diff options
Diffstat (limited to 'fs/nfsd/nfs4callback.c')
| -rw-r--r-- | fs/nfsd/nfs4callback.c | 2018 |
1 files changed, 2018 insertions, 0 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c new file mode 100644 index 000000000..a901bbe67 --- /dev/null +++ b/fs/nfsd/nfs4callback.c @@ -0,0 +1,2018 @@ +/* + * 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/nfs4.h> +#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 "stats.h" +#include "trace.h" +#include "xdr4cb.h" +#include "xdr4.h" +#include "nfs4xdr_gen.h" + +#define NFSDDBG_FACILITY NFSDDBG_PROC + +#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" + */ + +static void encode_uint32(struct xdr_stream *xdr, u32 n) +{ + WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0); +} + +static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap, + size_t len) +{ + xdr_stream_encode_uint32_array(xdr, bitmap, len); +} + +static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap, + struct nfs4_cb_fattr *fattr) +{ + fattr->ncf_cb_change = 0; + fattr->ncf_cb_fsize = 0; + fattr->ncf_cb_atime.tv_sec = 0; + fattr->ncf_cb_atime.tv_nsec = 0; + fattr->ncf_cb_mtime.tv_sec = 0; + fattr->ncf_cb_mtime.tv_nsec = 0; + + if (bitmap[0] & FATTR4_WORD0_CHANGE) + if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0) + return -EIO; + if (bitmap[0] & FATTR4_WORD0_SIZE) + if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0) + return -EIO; + if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) { + fattr4_time_deleg_access access; + + if (!xdrgen_decode_fattr4_time_deleg_access(xdr, &access)) + return -EIO; + if (access.nseconds >= NSEC_PER_SEC) + return -EIO; + fattr->ncf_cb_atime.tv_sec = access.seconds; + fattr->ncf_cb_atime.tv_nsec = access.nseconds; + + } + if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) { + fattr4_time_deleg_modify modify; + + if (!xdrgen_decode_fattr4_time_deleg_modify(xdr, &modify)) + return -EIO; + if (modify.nseconds >= NSEC_PER_SEC) + return -EIO; + fattr->ncf_cb_mtime.tv_sec = modify.seconds; + fattr->ncf_cb_mtime.tv_nsec = modify.nseconds; + + } + return 0; +} + +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, XDR_UNIT); + if (unlikely(p == NULL)) + goto out_overflow; + hdr->status = be32_to_cpup(p); + /* Ignore the tag */ + if (xdr_stream_decode_u32(xdr, &length) < 0) + goto out_overflow; + if (xdr_inline_decode(xdr, length) == NULL) + goto out_overflow; + if (xdr_stream_decode_u32(xdr, &hdr->nops) < 0) + goto out_overflow; + 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_RECALLANY4args + * + * struct CB_RECALLANY4args { + * uint32_t craa_objects_to_keep; + * bitmap4 craa_type_mask; + * }; + */ +static void +encode_cb_recallany4args(struct xdr_stream *xdr, + struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra) +{ + encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY); + encode_uint32(xdr, ra->ra_keep); + encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval)); + hdr->nops++; +} + +/* + * CB_GETATTR4args + * struct CB_GETATTR4args { + * nfs_fh4 fh; + * bitmap4 attr_request; + * }; + * + * The size and change attributes are the only one + * guaranteed to be serviced by the client. + */ +static void +encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr, + struct nfs4_cb_fattr *fattr) +{ + struct nfs4_delegation *dp = container_of(fattr, struct nfs4_delegation, dl_cb_fattr); + struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle; + struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr; + u32 bmap_size = 1; + u32 bmap[3]; + + bmap[0] = FATTR4_WORD0_SIZE; + if (!ncf->ncf_file_modified) + bmap[0] |= FATTR4_WORD0_CHANGE; + + if (deleg_attrs_deleg(dp->dl_type)) { + bmap[1] = 0; + bmap[2] = FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY; + bmap_size = 3; + } + encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR); + encode_nfs_fh4(xdr, fh); + encode_bitmap4(xdr, bmap, bmap_size); + hdr->nops++; +} + +static u32 highest_slotid(struct nfsd4_session *ses) +{ + u32 idx; + + spin_lock(&ses->se_lock); + idx = fls(~ses->se_cb_slot_avail); + if (idx > 0) + --idx; + idx = max(idx, ses->se_cb_highest_slot); + spin_unlock(&ses->se_lock); + return idx; +} + +static void +encode_referring_call4(struct xdr_stream *xdr, + const struct nfsd4_referring_call *rc) +{ + encode_uint32(xdr, rc->rc_sequenceid); + encode_uint32(xdr, rc->rc_slotid); +} + +static void +encode_referring_call_list4(struct xdr_stream *xdr, + const struct nfsd4_referring_call_list *rcl) +{ + struct nfsd4_referring_call *rc; + __be32 *p; + + p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN); + xdr_encode_opaque_fixed(p, rcl->rcl_sessionid.data, + NFS4_MAX_SESSIONID_LEN); + encode_uint32(xdr, rcl->__nr_referring_calls); + list_for_each_entry(rc, &rcl->rcl_referring_calls, __list) + encode_referring_call4(xdr, rc); +} + +/* + * 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; + struct nfsd4_referring_call_list *rcl; + __be32 *p; + + if (hdr->minorversion == 0) + return; + + rcu_read_lock(); + session = rcu_dereference(cb->cb_clp->cl_cb_session); + if (!session) { + rcu_read_unlock(); + return; + } + + encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE); + encode_sessionid4(xdr, session); + + p = xdr_reserve_space(xdr, XDR_UNIT * 4); + *p++ = cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]); /* csa_sequenceid */ + *p++ = cpu_to_be32(cb->cb_held_slot); /* csa_slotid */ + *p++ = cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */ + *p++ = xdr_zero; /* csa_cachethis */ + + /* csa_referring_call_lists */ + encode_uint32(xdr, cb->cb_nr_referring_call_list); + list_for_each_entry(rcl, &cb->cb_referring_call_list, __list) + encode_referring_call_list4(xdr, rcl); + + hdr->nops++; + rcu_read_unlock(); +} + +static void update_cb_slot_table(struct nfsd4_session *ses, u32 target) +{ + /* No need to do anything if nothing changed */ + if (likely(target == READ_ONCE(ses->se_cb_highest_slot))) + return; + + spin_lock(&ses->se_lock); + if (target > ses->se_cb_highest_slot) { + int i; + + target = min(target, NFSD_BC_SLOT_TABLE_SIZE - 1); + + /* + * Growing the slot table. Reset any new sequences to 1. + * + * NB: There is some debate about whether the RFC requires this, + * but the Linux client expects it. + */ + for (i = ses->se_cb_highest_slot + 1; i <= target; ++i) + ses->se_cb_seq_nr[i] = 1; + } + ses->se_cb_highest_slot = target; + spin_unlock(&ses->se_lock); +} + +/* + * 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; + int status = -ESERVERFAULT; + __be32 *p; + u32 seqid, slotid, target; + + rcu_read_lock(); + session = rcu_dereference(cb->cb_clp->cl_cb_session); + if (!session) { + rcu_read_unlock(); + cb->cb_seq_status = -NFS4ERR_BADSESSION; + return -NFS4ERR_BADSESSION; + } + + /* + * 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)) { + rcu_read_unlock(); + goto out_overflow; + } + + if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) { + dprintk("NFS: %s Invalid session id\n", __func__); + rcu_read_unlock(); + goto out; + } + p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); + + seqid = be32_to_cpup(p++); + if (seqid != session->se_cb_seq_nr[cb->cb_held_slot]) { + dprintk("NFS: %s Invalid sequence number\n", __func__); + rcu_read_unlock(); + goto out; + } + + slotid = be32_to_cpup(p++); + if (slotid != cb->cb_held_slot) { + dprintk("NFS: %s Invalid slotid\n", __func__); + rcu_read_unlock(); + goto out; + } + + p++; // ignore current highest slot value + + target = be32_to_cpup(p++); + update_cb_slot_table(session, target); + rcu_read_unlock(); + 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); +} + +/* + * 20.1. Operation 3: CB_GETATTR - Get Attributes + */ +static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req, + struct xdr_stream *xdr, const void *data) +{ + const struct nfsd4_callback *cb = data; + struct nfs4_cb_fattr *ncf = + container_of(cb, struct nfs4_cb_fattr, ncf_getattr); + 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_getattr4args(xdr, &hdr, ncf); + encode_cb_nops(&hdr); +} + +/* + * 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); +} + +/* + * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects + */ +static void +nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req, + struct xdr_stream *xdr, const void *data) +{ + const struct nfsd4_callback *cb = data; + struct nfsd4_cb_recall_any *ra; + struct nfs4_cb_compound_hdr hdr = { + .ident = cb->cb_clp->cl_cb_ident, + .minorversion = cb->cb_clp->cl_minorversion, + }; + + ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb); + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + encode_cb_recallany4args(xdr, &hdr, ra); + 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; +} + +/* + * 20.1. Operation 3: CB_GETATTR - Get Attributes + */ +static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp, + struct xdr_stream *xdr, + void *data) +{ + struct nfsd4_callback *cb = data; + struct nfs4_cb_compound_hdr hdr; + int status; + u32 bitmap[3] = {0}; + u32 attrlen, maxlen; + struct nfs4_cb_fattr *ncf = + container_of(cb, struct nfs4_cb_fattr, ncf_getattr); + + 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; + + status = decode_cb_op_status(xdr, OP_CB_GETATTR, &cb->cb_status); + if (unlikely(status || cb->cb_status)) + return status; + if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0) + return -EIO; + if (xdr_stream_decode_u32(xdr, &attrlen) < 0) + return -EIO; + maxlen = sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize); + if (bitmap[2] != 0) + maxlen += (sizeof(ncf->ncf_cb_mtime.tv_sec) + + sizeof(ncf->ncf_cb_mtime.tv_nsec)) * 2; + if (attrlen > maxlen) + return -EIO; + status = decode_cb_fattr4(xdr, bitmap, ncf); + return status; +} + +/* + * 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); +} + +/* + * 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects + */ +static int +nfs4_xdr_dec_cb_recall_any(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; + status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status); + return 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(struct rpc_rqst *req, + struct xdr_stream *xdr, + const void *data) +{ + const struct nfsd4_callback *cb = data; + struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb); + struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify); + struct nfs4_cb_compound_hdr hdr = { + .ident = 0, + .minorversion = cb->cb_clp->cl_minorversion, + }; + struct CB_NOTIFY4args args; + unsigned int start; + + WARN_ON_ONCE(hdr.minorversion == 0); + + encode_cb_compound4args(xdr, &hdr); + encode_cb_sequence4args(xdr, cb, &hdr); + + /* + * nfsd4_cb_notify_prepare() sized the payload against a single page, + * but did not account for the compound, sequence, stateid, and + * filehandle encoded here. If the variable-length encode overflows the + * backchannel send buffer, roll back to before the operation so that a + * truncated CB_NOTIFY is never placed on the wire. + */ + start = xdr_stream_pos(xdr); + + if (xdr_stream_encode_u32(xdr, OP_CB_NOTIFY) < 0) + goto out_err; + + args.cna_stateid.seqid = dp->dl_stid.sc_stateid.si_generation; + memcpy(&args.cna_stateid.other, &dp->dl_stid.sc_stateid.si_opaque, + ARRAY_SIZE(args.cna_stateid.other)); + args.cna_fh.len = dp->dl_stid.sc_file->fi_fhandle.fh_size; + args.cna_fh.data = dp->dl_stid.sc_file->fi_fhandle.fh_raw; + args.cna_changes.count = ncn->ncn_nf_cnt; + args.cna_changes.element = ncn->ncn_nf; + if (!xdrgen_encode_CB_NOTIFY4args(xdr, &args)) + goto out_err; + + hdr.nops++; + encode_cb_nops(&hdr); + return; + +out_err: + /* + * Drop the CB_NOTIFY op and emit a valid CB_SEQUENCE-only compound so + * the client still advances its slot. Flag the failure so the done + * handler recalls the delegation and the missed notification is not + * silently lost. The flag is written here in the transmit path and read + * in the done handler; the two are serialized phases of the same + * rpc_task, so no additional barrier is needed. + */ + ncn->ncn_encode_err = true; + xdr_truncate_encode(xdr, start); + encode_cb_nops(&hdr); +} + +static int nfs4_xdr_dec_cb_notify(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, &cb->cb_status); +} + +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.c.flc_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_CLNT_##proc, \ + .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, COMPOUND, cb_notify, cb_notify), + PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock), + PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload), + PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any), + PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr), +}; + +#define NFS4_CB_PROGRAM 0x40000000 +#define NFS4_CB_VERSION 1 + +struct nfsd_net_cb { + struct rpc_version version4; + const struct rpc_version *versions[NFS4_CB_VERSION + 1]; + struct rpc_program program; + struct rpc_stat stat; +}; + +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 bool nfsd4_queue_cb(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + + trace_nfsd_cb_queue(clp, cb); + return queue_work(clp->cl_callback_wq, &cb->cb_work); +} + +static void nfsd4_requeue_cb(struct rpc_task *task, struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + + if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) { + trace_nfsd_cb_restart(clp, cb); + task->tk_status = 0; + set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags); + } +} + +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) +{ + + atomic_dec_and_wake_up(&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(&init_task); + 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) +{ + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + 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, + .version = NFS4_CB_VERSION, + .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), + .cred = current_cred(), + }; + struct rpc_clnt *client; + const struct cred *cred; + + args.program = &nn->nfsd_cb->program; + 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 || !ses) + return -EINVAL; + args.bc_xprt = conn->cb_xprt; + args.prognumber = ses->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; + rcu_assign_pointer(clp->cl_cb_session, ses); + } + 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_new_state(clp); + } +} + +static void nfsd4_mark_cb_down(struct nfs4_client *clp) +{ + 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) +{ + 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); + 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(clp->cl_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); +} + +static int grab_slot(struct nfsd4_session *ses) +{ + int idx; + + spin_lock(&ses->se_lock); + idx = ffs(ses->se_cb_slot_avail) - 1; + if (idx < 0 || idx > ses->se_cb_highest_slot) { + spin_unlock(&ses->se_lock); + return -1; + } + /* clear the bit for the slot */ + ses->se_cb_slot_avail &= ~BIT(idx); + spin_unlock(&ses->se_lock); + return idx; +} + +/* + * 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; + struct nfsd4_session *ses; + + if (cb->cb_held_slot >= 0) + return true; + + rcu_read_lock(); + ses = rcu_dereference(clp->cl_cb_session); + if (!ses) { + rcu_read_unlock(); + rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); + return false; + } + cb->cb_held_slot = grab_slot(ses); + if (cb->cb_held_slot < 0) { + rcu_read_unlock(); + rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); + /* Race breaker */ + rcu_read_lock(); + ses = rcu_dereference(clp->cl_cb_session); + if (ses) + cb->cb_held_slot = grab_slot(ses); + rcu_read_unlock(); + if (cb->cb_held_slot < 0) + return false; + rpc_wake_up_queued_task(&clp->cl_cb_waitq, task); + } else { + rcu_read_unlock(); + } + return true; +} + +static void nfsd41_cb_release_slot(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + struct nfsd4_session *ses; + + if (cb->cb_held_slot >= 0) { + rcu_read_lock(); + ses = rcu_dereference(clp->cl_cb_session); + if (ses) { + spin_lock(&ses->se_lock); + ses->se_cb_slot_avail |= BIT(cb->cb_held_slot); + spin_unlock(&ses->se_lock); + } + rcu_read_unlock(); + cb->cb_held_slot = -1; + rpc_wake_up_next(&clp->cl_cb_waitq); + } +} + +static void nfsd41_destroy_cb(struct nfsd4_callback *cb) +{ + struct nfs4_client *clp = cb->cb_clp; + + trace_nfsd_cb_destroy(clp, cb); + nfsd41_cb_release_slot(cb); + if (test_bit(NFSD4_CALLBACK_WAKE, &cb->cb_flags)) + clear_and_wake_up_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags); + else + clear_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags); + + /* + * Order the clear of NFSD4_CALLBACK_RUNNING above before the ->release() + * callback below. A release op may re-check producer-side state to decide + * whether to requeue itself (see nfsd4_cb_notify_release()), and that + * check must not be reordered ahead of the clear. The plain clear_bit() + * path carries no ordering; clear_and_wake_up_bit() already issues this + * barrier internally, so the extra one is harmless there. + */ + smp_mb__after_atomic(); + + if (cb->cb_ops && cb->cb_ops->release) + cb->cb_ops->release(cb); + nfsd41_cb_inflight_end(clp); +} + +/** + * nfsd41_cb_referring_call - add a referring call to a callback operation + * @cb: context of callback to add the rc to + * @sessionid: referring call's session ID + * @slotid: referring call's session slot index + * @seqno: referring call's slot sequence number + * + * Caller serializes access to @cb. + * + * NB: If memory allocation fails, the referring call is not added. + */ +void nfsd41_cb_referring_call(struct nfsd4_callback *cb, + struct nfs4_sessionid *sessionid, + u32 slotid, u32 seqno) +{ + struct nfsd4_referring_call_list *rcl; + struct nfsd4_referring_call *rc; + bool found; + + might_sleep(); + + found = false; + list_for_each_entry(rcl, &cb->cb_referring_call_list, __list) { + if (!memcmp(rcl->rcl_sessionid.data, sessionid->data, + NFS4_MAX_SESSIONID_LEN)) { + found = true; + break; + } + } + if (!found) { + rcl = kmalloc_obj(*rcl); + if (!rcl) + return; + memcpy(rcl->rcl_sessionid.data, sessionid->data, + NFS4_MAX_SESSIONID_LEN); + rcl->__nr_referring_calls = 0; + INIT_LIST_HEAD(&rcl->rcl_referring_calls); + list_add(&rcl->__list, &cb->cb_referring_call_list); + cb->cb_nr_referring_call_list++; + } + + found = false; + list_for_each_entry(rc, &rcl->rcl_referring_calls, __list) { + if (rc->rc_sequenceid == seqno && rc->rc_slotid == slotid) { + found = true; + break; + } + } + if (!found) { + rc = kmalloc_obj(*rc); + if (!rc) + goto out; + rc->rc_sequenceid = seqno; + rc->rc_slotid = slotid; + rcl->__nr_referring_calls++; + list_add(&rc->__list, &rcl->rcl_referring_calls); + } + +out: + if (!rcl->__nr_referring_calls) { + cb->cb_nr_referring_call_list--; + list_del(&rcl->__list); + kfree(rcl); + } +} + +/** + * nfsd41_cb_destroy_referring_call_list - release referring call info + * @cb: context of a callback that has completed + * + * Callers who allocate referring calls using nfsd41_cb_referring_call() must + * release those resources by calling nfsd41_cb_destroy_referring_call_list. + * + * Caller serializes access to @cb. + */ +void nfsd41_cb_destroy_referring_call_list(struct nfsd4_callback *cb) +{ + struct nfsd4_referring_call_list *rcl; + struct nfsd4_referring_call *rc; + + while (!list_empty(&cb->cb_referring_call_list)) { + rcl = list_first_entry(&cb->cb_referring_call_list, + struct nfsd4_referring_call_list, + __list); + + while (!list_empty(&rcl->rcl_referring_calls)) { + rc = list_first_entry(&rcl->rcl_referring_calls, + struct nfsd4_referring_call, + __list); + list_del(&rc->__list); + kfree(rc); + } + list_del(&rcl->__list); + kfree(rcl); + } +} + +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. + */ + trace_nfsd_cb_rpc_prepare(clp); + cb->cb_seq_status = 1; + cb->cb_status = 0; + if (minorversion) { + if (!rcu_access_pointer(clp->cl_cb_session)) { + rpc_exit(task, -EIO); + return; + } + if (!nfsd41_cb_get_slot(cb, task)) + return; + } + rpc_call_start(task); +} + +/* Returns true if CB_COMPOUND processing should continue */ +static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb) +{ + struct nfsd4_session *session; + bool ret = false; + + if (cb->cb_held_slot < 0) + goto requeue; + + rcu_read_lock(); + session = rcu_dereference(cb->cb_clp->cl_cb_session); + if (!session) { + rcu_read_unlock(); + goto requeue; + } + + /* This is the operation status code for CB_SEQUENCE */ + trace_nfsd_cb_seq_status(task, cb, session); + 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[cb->cb_held_slot]; + ret = true; + break; + case -ESERVERFAULT: + /* + * Call succeeded, but the session, slot index, or slot + * sequence number in the response do not match the same + * in the server's call. The sequence information is thus + * untrustworthy. + */ + nfsd4_mark_cb_fault(cb->cb_clp); + break; + case 1: + /* + * cb_seq_status remains 1 if an RPC Reply was never + * received. NFSD can't know if the client processed + * the CB_SEQUENCE operation. Ask the client to send a + * DESTROY_SESSION to recover. + */ + fallthrough; + case -NFS4ERR_BADSESSION: + nfsd4_mark_cb_fault(cb->cb_clp); + rcu_read_unlock(); + goto requeue; + case -NFS4ERR_DELAY: + cb->cb_seq_status = 1; + if (RPC_SIGNALLED(task) || !rpc_restart_call(task)) { + rcu_read_unlock(); + goto requeue; + } + rpc_delay(task, 2 * HZ); + rcu_read_unlock(); + return false; + case -NFS4ERR_SEQ_MISORDERED: + case -NFS4ERR_BADSLOT: + /* + * A SEQ_MISORDERED or BADSLOT error means that the client and + * server are out of sync as to the backchannel parameters. Mark + * the backchannel faulty and restart the RPC, but leak the slot + * so that it's no longer used. + */ + nfsd4_mark_cb_fault(cb->cb_clp); + cb->cb_held_slot = -1; + rcu_read_unlock(); + goto retry_nowait; + default: + nfsd4_mark_cb_fault(cb->cb_clp); + } + trace_nfsd_cb_free_slot(task, cb, session); + rcu_read_unlock(); + nfsd41_cb_release_slot(cb); + return ret; +retry_nowait: + /* + * RPC_SIGNALLED() means that the rpc_client is being torn down and + * (possibly) recreated. Requeue the call in that case. + */ + if (!RPC_SIGNALLED(task)) { + if (rpc_restart_call_prepare(task)) + return false; + } +requeue: + nfsd41_cb_release_slot(cb); + nfsd4_requeue_cb(task, cb); + 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; + + trace_nfsd_cb_rpc_done(clp); + + 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)) + nfsd4_requeue_cb(task, cb); + } else if (!nfsd4_cb_sequence_done(task, cb)) { + return; + } + + if (cb->cb_status) { + WARN_ONCE(task->tk_status, + "cb_status=%d tk_status=%d cb_opcode=%d", + cb->cb_status, task->tk_status, cb->cb_ops->opcode); + 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); + } + break; + default: + BUG(); + } +} + +static void nfsd4_cb_release(void *calldata) +{ + struct nfsd4_callback *cb = calldata; + + trace_nfsd_cb_rpc_release(cb->cb_clp); + + if (test_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags)) + 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, +}; + +/* 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(clp->cl_callback_wq); + nfsd41_cb_inflight_wait_complete(clp); +} + +static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) +{ + struct nfsd4_session *s; + struct nfsd4_conn *c; + + lockdep_assert_held(&clp->cl_lock); + + 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 clp->cl_callback_wq, which won't run two + * work items at once. So, for example, clp->cl_callback_wq handles all + * access of cl_cb_client, and all calls to rpc_create or + * rpc_shutdown_client. + * + * cl_cb_session is written only from cl_callback_wq (via + * rcu_assign_pointer) and read from rpciod under rcu_read_lock (via + * rcu_dereference) by encode_cb_sequence4args(), decode_cb_sequence4resok(), + * nfsd4_cb_sequence_done(), and the cb-slot helpers. Sessions are freed + * with kfree_rcu() so that rpciod readers in an RCU read-side critical + * section never dereference a freed session. + */ +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; + + trace_nfsd_cb_bc_update(clp, cb); + + /* + * This is either an update, or the client dying; in either case, + * kill the old client: + */ + if (clp->cl_cb_client) { + trace_nfsd_cb_bc_shutdown(clp, cb); + 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: + */ + WARN_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); + if (c) + svc_xprt_put(c->cn_xprt); + rcu_assign_pointer(clp->cl_cb_session, ses); + 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, ret; + + trace_nfsd_cb_start(clp); + + if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK) + nfsd4_process_cb_update(cb); + + clnt = clp->cl_cb_client; + if (!clnt || clp->cl_state == NFSD4_COURTESY) { + /* + * Callback channel broken, client killed or + * nfs4_client in courtesy state; 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; + } + + if (!test_and_clear_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags)) { + if (cb->cb_ops && cb->cb_ops->prepare) + if (!cb->cb_ops->prepare(cb)) { + nfsd41_destroy_cb(cb); + return; + } + } + + cb->cb_msg.rpc_cred = clp->cl_cb_cred; + flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN; + ret = rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags, + cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb); + if (ret != 0) { + set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags); + nfsd4_queue_cb(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_flags = 0; + cb->cb_ops = ops; + INIT_WORK(&cb->cb_work, nfsd4_run_cb_work); + cb->cb_status = 0; + cb->cb_held_slot = -1; + cb->cb_nr_referring_call_list = 0; + INIT_LIST_HEAD(&cb->cb_referring_call_list); +} + +/** + * 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; + struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id); + const struct nfsd4_callback_ops *ops = cb->cb_ops; + u32 minorversion = clp->cl_minorversion; + bool queued; + + nfsd41_cb_inflight_begin(clp); + queued = nfsd4_queue_cb(cb); + if (queued) { + if (ops) { + nfsd_stats_cb_op_inc(nn, ops->opcode); + /* + * Minorversion > 0 callbacks prepend a CB_SEQUENCE op + * (see encode_cb_sequence4args()); count it like the + * forechannel counts SEQUENCE, so it isn't perpetually + * reported as zero. CB_NULL probes (ops == NULL) carry + * no CB_SEQUENCE -- and on 4.1+ they are dropped without + * sending any RPC (see nfsd4_run_cb_work()) -- so they + * must not be counted here. + */ + if (minorversion > 0) + nfsd_stats_cb_op_inc(nn, OP_CB_SEQUENCE); + } + } else { + nfsd41_cb_inflight_end(clp); + } + return queued; +} + +/** + * nfsd_net_cb_shutdown - release per-netns callback RPC program resources + * @nn: NFS server network namespace + * + * Frees resources allocated by nfsd_net_cb_init(). + */ +void nfsd_net_cb_shutdown(struct nfsd_net *nn) +{ + struct nfsd_net_cb *cb = nn->nfsd_cb; + + if (cb) { + kfree(cb->version4.counts); + kfree(cb); + nn->nfsd_cb = NULL; + } +} + +/** + * nfsd_net_cb_init - initialize per-netns callback RPC program + * @nn: NFS server network namespace + * + * Sets up the callback RPC program, version table, procedure + * counts, and statistics structure for @nn. Caller must release + * these resources using nfsd_net_cb_shutdown(). + * + * Return: 0 on success, or -ENOMEM if allocation fails. + */ +int nfsd_net_cb_init(struct nfsd_net *nn) +{ + struct nfsd_net_cb *cb; + + cb = kzalloc(sizeof(*cb), GFP_KERNEL); + if (!cb) + return -ENOMEM; + + cb->version4.counts = kzalloc_objs(unsigned int, + ARRAY_SIZE(nfs4_cb_procedures), GFP_KERNEL); + if (!cb->version4.counts) { + kfree(cb); + return -ENOMEM; + } + /* + * 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. + */ + cb->version4.number = NFS4_CB_VERSION; + cb->version4.nrprocs = ARRAY_SIZE(nfs4_cb_procedures); + cb->version4.procs = nfs4_cb_procedures; + cb->versions[NFS4_CB_VERSION] = &cb->version4; + + cb->program.name = "nfs4_cb"; + cb->program.number = NFS4_CB_PROGRAM; + cb->program.nrvers = ARRAY_SIZE(cb->versions); + cb->program.version = &cb->versions[0]; + cb->program.pipe_dir_name = "nfsd4_cb"; + cb->program.stats = &cb->stat; + cb->stat.program = &cb->program; + + nn->nfsd_cb = cb; + + return 0; +} |