iomap: Fix iomap_dio_rw return value for user copies

BugLink: https://bugs.launchpad.net/bugs/1976135
commit 42c498c18a94eed79896c50871889af52fa0822e upstream

When a user copy fails in one of the helpers of iomap_dio_rw, fail with
-EFAULT instead of returning 0.  This matches what iomap_dio_bio_actor
returns when it gets an -EFAULT from bio_iov_iter_get_pages.  With these
changes, iomap_dio_actor now consistently fails with -EFAULT when a user
page cannot be faulted in.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 4ecd255e0511ce8204fd6a4fee5ba08fa310c992..a2a368e824c03d6852c2e917eca7c2434c4396d6 100644 (file)
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -371,6 +371,8 @@ static loff_t iomap_dio_hole_iter(const struct iomap_iter *iter,
        loff_t length = iov_iter_zero(iomap_length(iter), dio->submit.iter);
 
        dio->size += length;
+       if (!length)
+               return -EFAULT;
        return length;
 }
 
@@ -402,6 +404,8 @@ static loff_t iomap_dio_inline_iter(const struct iomap_iter *iomi,
                copied = copy_to_iter(inline_data, length, iter);
        }
        dio->size += copied;
+       if (!copied)
+               return -EFAULT;
        return copied;
 }