- 06 12月, 2009 1 次提交
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由 David Daney 提交于
Starting with version 4.5, GCC has a new built-in function __builtin_unreachable() that can be used in places like the kernel's BUG() where inline assembly is used to transfer control flow. This eliminated the need for an endless loop in these places. The patch adds a new macro 'unreachable()' that will expand to either __builtin_unreachable() or an endless loop depending on the compiler version. Change from v1: Simplify unreachable() for non-GCC 4.5 case. Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com> Acked-by: NRalf Baechle <ralf@linux-mips.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 12月, 2009 6 次提交
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由 Patrick Mullaney 提交于
Provide common routine for the transition of operational state for a leaf device during a root device transition. Signed-off-by: NPatrick Mullaney <pmullaney@novell.com> Acked-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Oliver Neukum 提交于
Using remote wakeup and delayed transmission to allow online device to go into usb autosuspend. Minimal alternate support for devices that don't support remote wakeup. Signed-off-by: NOliver Neukum <oliver@neukum.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Matt Carlson 提交于
This patch cleans up the VPD code by creating preprocessor definitions and using them in the place of hardcoded constants. Signed-off-by: NMatt Carlson <mcarlson@broadcom.com> Reviewed-by: NMichael Chan <mchan@broadcom.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Patrick McHardy 提交于
commit 8ec1e0ebe26087bfc5c0394ada5feb5758014fc8 Author: Patrick McHardy <kaber@trash.net> Date: Thu Dec 3 12:16:35 2009 +0100 ipv4: add sysctl to accept packets with local source addresses Change fib_validate_source() to accept packets with a local source address when the "accept_local" sysctl is set for the incoming inet device. Combined with the previous patches, this allows to communicate between multiple local interfaces over the wire. Signed-off-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Patrick McHardy 提交于
commit 68144d350f4f6c348659c825cde6a82b34c27a91 Author: Patrick McHardy <kaber@trash.net> Date: Thu Dec 3 12:05:25 2009 +0100 net: fib_rules: add oif classification Support routing table lookup based on the flow's oif. This is useful to classify packets originating from sockets bound to interfaces differently. The route cache already includes the oif and needs no changes. Signed-off-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Patrick McHardy 提交于
commit 229e77eec406ad68662f18e49fda8b5d366768c5 Author: Patrick McHardy <kaber@trash.net> Date: Thu Dec 3 12:05:23 2009 +0100 net: fib_rules: rename ifindex/ifname/FRA_IFNAME to iifindex/iifname/FRA_IIFNAME The next patch will add oif classification, rename interface related members and attributes to reflect that they're used for iif classification. Signed-off-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 03 12月, 2009 7 次提交
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由 Steven Whitehouse 提交于
There are two spare field in the header common to all GFS2 metadata. One is just the right size to fit a journal id in it, and this patch updates the journal code so that each time a metadata block is modified, we tag it with the journal id of the node which is performing the modification. The reason for this is that it should make it much easier to debug issues which arise if we can tell which node was the last to modify a particular metadata block. Since the field is updated before the block is written into the journal, each journal should only contain metadata which is tagged with its own journal id. The one exception to this is the journal header block, which might have a different node's id in it, if that journal was recovered by another node in the cluster. Thus each journal will contain a record of which nodes recovered it, via the journal header. The other field in the metadata header could potentially be used to hold information about what kind of operation was performed, but for the time being we just zero it on each transaction so that if we use it for that in future, we'll know that the information (where it exists) is reliable. I did consider using the other field to hold the journal sequence number, however since in GFS2's journaling we write the modified data into the journal and not the original data, this gives no information as to what action caused the modification, so I think we can probably come up with a better use for those 64 bits in the future. Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
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由 Steven Whitehouse 提交于
Sending a message to userspace in a generic format to warn of events (e.g. quota exceeded) in the quota subsystem is a generically useful feature. This patch makes some minor changes to the send_message function from dquot.c renaming it quota_send_message, moving it to quota.c and exporting it for use by filesystems which do not use the dquot code. Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
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由 Steven Whitehouse 提交于
This is required for cluster filesystems which want to use cached ACLs so that they can invalidate the cache when required. Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com> Cc: Alexander Viro <aviro@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>
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由 William Allen Simpson 提交于
Data structures are carefully composed to require minimal additions. For example, the struct tcp_options_received cookie_plus variable fits between existing 16-bit and 8-bit variables, requiring no additional space (taking alignment into consideration). There are no additions to tcp_request_sock, and only 1 pointer in tcp_sock. This is a significantly revised implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 The principle difference is using a TCP option to carry the cookie nonce, instead of a user configured offset in the data. This is more flexible and less subject to user configuration error. Such a cookie option has been suggested for many years, and is also useful without SYN data, allowing several related concepts to use the same extension option. "Re: SYN floods (was: does history repeat itself?)", September 9, 1996. http://www.merit.net/mail.archives/nanog/1996-09/msg00235.html "Re: what a new TCP header might look like", May 12, 1998. ftp://ftp.isi.edu/end2end/end2end-interest-1998.mail These functions will also be used in subsequent patches that implement additional features. Requires: TCPCT part 1a: add request_values parameter for sending SYNACK TCPCT part 1b: generate Responder Cookie secret TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 William Allen Simpson 提交于
Define sysctl (tcp_cookie_size) to turn on and off the cookie option default globally, instead of a compiled configuration option. Define per socket option (TCP_COOKIE_TRANSACTIONS) for setting constant data values, retrieving variable cookie values, and other facilities. Move inline tcp_clear_options() unchanged from net/tcp.h to linux/tcp.h, near its corresponding struct tcp_options_received (prior to changes). This is a straightforward re-implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 These functions will also be used in subsequent patches that implement additional features. Requires: net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 William Allen Simpson 提交于
Define (missing) hash message size for SHA1. Define hashing size constants specific to TCP cookies. Add new function: tcp_cookie_generator(). Maintain global secret values for tcp_cookie_generator(). This is a significantly revised implementation of earlier (15-year-old) Photuris [RFC-2522] code for the KA9Q cooperative multitasking platform. Linux RCU technique appears to be well-suited to this application, though neither of the circular queue items are freed. These functions will also be used in subsequent patches that implement additional features. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Alexander Duyck 提交于
The two functions skb_dma_map/unmap are unsafe to use as they cause problems when packets are cloned and sent to multiple devices while a HW IOMMU is enabled. Due to this it is best to remove the code so it is not used by any other network driver maintainters. Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 12月, 2009 4 次提交
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由 Hiroshi Shimamoto 提交于
Reorder task_struct field for TRACE_IRQFLAGS to remove padding on 64-bit. Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4B135F50.8070302@ct.jp.nec.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Eric W. Biederman 提交于
I will need this shortly to implement network namespace shutdown batching. For sanity sake network devices should be removed in the reverse order they were created in. Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric W. Biederman 提交于
The motivation for an additional notifier in batched netdevice notification (rt_do_flush) only needs to be called once per batch not once per namespace. For further batching improvements I need a guarantee that the netdevices are unregistered in order allowing me to unregister an all of the network devices in a network namespace at the same time with the guarantee that the loopback device is really and truly unregistered last. Additionally it appears that we moved the route cache flush after the final synchronize_net, which seems wrong and there was no explanation. So I have restored the original location of the final synchronize_net. Cc: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David Howells 提交于
Move slow_work's debugging proc file to debugfs. Signed-off-by: NDavid Howells <dhowells@redhat.com> Requested-and-acked-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 12月, 2009 1 次提交
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由 Mark Brown 提交于
There was confusion between the array size and the highest ISEL value possible. Reported-by: NDan Carpenter <error27@gmail.com> Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>
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- 29 11月, 2009 2 次提交
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由 PJ Waskiewicz 提交于
This patch allows a base driver to specify Direct Attach as the type of port through the ethtool interface. Signed-off-by: NPeter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Samuel Ortiz 提交于
This is an interface to set, delete and flush PMKIDs through nl80211. Main users would be fullmac devices which firmwares are capable of generating the RSN IEs for the re-association requests, e.g. iwmc3200wifi. Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com> Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
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- 27 11月, 2009 3 次提交
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由 Patrick McHardy 提交于
Currently the UP/DOWN state of VLANs is synchronized to the state of the underlying device, meaning all VLANs are set down once the underlying device is set down. This causes all routes to the VLAN devices to vanish. Add a flag to specify a "loose binding" mode, in which only the operstate is transfered, but the VLAN device state is independant. Signed-off-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Arnd Bergmann 提交于
In order to support all three modes of macvlan at runtime, extend the existing netlink protocol to allow choosing the mode per macvlan slave interface. This depends on a matching patch to iproute2 in order to become accessible in user land. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Arnd Bergmann 提交于
The veth driver contains code to forward an skb from the start_xmit function of one network device into the receive path of another device. Moving that code into a common location lets us reuse the code for direct forwarding of data between macvlan ports, and possibly in other drivers. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NPatrick McHardy <kaber@trash.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 26 11月, 2009 1 次提交
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由 Martin Willi 提交于
The new XFRMA_ALG_AUTH_TRUNC attribute taking a xfrm_algo_auth as argument allows the installation of authentication algorithms with a truncation length specified in userspace, i.e. SHA256 with 128 bit instead of 96 bit truncation. Signed-off-by: NMartin Willi <martin@strongswan.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 11月, 2009 4 次提交
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由 Thomas Gleixner 提交于
SPIN_LOCK_UNLOCKED and RW_LOCK_UNLOCKED are deprecated. Replace them with the __*_LOCK_UNLOCKED variants. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
commit 910067d1(remove generic__raw_read_trylock()) removed the implementation but left the prototype around. Remove it. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Serge E. Hallyn 提交于
As far as I know, all distros currently ship kernels with default CONFIG_SECURITY_FILE_CAPABILITIES=y. Since having the option on leaves a 'no_file_caps' option to boot without file capabilities, the main reason to keep the option is that turning it off saves you (on my s390x partition) 5k. In particular, vmlinux sizes came to: without patch fscaps=n: 53598392 without patch fscaps=y: 53603406 with this patch applied: 53603342 with the security-next tree. Against this we must weigh the fact that there is no simple way for userspace to figure out whether file capabilities are supported, while things like per-process securebits, capability bounding sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for applications wanting to know whether they can use them and/or why something failed. It also adds another subtly different set of semantics which we must maintain at the risk of severe security regressions. So this patch removes the SECURITY_FILE_CAPABILITIES compile option. It drops the kernel size by about 50k over the stock SECURITY_FILE_CAPABILITIES=y kernel, by removing the cap_limit_ptraced_target() function. Changelog: Nov 20: remove cap_limit_ptraced_target() as it's logic was ifndef'ed. Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com> Acked-by: NAndrew G. Morgan" <morgan@kernel.org> Signed-off-by: NJames Morris <jmorris@namei.org>
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由 Wei Yongjun 提交于
This patch implement the definition for SACK-IMMEDIATELY extension. Section 3. The I-bit in the DATA Chunk Header The following Figure 1 shows the extended DATA chunk. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type = 0 | Res |I|U|B|E| Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TSN | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Stream Identifier | Stream Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Payload Protocol Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ \ \ / User Data / \ \ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 The only difference between the DATA chunk in Figure 1 and the DATA chunk defined in [RFC4960] is the addition of the I-bit in the flags field of the chunk header. Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
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- 23 11月, 2009 3 次提交
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由 Pablo Neira Ayuso 提交于
Without this patch, if we receive a SYN packet from the client while the firewall is out-of-sync, we let it go through. Then, if we see the SYN/ACK reply coming from the server, we destroy the conntrack entry and drop the packet to trigger a new retransmission. Then, the retransmision from the client is used to start a new clean session. This patch improves the current handling. Basically, if we see an unexpected SYN packet, we annotate the TCP options. Then, if we see the reply SYN/ACK, this means that the firewall was indeed out-of-sync. Therefore, we set a clean new session from the existing entry based on the annotated values. This patch adds two new 8-bits fields that fit in a 16-bits gap of the ip_ct_tcp structure. This patch is particularly useful for conntrackd since the asynchronous nature of the state-synchronization allows to have backup nodes that are not perfect copies of the master. This helps to improve the recovery under some worst-case scenarios. I have tested this by creating lots of conntrack entries in wrong state: for ((i=1024;i<65535;i++)); do conntrack -I -p tcp -s 192.168.2.101 -d 192.168.2.2 --sport $i --dport 80 -t 800 --state ESTABLISHED -u ASSURED,SEEN_REPLY; done Then, I make some TCP connections: $ echo GET / | nc 192.168.2.2 80 The events show the result: [UPDATE] tcp 6 60 SYN_RECV src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED] [UPDATE] tcp 6 432000 ESTABLISHED src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED] [UPDATE] tcp 6 120 FIN_WAIT src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED] [UPDATE] tcp 6 30 LAST_ACK src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED] [UPDATE] tcp 6 120 TIME_WAIT src=192.168.2.101 dst=192.168.2.2 sport=33220 dport=80 src=192.168.2.2 dst=192.168.2.101 sport=80 dport=33220 [ASSURED] and tcpdump shows no retransmissions: 20:47:57.271951 IP 192.168.2.101.33221 > 192.168.2.2.www: S 435402517:435402517(0) win 5840 <mss 1460,sackOK,timestamp 4294961827 0,nop,wscale 6> 20:47:57.273538 IP 192.168.2.2.www > 192.168.2.101.33221: S 3509927945:3509927945(0) ack 435402518 win 5792 <mss 1460,sackOK,timestamp 235681024 4294961827,nop,wscale 4> 20:47:57.273608 IP 192.168.2.101.33221 > 192.168.2.2.www: . ack 3509927946 win 92 <nop,nop,timestamp 4294961827 235681024> 20:47:57.273693 IP 192.168.2.101.33221 > 192.168.2.2.www: P 435402518:435402524(6) ack 3509927946 win 92 <nop,nop,timestamp 4294961827 235681024> 20:47:57.275492 IP 192.168.2.2.www > 192.168.2.101.33221: . ack 435402524 win 362 <nop,nop,timestamp 235681024 4294961827> 20:47:57.276492 IP 192.168.2.2.www > 192.168.2.101.33221: P 3509927946:3509928082(136) ack 435402524 win 362 <nop,nop,timestamp 235681025 4294961827> 20:47:57.276515 IP 192.168.2.101.33221 > 192.168.2.2.www: . ack 3509928082 win 108 <nop,nop,timestamp 4294961828 235681025> 20:47:57.276521 IP 192.168.2.2.www > 192.168.2.101.33221: F 3509928082:3509928082(0) ack 435402524 win 362 <nop,nop,timestamp 235681025 4294961827> 20:47:57.277369 IP 192.168.2.101.33221 > 192.168.2.2.www: F 435402524:435402524(0) ack 3509928083 win 108 <nop,nop,timestamp 4294961828 235681025> 20:47:57.279491 IP 192.168.2.2.www > 192.168.2.101.33221: . ack 435402525 win 362 <nop,nop,timestamp 235681025 4294961828> I also added a rule to log invalid packets, with no occurrences :-) . Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org> Acked-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: NPatrick McHardy <kaber@trash.net>
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由 Paul E. McKenney 提交于
Remove #ifdefs from kernel/rcupdate.c and include/linux/rcupdate.h by moving code to include/linux/rcutiny.h, include/linux/rcutree.h, and kernel/rcutree.c. Also remove some definitions that are no longer used. Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1258908830885-git-send-email-> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Paul E. McKenney 提交于
The functions rcu_init() is a wrapper for __rcu_init(), and also sets up the CPU-hotplug notifier for rcu_barrier_cpu_hotplug(). But TINY_RCU doesn't need CPU-hotplug notification, and the rcu_barrier_cpu_hotplug() is a simple wrapper for rcu_cpu_notify(). So push rcu_init() out to kernel/rcutree.c and kernel/rcutiny.c and get rid of the wrapper function rcu_barrier_cpu_hotplug(). Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12589088302320-git-send-email-> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 21 11月, 2009 1 次提交
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由 Eric Dumazet 提交于
To help grep games, rename iif to skb_iif Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 20 11月, 2009 7 次提交
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由 Kevin Wells 提交于
Made buf type unsigned to prevent sign extension Signed-off-by: NKevin Wells <kevin.wells@nxp.com> Signed-off-by: NBen Dooks <ben-linux@fluff.org>
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由 Alan Cox 提交于
As this struct is exposed to user space and the API was added for this release it's a bit of a pain for the C++ world and we still have time to fix it. Rename the fields before we end up with that pain in an actual release. Signed-off-by: NAlan Cox <alan@linux.intel.com> Reported-by: Olivier Goffart Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Howells 提交于
Catch an overly long wait for an old, dying active object when we want to replace it with a new one. The probability is that all the slow-work threads are hogged, and the delete can't get a look in. What we do instead is: (1) if there's nothing in the slow work queue, we sleep until either the dying object has finished dying or there is something in the slow work queue behind which we can queue our object. (2) if there is something in the slow work queue, we return ETIMEDOUT to fscache_lookup_object(), which then puts us back on the slow work queue, presumably behind the deletion that we're blocked by. We are then deferred for a while until we work our way back through the queue - without blocking a slow-work thread unnecessarily. A backtrace similar to the following may appear in the log without this patch: INFO: task kslowd004:5711 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kslowd004 D 0000000000000000 0 5711 2 0x00000080 ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000 ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8 Call Trace: [<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles] [<ffffffffa011c4e1>] cachefiles_wait_bit+0x9/0xd [cachefiles] [<ffffffff81353153>] __wait_on_bit+0x43/0x76 [<ffffffff8111ae39>] ? ext3_xattr_get+0x1ec/0x270 [<ffffffff813531ef>] out_of_line_wait_on_bit+0x69/0x74 [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles] [<ffffffff8104c125>] ? wake_bit_function+0x0/0x2e [<ffffffffa011bc79>] cachefiles_mark_object_active+0x203/0x23b [cachefiles] [<ffffffffa011c209>] cachefiles_walk_to_object+0x558/0x827 [cachefiles] [<ffffffffa011a429>] cachefiles_lookup_object+0xac/0x12a [cachefiles] [<ffffffffa00aa1e9>] fscache_lookup_object+0x1c7/0x214 [fscache] [<ffffffffa00aafc5>] fscache_object_state_machine+0xa5/0x52d [fscache] [<ffffffffa00ab4ac>] fscache_object_slow_work_execute+0x5f/0xa0 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 1 lock held by kslowd004/5711: #0: (&sb->s_type->i_mutex_key#7/1){+.+.+.}, at: [<ffffffffa011be64>] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles] Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
cachefiles_write_page() writes a full page to the backing file for the last page of the netfs file, even if the netfs file's last page is only a partial page. This causes the EOF on the backing file to be extended beyond the EOF of the netfs, and thus the backing file will be truncated by cachefiles_attr_changed() called from cachefiles_lookup_object(). So we need to limit the write we make to the backing file on that last page such that it doesn't push the EOF too far. Also, if a backing file that has a partial page at the end is expanded, we discard the partial page and refetch it on the basis that we then have a hole in the file with invalid data, and should the power go out... A better way to deal with this could be to record a note that the partial page contains invalid data until the correct data is written into it. This isn't a problem for netfs's that discard the whole backing file if the file size changes (such as NFS). Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
Start processing an object's operations when that object moves into the DYING state as the object cannot be destroyed until all its outstanding operations have completed. Furthermore, make sure that read and allocation operations handle being woken up on a dead object. Such events are recorded in the Allocs.abt and Retrvls.abt statistics as viewable through /proc/fs/fscache/stats. The code for waiting for object activation for the read and allocation operations is also extracted into its own function as it is much the same in all cases, differing only in the stats incremented. Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
Handle netfs pages that the vmscan algorithm wants to evict from the pagecache under OOM conditions, but that are waiting for write to the cache. Under these conditions, vmscan calls the releasepage() function of the netfs, asking if a page can be discarded. The problem is typified by the following trace of a stuck process: kslowd005 D 0000000000000000 0 4253 2 0x00000080 ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8 Call Trace: [<ffffffffa00782d8>] __fscache_wait_on_page_write+0x8b/0xa7 [fscache] [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffffa0078240>] ? __fscache_check_page_write+0x63/0x70 [fscache] [<ffffffffa00b671d>] nfs_fscache_release_page+0x4e/0xc4 [nfs] [<ffffffffa00927f0>] nfs_release_page+0x3c/0x41 [nfs] [<ffffffff810885d3>] try_to_release_page+0x32/0x3b [<ffffffff81093203>] shrink_page_list+0x316/0x4ac [<ffffffff8109372b>] shrink_inactive_list+0x392/0x67c [<ffffffff813532fa>] ? __mutex_unlock_slowpath+0x100/0x10b [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130 [<ffffffff8135330e>] ? mutex_unlock+0x9/0xb [<ffffffff81093aa2>] shrink_list+0x8d/0x8f [<ffffffff81093d1c>] shrink_zone+0x278/0x33c [<ffffffff81052d6c>] ? ktime_get_ts+0xad/0xba [<ffffffff81094b13>] try_to_free_pages+0x22e/0x392 [<ffffffff81091e24>] ? isolate_pages_global+0x0/0x212 [<ffffffff8108e743>] __alloc_pages_nodemask+0x3dc/0x5cf [<ffffffff81089529>] grab_cache_page_write_begin+0x65/0xaa [<ffffffff8110f8c0>] ext3_write_begin+0x78/0x1eb [<ffffffff81089ec5>] generic_file_buffered_write+0x109/0x28c [<ffffffff8103cb69>] ? current_fs_time+0x22/0x29 [<ffffffff8108a509>] __generic_file_aio_write+0x350/0x385 [<ffffffff8108a588>] ? generic_file_aio_write+0x4a/0xae [<ffffffff8108a59e>] generic_file_aio_write+0x60/0xae [<ffffffff810b2e82>] do_sync_write+0xe3/0x120 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810b18e1>] ? __dentry_open+0x1a5/0x2b8 [<ffffffff810b1a76>] ? dentry_open+0x82/0x89 [<ffffffffa00e693c>] cachefiles_write_page+0x298/0x335 [cachefiles] [<ffffffffa0077147>] fscache_write_op+0x178/0x2c2 [fscache] [<ffffffffa0075656>] fscache_op_execute+0x7a/0xd1 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8102ef83>] ? tg_shares_up+0x171/0x227 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 In the above backtrace, the following is happening: (1) A page storage operation is being executed by a slow-work thread (fscache_write_op()). (2) FS-Cache farms the operation out to the cache to perform (cachefiles_write_page()). (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3's standard write (do_sync_write()) under KERNEL_DS directly from the netfs page. (4) However, for Ext3 to perform the write, it must allocate some memory, in particular, it must allocate at least one page cache page into which it can copy the data from the netfs page. (5) Under OOM conditions, the memory allocator can't immediately come up with a page, so it uses vmscan to find something to discard (try_to_free_pages()). (6) vmscan finds a clean netfs page it might be able to discard (possibly the one it's trying to write out). (7) The netfs is called to throw the page away (nfs_release_page()) - but it's called with __GFP_WAIT, so the netfs decides to wait for the store to complete (__fscache_wait_on_page_write()). (8) This blocks a slow-work processing thread - possibly against itself. The system ends up stuck because it can't write out any netfs pages to the cache without allocating more memory. To avoid this, we make FS-Cache cancel some writes that aren't in the middle of actually being performed. This means that some data won't make it into the cache this time. To support this, a new FS-Cache function is added fscache_maybe_release_page() that replaces what the netfs releasepage() functions used to do with respect to the cache. The decisions fscache_maybe_release_page() makes are counted and displayed through /proc/fs/fscache/stats on a line labelled "VmScan". There are four counters provided: "nos=N" - pages that weren't pending storage; "gon=N" - pages that were pending storage when we first looked, but weren't by the time we got the object lock; "bsy=N" - pages that we ignored as they were actively being written when we looked; and "can=N" - pages that we cancelled the storage of. What I'd really like to do is alter the behaviour of the cancellation heuristics, depending on how necessary it is to expel pages. If there are plenty of other pages that aren't waiting to be written to the cache that could be ejected first, then it would be nice to hold up on immediate cancellation of cache writes - but I don't see a way of doing that. Signed-off-by: NDavid Howells <dhowells@redhat.com>
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由 David Howells 提交于
FS-Cache has two structs internally for keeping track of the internal state of a cached file: the fscache_cookie struct, which represents the netfs's state, and fscache_object struct, which represents the cache's state. Each has a pointer that points to the other (when both are in existence), and each has a spinlock for pointer maintenance. Since netfs operations approach these structures from the cookie side, they get the cookie lock first, then the object lock. Cache operations, on the other hand, approach from the object side, and get the object lock first. It is not then permitted for a cache operation to get the cookie lock whilst it is holding the object lock lest deadlock occur; instead, it must do one of two things: (1) increment the cookie usage counter, drop the object lock and then get both locks in order, or (2) simply hold the object lock as certain parts of the cookie may not be altered whilst the object lock is held. It is also not permitted to follow either pointer without holding the lock at the end you start with. To break the pointers between the cookie and the object, both locks must be held. fscache_write_op(), however, violates the locking rules: It attempts to get the cookie lock without (a) checking that the cookie pointer is a valid pointer, and (b) holding the object lock to protect the cookie pointer whilst it follows it. This is so that it can access the pending page store tree without interference from __fscache_write_page(). This is fixed by splitting the cookie lock, such that the page store tracking tree is protected by its own lock, and checking that the cookie pointer is non-NULL before we attempt to follow it whilst holding the object lock. The new lock is subordinate to both the cookie lock and the object lock, and so should be taken after those. Signed-off-by: NDavid Howells <dhowells@redhat.com>
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