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 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 #ifndef	_LINUX_FILE_H_
30 #define	_LINUX_FILE_H_
31 
32 #include <sys/param.h>
33 #include <sys/file.h>
34 #include <sys/filedesc.h>
35 #include <sys/refcount.h>
36 #include <sys/proc.h>
37 
38 #include <linux/fs.h>
39 
40 struct linux_file;
41 
42 #undef file
43 
44 extern struct fileops linuxfileops;
45 
46 static inline struct linux_file *
linux_fget(unsigned int fd)47 linux_fget(unsigned int fd)
48 {
49 	struct file *file;
50 
51 	file = fget_unlocked(curthread->td_proc->p_fd, fd);
52 	return (struct linux_file *)file->f_data;
53 }
54 
55 static inline void
fput(struct linux_file * filp)56 fput(struct linux_file *filp)
57 {
58 	if (filp->_file == NULL) {
59 		kfree(filp);
60 		return;
61 	}
62 	if (refcount_release(&filp->_file->f_count)) {
63 		_fdrop(filp->_file, curthread);
64 		kfree(filp);
65 	}
66 }
67 
68 static inline void
put_unused_fd(unsigned int fd)69 put_unused_fd(unsigned int fd)
70 {
71 	struct file *file;
72 
73 	file = fget_unlocked(curthread->td_proc->p_fd, fd);
74 	if (file == NULL)
75 		return;
76 	/*
77 	 * NOTE: We should only get here when the "fd" has not been
78 	 * installed, so no need to free the associated Linux file
79 	 * structure.
80 	 */
81 	fdclose(curthread->td_proc->p_fd, file, fd, curthread);
82 
83 	/* drop extra reference */
84 	fdrop(file, curthread);
85 }
86 
87 static inline void
fd_install(unsigned int fd,struct linux_file * filp)88 fd_install(unsigned int fd, struct linux_file *filp)
89 {
90 	struct file *file;
91 
92 	file = fget_unlocked(curthread->td_proc->p_fd, fd);
93 	if (file == NULL) {
94 		filp->_file = NULL;
95 	} else {
96 		filp->_file = file;
97 		finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
98 	}
99 
100 	/* drop the extra reference */
101 	fput(filp);
102 }
103 
104 static inline int
get_unused_fd(void)105 get_unused_fd(void)
106 {
107 	struct file *file;
108 	int error;
109 	int fd;
110 
111 	error = falloc(curthread, &file, &fd, 0);
112 	if (error)
113 		return -error;
114 	/* drop the extra reference */
115 	fdrop(file, curthread);
116 	return fd;
117 }
118 
119 static inline struct linux_file *
alloc_file(int mode,const struct file_operations * fops)120 alloc_file(int mode, const struct file_operations *fops)
121 {
122 	struct linux_file *filp;
123 
124 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
125 	if (filp == NULL)
126 		return (NULL);
127 	filp->f_op = fops;
128 	filp->f_mode = mode;
129 
130 	return filp;
131 }
132 
133 struct fd {
134 	struct linux_file *linux_file;
135 };
136 
fdput(struct fd fd)137 static inline void fdput(struct fd fd)
138 {
139 	fput(fd.linux_file);
140 }
141 
fdget(unsigned int fd)142 static inline struct fd fdget(unsigned int fd)
143 {
144 	struct linux_file *f = linux_fget(fd);
145 	return (struct fd){f};
146 }
147 
148 #define	file	linux_file
149 #define	fget	linux_fget
150 
151 #endif	/* _LINUX_FILE_H_ */
152