file.h revision 289644 
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 * $FreeBSD: head/sys/ofed/include/linux/file.h 289644 2015-10-20 19:08:26Z 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		file = NULL;
105	}
106	filp->_file = file;
107	finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
108
109	/* drop the extra reference */
110	fput(filp);
111}
112
113static inline int
114get_unused_fd(void)
115{
116	struct file *file;
117	int error;
118	int fd;
119
120	error = falloc(curthread, &file, &fd, 0);
121	if (error)
122		return -error;
123	/* drop the extra reference */
124	fdrop(file, curthread);
125	return fd;
126}
127
128static inline struct linux_file *
129alloc_file(int mode, const struct file_operations *fops)
130{
131	struct linux_file *filp;
132
133	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
134	if (filp == NULL)
135		return (NULL);
136	filp->f_op = fops;
137	filp->f_mode = mode;
138
139	return filp;
140}
141
142struct fd {
143	struct linux_file *linux_file;
144};
145
146static inline void fdput(struct fd fd)
147{
148	fput(fd.linux_file);
149}
150
151static inline struct fd fdget(unsigned int fd)
152{
153	struct linux_file *f = linux_fget(fd);
154	return (struct fd){f};
155}
156
157#define	file	linux_file
158#define	fget	linux_fget
159
160#endif	/* _LINUX_FILE_H_ */
161