linux_dsm_epyc7002/fs/nfsd/vfs.h
Jeff Layton 65294c1f2c nfsd: add a new struct file caching facility to nfsd
Currently, NFSv2/3 reads and writes have to open a file, do the read or
write and then close it again for each RPC. This is highly inefficient,
especially when the underlying filesystem has a relatively slow open
routine.

This patch adds a new open file cache to knfsd. Rather than doing an
open for each RPC, the read/write handlers can call into this cache to
see if there is one already there for the correct filehandle and
NFS_MAY_READ/WRITE flags.

If there isn't an entry, then we create a new one and attempt to
perform the open. If there is, then we wait until the entry is fully
instantiated and return it if it is at the end of the wait. If it's
not, then we attempt to take over construction.

Since the main goal is to speed up NFSv2/3 I/O, we don't want to
close these files on last put of these objects. We need to keep them
around for a little while since we never know when the next READ/WRITE
will come in.

Cache entries have a hardcoded 1s timeout, and we have a recurring
workqueue job that walks the cache and purges any entries that have
expired.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Richard Sharpe <richard.sharpe@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:39 -04:00

178 lines
6.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef LINUX_NFSD_VFS_H
#define LINUX_NFSD_VFS_H
#include "nfsfh.h"
#include "nfsd.h"
/*
* Flags for nfsd_permission
*/
#define NFSD_MAY_NOP 0
#define NFSD_MAY_EXEC 0x001 /* == MAY_EXEC */
#define NFSD_MAY_WRITE 0x002 /* == MAY_WRITE */
#define NFSD_MAY_READ 0x004 /* == MAY_READ */
#define NFSD_MAY_SATTR 0x008
#define NFSD_MAY_TRUNC 0x010
#define NFSD_MAY_LOCK 0x020
#define NFSD_MAY_MASK 0x03f
/* extra hints to permission and open routines: */
#define NFSD_MAY_OWNER_OVERRIDE 0x040
#define NFSD_MAY_LOCAL_ACCESS 0x080 /* for device special files */
#define NFSD_MAY_BYPASS_GSS_ON_ROOT 0x100
#define NFSD_MAY_NOT_BREAK_LEASE 0x200
#define NFSD_MAY_BYPASS_GSS 0x400
#define NFSD_MAY_READ_IF_EXEC 0x800
#define NFSD_MAY_64BIT_COOKIE 0x1000 /* 64 bit readdir cookies for >= NFSv3 */
#define NFSD_MAY_CREATE (NFSD_MAY_EXEC|NFSD_MAY_WRITE)
#define NFSD_MAY_REMOVE (NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC)
/*
* Callback function for readdir
*/
typedef int (*nfsd_filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
/* nfsd/vfs.c */
int nfsd_racache_init(int);
void nfsd_racache_shutdown(void);
int nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
struct svc_export **expp);
__be32 nfsd_lookup(struct svc_rqst *, struct svc_fh *,
const char *, unsigned int, struct svc_fh *);
__be32 nfsd_lookup_dentry(struct svc_rqst *, struct svc_fh *,
const char *, unsigned int,
struct svc_export **, struct dentry **);
__be32 nfsd_setattr(struct svc_rqst *, struct svc_fh *,
struct iattr *, int, time_t);
int nfsd_mountpoint(struct dentry *, struct svc_export *);
#ifdef CONFIG_NFSD_V4
__be32 nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *,
struct xdr_netobj *);
__be32 nfsd4_vfs_fallocate(struct svc_rqst *, struct svc_fh *,
struct file *, loff_t, loff_t, int);
__be32 nfsd4_clone_file_range(struct file *, u64, struct file *,
u64, u64);
#endif /* CONFIG_NFSD_V4 */
__be32 nfsd_create_locked(struct svc_rqst *, struct svc_fh *,
char *name, int len, struct iattr *attrs,
int type, dev_t rdev, struct svc_fh *res);
__be32 nfsd_create(struct svc_rqst *, struct svc_fh *,
char *name, int len, struct iattr *attrs,
int type, dev_t rdev, struct svc_fh *res);
#ifdef CONFIG_NFSD_V3
__be32 nfsd_access(struct svc_rqst *, struct svc_fh *, u32 *, u32 *);
__be32 do_nfsd_create(struct svc_rqst *, struct svc_fh *,
char *name, int len, struct iattr *attrs,
struct svc_fh *res, int createmode,
u32 *verifier, bool *truncp, bool *created);
__be32 nfsd_commit(struct svc_rqst *, struct svc_fh *,
loff_t, unsigned long);
#endif /* CONFIG_NFSD_V3 */
int nfsd_open_break_lease(struct inode *, int);
__be32 nfsd_open(struct svc_rqst *, struct svc_fh *, umode_t,
int, struct file **);
__be32 nfsd_open_verified(struct svc_rqst *, struct svc_fh *, umode_t,
int, struct file **);
struct raparms;
__be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct file *file, loff_t offset,
unsigned long *count);
__be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct file *file, loff_t offset,
struct kvec *vec, int vlen,
unsigned long *count);
__be32 nfsd_read(struct svc_rqst *, struct svc_fh *,
loff_t, struct kvec *, int, unsigned long *);
__be32 nfsd_write(struct svc_rqst *, struct svc_fh *, loff_t,
struct kvec *, int, unsigned long *, int);
__be32 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct file *file, loff_t offset,
struct kvec *vec, int vlen, unsigned long *cnt,
int stable);
__be32 nfsd_readlink(struct svc_rqst *, struct svc_fh *,
char *, int *);
__be32 nfsd_symlink(struct svc_rqst *, struct svc_fh *,
char *name, int len, char *path,
struct svc_fh *res);
__be32 nfsd_link(struct svc_rqst *, struct svc_fh *,
char *, int, struct svc_fh *);
ssize_t nfsd_copy_file_range(struct file *, u64,
struct file *, u64, u64);
__be32 nfsd_rename(struct svc_rqst *,
struct svc_fh *, char *, int,
struct svc_fh *, char *, int);
__be32 nfsd_unlink(struct svc_rqst *, struct svc_fh *, int type,
char *name, int len);
__be32 nfsd_readdir(struct svc_rqst *, struct svc_fh *,
loff_t *, struct readdir_cd *, nfsd_filldir_t);
__be32 nfsd_statfs(struct svc_rqst *, struct svc_fh *,
struct kstatfs *, int access);
__be32 nfsd_permission(struct svc_rqst *, struct svc_export *,
struct dentry *, int);
struct raparms *nfsd_init_raparms(struct file *file);
void nfsd_put_raparams(struct file *file, struct raparms *ra);
static inline int fh_want_write(struct svc_fh *fh)
{
int ret;
if (fh->fh_want_write)
return 0;
ret = mnt_want_write(fh->fh_export->ex_path.mnt);
if (!ret)
fh->fh_want_write = true;
return ret;
}
static inline void fh_drop_write(struct svc_fh *fh)
{
if (fh->fh_want_write) {
fh->fh_want_write = false;
mnt_drop_write(fh->fh_export->ex_path.mnt);
}
}
static inline __be32 fh_getattr(struct svc_fh *fh, struct kstat *stat)
{
struct path p = {.mnt = fh->fh_export->ex_path.mnt,
.dentry = fh->fh_dentry};
return nfserrno(vfs_getattr(&p, stat, STATX_BASIC_STATS,
AT_STATX_SYNC_AS_STAT));
}
static inline int nfsd_create_is_exclusive(int createmode)
{
return createmode == NFS3_CREATE_EXCLUSIVE
|| createmode == NFS4_CREATE_EXCLUSIVE4_1;
}
static inline bool nfsd_eof_on_read(long requested, long read,
loff_t offset, loff_t size)
{
/* We assume a short read means eof: */
if (requested > read)
return true;
/*
* A non-short read might also reach end of file. The spec
* still requires us to set eof in that case.
*
* Further operations may have modified the file size since
* the read, so the following check is not atomic with the read.
* We've only seen that cause a problem for a client in the case
* where the read returned a count of 0 without setting eof.
* That case was fixed by the addition of the above check.
*/
return (offset + read >= size);
}
#endif /* LINUX_NFSD_VFS_H */