diff options
| author | Jens Axboe <axboe@kernel.dk> | 2024-10-29 03:43:13 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-11-03 00:45:30 +0300 |
| commit | b16e920a1909da6799c43000db730d8fcdcae907 (patch) | |
| tree | f7e2dd08aa3ba7502b82a9ee70fe4c27a0d2920f /io_uring | |
| parent | d50f94d761a5d9a34e03a86e512e19d88cbeaf06 (diff) | |
| download | linux-b16e920a1909da6799c43000db730d8fcdcae907.tar.xz | |
io_uring/rsrc: allow cloning at an offset
Right now buffer cloning is an all-or-nothing kind of thing - either the
whole table is cloned from a source to a destination ring, or nothing at
all.
However, it's not always desired to clone the whole thing. Allow for
the application to specify a source and destination offset, and a
number of buffers to clone. If the destination offset is non-zero, then
allocate sparse nodes upfront.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/rsrc.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 7ad91f180566..289866315ecf 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -927,10 +927,11 @@ int io_import_fixed(int ddir, struct iov_iter *iter, return 0; } -static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx) +static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx, + struct io_uring_clone_buffers *arg) { + int i, ret, nbufs, off, nr; struct io_rsrc_data data; - int i, ret, nbufs; /* * Drop our own lock here. We'll setup the data we need and reference @@ -943,11 +944,29 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx nbufs = src_ctx->buf_table.nr; if (!nbufs) goto out_unlock; - ret = io_rsrc_data_alloc(&data, nbufs); + ret = -EINVAL; + if (!arg->nr) + arg->nr = nbufs; + else if (arg->nr > nbufs) + goto out_unlock; + ret = -EOVERFLOW; + if (check_add_overflow(arg->nr, arg->src_off, &off)) + goto out_unlock; + if (off > nbufs) + goto out_unlock; + if (check_add_overflow(arg->nr, arg->dst_off, &off)) + goto out_unlock; + ret = -EINVAL; + if (off > IORING_MAX_REG_BUFFERS) + goto out_unlock; + ret = io_rsrc_data_alloc(&data, off); if (ret) goto out_unlock; - for (i = 0; i < nbufs; i++) { + off = arg->dst_off; + i = arg->src_off; + nr = arg->nr; + while (nr--) { struct io_rsrc_node *dst_node, *src_node; src_node = io_rsrc_node_lookup(&src_ctx->buf_table, i); @@ -963,7 +982,8 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx refcount_inc(&src_node->buf->refs); dst_node->buf = src_node->buf; } - data.nodes[i] = dst_node; + data.nodes[off++] = dst_node; + i++; } /* Have a ref on the bufs now, drop src lock and re-grab our own lock */ @@ -1018,7 +1038,7 @@ int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg) file = io_uring_register_get_file(buf.src_fd, registered_src); if (IS_ERR(file)) return PTR_ERR(file); - ret = io_clone_buffers(ctx, file->private_data); + ret = io_clone_buffers(ctx, file->private_data, &buf); if (!registered_src) fput(file); return ret; |