md: raid1: check if adding pages to resync bio fails

Check if adding pages to resync bio fails and if bail out.

As the comment above suggests this cannot happen, WARN if it actually
happens. Technically __bio_add_pages() would be sufficient here, but
asserting the pages actually get added to the bio is preferred.

This way we can mark bio_add_pages as __must_check.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/33aea4c271220dc9bcab58c4b7bec478c1511142.1685532726.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
index e61f6cad4e08e9bef57faaecfef4305f1a621200..cd349e69ed7756ff85baf4b6a65f33b98c3588ae 100644 (file)
--- a/drivers/md/raid1-10.c
+++ b/drivers/md/raid1-10.c
@@ -101,11 +101,12 @@ static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
                struct page *page = resync_fetch_page(rp, idx);
                int len = min_t(int, size, PAGE_SIZE);
 
-               /*
-                * won't fail because the vec table is big
-                * enough to hold all these pages
-                */
-               bio_add_page(bio, page, len, 0);
+               if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
+                       bio->bi_status = BLK_STS_RESOURCE;
+                       bio_endio(bio);
+                       return;
+               }
+
                size -= len;
        } while (idx++ < RESYNC_PAGES && size > 0);
 }

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 4fcfcb350d2b43c3ffa5d2f2cb581d7ee47a5321..381c21f7fb06220c44d59fa9b8ca3b34c1fc86ae 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3819,11 +3819,11 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
                for (bio= biolist ; bio ; bio=bio->bi_next) {
                        struct resync_pages *rp = get_resync_pages(bio);
                        page = resync_fetch_page(rp, page_idx);
-                       /*
-                        * won't fail because the vec table is big enough
-                        * to hold all these pages
-                        */
-                       bio_add_page(bio, page, len, 0);
+                       if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
+                               bio->bi_status = BLK_STS_RESOURCE;
+                               bio_endio(bio);
+                               goto giveup;
+                       }
                }
                nr_sectors += len>>9;
                sector_nr += len>>9;
@@ -4997,11 +4997,11 @@ read_more:
                if (len > PAGE_SIZE)
                        len = PAGE_SIZE;
                for (bio = blist; bio ; bio = bio->bi_next) {
-                       /*
-                        * won't fail because the vec table is big enough
-                        * to hold all these pages
-                        */
-                       bio_add_page(bio, page, len, 0);
+                       if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
+                               bio->bi_status = BLK_STS_RESOURCE;
+                               bio_endio(bio);
+                               return sectors_done;
+                       }
                }
                sector_nr += len >> 9;
                nr_sectors += len >> 9;