do_generic_file_read(): fail immediately if killed

If a fatal signal has been received, fail immediately instead of trying
to read more data.

If wait_on_page_locked_killable() was interrupted then this page is most
likely is not PageUptodate() and in this case do_generic_file_read()
will fail after lock_page_killable().

See also commit ebded02788b5 ("mm: filemap: avoid unnecessary calls to
lock_page when waiting for IO to complete during a read")

[oleg@redhat.com: changelog addition]
Link: http://lkml.kernel.org/r/63068e8e-8bee-b208-8441-a3c39a9d9eb6@sandisk.com
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/filemap.c b/mm/filemap.c
index 68f1813..1b05f75 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1721,7 +1721,9 @@ find_page:
                         * wait_on_page_locked is used to avoid unnecessarily
                         * serialisations and why it's safe.
                         */
-                       wait_on_page_locked_killable(page);
+                       error = wait_on_page_locked_killable(page);
+                       if (unlikely(error))
+                               goto readpage_error;
                        if (PageUptodate(page))
                                goto page_ok;