[PATCH 5.15 24/33] iomap: Fix iomap_dio_rw return value for user copies

Greg Kroah-Hartman
2022-04-29T10:45:45Z

From: Andreas Gruenbacher <agruenba@redhat.com>

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>
---
fs/iomap/direct-io.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -371,6 +371,8 @@ static loff_t iomap_dio_hole_iter(const
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(cons
copied = copy_to_iter(inline_data, length, iter);
}
dio->size += copied;
+ if (!copied)
+ return -EFAULT;
return copied;
}