linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Gabriel Krisman Bertazi <krisman@collabora.com>
To: amir73il@gmail.com, jack@suse.com
Cc: djwong@kernel.org, tytso@mit.edu, david@fromorbit.com,
	dhowells@redhat.com, khazhy@google.com,
	linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org,
	linux-ext4@vger.kernel.org,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	kernel@collabora.com, Jan Kara <jack@suse.cz>
Subject: [PATCH v9 15/31] fanotify: Encode empty file handle when no inode is provided
Date: Mon, 25 Oct 2021 16:27:30 -0300	[thread overview]
Message-ID: <20211025192746.66445-16-krisman@collabora.com> (raw)
In-Reply-To: <20211025192746.66445-1-krisman@collabora.com>

Instead of failing, encode an invalid file handle in fanotify_encode_fh
if no inode is provided.  This bogus file handle will be reported by
FAN_FS_ERROR for non-inode errors.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

---
Changes since v6:
  - Use FILEID_ROOT as the internal value (jan)
  - Create an empty FH (jan)

Changes since v5:
  - Preserve flags initialization (jan)
  - Add BUILD_BUG_ON (amir)
  - Require minimum of FANOTIFY_NULL_FH_LEN for fh_len(amir)
  - Improve comment to explain the null FH length (jan)
  - Simplify logic
---
 fs/notify/fanotify/fanotify.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index ec84fee7ad01..c64d61b673ca 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -370,8 +370,14 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
 	fh->type = FILEID_ROOT;
 	fh->len = 0;
 	fh->flags = 0;
+
+	/*
+	 * Invalid FHs are used by FAN_FS_ERROR for errors not
+	 * linked to any inode. The f_handle won't be reported
+	 * back to userspace.
+	 */
 	if (!inode)
-		return 0;
+		goto out;
 
 	/*
 	 * !gpf means preallocated variable size fh, but fh_len could
@@ -403,6 +409,7 @@ static int fanotify_encode_fh(struct fanotify_fh *fh, struct inode *inode,
 	fh->type = type;
 	fh->len = fh_len;
 
+out:
 	/*
 	 * Mix fh into event merge key.  Hash might be NULL in case of
 	 * unhashed FID events (i.e. FAN_FS_ERROR).
-- 
2.33.0


  parent reply	other threads:[~2021-10-25 19:33 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-25 19:27 [PATCH v9 00/31] file system-wide error monitoring Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 01/31] fsnotify: pass data_type to fsnotify_name() Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 02/31] fsnotify: pass dentry instead of inode data Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 03/31] fsnotify: clarify contract for create event hooks Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 04/31] fsnotify: Don't insert unmergeable events in hashtable Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 05/31] fanotify: Fold event size calculation to its own function Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 06/31] fanotify: Split fsid check from other fid mode checks Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 07/31] inotify: Don't force FS_IN_IGNORED Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 08/31] fsnotify: Add helper to detect overflow_event Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 09/31] fsnotify: Add wrapper around fsnotify_add_event Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 10/31] fsnotify: Retrieve super block from the data field Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 11/31] fsnotify: Protect fsnotify_handle_inode_event from no-inode events Gabriel Krisman Bertazi
2021-10-26  7:01   ` Amir Goldstein
2021-10-26 11:47   ` Jan Kara
2021-10-25 19:27 ` [PATCH v9 12/31] fsnotify: Pass group argument to free_event Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 13/31] fanotify: Support null inode event in fanotify_dfid_inode Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 14/31] fanotify: Allow file handle encoding for unhashed events Gabriel Krisman Bertazi
2021-10-25 19:27 ` Gabriel Krisman Bertazi [this message]
2021-10-25 19:27 ` [PATCH v9 16/31] fanotify: Require fid_mode for any non-fd event Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 17/31] fsnotify: Support FS_ERROR event type Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 18/31] fanotify: Reserve UAPI bits for FAN_FS_ERROR Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 19/31] fanotify: Pre-allocate pool of error events Gabriel Krisman Bertazi
2021-10-26  7:09   ` Amir Goldstein
2021-10-25 19:27 ` [PATCH v9 20/31] fanotify: Support enqueueing " Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 21/31] fanotify: Support merging " Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 22/31] fanotify: Wrap object_fh inline space in a creator macro Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 23/31] fanotify: Add helpers to decide whether to report FID/DFID Gabriel Krisman Bertazi
2021-10-26  7:02   ` Amir Goldstein
2021-10-25 19:27 ` [PATCH v9 24/31] fanotify: Report fid entry even for zero-length file_handle Gabriel Krisman Bertazi
2021-10-26  9:09   ` Amir Goldstein
2021-10-26 12:06     ` Jan Kara
2021-10-25 19:27 ` [PATCH v9 25/31] fanotify: WARN_ON against too large file handles Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 26/31] fanotify: Report fid info for file related file system errors Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 27/31] fanotify: Emit generic error info for error event Gabriel Krisman Bertazi
2021-10-26 12:11   ` Jan Kara
2021-10-25 19:27 ` [PATCH v9 28/31] fanotify: Allow users to request FAN_FS_ERROR events Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 29/31] ext4: Send notifications on error Gabriel Krisman Bertazi
2021-10-26  4:00   ` Theodore Ts'o
2021-10-26  7:05   ` Amir Goldstein
2021-10-26 12:12   ` Jan Kara
2021-10-25 19:27 ` [PATCH v9 30/31] samples: Add fs error monitoring example Gabriel Krisman Bertazi
2021-10-25 19:27 ` [PATCH v9 31/31] docs: Document the FAN_FS_ERROR event Gabriel Krisman Bertazi
2021-10-26 12:19   ` Jan Kara
2021-10-26  9:12 ` [PATCH v9 00/31] file system-wide error monitoring Amir Goldstein
2021-10-27 11:22   ` Jan Kara
2021-10-27 12:36     ` Amir Goldstein
2021-10-27 13:03       ` Gabriel Krisman Bertazi
2021-10-28  5:55         ` Amir Goldstein
2021-10-29 22:23           ` Gabriel Krisman Bertazi
2021-10-30  6:53             ` Amir Goldstein

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211025192746.66445-16-krisman@collabora.com \
    --to=krisman@collabora.com \
    --cc=amir73il@gmail.com \
    --cc=david@fromorbit.com \
    --cc=dhowells@redhat.com \
    --cc=djwong@kernel.org \
    --cc=jack@suse.com \
    --cc=jack@suse.cz \
    --cc=kernel@collabora.com \
    --cc=khazhy@google.com \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=tytso@mit.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).