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[PULL 106/111] virtiofsd: fix lo_destroy() resource leaks
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[PULL 106/111] virtiofsd: fix lo_destroy() resource leaks |
Date: |
Thu, 23 Jan 2020 11:58:36 +0000 |
From: Stefan Hajnoczi <address@hidden>
Now that lo_destroy() is serialized we can call unref_inode() so that
all inode resources are freed.
Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
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 79b8b71a4f..eb001b9d1e 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 = {
--
2.24.1
- [PULL 085/111] virtiofsd: fix incorrect error handling in lo_do_lookup, (continued)
- [PULL 085/111] virtiofsd: fix incorrect error handling in lo_do_lookup, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 071/111] virtiofsd: passthrough_ll: control readdirplus, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 084/111] virtiofsd: enable PARALLEL_DIROPS during INIT, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 093/111] libvhost-user: Fix some memtable remap cases, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 092/111] virtiofsd: rename inode->refcount to inode->nlookup, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 098/111] virtiofsd: convert more fprintf and perror to use fuse log infra, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 097/111] virtiofsd: do not always set FUSE_FLOCK_LOCKS, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 099/111] virtiofsd: Reset O_DIRECT flag during file open, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 100/111] virtiofsd: Fix data corruption with O_APPEND write in writeback mode, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 102/111] virtiofsd: add definition of fuse_buf_writev(), Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 106/111] virtiofsd: fix lo_destroy() resource leaks,
Dr. David Alan Gilbert (git) <=
- [PULL 094/111] virtiofsd: add man page, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 109/111] virtiofsd/passthrough_ll: Pass errno to fuse_reply_err(), Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 110/111] virtiofsd: stop all queue threads on exit in virtio_loop(), Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 108/111] virtiofsd: Convert lo_destroy to take the lo->mutex lock itself, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 105/111] virtiofsd: prevent FUSE_INIT/FUSE_DESTROY races, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 104/111] virtiofsd: process requests in a thread pool, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 111/111] virtiofsd: add some options to the help message, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 096/111] virtiofsd: introduce inode refcount to prevent use-after-free, Dr. David Alan Gilbert (git), 2020/01/23