freebsd-dev/sys/nfsclient/nfsnode.h
Rick Macklem 651ff543f8 Fix a race that can occur when nfs nfsiod threads are being created.
Without this patch it was possible for a different thread that calls
nfs_asyncio() to snitch a newly created nfsiod thread that was
intended for another caller of nfs_asyncio(), because the nfs_iod_mtx
mutex was unlocked while the new nfsiod thread was created. This patch
labels the newly created nfsiod, so that it is not taken by another
caller of nfs_asyncio(). This is believed to fix the problem reported
on the freebsd-stable email list under the subject:
FreeBSD NFS client/Linux NFS server issue.

Tested by:	to DOT my DOT trociny AT gmail DOT com
Reviewed by:	jhb
MFC after:	2 weeks
2010-01-27 15:22:20 +00:00

232 lines
8.1 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.
* 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.
*
* @(#)nfsnode.h 8.9 (Berkeley) 5/14/95
* $FreeBSD$
*/
#ifndef _NFSCLIENT_NFSNODE_H_
#define _NFSCLIENT_NFSNODE_H_
#if !defined(_NFSCLIENT_NFS_H_) && !defined(_KERNEL)
#include <nfs/nfs.h>
#endif
/*
* Silly rename structure that hangs off the nfsnode until the name
* can be removed by nfs_inactive()
*/
struct sillyrename {
struct ucred *s_cred;
struct vnode *s_dvp;
int (*s_removeit)(struct sillyrename *sp);
long s_namlen;
char s_name[32];
};
/*
* This structure is used to save the logical directory offset to
* NFS cookie mappings.
* The mappings are stored in a list headed
* by n_cookies, as required.
* There is one mapping for each NFS_DIRBLKSIZ bytes of directory information
* stored in increasing logical offset byte order.
*/
#define NFSNUMCOOKIES 31
struct nfsdmap {
LIST_ENTRY(nfsdmap) ndm_list;
int ndm_eocookie;
union {
nfsuint64 ndmu3_cookies[NFSNUMCOOKIES];
uint64_t ndmu4_cookies[NFSNUMCOOKIES];
} ndm_un1;
};
#define ndm_cookies ndm_un1.ndmu3_cookies
#define ndm4_cookies ndm_un1.ndmu4_cookies
#define n_ac_ts_tid n_ac_ts.nfs_ac_ts_tid
#define n_ac_ts_pid n_ac_ts.nfs_ac_ts_pid
#define n_ac_ts_syscalls n_ac_ts.nfs_ac_ts_syscalls
struct nfs_attrcache_timestamp {
lwpid_t nfs_ac_ts_tid;
pid_t nfs_ac_ts_pid;
unsigned long nfs_ac_ts_syscalls;
};
struct nfs_accesscache {
u_int32_t mode; /* ACCESS mode cache */
uid_t uid; /* credentials having mode */
time_t stamp; /* mode cache timestamp */
};
/*
* The nfsnode is the nfs equivalent to ufs's inode. Any similarity
* is purely coincidental.
* There is a unique nfsnode allocated for each active file,
* each current directory, each mounted-on file, text file, and the root.
* An nfsnode is 'named' by its file handle. (nget/nfs_node.c)
* If this structure exceeds 256 bytes (it is currently 256 using 4.4BSD-Lite
* type definitions), file handles of > 32 bytes should probably be split out
* into a separate MALLOC()'d data structure. (Reduce the size of nfsfh_t by
* changing the definition in nfsproto.h of NFS_SMALLFH.)
* NB: Hopefully the current order of the fields is such that everything will
* be well aligned and, therefore, tightly packed.
*/
struct nfsnode {
struct mtx n_mtx; /* Protects all of these members */
u_quad_t n_size; /* Current size of file */
u_quad_t n_brev; /* Modify rev when cached */
u_quad_t n_lrev; /* Modify rev for lease */
struct vattr n_vattr; /* Vnode attribute cache */
time_t n_attrstamp; /* Attr. cache timestamp */
struct nfs_accesscache n_accesscache[NFS_ACCESSCACHESIZE];
struct timespec n_mtime; /* Prev modify time. */
time_t n_ctime; /* Prev create time. */
time_t n_dmtime; /* Prev dir modify time. */
int n_dmtime_ticks; /* Tick of -ve cache entry */
time_t n_expiry; /* Lease expiry time */
nfsfh_t *n_fhp; /* NFS File Handle */
struct vnode *n_vnode; /* associated vnode */
struct vnode *n_dvp; /* parent vnode */
int n_error; /* Save write error value */
union {
struct timespec nf_atim; /* Special file times */
nfsuint64 nd_cookieverf; /* Cookie verifier (dir only) */
u_char nd4_cookieverf[NFSX_V4VERF];
} n_un1;
union {
struct timespec nf_mtim;
off_t nd_direof; /* Dir. EOF offset cache */
} n_un2;
union {
struct sillyrename *nf_silly; /* Ptr to silly rename struct */
LIST_HEAD(, nfsdmap) nd_cook; /* cookies */
} n_un3;
short n_fhsize; /* size in bytes, of fh */
short n_flag; /* Flag for locking.. */
nfsfh_t n_fh; /* Small File Handle */
u_char *n_name; /* leaf name, for v4 OPEN op */
uint32_t n_namelen;
int n_directio_opens;
int n_directio_asyncwr;
struct nfs_attrcache_timestamp n_ac_ts;
};
#define n_atim n_un1.nf_atim
#define n_mtim n_un2.nf_mtim
#define n_sillyrename n_un3.nf_silly
#define n_cookieverf n_un1.nd_cookieverf
#define n4_cookieverf n_un1.nd4_cookieverf
#define n_direofoffset n_un2.nd_direof
#define n_cookies n_un3.nd_cook
/*
* Flags for n_flag
*/
#define NFSYNCWAIT 0x0002 /* fsync waiting for all directio async writes
to drain */
#define NMODIFIED 0x0004 /* Might have a modified buffer in bio */
#define NWRITEERR 0x0008 /* Flag write errors so close will know */
/* 0x20, 0x40, 0x80 free */
#define NACC 0x0100 /* Special file accessed */
#define NUPD 0x0200 /* Special file updated */
#define NCHG 0x0400 /* Special file times changed */
#define NCREATED 0x0800 /* Opened by nfs_create() */
#define NTRUNCATE 0x1000 /* Opened by nfs_setattr() */
#define NSIZECHANGED 0x2000 /* File size has changed: need cache inval */
#define NNONCACHE 0x4000 /* Node marked as noncacheable */
#define NDIRCOOKIELK 0x8000 /* Lock to serialize access to directory cookies */
/*
* Convert between nfsnode pointers and vnode pointers
*/
#define VTONFS(vp) ((struct nfsnode *)(vp)->v_data)
#define NFSTOV(np) ((struct vnode *)(np)->n_vnode)
#define NFS_TIMESPEC_COMPARE(T1, T2) (((T1)->tv_sec != (T2)->tv_sec) || ((T1)->tv_nsec != (T2)->tv_nsec))
/*
* NFS iod threads can be in one of these three states once spawned.
* NFSIOD_NOT_AVAILABLE - Cannot be assigned an I/O operation at this time.
* NFSIOD_AVAILABLE - Available to be assigned an I/O operation.
* NFSIOD_CREATED_FOR_NFS_ASYNCIO - Newly created for nfs_asyncio() and
* will be used by the thread that called nfs_asyncio().
*/
enum nfsiod_state {
NFSIOD_NOT_AVAILABLE = 0,
NFSIOD_AVAILABLE = 1,
NFSIOD_CREATED_FOR_NFS_ASYNCIO = 2,
};
/*
* Queue head for nfsiod's
*/
extern TAILQ_HEAD(nfs_bufq, buf) nfs_bufq;
extern enum nfsiod_state nfs_iodwant[NFS_MAXASYNCDAEMON];
extern struct nfsmount *nfs_iodmount[NFS_MAXASYNCDAEMON];
#if defined(_KERNEL)
extern struct vop_vector nfs_fifoops;
extern struct vop_vector nfs_vnodeops;
extern struct buf_ops buf_ops_nfs;
extern vop_advlock_t *nfs_advlock_p;
extern vop_reclaim_t *nfs_reclaim_p;
/*
* Prototypes for NFS vnode operations
*/
int nfs_getpages(struct vop_getpages_args *);
int nfs_putpages(struct vop_putpages_args *);
int nfs_write(struct vop_write_args *);
int nfs_inactive(struct vop_inactive_args *);
int nfs_reclaim(struct vop_reclaim_args *);
/* other stuff */
int nfs_removeit(struct sillyrename *);
int nfs_nget(struct mount *, nfsfh_t *, int, struct nfsnode **, int flags);
nfsuint64 *nfs_getcookie(struct nfsnode *, off_t, int);
void nfs_invaldir(struct vnode *);
int nfs_upgrade_vnlock(struct vnode *vp);
void nfs_downgrade_vnlock(struct vnode *vp, int old_lock);
void nfs_printf(const char *fmt, ...);
void nfs_dircookie_lock(struct nfsnode *np);
void nfs_dircookie_unlock(struct nfsnode *np);
#endif /* _KERNEL */
#endif