1 #include <linux/ceph/ceph_debug.h> 2 3 #include <linux/file.h> 4 #include <linux/namei.h> 5 6 #include "super.h" 7 #include "mds_client.h" 8 #include <linux/ceph/pagelist.h> 9 10 /** 11 * Implement fcntl and flock locking functions. 12 */ 13 static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, 14 int cmd, u8 wait, struct file_lock *fl) 15 { 16 struct inode *inode = file_inode(file); 17 struct ceph_mds_client *mdsc = 18 ceph_sb_to_client(inode->i_sb)->mdsc; 19 struct ceph_mds_request *req; 20 int err; 21 u64 length = 0; 22 23 req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); 24 if (IS_ERR(req)) 25 return PTR_ERR(req); 26 req->r_inode = inode; 27 ihold(inode); 28 29 /* mds requires start and length rather than start and end */ 30 if (LLONG_MAX == fl->fl_end) 31 length = 0; 32 else 33 length = fl->fl_end - fl->fl_start + 1; 34 35 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 36 "length: %llu, wait: %d, type: %d", (int)lock_type, 37 (int)operation, (u64)fl->fl_pid, fl->fl_start, 38 length, wait, fl->fl_type); 39 40 req->r_args.filelock_change.rule = lock_type; 41 req->r_args.filelock_change.type = cmd; 42 req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); 43 /* This should be adjusted, but I'm not sure if 44 namespaces actually get id numbers*/ 45 req->r_args.filelock_change.pid_namespace = 46 cpu_to_le64((u64)(unsigned long)fl->fl_nspid); 47 req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); 48 req->r_args.filelock_change.length = cpu_to_le64(length); 49 req->r_args.filelock_change.wait = wait; 50 51 err = ceph_mdsc_do_request(mdsc, inode, req); 52 53 if ( operation == CEPH_MDS_OP_GETFILELOCK){ 54 fl->fl_pid = le64_to_cpu(req->r_reply_info.filelock_reply->pid); 55 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) 56 fl->fl_type = F_RDLCK; 57 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) 58 fl->fl_type = F_WRLCK; 59 else 60 fl->fl_type = F_UNLCK; 61 62 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); 63 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + 64 le64_to_cpu(req->r_reply_info.filelock_reply->length); 65 if (length >= 1) 66 fl->fl_end = length -1; 67 else 68 fl->fl_end = 0; 69 70 } 71 ceph_mdsc_put_request(req); 72 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 73 "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type, 74 (int)operation, (u64)fl->fl_pid, fl->fl_start, 75 length, wait, fl->fl_type, err); 76 return err; 77 } 78 79 /** 80 * Attempt to set an fcntl lock. 81 * For now, this just goes away to the server. Later it may be more awesome. 82 */ 83 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 84 { 85 u8 lock_cmd; 86 int err; 87 u8 wait = 0; 88 u16 op = CEPH_MDS_OP_SETFILELOCK; 89 90 fl->fl_nspid = get_pid(task_tgid(current)); 91 dout("ceph_lock, fl_pid:%d", fl->fl_pid); 92 93 /* set wait bit as appropriate, then make command as Ceph expects it*/ 94 if (F_SETLKW == cmd) 95 wait = 1; 96 if (F_GETLK == cmd) 97 op = CEPH_MDS_OP_GETFILELOCK; 98 99 if (F_RDLCK == fl->fl_type) 100 lock_cmd = CEPH_LOCK_SHARED; 101 else if (F_WRLCK == fl->fl_type) 102 lock_cmd = CEPH_LOCK_EXCL; 103 else 104 lock_cmd = CEPH_LOCK_UNLOCK; 105 106 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file, lock_cmd, wait, fl); 107 if (!err) { 108 if ( op != CEPH_MDS_OP_GETFILELOCK ){ 109 dout("mds locked, locking locally"); 110 err = posix_lock_file(file, fl, NULL); 111 if (err && (CEPH_MDS_OP_SETFILELOCK == op)) { 112 /* undo! This should only happen if 113 * the kernel detects local 114 * deadlock. */ 115 ceph_lock_message(CEPH_LOCK_FCNTL, op, file, 116 CEPH_LOCK_UNLOCK, 0, fl); 117 dout("got %d on posix_lock_file, undid lock", 118 err); 119 } 120 } 121 122 } else if (err == -ERESTARTSYS) { 123 dout("undoing lock\n"); 124 ceph_lock_message(CEPH_LOCK_FCNTL, op, file, 125 CEPH_LOCK_UNLOCK, 0, fl); 126 } 127 return err; 128 } 129 130 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 131 { 132 u8 lock_cmd; 133 int err; 134 u8 wait = 1; 135 136 fl->fl_nspid = get_pid(task_tgid(current)); 137 dout("ceph_flock, fl_pid:%d", fl->fl_pid); 138 139 /* set wait bit, then clear it out of cmd*/ 140 if (cmd & LOCK_NB) 141 wait = 0; 142 cmd = cmd & (LOCK_SH | LOCK_EX | LOCK_UN); 143 /* set command sequence that Ceph wants to see: 144 shared lock, exclusive lock, or unlock */ 145 if (LOCK_SH == cmd) 146 lock_cmd = CEPH_LOCK_SHARED; 147 else if (LOCK_EX == cmd) 148 lock_cmd = CEPH_LOCK_EXCL; 149 else 150 lock_cmd = CEPH_LOCK_UNLOCK; 151 152 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 153 file, lock_cmd, wait, fl); 154 if (!err) { 155 err = flock_lock_file_wait(file, fl); 156 if (err) { 157 ceph_lock_message(CEPH_LOCK_FLOCK, 158 CEPH_MDS_OP_SETFILELOCK, 159 file, CEPH_LOCK_UNLOCK, 0, fl); 160 dout("got %d on flock_lock_file_wait, undid lock", err); 161 } 162 } else if (err == -ERESTARTSYS) { 163 dout("undoing lock\n"); 164 ceph_lock_message(CEPH_LOCK_FLOCK, 165 CEPH_MDS_OP_SETFILELOCK, 166 file, CEPH_LOCK_UNLOCK, 0, fl); 167 } 168 return err; 169 } 170 171 /** 172 * Must be called with lock_flocks() already held. Fills in the passed 173 * counter variables, so you can prepare pagelist metadata before calling 174 * ceph_encode_locks. 175 */ 176 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 177 { 178 struct file_lock *lock; 179 180 *fcntl_count = 0; 181 *flock_count = 0; 182 183 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 184 if (lock->fl_flags & FL_POSIX) 185 ++(*fcntl_count); 186 else if (lock->fl_flags & FL_FLOCK) 187 ++(*flock_count); 188 } 189 dout("counted %d flock locks and %d fcntl locks", 190 *flock_count, *fcntl_count); 191 } 192 193 /** 194 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 195 * array. Must be called with inode->i_lock already held. 196 * If we encounter more of a specific lock type than expected, return -ENOSPC. 197 */ 198 int ceph_encode_locks_to_buffer(struct inode *inode, 199 struct ceph_filelock *flocks, 200 int num_fcntl_locks, int num_flock_locks) 201 { 202 struct file_lock *lock; 203 int err = 0; 204 int seen_fcntl = 0; 205 int seen_flock = 0; 206 int l = 0; 207 208 dout("encoding %d flock and %d fcntl locks", num_flock_locks, 209 num_fcntl_locks); 210 211 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 212 if (lock->fl_flags & FL_POSIX) { 213 ++seen_fcntl; 214 if (seen_fcntl > num_fcntl_locks) { 215 err = -ENOSPC; 216 goto fail; 217 } 218 err = lock_to_ceph_filelock(lock, &flocks[l]); 219 if (err) 220 goto fail; 221 ++l; 222 } 223 } 224 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 225 if (lock->fl_flags & FL_FLOCK) { 226 ++seen_flock; 227 if (seen_flock > num_flock_locks) { 228 err = -ENOSPC; 229 goto fail; 230 } 231 err = lock_to_ceph_filelock(lock, &flocks[l]); 232 if (err) 233 goto fail; 234 ++l; 235 } 236 } 237 fail: 238 return err; 239 } 240 241 /** 242 * Copy the encoded flock and fcntl locks into the pagelist. 243 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 244 * sequential flock locks. 245 * Returns zero on success. 246 */ 247 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 248 struct ceph_pagelist *pagelist, 249 int num_fcntl_locks, int num_flock_locks) 250 { 251 int err = 0; 252 __le32 nlocks; 253 254 nlocks = cpu_to_le32(num_fcntl_locks); 255 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 256 if (err) 257 goto out_fail; 258 259 err = ceph_pagelist_append(pagelist, flocks, 260 num_fcntl_locks * sizeof(*flocks)); 261 if (err) 262 goto out_fail; 263 264 nlocks = cpu_to_le32(num_flock_locks); 265 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 266 if (err) 267 goto out_fail; 268 269 err = ceph_pagelist_append(pagelist, 270 &flocks[num_fcntl_locks], 271 num_flock_locks * sizeof(*flocks)); 272 out_fail: 273 return err; 274 } 275 276 /* 277 * Given a pointer to a lock, convert it to a ceph filelock 278 */ 279 int lock_to_ceph_filelock(struct file_lock *lock, 280 struct ceph_filelock *cephlock) 281 { 282 int err = 0; 283 284 cephlock->start = cpu_to_le64(lock->fl_start); 285 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 286 cephlock->client = cpu_to_le64(0); 287 cephlock->pid = cpu_to_le64(lock->fl_pid); 288 cephlock->pid_namespace = 289 cpu_to_le64((u64)(unsigned long)lock->fl_nspid); 290 291 switch (lock->fl_type) { 292 case F_RDLCK: 293 cephlock->type = CEPH_LOCK_SHARED; 294 break; 295 case F_WRLCK: 296 cephlock->type = CEPH_LOCK_EXCL; 297 break; 298 case F_UNLCK: 299 cephlock->type = CEPH_LOCK_UNLOCK; 300 break; 301 default: 302 dout("Have unknown lock type %d", lock->fl_type); 303 err = -EINVAL; 304 } 305 306 return err; 307 } 308