/* * Copyright (c) 2001 The Regents of the University of Michigan. * All rights reserved. * * Kendrick Smith * Andy Adamson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include "nfsd.h" #include "state.h" #define NFSDDBG_FACILITY NFSDDBG_PROC static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason); #define NFSPROC4_CB_NULL 0 #define NFSPROC4_CB_COMPOUND 1 /* Index of predefined Linux callback client operations */ enum { NFSPROC4_CLNT_CB_NULL = 0, NFSPROC4_CLNT_CB_RECALL, NFSPROC4_CLNT_CB_SEQUENCE, }; #define NFS4_MAXTAGLEN 20 #define NFS4_enc_cb_null_sz 0 #define NFS4_dec_cb_null_sz 0 #define cb_compound_enc_hdr_sz 4 #define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2)) #define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2) #define cb_sequence_enc_sz (sessionid_sz + 4 + \ 1 /* no referring calls list yet */) #define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4) #define op_enc_sz 1 #define op_dec_sz 2 #define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2)) #define enc_stateid_sz (NFS4_STATEID_SIZE >> 2) #define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \ cb_sequence_enc_sz + \ 1 + enc_stateid_sz + \ enc_nfs4_fh_sz) #define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \ cb_sequence_dec_sz + \ op_dec_sz) struct nfs4_cb_compound_hdr { /* args */ u32 ident; /* minorversion 0 only */ u32 nops; __be32 *nops_p; u32 minorversion; /* res */ int status; }; /* * Handle decode buffer overflows out-of-line. */ static void print_overflow_msg(const char *func, const struct xdr_stream *xdr) { dprintk("NFS: %s prematurely hit the end of our receive buffer. " "Remaining buffer length is %tu words.\n", func, xdr->end - xdr->p); } static __be32 *xdr_encode_empty_array(__be32 *p) { *p++ = xdr_zero; return p; } /* * Encode/decode NFSv4 CB basic data types * * Basic NFSv4 callback data types are defined in section 15 of RFC * 3530: "Network File System (NFS) version 4 Protocol" and section * 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version * 1 Protocol" */ /* * nfs_cb_opnum4 * * enum nfs_cb_opnum4 { * OP_CB_GETATTR = 3, * ... * }; */ enum nfs_cb_opnum4 { OP_CB_GETATTR = 3, OP_CB_RECALL = 4, OP_CB_LAYOUTRECALL = 5, OP_CB_NOTIFY = 6, OP_CB_PUSH_DELEG = 7, OP_CB_RECALL_ANY = 8, OP_CB_RECALLABLE_OBJ_AVAIL = 9, OP_CB_RECALL_SLOT = 10, OP_CB_SEQUENCE = 11, OP_CB_WANTS_CANCELLED = 12, OP_CB_NOTIFY_LOCK = 13, OP_CB_NOTIFY_DEVICEID = 14, OP_CB_ILLEGAL = 10044 }; static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op) { __be32 *p; p = xdr_reserve_space(xdr, 4); *p = cpu_to_be32(op); } /* * nfs_fh4 * * typedef opaque nfs_fh4; */ static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh) { u32 length = fh->fh_size; __be32 *p; BUG_ON(length > NFS4_FHSIZE); p = xdr_reserve_space(xdr, 4 + length); xdr_encode_opaque(p, &fh->fh_base, length); } /* * stateid4 * * struct stateid4 { * uint32_t seqid; * opaque other[12]; * }; */ static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid) { __be32 *p; p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE); *p++ = cpu_to_be32(sid->si_generation); xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE); } /* * sessionid4 * * typedef opaque sessionid4[NFS4_SESSIONID_SIZE]; */ static void encode_sessionid4(struct xdr_stream *xdr, const struct nfsd4_session *session) { __be32 *p; p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN); xdr_encode_opaque_fixed(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN); } /* * nfsstat4 */ static const struct { int stat; int errno; } nfs_cb_errtbl[] = { { NFS4_OK, 0 }, { NFS4ERR_PERM, -EPERM }, { NFS4ERR_NOENT, -ENOENT }, { NFS4ERR_IO, -EIO }, { NFS4ERR_NXIO, -ENXIO }, { NFS4ERR_ACCESS, -EACCES }, { NFS4ERR_EXIST, -EEXIST }, { NFS4ERR_XDEV, -EXDEV }, { NFS4ERR_NOTDIR, -ENOTDIR }, { NFS4ERR_ISDIR, -EISDIR }, { NFS4ERR_INVAL, -EINVAL }, { NFS4ERR_FBIG, -EFBIG }, { NFS4ERR_NOSPC, -ENOSPC }, { NFS4ERR_ROFS, -EROFS }, { NFS4ERR_MLINK, -EMLINK }, { NFS4ERR_NAMETOOLONG, -ENAMETOOLONG }, { NFS4ERR_NOTEMPTY, -ENOTEMPTY }, { NFS4ERR_DQUOT, -EDQUOT }, { NFS4ERR_STALE, -ESTALE }, { NFS4ERR_BADHANDLE, -EBADHANDLE }, { NFS4ERR_BAD_COOKIE, -EBADCOOKIE }, { NFS4ERR_NOTSUPP, -ENOTSUPP }, { NFS4ERR_TOOSMALL, -ETOOSMALL }, { NFS4ERR_SERVERFAULT, -ESERVERFAULT }, { NFS4ERR_BADTYPE, -EBADTYPE }, { NFS4ERR_LOCKED, -EAGAIN }, { NFS4ERR_RESOURCE, -EREMOTEIO }, { NFS4ERR_SYMLINK, -ELOOP }, { NFS4ERR_OP_ILLEGAL, -EOPNOTSUPP }, { NFS4ERR_DEADLOCK, -EDEADLK }, { -1, -EIO } }; /* * If we cannot translate the error, the recovery routines should * handle it. * * Note: remaining NFSv4 error codes have values > 10000, so should * not conflict with native Linux error codes. */ static int nfs_cb_stat_to_errno(int status) { int i; for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { if (nfs_cb_errtbl[i].stat == status) return nfs_cb_errtbl[i].errno; } dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status); return -status; } static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected, enum nfsstat4 *status) { __be32 *p; u32 op; p = xdr_inline_decode(xdr, 4 + 4); if (unlikely(p == NULL)) goto out_overflow; op = be32_to_cpup(p++); if (unlikely(op != expected)) goto out_unexpected; *status = be32_to_cpup(p); return 0; out_overflow: print_overflow_msg(__func__, xdr); return -EIO; out_unexpected: dprintk("NFSD: Callback server returned operation %d but " "we issued a request for %d\n", op, expected); return -EIO; } /* * CB_COMPOUND4args * * struct CB_COMPOUND4args { * utf8str_cs tag; * uint32_t minorversion; * uint32_t callback_ident; * nfs_cb_argop4 argarray<>; * }; */ static void encode_cb_compound4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr) { __be32 * p; p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4); p = xdr_encode_empty_array(p); /* empty tag */ *p++ = cpu_to_be32(hdr->minorversion); *p++ = cpu_to_be32(hdr->ident); hdr->nops_p = p; *p = cpu_to_be32(hdr->nops); /* argarray element count */ } /* * Update argarray element count */ static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) { BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS); *hdr->nops_p = cpu_to_be32(hdr->nops); } /* * CB_COMPOUND4res * * struct CB_COMPOUND4res { * nfsstat4 status; * utf8str_cs tag; * nfs_cb_resop4 resarray<>; * }; */ static int decode_cb_compound4res(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr) { u32 length; __be32 *p; p = xdr_inline_decode(xdr, 4 + 4); if (unlikely(p == NULL)) goto out_overflow; hdr->status = be32_to_cpup(p++); /* Ignore the tag */ length = be32_to_cpup(p++); p = xdr_inline_decode(xdr, length + 4); if (unlikely(p == NULL)) goto out_overflow; hdr->nops = be32_to_cpup(p); return 0; out_overflow: print_overflow_msg(__func__, xdr); return -EIO; } /* * CB_RECALL4args * * struct CB_RECALL4args { * stateid4 stateid; * bool truncate; * nfs_fh4 fh; * }; */ static void encode_cb_recall4args(struct xdr_stream *xdr, const struct nfs4_delegation *dp, struct nfs4_cb_compound_hdr *hdr) { __be32 *p; encode_nfs_cb_opnum4(xdr, OP_CB_RECALL); encode_stateid4(xdr, &dp->dl_stid.sc_stateid); p = xdr_reserve_space(xdr, 4); *p++ = xdr_zero; /* truncate */ encode_nfs_fh4(xdr, &dp->dl_fh); hdr->nops++; } /* * CB_SEQUENCE4args * * struct CB_SEQUENCE4args { * sessionid4 csa_sessionid; * sequenceid4 csa_sequenceid; * slotid4 csa_slotid; * slotid4 csa_highest_slotid; * bool csa_cachethis; * referring_call_list4 csa_referring_call_lists<>; * }; */ static void encode_cb_sequence4args(struct xdr_stream *xdr, const struct nfsd4_callback *cb, struct nfs4_cb_compound_hdr *hdr) { struct nfsd4_session *session = cb->cb_clp->cl_cb_session; __be32 *p; if (hdr->minorversion == 0) return; encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE); encode_sessionid4(xdr, session); p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4); *p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */ *p++ = xdr_zero; /* csa_slotid */ *p++ = xdr_zero; /* csa_highest_slotid */ *p++ = xdr_zero; /* csa_cachethis */ xdr_encode_empty_array(p); /* csa_referring_call_lists */ hdr->nops++; } /* * CB_SEQUENCE4resok * * struct CB_SEQUENCE4resok { * sessionid4 csr_sessionid; * sequenceid4 csr_sequenceid; * slotid4 csr_slotid; * slotid4 csr_highest_slotid; * slotid4 csr_target_highest_slotid; * }; * * union CB_SEQUENCE4res switch (nfsstat4 csr_status) { * case NFS4_OK: * CB_SEQUENCE4resok csr_resok4; * default: * void; * }; * * Our current back channel implmentation supports a single backchannel * with a single slot. */ static int decode_cb_sequence4resok(struct xdr_stream *xdr, struct nfsd4_callback *cb) { struct nfsd4_session *session = cb->cb_clp->cl_cb_session; struct nfs4_sessionid id; int status; __be32 *p; u32 dummy; status = -ESERVERFAULT; /* * If the server returns different values for sessionID, slotID or * sequence number, the server is looney tunes. */ p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4); if (unlikely(p == NULL)) goto out_overflow; memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); if (memcmp(id.data, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN) != 0) { dprintk("NFS: %s Invalid session id\n", __func__); goto out; } p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); dummy = be32_to_cpup(p++); if (dummy != session->se_cb_seq_nr) { dprintk("NFS: %s Invalid sequence number\n", __func__); goto out; } dummy = be32_to_cpup(p++); if (dummy != 0) { dprintk("NFS: %s Invalid slotid\n", __func__); goto out; } /* * FIXME: process highest slotid and target highest slotid */ status = 0; out: if (status) nfsd4_mark_cb_fault(cb->cb_clp, status); return status; out_overflow: print_overflow_msg(__func__, xdr); return -EIO; } static int decode_cb_sequence4res(struct xdr_stream *xdr, struct nfsd4_callback *cb) { enum nfsstat4 nfserr; int status; if (cb->cb_minorversion == 0) return 0; status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr); if (unlikely(status)) goto out; if (unlikely(nfserr != NFS4_OK)) goto out_default; status = decode_cb_sequence4resok(xdr, cb); out: return status; out_default: return nfs_cb_stat_to_errno(nfserr); } /* * NFSv4.0 and NFSv4.1 XDR encode functions * * NFSv4.0 callback argument types are defined in section 15 of RFC * 3530: "Network File System (NFS) version 4 Protocol" and section 20 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 * Protocol". */ /* * NB: Without this zero space reservation, callbacks over krb5p fail */ static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, void *__unused) { xdr_reserve_space(xdr, 0); } /* * 20.2. Operation 4: CB_RECALL - Recall a Delegation */ static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr, const struct nfsd4_callback *cb) { const struct nfs4_delegation *args = cb->cb_op; struct nfs4_cb_compound_hdr hdr = { .ident = cb->cb_clp->cl_cb_ident, .minorversion = cb->cb_minorversion, }; encode_cb_compound4args(xdr, &hdr); encode_cb_sequence4args(xdr, cb, &hdr); encode_cb_recall4args(xdr, args, &hdr); encode_cb_nops(&hdr); } /* * NFSv4.0 and NFSv4.1 XDR decode functions * * NFSv4.0 callback result types are defined in section 15 of RFC * 3530: "Network File System (NFS) version 4 Protocol" and section 20 * of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1 * Protocol". */ static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr, void *__unused) { return 0; } /* * 20.2. Operation 4: CB_RECALL - Recall a Delegation */ static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, struct xdr_stream *xdr, struct nfsd4_callback *cb) { struct nfs4_cb_compound_hdr hdr; enum nfsstat4 nfserr; int status; status = decode_cb_compound4res(xdr, &hdr); if (unlikely(status)) goto out; if (cb != NULL) { status = decode_cb_sequence4res(xdr, cb); if (unlikely(status)) goto out; } status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr); if (unlikely(status)) goto out; if (unlikely(nfserr != NFS4_OK)) status = nfs_cb_stat_to_errno(nfserr); out: return status; } /* * RPC procedure tables */ #define PROC(proc, call, argtype, restype) \ [NFSPROC4_CLNT_##proc] = { \ .p_proc = NFSPROC4_CB_##call, \ .p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \ .p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \ .p_arglen = NFS4_enc_##argtype##_sz, \ .p_replen = NFS4_dec_##restype##_sz, \ .p_statidx = NFSPROC4_CB_##call, \ .p_name = #proc, \ } static struct rpc_procinfo nfs4_cb_procedures[] = { PROC(CB_NULL, NULL, cb_null, cb_null), PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), }; static struct rpc_version nfs_cb_version4 = { /* * Note on the callback rpc program version number: despite language in rfc * 5661 section 18.36.3 requiring servers to use 4 in this field, the * official xdr descriptions for both 4.0 and 4.1 specify version 1, and * in practice that appears to be what implementations use. The section * 18.36.3 language is expected to be fixed in an erratum. */ .number = 1, .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), .procs = nfs4_cb_procedures }; static struct rpc_version *nfs_cb_version[] = { &nfs_cb_version4, }; static struct rpc_program cb_program; static struct rpc_stat cb_stats = { .program = &cb_program }; #define NFS4_CALLBACK 0x40000000 static struct rpc_program cb_program = { .name = "nfs4_cb", .number = NFS4_CALLBACK, .nrvers = ARRAY_SIZE(nfs_cb_version), .version = nfs_cb_version, .stats = &cb_stats, .pipe_dir_name = "/nfsd4_cb", }; static int max_cb_time(void) { return max(nfsd4_lease/10, (time_t)1) * HZ; } static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) { struct rpc_timeout timeparms = { .to_initval = max_cb_time(), .to_retries = 0, }; struct rpc_create_args args = { .net = &init_net, .address = (struct sockaddr *) &conn->cb_addr, .addrsize = conn->cb_addrlen, .saddress = (struct sockaddr *) &conn->cb_saddr, .timeout = &timeparms, .program = &cb_program, .version = 0, .authflavor = clp->cl_flavor, .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), }; struct rpc_clnt *client; if (clp->cl_minorversion == 0) { if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) return -EINVAL; args.client_name = clp->cl_principal; args.prognumber = conn->cb_prog, args.protocol = XPRT_TRANSPORT_TCP; clp->cl_cb_ident = conn->cb_ident; } else { if (!conn->cb_xprt) return -EINVAL; clp->cl_cb_conn.cb_xprt = conn->cb_xprt; clp->cl_cb_session = ses; args.bc_xprt = conn->cb_xprt; args.prognumber = clp->cl_cb_session->se_cb_prog; args.protocol = XPRT_TRANSPORT_BC_TCP; } /* Create RPC client */ client = rpc_create(&args); if (IS_ERR(client)) { dprintk("NFSD: couldn't create callback client: %ld\n", PTR_ERR(client)); return PTR_ERR(client); } clp->cl_cb_client = client; return 0; } static void warn_no_callback_path(struct nfs4_client *clp, int reason) { dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", (int)clp->cl_name.len, clp->cl_name.data, reason); } static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) { clp->cl_cb_state = NFSD4_CB_DOWN; warn_no_callback_path(clp, reason); } static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) { clp->cl_cb_state = NFSD4_CB_FAULT; warn_no_callback_path(clp, reason); } static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) { struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); if (task->tk_status) nfsd4_mark_cb_down(clp, task->tk_status); else clp->cl_cb_state = NFSD4_CB_UP; } static const struct rpc_call_ops nfsd4_cb_probe_ops = { /* XXX: release method to ensure we set the cb channel down if * necessary on early failure? */ .rpc_call_done = nfsd4_cb_probe_done, }; static struct rpc_cred *callback_cred; int set_callback_cred(void) { if (callback_cred) return 0; callback_cred = rpc_lookup_machine_cred(); if (!callback_cred) return -ENOMEM; return 0; } static struct workqueue_struct *callback_wq; static void run_nfsd4_cb(struct nfsd4_callback *cb) { queue_work(callback_wq, &cb->cb_work); } static void do_probe_callback(struct nfs4_client *clp) { struct nfsd4_callback *cb = &clp->cl_cb_null; cb->cb_op = NULL; cb->cb_clp = clp; cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL]; cb->cb_msg.rpc_argp = NULL; cb->cb_msg.rpc_resp = NULL; cb->cb_msg.rpc_cred = callback_cred; cb->cb_ops = &nfsd4_cb_probe_ops; run_nfsd4_cb(cb); } /* * Poke the callback thread to process any updates to the callback * parameters, and send a null probe. */ void nfsd4_probe_callback(struct nfs4_client *clp) { /* XXX: atomicity? Also, should we be using cl_cb_flags? */ clp->cl_cb_state = NFSD4_CB_UNKNOWN; set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); do_probe_callback(clp); } void nfsd4_probe_callback_sync(struct nfs4_client *clp) { nfsd4_probe_callback(clp); flush_workqueue(callback_wq); } void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn) { clp->cl_cb_state = NFSD4_CB_UNKNOWN; spin_lock(&clp->cl_lock); memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn)); spin_unlock(&clp->cl_lock); } /* * There's currently a single callback channel slot. * If the slot is available, then mark it busy. Otherwise, set the * thread for sleeping on the callback RPC wait queue. */ static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task) { if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); dprintk("%s slot is busy\n", __func__); return false; } return true; } /* * TODO: cb_sequence should support referring call lists, cachethis, multiple * slots, and mark callback channel down on communication errors. */ static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) { struct nfsd4_callback *cb = calldata; struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); struct nfs4_client *clp = dp->dl_stid.sc_client; u32 minorversion = clp->cl_minorversion; cb->cb_minorversion = minorversion; if (minorversion) { if (!nfsd41_cb_get_slot(clp, task)) return; } spin_lock(&clp->cl_lock); if (list_empty(&cb->cb_per_client)) { /* This is the first call, not a restart */ cb->cb_done = false; list_add(&cb->cb_per_client, &clp->cl_callbacks); } spin_unlock(&clp->cl_lock); rpc_call_start(task); } static void nfsd4_cb_done(struct rpc_task *task, void *calldata) { struct nfsd4_callback *cb = calldata; struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); struct nfs4_client *clp = dp->dl_stid.sc_client; dprintk("%s: minorversion=%d\n", __func__, clp->cl_minorversion); if (clp->cl_minorversion) { /* No need for lock, access serialized in nfsd4_cb_prepare */ ++clp->cl_cb_session->se_cb_seq_nr; clear_bit(0, &clp->cl_cb_slot_busy); rpc_wake_up_next(&clp->cl_cb_waitq); dprintk("%s: freed slot, new seqid=%d\n", __func__, clp->cl_cb_session->se_cb_seq_nr); /* We're done looking into the sequence information */ task->tk_msg.rpc_resp = NULL; } } static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) { struct nfsd4_callback *cb = calldata; struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); struct nfs4_client *clp = dp->dl_stid.sc_client; struct rpc_clnt *current_rpc_client = clp->cl_cb_client; nfsd4_cb_done(task, calldata); if (current_rpc_client != task->tk_client) { /* We're shutting down or changing cl_cb_client; leave * it to nfsd4_process_cb_update to restart the call if * necessary. */ return; } if (cb->cb_done) return; switch (task->tk_status) { case 0: cb->cb_done = true; return; case -EBADHANDLE: case -NFS4ERR_BAD_STATEID: /* Race: client probably got cb_recall * before open reply granting delegation */ break; default: /* Network partition? */ nfsd4_mark_cb_down(clp, task->tk_status); } if (dp->dl_retries--) { rpc_delay(task, 2*HZ); task->tk_status = 0; rpc_restart_call_prepare(task); return; } nfsd4_mark_cb_down(clp, task->tk_status); cb->cb_done = true; } static void nfsd4_cb_recall_release(void *calldata) { struct nfsd4_callback *cb = calldata; struct nfs4_client *clp = cb->cb_clp; struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall); if (cb->cb_done) { spin_lock(&clp->cl_lock); list_del(&cb->cb_per_client); spin_unlock(&clp->cl_lock); nfs4_put_delegation(dp); } } static const struct rpc_call_ops nfsd4_cb_recall_ops = { .rpc_call_prepare = nfsd4_cb_prepare, .rpc_call_done = nfsd4_cb_recall_done, .rpc_release = nfsd4_cb_recall_release, }; int nfsd4_create_callback_queue(void) { callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); if (!callback_wq) return -ENOMEM; return 0; } void nfsd4_destroy_callback_queue(void) { destroy_workqueue(callback_wq); } /* must be called under the state lock */ void nfsd4_shutdown_callback(struct nfs4_client *clp) { set_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags); /* * Note this won't actually result in a null callback; * instead, nfsd4_do_callback_rpc() will detect the killed * client, destroy the rpc client, and stop: */ do_probe_callback(clp); flush_workqueue(callback_wq); } static void nfsd4_release_cb(struct nfsd4_callback *cb) { if (cb->cb_ops->rpc_release) cb->cb_ops->rpc_release(cb); } /* requires cl_lock: */ static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) { struct nfsd4_session *s; struct nfsd4_conn *c; list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { list_for_each_entry(c, &s->se_conns, cn_persession) { if (c->cn_flags & NFS4_CDFC4_BACK) return c; } } return NULL; } static void nfsd4_process_cb_update(struct nfsd4_callback *cb) { struct nfs4_cb_conn conn; struct nfs4_client *clp = cb->cb_clp; struct nfsd4_session *ses = NULL; struct nfsd4_conn *c; int err; /* * This is either an update, or the client dying; in either case, * kill the old client: */ if (clp->cl_cb_client) { rpc_shutdown_client(clp->cl_cb_client); clp->cl_cb_client = NULL; } if (clp->cl_cb_conn.cb_xprt) { svc_xprt_put(clp->cl_cb_conn.cb_xprt); clp->cl_cb_conn.cb_xprt = NULL; } if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags)) return; spin_lock(&clp->cl_lock); /* * Only serialized callback code is allowed to clear these * flags; main nfsd code can only set them: */ BUG_ON(!clp->cl_cb_flags); clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); c = __nfsd4_find_backchannel(clp); if (c) { svc_xprt_get(c->cn_xprt); conn.cb_xprt = c->cn_xprt; ses = c->cn_session; } spin_unlock(&clp->cl_lock); err = setup_callback_client(clp, &conn, ses); if (err) { warn_no_callback_path(clp, err); return; } /* Yay, the callback channel's back! Restart any callbacks: */ list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client) run_nfsd4_cb(cb); } void nfsd4_do_callback_rpc(struct work_struct *w) { struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work); struct nfs4_client *clp = cb->cb_clp; struct rpc_clnt *clnt; if (clp->cl_cb_flags) nfsd4_process_cb_update(cb); clnt = clp->cl_cb_client; if (!clnt) { /* Callback channel broken, or client killed; give up: */ nfsd4_release_cb(cb); return; } rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN, cb->cb_ops, cb); } void nfsd4_cb_recall(struct nfs4_delegation *dp) { struct nfsd4_callback *cb = &dp->dl_recall; struct nfs4_client *clp = dp->dl_stid.sc_client; dp->dl_retries = 1; cb->cb_op = dp; cb->cb_clp = clp; cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL]; cb->cb_msg.rpc_argp = cb; cb->cb_msg.rpc_resp = cb; cb->cb_msg.rpc_cred = callback_cred; cb->cb_ops = &nfsd4_cb_recall_ops; dp->dl_retries = 1; INIT_LIST_HEAD(&cb->cb_per_client); cb->cb_done = true; run_nfsd4_cb(&dp->dl_recall); }