Commit | Line | Data |
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1da177e4 LT |
1 | |
2 | #include <linux/kernel.h> | |
3 | #include <linux/dirent.h> | |
4 | #include <linux/string.h> | |
5 | ||
6 | #include "do_mounts.h" | |
7 | ||
8 | void __init mount_devfs(void) | |
9 | { | |
10 | sys_mount("devfs", "/dev", "devfs", 0, NULL); | |
11 | } | |
12 | ||
13 | void __init umount_devfs(char *path) | |
14 | { | |
15 | sys_umount(path, 0); | |
16 | } | |
17 | ||
18 | /* | |
19 | * If the dir will fit in *buf, return its length. If it won't fit, return | |
20 | * zero. Return -ve on error. | |
21 | */ | |
22 | static int __init do_read_dir(int fd, void *buf, int len) | |
23 | { | |
24 | long bytes, n; | |
25 | char *p = buf; | |
26 | sys_lseek(fd, 0, 0); | |
27 | ||
28 | for (bytes = 0; bytes < len; bytes += n) { | |
29 | n = sys_getdents64(fd, (struct linux_dirent64 *)(p + bytes), | |
30 | len - bytes); | |
31 | if (n < 0) | |
32 | return n; | |
33 | if (n == 0) | |
34 | return bytes; | |
35 | } | |
36 | return 0; | |
37 | } | |
38 | ||
39 | /* | |
40 | * Try to read all of a directory. Returns the contents at *p, which | |
41 | * is kmalloced memory. Returns the number of bytes read at *len. Returns | |
42 | * NULL on error. | |
43 | */ | |
44 | static void * __init read_dir(char *path, int *len) | |
45 | { | |
46 | int size; | |
47 | int fd = sys_open(path, 0, 0); | |
48 | ||
49 | *len = 0; | |
50 | if (fd < 0) | |
51 | return NULL; | |
52 | ||
53 | for (size = 1 << 9; size <= (PAGE_SIZE << MAX_ORDER); size <<= 1) { | |
54 | void *p = kmalloc(size, GFP_KERNEL); | |
55 | int n; | |
56 | if (!p) | |
57 | break; | |
58 | n = do_read_dir(fd, p, size); | |
59 | if (n > 0) { | |
60 | sys_close(fd); | |
61 | *len = n; | |
62 | return p; | |
63 | } | |
64 | kfree(p); | |
65 | if (n == -EINVAL) | |
66 | continue; /* Try a larger buffer */ | |
67 | if (n < 0) | |
68 | break; | |
69 | } | |
70 | sys_close(fd); | |
71 | return NULL; | |
72 | } | |
73 | ||
74 | /* | |
75 | * recursively scan <path>, looking for a device node of type <dev> | |
76 | */ | |
77 | static int __init find_in_devfs(char *path, unsigned dev) | |
78 | { | |
79 | char *end = path + strlen(path); | |
80 | int rest = path + 64 - end; | |
81 | int size; | |
82 | char *p = read_dir(path, &size); | |
83 | char *s; | |
84 | ||
85 | if (!p) | |
86 | return -1; | |
87 | for (s = p; s < p + size; s += ((struct linux_dirent64 *)s)->d_reclen) { | |
88 | struct linux_dirent64 *d = (struct linux_dirent64 *)s; | |
89 | if (strlen(d->d_name) + 2 > rest) | |
90 | continue; | |
91 | switch (d->d_type) { | |
92 | case DT_BLK: | |
93 | sprintf(end, "/%s", d->d_name); | |
94 | if (bstat(path) != dev) | |
95 | break; | |
96 | kfree(p); | |
97 | return 0; | |
98 | case DT_DIR: | |
99 | if (strcmp(d->d_name, ".") == 0) | |
100 | break; | |
101 | if (strcmp(d->d_name, "..") == 0) | |
102 | break; | |
103 | sprintf(end, "/%s", d->d_name); | |
104 | if (find_in_devfs(path, dev) < 0) | |
105 | break; | |
106 | kfree(p); | |
107 | return 0; | |
108 | } | |
109 | } | |
110 | kfree(p); | |
111 | return -1; | |
112 | } | |
113 | ||
114 | /* | |
115 | * create a device node called <name> which points to | |
116 | * <devfs_name> if possible, otherwise find a device node | |
117 | * which matches <dev> and make <name> a symlink pointing to it. | |
118 | */ | |
119 | int __init create_dev(char *name, dev_t dev, char *devfs_name) | |
120 | { | |
121 | char path[64]; | |
122 | ||
123 | sys_unlink(name); | |
124 | if (devfs_name && devfs_name[0]) { | |
125 | if (strncmp(devfs_name, "/dev/", 5) == 0) | |
126 | devfs_name += 5; | |
127 | sprintf(path, "/dev/%s", devfs_name); | |
128 | if (sys_access(path, 0) == 0) | |
129 | return sys_symlink(devfs_name, name); | |
130 | } | |
131 | if (!dev) | |
132 | return -1; | |
133 | strcpy(path, "/dev"); | |
134 | if (find_in_devfs(path, new_encode_dev(dev)) < 0) | |
135 | return -1; | |
136 | return sys_symlink(path + 5, name); | |
137 | } |