linux/drivers/block/aoe/aoenet.c

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/* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoenet.c
* Ethernet portion of AoE driver
*/
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/netdevice.h>
#include <linux/moduleparam.h>
#include <net/net_namespace.h>
#include <asm/unaligned.h>
#include "aoe.h"
#define NECODES 5
static char *aoe_errlist[] =
{
"no such error",
"unrecognized command code",
"bad argument parameter",
"device unavailable",
"config string present",
"unsupported version"
};
enum {
IFLISTSZ = 1024,
};
static char aoe_iflist[IFLISTSZ];
module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=\"dev1 [dev2 ...]\"");
#ifndef MODULE
static int __init aoe_iflist_setup(char *str)
{
strncpy(aoe_iflist, str, IFLISTSZ);
aoe_iflist[IFLISTSZ - 1] = '\0';
return 1;
}
__setup("aoe_iflist=", aoe_iflist_setup);
#endif
int
is_aoe_netif(struct net_device *ifp)
{
register char *p, *q;
register int len;
if (aoe_iflist[0] == '\0')
return 1;
p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
for (; *p; p = q + strspn(q, WHITESPACE)) {
q = p + strcspn(p, WHITESPACE);
if (q != p)
len = q - p;
else
len = strlen(p); /* last token in aoe_iflist */
if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
return 1;
if (q == p)
break;
}
return 0;
}
int
set_aoe_iflist(const char __user *user_str, size_t size)
{
if (size >= IFLISTSZ)
return -EINVAL;
if (copy_from_user(aoe_iflist, user_str, size)) {
printk(KERN_INFO "aoe: copy from user failed\n");
return -EFAULT;
}
aoe_iflist[size] = 0x00;
return 0;
}
void
aoenet_xmit(struct sk_buff_head *queue)
{
struct sk_buff *skb, *tmp;
skb_queue_walk_safe(queue, skb, tmp) {
__skb_unlink(skb, queue);
dev_queue_xmit(skb);
}
}
/*
* (1) len doesn't include the header by default. I want this.
*/
static int
aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
{
struct aoe_hdr *h;
u32 n;
if (dev_net(ifp) != &init_net)
goto exit;
skb = skb_share_check(skb, GFP_ATOMIC);
if (skb == NULL)
return 0;
if (skb_linearize(skb))
goto exit;
if (!is_aoe_netif(ifp))
goto exit;
skb_push(skb, ETH_HLEN); /* (1) */
h = (struct aoe_hdr *) skb_mac_header(skb);
n = get_unaligned_be32(&h->tag);
if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
goto exit;
if (h->verfl & AOEFL_ERR) {
n = h->err;
if (n > NECODES)
n = 0;
if (net_ratelimit())
aoe: handle multiple network paths to AoE device A remote AoE device is something can process ATA commands and is identified by an AoE shelf number and an AoE slot number. Such a device might have more than one network interface, and it might be reachable by more than one local network interface. This patch tracks the available network paths available to each AoE device, allowing them to be used more efficiently. Andrew Morton asked about the call to msleep_interruptible in the revalidate function. Yes, if a signal is pending, then msleep_interruptible will not return 0. That means we will not loop but will call aoenet_xmit with a NULL skb, which is a noop. If the system is too low on memory or the aoe driver is too low on frames, then the user can hit control-C to interrupt the attempt to do a revalidate. I have added a comment to the code summarizing that. Andrew Morton asked whether the allocation performed inside addtgt could use a more relaxed allocation like GFP_KERNEL, but addtgt is called when the aoedev lock has been locked with spin_lock_irqsave. It would be nice to allocate the memory under fewer restrictions, but targets are only added when the device is being discovered, and if the target can't be added right now, we can try again in a minute when then next AoE config query broadcast goes out. Andrew Morton pointed out that the "too many targets" message could be printed for failing GFP_ATOMIC allocations. The last patch in this series makes the messages more specific. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:20:00 +00:00
printk(KERN_ERR
"%s%d.%d@%s; ecode=%d '%s'\n",
"aoe: error packet from ",
get_unaligned_be16(&h->major),
aoe: handle multiple network paths to AoE device A remote AoE device is something can process ATA commands and is identified by an AoE shelf number and an AoE slot number. Such a device might have more than one network interface, and it might be reachable by more than one local network interface. This patch tracks the available network paths available to each AoE device, allowing them to be used more efficiently. Andrew Morton asked about the call to msleep_interruptible in the revalidate function. Yes, if a signal is pending, then msleep_interruptible will not return 0. That means we will not loop but will call aoenet_xmit with a NULL skb, which is a noop. If the system is too low on memory or the aoe driver is too low on frames, then the user can hit control-C to interrupt the attempt to do a revalidate. I have added a comment to the code summarizing that. Andrew Morton asked whether the allocation performed inside addtgt could use a more relaxed allocation like GFP_KERNEL, but addtgt is called when the aoedev lock has been locked with spin_lock_irqsave. It would be nice to allocate the memory under fewer restrictions, but targets are only added when the device is being discovered, and if the target can't be added right now, we can try again in a minute when then next AoE config query broadcast goes out. Andrew Morton pointed out that the "too many targets" message could be printed for failing GFP_ATOMIC allocations. The last patch in this series makes the messages more specific. Signed-off-by: Ed L. Cashin <ecashin@coraid.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:20:00 +00:00
h->minor, skb->dev->name,
h->err, aoe_errlist[n]);
goto exit;
}
switch (h->cmd) {
case AOECMD_ATA:
aoecmd_ata_rsp(skb);
break;
case AOECMD_CFG:
aoecmd_cfg_rsp(skb);
break;
default:
if (h->cmd >= AOECMD_VEND_MIN)
break; /* don't complain about vendor commands */
printk(KERN_INFO "aoe: unknown cmd %d\n", h->cmd);
}
exit:
dev_kfree_skb(skb);
return 0;
}
static struct packet_type aoe_pt __read_mostly = {
.type = __constant_htons(ETH_P_AOE),
.func = aoenet_rcv,
};
int __init
aoenet_init(void)
{
dev_add_pack(&aoe_pt);
return 0;
}
void
aoenet_exit(void)
{
dev_remove_pack(&aoe_pt);
}