src/patches/suse-2.6.27.31/patches.fixes/md-raid1-handle-read-error.patch

   1 From: NeilBrown <neilb@suse.de>
   2 Subject: Allow read error in single drive in raid1 to be passed up
   3 Patch-mainline: 2.6.29
   4 References: bnc#447835
   5
   6 If a raid1 only has a single working device and gets a read error,
   7 we choose to simply return that error up to the filesystem (or whatever)
   8 rather than failing the whol array.
   9
  10 However the codes doesn't quite do that.  We attempt a readbalance
  11 which allocated the same drive, so we retry the read - indefinitely.
  12
  13 Instead:  If read_balance in the error case choose the same drive that just
  14 failed, treat it as a failure and don't retry.
  15
  16 Signed-off-by: Neil Brown <neilb@suse.de>
  17
  18 ---
  19  drivers/md/raid1.c |    3 ++-
  20  1 file changed, 2 insertions(+), 1 deletion(-)
  21
  22 --- a/drivers/md/raid1.c
  23 +++ b/drivers/md/raid1.c
  24 @@ -1637,7 +1637,8 @@ static void raid1d(mddev_t *mddev)
  25                         }
  26
  27                         bio = r1_bio->bios[r1_bio->read_disk];
  28 -                       if ((disk=read_balance(conf, r1_bio)) == -1) {
  29 +                       if ((disk=read_balance(conf, r1_bio)) == -1 ||
  30 +                           disk == r1_bio->read_disk) {
  31                                 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
  32                                        " read error for block %llu\n",
  33                                        bdevname(bio->bi_bdev,b),