From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754005AbaIHOpV (ORCPT ); Mon, 8 Sep 2014 10:45:21 -0400 Received: from cantor2.suse.de ([195.135.220.15]:57572 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753147AbaIHOpT (ORCPT ); Mon, 8 Sep 2014 10:45:19 -0400 Date: Mon, 8 Sep 2014 16:45:15 +0200 From: Jan Kara To: Andrey Vagin Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Alexander Viro , John McCutchan , Robert Love , Eric Paris , Cyrill Gorcunov , Pavel Emelyanov Subject: Re: [PATCH] fs: don't remove inotify watchers from alive inode-s Message-ID: <20140908144515.GA3532@quack.suse.cz> References: <1410177716-3965-1-git-send-email-avagin@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1410177716-3965-1-git-send-email-avagin@openvz.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 08-09-14 16:01:56, Andrey Vagin wrote: > Currently watchers are removed in dentry_iput(), if n_link is zero. > But other detries can be linked with this inode. For example if we > create two hard links, open the first one and set a watcher on the > second one. Then if we remove both links, the watcher will be removed. > But we will have the alive file descriptor, which allows us to generate > more events. > > With this patch, watchers will be removed, only if nlink is zero and > i_dentry list is empty. > > Look at a following example: > > fd = inotify_init1(IN_NONBLOCK); > deleted = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0666); > link(path, path_link); > > wd_deleted = inotify_add_watch(fd, path_link, IN_ALL_EVENTS); > > unlink(path); > unlink(path_link); > > printf(" --- unlink\n"); > read_evetns(fd); > > close(deleted); > printf(" --- close\n"); > read_evetns(fd); > > Without this patch: > --- unlink > 4 (IN_ATTRIB) > 400 (IN_DELETE_SELF) > 8000 (IN_IGNORED) > --- close > FAIL > > With this patch: > --- unlink > 4 (IN_ATTRIB) > 400 (IN_DELETE_SELF) > --- close > 8 (IN_CLOSE_WRITE) > 400 (IN_DELETE_SELF) > 8000 (IN_IGNORED) > PASS > > Cc: Alexander Viro > Cc: John McCutchan > Cc: Robert Love > Cc: Eric Paris > Cc: Cyrill Gorcunov > Cc: Pavel Emelyanov > Signed-off-by: Andrey Vagin OK, looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/dcache.c | 10 ++++++++-- > include/linux/fsnotify.h | 5 +++-- > 2 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/fs/dcache.c b/fs/dcache.c > index d30ce69..fb1ee58 100644 > --- a/fs/dcache.c > +++ b/fs/dcache.c > @@ -279,13 +279,16 @@ static void dentry_iput(struct dentry * dentry) > __releases(dentry->d_inode->i_lock) > { > struct inode *inode = dentry->d_inode; > + bool last_dentry; > + > if (inode) { > dentry->d_inode = NULL; > hlist_del_init(&dentry->d_alias); > + last_dentry = hlist_empty(&inode->i_dentry); > spin_unlock(&dentry->d_lock); > spin_unlock(&inode->i_lock); > if (!inode->i_nlink) > - fsnotify_inoderemove(inode); > + fsnotify_inoderemove(inode, last_dentry); > if (dentry->d_op && dentry->d_op->d_iput) > dentry->d_op->d_iput(dentry, inode); > else > @@ -304,14 +307,17 @@ static void dentry_unlink_inode(struct dentry * dentry) > __releases(dentry->d_inode->i_lock) > { > struct inode *inode = dentry->d_inode; > + bool last_dentry; > + > __d_clear_type(dentry); > dentry->d_inode = NULL; > hlist_del_init(&dentry->d_alias); > dentry_rcuwalk_barrier(dentry); > + last_dentry = hlist_empty(&inode->i_dentry); > spin_unlock(&dentry->d_lock); > spin_unlock(&inode->i_lock); > if (!inode->i_nlink) > - fsnotify_inoderemove(inode); > + fsnotify_inoderemove(inode, last_dentry); > if (dentry->d_op && dentry->d_op->d_iput) > dentry->d_op->d_iput(dentry, inode); > else > diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h > index 1c804b0..63dae9d 100644 > --- a/include/linux/fsnotify.h > +++ b/include/linux/fsnotify.h > @@ -144,10 +144,11 @@ static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) > /* > * fsnotify_inoderemove - an inode is going away > */ > -static inline void fsnotify_inoderemove(struct inode *inode) > +static inline void fsnotify_inoderemove(struct inode *inode, bool delete) > { > fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0); > - __fsnotify_inode_delete(inode); > + if (delete) > + __fsnotify_inode_delete(inode); > } > > /* > -- > 1.9.3 > > -- > 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 -- Jan Kara SUSE Labs, CR