linux/fs/coda/upcall.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Mostly platform independent upcall operations to Venus:
 *  -- upcalls
 *  -- upcall routines
 *
 * Linux 2.0 version
 * Copyright (C) 1996 Peter J. Braam <[email protected]>, 
 * Michael Callahan <[email protected]> 
 * 
 * Redone for Linux 2.1
 * Copyright (C) 1997 Carnegie Mellon University
 *
 * Carnegie Mellon University encourages users of this code to contribute
 * improvements to the Coda project. Contact Peter Braam <[email protected]>.
 */

#include <linux/signal.h>
#include <linux/sched/signal.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/vfs.h>

#include <linux/coda.h>
#include "coda_psdev.h"
#include "coda_linux.h"
#include "coda_cache.h"

#include "coda_int.h"

static int coda_upcall(struct venus_comm *vc, int inSize, int *outSize,
		       union inputArgs *buffer);

static void *alloc_upcall(int opcode, int size)
{ … }

#define UPARG(op) …

#define INSIZE(tag) …
#define OUTSIZE(tag) …
#define SIZE(tag) …


/* the upcalls */
int venus_rootfid(struct super_block *sb, struct CodaFid *fidp)
{ … }

int venus_getattr(struct super_block *sb, struct CodaFid *fid, 
		     struct coda_vattr *attr) 
{ … }

int venus_setattr(struct super_block *sb, struct CodaFid *fid, 
		  struct coda_vattr *vattr)
{ … }

int venus_lookup(struct super_block *sb, struct CodaFid *fid, 
		    const char *name, int length, int * type, 
		    struct CodaFid *resfid)
{ … }

int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
		kuid_t uid)
{ … }

int venus_open(struct super_block *sb, struct CodaFid *fid,
		  int flags, struct file **fh)
{ … }	

int venus_mkdir(struct super_block *sb, struct CodaFid *dirfid, 
		   const char *name, int length, 
		   struct CodaFid *newfid, struct coda_vattr *attrs)
{ … }


int venus_rename(struct super_block *sb, struct CodaFid *old_fid, 
		 struct CodaFid *new_fid, size_t old_length, 
		 size_t new_length, const char *old_name, 
		 const char *new_name)
{ … }

int venus_create(struct super_block *sb, struct CodaFid *dirfid, 
		 const char *name, int length, int excl, int mode,
		 struct CodaFid *newfid, struct coda_vattr *attrs) 
{ … }

int venus_rmdir(struct super_block *sb, struct CodaFid *dirfid, 
		    const char *name, int length)
{ … }

int venus_remove(struct super_block *sb, struct CodaFid *dirfid, 
		    const char *name, int length)
{ … }

int venus_readlink(struct super_block *sb, struct CodaFid *fid, 
		      char *buffer, int *length)
{ … }



int venus_link(struct super_block *sb, struct CodaFid *fid, 
		  struct CodaFid *dirfid, const char *name, int len )
{ … }

int venus_symlink(struct super_block *sb, struct CodaFid *fid,
		     const char *name, int len,
		     const char *symname, int symlen)
{ … }

int venus_fsync(struct super_block *sb, struct CodaFid *fid)
{ … }

int venus_access(struct super_block *sb, struct CodaFid *fid, int mask)
{ … }


int venus_pioctl(struct super_block *sb, struct CodaFid *fid,
		 unsigned int cmd, struct PioctlData *data)
{ … }

int venus_statfs(struct dentry *dentry, struct kstatfs *sfs)
{ … }

int venus_access_intent(struct super_block *sb, struct CodaFid *fid,
			bool *access_intent_supported,
			size_t count, loff_t ppos, int type)
{ … }

/*
 * coda_upcall and coda_downcall routines.
 */
static void coda_block_signals(sigset_t *old)
{ … }

static void coda_unblock_signals(sigset_t *old)
{ … }

/* Don't allow signals to interrupt the following upcalls before venus
 * has seen them,
 * - CODA_CLOSE or CODA_RELEASE upcall  (to avoid reference count problems)
 * - CODA_STORE				(to avoid data loss)
 * - CODA_ACCESS_INTENT                 (to avoid reference count problems)
 */
#define CODA_INTERRUPTIBLE(r) …

static inline void coda_waitfor_upcall(struct venus_comm *vcp,
				       struct upc_req *req)
{ … }


/*
 * coda_upcall will return an error in the case of
 * failed communication with Venus _or_ will peek at Venus
 * reply and return Venus' error.
 *
 * As venus has 2 types of errors, normal errors (positive) and internal
 * errors (negative), normal errors are negated, while internal errors
 * are all mapped to -EINTR, while showing a nice warning message. (jh)
 */
static int coda_upcall(struct venus_comm *vcp,
		       int inSize, int *outSize,
		       union inputArgs *buffer)
{ … }

/*  
    The statements below are part of the Coda opportunistic
    programming -- taken from the Mach/BSD kernel code for Coda. 
    You don't get correct semantics by stating what needs to be
    done without guaranteeing the invariants needed for it to happen.
    When will be have time to find out what exactly is going on?  (pjb)
*/


/* 
 * There are 7 cases where cache invalidations occur.  The semantics
 *  of each is listed here:
 *
 * CODA_FLUSH     -- flush all entries from the name cache and the cnode cache.
 * CODA_PURGEUSER -- flush all entries from the name cache for a specific user
 *                  This call is a result of token expiration.
 *
 * The next arise as the result of callbacks on a file or directory.
 * CODA_ZAPFILE   -- flush the cached attributes for a file.

 * CODA_ZAPDIR    -- flush the attributes for the dir and
 *                  force a new lookup for all the children
                    of this dir.

 *
 * The next is a result of Venus detecting an inconsistent file.
 * CODA_PURGEFID  -- flush the attribute for the file
 *                  purge it and its children from the dcache
 *
 * The last  allows Venus to replace local fids with global ones
 * during reintegration.
 *
 * CODA_REPLACE -- replace one CodaFid with another throughout the name cache */

int coda_downcall(struct venus_comm *vcp, int opcode, union outputArgs *out,
		  size_t nbytes)
{ … }