102 lines
2.7 KiB
C
Executable File
102 lines
2.7 KiB
C
Executable File
#include <defs.h>
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#include <string.h>
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#include <vfs.h>
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#include <inode.h>
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#include <error.h>
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#include <assert.h>
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/*
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* get_device- Common code to pull the device name, if any, off the front of a
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* path and choose the inode to begin the name lookup relative to.
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*/
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static int
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get_device(char *path, char **subpath, struct inode **node_store) {
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int i, slash = -1, colon = -1;
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for (i = 0; path[i] != '\0'; i ++) {
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if (path[i] == ':') { colon = i; break; }
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if (path[i] == '/') { slash = i; break; }
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}
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if (colon < 0 && slash != 0) {
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/* *
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* No colon before a slash, so no device name specified, and the slash isn't leading
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* or is also absent, so this is a relative path or just a bare filename. Start from
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* the current directory, and use the whole thing as the subpath.
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* */
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*subpath = path;
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return vfs_get_curdir(node_store);
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}
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if (colon > 0) {
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/* device:path - get root of device's filesystem */
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path[colon] = '\0';
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/* device:/path - skip slash, treat as device:path */
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while (path[++ colon] == '/');
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*subpath = path + colon;
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return vfs_get_root(path, node_store);
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}
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/* *
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* we have either /path or :path
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* /path is a path relative to the root of the "boot filesystem"
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* :path is a path relative to the root of the current filesystem
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* */
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int ret;
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if (*path == '/') {
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if ((ret = vfs_get_bootfs(node_store)) != 0) {
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return ret;
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}
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}
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else {
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assert(*path == ':');
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struct inode *node;
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if ((ret = vfs_get_curdir(&node)) != 0) {
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return ret;
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}
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/* The current directory may not be a device, so it must have a fs. */
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assert(node->in_fs != NULL);
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*node_store = fsop_get_root(node->in_fs);
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vop_ref_dec(node);
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}
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/* ///... or :/... */
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while (*(++ path) == '/');
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*subpath = path;
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return 0;
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}
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/*
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* vfs_lookup - get the inode according to the path filename
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*/
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int
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vfs_lookup(char *path, struct inode **node_store) {
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int ret;
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struct inode *node;
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if ((ret = get_device(path, &path, &node)) != 0) {
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return ret;
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}
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if (*path != '\0') {
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ret = vop_lookup(node, path, node_store);
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vop_ref_dec(node);
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return ret;
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}
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*node_store = node;
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return 0;
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}
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/*
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* vfs_lookup_parent - Name-to-vnode translation.
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* (In BSD, both of these are subsumed by namei().)
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*/
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int
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vfs_lookup_parent(char *path, struct inode **node_store, char **endp){
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int ret;
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struct inode *node;
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if ((ret = get_device(path, &path, &node)) != 0) {
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return ret;
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}
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*endp = path;
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*node_store = node;
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return 0;
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}
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