| Message ID | 20151012135005.GA10697@tucsk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12 October 2015 at 15:50, Miklos Szeredi <miklos@szeredi.hu> wrote: > On Wed, Oct 07, 2015 at 02:23:23PM +0200, Alban Crequy wrote: >> Hi, >> >> I'm reporting an issue in overlay fs that was introduced in v4.2 (it >> worked on v4.1): when overlay fs is mounted inside a overlay fs, I get >> a "no such device or address" error (ENXIO) during open(). After >> adding some debug printks, I found that the ENXIO comes from >> fs/inode.c:no_open(). >> >> The bug was initially reported on: >> https://github.com/coreos/rkt/issues/1537 >> >> The following commands can reproduce the issue: > > Thanks for the excellent report. > > See below for a fix. Please let me know if you see any issues. Thanks for the fix. I tested it and it fixes the test case with the commands I wrote in my previous email. Tested-by: Alban Crequy <alban.crequy@gmail.com> > Thanks, > Miklos > --- > > Subject: ovl: fix open in stacked overlay > From: Miklos Szeredi <mszeredi@suse.cz> > > If two overlayfs filesystems are stacked on top of each other, then we need > recursion in ovl_d_select_inode(). > > I guess d_backing_inode() is supposed to do that. But currently it doesn't > and that functionality is open coded in vfs_open(). This is now copied > into ovl_d_select_inode() to fix this regression. > > Reported-by: Alban Crequy <alban.crequy@gmail.com> > Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> > Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay...") > Cc: David Howells <dhowells@redhat.com> > Cc: <stable@vger.kernel.org> # v4.2+ > --- > fs/overlayfs/inode.c | 3 +++ > 1 file changed, 3 insertions(+) > > --- a/fs/overlayfs/inode.c > +++ b/fs/overlayfs/inode.c > @@ -363,6 +363,9 @@ struct inode *ovl_d_select_inode(struct > ovl_path_upper(dentry, &realpath); > } > > + if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE) > + return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags); > + > return d_backing_inode(realpath.dentry); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -363,6 +363,9 @@ struct inode *ovl_d_select_inode(struct ovl_path_upper(dentry, &realpath); } + if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE) + return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags); + return d_backing_inode(realpath.dentry); }