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linux-next/fs/nfs/nfs4_fs.h
Benjamin Coddington b4868b44c5 NFSv4: Wait for stateid updates after CLOSE/OPEN_DOWNGRADE
Since commit 0e0cb35b41 ("NFSv4: Handle NFS4ERR_OLD_STATEID in
CLOSE/OPEN_DOWNGRADE") the following livelock may occur if a CLOSE races
with the update of the nfs_state:

Process 1           Process 2           Server
=========           =========           ========
 OPEN file
                    OPEN file
                                        Reply OPEN (1)
                                        Reply OPEN (2)
 Update state (1)
 CLOSE file (1)
                                        Reply OLD_STATEID (1)
 CLOSE file (2)
                                        Reply CLOSE (-1)
                    Update state (2)
                    wait for state change
 OPEN file
                    wake
 CLOSE file
 OPEN file
                    wake
 CLOSE file
 ...
                    ...

We can avoid this situation by not issuing an immediate retry with a bumped
seqid when CLOSE/OPEN_DOWNGRADE receives NFS4ERR_OLD_STATEID.  Instead,
take the same approach used by OPEN and wait at least 5 seconds for
outstanding stateid updates to complete if we can detect that we're out of
sequence.

Note that after this change it is still possible (though unlikely) that
CLOSE waits a full 5 seconds, bumps the seqid, and retries -- and that
attempt races with another OPEN at the same time.  In order to avoid this
race (which would result in the livelock), update
nfs_need_update_open_stateid() to handle the case where:
 - the state is NFS_OPEN_STATE, and
 - the stateid doesn't match the current open stateid

Finally, nfs_need_update_open_stateid() is modified to be idempotent and
renamed to better suit the purpose of signaling that the stateid passed
is the next stateid in sequence.

Fixes: 0e0cb35b41 ("NFSv4: Handle NFS4ERR_OLD_STATEID in CLOSE/OPEN_DOWNGRADE")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-10-02 08:43:09 -04:00

668 lines
22 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/fs/nfs/nfs4_fs.h
*
* Copyright (C) 2005 Trond Myklebust
*
* NFSv4-specific filesystem definitions and declarations
*/
#ifndef __LINUX_FS_NFS_NFS4_FS_H
#define __LINUX_FS_NFS_NFS4_FS_H
#if defined(CONFIG_NFS_V4_2)
#define NFS4_MAX_MINOR_VERSION 2
#elif defined(CONFIG_NFS_V4_1)
#define NFS4_MAX_MINOR_VERSION 1
#else
#define NFS4_MAX_MINOR_VERSION 0
#endif
#if IS_ENABLED(CONFIG_NFS_V4)
#define NFS4_MAX_LOOP_ON_RECOVER (10)
#include <linux/seqlock.h>
struct idmap;
enum nfs4_client_state {
NFS4CLNT_MANAGER_RUNNING = 0,
NFS4CLNT_CHECK_LEASE,
NFS4CLNT_LEASE_EXPIRED,
NFS4CLNT_RECLAIM_REBOOT,
NFS4CLNT_RECLAIM_NOGRACE,
NFS4CLNT_DELEGRETURN,
NFS4CLNT_SESSION_RESET,
NFS4CLNT_LEASE_CONFIRM,
NFS4CLNT_SERVER_SCOPE_MISMATCH,
NFS4CLNT_PURGE_STATE,
NFS4CLNT_BIND_CONN_TO_SESSION,
NFS4CLNT_MOVED,
NFS4CLNT_LEASE_MOVED,
NFS4CLNT_DELEGATION_EXPIRED,
NFS4CLNT_RUN_MANAGER,
NFS4CLNT_RECALL_RUNNING,
NFS4CLNT_RECALL_ANY_LAYOUT_READ,
NFS4CLNT_RECALL_ANY_LAYOUT_RW,
};
#define NFS4_RENEW_TIMEOUT 0x01
#define NFS4_RENEW_DELEGATION_CB 0x02
struct nfs_seqid_counter;
struct nfs4_minor_version_ops {
u32 minor_version;
unsigned init_caps;
int (*init_client)(struct nfs_client *);
void (*shutdown_client)(struct nfs_client *);
bool (*match_stateid)(const nfs4_stateid *,
const nfs4_stateid *);
int (*find_root_sec)(struct nfs_server *, struct nfs_fh *,
struct nfs_fsinfo *);
void (*free_lock_state)(struct nfs_server *,
struct nfs4_lock_state *);
int (*test_and_free_expired)(struct nfs_server *,
nfs4_stateid *, const struct cred *);
struct nfs_seqid *
(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
void (*session_trunk)(struct rpc_clnt *clnt,
struct rpc_xprt *xprt, void *data);
const struct rpc_call_ops *call_sync_ops;
const struct nfs4_state_recovery_ops *reboot_recovery_ops;
const struct nfs4_state_recovery_ops *nograce_recovery_ops;
const struct nfs4_state_maintenance_ops *state_renewal_ops;
const struct nfs4_mig_recovery_ops *mig_recovery_ops;
};
#define NFS_SEQID_CONFIRMED 1
struct nfs_seqid_counter {
ktime_t create_time;
int owner_id;
int flags;
u32 counter;
spinlock_t lock; /* Protects the list */
struct list_head list; /* Defines sequence of RPC calls */
struct rpc_wait_queue wait; /* RPC call delay queue */
};
struct nfs_seqid {
struct nfs_seqid_counter *sequence;
struct list_head list;
struct rpc_task *task;
};
static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
{
if (seqid_mutating_err(-status))
seqid->flags |= NFS_SEQID_CONFIRMED;
}
/*
* NFS4 state_owners and lock_owners are simply labels for ordered
* sequences of RPC calls. Their sole purpose is to provide once-only
* semantics by allowing the server to identify replayed requests.
*/
struct nfs4_state_owner {
struct nfs_server *so_server;
struct list_head so_lru;
unsigned long so_expires;
struct rb_node so_server_node;
const struct cred *so_cred; /* Associated cred */
spinlock_t so_lock;
atomic_t so_count;
unsigned long so_flags;
struct list_head so_states;
struct nfs_seqid_counter so_seqid;
seqcount_spinlock_t so_reclaim_seqcount;
struct mutex so_delegreturn_mutex;
};
enum {
NFS_OWNER_RECLAIM_REBOOT,
NFS_OWNER_RECLAIM_NOGRACE
};
#define NFS_LOCK_NEW 0
#define NFS_LOCK_RECLAIM 1
#define NFS_LOCK_EXPIRED 2
/*
* struct nfs4_state maintains the client-side state for a given
* (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
*
* OPEN:
* In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
* we need to know how many files are open for reading or writing on a
* given inode. This information too is stored here.
*
* LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
*/
struct nfs4_lock_state {
struct list_head ls_locks; /* Other lock stateids */
struct nfs4_state * ls_state; /* Pointer to open state */
#define NFS_LOCK_INITIALIZED 0
#define NFS_LOCK_LOST 1
unsigned long ls_flags;
struct nfs_seqid_counter ls_seqid;
nfs4_stateid ls_stateid;
refcount_t ls_count;
fl_owner_t ls_owner;
};
/* bits for nfs4_state->flags */
enum {
LK_STATE_IN_USE,
NFS_DELEGATED_STATE, /* Current stateid is delegation */
NFS_OPEN_STATE, /* OPEN stateid is set */
NFS_O_RDONLY_STATE, /* OPEN stateid has read-only state */
NFS_O_WRONLY_STATE, /* OPEN stateid has write-only state */
NFS_O_RDWR_STATE, /* OPEN stateid has read/write state */
NFS_STATE_RECLAIM_REBOOT, /* OPEN stateid server rebooted */
NFS_STATE_RECLAIM_NOGRACE, /* OPEN stateid needs to recover state */
NFS_STATE_POSIX_LOCKS, /* Posix locks are supported */
NFS_STATE_RECOVERY_FAILED, /* OPEN stateid state recovery failed */
NFS_STATE_MAY_NOTIFY_LOCK, /* server may CB_NOTIFY_LOCK */
NFS_STATE_CHANGE_WAIT, /* A state changing operation is outstanding */
NFS_CLNT_DST_SSC_COPY_STATE, /* dst server open state on client*/
NFS_CLNT_SRC_SSC_COPY_STATE, /* src server open state on client*/
NFS_SRV_SSC_COPY_STATE, /* ssc state on the dst server */
};
struct nfs4_state {
struct list_head open_states; /* List of states for the same state_owner */
struct list_head inode_states; /* List of states for the same inode */
struct list_head lock_states; /* List of subservient lock stateids */
struct nfs4_state_owner *owner; /* Pointer to the open owner */
struct inode *inode; /* Pointer to the inode */
unsigned long flags; /* Do we hold any locks? */
spinlock_t state_lock; /* Protects the lock_states list */
seqlock_t seqlock; /* Protects the stateid/open_stateid */
nfs4_stateid stateid; /* Current stateid: may be delegation */
nfs4_stateid open_stateid; /* OPEN stateid */
/* The following 3 fields are protected by owner->so_lock */
unsigned int n_rdonly; /* Number of read-only references */
unsigned int n_wronly; /* Number of write-only references */
unsigned int n_rdwr; /* Number of read/write references */
fmode_t state; /* State on the server (R,W, or RW) */
refcount_t count;
wait_queue_head_t waitq;
struct rcu_head rcu_head;
};
struct nfs4_exception {
struct nfs4_state *state;
struct inode *inode;
nfs4_stateid *stateid;
long timeout;
unsigned char delay : 1,
recovering : 1,
retry : 1;
bool interruptible;
};
struct nfs4_state_recovery_ops {
int owner_flag_bit;
int state_flag_bit;
int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
int (*recover_lock)(struct nfs4_state *, struct file_lock *);
int (*establish_clid)(struct nfs_client *, const struct cred *);
int (*reclaim_complete)(struct nfs_client *, const struct cred *);
int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
const struct cred *);
};
struct nfs4_opendata {
struct kref kref;
struct nfs_openargs o_arg;
struct nfs_openres o_res;
struct nfs_open_confirmargs c_arg;
struct nfs_open_confirmres c_res;
struct nfs4_string owner_name;
struct nfs4_string group_name;
struct nfs4_label *a_label;
struct nfs_fattr f_attr;
struct nfs4_label *f_label;
struct dentry *dir;
struct dentry *dentry;
struct nfs4_state_owner *owner;
struct nfs4_state *state;
struct iattr attrs;
struct nfs4_layoutget *lgp;
unsigned long timestamp;
bool rpc_done;
bool file_created;
bool is_recover;
bool cancelled;
int rpc_status;
};
struct nfs4_add_xprt_data {
struct nfs_client *clp;
const struct cred *cred;
};
struct nfs4_state_maintenance_ops {
int (*sched_state_renewal)(struct nfs_client *, const struct cred *, unsigned);
const struct cred * (*get_state_renewal_cred)(struct nfs_client *);
int (*renew_lease)(struct nfs_client *, const struct cred *);
};
struct nfs4_mig_recovery_ops {
int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
struct page *, const struct cred *);
int (*fsid_present)(struct inode *, const struct cred *);
};
extern const struct dentry_operations nfs4_dentry_operations;
/* dir.c */
int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
unsigned, umode_t);
/* fs_context.c */
extern struct file_system_type nfs4_fs_type;
/* nfs4namespace.c */
struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
const struct qstr *);
int nfs4_submount(struct fs_context *, struct nfs_server *);
int nfs4_replace_transport(struct nfs_server *server,
const struct nfs4_fs_locations *locations);
/* nfs4proc.c */
extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
extern int nfs4_async_handle_error(struct rpc_task *task,
struct nfs_server *server,
struct nfs4_state *state, long *timeout);
extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
struct rpc_message *, struct nfs4_sequence_args *,
struct nfs4_sequence_res *, int);
extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int, int);
extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, const struct cred *, struct nfs4_setclientid_res *);
extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, const struct cred *);
extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, const struct cred *cred);
extern int nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred);
extern int nfs4_destroy_clientid(struct nfs_client *clp);
extern int nfs4_init_clientid(struct nfs_client *, const struct cred *);
extern int nfs41_init_clientid(struct nfs_client *, const struct cred *);
extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
struct nfs4_fs_locations *, struct page *);
extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
struct page *page, const struct cred *);
extern int nfs4_proc_fsid_present(struct inode *, const struct cred *);
extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *,
struct dentry *,
struct nfs_fh *,
struct nfs_fattr *);
extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
extern const struct xattr_handler *nfs4_xattr_handlers[];
extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
const struct nfs_open_context *ctx,
const struct nfs_lock_context *l_ctx,
fmode_t fmode);
extern int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
struct nfs_fattr *fattr, struct nfs4_label *label,
struct inode *inode);
extern int update_open_stateid(struct nfs4_state *state,
const nfs4_stateid *open_stateid,
const nfs4_stateid *deleg_stateid,
fmode_t fmode);
extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
struct nfs_fsinfo *fsinfo);
extern void nfs4_update_changeattr(struct inode *dir,
struct nfs4_change_info *cinfo,
unsigned long timestamp,
unsigned long cache_validity);
extern int nfs4_buf_to_pages_noslab(const void *buf, size_t buflen,
struct page **pages);
#if defined(CONFIG_NFS_V4_1)
extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
extern int nfs4_proc_create_session(struct nfs_client *, const struct cred *);
extern int nfs4_proc_destroy_session(struct nfs4_session *, const struct cred *);
extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
bool sync);
extern int nfs4_detect_session_trunking(struct nfs_client *clp,
struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);
static inline bool
is_ds_only_client(struct nfs_client *clp)
{
return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
EXCHGID4_FLAG_USE_PNFS_DS;
}
static inline bool
is_ds_client(struct nfs_client *clp)
{
return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
}
static inline bool
_nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
struct rpc_clnt **clntp, struct rpc_message *msg)
{
rpc_authflavor_t flavor;
if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
/* Using machine creds for cleanup operations
* is only relevent if the client credentials
* might expire. So don't bother for
* RPC_AUTH_UNIX. If file was only exported to
* sec=sys, the PUTFH would fail anyway.
*/
if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
return false;
}
if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
msg->rpc_cred = rpc_machine_cred();
flavor = clp->cl_rpcclient->cl_auth->au_flavor;
WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
flavor != RPC_AUTH_GSS_KRB5P);
*clntp = clp->cl_rpcclient;
return true;
}
return false;
}
/*
* Function responsible for determining if an rpc_message should use the
* machine cred under SP4_MACH_CRED and if so switching the credential and
* authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
* Should be called before rpc_call_sync/rpc_call_async.
*/
static inline void
nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
struct rpc_clnt **clntp, struct rpc_message *msg)
{
_nfs4_state_protect(clp, sp4_mode, clntp, msg);
}
/*
* Special wrapper to nfs4_state_protect for write.
* If WRITE can use machine cred but COMMIT cannot, make sure all writes
* that use machine cred use NFS_FILE_SYNC.
*/
static inline void
nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
struct rpc_message *msg, struct nfs_pgio_header *hdr)
{
if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
!test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
hdr->args.stable = NFS_FILE_SYNC;
}
#else /* CONFIG_NFS_v4_1 */
static inline bool
is_ds_only_client(struct nfs_client *clp)
{
return false;
}
static inline bool
is_ds_client(struct nfs_client *clp)
{
return false;
}
static inline void
nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
struct rpc_clnt **clntp, struct rpc_message *msg)
{
}
static inline void
nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
struct rpc_message *msg, struct nfs_pgio_header *hdr)
{
}
#endif /* CONFIG_NFS_V4_1 */
extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
extern const u32 nfs4_fattr_bitmap[3];
extern const u32 nfs4_statfs_bitmap[3];
extern const u32 nfs4_pathconf_bitmap[3];
extern const u32 nfs4_fsinfo_bitmap[3];
extern const u32 nfs4_fs_locations_bitmap[3];
void nfs40_shutdown_client(struct nfs_client *);
void nfs41_shutdown_client(struct nfs_client *);
int nfs40_init_client(struct nfs_client *);
int nfs41_init_client(struct nfs_client *);
void nfs4_free_client(struct nfs_client *);
struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
/* nfs4renewd.c */
extern void nfs4_schedule_state_renewal(struct nfs_client *);
extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
extern void nfs4_kill_renewd(struct nfs_client *);
extern void nfs4_renew_state(struct work_struct *);
extern void nfs4_set_lease_period(struct nfs_client *clp, unsigned long lease);
/* nfs4state.c */
extern const nfs4_stateid current_stateid;
const struct cred *nfs4_get_clid_cred(struct nfs_client *clp);
const struct cred *nfs4_get_machine_cred(struct nfs_client *clp);
const struct cred *nfs4_get_renew_cred(struct nfs_client *clp);
int nfs4_discover_server_trunking(struct nfs_client *clp,
struct nfs_client **);
int nfs40_discover_server_trunking(struct nfs_client *clp,
struct nfs_client **, const struct cred *);
#if defined(CONFIG_NFS_V4_1)
int nfs41_discover_server_trunking(struct nfs_client *clp,
struct nfs_client **, const struct cred *);
extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
extern void nfs41_notify_server(struct nfs_client *);
bool nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
struct nfs41_server_owner *o2);
#else
static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
{
}
#endif /* CONFIG_NFS_V4_1 */
extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, const struct cred *, gfp_t);
extern void nfs4_put_state_owner(struct nfs4_state_owner *);
extern void nfs4_purge_state_owners(struct nfs_server *, struct list_head *);
extern void nfs4_free_state_owners(struct list_head *head);
extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
extern void nfs4_put_open_state(struct nfs4_state *);
extern void nfs4_close_state(struct nfs4_state *, fmode_t);
extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
extern void nfs_inode_find_state_and_recover(struct inode *inode,
const nfs4_stateid *stateid);
extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
extern void nfs4_schedule_lease_recovery(struct nfs_client *);
extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
extern void nfs4_schedule_state_manager(struct nfs_client *);
extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
extern void nfs41_handle_server_scope(struct nfs_client *,
struct nfs41_server_scope **);
extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
const struct nfs_lock_context *, nfs4_stateid *,
const struct cred **);
extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
struct nfs4_state *state);
extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
extern void nfs_release_seqid(struct nfs_seqid *seqid);
extern void nfs_free_seqid(struct nfs_seqid *seqid);
extern int nfs4_setup_sequence(struct nfs_client *client,
struct nfs4_sequence_args *args,
struct nfs4_sequence_res *res,
struct rpc_task *task);
extern int nfs4_sequence_done(struct rpc_task *task,
struct nfs4_sequence_res *res);
extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
extern int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct nfs_commitres *res);
extern const nfs4_stateid zero_stateid;
extern const nfs4_stateid invalid_stateid;
/* nfs4super.c */
struct nfs_mount_info;
extern struct nfs_subversion nfs_v4;
extern bool nfs4_disable_idmapping;
extern unsigned short max_session_slots;
extern unsigned short max_session_cb_slots;
extern unsigned short send_implementation_id;
extern bool recover_lost_locks;
#define NFS4_CLIENT_ID_UNIQ_LEN (64)
extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
extern int nfs4_try_get_tree(struct fs_context *);
extern int nfs4_get_referral_tree(struct fs_context *);
/* nfs4sysctl.c */
#ifdef CONFIG_SYSCTL
int nfs4_register_sysctl(void);
void nfs4_unregister_sysctl(void);
#else
static inline int nfs4_register_sysctl(void)
{
return 0;
}
static inline void nfs4_unregister_sysctl(void)
{
}
#endif
/* nfs4xdr.c */
extern const struct rpc_procinfo nfs4_procedures[];
#ifdef CONFIG_NFS_V4_2
extern const u32 nfs42_maxsetxattr_overhead;
extern const u32 nfs42_maxgetxattr_overhead;
extern const u32 nfs42_maxlistxattrs_overhead;
#endif
struct nfs4_mount_data;
/* callback_xdr.c */
extern const struct svc_version nfs4_callback_version1;
extern const struct svc_version nfs4_callback_version4;
static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
{
memcpy(dst->data, src->data, sizeof(dst->data));
dst->type = src->type;
}
static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
{
if (dst->type != src->type)
return false;
return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
}
static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
{
return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
}
static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
{
return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
}
static inline bool nfs4_stateid_is_next(const nfs4_stateid *s1, const nfs4_stateid *s2)
{
u32 seq1 = be32_to_cpu(s1->seqid);
u32 seq2 = be32_to_cpu(s2->seqid);
return seq2 == seq1 + 1U || (seq2 == 1U && seq1 == 0xffffffffU);
}
static inline bool nfs4_stateid_match_or_older(const nfs4_stateid *dst, const nfs4_stateid *src)
{
return nfs4_stateid_match_other(dst, src) &&
!(src->seqid && nfs4_stateid_is_newer(dst, src));
}
static inline void nfs4_stateid_seqid_inc(nfs4_stateid *s1)
{
u32 seqid = be32_to_cpu(s1->seqid);
if (++seqid == 0)
++seqid;
s1->seqid = cpu_to_be32(seqid);
}
static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
{
return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
}
static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
const nfs4_stateid *stateid)
{
return test_bit(NFS_OPEN_STATE, &state->flags) &&
nfs4_stateid_match_other(&state->open_stateid, stateid);
}
/* nfs42xattr.c */
#ifdef CONFIG_NFS_V4_2
extern int __init nfs4_xattr_cache_init(void);
extern void nfs4_xattr_cache_exit(void);
extern void nfs4_xattr_cache_add(struct inode *inode, const char *name,
const char *buf, struct page **pages,
ssize_t buflen);
extern void nfs4_xattr_cache_remove(struct inode *inode, const char *name);
extern ssize_t nfs4_xattr_cache_get(struct inode *inode, const char *name,
char *buf, ssize_t buflen);
extern void nfs4_xattr_cache_set_list(struct inode *inode, const char *buf,
ssize_t buflen);
extern ssize_t nfs4_xattr_cache_list(struct inode *inode, char *buf,
ssize_t buflen);
extern void nfs4_xattr_cache_zap(struct inode *inode);
#else
static inline void nfs4_xattr_cache_zap(struct inode *inode)
{
}
#endif /* CONFIG_NFS_V4_2 */
#else /* CONFIG_NFS_V4 */
#define nfs4_close_state(a, b) do { } while (0)
#define nfs4_close_sync(a, b) do { } while (0)
#define nfs4_state_protect(a, b, c, d) do { } while (0)
#define nfs4_state_protect_write(a, b, c, d) do { } while (0)
#endif /* CONFIG_NFS_V4 */
#endif /* __LINUX_FS_NFS_NFS4_FS.H */