Commit c44bc449 authored Jan 06, 2014 by NeilBrown Committed by Greg Kroah-Hartman Jan 25, 2014

md/raid5: Fix possible confusion when multiple write errors occur.



commit 1cc03eb93245e63b0b7a7832165efdc52e25b4e6 upstream.

commit 5d8c71f9
    md: raid5 crash during degradation

Fixed a crash in an overly simplistic way which could leave
R5_WriteError or R5_MadeGood set in the stripe cache for devices
for which it is no longer relevant.
When those devices are removed and spares added the flags are still
set and can cause incorrect behaviour.

commit 14a75d3e
    md/raid5: preferentially read from replacement device if possible.

Fixed the same bug if a more effective way, so we can now revert
the original commit.

Reported-and-tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Fixes: 5d8c71f9
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ddd618aa

drivers/md/raid5.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -3391,7 +3391,7 @@ static void analyse_stripe(struct stripe_head sh, struct stripe_head_state s)
		*/
		set_bit(R5_Insync, &dev->flags);

		if (rdev && test_bit(R5_WriteError, &dev->flags)) {
		if (test_bit(R5_WriteError, &dev->flags)) {
		/* This flag does not apply to '.replacement'
		* only to .rdev, so make sure to check that*/
		struct md_rdev *rdev2 = rcu_dereference(
		@@ -3404,7 +3404,7 @@ static void analyse_stripe(struct stripe_head sh, struct stripe_head_state s)
		} else
		clear_bit(R5_WriteError, &dev->flags);
		}
		if (rdev && test_bit(R5_MadeGood, &dev->flags)) {
		if (test_bit(R5_MadeGood, &dev->flags)) {
		/* This flag does not apply to '.replacement'
		* only to .rdev, so make sure to check that*/
		struct md_rdev *rdev2 = rcu_dereference(