Commit Message
Greg KH
Oct. 24, 2022, 11:34 a.m. UTC
From: Pavel Begunkov <asml.silence@gmail.com> [ upstream commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523c ] Kernel test robot reports that we test negativity of an unsigned in io_fixup_rw_res() after a recent change, which masks error codes and messes up the return value in case I/O is re-retried and failed with an error. Fixes: 4d9cb92ca41dd ("io_uring/rw: fix short rw error handling") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/9754a0970af1861e7865f9014f735c70dc60bf79.1663071587.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Comments
Hi Greg, On 24/10/22 5:04 pm, Greg Kroah-Hartman wrote: > From: Pavel Begunkov <asml.silence@gmail.com> > > [ upstream commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523c ] > This commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523 also changes second argument from unsigned to long. > Kernel test robot reports that we test negativity of an unsigned in > io_fixup_rw_res() after a recent change, which masks error codes and > messes up the return value in case I/O is re-retried and failed with > an error. > > Fixes: 4d9cb92ca41dd ("io_uring/rw: fix short rw error handling") > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> > Link: https://lore.kernel.org/r/9754a0970af1861e7865f9014f735c70dc60bf79.1663071587.git.asml.silence@gmail.com > Signed-off-by: Jens Axboe <axboe@kernel.dk> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > fs/io_uring.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -2701,7 +2701,7 @@ static bool __io_complete_rw_common(stru > return false; > } > > -static inline unsigned io_fixup_rw_res(struct io_kiocb *req, unsigned res) > +static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) > { I think the res should be of type 'long'. I noticed this when I ran smatch on 5.10.y io_uring backport from 5.15.y patch. Smatch warning: io_fixup_rw_res() warn: unsigned 'res' is never less than zero. static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) { struct io_async_rw *io = req->async_data; /* add previously done IO, if any */ if (io && io->bytes_done > 0) { if (res < 0) //// unsigned comparison with zero. res = io->bytes_done; else res += io->bytes_done; } return res; } We don't have upstream commit to backport in this case. Should we fix this with no-upstream reference commit? Thanks, Harshit > struct io_async_rw *io = req->async_data; > > > > >
On Tue, Jan 10, 2023 at 08:36:00PM +0530, Harshit Mogalapalli wrote: > > Hi Greg, > > On 24/10/22 5:04 pm, Greg Kroah-Hartman wrote: > > From: Pavel Begunkov <asml.silence@gmail.com> > > > > [ upstream commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523c ] > > > > This commit 62bb0647b14646fa6c9aa25ecdf67ad18f13523 also changes second > argument from unsigned to long. > > > Kernel test robot reports that we test negativity of an unsigned in > > io_fixup_rw_res() after a recent change, which masks error codes and > > messes up the return value in case I/O is re-retried and failed with > > an error. > > > > Fixes: 4d9cb92ca41dd ("io_uring/rw: fix short rw error handling") > > Reported-by: kernel test robot <lkp@intel.com> > > Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> > > Link: https://lore.kernel.org/r/9754a0970af1861e7865f9014f735c70dc60bf79.1663071587.git.asml.silence@gmail.com > > Signed-off-by: Jens Axboe <axboe@kernel.dk> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > fs/io_uring.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > --- a/fs/io_uring.c > > +++ b/fs/io_uring.c > > @@ -2701,7 +2701,7 @@ static bool __io_complete_rw_common(stru > > return false; > > } > > -static inline unsigned io_fixup_rw_res(struct io_kiocb *req, unsigned res) > > +static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) > > { > > I think the res should be of type 'long'. > I noticed this when I ran smatch on 5.10.y io_uring backport from 5.15.y > patch. > > Smatch warning: io_fixup_rw_res() warn: unsigned 'res' is never less than > zero. > > static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) > { > struct io_async_rw *io = req->async_data; > > /* add previously done IO, if any */ > if (io && io->bytes_done > 0) { > if (res < 0) //// unsigned comparison with zero. > res = io->bytes_done; > else > res += io->bytes_done; > } > return res; > } > > We don't have upstream commit to backport in this case. Should we fix this > with no-upstream reference commit? Just reference the commit that this fixes properly and that should be fine, thanks for the review and catching this! greg k-h
--- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2701,7 +2701,7 @@ static bool __io_complete_rw_common(stru return false; } -static inline unsigned io_fixup_rw_res(struct io_kiocb *req, unsigned res) +static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res) { struct io_async_rw *io = req->async_data;