When -EIOCBQUEUED returns, it means that aio_complete() will be called from dio_complete(), which is an asynchronous progress against write_iter. Generally, IO is a very slow progress than executing instruction, but we still can't take the risk to access a freed iocb.
And we do face a BUG crash issue. >From crash tool, iocb is obviously freed already. crash> struct -x kiocb ffff881a350f5900 struct kiocb { ki_filp = 0xffff881a350f5a80, ki_pos = 0x0, ki_complete = 0x0, private = 0x0, ki_flags = 0x0 } And the backtrace shows: ocfs2_file_write_iter+0xcaa/0xd00 [ocfs2] ? ocfs2_check_range_for_refcount+0x150/0x150 [ocfs2] aio_run_iocb+0x229/0x2f0 ? try_to_wake_up+0x380/0x380 do_io_submit+0x291/0x540 ? syscall_trace_leave+0xad/0x130 SyS_io_submit+0x10/0x20 system_call_fastpath+0x16/0x75 Signed-off-by: Changwei Ge <ge.chang...@h3c.com> --- fs/ocfs2/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 5d1784a..1393ff2 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2343,7 +2343,7 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, written = __generic_file_write_iter(iocb, from); /* buffered aio wouldn't have proper lock coverage today */ - BUG_ON(written == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT)); + BUG_ON(written == -EIOCBQUEUED && !direct_io); /* * deep in g_f_a_w_n()->ocfs2_direct_IO we pass in a ocfs2_dio_end_io @@ -2463,7 +2463,7 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb, trace_generic_file_aio_read_ret(ret); /* buffered aio wouldn't have proper lock coverage today */ - BUG_ON(ret == -EIOCBQUEUED && !(iocb->ki_flags & IOCB_DIRECT)); + BUG_ON(ret == -EIOCBQUEUED && !direct_io); /* see ocfs2_file_write_iter */ if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) { -- 2.7.4 _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel