Holding locks over device_del -> kobject_del -> sysfs_deactivate can
cause deadlocks if those same locks are grabbed in sysfs show or store
methods.
The I model s_active count + completion as a sleeping read/write lock.
I describe to lockdep sysfs_get_active as a read_trylock,
sysfs_put_active as a read_unlock, and sysfs_deactivate as a
write_lock and write_unlock pair. This seems to capture the essence
for purposes of finding deadlocks, and in my testing gives finds real
issues and ignores non-issues.
This brings us back to holding locks over kobject_del is a problem
that ideally we should find a way of addressing, but at least lockdep
can tell us about the problems instead of requiring developers to debug
rare strange system deadlocks, that happen when sysfs files are removed
while being written to.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We kill the guest, but then we blatt random stuff.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] Update default configuration.
[S390] Have param.h simply include <asm-generic/param.h>.
[S390] qdio: convert global statistics to per-device stats
We wrap the smm calls and other bits with the BKL push down as a
precaution but they can probably go
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nobody seems to want to own I2O patches so sending this one directly.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The BKL is in this function because of the BKL pushdown (see commit
f8f2c79d59)
It is not needed here because the mutex_lock sonypi_device.lock provides
the necessary locking.
sonypi_misc_ioctl can be converted to unlocked ioctls since it relies on
its own locking (the mutex sonypi_device.lock) and not the bkl
Document that llseek is not needed by explictly setting it to no_llseek
LKML-Reference: <alpine.LFD.2.00.0910192019420.3563@localhost.localdomain>
Signed-off-by: John Kacur <jkacur@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: update mailing list address
nilfs2: Storage class should be before const qualifier
nilfs2: trivial coding style fix
Since the files have identical content, might as well simplify.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Revamp the qdio performance statistics and move them from procfs to
debugfs using the seq_file interface. Since the statistics are not
intended for the general user the removal of /proc/qdio_perf should
not surprise anyone.
The per device statistics are disabled by default, writing 1 to
/<debugfs mountpoint>/qdio/<device bus ID>/statistics enables the
statistics for the given device.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit f6151dfea2 introduces build
breakage, so this patch fixes it together with some printk formatting
cleanup.
Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This has the adverse effect of converting many 29bit configs to 32bit
mode, while this is a change that needs to be done manually for each
platform. Turn it off by default in order to cut down on spurious bug
reports.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
While the PMB is available on SH-4A parts, SH4AL-DSP parts exclude it
altogether. As such, explicitly disable PMB support for these parts. If
this changes in the future for newer subtypes, this will have to be made
more fine-grained.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
It seems that Documentation/DMA-mapping.txt was supposed to be renamed
to Documentation/PCI/PCI-DMA-mapping.txt.
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ioremap() returns a void __iomem * not an unsigned long. Update the
Documentation file to reflect this.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ioremap() returns a void __iomem * not a char *. Update the documentation
file to reflect this.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following htmldocs warning:
Warning(fs/fs-writeback.c:255): No description found for parameter 'sb'
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This replaces the list address for nilfs discussion to linux-nilfs at
vger.kernel.org from users at nilfs.org.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Relax the reiserfs lock before taking the inode mutex from
xattr_rmdir() to avoid the usual reiserfs lock <-> inode mutex
bad dependency.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
While deleting the xattrs of an inode, we hold the reiserfs lock
and grab the inode->i_mutex of the targeted inode and the root
private xattr directory.
Later on, we may relax the reiserfs lock for various reasons, this
creates inverted dependencies.
We can remove the reiserfs lock -> i_mutex dependency by relaxing
the former before calling open_xa_dir(). This is fine because the
lookup and creation of xattr private directories done in
open_xa_dir() are covered by the targeted inode mutexes. And deeper
operations in the tree are still done under the write lock.
This fixes the following lockdep report:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.32-atom #173
-------------------------------------------------------
cp/3204 is trying to acquire lock:
(&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11432b9>] reiserfs_write_lock_once+0x29/0x50
but task is already holding lock:
(&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}:
[<c105ea7f>] __lock_acquire+0x11ff/0x19e0
[<c105f2c8>] lock_acquire+0x68/0x90
[<c1401a2b>] mutex_lock_nested+0x5b/0x340
[<c1141d83>] open_xa_dir+0x43/0x1b0
[<c1142722>] reiserfs_for_each_xattr+0x62/0x260
[<c114299a>] reiserfs_delete_xattrs+0x1a/0x60
[<c111ea1f>] reiserfs_delete_inode+0x9f/0x150
[<c10c9c32>] generic_delete_inode+0xa2/0x170
[<c10c9d4f>] generic_drop_inode+0x4f/0x70
[<c10c8b07>] iput+0x47/0x50
[<c10c0965>] do_unlinkat+0xd5/0x160
[<c10c0a00>] sys_unlink+0x10/0x20
[<c1002ec4>] sysenter_do_call+0x12/0x32
-> #0 (&REISERFS_SB(s)->lock){+.+.+.}:
[<c105f176>] __lock_acquire+0x18f6/0x19e0
[<c105f2c8>] lock_acquire+0x68/0x90
[<c1401a2b>] mutex_lock_nested+0x5b/0x340
[<c11432b9>] reiserfs_write_lock_once+0x29/0x50
[<c1117012>] reiserfs_lookup+0x62/0x140
[<c10bd85f>] __lookup_hash+0xef/0x110
[<c10bf21d>] lookup_one_len+0x8d/0xc0
[<c1141e2a>] open_xa_dir+0xea/0x1b0
[<c1141fe5>] xattr_lookup+0x15/0x160
[<c1142476>] reiserfs_xattr_get+0x56/0x2a0
[<c1144042>] reiserfs_get_acl+0xa2/0x360
[<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
[<c111789c>] reiserfs_mkdir+0x6c/0x2c0
[<c10bea96>] vfs_mkdir+0xd6/0x180
[<c10c0c10>] sys_mkdirat+0xc0/0xd0
[<c10c0c40>] sys_mkdir+0x20/0x30
[<c1002ec4>] sysenter_do_call+0x12/0x32
other info that might help us debug this:
2 locks held by cp/3204:
#0: (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [<c10bd8d6>] lookup_create+0x26/0xa0
#1: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0
stack backtrace:
Pid: 3204, comm: cp Not tainted 2.6.32-atom #173
Call Trace:
[<c13ff993>] ? printk+0x18/0x1a
[<c105d33a>] print_circular_bug+0xca/0xd0
[<c105f176>] __lock_acquire+0x18f6/0x19e0
[<c105d3aa>] ? check_usage+0x6a/0x460
[<c105f2c8>] lock_acquire+0x68/0x90
[<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
[<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
[<c1401a2b>] mutex_lock_nested+0x5b/0x340
[<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50
[<c11432b9>] reiserfs_write_lock_once+0x29/0x50
[<c1117012>] reiserfs_lookup+0x62/0x140
[<c105ccca>] ? debug_check_no_locks_freed+0x8a/0x140
[<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170
[<c10bd85f>] __lookup_hash+0xef/0x110
[<c10bf21d>] lookup_one_len+0x8d/0xc0
[<c1141e2a>] open_xa_dir+0xea/0x1b0
[<c1141fe5>] xattr_lookup+0x15/0x160
[<c1142476>] reiserfs_xattr_get+0x56/0x2a0
[<c1144042>] reiserfs_get_acl+0xa2/0x360
[<c10ca2e7>] ? new_inode+0x27/0xa0
[<c114461a>] reiserfs_cache_default_acl+0x3a/0x160
[<c1402eb7>] ? _spin_unlock+0x27/0x40
[<c111789c>] reiserfs_mkdir+0x6c/0x2c0
[<c10c7cb8>] ? __d_lookup+0x108/0x190
[<c105c932>] ? mark_held_locks+0x62/0x80
[<c1401c8d>] ? mutex_lock_nested+0x2bd/0x340
[<c10bd17a>] ? generic_permission+0x1a/0xa0
[<c11788fe>] ? security_inode_permission+0x1e/0x20
[<c10bea96>] vfs_mkdir+0xd6/0x180
[<c10c0c10>] sys_mkdirat+0xc0/0xd0
[<c10505c6>] ? up_read+0x16/0x30
[<c1002fd8>] ? restore_all_notrace+0x0/0x18
[<c10c0c40>] sys_mkdir+0x20/0x30
[<c1002ec4>] sysenter_do_call+0x12/0x32
v2: Don't drop reiserfs_mutex_lock_nested_safe() as we'll still
need it later
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
When we relax the reiserfs lock to avoid creating unwanted
dependencies against others locks while grabbing these,
we want to ensure it has not been taken recursively, otherwise
the lock won't be really relaxed. Only its depth will be decreased.
The unwanted dependency would then actually happen.
To prevent from that, add a reiserfs_lock_check_recursive() call
in the places that need it.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
In the past, ext4_calc_metadata_amount(), and its sub-functions
ext4_ext_calc_metadata_amount() and ext4_indirect_calc_metadata_amount()
badly over-estimated the number of metadata blocks that might be
required for delayed allocation blocks. This didn't matter as much
when functions which managed the reserved metadata blocks were more
aggressive about dropping reserved metadata blocks as delayed
allocation blocks were written, but unfortunately they were too
aggressive. This was fixed in commit 0637c6f, but as a result the
over-estimation by ext4_calc_metadata_amount() would lead to reserving
2-3 times the number of pending delayed allocation blocks as
potentially required metadata blocks. So if there are 1 megabytes of
blocks which have been not yet been allocation, up to 3 megabytes of
space would get reserved out of the user's quota and from the file
system free space pool until all of the inode's data blocks have been
allocated.
This commit addresses this problem by much more accurately estimating
the number of metadata blocks that will be required. It will still
somewhat over-estimate the number of blocks needed, since it must make
a worst case estimate not knowing which physical blocks will be
needed, but it is much more accurate than before.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Commit 0637c6f had a typo which caused the reserved metadata blocks to
not be released correctly. Fix this.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Commit 239007b844 ("genirq: Convert irq_desc.lock to raw_spinlock")
seems to have missed this driver, leaving it to use the normal spin-lock
functions for the irq descriptor lock, which is now a raw lock.
Reported-and-compile-tested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduced by commit 5b889bf23 ("PCI: Fix build if quirks are not
enabled"), which made the pci_dev_reset_methods[] array static and
'const', but didn't then change the code to match, and use a const
pointer when moving it to quirks.c.
Trivially fixed by just adding the required 'const' to the iterator
variable.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Enable mmap on forcedirectio mounts
cifs: NULL out tcon, pSesInfo, and srvTcp pointers when chasing DFS referrals
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire, ieee1394: update Kconfig help
firewire, ieee1394: update MAINTAINERS entries
firewire: ohci: always use packet-per-buffer mode for isochronous reception
firewire: cdev: fix another memory leak in an error path
firewire: fix use of multiple AV/C devices, allow multiple FCP listeners
Comments from Stefan:
Distributors who still ship the old stack (ieee1394, ohci1394,
raw1394, sbp2, eth1394 and more) should now switch to the new one
(firewire-core, firewire-ohci, firewire-sbp2, firewire-net). In the
first iteration, those distributors might want to ship the old stack
also (but blacklisted) as a fallback for their users if unforeseen
problems with the newer replacement drivers are encountered.
The older FireWire stack contains several known problems which are
not going to be fixed; instead, those issues are addressed by the new
stack. An incomplete list of these issues is kept in bugzilla:
http://bugzilla.kernel.org/show_bug.cgi?id=10046
We have a guide on migration from the older to the newer stack:
http://ieee1394.wiki.kernel.org/index.php/Juju_Migration
After commit b9c3b26641 ("PCI: support
device-specific reset methods") the kernel build is broken if
CONFIG_PCI_QUIRKS is unset.
Fix this by moving pci_dev_specific_reset() to drivers/pci/quirks.c and
providing an empty replacement for !CONFIG_PCI_QUIRKS builds.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/agp: Fix agp_amd64_init() initialization with CONFIG_GART_IOMMU enabled
x86: SGI UV: Fix writes to led registers on remote uv hubs
x86, kmemcheck: Use KERN_WARNING for error reporting
x86: Use KERN_DEFAULT log-level in __show_regs()
x86, compress: Force i386 instructions for the decompressor
x86/amd-iommu: Fix initialization failure panic
dma-debug: Do not add notifier when dma debugging is disabled.
x86: Fix objdump version check in chkobjdump.awk for different formats.
Trivial conflicts in arch/x86/include/asm/uv/uv_hub.h due to me having
applied an earlier version of an SGI UV fix.
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf kmem: Fix statistics typo
kprobes: Fix distinct type warning
perf: Rename perf_event_hw_event in design document
perf tools: Add missing header files to LIB_H Makefile variable
perf record: We should fork only if a program was specified to run
perf diff: Fix usage array, it must end with a NULL entry
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Fix sign fields in ftrace_define_fields_##call()
tracing/syscalls: Fix typo in SYSCALL_DEFINE0
tracing/kprobe: Show sign of fields in trace_kprobe format files
ksym_tracer: Remove trace_stat
ksym_tracer: Fix race when incrementing count
ksym_tracer: Fix to allow writing newline to ksym_trace_filter
ksym_tracer: Fix to make the tracer work
tracing: Kconfig spelling fixes and cleanups
tracing: Fix setting tracer specific options
Documentation: Update ftrace-design.txt
Documentation: Update tracepoint-analysis.txt
Documentation: Update mmiotrace.txt
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: iforce - wait for command completion when closing the device
Input: twl4030-pwrbutton - switch to using threaded IRQ
Input: twl4030_keypad - switch to using threaded IRQ
Input: lifebook - add CONFIG_DMI dependency
Input: wistron - fix test for CONFIG_PM
Input: psmouse - fix compile warning in hgpk module
Input: matrix-keypad - handle cases when GPIOs can't be wakeup sources
Input: iforce - fix oops on device disconnect
Input: ff-memless - add notion of direction to for rumble effects
Input: ff-memless - another fix for signed to unsigned overflow
Input: ff-memless - start playing FF effects immediately
Input: serio - do not mark kseriod freezable anymore
Input: speed up suspend/shutdown for PS/2 mice and keyboards
Stephen Rothwell reported the following build warning:
lib/dma-debug.c: In function 'dma_debug_device_change':
lib/dma-debug.c:680: warning: 'return' with no value, in function returning non-void
Introduced by commit f797d9881b
("dma-debug: Do not add notifier when dma debugging is disabled").
Return 0 [notify-done] when disabled. (this is standard bus notifier behavior.)
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <20091231125624.GA14666@liondog.tnic>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Liming found a NULL deref when a task has a perf context but no
counters when it forks.
This can occur in two cases, a race during construction where
the fork hits after installing the context but before the first
counter gets inserted, or more reproducably, a fork after the
last counter is closed (which leaves the context around).
Reported-by: Wang Liming <liming.wang@windriver.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
CC: <stable@kernel.org>
LKML-Reference: <1262185684.7135.222.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Pass the frame pointer from the regs of the interrupted path
to dump_trace() while processing the stack trace.
Currently, dump_trace() takes the current bp and starts the
callchain from dump_trace() itself. This is wasteful because
we need to walk through the entire NMI/DEBUG stack before
retrieving the interrupted point.
We can fix that by just using the frame pointer from the
captured regs. It points exactly where we want to start.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1262235183-5320-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI: introduce kernel parameter acpi_sleep=sci_force_enable
ACPI: WMI: Survive BIOS with duplicate GUIDs
dell-wmi - fix condition to abort driver loading
wmi: check find_guid() return value to prevent oops
dell-wmi, hp-wmi, msi-wmi: check wmi_get_event_data() return value
ACPI: hp-wmi, msi-wmi: clarify that wmi_install_notify_handler() returns an acpi_status
dell-wmi: sys_init_module: 'dell_wmi'->init suspiciously returned 21, it should
ACPI video: correct error-handling code
ACPI video: no warning message if "acpi_backlight=vendor" is used
ACPI: fix ACPI=n allmodconfig build
thinkpad-acpi: improve Kconfig help text
thinkpad-acpi: update volume subdriver documentation
thinkpad-acpi: make volume subdriver optional
thinkpad-acpi: don't fail to load the entire module due to ALSA problems
thinkpad-acpi: don't take the first ALSA slot by default
Introduce kernel parameter acpi_sleep=sci_force_enable
some laptop requires SCI_EN being set directly on resume,
or else they hung somewhere in the resume code path.
We already have a blacklist for these laptops but we still need
this option, especially when debugging some suspend/resume problems,
in case there are systems that need this workaround and are not yet
in the blacklist.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
Eric W. Biederman