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authorMike Snitzer <snitzer@kernel.org>2022-03-24 16:35:24 -0400
committerJens Axboe <axboe@kernel.dk>2022-04-17 16:49:40 -0600
commit0df71650c051ab106c921de257f4b38e9e3dd251 (patch)
tree39bed0b9aae98b2357378bbfb077a192d2f4dcbd /block/bio.c
parentb2d229d4ddb17db541098b83524d901257e93845 (diff)
downloadlwn-0df71650c051ab106c921de257f4b38e9e3dd251.tar.gz
lwn-0df71650c051ab106c921de257f4b38e9e3dd251.zip
block: allow using the per-cpu bio cache from bio_alloc_bioset
Replace the BIO_PERCPU_CACHE bio-internal flag with a REQ_ALLOC_CACHE one that can be passed to bio_alloc / bio_alloc_bioset, and implement the percpu cache allocation logic in a helper called from bio_alloc_bioset. This allows any bio_alloc_bioset user to use the percpu caches instead of having the functionality tied to struct kiocb. Signed-off-by: Mike Snitzer <snitzer@kernel.org> [hch: refactored a bit] Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220324203526.62306-2-snitzer@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c86
1 files changed, 41 insertions, 45 deletions
diff --git a/block/bio.c b/block/bio.c
index 4259125e16ab..c67f47c6cc8c 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -419,6 +419,28 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
queue_work(bs->rescue_workqueue, &bs->rescue_work);
}
+static struct bio *bio_alloc_percpu_cache(struct block_device *bdev,
+ unsigned short nr_vecs, unsigned int opf, gfp_t gfp,
+ struct bio_set *bs)
+{
+ struct bio_alloc_cache *cache;
+ struct bio *bio;
+
+ cache = per_cpu_ptr(bs->cache, get_cpu());
+ if (!cache->free_list) {
+ put_cpu();
+ return NULL;
+ }
+ bio = cache->free_list;
+ cache->free_list = bio->bi_next;
+ cache->nr--;
+ put_cpu();
+
+ bio_init(bio, bdev, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs, opf);
+ bio->bi_pool = bs;
+ return bio;
+}
+
/**
* bio_alloc_bioset - allocate a bio for I/O
* @bdev: block device to allocate the bio for (can be %NULL)
@@ -451,6 +473,9 @@ static void punt_bios_to_rescuer(struct bio_set *bs)
* submit_bio_noacct() should be avoided - instead, use bio_set's front_pad
* for per bio allocations.
*
+ * If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done from process
+ * context, not hard/soft IRQ.
+ *
* Returns: Pointer to new bio on success, NULL on failure.
*/
struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
@@ -465,6 +490,21 @@ struct bio *bio_alloc_bioset(struct block_device *bdev, unsigned short nr_vecs,
if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_vecs > 0))
return NULL;
+ if (opf & REQ_ALLOC_CACHE) {
+ if (bs->cache && nr_vecs <= BIO_INLINE_VECS) {
+ bio = bio_alloc_percpu_cache(bdev, nr_vecs, opf,
+ gfp_mask, bs);
+ if (bio)
+ return bio;
+ /*
+ * No cached bio available, bio returned below marked with
+ * REQ_ALLOC_CACHE to particpate in per-cpu alloc cache.
+ */
+ } else {
+ opf &= ~REQ_ALLOC_CACHE;
+ }
+ }
+
/*
* submit_bio_noacct() converts recursion to iteration; this means if
* we're running beneath it, any bios we allocate and submit will not be
@@ -711,7 +751,7 @@ void bio_put(struct bio *bio)
return;
}
- if (bio_flagged(bio, BIO_PERCPU_CACHE)) {
+ if (bio->bi_opf & REQ_ALLOC_CACHE) {
struct bio_alloc_cache *cache;
bio_uninit(bio);
@@ -1732,50 +1772,6 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src)
}
EXPORT_SYMBOL(bioset_init_from_src);
-/**
- * bio_alloc_kiocb - Allocate a bio from bio_set based on kiocb
- * @kiocb: kiocb describing the IO
- * @bdev: block device to allocate the bio for (can be %NULL)
- * @nr_vecs: number of iovecs to pre-allocate
- * @opf: operation and flags for bio
- * @bs: bio_set to allocate from
- *
- * Description:
- * Like @bio_alloc_bioset, but pass in the kiocb. The kiocb is only
- * used to check if we should dip into the per-cpu bio_set allocation
- * cache. The allocation uses GFP_KERNEL internally. On return, the
- * bio is marked BIO_PERCPU_CACHEABLE, and the final put of the bio
- * MUST be done from process context, not hard/soft IRQ.
- *
- */
-struct bio *bio_alloc_kiocb(struct kiocb *kiocb, struct block_device *bdev,
- unsigned short nr_vecs, unsigned int opf, struct bio_set *bs)
-{
- struct bio_alloc_cache *cache;
- struct bio *bio;
-
- if (!(kiocb->ki_flags & IOCB_ALLOC_CACHE) || nr_vecs > BIO_INLINE_VECS)
- return bio_alloc_bioset(bdev, nr_vecs, opf, GFP_KERNEL, bs);
-
- cache = per_cpu_ptr(bs->cache, get_cpu());
- if (cache->free_list) {
- bio = cache->free_list;
- cache->free_list = bio->bi_next;
- cache->nr--;
- put_cpu();
- bio_init(bio, bdev, nr_vecs ? bio->bi_inline_vecs : NULL,
- nr_vecs, opf);
- bio->bi_pool = bs;
- bio_set_flag(bio, BIO_PERCPU_CACHE);
- return bio;
- }
- put_cpu();
- bio = bio_alloc_bioset(bdev, nr_vecs, opf, GFP_KERNEL, bs);
- bio_set_flag(bio, BIO_PERCPU_CACHE);
- return bio;
-}
-EXPORT_SYMBOL_GPL(bio_alloc_kiocb);
-
static int __init init_bio(void)
{
int i;