diff options
Diffstat (limited to 'fs/btrfs/super.c')
| -rw-r--r-- | fs/btrfs/super.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c new file mode 100644 index 00000000000..4ae76044aea --- /dev/null +++ b/fs/btrfs/super.c @@ -0,0 +1,205 @@ +#include <linux/module.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" + +#define BTRFS_SUPER_MAGIC 0x9123682E +#if 0 +/* some random number */ + +static struct super_operations ramfs_ops; +static struct inode_operations ramfs_dir_inode_operations; + +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 + +struct inode *btrfs_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_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; + } + return inode; +} + +static struct super_operations btrfs_ops = { + .statfs = simple_statfs, + .drop_inode = generic_delete_inode, +}; + +static int btrfs_fill_super(struct super_block * sb, void * data, int silent) +{ + struct inode * inode; + struct dentry * 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_ops; + sb->s_time_gran = 1; + inode = btrfs_get_inode(sb, S_IFDIR | 0755, 0); + if (!inode) + return -ENOMEM; + + root = d_alloc_root(inode); + if (!root) { + iput(inode); + return -ENOMEM; + } + sb->s_root = root; + 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 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"); |