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1 /*
2  * valid_blk.c --- does the inode have valid blocks?
3  *
4  * Copyright 1997 by Theodore Ts'o
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Library
8  * General Public License, version 2.
9  * %End-Header%
10  */
11 
12 #include <stdio.h>
13 #if HAVE_UNISTD_H
14 #include <unistd.h>
15 #endif
16 #include <string.h>
17 #include <time.h>
18 
19 #include "ext2_fs.h"
20 #include "ext2fs.h"
21 
22 /*
23  * This function returns 1 if the inode's block entries actually
24  * contain block entries.
25  */
ext2fs_inode_has_valid_blocks2(ext2_filsys fs,struct ext2_inode * inode)26 int ext2fs_inode_has_valid_blocks2(ext2_filsys fs, struct ext2_inode *inode)
27 {
28 	/*
29 	 * Only directories, regular files, and some symbolic links
30 	 * have valid block entries.
31 	 */
32 	if (!LINUX_S_ISDIR(inode->i_mode) && !LINUX_S_ISREG(inode->i_mode) &&
33 	    !LINUX_S_ISLNK(inode->i_mode))
34 		return 0;
35 
36 	/*
37 	 * If the symbolic link is a "fast symlink", then the symlink
38 	 * target is stored in the block entries.
39 	 */
40 	if (LINUX_S_ISLNK (inode->i_mode)) {
41 		if (ext2fs_file_acl_block(fs, inode) == 0) {
42 			/* With no EA block, we can rely on i_blocks */
43 			if (inode->i_blocks == 0)
44 				return 0;
45 		} else {
46 			/* With an EA block, life gets more tricky */
47 			if (inode->i_size >= EXT2_N_BLOCKS*4)
48 				return 1; /* definitely using i_block[] */
49 			if (inode->i_size > 4 && inode->i_block[1] == 0)
50 				return 1; /* definitely using i_block[] */
51 			return 0; /* Probably a fast symlink */
52 		}
53 	}
54 	return 1;
55 }
56 
ext2fs_inode_has_valid_blocks(struct ext2_inode * inode)57 int ext2fs_inode_has_valid_blocks(struct ext2_inode *inode)
58 {
59 	return ext2fs_inode_has_valid_blocks2(NULL, inode);
60 }
61