bio: fix bio_copy_kern() handling of bio->bv_len
The commit 68154e90c9
introduced
bio_copy_kern() to add bounce support to blk_rq_map_kern.
bio_copy_kern() uses bio->bv_len to copy data for READ commands after
the completion but it doesn't work with a request that partially
completed. SCSI always completes a PC request as a whole but seems
some don't.
This patch fixes bio_copy_kern to handle the above case. As
bio_copy_user does, bio_copy_kern uses struct bio_map_data to store
struct bio_vec.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reported-by: Nix <nix@esperi.org.uk>
Tested-by: Nix <nix@esperi.org.uk>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
parent
48fd4f93a0
commit
76029ff37f
38
fs/bio.c
38
fs/bio.c
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@ -469,20 +469,21 @@ static void bio_free_map_data(struct bio_map_data *bmd)
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kfree(bmd);
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}
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static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count)
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static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
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gfp_t gfp_mask)
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{
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struct bio_map_data *bmd = kmalloc(sizeof(*bmd), GFP_KERNEL);
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struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask);
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if (!bmd)
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return NULL;
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bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, GFP_KERNEL);
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bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
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if (!bmd->iovecs) {
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kfree(bmd);
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return NULL;
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}
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bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, GFP_KERNEL);
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bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
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if (bmd->sgvecs)
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return bmd;
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@ -596,7 +597,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
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len += iov[i].iov_len;
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}
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bmd = bio_alloc_map_data(nr_pages, iov_count);
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bmd = bio_alloc_map_data(nr_pages, iov_count, GFP_KERNEL);
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if (!bmd)
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return ERR_PTR(-ENOMEM);
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@ -942,19 +943,22 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
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{
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struct bio_vec *bvec;
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const int read = bio_data_dir(bio) == READ;
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char *p = bio->bi_private;
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struct bio_map_data *bmd = bio->bi_private;
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int i;
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char *p = bmd->sgvecs[0].iov_base;
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__bio_for_each_segment(bvec, bio, i, 0) {
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char *addr = page_address(bvec->bv_page);
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int len = bmd->iovecs[i].bv_len;
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if (read && !err)
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memcpy(p, addr, bvec->bv_len);
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memcpy(p, addr, len);
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__free_page(bvec->bv_page);
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p += bvec->bv_len;
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p += len;
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}
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bio_free_map_data(bmd);
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bio_put(bio);
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}
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@ -978,11 +982,21 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
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const int nr_pages = end - start;
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struct bio *bio;
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struct bio_vec *bvec;
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struct bio_map_data *bmd;
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int i, ret;
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struct sg_iovec iov;
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iov.iov_base = data;
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iov.iov_len = len;
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bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
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if (!bmd)
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return ERR_PTR(-ENOMEM);
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ret = -ENOMEM;
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bio = bio_alloc(gfp_mask, nr_pages);
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if (!bio)
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return ERR_PTR(-ENOMEM);
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goto out_bmd;
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while (len) {
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struct page *page;
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@ -1016,14 +1030,18 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
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}
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}
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bio->bi_private = data;
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bio->bi_private = bmd;
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bio->bi_end_io = bio_copy_kern_endio;
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bio_set_map_data(bmd, bio, &iov, 1);
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return bio;
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cleanup:
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bio_for_each_segment(bvec, bio, i)
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__free_page(bvec->bv_page);
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bio_put(bio);
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out_bmd:
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bio_free_map_data(bmd);
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return ERR_PTR(ret);
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}
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