md/raid1: Fix data corruption for degraded array with slow disk

read_balance() will avoid reading from slow disks as much as possible,
however, if valid data only lands in slow disks, and a new normal disk
is still in recovery, unrecovered data can be read:

raid1_read_request
 read_balance
  raid1_should_read_first
  -> return false
  choose_best_rdev
  -> normal disk is not recovered, return -1
  choose_bb_rdev
  -> missing the checking of recovery, return the normal disk
 -> read unrecovered data

Root cause is that the checking of recovery is missing in
choose_bb_rdev(). Hence add such checking to fix the problem.

Also fix similar problem in choose_slow_rdev().

Cc: [email protected]
Fixes: 9f3ced792203 ("md/raid1: factor out choose_bb_rdev() from read_balance()")
Fixes: dfa8ecd167c1 ("md/raid1: factor out choose_slow_rdev() from read_balance()")
Reported-and-tested-by: Mateusz Jończyk <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Song Liu <[email protected]>

0 files changed, 0 insertions, 0 deletions