On 2019-11-13, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
On Tue, Nov 05, 2019 at 08:05:49PM +1100, Aleksa Sarai wrote:@@ -2277,12 +2277,20 @@ static const char *path_init(struct nameidata *nd, unsigned flags) nd->m_seq = read_seqbegin(&mount_lock); - /* Figure out the starting path and root (if needed). */ - if (*s == '/') { + /* Absolute pathname -- fetch the root. */ + if (flags & LOOKUP_IN_ROOT) { + /* With LOOKUP_IN_ROOT, act as a relative path. */ + while (*s == '/') + s++;Er... Why bother skipping slashes? I mean, not only link_path_walk() will skip them just fine, you are actually risking breakage in this: if (*s && unlikely(!d_can_lookup(dentry))) { fdput(f); return ERR_PTR(-ENOTDIR); } which is downstream from there with you patch, AFAICS.
I switched to stripping the slashes at your suggestion a few revisions ago[1], and had (wrongly) assumed we needed to handle "/" somehow in path_init(). But you're quite right about link_path_walk() -- and I'd be more than happy to drop it. [1]: https://lore.kernel.org/lkml/20190712125552.GL17978@xxxxxxxxxxxxxxxxxx/ -- Aleksa Sarai Senior Software Engineer (Containers) SUSE Linux GmbH <https://www.cyphar.com/>
Attachment:
signature.asc
Description: PGP signature
