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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-17 02:20:36 +0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /init/do_mounts_devfs.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'init/do_mounts_devfs.c')
-rw-r--r-- | init/do_mounts_devfs.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/init/do_mounts_devfs.c b/init/do_mounts_devfs.c new file mode 100644 index 000000000000..cc526474690a --- /dev/null +++ b/init/do_mounts_devfs.c @@ -0,0 +1,137 @@ + +#include <linux/kernel.h> +#include <linux/dirent.h> +#include <linux/string.h> + +#include "do_mounts.h" + +void __init mount_devfs(void) +{ + sys_mount("devfs", "/dev", "devfs", 0, NULL); +} + +void __init umount_devfs(char *path) +{ + sys_umount(path, 0); +} + +/* + * If the dir will fit in *buf, return its length. If it won't fit, return + * zero. Return -ve on error. + */ +static int __init do_read_dir(int fd, void *buf, int len) +{ + long bytes, n; + char *p = buf; + sys_lseek(fd, 0, 0); + + for (bytes = 0; bytes < len; bytes += n) { + n = sys_getdents64(fd, (struct linux_dirent64 *)(p + bytes), + len - bytes); + if (n < 0) + return n; + if (n == 0) + return bytes; + } + return 0; +} + +/* + * Try to read all of a directory. Returns the contents at *p, which + * is kmalloced memory. Returns the number of bytes read at *len. Returns + * NULL on error. + */ +static void * __init read_dir(char *path, int *len) +{ + int size; + int fd = sys_open(path, 0, 0); + + *len = 0; + if (fd < 0) + return NULL; + + for (size = 1 << 9; size <= (PAGE_SIZE << MAX_ORDER); size <<= 1) { + void *p = kmalloc(size, GFP_KERNEL); + int n; + if (!p) + break; + n = do_read_dir(fd, p, size); + if (n > 0) { + sys_close(fd); + *len = n; + return p; + } + kfree(p); + if (n == -EINVAL) + continue; /* Try a larger buffer */ + if (n < 0) + break; + } + sys_close(fd); + return NULL; +} + +/* + * recursively scan <path>, looking for a device node of type <dev> + */ +static int __init find_in_devfs(char *path, unsigned dev) +{ + char *end = path + strlen(path); + int rest = path + 64 - end; + int size; + char *p = read_dir(path, &size); + char *s; + + if (!p) + return -1; + for (s = p; s < p + size; s += ((struct linux_dirent64 *)s)->d_reclen) { + struct linux_dirent64 *d = (struct linux_dirent64 *)s; + if (strlen(d->d_name) + 2 > rest) + continue; + switch (d->d_type) { + case DT_BLK: + sprintf(end, "/%s", d->d_name); + if (bstat(path) != dev) + break; + kfree(p); + return 0; + case DT_DIR: + if (strcmp(d->d_name, ".") == 0) + break; + if (strcmp(d->d_name, "..") == 0) + break; + sprintf(end, "/%s", d->d_name); + if (find_in_devfs(path, dev) < 0) + break; + kfree(p); + return 0; + } + } + kfree(p); + return -1; +} + +/* + * create a device node called <name> which points to + * <devfs_name> if possible, otherwise find a device node + * which matches <dev> and make <name> a symlink pointing to it. + */ +int __init create_dev(char *name, dev_t dev, char *devfs_name) +{ + char path[64]; + + sys_unlink(name); + if (devfs_name && devfs_name[0]) { + if (strncmp(devfs_name, "/dev/", 5) == 0) + devfs_name += 5; + sprintf(path, "/dev/%s", devfs_name); + if (sys_access(path, 0) == 0) + return sys_symlink(devfs_name, name); + } + if (!dev) + return -1; + strcpy(path, "/dev"); + if (find_in_devfs(path, new_encode_dev(dev)) < 0) + return -1; + return sys_symlink(path + 5, name); +} |