diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2020-02-28 10:17:52 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-04-02 01:09:21 -0400 |
| commit | 165200d6cb88a3cc1fdeb12e11e97fb96bf685d9 (patch) | |
| tree | 902a294e9a8e8cc86d7320b434c8411f59fd8e44 | |
| parent | efe772d6283b3672c0880b10fc4ceea69bc782ca (diff) | |
follow_dotdot(): be lazy about changing nd->path
Change nd->path only after the loop is done and only in case we hadn't
ended up finding ourselves in root. Same for NO_XDEV check.
That separates the "check how far back do we need to go through the
mount stack" logics from the rest of .. traversal.
NOTE: path_get/path_put introduced here are temporary. They will
go away later in the series.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namei.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/fs/namei.c b/fs/namei.c index af18ede95e2d..9cfb7096e307 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1748,16 +1748,24 @@ static struct dentry *follow_dotdot(struct nameidata *nd, if (path_equal(&nd->path, &nd->root)) goto in_root; if (unlikely(nd->path.dentry == nd->path.mnt->mnt_root)) { + struct path path = nd->path; + path_get(&path); while (1) { - if (!follow_up(&nd->path)) + if (!follow_up(&path)) { + path_put(&path); goto in_root; - if (unlikely(nd->flags & LOOKUP_NO_XDEV)) - return ERR_PTR(-EXDEV); - if (path_equal(&nd->path, &nd->root)) + } + if (path_equal(&path, &nd->root)) { + path_put(&path); goto in_root; - if (nd->path.dentry != nd->path.mnt->mnt_root) + } + if (path.dentry != nd->path.mnt->mnt_root) break; } + path_put(&nd->path); + nd->path = path; + if (unlikely(nd->flags & LOOKUP_NO_XDEV)) + return ERR_PTR(-EXDEV); } /* rare case of legitimate dget_parent()... */ parent = dget_parent(nd->path.dentry); |