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From: Vlastimil Babka <vbabka@suse.cz>
To: stable@vger.kernel.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Ajay Kaher <akaher@vmware.com>,
	Miklos Szeredi <mszeredi@redhat.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH STABLE 4.4 6/8] pipe: add pipe_buf_get() helper
Date: Fri,  8 Nov 2019 10:38:12 +0100	[thread overview]
Message-ID: <20191108093814.16032-7-vbabka@suse.cz> (raw)
In-Reply-To: <20191108093814.16032-1-vbabka@suse.cz>

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: Vlastimil Babka <vbabka@suse.cz>
---
 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 f5d2d2340b44..36a5df92eb9c 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 8398974e1538..fde126369966 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1876,7 +1876,7 @@ static int splice_pipe_to_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 = *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 24f5470d3944..10876f3cb3da 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
-- 
2.23.0


  parent reply	other threads:[~2019-11-08  9:38 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-08  9:38 [PATCH STABLE 4.4 0/8] page refcount overflow backports Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 1/8] mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 2/8] mm, gup: ensure real head page is ref-counted when using hugepages Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 3/8] mm: make page ref count overflow check tighter and more explicit Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 4/8] mm: add 'try_get_page()' helper function Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 5/8] mm: prevent get_user_pages() from overflowing page refcount Vlastimil Babka
2019-12-03 12:25   ` Ajay Kaher
2019-12-03 12:57     ` Vlastimil Babka
2019-12-06  4:15       ` Ajay Kaher
2019-12-06 14:32         ` Vlastimil Babka
2019-12-09  8:54           ` Ajay Kaher
2019-12-09  9:10             ` Vlastimil Babka
2019-11-08  9:38 ` Vlastimil Babka [this message]
2019-11-08  9:38 ` [PATCH STABLE 4.4 7/8] fs: prevent page refcount overflow in pipe_buf_get Vlastimil Babka
2019-11-08  9:38 ` [PATCH STABLE 4.4 8/8] x86, mm, gup: prevent get_page() race with munmap in paravirt guest Vlastimil Babka

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