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 = igrab(inode); 27 28 /* mds requires start and length rather than start and end */ 29 if (LLONG_MAX == fl->fl_end) 30 length = 0; 31 else 32 length = fl->fl_end - fl->fl_start + 1; 33 34 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 35 "length: %llu, wait: %d, type`: %d", (int)lock_type, 36 (int)operation, (u64)fl->fl_pid, fl->fl_start, 37 length, wait, fl->fl_type); 38 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 the kernel detects 113 * local deadlock. */ 114 ceph_lock_message(CEPH_LOCK_FCNTL, op, file, 115 CEPH_LOCK_UNLOCK, 0, fl); 116 dout("got %d on posix_lock_file, undid lock", err); 117 } 118 } 119 120 } else { 121 dout("mds returned error code %d", err); 122 } 123 return err; 124 } 125 126 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 127 { 128 u8 lock_cmd; 129 int err; 130 u8 wait = 1; 131 132 fl->fl_nspid = get_pid(task_tgid(current)); 133 dout("ceph_flock, fl_pid:%d", fl->fl_pid); 134 135 /* set wait bit, then clear it out of cmd*/ 136 if (cmd & LOCK_NB) 137 wait = 0; 138 cmd = cmd & (LOCK_SH | LOCK_EX | LOCK_UN); 139 /* set command sequence that Ceph wants to see: 140 shared lock, exclusive lock, or unlock */ 141 if (LOCK_SH == cmd) 142 lock_cmd = CEPH_LOCK_SHARED; 143 else if (LOCK_EX == cmd) 144 lock_cmd = CEPH_LOCK_EXCL; 145 else 146 lock_cmd = CEPH_LOCK_UNLOCK; 147 148 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 149 file, lock_cmd, wait, fl); 150 if (!err) { 151 err = flock_lock_file_wait(file, fl); 152 if (err) { 153 ceph_lock_message(CEPH_LOCK_FLOCK, 154 CEPH_MDS_OP_SETFILELOCK, 155 file, CEPH_LOCK_UNLOCK, 0, fl); 156 dout("got %d on flock_lock_file_wait, undid lock", err); 157 } 158 } else { 159 dout("mds error code %d", err); 160 } 161 return err; 162 } 163 164 /** 165 * Must be called with BKL already held. Fills in the passed 166 * counter variables, so you can prepare pagelist metadata before calling 167 * ceph_encode_locks. 168 */ 169 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 170 { 171 struct file_lock *lock; 172 173 *fcntl_count = 0; 174 *flock_count = 0; 175 176 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 177 if (lock->fl_flags & FL_POSIX) 178 ++(*fcntl_count); 179 else if (lock->fl_flags & FL_FLOCK) 180 ++(*flock_count); 181 } 182 dout("counted %d flock locks and %d fcntl locks", 183 *flock_count, *fcntl_count); 184 } 185 186 /** 187 * Encode the flock and fcntl locks for the given inode into the pagelist. 188 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 189 * sequential flock locks. 190 * Must be called with lock_flocks() already held. 191 * If we encounter more of a specific lock type than expected, 192 * we return the value 1. 193 */ 194 int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist, 195 int num_fcntl_locks, int num_flock_locks) 196 { 197 struct file_lock *lock; 198 struct ceph_filelock cephlock; 199 int err = 0; 200 int seen_fcntl = 0; 201 int seen_flock = 0; 202 203 dout("encoding %d flock and %d fcntl locks", num_flock_locks, 204 num_fcntl_locks); 205 err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32)); 206 if (err) 207 goto fail; 208 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 209 if (lock->fl_flags & FL_POSIX) { 210 ++seen_fcntl; 211 if (seen_fcntl > num_fcntl_locks) { 212 err = -ENOSPC; 213 goto fail; 214 } 215 err = lock_to_ceph_filelock(lock, &cephlock); 216 if (err) 217 goto fail; 218 err = ceph_pagelist_append(pagelist, &cephlock, 219 sizeof(struct ceph_filelock)); 220 } 221 if (err) 222 goto fail; 223 } 224 225 err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32)); 226 if (err) 227 goto fail; 228 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) { 229 if (lock->fl_flags & FL_FLOCK) { 230 ++seen_flock; 231 if (seen_flock > num_flock_locks) { 232 err = -ENOSPC; 233 goto fail; 234 } 235 err = lock_to_ceph_filelock(lock, &cephlock); 236 if (err) 237 goto fail; 238 err = ceph_pagelist_append(pagelist, &cephlock, 239 sizeof(struct ceph_filelock)); 240 } 241 if (err) 242 goto fail; 243 } 244 fail: 245 return err; 246 } 247 248 /* 249 * Given a pointer to a lock, convert it to a ceph filelock 250 */ 251 int lock_to_ceph_filelock(struct file_lock *lock, 252 struct ceph_filelock *cephlock) 253 { 254 int err = 0; 255 256 cephlock->start = cpu_to_le64(lock->fl_start); 257 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 258 cephlock->client = cpu_to_le64(0); 259 cephlock->pid = cpu_to_le64(lock->fl_pid); 260 cephlock->pid_namespace = 261 cpu_to_le64((u64)(unsigned long)lock->fl_nspid); 262 263 switch (lock->fl_type) { 264 case F_RDLCK: 265 cephlock->type = CEPH_LOCK_SHARED; 266 break; 267 case F_WRLCK: 268 cephlock->type = CEPH_LOCK_EXCL; 269 break; 270 case F_UNLCK: 271 cephlock->type = CEPH_LOCK_UNLOCK; 272 break; 273 default: 274 dout("Have unknown lock type %d", lock->fl_type); 275 err = -EINVAL; 276 } 277 278 return err; 279 } 280