new helper: iov_iter_npages()
counts the pages covered by iov_iter, up to given limit.
do_block_direct_io() and fuse_iter_npages() switched to
it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 4b410d5..98040ba 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1100,7 +1100,6 @@
get_block_t get_block, dio_iodone_t end_io,
dio_submit_t submit_io, int flags)
{
- int seg;
unsigned i_blkbits = ACCESS_ONCE(inode->i_blkbits);
unsigned blkbits = i_blkbits;
unsigned blocksize_mask = (1 << blkbits) - 1;
@@ -1108,7 +1107,6 @@
loff_t end = offset + iov_iter_count(iter);
struct dio *dio;
struct dio_submit sdio = { 0, };
- unsigned long user_addr;
struct buffer_head map_bh = { 0, };
struct blk_plug plug;
unsigned long align = offset | iov_iter_alignment(iter);
@@ -1231,12 +1229,7 @@
if (unlikely(sdio.blkfactor))
sdio.pages_in_io = 2;
- for (seg = 0; seg < iter->nr_segs; seg++) {
- user_addr = (unsigned long)iter->iov[seg].iov_base;
- sdio.pages_in_io +=
- ((user_addr + iter->iov[seg].iov_len + PAGE_SIZE-1) /
- PAGE_SIZE - user_addr / PAGE_SIZE);
- }
+ sdio.pages_in_io += iov_iter_npages(iter, INT_MAX);
blk_start_plug(&plug);