2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 /** @addtogroup lwext4
34 * @brief Ext4 high level operations (files, directories, mount points...).
35 * Client has to include only this file.
48 #include "ext4_config.h"
49 #include "ext4_errno.h"
50 #include "ext4_oflags.h"
51 #include "ext4_types.h"
52 #include "ext4_blockdev.h"
54 /********************************OS LOCK INFERFACE***************************/
56 /**@brief OS dependent lock interface.*/
59 /**@brief Lock access to mount point*/
62 /**@brief Unlock access to mount point*/
66 /********************************FILE DESCRIPTOR*****************************/
68 /**@brief File descriptor*/
69 typedef struct ext4_file {
71 /**@brief Mount point handle.*/
72 struct ext4_mountpoint *mp;
74 /**@brief File inode id*/
77 /**@brief Open flags.*/
80 /**@brief File size.*/
83 /**@brief File position*/
87 /*****************************DIRECTORY DESCRIPTOR***************************/
89 /**@brief Directory entry descriptor. Copy from ext4_types.h*/
90 typedef struct ext4_direntry {
92 uint16_t entry_length;
98 typedef struct ext4_dir {
99 /**@brief File descriptor*/
101 /**@brief Current directory entry.*/
103 /**@brief Next entry offset*/
107 /********************************MOUNT OPERATIONS****************************/
109 /**@brief Register a block device to a name.
110 * @warning Block device has to be filled by
111 * Block cache may by created automatically when bc parameter is NULL.
112 * @param bd block device
113 * @param bd block device cache
114 * @param dev_name register name
115 * @param standard error code*/
116 int ext4_device_register(struct ext4_blockdev *bd, struct ext4_bcache *bc,
117 const char *dev_name);
119 /**@brief Mount a block device with EXT4 partition to the mount point.
120 * @param dev_name block device name (@ref ext4_device_register)
121 * @param mount_point mount point, for example
124 * - /my_second_partition/
125 * @param read_only mount as read-only mode.
127 * @return standard error code */
128 int ext4_mount(const char *dev_name,
129 const char *mount_point,
132 /**@brief Umount operation.
133 * @param mount_point mount name
134 * @return standard error code */
135 int ext4_umount(const char *mount_point);
137 /**@brief Start journaling. Journaling start/stop functions are transparent
138 * and might be used on filesystems without journaling support.
140 * ext4_mount("sda1", "/");
141 * ext4_journal_start("/");
143 * //File operations here...
145 * ext4_journal_stop("/");
147 * @param mount_point mount name
148 * @return standard error code */
149 int ext4_journal_start(const char *mount_point);
151 /**@brief Stop journaling. Journaling start/stop functions are transparent
152 * and might be used on filesystems without journaling support.
153 * @param mount_point mount name
154 * @return standard error code */
155 int ext4_journal_stop(const char *mount_point);
157 /**@brief Journal recovery.
158 * @param mount_point mount point
159 * @warning Must be called after @ref ext4_mount
160 * @return standard error code */
161 int ext4_recover(const char *mount_point);
163 /**@brief Some of the filesystem stats.*/
164 struct ext4_mount_stats {
165 uint32_t inodes_count;
166 uint32_t free_inodes_count;
167 uint64_t blocks_count;
168 uint64_t free_blocks_count;
171 uint32_t block_group_count;
172 uint32_t blocks_per_group;
173 uint32_t inodes_per_group;
175 char volume_name[16];
178 /**@brief Get file system params.
179 * @param mount_point mount path
180 * @param stats ext fs stats
181 * @return standard error code */
182 int ext4_mount_point_stats(const char *mount_point,
183 struct ext4_mount_stats *stats);
185 /**@brief Setup OS lock routines.
186 * @param mount_point mount path
187 * @param locks - lock and unlock functions
188 * @return standard error code */
189 int ext4_mount_setup_locks(const char *mount_point,
190 const struct ext4_lock *locks);
192 /**@brief Acquire the filesystem superblock pointer of a mp.
193 * @param mount_point mount path
194 * @param superblock pointer
195 * @return standard error code */
196 int ext4_get_sblock(const char *mount_point, struct ext4_sblock **sb);
198 /**@brief Enable/disable write back cache mode.
199 * @warning Default model of cache is write trough. It means that when You do:
203 * < --- data is flushed to physical drive
206 * ext4_cache_write_back(..., 1);
209 * < --- data is NOT flushed to physical drive
210 * ext4_cache_write_back(..., 0);
211 * < --- when write back mode is disabled all
212 * cache data will be flushed
213 * To enable write back mode permanently just call this function
214 * once after ext4_mount (and disable before ext4_umount).
216 * Some of the function use write back cache mode internally.
217 * If you enable write back mode twice you have to disable it twice
220 * ext4_cache_write_back(..., 1);
221 * ext4_cache_write_back(..., 1);
223 * ext4_cache_write_back(..., 0);
224 * ext4_cache_write_back(..., 0);
226 * Write back mode is useful when you want to create a lot of empty
229 * @param path mount point path
230 * @param on enable/disable
232 * @return standard error code */
233 int ext4_cache_write_back(const char *path, bool on);
235 /********************************FILE OPERATIONS*****************************/
237 /**@brief Remove file by path.
238 * @param path path to file
239 * @return standard error code */
240 int ext4_fremove(const char *path);
242 /**@brief create a hardlink for a file.
243 * @param path path to file
244 * @param hardlink_path path of hardlink
245 * @return standard error code */
246 int ext4_flink(const char *path, const char *hardlink_path);
248 /**@brief Rename file
250 * @param new_path destination
251 * @return standard error code */
252 int ext4_frename(const char *path, const char *new_path);
254 /**@brief File open function.
255 * @param path filename (has to start from mount point)
256 * /my_partition/my_file
257 * @param flags open file flags
258 * |---------------------------------------------------------------|
259 * | r or rb O_RDONLY |
260 * |---------------------------------------------------------------|
261 * | w or wb O_WRONLY|O_CREAT|O_TRUNC |
262 * |---------------------------------------------------------------|
263 * | a or ab O_WRONLY|O_CREAT|O_APPEND |
264 * |---------------------------------------------------------------|
265 * | r+ or rb+ or r+b O_RDWR |
266 * |---------------------------------------------------------------|
267 * | w+ or wb+ or w+b O_RDWR|O_CREAT|O_TRUNC |
268 * |---------------------------------------------------------------|
269 * | a+ or ab+ or a+b O_RDWR|O_CREAT|O_APPEND |
270 * |---------------------------------------------------------------|
272 * @return standard error code*/
273 int ext4_fopen(ext4_file *f, const char *path, const char *flags);
275 /**@brief Alternate file open function.
276 * @param filename, (has to start from mount point)
277 * /my_partition/my_file
278 * @param flags open file flags
279 * @return standard error code*/
280 int ext4_fopen2(ext4_file *f, const char *path, int flags);
282 /**@brief File close function.
283 * @param f file handle
284 * @return standard error code*/
285 int ext4_fclose(ext4_file *f);
287 /**@brief Fill in the ext4_inode buffer.
288 * @param path fetch inode data of the path
289 * @param ret_ino the inode id of the path
290 * @param ext4_inode buffer
291 * @return standard error code*/
292 int ext4_fill_raw_inode(const char *path, uint32_t *ret_ino,
293 struct ext4_inode *inode);
295 /**@brief File truncate function.
296 * @param f file handle
297 * @param new file size
298 * @return standard error code*/
299 int ext4_ftruncate(ext4_file *f, uint64_t size);
301 /**@brief Read data from file.
302 * @param f file handle
303 * @param buf output buffer
304 * @param size bytes to read
305 * @param rcnt bytes read (may be NULL)
306 * @return standard error code*/
307 int ext4_fread(ext4_file *f, void *buf, size_t size, size_t *rcnt);
309 /**@brief Write data to file.
310 * @param f file handle
311 * @param buf data to write
312 * @param size write length
313 * @param wcnt bytes written (may be NULL)
314 * @return standard error code*/
315 int ext4_fwrite(ext4_file *f, const void *buf, size_t size, size_t *wcnt);
317 /**@brief File seek operation.
318 * @param f file handle
319 * @param offset offset to seek
320 * @param origin seek type:
324 * @return standard error code*/
325 int ext4_fseek(ext4_file *f, uint64_t offset, uint32_t origin);
327 /**@brief Get file position.
328 * @param f file handle
329 * @return actual file position */
330 uint64_t ext4_ftell(ext4_file *f);
332 /**@brief Get file size.
333 * @param f file handle
334 * @return file size */
335 uint64_t ext4_fsize(ext4_file *f);
337 /**@brief Change file/directory/link mode bits
338 * @param path to file/dir/link
339 * @param mode new mode bits (for example 0777)
340 * @return standard error code*/
341 int ext4_chmod(const char *path, uint32_t mode);
343 /**@brief Change file owner and group
344 * @param path to file/dir/link
346 * @param gid group id
347 * @return standard error code*/
348 int ext4_chown(const char *path, uint32_t uid, uint32_t gid);
350 /**@brief Set file access time
351 * @param path to file/dir/link
352 * @param atime access timestamp
353 * @return standard error code*/
354 int ext4_file_set_atime(const char *path, uint32_t atime);
356 /**@brief Set file modify time
357 * @param path to file/dir/link
358 * @param mtime modify timestamp
359 * @return standard error code*/
360 int ext4_file_set_mtime(const char *path, uint32_t mtime);
362 /**@brief Set file change time
363 * @param path to file/dir/link
364 * @param ctime change timestamp
365 * @return standard error code*/
366 int ext4_file_set_ctime(const char *path, uint32_t ctime);
368 /**@brief Create symbolic link
369 * @param target destination path
370 * @param path source entry
371 * @return standard error code*/
372 int ext4_fsymlink(const char *target, const char *path);
375 /**@brief Read symbolic link payload
376 * @param path to symlink
377 * @param buf output buffer
378 * @param bufsize output buffer max size
379 * @param rcnt bytes read
380 * @return standard error code*/
381 int ext4_readlink(const char *path, char *buf, size_t bufsize, size_t *rcnt);
383 /**@brief Set extended attribute
384 * @param path to file/directory
385 * @param name name of the entry to add
386 * @param name_len length of @name in bytes
387 * @param data data of the entry to add
388 * @param data_size size of data to add
389 * @param replace whether existing entries should be replaced
390 * @return standard error code*/
391 int ext4_setxattr(const char *path, const char *name, size_t name_len,
392 const void *data, size_t data_size, bool replace);
394 /**@brief Get extended attribute
395 * @param path to file/directory
396 * @param name name of the entry to get
397 * @param name_len length of @name in bytes
398 * @param data data of the entry to get
399 * @param data_size size of data to get
400 * @return standard error code*/
401 int ext4_getxattr(const char *path, const char *name, size_t name_len,
402 void *buf, size_t buf_size, size_t *data_size);
404 /**@brief List extended attributes
405 * @param path to file/directory
406 * @param list list to hold the name of entries
407 * @param size size of @list in bytes
408 * @param ret_size used bytes of @list
409 * @return standard error code*/
410 int ext4_listxattr(const char *path, char *list, size_t size, size_t *ret_size);
412 /**@brief Remove extended attribute
413 * @param path to file/directory
414 * @param name name of the entry to remove
415 * @param name_len length of @name in bytes
416 * @return standard error code*/
417 int ext4_removexattr(const char *path, const char *name, size_t name_len);
420 /*********************************DIRECTORY OPERATION***********************/
422 /**@brief Recursive directory remove.
423 * @param path directory path to remove
424 * @return standard error code*/
425 int ext4_dir_rm(const char *path);
427 /**@brief Create new directory.
428 * @param name new directory name
429 * @return standard error code*/
430 int ext4_dir_mk(const char *path);
432 /**@brief Directory open.
433 * @param d directory handle
434 * @param path directory path
435 * @return standard error code*/
436 int ext4_dir_open(ext4_dir *d, const char *path);
438 /**@brief Directory close.
439 * @param d directory handle
440 * @return standard error code*/
441 int ext4_dir_close(ext4_dir *d);
443 /**@brief Return next directory entry.
444 * @param d directory handle
446 * @return directory entry id (NULL if no entry)*/
447 const ext4_direntry *ext4_dir_entry_next(ext4_dir *d);
449 /**@brief Rewine directory entry offset.
450 * @param d directory handle*/
451 void ext4_dir_entry_rewind(ext4_dir *d);