file.h revision 270710 
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
40struct linux_file;
41
42#undef file
43
44extern struct fileops linuxfileops;
45
46static inline struct linux_file *
47linux_fget(unsigned int fd)
48{
49	struct file *file;
50
51	if (fget_unlocked(curthread->td_proc->p_fd, fd, NULL, 0, &file,
52	    NULL) != 0) {
53		return (NULL);
54	}
55	return (struct linux_file *)file->f_data;
56}
57
58static inline void
59fput(struct linux_file *filp)
60{
61	if (filp->_file == NULL) {
62		kfree(filp);
63		return;
64	}
65	if (refcount_release(&filp->_file->f_count)) {
66		_fdrop(filp->_file, curthread);
67		kfree(filp);
68	}
69}
70
71static inline void
72put_unused_fd(unsigned int fd)
73{
74	struct file *file;
75
76	if (fget_unlocked(curthread->td_proc->p_fd, fd, NULL, 0, &file,
77	    NULL) != 0) {
78		return;
79	}
80	fdclose(curthread->td_proc->p_fd, file, fd, curthread);
81}
82
83static inline void
84fd_install(unsigned int fd, struct linux_file *filp)
85{
86	struct file *file;
87
88	if (fget_unlocked(curthread->td_proc->p_fd, fd, NULL, 0, &file,
89	    NULL) != 0) {
90		file = NULL;
91	}
92	filp->_file = file;
93        finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
94}
95
96static inline int
97get_unused_fd(void)
98{
99	struct file *file;
100	int error;
101	int fd;
102
103	error = falloc(curthread, &file, &fd, 0);
104	if (error)
105		return -error;
106	return fd;
107}
108
109static inline struct linux_file *
110alloc_file(int mode, const struct file_operations *fops)
111{
112	struct linux_file *filp;
113
114	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
115	if (filp == NULL)
116		return (NULL);
117	filp->f_op = fops;
118	filp->f_mode = mode;
119
120	return filp;
121}
122
123struct fd {
124	struct linux_file *linux_file;
125};
126
127static inline void fdput(struct fd fd)
128{
129	fput(fd.linux_file);
130}
131
132static inline struct fd fdget(unsigned int fd)
133{
134	struct linux_file *f = linux_fget(fd);
135	return (struct fd){f};
136}
137
138#define	file	linux_file
139#define	fget	linux_fget
140
141#endif	/* _LINUX_FILE_H_ */
142