|
|
extent_io_exit();
|
|
btrfs_interface_exit();
|
|
unregister_filesystem(&btrfs_fs_type);
|
|
btrfs_exit_sysfs();
|
|
btrfs_cleanup_fs_uuids();
|
|
}
|
|
|
|
module_init(init_btrfs_fs)
|
|
module_exit(exit_btrfs_fs)
|
|
|
|
MODULE_LICENSE("GPL");
|