From 7d43d92c53afefc0722b2b565a9e68f4837bde4c Mon Sep 17 00:00:00 2001 From: Erez Zadok Date: Mon, 4 Jan 2010 20:45:06 -0500 Subject: [PATCH] Wrapfs: main header file Signed-off-by: Erez Zadok --- fs/wrapfs/wrapfs.h | 203 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 fs/wrapfs/wrapfs.h diff --git a/fs/wrapfs/wrapfs.h b/fs/wrapfs/wrapfs.h new file mode 100644 index 000000000000..1e7fcb6fec06 --- /dev/null +++ b/fs/wrapfs/wrapfs.h @@ -0,0 +1,203 @@ +/* + * Copyright (c) 1998-2010 Erez Zadok + * Copyright (c) 2009 Shrikar Archak + * Copyright (c) 2003-2010 Stony Brook University + * Copyright (c) 2003-2010 The Research Foundation of SUNY + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef _WRAPFS_H_ +#define _WRAPFS_H_ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* the file system name */ +#define WRAPFS_NAME "wrapfs" + +/* wrapfs root inode number */ +#define WRAPFS_ROOT_INO 1 + +/* useful for tracking code reachability */ +#define UDBG printk("DBG:%s:%s:%d\n", __FILE__, __func__, __LINE__) + +/* operations vectors defined in specific files */ +extern const struct file_operations wrapfs_main_fops; +extern const struct file_operations wrapfs_dir_fops; +extern const struct inode_operations wrapfs_main_iops; +extern const struct inode_operations wrapfs_dir_iops; +extern const struct inode_operations wrapfs_symlink_iops; +extern const struct super_operations wrapfs_sops; +extern const struct dentry_operations wrapfs_dops; +extern const struct address_space_operations wrapfs_aops, wrapfs_dummy_aops; +extern const struct vm_operations_struct wrapfs_vm_ops; + +extern int wrapfs_init_inode_cache(void); +extern void wrapfs_destroy_inode_cache(void); +extern int wrapfs_init_dentry_cache(void); +extern void wrapfs_destroy_dentry_cache(void); +extern int new_dentry_private_data(struct dentry *dentry); +extern void free_dentry_private_data(struct dentry *dentry); +extern int init_lower_nd(struct nameidata *nd, unsigned int flags); +extern void release_lower_nd(struct nameidata *nd, int err); +extern struct dentry *wrapfs_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd); +extern int wrapfs_interpose(struct dentry *dentry, struct super_block *sb, + struct path *lower_path); + +/* file private data */ +struct wrapfs_file_info { + struct file *lower_file; + const struct vm_operations_struct *lower_vm_ops; +}; + +/* wrapfs inode data in memory */ +struct wrapfs_inode_info { + struct inode *lower_inode; + struct inode vfs_inode; +}; + +/* wrapfs dentry data in memory */ +struct wrapfs_dentry_info { + spinlock_t lock; /* protects lower_path */ + struct path lower_path; +}; + +/* wrapfs super-block data in memory */ +struct wrapfs_sb_info { + struct super_block *lower_sb; +}; + +/* + * inode to private data + * + * Since we use containers and the struct inode is _inside_ the + * wrapfs_inode_info structure, WRAPFS_I will always (given a non-NULL + * inode pointer), return a valid non-NULL pointer. + */ +static inline struct wrapfs_inode_info *WRAPFS_I(const struct inode *inode) +{ + return container_of(inode, struct wrapfs_inode_info, vfs_inode); +} + +/* dentry to private data */ +#define WRAPFS_D(dent) ((struct wrapfs_dentry_info *)(dent)->d_fsdata) + +/* superblock to private data */ +#define WRAPFS_SB(super) ((struct wrapfs_sb_info *)(super)->s_fs_info) + +/* file to private Data */ +#define WRAPFS_F(file) ((struct wrapfs_file_info *)((file)->private_data)) + +/* file to lower file */ +static inline struct file *wrapfs_lower_file(const struct file *f) +{ + return WRAPFS_F(f)->lower_file; +} + +static inline void wrapfs_set_lower_file(struct file *f, struct file *val) +{ + WRAPFS_F(f)->lower_file = val; +} + +/* inode to lower inode. */ +static inline struct inode *wrapfs_lower_inode(const struct inode *i) +{ + return WRAPFS_I(i)->lower_inode; +} + +static inline void wrapfs_set_lower_inode(struct inode *i, struct inode *val) +{ + WRAPFS_I(i)->lower_inode = val; +} + +/* superblock to lower superblock */ +static inline struct super_block *wrapfs_lower_super( + const struct super_block *sb) +{ + return WRAPFS_SB(sb)->lower_sb; +} + +static inline void wrapfs_set_lower_super(struct super_block *sb, + struct super_block *val) +{ + WRAPFS_SB(sb)->lower_sb = val; +} + +/* path based (dentry/mnt) macros */ +static inline void pathcpy(struct path *dst, const struct path *src) +{ + dst->dentry = src->dentry; + dst->mnt = src->mnt; +} +/* Returns struct path. Caller must path_put it. */ +static inline void wrapfs_get_lower_path(const struct dentry *dent, + struct path *lower_path) +{ + spin_lock(&WRAPFS_D(dent)->lock); + pathcpy(lower_path, &WRAPFS_D(dent)->lower_path); + path_get(lower_path); + spin_unlock(&WRAPFS_D(dent)->lock); + return; +} +static inline void wrapfs_put_lower_path(const struct dentry *dent, + struct path *lower_path) +{ + path_put(lower_path); + return; +} +static inline void wrapfs_set_lower_path(const struct dentry *dent, + struct path *lower_path) +{ + spin_lock(&WRAPFS_D(dent)->lock); + pathcpy(&WRAPFS_D(dent)->lower_path, lower_path); + spin_unlock(&WRAPFS_D(dent)->lock); + return; +} +static inline void wrapfs_reset_lower_path(const struct dentry *dent) +{ + spin_lock(&WRAPFS_D(dent)->lock); + WRAPFS_D(dent)->lower_path.dentry = NULL; + WRAPFS_D(dent)->lower_path.mnt = NULL; + spin_unlock(&WRAPFS_D(dent)->lock); + return; +} +static inline void wrapfs_put_reset_lower_path(const struct dentry *dent) +{ + struct path lower_path; + spin_lock(&WRAPFS_D(dent)->lock); + pathcpy(&lower_path, &WRAPFS_D(dent)->lower_path); + WRAPFS_D(dent)->lower_path.dentry = NULL; + WRAPFS_D(dent)->lower_path.mnt = NULL; + spin_unlock(&WRAPFS_D(dent)->lock); + path_put(&lower_path); + return; +} + +/* locking helpers */ +static inline struct dentry *lock_parent(struct dentry *dentry) +{ + struct dentry *dir = dget_parent(dentry); + mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); + return dir; +} + +static inline void unlock_dir(struct dentry *dir) +{ + mutex_unlock(&dir->d_inode->i_mutex); + dput(dir); +} +#endif /* not _WRAPFS_H_ */ -- 2.43.0