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| author | Changwei Ge <ge.changwei@h3c.com> | 2018-11-02 15:48:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-11-03 10:09:37 -0700 |
| commit | 9e985787750db8aae87f02b67e908f28ac4d6b83 (patch) | |
| tree | b7693d418aa7201f4bc290774c5b8540350356c9 | |
| parent | 21158ca85b73ddd0088076a5209cfd040513a8b5 (diff) | |
| download | linux-9e985787750db8aae87f02b67e908f28ac4d6b83.tar.bz2 | |
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>
| -rw-r--r-- | fs/ocfs2/file.c | 4 |
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, trace_generic_file_read_iter_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)) { |