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From: Ajay Kaher <akaher@vmware.com>
To: <gregkh@linuxfoundation.org>
Cc: <torvalds@linux-foundation.org>, <punit.agrawal@arm.com>,
	<akpm@linux-foundation.org>, <kirill.shutemov@linux.intel.com>,
	<willy@infradead.org>, <will.deacon@arm.com>,
	<mszeredi@redhat.com>, <stable@vger.kernel.org>,
	<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
	<srivatsab@vmware.com>, <srivatsa@csail.mit.edu>,
	<amakhalov@vmware.com>, <srinidhir@vmware.com>,
	<bvikas@vmware.com>, <anishs@vmware.com>,
	<vsirnapalli@vmware.com>, <srostedt@vmware.com>,
	<akaher@vmware.com>, Al Viro <viro@zeniv.linux.org.uk>
Subject: [PATCH v2 7/8] pipe: add pipe_buf_get() helper
Date: Wed, 9 Oct 2019 06:14:22 +0530
Message-ID: <1570581863-12090-8-git-send-email-akaher@vmware.com> (raw)
In-Reply-To: <1570581863-12090-1-git-send-email-akaher@vmware.com>

From: Miklos Szeredi <mszeredi@redhat.com>

commit 7bf2d1df80822ec056363627e2014990f068f7aa upstream.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
---
 fs/fuse/dev.c             |  2 +-
 fs/splice.c               |  4 ++--
 include/linux/pipe_fs_i.h | 11 +++++++++++
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f5d2d23..36a5df9 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -2052,7 +2052,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
 			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
 			pipe->nrbufs--;
 		} else {
-			ibuf->ops->get(pipe, ibuf);
+			pipe_buf_get(pipe, ibuf);
 			*obuf = *ibuf;
 			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
 			obuf->len = rem;
diff --git a/fs/splice.c b/fs/splice.c
index 8398974..fde1263 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1876,7 +1876,7 @@ retry:
 			 * Get a reference to this pipe buffer,
 			 * so we can copy the contents over.
 			 */
-			ibuf->ops->get(ipipe, ibuf);
+			pipe_buf_get(ipipe, ibuf);
 			*obuf = *ibuf;
 
 			/*
@@ -1948,7 +1948,7 @@ static int link_pipe(struct pipe_inode_info *ipipe,
 		 * Get a reference to this pipe buffer,
 		 * so we can copy the contents over.
 		 */
-		ibuf->ops->get(ipipe, ibuf);
+		pipe_buf_get(ipipe, ibuf);
 
 		obuf = opipe->bufs + nbuf;
 		*obuf = *ibuf;
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 24f5470..10876f3 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -115,6 +115,17 @@ struct pipe_buf_operations {
 	void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
 };
 
+/**
+ * pipe_buf_get - get a reference to a pipe_buffer
+ * @pipe:	the pipe that the buffer belongs to
+ * @buf:	the buffer to get a reference to
+ */
+static inline void pipe_buf_get(struct pipe_inode_info *pipe,
+				struct pipe_buffer *buf)
+{
+	buf->ops->get(pipe, buf);
+}
+
 /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
    memory allocation, whereas PIPE_BUF makes atomicity guarantees.  */
 #define PIPE_SIZE		PAGE_SIZE
-- 
2.7.4


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-09  0:44 [PATCH v2 0/8] Backported fixes for 4.4 stable tree Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 1/8] mm: make page ref count overflow check tighter and more explicit Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 2/8] mm: add 'try_get_page()' helper function Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 3/8] mm: handle PTE-mapped tail pages in gerneric fast gup implementaiton Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 4/8] mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 5/8] mm, gup: ensure real head page is ref-counted when using hugepages Ajay Kaher
2019-10-09  0:44 ` [PATCH v2 6/8] mm: prevent get_user_pages() from overflowing page refcount Ajay Kaher
2019-10-09 13:13   ` Vlastimil Babka
2019-10-17 16:28     ` Ajay Kaher
2019-10-25  6:18       ` Ajay Kaher
2019-11-06  8:55         ` Vlastimil Babka
2019-11-11  5:00           ` Ajay Kaher
2019-11-21 20:38             ` gregkh
2019-11-29  9:08               ` Vlastimil Babka
2019-10-09  0:44 ` Ajay Kaher [this message]
2019-10-09  0:44 ` [PATCH v2 8/8] fs: prevent page refcount overflow in pipe_buf_get Ajay Kaher

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