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 * 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) != 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 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 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 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) != 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 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) != 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 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 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 * 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 }; 175 176 static inline void fdput(struct fd fd) 177 { 178 fput(fd.linux_file); 179 } 180 181 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