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#ifndef UMSDOS_FS_I_H
#define UMSDOS_FS_I_H
#ifndef _LINUX_TYPES_H
#include <linux/types.h>
#endif
#include <linux/msdos_fs_i.h>
#include <linux/pipe_fs_i.h>
/* #Specification: strategy / in memory inode
* Here is the information specific to the inode of the UMSDOS file
* system. This information is added to the end of the standard struct
* inode. Each file system has its own extension to struct inode,
* so do the umsdos file system.
*
* The strategy is to have the umsdos_inode_info as a superset of
* the msdos_inode_info, since most of the time the job is done
* by the msdos fs code.
*
* So we duplicate the msdos_inode_info, and add our own info at the
* end.
*
* For all file type (and directory) the inode has a reference to:
* the directory which hold this entry: i_dir_owner
* The EMD file of i_dir_owner: i_emd_owner
* The offset in this EMD file of the entry: pos
*
* For directory, we also have a reference to the inode of its
* own EMD file. Also, we have dir_locking_info to help synchronise
* file creation and file lookup. This data is sharing space with
* the pipe_inode_info not used by directory. See also msdos_fs_i.h
* for more information about pipe_inode_info and msdos_inode_info.
*
* Special file and fifo do have an inode which correspond to an
* empty MSDOS file.
*
* symlink are processed mostly like regular file. The content is the
* link.
*
* fifos add there own extension to the inode. I have reserved some
* space for fifos side by side with msdos_inode_info. This is just
* to for the show, because msdos_inode_info already include the
* pipe_inode_info.
*
* The UMSDOS specific extension is placed after the union.
*/
struct dir_locking_info {
struct wait_queue *p;
short int looking; /* How many process doing a lookup */
short int creating; /* Is there any creation going on here
* Only one at a time, although one
* may recursively lock, so it is a counter
*/
long pid; /* pid of the process owning the creation */
/* lock */
};
struct umsdos_inode_info {
union {
struct msdos_inode_info msdos_info;
struct pipe_inode_info pipe_info;
struct dir_locking_info dir_info;
} u; /* Simply a filler, never referenced by fs/umsdos/... */
unsigned long i_dir_owner; /* Inode of the dir which hold this entry */
unsigned long i_emd_owner; /* Inode of the EMD file of i_dir_owner */
off_t pos; /* Entry offset in the emd_owner file */
/* The rest is used only if this inode describe a directory */
unsigned long i_emd_dir; /* Inode of the EMD file of this inode */
};
#endif
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