From 825978fd6a0defc3c29d8a38b6cea76a0938d21e Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Mon, 25 Apr 2022 16:08:24 +0800 Subject: ceph: fix possible deadlock when holding Fwb to get inline_data 1, mount with wsync. 2, create a file with O_RDWR, and the request was sent to mds.0: ceph_atomic_open()--> ceph_mdsc_do_request(openc) finish_open(file, dentry, ceph_open)--> ceph_open()--> ceph_init_file()--> ceph_init_file_info()--> ceph_uninline_data()--> { ... if (inline_version == 1 || /* initial version, no data */ inline_version == CEPH_INLINE_NONE) goto out_unlock; ... } The inline_version will be 1, which is the initial version for the new create file. And here the ci->i_inline_version will keep with 1, it's buggy. 3, buffer write to the file immediately: ceph_write_iter()--> ceph_get_caps(file, need=Fw, want=Fb, ...); generic_perform_write()--> a_ops->write_begin()--> ceph_write_begin()--> netfs_write_begin()--> netfs_begin_read()--> netfs_rreq_submit_slice()--> netfs_read_from_server()--> rreq->netfs_ops->issue_read()--> ceph_netfs_issue_read()--> { ... if (ci->i_inline_version != CEPH_INLINE_NONE && ceph_netfs_issue_op_inline(subreq)) return; ... } ceph_put_cap_refs(ci, Fwb); The ceph_netfs_issue_op_inline() will send a getattr(Fsr) request to mds.1. 4, then the mds.1 will request the rd lock for CInode::filelock from the auth mds.0, the mds.0 will do the CInode::filelock state transation from excl --> sync, but it need to revoke the Fxwb caps back from the clients. While the kernel client has aleady held the Fwb caps and waiting for the getattr(Fsr). It's deadlock! URL: https://tracker.ceph.com/issues/55377 Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- fs/ceph/addr.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) (limited to 'fs/ceph') diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 18956c629ad4..1a108f24e7d9 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1648,7 +1648,7 @@ int ceph_uninline_data(struct file *file) struct inode *inode = file_inode(file); struct ceph_inode_info *ci = ceph_inode(inode); struct ceph_fs_client *fsc = ceph_inode_to_client(inode); - struct ceph_osd_request *req; + struct ceph_osd_request *req = NULL; struct ceph_cap_flush *prealloc_cf; struct folio *folio = NULL; u64 inline_version = CEPH_INLINE_NONE; @@ -1656,10 +1656,23 @@ int ceph_uninline_data(struct file *file) int err = 0; u64 len; + spin_lock(&ci->i_ceph_lock); + inline_version = ci->i_inline_version; + spin_unlock(&ci->i_ceph_lock); + + dout("uninline_data %p %llx.%llx inline_version %llu\n", + inode, ceph_vinop(inode), inline_version); + + if (inline_version == CEPH_INLINE_NONE) + return 0; + prealloc_cf = ceph_alloc_cap_flush(); if (!prealloc_cf) return -ENOMEM; + if (inline_version == 1) /* initial version, no data */ + goto out_uninline; + folio = read_mapping_folio(inode->i_mapping, 0, file); if (IS_ERR(folio)) { err = PTR_ERR(folio); @@ -1668,17 +1681,6 @@ int ceph_uninline_data(struct file *file) folio_lock(folio); - spin_lock(&ci->i_ceph_lock); - inline_version = ci->i_inline_version; - spin_unlock(&ci->i_ceph_lock); - - dout("uninline_data %p %llx.%llx inline_version %llu\n", - inode, ceph_vinop(inode), inline_version); - - if (inline_version == 1 || /* initial version, no data */ - inline_version == CEPH_INLINE_NONE) - goto out_unlock; - len = i_size_read(inode); if (len > folio_size(folio)) len = folio_size(folio); @@ -1743,6 +1745,7 @@ int ceph_uninline_data(struct file *file) ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency, req->r_end_latency, len, err); +out_uninline: if (!err) { int dirty; @@ -1761,8 +1764,10 @@ out_put_req: if (err == -ECANCELED) err = 0; out_unlock: - folio_unlock(folio); - folio_put(folio); + if (folio) { + folio_unlock(folio); + folio_put(folio); + } out: ceph_free_cap_flush(prealloc_cf); dout("uninline_data %p %llx.%llx inline_version %llu = %d\n", -- cgit v1.2.3