Tejun Heo e2f15f9a79 netconsole: implement extended console support ... printk logbuf keeps various metadata and optional key=value dictionary for structured messages, both of which are stripped when messages are handed to regular console drivers. It can be useful to have this metadata and dictionary available to netconsole consumers. This obviously makes logging via netconsole more complete and the sequence number in particular is useful in environments where messages may be lost or reordered in transit - e.g. when netconsole is used to collect messages in a large cluster where packets may have to travel congested hops to reach the aggregator. The lost and reordered messages can easily be identified and handled accordingly using the sequence numbers. printk recently added extended console support which can be selected by setting CON_EXTENDED flag. From console driver side, not much changes. The only difference is that the text passed to the write callback is formatted the same way as /dev/kmsg. This patch implements extended console support for netconsole which can be enabled by either prepending "+" to a netconsole boot param entry or echoing 1 to "extended" file in configfs. When enabled, netconsole transmits extended log messages with headers identical to /dev/kmsg output. There's one complication due to message fragments. netconsole limits the maximum message size to 1k and messages longer than that are split into multiple fragments. As all extended console messages should carry matching headers and be uniquely identifiable, each extended message fragment carries full copy of the metadata and an extra header field to identify the specific fragment. The optional header is of the form "ncfrag=OFF/LEN" where OFF is the byte offset into the message body and LEN is the total length. To avoid unnecessarily making printk format extended messages, Extended netconsole is registered with printk when the first extended netconsole is configured. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David Miller <davem@davemloft.net> Cc: Kay Sievers <kay@vrfy.org> Cc: Petr Mladek <pmladek@suse.cz> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2015-06-25 17:00:39 -07:00
..
ABI	printk: implement support for extended console drivers	2015-06-25 17:00:38 -07:00
accounting	Documentation: use subdir-y to avoid unnecessary built-in.o files	2014-09-26 11:02:55 +02:00
acpi	ACPI: Constify ACPI device IDs in documentation	2015-06-19 01:14:15 +02:00
aoe
arm	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
arm64	arm64: use fixmap region for permanent FDT mapping	2015-06-02 16:31:33 +01:00
auxdisplay	Documentation: use subdir-y to avoid unnecessary built-in.o files	2014-09-26 11:02:55 +02:00
backlight
blackfin	Docs: blackfin: Use new switch macro SAMPLE_IRQ_TIMER instead of IRQ_TIMER5	2015-05-07 09:35:14 -06:00
block	Documentation: Remove mentioning of block barriers	2015-03-20 07:41:56 -06:00
blockdev	zram: add dynamic device add/remove functionality	2015-06-25 17:00:36 -07:00
bus-devices
cdrom
cgroups	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
cma	cma: debug: document new debugfs interface	2015-04-14 16:49:00 -07:00
connector
console
cpu-freq	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
cpuidle
cris
crypto	crypto: doc - AEAD / RNG AF_ALG interface	2015-03-09 21:06:18 +11:00
development-process	Documentation: remove outdated references to the linux-next wiki	2014-10-28 09:06:11 -04:00
device-mapper	dm crypt: update URLs to new cryptsetup project page	2015-04-15 12:10:24 -04:00
devicetree	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2015-06-24 19:56:58 -07:00
dmaengine	Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma	2015-02-18 08:49:20 -08:00
DocBook	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
driver-model	Char/Misc driver patches for 4.1-rc1	2015-04-21 09:42:58 -07:00
dvb
early-userspace
EDID
extcon
fault-injection
fb
features	Documentation/features: Explain kernel feature descriptions and add visualization script	2015-06-03 12:59:38 +02:00
filesystems	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2015-06-24 20:07:10 -07:00
firmware_class
fmc
frv
gpio	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
hid	HID: sensor: Update document for custom sensor	2015-04-10 22:22:56 +02:00
hwmon	hwmon: add driver for Microchip TC74	2015-06-21 22:54:53 -07:00
i2c	i2c: slave: fix the example how to instantiate from userspace	2015-06-17 14:16:27 +02:00
ia64	virtual: Documentation: simplify and generalize paravirt_ops.txt	2015-02-13 17:15:44 +10:30
ide
infiniband
input	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
ioctl	platform/chrome: Add Chrome OS EC userspace device interface	2015-02-26 15:45:06 -08:00
isdn
ja_JP	Doc: ja_JP: Fix typo in HOWTO	2015-06-08 16:43:09 -06:00
kbuild	kbuild : Fix documentation of INSTALL_HDR_PATH	2015-06-22 09:56:07 -06:00
kdump	kernel: add panic_on_warn	2014-12-10 17:41:10 -08:00
ko_KR
laptops	Move freefall program from Documentation/ to tools/	2015-06-08 16:42:07 -06:00
leds	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2015-06-24 19:56:58 -07:00
locking	Documentation changes for 3.20	2015-02-11 13:03:11 -08:00
m68k
memory-devices
metag
mic	Documentation/mic/mpssd: don't build x86 userspace when cross compiling	2015-06-22 16:05:11 -06:00
mips
misc-devices	Pratyush Anand has moved	2015-06-25 17:00:38 -07:00
mmc
mn10300
mtd
namespaces
netlabel
networking	netconsole: implement extended console support	2015-06-25 17:00:39 -07:00
nfc	NFC: Fix typo in nfc-hci.txt	2015-06-08 23:15:45 +02:00
nios2	Documentation: Add documentation for Nios2 architecture	2014-12-08 12:56:06 +08:00
parisc
PCI	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
pcmcia	Documentation: use subdir-y to avoid unnecessary built-in.o files	2014-09-26 11:02:55 +02:00
phy
platform
power	PM / runtime: add note about re-calling in during device probe()	2015-05-13 00:02:38 +02:00
powerpc	powerpc/tm: Abort syscalls in active transactions	2015-06-19 17:10:28 +10:00
pps	Doc:pps: Fix typo in pps.txt	2015-06-22 09:59:28 -06:00
prctl	Documentation/prctl: don't build tsc tests when cross compiling	2015-06-22 16:05:04 -06:00
pti
ptp	ptp: restore the makefile for building the test program.	2014-10-24 16:07:10 -04:00
rapidio
RCU	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
s390	qeth: OSA version of SETBRIDGEPORT command	2015-05-18 12:14:17 -04:00
scheduler	sched/dl/Documentation: Split Section 3	2015-05-19 08:39:21 +02:00
scsi	st: implement tape statistics	2015-06-02 08:03:25 -07:00
security	Smack: Updates for Smack documentation	2015-03-31 10:35:31 -07:00
serial	pty: Fix input race when closing	2015-05-10 19:26:37 +02:00
sh
sound	ASoC: Updates for v4.1	2015-04-13 14:14:29 +02:00
spi	Documentation/spi/spidev_test.c: fix warning	2015-04-17 09:04:12 -04:00
sysctl	watchdog: add watchdog_cpumask sysctl to assist nohz	2015-06-24 17:49:40 -07:00
target	SCSI misc on 20150622	2015-06-23 15:55:44 -07:00
thermal	Documentation: thermal: document of_cpufreq_cooling_register()	2015-01-06 14:39:17 -04:00
timers	documentation: Update NO_HZ_FULL interaction with POSIX timers	2015-02-26 11:57:29 -08:00
tpm
trace	Documentation: tracing: fix grammar	2015-05-13 15:39:04 -04:00
usb	Documentation usb serial: fixed how to provide vendor and product id	2015-05-07 09:44:04 -06:00
vDSO	Documentation/vDSO: don't build tests when cross compiling	2015-06-22 16:04:57 -06:00
video4linux	[media] media/Documentation: New flag EXECUTE_ON_WRITE	2015-04-08 06:35:16 -03:00
virtual	KVM: x86: mark legacy PCI device assignment as deprecated	2015-06-05 17:26:39 +02:00
vm	zswap: runtime enable/disable	2015-06-25 17:00:37 -07:00
w1
watchdog	Documentation: use subdir-y to avoid unnecessary built-in.o files	2014-09-26 11:02:55 +02:00
wimax
x86	Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-06-22 17:59:09 -07:00
xtensa
zh_CN	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
00-INDEX	Update of Documentation/dmaengine/00-INDEX	2014-12-29 15:28:24 -07:00
applying-patches.txt	Documentation: change "&" to "and" in Documentation/applying-patches.txt	2014-09-26 11:10:11 +02:00
assoc_array.txt
atomic_ops.txt	documentation: Clarify memory-barrier semantics of atomic operations	2015-02-26 11:57:31 -08:00
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt	binfmt_misc: touch up documentation a bit	2014-10-14 02:18:16 +02:00
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt	rmap: drop support of non-linear mappings	2015-02-10 14:30:31 -08:00
Changes	Documentation: GNU is frequently spelled Gnu	2014-12-29 15:33:17 -07:00
circular-buffers.txt
clk.txt	clk: Add rate constraints to clocks	2015-02-02 14:23:42 -08:00
coccinelle.txt
CodeOfConflict	Code of Conflict	2015-02-27 11:44:24 -08:00
CodingStyle	Documentation/CodingStyle: fix example macro parenthesis imbalance	2015-05-07 17:07:41 -06:00
cpu-hotplug.txt	cpumask: fix cpu-hotplug documentation	2015-03-05 13:37:01 +10:30
cpu-load.txt
cputopology.txt	Documentation: Update cputopology.txt	2015-05-27 15:22:15 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
dell_rbu.txt
devices.txt
digsig.txt
DMA-API-HOWTO.txt	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
DMA-API.txt	PCI: Add pci_bus_addr_t	2015-05-29 17:21:45 -05:00
DMA-attributes.txt
dma-buf-sharing.txt	dma-buf: cleanup dma_buf_export() to make it easily extensible	2015-04-21 14:47:16 +05:30
DMA-ISA-LPC.txt
dontdiff
dynamic-debug-howto.txt
edac.txt	EDAC: Update Documentation/edac.txt	2015-06-24 18:17:40 +02:00
efi-stub.txt
eisa.txt
email-clients.txt	Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB	2015-03-20 07:41:55 -06:00
flexible-arrays.txt
futex-requeue-pi.txt	doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants	2015-01-19 12:05:32 +01:00
gcov.txt
gdb-kernel-debugging.txt	scripts/gdb: add basic documentation	2015-02-17 14:34:54 -08:00
highuid.txt
HOWTO	Documentation: remove outdated references to the linux-next wiki	2014-10-28 09:06:11 -04:00
hsi.txt
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt	ipmi:ssif: Ignore spaces when comparing I2C adapter names	2015-05-05 14:24:45 -05:00
IRQ-affinity.txt
IRQ-domain.txt	IRQCHIP: Update docs regarding irq_domain_add_tree()	2015-04-01 17:21:35 +02:00
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kasan.txt	Merge branch 'doc/4.2' into docs-next	2015-06-08 17:04:11 -06:00
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt	Documentation updates for 4.2	2015-06-24 20:01:36 -07:00
kernel-per-CPU-kthreads.txt	documentation: Update per-CPU kthreads documentation	2015-02-26 11:57:30 -08:00
kmemcheck.txt	Documentation: update the CONFIG_DEBUG_PAGEALLOC description	2015-03-20 07:41:55 -06:00
kmemleak.txt	Doc: Change wikipedia's URL from http to https	2015-06-22 10:14:05 -06:00
kobject.txt	kobject: grammar fix	2014-12-08 09:07:11 -05:00
kprobes.txt	kprobes: Update Documentation/kprobes.txt	2015-03-20 07:41:55 -06:00
kref.txt
kselftest.txt	kselftest: Move the docs to the Documentation dir	2014-11-24 10:49:54 -07:00
ldm.txt
local_ops.txt	percpu: update local_ops.txt to reflect this_cpu operations	2014-12-13 12:42:53 -08:00
lockup-watchdogs.txt	watchdog: add watchdog_cpumask sysctl to assist nohz	2015-06-24 17:49:40 -07:00
logo.gif
logo.txt
lzo.txt	Documentation: lzo: document part of the encoding	2014-09-28 11:08:00 +02:00
magic-number.txt	Documentation/magic-number: Remove SCC_MAGIC	2015-05-13 15:39:04 -04:00
mailbox.txt	Documentation: Fix a typo in mailbox.txt	2014-11-03 11:54:50 -05:00
Makefile	Documentation: Remove ZBOOT MMC/SDHI utility and docs	2015-02-24 06:45:25 +09:00
ManagementStyle
md-cluster.txt	md-cluster: Design Documentation	2015-02-23 07:16:46 -06:00
md.txt	doc:md: fix typo in md.txt.	2015-06-23 06:49:44 -06:00
media-framework.txt
memory-barriers.txt	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-06-22 14:54:22 -07:00
memory-hotplug.txt	mem-hotplug: fix typo in Documentation/memory-hotplug.txt	2015-03-20 07:41:55 -06:00
module-signing.txt	modsign: change default key details	2015-04-30 09:35:41 -07:00
mono.txt
nommu-mmap.txt	fs: introduce f_op->mmap_capabilities for nommu mmap support	2015-01-20 14:02:58 -07:00
numastat.txt
oops-tracing.txt	livepatch: kernel: add TAINT_LIVEPATCH	2014-12-22 15:40:48 +01:00
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt	phy: improved lookup method	2014-11-21 19:48:50 +05:30
pi-futex.txt
pinctrl.txt	pinctrl: move strict option to pinmux_ops	2015-05-06 14:45:19 +02:00
pnp.txt
preempt-locking.txt	x86/fpu: Rename math_state_restore() to fpu__restore()	2015-05-19 15:47:18 +02:00
printk-formats.txt	The documentation tree update for 4.1. Numerous fixes, the overdue removal	2015-04-18 11:10:49 -04:00
pwm.txt
ramoops.txt	pstore-ram: Allow optional mapping with pgprot_noncached	2014-12-11 13:38:31 -08:00
rbtree.txt
remoteproc.txt
rfkill.txt	rfkill: document rfkill module parameters	2015-01-09 23:22:12 +01:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt	Documentation, split up rtc.txt into documentation and test file	2015-03-24 22:01:58 -06:00
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable: Update documentation to clarify preferred procedure	2015-05-22 09:38:56 -06:00
static-keys.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches	SubmittingPatches: Clarify requirements for patches directed toward stable	2015-05-14 15:34:52 -04:00
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt	Docs: this_cpu_ops: remove redundant add forms	2014-09-26 11:03:00 +02:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt	vfio: powerpc/spapr: Support Dynamic DMA windows	2015-06-11 15:16:55 +10:00
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt
xillybus.txt
xz.txt
zorro.txt