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 */
ceph_lock_message(u8 lock_type,u16 operation,struct file * file,int cmd,u8 wait,struct file_lock * fl)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 */
ceph_lock(struct file * file,int cmd,struct file_lock * fl)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
ceph_flock(struct file * file,int cmd,struct file_lock * fl)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 */
ceph_count_locks(struct inode * inode,int * fcntl_count,int * flock_count)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 */
ceph_encode_locks(struct inode * inode,struct ceph_pagelist * pagelist,int num_fcntl_locks,int num_flock_locks)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 */
lock_to_ceph_filelock(struct file_lock * lock,struct ceph_filelock * cephlock)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