io_uring: don't inline io_put_kbuf

io_put_kbuf() is huge, don't bloat the kernel with inlining.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2e21ccf0be471ffa654032914b9430813cae53f8.1655371007.git.asml.silence@gmail.com
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 33 insertions, 0 deletions

diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c
index bc58890d932b..b9c7f6e87cc9 100644
--- a/io_uring/kbuf.c
+++ b/io_uring/kbuf.c
@@ -83,6 +83,39 @@ static int io_buffer_add_list(struct io_ring_ctx *ctx,
 	return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL));
 }
 
+unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags)
+{
+	unsigned int cflags;
+
+	/*
+	 * We can add this buffer back to two lists:
+	 *
+	 * 1) The io_buffers_cache list. This one is protected by the
+	 *    ctx->uring_lock. If we already hold this lock, add back to this
+	 *    list as we can grab it from issue as well.
+	 * 2) The io_buffers_comp list. This one is protected by the
+	 *    ctx->completion_lock.
+	 *
+	 * We migrate buffers from the comp_list to the issue cache list
+	 * when we need one.
+	 */
+	if (req->flags & REQ_F_BUFFER_RING) {
+		/* no buffers to recycle for this case */
+		cflags = __io_put_kbuf_list(req, NULL);
+	} else if (issue_flags & IO_URING_F_UNLOCKED) {
+		struct io_ring_ctx *ctx = req->ctx;
+
+		spin_lock(&ctx->completion_lock);
+		cflags = __io_put_kbuf_list(req, &ctx->io_buffers_comp);
+		spin_unlock(&ctx->completion_lock);
+	} else {
+		lockdep_assert_held(&req->ctx->uring_lock);
+
+		cflags = __io_put_kbuf_list(req, &req->ctx->io_buffers_cache);
+	}
+	return cflags;
+}
+
 static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len,
 					      struct io_buffer_list *bl)
 {