Annotation of /trunk/mkinitrd-magellan/busybox/libbb/find_root_device.c
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Revision 816 -
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Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
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Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 1721 byte(s)
-updated to busybox-1.13.4
1 | niro | 532 | /* vi: set sw=4 ts=4: */ |
2 | /* | ||
3 | * Utility routines. | ||
4 | * | ||
5 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> | ||
6 | * | ||
7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. | ||
8 | */ | ||
9 | |||
10 | #include "libbb.h" | ||
11 | |||
12 | niro | 816 | /* Find block device /dev/XXX which contains specified file |
13 | * We handle /dev/dir/dir/dir too, at a cost of ~80 more bytes code */ | ||
14 | |||
15 | /* Do not reallocate all this stuff on each recursion */ | ||
16 | enum { DEVNAME_MAX = 256 }; | ||
17 | struct arena { | ||
18 | struct stat st; | ||
19 | dev_t dev; | ||
20 | /* Was PATH_MAX, but we recurse _/dev_. We can assume | ||
21 | * people are not crazy enough to have mega-deep tree there */ | ||
22 | char devpath[DEVNAME_MAX]; | ||
23 | }; | ||
24 | |||
25 | static char *find_block_device_in_dir(struct arena *ap) | ||
26 | niro | 532 | { |
27 | DIR *dir; | ||
28 | struct dirent *entry; | ||
29 | niro | 816 | char *retpath = NULL; |
30 | int len, rem; | ||
31 | niro | 532 | |
32 | niro | 816 | dir = opendir(ap->devpath); |
33 | if (!dir) | ||
34 | niro | 532 | return NULL; |
35 | niro | 816 | |
36 | len = strlen(ap->devpath); | ||
37 | rem = DEVNAME_MAX-2 - len; | ||
38 | if (rem <= 0) | ||
39 | return NULL; | ||
40 | ap->devpath[len++] = '/'; | ||
41 | |||
42 | niro | 532 | while ((entry = readdir(dir)) != NULL) { |
43 | niro | 816 | safe_strncpy(ap->devpath + len, entry->d_name, rem); |
44 | /* lstat: do not follow links */ | ||
45 | if (lstat(ap->devpath, &ap->st) != 0) | ||
46 | continue; | ||
47 | if (S_ISBLK(ap->st.st_mode) && ap->st.st_rdev == ap->dev) { | ||
48 | retpath = xstrdup(ap->devpath); | ||
49 | niro | 532 | break; |
50 | } | ||
51 | niro | 816 | if (S_ISDIR(ap->st.st_mode)) { |
52 | /* Do not recurse for '.' and '..' */ | ||
53 | if (DOT_OR_DOTDOT(entry->d_name)) | ||
54 | continue; | ||
55 | retpath = find_block_device_in_dir(ap); | ||
56 | if (retpath) | ||
57 | break; | ||
58 | } | ||
59 | niro | 532 | } |
60 | closedir(dir); | ||
61 | |||
62 | return retpath; | ||
63 | } | ||
64 | niro | 816 | |
65 | char* FAST_FUNC find_block_device(const char *path) | ||
66 | { | ||
67 | struct arena a; | ||
68 | |||
69 | if (stat(path, &a.st) != 0) | ||
70 | return NULL; | ||
71 | a.dev = S_ISBLK(a.st.st_mode) ? a.st.st_rdev : a.st.st_dev; | ||
72 | strcpy(a.devpath, "/dev"); | ||
73 | return find_block_device_in_dir(&a); | ||
74 | } |