From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maximilian Heyne Subject: [PATCH] fs: fix lost error code in dio_complete Date: Tue, 30 Oct 2018 21:57:39 +0000 Message-ID: <20181030215739.4557-1-mheyne@amazon.de> Mime-Version: 1.0 Content-Type: text/plain Cc: Christoph Hellwig , Maximilian Heyne , , Torsten Mehlan , Uwe Dannowski , Amit Shah , David Woodhouse , Alexander Viro , , To: unlisted-recipients:; (no To-header on input) Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org commit e259221763a40403d5bb232209998e8c45804ab8 ("fs: simplify the generic_write_sync prototype") reworked callers of generic_write_sync(), and ended up dropping the error return for the directio path. Prior to that commit, in dio_complete(), an error would be bubbled up the stack, but after that commit, errors passed on to dio_complete were eaten up. This was reported on the list earlier, and a fix was proposed in https://lore.kernel.org/lkml/20160921141539.GA17898@infradead.org/, but never followed up with. We recently hit this bug in our testing where fencing io errors, which were previously erroring out with EIO, were being returned as success operations after this commit. The fix proposed on the list earlier was a little short -- it would have still called generic_write_sync() in case `ret` already contained an error. This fix ensures generic_write_sync() is only called when there's no pending error in the write. CC: stable@vger.kernel.org Reported-by: Ravi Nankani Signed-off-by: Maximilian Heyne Signed-off-by: Torsten Mehlan Signed-off-by: Uwe Dannowski Signed-off-by: Amit Shah Signed-off-by: David Woodhouse --- fs/direct-io.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index 093fb54cd316..199146036093 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -325,8 +325,8 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags) */ dio->iocb->ki_pos += transferred; - if (dio->op == REQ_OP_WRITE) - ret = generic_write_sync(dio->iocb, transferred); + if (ret > 0 && dio->op == REQ_OP_WRITE) + ret = generic_write_sync(dio->iocb, ret); dio->iocb->ki_complete(dio->iocb, ret, 0); } -- 2.16.2 Amazon Development Center Germany GmbH Berlin - Dresden - Aachen main office: Krausenstr. 38, 10117 Berlin Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger Ust-ID: DE289237879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B