io_uring: make OP_CLOSE consistent with direct open

From recently open/accept are now able to manipulate fixed file table,
but it's inconsistent that close can't. Close the gap, keep API same as
with open/accept, i.e. via sqe->file_slot.

Signed-off-by: Pavel Begunkov <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 2b3232d53e79d7b8dfc64af31741a11d04ad0a9a..82f867983bb3279a323a2245220e109e9df01928 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -502,6 +502,7 @@ struct io_poll_update {
 struct io_close {
        struct file                     *file;
        int                             fd;
+       u32                             file_slot;
 };
 
 struct io_timeout_data {
@@ -1098,6 +1099,8 @@ static int io_req_prep_async(struct io_kiocb *req);
 
 static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
                                 unsigned int issue_flags, u32 slot_index);
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags);
+
 static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);
 
 static struct kmem_cache *req_cachep;
@@ -4591,12 +4594,16 @@ static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
                return -EINVAL;
        if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
-           sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
+           sqe->rw_flags || sqe->buf_index)
                return -EINVAL;
        if (req->flags & REQ_F_FIXED_FILE)
                return -EBADF;
 
        req->close.fd = READ_ONCE(sqe->fd);
+       req->close.file_slot = READ_ONCE(sqe->file_index);
+       if (req->close.file_slot && req->close.fd)
+               return -EINVAL;
+
        return 0;
 }
 
@@ -4608,6 +4615,11 @@ static int io_close(struct io_kiocb *req, unsigned int issue_flags)
        struct file *file = NULL;
        int ret = -EBADF;
 
+       if (req->close.file_slot) {
+               ret = io_close_fixed(req, issue_flags);
+               goto err;
+       }
+
        spin_lock(&files->file_lock);
        fdt = files_fdtable(files);
        if (close->fd >= fdt->max_fds) {
@@ -8401,6 +8413,44 @@ err:
        return ret;
 }
 
+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
+{
+       unsigned int offset = req->close.file_slot - 1;
+       struct io_ring_ctx *ctx = req->ctx;
+       struct io_fixed_file *file_slot;
+       struct file *file;
+       int ret, i;
+
+       io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+       ret = -ENXIO;
+       if (unlikely(!ctx->file_data))
+               goto out;
+       ret = -EINVAL;
+       if (offset >= ctx->nr_user_files)
+               goto out;
+       ret = io_rsrc_node_switch_start(ctx);
+       if (ret)
+               goto out;
+
+       i = array_index_nospec(offset, ctx->nr_user_files);
+       file_slot = io_fixed_file_slot(&ctx->file_table, i);
+       ret = -EBADF;
+       if (!file_slot->file_ptr)
+               goto out;
+
+       file = (struct file *)(file_slot->file_ptr & FFS_MASK);
+       ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
+       if (ret)
+               goto out;
+
+       file_slot->file_ptr = 0;
+       io_rsrc_node_switch(ctx, ctx->file_data);
+       ret = 0;
+out:
+       io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
+       return ret;
+}
+
 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
                                 struct io_uring_rsrc_update2 *up,
                                 unsigned nr_args)