md/bitmap: update dirty flag when bitmap bits are explicitly set.

There is a sysfs file which allows bits in the write-intent
bitmap to be explicit set - indicating that the block is thought
to be 'dirty'.
When this happens we should really set recovery_cp backwards
to include the block to reflect this dirtiness.

In particular, a 'resync' process will refuse to start if
recovery_cp is beyond the end of the array, so this is needed
to allow a resync to be triggered.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index de5c42df8d17..26ac8aad0b19 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1566,6 +1566,12 @@ void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
                 sector_t sec = (sector_t)chunk << CHUNK_BLOCK_SHIFT(bitmap);
                 bitmap_set_memory_bits(bitmap, sec, 1);
                 bitmap_file_set_bit(bitmap, sec);
+                if (sec < bitmap->mddev->recovery_cp)
+                        /* We are asserting that the array is dirty,
+                         * so move the recovery_cp address back so
+                         * that it is obvious that it is dirty
+                         */
+                        bitmap->mddev->recovery_cp = sec;
         }
 }