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authorAl Viro <viro@zeniv.linux.org.uk>2014-03-05 13:50:45 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-05-06 17:32:47 -0400
commit886a39115005ced8b15ab067c9c2a8d546b40a5e (patch)
treecb72af0480369f31a449aa7a8451d407315c2bf3 /fs
parent26978b8b4d83c46f4310b253db70fa9e65149e7c (diff)
downloadlinux-886a39115005ced8b15ab067c9c2a8d546b40a5e.tar.bz2
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/direct-io.c27
1 files changed, 5 insertions, 22 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 1c677899b989..adfa1fb33456 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1112,19 +1112,18 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
* 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);