ceph: fix pending vmtruncate race
The locking order for pending vmtruncate is wrong, it can lead to
following race:
write wmtruncate work
------------------------ ----------------------
lock i_mutex
check i_truncate_pending check i_truncate_pending
truncate_inode_pages() lock i_mutex (blocked)
copy data to page cache
unlock i_mutex
truncate_inode_pages()
The fix is take i_mutex before calling __ceph_do_pending_vmtruncate()
Fixes: http://tracker.ceph.com/issues/5453
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 7c69f4f..a44d515 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -822,7 +822,7 @@
int ret;
mutex_lock(&inode->i_mutex);
- __ceph_do_pending_vmtruncate(inode, false);
+ __ceph_do_pending_vmtruncate(inode);
if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);