From: Jan Kara <jack@suse.cz>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>,
Gabriel Krisman Bertazi <krisman@collabora.com>,
Jan Kara <jack@suse.com>, Linux API <linux-api@vger.kernel.org>,
Ext4 <linux-ext4@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Khazhismel Kumykov <khazhy@google.com>,
David Howells <dhowells@redhat.com>,
Dave Chinner <david@fromorbit.com>, Theodore Tso <tytso@mit.edu>,
"Darrick J. Wong" <djwong@kernel.org>,
Matthew Bobrowski <repnop@google.com>,
kernel@collabora.com
Subject: Re: [PATCH v6 12/21] fanotify: Encode invalid file handle when no inode is provided
Date: Mon, 16 Aug 2021 18:11:43 +0200 [thread overview]
Message-ID: <20210816161143.GG30215@quack2.suse.cz> (raw)
In-Reply-To: <CAOQ4uxjQ6R0SvUjasyU3c_ZHTAC1J4=2eamgxJAOyq7C9HZFbQ@mail.gmail.com>
On Mon 16-08-21 18:54:58, Amir Goldstein wrote:
> On Mon, Aug 16, 2021 at 5:07 PM Jan Kara <jack@suse.cz> wrote:
> > Dunno, it still seems like quite some complications (simple ones but
> > non-trivial amount of them) for what is rather a corner case. What if we
> > *internally* propagated the information that there's no inode info with
> > FILEID_ROOT fh? That means: No changes to fanotify_encode_fh_len(),
> > fanotify_encode_fh(), or fanotify_alloc_name_event(). In
> > copy_info_to_user() we just mangle FILEID_ROOT to FILEID_INVALID and that's
> > all. No useless padding, no specialcasing of copying etc. Am I missing
> > something?
>
> I am perfectly fine with encoding "no inode" with FILEID_ROOT internally.
> It's already the value used by fanotify_encode_fh() in upstream.
>
> However, if we use zero len internally, we need to pass fh_type to
> fanotify_fid_info_len() and special case FILEID_ROOT in order to
> take FANOTIFY_FID_INFO_HDR_LEN into account.
>
> And special case fanotify_event_object_fh_len() in
> fanotify_event_info_len() and in copy_info_records_to_user().
Right, this will need some tweaking. I would actually leave
fanotify_fid_info_len() alone, just have in fanotify_event_info_len()
something like:
- if (fh_len)
+ if (fh_len || fanotify_event_needs_fsid(event))
and similarly in copy_info_records_to_user():
- if (fanotify_event_object_fh_len(event)) {
+ if (fanotify_event_object_fh_len(event) ||
+ fanotify_event_needs_fsid(event)) {
And that should be all that's needed as far as I'm reading the code.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2021-08-16 16:11 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-12 21:39 [PATCH v6 00/21] File system wide monitoring Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 01/21] fsnotify: Don't insert unmergeable events in hashtable Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 02/21] fanotify: Fold event size calculation to its own function Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 03/21] fanotify: Split fsid check from other fid mode checks Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 04/21] fsnotify: Reserve mark flag bits for backends Gabriel Krisman Bertazi
2021-08-13 7:28 ` Amir Goldstein
2021-08-16 13:15 ` Jan Kara
2021-08-23 14:36 ` Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 05/21] fanotify: Split superblock marks out to a new cache Gabriel Krisman Bertazi
2021-08-16 13:18 ` Jan Kara
2021-08-12 21:39 ` [PATCH v6 06/21] inotify: Don't force FS_IN_IGNORED Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 07/21] fsnotify: Add helper to detect overflow_event Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 08/21] fsnotify: Add wrapper around fsnotify_add_event Gabriel Krisman Bertazi
2021-08-12 21:39 ` [PATCH v6 09/21] fsnotify: Allow events reported with an empty inode Gabriel Krisman Bertazi
2021-08-13 7:58 ` Amir Goldstein
2021-08-25 18:40 ` Gabriel Krisman Bertazi
2021-08-25 19:45 ` Amir Goldstein
2021-08-25 21:50 ` Gabriel Krisman Bertazi
2021-08-26 10:44 ` Amir Goldstein
2021-08-27 2:26 ` Paul Moore
2021-08-12 21:39 ` [PATCH v6 10/21] fsnotify: Support FS_ERROR event type Gabriel Krisman Bertazi
2021-08-13 7:48 ` Amir Goldstein
2021-08-16 13:23 ` Jan Kara
2021-08-12 21:40 ` [PATCH v6 11/21] fanotify: Allow file handle encoding for unhashed events Gabriel Krisman Bertazi
2021-08-13 7:59 ` Amir Goldstein
2021-08-12 21:40 ` [PATCH v6 12/21] fanotify: Encode invalid file handle when no inode is provided Gabriel Krisman Bertazi
2021-08-13 8:27 ` Amir Goldstein
2021-08-16 14:06 ` Jan Kara
2021-08-16 15:54 ` Amir Goldstein
2021-08-16 16:11 ` Jan Kara [this message]
2021-08-12 21:40 ` [PATCH v6 13/21] fanotify: Require fid_mode for any non-fd event Gabriel Krisman Bertazi
2021-08-13 8:28 ` Amir Goldstein
2021-08-12 21:40 ` [PATCH v6 14/21] fanotify: Reserve UAPI bits for FAN_FS_ERROR Gabriel Krisman Bertazi
2021-08-13 8:29 ` Amir Goldstein
2021-08-12 21:40 ` [PATCH v6 15/21] fanotify: Preallocate per superblock mark error event Gabriel Krisman Bertazi
2021-08-13 8:40 ` Amir Goldstein
2021-08-16 15:57 ` Jan Kara
2021-08-27 18:18 ` Gabriel Krisman Bertazi
2021-09-02 21:24 ` Gabriel Krisman Bertazi
2021-09-03 4:16 ` Amir Goldstein
2021-09-15 10:31 ` Jan Kara
2021-08-12 21:40 ` [PATCH v6 16/21] fanotify: Handle FAN_FS_ERROR events Gabriel Krisman Bertazi
2021-08-13 9:35 ` Amir Goldstein
2021-08-12 21:40 ` [PATCH v6 17/21] fanotify: Report fid info for file related file system errors Gabriel Krisman Bertazi
2021-08-13 9:00 ` Amir Goldstein
2021-08-13 9:03 ` Amir Goldstein
2021-08-16 16:18 ` Jan Kara
2021-08-12 21:40 ` [PATCH v6 18/21] fanotify: Emit generic error info type for error event Gabriel Krisman Bertazi
2021-08-13 8:47 ` Amir Goldstein
2021-08-16 16:23 ` Jan Kara
2021-08-16 21:41 ` Darrick J. Wong
2021-08-17 9:05 ` Jan Kara
2021-08-17 10:08 ` Amir Goldstein
2021-08-18 0:16 ` Darrick J. Wong
2021-08-18 3:24 ` Amir Goldstein
2021-08-18 9:58 ` Jan Kara
2021-08-19 3:58 ` Darrick J. Wong
2021-08-18 0:10 ` Darrick J. Wong
2021-08-24 16:53 ` Gabriel Krisman Bertazi
2021-08-25 4:09 ` Darrick J. Wong
2021-08-12 21:40 ` [PATCH v6 19/21] ext4: Send notifications on error Gabriel Krisman Bertazi
2021-08-16 16:26 ` Jan Kara
2021-08-12 21:40 ` [PATCH v6 20/21] samples: Add fs error monitoring example Gabriel Krisman Bertazi
2021-08-18 13:02 ` Jan Kara
2021-08-23 14:49 ` Gabriel Krisman Bertazi
2021-08-12 21:40 ` [PATCH v6 21/21] docs: Document the FAN_FS_ERROR event Gabriel Krisman Bertazi
2021-08-16 16:40 ` Jan Kara
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