2015-05-20 05:14:03

by Ming Lin

[permalink] [raw]
Subject: [PATCH RESEND] bio: switch to iov_iter_{npages,alignment}

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Ming Lin <[email protected]>
---
block/bio.c | 45 +++++++--------------------------------------
1 file changed, 7 insertions(+), 38 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index ae31cdb..e6bd9c2 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1129,29 +1129,14 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
struct bio_map_data *bmd;
struct page *page;
struct bio *bio;
- int i, ret;
+ int uninitialized_var(i), ret;
int nr_pages = 0;
unsigned int len = iter->count;
unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;

- for (i = 0; i < iter->nr_segs; i++) {
- unsigned long uaddr;
- unsigned long end;
- unsigned long start;
-
- uaddr = (unsigned long) iter->iov[i].iov_base;
- end = (uaddr + iter->iov[i].iov_len + PAGE_SIZE - 1)
- >> PAGE_SHIFT;
- start = uaddr >> PAGE_SHIFT;
-
- /*
- * Overflow, abort
- */
- if (end < start)
- return ERR_PTR(-EINVAL);
-
- nr_pages += end - start;
- }
+ nr_pages = iov_iter_npages(iter, INT_MAX);
+ if (!nr_pages)
+ return ERR_PTR(-EINVAL);

if (offset)
nr_pages++;
@@ -1263,26 +1248,10 @@ struct bio *bio_map_user_iov(struct request_queue *q,
struct iov_iter i;
struct iovec iov;

- iov_for_each(iov, i, *iter) {
- unsigned long uaddr = (unsigned long) iov.iov_base;
- unsigned long len = iov.iov_len;
- unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned long start = uaddr >> PAGE_SHIFT;
-
- /*
- * Overflow, abort
- */
- if (end < start)
- return ERR_PTR(-EINVAL);
-
- nr_pages += end - start;
- /*
- * buffer must be aligned to at least hardsector size for now
- */
- if (uaddr & queue_dma_alignment(q))
- return ERR_PTR(-EINVAL);
- }
+ if (iov_iter_alignment(iter) & queue_dma_alignment(q))
+ return ERR_PTR(-EINVAL);

+ nr_pages = iov_iter_npages(iter, INT_MAX);
if (!nr_pages)
return ERR_PTR(-EINVAL);

--
1.9.1