linux_dsm_epyc7002/include/linux/sunrpc/clnt.h
Jeff Layton 3c87ef6efb sunrpc: keep a count of swapfiles associated with the rpc_clnt
Jerome reported seeing a warning pop when working with a swapfile on
NFS. The nfs_swap_activate can end up calling sk_set_memalloc while
holding the rcu_read_lock and that function can sleep.

To fix that, we need to take a reference to the xprt while holding the
rcu_read_lock, set the socket up for swapping and then drop that
reference. But, xprt_put is not exported and having NFS deal with the
underlying xprt is a bit of layering violation anyway.

Fix this by adding a set of activate/deactivate functions that take a
rpc_clnt pointer instead of an rpc_xprt, and have nfs_swap_activate and
nfs_swap_deactivate call those.

Also, add a per-rpc_clnt atomic counter to keep track of the number of
active swapfiles associated with it. When the counter does a 0->1
transition, we enable swapping on the xprt, when we do a 1->0 transition
we disable swapping on it.

This also allows us to be a bit more selective with the RPC_TASK_SWAPPER
flag. If non-swapper and swapper clnts are sharing a xprt, then we only
need to flag the tasks from the swapper clnt with that flag.

Acked-by: Mel Gorman <mgorman@suse.de>
Reported-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-06-10 18:26:14 -04:00

187 lines
6.1 KiB
C

/*
* linux/include/linux/sunrpc/clnt.h
*
* Declarations for the high-level RPC client interface
*
* Copyright (C) 1995, 1996, Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_SUNRPC_CLNT_H
#define _LINUX_SUNRPC_CLNT_H
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/xprt.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/timer.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <asm/signal.h>
#include <linux/path.h>
#include <net/ipv6.h>
struct rpc_inode;
/*
* The high-level client handle
*/
struct rpc_clnt {
atomic_t cl_count; /* Number of references */
unsigned int cl_clid; /* client id */
struct list_head cl_clients; /* Global list of clients */
struct list_head cl_tasks; /* List of tasks */
spinlock_t cl_lock; /* spinlock */
struct rpc_xprt __rcu * cl_xprt; /* transport */
struct rpc_procinfo * cl_procinfo; /* procedure info */
u32 cl_prog, /* RPC program number */
cl_vers, /* RPC version number */
cl_maxproc; /* max procedure number */
struct rpc_auth * cl_auth; /* authenticator */
struct rpc_stat * cl_stats; /* per-program statistics */
struct rpc_iostats * cl_metrics; /* per-client statistics */
unsigned int cl_softrtry : 1,/* soft timeouts */
cl_discrtry : 1,/* disconnect before retry */
cl_noretranstimeo: 1,/* No retransmit timeouts */
cl_autobind : 1,/* use getport() */
cl_chatty : 1;/* be verbose */
struct rpc_rtt * cl_rtt; /* RTO estimator data */
const struct rpc_timeout *cl_timeout; /* Timeout strategy */
atomic_t cl_swapper; /* swapfile count */
int cl_nodelen; /* nodename length */
char cl_nodename[UNX_MAXNODENAME+1];
struct rpc_pipe_dir_head cl_pipedir_objects;
struct rpc_clnt * cl_parent; /* Points to parent of clones */
struct rpc_rtt cl_rtt_default;
struct rpc_timeout cl_timeout_default;
const struct rpc_program *cl_program;
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct dentry *cl_debugfs; /* debugfs directory */
#endif
};
/*
* General RPC program info
*/
#define RPC_MAXVERSION 4
struct rpc_program {
const char * name; /* protocol name */
u32 number; /* program number */
unsigned int nrvers; /* number of versions */
const struct rpc_version ** version; /* version array */
struct rpc_stat * stats; /* statistics */
const char * pipe_dir_name; /* path to rpc_pipefs dir */
};
struct rpc_version {
u32 number; /* version number */
unsigned int nrprocs; /* number of procs */
struct rpc_procinfo * procs; /* procedure array */
};
/*
* Procedure information
*/
struct rpc_procinfo {
u32 p_proc; /* RPC procedure number */
kxdreproc_t p_encode; /* XDR encode function */
kxdrdproc_t p_decode; /* XDR decode function */
unsigned int p_arglen; /* argument hdr length (u32) */
unsigned int p_replen; /* reply hdr length (u32) */
unsigned int p_count; /* call count */
unsigned int p_timer; /* Which RTT timer to use */
u32 p_statidx; /* Which procedure to account */
const char * p_name; /* name of procedure */
};
#ifdef __KERNEL__
struct rpc_create_args {
struct net *net;
int protocol;
struct sockaddr *address;
size_t addrsize;
struct sockaddr *saddress;
const struct rpc_timeout *timeout;
const char *servername;
const char *nodename;
const struct rpc_program *program;
u32 prognumber; /* overrides program->number */
u32 version;
rpc_authflavor_t authflavor;
unsigned long flags;
char *client_name;
struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
};
/* Values for "flags" field */
#define RPC_CLNT_CREATE_HARDRTRY (1UL << 0)
#define RPC_CLNT_CREATE_AUTOBIND (1UL << 2)
#define RPC_CLNT_CREATE_NONPRIVPORT (1UL << 3)
#define RPC_CLNT_CREATE_NOPING (1UL << 4)
#define RPC_CLNT_CREATE_DISCRTRY (1UL << 5)
#define RPC_CLNT_CREATE_QUIET (1UL << 6)
#define RPC_CLNT_CREATE_INFINITE_SLOTS (1UL << 7)
#define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT (1UL << 8)
#define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT (1UL << 9)
struct rpc_clnt *rpc_create(struct rpc_create_args *args);
struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
struct rpc_xprt *xprt);
struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *,
const struct rpc_program *, u32);
void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt);
struct rpc_clnt *rpc_clone_client(struct rpc_clnt *);
struct rpc_clnt *rpc_clone_client_set_auth(struct rpc_clnt *,
rpc_authflavor_t);
int rpc_switch_client_transport(struct rpc_clnt *,
struct xprt_create *,
const struct rpc_timeout *);
void rpc_shutdown_client(struct rpc_clnt *);
void rpc_release_client(struct rpc_clnt *);
void rpc_task_release_client(struct rpc_task *);
int rpcb_create_local(struct net *);
void rpcb_put_local(struct net *);
int rpcb_register(struct net *, u32, u32, int, unsigned short);
int rpcb_v4_register(struct net *net, const u32 program,
const u32 version,
const struct sockaddr *address,
const char *netid);
void rpcb_getport_async(struct rpc_task *);
void rpc_call_start(struct rpc_task *);
int rpc_call_async(struct rpc_clnt *clnt,
const struct rpc_message *msg, int flags,
const struct rpc_call_ops *tk_ops,
void *calldata);
int rpc_call_sync(struct rpc_clnt *clnt,
const struct rpc_message *msg, int flags);
struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred,
int flags);
int rpc_restart_call_prepare(struct rpc_task *);
int rpc_restart_call(struct rpc_task *);
void rpc_setbufsize(struct rpc_clnt *, unsigned int, unsigned int);
int rpc_protocol(struct rpc_clnt *);
struct net * rpc_net_ns(struct rpc_clnt *);
size_t rpc_max_payload(struct rpc_clnt *);
unsigned long rpc_get_timeout(struct rpc_clnt *clnt);
void rpc_force_rebind(struct rpc_clnt *);
size_t rpc_peeraddr(struct rpc_clnt *, struct sockaddr *, size_t);
const char *rpc_peeraddr2str(struct rpc_clnt *, enum rpc_display_format_t);
int rpc_localaddr(struct rpc_clnt *, struct sockaddr *, size_t);
const char *rpc_proc_name(const struct rpc_task *task);
#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_CLNT_H */