Subject: linux-next: build failure after merge of the device-mapper tree

From: Stephen Rothwell <[email-masked]>
Date: Thu, 31 May 2018 14:23:02 +1000

Hi all,

After merging the device-mapper tree, today's linux-next build (x86_64
allmodconfig) failed like this:

drivers/md/dm-writecache.c: In function 'writecache_dtr':
drivers/md/dm-writecache.c:1799:3: error: implicit declaration of function 'bioset_free'; did you mean 'bvec_free'? [-Werror=implicit-function-declaration]
   bioset_free(wc->bio_set);
   ^~~~~~~~~~~
   bvec_free
drivers/md/dm-writecache.c: In function 'writecache_ctr':
drivers/md/dm-writecache.c:1929:17: error: implicit declaration of function 'bioset_create'; did you mean 'bioset_exit'? [-Werror=implicit-function-declaration]
   wc->bio_set = bioset_create(BIO_POOL_SIZE,
                 ^~~~~~~~~~~~~
                 bioset_exit
drivers/md/dm-writecache.c:1929:15: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
   wc->bio_set = bioset_create(BIO_POOL_SIZE,
               ^

Caused by commit

  2105231db61b ("dm: add writecache target")

interacting with commit

  dad08527525f ("block: Drop bioset_create()")

from the block tree.

Can we please consider not immediately dropping APIs if at all
possible. :-(

I have added the following merge fix patch (hopefully this is enough):

From: Stephen Rothwell <[email-masked]>
Date: Thu, 31 May 2018 14:06:10 +1000
Subject: [PATCH] dm: fixup for "block: Drop bioset_create()"

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 drivers/md/dm-writecache.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 844c4fb2fcfc..b95f1f0e199d 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -211,7 +211,7 @@ struct dm_writecache {
 	struct completion flush_completion;
 	struct bio *flush_bio;
 
-	struct bio_set *bio_set;
+	struct bio_set bio_set;
 	mempool_t *copy_pool;
 
 	struct dm_kcopyd_client *dm_kcopyd;
@@ -1494,7 +1494,7 @@ static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeba
 
 		max_pages = e->wc_list_contiguous;
 
-		bio = bio_alloc_bioset(GFP_NOIO, max_pages, wc->bio_set);
+		bio = bio_alloc_bioset(GFP_NOIO, max_pages, &wc->bio_set);
 		wb = container_of(bio, struct writeback_struct, bio);
 		wb->wc = wc;
 		wb->bio.bi_end_io = writecache_writeback_endio;
@@ -1795,8 +1795,7 @@ static void writecache_dtr(struct dm_target *ti)
 	if (wc->flush_thread)
 		kthread_stop(wc->flush_thread);
 
-	if (wc->bio_set)
-		bioset_free(wc->bio_set);
+	bioset_exit(&wc->bio_set);
 
 	mempool_destroy(wc->copy_pool);
 
@@ -1926,11 +1925,10 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv)
 	}
 
 	if (WC_MODE_PMEM(wc)) {
-		wc->bio_set = bioset_create(BIO_POOL_SIZE,
+		r = bioset_init(&wc->bio_set, BIO_POOL_SIZE,
 					    offsetof(struct writeback_struct, bio),
 					    BIOSET_NEED_BVECS);
-		if (!wc->bio_set) {
-			r = -ENOMEM;
+		if (r) {
 			ti->error = "Could not allocate bio set";
 			goto bad;
 		}
-- 
2.17.0

-- 
Cheers,
Stephen Rothwell