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Message-Id: <1385513128-5035-20-git-send-email-kmo@daterainc.com>
Date: Tue, 26 Nov 2013 16:45:23 -0800
From: Kent Overstreet <kmo@...erainc.com>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
hch@...radead.org
Cc: Kent Overstreet <kmo@...erainc.com>, Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 20/25] block: Don't save/copy bvec array anymore
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@...erainc.com>
Cc: Jens Axboe <axboe@...nel.dk>
---
fs/bio.c | 54 +++++++++++++-----------------------------------------
1 file changed, 13 insertions(+), 41 deletions(-)
diff --git a/fs/bio.c b/fs/bio.c
index 6e42b68..9cff939 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -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);
}
--
1.8.4.4
--
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