From 76029ff37f31dad64641489c610d98955217bb68 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 25 Aug 2008 20:36:08 +0200 Subject: [PATCH] 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 Reported-by: Nix Tested-by: Nix Cc: stable@kernel.org Signed-off-by: Jens Axboe --- fs/bio.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/fs/bio.c b/fs/bio.c index 8000e2f..8b1f5ee 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); } -- 2.7.4