static int
myfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
{
struct inode *inode = myfs_get_inode(dir->i_sb, dir, mode, dev);
int error = -ENOSPC;
if(inode) {
/* Fill in inode information for a dentry */
d_instantiate(dentry, inode);
dget(dentry);
error = 0;
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
}
return error;
}
static int myfs_mknod(struct inode *dir, struct dentry *dentry,
int mode, dev_t dev)
{
struct inode *inode;
int error = -EPERM;
if (dentry->d_inode)
return -EEXIST;
inode = myfs_get_inode(dir->i_sb, mode, dev);
if (inode) {
d_instantiate(dentry, inode);
dget(dentry);
error = 0;
}
return error;
}
static int
myfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct inode *inode;
int error = -ENOSPC;
inode = myfs_get_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO, 0);
if(inode) {
int l = strlen(symname)+1;
error = page_symlink(inode, symname, l);
if(!error) {
d_instantiate(dentry, inode);
dget(dentry);
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
} else
iput(inode);
}
return error;
}
// 填充超级块入口
static int myfs_fill_sb(struct super_block *sb, void *data, int silent)
{
struct inode *root = NULL;
struct myfs_fs_info *fsi;
int err;
int logval;
sb->s_magic = MYFS_MAGIC_NUMBER; // 文件系统标识符
sb->s_op = &myfs_super_ops; // 超级块上的操作
sb->s_fs_info = fsi = kzalloc(sizeof(struct myfs_fs_info), GFP_KERNEL);
if (!fsi)
{
printk("myfs: fsinfo allocation failed\n");
return -ENOMEM;
}
err = myfs_parse_options(data, fsi);
printk("myfs: options - blksz=%lu, filemsz=%lu, mode=%o, fssize=%lu!\n",
fsi->block_size, fsi->file_max_size, fsi->root_mode, fsi->fs_max_size);
if (err)
return err;
sb->s_maxbytes = fsi->file_max_size;
sb->s_blocksize = fsi->block_size;
for (logval = 0; fsi->block_size > 1; logval++, fsi->block_size >>= 1);
fsi->block_size = sb->s_blocksize;
sb->s_blocksize_bits = logval;
sb->s_time_gran = 1;
root = myfs_get_inode(sb, NULL, S_IFDIR | fsi->root_mode, 0);
sb->s_root = d_make_root(root);
if (!sb->s_root)
{
printk("myfs: root creation failed\n");
return -ENOMEM;
}
return 0;
}
static int myfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *root_inode;
struct dentry *root_dentry;
/* TODO 2: fill super_block
* - blocksize, blocksize_bits
* - magic
* - super operations
* - maxbytes
*/
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = MYFS_BLOCKSIZE;
sb->s_blocksize_bits = MYFS_BLOCKSIZE_BITS;
sb->s_magic = MYFS_MAGIC;
sb->s_op = &myfs_ops;
/* mode = directory & access rights (755) */
root_inode = myfs_get_inode(sb, S_IFDIR | S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
root_inode->i_ino = 1;
printk(LOG_LEVEL "root inode has %d link(s)\n", root_inode->i_nlink);
if (!root_inode)
return -ENOMEM;
root_dentry = d_make_root(root_inode);
if (!root_dentry)
goto out_no_root;
sb->s_root = root_dentry;
return 0;
out_no_root:
iput(root_inode);
return -ENOMEM;
}