e2f15f9a79
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> |
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| .. | ||
| appletalk | ||
| arcnet | ||
| bonding | ||
| caif | ||
| can | ||
| cris | ||
| dsa | ||
| ethernet | ||
| fddi | ||
| hamradio | ||
| hippi | ||
| hyperv | ||
| ieee802154 | ||
| ipvlan | ||
| irda | ||
| phy | ||
| plip | ||
| ppp | ||
| slip | ||
| team | ||
| usb | ||
| vmxnet3 | ||
| wan | ||
| wimax | ||
| wireless | ||
| xen-netback | ||
| Kconfig | ||
| LICENSE.SRC | ||
| Makefile | ||
| Space.c | ||
| dummy.c | ||
| eql.c | ||
| geneve.c | ||
| ifb.c | ||
| loopback.c | ||
| macvlan.c | ||
| macvtap.c | ||
| mdio.c | ||
| mii.c | ||
| netconsole.c | ||
| nlmon.c | ||
| ntb_netdev.c | ||
| rionet.c | ||
| sb1000.c | ||
| sungem_phy.c | ||
| tun.c | ||
| veth.c | ||
| virtio_net.c | ||
| vxlan.c | ||
| xen-netfront.c | ||