diff options
author | Linus Torvalds | 2021-05-05 13:44:19 -0700 |
---|---|---|
committer | Linus Torvalds | 2021-05-05 13:44:19 -0700 |
commit | a79cdfba68a13b731004f0aafe1155a83830d472 (patch) | |
tree | d2159aa7e27e977ce1807ccb3de67fd7dd713131 /fs | |
parent | 7c9e41e0ef7d44a0818a3beec30634f3f588a23d (diff) | |
parent | b9f83ffaa0c096b4c832a43964fe6bff3acffe10 (diff) |
Merge tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull more nfsd updates from Chuck Lever:
"Additional fixes and clean-ups for NFSD since tags/nfsd-5.13,
including a fix to grant read delegations for files open for writing"
* tag 'nfsd-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
SUNRPC: Fix null pointer dereference in svc_rqst_free()
SUNRPC: fix ternary sign expansion bug in tracing
nfsd: Fix fall-through warnings for Clang
nfsd: grant read delegations to clients holding writes
nfsd: reshuffle some code
nfsd: track filehandle aliasing in nfs4_files
nfsd: hash nfs4_files by inode number
nfsd: ensure new clients break delegations
nfsd: removed unused argument in nfsd_startup_generic()
nfsd: remove unused function
svcrdma: Pass a useful error code to the send_err tracepoint
svcrdma: Rename goto labels in svc_rdma_sendto()
svcrdma: Don't leak send_ctxt on Send errors
Diffstat (limited to 'fs')
-rw-r--r-- | fs/locks.c | 3 | ||||
-rw-r--r-- | fs/nfsd/nfs4state.c | 415 | ||||
-rw-r--r-- | fs/nfsd/nfsctl.c | 1 | ||||
-rw-r--r-- | fs/nfsd/nfssvc.c | 8 | ||||
-rw-r--r-- | fs/nfsd/state.h | 3 |
5 files changed, 256 insertions, 174 deletions
diff --git a/fs/locks.c b/fs/locks.c index 5c42363aa811..74b2a1dfe8d8 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1808,6 +1808,9 @@ check_conflicting_open(struct file *filp, const long arg, int flags) if (flags & FL_LAYOUT) return 0; + if (flags & FL_DELEG) + /* We leave these checks to the caller */ + return 0; if (arg == F_RDLCK) return inode_is_open_for_write(inode) ? -EAGAIN : 0; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 7698172ac0c7..b517a8794400 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -354,6 +354,124 @@ static const struct nfsd4_callback_ops nfsd4_cb_notify_lock_ops = { .release = nfsd4_cb_notify_lock_release, }; +/* + * We store the NONE, READ, WRITE, and BOTH bits separately in the + * st_{access,deny}_bmap field of the stateid, in order to track not + * only what share bits are currently in force, but also what + * combinations of share bits previous opens have used. This allows us + * to enforce the recommendation of rfc 3530 14.2.19 that the server + * return an error if the client attempt to downgrade to a combination + * of share bits not explicable by closing some of its previous opens. + * + * XXX: This enforcement is actually incomplete, since we don't keep + * track of access/deny bit combinations; so, e.g., we allow: + * + * OPEN allow read, deny write + * OPEN allow both, deny none + * DOWNGRADE allow read, deny none + * + * which we should reject. + */ +static unsigned int +bmap_to_share_mode(unsigned long bmap) +{ + int i; + unsigned int access = 0; + + for (i = 1; i < 4; i++) { + if (test_bit(i, &bmap)) + access |= i; + } + return access; +} + +/* set share access for a given stateid */ +static inline void +set_access(u32 access, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << access; + + WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH); + stp->st_access_bmap |= mask; +} + +/* clear share access for a given stateid */ +static inline void +clear_access(u32 access, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << access; + + WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH); + stp->st_access_bmap &= ~mask; +} + +/* test whether a given stateid has access */ +static inline bool +test_access(u32 access, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << access; + + return (bool)(stp->st_access_bmap & mask); +} + +/* set share deny for a given stateid */ +static inline void +set_deny(u32 deny, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << deny; + + WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH); + stp->st_deny_bmap |= mask; +} + +/* clear share deny for a given stateid */ +static inline void +clear_deny(u32 deny, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << deny; + + WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH); + stp->st_deny_bmap &= ~mask; +} + +/* test whether a given stateid is denying specific access */ +static inline bool +test_deny(u32 deny, struct nfs4_ol_stateid *stp) +{ + unsigned char mask = 1 << deny; + + return (bool)(stp->st_deny_bmap & mask); +} + +static int nfs4_access_to_omode(u32 access) +{ + switch (access & NFS4_SHARE_ACCESS_BOTH) { + case NFS4_SHARE_ACCESS_READ: + return O_RDONLY; + case NFS4_SHARE_ACCESS_WRITE: + return O_WRONLY; + case NFS4_SHARE_ACCESS_BOTH: + return O_RDWR; + } + WARN_ON_ONCE(1); + return O_RDONLY; +} + +static inline int +access_permit_read(struct nfs4_ol_stateid *stp) +{ + return test_access(NFS4_SHARE_ACCESS_READ, stp) || + test_access(NFS4_SHARE_ACCESS_BOTH, stp) || + test_access(NFS4_SHARE_ACCESS_WRITE, stp); +} + +static inline int +access_permit_write(struct nfs4_ol_stateid *stp) +{ + return test_access(NFS4_SHARE_ACCESS_WRITE, stp) || + test_access(NFS4_SHARE_ACCESS_BOTH, stp); +} + static inline struct nfs4_stateowner * nfs4_get_stateowner(struct nfs4_stateowner *sop) { @@ -543,14 +661,12 @@ static unsigned int ownerstr_hashval(struct xdr_netobj *ownername) #define FILE_HASH_BITS 8 #define FILE_HASH_SIZE (1 << FILE_HASH_BITS) -static unsigned int nfsd_fh_hashval(struct knfsd_fh *fh) +static unsigned int file_hashval(struct svc_fh *fh) { - return jhash2(fh->fh_base.fh_pad, XDR_QUADLEN(fh->fh_size), 0); -} + struct inode *inode = d_inode(fh->fh_dentry); -static unsigned int file_hashval(struct knfsd_fh *fh) -{ - return nfsd_fh_hashval(fh) & (FILE_HASH_SIZE - 1); + /* XXX: why not (here & in file cache) use inode? */ + return (unsigned int)hash_long(inode->i_ino, FILE_HASH_BITS); } static struct hlist_head file_hashtbl[FILE_HASH_SIZE]; @@ -1153,108 +1269,6 @@ static unsigned int clientstr_hashval(struct xdr_netobj name) } /* - * We store the NONE, READ, WRITE, and BOTH bits separately in the - * st_{access,deny}_bmap field of the stateid, in order to track not - * only what share bits are currently in force, but also what - * combinations of share bits previous opens have used. This allows us - * to enforce the recommendation of rfc 3530 14.2.19 that the server - * return an error if the client attempt to downgrade to a combination - * of share bits not explicable by closing some of its previous opens. - * - * XXX: This enforcement is actually incomplete, since we don't keep - * track of access/deny bit combinations; so, e.g., we allow: - * - * OPEN allow read, deny write - * OPEN allow both, deny none - * DOWNGRADE allow read, deny none - * - * which we should reject. - */ -static unsigned int -bmap_to_share_mode(unsigned long bmap) { - int i; - unsigned int access = 0; - - for (i = 1; i < 4; i++) { - if (test_bit(i, &bmap)) - access |= i; - } - return access; -} - -/* set share access for a given stateid */ -static inline void -set_access(u32 access, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << access; - - WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH); - stp->st_access_bmap |= mask; -} - -/* clear share access for a given stateid */ -static inline void -clear_access(u32 access, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << access; - - WARN_ON_ONCE(access > NFS4_SHARE_ACCESS_BOTH); - stp->st_access_bmap &= ~mask; -} - -/* test whether a given stateid has access */ -static inline bool -test_access(u32 access, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << access; - - return (bool)(stp->st_access_bmap & mask); -} - -/* set share deny for a given stateid */ -static inline void -set_deny(u32 deny, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << deny; - - WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH); - stp->st_deny_bmap |= mask; -} - -/* clear share deny for a given stateid */ -static inline void -clear_deny(u32 deny, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << deny; - - WARN_ON_ONCE(deny > NFS4_SHARE_DENY_BOTH); - stp->st_deny_bmap &= ~mask; -} - -/* test whether a given stateid is denying specific access */ -static inline bool -test_deny(u32 deny, struct nfs4_ol_stateid *stp) -{ - unsigned char mask = 1 << deny; - - return (bool)(stp->st_deny_bmap & mask); -} - -static int nfs4_access_to_omode(u32 access) -{ - switch (access & NFS4_SHARE_ACCESS_BOTH) { - case NFS4_SHARE_ACCESS_READ: - return O_RDONLY; - case NFS4_SHARE_ACCESS_WRITE: - return O_WRONLY; - case NFS4_SHARE_ACCESS_BOTH: - return O_RDWR; - } - WARN_ON_ONCE(1); - return O_RDONLY; -} - -/* * A stateid that had a deny mode associated with it is being released * or downgraded. Recalculate the deny mode on the file. */ @@ -3125,6 +3139,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, goto out_nolock; } new->cl_mach_cred = true; + break; case SP4_NONE: break; default: /* checked by xdr code */ @@ -4072,7 +4087,7 @@ static struct nfs4_file *nfsd4_alloc_file(void) } /* OPEN Share state helper functions */ -static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval, +static void nfsd4_init_file(struct svc_fh *fh, unsigned int hashval, struct nfs4_file *fp) { lockdep_assert_held(&state_lock); @@ -4082,12 +4097,14 @@ static void nfsd4_init_file(struct knfsd_fh *fh, unsigned int hashval, INIT_LIST_HEAD(&fp->fi_stateids); INIT_LIST_HEAD(&fp->fi_delegations); INIT_LIST_HEAD(&fp->fi_clnt_odstate); - fh_copy_shallow(&fp->fi_fhandle, fh); + fh_copy_shallow(&fp->fi_fhandle, &fh->fh_handle); fp->fi_deleg_file = NULL; fp->fi_had_conflict = false; fp->fi_share_deny = 0; memset(fp->fi_fds, 0, sizeof(fp->fi_fds)); memset(fp->fi_access, 0, sizeof(fp->fi_access)); + fp->fi_aliased = false; + fp->fi_inode = d_inode(fh->fh_dentry); #ifdef CONFIG_NFSD_PNFS INIT_LIST_HEAD(&fp->fi_lo_states); atomic_set(&fp->fi_lo_recalls, 0); @@ -4426,13 +4443,13 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net) /* search file_hashtbl[] for file */ static struct nfs4_file * -find_file_locked(struct knfsd_fh *fh, unsigned int hashval) +find_file_locked(struct svc_fh *fh, unsigned int hashval) { struct nfs4_file *fp; hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash, lockdep_is_held(&state_lock)) { - if (fh_match(&fp->fi_fhandle, fh)) { + if (fh_match(&fp->fi_fhandle, &fh->fh_handle)) { if (refcount_inc_not_zero(&fp->fi_ref)) return fp; } @@ -4440,8 +4457,32 @@ find_file_locked(struct knfsd_fh *fh, unsigned int hashval) return NULL; } -struct nfs4_file * -find_file(struct knfsd_fh *fh) +static struct nfs4_file *insert_file(struct nfs4_file *new, struct svc_fh *fh, + unsigned int hashval) +{ + struct nfs4_file *fp; + struct nfs4_file *ret = NULL; + bool alias_found = false; + + spin_lock(&state_lock); + hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash, + lockdep_is_held(&state_lock)) { + if (fh_match(&fp->fi_fhandle, &fh->fh_handle)) { + if (refcount_inc_not_zero(&fp->fi_ref)) + ret = fp; + } else if (d_inode(fh->fh_dentry) == fp->fi_inode) + fp->fi_aliased = alias_found = true; + } + if (likely(ret == NULL)) { + nfsd4_init_file(fh, hashval, new); + new->fi_aliased = alias_found; + ret = new; + } + spin_unlock(&state_lock); + return ret; +} + +static struct nfs4_file * find_file(struct svc_fh *fh) { struct nfs4_file *fp; unsigned int hashval = file_hashval(fh); @@ -4453,7 +4494,7 @@ find_file(struct knfsd_fh *fh) } static struct nfs4_file * -find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh) +find_or_add_file(struct nfs4_file *new, struct svc_fh *fh) { struct nfs4_file *fp; unsigned int hashval = file_hashval(fh); @@ -4464,15 +4505,7 @@ find_or_add_file(struct nfs4_file *new, struct knfsd_fh *fh) if (fp) return fp; - spin_lock(&state_lock); - fp = find_file_locked(fh, hashval); - if (likely(fp == NULL)) { - nfsd4_init_file(fh, hashval, new); - fp = new; - } - spin_unlock(&state_lock); - - return fp; + return insert_file(new, fh, hashval); } /* @@ -4485,7 +4518,7 @@ nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type) struct nfs4_file *fp; __be32 ret = nfs_ok; - fp = find_file(¤t_fh->fh_handle); + fp = find_file(current_fh); if (!fp) return ret; /* Check for conflicting share reservations */ @@ -4880,6 +4913,11 @@ static __be32 nfs4_get_vfs_file(struct svc_rqst *rqstp, struct nfs4_file *fp, if (nf) nfsd_file_put(nf); + status = nfserrno(nfsd_open_break_lease(cur_fh->fh_dentry->d_inode, + access)); + if (status) + goto out_put_access; + status = nfsd4_truncate(rqstp, cur_fh, open); if (status) goto out_put_access; @@ -4951,6 +4989,65 @@ static struct file_lock *nfs4_alloc_init_lease(struct nfs4_delegation *dp, return fl; } +static int nfsd4_check_conflicting_opens(struct nfs4_client *clp, + struct nfs4_file *fp) +{ + struct nfs4_ol_stateid *st; + struct file *f = fp->fi_deleg_file->nf_file; + struct inode *ino = locks_inode(f); + int writes; + + writes = atomic_read(&ino->i_writecount); + if (!writes) + return 0; + /* + * There could be multiple filehandles (hence multiple + * nfs4_files) referencing this file, but that's not too + * common; let's just give up in that case rather than + * trying to go look up all the clients using that other + * nfs4_file as well: + */ + if (fp->fi_aliased) + return -EAGAIN; + /* + * If there's a close in progress, make sure that we see it + * clear any fi_fds[] entries before we see it decrement + * i_writecount: + */ + smp_mb__after_atomic(); + + if (fp->fi_fds[O_WRONLY]) + writes--; + if (fp->fi_fds[O_RDWR]) + writes--; + if (writes > 0) + return -EAGAIN; /* There may be non-NFSv4 writers */ + /* + * It's possible there are non-NFSv4 write opens in progress, + * but if they haven't incremented i_writecount yet then they + * also haven't called break lease yet; so, they'll break this + * lease soon enough. So, all that's left to check for is NFSv4 + * opens: + */ + spin_lock(&fp->fi_lock); + list_for_each_entry(st, &fp->fi_stateids, st_perfile) { + if (st->st_openstp == NULL /* it's an open */ && + access_permit_write(st) && + st->st_stid.sc_client != clp) { + spin_unlock(&fp->fi_lock); + return -EAGAIN; + } + } + spin_unlock(&fp->fi_lock); + /* + * There's a small chance that we could be racing with another + * NFSv4 open. However, any open that hasn't added itself to + * the fi_stateids list also hasn't called break_lease yet; so, + * they'll break this lease soon enough. + */ + return 0; +} + static struct nfs4_delegation * nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh, struct nfs4_file *fp, struct nfs4_clnt_odstate *odstate) @@ -4970,9 +5067,12 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh, nf = find_readable_file(fp); if (!nf) { - /* We should always have a readable file here */ - WARN_ON_ONCE(1); - return ERR_PTR(-EBADF); + /* + * We probably could attempt another open and get a read + * delegation, but for now, don't bother until the + * client actually sends us one. + */ + return ERR_PTR(-EAGAIN); } spin_lock(&state_lock); spin_lock(&fp->fi_lock); @@ -5007,6 +5107,9 @@ nfs4_set_delegation(struct nfs4_client *clp, struct svc_fh *fh, locks_free_lock(fl); if (status) goto out_clnt_odstate; + status = nfsd4_check_conflicting_opens(clp, fp); + if (status) + goto out_unlock; spin_lock(&state_lock); spin_lock(&fp->fi_lock); @@ -5088,17 +5191,6 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, goto out_no_deleg; if (!cb_up || !(oo->oo_flags & NFS4_OO_CONFIRMED)) goto out_no_deleg; - /* - * Also, if the file was opened for write or - * create, there's a good chance the client's - * about to write to it, resulting in an - * immediate recall (since we don't support - * write delegations): - */ - if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE) - goto out_no_deleg; - if (open->op_create == NFS4_OPEN_CREATE) - goto out_no_deleg; break; default: goto out_no_deleg; @@ -5161,7 +5253,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf * and check for delegations in the process of being recalled. * If not found, create the nfs4_file struct */ - fp = find_or_add_file(open->op_file, ¤t_fh->fh_handle); + fp = find_or_add_file(open->op_file, current_fh); if (fp != open->op_file) { status = nfs4_check_deleg(cl, open, &dp); if (status) @@ -5502,21 +5594,6 @@ static inline __be32 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stid *stp) return nfs_ok; } -static inline int -access_permit_read(struct nfs4_ol_stateid *stp) -{ - return test_access(NFS4_SHARE_ACCESS_READ, stp) || - test_access(NFS4_SHARE_ACCESS_BOTH, stp) || - test_access(NFS4_SHARE_ACCESS_WRITE, stp); -} - -static inline int -access_permit_write(struct nfs4_ol_stateid *stp) -{ - return test_access(NFS4_SHARE_ACCESS_WRITE, stp) || - test_access(NFS4_SHARE_ACCESS_BOTH, stp); -} - static __be32 nfs4_check_openmode(struct nfs4_ol_stateid *stp, int flags) { @@ -6288,15 +6365,6 @@ out: return status; } -static inline u64 -end_offset(u64 start, u64 len) -{ - u64 end; - - end = start + len; - return end >= start ? end: NFS4_MAX_UINT64; -} - /* last octet in a range */ static inline u64 last_byte_offset(u64 start, u64 len) @@ -6865,11 +6933,20 @@ out: static __be32 nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock) { struct nfsd_file *nf; - __be32 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf); - if (!err) { - err = nfserrno(vfs_test_lock(nf->nf_file, lock)); - nfsd_file_put(nf); - } + __be32 err; + + err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf); + if (err) + return err; + fh_lock(fhp); /* to block new leases till after test_lock: */ + err = nfserrno(nfsd_open_break_lease(fhp->fh_dentry->d_inode, + NFSD_MAY_READ)); + if (err) + goto out; + err = nfserrno(vfs_test_lock(nf->nf_file, lock)); +out: + fh_unlock(fhp); + nfsd_file_put(nf); return err; } diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 853bf50a2a9b..c2c3d9077dc5 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1166,6 +1166,7 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode) inode->i_fop = &simple_dir_operations; inode->i_op = &simple_dir_inode_operations; inc_nlink(inode); + break; default: break; } diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 82ba034fa579..dd5d69921676 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -308,7 +308,7 @@ static int nfsd_init_socks(struct net *net, const struct cred *cred) static int nfsd_users = 0; -static int nfsd_startup_generic(int nrservs) +static int nfsd_startup_generic(void) { int ret; @@ -374,7 +374,7 @@ void nfsd_reset_boot_verifier(struct nfsd_net *nn) write_sequnlock(&nn->boot_lock); } -static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred) +static int nfsd_startup_net(struct net *net, const struct cred *cred) { struct nfsd_net *nn = net_generic(net, nfsd_net_id); int ret; @@ -382,7 +382,7 @@ static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cre if (nn->nfsd_net_up) return 0; - ret = nfsd_startup_generic(nrservs); + ret = nfsd_startup_generic(); if (ret) return ret; ret = nfsd_init_socks(net, cred); @@ -790,7 +790,7 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) nfsd_up_before = nn->nfsd_net_up; - error = nfsd_startup_net(nrservs, net, cred); + error = nfsd_startup_net(net, cred); if (error) goto out_destroy; error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv, diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index 54cab651ac1d..e73bdbb1634a 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -516,6 +516,8 @@ struct nfs4_clnt_odstate { */ struct nfs4_file { refcount_t fi_ref; + struct inode * fi_inode; + bool fi_aliased; spinlock_t fi_lock; struct hlist_node fi_hash; /* hash on fi_fhandle */ struct list_head fi_stateids; @@ -669,7 +671,6 @@ extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name struct xdr_netobj princhash, struct nfsd_net *nn); extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn); -struct nfs4_file *find_file(struct knfsd_fh *fh); void put_nfs4_file(struct nfs4_file *fi); extern void nfs4_put_copy(struct nfsd4_copy *copy); extern struct nfsd4_copy * |