Patch "ocfs2: should wait dio before inode lock in ocfs2_setattr()" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

ocfs2: should wait dio before inode lock in ocfs2_setattr()

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ocfs2-should-wait-dio-before-inode-lock-in-ocfs2_setattr.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: alex chen <[email protected]>
Date: Wed, 15 Nov 2017 17:31:40 -0800
Subject: ocfs2: should wait dio before inode lock in ocfs2_setattr()

From: alex chen <[email protected]>

commit 28f5a8a7c033cbf3e32277f4cc9c6afd74f05300 upstream.

we should wait dio requests to finish before inode lock in ocfs2_setattr(), otherwise the following deadlock will happen:

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.

---
 fs/ocfs2/file.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

@@ -1161,6 +1161,13 @@ int ocfs2_setattr(struct dentry *dentry,
 	}
 	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,
 		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,

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/ocfs2-should-wait-dio-before-inode-lock-in-ocfs2_setattr.patch