From a8da73a32b6e9271a613e5a0e90a8c35f40abeb8 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 9 May 2022 09:29:14 -0600 Subject: io_uring: add flag for allocating a fully sparse direct descriptor space Currently to setup a fully sparse descriptor space upfront, the app needs to alloate an array of the full size and memset it to -1 and then pass that in. Make this a bit easier by allowing a flag that simply does this internally rather than needing to copy each slot separately. This works with IORING_REGISTER_FILES2 as the flag is set in struct io_uring_rsrc_register, and is only allow when the type is IORING_RSRC_FILE as this doesn't make sense for registered buffers. Reviewed-by: Hao Xu Signed-off-by: Jens Axboe --- fs/io_uring.c | 15 ++++++++++++--- include/uapi/linux/io_uring.h | 8 +++++++- 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index b75a49d3831b..362189819898 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -9111,12 +9111,12 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { struct io_fixed_file *file_slot; - if (copy_from_user(&fd, &fds[i], sizeof(fd))) { + if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) { ret = -EFAULT; goto fail; } /* allow sparse sets */ - if (fd == -1) { + if (!fds || fd == -1) { ret = -EINVAL; if (unlikely(*io_get_tag_slot(ctx->file_data, i))) goto fail; @@ -11759,14 +11759,20 @@ static __cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, memset(&rr, 0, sizeof(rr)); if (copy_from_user(&rr, arg, size)) return -EFAULT; - if (!rr.nr || rr.resv || rr.resv2) + if (!rr.nr || rr.resv2) + return -EINVAL; + if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE) return -EINVAL; switch (type) { case IORING_RSRC_FILE: + if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data) + break; return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data), rr.nr, u64_to_user_ptr(rr.tags)); case IORING_RSRC_BUFFER: + if (rr.flags & IORING_RSRC_REGISTER_SPARSE) + break; return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data), rr.nr, u64_to_user_ptr(rr.tags)); } @@ -11935,6 +11941,9 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, ret = io_sqe_buffers_unregister(ctx); break; case IORING_REGISTER_FILES: + ret = -EFAULT; + if (!arg) + break; ret = io_sqe_files_register(ctx, arg, nr_args, NULL); break; case IORING_UNREGISTER_FILES: diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index b7f02a55032a..36ec43dc7bf9 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -396,9 +396,15 @@ struct io_uring_files_update { __aligned_u64 /* __s32 * */ fds; }; +/* + * Register a fully sparse file space, rather than pass in an array of all + * -1 file descriptors. + */ +#define IORING_RSRC_REGISTER_SPARSE (1U << 0) + struct io_uring_rsrc_register { __u32 nr; - __u32 resv; + __u32 flags; __u64 resv2; __aligned_u64 data; __aligned_u64 tags; -- cgit v1.2.3