new primitive: iov_iter_alignment()
returns the value aligned as badly as the worst remaining segment
in iov_iter is. Use instead of open-coded equivalents.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 1c67789..adfa1fb 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1112,19 +1112,18 @@
dio_submit_t submit_io, int flags)
{
int seg;
- size_t size;
- unsigned long addr;
unsigned i_blkbits = ACCESS_ONCE(inode->i_blkbits);
unsigned blkbits = i_blkbits;
unsigned blocksize_mask = (1 << blkbits) - 1;
ssize_t retval = -EINVAL;
- loff_t end = offset;
+ loff_t end = offset + iov_iter_count(iter);
struct dio *dio;
struct dio_submit sdio = { 0, };
unsigned long user_addr;
size_t bytes;
struct buffer_head map_bh = { 0, };
struct blk_plug plug;
+ unsigned long align = offset | iov_iter_alignment(iter);
if (rw & WRITE)
rw = WRITE_ODIRECT;
@@ -1134,32 +1133,16 @@
* the early prefetch in the caller enough time.
*/
- if (offset & blocksize_mask) {
+ if (align & blocksize_mask) {
if (bdev)
blkbits = blksize_bits(bdev_logical_block_size(bdev));
blocksize_mask = (1 << blkbits) - 1;
- if (offset & blocksize_mask)
+ if (align & blocksize_mask)
goto out;
}
- /* Check the memory alignment. Blocks cannot straddle pages */
- for (seg = 0; seg < iter->nr_segs; seg++) {
- addr = (unsigned long)iter->iov[seg].iov_base;
- size = iter->iov[seg].iov_len;
- end += size;
- if (unlikely((addr & blocksize_mask) ||
- (size & blocksize_mask))) {
- if (bdev)
- blkbits = blksize_bits(
- bdev_logical_block_size(bdev));
- blocksize_mask = (1 << blkbits) - 1;
- if ((addr & blocksize_mask) || (size & blocksize_mask))
- goto out;
- }
- }
-
/* watch out for a 0 len io from a tricksy fs */
- if (rw == READ && end == offset)
+ if (rw == READ && !iov_iter_count(iter))
return 0;
dio = kmem_cache_alloc(dio_cache, GFP_KERNEL);