From bd54b6fe3316ec1d469513b888ced31eec20032a Mon Sep 17 00:00:00 2001 From: Bijan Mottahedeh Date: Sun, 25 Apr 2021 14:32:25 +0100 Subject: io_uring: implement fixed buffers registration similar to fixed files Apply fixed_rsrc functionality for fixed buffers support. Signed-off-by: Bijan Mottahedeh [rebase, remove multi-level tables, fix unregister on exit] Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/17035f4f75319dc92962fce4fc04bc0afb5a68dc.1619356238.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 56 insertions(+), 15 deletions(-) (limited to 'fs') diff --git a/fs/io_uring.c b/fs/io_uring.c index 4f427cf53537..0680d241fedc 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -218,6 +218,7 @@ struct io_rsrc_put { union { void *rsrc; struct file *file; + struct io_mapped_ubuf *buf; }; }; @@ -404,6 +405,7 @@ struct io_ring_ctx { unsigned nr_user_files; /* if used, fixed mapped user buffers */ + struct io_rsrc_data *buf_data; unsigned nr_user_bufs; struct io_mapped_ubuf **user_bufs; @@ -5927,7 +5929,7 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", req->opcode); - return-EINVAL; + return -EINVAL; } static int io_req_prep_async(struct io_kiocb *req) @@ -8110,19 +8112,36 @@ static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slo *slot = NULL; } -static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) { - unsigned int i; + /* no updates yet, so not used */ + WARN_ON_ONCE(1); +} - if (!ctx->user_bufs) - return -ENXIO; +static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + unsigned int i; for (i = 0; i < ctx->nr_user_bufs; i++) io_buffer_unmap(ctx, &ctx->user_bufs[i]); kfree(ctx->user_bufs); + kfree(ctx->buf_data); ctx->user_bufs = NULL; + ctx->buf_data = NULL; ctx->nr_user_bufs = 0; - return 0; +} + +static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) +{ + int ret; + + if (!ctx->buf_data) + return -ENXIO; + + ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx); + if (!ret) + __io_sqe_buffers_unregister(ctx); + return ret; } static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, @@ -8342,17 +8361,26 @@ 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) { + struct page *last_hpage = NULL; + struct io_rsrc_data *data; int i, ret; struct iovec iov; - struct page *last_hpage = NULL; if (ctx->user_bufs) return -EBUSY; if (!nr_args || nr_args > UIO_MAXIOV) return -EINVAL; - ret = io_buffers_map_alloc(ctx, nr_args); + ret = io_rsrc_node_switch_start(ctx); if (ret) return ret; + data = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, nr_args); + if (!data) + return -ENOMEM; + ret = io_buffers_map_alloc(ctx, nr_args); + if (ret) { + kfree(data); + return ret; + } for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { ret = io_copy_iov(ctx, &iov, arg, i); @@ -8368,9 +8396,13 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, break; } - if (ret) - io_sqe_buffers_unregister(ctx); + WARN_ON_ONCE(ctx->buf_data); + ctx->buf_data = data; + if (ret) + __io_sqe_buffers_unregister(ctx); + else + io_rsrc_node_switch(ctx, NULL); return ret; } @@ -8445,10 +8477,18 @@ static void io_req_caches_free(struct io_ring_ctx *ctx) mutex_unlock(&ctx->uring_lock); } +static bool io_wait_rsrc_data(struct io_rsrc_data *data) +{ + if (!data) + return false; + if (!atomic_dec_and_test(&data->refs)) + wait_for_completion(&data->done); + return true; +} + static void io_ring_ctx_free(struct io_ring_ctx *ctx) { io_sq_thread_finish(ctx); - io_sqe_buffers_unregister(ctx); if (ctx->mm_account) { mmdrop(ctx->mm_account); @@ -8456,11 +8496,10 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) } mutex_lock(&ctx->uring_lock); - if (ctx->file_data) { - if (!atomic_dec_and_test(&ctx->file_data->refs)) - wait_for_completion(&ctx->file_data->done); + if (io_wait_rsrc_data(ctx->buf_data)) + __io_sqe_buffers_unregister(ctx); + if (io_wait_rsrc_data(ctx->file_data)) __io_sqe_files_unregister(ctx); - } if (ctx->rings) __io_cqring_overflow_flush(ctx, true); mutex_unlock(&ctx->uring_lock); @@ -9825,6 +9864,8 @@ static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, static bool io_register_op_must_quiesce(int op) { switch (op) { + case IORING_REGISTER_BUFFERS: + case IORING_UNREGISTER_BUFFERS: case IORING_REGISTER_FILES: case IORING_UNREGISTER_FILES: case IORING_REGISTER_FILES_UPDATE: -- cgit v1.2.3