From: Stefan Hajnoczi <stefa...@redhat.com>
Hold the lock across both lo_map_get() and lo_map_remove() to prevent
races between two FUSE_RELEASE requests. In this case I don't see a
serious bug but it's safer to do things atomically.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
tools/virtiofsd/passthrough_ll.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 9414935b52..690edbc4c5 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -1772,14 +1772,18 @@ static void lo_release(fuse_req_t req, fuse_ino_t ino,
struct fuse_file_info *fi)
{
struct lo_data *lo = lo_data(req);
- int fd;
+ struct lo_map_elem *elem;
+ int fd = -1;
(void)ino;
- fd = lo_fi_fd(req, fi);
-
pthread_mutex_lock(&lo->mutex);
- lo_map_remove(&lo->fd_map, fi->fh);
+ elem = lo_map_get(&lo->fd_map, fi->fh);
+ if (elem) {
+ fd = elem->fd;
+ elem = NULL;
+ lo_map_remove(&lo->fd_map, fi->fh);
+ }
pthread_mutex_unlock(&lo->mutex);
close(fd);
--
2.24.1
