David Howells dhowells@redhat.com writes:
If a DIO read or an unbuffered read request extends beyond the EOF, the server will return a short read and a status code indicating that EOF was hit, which gets translated to -ENODATA. Note that the client does not cap the request at i_size, but asks for the amount requested in case there's a race on the server with a third party.
Now, on the client side, the request will get split into multiple subrequests if rsize is smaller than the full request size. A subrequest that starts before or at the EOF and returns short data up to the EOF will be correctly handled, with the NETFS_SREQ_HIT_EOF flag being set, indicating to netfslib that we can't read more.
If a subrequest, however, starts after the EOF and not at it, HIT_EOF will not be flagged, its error will be set to -ENODATA and it will be abandoned. This will cause the request as a whole to fail with -ENODATA.
Fix this by setting NETFS_SREQ_HIT_EOF on any subrequest that lies beyond the EOF marker.
Fixes: 1da29f2c39b6 ("netfs, cifs: Fix handling of short DIO read") Signed-off-by: David Howells dhowells@redhat.com cc: Steve French sfrench@samba.org cc: Paulo Alcantara pc@manguebit.org cc: Shyam Prasad N sprasad@microsoft.com cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Paulo Alcantara (Red Hat) pc@manguebit.org