From 886a39115005ced8b15ab067c9c2a8d546b40a5e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 5 Mar 2014 13:50:45 -0500 Subject: 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 --- fs/direct-io.c | 27 +++++---------------------- 1 file changed, 5 insertions(+), 22 deletions(-) (limited to 'fs/direct-io.c') 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); -- cgit v1.2.3-59-g8ed1b