4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: alex chen <alex.c...@huawei.com>
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.
Link: http://lkml.kernel.org/r/59f81636.70...@huawei.com
Signed-off-by: Alex Chen <alex.c...@huawei.com>
Reviewed-by: Jun Piao <piao...@huawei.com>
Reviewed-by: Joseph Qi <jiangqi...@gmail.com>
Acked-by: Changwei Ge <ge.chang...@h3c.com>
Cc: Mark Fasheh <mfas...@versity.com>
Cc: Joel Becker <jl...@evilplan.org>
Cc: Junxiao Bi <junxiao...@oracle.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/ocfs2/file.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1166,6 +1166,13 @@ 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);
@@ -1186,8 +1193,6 @@ 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,
