file.h revision 278930 
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, &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, &file,
77	    NULL) != 0) {
78		return;
79	}
80	/*
81	 * NOTE: We should only get here when the "fd" has not been
82	 * installed, so no need to free the associated Linux file
83	 * structure.
84	 */
85	fdclose(curthread->td_proc->p_fd, file, fd, curthread);
86
87	/* drop extra reference */
88	fdrop(file, curthread);
89}
90
91static inline void
92fd_install(unsigned int fd, struct linux_file *filp)
93{
94	struct file *file;
95
96	if (fget_unlocked(curthread->td_proc->p_fd, fd, NULL, &file,
97	    NULL) != 0) {
98		file = NULL;
99	}
100	filp->_file = file;
101	finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
102
103	/* drop the extra reference */
104	fput(filp);
105}
106
107static inline int
108get_unused_fd(void)
109{
110	struct file *file;
111	int error;
112	int fd;
113
114	error = falloc(curthread, &file, &fd, 0);
115	if (error)
116		return -error;
117	/* drop the extra reference */
118	fdrop(file, curthread);
119	return fd;
120}
121
122static inline struct linux_file *
123alloc_file(int mode, const struct file_operations *fops)
124{
125	struct linux_file *filp;
126
127	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
128	if (filp == NULL)
129		return (NULL);
130	filp->f_op = fops;
131	filp->f_mode = mode;
132
133	return filp;
134}
135
136struct fd {
137	struct linux_file *linux_file;
138};
139
140static inline void fdput(struct fd fd)
141{
142	fput(fd.linux_file);
143}
144
145static inline struct fd fdget(unsigned int fd)
146{
147	struct linux_file *f = linux_fget(fd);
148	return (struct fd){f};
149}
150
151#define	file	linux_file
152#define	fget	linux_fget
153
154#endif	/* _LINUX_FILE_H_ */
155