From 9a44d78f5019280b006bb5b3de7164336289d639 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 27 Jan 2020 19:02:21 +0100 Subject: [PATCH 110/116] virtiofsd: fix lo_destroy() resource leaks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Dr. David Alan Gilbert Message-id: <20200127190227.40942-107-dgilbert@redhat.com> Patchwork-id: 93560 O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 106/112] virtiofsd: fix lo_destroy() resource leaks Bugzilla: 1694164 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Sergio Lopez Pascual From: Stefan Hajnoczi Now that lo_destroy() is serialized we can call unref_inode() so that all inode resources are freed. Signed-off-by: Stefan Hajnoczi Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit 28f7a3b026f231bfe8de5fed6a18a8d27b1dfcee) Signed-off-by: Miroslav Rezanina --- tools/virtiofsd/passthrough_ll.c | 41 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 21 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 79b8b71..eb001b9 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1371,26 +1371,6 @@ static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inode, } } -static int unref_all_inodes_cb(gpointer key, gpointer value, gpointer user_data) -{ - struct lo_inode *inode = value; - struct lo_data *lo = user_data; - - inode->nlookup = 0; - lo_map_remove(&lo->ino_map, inode->fuse_ino); - close(inode->fd); - lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ - - return TRUE; -} - -static void unref_all_inodes(struct lo_data *lo) -{ - pthread_mutex_lock(&lo->mutex); - g_hash_table_foreach_remove(lo->inodes, unref_all_inodes_cb, lo); - pthread_mutex_unlock(&lo->mutex); -} - static void lo_forget_one(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) { struct lo_data *lo = lo_data(req); @@ -2477,7 +2457,26 @@ static void lo_lseek(fuse_req_t req, fuse_ino_t ino, off_t off, int whence, static void lo_destroy(void *userdata) { struct lo_data *lo = (struct lo_data *)userdata; - unref_all_inodes(lo); + + /* + * Normally lo->mutex must be taken when traversing lo->inodes but + * lo_destroy() is a serialized request so no races are possible here. + * + * In addition, we cannot acquire lo->mutex since unref_inode() takes it + * too and this would result in a recursive lock. + */ + while (true) { + GHashTableIter iter; + gpointer key, value; + + g_hash_table_iter_init(&iter, lo->inodes); + if (!g_hash_table_iter_next(&iter, &key, &value)) { + break; + } + + struct lo_inode *inode = value; + unref_inode_lolocked(lo, inode, inode->nlookup); + } } static struct fuse_lowlevel_ops lo_oper = { -- 1.8.3.1