io_uring: hide rsrc tag copy into generic helpers

Make io_rsrc_data_alloc() taking care of rsrc tags loading on
registration, so we don't need to repeat it for each new rsrc type.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5609680697bd09735de10561b75edb95283459da.1623634181.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 41483ed..6fda9fd 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7161,27 +7161,38 @@ static void io_rsrc_data_free(struct io_rsrc_data *data)
        kfree(data);
 }
 
-static struct io_rsrc_data *io_rsrc_data_alloc(struct io_ring_ctx *ctx,
-                                              rsrc_put_fn *do_put,
-                                              unsigned nr)
+static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put,
+                             u64 __user *utags, unsigned nr,
+                             struct io_rsrc_data **pdata)
 {
        struct io_rsrc_data *data;
+       unsigned i;
 
        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
-               return NULL;
+               return -ENOMEM;
 
        data->tags = kvcalloc(nr, sizeof(*data->tags), GFP_KERNEL);
        if (!data->tags) {
                kfree(data);
-               return NULL;
+               return -ENOMEM;
+       }
+       if (utags) {
+               for (i = 0; i < nr; i++) {
+                       if (copy_from_user(&data->tags[i], &utags[i],
+                                          sizeof(data->tags[i]))) {
+                               io_rsrc_data_free(data);
+                               return -EFAULT;
+                       }
+               }
        }
 
        atomic_set(&data->refs, 1);
        data->ctx = ctx;
        data->do_put = do_put;
        init_completion(&data->done);
-       return data;
+       *pdata = data;
+       return 0;
 }
 
 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
@@ -7633,7 +7644,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
        struct file *file;
        int fd, ret;
        unsigned i;
-       struct io_rsrc_data *file_data;
 
        if (ctx->file_data)
                return -EBUSY;
@@ -7644,27 +7654,24 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
        ret = io_rsrc_node_switch_start(ctx);
        if (ret)
                return ret;
+       ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
+                                &ctx->file_data);
+       if (ret)
+               return ret;
 
-       file_data = io_rsrc_data_alloc(ctx, io_rsrc_file_put, nr_args);
-       if (!file_data)
-               return -ENOMEM;
-       ctx->file_data = file_data;
        ret = -ENOMEM;
        if (!io_alloc_file_tables(&ctx->file_table, nr_args))
                goto out_free;
 
        for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
-               u64 tag = 0;
-
-               if ((tags && copy_from_user(&tag, &tags[i], sizeof(tag))) ||
-                   copy_from_user(&fd, &fds[i], sizeof(fd))) {
+               if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
                        ret = -EFAULT;
                        goto out_fput;
                }
                /* allow sparse sets */
                if (fd == -1) {
                        ret = -EINVAL;
-                       if (unlikely(tag))
+                       if (unlikely(ctx->file_data->tags[i]))
                                goto out_fput;
                        continue;
                }
@@ -7685,7 +7692,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
                        fput(file);
                        goto out_fput;
                }
-               ctx->file_data->tags[i] = tag;
                io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
        }
 
@@ -8403,9 +8409,9 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
        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_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
+       if (ret)
+               return ret;
        ret = io_buffers_map_alloc(ctx, nr_args);
        if (ret) {
                io_rsrc_data_free(data);
@@ -8413,19 +8419,13 @@ 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;
                ret = io_buffer_validate(&iov);
                if (ret)
                        break;
-               if (!iov.iov_base && tag) {
+               if (!iov.iov_base && data->tags[i]) {
                        ret = -EINVAL;
                        break;
                }
@@ -8434,7 +8434,6 @@ 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);