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[PULL 088/108] virtiofsd: make lo_release() atomic
From: |
Dr. David Alan Gilbert (git) |
Subject: |
[PULL 088/108] virtiofsd: make lo_release() atomic |
Date: |
Thu, 23 Jan 2020 16:46:10 +0000 |
From: Stefan Hajnoczi <address@hidden>
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 <address@hidden>
Reviewed-by: Daniel P. Berrangé <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
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
- [PULL 076/108] virtiofsd: support nanosecond resolution for file timestamp, (continued)
- [PULL 076/108] virtiofsd: support nanosecond resolution for file timestamp, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 080/108] virtiofsd: add helper for lo_data cleanup, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 078/108] virtiofsd: cleanup allocated resource in se, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 079/108] virtiofsd: fix memory leak on lo.source, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 081/108] virtiofsd: Prevent multiply running with same vhost_user_socket, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 082/108] virtiofsd: enable PARALLEL_DIROPS during INIT, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 083/108] virtiofsd: fix incorrect error handling in lo_do_lookup, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 084/108] Virtiofsd: fix memory leak on fuse queueinfo, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 086/108] virtiofsd: use fuse_lowlevel_is_virtio() in fuse_session_destroy(), Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 085/108] virtiofsd: Support remote posix locks, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 088/108] virtiofsd: make lo_release() atomic,
Dr. David Alan Gilbert (git) <=
- [PULL 087/108] virtiofsd: prevent fv_queue_thread() vs virtio_loop() races, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 090/108] virtiofsd: rename inode->refcount to inode->nlookup, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 089/108] virtiofsd: prevent races with lo_dirp_put(), Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 091/108] libvhost-user: Fix some memtable remap cases, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 092/108] virtiofsd: passthrough_ll: fix refcounting on remove/rename, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 097/108] virtiofsd: Fix data corruption with O_APPEND write in writeback mode, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 096/108] virtiofsd: Reset O_DIRECT flag during file open, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 095/108] virtiofsd: convert more fprintf and perror to use fuse log infra, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 094/108] virtiofsd: do not always set FUSE_FLOCK_LOCKS, Dr. David Alan Gilbert (git), 2020/01/23
- [PULL 093/108] virtiofsd: introduce inode refcount to prevent use-after-free, Dr. David Alan Gilbert (git), 2020/01/23