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authorChristoph Hellwig <hch@lst.de>2022-04-06 08:12:27 +0200
committerJens Axboe <axboe@kernel.dk>2022-04-17 19:30:41 -0600
commit066ff571011d8416e903d3d4f1f41e0b5eb91e1d (patch)
tree749f3f28b12204c02e223ec27318d5a231eede0f /block/bio.c
parent7655db80932d95f501a0811544d9520ec720e38d (diff)
block: turn bio_kmalloc into a simple kmalloc wrapper
Remove the magic autofree semantics and require the callers to explicitly call bio_init to initialize the bio. This allows bio_free to catch accidental bio_put calls on bio_init()ed bios as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> Acked-by: Mike Snitzer <snitzer@kernel.org> Link: https://lore.kernel.org/r/20220406061228.410163-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c47
1 files changed, 18 insertions, 29 deletions
diff --git a/block/bio.c b/block/bio.c
index 643a3a052c7e..212ccd5b5212 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -224,24 +224,13 @@ EXPORT_SYMBOL(bio_uninit);
static void bio_free(struct bio *bio)
{
struct bio_set *bs = bio->bi_pool;
- void *p;
-
- bio_uninit(bio);
+ void *p = bio;
- if (bs) {
- bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs);
+ WARN_ON_ONCE(!bs);
- /*
- * If we have front padding, adjust the bio pointer before freeing
- */
- p = bio;
- p -= bs->front_pad;
-
- mempool_free(p, &bs->bio_pool);
- } else {
- /* Bio was allocated by bio_kmalloc() */
- kfree(bio);
- }
+ bio_uninit(bio);
+ bvec_free(&bs->bvec_pool, bio->bi_io_vec, bio->bi_max_vecs);
+ mempool_free(p - bs->front_pad, &bs->bio_pool);
}
/*
@@ -568,28 +557,28 @@ err_free:
EXPORT_SYMBOL(bio_alloc_bioset);
/**
- * bio_kmalloc - kmalloc a bio for I/O
+ * bio_kmalloc - kmalloc a bio
+ * @nr_vecs: number of bio_vecs to allocate
* @gfp_mask: the GFP_* mask given to the slab allocator
- * @nr_iovecs: number of iovecs to pre-allocate
*
- * Use kmalloc to allocate and initialize a bio.
+ * Use kmalloc to allocate a bio (including bvecs). The bio must be initialized
+ * using bio_init() before use. To free a bio returned from this function use
+ * kfree() after calling bio_uninit(). A bio returned from this function can
+ * be reused by calling bio_uninit() before calling bio_init() again.
+ *
+ * Note that unlike bio_alloc() or bio_alloc_bioset() allocations from this
+ * function are not backed by a mempool can can fail. Do not use this function
+ * for allocations in the file system I/O path.
*
* Returns: Pointer to new bio on success, NULL on failure.
*/
-struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs)
+struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask)
{
struct bio *bio;
- if (nr_iovecs > UIO_MAXIOV)
+ if (nr_vecs > UIO_MAXIOV)
return NULL;
-
- bio = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask);
- if (unlikely(!bio))
- return NULL;
- bio_init(bio, NULL, nr_iovecs ? bio->bi_inline_vecs : NULL, nr_iovecs,
- 0);
- bio->bi_pool = NULL;
- return bio;
+ return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask);
}
EXPORT_SYMBOL(bio_kmalloc);