[PATCH 4.18 046/168] md/raid5-cache: disable reshape completely

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shaohua Li <shli@xxxxxx>

[ Upstream commit e254de6bcf3f5b6e78a92ac95fb91acef8adfe1a ]

We don't support reshape yet if an array supports log device. Previously we
determine the fact by checking ->log. However, ->log could be NULL after a log
device is removed, but the array is still marked to support log device. Don't
allow reshape in this case too. User can disable log device support by setting
'consistency_policy' to 'resync' then do reshape.

Reported-by: Xiao Ni <xni@xxxxxxxxxx>
Tested-by: Xiao Ni <xni@xxxxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/md/raid5-log.h |    5 +++++
 drivers/md/raid5.c     |    6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/md/raid5-log.h
+++ b/drivers/md/raid5-log.h
@@ -46,6 +46,11 @@ extern int ppl_modify_log(struct r5conf
 extern void ppl_quiesce(struct r5conf *conf, int quiesce);
 extern int ppl_handle_flush_request(struct r5l_log *log, struct bio *bio);
 
+static inline bool raid5_has_log(struct r5conf *conf)
+{
+	return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
+}
+
 static inline bool raid5_has_ppl(struct r5conf *conf)
 {
 	return test_bit(MD_HAS_PPL, &conf->mddev->flags);
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -735,7 +735,7 @@ static bool stripe_can_batch(struct stri
 {
 	struct r5conf *conf = sh->raid_conf;
 
-	if (conf->log || raid5_has_ppl(conf))
+	if (raid5_has_log(conf) || raid5_has_ppl(conf))
 		return false;
 	return test_bit(STRIPE_BATCH_READY, &sh->state) &&
 		!test_bit(STRIPE_BITMAP_PENDING, &sh->state) &&
@@ -7739,7 +7739,7 @@ static int raid5_resize(struct mddev *md
 	sector_t newsize;
 	struct r5conf *conf = mddev->private;
 
-	if (conf->log || raid5_has_ppl(conf))
+	if (raid5_has_log(conf) || raid5_has_ppl(conf))
 		return -EINVAL;
 	sectors &= ~((sector_t)conf->chunk_sectors - 1);
 	newsize = raid5_size(mddev, sectors, mddev->raid_disks);
@@ -7790,7 +7790,7 @@ static int check_reshape(struct mddev *m
 {
 	struct r5conf *conf = mddev->private;
 
-	if (conf->log || raid5_has_ppl(conf))
+	if (raid5_has_log(conf) || raid5_has_ppl(conf))
 		return -EINVAL;
 	if (mddev->delta_disks == 0 &&
 	    mddev->new_layout == mddev->layout &&