From 634d00df5e1cfc4a707b629a814bd607f726bd52 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sun, 25 Apr 2021 14:32:26 +0100 Subject: [PATCH] io_uring: add full-fledged dynamic buffers support Hook buffers into all rsrc infrastructure, including tagging and updates. Suggested-by: Bijan Mottahedeh Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/119ed51d68a491dae87eb55fb467a47870c86aad.1619356238.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 76 ++++++++++++++++++++++++++++++++++++++++--- include/uapi/linux/io_uring.h | 1 + 2 files changed, 73 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0680d24..0ab09f7 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8114,8 +8114,8 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slo static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) { - /* no updates yet, so not used */ - WARN_ON_ONCE(1); + io_buffer_unmap(ctx, &prsrc->buf); + prsrc->buf = NULL; } static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx) @@ -8359,7 +8359,7 @@ static int io_buffer_validate(struct iovec *iov) } static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, - unsigned int nr_args) + unsigned int nr_args, u64 __user *tags) { struct page *last_hpage = NULL; struct io_rsrc_data *data; @@ -8383,6 +8383,12 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, } for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { + u64 tag = 0; + + if (tags && copy_from_user(&tag, &tags[i], sizeof(tag))) { + ret = -EFAULT; + break; + } ret = io_copy_iov(ctx, &iov, arg, i); if (ret) break; @@ -8394,6 +8400,7 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, &last_hpage); if (ret) break; + data->tags[i] = tag; } WARN_ON_ONCE(ctx->buf_data); @@ -8406,6 +8413,62 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, return ret; } +static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, + struct io_uring_rsrc_update2 *up, + unsigned int nr_args) +{ + u64 __user *tags = u64_to_user_ptr(up->tags); + struct iovec iov, __user *iovs = u64_to_user_ptr(up->data); + struct io_mapped_ubuf *imu; + struct page *last_hpage = NULL; + bool needs_switch = false; + __u32 done; + int i, err; + + if (!ctx->buf_data) + return -ENXIO; + if (up->offset + nr_args > ctx->nr_user_bufs) + return -EINVAL; + + for (done = 0; done < nr_args; done++) { + u64 tag = 0; + + err = io_copy_iov(ctx, &iov, iovs, done); + if (err) + break; + if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) { + err = -EFAULT; + break; + } + + i = array_index_nospec(up->offset + done, ctx->nr_user_bufs); + imu = ctx->user_bufs[i]; + if (imu) { + err = io_queue_rsrc_removal(ctx->buf_data, up->offset + done, + ctx->rsrc_node, imu); + if (err) + break; + ctx->user_bufs[i] = NULL; + needs_switch = true; + } + + if (iov.iov_base || iov.iov_len) { + err = io_buffer_validate(&iov); + if (err) + break; + err = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i], + &last_hpage); + if (err) + break; + ctx->buf_data->tags[up->offset + done] = tag; + } + } + + if (needs_switch) + io_rsrc_node_switch(ctx, ctx->buf_data); + return done ? done : err; +} + static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) { __s32 __user *fds = arg; @@ -9807,6 +9870,8 @@ static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, switch (type) { case IORING_RSRC_FILE: return __io_sqe_files_update(ctx, up, nr_args); + case IORING_RSRC_BUFFER: + return __io_sqe_buffers_update(ctx, up, nr_args); } return -EINVAL; } @@ -9857,6 +9922,9 @@ static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, case IORING_RSRC_FILE: return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data), rr.nr, u64_to_user_ptr(rr.tags)); + case IORING_RSRC_BUFFER: + return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data), + rr.nr, u64_to_user_ptr(rr.tags)); } return -EINVAL; } @@ -9933,7 +10001,7 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, switch (opcode) { case IORING_REGISTER_BUFFERS: - ret = io_sqe_buffers_register(ctx, arg, nr_args); + ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL); break; case IORING_UNREGISTER_BUFFERS: ret = -EINVAL; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 6d8360b..e1ae466 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -314,6 +314,7 @@ struct io_uring_files_update { enum { IORING_RSRC_FILE = 0, + IORING_RSRC_BUFFER = 1, }; struct io_uring_rsrc_register { -- 2.7.4