md/raid1: don't clear bitmap bits on interrupted recovery.

sync_request_write no longer submits writes to a Faulty device. This has
the unfortunate side effect that bitmap bits can be incorrectly cleared
if a recovery is interrupted (previously, end_sync_write would have
prevented this). This means the next recovery may not copy everything
it should, potentially corrupting data.

Add a function for doing the proper md_bitmap_end_sync, called from
end_sync_write and the Faulty case in sync_request_write.

backport note to 4.14: s/md_bitmap_end_sync/bitmap_end_sync
Cc: stable@vger.kernel.org 4.14+
Fixes: 0c9d5b127f69 ("md/raid1: avoid reusing a resync bio after error handling.")
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Tested-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1d54109..fa47249 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1863,6 +1863,20 @@ static void end_sync_read(struct bio *bio)
                reschedule_retry(r1_bio);
 }
 
+static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
+{
+       sector_t sync_blocks = 0;
+       sector_t s = r1_bio->sector;
+       long sectors_to_go = r1_bio->sectors;
+
+       /* make sure these bits don't get cleared. */
+       do {
+               md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
+               s += sync_blocks;
+               sectors_to_go -= sync_blocks;
+       } while (sectors_to_go > 0);
+}
+
 static void end_sync_write(struct bio *bio)
 {
        int uptodate = !bio->bi_status;
@@ -1874,15 +1888,7 @@ static void end_sync_write(struct bio *bio)
        struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
 
        if (!uptodate) {
-               sector_t sync_blocks = 0;
-               sector_t s = r1_bio->sector;
-               long sectors_to_go = r1_bio->sectors;
-               /* make sure these bits doesn't get cleared. */
-               do {
-                       md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
-                       s += sync_blocks;
-                       sectors_to_go -= sync_blocks;
-               } while (sectors_to_go > 0);
+               abort_sync_write(mddev, r1_bio);
                set_bit(WriteErrorSeen, &rdev->flags);
                if (!test_and_set_bit(WantReplacement, &rdev->flags))
                        set_bit(MD_RECOVERY_NEEDED, &
@@ -2172,8 +2178,10 @@ static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
                     (i == r1_bio->read_disk ||
                      !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
                        continue;
-               if (test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+               if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
+                       abort_sync_write(mddev, r1_bio);
                        continue;
+               }
 
                bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
                if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))