linux/drivers/block/aoe/aoenet.c

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/* Copyright (c) 2012 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoenet.c
* Ethernet portion of AoE driver
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#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...]");
static wait_queue_head_t txwq;
static struct ktstate kts;
#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
static spinlock_t txlock;
static struct sk_buff_head skbtxq;
/* enters with txlock held */
static int
tx(void) __must_hold(&txlock)
{
struct sk_buff *skb;
struct net_device *ifp;
while ((skb = skb_dequeue(&skbtxq))) {
spin_unlock_irq(&txlock);
ifp = skb->dev;
if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
pr_warn("aoe: packet could not be sent on %s. %s\n",
ifp ? ifp->name : "netif",
"consider increasing tx_queue_len");
spin_lock_irq(&txlock);
}
return 0;
}
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;
ulong flags;
skb_queue_walk_safe(queue, skb, tmp) {
__skb_unlink(skb, queue);
spin_lock_irqsave(&txlock, flags);
skb_queue_tail(&skbtxq, skb);
spin_unlock_irqrestore(&txlock, flags);
wake_up(&txwq);
}
}
/*
* (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())
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:
/* 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 */
pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
break;
}
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)
{
skb_queue_head_init(&skbtxq);
init_waitqueue_head(&txwq);
spin_lock_init(&txlock);
kts.lock = &txlock;
kts.fn = tx;
kts.waitq = &txwq;
kts.name = "aoe_tx";
if (aoe_ktstart(&kts))
return -EAGAIN;
dev_add_pack(&aoe_pt);
return 0;
}
void
aoenet_exit(void)
{
aoe_ktstop(&kts);
skb_queue_purge(&skbtxq);
dev_remove_pack(&aoe_pt);
}