From: Christian Brauner <brauner@kernel.org>
Date: Mon, 10 Mar 2025 07:55:13 +0000 (+0100)
Subject: Merge patch series "pipe: Trivial cleanups"
X-Git-Tag: v6.15-rc1~251^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3732d8f16531ddc591622bc64ce4d4c160c34bb4;p=thirdparty%2Flinux.git

Merge patch series "pipe: Trivial cleanups"

K Prateek Nayak <kprateek.nayak@amd.com> says:

Based on the suggestion on the RFC, the treewide conversion of
references to pipe->{head,tail} from unsigned int to pipe_index_t has
been dropped for now. The series contains trivial cleanup suggested to
limit the nr_slots in pipe_resize_ring() to be covered between
pipe_index_t limits of pipe->{head,tail} and using pipe_buf() to remove
the open-coded usage of masks to access pipe buffer building on Linus'
cleanup of fs/fuse/dev.c in commit ebb0f38bb47f ("fs/pipe: fix pipe
buffer index use in FUSE")

* patches from https://lore.kernel.org/r/20250307052919.34542-1-kprateek.nayak@amd.com:
  fs/splice: Use pipe_buf() helper to retrieve pipe buffer
  fs/pipe: Use pipe_buf() helper to retrieve pipe buffer
  kernel/watch_queue: Use pipe_buf() to retrieve the pipe buffer
  fs/pipe: Limit the slots in pipe_resize_ring()

Link: https://lore.kernel.org/r/20250307052919.34542-1-kprateek.nayak@amd.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
---

3732d8f16531ddc591622bc64ce4d4c160c34bb4
diff --cc fs/pipe.c
index 47e96192898d4,4d6ca0f892b1c..da45edd68c416
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@@ -509,29 -501,28 +507,28 @@@ anon_pipe_write(struct kiocb *iocb, str
  
  		head = pipe->head;
  		if (!pipe_full(head, pipe->tail, pipe->max_usage)) {
- 			unsigned int mask = pipe->ring_size - 1;
  			struct pipe_buffer *buf;
 -			struct page *page = pipe->tmp_page;
 +			struct page *page;
  			int copied;
  
 -			if (!page) {
 -				page = alloc_page(GFP_HIGHUSER | __GFP_ACCOUNT);
 -				if (unlikely(!page)) {
 -					ret = ret ? : -ENOMEM;
 -					break;
 -				}
 -				pipe->tmp_page = page;
 +			page = anon_pipe_get_page(pipe);
 +			if (unlikely(!page)) {
 +				if (!ret)
 +					ret = -ENOMEM;
 +				break;
  			}
  
 -			/* Allocate a slot in the ring in advance and attach an
 -			 * empty buffer.  If we fault or otherwise fail to use
 -			 * it, either the reader will consume it or it'll still
 -			 * be there for the next write.
 -			 */
 -			pipe->head = head + 1;
 +			copied = copy_page_from_iter(page, 0, PAGE_SIZE, from);
 +			if (unlikely(copied < PAGE_SIZE && iov_iter_count(from))) {
 +				anon_pipe_put_page(pipe, page);
 +				if (!ret)
 +					ret = -EFAULT;
 +				break;
 +			}
  
 +			pipe->head = head + 1;
  			/* Insert it into the buffer array */
- 			buf = &pipe->bufs[head & mask];
+ 			buf = pipe_buf(pipe, head);
  			buf->page = page;
  			buf->ops = &anon_pipe_buf_ops;
  			buf->offset = 0;