Messages in this thread | | | From | "Hatayama, Daisuke" <> | Subject | RE: [PATCH] kernfs: fix dentry unexpected skip | Date | Mon, 21 May 2018 05:46:31 +0000 |
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> -----Original Message----- > From: linux-kernel-owner@vger.kernel.org > [mailto:linux-kernel-owner@vger.kernel.org] On Behalf Of Hatayama, Daisuke > Sent: Saturday, May 19, 2018 12:43 AM > To: 'gregkh@linuxfoundation.org' <gregkh@linuxfoundation.org> > Cc: Okajima, Toshiyuki/岡嶋 寿行 <toshi.okajima@jp.fujitsu.com>; > linux-kernel@vger.kernel.org; 'ebiederm@aristanetworks.com' > <ebiederm@aristanetworks.com> > Subject: [PATCH] kernfs: fix dentry unexpected skip > > kernfs_dir_next_pos() overlooks the situation that the dentry > corresponding to a given pos object has already been inactive. Hence, > when kernfs_dir_pos() returns the dentry with a hash value larger than > the original one, kernfs_dir_next_pos() returns the dentry next to the > one returned by kernfs_dir_pos(). As a result, the dentry returned by > kernfs_dir_pos() is skipped. > > To fix this issue, try to find a next node only when the returned > object has a hash value equal to or smaller than the original one. > > Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> > Suggested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> > Cc: Eric W. Biederman <ebiederm@aristanetworks.com> > --- > fs/kernfs/dir.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c > index 89d1dc1..8a2f49c 100644 > --- a/fs/kernfs/dir.c > +++ b/fs/kernfs/dir.c > @@ -1622,7 +1622,7 @@ static int kernfs_dir_fop_release(struct inode *inode, > struct file *filp) > struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) > { > pos = kernfs_dir_pos(ns, parent, ino, pos); > - if (pos) { > + if (pos && pos->hash <= ino) {
I found this condition still misses the case that the returend pos with the same hash value but with different name is skipped. I'll post v2 patch.
> do { > struct rb_node *node = rb_next(&pos->rb); > if (!node) > -- > 1.7.1 > > >
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