[PATCH 61/79] link_path_walk: nd->depth massage, part 10

From: Al Viro
Date: Tue May 05 2015 - 01:36:12 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Get rid of orig_depth checks in OK: logics. If nd->depth is
zero, we had been called from path_init() and we are done.
If it is greater than 1, we are not done, whether we'd been
called from path_init() or trailing_symlink(). And in
case when it's 1, we might have been called from path_init()
and reached the end of nested symlink (in which case
nd->stack[0].name will point to the rest of pathname and
we are not done) or from trailing_symlink(), in which case
we are done.

Just have trailing_symlink() leave NULL in nd->stack[0].name
and use that to discriminate between those cases.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 10cb0be..f8371e5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1864,13 +1864,15 @@ Err:
put_link(nd);
return err;
OK:
- if (unlikely(nd->depth > orig_depth)) {
- name = nd->stack[nd->depth - 1].name;
- err = walk_component(nd, LOOKUP_FOLLOW);
- put_link(nd);
- goto Walked;
- }
- return 0;
+ if (!nd->depth) /* called from path_init(), done */
+ return 0;
+ name = nd->stack[nd->depth - 1].name;
+ if (!name) /* called from trailing_symlink(), done */
+ return 0;
+
+ err = walk_component(nd, LOOKUP_FOLLOW);
+ put_link(nd);
+ goto Walked;
}

static int path_init(int dfd, const struct filename *name, unsigned int flags,
@@ -2006,6 +2008,7 @@ static int trailing_symlink(struct nameidata *nd)
nd->flags |= LOOKUP_JUMPED;
}
nd->inode = nd->path.dentry->d_inode;
+ nd->stack[0].name = NULL;
error = link_path_walk(s, nd);
if (unlikely(error))
put_link(nd);
--
2.1.4

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