md/raid5: rearrange a test in fetch_block6. (5d35e09c) · Commits · 戴 / test

Next patch will unite fetch_block5 and fetch_block6. First I want to make the differences a little more clear. For RAID6 if we are writing at all and there is a failed device, then we need to load or compute every block so we can do a reconstruct-write. This case isn't needed for RAID5 - we will do a read-modify-write in that case. So make that test a separate test in fetch_block6 rather than merged with two other tests. Make a similar change in fetch_block5 so the one bit that is not needed for RAID6 is clearly separate. Signed-off-by:

NeilBrown <neilb@suse.de> Reviewed-by:

Namhyung Kim <namhyung@gmail.com>

drivers/md/raid5.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -2326,9 +2326,8 @@ static int fetch_block5(struct stripe_head sh, struct stripe_head_state s,
		(dev->toread \|\|
		(dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) \|\|
		s->syncing \|\| s->expanding \|\|
		(s->failed &&
		(failed_dev->toread \|\|
		(failed_dev->towrite &&
		(s->failed && failed_dev->toread) \|\|
		(s->failed && failed_dev->towrite &&
		!test_bit(R5_OVERWRITE, &failed_dev->flags)))))) {
		/* We would like to get this block, possibly by computing it,
		* otherwise read it if the backing disk is insync
		@@ -2399,10 +2398,9 @@ static int fetch_block6(struct stripe_head sh, struct stripe_head_state s,
		(dev->toread \|\|
		(dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)) \|\|
		s->syncing \|\| s->expanding \|\|
		(s->failed >= 1 &&
		(fdev[0]->toread \|\| s->to_write)) \|\|
		(s->failed >= 2 &&
		(fdev[1]->toread \|\| s->to_write)))) {
		(s->failed >= 1 && fdev[0]->toread) \|\|
		(s->failed >= 2 && fdev[1]->toread) \|\|
		(s->failed && s->to_write)) {
		/* we would like to get this block, possibly by computing it,
		* otherwise read it if the backing disk is insync
		*/

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