When ceph_readdir_prepopulate calls ceph_get_inode while holding mdsc->snap_rwsem, a deadlock may occur, blocking all subsequent requests of the current session. Fix by release the mds->snap_rwsem read lock before calling the ceph_get_inode function. Link: https://tracker.ceph.com/issues/72307 Signed-off-by: Zhao Sun <sunzhao03@xxxxxxxxxxxx> --- fs/ceph/inode.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 06cd2963e41e..3d7fb045ba76 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1900,6 +1900,7 @@ static int fill_readdir_cache(struct inode *dir, struct dentry *dn, int ceph_readdir_prepopulate(struct ceph_mds_request *req, struct ceph_mds_session *session) { + struct ceph_mds_client *mdsc = session->s_mdsc; struct dentry *parent = req->r_dentry; struct inode *inode = d_inode(parent); struct ceph_inode_info *ci = ceph_inode(inode); @@ -2029,7 +2030,10 @@ int ceph_readdir_prepopulate(struct ceph_mds_request *req, if (d_really_is_positive(dn)) { in = d_inode(dn); } else { + /* Release mdsc->snap_rwsem in advance to avoid deadlock */ + up_read(&mdsc->snap_rwsem); in = ceph_get_inode(parent->d_sb, tvino, NULL); + down_read(&mdsc->snap_rwsem); if (IS_ERR(in)) { doutc(cl, "new_inode badness\n"); d_drop(dn); -- 2.39.2 (Apple Git-143)
