linux_dsm_epyc7002/drivers/block/aoe/aoenet.c
Ed Cashin 896831f590 aoe: kernel thread handles I/O completions for simple locking
Make the frames the aoe driver uses to track the relationship between bios
and packets more flexible and detached, so that they can be passed to an
"aoe_ktio" thread for completion of I/O.

The frames are handled much like skbs, with a capped amount of
preallocation so that real-world use cases are likely to run smoothly and
degenerate gracefully even under memory pressure.

Decoupling I/O completion from the receive path and serializing it in a
process makes it easier to think about the correctness of the locking in
the driver, especially in the case of a remote MAC address becoming
unusable.

[dan.carpenter@oracle.com: cleanup an allocation a bit]
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:05:24 +09:00

182 lines
3.4 KiB
C

/* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoenet.c
* Ethernet portion of AoE driver
*/
#include <linux/gfp.h>
#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;
struct aoe_atahdr *ah;
u32 n;
int sn;
if (dev_net(ifp) != &init_net)
goto exit;
skb = skb_share_check(skb, GFP_ATOMIC);
if (skb == NULL)
return 0;
if (!is_aoe_netif(ifp))
goto exit;
skb_push(skb, ETH_HLEN); /* (1) */
sn = sizeof(*h) + sizeof(*ah);
if (skb->len >= sn) {
sn -= skb_headlen(skb);
if (sn > 0 && !__pskb_pull_tail(skb, sn))
goto exit;
}
h = (struct aoe_hdr *) skb->data;
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())
printk(KERN_ERR
"%s%d.%d@%s; ecode=%d '%s'\n",
"aoe: error packet from ",
get_unaligned_be16(&h->major),
h->minor, skb->dev->name,
h->err, aoe_errlist[n]);
goto exit;
}
switch (h->cmd) {
case AOECMD_ATA:
/* ata_rsp may keep skb for later processing or give it back */
skb = 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);
}
if (!skb)
return 0;
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);
}