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[PULL 01/12] virtiofsd: Do not support blocking flock
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[PULL 01/12] virtiofsd: Do not support blocking flock |
Date: |
Thu, 17 Feb 2022 14:23:51 +0000 |
From: Sebastian Hasler <sebastian.hasler@stuvus.uni-stuttgart.de>
With the current implementation, blocking flock can lead to
deadlock. Thus, it's better to return EOPNOTSUPP if a user attempts
to perform a blocking flock request.
Signed-off-by: Sebastian Hasler <sebastian.hasler@stuvus.uni-stuttgart.de>
Message-Id: <20220113153249.710216-1-sebastian.hasler@stuvus.uni-stuttgart.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
---
tools/virtiofsd/passthrough_ll.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index b3d0674f6d..3e56d1cd95 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -2467,6 +2467,15 @@ static void lo_flock(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi,
int res;
(void)ino;
+ if (!(op & LOCK_NB)) {
+ /*
+ * Blocking flock can deadlock as there is only one thread
+ * serving the queue.
+ */
+ fuse_reply_err(req, EOPNOTSUPP);
+ return;
+ }
+
res = flock(lo_fi_fd(req, fi), op);
fuse_reply_err(req, res == -1 ? errno : 0);
--
2.35.1
- [PULL 08/12] virtiofsd: Add helpers to work with /proc/self/task/tid/attr/fscreate, (continued)
- [PULL 08/12] virtiofsd: Add helpers to work with /proc/self/task/tid/attr/fscreate, Dr. David Alan Gilbert (git), 2022/02/16
- [PULL 09/12] virtiofsd: Create new file with security context, Dr. David Alan Gilbert (git), 2022/02/16
- [PULL 10/12] virtiofsd: Create new file using O_TMPFILE and set security context, Dr. David Alan Gilbert (git), 2022/02/16
- [PULL 11/12] virtiofsd: Add an option to enable/disable security label, Dr. David Alan Gilbert (git), 2022/02/16
- [PULL 12/12] virtiofsd: Add basic support for FUSE_SYNCFS request, Dr. David Alan Gilbert (git), 2022/02/16
- Re: [Virtio-fs] [PULL 00/12] virtiofs queue, Dr. David Alan Gilbert, 2022/02/16
- [PULL 00/12] virtiofs queue, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 02/12] virtiofsd: Fix breakage due to fuse_init_in size change, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 01/12] virtiofsd: Do not support blocking flock,
Dr. David Alan Gilbert (git) <=
- [PULL 03/12] linux-headers: Update headers to v5.17-rc1, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 04/12] virtiofsd: Parse extended "struct fuse_init_in", Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 05/12] virtiofsd: Extend size of fuse_conn_info->capable and ->want fields, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 06/12] virtiofsd, fuse_lowlevel.c: Add capability to parse security context, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 07/12] virtiofsd: Move core file creation code in separate function, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 08/12] virtiofsd: Add helpers to work with /proc/self/task/tid/attr/fscreate, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 09/12] virtiofsd: Create new file with security context, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 10/12] virtiofsd: Create new file using O_TMPFILE and set security context, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 11/12] virtiofsd: Add an option to enable/disable security label, Dr. David Alan Gilbert (git), 2022/02/17
- [PULL 12/12] virtiofsd: Add basic support for FUSE_SYNCFS request, Dr. David Alan Gilbert (git), 2022/02/17