Contents of /trunk/mkinitrd-magellan/klibc/usr/kinit/name_to_dev.c
Parent Directory | Revision Log
Revision 815 -
(show annotations)
(download)
Fri Apr 24 18:32:46 2009 UTC (15 years ago) by niro
File MIME type: text/plain
File size: 4492 byte(s)
Fri Apr 24 18:32:46 2009 UTC (15 years ago) by niro
File MIME type: text/plain
File size: 4492 byte(s)
-updated to klibc-1.5.15
1 | #include <ctype.h> |
2 | #include <errno.h> |
3 | #include <fcntl.h> |
4 | #include <sys/stat.h> |
5 | #include <stdio.h> |
6 | #include <stdlib.h> |
7 | #include <string.h> |
8 | #include <unistd.h> |
9 | #include <alloca.h> |
10 | #include <inttypes.h> |
11 | |
12 | #include "do_mounts.h" |
13 | #include "kinit.h" |
14 | |
15 | #define BUF_SZ 65536 |
16 | |
17 | /* Find dev_t for e.g. "hda,NULL" or "hdb,2" */ |
18 | static dev_t try_name(char *name, int part) |
19 | { |
20 | char path[BUF_SZ]; |
21 | char buf[BUF_SZ]; |
22 | int range; |
23 | unsigned int major_num, minor_num; |
24 | dev_t res; |
25 | char *s; |
26 | int len; |
27 | int fd; |
28 | |
29 | /* read device number from /sys/block/.../dev */ |
30 | snprintf(path, sizeof(path), "/sys/block/%s/dev", name); |
31 | fd = open(path, 0, 0); |
32 | if (fd < 0) |
33 | goto fail; |
34 | len = read(fd, buf, BUF_SZ); |
35 | close(fd); |
36 | |
37 | if (len <= 0 || len == BUF_SZ || buf[len - 1] != '\n') |
38 | goto fail; |
39 | buf[len - 1] = '\0'; |
40 | major_num = strtoul(buf, &s, 10); |
41 | if (*s != ':') |
42 | goto fail; |
43 | minor_num = strtoul(s + 1, &s, 10); |
44 | if (*s) |
45 | goto fail; |
46 | res = makedev(major_num, minor_num); |
47 | |
48 | /* if it's there and we are not looking for a partition - that's it */ |
49 | if (!part) |
50 | return res; |
51 | |
52 | /* otherwise read range from .../range */ |
53 | snprintf(path, sizeof(path), "/sys/block/%s/range", name); |
54 | fd = open(path, 0, 0); |
55 | if (fd < 0) |
56 | goto fail; |
57 | len = read(fd, buf, 32); |
58 | close(fd); |
59 | if (len <= 0 || len == 32 || buf[len - 1] != '\n') |
60 | goto fail; |
61 | buf[len - 1] = '\0'; |
62 | range = strtoul(buf, &s, 10); |
63 | if (*s) |
64 | goto fail; |
65 | |
66 | /* if partition is within range - we got it */ |
67 | if (part < range) { |
68 | DEBUG(("kinit: try_name %s,%d = %s\n", name, part, |
69 | bdevname(res + part))); |
70 | return res + part; |
71 | } |
72 | |
73 | fail: |
74 | return (dev_t) 0; |
75 | } |
76 | |
77 | /* |
78 | * Convert a name into device number. We accept the following variants: |
79 | * |
80 | * 1) device number in hexadecimal represents itself |
81 | * 2) device number in major:minor decimal represents itself |
82 | * 3) /dev/nfs represents Root_NFS |
83 | * 4) /dev/<disk_name> represents the device number of disk |
84 | * 5) /dev/<disk_name><decimal> represents the device number |
85 | * of partition - device number of disk plus the partition number |
86 | * 6) /dev/<disk_name>p<decimal> - same as the above, that form is |
87 | * used when disk name of partitioned disk ends on a digit. |
88 | * 7) an actual block device node in the initramfs filesystem |
89 | * |
90 | * If name doesn't have fall into the categories above, we return 0. |
91 | * Driverfs is used to check if something is a disk name - it has |
92 | * all known disks under bus/block/devices. If the disk name |
93 | * contains slashes, name of driverfs node has them replaced with |
94 | * dots. try_name() does the actual checks, assuming that driverfs |
95 | * is mounted on rootfs /sys. |
96 | */ |
97 | |
98 | static inline dev_t name_to_dev_t_real(const char *name) |
99 | { |
100 | char *p; |
101 | dev_t res = 0; |
102 | char *s; |
103 | int part; |
104 | struct stat st; |
105 | int len; |
106 | const char *devname; |
107 | char *cptr, *e1, *e2; |
108 | int major_num, minor_num; |
109 | |
110 | |
111 | if (name[0] == '/') { |
112 | devname = name; |
113 | } else { |
114 | char *dname = alloca(strlen(name) + 6); |
115 | sprintf(dname, "/dev/%s", name); |
116 | devname = dname; |
117 | } |
118 | |
119 | if (!stat(devname, &st) && S_ISBLK(st.st_mode)) |
120 | return st.st_rdev; |
121 | |
122 | if (strncmp(name, "/dev/", 5)) { |
123 | if ((cptr = strchr(devname+5, ':')) && |
124 | cptr[1] != '\0') { |
125 | /* Colon-separated decimal device number */ |
126 | *cptr = '\0'; |
127 | major_num = strtoul(devname+5, &e1, 10); |
128 | minor_num = strtoul(cptr+1, &e2, 10); |
129 | if (!*e1 && !*e2) |
130 | return makedev(major_num, minor_num); |
131 | *cptr = ':'; |
132 | } else { |
133 | /* Hexadecimal device number */ |
134 | res = (dev_t) strtoul(name, &p, 16); |
135 | if (!*p) |
136 | return res; |
137 | } |
138 | } else { |
139 | name += 5; |
140 | } |
141 | |
142 | if (!strcmp(name, "nfs")) |
143 | return Root_NFS; |
144 | |
145 | if (!strcmp(name, "ram")) /* /dev/ram - historic alias for /dev/ram0 */ |
146 | return Root_RAM0; |
147 | |
148 | if (!strncmp(name, "mtd", 3)) |
149 | return Root_MTD; |
150 | |
151 | len = strlen(name); |
152 | s = alloca(len + 1); |
153 | memcpy(s, name, len + 1); |
154 | |
155 | for (p = s; *p; p++) |
156 | if (*p == '/') |
157 | *p = '!'; |
158 | res = try_name(s, 0); |
159 | if (res) |
160 | return res; |
161 | |
162 | while (p > s && isdigit(p[-1])) |
163 | p--; |
164 | if (p == s || !*p || *p == '0') |
165 | goto fail; |
166 | part = strtoul(p, NULL, 10); |
167 | *p = '\0'; |
168 | res = try_name(s, part); |
169 | if (res) |
170 | return res; |
171 | |
172 | if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p') |
173 | goto fail; |
174 | p[-1] = '\0'; |
175 | res = try_name(s, part); |
176 | return res; |
177 | |
178 | fail: |
179 | return (dev_t) 0; |
180 | } |
181 | |
182 | dev_t name_to_dev_t(const char *name) |
183 | { |
184 | dev_t dev = name_to_dev_t_real(name); |
185 | |
186 | DEBUG(("kinit: name_to_dev_t(%s) = %s\n", name, bdevname(dev))); |
187 | return dev; |
188 | } |
189 | |
190 | #ifdef TEST_NAMETODEV /* Standalone test */ |
191 | |
192 | int main(int argc, char *argv[]) |
193 | { |
194 | int i; |
195 | |
196 | for (i = 1; i < argc; i++) |
197 | name_to_dev_t(argv[i]); |
198 | |
199 | return 0; |
200 | } |
201 | |
202 | #endif |