[PATCH 1/3] slab, block: generalize bvec_alloc_gfp

[Christoph Hellwig <hch@lst.de>]

bvec_alloc_gfp is useful for any place that tries to kmalloc first and
then fall back to a mempool.  Rename it and move it to blk.h to prepare
for using it to allocate the default integrity buffer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bio.c          | 13 ++-----------
 include/linux/slab.h | 10 ++++++++++
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index b3a79285c278..4ea5833a7637 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -169,16 +169,6 @@ void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs)
 		kmem_cache_free(biovec_slab(nr_vecs)->slab, bv);
 }
 
-/*
- * Make the first allocation restricted and don't dump info on allocation
- * failures, since we'll fall back to the mempool in case of failure.
- */
-static inline gfp_t bvec_alloc_gfp(gfp_t gfp)
-{
-	return (gfp & ~(__GFP_DIRECT_RECLAIM | __GFP_IO)) |
-		__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
-}
-
 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
 		gfp_t gfp_mask)
 {
@@ -201,7 +191,8 @@ struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
 	if (*nr_vecs < BIO_MAX_VECS) {
 		struct bio_vec *bvl;
 
-		bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask));
+		bvl = kmem_cache_alloc(bvs->slab,
+				try_alloc_gfp(gfp_mask & ~__GFP_IO));
 		if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM))
 			return bvl;
 		*nr_vecs = BIO_MAX_VECS;
diff --git a/include/linux/slab.h b/include/linux/slab.h
index d5a8ab98035c..a6672cead03e 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -1113,6 +1113,16 @@ void kfree_rcu_scheduler_running(void);
  */
 size_t kmalloc_size_roundup(size_t size);
 
+/*
+ * Make the first allocation restricted and don't dump info on allocation
+ * failures, for callers that will fall back to a mempool in case of failure.
+ */
+static inline gfp_t try_alloc_gfp(gfp_t gfp)
+{
+	return (gfp & ~__GFP_DIRECT_RECLAIM) |
+		__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
+}
+
 void __init kmem_cache_init_late(void);
 void __init kvfree_rcu_init(void);
 
-- 
2.47.3