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->f_dentry->d_inode; 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 BKL 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 pagelist. 195 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 196 * sequential flock locks. 197 * Must be called with lock_flocks() already held. 198 * If we encounter more of a specific lock type than expected, 199 * we return the value 1. 200 */ 201 int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist, 202 int num_fcntl_locks, int num_flock_locks) 203 { 204 struct file_lock *lock; 205 struct ceph_filelock cephlock; 206 int err = 0; 207 int seen_fcntl = 0; 208 int seen_flock = 0; 209 210 dout("encoding %d flock and %d fcntl locks", num_flock_locks, 211 num_fcntl_locks); 212 err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32)); 213 if (err) 214 goto fail; 215 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 216 if (lock->fl_flags & FL_POSIX) { 217 ++seen_fcntl; 218 if (seen_fcntl > num_fcntl_locks) { 219 err = -ENOSPC; 220 goto fail; 221 } 222 err = lock_to_ceph_filelock(lock, &cephlock); 223 if (err) 224 goto fail; 225 err = ceph_pagelist_append(pagelist, &cephlock, 226 sizeof(struct ceph_filelock)); 227 } 228 if (err) 229 goto fail; 230 } 231 232 err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32)); 233 if (err) 234 goto fail; 235 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 236 if (lock->fl_flags & FL_FLOCK) { 237 ++seen_flock; 238 if (seen_flock > num_flock_locks) { 239 err = -ENOSPC; 240 goto fail; 241 } 242 err = lock_to_ceph_filelock(lock, &cephlock); 243 if (err) 244 goto fail; 245 err = ceph_pagelist_append(pagelist, &cephlock, 246 sizeof(struct ceph_filelock)); 247 } 248 if (err) 249 goto fail; 250 } 251 fail: 252 return err; 253 } 254 255 /* 256 * Given a pointer to a lock, convert it to a ceph filelock 257 */ 258 int lock_to_ceph_filelock(struct file_lock *lock, 259 struct ceph_filelock *cephlock) 260 { 261 int err = 0; 262 263 cephlock->start = cpu_to_le64(lock->fl_start); 264 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 265 cephlock->client = cpu_to_le64(0); 266 cephlock->pid = cpu_to_le64(lock->fl_pid); 267 cephlock->pid_namespace = 268 cpu_to_le64((u64)(unsigned long)lock->fl_nspid); 269 270 switch (lock->fl_type) { 271 case F_RDLCK: 272 cephlock->type = CEPH_LOCK_SHARED; 273 break; 274 case F_WRLCK: 275 cephlock->type = CEPH_LOCK_EXCL; 276 break; 277 case F_UNLCK: 278 cephlock->type = CEPH_LOCK_UNLOCK; 279 break; 280 default: 281 dout("Have unknown lock type %d", lock->fl_type); 282 err = -EINVAL; 283 } 284 285 return err; 286 } 287