From: Benjamin LaHaise Subject: Re: [PATCH] ext4: make it possible to interrupt initial readdir call Date: Fri, 8 Apr 2016 14:18:41 -0400 Message-ID: <20160408181841.GI8871@kvack.org> References: <20160302171511.GM12913@kvack.org> <20160302214330.GB24012@thunk.org> <20160314175732.GL17923@kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Theodore Ts'o Return-path: Received: from kanga.kvack.org ([205.233.56.17]:42740 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751046AbcDHSSm (ORCPT ); Fri, 8 Apr 2016 14:18:42 -0400 Content-Disposition: inline In-Reply-To: <20160314175732.GL17923@kvack.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: No response on this patch yet.... Given that it's clearly a bug, and we've got a test case that reproduces it, why isn't this being applied? -ben On Mon, Mar 14, 2016 at 01:57:32PM -0400, Benjamin LaHaise wrote: > This patch is a follow up to the email "ext4 bug: getdents uninterruptible > for 117 seconds". When doing the initial readdir on an ext4 filesystem > that grew a directory to 497MB (the filesystem image can be downloaded at > http://www.kvack.org/~bcrl/ext4/ext4-readdir.img.xz), the first getdents64() > system call blocked for 117 seconds. Begin to address this issue by making > the ext4 readdir() operation interruptible by fatal signals so that it is > possible to abort a process that is stuck on this operation. > > fs/ext4/dir.c | 3 +++ > fs/ext4/namei.c | 4 ++++ > 2 files changed, 7 insertions(+) > > diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c > index 33f5e2a..a3e32e8 100644 > --- a/fs/ext4/dir.c > +++ b/fs/ext4/dir.c > @@ -553,6 +553,9 @@ static int ext4_dx_readdir(struct file *file, struct dir_context *ctx) > info->curr_node = rb_first(&info->root); > > while (1) { > + if (fatal_signal_pending(current)) > + return -ERESTARTSYS; > + > /* > * Fill the rbtree if we have no more entries, > * or the inode has changed since we last read in the > diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c > index 48e4b89..8097cd1 100644 > --- a/fs/ext4/namei.c > +++ b/fs/ext4/namei.c > @@ -959,6 +959,10 @@ static int htree_dirblock_to_tree(struct file *dir_file, > bh = ext4_read_dirblock(dir, block, DIRENT); > if (IS_ERR(bh)) > return PTR_ERR(bh); > + if (fatal_signal_pending(current)) { > + brelse(bh); > + return -ERESTARTSYS; > + } > > de = (struct ext4_dir_entry_2 *) bh->b_data; > top = (struct ext4_dir_entry_2 *) ((char *) de + > -- > "Thought is the essence of where you are now." -- "Thought is the essence of where you are now."