Commit | Line | Data |
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328970de | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
fa60ce2c | 2 | /* |
53fc622b MF |
3 | * locks.c |
4 | * | |
5 | * Userspace file locking support | |
6 | * | |
7 | * Copyright (C) 2007 Oracle. All rights reserved. | |
53fc622b MF |
8 | */ |
9 | ||
10 | #include <linux/fs.h> | |
53da4939 | 11 | #include <linux/fcntl.h> |
53fc622b | 12 | |
53fc622b MF |
13 | #include <cluster/masklog.h> |
14 | ||
15 | #include "ocfs2.h" | |
16 | ||
17 | #include "dlmglue.h" | |
18 | #include "file.h" | |
53da4939 | 19 | #include "inode.h" |
53fc622b MF |
20 | #include "locks.h" |
21 | ||
22 | static int ocfs2_do_flock(struct file *file, struct inode *inode, | |
23 | int cmd, struct file_lock *fl) | |
24 | { | |
25 | int ret = 0, level = 0, trylock = 0; | |
26 | struct ocfs2_file_private *fp = file->private_data; | |
27 | struct ocfs2_lock_res *lockres = &fp->fp_flock; | |
28 | ||
29 | if (fl->fl_type == F_WRLCK) | |
30 | level = 1; | |
31 | if (!IS_SETLKW(cmd)) | |
32 | trylock = 1; | |
33 | ||
34 | mutex_lock(&fp->fp_mutex); | |
35 | ||
36 | if (lockres->l_flags & OCFS2_LOCK_ATTACHED && | |
37 | lockres->l_level > LKM_NLMODE) { | |
38 | int old_level = 0; | |
4316c3c6 | 39 | struct file_lock request; |
53fc622b MF |
40 | |
41 | if (lockres->l_level == LKM_EXMODE) | |
42 | old_level = 1; | |
43 | ||
44 | if (level == old_level) | |
45 | goto out; | |
46 | ||
47 | /* | |
48 | * Converting an existing lock is not guaranteed to be | |
49 | * atomic, so we can get away with simply unlocking | |
50 | * here and allowing the lock code to try at the new | |
51 | * level. | |
52 | */ | |
53 | ||
4316c3c6 N |
54 | locks_init_lock(&request); |
55 | request.fl_type = F_UNLCK; | |
56 | request.fl_flags = FL_FLOCK; | |
57 | locks_lock_file_wait(file, &request); | |
53fc622b MF |
58 | |
59 | ocfs2_file_unlock(file); | |
60 | } | |
61 | ||
62 | ret = ocfs2_file_lock(file, level, trylock); | |
63 | if (ret) { | |
64 | if (ret == -EAGAIN && trylock) | |
65 | ret = -EWOULDBLOCK; | |
66 | else | |
67 | mlog_errno(ret); | |
68 | goto out; | |
69 | } | |
70 | ||
4f656367 | 71 | ret = locks_lock_file_wait(file, fl); |
e228f643 WW |
72 | if (ret) |
73 | ocfs2_file_unlock(file); | |
53fc622b MF |
74 | |
75 | out: | |
76 | mutex_unlock(&fp->fp_mutex); | |
77 | ||
78 | return ret; | |
79 | } | |
80 | ||
81 | static int ocfs2_do_funlock(struct file *file, int cmd, struct file_lock *fl) | |
82 | { | |
83 | int ret; | |
84 | struct ocfs2_file_private *fp = file->private_data; | |
85 | ||
86 | mutex_lock(&fp->fp_mutex); | |
87 | ocfs2_file_unlock(file); | |
4f656367 | 88 | ret = locks_lock_file_wait(file, fl); |
53fc622b MF |
89 | mutex_unlock(&fp->fp_mutex); |
90 | ||
91 | return ret; | |
92 | } | |
93 | ||
94 | /* | |
95 | * Overall flow of ocfs2_flock() was influenced by gfs2_flock(). | |
96 | */ | |
97 | int ocfs2_flock(struct file *file, int cmd, struct file_lock *fl) | |
98 | { | |
99 | struct inode *inode = file->f_mapping->host; | |
100 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); | |
101 | ||
102 | if (!(fl->fl_flags & FL_FLOCK)) | |
103 | return -ENOLCK; | |
53fc622b MF |
104 | |
105 | if ((osb->s_mount_opt & OCFS2_MOUNT_LOCALFLOCKS) || | |
106 | ocfs2_mount_local(osb)) | |
4f656367 | 107 | return locks_lock_file_wait(file, fl); |
53fc622b MF |
108 | |
109 | if (fl->fl_type == F_UNLCK) | |
110 | return ocfs2_do_funlock(file, cmd, fl); | |
111 | else | |
112 | return ocfs2_do_flock(file, inode, cmd, fl); | |
113 | } | |
53da4939 MF |
114 | |
115 | int ocfs2_lock(struct file *file, int cmd, struct file_lock *fl) | |
116 | { | |
117 | struct inode *inode = file->f_mapping->host; | |
118 | struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); | |
119 | ||
120 | if (!(fl->fl_flags & FL_POSIX)) | |
121 | return -ENOLCK; | |
53da4939 MF |
122 | |
123 | return ocfs2_plock(osb->cconn, OCFS2_I(inode)->ip_blkno, file, cmd, fl); | |
124 | } |