On Thu, 9 Apr 2015 17:07:56 +0900 Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> wrote: > On 2015/04/07 23:39, Steve French wrote: > > On Tue, Apr 7, 2015 at 5:45 AM, Jeff Layton <jlayton@xxxxxxxxx> wrote: > >> On Wed, 24 Dec 2014 11:27:38 +0900 > >> Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> wrote: > >> > >>> When refer file "directly" (e.g. ls -li <filename>), > >>> if file is same name, old inode cache is used. > >>> This causes that client shows wrong(old) inode number. > >>> So this patch is that if uniqueid is different, return error. > >>> > >>> ## But this patch is applicable to when Server is UNIX. > >>> ## When Server is Windows, we need another new patch. > >>> > >>> > >>> Reproducible sample : > >>> 1. create file 'a' at cifs client. > >>> 2. rm 'a' and touch 'b a' at server. > >>> 3. ls -li 'a' at client, then client shows wrong(old) inode number. > >>> > >>> Bug link: > >>> https://bugzilla.kernel.org/show_bug.cgi?id=90021 > >>> > >>> > >>> > >>> Signed-off-by: Nakajima Akira <nakajima.akira@xxxxxxxxxxxx> > >>> diff -uprN -X linux-3.18-vanilla/Documentation/dontdiff linux-3.18-vanilla/fs/cifs/inode.c linux-3.18/fs/cifs/inode.c > >>> --- linux-3.18-vanilla/fs/cifs/inode.c 2014-12-08 07:21:05.000000000 +0900 > >>> +++ linux-3.18/fs/cifs/inode.c 2014-12-19 11:07:59.127000000 +0900 > >>> @@ -402,9 +402,18 @@ int cifs_get_inode_info_unix(struct inod > >>> rc = -ENOMEM; > >>> } else { > >>> /* we already have inode, update it */ > >>> + > >>> + /* if uniqueid is different, return error */ > >>> + if (unlikely(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM && > >>> + CIFS_I(*pinode)->uniqueid != fattr.cf_uniqueid)) { > >>> + rc = -ENOENT; > >>> + goto cgiiu_exit; > >>> + } > >>> + > >>> cifs_fattr_to_inode(*pinode, &fattr); > >>> } > >>> > >>> +cgiiu_exit: > >>> return rc; > >>> } > >>> > >> > >> Returning ENOENT here seems like the wrong error to me. That path does > >> exist, it just no longer refers to the same file as before. > >> > >> Maybe ESTALE would be better as it would allow the VFS layer > >> to revalidate the dcache and invalidate the old dentry? > >> > >> -- > >> Jeff Layton <jlayton@xxxxxxxxx> > > > > Similar to what Jeff mentioned, isn't the nfs_relavidate_inode path > > roughly equivalent to what we want here (where nfs.ko returns ESTALE > > on various cases where we detect an inode that doesn't match what we > > expect)? > > If uniqueid is different, return -ESTALE. > If filetype is different, return -ENOENT. > That's right? > > + /* if filetype is different, return error */ > + if (unlikely(((*pinode)->i_mode & S_IFMT) != > + (fattr.cf_mode & S_IFMT))) { > + rc = -ENOENT; > + goto cgiiu_exit; > + } > No, I don't think so. In both cases, the dcache is wrong and the dentry should be dropped and reinstantiated to point to a new inode. An ESTALE return is the trigger for that to occur. An ENOENT return is going to mean a stat() failure in your testcase, I think. So I think you want to return ESTALE in both cases. That said, please do test it and ensure that it does the right thing. -- Jeff Layton <jlayton@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
