kernel-ark/include/linux/nfs_fs_sb.h
Chuck Lever 05f4c350ee NFS: Discover NFSv4 server trunking when mounting
"Server trunking" is a fancy named for a multi-homed NFS server.
Trunking might occur if a client sends NFS requests for a single
workload to multiple network interfaces on the same server.  There
are some implications for NFSv4 state management that make it useful
for a client to know if a single NFSv4 server instance is
multi-homed.  (Note this is only a consideration for NFSv4, not for
legacy versions of NFS, which are stateless).

If a client cares about server trunking, no NFSv4 operations can
proceed until that client determines who it is talking to.  Thus
server IP trunking discovery must be done when the client first
encounters an unfamiliar server IP address.

The nfs_get_client() function walks the nfs_client_list and matches
on server IP address.  The outcome of that walk tells us immediately
if we have an unfamiliar server IP address.  It invokes
nfs_init_client() in this case.  Thus, nfs4_init_client() is a good
spot to perform trunking discovery.

Discovery requires a client to establish a fresh client ID, so our
client will now send SETCLIENTID or EXCHANGE_ID as the first NFS
operation after a successful ping, rather than waiting for an
application to perform an operation that requires NFSv4 state.

The exact process for detecting trunking is different for NFSv4.0 and
NFSv4.1, so a minorversion-specific init_client callout method is
introduced.

CLID_INUSE recovery is important for the trunking discovery process.
CLID_INUSE is a sign the server recognizes the client's nfs_client_id4
id string, but the client is using the wrong principal this time for
the SETCLIENTID operation.  The SETCLIENTID must be retried with a
series of different principals until one works, and then the rest of
trunking discovery can proceed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-10-01 15:33:33 -07:00

249 lines
7.9 KiB
C

#ifndef _NFS_FS_SB
#define _NFS_FS_SB
#include <linux/list.h>
#include <linux/backing-dev.h>
#include <linux/idr.h>
#include <linux/wait.h>
#include <linux/nfs_xdr.h>
#include <linux/sunrpc/xprt.h>
#include <linux/atomic.h>
struct nfs4_session;
struct nfs_iostats;
struct nlm_host;
struct nfs4_sequence_args;
struct nfs4_sequence_res;
struct nfs_server;
struct nfs4_minor_version_ops;
struct nfs41_server_scope;
struct nfs41_impl_id;
/*
* The nfs_client identifies our client state to the server.
*/
struct nfs_client {
atomic_t cl_count;
atomic_t cl_mds_count;
int cl_cons_state; /* current construction state (-ve: init error) */
#define NFS_CS_READY 0 /* ready to be used */
#define NFS_CS_INITING 1 /* busy initialising */
#define NFS_CS_SESSION_INITING 2 /* busy initialising session */
unsigned long cl_res_state; /* NFS resources state */
#define NFS_CS_CALLBACK 1 /* - callback started */
#define NFS_CS_IDMAP 2 /* - idmap started */
#define NFS_CS_RENEWD 3 /* - renewd started */
#define NFS_CS_STOP_RENEW 4 /* no more state to renew */
#define NFS_CS_CHECK_LEASE_TIME 5 /* need to check lease time */
unsigned long cl_flags; /* behavior switches */
#define NFS_CS_NORESVPORT 0 /* - use ephemeral src port */
#define NFS_CS_DISCRTRY 1 /* - disconnect on RPC retry */
#define NFS_CS_MIGRATION 2 /* - transparent state migr */
struct sockaddr_storage cl_addr; /* server identifier */
size_t cl_addrlen;
char * cl_hostname; /* hostname of server */
struct list_head cl_share_link; /* link in global client list */
struct list_head cl_superblocks; /* List of nfs_server structs */
struct rpc_clnt * cl_rpcclient;
const struct nfs_rpc_ops *rpc_ops; /* NFS protocol vector */
int cl_proto; /* Network transport protocol */
struct nfs_subversion * cl_nfs_mod; /* pointer to nfs version module */
u32 cl_minorversion;/* NFSv4 minorversion */
struct rpc_cred *cl_machine_cred;
#if IS_ENABLED(CONFIG_NFS_V4)
u64 cl_clientid; /* constant */
nfs4_verifier cl_confirm; /* Clientid verifier */
unsigned long cl_state;
spinlock_t cl_lock;
unsigned long cl_lease_time;
unsigned long cl_last_renewal;
struct delayed_work cl_renewd;
struct rpc_wait_queue cl_rpcwaitq;
/* idmapper */
struct idmap * cl_idmap;
/* Our own IP address, as a null-terminated string.
* This is used to generate the mv0 callback address.
*/
char cl_ipaddr[48];
u32 cl_cb_ident; /* v4.0 callback identifier */
const struct nfs4_minor_version_ops *cl_mvops;
/* The sequence id to use for the next CREATE_SESSION */
u32 cl_seqid;
/* The flags used for obtaining the clientid during EXCHANGE_ID */
u32 cl_exchange_flags;
struct nfs4_session *cl_session; /* shared session */
bool cl_preserve_clid;
struct nfs41_server_owner *cl_serverowner;
struct nfs41_server_scope *cl_serverscope;
struct nfs41_impl_id *cl_implid;
#endif /* CONFIG_NFS_V4 */
#ifdef CONFIG_NFS_FSCACHE
struct fscache_cookie *fscache; /* client index cache cookie */
#endif
struct net *cl_net;
};
/*
* NFS client parameters stored in the superblock.
*/
struct nfs_server {
struct nfs_client * nfs_client; /* shared client and NFS4 state */
struct list_head client_link; /* List of other nfs_server structs
* that share the same client
*/
struct list_head master_link; /* link in master servers list */
struct rpc_clnt * client; /* RPC client handle */
struct rpc_clnt * client_acl; /* ACL RPC client handle */
struct nlm_host *nlm_host; /* NLM client handle */
struct nfs_iostats __percpu *io_stats; /* I/O statistics */
struct backing_dev_info backing_dev_info;
atomic_long_t writeback; /* number of writeback pages */
int flags; /* various flags */
unsigned int caps; /* server capabilities */
unsigned int rsize; /* read size */
unsigned int rpages; /* read size (in pages) */
unsigned int wsize; /* write size */
unsigned int wpages; /* write size (in pages) */
unsigned int wtmult; /* server disk block size */
unsigned int dtsize; /* readdir size */
unsigned short port; /* "port=" setting */
unsigned int bsize; /* server block size */
unsigned int acregmin; /* attr cache timeouts */
unsigned int acregmax;
unsigned int acdirmin;
unsigned int acdirmax;
unsigned int namelen;
unsigned int options; /* extra options enabled by mount */
#define NFS_OPTION_FSCACHE 0x00000001 /* - local caching enabled */
#define NFS_OPTION_MIGRATION 0x00000002 /* - NFSv4 migration enabled */
struct nfs_fsid fsid;
__u64 maxfilesize; /* maximum file size */
struct timespec time_delta; /* smallest time granularity */
unsigned long mount_time; /* when this fs was mounted */
dev_t s_dev; /* superblock dev numbers */
#ifdef CONFIG_NFS_FSCACHE
struct nfs_fscache_key *fscache_key; /* unique key for superblock */
struct fscache_cookie *fscache; /* superblock cookie */
#endif
u32 pnfs_blksize; /* layout_blksize attr */
#if IS_ENABLED(CONFIG_NFS_V4)
u32 attr_bitmask[3];/* V4 bitmask representing the set
of attributes supported on this
filesystem */
u32 cache_consistency_bitmask[2];
/* V4 bitmask representing the subset
of change attribute, size, ctime
and mtime attributes supported by
the server */
u32 acl_bitmask; /* V4 bitmask representing the ACEs
that are supported on this
filesystem */
u32 fh_expire_type; /* V4 bitmask representing file
handle volatility type for
this filesystem */
struct pnfs_layoutdriver_type *pnfs_curr_ld; /* Active layout driver */
struct rpc_wait_queue roc_rpcwaitq;
void *pnfs_ld_data; /* per mount point data */
/* the following fields are protected by nfs_client->cl_lock */
struct rb_root state_owners;
#endif
struct ida openowner_id;
struct ida lockowner_id;
struct list_head state_owners_lru;
struct list_head layouts;
struct list_head delegations;
void (*destroy)(struct nfs_server *);
atomic_t active; /* Keep trace of any activity to this server */
/* mountd-related mount options */
struct sockaddr_storage mountd_address;
size_t mountd_addrlen;
u32 mountd_version;
unsigned short mountd_port;
unsigned short mountd_protocol;
};
/* Server capabilities */
#define NFS_CAP_READDIRPLUS (1U << 0)
#define NFS_CAP_HARDLINKS (1U << 1)
#define NFS_CAP_SYMLINKS (1U << 2)
#define NFS_CAP_ACLS (1U << 3)
#define NFS_CAP_ATOMIC_OPEN (1U << 4)
#define NFS_CAP_CHANGE_ATTR (1U << 5)
#define NFS_CAP_FILEID (1U << 6)
#define NFS_CAP_MODE (1U << 7)
#define NFS_CAP_NLINK (1U << 8)
#define NFS_CAP_OWNER (1U << 9)
#define NFS_CAP_OWNER_GROUP (1U << 10)
#define NFS_CAP_ATIME (1U << 11)
#define NFS_CAP_CTIME (1U << 12)
#define NFS_CAP_MTIME (1U << 13)
#define NFS_CAP_POSIX_LOCK (1U << 14)
#define NFS_CAP_UIDGID_NOMAP (1U << 15)
/* maximum number of slots to use */
#define NFS4_DEF_SLOT_TABLE_SIZE (16U)
#define NFS4_MAX_SLOT_TABLE (256U)
#define NFS4_NO_SLOT ((u32)-1)
#if IS_ENABLED(CONFIG_NFS_V4)
/* Sessions */
#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
struct nfs4_slot_table {
struct nfs4_slot *slots; /* seqid per slot */
unsigned long used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
spinlock_t slot_tbl_lock;
struct rpc_wait_queue slot_tbl_waitq; /* allocators may wait here */
u32 max_slots; /* # slots in table */
u32 highest_used_slotid; /* sent to server on each SEQ.
* op for dynamic resizing */
u32 target_max_slots; /* Set by CB_RECALL_SLOT as
* the new max_slots */
struct completion complete;
};
static inline int slot_idx(struct nfs4_slot_table *tbl, struct nfs4_slot *sp)
{
return sp - tbl->slots;
}
/*
* Session related parameters
*/
struct nfs4_session {
struct nfs4_sessionid sess_id;
u32 flags;
unsigned long session_state;
u32 hash_alg;
u32 ssv_len;
/* The fore and back channel */
struct nfs4_channel_attrs fc_attrs;
struct nfs4_slot_table fc_slot_table;
struct nfs4_channel_attrs bc_attrs;
struct nfs4_slot_table bc_slot_table;
struct nfs_client *clp;
};
#endif /* CONFIG_NFS_V4 */
#endif