file.h revision 292989 
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: head/sys/compat/linuxkpi/common/include/linux/file.h 292989 2015-12-31 14:47:45Z hselasky $
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
43struct linux_file;
44
45#undef file
46
47extern struct fileops linuxfileops;
48
49static inline struct linux_file *
50linux_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
62static inline void
63fput(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
75static inline void
76put_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
96static inline void
97fd_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
114static inline int
115get_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
129static inline int
130get_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
144static inline struct linux_file *
145alloc_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
158struct fd {
159	struct linux_file *linux_file;
160};
161
162static inline void fdput(struct fd fd)
163{
164	fput(fd.linux_file);
165}
166
167static 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