[PATCH 1/3] io_uring: Fix use of XArray in __io_uring_files_cancel

From: Matthew Wilcox (Oracle)
Date: Fri Oct 09 2020 - 08:50:14 EST


We have to drop the lock during each iteration, so there's no advantage
to using the advanced API. Convert this to a standard xa_for_each() loop.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/io_uring.c | 19 +++++--------------
1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 299c530c66f9..2978cc78538a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8665,28 +8665,19 @@ static void io_uring_attempt_task_drop(struct file *file, bool exiting)
void __io_uring_files_cancel(struct files_struct *files)
{
struct io_uring_task *tctx = current->io_uring;
- XA_STATE(xas, &tctx->xa, 0);
+ struct file *file;
+ unsigned long index;

/* make sure overflow events are dropped */
tctx->in_idle = true;

- do {
- struct io_ring_ctx *ctx;
- struct file *file;
-
- xas_lock(&xas);
- file = xas_next_entry(&xas, ULONG_MAX);
- xas_unlock(&xas);
-
- if (!file)
- break;
-
- ctx = file->private_data;
+ xa_for_each(&tctx->xa, index, file) {
+ struct io_ring_ctx *ctx = file->private_data;

io_uring_cancel_task_requests(ctx, files);
if (files)
io_uring_del_task_file(file);
- } while (1);
+ }
}

static inline bool io_uring_task_idle(struct io_uring_task *tctx)
--
2.28.0