From: Al Viro <[email protected]>
To: Keith Busch <[email protected]>
Cc: [email protected], [email protected],
[email protected], [email protected],
[email protected], [email protected], Keith Busch <[email protected]>
Subject: Re: [PATCH 4/5] io_uring: add support for dma pre-mapping
Date: Wed, 27 Jul 2022 15:11:05 +0100 [thread overview]
Message-ID: <YuFHeT0UaQsYssin@ZenIV> (raw)
In-Reply-To: <[email protected]>
On Tue, Jul 26, 2022 at 10:38:13AM -0700, Keith Busch wrote:
> + file = fget(map.fd);
> + if (!file)
> + return -EBADF;
> +
> + if (S_ISBLK(file_inode(file)->i_mode))
> + bdev = I_BDEV(file->f_mapping->host);
> + else if (S_ISREG(file_inode(file)->i_mode))
> + bdev = file->f_inode->i_sb->s_bdev;
> + else
> + return -EOPNOTSUPP;
> +
> + for (i = map.buf_start; i < map.buf_end; i++) {
> + struct io_mapped_ubuf *imu = ctx->user_bufs[i];
> + void *tag;
> +
> + if (imu->dma_tag) {
> + ret = -EBUSY;
> + goto err;
> + }
> +
> + tag = block_dma_map(bdev, imu->bvec, imu->nr_bvecs);
> + if (IS_ERR(tag)) {
> + ret = PTR_ERR(tag);
> + goto err;
> + }
> +
> + imu->dma_tag = tag;
> + imu->dma_file = file;
> + imu->bdev = bdev;
> + }
> +
> + fput(file);
This, BTW, is completely insane - what happens if you follow that
with close(map.fd)? A bunch of dangling struct file references?
I really don't understand what you are trying to do here.
next prev parent reply other threads:[~2022-07-27 14:11 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-26 17:38 [PATCH 0/5] dma mapping optimisations Keith Busch
2022-07-26 17:38 ` [PATCH 1/5] blk-mq: add ops to dma map bvec Keith Busch
2022-07-26 17:38 ` [PATCH 2/5] iov_iter: introduce type for preregistered dma tags Keith Busch
2022-07-26 23:10 ` Al Viro
2022-07-27 13:52 ` Keith Busch
2022-07-26 17:38 ` [PATCH 3/5] block: add dma tag bio type Keith Busch
2022-07-26 17:38 ` [PATCH 4/5] io_uring: add support for dma pre-mapping Keith Busch
2022-07-26 23:12 ` Al Viro
2022-07-27 13:58 ` Keith Busch
2022-07-27 14:04 ` Al Viro
2022-07-27 15:04 ` Keith Busch
2022-07-27 22:32 ` Dave Chinner
2022-07-27 23:00 ` Keith Busch
2022-07-28 2:35 ` Dave Chinner
2022-07-28 13:25 ` Keith Busch
2022-07-27 14:11 ` Al Viro [this message]
2022-07-27 14:48 ` Keith Busch
2022-07-27 15:26 ` Al Viro
2022-07-26 17:38 ` [PATCH 5/5] nvme-pci: implement dma_map support Keith Busch
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