diff options
| author | Sebastian Hasler | 2022-01-13 16:32:49 +0100 |
|---|---|---|
| committer | Dr. David Alan Gilbert | 2022-02-16 18:29:31 +0100 |
| commit | 41af4459ac47e107093c3f54b6875d54723aa613 (patch) | |
| tree | 85cef71580611193c403b071c403a304c69ee789 /tools/virtiofsd | |
| parent | Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20220... (diff) | |
| download | qemu-41af4459ac47e107093c3f54b6875d54723aa613.tar.gz qemu-41af4459ac47e107093c3f54b6875d54723aa613.tar.xz qemu-41af4459ac47e107093c3f54b6875d54723aa613.zip | |
virtiofsd: Do not support blocking flock
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>
Diffstat (limited to 'tools/virtiofsd')
| -rw-r--r-- | tools/virtiofsd/passthrough_ll.c | 9 |
1 files changed, 9 insertions, 0 deletions
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); |