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799 lines
20 KiB
799 lines
20 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* The Virtio 9p transport driver |
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* |
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* This is a block based transport driver based on the lguest block driver |
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* code. |
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* |
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* Copyright (C) 2007, 2008 Eric Van Hensbergen, IBM Corporation |
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* |
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* Based on virtio console driver |
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* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation |
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*/ |
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|
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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|
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#include <linux/in.h> |
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#include <linux/module.h> |
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#include <linux/net.h> |
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#include <linux/ipv6.h> |
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#include <linux/errno.h> |
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#include <linux/kernel.h> |
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#include <linux/un.h> |
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#include <linux/uaccess.h> |
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#include <linux/inet.h> |
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#include <linux/idr.h> |
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#include <linux/file.h> |
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#include <linux/highmem.h> |
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#include <linux/slab.h> |
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#include <net/9p/9p.h> |
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#include <linux/parser.h> |
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#include <net/9p/client.h> |
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#include <net/9p/transport.h> |
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#include <linux/scatterlist.h> |
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#include <linux/swap.h> |
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#include <linux/virtio.h> |
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#include <linux/virtio_9p.h> |
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#include "trans_common.h" |
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|
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#define VIRTQUEUE_NUM 128 |
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|
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/* a single mutex to manage channel initialization and attachment */ |
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static DEFINE_MUTEX(virtio_9p_lock); |
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static DECLARE_WAIT_QUEUE_HEAD(vp_wq); |
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static atomic_t vp_pinned = ATOMIC_INIT(0); |
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|
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/** |
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* struct virtio_chan - per-instance transport information |
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* @inuse: whether the channel is in use |
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* @lock: protects multiple elements within this structure |
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* @client: client instance |
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* @vdev: virtio dev associated with this channel |
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* @vq: virtio queue associated with this channel |
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* @ring_bufs_avail: flag to indicate there is some available in the ring buf |
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* @vc_wq: wait queue for waiting for thing to be added to ring buf |
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* @p9_max_pages: maximum number of pinned pages |
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* @sg: scatter gather list which is used to pack a request (protected?) |
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* @chan_list: linked list of channels |
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* |
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* We keep all per-channel information in a structure. |
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* This structure is allocated within the devices dev->mem space. |
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* A pointer to the structure will get put in the transport private. |
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* |
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*/ |
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|
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struct virtio_chan { |
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bool inuse; |
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|
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spinlock_t lock; |
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|
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struct p9_client *client; |
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struct virtio_device *vdev; |
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struct virtqueue *vq; |
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int ring_bufs_avail; |
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wait_queue_head_t *vc_wq; |
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/* This is global limit. Since we don't have a global structure, |
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* will be placing it in each channel. |
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*/ |
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unsigned long p9_max_pages; |
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/* Scatterlist: can be too big for stack. */ |
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struct scatterlist sg[VIRTQUEUE_NUM]; |
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/** |
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* @tag: name to identify a mount null terminated |
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*/ |
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char *tag; |
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|
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struct list_head chan_list; |
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}; |
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|
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static struct list_head virtio_chan_list; |
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|
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/* How many bytes left in this page. */ |
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static unsigned int rest_of_page(void *data) |
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{ |
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return PAGE_SIZE - offset_in_page(data); |
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} |
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|
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/** |
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* p9_virtio_close - reclaim resources of a channel |
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* @client: client instance |
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* |
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* This reclaims a channel by freeing its resources and |
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* resetting its inuse flag. |
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* |
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*/ |
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static void p9_virtio_close(struct p9_client *client) |
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{ |
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struct virtio_chan *chan = client->trans; |
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|
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mutex_lock(&virtio_9p_lock); |
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if (chan) |
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chan->inuse = false; |
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mutex_unlock(&virtio_9p_lock); |
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} |
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|
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/** |
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* req_done - callback which signals activity from the server |
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* @vq: virtio queue activity was received on |
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* |
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* This notifies us that the server has triggered some activity |
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* on the virtio channel - most likely a response to request we |
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* sent. Figure out which requests now have responses and wake up |
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* those threads. |
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* |
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* Bugs: could do with some additional sanity checking, but appears to work. |
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* |
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*/ |
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|
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static void req_done(struct virtqueue *vq) |
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{ |
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struct virtio_chan *chan = vq->vdev->priv; |
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unsigned int len; |
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struct p9_req_t *req; |
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bool need_wakeup = false; |
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unsigned long flags; |
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|
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p9_debug(P9_DEBUG_TRANS, ": request done\n"); |
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|
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spin_lock_irqsave(&chan->lock, flags); |
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while ((req = virtqueue_get_buf(chan->vq, &len)) != NULL) { |
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if (!chan->ring_bufs_avail) { |
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chan->ring_bufs_avail = 1; |
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need_wakeup = true; |
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} |
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|
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if (len) { |
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req->rc.size = len; |
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p9_client_cb(chan->client, req, REQ_STATUS_RCVD); |
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} |
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} |
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spin_unlock_irqrestore(&chan->lock, flags); |
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/* Wakeup if anyone waiting for VirtIO ring space. */ |
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if (need_wakeup) |
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wake_up(chan->vc_wq); |
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} |
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|
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/** |
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* pack_sg_list - pack a scatter gather list from a linear buffer |
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* @sg: scatter/gather list to pack into |
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* @start: which segment of the sg_list to start at |
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* @limit: maximum segment to pack data to |
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* @data: data to pack into scatter/gather list |
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* @count: amount of data to pack into the scatter/gather list |
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* |
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* sg_lists have multiple segments of various sizes. This will pack |
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* arbitrary data into an existing scatter gather list, segmenting the |
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* data as necessary within constraints. |
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* |
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*/ |
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|
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static int pack_sg_list(struct scatterlist *sg, int start, |
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int limit, char *data, int count) |
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{ |
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int s; |
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int index = start; |
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|
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while (count) { |
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s = rest_of_page(data); |
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if (s > count) |
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s = count; |
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BUG_ON(index >= limit); |
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/* Make sure we don't terminate early. */ |
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sg_unmark_end(&sg[index]); |
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sg_set_buf(&sg[index++], data, s); |
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count -= s; |
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data += s; |
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} |
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if (index-start) |
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sg_mark_end(&sg[index - 1]); |
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return index-start; |
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} |
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|
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/* We don't currently allow canceling of virtio requests */ |
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static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) |
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{ |
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return 1; |
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} |
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|
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/* Reply won't come, so drop req ref */ |
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static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req) |
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{ |
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p9_req_put(req); |
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return 0; |
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} |
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|
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/** |
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* pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer, |
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* this takes a list of pages. |
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* @sg: scatter/gather list to pack into |
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* @start: which segment of the sg_list to start at |
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* @limit: maximum number of pages in sg list. |
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* @pdata: a list of pages to add into sg. |
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* @nr_pages: number of pages to pack into the scatter/gather list |
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* @offs: amount of data in the beginning of first page _not_ to pack |
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* @count: amount of data to pack into the scatter/gather list |
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*/ |
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static int |
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pack_sg_list_p(struct scatterlist *sg, int start, int limit, |
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struct page **pdata, int nr_pages, size_t offs, int count) |
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{ |
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int i = 0, s; |
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int data_off = offs; |
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int index = start; |
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|
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BUG_ON(nr_pages > (limit - start)); |
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/* |
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* if the first page doesn't start at |
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* page boundary find the offset |
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*/ |
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while (nr_pages) { |
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s = PAGE_SIZE - data_off; |
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if (s > count) |
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s = count; |
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BUG_ON(index >= limit); |
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/* Make sure we don't terminate early. */ |
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sg_unmark_end(&sg[index]); |
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sg_set_page(&sg[index++], pdata[i++], s, data_off); |
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data_off = 0; |
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count -= s; |
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nr_pages--; |
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} |
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|
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if (index-start) |
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sg_mark_end(&sg[index - 1]); |
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return index - start; |
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} |
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|
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/** |
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* p9_virtio_request - issue a request |
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* @client: client instance issuing the request |
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* @req: request to be issued |
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* |
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*/ |
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|
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static int |
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p9_virtio_request(struct p9_client *client, struct p9_req_t *req) |
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{ |
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int err; |
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int in, out, out_sgs, in_sgs; |
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unsigned long flags; |
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struct virtio_chan *chan = client->trans; |
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struct scatterlist *sgs[2]; |
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p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n"); |
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req->status = REQ_STATUS_SENT; |
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req_retry: |
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spin_lock_irqsave(&chan->lock, flags); |
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out_sgs = in_sgs = 0; |
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/* Handle out VirtIO ring buffers */ |
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out = pack_sg_list(chan->sg, 0, |
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VIRTQUEUE_NUM, req->tc.sdata, req->tc.size); |
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if (out) |
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sgs[out_sgs++] = chan->sg; |
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|
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in = pack_sg_list(chan->sg, out, |
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VIRTQUEUE_NUM, req->rc.sdata, req->rc.capacity); |
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if (in) |
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sgs[out_sgs + in_sgs++] = chan->sg + out; |
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|
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err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req, |
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GFP_ATOMIC); |
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if (err < 0) { |
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if (err == -ENOSPC) { |
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chan->ring_bufs_avail = 0; |
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spin_unlock_irqrestore(&chan->lock, flags); |
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err = wait_event_killable(*chan->vc_wq, |
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chan->ring_bufs_avail); |
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if (err == -ERESTARTSYS) |
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return err; |
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|
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p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n"); |
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goto req_retry; |
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} else { |
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spin_unlock_irqrestore(&chan->lock, flags); |
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p9_debug(P9_DEBUG_TRANS, |
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"virtio rpc add_sgs returned failure\n"); |
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return -EIO; |
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} |
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} |
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virtqueue_kick(chan->vq); |
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spin_unlock_irqrestore(&chan->lock, flags); |
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p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); |
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return 0; |
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} |
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static int p9_get_mapped_pages(struct virtio_chan *chan, |
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struct page ***pages, |
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struct iov_iter *data, |
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int count, |
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size_t *offs, |
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int *need_drop) |
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{ |
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int nr_pages; |
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int err; |
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|
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if (!iov_iter_count(data)) |
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return 0; |
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|
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if (!iov_iter_is_kvec(data)) { |
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int n; |
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/* |
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* We allow only p9_max_pages pinned. We wait for the |
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* Other zc request to finish here |
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*/ |
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if (atomic_read(&vp_pinned) >= chan->p9_max_pages) { |
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err = wait_event_killable(vp_wq, |
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(atomic_read(&vp_pinned) < chan->p9_max_pages)); |
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if (err == -ERESTARTSYS) |
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return err; |
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} |
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n = iov_iter_get_pages_alloc(data, pages, count, offs); |
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if (n < 0) |
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return n; |
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*need_drop = 1; |
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nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE); |
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atomic_add(nr_pages, &vp_pinned); |
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return n; |
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} else { |
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/* kernel buffer, no need to pin pages */ |
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int index; |
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size_t len; |
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void *p; |
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|
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/* we'd already checked that it's non-empty */ |
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while (1) { |
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len = iov_iter_single_seg_count(data); |
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if (likely(len)) { |
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p = data->kvec->iov_base + data->iov_offset; |
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break; |
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} |
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iov_iter_advance(data, 0); |
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} |
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if (len > count) |
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len = count; |
|
|
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nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) - |
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(unsigned long)p / PAGE_SIZE; |
|
|
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*pages = kmalloc_array(nr_pages, sizeof(struct page *), |
|
GFP_NOFS); |
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if (!*pages) |
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return -ENOMEM; |
|
|
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*need_drop = 0; |
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p -= (*offs = offset_in_page(p)); |
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for (index = 0; index < nr_pages; index++) { |
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if (is_vmalloc_addr(p)) |
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(*pages)[index] = vmalloc_to_page(p); |
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else |
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(*pages)[index] = kmap_to_page(p); |
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p += PAGE_SIZE; |
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} |
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return len; |
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} |
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} |
|
|
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/** |
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* p9_virtio_zc_request - issue a zero copy request |
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* @client: client instance issuing the request |
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* @req: request to be issued |
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* @uidata: user buffer that should be used for zero copy read |
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* @uodata: user buffer that should be used for zero copy write |
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* @inlen: read buffer size |
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* @outlen: write buffer size |
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* @in_hdr_len: reader header size, This is the size of response protocol data |
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* |
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*/ |
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static int |
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p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req, |
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struct iov_iter *uidata, struct iov_iter *uodata, |
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int inlen, int outlen, int in_hdr_len) |
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{ |
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int in, out, err, out_sgs, in_sgs; |
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unsigned long flags; |
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int in_nr_pages = 0, out_nr_pages = 0; |
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struct page **in_pages = NULL, **out_pages = NULL; |
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struct virtio_chan *chan = client->trans; |
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struct scatterlist *sgs[4]; |
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size_t offs; |
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int need_drop = 0; |
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int kicked = 0; |
|
|
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p9_debug(P9_DEBUG_TRANS, "virtio request\n"); |
|
|
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if (uodata) { |
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__le32 sz; |
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int n = p9_get_mapped_pages(chan, &out_pages, uodata, |
|
outlen, &offs, &need_drop); |
|
if (n < 0) { |
|
err = n; |
|
goto err_out; |
|
} |
|
out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE); |
|
if (n != outlen) { |
|
__le32 v = cpu_to_le32(n); |
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memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4); |
|
outlen = n; |
|
} |
|
/* The size field of the message must include the length of the |
|
* header and the length of the data. We didn't actually know |
|
* the length of the data until this point so add it in now. |
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*/ |
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sz = cpu_to_le32(req->tc.size + outlen); |
|
memcpy(&req->tc.sdata[0], &sz, sizeof(sz)); |
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} else if (uidata) { |
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int n = p9_get_mapped_pages(chan, &in_pages, uidata, |
|
inlen, &offs, &need_drop); |
|
if (n < 0) { |
|
err = n; |
|
goto err_out; |
|
} |
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in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE); |
|
if (n != inlen) { |
|
__le32 v = cpu_to_le32(n); |
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memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4); |
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inlen = n; |
|
} |
|
} |
|
req->status = REQ_STATUS_SENT; |
|
req_retry_pinned: |
|
spin_lock_irqsave(&chan->lock, flags); |
|
|
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out_sgs = in_sgs = 0; |
|
|
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/* out data */ |
|
out = pack_sg_list(chan->sg, 0, |
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VIRTQUEUE_NUM, req->tc.sdata, req->tc.size); |
|
|
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if (out) |
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sgs[out_sgs++] = chan->sg; |
|
|
|
if (out_pages) { |
|
sgs[out_sgs++] = chan->sg + out; |
|
out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM, |
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out_pages, out_nr_pages, offs, outlen); |
|
} |
|
|
|
/* |
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* Take care of in data |
|
* For example TREAD have 11. |
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* 11 is the read/write header = PDU Header(7) + IO Size (4). |
|
* Arrange in such a way that server places header in the |
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* allocated memory and payload onto the user buffer. |
|
*/ |
|
in = pack_sg_list(chan->sg, out, |
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VIRTQUEUE_NUM, req->rc.sdata, in_hdr_len); |
|
if (in) |
|
sgs[out_sgs + in_sgs++] = chan->sg + out; |
|
|
|
if (in_pages) { |
|
sgs[out_sgs + in_sgs++] = chan->sg + out + in; |
|
in += pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM, |
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in_pages, in_nr_pages, offs, inlen); |
|
} |
|
|
|
BUG_ON(out_sgs + in_sgs > ARRAY_SIZE(sgs)); |
|
err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req, |
|
GFP_ATOMIC); |
|
if (err < 0) { |
|
if (err == -ENOSPC) { |
|
chan->ring_bufs_avail = 0; |
|
spin_unlock_irqrestore(&chan->lock, flags); |
|
err = wait_event_killable(*chan->vc_wq, |
|
chan->ring_bufs_avail); |
|
if (err == -ERESTARTSYS) |
|
goto err_out; |
|
|
|
p9_debug(P9_DEBUG_TRANS, "Retry virtio request\n"); |
|
goto req_retry_pinned; |
|
} else { |
|
spin_unlock_irqrestore(&chan->lock, flags); |
|
p9_debug(P9_DEBUG_TRANS, |
|
"virtio rpc add_sgs returned failure\n"); |
|
err = -EIO; |
|
goto err_out; |
|
} |
|
} |
|
virtqueue_kick(chan->vq); |
|
spin_unlock_irqrestore(&chan->lock, flags); |
|
kicked = 1; |
|
p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); |
|
err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD); |
|
/* |
|
* Non kernel buffers are pinned, unpin them |
|
*/ |
|
err_out: |
|
if (need_drop) { |
|
if (in_pages) { |
|
p9_release_pages(in_pages, in_nr_pages); |
|
atomic_sub(in_nr_pages, &vp_pinned); |
|
} |
|
if (out_pages) { |
|
p9_release_pages(out_pages, out_nr_pages); |
|
atomic_sub(out_nr_pages, &vp_pinned); |
|
} |
|
/* wakeup anybody waiting for slots to pin pages */ |
|
wake_up(&vp_wq); |
|
} |
|
kvfree(in_pages); |
|
kvfree(out_pages); |
|
if (!kicked) { |
|
/* reply won't come */ |
|
p9_req_put(req); |
|
} |
|
return err; |
|
} |
|
|
|
static ssize_t p9_mount_tag_show(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct virtio_chan *chan; |
|
struct virtio_device *vdev; |
|
int tag_len; |
|
|
|
vdev = dev_to_virtio(dev); |
|
chan = vdev->priv; |
|
tag_len = strlen(chan->tag); |
|
|
|
memcpy(buf, chan->tag, tag_len + 1); |
|
|
|
return tag_len + 1; |
|
} |
|
|
|
static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL); |
|
|
|
/** |
|
* p9_virtio_probe - probe for existence of 9P virtio channels |
|
* @vdev: virtio device to probe |
|
* |
|
* This probes for existing virtio channels. |
|
* |
|
*/ |
|
|
|
static int p9_virtio_probe(struct virtio_device *vdev) |
|
{ |
|
__u16 tag_len; |
|
char *tag; |
|
int err; |
|
struct virtio_chan *chan; |
|
|
|
if (!vdev->config->get) { |
|
dev_err(&vdev->dev, "%s failure: config access disabled\n", |
|
__func__); |
|
return -EINVAL; |
|
} |
|
|
|
chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL); |
|
if (!chan) { |
|
pr_err("Failed to allocate virtio 9P channel\n"); |
|
err = -ENOMEM; |
|
goto fail; |
|
} |
|
|
|
chan->vdev = vdev; |
|
|
|
/* We expect one virtqueue, for requests. */ |
|
chan->vq = virtio_find_single_vq(vdev, req_done, "requests"); |
|
if (IS_ERR(chan->vq)) { |
|
err = PTR_ERR(chan->vq); |
|
goto out_free_chan; |
|
} |
|
chan->vq->vdev->priv = chan; |
|
spin_lock_init(&chan->lock); |
|
|
|
sg_init_table(chan->sg, VIRTQUEUE_NUM); |
|
|
|
chan->inuse = false; |
|
if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) { |
|
virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len); |
|
} else { |
|
err = -EINVAL; |
|
goto out_free_vq; |
|
} |
|
tag = kzalloc(tag_len + 1, GFP_KERNEL); |
|
if (!tag) { |
|
err = -ENOMEM; |
|
goto out_free_vq; |
|
} |
|
|
|
virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag), |
|
tag, tag_len); |
|
chan->tag = tag; |
|
err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); |
|
if (err) { |
|
goto out_free_tag; |
|
} |
|
chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL); |
|
if (!chan->vc_wq) { |
|
err = -ENOMEM; |
|
goto out_free_tag; |
|
} |
|
init_waitqueue_head(chan->vc_wq); |
|
chan->ring_bufs_avail = 1; |
|
/* Ceiling limit to avoid denial of service attacks */ |
|
chan->p9_max_pages = nr_free_buffer_pages()/4; |
|
|
|
virtio_device_ready(vdev); |
|
|
|
mutex_lock(&virtio_9p_lock); |
|
list_add_tail(&chan->chan_list, &virtio_chan_list); |
|
mutex_unlock(&virtio_9p_lock); |
|
|
|
/* Let udev rules use the new mount_tag attribute. */ |
|
kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); |
|
|
|
return 0; |
|
|
|
out_free_tag: |
|
kfree(tag); |
|
out_free_vq: |
|
vdev->config->del_vqs(vdev); |
|
out_free_chan: |
|
kfree(chan); |
|
fail: |
|
return err; |
|
} |
|
|
|
|
|
/** |
|
* p9_virtio_create - allocate a new virtio channel |
|
* @client: client instance invoking this transport |
|
* @devname: string identifying the channel to connect to (unused) |
|
* @args: args passed from sys_mount() for per-transport options (unused) |
|
* |
|
* This sets up a transport channel for 9p communication. Right now |
|
* we only match the first available channel, but eventually we couldlook up |
|
* alternate channels by matching devname versus a virtio_config entry. |
|
* We use a simple reference count mechanism to ensure that only a single |
|
* mount has a channel open at a time. |
|
* |
|
*/ |
|
|
|
static int |
|
p9_virtio_create(struct p9_client *client, const char *devname, char *args) |
|
{ |
|
struct virtio_chan *chan; |
|
int ret = -ENOENT; |
|
int found = 0; |
|
|
|
if (devname == NULL) |
|
return -EINVAL; |
|
|
|
mutex_lock(&virtio_9p_lock); |
|
list_for_each_entry(chan, &virtio_chan_list, chan_list) { |
|
if (!strcmp(devname, chan->tag)) { |
|
if (!chan->inuse) { |
|
chan->inuse = true; |
|
found = 1; |
|
break; |
|
} |
|
ret = -EBUSY; |
|
} |
|
} |
|
mutex_unlock(&virtio_9p_lock); |
|
|
|
if (!found) { |
|
pr_err("no channels available for device %s\n", devname); |
|
return ret; |
|
} |
|
|
|
client->trans = (void *)chan; |
|
client->status = Connected; |
|
chan->client = client; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* p9_virtio_remove - clean up resources associated with a virtio device |
|
* @vdev: virtio device to remove |
|
* |
|
*/ |
|
|
|
static void p9_virtio_remove(struct virtio_device *vdev) |
|
{ |
|
struct virtio_chan *chan = vdev->priv; |
|
unsigned long warning_time; |
|
|
|
mutex_lock(&virtio_9p_lock); |
|
|
|
/* Remove self from list so we don't get new users. */ |
|
list_del(&chan->chan_list); |
|
warning_time = jiffies; |
|
|
|
/* Wait for existing users to close. */ |
|
while (chan->inuse) { |
|
mutex_unlock(&virtio_9p_lock); |
|
msleep(250); |
|
if (time_after(jiffies, warning_time + 10 * HZ)) { |
|
dev_emerg(&vdev->dev, |
|
"p9_virtio_remove: waiting for device in use.\n"); |
|
warning_time = jiffies; |
|
} |
|
mutex_lock(&virtio_9p_lock); |
|
} |
|
|
|
mutex_unlock(&virtio_9p_lock); |
|
|
|
vdev->config->reset(vdev); |
|
vdev->config->del_vqs(vdev); |
|
|
|
sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); |
|
kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); |
|
kfree(chan->tag); |
|
kfree(chan->vc_wq); |
|
kfree(chan); |
|
|
|
} |
|
|
|
static struct virtio_device_id id_table[] = { |
|
{ VIRTIO_ID_9P, VIRTIO_DEV_ANY_ID }, |
|
{ 0 }, |
|
}; |
|
|
|
static unsigned int features[] = { |
|
VIRTIO_9P_MOUNT_TAG, |
|
}; |
|
|
|
/* The standard "struct lguest_driver": */ |
|
static struct virtio_driver p9_virtio_drv = { |
|
.feature_table = features, |
|
.feature_table_size = ARRAY_SIZE(features), |
|
.driver.name = KBUILD_MODNAME, |
|
.driver.owner = THIS_MODULE, |
|
.id_table = id_table, |
|
.probe = p9_virtio_probe, |
|
.remove = p9_virtio_remove, |
|
}; |
|
|
|
static struct p9_trans_module p9_virtio_trans = { |
|
.name = "virtio", |
|
.create = p9_virtio_create, |
|
.close = p9_virtio_close, |
|
.request = p9_virtio_request, |
|
.zc_request = p9_virtio_zc_request, |
|
.cancel = p9_virtio_cancel, |
|
.cancelled = p9_virtio_cancelled, |
|
/* |
|
* We leave one entry for input and one entry for response |
|
* headers. We also skip one more entry to accommodate, address |
|
* that are not at page boundary, that can result in an extra |
|
* page in zero copy. |
|
*/ |
|
.maxsize = PAGE_SIZE * (VIRTQUEUE_NUM - 3), |
|
.def = 1, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
/* The standard init function */ |
|
static int __init p9_virtio_init(void) |
|
{ |
|
int rc; |
|
|
|
INIT_LIST_HEAD(&virtio_chan_list); |
|
|
|
v9fs_register_trans(&p9_virtio_trans); |
|
rc = register_virtio_driver(&p9_virtio_drv); |
|
if (rc) |
|
v9fs_unregister_trans(&p9_virtio_trans); |
|
|
|
return rc; |
|
} |
|
|
|
static void __exit p9_virtio_cleanup(void) |
|
{ |
|
unregister_virtio_driver(&p9_virtio_drv); |
|
v9fs_unregister_trans(&p9_virtio_trans); |
|
} |
|
|
|
module_init(p9_virtio_init); |
|
module_exit(p9_virtio_cleanup); |
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table); |
|
MODULE_AUTHOR("Eric Van Hensbergen <[email protected]>"); |
|
MODULE_DESCRIPTION("Virtio 9p Transport"); |
|
MODULE_LICENSE("GPL");
|
|
|