block: cleanup bio_alloc_bioset()
this warning (which got fixed by commit b2bf968):
fs/bio.c: In function ‘bio_alloc_bioset’:
fs/bio.c:305: warning: ‘p’ may be used uninitialized in this function
Triggered because the code flow in bio_alloc_bioset() is correct
but a bit complex for the compiler to see through.
Streamline it a bit - this also makes the code a tiny bit more compact:
text data bss dec hex filename
7540 256 40 7836 1e9c bio.o.before
7539 256 40 7835 1e9b bio.o.after
Also remove an older compiler-warnings annotation from this function,
it's not needed.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/bio.c b/fs/bio.c
index d4f0632..cef6258 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -301,48 +301,51 @@
**/
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
+ struct bio_vec *bvl = NULL;
struct bio *bio = NULL;
- void *uninitialized_var(p);
+ unsigned long idx = 0;
+ void *p = NULL;
if (bs) {
p = mempool_alloc(bs->bio_pool, gfp_mask);
-
- if (p)
- bio = p + bs->front_pad;
- } else
+ if (!p)
+ goto err;
+ bio = p + bs->front_pad;
+ } else {
bio = kmalloc(sizeof(*bio), gfp_mask);
-
- if (likely(bio)) {
- struct bio_vec *bvl = NULL;
-
- bio_init(bio);
- if (likely(nr_iovecs)) {
- unsigned long uninitialized_var(idx);
-
- if (nr_iovecs <= BIO_INLINE_VECS) {
- idx = 0;
- bvl = bio->bi_inline_vecs;
- nr_iovecs = BIO_INLINE_VECS;
- } else {
- bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx,
- bs);
- nr_iovecs = bvec_nr_vecs(idx);
- }
- if (unlikely(!bvl)) {
- if (bs)
- mempool_free(p, bs->bio_pool);
- else
- kfree(bio);
- bio = NULL;
- goto out;
- }
- bio->bi_flags |= idx << BIO_POOL_OFFSET;
- bio->bi_max_vecs = nr_iovecs;
- }
- bio->bi_io_vec = bvl;
+ if (!bio)
+ goto err;
}
-out:
+
+ bio_init(bio);
+
+ if (unlikely(!nr_iovecs))
+ goto out_set;
+
+ if (nr_iovecs <= BIO_INLINE_VECS) {
+ bvl = bio->bi_inline_vecs;
+ nr_iovecs = BIO_INLINE_VECS;
+ } else {
+ bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
+ if (unlikely(!bvl))
+ goto err_free;
+
+ nr_iovecs = bvec_nr_vecs(idx);
+ }
+ bio->bi_flags |= idx << BIO_POOL_OFFSET;
+ bio->bi_max_vecs = nr_iovecs;
+out_set:
+ bio->bi_io_vec = bvl;
+
return bio;
+
+err_free:
+ if (bs)
+ mempool_free(p, bs->bio_pool);
+ else
+ kfree(bio);
+err:
+ return NULL;
}
struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)