The amount of pipe->buffers is basically controlled by userspace by
fcntl(... F_SETPIPE_SZ ...) so it could be large. High order allocations
could be slow (if memory is heavily fragmented) or may fail if the order
is larger than PAGE_ALLOC_COSTLY_ORDER.

Since the 'bufs' doesn't need to be physically contiguous, use
the kvmalloc_array() to allocate memory. If high order
page isn't available, the kvamalloc*() will fallback to 0-order.

Signed-off-by: Andrey Ryabinin <[email protected]>
---
 fs/fuse/dev.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index c6b88fa85e2e..74900571546d 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1362,8 +1362,8 @@ static ssize_t fuse_dev_splice_read(struct file *in, 
loff_t *ppos,
        if (!fud)
                return -EPERM;
 
-       bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
-                            GFP_KERNEL);
+       bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
+                             GFP_KERNEL);
        if (!bufs)
                return -ENOMEM;
 
@@ -1396,7 +1396,7 @@ static ssize_t fuse_dev_splice_read(struct file *in, 
loff_t *ppos,
        for (; page_nr < cs.nr_segs; page_nr++)
                put_page(bufs[page_nr].page);
 
-       kfree(bufs);
+       kvfree(bufs);
        return ret;
 }
 
@@ -1944,8 +1944,8 @@ static ssize_t fuse_dev_splice_write(struct 
pipe_inode_info *pipe,
        if (!fud)
                return -EPERM;
 
-       bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
-                            GFP_KERNEL);
+       bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
+                             GFP_KERNEL);
        if (!bufs)
                return -ENOMEM;
 
@@ -2003,7 +2003,7 @@ static ssize_t fuse_dev_splice_write(struct 
pipe_inode_info *pipe,
                pipe_buf_release(pipe, &bufs[idx]);
 
 out:
-       kfree(bufs);
+       kvfree(bufs);
        return ret;
 }
 
-- 
2.16.4

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