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87183 commits

Author SHA1 Message Date
Eric Paris
f9c3a38021 NFS: use new LSM interfaces to explicitly set mount options
NFS and SELinux worked together previously because SELinux had NFS
specific knowledge built in.  This design was approved by both groups
back in 2004 but the recent NFS changes to use nfs_parsed_mount_data and
the usage of nfs_clone_mount_data showed this to be a poor fragile
solution.  This patch fixes the NFS functionality regression by making
use of the new LSM interfaces to allow an FS to explicitly set its own
mount options.

The explicit setting of mount options is done in the nfs get_sb
functions which are called before the generic vfs hooks try to set mount
options for filesystems which use text mount data.

This does not currently support NFSv4 as that functionality did not
exist in previous kernels and thus there is no regression.  I will be
adding the needed code, which I believe to be the exact same as the v3
code, in nfs4_get_sb for 2.6.26.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-03-06 08:40:59 +11:00
Eric Paris
e000752989 LSM/SELinux: Interfaces to allow FS to control mount options
Introduce new LSM interfaces to allow an FS to deal with their own mount
options.  This includes a new string parsing function exported from the
LSM that an FS can use to get a security data blob and a new security
data blob.  This is particularly useful for an FS which uses binary
mount data, like NFS, which does not pass strings into the vfs to be
handled by the loaded LSM.  Also fix a BUG() in both SELinux and SMACK
when dealing with binary mount data.  If the binary mount data is less
than one page the copy_page() in security_sb_copy_data() can cause an
illegal page fault and boom.  Remove all NFSisms from the SELinux code
since they were broken by past NFS changes.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-03-06 08:40:53 +11:00
Krzysztof Oledzki
51f39eae14 [SCSI] mpt fusion: don't oops if NumPhys==0
Don't oops if NumPhys==0, instead return -ENODEV.
This patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=9909

Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Acked-by: Eric Moore <Eric.Moore@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-03-05 14:57:57 -06:00
Sam Ravnborg
f6ebef30e2 [CPUFREQ] fix section mismatch warnings
Fix the following warnings:
WARNING: vmlinux.o(.text+0xfe6711): Section mismatch in reference from the function cpufreq_unregister_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier
WARNING: vmlinux.o(.text+0xfe68af): Section mismatch in reference from the function cpufreq_register_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier
WARNING: vmlinux.o(.exit.text+0xc4fa): Section mismatch in reference from the function cpufreq_stats_exit() to the variable .cpuinit.data:cpufreq_stat_cpu_notifier

The warnings were casued by references to unregister_hotcpu_notifier()
from normal functions or exit functions.
This is flagged by modpost as a potential error because
it does not know that for the non HOTPLUG_CPU
scenario the unregister_hotcpu_notifier() is a nop.
Silence the warning by replacing the __initdata
annotation with a __refdata annotation.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
2008-03-05 14:45:31 -05:00
Dave Jones
0e5aa8d621 [CPUFREQ] Remove debugging message from e_powersaver
We don't need to printk a message every time we transition.
Leave the code there, but ifdef'd out, as it's useful when
adding support for new processors.

Reported-by: Petr Titěra <P.Titera@century.cz>
Signed-off-by: Dave Jones <davej@redhat.com>
2008-03-05 14:45:31 -05:00
Dave Jones
a07530b445 [CPUFREQ] Fix missing cpufreq_cpu_put() call in ->store
refactor to use gotos instead of explicit exit paths

Signed-off-by: Dave Jones <davej@redhat.com>
2008-03-05 14:45:31 -05:00
Dave Jones
0db4a8a99f [CPUFREQ] Fix missing cpufreq_cpu_put() call in ->show
refactor to use gotos instead of explicit exit paths

Signed-off-by: Dave Jones <davej@redhat.com>
2008-03-05 14:45:31 -05:00
Mike Christie
45ab33b6c1 [SCSI] iscsi class: regression - fix races with state manipulation and blocking/unblocking
For qla4xxx, we could be starting a session, but some error (network,
target, IO from a device that got started, etc) could cause the session
to fail and curring the block/unblock and state manipulation could race
with each other. This patch just has those operations done in the
single threaded iscsi eh work queue, so that way they are serialized.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-03-05 12:04:09 -06:00
Mike Christie
024f801f52 [SCSI] qla4xxx: regression - add start scan callout
We are seeing EXIST errors from sysfs during device addition.
We need a start scan callout so we do not start scanning sessions
found during hba setup, before the async scsi scan code is ready.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-03-05 12:03:54 -06:00
Mike Christie
50a29aec9c [SCSI] qla4xxx: fix host reset dpc race
The host reset callout could be starting to reset the hba at the same
time the dpc thread is. This creates lots of problems because they both
want to do wierd things with the firmware and interrupts, etc.

This patch just has the host reset function fully shutdown the dpc
thread before resetting the hba.

This patch also moves the setting of the session online bit to fix
a potential race with the dpc thread and iscsi recovery thread.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-03-05 12:03:17 -06:00
Jeff Garzik
a878539ef9 ahci: work around ATI SB600 h/w quirk
This addresses the recent ATI SB600 errata, where the hardware does
not like 256-length PRD entries during FPDMA (aka NCQ).

It hurts performance on SB600, but it is more important to get a
correct patch eliminating the data corruption/lockups, and then later
on tune for performance.

We simply limit each command to a maximum of 255 sectors, on SB600.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-03-05 07:53:06 -05:00
Alan Cox
6ddd68615a pata_hpt*, pata_serverworks: fix UDMA masking
When masking, mask out the modes that are unsupported not the ones
that are supported.  This makes life happier.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2008-03-05 07:46:34 -05:00
Hongjie Yang
583b33bc83 [S390] incorrect reipl nss name.
/sys/firmware/reipl/nss/name contains the nss name when defsys or
savesys command has been executed. If the defsys or savesys command
fails the kernel_nss_name has to be cleared since a reipl on that
nss name won't be possible.

Signed-off-by: Hongjie Yang <hongjie@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:20 +01:00
Michael Holzheu
208e559155 [S390] Load disabled wait psw if reipl fails.
Normally this should not happen, but it's cleaner to do it that way.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:19 +01:00
Heiko Carstens
684de39bd7 [S390] Fix IPL from NSS.
IPL from NSS didn't work because the memory detection routine omits any
memory sections with a size lower than what MAX_ORDER defines.
This causes the detection routine to skip the first memory segment which
has a size of 1MB. Which later on will let the kernel think that there
is no memory available at all.
Since in addition the z/VM memory increment size is 1MB force MAX_ORDER
to be 9, so we can support 1MB segments.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:19 +01:00
Ralph Wuerthner
faa582ca80 [S390] zcrypt: fix ap_device_list handling
In ap_device_probe() we can add the new ap device to the internal
device list only if the device probe function successfully returns.
Otherwise we might end up with an invalid device in the internal ap
device list.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:19 +01:00
Christian Borntraeger
fa331ffc56 [S390] sclp_vt220: speed up console output for interactive work
Currently an output buffer can wait up to HZ/2 until the buffer is
flushed. The wait time is noticeable in interactive tools like mc.

Change the value to HZ/20, which seems enough for interactive work.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:18 +01:00
Stefan Weinhuber
a5e2383991 [S390] dasd: fix reference counting in display method for proc/dasd/devices
Using the /proc/dasd/devices interface leaves the reference counter
of alias devices in an inconsistent state. A process that tries to set
such a device offline afterwards will hang.
The dasd_devices_show function returns immediately for alias devices
and this code path was missing a dasd_put_device call.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:18 +01:00
Stefan Weinhuber
5c12f2406c [S390] dasd: let dasd erp matching recognize alias recovery
When a request fails that was started on an alias device then the
first recovery step is to retry it on the base device. If the
recovery request fails again with the same symptoms, the next step
should not be a simple retry, but should be a proper recovery based
on sense data, etc. To do so, the dasd recovery functions need to
recognize the alias recovery step in the erp chain by comparing
the start devices.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:18 +01:00
Heiko Carstens
98c7b388af [S390] Get rid of memcpy gcc warning workaround.
Compile smp.o with -Wno-nonnull so gcc stops warning about memcpy
being used with a null parameter. Also remove the workaround code
and use a char * cast instead of a void * cast to do computations.

Cc: Bastian Blank <bastian@waldi.eu.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:17 +01:00
Heiko Carstens
5ccd0e43bb [S390] idle: Fix machine check handling in idle loop.
If a machine check handling is pending when the idle loop is entered
default_idle will be left with timer ticks and virtual timer disabled.
Fix this by "calling" the idle_chain. Also a BUG_ON(!in_interrupt) in
start_hz_timer must be removed since the function now gets called from
non interrupt context as well.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:17 +01:00
Martin Schwidefsky
9361a492cd [S390] Update default configuration.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-03-05 12:37:16 +01:00
Adrian Bunk
bc97f19dc8 [CRYPTO] digest: Include internal.h for prototypes
Every file should include the headers containing the externs for its 
global code (in this case for struct crypto_{init,exit}_digest_ops()).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-03-05 19:05:54 +08:00
Linus Torvalds
29e8c3c304 Linux 2.6.25-rc4 2008-03-04 20:33:54 -08:00
Pavel Roskin
9b37ccfc63 module: allow ndiswrapper to use GPL-only symbols
A change after 2.6.24 broke ndiswrapper by accidentally removing its
access to GPL-only symbols.  Revert that change and add comments about
the reasons why ndiswrapper and driverloader are treated in a special
way.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Acked-by: Greg KH <gregkh@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jon Masters <jonathan@jonmasters.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 20:29:40 -08:00
Linus Torvalds
27d0483aa1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (22 commits)
  [IPCONFIG]: The kernel gets no IP from some DHCP servers
  b43legacy: Fix module init message
  rndis_wlan: fix broken data copy
  libertas: compare the current command with response
  libertas: fix sanity check on sequence number in command response
  p54: fix eeprom parser length sanity checks
  p54: fix EEPROM structure endianness
  ssb: Add pcibios_enable_device() return value check
  rc80211-pid: fix rate adjustment
  [ESP]: Add select on AUTHENC
  [TCP]: Improve ipv4 established hash function.
  [NETPOLL]: Revert two bogus cleanups that broke netconsole.
  [PPPOL2TP]: Add missing sock_put() in pppol2tp_tunnel_closeall()
  Subject: [PPPOL2TP] add missing sock_put() in pppol2tp_recv_dequeue()
  [BLUETOOTH]: l2cap info_timer delete fix in hci_conn_del
  [NET]: Fix race in generic address resolution.
  iucv: fix build error on !SMP
  [TCP]: Must count fack_count also when skipping
  [TUN]: Fix RTNL-locking in tun/tap driver
  [SCTP]: Use proc_create to setup de->proc_fops.
  ...
2008-03-04 20:20:58 -08:00
Linus Torvalds
665c1ef836 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC]: Fix link errors with gcc-4.3
  sparc64: replace remaining __FUNCTION__ occurances
  sparc: replace remaining __FUNCTION__ occurances
  [SPARC]: Add reboot_command[] extern decl to asm/system.h
  [SPARC]: Mark linux_sparc_{fpu,chips} static.
2008-03-04 20:20:32 -08:00
Stephen Hemminger
dea75bdfa5 [IPCONFIG]: The kernel gets no IP from some DHCP servers
From: Stephen Hemminger <shemminger@linux-foundation.org>

Based upon a patch by Marcel Wappler:
 
   This patch fixes a DHCP issue of the kernel: some DHCP servers
   (i.e.  in the Linksys WRT54Gv5) are very strict about the contents
   of the DHCPDISCOVER packet they receive from clients.
 
   Table 5 in RFC2131 page 36 requests the fields 'ciaddr' and
   'siaddr' MUST be set to '0'.  These DHCP servers ignore Linux
   kernel's DHCP discovery packets with these two fields set to
   '255.255.255.255' (in contrast to popular DHCP clients, such as
   'dhclient' or 'udhcpc').  This leads to a not booting system.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-04 17:03:49 -08:00
David S. Miller
3123e666ea Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/linville/wireless-2.6 2008-03-04 16:44:01 -08:00
Linus Torvalds
71ca44dac4 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] fix ia64 kprobes compilation
  [IA64] move gcc_intrin.h from header-y to unifdef-y
  [IA64] workaround tiger ia64_sal_get_physical_id_info hang
  [IA64] move defconfig to arch/ia64/configs/
  [IA64] Fix irq migration in multiple vector domain
  [IA64] signal(ia64_ia32): add a signal stack overflow check
  [IA64] signal(ia64): add a signal stack overflow check
  [IA64] CONFIG_SGI_SN2 - auto select NUMA and ACPI_NUMA
2008-03-04 16:39:23 -08:00
Linus Torvalds
2c6f2db13a Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  debugfs: fix sparse warnings
  Driver core: Fix cleanup when failing device_add().
  driver core: Remove dpm_sysfs_remove() from error path of device_add()
  PM: fix new mutex-locking bug in the PM core
  PM: Do not acquire device semaphores upfront during suspend
  kobject: properly initialize ksets
  sysfs: CONFIG_SYSFS_DEPRECATED fix
  driver core: fix up Kconfig text for CONFIG_SYSFS_DEPRECATED
2008-03-04 16:37:35 -08:00
Linus Torvalds
12f981f902 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/pci-2.6:
  pci: hotplug: pciehp: fix error code path in hpc_power_off_slot
  PCI: Add DECLARE_PCI_DEVICE_TABLE macro
  PCI: fix up error messages for pci_bus registering
  PCI: fix section mismatch warning in pci_scan_child_bus
  PCI: consolidate duplicated MSI enable functions
  PCI: use dev_printk in quirk messages
2008-03-04 16:37:10 -08:00
Linus Torvalds
10955d2251 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: ftdi_sio - really enable EM1010PC
  USB: remove incorrect struct class_device from the printer gadget
  USB: pxa2xx_udc: fix misuse of clock enable/disable calls
  USB: ftdi_sio: Workaround for broken Matrix Orbital serial port
  USB: Add support for AXESSTEL MV110H CDMA modem
  usb-storage: update earlier scatter-gather bug fix
  USB: isp116x: fix enumeration on boot
  USB: ehci: handle large bulk URBs correctly (again)
  USB: spruce up the device blacklist
  USB: fix comment of struct usb_interface
  USB: update Kconfig entry for USB_SUSPEND
  usb: Add support for the mos7820/7840-based B&B USB/RS485 converter to mos7840.c
2008-03-04 16:36:53 -08:00
Masami Hiramatsu
b2a5cd6938 kprobes: fix a null pointer bug in register_kretprobe()
Fix a bug in regiseter_kretprobe() which does not check rp->kp.symbol_name ==
NULL before calling kprobe_lookup_name.

For maintainability, this introduces kprobe_addr helper function which
resolves addr field.  It is used by register_kprobe and register_kretprobe.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:19 -08:00
Randy Dunlap
1913130553 input: add I2C to config since the driver makes several i2c*() calls
Add to help text that the Intel I2C ICH (i801) driver is also needed
for this kernel.

Add LEDS_CLASS to config since the driver makes les_classdev_*() calls:
ERROR: "led_classdev_register" [drivers/input/misc/apanel.ko] undefined!
ERROR: "__led_classdev_unregister" [drivers/input/misc/apanel.ko]
undefined!

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
Josef Bacik
92587216f8 ext3: fix mount option parsing
The "resize" option won't be noticed as it comes after the NULL option, so if
you try to mount (or in this case remount) with that option it won't be
recognized.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
Nishanth Aravamudan
348e1e04b5 hugetlb: fix pool shrinking while in restricted cpuset
Adam Litke noticed that currently we grow the hugepage pool independent of any
cpuset the running process may be in, but when shrinking the pool, the cpuset
is checked.  This leads to inconsistency when shrinking the pool in a
restricted cpuset -- an administrator may have been able to grow the pool on a
node restricted by a containing cpuset, but they cannot shrink it there.

There are two options: either prevent growing of the pool outside of the
cpuset or allow shrinking outside of the cpuset.  >From previous discussions
on linux-mm, /proc/sys/vm/nr_hugepages is an administrative interface that
should not be restricted by cpusets.  So allow shrinking the pool by removing
pages from nodes outside of current's cpuset.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: William Irwin <wli@holomorphy.com>
Cc: Lee Schermerhorn <Lee.Schermerhonr@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
Adam Litke
ac09b3a151 hugetlb: close a difficult to trigger reservation race
A hugetlb reservation may be inadequately backed in the event of racing
allocations and frees when utilizing surplus huge pages.  Consider the
following series of events in processes A and B:

 A) Allocates some surplus pages to satisfy a reservation
 B) Frees some huge pages
 A) A notices the extra free pages and drops hugetlb_lock to free some of
    its surplus pages back to the buddy allocator.
 B) Allocates some huge pages
 A) Reacquires hugetlb_lock and returns from gather_surplus_huge_pages()

Avoid this by commiting the reservation after pages have been allocated but
before dropping the lock to free excess pages.  For parity, release the
reservation in return_unused_surplus_pages().

This patch also corrects the cpuset_mems_nr() error path in
hugetlb_acct_memory().  If the cpuset check fails, uncommit the
reservation, but also be sure to return any surplus huge pages that may
have been allocated to back the failed reservation.

Thanks to Andy Whitcroft for discovering this.

Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
K.Tanaka
a07e6ab41b md: the md RAID10 resync thread could cause a md RAID10 array deadlock
This message describes another issue about md RAID10 found by testing the
2.6.24 md RAID10 using new scsi fault injection framework.

Abstract:

When a scsi error results in disabling a disk during RAID10 recovery, the
resync threads of md RAID10 could stall.

This case, the raid array has already been broken and it may not matter.  But
I think stall is not preferable.  If it occurs, even shutdown or reboot will
fail because of resource busy.

The deadlock mechanism:

The r10bio_s structure has a "remaining" member to keep track of BIOs yet to
be handled when recovering.  The "remaining" counter is incremented when
building a BIO in sync_request() and is decremented when finish a BIO in
end_sync_write().

If building a BIO fails for some reasons in sync_request(), the "remaining"
should be decremented if it has already been incremented.  I found a case
where this decrement is forgotten.  This causes a md_do_sync() deadlock
because md_do_sync() waits for md_done_sync() called by end_sync_write(), but
end_sync_write() never calls md_done_sync() because of the "remaining" counter
mismatch.

For example, this problem would be reproduced in the following case:

Personalities : [raid10]
md0 : active raid10 sdf1[4] sde1[5](F) sdd1[2] sdc1[1] sdb1[6](F)
      3919616 blocks 64K chunks 2 near-copies [4/2] [_UU_]
      [>....................]  recovery =  2.2% (45376/1959808) finish=0.7min speed=45376K/sec

This case, sdf1 is recovering, sdb1 and sde1 are disabled.
An additional error with detaching sdd will cause a deadlock.

md0 : active raid10 sdf1[4] sde1[5](F) sdd1[6](F) sdc1[1] sdb1[7](F)
      3919616 blocks 64K chunks 2 near-copies [4/1] [_U__]
      [=>...................]  recovery =  5.0% (99520/1959808) finish=5.9min speed=5237K/sec

 2739 ?        S<     0:17 [md0_raid10]
28608 ?        D<     0:00 [md0_resync]
28629 pts/1    Ss     0:00 bash
28830 pts/1    R+     0:00 ps ax
31819 ?        D<     0:00 [kjournald]

The resync thread keeps working, but actually it is deadlocked.

Patch:
By this patch, the remaining counter will be decremented if needed.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
NeilBrown
1c830532f6 md: fix possible raid1/raid10 deadlock on read error during resync
Thanks to K.Tanaka and the scsi fault injection framework, here is a fix for
another possible deadlock in raid1/raid10 error handing.

If a read request returns an error while a resync is happening and a resync
request is pending, the attempt to fix the error will block until the resync
progresses, and the resync will block until the read request completes.  Thus
a deadlock.

This patch fixes the problem.

Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
Keld Simonsen
8ed3a19563 md: don't attempt read-balancing for raid10 'far' layouts
This patch changes the disk to be read for layout "far > 1" to always be the
disk with the lowest block address.

Thus the chunks to be read will always be (for a fully functioning array) from
the first band of stripes, and the raid will then work as a raid0 consisting
of the first band of stripes.

Some advantages:

The fastest part which is the outer sectors of the disks involved will be
used.  The outer blocks of a disk may be as much as 100 % faster than the
inner blocks.

Average seek time will be smaller, as seeks will always be confined to the
first part of the disks.

Mixed disks with different performance characteristics will work better, as
they will work as raid0, the sequential read rate will be number of disks
involved times the IO rate of the slowest disk.

If a disk is malfunctioning, the first disk which is working, and has the
lowest block address for the logical block will be used.

Signed-off-by: Keld Simonsen <keld@dkuug.dk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
NeilBrown
27c529bb8e md: lock access to rdev attributes properly
When we access attributes of an rdev (component device on an md array) through
sysfs, we really need to lock the array against concurrent changes.  We
currently do that when we change an attribute, but not when we read an
attribute.  We need to lock when reading as well else rdev->mddev could become
NULL while we are accessing it.

So add appropriate locking (mddev_lock) to rdev_attr_show.

rdev_size_store requires some extra care as well as it needs to unlock the
mddev while scanning other mddevs for overlapping regions.  We currently
assume that rdev->mddev will still be unchanged after the scan, but that
cannot be certain.  So take a copy of rdev->mddev for use at the end of the
function.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
NeilBrown
2515619823 md: make sure a reshape is started when device switches to read-write
A resync/reshape/recovery thread will refuse to progress when the array is
marked read-only.  So whenever it mark it not read-only, it is important to
wake up thread resync thread.  There is one place we didn't do this.

The problem manifests if the start_ro module parameters is set, and a raid5
array that is in the middle of a reshape (restripe) is started.  The array
will initially be semi-read-only (meaning it acts like it is readonly until
the first write).  So the reshape will not proceed.

On the first write, the array will become read-write, but the reshape will not
be started, and there is no event which will ever restart that thread.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
NeilBrown
d0fae18f1b md: clean up irregularity with raid autodetect
When a raid1 array is stopped, all components currently get added to the list
for auto-detection.  However we should really only add components that were
found by autodetection in the first place.  So add a flag to record that
information, and use it.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:18 -08:00
NeilBrown
a1801f858e md: guard against possible bad array geometry in v1 metadata
Make sure the data doesn't start before the end of the superblock when the
superblock is at the start of the device.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00
NeilBrown
8311c29d40 md: reduce CPU wastage on idle md array with a write-intent bitmap
On an md array with a write-intent bitmap, a thread wakes up every few seconds
and scans the bitmap looking for work to do.  If the array is idle, there will
be no work to do, but a lot of scanning is done to discover this.

So cache the fact that the bitmap is completely clean, and avoid scanning the
whole bitmap when the cache is known to be clean.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00
NeilBrown
a35e63efa1 md: fix deadlock in md/raid1 and md/raid10 when handling a read error
When handling a read error, we freeze the array to stop any other IO while
attempting to over-write with correct data.

This is done in the raid1d(raid10d) thread and must wait for all submitted IO
to complete (except for requests that failed and are sitting in the retry
queue - these are counted in ->nr_queue and will stay there during a freeze).

However write requests need attention from raid1d as bitmap updates might be
required.  This can cause a deadlock as raid1 is waiting for requests to
finish that themselves need attention from raid1d.

So we create a new function 'flush_pending_writes' to give that attention, and
call it in freeze_array to be sure that we aren't waiting on raid1d.

Thanks to "K.Tanaka" <k-tanaka@ce.jp.nec.com> for finding and reporting this
problem.

Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00
FUJITA Tomonori
466634488e iommu: parisc: make the IOMMUs respect the segment boundary limits
Make PARISC's two IOMMU implementations not allocate a memory area spanning
LLD's segment boundary.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00
FUJITA Tomonori
7c8cda625a iommu: parisc: pass struct device to iommu_alloc_range
This adds struct device argument to sba_alloc_range and ccio_alloc_range, a
preparation for modifications to fix the IOMMU segment boundary problem.  This
change enables ccio_alloc_range to access to LLD's segment boundary limits.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00
FUJITA Tomonori
3715863aa1 iommu: export iommu_is_span_boundary helper function
iommu_is_span_boundary is used internally in the IOMMU helper
(lib/iommu-helper.c), a primitive function that judges whether a memory area
spans LLD's segment boundary or not.

It's difficult to convert some IOMMUs to use the IOMMU helper but
iommu_is_span_boundary is still useful for them.  So this patch exports it.

This is needed for the parisc iommu fixes.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:17 -08:00