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| author |   Andreas Gruenbacher <agruenba@redhat.com> | 2021-07-23 01:59:41 +0200 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2021-10-24 15:26:05 +0200 |
| commit | 97308f8b0d867e9ef59528cd97f0db55ffdf5651 (patch) | |
| tree | ddf419571b6bf50ea98c445d822627b24a5fbb0b /fs/iomap/direct-io.c | |
| parent | iomap: Fix iomap_dio_rw return value for user copies (diff) | |
| download | wireguard-linux-97308f8b0d867e9ef59528cd97f0db55ffdf5651.tar.xz wireguard-linux-97308f8b0d867e9ef59528cd97f0db55ffdf5651.zip | |
iomap: Support partial direct I/O on user copy failures
In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the
IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and
return a partial result. This allows the caller to deal with the page
fault and retry the remainder of the request.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/iomap/direct-io.c')
| -rw-r--r-- | fs/iomap/direct-io.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index a2a368e824c0..a434fb7887b2 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -581,6 +581,12 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (iov_iter_rw(iter) == READ && iomi.pos >= dio->i_size) iov_iter_revert(iter, iomi.pos - dio->i_size); + if (ret == -EFAULT && dio->size && (dio_flags & IOMAP_DIO_PARTIAL)) { + if (!(iocb->ki_flags & IOCB_NOWAIT)) + wait_for_completion = true; + ret = 0; + } + /* magic error code to fall back to buffered I/O */ if (ret == -ENOTBLK) { wait_for_completion = true; |