linux/net
Herbert Xu 932ff279a4 [NET]: Add netif_tx_lock
Various drivers use xmit_lock internally to synchronise with their
transmission routines.  They do so without setting xmit_lock_owner.
This is fine as long as netpoll is not in use.

With netpoll it is possible for deadlocks to occur if xmit_lock_owner
isn't set.  This is because if a printk occurs while xmit_lock is held
and xmit_lock_owner is not set can cause netpoll to attempt to take
xmit_lock recursively.

While it is possible to resolve this by getting netpoll to use
trylock, it is suboptimal because netpoll's sole objective is to
maximise the chance of getting the printk out on the wire.  So
delaying or dropping the message is to be avoided as much as possible.

So the only alternative is to always set xmit_lock_owner.  The
following patch does this by introducing the netif_tx_lock family of
functions that take care of setting/unsetting xmit_lock_owner.

I renamed xmit_lock to _xmit_lock to indicate that it should not be
used directly.  I didn't provide irq versions of the netif_tx_lock
functions since xmit_lock is meant to be a BH-disabling lock.

This is pretty much a straight text substitution except for a small
bug fix in winbond.  It currently uses
netif_stop_queue/spin_unlock_wait to stop transmission.  This is
unsafe as an IRQ can potentially wake up the queue.  So it is safer to
use netif_tx_disable.

The hamradio bits used spin_lock_irq but it is unnecessary as
xmit_lock must never be taken in an IRQ handler.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:30:14 -07:00
..
802 [TR]: Remove an unused export. 2006-05-16 15:23:40 -07:00
8021q [NET]: Replace skb_pull/skb_postpull_rcsum with skb_pull_rcsum 2006-03-20 22:43:56 -08:00
appletalk [NET]: Fix ipx/econet/appletalk/irda ioctl crashes 2006-03-28 17:02:43 -08:00
atm [NET]: Add netif_tx_lock 2006-06-17 21:30:14 -07:00
ax25 [AX.25]: Eleminate HZ from AX.25 kernel interfaces 2006-05-03 23:27:16 -07:00
bluetooth [BLUETOOTH] sco: Possible double free. 2006-04-09 22:25:29 -07:00
bridge [BRIDGE]: netlink interface for link management 2006-06-17 21:26:14 -07:00
core [NET]: Add netif_tx_lock 2006-06-17 21:30:14 -07:00
dccp [I/OAT]: Make sk_eat_skb I/OAT aware. 2006-06-17 21:25:52 -07:00
decnet [DECNET]: Fix level1 router hello 2006-05-03 23:36:23 -07:00
econet [ECONET]: Convert away from SOCKOPS_WRAPPED 2006-03-28 17:02:43 -08:00
ethernet [NET]: Eliminate unused /proc/sys/net/ethernet 2006-06-05 15:34:11 -07:00
ieee80211 [PATCH] softmac: make non-operational after being stopped 2006-05-05 16:55:22 -04:00
ipv4 [NETFILTER]: hashlimit match: fix random initialization 2006-06-17 21:30:11 -07:00
ipv6 [SECMARK]: Add secmark support to core networking. 2006-06-17 21:29:57 -07:00
ipx [IPX]: Correct return type of ipx_map_frame_type(). 2006-05-16 15:17:49 -07:00
irda [IRDA]: Missing allocation result check in irlap_change_speed(). 2006-06-05 15:34:52 -07:00
key [LSM-IPsec]: SELinux Authorize 2006-06-17 21:29:45 -07:00
lapb [NET]: Kill skb->list 2005-08-29 15:31:14 -07:00
llc [LLC]: Fix double receive of SKB. 2006-06-17 21:29:19 -07:00
netfilter [SECMARK]: Add CONNSECMARK xtables target 2006-06-17 21:30:03 -07:00
netlink Merge branch 'audit.b10' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current 2006-05-01 21:43:05 -07:00
netrom [NETROM/ROSE]: Kill module init version kernel log messages. 2006-05-05 17:19:26 -07:00
packet [NET]: Fix some whitespace issues in af_packet.c 2006-01-23 16:28:02 -08:00
rose [NETROM/ROSE]: Kill module init version kernel log messages. 2006-05-05 17:19:26 -07:00
rxrpc [PATCH] fix 'defined but not used' warning in net/rxrpc/main.c::rxrpc_initialise 2006-03-25 08:22:52 -08:00
sched [NET]: Add netif_tx_lock 2006-06-17 21:30:14 -07:00
sctp [SCTP]: Allow linger to abort 1-N style sockets. 2006-05-19 14:32:06 -07:00
sunrpc [PATCH] knfsd: Fix two problems that can cause rmmod nfsd to die 2006-05-23 10:35:31 -07:00
tipc [NET]: Remove redundant NULL checks before [kv]free 2006-04-18 15:57:55 -07:00
unix [PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications 2006-03-25 08:22:56 -08:00
wanrouter [WAN]: Remove broken and unmaintained Sangoma drivers. 2006-04-11 17:28:33 -07:00
x25 [X25]: fix for spinlock recurse and spinlock lockup with timer handler 2006-04-29 18:33:11 -07:00
xfrm [NET]: Fix warnings after LSM-IPSEC changes. 2006-06-17 21:29:49 -07:00
compat.c [NETFILTER]: iptables 32bit compat layer 2006-04-01 02:25:19 -08:00
Kconfig [SECMARK]: Add secmark support to core networking. 2006-06-17 21:29:57 -07:00
Makefile [TIPC] Initial merge 2006-01-12 14:06:31 -08:00
nonet.c [PATCH] Make most file operations structs in fs/ const 2006-03-28 09:16:06 -08:00
socket.c [PATCH] sockaddr patch 2006-05-01 06:06:10 -04:00
sysctl_net.c [NET]: Eliminate unused /proc/sys/net/ethernet 2006-06-05 15:34:11 -07:00
TUNABLE Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00