xref: /freebsd/sys/compat/linuxkpi/common/include/linux/file.h (revision 99429157e8615dc3b7f11afbe3ed92de7476a5db)
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 #include <linux/slab.h>
43 
44 struct linux_file;
45 
46 #undef file
47 
48 extern struct fileops linuxfileops;
49 
50 static inline struct linux_file *
51 linux_fget(unsigned int fd)
52 {
53 	cap_rights_t rights;
54 	struct file *file;
55 
56 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
57 	    cap_rights_init(&rights), &file, NULL) != 0) {
58 		return (NULL);
59 	}
60 	return (struct linux_file *)file->f_data;
61 }
62 
63 static inline void
64 fput(struct linux_file *filp)
65 {
66 	if (filp->_file == NULL) {
67 		kfree(filp);
68 		return;
69 	}
70 	if (refcount_release(&filp->_file->f_count)) {
71 		_fdrop(filp->_file, curthread);
72 		kfree(filp);
73 	}
74 }
75 
76 static inline void
77 put_unused_fd(unsigned int fd)
78 {
79 	cap_rights_t rights;
80 	struct file *file;
81 
82 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
83 	    cap_rights_init(&rights), &file, NULL) != 0) {
84 		return;
85 	}
86 	/*
87 	 * NOTE: We should only get here when the "fd" has not been
88 	 * installed, so no need to free the associated Linux file
89 	 * structure.
90 	 */
91 	fdclose(curthread, file, fd);
92 
93 	/* drop extra reference */
94 	fdrop(file, curthread);
95 }
96 
97 static inline void
98 fd_install(unsigned int fd, struct linux_file *filp)
99 {
100 	cap_rights_t rights;
101 	struct file *file;
102 
103 	if (fget_unlocked(curthread->td_proc->p_fd, fd,
104 	    cap_rights_init(&rights), &file, NULL) != 0) {
105 		filp->_file = NULL;
106 	} else {
107 		filp->_file = file;
108 		finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
109 	}
110 
111 	/* drop the extra reference */
112 	fput(filp);
113 }
114 
115 static inline int
116 get_unused_fd(void)
117 {
118 	struct file *file;
119 	int error;
120 	int fd;
121 
122 	error = falloc(curthread, &file, &fd, 0);
123 	if (error)
124 		return -error;
125 	/* drop the extra reference */
126 	fdrop(file, curthread);
127 	return fd;
128 }
129 
130 static inline int
131 get_unused_fd_flags(int flags)
132 {
133 	struct file *file;
134 	int error;
135 	int fd;
136 
137 	error = falloc(curthread, &file, &fd, flags);
138 	if (error)
139 		return -error;
140 	/* drop the extra reference */
141 	fdrop(file, curthread);
142 	return fd;
143 }
144 
145 static inline struct linux_file *
146 alloc_file(int mode, const struct file_operations *fops)
147 {
148 	struct linux_file *filp;
149 
150 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
151 	if (filp == NULL)
152 		return (NULL);
153 	filp->f_op = fops;
154 	filp->f_mode = mode;
155 
156 	return filp;
157 }
158 
159 struct fd {
160 	struct linux_file *linux_file;
161 };
162 
163 static inline void fdput(struct fd fd)
164 {
165 	fput(fd.linux_file);
166 }
167 
168 static inline struct fd fdget(unsigned int fd)
169 {
170 	struct linux_file *f = linux_fget(fd);
171 	return (struct fd){f};
172 }
173 
174 #define	file	linux_file
175 #define	fget	linux_fget
176 
177 #endif	/* _LINUX_FILE_H_ */
178