From 37c1209d413242d9560e343c040777049a8dd869 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 15 Feb 2010 17:27:01 +0000 Subject: [PATCH] net/9p: Remove MAX_9P_CHAN limit Use a list to track the channel instead of statically allocated array Signed-off-by: Aneesh Kumar K.V Signed-off-by: Eric Van Hensbergen --- include/linux/virtio_9p.h | 3 -- net/9p/trans_virtio.c | 70 +++++++++++++++------------------------ 2 files changed, 27 insertions(+), 46 deletions(-) diff --git a/include/linux/virtio_9p.h b/include/linux/virtio_9p.h index 7a615c3f5e3d..332275080083 100644 --- a/include/linux/virtio_9p.h +++ b/include/linux/virtio_9p.h @@ -5,7 +5,4 @@ #include #include -/* Maximum number of virtio channels per partition (1 for now) */ -#define MAX_9P_CHAN 10 - #endif /* _LINUX_VIRTIO_9P_H */ diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index df924e5657d3..05918d3cb40d 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -49,8 +49,6 @@ /* a single mutex to manage channel initialization and attachment */ static DEFINE_MUTEX(virtio_9p_lock); -/* global which tracks highest initialized channel */ -static int chan_index; /** * struct virtio_chan - per-instance transport information @@ -68,8 +66,7 @@ static int chan_index; * */ -static struct virtio_chan { - bool initialized; +struct virtio_chan { bool inuse; spinlock_t lock; @@ -80,7 +77,11 @@ static struct virtio_chan { /* Scatterlist: can be too big for stack. */ struct scatterlist sg[VIRTQUEUE_NUM]; -} channels[MAX_9P_CHAN]; + + struct list_head chan_list; +}; + +static struct list_head virtio_chan_list; /* How many bytes left in this page. */ static unsigned int rest_of_page(void *data) @@ -217,9 +218,7 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req) * p9_virtio_probe - probe for existence of 9P virtio channels * @vdev: virtio device to probe * - * This probes for existing virtio channels. At present only - * a single channel is in use, so in the future more work may need - * to be done here. + * This probes for existing virtio channels. * */ @@ -227,16 +226,10 @@ static int p9_virtio_probe(struct virtio_device *vdev) { int err; struct virtio_chan *chan; - int index; - mutex_lock(&virtio_9p_lock); - index = chan_index++; - chan = &channels[index]; - mutex_unlock(&virtio_9p_lock); - - if (chan_index > MAX_9P_CHAN) { - printk(KERN_ERR "9p: virtio: Maximum channels exceeded\n"); - BUG(); + chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL); + if (!chan) { + printk(KERN_ERR "9p: Failed to allocate virtio 9P channel\n"); err = -ENOMEM; goto fail; } @@ -255,15 +248,15 @@ static int p9_virtio_probe(struct virtio_device *vdev) sg_init_table(chan->sg, VIRTQUEUE_NUM); chan->inuse = false; - chan->initialized = true; + mutex_lock(&virtio_9p_lock); + list_add_tail(&chan->chan_list, &virtio_chan_list); + mutex_unlock(&virtio_9p_lock); return 0; out_free_vq: vdev->config->del_vqs(vdev); + kfree(chan); fail: - mutex_lock(&virtio_9p_lock); - chan_index--; - mutex_unlock(&virtio_9p_lock); return err; } @@ -280,35 +273,27 @@ static int p9_virtio_probe(struct virtio_device *vdev) * We use a simple reference count mechanism to ensure that only a single * mount has a channel open at a time. * - * Bugs: doesn't allow identification of a specific channel - * to allocate, channels are allocated sequentially. This was - * a pragmatic decision to get things rolling, but ideally some - * way of identifying the channel to attach to would be nice - * if we are going to support multiple channels. - * */ static int p9_virtio_create(struct p9_client *client, const char *devname, char *args) { - struct virtio_chan *chan = channels; - int index = 0; + struct virtio_chan *chan; + int found = 0; mutex_lock(&virtio_9p_lock); - while (index < MAX_9P_CHAN) { - if (chan->initialized && - !strcmp(devname, dev_name(&chan->vdev->dev))) { + list_for_each_entry(chan, &virtio_chan_list, chan_list) { + if (!strcmp(devname, dev_name(&chan->vdev->dev))) { if (!chan->inuse) { chan->inuse = true; + found = 1; break; } } - index++; - chan = &channels[index]; } mutex_unlock(&virtio_9p_lock); - if (index >= MAX_9P_CHAN) { + if (!found) { printk(KERN_ERR "9p: no channels available\n"); return -ENODEV; } @@ -331,11 +316,13 @@ static void p9_virtio_remove(struct virtio_device *vdev) struct virtio_chan *chan = vdev->priv; BUG_ON(chan->inuse); + vdev->config->del_vqs(vdev); + + mutex_lock(&virtio_9p_lock); + list_del(&chan->chan_list); + mutex_unlock(&virtio_9p_lock); + kfree(chan); - if (chan->initialized) { - vdev->config->del_vqs(vdev); - chan->initialized = false; - } } static struct virtio_device_id id_table[] = { @@ -366,10 +353,7 @@ static struct p9_trans_module p9_virtio_trans = { /* The standard init function */ static int __init p9_virtio_init(void) { - int count; - - for (count = 0; count < MAX_9P_CHAN; count++) - channels[count].initialized = false; + INIT_LIST_HEAD(&virtio_chan_list); v9fs_register_trans(&p9_virtio_trans); return register_virtio_driver(&p9_virtio_drv);