kernel-ark/include/linux/coda_linux.h
Jan Harkes d3fec424b2 coda: remove CODA_STORE/CODA_RELEASE upcalls
This is an variation on the patch sent by Christoph Hellwig which kills
file_count abuse by the Coda kernel module by moving the coda_flush
functionality into coda_release.  However part of reason we were using the
coda_flush callback was to allow Coda to pass errors that occur during
writeback from the userspace cache manager back to close().

As Al Viro explained on linux-fsdevel, it is impossible to guarantee that
such errors can in fact be returned back to the caller.  There are many
cases where the last reference to a file is not released by the close
system call and it is also impossible to pick some close as a 'last-close'
and delay it until all other references have been destroyed.

The CODA_STORE/CODA_RELEASE upcall combination is clearly a broken design,
and it is better to remove it completely.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:14 -07:00

99 lines
3.0 KiB
C

/*
* Coda File System, Linux Kernel module
*
* Original version, adapted from cfs_mach.c, (C) Carnegie Mellon University
* Linux modifications (C) 1996, Peter J. Braam
* Rewritten for Linux 2.1 (C) 1997 Carnegie Mellon University
*
* Carnegie Mellon University encourages users of this software to
* contribute improvements to the Coda project.
*/
#ifndef _LINUX_CODA_FS
#define _LINUX_CODA_FS
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/coda_fs_i.h>
/* operations */
extern const struct inode_operations coda_dir_inode_operations;
extern const struct inode_operations coda_file_inode_operations;
extern const struct inode_operations coda_ioctl_inode_operations;
extern const struct address_space_operations coda_file_aops;
extern const struct address_space_operations coda_symlink_aops;
extern const struct file_operations coda_dir_operations;
extern const struct file_operations coda_file_operations;
extern const struct file_operations coda_ioctl_operations;
/* operations shared over more than one file */
int coda_open(struct inode *i, struct file *f);
int coda_release(struct inode *i, struct file *f);
int coda_permission(struct inode *inode, int mask, struct nameidata *nd);
int coda_revalidate_inode(struct dentry *);
int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *);
int coda_setattr(struct dentry *, struct iattr *);
/* this file: heloers */
static __inline__ struct CodaFid *coda_i2f(struct inode *);
static __inline__ char *coda_i2s(struct inode *);
static __inline__ void coda_flag_inode(struct inode *, int flag);
char *coda_f2s(struct CodaFid *f);
int coda_isroot(struct inode *i);
int coda_iscontrol(const char *name, size_t length);
void coda_vattr_to_iattr(struct inode *, struct coda_vattr *);
void coda_iattr_to_vattr(struct iattr *, struct coda_vattr *);
unsigned short coda_flags_to_cflags(unsigned short);
/* sysctl.h */
void coda_sysctl_init(void);
void coda_sysctl_clean(void);
#define CODA_ALLOC(ptr, cast, size) do { \
if (size < PAGE_SIZE) \
ptr = kmalloc((unsigned long) size, GFP_KERNEL); \
else \
ptr = (cast)vmalloc((unsigned long) size); \
if (!ptr) \
printk("kernel malloc returns 0 at %s:%d\n", __FILE__, __LINE__); \
else memset( ptr, 0, size ); \
} while (0)
#define CODA_FREE(ptr,size) \
do { if (size < PAGE_SIZE) kfree((ptr)); else vfree((ptr)); } while (0)
/* inode to cnode access functions */
static inline struct coda_inode_info *ITOC(struct inode *inode)
{
return list_entry(inode, struct coda_inode_info, vfs_inode);
}
static __inline__ struct CodaFid *coda_i2f(struct inode *inode)
{
return &(ITOC(inode)->c_fid);
}
static __inline__ char *coda_i2s(struct inode *inode)
{
return coda_f2s(&(ITOC(inode)->c_fid));
}
/* this will not zap the inode away */
static __inline__ void coda_flag_inode(struct inode *inode, int flag)
{
ITOC(inode)->c_flags |= flag;
}
#endif