1 /** 2 * unix_io.c - Unix style disk io functions. Originated from the Linux-NTFS project. 3 * 4 * Copyright (c) 2000-2006 Anton Altaparmakov 5 * 6 * This program/include file is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program/include file is distributed in the hope that it will be 12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program (in the main directory of the NTFS-3G 18 * distribution in the file COPYING); if not, write to the Free Software 19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #ifdef HAVE_CONFIG_H 23 #include "config.h" 24 #endif 25 26 #ifdef HAVE_UNISTD_H 27 #include <unistd.h> 28 #endif 29 #ifdef HAVE_STDLIB_H 30 #include <stdlib.h> 31 #endif 32 #ifdef HAVE_STRING_H 33 #include <string.h> 34 #endif 35 #ifdef HAVE_ERRNO_H 36 #include <errno.h> 37 #endif 38 #ifdef HAVE_STDIO_H 39 #include <stdio.h> 40 #endif 41 #ifdef HAVE_SYS_TYPES_H 42 #include <sys/types.h> 43 #endif 44 #ifdef HAVE_SYS_STAT_H 45 #include <sys/stat.h> 46 #endif 47 #ifdef HAVE_FCNTL_H 48 #include <fcntl.h> 49 #endif 50 #ifdef HAVE_SYS_IOCTL_H 51 #include <sys/ioctl.h> 52 #endif 53 #ifdef HAVE_LINUX_FD_H 54 #include <linux/fd.h> 55 #endif 56 57 #include "types.h" 58 #include "mst.h" 59 #include "debug.h" 60 #include "device.h" 61 #include "logging.h" 62 #include "misc.h" 63 64 #define DEV_FD(dev) (*(int *)dev->d_private) 65 66 /* Define to nothing if not present on this system. */ 67 #ifndef O_EXCL 68 # define O_EXCL 0 69 #endif 70 71 /** 72 * ntfs_device_unix_io_open - Open a device and lock it exclusively 73 * @dev: 74 * @flags: 75 * 76 * Description... 77 * 78 * Returns: 79 */ 80 static int ntfs_device_unix_io_open(struct ntfs_device *dev, int flags) 81 { 82 struct flock flk; 83 struct stat sbuf; 84 int err; 85 86 if (NDevOpen(dev)) { 87 errno = EBUSY; 88 return -1; 89 } 90 if (stat(dev->d_name, &sbuf)) { 91 ntfs_log_perror("Failed to access '%s'", dev->d_name); 92 return -1; 93 } 94 if (S_ISBLK(sbuf.st_mode)) 95 NDevSetBlock(dev); 96 97 dev->d_private = ntfs_malloc(sizeof(int)); 98 if (!dev->d_private) 99 return -1; 100 /* 101 * Open file for exclusive access if mounting r/w. 102 * Fuseblk takes care about block devices. 103 */ 104 if (!NDevBlock(dev) && (flags & O_RDWR) == O_RDWR) 105 flags |= O_EXCL; 106 *(int*)dev->d_private = open(dev->d_name, flags); 107 if (*(int*)dev->d_private == -1) { 108 err = errno; 109 goto err_out; 110 } 111 112 if ((flags & O_RDWR) != O_RDWR) 113 NDevSetReadOnly(dev); 114 115 /* locking not implemented in BeOS */ 116 #if !defined(__BEOS__) && !defined(__HAIKU__) 117 memset(&flk, 0, sizeof(flk)); 118 if (NDevReadOnly(dev)) 119 flk.l_type = F_RDLCK; 120 else 121 flk.l_type = F_WRLCK; 122 flk.l_whence = SEEK_SET; 123 flk.l_start = flk.l_len = 0LL; 124 if (fcntl(DEV_FD(dev), F_SETLK, &flk)) { 125 err = errno; 126 ntfs_log_perror("Failed to %s lock '%s'", NDevReadOnly(dev) ? 127 "read" : "write", dev->d_name); 128 if (close(DEV_FD(dev))) 129 ntfs_log_perror("Failed to close '%s'", dev->d_name); 130 goto err_out; 131 } 132 #endif 133 NDevSetOpen(dev); 134 return 0; 135 err_out: 136 free(dev->d_private); 137 dev->d_private = NULL; 138 errno = err; 139 return -1; 140 } 141 142 /** 143 * ntfs_device_unix_io_close - Close the device, releasing the lock 144 * @dev: 145 * 146 * Description... 147 * 148 * Returns: 149 */ 150 static int ntfs_device_unix_io_close(struct ntfs_device *dev) 151 { 152 struct flock flk; 153 154 if (!NDevOpen(dev)) { 155 errno = EBADF; 156 return -1; 157 } 158 if (NDevDirty(dev)) 159 fsync(DEV_FD(dev)); 160 161 /* locking not implemented in BeOS */ 162 #if !defined(__BEOS__) && !defined(__HAIKU__) 163 /* Release exclusive (mandatory) lock on the whole device. */ 164 memset(&flk, 0, sizeof(flk)); 165 flk.l_type = F_UNLCK; 166 flk.l_whence = SEEK_SET; 167 flk.l_start = flk.l_len = 0LL; 168 if (fcntl(DEV_FD(dev), F_SETLK, &flk)) 169 ntfs_log_perror("ntfs_device_unix_io_close: Warning: Could not " 170 "unlock %s", dev->d_name); 171 #endif 172 /* Close the file descriptor and clear our open flag. */ 173 if (close(DEV_FD(dev))) 174 return -1; 175 NDevClearOpen(dev); 176 free(dev->d_private); 177 dev->d_private = NULL; 178 return 0; 179 } 180 181 /** 182 * ntfs_device_unix_io_seek - Seek to a place on the device 183 * @dev: 184 * @offset: 185 * @whence: 186 * 187 * Description... 188 * 189 * Returns: 190 */ 191 static s64 ntfs_device_unix_io_seek(struct ntfs_device *dev, s64 offset, 192 int whence) 193 { 194 return lseek(DEV_FD(dev), offset, whence); 195 } 196 197 /** 198 * ntfs_device_unix_io_read - Read from the device, from the current location 199 * @dev: 200 * @buf: 201 * @count: 202 * 203 * Description... 204 * 205 * Returns: 206 */ 207 static s64 ntfs_device_unix_io_read(struct ntfs_device *dev, void *buf, 208 s64 count) 209 { 210 return read(DEV_FD(dev), buf, count); 211 } 212 213 /** 214 * ntfs_device_unix_io_write - Write to the device, at the current location 215 * @dev: 216 * @buf: 217 * @count: 218 * 219 * Description... 220 * 221 * Returns: 222 */ 223 static s64 ntfs_device_unix_io_write(struct ntfs_device *dev, const void *buf, 224 s64 count) 225 { 226 if (NDevReadOnly(dev)) { 227 errno = EROFS; 228 return -1; 229 } 230 NDevSetDirty(dev); 231 return write(DEV_FD(dev), buf, count); 232 } 233 234 /** 235 * ntfs_device_unix_io_pread - Perform a positioned read from the device 236 * @dev: 237 * @buf: 238 * @count: 239 * @offset: 240 * 241 * Description... 242 * 243 * Returns: 244 */ 245 static s64 ntfs_device_unix_io_pread(struct ntfs_device *dev, void *buf, 246 s64 count, s64 offset) 247 { 248 #if defined(__BEOS__) || defined(__HAIKU__) 249 return read_pos(DEV_FD(dev), offset, buf,count); 250 #else 251 return pread(DEV_FD(dev), buf, count, offset); 252 #endif 253 } 254 255 /** 256 * ntfs_device_unix_io_pwrite - Perform a positioned write to the device 257 * @dev: 258 * @buf: 259 * @count: 260 * @offset: 261 * 262 * Description... 263 * 264 * Returns: 265 */ 266 static s64 ntfs_device_unix_io_pwrite(struct ntfs_device *dev, const void *buf, 267 s64 count, s64 offset) 268 { 269 if (NDevReadOnly(dev)) { 270 errno = EROFS; 271 return -1; 272 } 273 NDevSetDirty(dev); 274 #if defined(__BEOS__) || defined(__HAIKU__) 275 return write_pos(DEV_FD(dev), offset, buf,count); 276 #else 277 return pwrite(DEV_FD(dev), buf, count, offset); 278 #endif 279 } 280 281 /** 282 * ntfs_device_unix_io_sync - Flush any buffered changes to the device 283 * @dev: 284 * 285 * Description... 286 * 287 * Returns: 288 */ 289 static int ntfs_device_unix_io_sync(struct ntfs_device *dev) 290 { 291 if (!NDevReadOnly(dev)) { 292 int res = fsync(DEV_FD(dev)); 293 if (!res) 294 NDevClearDirty(dev); 295 return res; 296 } 297 return 0; 298 } 299 300 /** 301 * ntfs_device_unix_io_stat - Get information about the device 302 * @dev: 303 * @buf: 304 * 305 * Description... 306 * 307 * Returns: 308 */ 309 static int ntfs_device_unix_io_stat(struct ntfs_device *dev, struct stat *buf) 310 { 311 return fstat(DEV_FD(dev), buf); 312 } 313 314 /** 315 * ntfs_device_unix_io_ioctl - Perform an ioctl on the device 316 * @dev: 317 * @request: 318 * @argp: 319 * 320 * Description... 321 * 322 * Returns: 323 */ 324 static int ntfs_device_unix_io_ioctl(struct ntfs_device *dev, int request, 325 void *argp) 326 { 327 return ioctl(DEV_FD(dev), request, argp); 328 } 329 330 /** 331 * Device operations for working with unix style devices and files. 332 */ 333 struct ntfs_device_operations ntfs_device_unix_io_ops = { 334 .open = ntfs_device_unix_io_open, 335 .close = ntfs_device_unix_io_close, 336 .seek = ntfs_device_unix_io_seek, 337 .read = ntfs_device_unix_io_read, 338 .write = ntfs_device_unix_io_write, 339 .pread = ntfs_device_unix_io_pread, 340 .pwrite = ntfs_device_unix_io_pwrite, 341 .sync = ntfs_device_unix_io_sync, 342 .stat = ntfs_device_unix_io_stat, 343 .ioctl = ntfs_device_unix_io_ioctl, 344 }; 345