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path: root/drivers/net/bonding
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2007-05-09Fix occurrences of "the the "Michael Opdenacker
Signed-off-by: Michael Opdenacker <michael@free-electrons.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-04-28[NET]: Remove NETIF_F_INTERNAL_STATS, default to internal stats.Rusty Russell
Herbert Xu conviced me that a new flag was overkill; every driver currently overrides get_stats, so we might as well make the internal one the default. If someone did fail to set get_stats, they would now get all 0 stats instead of "No statistics available". Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[NET]: Inline net_device_statsRusty Russell
Network drivers which keep stats allocate their own stats structure then write a get_stats() function to return them. It would be nice if this were done by default. 1) Add a new "stats" field to "struct net_device". 2) Add a new feature field to say "this driver uses the internal one" 3) Have a default "get_stats" which returns NULL if that feature not set. 4) Change callers to check result of get_stats call for NULL, not if ->get_stats is set. This should not break backwards compatibility with older drivers, yet allow modern drivers to shed some boilerplate code. Lightly tested: works for a modified lguest network driver. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: unions of just one member don't get anything done, kill themArnaldo Carvalho de Melo
Renaming skb->h to skb->transport_header, skb->nh to skb->network_header and skb->mac to skb->mac_header, to match the names of the associated helpers (skb[_[re]set]_{transport,network,mac}_header). Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce ipv6_hdr(), remove skb->nh.ipv6hArnaldo Carvalho de Melo
Now the skb->nh union has just one member, .raw, i.e. it is just like the skb->mac union, strange, no? I'm just leaving it like that till the transport layer is done with, when we'll rename skb->mac.raw to skb->mac_header (or ->mac_header_offset?), ditto for ->{h,nh}. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce arp_hdr(), remove skb->nh.arphArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iphArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_network_header()Arnaldo Carvalho de Melo
For the places where we need a pointer to the network header, it is still legal to touch skb->nh.raw directly if just adding to, subtracting from or setting it to another layer header. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF] bonding: Set skb->nh.raw relative to skb->mac.rawArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[BONDING]: Introduce arp_pkt()Arnaldo Carvalho de Melo
For consistency with all the other skb->nh.raw accessors. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[SK_BUFF]: Introduce skb_reset_mac_header(skb)Arnaldo Carvalho de Melo
For the common, open coded 'skb->mac.raw = skb->data' operation, so that we can later turn skb->mac.raw into a offset, reducing the size of struct sk_buff in 64bit land while possibly keeping it as a pointer on 32bit. This one touches just the most simple case, next will handle the slightly more "complex" cases. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-06bonding: Improve IGMP join processingJay Vosburgh
In active-backup mode, the current bonding code duplicates IGMP traffic to all slaves, so that switches are up to date in case of a failover from an active to a backup interface. If bonding then fails back to the original active interface, it is likely that the "active slave" switch's IGMP forwarding for the port will be out of date until some event occurs to refresh the switch (e.g., a membership query). This patch alters the behavior of bonding to no longer flood IGMP to all ports, and to issue IGMP JOINs to the newly active port at the time of a failover. This insures that switches are kept up to date for all cases. "GOELLESCH Niels" <niels.goellesch@eurocontrol.int> originally reported this problem, and included a patch. His original patch was modified by Jay Vosburgh to additionally remove the existing IGMP flood behavior, use RCU, streamline code paths, fix trailing white space, and adjust for style. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-06bonding: only receive ARPs for usJay Vosburgh
The ARP validation code only needs ARPs for the bonding device. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-06bonding: fix double dev_add_packJay Vosburgh
Bonding can erroneously register the same packet_type to receive ARPs (for use by ARP validation): once at device open time, and once via sysfs. Since sysfs can change the validate setting (and thus register or unregister) at any time, a flag is needed to synchronize with device open in order to avoid double registrations, and the simplest place is within the packet_type structure itself. Double unregister is not an issue. Bug reported by Ulrich Oelmann <ulrich.oelmann@web.de>. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-03-02[VLAN]: Avoid a 4-order allocation.Dan Aloni
This patch splits the vlan_group struct into a multi-allocated struct. On x86_64, the size of the original struct is a little more than 32KB, causing a 4-order allocation, which is prune to problems caused by buddy-system external fragmentation conditions. I couldn't just use vmalloc() because vfree() cannot be called in the softirq context of the RCU callback. Signed-off-by: Dan Aloni <da-x@monatomic.org> Acked-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] mark struct file_operations const 5Arjan van de Ven
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-08[BONDING]: Replace kmalloc() + memset() pairs with the appropriate kzalloc() ↵Joe Jin
calls Replace kmalloc() + memset() pairs with the appropriate kzalloc() calls in the bonding driver. Signed-off-by: Joe Jin <lkmaillist@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-02-07Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (28 commits) sysfs: Shadow directory support Driver Core: Increase the default timeout value of the firmware subsystem Driver core: allow to delay the uevent at device creation time Driver core: add device_type to struct device Driver core: add uevent vars for devices of a class SYSFS: Fix missing include of list.h in sysfs.h HOWTO: Add a reference to Harbison and Steele sysfs: error handling in sysfs, fill_read_buffer() kobject: kobject_put cleanup sysfs: kobject_put cleanup sysfs: suppress lockdep warnings Driver core: fix race in sysfs between sysfs_remove_file() and read()/write() driver core: Change function call order in device_bind_driver(). driver core: Don't stop probing on ->probe errors. driver core fixes: device_register() retval check in platform.c driver core fixes: make_class_name() retval checks /sys/modules/*/holders USB: add the sysfs driver name to all modules SERIO: add the sysfs driver name to all modules PCI: add the sysfs driver name to all modules ...
2007-02-07Network: convert network devices to use struct device instead of class_deviceGreg Kroah-Hartman
This lets the network core have the ability to handle suspend/resume issues, if it wants to. Thanks to Frederik Deweerdt <frederik.deweerdt@gmail.com> for the arm driver fixes. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-05bonding: update versionJay Vosburgh
Update version number to reflect recent changes. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-02-05bonding: modify sysfs support to permit multiple loadsJay Vosburgh
The existing code would blindly attempt to create the bonding_masters file (in /sys/class/net) every time the module was loaded. When the module is loaded multiple times (which is the historical method used by initscripts and sysconfig to create multiple bonding interfaces), this caused load failure of the second module load attempt, as the creation request would fail. This changes the code to note the failure, arrange to not remove the bonding_masters file upon module exit, and then return success. Bonding interfaces created by the second or subsequent loads of the module will not exist in bonding_masters. This is not a significant change, as previously only the interfaces from the most recent load of the module would be listed. Both situations are less than optimal, but this case permits compatibility with existing distro configuration scripts, and is consistent. Note that previously, the sysfs create request would overwrite the exsting bonding_masters file and succeed, allowing multiple loads of the module. The sysfs code has recently changed to return an error if the file being created already exists. Patrick McHardy <kaber@trash.net>, who reported this problem, observed crashes on the old kernel (before sysfs checked for duplicates). I did not experience such crashes, but this change should resolve them. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-02-05bonding: fix error check in sysfs creationJay Vosburgh
The existing code did not correctly handle failures to create the per-interface sysfs group for bonding. Modified code to notice errors, and correctly unwind. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-02-05bonding: fix device name allocation errorJay Vosburgh
The code to select names for the bonding interfaces was, for the non-sysfs creation case, always using a hard-coded set of bond0, bond1, etc, up to max_bonds. This caused conflicts for the second or subsequent loads of the module. Changed the code to obtain device names from dev_alloc_name(). Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-02-05bonding.h: "extern inline" -> "static inline"Adrian Bunk
"extern inline" generates a warning with -Wmissing-prototypes and I'm currently working on getting the kernel cleaned up for adding this to the CFLAGS since it will help us to avoid a nasty class of runtime errors. If there are places that really need a forced inline, __always_inline would be the correct solution. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-01-30bonding: ARP monitoring broken on x86_64Andy Gospodarek
While working with the latest bonding code I noticed a nasty problem that will prevent arp monitoring from always functioning correctly on x86_64 systems. Comparing ints to longs and expecting reliable results on x86_64 is a bad idea. With this patch, arp monitoring works correctly again. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Hemminger <shemminger@osdl.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-12-04[PATCH] bonding: incorrect bonding state reported via ioctlAndy Gospodarek
This is a small fix-up to finish out the work done by Jay Vosburgh to add carrier-state support for bonding devices. The output in /proc/net/bonding/bondX was correct, but when collecting the same info via an iotcl it could still be incorrect. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Cc: Jeff Garzik <jeff@garzik.org> Cc: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-11-30[PATCH] bonding: fix an oops when slave device does not provide get_statsLaurent Riffard
Bonding driver unconditionnaly dereference get_stats function pointer for each of its slave device. This patch - adds a check for NULL dev->get_stats pointer in bond_get_stats - prints a notice when the bonding device enslave a device without get_stats function. Signed-off-by: Laurent Riffard <laurent.riffard@free.fr> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-11-10[PATCH] bonding: lockdep annotationPeter Zijlstra
============================================= [ INFO: possible recursive locking detected ] 2.6.17-1.2600.fc6 #1 Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-10-05[PATCH] bonding: fix deadlock on high loads in bond_alb_monitor()Karsten Keil
In bond_alb_monitor the bond->curr_slave_lock write lock is taken and then dev_set_promiscuity maybe called which can take some time, depending on the network HW. If a network IRQ for this card come in the softirq handler maybe try to deliver more packets which end up in a request to the read lock of bond->curr_slave_lock -> deadlock. This issue was found by a test lab during network stress tests, this patch disable the softirq handler for this case and solved the issue. Signed-off-by: Karsten Keil <kkeil@suse.de> Acked-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-28[IPV4]: annotate struct in_ifaddrAl Viro
ifa_local, ifa_address, ifa_mask, ifa_broadcast and ifa_anycast are net-endian. Annotated them and variables that are inferred to be net-endian. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-27[PATCH] bonding: update version numberJay Vosburgh
I neglected to properly update the version number in the recent patch series; this sets it to something reasonable. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Fix primary selection error at enslavement timeJay Vosburgh
At enslavement time, the primary slave might not be activated if there is already an active slave and the new slave is the primary. Replaced complicated logic with a call to bond_select_active_slave(), which does the right thing. Fixes http://bugzilla.kernel.org/show_bug.cgi?id=6378 Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Don't mangle LACPDUsJay Vosburgh
Fixed handling of 802.3ad LACPDUs. Do not byte swap data in place in the packet. Updated nomenclature of "__ntohs_lacpdu" to be "htons"; it was previously used for both ntohs and htons operations, but only called ntohs functions. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Validate probe replies in ARP monitorJay Vosburgh
Add logic to check ARP request / reply packets used for ARP monitor link integrity checking. The current method simply examines the slave device to see if it has sent and received traffic; this can be fooled by extraneous traffic. For example, if multiple hosts running bonding are behind a common switch, the probe traffic from the multiple instances of bonding will update the tx/rx times on each other's slave devices. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Don't release slaves when master is admin downjamal
When a bonding netdevice is admin-ed down it loses the slaves attributes (set via ifenslave). This is not consistent with other behavior of netdevices (example a qdisc attached to a netdevice doesnt disappear or an attached IP address etc). The included patch fixes this. Ive tested by ifenslaving, downing the bond, checking /proc and making sure it still has the slaves, up-ing the bond and making sure things continue to work. Jay/Bonding folks if you are ok with it, just ACK it or include it in your tree etc. Otherwise we can discuss. Acked-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Add priv_flag to avoid event mishandlingJay Vosburgh
Add priv_flag to specifically identify bonding-involved devices. Needed because IFF_MASTER is an unreliable identifier (vlan interfaces above bonding will inherit IFF_MASTER). Misidentification of devices would cause notifier events for other devices to be erroneously processed by bonding, causing various havoc. Bug discovered by Martin Papik <martin.papik@ipsec.info>; this patch is modified from his original. Signed-off-by: Martin Papik <martin.papik@ipsec.info> Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Handle large hard_header_lenJay Vosburgh
The bonding driver fails to adjust its hard_header_len when enslaving interfaces. Whenever an interface with a hard_header_len greater than the ETH_HLEN default is enslaved, the potential for an oops exists, and if the oops happens while responding to an arp request, for example, the system panics. GIANFAR devices may use an extended hard_header for VLAN or hardware checksumming. Enslaving such a device and then transmitting over it causes a kernel panic. Patch modified from submitter's original, but submitter agreed with this patch in private email. Signed-off-by: Mark Huth <mhuth@mvista.com> Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Remove unneeded NULL testJay Vosburgh
Remove unneeded test for NULL. Reported by Thomas Dillig <tdillig@stanford.edu> and Isil Dillig <isil@stanford.edu> via Stephen Hemminger <shemminger@osdl.org>. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Format fix in seq_printf callKenzo Iwami
Though link_failure_count is type unsigned int, this value is outputted to /proc/net/bonding/bondX file using "%d" instead of "%u". The attached patch fixes this problem. Signed-off-by: Kenzo Iwami <k-iwami@cj.jp.nec.com> Acked-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Convert delay value from s16 to intJay Vosburgh
The value of "downdelay/miimon" and "updelay/miimon" are stored in slave->delay. The type of downdelay, updelay, and miimon are all int. However, slave->delay is type short, and it is not possible to store the value of "downdelay/miimon" or "updelay/miimon" in some cases. (For example, miimon=1 downdelay=32768) The attached patch fixes this problem. Signed-off-by: Kenzo Iwami <k-iwami@cj.jp.nec.com> Acked-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-25[PATCH] bonding: Allow bonding to enslave a 10 Gig adapterJay Vosburgh
Allow channel bonding to enslave a 10 Gig adapter without errors. Signed-off-by: Mitch Williams <mitch.a.williams@intel.com> Acked-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-13drivers/net: const-ify ethtool_ops declarationsJeff Garzik
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-17[NET]: Add NETIF_F_GEN_CSUM and NETIF_F_ALL_CSUMHerbert Xu
The current stack treats NETIF_F_HW_CSUM and NETIF_F_NO_CSUM identically so we test for them in quite a few places. For the sake of brevity, I'm adding the macro NETIF_F_GEN_CSUM for these two. We also test the disjunct of NETIF_F_IP_CSUM and the other two in various places, for that purpose I've added NETIF_F_ALL_CSUM. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17[NET]: Add netif_tx_lockHerbert Xu
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>
2006-03-29[PATCH] bonding: support carrier state for masterJay Vosburgh
Add support for the bonding master to specify its carrier state based upon the state of the slaves. For 802.3ad, the bond is up if there is an active, parterned aggregator. For other modes, the bond is up if any slaves are up. Updates driver version to 3.0.3. Based on a patch by jamal <hadi@cyberus.ca>. Signed-off-by: Jay Vosburgh <fubar@us.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-27[PATCH] Notifier chain update: API changesAlan Stern
The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-03Merge branch 'net-const'Jeff Garzik
2006-03-03Massive net driver const-ification.Arjan van de Ven