2  * fileio.c --- Simple file I/O routines
7  * This file may be redistributed under the terms of the GNU Library
34 #define BMAP_BUFFER (file->buf + fs->blocksize)
40 	ext2_file_t 	file;  in ext2fs_file_open2()  local
44 	 * Don't let caller create or open a file for writing if the  in ext2fs_file_open2()
51 	retval = ext2fs_get_mem(sizeof(struct ext2_file), &file);  in ext2fs_file_open2()
55 	memset(file, 0, sizeof(struct ext2_file));  in ext2fs_file_open2()
56 	file->magic = EXT2_ET_MAGIC_EXT2_FILE;  in ext2fs_file_open2()
57 	file->fs = fs;  in ext2fs_file_open2()
58 	file->ino = ino;  in ext2fs_file_open2()
59 	file->flags = flags & EXT2_FILE_MASK;  in ext2fs_file_open2()
62 		memcpy(&file->inode, inode, sizeof(struct ext2_inode));  in ext2fs_file_open2()
64 		retval = ext2fs_read_inode(fs, ino, &file->inode);  in ext2fs_file_open2()
69 	retval = ext2fs_get_array(3, fs->blocksize, &file->buf);  in ext2fs_file_open2()
73 	*ret = file;  in ext2fs_file_open2()
77 	if (file->buf)  in ext2fs_file_open2()
78 		ext2fs_free_mem(&file->buf);  in ext2fs_file_open2()
79 	ext2fs_free_mem(&file);  in ext2fs_file_open2()
90  * This function returns the filesystem handle of a file from the structure
92 ext2_filsys ext2fs_file_get_fs(ext2_file_t file)  in ext2fs_file_get_fs()  argument
94 	if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)  in ext2fs_file_get_fs()
96 	return file->fs;  in ext2fs_file_get_fs()
100  * This function returns the pointer to the inode of a file from the structure
102 struct ext2_inode *ext2fs_file_get_inode(ext2_file_t file)  in ext2fs_file_get_inode()  argument
104 	if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)  in ext2fs_file_get_inode()
106 	return &file->inode;  in ext2fs_file_get_inode()
110 ext2_ino_t ext2fs_file_get_inode_num(ext2_file_t file)  in ext2fs_file_get_inode_num()  argument
112 	if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)  in ext2fs_file_get_inode_num()
114 	return file->ino;  in ext2fs_file_get_inode_num()
121 errcode_t ext2fs_file_flush(ext2_file_t file)  in ext2fs_file_flush()  argument
126 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_flush()
127 	fs = file->fs;  in ext2fs_file_flush()
129 	if (!(file->flags & EXT2_FILE_BUF_VALID) ||  in ext2fs_file_flush()
130 	    !(file->flags & EXT2_FILE_BUF_DIRTY))  in ext2fs_file_flush()
137 	if (!file->physblock) {  in ext2fs_file_flush()
138 		retval = ext2fs_bmap2(fs, file->ino, &file->inode,  in ext2fs_file_flush()
139 				     BMAP_BUFFER, file->ino ? BMAP_ALLOC : 0,  in ext2fs_file_flush()
140 				     file->blockno, 0, &file->physblock);  in ext2fs_file_flush()
145 	retval = io_channel_write_blk64(fs->io, file->physblock, 1, file->buf);  in ext2fs_file_flush()
149 	file->flags &= ~EXT2_FILE_BUF_DIRTY;  in ext2fs_file_flush()
155  * This function synchronizes the file's block buffer and the current
156  * file position, possibly invalidating block buffer if necessary
158 static errcode_t sync_buffer_position(ext2_file_t file)  in sync_buffer_position()  argument
163 	b = file->pos / file->fs->blocksize;  in sync_buffer_position()
164 	if (b != file->blockno) {  in sync_buffer_position()
165 		retval = ext2fs_file_flush(file);  in sync_buffer_position()
168 		file->flags &= ~EXT2_FILE_BUF_VALID;  in sync_buffer_position()
170 	file->blockno = b;  in sync_buffer_position()
175  * This function loads the file's block buffer with valid data from
180  * function basically only sets file->physblock and EXT2_FILE_BUF_VALID
183 static errcode_t load_buffer(ext2_file_t file, int dontfill)  in load_buffer()  argument
185 	ext2_filsys	fs = file->fs;  in load_buffer()
188 	if (!(file->flags & EXT2_FILE_BUF_VALID)) {  in load_buffer()
189 		retval = ext2fs_bmap2(fs, file->ino, &file->inode,  in load_buffer()
190 				     BMAP_BUFFER, 0, file->blockno, 0,  in load_buffer()
191 				     &file->physblock);  in load_buffer()
195 			if (file->physblock) {  in load_buffer()
197 							       file->physblock,  in load_buffer()
198 							       1, file->buf);  in load_buffer()
202 				memset(file->buf, 0, fs->blocksize);  in load_buffer()
204 		file->flags |= EXT2_FILE_BUF_VALID;  in load_buffer()
210 errcode_t ext2fs_file_close(ext2_file_t file)  in ext2fs_file_close()  argument
214 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_close()
216 	retval = ext2fs_file_flush(file);  in ext2fs_file_close()
218 	if (file->buf)  in ext2fs_file_close()
219 		ext2fs_free_mem(&file->buf);  in ext2fs_file_close()
220 	ext2fs_free_mem(&file);  in ext2fs_file_close()
226 errcode_t ext2fs_file_read(ext2_file_t file, void *buf,  in ext2fs_file_read()  argument
235 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_read()
236 	fs = file->fs;  in ext2fs_file_read()
238 	while ((file->pos < EXT2_I_SIZE(&file->inode)) && (wanted > 0)) {  in ext2fs_file_read()
239 		retval = sync_buffer_position(file);  in ext2fs_file_read()
242 		retval = load_buffer(file, 0);  in ext2fs_file_read()
246 		start = file->pos % fs->blocksize;  in ext2fs_file_read()
250 		left = EXT2_I_SIZE(&file->inode) - file->pos ;  in ext2fs_file_read()
254 		memcpy(ptr, file->buf+start, c);  in ext2fs_file_read()
255 		file->pos += c;  in ext2fs_file_read()
268 errcode_t ext2fs_file_write(ext2_file_t file, const void *buf,  in ext2fs_file_write()  argument
276 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_write()
277 	fs = file->fs;  in ext2fs_file_write()
279 	if (!(file->flags & EXT2_FILE_WRITE))  in ext2fs_file_write()
283 		retval = sync_buffer_position(file);  in ext2fs_file_write()
287 		start = file->pos % fs->blocksize;  in ext2fs_file_write()
296 		retval = load_buffer(file, (c == fs->blocksize));  in ext2fs_file_write()
304 		if (!file->physblock) {  in ext2fs_file_write()
305 			retval = ext2fs_bmap2(fs, file->ino, &file->inode,  in ext2fs_file_write()
307 					      file->ino ? BMAP_ALLOC : 0,  in ext2fs_file_write()
308 					      file->blockno, 0,  in ext2fs_file_write()
309 					      &file->physblock);  in ext2fs_file_write()
314 		file->flags |= EXT2_FILE_BUF_DIRTY;  in ext2fs_file_write()
315 		memcpy(file->buf+start, ptr, c);  in ext2fs_file_write()
316 		file->pos += c;  in ext2fs_file_write()
324 	if (count != 0 && EXT2_I_SIZE(&file->inode) < file->pos) {  in ext2fs_file_write()
327 		rc = ext2fs_file_set_size2(file, file->pos);  in ext2fs_file_write()
337 errcode_t ext2fs_file_llseek(ext2_file_t file, __u64 offset,  in ext2fs_file_llseek()  argument
340 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_llseek()
343 		file->pos = offset;  in ext2fs_file_llseek()
345 		file->pos += offset;  in ext2fs_file_llseek()
347 		file->pos = EXT2_I_SIZE(&file->inode) + offset;  in ext2fs_file_llseek()
352 		*ret_pos = file->pos;  in ext2fs_file_llseek()
357 errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,  in ext2fs_file_lseek()  argument
364 	retval = ext2fs_file_llseek(file, loffset, whence, &ret_loffset);  in ext2fs_file_lseek()
372  * This function returns the size of the file, according to the inode
374 errcode_t ext2fs_file_get_lsize(ext2_file_t file, __u64 *ret_size)  in ext2fs_file_get_lsize()  argument
376 	if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)  in ext2fs_file_get_lsize()
378 	*ret_size = EXT2_I_SIZE(&file->inode);  in ext2fs_file_get_lsize()
383  * This function returns the size of the file, according to the inode
385 ext2_off_t ext2fs_file_get_size(ext2_file_t file)  in ext2fs_file_get_size()  argument
389 	if (ext2fs_file_get_lsize(file, &size))  in ext2fs_file_get_size()
397 static errcode_t ext2fs_file_zero_past_offset(ext2_file_t file,  in ext2fs_file_zero_past_offset()  argument
400 	ext2_filsys fs = file->fs;  in ext2fs_file_zero_past_offset()
410 	retval = sync_buffer_position(file);  in ext2fs_file_zero_past_offset()
415 	retval = ext2fs_bmap2(fs, file->ino, NULL, NULL, 0,  in ext2fs_file_zero_past_offset()
444  * This function sets the size of the file, truncating it if necessary
447 errcode_t ext2fs_file_set_size2(ext2_file_t file, ext2_off64_t size)  in ext2fs_file_set_size2()  argument
453 	EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);  in ext2fs_file_set_size2()
455 	if (size && ext2fs_file_block_offset_too_big(file->fs, &file->inode,  in ext2fs_file_set_size2()
456 					(size - 1) / file->fs->blocksize))  in ext2fs_file_set_size2()
458 	truncate_block = ((size + file->fs->blocksize - 1) >>  in ext2fs_file_set_size2()
459 			  EXT2_BLOCK_SIZE_BITS(file->fs->super));  in ext2fs_file_set_size2()
460 	old_size = EXT2_I_SIZE(&file->inode);  in ext2fs_file_set_size2()
461 	old_truncate = ((old_size + file->fs->blocksize - 1) >>  in ext2fs_file_set_size2()
462 		      EXT2_BLOCK_SIZE_BITS(file->fs->super));  in ext2fs_file_set_size2()
464 	/* If we're writing a large file, set the large_file flag */  in ext2fs_file_set_size2()
465 	if (LINUX_S_ISREG(file->inode.i_mode) &&  in ext2fs_file_set_size2()
466 	    ext2fs_needs_large_file_feature(EXT2_I_SIZE(&file->inode)) &&  in ext2fs_file_set_size2()
467 	    (!EXT2_HAS_RO_COMPAT_FEATURE(file->fs->super,  in ext2fs_file_set_size2()
469 	     file->fs->super->s_rev_level == EXT2_GOOD_OLD_REV)) {  in ext2fs_file_set_size2()
470 		file->fs->super->s_feature_ro_compat |=  in ext2fs_file_set_size2()
472 		ext2fs_update_dynamic_rev(file->fs);  in ext2fs_file_set_size2()
473 		ext2fs_mark_super_dirty(file->fs);  in ext2fs_file_set_size2()
476 	file->inode.i_size = size & 0xffffffff;  in ext2fs_file_set_size2()
477 	file->inode.i_size_high = (size >> 32);  in ext2fs_file_set_size2()
478 	if (file->ino) {  in ext2fs_file_set_size2()
479 		retval = ext2fs_write_inode(file->fs, file->ino, &file->inode);  in ext2fs_file_set_size2()
484 	retval = ext2fs_file_zero_past_offset(file, size);  in ext2fs_file_set_size2()
491 	return ext2fs_punch(file->fs, file->ino, &file->inode, 0,  in ext2fs_file_set_size2()
495 errcode_t ext2fs_file_set_size(ext2_file_t file, ext2_off_t size)  in ext2fs_file_set_size()  argument
497 	return ext2fs_file_set_size2(file, size);  in ext2fs_file_set_size()