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 #ifndef _LINUXKPI_LINUX_FILE_H_
30 #define _LINUXKPI_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/capsicum.h>
37 #include <sys/proc.h>
38
39 #include <linux/fs.h>
40 #include <linux/slab.h>
41
42 struct linux_file;
43
44 #undef file
45
46 extern const struct fileops linuxfileops;
47
48 static inline struct linux_file *
linux_fget(unsigned int fd)49 linux_fget(unsigned int fd)
50 {
51 struct file *file;
52
53 /* lookup file pointer by file descriptor index */
54 if (fget_unlocked(curthread, fd, &cap_no_rights, &file) != 0)
55 return (NULL);
56
57 /* check if file handle really belongs to us */
58 if (file->f_data == NULL ||
59 file->f_ops != &linuxfileops) {
60 fdrop(file, curthread);
61 return (NULL);
62 }
63 return ((struct linux_file *)file->f_data);
64 }
65
66 extern void linux_file_free(struct linux_file *filp);
67
68 static inline void
fput(struct linux_file * filp)69 fput(struct linux_file *filp)
70 {
71 if (refcount_release(filp->_file == NULL ?
72 &filp->f_count : &filp->_file->f_count)) {
73 linux_file_free(filp);
74 }
75 }
76
77 static inline unsigned int
file_count(struct linux_file * filp)78 file_count(struct linux_file *filp)
79 {
80 return (filp->_file == NULL ?
81 filp->f_count : filp->_file->f_count);
82 }
83
84 static inline void
put_unused_fd(unsigned int fd)85 put_unused_fd(unsigned int fd)
86 {
87 struct file *file;
88
89 if (fget_unlocked(curthread, fd, &cap_no_rights, &file) != 0) {
90 return;
91 }
92 /*
93 * NOTE: We should only get here when the "fd" has not been
94 * installed, so no need to free the associated Linux file
95 * structure.
96 */
97 fdclose(curthread, file, fd);
98
99 /* drop extra reference */
100 fdrop(file, curthread);
101 }
102
103 static inline void
fd_install(unsigned int fd,struct linux_file * filp)104 fd_install(unsigned int fd, struct linux_file *filp)
105 {
106 struct file *file;
107
108 if (fget_unlocked(curthread, fd, &cap_no_rights, &file) != 0) {
109 filp->_file = NULL;
110 } else {
111 filp->_file = file;
112 finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
113
114 /* transfer reference count from "filp" to "file" */
115 while (refcount_release(&filp->f_count) == 0)
116 refcount_acquire(&file->f_count);
117 }
118
119 /* drop the extra reference */
120 fput(filp);
121 }
122
123 static inline int
get_unused_fd(void)124 get_unused_fd(void)
125 {
126 struct file *file;
127 int error;
128 int fd;
129
130 error = falloc(curthread, &file, &fd, 0);
131 if (error)
132 return -error;
133 /* drop the extra reference */
134 fdrop(file, curthread);
135 return fd;
136 }
137
138 static inline int
get_unused_fd_flags(int flags)139 get_unused_fd_flags(int flags)
140 {
141 struct file *file;
142 int error;
143 int fd;
144
145 error = falloc(curthread, &file, &fd, flags);
146 if (error)
147 return -error;
148 /* drop the extra reference */
149 fdrop(file, curthread);
150 return fd;
151 }
152
153 extern struct linux_file *linux_file_alloc(void);
154
155 static inline struct linux_file *
alloc_file(int mode,const struct file_operations * fops)156 alloc_file(int mode, const struct file_operations *fops)
157 {
158 struct linux_file *filp;
159
160 filp = linux_file_alloc();
161 filp->f_op = fops;
162 filp->f_mode = mode;
163
164 return (filp);
165 }
166
167 struct fd {
168 struct linux_file *linux_file;
169 };
170
fdput(struct fd fd)171 static inline void fdput(struct fd fd)
172 {
173 fput(fd.linux_file);
174 }
175
fdget(unsigned int fd)176 static inline struct fd fdget(unsigned int fd)
177 {
178 struct linux_file *f = linux_fget(fd);
179 return (struct fd){f};
180 }
181
182 #define file linux_file
183 #define fget(...) linux_fget(__VA_ARGS__)
184
185 #endif /* _LINUXKPI_LINUX_FILE_H_ */
186