Turn do_link spaghetty into a normal loop
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 675a712..08da937 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1844,17 +1844,38 @@
if (open_flag & O_EXCL)
nd.flags |= LOOKUP_EXCL;
filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
- if (!filp)
- goto do_link;
- goto out;
-
-exit_dput:
- path_put_conditional(&path, &nd);
- if (!IS_ERR(nd.intent.open.file))
- release_open_intent(&nd);
-exit_parent:
- path_put(&nd.path);
- filp = ERR_PTR(error);
+ while (unlikely(!filp)) { /* trailing symlink */
+ error = -ELOOP;
+ if ((open_flag & O_NOFOLLOW) || count++ == 32)
+ goto exit_dput;
+ /*
+ * This is subtle. Instead of calling do_follow_link() we do
+ * the thing by hands. The reason is that this way we have zero
+ * link_count and path_walk() (called from ->follow_link)
+ * honoring LOOKUP_PARENT. After that we have the parent and
+ * last component, i.e. we are in the same situation as after
+ * the first path_walk(). Well, almost - if the last component
+ * is normal we get its copy stored in nd->last.name and we will
+ * have to putname() it when we are done. Procfs-like symlinks
+ * just set LAST_BIND.
+ */
+ nd.flags |= LOOKUP_PARENT;
+ error = security_inode_follow_link(path.dentry, &nd);
+ if (error)
+ goto exit_dput;
+ error = __do_follow_link(&path, &nd);
+ path_put(&path);
+ if (error) {
+ /* nd.path had been dropped */
+ release_open_intent(&nd);
+ filp = ERR_PTR(error);
+ goto out;
+ }
+ nd.flags &= ~LOOKUP_PARENT;
+ filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
+ if (nd.last_type == LAST_NORM)
+ __putname(nd.last.name);
+ }
out:
if (nd.root.mnt)
path_put(&nd.root);
@@ -1864,41 +1885,13 @@
}
return filp;
-do_link:
- error = -ELOOP;
- if ((open_flag & O_NOFOLLOW) || count++ == 32)
- goto exit_dput;
- /*
- * This is subtle. Instead of calling do_follow_link() we do the
- * thing by hands. The reason is that this way we have zero link_count
- * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT.
- * After that we have the parent and last component, i.e.
- * we are in the same situation as after the first path_walk().
- * Well, almost - if the last component is normal we get its copy
- * stored in nd->last.name and we will have to putname() it when we
- * are done. Procfs-like symlinks just set LAST_BIND.
- */
- nd.flags |= LOOKUP_PARENT;
- error = security_inode_follow_link(path.dentry, &nd);
- if (error)
- goto exit_dput;
- error = __do_follow_link(&path, &nd);
- path_put(&path);
- if (error) {
- /* Does someone understand code flow here? Or it is only
- * me so stupid? Anathema to whoever designed this non-sense
- * with "intent.open".
- */
+exit_dput:
+ path_put_conditional(&path, &nd);
+ if (!IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
- filp = ERR_PTR(error);
- goto out;
- }
- nd.flags &= ~LOOKUP_PARENT;
- filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
- if (nd.last_type == LAST_NORM)
- __putname(nd.last.name);
- if (!filp)
- goto do_link;
+exit_parent:
+ path_put(&nd.path);
+ filp = ERR_PTR(error);
goto out;
}