Btrfs: initial move to kernel module land
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
new file mode 100644
index 0000000..4ae7604
--- /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");
