diff options
Diffstat (limited to 'net/9p/trans_virtio.c')
| -rw-r--r-- | net/9p/trans_virtio.c | 66 |
1 files changed, 55 insertions, 11 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index a3cd90a74012..e757f0601304 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -50,7 +50,11 @@ static atomic_t vp_pinned = ATOMIC_INIT(0); * @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. @@ -74,8 +78,8 @@ struct virtio_chan { unsigned long p9_max_pages; /* Scatterlist: can be too big for stack. */ struct scatterlist sg[VIRTQUEUE_NUM]; - /* - * tag name to identify a mount null terminated + /** + * @tag: name to identify a mount null terminated */ char *tag; @@ -95,7 +99,7 @@ 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. * */ @@ -195,7 +199,7 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) /* 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(req); + p9_req_put(client, req); return 0; } @@ -204,6 +208,7 @@ static int p9_virtio_cancelled(struct p9_client *client, struct p9_req_t *req) * 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 * @offs: amount of data in the beginning of first page _not_ to pack @@ -326,7 +331,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, if (err == -ERESTARTSYS) return err; } - n = iov_iter_get_pages_alloc(data, pages, count, offs); + n = iov_iter_get_pages_alloc2(data, pages, count, offs); if (n < 0) return n; *need_drop = 1; @@ -368,10 +373,40 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, (*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) + 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; + } + memcpy_from_page(to, *pages, offs, size); +} + /** * p9_virtio_zc_request - issue a zero copy request * @client: client instance issuing the request @@ -458,7 +493,7 @@ req_retry_pinned: * 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); @@ -498,6 +533,11 @@ req_retry_pinned: kicked = 1; p9_debug(P9_DEBUG_TRANS, "virtio request kicked\n"); err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD); + // RERROR needs reply (== error string) in static data + if (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 */ @@ -518,7 +558,7 @@ err_out: kvfree(out_pages); if (!kicked) { /* reply won't come */ - p9_req_put(req); + p9_req_put(client, req); } return err; } @@ -605,7 +645,7 @@ 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; @@ -623,6 +663,8 @@ static int p9_virtio_probe(struct virtio_device *vdev) return 0; +out_remove_file: + sysfs_remove_file(&vdev->dev.kobj, &dev_attr_mount_tag.attr); out_free_tag: kfree(tag); out_free_vq: @@ -641,7 +683,7 @@ fail: * @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 + * 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. @@ -714,7 +756,7 @@ static void p9_virtio_remove(struct virtio_device *vdev) mutex_unlock(&virtio_9p_lock); - vdev->config->reset(vdev); + virtio_reset_device(vdev); vdev->config->del_vqs(vdev); sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); @@ -755,11 +797,12 @@ static struct p9_trans_module p9_virtio_trans = { .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), + .pooled_rbuffers = false, .def = 1, .owner = THIS_MODULE, }; @@ -787,6 +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>"); |