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Commit d6d931ad authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by Miklos Szeredi
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fuse: use kvmalloc to allocate array of pipe_buffer structs. 



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: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent a64ba10f

fs/fuse/dev.c

+6 −6
Original line number Diff line number Diff line
@@ -1373,7 +1373,7 @@ 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),

	bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),

			      GFP_KERNEL);

	if (!bufs)

		return -ENOMEM;
@@ -1407,7 +1407,7 @@ 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;

}
@@ -1957,7 +1957,7 @@ static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe, 


	pipe_lock(pipe);



	bufs = kmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),

	bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),

			      GFP_KERNEL);

	if (!bufs) {

		pipe_unlock(pipe);
@@ -2017,7 +2017,7 @@ 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;

}