diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/nfsd/nfs4callback.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/nfsd/nfs4callback.c | 1037 |
1 files changed, 1037 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/nfsd/nfs4callback.c b/ANDROID_3.4.5/fs/nfsd/nfs4callback.c new file mode 100644 index 00000000..c8e9f637 --- /dev/null +++ b/ANDROID_3.4.5/fs/nfsd/nfs4callback.c @@ -0,0 +1,1037 @@ +/* + * Copyright (c) 2001 The Regents of the University of Michigan. + * All rights reserved. + * + * Kendrick Smith <kmsmith@umich.edu> + * Andy Adamson <andros@umich.edu> + * + * 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 <linux/sunrpc/clnt.h> +#include <linux/sunrpc/svc_xprt.h> +#include <linux/slab.h> +#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<NFS4_FHSIZE>; + */ +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 const struct rpc_version *nfs_cb_version[] = { + &nfs_cb_version4, +}; + +static const struct rpc_program cb_program; + +static struct rpc_stat cb_stats = { + .program = &cb_program +}; + +#define NFS4_CALLBACK 0x40000000 +static const 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, + .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; + args.authflavor = clp->cl_flavor; + 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; + args.authflavor = RPC_AUTH_UNIX; + } + /* 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("nfs"); + 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_flags? */ + clp->cl_cb_state = NFSD4_CB_UNKNOWN; + set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_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_CB_KILL, &clp->cl_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_CB_KILL, &clp->cl_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_flags & NFSD4_CLIENT_CB_FLAG_MASK)); + clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_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) { + nfsd4_mark_cb_down(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_flags & NFSD4_CLIENT_CB_FLAG_MASK) + 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); +} |