1 /* 2 * linux/fs/nfs/callback_proc.c 3 * 4 * Copyright (C) 2004 Trond Myklebust 5 * 6 * NFSv4 callback procedures 7 */ 8 #include <linux/nfs4.h> 9 #include <linux/nfs_fs.h> 10 #include "nfs4_fs.h" 11 #include "callback.h" 12 #include "delegation.h" 13 #include "internal.h" 14 15 #ifdef NFS_DEBUG 16 #define NFSDBG_FACILITY NFSDBG_CALLBACK 17 #endif 18 19 __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *res) 20 { 21 struct nfs_client *clp; 22 struct nfs_delegation *delegation; 23 struct nfs_inode *nfsi; 24 struct inode *inode; 25 26 res->bitmap[0] = res->bitmap[1] = 0; 27 res->status = htonl(NFS4ERR_BADHANDLE); 28 clp = nfs_find_client(args->addr, 4); 29 if (clp == NULL) 30 goto out; 31 32 dprintk("NFS: GETATTR callback request from %s\n", 33 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)); 34 35 inode = nfs_delegation_find_inode(clp, &args->fh); 36 if (inode == NULL) 37 goto out_putclient; 38 nfsi = NFS_I(inode); 39 down_read(&nfsi->rwsem); 40 delegation = nfsi->delegation; 41 if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0) 42 goto out_iput; 43 res->size = i_size_read(inode); 44 res->change_attr = delegation->change_attr; 45 if (nfsi->npages != 0) 46 res->change_attr++; 47 res->ctime = inode->i_ctime; 48 res->mtime = inode->i_mtime; 49 res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) & 50 args->bitmap[0]; 51 res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) & 52 args->bitmap[1]; 53 res->status = 0; 54 out_iput: 55 up_read(&nfsi->rwsem); 56 iput(inode); 57 out_putclient: 58 nfs_put_client(clp); 59 out: 60 dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status)); 61 return res->status; 62 } 63 64 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy) 65 { 66 struct nfs_client *clp; 67 struct inode *inode; 68 __be32 res; 69 70 res = htonl(NFS4ERR_BADHANDLE); 71 clp = nfs_find_client(args->addr, 4); 72 if (clp == NULL) 73 goto out; 74 75 dprintk("NFS: RECALL callback request from %s\n", 76 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)); 77 78 do { 79 struct nfs_client *prev = clp; 80 81 inode = nfs_delegation_find_inode(clp, &args->fh); 82 if (inode != NULL) { 83 /* Set up a helper thread to actually return the delegation */ 84 switch(nfs_async_inode_return_delegation(inode, &args->stateid)) { 85 case 0: 86 res = 0; 87 break; 88 case -ENOENT: 89 if (res != 0) 90 res = htonl(NFS4ERR_BAD_STATEID); 91 break; 92 default: 93 res = htonl(NFS4ERR_RESOURCE); 94 } 95 iput(inode); 96 } 97 clp = nfs_find_client_next(prev); 98 nfs_put_client(prev); 99 } while (clp != NULL); 100 out: 101 dprintk("%s: exit with status = %d\n", __func__, ntohl(res)); 102 return res; 103 } 104 105 #if defined(CONFIG_NFS_V4_1) 106 107 /* 108 * Validate the sequenceID sent by the server. 109 * Return success if the sequenceID is one more than what we last saw on 110 * this slot, accounting for wraparound. Increments the slot's sequence. 111 * 112 * We don't yet implement a duplicate request cache, so at this time 113 * we will log replays, and process them as if we had not seen them before, 114 * but we don't bump the sequence in the slot. Not too worried about it, 115 * since we only currently implement idempotent callbacks anyway. 116 * 117 * We have a single slot backchannel at this time, so we don't bother 118 * checking the used_slots bit array on the table. The lower layer guarantees 119 * a single outstanding callback request at a time. 120 */ 121 static int 122 validate_seqid(struct nfs4_slot_table *tbl, u32 slotid, u32 seqid) 123 { 124 struct nfs4_slot *slot; 125 126 dprintk("%s enter. slotid %d seqid %d\n", 127 __func__, slotid, seqid); 128 129 if (slotid > NFS41_BC_MAX_CALLBACKS) 130 return htonl(NFS4ERR_BADSLOT); 131 132 slot = tbl->slots + slotid; 133 dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr); 134 135 /* Normal */ 136 if (likely(seqid == slot->seq_nr + 1)) { 137 slot->seq_nr++; 138 return htonl(NFS4_OK); 139 } 140 141 /* Replay */ 142 if (seqid == slot->seq_nr) { 143 dprintk("%s seqid %d is a replay - no DRC available\n", 144 __func__, seqid); 145 return htonl(NFS4_OK); 146 } 147 148 /* Wraparound */ 149 if (seqid == 1 && (slot->seq_nr + 1) == 0) { 150 slot->seq_nr = 1; 151 return htonl(NFS4_OK); 152 } 153 154 /* Misordered request */ 155 return htonl(NFS4ERR_SEQ_MISORDERED); 156 } 157 158 /* 159 * Returns a pointer to a held 'struct nfs_client' that matches the server's 160 * address, major version number, and session ID. It is the caller's 161 * responsibility to release the returned reference. 162 * 163 * Returns NULL if there are no connections with sessions, or if no session 164 * matches the one of interest. 165 */ 166 static struct nfs_client *find_client_with_session( 167 const struct sockaddr *addr, u32 nfsversion, 168 struct nfs4_sessionid *sessionid) 169 { 170 struct nfs_client *clp; 171 172 clp = nfs_find_client(addr, 4); 173 if (clp == NULL) 174 return NULL; 175 176 do { 177 struct nfs_client *prev = clp; 178 179 if (clp->cl_session != NULL) { 180 if (memcmp(clp->cl_session->sess_id.data, 181 sessionid->data, 182 NFS4_MAX_SESSIONID_LEN) == 0) { 183 /* Returns a held reference to clp */ 184 return clp; 185 } 186 } 187 clp = nfs_find_client_next(prev); 188 nfs_put_client(prev); 189 } while (clp != NULL); 190 191 return NULL; 192 } 193 194 /* FIXME: referring calls should be processed */ 195 unsigned nfs4_callback_sequence(struct cb_sequenceargs *args, 196 struct cb_sequenceres *res) 197 { 198 struct nfs_client *clp; 199 int i, status; 200 201 for (i = 0; i < args->csa_nrclists; i++) 202 kfree(args->csa_rclists[i].rcl_refcalls); 203 kfree(args->csa_rclists); 204 205 status = htonl(NFS4ERR_BADSESSION); 206 clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid); 207 if (clp == NULL) 208 goto out; 209 210 status = validate_seqid(&clp->cl_session->bc_slot_table, 211 args->csa_slotid, args->csa_sequenceid); 212 if (status) 213 goto out_putclient; 214 215 memcpy(&res->csr_sessionid, &args->csa_sessionid, 216 sizeof(res->csr_sessionid)); 217 res->csr_sequenceid = args->csa_sequenceid; 218 res->csr_slotid = args->csa_slotid; 219 res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1; 220 res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1; 221 222 out_putclient: 223 nfs_put_client(clp); 224 out: 225 dprintk("%s: exit with status = %d\n", __func__, ntohl(status)); 226 res->csr_status = status; 227 return res->csr_status; 228 } 229 230 #endif /* CONFIG_NFS_V4_1 */ 231