From 1dfa0f68c040080c5fefa7211b4ec34d202f8570 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 18 Jan 2015 16:16:30 +0100 Subject: [PATCH] block: add a helper to free bio bounce buffer pages The code sniplet to walk all bio_vecs and free their pages is opencoded in way to many places, so factor it into a helper. Also convert the slightly more complex cases in bio_kern_endio and __bio_copy_iov where we break the freeing from an existing loop into a separate one. Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Signed-off-by: Jens Axboe --- block/bio.c | 65 +++++++++++++++++++++++++++-------------------------- 1 file changed, 33 insertions(+), 32 deletions(-) diff --git a/block/bio.c b/block/bio.c index 879921e6b049..0895f694f440 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1048,7 +1048,7 @@ static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count, } static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_count, - int to_user, int from_user, int do_free_page) + int to_user, int from_user) { int ret = 0, i; struct bio_vec *bvec; @@ -1090,14 +1090,20 @@ static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_c iov_off = 0; } } - - if (do_free_page) - __free_page(bvec->bv_page); } return ret; } +static void bio_free_pages(struct bio *bio) +{ + struct bio_vec *bvec; + int i; + + bio_for_each_segment_all(bvec, bio, i) + __free_page(bvec->bv_page); +} + /** * bio_uncopy_user - finish previously mapped bio * @bio: bio being terminated @@ -1108,8 +1114,7 @@ static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_c int bio_uncopy_user(struct bio *bio) { struct bio_map_data *bmd = bio->bi_private; - struct bio_vec *bvec; - int ret = 0, i; + int ret = 0; if (!bio_flagged(bio, BIO_NULL_MAPPED)) { /* @@ -1118,11 +1123,9 @@ int bio_uncopy_user(struct bio *bio) */ if (current->mm) ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs, - bio_data_dir(bio) == READ, - 0, bmd->is_our_pages); - else if (bmd->is_our_pages) - bio_for_each_segment_all(bvec, bio, i) - __free_page(bvec->bv_page); + bio_data_dir(bio) == READ, 0); + if (bmd->is_our_pages) + bio_free_pages(bio); } kfree(bmd); bio_put(bio); @@ -1149,7 +1152,6 @@ struct bio *bio_copy_user_iov(struct request_queue *q, int write_to_vm, gfp_t gfp_mask) { struct bio_map_data *bmd; - struct bio_vec *bvec; struct page *page; struct bio *bio; int i, ret; @@ -1238,7 +1240,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, */ if ((!write_to_vm && (!map_data || !map_data->null_mapped)) || (map_data && map_data->from_user)) { - ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0); + ret = __bio_copy_iov(bio, iov, iov_count, 0, 1); if (ret) goto cleanup; } @@ -1247,9 +1249,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, return bio; cleanup: if (!map_data) - bio_for_each_segment_all(bvec, bio, i) - __free_page(bvec->bv_page); - + bio_free_pages(bio); bio_put(bio); out_bmd: kfree(bmd); @@ -1510,22 +1510,22 @@ EXPORT_SYMBOL(bio_map_kern); static void bio_copy_kern_endio(struct bio *bio, int err) { - struct bio_vec *bvec; - const int read = bio_data_dir(bio) == READ; + bio_free_pages(bio); + bio_put(bio); +} + +static void bio_copy_kern_endio_read(struct bio *bio, int err) +{ char *p = bio->bi_private; + struct bio_vec *bvec; int i; bio_for_each_segment_all(bvec, bio, i) { - char *addr = page_address(bvec->bv_page); - - if (read) - memcpy(p, addr, bvec->bv_len); - - __free_page(bvec->bv_page); + memcpy(p, page_address(bvec->bv_page), bvec->bv_len); p += bvec->bv_len; } - bio_put(bio); + bio_copy_kern_endio(bio, err); } /** @@ -1545,10 +1545,9 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, unsigned long kaddr = (unsigned long)data; unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; unsigned long start = kaddr >> PAGE_SHIFT; - struct bio_vec *bvec; struct bio *bio; void *p = data; - int nr_pages = 0, i; + int nr_pages = 0; /* * Overflow, abort @@ -1582,16 +1581,18 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, p += bytes; } - if (!reading) + if (reading) { + bio->bi_end_io = bio_copy_kern_endio_read; + bio->bi_private = data; + } else { + bio->bi_end_io = bio_copy_kern_endio; bio->bi_rw |= REQ_WRITE; + } - bio->bi_private = data; - bio->bi_end_io = bio_copy_kern_endio; return bio; cleanup: - bio_for_each_segment_all(bvec, bio, i) - __free_page(bvec->bv_page); + bio_free_pages(bio); bio_put(bio); return ERR_PTR(-ENOMEM); } -- 2.20.1