io_uring: implement fixed buffers registration similar to fixed files
Apply fixed_rsrc functionality for fixed buffers support.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
[rebase, remove multi-level tables, fix unregister on exit]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/17035f4f75319dc92962fce4fc04bc0afb5a68dc.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 4f427cf..0680d24 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)
+{
+ /* no updates yet, so not used */
+ WARN_ON_ONCE(1);
+}
+
+static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
{
unsigned int i;
- if (!ctx->user_bufs)
- return -ENXIO;
-
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:
