The patch titled
netpoll: revert two bogus cleanups that broke netconsole
has been added to the -mm tree. Its filename is
netpoll-revert-two-bogus-cleanups-that-broke-netconsole.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: netpoll: revert two bogus cleanups that broke netconsole
From: David Miller <davem@xxxxxxxxxxxxx>
Based upon a report by Andrew Morton and code analysis done by Jarek
Poplawski.
This reverts 33f807ba0d9259e7c75c7a2ce8bd2787e5b540c7 ("[NETPOLL]: Kill
NETPOLL_RX_DROP, set but never tested.") and
c7b6ea24b43afb5749cb704e143df19d70e23dea ("[NETPOLL]: Don't need rx_flags.").
The rx_flags did get tested for zero vs. non-zero and therefore we do need
those tests and that code which sets NETPOLL_RX_DROP et al.
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/netpoll.h | 7 ++++---
net/core/netpoll.c | 12 ++++++++----
2 files changed, 12 insertions(+), 7 deletions(-)
diff -puN include/linux/netpoll.h~netpoll-revert-two-bogus-cleanups-that-broke-netconsole include/linux/netpoll.h
--- a/include/linux/netpoll.h~netpoll-revert-two-bogus-cleanups-that-broke-netconsole
+++ a/include/linux/netpoll.h
@@ -25,6 +25,7 @@ struct netpoll {
struct netpoll_info {
atomic_t refcnt;
+ int rx_flags;
spinlock_t rx_lock;
struct netpoll *rx_np; /* netpoll that registered an rx_hook */
struct sk_buff_head arp_tx; /* list of arp requests to reply to */
@@ -50,12 +51,12 @@ static inline int netpoll_rx(struct sk_b
unsigned long flags;
int ret = 0;
- if (!npinfo || !npinfo->rx_np)
+ if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
return 0;
spin_lock_irqsave(&npinfo->rx_lock, flags);
- /* check rx_np again with the lock held */
- if (npinfo->rx_np && __netpoll_rx(skb))
+ /* check rx_flags again with the lock held */
+ if (npinfo->rx_flags && __netpoll_rx(skb))
ret = 1;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
diff -puN net/core/netpoll.c~netpoll-revert-two-bogus-cleanups-that-broke-netconsole net/core/netpoll.c
--- a/net/core/netpoll.c~netpoll-revert-two-bogus-cleanups-that-broke-netconsole
+++ a/net/core/netpoll.c
@@ -39,6 +39,8 @@ static struct sk_buff_head skb_pool;
static atomic_t trapped;
#define USEC_PER_POLL 50
+#define NETPOLL_RX_ENABLED 1
+#define NETPOLL_RX_DROP 2
#define MAX_SKB_SIZE \
(MAX_UDP_CHUNK + sizeof(struct udphdr) + \
@@ -126,11 +128,13 @@ static int poll_one_napi(struct netpoll_
if (!test_bit(NAPI_STATE_SCHED, &napi->state))
return budget;
+ npinfo->rx_flags |= NETPOLL_RX_DROP;
atomic_inc(&trapped);
work = napi->poll(napi, budget);
atomic_dec(&trapped);
+ npinfo->rx_flags &= ~NETPOLL_RX_DROP;
return budget - work;
}
@@ -472,7 +476,7 @@ int __netpoll_rx(struct sk_buff *skb)
if (skb->dev->type != ARPHRD_ETHER)
goto out;
- /* if receive ARP during middle of NAPI poll, then queue */
+ /* check if netpoll clients need ARP */
if (skb->protocol == htons(ETH_P_ARP) &&
atomic_read(&trapped)) {
skb_queue_tail(&npi->arp_tx, skb);
@@ -534,9 +538,6 @@ int __netpoll_rx(struct sk_buff *skb)
return 1;
out:
- /* If packet received while already in poll then just
- * silently drop.
- */
if (atomic_read(&trapped)) {
kfree_skb(skb);
return 1;
@@ -675,6 +676,7 @@ int netpoll_setup(struct netpoll *np)
goto release;
}
+ npinfo->rx_flags = 0;
npinfo->rx_np = NULL;
spin_lock_init(&npinfo->rx_lock);
@@ -756,6 +758,7 @@ int netpoll_setup(struct netpoll *np)
if (np->rx_hook) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_flags |= NETPOLL_RX_ENABLED;
npinfo->rx_np = np;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
@@ -797,6 +800,7 @@ void netpoll_cleanup(struct netpoll *np)
if (npinfo->rx_np == np) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
npinfo->rx_np = NULL;
+ npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
_
Patches currently in -mm which might be from davem@xxxxxxxxxxxxx are
origin.patch
git-powerpc.patch
git-net.patch
execute-tasklets-in-the-same-order-they-were-queued.patch
git-sparc64.patch
bluetooth-hci_core-defer-hci_unregister_sysfs.patch
bluetooth-conwise-technology-based-adapters-with-buggy-sco-support-bugzilla-9027.patch
the-kernel-gets-no-ip-from-some-dhcp-servers.patch
rxrpc-fix-rxrpc_recvmsgs-returning-of-msg_name.patch
netpoll-revert-two-bogus-cleanups-that-broke-netconsole.patch
netlink-use-generic-lsm-hook.patch
kprobes-prevent-probing-of-preempt_schedule-fix.patch
sysctl-merge-equal-proc_sys_read-and-proc_sys_write.patch
sysctl-clean-from-unneeded-extern-and-forward-declarations.patch
sysctl-add-the-permissions-callback-on-the-ctl_table_root.patch
asm-futexh-should-include-linux-uaccessh.patch
remove-duplicated-unlikely-in-is_err.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
