linux-sg2042/fs/btrfs/super.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;
#if 0
/* some random number */
static struct super_operations ramfs_ops;
static struct backing_dev_info ramfs_backing_dev_info = {
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK |
BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP,
};
struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev)
{
struct inode * inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
inode->i_blocks = 0;
inode->i_mapping->a_ops = &ramfs_aops;
inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
switch (mode & S_IFMT) {
default:
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
inode->i_op = &ramfs_file_inode_operations;
inode->i_fop = &ramfs_file_operations;
break;
case S_IFDIR:
inode->i_op = &ramfs_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
/* directory inodes start off with i_nlink == 2 (for "." entry) */
inc_nlink(inode);
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
break;
}
}
return inode;
}
/*
* File creation. Allocate an inode, and we're done..
*/
/* SMP-safe */
static int
ramfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
struct inode * inode = ramfs_get_inode(dir->i_sb, mode, dev);
int error = -ENOSPC;
if (inode) {
if (dir->i_mode & S_ISGID) {
inode->i_gid = dir->i_gid;
if (S_ISDIR(mode))
inode->i_mode |= S_ISGID;
}
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
error = 0;
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
}
return error;
}
static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
{
int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0);
if (!retval)
inc_nlink(dir);
return retval;
}
static int ramfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
{
return ramfs_mknod(dir, dentry, mode | S_IFREG, 0);
}
static int ramfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
{
struct inode *inode;
int error = -ENOSPC;
inode = ramfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0);
if (inode) {
int l = strlen(symname)+1;
error = page_symlink(inode, symname, l);
if (!error) {
if (dir->i_mode & S_ISGID)
inode->i_gid = dir->i_gid;
d_instantiate(dentry, inode);
dget(dentry);
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
} else
iput(inode);
}
return error;
}
static struct inode_operations ramfs_dir_inode_operations = {
.create = ramfs_create,
.lookup = simple_lookup,
.link = simple_link,
.unlink = simple_unlink,
.symlink = ramfs_symlink,
.mkdir = ramfs_mkdir,
.rmdir = simple_rmdir,
.mknod = ramfs_mknod,
.rename = simple_rename,
};
#endif
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);
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_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 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;
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];
} 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 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);
// FIXME mark_inode_dirty(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);
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;
}
inode_dec_link_count(inode);
iput(inode);
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;
trans = btrfs_start_transaction(root, 1);
inode = btrfs_new_inode(trans, dir, mode);
err = PTR_ERR(inode);
if (IS_ERR(inode))
return err;
// FIXME mark the inode dirty
err = btrfs_add_nondir(trans, dentry, inode);
dir->i_sb->s_dirt = 1;
btrfs_end_transaction(trans, root);
return err;
}
static void btrfs_write_super(struct super_block *sb)
{
sb->s_dirt = 0;
printk("btrfs write_super!\n");
filemap_flush(sb->s_bdev->bd_inode->i_mapping);
}
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;
return 0;
root = btrfs_sb(sb);
trans = btrfs_start_transaction(root, 1);
ret = btrfs_commit_transaction(trans, root);
sb->s_dirt = 0;
BUG_ON(ret);
printk("btrfs sync_fs\n");
return 0;
}
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,
.drop_inode = generic_delete_inode,
.put_super = btrfs_put_super,
.read_inode = btrfs_read_locked_inode,
.write_super = btrfs_write_super,
.sync_fs = btrfs_sync_fs,
};
static struct inode_operations btrfs_dir_inode_operations = {
.lookup = btrfs_lookup,
.create = btrfs_create,
};
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");