From 72ecad22d9f198aafee64218512e02ffa7818671 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 16 Nov 2016 23:11:42 -0700 Subject: [PATCH] block: support a full bio worth of IO for simplified bdev direct-io Just alloc the bio_vec array if we exceed the inline limit. Signed-off-by: Jens Axboe --- fs/block_dev.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 7c3ec6049073..dad97e19bb1f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -193,7 +193,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, struct file *file = iocb->ki_filp; struct block_device *bdev = I_BDEV(bdev_file_inode(file)); unsigned blkbits = blksize_bits(bdev_logical_block_size(bdev)); - struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *bvec; + struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs, *bvec; loff_t pos = iocb->ki_pos; bool should_dirty = false; struct bio bio; @@ -204,9 +204,17 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, if ((pos | iov_iter_alignment(iter)) & ((1 << blkbits) - 1)) return -EINVAL; + if (nr_pages <= DIO_INLINE_BIO_VECS) + vecs = inline_vecs; + else { + vecs = kmalloc(nr_pages * sizeof(struct bio_vec), GFP_KERNEL); + if (!vecs) + return -ENOMEM; + } + bio_init(&bio); bio.bi_max_vecs = nr_pages; - bio.bi_io_vec = inline_vecs; + bio.bi_io_vec = vecs; bio.bi_bdev = bdev; bio.bi_iter.bi_sector = pos >> blkbits; bio.bi_private = current; @@ -243,6 +251,9 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, put_page(bvec->bv_page); } + if (vecs != inline_vecs) + kfree(vecs); + if (unlikely(bio.bi_error)) return bio.bi_error; iocb->ki_pos += ret; @@ -256,10 +267,10 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) struct inode *inode = bdev_file_inode(file); int nr_pages; - nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); + nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1); if (!nr_pages) return 0; - if (is_sync_kiocb(iocb) && nr_pages <= DIO_INLINE_BIO_VECS) + if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) return __blkdev_direct_IO_simple(iocb, iter, nr_pages); return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter, blkdev_get_block, NULL, NULL, -- 2.20.1