From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex chen Date: Fri, 27 Oct 2017 15:57:38 +0800 Subject: [Ocfs2-devel] [PATCH] ocfs2: should wait dio before inode lock in ocfs2_setattr() Message-ID: <59F2E6F2.7090803@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com we should wait dio requests to finish before inode lock in ocfs2_setattr(), otherwise the following deadlock will be happened: process 1 process 2 process 3 truncate file 'A' end_io of writing file 'A' receiving the bast messages ocfs2_setattr ocfs2_inode_lock_tracker ocfs2_inode_lock_full inode_dio_wait __inode_dio_wait -->waiting for all dio requests finish dlm_proxy_ast_handler dlm_do_local_bast ocfs2_blocking_ast ocfs2_generic_handle_bast set OCFS2_LOCK_BLOCKED flag dio_end_io dio_bio_end_aio dio_complete ocfs2_dio_end_io ocfs2_dio_end_io_write ocfs2_inode_lock __ocfs2_cluster_lock ocfs2_wait_for_mask -->waiting for OCFS2_LOCK_BLOCKED flag to be cleared, that is waiting for 'process 1' unlocking the inode lock inode_dio_end -->here dec the i_dio_count, but will never be called, so a deadlock happened. Signed-off-by: Alex Chen Reviewed-by: Jun Piao --- fs/ocfs2/file.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 6e41fc8..50e09a6 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1161,6 +1161,13 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) } size_change = S_ISREG(inode->i_mode) && attr->ia_valid & ATTR_SIZE; if (size_change) { + + /* here we should wait dio to finish before inode lock + * to avoid a deadlock between ocfs2_setattr() and + * ocfs2_dio_end_io_write() + */ + inode_dio_wait(inode); + status = ocfs2_rw_lock(inode, 1); if (status < 0) { mlog_errno(status); @@ -1200,8 +1207,6 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) if (status) goto bail_unlock; - inode_dio_wait(inode); - if (i_size_read(inode) >= attr->ia_size) { if (ocfs2_should_order_data(inode)) { status = ocfs2_begin_ordered_truncate(inode, -- 1.9.5.msysgit.1