md: raid10: remove VLAIS

commit 584ed9fa9532f8b9d5955628ff87ee3b2ab9f5a9 upstream.

The raid10 driver can't be built with clang since it uses a variable
length array in a structure (VLAIS):

drivers/md/raid10.c:4583:17: error: fields must have a constant size:
  'variable length array in structure' extension will never be supported

Allocate the r10bio struct with kmalloc instead of using the VLAIS
construct.

Shaohua: set the MD_RECOVERY_INTR bit
Neil Brown: use GFP_NOIO

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index e786546..52ddfa0 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4591,15 +4591,18 @@ static int handle_reshape_read_error(struct mddev *mddev,
        /* Use sync reads to get the blocks from somewhere else */
        int sectors = r10_bio->sectors;
        struct r10conf *conf = mddev->private;
-       struct {
-               struct r10bio r10_bio;
-               struct r10dev devs[conf->copies];
-       } on_stack;
-       struct r10bio *r10b = &on_stack.r10_bio;
+       struct r10bio *r10b;
        int slot = 0;
        int idx = 0;
        struct page **pages;
 
+       r10b = kmalloc(sizeof(*r10b) +
+              sizeof(struct r10dev) * conf->copies, GFP_NOIO);
+       if (!r10b) {
+               set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+               return -ENOMEM;
+       }
+
        /* reshape IOs share pages from .devs[0].bio */
        pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
 
@@ -4648,11 +4651,13 @@ static int handle_reshape_read_error(struct mddev *mddev,
                        /* couldn't read this block, must give up */
                        set_bit(MD_RECOVERY_INTR,
                                &mddev->recovery);
+                       kfree(r10b);
                        return -EIO;
                }
                sectors -= s;
                idx++;
        }
+       kfree(r10b);
        return 0;
 }