Commit Graph

59951 Commits

Author SHA1 Message Date
Alex Elder
2a24d1f4bd libceph: use (void *) for untyped data in osd ops
Two of the fields defining osd operations are defined using (char *)
while the data they represent are really untyped, not character
strings.  Change them to have type (void *).

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:15 -07:00
Alex Elder
0d5af16435 libceph: complete lingering requests only once
An osd request marked to linger will be re-submitted in the event
a connection to the target osd gets dropped.  Currently, if there
is a callback function associated with a request it will be called
each time a request is submitted--which for lingering requests can
be more than once.

Change it so a request--including lingering ones--will get completed
(from the perspective of the user of the osd client) exactly once.

This resolves:
    http://tracker.ceph.com/issues/3967

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:16:12 -07:00
Alex Elder
d4b515fa10 libceph: distinguish page array and pagelist count
Use distinct fields for tracking the number of pages in a message's
page array and in a message's page list.  Currently only one or the
other is used at a time, but that will be changing soon.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:28 -07:00
Alex Elder
07c09b7255 libceph: make ceph_msg->bio_seg be unsigned
The bio_seg field is used by the ceph messenger in iterating through
a bio.  It should never have a negative value, so make it an
unsigned.  (I contemplated making it unsigned short to match the
struct bio definition, but it offered no benefit.)

Change variables used to hold bio_seg values to all be unsigned as
well.  Change two variable names in init_bio_iter() to match the
convention used everywhere else.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-05-01 21:14:23 -07:00
Linus Torvalds
20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Linus Torvalds
b9394d8a65 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/efi changes from Peter Anvin:
 "The bulk of these changes are cleaning up the efivars handling and
  breaking it up into a tree of files.  There are a number of fixes as
  well.

  The entire changeset is pretty big, but most of it is code movement.

  Several of these commits are quite new; the history got very messed up
  due to a mismerge with the urgent changes for rc8 which completely
  broke IA64, and so Ingo requested that we rebase it to straighten it
  out."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: remove "kfree(NULL)"
  efi: locking fix in efivar_entry_set_safe()
  efi, pstore: Read data from variable store before memcpy()
  efi, pstore: Remove entry from list when erasing
  efi, pstore: Initialise 'entry' before iterating
  efi: split efisubsystem from efivars
  efivarfs: Move to fs/efivarfs
  efivars: Move pstore code into the new EFI directory
  efivars: efivar_entry API
  efivars: Keep a private global pointer to efivars
  efi: move utf16 string functions to efi.h
  x86, efi: Make efi_memblock_x86_reserve_range more readable
  efivarfs: convert to use simple_open()
2013-05-01 15:51:46 -07:00
James Hogan
126de6b20b linkage.h: fix build breakage due to symbol prefix handling
Al's commit e1b5bb6d12 ("consolidate cond_syscall and SYSCALL_ALIAS
declarations") broke the build on blackfin and metag due to the
following code:

  #ifndef SYMBOL_NAME
  #ifdef CONFIG_SYMBOL_PREFIX
  #define SYMBOL_NAME(x) CONFIG_SYMBOL_PREFIX ## x
  #else
  #define SYMBOL_NAME(x) x
  #endif
  #endif
  #define __SYMBOL_NAME(x) __stringify(SYMBOL_NAME(x))

__stringify literally stringifies CONFIG_SYMBOL_PREFIX ##x, so you get
lines like this in kernel/sys_ni.s:

  .weak CONFIG_SYMBOL_PREFIXsys_quotactl
  .set CONFIG_SYMBOL_PREFIXsys_quotactl,CONFIG_SYMBOL_PREFIXsys_ni_syscall

The patches in Rusty's modules-next tree such as "CONFIG_SYMBOL_PREFIX:
cleanup." cleans up the whole mess around symbol prefixes, so this patch
just attempts to fix the build in the meantime.

The intermediate definition of SYMBOL_NAME above isn't used and is
incorrect when CONFIG_SYMBOL_PREFIX is defined as CONFIG_SYMBOL_PREFIX
is a quoted string literal, so define __SYMBOL_NAME directly depending
on CONFIG_SYMBOL_PREFIX.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Mea-culpa-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 15:51:29 -07:00
Al Viro
ac3e3c5b11 don't bother with deferred freeing of fdtables
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:31:42 -04:00
David Howells
59d8053f1e proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
Move non-public declarations and definitions from linux/proc_fs.h to
fs/proc/internal.h.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:47 -04:00
David Howells
c30480b92c proc: Make the PROC_I() and PDE() macros internal to procfs
Make the PROC_I() and PDE() macros internal to procfs.  This means making
PDE_DATA() out of line.  This could be made more optimal by storing
PDE()->data into inode->i_private.

Also provide a __PDE_DATA() that is inline and internal to procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:47 -04:00
David Howells
a8ca16ea7b proc: Supply a function to remove a proc entry by PDE
Supply a function (proc_remove()) to remove a proc entry (and any subtree
rooted there) by proc_dir_entry pointer rather than by name and (optionally)
root dir entry pointer.  This allows us to eliminate all remaining pde->name
accesses outside of procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Grant Likely <grant.likely@linaro.or>
cc: linux-acpi@vger.kernel.org
cc: openipmi-developer@lists.sourceforge.net
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-pci@vger.kernel.org
cc: netdev@vger.kernel.org
cc: netfilter-devel@vger.kernel.org
cc: alsa-devel@alsa-project.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:46 -04:00
Al Viro
8d8b97ba49 take cgroup_open() and cpuset_open() to fs/proc/base.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:46 -04:00
David Howells
b63e6aa502 drm: proc: Use minor->index to label things, not PDE->name
Use minor->index to label things, not the name field from the proc_dir_entry
of the /proc/dwm/<minor>/ directory.

Also, use "%u" not "%d" to render the value and use a 12-byte buffer in which
to render the integer, not a 16-byte buffer.  The longest string an unsigned
int can give you is 10 chars (4294967295) plus a NUL, so round up to 12 as the
stack is likely to be 4- or 8-byte aligned.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: dri-devel@lists.freedesktop.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:44 -04:00
David Howells
ce089b5472 drm: Constify drm_proc_list[]
Constify drm_proc_list[] and related pointers.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: dri-devel@lists.freedesktop.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:43 -04:00
David Howells
4a520d2769 proc: Supply an accessor for getting the data from a PDE's parent
Supply an accessor function for getting the private data from the parent
proc_dir_entry struct of the proc_dir_entry struct associated with an inode.

ReiserFS, for instance, stores the super_block pointer in the proc directory
it makes for that super_block, and a pointer to the respective seq_file show
function in each of the proc files in that directory.

This allows a reduction in the number of file_operations structs, open
functions and seq_operations structs required.  The problem otherwise is that
each show function requires two pieces of data but only has storage for one
per PDE (and this has no release function).

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jerry Chuang <jerry-chuang@realtek.com>
cc: Maxim Mikityanskiy <maxtram95@gmail.com>
cc: YAMANE Toshiaki <yamanetoshi@gmail.com>
cc: linux-wireless@vger.kernel.org
cc: linux-scsi@vger.kernel.org
cc: devel@driverdev.osuosl.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:42 -04:00
David Howells
270b5ac215 proc: Add proc_mkdir_data()
Add proc_mkdir_data() to allow procfs directories to be created that are
annotated at the time of creation with private data rather than doing this
post-creation.  This means no access is then required to the proc_dir_entry
struct to set this.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Neela Syam Kolli <megaraidlinux@lsi.com>
cc: Jerry Chuang <jerry-chuang@realtek.com>
cc: linux-scsi@vger.kernel.org
cc: devel@driverdev.osuosl.org
cc: linux-wireless@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:41 -04:00
David Howells
34db8aaf0f proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
Move some bits from linux/proc_fs.h to linux/of.h, signal.h and tty.h.

Also move proc_tty_init() and proc_device_tree_init() to fs/proc/internal.h as
they're internal to procfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-arch@vger.kernel.org
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Jri Slaby <jslaby@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:40 -04:00
David Howells
4abfd02989 proc: Move PDE_NET() to fs/proc/proc_net.c
Move PDE_NET() to fs/proc/proc_net.c as that's where the only user is.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:40 -04:00
David Howells
0bb80f2405 proc: Split the namespace stuff out into linux/proc_ns.h
Split the proc namespace stuff out into linux/proc_ns.h.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: netdev@vger.kernel.org
cc: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:39 -04:00
David Howells
271a15eabe proc: Supply PDE attribute setting accessor functions
Supply accessor functions to set attributes in proc_dir_entry structs.

The following are supplied: proc_set_size() and proc_set_user().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
cc: linuxppc-dev@lists.ozlabs.org
cc: linux-media@vger.kernel.org
cc: netdev@vger.kernel.org
cc: linux-wireless@vger.kernel.org
cc: linux-pci@vger.kernel.org
cc: netfilter-devel@vger.kernel.org
cc: alsa-devel@alsa-project.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-01 17:29:18 -04:00
Linus Torvalds
73287a43cc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights (1721 non-merge commits, this has to be a record of some
  sort):

   1) Add 'random' mode to team driver, from Jiri Pirko and Eric
      Dumazet.

   2) Make it so that any driver that supports configuration of multiple
      MAC addresses can provide the forwarding database add and del
      calls by providing a default implementation and hooking that up if
      the driver doesn't have an explicit set of handlers.  From Vlad
      Yasevich.

   3) Support GSO segmentation over tunnels and other encapsulating
      devices such as VXLAN, from Pravin B Shelar.

   4) Support L2 GRE tunnels in the flow dissector, from Michael Dalton.

   5) Implement Tail Loss Probe (TLP) detection in TCP, from Nandita
      Dukkipati.

   6) In the PHY layer, allow supporting wake-on-lan in situations where
      the PHY registers have to be written for it to be configured.

      Use it to support wake-on-lan in mv643xx_eth.

      From Michael Stapelberg.

   7) Significantly improve firewire IPV6 support, from YOSHIFUJI
      Hideaki.

   8) Allow multiple packets to be sent in a single transmission using
      network coding in batman-adv, from Martin Hundebøll.

   9) Add support for T5 cxgb4 chips, from Santosh Rastapur.

  10) Generalize the VXLAN forwarding tables so that there is more
      flexibility in configurating various aspects of the endpoints.
      From David Stevens.

  11) Support RSS and TSO in hardware over GRE tunnels in bxn2x driver,
      from Dmitry Kravkov.

  12) Zero copy support in nfnelink_queue, from Eric Dumazet and Pablo
      Neira Ayuso.

  13) Start adding networking selftests.

  14) In situations of overload on the same AF_PACKET fanout socket, or
      per-cpu packet receive queue, minimize drop by distributing the
      load to other cpus/fanouts.  From Willem de Bruijn and Eric
      Dumazet.

  15) Add support for new payload offset BPF instruction, from Daniel
      Borkmann.

  16) Convert several drivers over to mdoule_platform_driver(), from
      Sachin Kamat.

  17) Provide a minimal BPF JIT image disassembler userspace tool, from
      Daniel Borkmann.

  18) Rewrite F-RTO implementation in TCP to match the final
      specification of it in RFC4138 and RFC5682.  From Yuchung Cheng.

  19) Provide netlink socket diag of netlink sockets ("Yo dawg, I hear
      you like netlink, so I implemented netlink dumping of netlink
      sockets.") From Andrey Vagin.

  20) Remove ugly passing of rtnetlink attributes into rtnl_doit
      functions, from Thomas Graf.

  21) Allow userspace to be able to see if a configuration change occurs
      in the middle of an address or device list dump, from Nicolas
      Dichtel.

  22) Support RFC3168 ECN protection for ipv6 fragments, from Hannes
      Frederic Sowa.

  23) Increase accuracy of packet length used by packet scheduler, from
      Jason Wang.

  24) Beginning set of changes to make ipv4/ipv6 fragment handling more
      scalable and less susceptible to overload and locking contention,
      from Jesper Dangaard Brouer.

  25) Get rid of using non-type-safe NLMSG_* macros and use nlmsg_*()
      instead.  From Hong Zhiguo.

  26) Optimize route usage in IPVS by avoiding reference counting where
      possible, from Julian Anastasov.

  27) Convert IPVS schedulers to RCU, also from Julian Anastasov.

  28) Support cpu fanouts in xt_NFQUEUE netfilter target, from Holger
      Eitzenberger.

  29) Network namespace support for nf_log, ebt_log, xt_LOG, ipt_ULOG,
      nfnetlink_log, and nfnetlink_queue.  From Gao feng.

  30) Implement RFC3168 ECN protection, from Hannes Frederic Sowa.

  31) Support several new r8169 chips, from Hayes Wang.

  32) Support tokenized interface identifiers in ipv6, from Daniel
      Borkmann.

  33) Use usbnet_link_change() helper in USB net driver, from Ming Lei.

  34) Add 802.1ad vlan offload support, from Patrick McHardy.

  35) Support mmap() based netlink communication, also from Patrick
      McHardy.

  36) Support HW timestamping in mlx4 driver, from Amir Vadai.

  37) Rationalize AF_PACKET packet timestamping when transmitting, from
      Willem de Bruijn and Daniel Borkmann.

  38) Bring parity to what's provided by /proc/net/packet socket dumping
      and the info provided by netlink socket dumping of AF_PACKET
      sockets.  From Nicolas Dichtel.

  39) Fix peeking beyond zero sized SKBs in AF_UNIX, from Benjamin
      Poirier"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1722 commits)
  filter: fix va_list build error
  af_unix: fix a fatal race with bit fields
  bnx2x: Prevent memory leak when cnic is absent
  bnx2x: correct reading of speed capabilities
  net: sctp: attribute printl with __printf for gcc fmt checks
  netlink: kconfig: move mmap i/o into netlink kconfig
  netpoll: convert mutex into a semaphore
  netlink: Fix skb ref counting.
  net_sched: act_ipt forward compat with xtables
  mlx4_en: fix a build error on 32bit arches
  Revert "bnx2x: allow nvram test to run when device is down"
  bridge: avoid OOPS if root port not found
  drivers: net: cpsw: fix kernel warn on cpsw irq enable
  sh_eth: use random MAC address if no valid one supplied
  3c509.c: call SET_NETDEV_DEV for all device types (ISA/ISAPnP/EISA)
  tg3: fix to append hardware time stamping flags
  unix/stream: fix peeking with an offset larger than data in queue
  unix/dgram: fix peeking with an offset larger than data in queue
  unix/dgram: peek beyond 0-sized skbs
  openvswitch: Remove unneeded ovs_netdev_get_ifindex()
  ...
2013-05-01 14:08:52 -07:00
Xi Wang
20074f357d filter: fix va_list build error
This patch fixes the following build error.

In file included from include/linux/filter.h:52:0,
                 from arch/arm/net/bpf_jit_32.c:14:
include/linux/printk.h:54:2: error: unknown type name ‘va_list’
include/linux/printk.h:105:21: error: unknown type name ‘va_list’
include/linux/printk.h:108:30: error: unknown type name ‘va_list’

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01 16:28:48 -04:00
Linus Torvalds
251df49db3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
 "Assorted fixes and cleanups to the existing drivers plus a new driver
  for IMS Passenger Control Unit device they use for ther in-flight
  entertainment system."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (44 commits)
  Input: trackpoint - Optimize trackpoint init to use power-on reset
  Input: apbps2 - convert to devm_ioremap_resource()
  Input: ALPS - use %ph to print buffers
  ARM - shmobile: Armadillo800EVA: Move st1232 reset pin handling
  Input: st1232 - add reset pin handling
  Input: st1232 - convert to devm_* infrastructure
  Input: MT - handle semi-mt devices in core
  Input: adxl34x - use spi_get_drvdata()
  Input: ad7877 - use spi_get_drvdata() and spi_set_drvdata()
  Input: ads7846 - use spi_get_drvdata() and spi_set_drvdata()
  Input: ims-pcu - fix a memory leak on error
  Input: sysrq - supplement reset sequence with timeout functionality
  Input: tegra-kbc - support for defining row/columns based on SoC
  Input: imx_keypad - switch to using managed resources
  Input: arc_ps2 - add support for device tree
  Input: mma8450 - fix signed 12bits to 32bits conversion
  Input: eeti_ts - remove redundant null check
  Input: edt-ft5x06 - remove redundant null check before kfree
  Input: ad714x - add CONFIG_PM_SLEEP to suspend/resume functions
  Input: adxl34x - add CONFIG_PM_SLEEP to suspend/resume functions
  ...
2013-05-01 13:20:04 -07:00
Eric Dumazet
60bc851ae5 af_unix: fix a fatal race with bit fields
Using bit fields is dangerous on ppc64/sparc64, as the compiler [1]
uses 64bit instructions to manipulate them.
If the 64bit word includes any atomic_t or spinlock_t, we can lose
critical concurrent changes.

This is happening in af_unix, where unix_sk(sk)->gc_candidate/
gc_maybe_cycle/lock share the same 64bit word.

This leads to fatal deadlock, as one/several cpus spin forever
on a spinlock that will never be available again.

A safer way would be to use a long to store flags.
This way we are sure compiler/arch wont do bad things.

As we own unix_gc_lock spinlock when clearing or setting bits,
we can use the non atomic __set_bit()/__clear_bit().

recursion_level can share the same 64bit location with the spinlock,
as it is set only with this spinlock held.

[1] bug fixed in gcc-4.8.0 :
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52080

Reported-by: Ambrose Feinstein <ambrose@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01 15:13:49 -04:00
Neil Horman
bd7c4b604a netpoll: convert mutex into a semaphore
Bart Van Assche recently reported a warning to me:

<IRQ>  [<ffffffff8103d79f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8103d7fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff814761dd>] mutex_trylock+0x16d/0x180
[<ffffffff813968c9>] netpoll_poll_dev+0x49/0xc30
[<ffffffff8136a2d2>] ? __alloc_skb+0x82/0x2a0
[<ffffffff81397715>] netpoll_send_skb_on_dev+0x265/0x410
[<ffffffff81397c5a>] netpoll_send_udp+0x28a/0x3a0
[<ffffffffa0541843>] ? write_msg+0x53/0x110 [netconsole]
[<ffffffffa05418bf>] write_msg+0xcf/0x110 [netconsole]
[<ffffffff8103eba1>] call_console_drivers.constprop.17+0xa1/0x1c0
[<ffffffff8103fb76>] console_unlock+0x2d6/0x450
[<ffffffff8104011e>] vprintk_emit+0x1ee/0x510
[<ffffffff8146f9f6>] printk+0x4d/0x4f
[<ffffffffa0004f1d>] scsi_print_command+0x7d/0xe0 [scsi_mod]

This resulted from my commit ca99ca14c which introduced a mutex_trylock
operation in a path that could execute in interrupt context.  When mutex
debugging is enabled, the above warns the user when we are in fact
exectuting in interrupt context
interrupt context.

After some discussion, It seems that a semaphore is the proper mechanism to use
here.  While mutexes are defined to be unusable in interrupt context, no such
condition exists for semaphores (save for the fact that the non blocking api
calls, like up and down_trylock must be used when in irq context).

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Bart Van Assche <bvanassche@acm.org>
CC: Bart Van Assche <bvanassche@acm.org>
CC: David Miller <davem@davemloft.net>
CC: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01 15:00:24 -04:00
Linus Torvalds
a49fe6d59a Merge branch 'topic/omap3isp' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull omap3isp clk support from Mauro Carvalho Chehab:
 "This patch were sent in separate as it depends on a merge from clock
  framework, that you merged in commit 362ed48dee50"

* 'topic/omap3isp' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] omap3isp: Use the common clock framework
2013-05-01 09:57:04 -07:00
Linus Torvalds
823e75f723 Merge branch 'ipc-scalability'
Merge IPC cleanup and scalability patches from Andrew Morton.

This cleans up many of the oddities in the IPC code, uses the list
iterator helpers, splits out locking and adds per-semaphore locks for
greater scalability of the IPC semaphore code.

Most normal user-level locking by now uses futexes (ie pthreads, but
also a lot of specialized locks), but SysV IPC semaphores are apparently
still used in some big applications, either for portability reasons, or
because they offer tracking and undo (and you don't need to have a
special shared memory area for them).

Our IPC semaphore scalability was pitiful.  We used to lock much too big
ranges, and we used to have a single ipc lock per ipc semaphore array.
Most loads never cared, but some do.  There are some numbers in the
individual commits.

* ipc-scalability:
  ipc: sysv shared memory limited to 8TiB
  ipc/msg.c: use list_for_each_entry_[safe] for list traversing
  ipc,sem: fine grained locking for semtimedop
  ipc,sem: have only one list in struct sem_queue
  ipc,sem: open code and rename sem_lock
  ipc,sem: do not hold ipc lock more than necessary
  ipc: introduce lockless pre_down ipcctl
  ipc: introduce obtaining a lockless ipc object
  ipc: remove bogus lock comment for ipc_checkid
  ipc/msgutil.c: use linux/uaccess.h
  ipc: refactor msg list search into separate function
  ipc: simplify msg list search
  ipc: implement MSG_COPY as a new receive mode
  ipc: remove msg handling from queue scan
  ipc: set EFAULT as default error in load_msg()
  ipc: tighten msg copy loops
  ipc: separate msg allocation from userspace copy
  ipc: clamp with min()
2013-05-01 08:17:51 -07:00
Robin Holt
d69f3bad46 ipc: sysv shared memory limited to 8TiB
Trying to run an application which was trying to put data into half of
memory using shmget(), we found that having a shmall value below 8EiB-8TiB
would prevent us from using anything more than 8TiB.  By setting
kernel.shmall greater than 8EiB-8TiB would make the job work.

In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX.

ipc/shm.c:
 458 static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 459 {
...
 465         int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
...
 474         if (ns->shm_tot + numpages > ns->shm_ctlall)
 475                 return -ENOSPC;

[akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int]
Signed-off-by: Robin Holt <holt@sgi.com>
Reported-by: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 08:12:58 -07:00
Linus Torvalds
149b306089 Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
 "Mostly performance and bug fixes, plus some cleanups.  The one new
  feature this merge window is a new ioctl EXT4_IOC_SWAP_BOOT which
  allows installation of a hidden inode designed for boot loaders."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (50 commits)
  ext4: fix type-widening bug in inode table readahead code
  ext4: add check for inodes_count overflow in new resize ioctl
  ext4: fix Kconfig documentation for CONFIG_EXT4_DEBUG
  ext4: fix online resizing for ext3-compat file systems
  jbd2: trace when lock_buffer in do_get_write_access takes a long time
  ext4: mark metadata blocks using bh flags
  buffer: add BH_Prio and BH_Meta flags
  ext4: mark all metadata I/O with REQ_META
  ext4: fix readdir error in case inline_data+^dir_index.
  ext4: fix readdir error in the case of inline_data+dir_index
  jbd2: use kmem_cache_zalloc instead of kmem_cache_alloc/memset
  ext4: mext_insert_extents should update extent block checksum
  ext4: move quota initialization out of inode allocation transaction
  ext4: reserve xattr index for Rich ACL support
  jbd2: reduce journal_head size
  ext4: clear buffer_uninit flag when submitting IO
  ext4: use io_end for multiple bios
  ext4: make ext4_bio_write_page() use BH_Async_Write flags
  ext4: Use kstrtoul() instead of parse_strtoul()
  ext4: defragmentation code cleanup
  ...
2013-05-01 08:04:12 -07:00
Linus Torvalds
b0ca4d0123 Merge tag 'tag-for-linus-3.10' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf
Pull dma-buf updates from Sumit Semwal:
 "Added debugfs support to dma-buf"

* tag 'tag-for-linus-3.10' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf:
  dma-buf: Add debugfs support
  dma-buf: replace dma_buf_export() with dma_buf_export_named()
2013-05-01 07:44:37 -07:00
Linus Torvalds
08d7676083 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull compat cleanup from Al Viro:
 "Mostly about syscall wrappers this time; there will be another pile
  with patches in the same general area from various people, but I'd
  rather push those after both that and vfs.git pile are in."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  syscalls.h: slightly reduce the jungles of macros
  get rid of union semop in sys_semctl(2) arguments
  make do_mremap() static
  sparc: no need to sign-extend in sync_file_range() wrapper
  ppc compat wrappers for add_key(2) and request_key(2) are pointless
  x86: trim sys_ia32.h
  x86: sys32_kill and sys32_mprotect are pointless
  get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC
  merge compat sys_ipc instances
  consolidate compat lookup_dcookie()
  convert vmsplice to COMPAT_SYSCALL_DEFINE
  switch getrusage() to COMPAT_SYSCALL_DEFINE
  switch epoll_pwait to COMPAT_SYSCALL_DEFINE
  convert sendfile{,64} to COMPAT_SYSCALL_DEFINE
  switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE
  make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect
  make HAVE_SYSCALL_WRAPPERS unconditional
  consolidate cond_syscall and SYSCALL_ALIAS declarations
  teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long
  get rid of duplicate logics in __SC_....[1-6] definitions
2013-05-01 07:21:43 -07:00
Miklos Szeredi
60b9df7a54 fuse: add flag to turn on async direct IO
Without async DIO write requests to a single file were always serialized.
With async DIO that's no longer the case.

So don't turn on async DIO by default for fear of breaking backward
compatibility.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2013-05-01 14:37:21 +02:00
Sumit Semwal
b89e35636b dma-buf: Add debugfs support
Add debugfs support to make it easier to print debug information
about the dma-buf buffers.

Cc: Dave Airlie <airlied@redhat.com>
 [minor fixes on init and warning fix]
Cc: Dan Carpenter <dan.carpenter@oracle.com>
 [remove double unlock in fail case]
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2013-05-01 16:36:22 +05:30
Sumit Semwal
78df969550 dma-buf: replace dma_buf_export() with dma_buf_export_named()
For debugging purposes, it is useful to have a name-string added
while exporting buffers. Hence, dma_buf_export() is replaced with
dma_buf_export_named(), which additionally takes 'exp_name' as a
parameter.

For backward compatibility, and for lazy exporters who don't wish to
name themselves, a #define dma_buf_export() is also made available,
which adds a __FILE__ instead of 'exp_name'.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
  [Thanks for the idea!]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
2013-05-01 16:35:36 +05:30
Michael S. Tsirkin
bc7562355f Merge branch 'for-next-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending into vhost-net-next 2013-05-01 09:16:50 +03:00
Linus Torvalds
5f56886521 Merge branch 'akpm' (incoming from Andrew)
Merge third batch of fixes from Andrew Morton:
 "Most of the rest.  I still have two large patchsets against AIO and
  IPC, but they're a bit stuck behind other trees and I'm about to
  vanish for six days.

   - random fixlets
   - inotify
   - more of the MM queue
   - show_stack() cleanups
   - DMI update
   - kthread/workqueue things
   - compat cleanups
   - epoll udpates
   - binfmt updates
   - nilfs2
   - hfs
   - hfsplus
   - ptrace
   - kmod
   - coredump
   - kexec
   - rbtree
   - pids
   - pidns
   - pps
   - semaphore tweaks
   - some w1 patches
   - relay updates
   - core Kconfig changes
   - sysrq tweaks"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  Documentation/sysrq: fix inconstistent help message of sysrq key
  ethernet/emac/sysrq: fix inconstistent help message of sysrq key
  sparc/sysrq: fix inconstistent help message of sysrq key
  powerpc/xmon/sysrq: fix inconstistent help message of sysrq key
  ARM/etm/sysrq: fix inconstistent help message of sysrq key
  power/sysrq: fix inconstistent help message of sysrq key
  kgdb/sysrq: fix inconstistent help message of sysrq key
  lib/decompress.c: fix initconst
  notifier-error-inject: fix module names in Kconfig
  kernel/sys.c: make prctl(PR_SET_MM) generally available
  UAPI: remove empty Kbuild files
  menuconfig: print more info for symbol without prompts
  init/Kconfig: re-order CONFIG_EXPERT options to fix menuconfig display
  kconfig menu: move Virtualization drivers near other virtualization options
  Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
  relay: use macro PAGE_ALIGN instead of FIX_SIZE
  kernel/relay.c: move FIX_SIZE macro into relay.c
  kernel/relay.c: remove unused function argument actor
  drivers/w1/slaves/w1_ds2760.c: fix the error handling in w1_ds2760_add_slave()
  drivers/w1/slaves/w1_ds2781.c: fix the error handling in w1_ds2781_add_slave()
  ...
2013-04-30 17:37:43 -07:00
David Howells
22145aa1f6 UAPI: remove empty Kbuild files
Remove empty Kbuild files as they cause problems with the patch program which
removes files that become empty.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:09 -07:00
zhangwei(Jovi)
536b39ecf1 kernel/relay.c: move FIX_SIZE macro into relay.c
It's better to place FIX_SIZE macro in relay.c, instead of relay.h

Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:09 -07:00
Raphael S.Carvalho
5cc5445164 pid_namespace.c/.h: simplify defines
Move BITS_PER_PAGE from pid_namespace.c to pid_namespace.h, since we can
simplify the define PID_MAP_ENTRIES by using the BITS_PER_PAGE.

[akpm@linux-foundation.org: kernel/pid.c:54:1: warning: "BITS_PER_PAGE" redefined]
Signed-off-by: Raphael S.Carvalho <raphael.scarv@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Oleg Nesterov
e56fb28740 exec: do not abuse ->cred_guard_mutex in threadgroup_lock()
threadgroup_lock() takes signal->cred_guard_mutex to ensure that
thread_group_leader() is stable.  This doesn't look nice, the scope of
this lock in do_execve() is huge.

And as Dave pointed out this can lead to deadlock, we have the
following dependencies:

	do_execve:		cred_guard_mutex -> i_mutex
	cgroup_mount:		i_mutex -> cgroup_mutex
	attach_task_by_pid:	cgroup_mutex -> cred_guard_mutex

Change de_thread() to take threadgroup_change_begin() around the
switch-the-leader code and change threadgroup_lock() to avoid
->cred_guard_mutex.

Note that de_thread() can't sleep with ->group_rwsem held, this can
obviously deadlock with the exiting leader if the writer is active, so it
does threadgroup_change_end() before schedule().

Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Oleg Nesterov
403bad72b6 coredump: only SIGKILL should interrupt the coredumping task
There are 2 well known and ancient problems with coredump/signals, and a
lot of related bug reports:

- do_coredump() clears TIF_SIGPENDING but of course this can't help
  if, say, SIGCHLD comes after that.

  In this case the coredump can fail unexpectedly. See for example
  wait_for_dump_helper()->signal_pending() check but there are other
  reasons.

- At the same time, dumping a huge core on the slow media can take a
  lot of time/resources and there is no way to kill the coredumping
  task reliably. In particular this is not oom_kill-friendly.

This patch tries to fix the 1st problem, and makes the preparation for the
next changes.

We add the new SIGNAL_GROUP_COREDUMP flag set by zap_threads() to indicate
that this process dumps the core.  prepare_signal() checks this flag and
nacks any signal except SIGKILL.

Note that this check tries to be conservative, in the long term we should
probably treat the SIGNAL_GROUP_EXIT case equally but this needs more
discussion.  See marc.info/?l=linux-kernel&m=120508897917439

Notes:
	- recalc_sigpending() doesn't check SIGNAL_GROUP_COREDUMP.
	  The patch assumes that dump_write/etc paths should never
	  call it, but we can change it as well.

	- There is another source of TIF_SIGPENDING, freezer. This
	  will be addressed separately.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:06 -07:00
Lucas De Marchi
66e5b7e194 kmod: remove call_usermodehelper_fns()
This function suffers from not being able to determine if the cleanup is
called in case it returns -ENOMEM.  Nobody is using it anymore, so let's
remove it.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:06 -07:00
Lucas De Marchi
938e4b22e2 usermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup()
call_usermodehelper_setup() + call_usermodehelper_exec() need to be
called instead of call_usermodehelper_fns() when the cleanup function
needs to be called even when an ENOMEM error occurs.  In this case using
call_usermodehelper_fns() the user can't distinguish if the cleanup
function was called or not.

[akpm@linux-foundation.org: export call_usermodehelper_setup() to modules]
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:05 -07:00
Andrey Vagin
84c751bd4a ptrace: add ability to retrieve signals without removing from a queue (v4)
This patch adds a new ptrace request PTRACE_PEEKSIGINFO.

This request is used to retrieve information about pending signals
starting with the specified sequence number.  Siginfo_t structures are
copied from the child into the buffer starting at "data".

The argument "addr" is a pointer to struct ptrace_peeksiginfo_args.
struct ptrace_peeksiginfo_args {
	u64 off;	/* from which siginfo to start */
	u32 flags;
	s32 nr;		/* how may siginfos to take */
};

"nr" has type "s32", because ptrace() returns "long", which has 32 bits on
i386 and a negative values is used for errors.

Currently here is only one flag PTRACE_PEEKSIGINFO_SHARED for dumping
signals from process-wide queue.  If this flag is not set, signals are
read from a per-thread queue.

The request PTRACE_PEEKSIGINFO returns a number of dumped signals.  If a
signal with the specified sequence number doesn't exist, ptrace returns
zero.  The request returns an error, if no signal has been dumped.

Errors:
EINVAL - one or more specified flags are not supported or nr is negative
EFAULT - buf or addr is outside your accessible address space.

A result siginfo contains a kernel part of si_code which usually striped,
but it's required for queuing the same siginfo back during restore of
pending signals.

This functionality is required for checkpointing pending signals.  Pedro
Alves suggested using it in "gdb" to peek at pending signals.  gdb already
uses PTRACE_GETSIGINFO to get the siginfo for the signal which was already
dequeued.  This functionality allows gdb to look at the pending signals
which were not reported yet.

The prototype of this code was developed by Oleg Nesterov.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pedro Alves <palves@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:05 -07:00
Stephen Rothwell
1a0df59444 kernel/compat.c: make do_sysinfo() static
The only use outside of kernel/timer.c was in kernel/compat.c, so move
compat_sys_sysinfo() next to sys_sysinfo() in kernel/timer.c.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:03 -07:00
Andy Shevchenko
16c7fa0582 lib/string_helpers: introduce generic string_unescape
There are several places in kernel where modules unescapes input to convert
C-Style Escape Sequences into byte codes.

The patch provides generic implementation of such approach. Test cases are
also included into the patch.

[akpm@linux-foundation.org: clarify comment]
[akpm@linux-foundation.org: export get_random_int() to modules]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:03 -07:00
Fan Du
74e3d1e17b include/linux/fs.h: disable preempt when acquire i_size_seqcount write lock
Two rt tasks bind to one CPU core.

The higher priority rt task A preempts a lower priority rt task B which
has already taken the write seq lock, and then the higher priority rt
task A try to acquire read seq lock, it's doomed to lockup.

rt task A with lower priority: call write
i_size_write                                        rt task B with higher priority: call sync, and preempt task A
  write_seqcount_begin(&inode->i_size_seqcount);    i_size_read
  inode->i_size = i_size;                             read_seqcount_begin <-- lockup here...

So disable preempt when acquiring every i_size_seqcount *write* lock will
cure the problem.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:03 -07:00
liguang
3440a1ca99 kernel/smp.c: remove 'priv' of call_single_data
The 'priv' field is redundant; we can pass data via 'info'.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:03 -07:00
Tejun Heo
3d1cb2059d workqueue: include workqueue info when printing debug dump of a worker task
One of the problems that arise when converting dedicated custom
threadpool to workqueue is that the shared worker pool used by workqueue
anonimizes each worker making it more difficult to identify what the
worker was doing on which target from the output of sysrq-t or debug
dump from oops, BUG() and friends.

This patch implements set_worker_desc() which can be called from any
workqueue work function to set its description.  When the worker task is
dumped for whatever reason - sysrq-t, WARN, BUG, oops, lockdep assertion
and so on - the description will be printed out together with the
workqueue name and the worker function pointer.

The printing side is implemented by print_worker_info() which is called
from functions in task dump paths - sched_show_task() and
dump_stack_print_info().  print_worker_info() can be safely called on
any task in any state as long as the task struct itself is accessible.
It uses probe_*() functions to access worker fields.  It may print
garbage if something went very wrong, but it wouldn't cause (another)
oops.

The description is currently limited to 24bytes including the
terminating \0.  worker->desc_valid and workder->desc[] are added and
the 64 bytes marker which was already incorrect before adding the new
fields is moved to the correct position.

Here's an example dump with writeback updated to set the bdi name as
worker desc.

 Hardware name: Bochs
 Modules linked in:
 Pid: 7, comm: kworker/u9:0 Not tainted 3.9.0-rc1-work+ #1
 Workqueue: writeback bdi_writeback_workfn (flush-8:0)
  ffffffff820a3ab0 ffff88000f6e9cb8 ffffffff81c61845 ffff88000f6e9cf8
  ffffffff8108f50f 0000000000000000 0000000000000000 ffff88000cde16b0
  ffff88000cde1aa8 ffff88001ee19240 ffff88000f6e9fd8 ffff88000f6e9d08
 Call Trace:
  [<ffffffff81c61845>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff81200150>] bdi_writeback_workfn+0x2a0/0x3b0
 ...

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo
cd42d559e4 kthread: implement probe_kthread_data()
One of the problems that arise when converting dedicated custom threadpool
to workqueue is that the shared worker pool used by workqueue anonimizes
each worker making it more difficult to identify what the worker was doing
on which target from the output of sysrq-t or debug dump from oops, BUG()
and friends.

For example, after writeback is converted to use workqueue instead of
priviate thread pool, there's no easy to tell which backing device a
writeback work item was working on at the time of task dump, which,
according to our writeback brethren, is important in tracking down issues
with a lot of mounted file systems on a lot of different devices.

This patchset implements a way for a work function to mark its execution
instance so that task dump of the worker task includes information to
indicate what the work item was doing.

An example WARN dump would look like the following.

 WARNING: at fs/fs-writeback.c:1015 bdi_writeback_workfn+0x2b4/0x3c0()
 Modules linked in:
 CPU: 0 Pid: 28 Comm: kworker/u18:0 Not tainted 3.9.0-rc1-work+ #24
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 Workqueue: writeback bdi_writeback_workfn (flush-8:16)
  ffffffff820a3a98 ffff88015b927cb8 ffffffff81c61855 ffff88015b927cf8
  ffffffff8108f500 0000000000000000 ffff88007a171948 ffff88007a1716b0
  ffff88015b49df00 ffff88015b8d3940 0000000000000000 ffff88015b927d08
 Call Trace:
  [<ffffffff81c61855>] dump_stack+0x19/0x1b
  [<ffffffff8108f500>] warn_slowpath_common+0x70/0xa0
  ...

This patch:

Implement probe_kthread_data() which returns kthread_data if accessible.
The function is equivalent to kthread_data() except that the specified
@task may not be a kthread or its vfork_done is already cleared rendering
struct kthread inaccessible.  In the former case, probe_kthread_data() may
return any value.  In the latter, NULL.

This will be used to safely print debug information without affecting
synchronization in the normal paths.  Workqueue debug info printing on
dump_stack() and friends will make use of it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00