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Diffstat (limited to '')
| -rw-r--r-- | fs/nfsd/nfs4callback.c | 1393 |
1 files changed, 1393 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c new file mode 100644 index 000000000..39989c14c --- /dev/null +++ b/fs/nfsd/nfs4callback.c @@ -0,0 +1,1393 @@ +/* + * 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/xprt.h> +#include <linux/sunrpc/svc_xprt.h> +#include <linux/slab.h> +#include "nfsd.h" +#include "state.h" +#include "netns.h" +#include "trace.h" +#include "xdr4cb.h" +#include "xdr4.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 */ + +struct nfs4_cb_compound_hdr { + /* args */ + u32 ident; /* minorversion 0 only */ + u32 nops; + __be32 *nops_p; + u32 minorversion; + /* res */ + int status; +}; + +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_OFFLOAD = 15, + 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_raw, 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_cb_opnum4 expected, int *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 = nfs_cb_stat_to_errno(be32_to_cpup(p)); + return 0; +out_overflow: + 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; + p += XDR_QUADLEN(length); + hdr->nops = be32_to_cpup(p); + return 0; +out_overflow: + 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_stid.sc_file->fi_fhandle); + + 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; + int status = -ESERVERFAULT; + __be32 *p; + u32 dummy; + + /* + * 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; + + if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) { + 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: + cb->cb_seq_status = status; + return status; +out_overflow: + status = -EIO; + goto out; +} + +static int decode_cb_sequence4res(struct xdr_stream *xdr, + struct nfsd4_callback *cb) +{ + int status; + + if (cb->cb_clp->cl_minorversion == 0) + return 0; + + status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status); + if (unlikely(status || cb->cb_seq_status)) + return status; + + return decode_cb_sequence4resok(xdr, cb); +} + +/* + * 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, + const 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 void *data) +{ + const struct nfsd4_callback *cb = data; + const struct nfs4_delegation *dp = cb_to_delegation(cb); + struct nfs4_cb_compound_hdr hdr = { + .ident = cb->cb_clp->cl_cb_ident, + .minorversion = cb->cb_clp->cl_minorversion, + }; + + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + encode_cb_recall4args(xdr, dp, &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, + void *data) +{ + struct nfsd4_callback *cb = data; + struct nfs4_cb_compound_hdr hdr; + int status; + + status = decode_cb_compound4res(xdr, &hdr); + if (unlikely(status)) + return status; + + status = decode_cb_sequence4res(xdr, cb); + if (unlikely(status || cb->cb_seq_status)) + return status; + + return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status); +} + +#ifdef CONFIG_NFSD_PNFS +/* + * CB_LAYOUTRECALL4args + * + * struct layoutrecall_file4 { + * nfs_fh4 lor_fh; + * offset4 lor_offset; + * length4 lor_length; + * stateid4 lor_stateid; + * }; + * + * union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) { + * case LAYOUTRECALL4_FILE: + * layoutrecall_file4 lor_layout; + * case LAYOUTRECALL4_FSID: + * fsid4 lor_fsid; + * case LAYOUTRECALL4_ALL: + * void; + * }; + * + * struct CB_LAYOUTRECALL4args { + * layouttype4 clora_type; + * layoutiomode4 clora_iomode; + * bool clora_changed; + * layoutrecall4 clora_recall; + * }; + */ +static void encode_cb_layout4args(struct xdr_stream *xdr, + const struct nfs4_layout_stateid *ls, + struct nfs4_cb_compound_hdr *hdr) +{ + __be32 *p; + + BUG_ON(hdr->minorversion == 0); + + p = xdr_reserve_space(xdr, 5 * 4); + *p++ = cpu_to_be32(OP_CB_LAYOUTRECALL); + *p++ = cpu_to_be32(ls->ls_layout_type); + *p++ = cpu_to_be32(IOMODE_ANY); + *p++ = cpu_to_be32(1); + *p = cpu_to_be32(RETURN_FILE); + + encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle); + + p = xdr_reserve_space(xdr, 2 * 8); + p = xdr_encode_hyper(p, 0); + xdr_encode_hyper(p, NFS4_MAX_UINT64); + + encode_stateid4(xdr, &ls->ls_recall_sid); + + hdr->nops++; +} + +static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req, + struct xdr_stream *xdr, + const void *data) +{ + const struct nfsd4_callback *cb = data; + const struct nfs4_layout_stateid *ls = + container_of(cb, struct nfs4_layout_stateid, ls_recall); + struct nfs4_cb_compound_hdr hdr = { + .ident = 0, + .minorversion = cb->cb_clp->cl_minorversion, + }; + + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + encode_cb_layout4args(xdr, ls, &hdr); + encode_cb_nops(&hdr); +} + +static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp, + struct xdr_stream *xdr, + void *data) +{ + struct nfsd4_callback *cb = data; + struct nfs4_cb_compound_hdr hdr; + int status; + + status = decode_cb_compound4res(xdr, &hdr); + if (unlikely(status)) + return status; + + status = decode_cb_sequence4res(xdr, cb); + if (unlikely(status || cb->cb_seq_status)) + return status; + + return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status); +} +#endif /* CONFIG_NFSD_PNFS */ + +static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so) +{ + __be32 *p; + + p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len); + p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8); + xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len); +} + +static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req, + struct xdr_stream *xdr, + const void *data) +{ + const struct nfsd4_callback *cb = data; + const struct nfsd4_blocked_lock *nbl = + container_of(cb, struct nfsd4_blocked_lock, nbl_cb); + struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner; + struct nfs4_cb_compound_hdr hdr = { + .ident = 0, + .minorversion = cb->cb_clp->cl_minorversion, + }; + + __be32 *p; + + BUG_ON(hdr.minorversion == 0); + + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + + p = xdr_reserve_space(xdr, 4); + *p = cpu_to_be32(OP_CB_NOTIFY_LOCK); + encode_nfs_fh4(xdr, &nbl->nbl_fh); + encode_stateowner(xdr, &lo->lo_owner); + hdr.nops++; + + encode_cb_nops(&hdr); +} + +static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp, + struct xdr_stream *xdr, + void *data) +{ + struct nfsd4_callback *cb = data; + struct nfs4_cb_compound_hdr hdr; + int status; + + status = decode_cb_compound4res(xdr, &hdr); + if (unlikely(status)) + return status; + + status = decode_cb_sequence4res(xdr, cb); + if (unlikely(status || cb->cb_seq_status)) + return status; + + return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status); +} + +/* + * struct write_response4 { + * stateid4 wr_callback_id<1>; + * length4 wr_count; + * stable_how4 wr_committed; + * verifier4 wr_writeverf; + * }; + * union offload_info4 switch (nfsstat4 coa_status) { + * case NFS4_OK: + * write_response4 coa_resok4; + * default: + * length4 coa_bytes_copied; + * }; + * struct CB_OFFLOAD4args { + * nfs_fh4 coa_fh; + * stateid4 coa_stateid; + * offload_info4 coa_offload_info; + * }; + */ +static void encode_offload_info4(struct xdr_stream *xdr, + const struct nfsd4_cb_offload *cbo) +{ + __be32 *p; + + p = xdr_reserve_space(xdr, 4); + *p = cbo->co_nfserr; + switch (cbo->co_nfserr) { + case nfs_ok: + p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE); + p = xdr_encode_empty_array(p); + p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written); + *p++ = cpu_to_be32(cbo->co_res.wr_stable_how); + p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data, + NFS4_VERIFIER_SIZE); + break; + default: + p = xdr_reserve_space(xdr, 8); + /* We always return success if bytes were written */ + p = xdr_encode_hyper(p, 0); + } +} + +static void encode_cb_offload4args(struct xdr_stream *xdr, + const struct nfsd4_cb_offload *cbo, + struct nfs4_cb_compound_hdr *hdr) +{ + __be32 *p; + + p = xdr_reserve_space(xdr, 4); + *p = cpu_to_be32(OP_CB_OFFLOAD); + encode_nfs_fh4(xdr, &cbo->co_fh); + encode_stateid4(xdr, &cbo->co_res.cb_stateid); + encode_offload_info4(xdr, cbo); + + hdr->nops++; +} + +static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req, + struct xdr_stream *xdr, + const void *data) +{ + const struct nfsd4_callback *cb = data; + const struct nfsd4_cb_offload *cbo = + container_of(cb, struct nfsd4_cb_offload, co_cb); + struct nfs4_cb_compound_hdr hdr = { + .ident = 0, + .minorversion = cb->cb_clp->cl_minorversion, + }; + + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + encode_cb_offload4args(xdr, cbo, &hdr); + encode_cb_nops(&hdr); +} + +static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp, + struct xdr_stream *xdr, + void *data) +{ + struct nfsd4_callback *cb = data; + struct nfs4_cb_compound_hdr hdr; + int status; + + status = decode_cb_compound4res(xdr, &hdr); + if (unlikely(status)) + return status; + + status = decode_cb_sequence4res(xdr, cb); + if (unlikely(status || cb->cb_seq_status)) + return status; + + return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status); +} +/* + * RPC procedure tables + */ +#define PROC(proc, call, argtype, restype) \ +[NFSPROC4_CLNT_##proc] = { \ + .p_proc = NFSPROC4_CB_##call, \ + .p_encode = nfs4_xdr_enc_##argtype, \ + .p_decode = 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 const struct rpc_procinfo nfs4_cb_procedures[] = { + PROC(CB_NULL, NULL, cb_null, cb_null), + PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall), +#ifdef CONFIG_NFSD_PNFS + PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout), +#endif + PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock), + PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload), +}; + +static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)]; +static const 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, + .counts = nfs4_cb_counts, +}; + +static const struct rpc_version *nfs_cb_version[2] = { + [1] = &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(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + /* + * nfsd4_lease is set to at most one hour in __nfsd4_write_time, + * so we can use 32-bit math on it. Warn if that assumption + * ever stops being true. + */ + if (WARN_ON_ONCE(nn->nfsd4_lease > 3600)) + return 360 * HZ; + + return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ; +} + +static struct workqueue_struct *callback_wq; + +static bool nfsd4_queue_cb(struct nfsd4_callback *cb) +{ + return queue_work(callback_wq, &cb->cb_work); +} + +static void nfsd41_cb_inflight_begin(struct nfs4_client *clp) +{ + atomic_inc(&clp->cl_cb_inflight); +} + +static void nfsd41_cb_inflight_end(struct nfs4_client *clp) +{ + + if (atomic_dec_and_test(&clp->cl_cb_inflight)) + wake_up_var(&clp->cl_cb_inflight); +} + +static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp) +{ + wait_var_event(&clp->cl_cb_inflight, + !atomic_read(&clp->cl_cb_inflight)); +} + +static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses) +{ + if (clp->cl_minorversion == 0) { + client->cl_principal = clp->cl_cred.cr_targ_princ ? + clp->cl_cred.cr_targ_princ : "nfs"; + + return get_cred(rpc_machine_cred()); + } else { + struct cred *kcred; + + kcred = prepare_kernel_cred(NULL); + if (!kcred) + return NULL; + + kcred->fsuid = ses->se_cb_sec.uid; + kcred->fsgid = ses->se_cb_sec.gid; + return kcred; + } +} + +static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) +{ + int maxtime = max_cb_time(clp->net); + struct rpc_timeout timeparms = { + .to_initval = maxtime, + .to_retries = 0, + .to_maxval = maxtime, + }; + struct rpc_create_args args = { + .net = clp->net, + .address = (struct sockaddr *) &conn->cb_addr, + .addrsize = conn->cb_addrlen, + .saddress = (struct sockaddr *) &conn->cb_saddr, + .timeout = &timeparms, + .program = &cb_program, + .version = 1, + .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), + .cred = current_cred(), + }; + struct rpc_clnt *client; + const struct cred *cred; + + if (clp->cl_minorversion == 0) { + if (!clp->cl_cred.cr_principal && + (clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) { + trace_nfsd_cb_setup_err(clp, -EINVAL); + return -EINVAL; + } + args.client_name = clp->cl_cred.cr_principal; + args.prognumber = conn->cb_prog; + args.protocol = XPRT_TRANSPORT_TCP; + args.authflavor = clp->cl_cred.cr_flavor; + clp->cl_cb_ident = conn->cb_ident; + } else { + if (!conn->cb_xprt) + return -EINVAL; + clp->cl_cb_session = ses; + args.bc_xprt = conn->cb_xprt; + args.prognumber = clp->cl_cb_session->se_cb_prog; + args.protocol = conn->cb_xprt->xpt_class->xcl_ident | + XPRT_TRANSPORT_BC; + args.authflavor = ses->se_cb_sec.flavor; + } + /* Create RPC client */ + client = rpc_create(&args); + if (IS_ERR(client)) { + trace_nfsd_cb_setup_err(clp, PTR_ERR(client)); + return PTR_ERR(client); + } + cred = get_backchannel_cred(clp, client, ses); + if (!cred) { + trace_nfsd_cb_setup_err(clp, -ENOMEM); + rpc_shutdown_client(client); + return -ENOMEM; + } + + if (clp->cl_minorversion != 0) + clp->cl_cb_conn.cb_xprt = conn->cb_xprt; + clp->cl_cb_client = client; + clp->cl_cb_cred = cred; + rcu_read_lock(); + trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID), + args.authflavor); + rcu_read_unlock(); + return 0; +} + +static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate) +{ + if (clp->cl_cb_state != newstate) { + clp->cl_cb_state = newstate; + trace_nfsd_cb_state(clp); + } +} + +static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason) +{ + if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags)) + return; + nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN); +} + +static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason) +{ + if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags)) + return; + nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT); +} + +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 + nfsd4_mark_cb_state(clp, NFSD4_CB_UP); +} + +static void nfsd4_cb_probe_release(void *calldata) +{ + struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null); + + nfsd41_cb_inflight_end(clp); + +} + +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, + .rpc_release = nfsd4_cb_probe_release, +}; + +/* + * 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) +{ + trace_nfsd_cb_probe(clp); + nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN); + set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags); + nfsd4_run_cb(&clp->cl_cb_null); +} + +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) +{ + nfsd4_mark_cb_state(clp, 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 nfsd4_callback *cb, struct rpc_task *task) +{ + struct nfs4_client *clp = cb->cb_clp; + + if (!cb->cb_holds_slot && + test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { + rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); + /* Race breaker */ + if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { + dprintk("%s slot is busy\n", __func__); + return false; + } + rpc_wake_up_queued_task(&clp->cl_cb_waitq, task); + } + cb->cb_holds_slot = true; + return true; +} + +static void nfsd41_cb_release_slot(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + + if (cb->cb_holds_slot) { + cb->cb_holds_slot = false; + clear_bit(0, &clp->cl_cb_slot_busy); + rpc_wake_up_next(&clp->cl_cb_waitq); + } +} + +static void nfsd41_destroy_cb(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + + nfsd41_cb_release_slot(cb); + if (cb->cb_ops && cb->cb_ops->release) + cb->cb_ops->release(cb); + nfsd41_cb_inflight_end(clp); +} + +/* + * 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_client *clp = cb->cb_clp; + u32 minorversion = clp->cl_minorversion; + + /* + * cb_seq_status is only set in decode_cb_sequence4res, + * and so will remain 1 if an rpc level failure occurs. + */ + cb->cb_seq_status = 1; + cb->cb_status = 0; + if (minorversion && !nfsd41_cb_get_slot(cb, task)) + return; + rpc_call_start(task); +} + +static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + struct nfsd4_session *session = clp->cl_cb_session; + bool ret = true; + + if (!clp->cl_minorversion) { + /* + * If the backchannel connection was shut down while this + * task was queued, we need to resubmit it after setting up + * a new backchannel connection. + * + * Note that if we lost our callback connection permanently + * the submission code will error out, so we don't need to + * handle that case here. + */ + if (RPC_SIGNALLED(task)) + goto need_restart; + + return true; + } + + if (!cb->cb_holds_slot) + goto need_restart; + + switch (cb->cb_seq_status) { + case 0: + /* + * No need for lock, access serialized in nfsd4_cb_prepare + * + * RFC5661 20.9.3 + * If CB_SEQUENCE returns an error, then the state of the slot + * (sequence ID, cached reply) MUST NOT change. + */ + ++session->se_cb_seq_nr; + break; + case -ESERVERFAULT: + ++session->se_cb_seq_nr; + fallthrough; + case 1: + case -NFS4ERR_BADSESSION: + nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status); + ret = false; + break; + case -NFS4ERR_DELAY: + if (!rpc_restart_call(task)) + goto out; + + rpc_delay(task, 2 * HZ); + return false; + case -NFS4ERR_BADSLOT: + goto retry_nowait; + case -NFS4ERR_SEQ_MISORDERED: + if (session->se_cb_seq_nr != 1) { + session->se_cb_seq_nr = 1; + goto retry_nowait; + } + break; + default: + nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status); + dprintk("%s: unprocessed error %d\n", __func__, + cb->cb_seq_status); + } + + nfsd41_cb_release_slot(cb); + dprintk("%s: freed slot, new seqid=%d\n", __func__, + clp->cl_cb_session->se_cb_seq_nr); + + if (RPC_SIGNALLED(task)) + goto need_restart; +out: + return ret; +retry_nowait: + if (rpc_restart_call_prepare(task)) + ret = false; + goto out; +need_restart: + if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) { + task->tk_status = 0; + cb->cb_need_restart = true; + } + return false; +} + +static void nfsd4_cb_done(struct rpc_task *task, void *calldata) +{ + struct nfsd4_callback *cb = calldata; + struct nfs4_client *clp = cb->cb_clp; + + if (!nfsd4_cb_sequence_done(task, cb)) + return; + + if (cb->cb_status) { + WARN_ON_ONCE(task->tk_status); + task->tk_status = cb->cb_status; + } + + switch (cb->cb_ops->done(cb, task)) { + case 0: + task->tk_status = 0; + rpc_restart_call_prepare(task); + return; + case 1: + switch (task->tk_status) { + case -EIO: + case -ETIMEDOUT: + case -EACCES: + nfsd4_mark_cb_down(clp, task->tk_status); + } + break; + default: + BUG(); + } +} + +static void nfsd4_cb_release(void *calldata) +{ + struct nfsd4_callback *cb = calldata; + + if (cb->cb_need_restart) + nfsd4_queue_cb(cb); + else + nfsd41_destroy_cb(cb); + +} + +static const struct rpc_call_ops nfsd4_cb_ops = { + .rpc_call_prepare = nfsd4_cb_prepare, + .rpc_call_done = nfsd4_cb_done, + .rpc_release = nfsd4_cb_release, +}; + +int nfsd4_create_callback_queue(void) +{ + callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0); + 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) +{ + if (clp->cl_cb_state != NFSD4_CB_UNKNOWN) + trace_nfsd_cb_shutdown(clp); + + set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags); + /* + * Note this won't actually result in a null callback; + * instead, nfsd4_run_cb_null() will detect the killed + * client, destroy the rpc client, and stop: + */ + nfsd4_run_cb(&clp->cl_cb_null); + flush_workqueue(callback_wq); + nfsd41_cb_inflight_wait_complete(clp); +} + +/* 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; +} + +/* + * Note there isn't a lot of locking in this code; instead we depend on + * the fact that it is run from the callback_wq, which won't run two + * work items at once. So, for example, callback_wq handles all access + * of cl_cb_client and all calls to rpc_create or rpc_shutdown_client. + */ +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; + put_cred(clp->cl_cb_cred); + clp->cl_cb_cred = 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); + if (c) + svc_xprt_put(c->cn_xprt); + return; + } +} + +static void +nfsd4_run_cb_work(struct work_struct *work) +{ + struct nfsd4_callback *cb = + container_of(work, struct nfsd4_callback, cb_work); + struct nfs4_client *clp = cb->cb_clp; + struct rpc_clnt *clnt; + int flags; + + if (cb->cb_need_restart) { + cb->cb_need_restart = false; + } else { + if (cb->cb_ops && cb->cb_ops->prepare) + cb->cb_ops->prepare(cb); + } + + 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: */ + nfsd41_destroy_cb(cb); + return; + } + + /* + * Don't send probe messages for 4.1 or later. + */ + if (!cb->cb_ops && clp->cl_minorversion) { + nfsd4_mark_cb_state(clp, NFSD4_CB_UP); + nfsd41_destroy_cb(cb); + return; + } + + cb->cb_msg.rpc_cred = clp->cl_cb_cred; + flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; + rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags, + cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); +} + +void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp, + const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op) +{ + cb->cb_clp = clp; + cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op]; + cb->cb_msg.rpc_argp = cb; + cb->cb_msg.rpc_resp = cb; + cb->cb_ops = ops; + INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); + cb->cb_seq_status = 1; + cb->cb_status = 0; + cb->cb_need_restart = false; + cb->cb_holds_slot = false; +} + +/** + * nfsd4_run_cb - queue up a callback job to run + * @cb: callback to queue + * + * Kick off a callback to do its thing. Returns false if it was already + * on a queue, true otherwise. + */ +bool nfsd4_run_cb(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + bool queued; + + nfsd41_cb_inflight_begin(clp); + queued = nfsd4_queue_cb(cb); + if (!queued) + nfsd41_cb_inflight_end(clp); + return queued; +} |