namei: split off filename_lookupat() with LOOKUP_PARENT
new functions: filename_parentat() and path_parentat() resp.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 51e2214..6f95bc9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2034,7 +2034,7 @@
* be able to complete).
*/
err = path_init(dfd, name, flags, nd);
- if (!err && !(flags & LOOKUP_PARENT)) {
+ if (!err) {
while ((err = lookup_last(nd)) > 0) {
err = trailing_symlink(nd);
if (err)
@@ -2074,6 +2074,35 @@
return retval;
}
+/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
+static int path_parentat(int dfd, const struct filename *name,
+ unsigned int flags, struct nameidata *nd)
+{
+ int err = path_init(dfd, name, flags | LOOKUP_PARENT, nd);
+ if (!err)
+ err = complete_walk(nd);
+ path_cleanup(nd);
+ return err;
+}
+
+static int filename_parentat(int dfd, struct filename *name,
+ unsigned int flags, struct nameidata *nd)
+{
+ int retval;
+ struct nameidata *saved_nd = set_nameidata(nd);
+
+ retval = path_parentat(dfd, name, flags | LOOKUP_RCU, nd);
+ if (unlikely(retval == -ECHILD))
+ retval = path_parentat(dfd, name, flags, nd);
+ if (unlikely(retval == -ESTALE))
+ retval = path_parentat(dfd, name, flags | LOOKUP_REVAL, nd);
+
+ if (likely(!retval))
+ audit_inode(name, nd->path.dentry, LOOKUP_PARENT);
+ restore_nameidata(saved_nd);
+ return retval;
+}
+
/* does lookup, returns the object with parent locked */
struct dentry *kern_path_locked(const char *name, struct path *path)
{
@@ -2085,7 +2114,7 @@
if (IS_ERR(filename))
return ERR_CAST(filename);
- err = filename_lookup(AT_FDCWD, filename, LOOKUP_PARENT, &nd);
+ err = filename_parentat(AT_FDCWD, filename, 0, &nd);
if (err) {
d = ERR_PTR(err);
goto out;
@@ -2255,7 +2284,7 @@
if (IS_ERR(s))
return s;
- error = filename_lookup(dfd, s, flags | LOOKUP_PARENT, &nd);
+ error = filename_parentat(dfd, s, flags, &nd);
if (error) {
putname(s);
return ERR_PTR(error);
@@ -3344,7 +3373,7 @@
*/
lookup_flags &= LOOKUP_REVAL;
- error = filename_lookup(dfd, name, LOOKUP_PARENT|lookup_flags, &nd);
+ error = filename_parentat(dfd, name, lookup_flags, &nd);
if (error)
return ERR_PTR(error);