locks: move flock locks to file_lock_context
[linux-2.6-block.git] / fs / ceph / locks.c
CommitLineData
3d14c5d2 1#include <linux/ceph/ceph_debug.h>
40819f6f
GF
2
3#include <linux/file.h>
4#include <linux/namei.h>
eb13e832 5#include <linux/random.h>
40819f6f
GF
6
7#include "super.h"
8#include "mds_client.h"
3d14c5d2 9#include <linux/ceph/pagelist.h>
40819f6f 10
eb13e832 11static u64 lock_secret;
9280be24
YZ
12static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
13 struct ceph_mds_request *req);
eb13e832
YZ
14
15static inline u64 secure_addr(void *addr)
16{
17 u64 v = lock_secret ^ (u64)(unsigned long)addr;
18 /*
19 * Set the most significant bit, so that MDS knows the 'owner'
20 * is sufficient to identify the owner of lock. (old code uses
21 * both 'owner' and 'pid')
22 */
23 v |= (1ULL << 63);
24 return v;
25}
26
27void __init ceph_flock_init(void)
28{
29 get_random_bytes(&lock_secret, sizeof(lock_secret));
30}
31
40819f6f
GF
32/**
33 * Implement fcntl and flock locking functions.
34 */
35static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
637ae8d5 36 int cmd, u8 wait, struct file_lock *fl)
40819f6f 37{
496ad9aa 38 struct inode *inode = file_inode(file);
eb13e832 39 struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
40819f6f
GF
40 struct ceph_mds_request *req;
41 int err;
637ae8d5 42 u64 length = 0;
eb13e832 43 u64 owner;
40819f6f 44
9280be24
YZ
45 if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK)
46 wait = 0;
47
40819f6f
GF
48 req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS);
49 if (IS_ERR(req))
50 return PTR_ERR(req);
70b666c3
SW
51 req->r_inode = inode;
52 ihold(inode);
3bd58143 53 req->r_num_caps = 1;
40819f6f 54
637ae8d5
HS
55 /* mds requires start and length rather than start and end */
56 if (LLONG_MAX == fl->fl_end)
57 length = 0;
58 else
59 length = fl->fl_end - fl->fl_start + 1;
60
130d1f95 61 owner = secure_addr(fl->fl_owner);
eb13e832
YZ
62
63 dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
64 "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type,
65 (int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length,
66 wait, fl->fl_type);
637ae8d5 67
40819f6f
GF
68 req->r_args.filelock_change.rule = lock_type;
69 req->r_args.filelock_change.type = cmd;
eb13e832 70 req->r_args.filelock_change.owner = cpu_to_le64(owner);
637ae8d5 71 req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid);
637ae8d5 72 req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start);
40819f6f
GF
73 req->r_args.filelock_change.length = cpu_to_le64(length);
74 req->r_args.filelock_change.wait = wait;
75
9280be24
YZ
76 if (wait)
77 req->r_wait_for_completion = ceph_lock_wait_for_completion;
78
40819f6f 79 err = ceph_mdsc_do_request(mdsc, inode, req);
a5b10629 80
eb13e832 81 if (operation == CEPH_MDS_OP_GETFILELOCK) {
a5b10629
HS
82 fl->fl_pid = le64_to_cpu(req->r_reply_info.filelock_reply->pid);
83 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type)
84 fl->fl_type = F_RDLCK;
85 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type)
86 fl->fl_type = F_WRLCK;
87 else
88 fl->fl_type = F_UNLCK;
89
90 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start);
91 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) +
92 le64_to_cpu(req->r_reply_info.filelock_reply->length);
93 if (length >= 1)
94 fl->fl_end = length -1;
95 else
96 fl->fl_end = 0;
97
98 }
40819f6f
GF
99 ceph_mdsc_put_request(req);
100 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
0c1f91f2 101 "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type,
637ae8d5
HS
102 (int)operation, (u64)fl->fl_pid, fl->fl_start,
103 length, wait, fl->fl_type, err);
40819f6f
GF
104 return err;
105}
106
9280be24
YZ
107static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc,
108 struct ceph_mds_request *req)
109{
110 struct ceph_mds_request *intr_req;
111 struct inode *inode = req->r_inode;
112 int err, lock_type;
113
114 BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK);
115 if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL)
116 lock_type = CEPH_LOCK_FCNTL_INTR;
117 else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK)
118 lock_type = CEPH_LOCK_FLOCK_INTR;
119 else
120 BUG_ON(1);
121 BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK);
122
123 err = wait_for_completion_interruptible(&req->r_completion);
124 if (!err)
125 return 0;
126
127 dout("ceph_lock_wait_for_completion: request %llu was interrupted\n",
128 req->r_tid);
129
130 intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK,
131 USE_AUTH_MDS);
132 if (IS_ERR(intr_req))
133 return PTR_ERR(intr_req);
134
135 intr_req->r_inode = inode;
136 ihold(inode);
137 intr_req->r_num_caps = 1;
138
139 intr_req->r_args.filelock_change = req->r_args.filelock_change;
140 intr_req->r_args.filelock_change.rule = lock_type;
141 intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK;
142
143 err = ceph_mdsc_do_request(mdsc, inode, intr_req);
144 ceph_mdsc_put_request(intr_req);
145
146 if (err && err != -ERESTARTSYS)
147 return err;
148
149 wait_for_completion(&req->r_completion);
150 return 0;
151}
152
40819f6f
GF
153/**
154 * Attempt to set an fcntl lock.
155 * For now, this just goes away to the server. Later it may be more awesome.
156 */
157int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
158{
40819f6f
GF
159 u8 lock_cmd;
160 int err;
161 u8 wait = 0;
162 u16 op = CEPH_MDS_OP_SETFILELOCK;
163
eb70c0ce
YZ
164 if (!(fl->fl_flags & FL_POSIX))
165 return -ENOLCK;
166 /* No mandatory locks */
167 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK)
168 return -ENOLCK;
169
eb13e832 170 dout("ceph_lock, fl_owner: %p", fl->fl_owner);
40819f6f
GF
171
172 /* set wait bit as appropriate, then make command as Ceph expects it*/
0e8e95d6 173 if (IS_GETLK(cmd))
40819f6f 174 op = CEPH_MDS_OP_GETFILELOCK;
0e8e95d6
YZ
175 else if (IS_SETLKW(cmd))
176 wait = 1;
40819f6f
GF
177
178 if (F_RDLCK == fl->fl_type)
179 lock_cmd = CEPH_LOCK_SHARED;
180 else if (F_WRLCK == fl->fl_type)
181 lock_cmd = CEPH_LOCK_EXCL;
182 else
183 lock_cmd = CEPH_LOCK_UNLOCK;
184
637ae8d5 185 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file, lock_cmd, wait, fl);
40819f6f 186 if (!err) {
eb13e832 187 if (op != CEPH_MDS_OP_GETFILELOCK) {
a5b10629
HS
188 dout("mds locked, locking locally");
189 err = posix_lock_file(file, fl, NULL);
190 if (err && (CEPH_MDS_OP_SETFILELOCK == op)) {
0c1f91f2
SW
191 /* undo! This should only happen if
192 * the kernel detects local
193 * deadlock. */
a5b10629
HS
194 ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
195 CEPH_LOCK_UNLOCK, 0, fl);
0c1f91f2
SW
196 dout("got %d on posix_lock_file, undid lock",
197 err);
a5b10629 198 }
40819f6f 199 }
40819f6f
GF
200 }
201 return err;
202}
203
204int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
205{
40819f6f
GF
206 u8 lock_cmd;
207 int err;
0e8e95d6 208 u8 wait = 0;
40819f6f 209
eb70c0ce
YZ
210 if (!(fl->fl_flags & FL_FLOCK))
211 return -ENOLCK;
212 /* No mandatory locks */
213 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK)
214 return -ENOLCK;
215
eb13e832 216 dout("ceph_flock, fl_file: %p", fl->fl_file);
40819f6f 217
0e8e95d6
YZ
218 if (IS_SETLKW(cmd))
219 wait = 1;
220
221 if (F_RDLCK == fl->fl_type)
40819f6f 222 lock_cmd = CEPH_LOCK_SHARED;
0e8e95d6 223 else if (F_WRLCK == fl->fl_type)
40819f6f
GF
224 lock_cmd = CEPH_LOCK_EXCL;
225 else
226 lock_cmd = CEPH_LOCK_UNLOCK;
40819f6f
GF
227
228 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
637ae8d5 229 file, lock_cmd, wait, fl);
40819f6f
GF
230 if (!err) {
231 err = flock_lock_file_wait(file, fl);
232 if (err) {
233 ceph_lock_message(CEPH_LOCK_FLOCK,
234 CEPH_MDS_OP_SETFILELOCK,
637ae8d5 235 file, CEPH_LOCK_UNLOCK, 0, fl);
40819f6f
GF
236 dout("got %d on flock_lock_file_wait, undid lock", err);
237 }
40819f6f
GF
238 }
239 return err;
240}
241
5263e31e
JL
242/*
243 * Fills in the passed counter variables, so you can prepare pagelist metadata
244 * before calling ceph_encode_locks.
245 *
246 * FIXME: add counters to struct file_lock_context so we don't need to do this?
40819f6f
GF
247 */
248void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count)
249{
250 struct file_lock *lock;
5263e31e 251 struct file_lock_context *ctx;
40819f6f
GF
252
253 *fcntl_count = 0;
254 *flock_count = 0;
255
c362781c 256 spin_lock(&inode->i_lock);
40819f6f
GF
257 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
258 if (lock->fl_flags & FL_POSIX)
259 ++(*fcntl_count);
5263e31e
JL
260 }
261
262 ctx = inode->i_flctx;
263 if (ctx) {
264 list_for_each_entry(lock, &ctx->flc_flock, fl_list)
40819f6f
GF
265 ++(*flock_count);
266 }
c362781c 267 spin_unlock(&inode->i_lock);
40819f6f
GF
268 dout("counted %d flock locks and %d fcntl locks",
269 *flock_count, *fcntl_count);
270}
271
272/**
39be95e9 273 * Encode the flock and fcntl locks for the given inode into the ceph_filelock
1c8c601a 274 * array. Must be called with inode->i_lock already held.
39be95e9 275 * If we encounter more of a specific lock type than expected, return -ENOSPC.
40819f6f 276 */
39be95e9
JS
277int ceph_encode_locks_to_buffer(struct inode *inode,
278 struct ceph_filelock *flocks,
279 int num_fcntl_locks, int num_flock_locks)
40819f6f
GF
280{
281 struct file_lock *lock;
5263e31e 282 struct file_lock_context *ctx;
40819f6f 283 int err = 0;
fca4451a
GF
284 int seen_fcntl = 0;
285 int seen_flock = 0;
39be95e9 286 int l = 0;
40819f6f
GF
287
288 dout("encoding %d flock and %d fcntl locks", num_flock_locks,
289 num_fcntl_locks);
39be95e9 290
c362781c 291 spin_lock(&inode->i_lock);
40819f6f
GF
292 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
293 if (lock->fl_flags & FL_POSIX) {
fca4451a
GF
294 ++seen_fcntl;
295 if (seen_fcntl > num_fcntl_locks) {
296 err = -ENOSPC;
297 goto fail;
298 }
39be95e9 299 err = lock_to_ceph_filelock(lock, &flocks[l]);
40819f6f
GF
300 if (err)
301 goto fail;
39be95e9 302 ++l;
40819f6f 303 }
40819f6f 304 }
5263e31e
JL
305
306 ctx = inode->i_flctx;
307 if (ctx) {
308 list_for_each_entry(lock, &ctx->flc_flock, fl_list) {
fca4451a
GF
309 ++seen_flock;
310 if (seen_flock > num_flock_locks) {
311 err = -ENOSPC;
312 goto fail;
313 }
39be95e9 314 err = lock_to_ceph_filelock(lock, &flocks[l]);
40819f6f
GF
315 if (err)
316 goto fail;
39be95e9 317 ++l;
40819f6f 318 }
40819f6f
GF
319 }
320fail:
c362781c 321 spin_unlock(&inode->i_lock);
40819f6f
GF
322 return err;
323}
324
39be95e9
JS
325/**
326 * Copy the encoded flock and fcntl locks into the pagelist.
327 * Format is: #fcntl locks, sequential fcntl locks, #flock locks,
328 * sequential flock locks.
329 * Returns zero on success.
330 */
331int ceph_locks_to_pagelist(struct ceph_filelock *flocks,
332 struct ceph_pagelist *pagelist,
333 int num_fcntl_locks, int num_flock_locks)
334{
335 int err = 0;
336 __le32 nlocks;
337
338 nlocks = cpu_to_le32(num_fcntl_locks);
339 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
340 if (err)
341 goto out_fail;
342
343 err = ceph_pagelist_append(pagelist, flocks,
344 num_fcntl_locks * sizeof(*flocks));
345 if (err)
346 goto out_fail;
347
348 nlocks = cpu_to_le32(num_flock_locks);
349 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
350 if (err)
351 goto out_fail;
352
353 err = ceph_pagelist_append(pagelist,
354 &flocks[num_fcntl_locks],
355 num_flock_locks * sizeof(*flocks));
356out_fail:
357 return err;
358}
359
40819f6f
GF
360/*
361 * Given a pointer to a lock, convert it to a ceph filelock
362 */
363int lock_to_ceph_filelock(struct file_lock *lock,
364 struct ceph_filelock *cephlock)
365{
366 int err = 0;
40819f6f
GF
367 cephlock->start = cpu_to_le64(lock->fl_start);
368 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
369 cephlock->client = cpu_to_le64(0);
eb13e832 370 cephlock->pid = cpu_to_le64((u64)lock->fl_pid);
130d1f95 371 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
40819f6f
GF
372
373 switch (lock->fl_type) {
374 case F_RDLCK:
375 cephlock->type = CEPH_LOCK_SHARED;
376 break;
377 case F_WRLCK:
378 cephlock->type = CEPH_LOCK_EXCL;
379 break;
380 case F_UNLCK:
381 cephlock->type = CEPH_LOCK_UNLOCK;
382 break;
383 default:
384 dout("Have unknown lock type %d", lock->fl_type);
385 err = -EINVAL;
386 }
387
388 return err;
389}