From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH] reiserfs: call truncate_setsize under tailpack mutex Date: Wed, 21 May 2014 22:37:03 +0200 Message-ID: <20140521203703.GA5685@quack.suse.cz> References: <537CE227.4040803@suse.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <537CE227.4040803@suse.com> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jeff Mahoney Cc: reiserfs-devel , Jan Kara On Wed 21-05-14 13:28:07, Jeff Mahoney wrote: > Prior to commit 0e4f6a791b1e (Fix reiserfs_file_release()), reiserfs > truncates serialized on i_mutex. They mostly still do, with the exception > of reiserfs_file_release. That blocks out other writers via the tailpack > mutex and the inode openers counter adjusted in reiserfs_file_open. > > However, NFS will call reiserfs_setattr without having called ->open, so > we end up with a race when nfs is calling ->setattr while another > process is releasing the file. Ultimately, it triggers the > BUG_ON(inode->i_size != new_file_size) check in maybe_indirect_to_direct. > > The solution is to pull the lock into reiserfs_setattr to encompass the > truncate_setsize call as well. Thanks. I've merged the patch to my tree. Honza > > Signed-off-by: Jeff Mahoney > Cc: > --- > fs/reiserfs/inode.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > --- a/fs/reiserfs/inode.c > +++ b/fs/reiserfs/inode.c > @@ -3214,8 +3214,14 @@ int reiserfs_setattr(struct dentry *dent > attr->ia_size != i_size_read(inode)) { > error = inode_newsize_ok(inode, attr->ia_size); > if (!error) { > + /* > + * Could race against reiserfs_file_release > + * if called from NFS, so take tailpack mutex. > + */ > + mutex_lock(&REISERFS_I(inode)->tailpack); > truncate_setsize(inode, attr->ia_size); > - reiserfs_vfs_truncate_file(inode); > + reiserfs_truncate_file(inode, 1); > + mutex_unlock(&REISERFS_I(inode)->tailpack); > } > } > > -- > Jeff Mahoney > SUSE Labs -- Jan Kara SUSE Labs, CR