Merge tag 'io_uring-6.7-2023-11-30' of git://git.kernel.dk/linux

Pull io_uring fixes from Jens Axboe:

 - Fix an issue with discontig page checking for IORING_SETUP_NO_MMAP

 - Fix an issue with not allowing IORING_SETUP_NO_MMAP also disallowing
   mmap'ed buffer rings

 - Fix an issue with deferred release of memory mapped pages

 - Fix a lockdep issue with IORING_SETUP_NO_MMAP

 - Use fget/fput consistently, even from our sync system calls. No real
   issue here, but if we were ever to allow closing io_uring descriptors
   it would be required. Let's play it safe and just use the full ref
   counted versions upfront. Most uses of io_uring are threaded anyway,
   and hence already doing the full version underneath.

* tag 'io_uring-6.7-2023-11-30' of git://git.kernel.dk/linux:
  io_uring: use fget/fput consistently
  io_uring: free io_buffer_list entries via RCU
  io_uring/kbuf: prune deferred locked cache when tearing down
  io_uring/kbuf: recycle freed mapped buffer ring entries
  io_uring/kbuf: defer release of mapped buffer rings
  io_uring: enable io_mem_alloc/free to be used in other parts
  io_uring: don't guard IORING_OFF_PBUF_RING with SETUP_NO_MMAP
  io_uring: don't allow discontig pages for IORING_SETUP_NO_MMAP

1 files changed, 6 insertions, 5 deletions

diff --git a/io_uring/cancel.c b/io_uring/cancel.c
index 3c19cccb1aec..8a8b07dfc444 100644
--- a/io_uring/cancel.c
+++ b/io_uring/cancel.c
@@ -273,7 +273,7 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg)
 	};
 	ktime_t timeout = KTIME_MAX;
 	struct io_uring_sync_cancel_reg sc;
-	struct fd f = { };
+	struct file *file = NULL;
 	DEFINE_WAIT(wait);
 	int ret, i;
 
@@ -295,10 +295,10 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg)
 	/* we can grab a normal file descriptor upfront */
 	if ((cd.flags & IORING_ASYNC_CANCEL_FD) &&
 	   !(cd.flags & IORING_ASYNC_CANCEL_FD_FIXED)) {
-		f = fdget(sc.fd);
-		if (!f.file)
+		file = fget(sc.fd);
+		if (!file)
 			return -EBADF;
-		cd.file = f.file;
+		cd.file = file;
 	}
 
 	ret = __io_sync_cancel(current->io_uring, &cd, sc.fd);
@@ -348,6 +348,7 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg)
 	if (ret == -ENOENT || ret > 0)
 		ret = 0;
 out:
-	fdput(f);
+	if (file)
+		fput(file);
 	return ret;
 }