io_uring: add full-fledged dynamic buffers support
Hook buffers into all rsrc infrastructure, including tagging and
updates.
Suggested-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/119ed51d68a491dae87eb55fb467a47870c86aad.1619356238.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 {
