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block: Don't save/copy bvec array anymore

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Now that drivers have been converted to the bvec_iter primitives, they
shouldn't be modifying the biovec anymore and thus saving it is
unnecessary - code that was previously making a backup of the bvec array
can now just save bio->bi_iter.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Kent Overstreet 2013-11-22 19:39:06 -08:00
parent 1c3b13e64c
commit c8db444820
1 changed files with 13 additions and 41 deletions
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54
fs/bio.c
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@ -967,60 +967,33 @@ void bio_copy_data(struct bio *dst, struct bio *src)
EXPORT_SYMBOL(bio_copy_data);
struct bio_map_data {
struct bio_vec *iovecs;
struct sg_iovec *sgvecs;
int nr_sgvecs;
int is_our_pages;
struct sg_iovec sgvecs[];
};
static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
struct sg_iovec *iov, int iov_count,
int is_our_pages)
{
memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
bmd->nr_sgvecs = iov_count;
bmd->is_our_pages = is_our_pages;
bio->bi_private = bmd;
}
static void bio_free_map_data(struct bio_map_data *bmd)
{
kfree(bmd->iovecs);
kfree(bmd->sgvecs);
kfree(bmd);
}
static struct bio_map_data *bio_alloc_map_data(int nr_segs,
unsigned int iov_count,
gfp_t gfp_mask)
{
struct bio_map_data *bmd;
if (iov_count > UIO_MAXIOV)
return NULL;
bmd = kmalloc(sizeof(*bmd), gfp_mask);
if (!bmd)
return NULL;
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_mask);
if (bmd->sgvecs)
return bmd;
kfree(bmd->iovecs);
kfree(bmd);
return NULL;
return kmalloc(sizeof(struct bio_map_data) +
sizeof(struct sg_iovec) * iov_count, gfp_mask);
}
static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
struct sg_iovec *iov, int iov_count,
static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count,
int to_user, int from_user, int do_free_page)
{
int ret = 0, i;
@ -1030,7 +1003,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
bio_for_each_segment_all(bvec, bio, i) {
char *bv_addr = page_address(bvec->bv_page);
unsigned int bv_len = iovecs[i].bv_len;
unsigned int bv_len = bvec->bv_len;
while (bv_len && iov_idx < iov_count) {
unsigned int bytes;
@ -1090,14 +1063,14 @@ int bio_uncopy_user(struct bio *bio)
* don't copy into a random user address space, just free.
*/
if (current->mm)
ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
bmd->nr_sgvecs, bio_data_dir(bio) == READ,
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_free_map_data(bmd);
kfree(bmd);
bio_put(bio);
return ret;
}
@ -1211,7 +1184,7 @@ 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, bio->bi_io_vec, iov, iov_count, 0, 1, 0);
ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0);
if (ret)
goto cleanup;
}
@ -1225,7 +1198,7 @@ cleanup:
bio_put(bio);
out_bmd:
bio_free_map_data(bmd);
kfree(bmd);
return ERR_PTR(ret);
}
@ -1542,16 +1515,15 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
bio_for_each_segment_all(bvec, bio, i) {
char *addr = page_address(bvec->bv_page);
int len = bmd->iovecs[i].bv_len;
if (read)
memcpy(p, addr, len);
memcpy(p, addr, bvec->bv_len);
__free_page(bvec->bv_page);
p += len;
p += bvec->bv_len;
}
bio_free_map_data(bmd);
kfree(bmd);
bio_put(bio);
}