blob: ff4e753aae929d37d414567d22fd6afef7316c7e [file] [log] [blame]
Greg Farnum40819f62010-08-02 15:34:23 -07001#include "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 "pagelist.h"
9
10/**
11 * Implement fcntl and flock locking functions.
12 */
13static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
14 u64 pid, u64 pid_ns,
15 int cmd, u64 start, u64 length, u8 wait)
16{
17 struct inode *inode = file->f_dentry->d_inode;
18 struct ceph_mds_client *mdsc =
19 &ceph_sb_to_client(inode->i_sb)->mdsc;
20 struct ceph_mds_request *req;
21 int err;
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 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
29 "length: %llu, wait: %d, type`: %d", (int)lock_type,
30 (int)operation, pid, start, length, wait, cmd);
31
32 req->r_args.filelock_change.rule = lock_type;
33 req->r_args.filelock_change.type = cmd;
34 req->r_args.filelock_change.pid = cpu_to_le64(pid);
35 /* This should be adjusted, but I'm not sure if
36 namespaces actually get id numbers*/
37 req->r_args.filelock_change.pid_namespace =
38 cpu_to_le64((u64)pid_ns);
39 req->r_args.filelock_change.start = cpu_to_le64(start);
40 req->r_args.filelock_change.length = cpu_to_le64(length);
41 req->r_args.filelock_change.wait = wait;
42
43 err = ceph_mdsc_do_request(mdsc, inode, req);
44 ceph_mdsc_put_request(req);
45 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, "
46 "length: %llu, wait: %d, type`: %d err code %d", (int)lock_type,
47 (int)operation, pid, start, length, wait, cmd, err);
48 return err;
49}
50
51/**
52 * Attempt to set an fcntl lock.
53 * For now, this just goes away to the server. Later it may be more awesome.
54 */
55int ceph_lock(struct file *file, int cmd, struct file_lock *fl)
56{
57 u64 length;
58 u8 lock_cmd;
59 int err;
60 u8 wait = 0;
61 u16 op = CEPH_MDS_OP_SETFILELOCK;
62
63 fl->fl_nspid = get_pid(task_tgid(current));
64 dout("ceph_lock, fl_pid:%d", fl->fl_pid);
65
66 /* set wait bit as appropriate, then make command as Ceph expects it*/
67 if (F_SETLKW == cmd)
68 wait = 1;
69 if (F_GETLK == cmd)
70 op = CEPH_MDS_OP_GETFILELOCK;
71
72 if (F_RDLCK == fl->fl_type)
73 lock_cmd = CEPH_LOCK_SHARED;
74 else if (F_WRLCK == fl->fl_type)
75 lock_cmd = CEPH_LOCK_EXCL;
76 else
77 lock_cmd = CEPH_LOCK_UNLOCK;
78
79 if (LLONG_MAX == fl->fl_end)
80 length = 0;
81 else
82 length = fl->fl_end - fl->fl_start + 1;
83
84 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
Alan Coxad8453a2010-08-25 13:26:32 +010085 (u64)fl->fl_pid,
86 (u64)(unsigned long)fl->fl_nspid,
Greg Farnum40819f62010-08-02 15:34:23 -070087 lock_cmd, fl->fl_start,
88 length, wait);
89 if (!err) {
90 dout("mds locked, locking locally");
91 err = posix_lock_file(file, fl, NULL);
92 if (err && (CEPH_MDS_OP_SETFILELOCK == op)) {
93 /* undo! This should only happen if the kernel detects
94 * local deadlock. */
95 ceph_lock_message(CEPH_LOCK_FCNTL, op, file,
Alan Coxad8453a2010-08-25 13:26:32 +010096 (u64)fl->fl_pid,
97 (u64)(unsigned long)fl->fl_nspid,
Greg Farnum40819f62010-08-02 15:34:23 -070098 CEPH_LOCK_UNLOCK, fl->fl_start,
99 length, 0);
100 dout("got %d on posix_lock_file, undid lock", err);
101 }
102 } else {
103 dout("mds returned error code %d", err);
104 }
105 return err;
106}
107
108int ceph_flock(struct file *file, int cmd, struct file_lock *fl)
109{
110 u64 length;
111 u8 lock_cmd;
112 int err;
113 u8 wait = 1;
114
115 fl->fl_nspid = get_pid(task_tgid(current));
116 dout("ceph_flock, fl_pid:%d", fl->fl_pid);
117
118 /* set wait bit, then clear it out of cmd*/
119 if (cmd & LOCK_NB)
120 wait = 0;
121 cmd = cmd & (LOCK_SH | LOCK_EX | LOCK_UN);
122 /* set command sequence that Ceph wants to see:
123 shared lock, exclusive lock, or unlock */
124 if (LOCK_SH == cmd)
125 lock_cmd = CEPH_LOCK_SHARED;
126 else if (LOCK_EX == cmd)
127 lock_cmd = CEPH_LOCK_EXCL;
128 else
129 lock_cmd = CEPH_LOCK_UNLOCK;
130 /* mds requires start and length rather than start and end */
131 if (LLONG_MAX == fl->fl_end)
132 length = 0;
133 else
134 length = fl->fl_end - fl->fl_start + 1;
135
136 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK,
Alan Coxad8453a2010-08-25 13:26:32 +0100137 file, (u64)fl->fl_pid,
138 (u64)(unsigned long)fl->fl_nspid,
Greg Farnum40819f62010-08-02 15:34:23 -0700139 lock_cmd, fl->fl_start,
140 length, wait);
141 if (!err) {
142 err = flock_lock_file_wait(file, fl);
143 if (err) {
144 ceph_lock_message(CEPH_LOCK_FLOCK,
145 CEPH_MDS_OP_SETFILELOCK,
146 file, (u64)fl->fl_pid,
Alan Coxad8453a2010-08-25 13:26:32 +0100147 (u64)(unsigned long)fl->fl_nspid,
Greg Farnum40819f62010-08-02 15:34:23 -0700148 CEPH_LOCK_UNLOCK, fl->fl_start,
149 length, 0);
150 dout("got %d on flock_lock_file_wait, undid lock", err);
151 }
152 } else {
153 dout("mds error code %d", err);
154 }
155 return err;
156}
157
158/**
159 * Must be called with BKL already held. Fills in the passed
160 * counter variables, so you can prepare pagelist metadata before calling
161 * ceph_encode_locks.
162 */
163void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count)
164{
165 struct file_lock *lock;
166
167 *fcntl_count = 0;
168 *flock_count = 0;
169
170 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
171 if (lock->fl_flags & FL_POSIX)
172 ++(*fcntl_count);
173 else if (lock->fl_flags & FL_FLOCK)
174 ++(*flock_count);
175 }
176 dout("counted %d flock locks and %d fcntl locks",
177 *flock_count, *fcntl_count);
178}
179
180/**
181 * Encode the flock and fcntl locks for the given inode into the pagelist.
182 * Format is: #fcntl locks, sequential fcntl locks, #flock locks,
183 * sequential flock locks.
184 * Must be called with BLK already held, and the lock numbers should have
185 * been gathered under the same lock holding window.
186 */
187int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
188 int num_fcntl_locks, int num_flock_locks)
189{
190 struct file_lock *lock;
191 struct ceph_filelock cephlock;
192 int err = 0;
193
194 dout("encoding %d flock and %d fcntl locks", num_flock_locks,
195 num_fcntl_locks);
196 err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32));
197 if (err)
198 goto fail;
199 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
200 if (lock->fl_flags & FL_POSIX) {
201 err = lock_to_ceph_filelock(lock, &cephlock);
202 if (err)
203 goto fail;
204 err = ceph_pagelist_append(pagelist, &cephlock,
205 sizeof(struct ceph_filelock));
206 }
207 if (err)
208 goto fail;
209 }
210
211 err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32));
212 if (err)
213 goto fail;
214 for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
215 if (lock->fl_flags & FL_FLOCK) {
216 err = lock_to_ceph_filelock(lock, &cephlock);
217 if (err)
218 goto fail;
219 err = ceph_pagelist_append(pagelist, &cephlock,
220 sizeof(struct ceph_filelock));
221 }
222 if (err)
223 goto fail;
224 }
225fail:
226 return err;
227}
228
229/*
230 * Given a pointer to a lock, convert it to a ceph filelock
231 */
232int lock_to_ceph_filelock(struct file_lock *lock,
233 struct ceph_filelock *cephlock)
234{
235 int err = 0;
236
237 cephlock->start = cpu_to_le64(lock->fl_start);
238 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
239 cephlock->client = cpu_to_le64(0);
240 cephlock->pid = cpu_to_le64(lock->fl_pid);
Alan Coxad8453a2010-08-25 13:26:32 +0100241 cephlock->pid_namespace =
242 cpu_to_le64((u64)(unsigned long)lock->fl_nspid);
Greg Farnum40819f62010-08-02 15:34:23 -0700243
244 switch (lock->fl_type) {
245 case F_RDLCK:
246 cephlock->type = CEPH_LOCK_SHARED;
247 break;
248 case F_WRLCK:
249 cephlock->type = CEPH_LOCK_EXCL;
250 break;
251 case F_UNLCK:
252 cephlock->type = CEPH_LOCK_UNLOCK;
253 break;
254 default:
255 dout("Have unknown lock type %d", lock->fl_type);
256 err = -EINVAL;
257 }
258
259 return err;
260}