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-rw-r--r--net/9p/trans_virtio.c402
1 files changed, 259 insertions, 143 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index e1c26b101830..10c2dd486438 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* The Virtio 9p transport driver
*
@@ -8,22 +9,6 @@
*
* Based on virtio console driver
* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to:
- * Free Software Foundation
- * 51 Franklin Street, Fifth Floor
- * Boston, MA 02111-1301 USA
- *
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -37,12 +22,11 @@
#include <linux/un.h>
#include <linux/uaccess.h>
#include <linux/inet.h>
-#include <linux/idr.h>
#include <linux/file.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <net/9p/9p.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include <linux/scatterlist.h>
@@ -60,13 +44,16 @@ static atomic_t vp_pinned = ATOMIC_INIT(0);
/**
* struct virtio_chan - per-instance transport information
- * @initialized: whether the channel is initialized
* @inuse: whether the channel is in use
* @lock: protects multiple elements within this structure
* @client: client instance
* @vdev: virtio dev associated with this channel
* @vq: virtio queue associated with this channel
+ * @ring_bufs_avail: flag to indicate there is some available in the ring buf
+ * @vc_wq: wait queue for waiting for thing to be added to ring buf
+ * @p9_max_pages: maximum number of pinned pages
* @sg: scatter gather list which is used to pack a request (protected?)
+ * @chan_list: linked list of channels
*
* We keep all per-channel information in a structure.
* This structure is allocated within the devices dev->mem space.
@@ -90,10 +77,8 @@ struct virtio_chan {
unsigned long p9_max_pages;
/* Scatterlist: can be too big for stack. */
struct scatterlist sg[VIRTQUEUE_NUM];
-
- int tag_len;
- /*
- * tag name to identify a mount Non-null terminated
+ /**
+ * @tag: name to identify a mount null terminated
*/
char *tag;
@@ -105,7 +90,7 @@ static struct list_head virtio_chan_list;
/* How many bytes left in this page. */
static unsigned int rest_of_page(void *data)
{
- return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
+ return PAGE_SIZE - offset_in_page(data);
}
/**
@@ -113,7 +98,7 @@ static unsigned int rest_of_page(void *data)
* @client: client instance
*
* This reclaims a channel by freeing its resources and
- * reseting its inuse flag.
+ * resetting its inuse flag.
*
*/
@@ -143,30 +128,29 @@ static void p9_virtio_close(struct p9_client *client)
static void req_done(struct virtqueue *vq)
{
struct virtio_chan *chan = vq->vdev->priv;
- struct p9_fcall *rc;
unsigned int len;
struct p9_req_t *req;
+ bool need_wakeup = false;
unsigned long flags;
p9_debug(P9_DEBUG_TRANS, ": request done\n");
- while (1) {
- spin_lock_irqsave(&chan->lock, flags);
- rc = virtqueue_get_buf(chan->vq, &len);
- if (rc == NULL) {
- spin_unlock_irqrestore(&chan->lock, flags);
- break;
+ spin_lock_irqsave(&chan->lock, flags);
+ while ((req = virtqueue_get_buf(chan->vq, &len)) != NULL) {
+ if (!chan->ring_bufs_avail) {
+ chan->ring_bufs_avail = 1;
+ need_wakeup = true;
+ }
+
+ if (len) {
+ req->rc.size = len;
+ p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
}
- chan->ring_bufs_avail = 1;
- spin_unlock_irqrestore(&chan->lock, flags);
- /* Wakeup if anyone waiting for VirtIO ring space. */
- wake_up(chan->vc_wq);
- p9_debug(P9_DEBUG_TRANS, ": rc %p\n", rc);
- p9_debug(P9_DEBUG_TRANS, ": lookup tag %d\n", rc->tag);
- req = p9_tag_lookup(chan->client, rc->tag);
- req->status = REQ_STATUS_RCVD;
- p9_client_cb(chan->client, req);
}
+ spin_unlock_irqrestore(&chan->lock, flags);
+ /* Wakeup if anyone waiting for VirtIO ring space. */
+ if (need_wakeup)
+ wake_up(chan->vc_wq);
}
/**
@@ -193,7 +177,7 @@ static int pack_sg_list(struct scatterlist *sg, int start,
s = rest_of_page(data);
if (s > count)
s = count;
- BUG_ON(index > limit);
+ BUG_ON(index >= limit);
/* Make sure we don't terminate early. */
sg_unmark_end(&sg[index]);
sg_set_buf(&sg[index++], data, s);
@@ -211,22 +195,30 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req)
return 1;
}
+/* Reply won't come, so drop req ref */
+static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req)
+{
+ p9_req_put(client, req);
+ return 0;
+}
+
/**
* pack_sg_list_p - Just like pack_sg_list. Instead of taking a buffer,
* this takes a list of pages.
* @sg: scatter/gather list to pack into
* @start: which segment of the sg_list to start at
+ * @limit: maximum number of pages in sg list.
* @pdata: a list of pages to add into sg.
* @nr_pages: number of pages to pack into the scatter/gather list
- * @data: data to pack into scatter/gather list
+ * @offs: amount of data in the beginning of first page _not_ to pack
* @count: amount of data to pack into the scatter/gather list
*/
static int
pack_sg_list_p(struct scatterlist *sg, int start, int limit,
- struct page **pdata, int nr_pages, char *data, int count)
+ struct page **pdata, int nr_pages, size_t offs, int count)
{
int i = 0, s;
- int data_off;
+ int data_off = offs;
int index = start;
BUG_ON(nr_pages > (limit - start));
@@ -234,16 +226,15 @@ pack_sg_list_p(struct scatterlist *sg, int start, int limit,
* if the first page doesn't start at
* page boundary find the offset
*/
- data_off = offset_in_page(data);
while (nr_pages) {
- s = rest_of_page(data);
+ s = PAGE_SIZE - data_off;
if (s > count)
s = count;
+ BUG_ON(index >= limit);
/* Make sure we don't terminate early. */
sg_unmark_end(&sg[index]);
sg_set_page(&sg[index++], pdata[i++], s, data_off);
data_off = 0;
- data += s;
count -= s;
nr_pages--;
}
@@ -271,30 +262,30 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
p9_debug(P9_DEBUG_TRANS, "9p debug: virtio request\n");
- req->status = REQ_STATUS_SENT;
+ WRITE_ONCE(req->status, REQ_STATUS_SENT);
req_retry:
spin_lock_irqsave(&chan->lock, flags);
out_sgs = in_sgs = 0;
/* Handle out VirtIO ring buffers */
out = pack_sg_list(chan->sg, 0,
- VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+ VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
if (out)
sgs[out_sgs++] = chan->sg;
in = pack_sg_list(chan->sg, out,
- VIRTQUEUE_NUM, req->rc->sdata, req->rc->capacity);
+ VIRTQUEUE_NUM, req->rc.sdata, req->rc.capacity);
if (in)
sgs[out_sgs + in_sgs++] = chan->sg + out;
- err = virtqueue_add_sgs(chan->vq, sgs, out_sgs, in_sgs, req->tc,
+ 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_interruptible(*chan->vc_wq,
- chan->ring_bufs_avail);
+ err = wait_event_killable(*chan->vc_wq,
+ chan->ring_bufs_avail);
if (err == -ERESTARTSYS)
return err;
@@ -315,55 +306,121 @@ req_retry:
}
static int p9_get_mapped_pages(struct virtio_chan *chan,
- struct page **pages, char *data,
- int nr_pages, int write, int kern_buf)
+ struct page ***pages,
+ struct iov_iter *data,
+ int count,
+ size_t *offs,
+ int *need_drop)
{
+ int nr_pages;
int err;
- if (!kern_buf) {
+
+ if (!iov_iter_count(data))
+ return 0;
+
+ if (!iov_iter_is_kvec(data)) {
+ int n;
/*
* We allow only p9_max_pages pinned. We wait for the
* Other zc request to finish here
*/
if (atomic_read(&vp_pinned) >= chan->p9_max_pages) {
- err = wait_event_interruptible(vp_wq,
+ err = wait_event_killable(vp_wq,
(atomic_read(&vp_pinned) < chan->p9_max_pages));
if (err == -ERESTARTSYS)
return err;
}
- err = p9_payload_gup(data, &nr_pages, pages, write);
- if (err < 0)
- return err;
+ n = iov_iter_get_pages_alloc2(data, pages, count, offs);
+ if (n < 0)
+ return n;
+ *need_drop = 1;
+ nr_pages = DIV_ROUND_UP(n + *offs, PAGE_SIZE);
atomic_add(nr_pages, &vp_pinned);
+ return n;
} else {
/* kernel buffer, no need to pin pages */
- int s, index = 0;
- int count = nr_pages;
- while (nr_pages) {
- s = rest_of_page(data);
- pages[index++] = kmap_to_page(data);
- data += s;
- nr_pages--;
+ int index;
+ size_t len;
+ void *p;
+
+ /* we'd already checked that it's non-empty */
+ while (1) {
+ len = iov_iter_single_seg_count(data);
+ if (likely(len)) {
+ p = data->kvec->iov_base + data->iov_offset;
+ break;
+ }
+ iov_iter_advance(data, 0);
}
- nr_pages = count;
+ if (len > count)
+ len = count;
+
+ nr_pages = DIV_ROUND_UP((unsigned long)p + len, PAGE_SIZE) -
+ (unsigned long)p / PAGE_SIZE;
+
+ *pages = kmalloc_array(nr_pages, sizeof(struct page *),
+ GFP_NOFS);
+ if (!*pages)
+ return -ENOMEM;
+
+ *need_drop = 0;
+ p -= (*offs = offset_in_page(p));
+ for (index = 0; index < nr_pages; index++) {
+ if (is_vmalloc_addr(p))
+ (*pages)[index] = vmalloc_to_page(p);
+ else
+ (*pages)[index] = kmap_to_page(p);
+ p += PAGE_SIZE;
+ }
+ iov_iter_advance(data, len);
+ return len;
+ }
+}
+
+static void handle_rerror(struct p9_req_t *req, int in_hdr_len,
+ size_t offs, struct page **pages)
+{
+ unsigned size, n;
+ void *to = req->rc.sdata + in_hdr_len;
+
+ // Fits entirely into the static data? Nothing to do.
+ if (req->rc.size < in_hdr_len || !pages)
+ return;
+
+ // Really long error message? Tough, truncate the reply. Might get
+ // rejected (we can't be arsed to adjust the size encoded in header,
+ // or string size for that matter), but it wouldn't be anything valid
+ // anyway.
+ if (unlikely(req->rc.size > P9_ZC_HDR_SZ))
+ req->rc.size = P9_ZC_HDR_SZ;
+
+ // data won't span more than two pages
+ size = req->rc.size - in_hdr_len;
+ n = PAGE_SIZE - offs;
+ if (size > n) {
+ memcpy_from_page(to, *pages++, offs, n);
+ offs = 0;
+ to += n;
+ size -= n;
}
- return nr_pages;
+ memcpy_from_page(to, *pages, offs, size);
}
/**
* p9_virtio_zc_request - issue a zero copy request
* @client: client instance issuing the request
* @req: request to be issued
- * @uidata: user bffer that should be ued for zero copy read
- * @uodata: user buffer that shoud be user for zero copy write
+ * @uidata: user buffer that should be used for zero copy read
+ * @uodata: user buffer that should be used for zero copy write
* @inlen: read buffer size
- * @olen: write buffer size
- * @hdrlen: reader header size, This is the size of response protocol data
+ * @outlen: write buffer size
+ * @in_hdr_len: reader header size, This is the size of response protocol data
*
*/
static int
p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
- char *uidata, char *uodata, int inlen,
- int outlen, int in_hdr_len, int kern_buf)
+ struct iov_iter *uidata, struct iov_iter *uodata,
+ int inlen, int outlen, int in_hdr_len)
{
int in, out, err, out_sgs, in_sgs;
unsigned long flags;
@@ -371,44 +428,47 @@ p9_virtio_zc_request(struct p9_client *client, struct p9_req_t *req,
struct page **in_pages = NULL, **out_pages = NULL;
struct virtio_chan *chan = client->trans;
struct scatterlist *sgs[4];
+ size_t offs = 0;
+ int need_drop = 0;
+ int kicked = 0;
p9_debug(P9_DEBUG_TRANS, "virtio request\n");
if (uodata) {
- out_nr_pages = p9_nr_pages(uodata, outlen);
- out_pages = kmalloc(sizeof(struct page *) * out_nr_pages,
- GFP_NOFS);
- if (!out_pages) {
- err = -ENOMEM;
+ __le32 sz;
+ 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 = p9_get_mapped_pages(chan, out_pages, uodata,
- out_nr_pages, 0, kern_buf);
- if (out_nr_pages < 0) {
- err = out_nr_pages;
- kfree(out_pages);
- out_pages = NULL;
- goto err_out;
+ out_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
+ if (n != outlen) {
+ __le32 v = cpu_to_le32(n);
+ memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
+ outlen = n;
}
- }
- if (uidata) {
- in_nr_pages = p9_nr_pages(uidata, inlen);
- in_pages = kmalloc(sizeof(struct page *) * in_nr_pages,
- GFP_NOFS);
- if (!in_pages) {
- err = -ENOMEM;
+ /* 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.
+ */
+ sz = cpu_to_le32(req->tc.size + outlen);
+ memcpy(&req->tc.sdata[0], &sz, sizeof(sz));
+ } else if (uidata) {
+ int n = p9_get_mapped_pages(chan, &in_pages, uidata,
+ inlen, &offs, &need_drop);
+ if (n < 0) {
+ err = n;
goto err_out;
}
- in_nr_pages = p9_get_mapped_pages(chan, in_pages, uidata,
- in_nr_pages, 1, kern_buf);
- if (in_nr_pages < 0) {
- err = in_nr_pages;
- kfree(in_pages);
- in_pages = NULL;
- goto err_out;
+ in_nr_pages = DIV_ROUND_UP(n + offs, PAGE_SIZE);
+ if (n != inlen) {
+ __le32 v = cpu_to_le32(n);
+ memcpy(&req->tc.sdata[req->tc.size - 4], &v, 4);
+ inlen = n;
}
}
- req->status = REQ_STATUS_SENT;
+ WRITE_ONCE(req->status, REQ_STATUS_SENT);
req_retry_pinned:
spin_lock_irqsave(&chan->lock, flags);
@@ -416,7 +476,7 @@ req_retry_pinned:
/* out data */
out = pack_sg_list(chan->sg, 0,
- VIRTQUEUE_NUM, req->tc->sdata, req->tc->size);
+ VIRTQUEUE_NUM, req->tc.sdata, req->tc.size);
if (out)
sgs[out_sgs++] = chan->sg;
@@ -424,36 +484,36 @@ req_retry_pinned:
if (out_pages) {
sgs[out_sgs++] = chan->sg + out;
out += pack_sg_list_p(chan->sg, out, VIRTQUEUE_NUM,
- out_pages, out_nr_pages, uodata, outlen);
+ out_pages, out_nr_pages, offs, outlen);
}
-
+
/*
* Take care of in data
* For example TREAD have 11.
* 11 is the read/write header = PDU Header(7) + IO Size (4).
* Arrange in such a way that server places header in the
- * alloced memory and payload onto the user buffer.
+ * allocated memory and payload onto the user buffer.
*/
in = pack_sg_list(chan->sg, out,
- VIRTQUEUE_NUM, req->rc->sdata, in_hdr_len);
+ 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,
- in_pages, in_nr_pages, uidata, inlen);
+ pack_sg_list_p(chan->sg, out + in, VIRTQUEUE_NUM,
+ 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->tc,
+ 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_interruptible(*chan->vc_wq,
- chan->ring_bufs_avail);
+ err = wait_event_killable(*chan->vc_wq,
+ chan->ring_bufs_avail);
if (err == -ERESTARTSYS)
goto err_out;
@@ -469,14 +529,20 @@ req_retry_pinned:
}
virtqueue_kick(chan->vq);
spin_unlock_irqrestore(&chan->lock, flags);
+ kicked = 1;
p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n");
- err = wait_event_interruptible(*req->wq,
- req->status >= REQ_STATUS_RCVD);
+ err = wait_event_killable(req->wq,
+ READ_ONCE(req->status) >= REQ_STATUS_RCVD);
+ // RERROR needs reply (== error string) in static data
+ if (READ_ONCE(req->status) == REQ_STATUS_RCVD &&
+ unlikely(req->rc.sdata[4] == P9_RERROR))
+ handle_rerror(req, in_hdr_len, offs, in_pages);
+
/*
* Non kernel buffers are pinned, unpin them
*/
err_out:
- if (!kern_buf) {
+ if (need_drop) {
if (in_pages) {
p9_release_pages(in_pages, in_nr_pages);
atomic_sub(in_nr_pages, &vp_pinned);
@@ -488,8 +554,12 @@ err_out:
/* wakeup anybody waiting for slots to pin pages */
wake_up(&vp_wq);
}
- kfree(in_pages);
- kfree(out_pages);
+ kvfree(in_pages);
+ kvfree(out_pages);
+ if (!kicked) {
+ /* reply won't come */
+ p9_req_put(client, req);
+ }
return err;
}
@@ -498,11 +568,15 @@ static ssize_t p9_mount_tag_show(struct device *dev,
{
struct virtio_chan *chan;
struct virtio_device *vdev;
+ int tag_len;
vdev = dev_to_virtio(dev);
chan = vdev->priv;
+ tag_len = strlen(chan->tag);
- return snprintf(buf, chan->tag_len + 1, "%s", chan->tag);
+ memcpy(buf, chan->tag, tag_len + 1);
+
+ return tag_len + 1;
}
static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
@@ -522,6 +596,12 @@ static int p9_virtio_probe(struct virtio_device *vdev)
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");
@@ -535,7 +615,7 @@ static int p9_virtio_probe(struct virtio_device *vdev)
chan->vq = virtio_find_single_vq(vdev, req_done, "requests");
if (IS_ERR(chan->vq)) {
err = PTR_ERR(chan->vq);
- goto out_free_vq;
+ goto out_free_chan;
}
chan->vq->vdev->priv = chan;
spin_lock_init(&chan->lock);
@@ -544,22 +624,20 @@ static int p9_virtio_probe(struct virtio_device *vdev)
chan->inuse = false;
if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
- vdev->config->get(vdev,
- offsetof(struct virtio_9p_config, tag_len),
- &tag_len, sizeof(tag_len));
+ virtio_cread(vdev, struct virtio_9p_config, tag_len, &tag_len);
} else {
err = -EINVAL;
goto out_free_vq;
}
- tag = kmalloc(tag_len, GFP_KERNEL);
+ tag = kzalloc(tag_len + 1, GFP_KERNEL);
if (!tag) {
err = -ENOMEM;
goto out_free_vq;
}
- vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
- tag, tag_len);
+
+ virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag),
+ tag, tag_len);
chan->tag = tag;
- chan->tag_len = tag_len;
err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
if (err) {
goto out_free_tag;
@@ -567,22 +645,31 @@ static int p9_virtio_probe(struct virtio_device *vdev)
chan->vc_wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
if (!chan->vc_wq) {
err = -ENOMEM;
- goto out_free_tag;
+ goto out_remove_file;
}
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_remove_file:
+ sysfs_remove_file(&vdev->dev.kobj, &dev_attr_mount_tag.attr);
out_free_tag:
kfree(tag);
out_free_vq:
vdev->config->del_vqs(vdev);
+out_free_chan:
kfree(chan);
fail:
return err;
@@ -592,11 +679,10 @@ fail:
/**
* 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)
+ * @fc: the filesystem context
*
* This sets up a transport channel for 9p communication. Right now
- * we only match the first available channel, but eventually we couldlook up
+ * we only match the first available channel, but eventually we could look 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.
@@ -604,16 +690,19 @@ fail:
*/
static int
-p9_virtio_create(struct p9_client *client, const char *devname, char *args)
+p9_virtio_create(struct p9_client *client, struct fs_context *fc)
{
+ const char *devname = fc->source;
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 (!strncmp(devname, chan->tag, chan->tag_len) &&
- strlen(devname) == chan->tag_len) {
+ if (!strcmp(devname, chan->tag)) {
if (!chan->inuse) {
chan->inuse = true;
found = 1;
@@ -625,7 +714,7 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
mutex_unlock(&virtio_9p_lock);
if (!found) {
- pr_err("no channels available\n");
+ pr_err("no channels available for device %s\n", devname);
return ret;
}
@@ -645,15 +734,33 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
static void p9_virtio_remove(struct virtio_device *vdev)
{
struct virtio_chan *chan = vdev->priv;
-
- if (chan->inuse)
- p9_virtio_close(chan->client);
- vdev->config->del_vqs(vdev);
+ 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);
+
+ virtio_reset_device(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);
@@ -674,7 +781,6 @@ 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,
@@ -687,24 +793,33 @@ static struct p9_trans_module p9_virtio_trans = {
.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 accomodate, address
+ * 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 = 0,
+ .pooled_rbuffers = false,
+ .def = true,
+ .supports_vmalloc = false,
.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);
- return register_virtio_driver(&p9_virtio_drv);
+ rc = register_virtio_driver(&p9_virtio_drv);
+ if (rc)
+ v9fs_unregister_trans(&p9_virtio_trans);
+
+ return rc;
}
static void __exit p9_virtio_cleanup(void)
@@ -715,6 +830,7 @@ static void __exit p9_virtio_cleanup(void)
module_init(p9_virtio_init);
module_exit(p9_virtio_cleanup);
+MODULE_ALIAS_9P("virtio");
MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
generated by cgit (git 2.34.1) at 2025-12-25 09:51:02 +0000