Commit Graph

13664 Commits

Author SHA1 Message Date
Yasuyuki Kozakai
9fb9cbb108 [NETFILTER]: Add nf_conntrack subsystem.
The existing connection tracking subsystem in netfilter can only
handle ipv4.  There were basically two choices present to add
connection tracking support for ipv6.  We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.

In fact nf_conntrack is capable of working with any layer 3
protocol.

The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here.  For example, these issues include:

1) ICMPv6 handling, which is used for neighbour discovery in
   ipv6 thus some messages such as these should not participate
   in connection tracking since effectively they are like ARP
   messages

2) fragmentation must be handled differently in ipv6, because
   the simplistic "defrag, connection track and NAT, refrag"
   (which the existing ipv4 connection tracking does) approach simply
   isn't feasible in ipv6

3) ipv6 extension header parsing must occur at the correct spots
   before and after connection tracking decisions, and there were
   no provisions for this in the existing connection tracking
   design

4) ipv6 has no need for stateful NAT

The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete.  Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-11-09 16:38:16 -08:00
Linus Torvalds
6730c3c144 Fix AGP compile on non-x86 architectures
AGP shouldn't use "global_flush_tlb()" to flush the AGP mappings, that i
spurely an x86'ism.  The proper AGP mapping flusher that should be used
is "flush_agp_mappings()", which on x86 obviously happens to do a global
TLB flush.

This makes AGP (or at least the config _I_ happen to use) compile again
on ppc64.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 14:56:00 -08:00
Linus Torvalds
969780f807 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/i2c-2.6 2005-11-09 14:13:53 -08:00
Linus Torvalds
ad8f76be48 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy/jfs-2.6 2005-11-09 13:47:34 -08:00
Linus Torvalds
cad8e94436 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2005-11-09 13:40:21 -08:00
Ken-ichirou MATSUZAWA
9f0ede52a0 [IPV6]: ip6ip6_lock is not unlocked in error path.
From: Ken-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:08:29 -08:00
Peter Chubb
44fd0261d3 [IPV6]: Fix fallout from CONFIG_IPV6_PRIVACY
Trying to build today's 2.6.14+git snapshot gives undefined references
to use_tempaddr

Looks like an ifdef got left out.

Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:05:47 -08:00
Krzysztof Piotr Oledzki
5fd52fe098 [NETFILTER] ctnetlink: ICMP_ID is u_int16_t not u_int8_t.
Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:04:32 -08:00
Krzysztof Piotr Oledzki
439a9994bb [NETFILTER] ctnetlink: Fix oops when no ICMP ID info in message
This patch fixes an userspace triggered oops. If there is no ICMP_ID
info the reference to attr will be NULL.

Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:04:08 -08:00
Pablo Neira Ayuso
a856a19a9f [NETFILTER] ctnetlink: Add support to identify expectations by ID's
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:03:42 -08:00
Pablo Neira Ayuso
fcda46128d [NETFILTER] ctnetlink: propagate error instaed of returning -EPERM
Propagate the error to userspace instead of returning -EPERM if the get
conntrack operation fails.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:03:26 -08:00
Pablo Neira Ayuso
fe902a91ff [NETFILTER] ctnetlink: return -EINVAL if size is wrong
Return -EINVAL if the size isn't OK instead of -EPERM.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:03:09 -08:00
Yasuyuki Kozakai
d63a928108 [NETFILTER]: stop tracking ICMP error at early point
Currently connection tracking handles ICMP error like normal packets
if it failed to get related connection. But it fails that after all.

This makes connection tracking stop tracking ICMP error at early point.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:02:45 -08:00
Harald Welte
ed77de9fc6 [NETFILTER] nfnetlink: only load subsystems if CAP_NET_ADMIN is set
Without this patch, any user can cause nfnetlink subsystems to be
autoloaded.  Those subsystems however could add significant processing
overhead to packet processing, and would refuse any configuration messages
from non-CAP_NET_ADMIN processes anyway.

This patch follows a suggestion from Patrick McHardy.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:02:16 -08:00
Philip Craig
5978a9b82c [NETFILTER] PPTP helper: fix PNS-PAC expectation call id
The reply tuple of the PNS->PAC expectation was using the wrong call id.

So we had the following situation:
- PNS behind NAT firewall
- PNS call id requires NATing
- PNS->PAC gre packet arrives first

then the PNS->PAC expectation is matched, and the other expectation
is deleted, but the PAC->PNS gre packets do not match the gre conntrack
because the call id is wrong.

We also cannot use ip_nat_follow_master().

Signed-off-by: Philip Craig <philipc@snapgear.com>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:01:53 -08:00
Pablo Neira Ayuso
81e5c27d08 [NETFILTER] ctnetlink: get_conntrack can use GFP_KERNEL
ctnetlink_get_conntrack is always called from user context, so GFP_KERNEL
is enough.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:01:19 -08:00
Pablo Neira Ayuso
7a4fe3664b [NETFILTER] ctnetlink: kill unused includes
Kill some useless headers included in ctnetlink. They aren't used in any
way.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:00:47 -08:00
Pablo Neira Ayuso
119a318494 [NETFILTER] ctnetlink: add module alias to fix autoloading
Add missing module alias. This is a must to load ctnetlink on demand. For
example, the conntrack tool will fail if the module isn't loaded.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:00:29 -08:00
Pablo Neira Ayuso
02a78cdf42 [NETFILTER] ctnetlink: add marking support from userspace
This patch adds support for conntrack marking from user space.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 13:00:04 -08:00
Pablo Neira Ayuso
51df784ed7 [NETFILTER] ctnetlink: check if protoinfo is present
This fixes an oops triggered from userspace. If we don't pass information
about the private protocol info, the reference to attr will be NULL. This is
likely to happen in update messages.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:59:41 -08:00
Harald Welte
a2506c0432 [NETFILTER] nfnetlink: nfattr_parse() can never fail, make it void
nfattr_parse (and thus nfattr_parse_nested) always returns success. So we
can make them 'void' and remove all the checking at the caller side.

Based on original patch by Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:59:13 -08:00
Yasuyuki Kozakai
eaae4fa45e [NETFILTER]: refcount leak of proto when ctnetlink dumping tuple
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:58:46 -08:00
Yasuyuki Kozakai
46998f59c0 [NETFILTER]: packet counter of conntrack is 32bits
The packet counter variable of conntrack was changed to 32bits from 64bits.
This follows that change.
		    
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:58:05 -08:00
Christoph Hellwig
8ca2bdc7a9 [SPARC] sbus rtc: implement ->compat_ioctl
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:07:18 -08:00
David S. Miller
feee207e44 [SPARC]: Fix locking thinkos in display7seg and cpwatchdog drivers.
Noticed by Eric Brower.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:05:37 -08:00
Tobias Klauser
84c1a13a30 [SPARC64]: Use ARRAY_SIZE macro
Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove a
duplicate of ARRAY_SIZE which is never used anyways.

Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:03:42 -08:00
Tobias Klauser
940fdc6e12 [SPARC]: Use ARRAY_SIZE macro
Use ARRAY_SIZE macro instead of sizeof(x)/sizeof(x[0]) and remove a
duplicate of ARRAY_SIZE which is never used anyways.

Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-09 12:03:05 -08:00
Linus Torvalds
a5ee363463 Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart 2005-11-09 11:45:00 -08:00
Linus Torvalds
28d838cc4d Fix ptrace self-attach rule
Before we did CLONE_THREAD, the way to check whether we were attaching
to ourselves was to just check "current == task", but with CLONE_THREAD
we should check that the thread group ID matches instead.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 11:33:07 -08:00
Linus Torvalds
ac111bfaa6 Merge master.kernel.org:/home/rmk/linux-2.6-arm 2005-11-09 08:55:53 -08:00
Linus Torvalds
19da9b8b6e Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev 2005-11-09 08:35:50 -08:00
Linus Torvalds
a7c243b544 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6 2005-11-09 08:34:36 -08:00
Linus Torvalds
7df446e7e0 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2005-11-09 08:33:27 -08:00
Adrian Bunk
8d3d81cf02 [PATCH] fs/hugetlbfs/inode.c: make a function static
This patch makes a needlessly global function static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:41 -08:00
Adrian Bunk
252ac86553 [PATCH] drivers/message/fusion/mptbase.c: make code static
This patch makes the following previously global and EXPORT_SYMBOL'ed
code static:
- struct mpt_proc_root_dir
- int mpt_stm_index

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:41 -08:00
Adrian Bunk
cf62ddce2e [PATCH] drivers/char/sysrq.c: make two functions static
This patch makes two needlessly global functions static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
Adrian Bunk
0ce6e62bd6 [PATCH] fs/namei.c: make path_lookup_create() static
This patch makes the needlessly global function path_lookup_create()
static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
bb636547b0 [PATCH] md: document sysfs usage of md, and make a couple of small refinements
Document in Documentation/md.txt the files that now appear in sysfs, and make
a couple of small refinements to exactly when 'level' and 'raid_disks' are
empty, to make it match the documentation.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
7eec314d75 [PATCH] md: improve 'scan_mode' and rename it to 'sync_action'
The current sync_action for an array can be one of

   idle  - nothing happening
   resync - reduncancy being recalcualted
   recover - missing device being recoverred to spare
   check   - user initiated check of redundancy
   repair  - like resync but user-initiated and ignores
             bitmap optimisation.

Each of these strings can also be written to the 'sync_action' file to cause
that action to happen (if appropriate).

While 'sync' is not technically correct, as a recovery is *not* a 'sync', I
think it is the most servicable word here.  Also 'action' is a strong word
than 'mode'.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
787453c239 [PATCH] md: complete conversion of md to use kthreads
There are a few loose ends following the conversion of md to use kthreads:

- Some fields in mdk_thread_t that aren't needed (kthreads does it's own
  completion and manages it's own name).

- thread->run is now never NULL, so no need to check

- Some tests for signal_pending that aren't needed (As we don't use signals
  to stop threads any more)

- Some flush_signals are not needed

- Some waits are interruptible and don't need to be.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:40 -08:00
NeilBrown
fd9d49cac4 [PATCH] md: ignore auto-readonly flag for arrays where it isn't meaningful
The 'auto-readonly' flag (which suppresses resync and superblock updates until
the first write) is not meaningful for personalities that don't support resync
or superblock writes (raid0, linear, etc).

So clear the setting early to avoid it confusing anything - e.g.  appearing in
/proc/mdstat

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
8e1b39d623 [PATCH] md: only try to print recovery/resync status for personalities that support recovery
The introduction of 'resync=PENDING' (for read-only devices) caused that
message to appear for non-syncable arrays like raid0 and linear.  Simplest
thing is to not try to print any resync info unless the personality clearly
supports it.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
411036fa19 [PATCH] md: split off some md attributes in sysfs to a separate group
Some, but not all, md array support data redundancy and hence support checking
and restoring that redundancy (resync, rebuild).

Some attributes apply specifically to functions involving this redundancy, and
so should only appear for md arrays for which they are meaningful.  i.e.  they
should not appear for raid0, linear, multpath, faulty.

This patch separates these into a distinct group and creates the group only if
the personality supports sync_request.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
96de1e663c [PATCH] md: fix some locking and module refcounting issues with md's use of sysfs
1/ I really should be using the __ATTR macros for defining attributes, so
   that the .owner field get set properly, otherwise modules can be removed
   while sysfs files are open.  This also involves some name changes of _show
   routines.

2/ Always lock the mddev (against reconfiguration) for all sysfs attribute
   access.  This easily avoid certain races and is completely consistant with
   other interfaces (ioctl and /proc/mdstat both always lock against
   reconfiguration).

3/ raid5 attributes must check that the 'conf' structure actually exists
   (the array could have been stopped while an attribute file was open).

4/ A missing 'kfree' from when the raid5_conf_t was converted to have a
   kobject embedded, and then converted back again.

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
3855ad9f39 [PATCH] md: make sure a user-request sync of raid5 ignores intent bitmap
A sync of raid5 usually ignore blocks which the bitmap says are in-sync.  But
a user-request check or repair should not ignore these.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
e5de485f00 [PATCH] md: make manual repair work for raid1
Raid1 currently optimises resync using the intent bitmap etc.  This
optimisation is not wanted when we explicitly request a repair through sysfs,
so add appropriate checks.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
f637b9f9fc [PATCH] md: make sure /block link in /sys/.../md/ goes to correct devices
If a block_device is a partition, then it's kobject is
  bdev->bd_part->kobj
otherwise (if it is a full device), the kobject is
  bdev->bd_disk->kobj

As md wants back-links to the correct object (whether partition or not), we
need to respect this difference...  (Thus current code shows a link to the
whole device, whether we are using a partition or not, which is wrong).

Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:39 -08:00
NeilBrown
f91de92ed6 [PATCH] md: allow md arrays to be started read-only (module parameter).
When an md array is started, the superblock will be written, and resync may
commense.  This is not good if you want to be completely read-only as, for
example, when preparing to resume from a suspend-to-disk image.

So introduce a module parameter "start_ro" which can be set
to '1' at boot, at module load, or via
  /sys/module/md_mod/parameters/start_ro

When this is set, new arrays get an 'auto-ro' mode, which disables all
internal io (superblock updates, resync, recovery) and is automatically
switched to 'rw' when the first write request arrives.

The array can be set to true 'ro' mode using 'mdadm -r' before the first
write request, or resync can be started without a write using 'mdadm -w'.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
19133a4298 [PATCH] md: Remove attempt to use dynamic names in sysfs for component devices on an MD array.
With version-0.90 superblock, component devices on an md device to not have
any stable name related to the array -(version-1 assigns a fixed index when
a device is added to an array, and this remains despit any hot-swap).

The intial code for making these devices appear in sysfs used dynamic
names, which would change whenever a hot-spare was swapped for a failed or
missing device.  This turns out not to be practical in sysfs for a number
of reasons.

This patch changes then naming of component devices to be based on the
result of 'bdevname'.  This is stable and should be unique.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00
NeilBrown
a9701a3047 [PATCH] md: support BIO_RW_BARRIER for md/raid1
We can only accept BARRIER requests if all slaves handle
barriers, and that can, of course, change with time....

So we keep track of whether the whole array seems safe for barriers,
and also whether each individual rdev handles barriers.

We initially assumes barriers are OK.

When writing the superblock we try a barrier, and if that fails, we flag
things for no-barriers.  This will usually clear the flags fairly quickly.

If writing the superblock finds that BIO_RW_BARRIER is -ENOTSUPP, we need to
resubmit, so introduce function "md_super_wait" which waits for requests to
finish, and retries ENOTSUPP requests without the barrier flag.

When writing the real raid1, write requests which were BIO_RW_BARRIER but
which aresn't supported need to be retried.  So raid1d is enhanced to do this,
and when any bio write completes (i.e.  no retry needed) we remove it from the
r1bio, so that devices needing retry are easy to find.

We should hardly ever get -ENOTSUPP errors when writing data to the raid.
It should only happen if:
  1/ the device used to support BARRIER, but now doesn't.  Few devices
     change like this, though raid1 can!
or
  2/ the array has no persistent superblock, so there was no opportunity to
     pre-test for barriers when writing the superblock.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:38 -08:00