xref: /freebsd/sys/compat/linuxkpi/common/include/linux/file.h (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 #ifndef	_LINUX_FILE_H_
32 #define	_LINUX_FILE_H_
33 
34 #include <sys/param.h>
35 #include <sys/file.h>
36 #include <sys/filedesc.h>
37 #include <sys/refcount.h>
38 #include <sys/capsicum.h>
39 #include <sys/proc.h>
40 
41 #include <linux/fs.h>
42 
43 struct linux_file;
44 
45 #undef file
46 
47 extern struct fileops linuxfileops;
48 
49 static inline struct linux_file *
50 linux_fget(unsigned int fd)
51 {
52 	cap_rights_t rights;
53 	struct file *file;
54 
55 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
56 	    cap_rights_init(&rights), &file, NULL) != 0) {
57 		return (NULL);
58 	}
59 	return (struct linux_file *)file->f_data;
60 }
61 
62 static inline void
63 fput(struct linux_file *filp)
64 {
65 	if (filp->_file == NULL) {
66 		kfree(filp);
67 		return;
68 	}
69 	if (refcount_release(&filp->_file->f_count)) {
70 		_fdrop(filp->_file, curthread);
71 		kfree(filp);
72 	}
73 }
74 
75 static inline void
76 put_unused_fd(unsigned int fd)
77 {
78 	cap_rights_t rights;
79 	struct file *file;
80 
81 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
82 	    cap_rights_init(&rights), &file, NULL) != 0) {
83 		return;
84 	}
85 	/*
86 	 * NOTE: We should only get here when the "fd" has not been
87 	 * installed, so no need to free the associated Linux file
88 	 * structure.
89 	 */
90 	fdclose(curthread, file, fd);
91 
92 	/* drop extra reference */
93 	fdrop(file, curthread);
94 }
95 
96 static inline void
97 fd_install(unsigned int fd, struct linux_file *filp)
98 {
99 	cap_rights_t rights;
100 	struct file *file;
101 
102 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
103 	    cap_rights_init(&rights), &file, NULL) != 0) {
104 		filp->_file = NULL;
105 	} else {
106 		filp->_file = file;
107 		finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
108 	}
109 
110 	/* drop the extra reference */
111 	fput(filp);
112 }
113 
114 static inline int
115 get_unused_fd(void)
116 {
117 	struct file *file;
118 	int error;
119 	int fd;
120 
121 	error = falloc(curthread, &file, &fd, 0);
122 	if (error)
123 		return -error;
124 	/* drop the extra reference */
125 	fdrop(file, curthread);
126 	return fd;
127 }
128 
129 static inline int
130 get_unused_fd_flags(int flags)
131 {
132 	struct file *file;
133 	int error;
134 	int fd;
135 
136 	error = falloc(curthread, &file, &fd, flags);
137 	if (error)
138 		return -error;
139 	/* drop the extra reference */
140 	fdrop(file, curthread);
141 	return fd;
142 }
143 
144 static inline struct linux_file *
145 alloc_file(int mode, const struct file_operations *fops)
146 {
147 	struct linux_file *filp;
148 
149 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
150 	if (filp == NULL)
151 		return (NULL);
152 	filp->f_op = fops;
153 	filp->f_mode = mode;
154 
155 	return filp;
156 }
157 
158 struct fd {
159 	struct linux_file *linux_file;
160 };
161 
162 static inline void fdput(struct fd fd)
163 {
164 	fput(fd.linux_file);
165 }
166 
167 static inline struct fd fdget(unsigned int fd)
168 {
169 	struct linux_file *f = linux_fget(fd);
170 	return (struct fd){f};
171 }
172 
173 #define	file	linux_file
174 #define	fget	linux_fget
175 
176 #endif	/* _LINUX_FILE_H_ */
177