From: Christian Schoenebeck <linux_oss@crudebyte.com>
To: v9fs-developer@lists.sourceforge.net
Cc: netdev@vger.kernel.org,
Dominique Martinet <asmadeus@codewreck.org>,
Eric Van Hensbergen <ericvh@gmail.com>,
Latchesar Ionkov <lucho@ionkov.net>, Greg Kurz <groug@kaod.org>,
Vivek Goyal <vgoyal@redhat.com>,
Nikolay Kichukov <nikolay@oldum.net>
Subject: [PATCH v4 06/12] 9p/trans_virtio: support larger msize values
Date: Thu, 30 Dec 2021 14:23:18 +0100 [thread overview]
Message-ID: <92bbeadaf5c6a0615b970bd01d6f51c455d6d988.1640870037.git.linux_oss@crudebyte.com> (raw)
In-Reply-To: <cover.1640870037.git.linux_oss@crudebyte.com>
The virtio transport supports by default a 9p 'msize' of up to
approximately 500 kB. This patch adds support for larger 'msize'
values by resizing the amount of scatter/gather lists if required.
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
---
net/9p/trans_virtio.c | 61 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 61 insertions(+)
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 656562a66f06..a02050c9742a 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -203,6 +203,31 @@ static struct virtqueue_sg *vq_sg_alloc(unsigned int nsgl)
return vq_sg;
}
+/**
+ * vq_sg_resize - resize passed virtqueue scatter/gather lists to the passed
+ * amount of lists
+ * @_vq_sg: scatter/gather lists to be resized
+ * @nsgl: new amount of scatter/gather lists
+ */
+static int vq_sg_resize(struct virtqueue_sg **_vq_sg, unsigned int nsgl)
+{
+ struct virtqueue_sg *vq_sg;
+
+ BUG_ON(!_vq_sg || !nsgl);
+ vq_sg = *_vq_sg;
+ if (vq_sg->nsgl == nsgl)
+ return 0;
+
+ /* lazy resize implementation for now */
+ vq_sg = vq_sg_alloc(nsgl);
+ if (!vq_sg)
+ return -ENOMEM;
+
+ kfree(*_vq_sg);
+ *_vq_sg = vq_sg;
+ return 0;
+}
+
/**
* p9_virtio_close - reclaim resources of a channel
* @client: client instance
@@ -774,6 +799,10 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
struct virtio_chan *chan;
int ret = -ENOENT;
int found = 0;
+#if !defined(CONFIG_ARCH_NO_SG_CHAIN)
+ size_t npages;
+ size_t nsgl;
+#endif
if (devname == NULL)
return -EINVAL;
@@ -796,6 +825,38 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
return ret;
}
+ /*
+ * if user supplied an 'msize' option that's larger than what this
+ * transport supports by default, then try to allocate more sg lists
+ */
+ if (client->msize > client->trans_maxsize) {
+#ifdef CONFIG_ARCH_NO_SG_CHAIN
+ pr_info("limiting 'msize' to %d because architecture does not "
+ "support chained scatter gather lists\n",
+ client->trans_maxsize);
+#else
+ npages = DIV_ROUND_UP(client->msize, PAGE_SIZE);
+ if (npages > chan->p9_max_pages) {
+ npages = chan->p9_max_pages;
+ pr_info("limiting 'msize' as it would exceed the max. "
+ "of %lu pages allowed on this system\n",
+ chan->p9_max_pages);
+ }
+ nsgl = DIV_ROUND_UP(npages, SG_USER_PAGES_PER_LIST);
+ if (nsgl > chan->vq_sg->nsgl) {
+ /*
+ * if resize fails, no big deal, then just
+ * continue with default msize instead
+ */
+ if (!vq_sg_resize(&chan->vq_sg, nsgl)) {
+ client->trans_maxsize =
+ PAGE_SIZE *
+ ((nsgl * SG_USER_PAGES_PER_LIST) - 3);
+ }
+ }
+#endif /* CONFIG_ARCH_NO_SG_CHAIN */
+ }
+
client->trans = (void *)chan;
client->status = Connected;
chan->client = client;
--
2.30.2
next prev parent reply other threads:[~2021-12-30 14:42 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-30 13:23 [PATCH v4 00/12] remove msize limit in virtio transport Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 12/12] net/9p: allocate appropriate reduced message buffers Christian Schoenebeck
2022-04-02 14:05 ` Dominique Martinet
2022-04-03 11:29 ` Christian Schoenebeck
2022-04-03 12:37 ` Dominique Martinet
2022-04-03 14:00 ` Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 08/12] net/9p: limit 'msize' to KMALLOC_MAX_SIZE for all transports Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 04/12] 9p/trans_virtio: introduce struct virtqueue_sg Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 01/12] net/9p: show error message if user 'msize' cannot be satisfied Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 10/12] 9p: add P9_ERRMAX for 9p2000 and 9p2000.u Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 11/12] net/9p: add p9_msg_buf_size() Christian Schoenebeck
2021-12-30 13:23 ` Christian Schoenebeck [this message]
2021-12-30 13:23 ` [PATCH v4 02/12] 9p/trans_virtio: separate allocation of scatter gather list Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 09/12] net/9p: split message size argument into 't_size' and 'r_size' pair Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 07/12] 9p/trans_virtio: resize sg lists to whatever is possible Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 05/12] net/9p: add trans_maxsize to struct p9_client Christian Schoenebeck
2021-12-30 13:23 ` [PATCH v4 03/12] 9p/trans_virtio: turn amount of sg lists into runtime info Christian Schoenebeck
2022-01-20 22:43 ` [PATCH v4 00/12] remove msize limit in virtio transport Nikolay Kichukov
2022-01-22 13:34 ` Christian Schoenebeck
2022-01-24 10:21 ` Nikolay Kichukov
2022-01-24 11:07 ` Dominique Martinet
2022-01-24 11:57 ` Christian Schoenebeck
2022-01-24 12:56 ` Dominique Martinet
2022-01-24 13:55 ` Christian Schoenebeck
2022-01-25 8:45 ` Nikolay Kichukov
2022-05-24 8:10 ` Nikolay Kichukov
2022-05-24 11:29 ` Christian Schoenebeck
2022-07-07 14:30 ` Christian Schoenebeck
[not found] ` <CAFkjPT=GAoViYd0E7CZQDq3ZjhmYT0DsBytfZXnE10JL0P8O-Q@mail.gmail.com>
2022-07-08 1:15 ` Dominique Martinet
[not found] ` <CAFkjPTngeFh=0mPVW-Yf1Sxkxp_HDNUeANndoYN3-eU9_rGLuQ@mail.gmail.com>
2022-07-08 11:18 ` Christian Schoenebeck
2022-07-08 11:40 ` Dominique Martinet
2022-07-08 13:00 ` Christian Schoenebeck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=92bbeadaf5c6a0615b970bd01d6f51c455d6d988.1640870037.git.linux_oss@crudebyte.com \
--to=linux_oss@crudebyte.com \
--cc=asmadeus@codewreck.org \
--cc=ericvh@gmail.com \
--cc=groug@kaod.org \
--cc=lucho@ionkov.net \
--cc=netdev@vger.kernel.org \
--cc=nikolay@oldum.net \
--cc=v9fs-developer@lists.sourceforge.net \
--cc=vgoyal@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).