From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A43F1C433E1 for ; Thu, 16 Jul 2020 13:45:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86E1A207DD for ; Thu, 16 Jul 2020 13:45:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728163AbgGPNp7 (ORCPT ); Thu, 16 Jul 2020 09:45:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:41092 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726986AbgGPNp7 (ORCPT ); Thu, 16 Jul 2020 09:45:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D2197B1E2; Thu, 16 Jul 2020 13:46:00 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id C39171E12C9; Thu, 16 Jul 2020 15:45:56 +0200 (CEST) Date: Thu, 16 Jul 2020 15:45:56 +0200 From: Jan Kara To: Amir Goldstein Cc: Jan Kara , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v5 17/22] fsnotify: send MOVE_SELF event with parent/name info Message-ID: <20200716134556.GE5022@quack2.suse.cz> References: <20200716084230.30611-1-amir73il@gmail.com> <20200716084230.30611-18-amir73il@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200716084230.30611-18-amir73il@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu 16-07-20 11:42:25, Amir Goldstein wrote: > MOVE_SELF event does not get reported to a parent watching children > when a child is moved, but it can be reported to sb/mount mark or to > the moved inode itself with parent/name info if group is interested > in parent/name info. > > Use the fsnotify_parent() helper to send a MOVE_SELF event and adjust > fsnotify() to handle the case of an event "on child" that should not > be sent to the watching parent's inode mark. > > Signed-off-by: Amir Goldstein What I find strange about this is that the MOVE_SELF event will be reported to the new parent under the new name (just due to the way how dentry handling in vfs_rename() works). That seems rather arbitrary and I'm not sure it would be useful? I guess anybody needing dir info with renames will rather use FS_MOVED_FROM / FS_MOVED_TO where it is well defined? So can we leave FS_MOVE_SELF as one of those cases that doesn't report parent + name info? Honza > --- > fs/notify/fsnotify.c | 22 ++++++++++++++++++---- > include/linux/fsnotify.h | 4 +--- > include/linux/fsnotify_backend.h | 2 +- > 3 files changed, 20 insertions(+), 8 deletions(-) > > diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c > index efa5c1c4908a..fa84aea47b20 100644 > --- a/fs/notify/fsnotify.c > +++ b/fs/notify/fsnotify.c > @@ -367,6 +367,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > struct super_block *sb = to_tell->i_sb; > struct inode *dir = S_ISDIR(to_tell->i_mode) ? to_tell : NULL; > struct mount *mnt = NULL; > + struct inode *inode = NULL; > struct inode *child = NULL; > int ret = 0; > __u32 test_mask, marks_mask; > @@ -377,6 +378,14 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > if (mask & FS_EVENT_ON_CHILD) > child = fsnotify_data_inode(data, data_type); > > + /* > + * If event is "on child" then to_tell is a watching parent. > + * An event "on child" may be sent to mount/sb mark with parent/name > + * info, but not appropriate for watching parent (e.g. FS_MOVE_SELF). > + */ > + if (!child || (mask & FS_EVENTS_POSS_ON_CHILD)) > + inode = to_tell; > + > /* > * Optimization: srcu_read_lock() has a memory barrier which can > * be expensive. It protects walking the *_fsnotify_marks lists. > @@ -384,14 +393,17 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > * SRCU because we have no references to any objects and do not > * need SRCU to keep them "alive". > */ > - if (!to_tell->i_fsnotify_marks && !sb->s_fsnotify_marks && > + if (!sb->s_fsnotify_marks && > (!mnt || !mnt->mnt_fsnotify_marks) && > + (!inode || !inode->i_fsnotify_marks) && > (!child || !child->i_fsnotify_marks)) > return 0; > > - marks_mask = to_tell->i_fsnotify_mask | sb->s_fsnotify_mask; > + marks_mask = sb->s_fsnotify_mask; > if (mnt) > marks_mask |= mnt->mnt_fsnotify_mask; > + if (inode) > + marks_mask |= inode->i_fsnotify_mask; > if (child) > marks_mask |= child->i_fsnotify_mask; > > @@ -406,14 +418,16 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_type, > > iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu); > > - iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = > - fsnotify_first_mark(&to_tell->i_fsnotify_marks); > iter_info.marks[FSNOTIFY_OBJ_TYPE_SB] = > fsnotify_first_mark(&sb->s_fsnotify_marks); > if (mnt) { > iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] = > fsnotify_first_mark(&mnt->mnt_fsnotify_marks); > } > + if (inode) { > + iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] = > + fsnotify_first_mark(&inode->i_fsnotify_marks); > + } > if (child) { > iter_info.marks[FSNOTIFY_OBJ_TYPE_CHILD] = > fsnotify_first_mark(&child->i_fsnotify_marks); > diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h > index fe4f2bc5b4c2..61dccaf21e7b 100644 > --- a/include/linux/fsnotify.h > +++ b/include/linux/fsnotify.h > @@ -131,7 +131,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > u32 fs_cookie = fsnotify_get_cookie(); > __u32 old_dir_mask = FS_MOVED_FROM; > __u32 new_dir_mask = FS_MOVED_TO; > - __u32 mask = FS_MOVE_SELF; > const struct qstr *new_name = &moved->d_name; > > if (old_dir == new_dir) > @@ -140,7 +139,6 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > if (isdir) { > old_dir_mask |= FS_ISDIR; > new_dir_mask |= FS_ISDIR; > - mask |= FS_ISDIR; > } > > fsnotify_name(old_dir, old_dir_mask, source, old_name, fs_cookie); > @@ -149,7 +147,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, > if (target) > fsnotify_link_count(target); > > - fsnotify(source, mask, source, FSNOTIFY_EVENT_INODE, NULL, 0); > + fsnotify_dentry(moved, FS_MOVE_SELF); > audit_inode_child(new_dir, moved, AUDIT_TYPE_CHILD_CREATE); > } > > diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h > index 6f0df110e9f8..acce2ec17edf 100644 > --- a/include/linux/fsnotify_backend.h > +++ b/include/linux/fsnotify_backend.h > @@ -89,7 +89,7 @@ > * It may include events that can be sent to an inode/sb/mount mark, but cannot > * be sent to a parent watching children. > */ > -#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD) > +#define FS_EVENTS_POSS_TO_PARENT (FS_EVENTS_POSS_ON_CHILD | FS_MOVE_SELF) > > /* Events that can be reported to backends */ > #define ALL_FSNOTIFY_EVENTS (ALL_FSNOTIFY_DIRENT_EVENTS | \ > -- > 2.17.1 > -- Jan Kara SUSE Labs, CR