From: Kent Overstreet <kent.overstr...@gmail.com>
Refactor the common part in bio_copy_user_iov() and
__bio_map_user_iov() to separate out iov_count_pages() into the general
iov_iter API, instead of open coding iov iterations as done previously.
This commit should contain only literal replacements, without
functional changes.
Cc: Christoph Hellwig <h...@infradead.org>
Cc: Jens Axboe <ax...@kernel.dk>
Cc: "Hans J. Koch" <h...@hansjkoch.de>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Kent Overstreet <kent.overstr...@gmail.com>
[dpark: add more description in commit message]
[mlin: move iov_count_pages to block/bio.c]
Signed-off-by: Dongsu Park <dongsu.p...@profitbricks.com>
Signed-off-by: Ming Lin <m...@kernel.org>
---
block/bio.c | 70 +++++++++++++++++++++++++++++--------------------------------
1 file changed, 33 insertions(+), 37 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 05c2864..eb4471a 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1139,6 +1139,33 @@ int bio_uncopy_user(struct bio *bio)
}
EXPORT_SYMBOL(bio_uncopy_user);
+static int iov_count_pages(const struct iov_iter *iter, unsigned align)
+{
+ struct iov_iter i = *iter;
+ int nr_pages = 0;
+
+ while (iov_iter_count(&i)) {
+ unsigned long uaddr = (unsigned long) i.iov->iov_base +
+ i.iov_offset;
+ unsigned long len = i.iov->iov_len - i.iov_offset;
+
+ if ((uaddr & align) || (len & align))
+ return -EINVAL;
+
+ /*
+ * Overflow, abort
+ */
+ if (uaddr + len < uaddr)
+ return -EINVAL;
+
+ nr_pages += DIV_ROUND_UP(len + offset_in_page(uaddr),
+ PAGE_SIZE);
+ iov_iter_advance(&i, len);
+ }
+
+ return nr_pages;
+}
+
/**
* bio_copy_user_iov - copy user data to bio
* @q: destination block queue
@@ -1163,24 +1190,9 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
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_count_pages(iter, 0);
+ if (nr_pages < 0)
+ return ERR_PTR(nr_pages);
if (offset)
nr_pages++;
@@ -1292,25 +1304,9 @@ 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);
- }
+ nr_pages = iov_count_pages(iter, queue_dma_alignment(q));
+ if (nr_pages < 0)
+ return ERR_PTR(nr_pages);
if (!nr_pages)
return ERR_PTR(-EINVAL);
--
1.9.1
--
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