1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013-2017 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 * $FreeBSD$
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 #include <linux/slab.h>
43
44 struct linux_file;
45
46 #undef file
47
48 extern struct fileops linuxfileops;
49
50 static inline struct linux_file *
linux_fget(unsigned int fd)51 linux_fget(unsigned int fd)
52 {
53 struct file *file;
54
55 /* lookup file pointer by file descriptor index */
56 if (fget_unlocked(curthread->td_proc->p_fd, fd,
57 &cap_no_rights, &file, NULL) != 0)
58 return (NULL);
59
60 /* check if file handle really belongs to us */
61 if (file->f_data == NULL ||
62 file->f_ops != &linuxfileops) {
63 fdrop(file, curthread);
64 return (NULL);
65 }
66 return ((struct linux_file *)file->f_data);
67 }
68
69 extern void linux_file_free(struct linux_file *filp);
70
71 static inline void
fput(struct linux_file * filp)72 fput(struct linux_file *filp)
73 {
74 if (refcount_release(filp->_file == NULL ?
75 &filp->f_count : &filp->_file->f_count)) {
76 linux_file_free(filp);
77 }
78 }
79
80 static inline unsigned int
file_count(struct linux_file * filp)81 file_count(struct linux_file *filp)
82 {
83 return (filp->_file == NULL ?
84 filp->f_count : filp->_file->f_count);
85 }
86
87 static inline void
put_unused_fd(unsigned int fd)88 put_unused_fd(unsigned int fd)
89 {
90 struct file *file;
91
92 if (fget_unlocked(curthread->td_proc->p_fd, fd,
93 &cap_no_rights, &file, NULL) != 0) {
94 return;
95 }
96 /*
97 * NOTE: We should only get here when the "fd" has not been
98 * installed, so no need to free the associated Linux file
99 * structure.
100 */
101 fdclose(curthread, file, fd);
102
103 /* drop extra reference */
104 fdrop(file, curthread);
105 }
106
107 static inline void
fd_install(unsigned int fd,struct linux_file * filp)108 fd_install(unsigned int fd, struct linux_file *filp)
109 {
110 struct file *file;
111
112 if (fget_unlocked(curthread->td_proc->p_fd, fd,
113 &cap_no_rights, &file, NULL) != 0) {
114 filp->_file = NULL;
115 } else {
116 filp->_file = file;
117 finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
118
119 /* transfer reference count from "filp" to "file" */
120 while (refcount_release(&filp->f_count) == 0)
121 refcount_acquire(&file->f_count);
122 }
123
124 /* drop the extra reference */
125 fput(filp);
126 }
127
128 static inline int
get_unused_fd(void)129 get_unused_fd(void)
130 {
131 struct file *file;
132 int error;
133 int fd;
134
135 error = falloc(curthread, &file, &fd, 0);
136 if (error)
137 return -error;
138 /* drop the extra reference */
139 fdrop(file, curthread);
140 return fd;
141 }
142
143 static inline int
get_unused_fd_flags(int flags)144 get_unused_fd_flags(int flags)
145 {
146 struct file *file;
147 int error;
148 int fd;
149
150 error = falloc(curthread, &file, &fd, flags);
151 if (error)
152 return -error;
153 /* drop the extra reference */
154 fdrop(file, curthread);
155 return fd;
156 }
157
158 extern struct linux_file *linux_file_alloc(void);
159
160 static inline struct linux_file *
alloc_file(int mode,const struct file_operations * fops)161 alloc_file(int mode, const struct file_operations *fops)
162 {
163 struct linux_file *filp;
164
165 filp = linux_file_alloc();
166 filp->f_op = fops;
167 filp->f_mode = mode;
168
169 return (filp);
170 }
171
172 struct fd {
173 struct linux_file *linux_file;
174 };
175
fdput(struct fd fd)176 static inline void fdput(struct fd fd)
177 {
178 fput(fd.linux_file);
179 }
180
fdget(unsigned int fd)181 static inline struct fd fdget(unsigned int fd)
182 {
183 struct linux_file *f = linux_fget(fd);
184 return (struct fd){f};
185 }
186
187 #define file linux_file
188 #define fget(...) linux_fget(__VA_ARGS__)
189
190 #endif /* _LINUX_FILE_H_ */
191