From 149c69b04a901c8b611b643af8f4dd6b104e7379 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Sat, 30 Apr 2022 12:22:02 -0600
Subject: [PATCH] io_uring: abstract out provided buffer list selection
Git-commit: 149c69b04a901c8b611b643af8f4dd6b104e7379
Patch-mainline: v5.19-rc1
References: bsc#1205205
In preparation for providing another way to select a buffer, move the
existing logic into a helper.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
fs/io_uring.c | 34 +++++++++++++++++++++++-----------
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 26b69ff5c4c3..3d5a4e64d6fe 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3448,29 +3448,41 @@ static int io_buffer_add_list(struct io_ring_ctx *ctx,
return xa_err(xa_store(&ctx->io_bl_xa, bgid, bl, GFP_KERNEL));
}
+static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len,
+ struct io_buffer_list *bl,
+ unsigned int issue_flags)
+{
+ struct io_buffer *kbuf;
+
+ if (list_empty(&bl->buf_list))
+ return ERR_PTR(-ENOBUFS);
+
+ kbuf = list_first_entry(&bl->buf_list, struct io_buffer, list);
+ list_del(&kbuf->list);
+ if (*len > kbuf->len)
+ *len = kbuf->len;
+ req->flags |= REQ_F_BUFFER_SELECTED;
+ req->kbuf = kbuf;
+ io_ring_submit_unlock(req->ctx, issue_flags);
+ return u64_to_user_ptr(kbuf->addr);
+}
+
static void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
unsigned int issue_flags)
{
- struct io_buffer *kbuf = req->kbuf;
struct io_ring_ctx *ctx = req->ctx;
struct io_buffer_list *bl;
io_ring_submit_lock(req->ctx, issue_flags);
bl = io_buffer_get_list(ctx, req->buf_index);
- if (bl && !list_empty(&bl->buf_list)) {
- kbuf = list_first_entry(&bl->buf_list, struct io_buffer, list);
- list_del(&kbuf->list);
- if (*len > kbuf->len)
- *len = kbuf->len;
- req->flags |= REQ_F_BUFFER_SELECTED;
- req->kbuf = kbuf;
+ if (unlikely(!bl)) {
io_ring_submit_unlock(req->ctx, issue_flags);
- return u64_to_user_ptr(kbuf->addr);
+ return ERR_PTR(-ENOBUFS);
}
- io_ring_submit_unlock(req->ctx, issue_flags);
- return ERR_PTR(-ENOBUFS);
+ /* selection helpers drop the submit lock again, if needed */
+ return io_provided_buffer_select(req, len, bl, issue_flags);
}
#ifdef CONFIG_COMPAT
--
2.35.3