freebsd-dev/sys/nfsclient/nfsmount.h
Doug Rabson f438ae02f5 Improve the queuing algorithms used by NFS' asynchronous i/o. The
existing mechanism uses a global queue for some buffers and the
vp->b_dirtyblkhd queue for others.  This turns sequential writes into
randomly ordered writes to the server, affecting both read and write
performance.  The existing mechanism also copes badly with hung
servers, tending to block accesses to other servers when all the iods
are waiting for a hung server.

The new mechanism uses a queue for each mount point.  All asynchronous
i/o goes through this queue which preserves the ordering of requests.
A simple mechanism ensures that the iods are shared out fairly between
active mount points.  This removes the sysctl variable vfs.nfs.dwrite
since the new queueing mechanism removes the old delayed write code
completely.

This should go into the 2.2 branch.
1996-11-06 10:53:16 +00:00

116 lines
4.4 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)nfsmount.h 8.1 (Berkeley) 6/10/93
* $Id: nfsmount.h,v 1.7 1995/12/17 21:12:36 phk Exp $
*/
#ifndef _NFS_NFSMOUNT_H_
#define _NFS_NFSMOUNT_H_
/*
* Mount structure.
* One allocated on every NFS mount.
* Holds NFS specific information for mount.
*/
struct nfsmount {
int nm_flag; /* Flags for soft/hard... */
struct mount *nm_mountp; /* Vfs structure for this filesystem */
int nm_numgrps; /* Max. size of groupslist */
u_char nm_fh[NFSX_V3FHMAX]; /* File handle of root dir */
int nm_fhsize; /* Size of root file handle */
struct socket *nm_so; /* Rpc socket */
int nm_sotype; /* Type of socket */
int nm_soproto; /* and protocol */
int nm_soflags; /* pr_flags for socket protocol */
struct mbuf *nm_nam; /* Addr of server */
int nm_timeo; /* Init timer for NFSMNT_DUMBTIMR */
int nm_retry; /* Max retries */
int nm_srtt[4]; /* Timers for rpcs */
int nm_sdrtt[4];
int nm_sent; /* Request send count */
int nm_cwnd; /* Request send window */
int nm_timeouts; /* Request timeouts */
int nm_deadthresh; /* Threshold of timeouts-->dead server*/
int nm_rsize; /* Max size of read rpc */
int nm_wsize; /* Max size of write rpc */
int nm_readdirsize; /* Size of a readdir rpc */
int nm_readahead; /* Num. of blocks to readahead */
int nm_leaseterm; /* Term (sec) for NQNFS lease */
CIRCLEQ_HEAD(, nfsnode) nm_timerhead; /* Head of lease timer queue */
struct vnode *nm_inprog; /* Vnode in prog by nqnfs_clientd() */
uid_t nm_authuid; /* Uid for authenticator */
int nm_authtype; /* Authenticator type */
int nm_authlen; /* and length */
char *nm_authstr; /* Authenticator string */
char *nm_verfstr; /* and the verifier */
int nm_verflen;
u_char nm_verf[NFSX_V3WRITEVERF]; /* V3 write verifier */
NFSKERBKEY_T nm_key; /* and the session key */
int nm_numuids; /* Number of nfsuid mappings */
TAILQ_HEAD(, nfsuid) nm_uidlruhead; /* Lists of nfsuid mappings */
LIST_HEAD(, nfsuid) nm_uidhashtbl[NFS_MUIDHASHSIZ];
TAILQ_HEAD(, buf) nm_bufq; /* async io buffer queue */
short nm_bufqlen; /* number of buffers in queue */
short nm_bufqwant; /* process wants to add to the queue */
int nm_bufqiods; /* number of iods processing queue */
};
#if defined(KERNEL) || defined(_KERNEL)
/*
* Convert mount ptr to nfsmount ptr.
*/
#define VFSTONFS(mp) ((struct nfsmount *)((mp)->mnt_data))
#ifdef NFS_DEBUG
extern int nfs_debug;
#define NFS_DEBUG_ASYNCIO 1
#define NFS_DPF(cat, args) \
do { \
if (nfs_debug & NFS_DEBUG_##cat) printf args; \
} while (0)
#else
#define NFS_DPF(cat, args)
#endif
#endif /* KERNEL */
#endif