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 cap_rights_t rights; 54 struct file *file; 55 56 /* lookup file pointer by file descriptor index */ 57 if (fget_unlocked(curthread->td_proc->p_fd, fd, 58 cap_rights_init(&rights), &file, NULL) != 0) 59 return (NULL); 60 61 /* check if file handle really belongs to us */ 62 if (file->f_data == NULL || 63 file->f_ops != &linuxfileops) { 64 fdrop(file, curthread); 65 return (NULL); 66 } 67 return ((struct linux_file *)file->f_data); 68 } 69 70 extern void linux_file_free(struct linux_file *filp); 71 72 static inline void 73 fput(struct linux_file *filp) 74 { 75 if (refcount_release(filp->_file == NULL ? 76 &filp->f_count : &filp->_file->f_count)) { 77 linux_file_free(filp); 78 } 79 } 80 81 static inline unsigned int 82 file_count(struct linux_file *filp) 83 { 84 return (filp->_file == NULL ? 85 filp->f_count : filp->_file->f_count); 86 } 87 88 static inline void 89 put_unused_fd(unsigned int fd) 90 { 91 cap_rights_t rights; 92 struct file *file; 93 94 if (fget_unlocked(curthread->td_proc->p_fd, fd, 95 cap_rights_init(&rights), &file, NULL) != 0) { 96 return; 97 } 98 /* 99 * NOTE: We should only get here when the "fd" has not been 100 * installed, so no need to free the associated Linux file 101 * structure. 102 */ 103 fdclose(curthread, file, fd); 104 105 /* drop extra reference */ 106 fdrop(file, curthread); 107 } 108 109 static inline void 110 fd_install(unsigned int fd, struct linux_file *filp) 111 { 112 cap_rights_t rights; 113 struct file *file; 114 115 if (fget_unlocked(curthread->td_proc->p_fd, fd, 116 cap_rights_init(&rights), &file, NULL) != 0) { 117 filp->_file = NULL; 118 } else { 119 filp->_file = file; 120 finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops); 121 122 /* transfer reference count from "filp" to "file" */ 123 while (refcount_release(&filp->f_count) == 0) 124 refcount_acquire(&file->f_count); 125 } 126 127 /* drop the extra reference */ 128 fput(filp); 129 } 130 131 static inline int 132 get_unused_fd(void) 133 { 134 struct file *file; 135 int error; 136 int fd; 137 138 error = falloc(curthread, &file, &fd, 0); 139 if (error) 140 return -error; 141 /* drop the extra reference */ 142 fdrop(file, curthread); 143 return fd; 144 } 145 146 static inline int 147 get_unused_fd_flags(int flags) 148 { 149 struct file *file; 150 int error; 151 int fd; 152 153 error = falloc(curthread, &file, &fd, flags); 154 if (error) 155 return -error; 156 /* drop the extra reference */ 157 fdrop(file, curthread); 158 return fd; 159 } 160 161 extern struct linux_file *linux_file_alloc(void); 162 163 static inline struct linux_file * 164 alloc_file(int mode, const struct file_operations *fops) 165 { 166 struct linux_file *filp; 167 168 filp = linux_file_alloc(); 169 filp->f_op = fops; 170 filp->f_mode = mode; 171 172 return (filp); 173 } 174 175 struct fd { 176 struct linux_file *linux_file; 177 }; 178 179 static inline void fdput(struct fd fd) 180 { 181 fput(fd.linux_file); 182 } 183 184 static inline struct fd fdget(unsigned int fd) 185 { 186 struct linux_file *f = linux_fget(fd); 187 return (struct fd){f}; 188 } 189 190 #define file linux_file 191 #define fget(...) linux_fget(__VA_ARGS__) 192 193 #endif /* _LINUX_FILE_H_ */ 194