diff options
authorChangwei Ge <ge.changwei@h3c.com>2018-11-02 15:48:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-03 10:09:37 -0700
commit9e985787750db8aae87f02b67e908f28ac4d6b83 (patch)
parent21158ca85b73ddd0088076a5209cfd040513a8b5 (diff)
ocfs2: don't use iocb when EIOCBQUEUED returns
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. Using the 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] aio_run_iocb+0x229/0x2f0 do_io_submit+0x291/0x540 SyS_io_submit+0x10/0x20 system_call_fastpath+0x16/0x75 Link: http://lkml.kernel.org/r/1523361653-14439-1-git-send-email-ge.changwei@h3c.com Signed-off-by: Changwei Ge <ge.changwei@h3c.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index fe570824b991..d640c5f8a85d 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,
/* 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)) {