alistair23-linux/include/linux/nfs_fs_sb.h
David Howells 08734048b3 NFS: Define and create superblock-level objects
Define and create superblock-level cache index objects (as managed by
nfs_server structs).

Each superblock object is created in a server level index object and is itself
an index into which inode-level objects are inserted.

Ideally there would be one superblock-level object per server, and the former
would be folded into the latter; however, since the "nosharecache" option
exists this isn't possible.

The superblock object key is a sequence consisting of:

 (1) Certain superblock s_flags.

 (2) Various connection parameters that serve to distinguish superblocks for
     sget().

 (3) The volume FSID.

 (4) The security flavour.

 (5) The uniquifier length.

 (6) The uniquifier text.  This is normally an empty string, unless the fsc=xyz
     mount option was used to explicitly specify a uniquifier.

The key blob is of variable length, depending on the length of (6).

The superblock object is given no coherency data to carry in the auxiliary data
permitted by the cache.  It is assumed that the superblock is always coherent.

This patch also adds uniquification handling such that two otherwise identical
superblocks, at least one of which is marked "nosharecache", won't end up
trying to share the on-disk cache.  It will be possible to manually provide a
uniquifier through a mount option with a later patch to avoid the error
otherwise produced.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:42 +01:00

149 lines
4.5 KiB
C

#ifndef _NFS_FS_SB
#define _NFS_FS_SB
#include <linux/list.h>
#include <linux/backing-dev.h>
#include <linux/wait.h>
#include <asm/atomic.h>
struct nfs_iostats;
struct nlm_host;
/*
* The nfs_client identifies our client state to the server.
*/
struct nfs_client {
atomic_t cl_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 */
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 */
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 rpc_cred *cl_machine_cred;
#ifdef CONFIG_NFS_V4
u64 cl_clientid; /* constant */
nfs4_verifier cl_confirm;
unsigned long cl_state;
struct rb_root cl_openowner_id;
struct rb_root cl_lockowner_id;
struct list_head cl_delegations;
struct rb_root cl_state_owners;
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;
/* used for the setclientid verifier */
struct timespec cl_boot_time;
/* idmapper */
struct idmap * cl_idmap;
/* Our own IP address, as a null-terminated string.
* This is used to generate the clientid, and the callback address.
*/
char cl_ipaddr[48];
unsigned char cl_id_uniquifier;
#endif
#ifdef CONFIG_NFS_FSCACHE
struct fscache_cookie *fscache; /* client index cache cookie */
#endif
};
/*
* 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 * 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 */
struct nfs_fsid fsid;
__u64 maxfilesize; /* maximum file size */
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
#ifdef CONFIG_NFS_V4
u32 attr_bitmask[2];/* 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 */
#endif
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)
#endif