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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-08-25 20:36:08 +0200
committerJens Axboe <jens.axboe@oracle.com>2008-08-27 09:50:19 +0200
commit76029ff37f31dad64641489c610d98955217bb68 (patch)
treee8f729fa6288676be357295141a0950f171a62d8
parent48fd4f93a00eac844678629f2f00518e146ed30d (diff)
bio: fix bio_copy_kern() handling of bio->bv_len
The commit 68154e90c9d1492d570671ae181d9a8f8530da55 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>
-rw-r--r--fs/bio.c38
1 files changed, 28 insertions, 10 deletions
diff --git a/fs/bio.c b/fs/bio.c
index 8000e2fa16c..8b1f5ee6f83 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -469,20 +469,21 @@ static void bio_free_map_data(struct bio_map_data *bmd)
kfree(bmd);
}
-static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count)
+static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
+ gfp_t gfp_mask)
{
- struct bio_map_data *bmd = kmalloc(sizeof(*bmd), GFP_KERNEL);
+ struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask);
if (!bmd)
return NULL;
- bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, GFP_KERNEL);
+ bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
if (!bmd->iovecs) {
kfree(bmd);
return NULL;
}
- bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, GFP_KERNEL);
+ bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
if (bmd->sgvecs)
return bmd;
@@ -596,7 +597,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
len += iov[i].iov_len;
}
- bmd = bio_alloc_map_data(nr_pages, iov_count);
+ bmd = bio_alloc_map_data(nr_pages, iov_count, GFP_KERNEL);
if (!bmd)
return ERR_PTR(-ENOMEM);
@@ -942,19 +943,22 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
{
struct bio_vec *bvec;
const int read = bio_data_dir(bio) == READ;
- char *p = bio->bi_private;
+ struct bio_map_data *bmd = bio->bi_private;
int i;
+ char *p = bmd->sgvecs[0].iov_base;
__bio_for_each_segment(bvec, bio, i, 0) {
char *addr = page_address(bvec->bv_page);
+ int len = bmd->iovecs[i].bv_len;
if (read && !err)
- memcpy(p, addr, bvec->bv_len);
+ memcpy(p, addr, len);
__free_page(bvec->bv_page);
- p += bvec->bv_len;
+ p += len;
}
+ bio_free_map_data(bmd);
bio_put(bio);
}
@@ -978,11 +982,21 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
const int nr_pages = end - start;
struct bio *bio;
struct bio_vec *bvec;
+ struct bio_map_data *bmd;
int i, ret;
+ struct sg_iovec iov;
+
+ iov.iov_base = data;
+ iov.iov_len = len;
+
+ bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
+ if (!bmd)
+ return ERR_PTR(-ENOMEM);
+ ret = -ENOMEM;
bio = bio_alloc(gfp_mask, nr_pages);
if (!bio)
- return ERR_PTR(-ENOMEM);
+ goto out_bmd;
while (len) {
struct page *page;
@@ -1016,14 +1030,18 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
}
}
- bio->bi_private = data;
+ bio->bi_private = bmd;
bio->bi_end_io = bio_copy_kern_endio;
+
+ bio_set_map_data(bmd, bio, &iov, 1);
return bio;
cleanup:
bio_for_each_segment(bvec, bio, i)
__free_page(bvec->bv_page);
bio_put(bio);
+out_bmd:
+ bio_free_map_data(bmd);
return ERR_PTR(ret);
}