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 _LINUXKPI_LINUX_FILE_H_ 32 #define _LINUXKPI_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 * 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, fd, &cap_no_rights, &file) != 0) 57 return (NULL); 58 59 /* check if file handle really belongs to us */ 60 if (file->f_data == NULL || 61 file->f_ops != &linuxfileops) { 62 fdrop(file, curthread); 63 return (NULL); 64 } 65 return ((struct linux_file *)file->f_data); 66 } 67 68 extern void linux_file_free(struct linux_file *filp); 69 70 static inline void 71 fput(struct linux_file *filp) 72 { 73 if (refcount_release(filp->_file == NULL ? 74 &filp->f_count : &filp->_file->f_count)) { 75 linux_file_free(filp); 76 } 77 } 78 79 static inline unsigned int 80 file_count(struct linux_file *filp) 81 { 82 return (filp->_file == NULL ? 83 filp->f_count : filp->_file->f_count); 84 } 85 86 static inline void 87 put_unused_fd(unsigned int fd) 88 { 89 struct file *file; 90 91 if (fget_unlocked(curthread, fd, &cap_no_rights, &file) != 0) { 92 return; 93 } 94 /* 95 * NOTE: We should only get here when the "fd" has not been 96 * installed, so no need to free the associated Linux file 97 * structure. 98 */ 99 fdclose(curthread, file, fd); 100 101 /* drop extra reference */ 102 fdrop(file, curthread); 103 } 104 105 static inline void 106 fd_install(unsigned int fd, struct linux_file *filp) 107 { 108 struct file *file; 109 110 if (fget_unlocked(curthread, fd, &cap_no_rights, &file) != 0) { 111 filp->_file = NULL; 112 } else { 113 filp->_file = file; 114 finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops); 115 116 /* transfer reference count from "filp" to "file" */ 117 while (refcount_release(&filp->f_count) == 0) 118 refcount_acquire(&file->f_count); 119 } 120 121 /* drop the extra reference */ 122 fput(filp); 123 } 124 125 static inline int 126 get_unused_fd(void) 127 { 128 struct file *file; 129 int error; 130 int fd; 131 132 error = falloc(curthread, &file, &fd, 0); 133 if (error) 134 return -error; 135 /* drop the extra reference */ 136 fdrop(file, curthread); 137 return fd; 138 } 139 140 static inline int 141 get_unused_fd_flags(int flags) 142 { 143 struct file *file; 144 int error; 145 int fd; 146 147 error = falloc(curthread, &file, &fd, flags); 148 if (error) 149 return -error; 150 /* drop the extra reference */ 151 fdrop(file, curthread); 152 return fd; 153 } 154 155 extern struct linux_file *linux_file_alloc(void); 156 157 static inline struct linux_file * 158 alloc_file(int mode, const struct file_operations *fops) 159 { 160 struct linux_file *filp; 161 162 filp = linux_file_alloc(); 163 filp->f_op = fops; 164 filp->f_mode = mode; 165 166 return (filp); 167 } 168 169 struct fd { 170 struct linux_file *linux_file; 171 }; 172 173 static inline void fdput(struct fd fd) 174 { 175 fput(fd.linux_file); 176 } 177 178 static inline struct fd fdget(unsigned int fd) 179 { 180 struct linux_file *f = linux_fget(fd); 181 return (struct fd){f}; 182 } 183 184 #define file linux_file 185 #define fget(...) linux_fget(__VA_ARGS__) 186 187 #endif /* _LINUXKPI_LINUX_FILE_H_ */ 188