linux/fs/btrfs/super.c

687 lines
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C
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#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 "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#define BTRFS_SUPER_MAGIC 0x9123682E
static struct inode_operations btrfs_dir_inode_operations;
static struct super_operations btrfs_super_ops;
static struct file_operations btrfs_dir_file_operations;
static void btrfs_read_locked_inode(struct inode *inode)
{
struct btrfs_path path;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
btrfs_init_path(&path);
ret = btrfs_lookup_inode(NULL, root, &path, inode->i_ino, 0);
if (ret) {
make_bad_inode(inode);
btrfs_release_path(root, &path);
return;
}
inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
path.slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(inode_item);
inode->i_nlink = btrfs_inode_nlink(inode_item);
inode->i_uid = btrfs_inode_uid(inode_item);
inode->i_gid = btrfs_inode_gid(inode_item);
inode->i_size = btrfs_inode_size(inode_item);
inode->i_atime.tv_sec = btrfs_timespec_sec(&inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(&inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(&inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(&inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(&inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(&inode_item->ctime);
inode->i_blocks = btrfs_inode_nblocks(inode_item);
inode->i_generation = btrfs_inode_generation(inode_item);
btrfs_release_path(root, &path);
switch (inode->i_mode & S_IFMT) {
#if 0
default:
init_special_inode(inode, inode->i_mode,
btrfs_inode_rdev(inode_item));
break;
#endif
case S_IFREG:
break;
case S_IFDIR:
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
break;
case S_IFLNK:
// inode->i_op = &page_symlink_inode_operations;
break;
}
return;
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_path path;
struct btrfs_root *root;
struct btrfs_trans_handle *trans;
const char *name = dentry->d_name.name;
int name_len = dentry->d_name.len;
int ret;
u64 objectid;
struct btrfs_dir_item *di;
btrfs_init_path(&path);
root = btrfs_sb(dir->i_sb);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_lookup_dir_item(trans, root, &path, dir->i_ino,
name, name_len, -1);
if (ret < 0)
goto err;
if (ret > 0) {
ret = -ENOENT;
goto err;
}
di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_dir_item);
objectid = btrfs_dir_objectid(di);
ret = btrfs_del_item(trans, root, &path);
BUG_ON(ret);
dentry->d_inode->i_ctime = dir->i_ctime;
err:
btrfs_release_path(root, &path);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
if (ret == 0)
inode_dec_link_count(dentry->d_inode);
return ret;
}
static int btrfs_free_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
u64 objectid = inode->i_ino;
struct btrfs_path path;
struct btrfs_inode_map_item *map;
struct btrfs_key stat_data_key;
int ret;
clear_inode(inode);
btrfs_init_path(&path);
ret = btrfs_lookup_inode_map(trans, root, &path, objectid, -1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
btrfs_release_path(root, &path);
goto error;
}
map = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_inode_map_item);
btrfs_disk_key_to_cpu(&stat_data_key, &map->key);
ret = btrfs_del_item(trans, root->fs_info->inode_root, &path);
BUG_ON(ret);
btrfs_release_path(root, &path);
btrfs_init_path(&path);
ret = btrfs_lookup_inode(trans, root, &path, objectid, -1);
BUG_ON(ret);
ret = btrfs_del_item(trans, root, &path);
BUG_ON(ret);
btrfs_release_path(root, &path);
error:
return ret;
}
static void btrfs_delete_inode(struct inode *inode)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
truncate_inode_pages(&inode->i_data, 0);
if (is_bad_inode(inode)) {
goto no_delete;
}
inode->i_size = 0;
if (inode->i_blocks)
WARN_ON(1);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
btrfs_free_inode(trans, root, inode);
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
return;
no_delete:
clear_inode(inode);
}
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
ino_t *ino)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path path;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
int ret;
btrfs_init_path(&path);
ret = btrfs_lookup_dir_item(NULL, root, &path, dir->i_ino, name,
namelen, 0);
if (ret || !btrfs_match_dir_item_name(root, &path, name, namelen)) {
*ino = 0;
goto out;
}
di = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0],
struct btrfs_dir_item);
*ino = btrfs_dir_objectid(di);
out:
btrfs_release_path(root, &path);
return ret;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct inode * inode;
ino_t ino;
int ret;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &ino);
if (ret < 0)
return ERR_PTR(ret);
inode = NULL;
if (ino) {
inode = iget(dir->i_sb, ino);
if (!inode)
return ERR_PTR(-EACCES);
}
return d_splice_alias(inode, dentry);
}
static void reada_leaves(struct btrfs_root *root, struct btrfs_path *path)
{
struct buffer_head *bh;
struct btrfs_node *node;
int i;
int nritems;
u64 objectid;
u64 item_objectid;
u64 blocknr;
int slot;
if (!path->nodes[1])
return;
node = btrfs_buffer_node(path->nodes[1]);
slot = path->slots[1];
objectid = btrfs_disk_key_objectid(&node->ptrs[slot].key);
nritems = btrfs_header_nritems(&node->header);
for (i = slot; i < nritems; i++) {
item_objectid = btrfs_disk_key_objectid(&node->ptrs[i].key);
if (item_objectid != objectid)
break;
blocknr = btrfs_node_blockptr(node, i);
bh = sb_getblk(root->fs_info->sb, blocknr);
ll_rw_block(READ, 1, &bh);
brelse(bh);
}
}
static int btrfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
struct btrfs_item *item;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_path path;
int ret;
u32 nritems;
struct btrfs_leaf *leaf;
int slot;
int advance;
unsigned char d_type = DT_UNKNOWN;
int over = 0;
key.objectid = inode->i_ino;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
key.offset = filp->f_pos;
btrfs_init_path(&path);
ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
if (ret < 0) {
goto err;
}
advance = 0;
reada_leaves(root, &path);
while(1) {
leaf = btrfs_buffer_leaf(path.nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path.slots[0];
if (advance) {
if (slot == nritems -1) {
ret = btrfs_next_leaf(root, &path);
if (ret)
break;
leaf = btrfs_buffer_leaf(path.nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path.slots[0];
if (path.nodes[1] && path.slots[1] == 0)
reada_leaves(root, &path);
} else {
slot++;
path.slots[0]++;
}
}
advance = 1;
item = leaf->items + slot;
if (btrfs_disk_key_objectid(&item->key) != key.objectid)
break;
if (btrfs_disk_key_type(&item->key) != BTRFS_DIR_ITEM_KEY)
continue;
if (btrfs_disk_key_offset(&item->key) < filp->f_pos)
continue;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
over = filldir(dirent, (const char *)(di + 1),
btrfs_dir_name_len(di),
btrfs_disk_key_offset(&item->key),
btrfs_dir_objectid(di), d_type);
if (over) {
filp->f_pos = btrfs_disk_key_offset(&item->key);
break;
}
filp->f_pos = btrfs_disk_key_offset(&item->key) + 1;
}
ret = 0;
err:
btrfs_release_path(root, &path);
return ret;
}
static void btrfs_put_super (struct super_block * sb)
{
struct btrfs_root *root = btrfs_sb(sb);
int ret;
ret = close_ctree(root);
if (ret) {
printk("close ctree returns %d\n", ret);
}
sb->s_fs_info = NULL;
}
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 buffer_head *bh;
struct btrfs_root *root;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = BTRFS_SUPER_MAGIC;
sb->s_op = &btrfs_super_ops;
sb->s_time_gran = 1;
bh = sb_bread(sb, BTRFS_SUPER_INFO_OFFSET / sb->s_blocksize);
if (!bh) {
printk("btrfs: unable to read on disk super\n");
return -EIO;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
root = open_ctree(sb, bh, disk_super);
sb->s_fs_info = root;
if (!root) {
printk("btrfs: open_ctree failed\n");
return -EIO;
}
printk("read in super total blocks %Lu root %Lu\n",
btrfs_super_total_blocks(disk_super),
btrfs_super_root_dir(disk_super));
inode = iget_locked(sb, btrfs_super_root_dir(disk_super));
if (!inode)
return -ENOMEM;
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);
return -ENOMEM;
}
sb->s_root = root_dentry;
return 0;
}
static void fill_inode_item(struct btrfs_inode_item *item,
struct inode *inode)
{
btrfs_set_inode_uid(item, inode->i_uid);
btrfs_set_inode_gid(item, inode->i_gid);
btrfs_set_inode_size(item, inode->i_size);
btrfs_set_inode_mode(item, inode->i_mode);
btrfs_set_inode_nlink(item, inode->i_nlink);
btrfs_set_timespec_sec(&item->atime, inode->i_atime.tv_sec);
btrfs_set_timespec_nsec(&item->atime, inode->i_atime.tv_nsec);
btrfs_set_timespec_sec(&item->mtime, inode->i_mtime.tv_sec);
btrfs_set_timespec_nsec(&item->mtime, inode->i_mtime.tv_nsec);
btrfs_set_timespec_sec(&item->ctime, inode->i_ctime.tv_sec);
btrfs_set_timespec_nsec(&item->ctime, inode->i_ctime.tv_nsec);
btrfs_set_inode_nblocks(item, inode->i_blocks);
btrfs_set_inode_generation(item, inode->i_generation);
}
static int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path path;
int ret;
btrfs_init_path(&path);
ret = btrfs_lookup_inode(trans, root, &path, inode->i_ino, 1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
path.slots[0],
struct btrfs_inode_item);
fill_inode_item(inode_item, inode);
mark_buffer_dirty(path.nodes[0]);
failed:
btrfs_release_path(root, &path);
return 0;
}
static int btrfs_write_inode(struct inode *inode, int wait)
{
struct btrfs_root *root = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
int ret;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_update_inode(trans, root, inode);
if (wait)
btrfs_commit_transaction(trans, root);
else
btrfs_end_transaction(trans, root);
mutex_unlock(&root->fs_info->fs_mutex);
return ret;
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct inode *dir, int mode)
{
struct inode *inode;
struct btrfs_inode_item inode_item;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
struct btrfs_key key;
int ret;
u64 objectid;
inode = new_inode(dir->i_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
ret = btrfs_find_free_objectid(trans, root, dir->i_ino, &objectid);
BUG_ON(ret);
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_mode = mode;
inode->i_ino = objectid;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
fill_inode_item(&inode_item, inode);
key.objectid = objectid;
key.flags = 0;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
ret = btrfs_insert_inode_map(trans, root, objectid, &key);
BUG_ON(ret);
ret = btrfs_insert_inode(trans, root, objectid, &inode_item);
BUG_ON(ret);
insert_inode_hash(inode);
return inode;
}
static int btrfs_add_link(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode)
{
int ret;
ret = btrfs_insert_dir_item(trans, btrfs_sb(inode->i_sb),
dentry->d_name.name, dentry->d_name.len,
dentry->d_parent->d_inode->i_ino,
inode->i_ino, 0);
if (ret == 0) {
dentry->d_parent->d_inode->i_size += dentry->d_name.len;
ret = btrfs_update_inode(trans, btrfs_sb(inode->i_sb),
dentry->d_parent->d_inode);
}
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct dentry *dentry, struct inode *inode)
{
int err = btrfs_add_link(trans, dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
return err;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
int mode, struct nameidata *nd)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
struct inode *inode;
int err;
int drop_inode = 0;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
inode = btrfs_new_inode(trans, dir, mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_unlock;
// FIXME mark the inode dirty
err = btrfs_add_nondir(trans, dentry, inode);
if (err)
drop_inode = 1;
dir->i_sb->s_dirt = 1;
btrfs_end_transaction(trans, root);
out_unlock:
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
return err;
}
static int btrfs_make_empty_dir(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir)
{
struct btrfs_root *root = btrfs_sb(inode->i_sb);
int ret;
char buf[2];
buf[0] = '.';
buf[1] = '.';
ret = btrfs_insert_dir_item(trans, root, buf, 1, inode->i_ino,
inode->i_ino, 1);
if (ret)
goto error;
ret = btrfs_insert_dir_item(trans, root, buf, 2, inode->i_ino,
dir->i_ino, 1);
if (ret)
goto error;
inode->i_size = 3;
ret = btrfs_update_inode(trans, root, inode);
error:
return ret;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = btrfs_sb(dir->i_sb);
int err = 0;
int drop_on_err = 0;
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_unlock;
}
inode = btrfs_new_inode(trans, dir, S_IFDIR | mode);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_fail;
}
drop_on_err = 1;
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
err = btrfs_make_empty_dir(trans, inode, dir);
if (err)
goto out_fail;
err = btrfs_add_link(trans, dentry, inode);
if (err)
goto out_fail;
d_instantiate(dentry, inode);
drop_on_err = 0;
out_fail:
btrfs_end_transaction(trans, root);
out_unlock:
mutex_unlock(&root->fs_info->fs_mutex);
if (drop_on_err)
iput(inode);
return err;
}
static int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
int ret;
sb->s_dirt = 0;
if (!wait) {
filemap_flush(sb->s_bdev->bd_inode->i_mapping);
return 0;
}
filemap_write_and_wait(sb->s_bdev->bd_inode->i_mapping);
root = btrfs_sb(sb);
mutex_lock(&root->fs_info->fs_mutex);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sb->s_dirt = 0;
BUG_ON(ret);
printk("btrfs sync_fs\n");
mutex_unlock(&root->fs_info->fs_mutex);
return 0;
}
static void btrfs_write_super(struct super_block *sb)
{
btrfs_sync_fs(sb, 1);
}
static int btrfs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, data,
btrfs_fill_super, mnt);
}
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 = {
.statfs = simple_statfs,
.delete_inode = btrfs_delete_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,
};
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.mkdir = btrfs_mkdir,
};
static struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.readdir = btrfs_readdir,
};
static int __init init_btrfs_fs(void)
{
printk("btrfs loaded!\n");
return register_filesystem(&btrfs_fs_type);
}
static void __exit exit_btrfs_fs(void)
{
unregister_filesystem(&btrfs_fs_type);
printk("btrfs unloaded\n");
}
module_init(init_btrfs_fs)
module_exit(exit_btrfs_fs)
MODULE_LICENSE("GPL");